TRANSPORTE DE GAMETAS, FERTILIZAÇÃO E SEGMENTAÇÃO -/- • _____OBJETIVO -/- O entendimento do desenvolvimento embrionário nos estágios iniciais, desde a deposição dos espermatozoides na fêmea, passando pela fertilização deste no ovócito e na formação do zigoto, é de suma importância para diferenciar especialistas em reprodução e manejo reprodutivo no mercado de trabalho e, também, durante a vida acadêmica. Compreender os processos que levam à formação do zigoto na fêmea é essencial para avaliar a capacidade reprodutiva dos animais e, mediante técnicas, (...) avaliar o trato reprodutivo da fêmea e o desenvolvimento do embrião até a formação do feto e, por fim, em um novo animal sadio na propriedade. Com esse trabalho, o estudante de veterinária ou zootecnia, que deseja se aprofundar na fisiologia da reprodução animal, identificará os mecanismos que são envolvidos no transporte dos gametas, bem como os processos que estes últimos devem completar para alcançar a fertilização e para desencadear as divisões iniciais do embrião. -/- • _____INTRODUÇÃO -/- A fertilização ou fecundação é o processo pelo qual os gametas masculino (espermatozoide) e feminino (ovócito) se fundem para gerar um novo indivíduo. Seu êxito depende da culminação adequada dos diferentes processos que devem sofrer os gametas durante sua maduração e percurso; do transporte oportuno destes no trato reprodutivo da fêmea, assim como de uma série de adaptações dos órgãos genitais internos da mãe. A segmentação refere-se às primeiras divisões celulares do embrião. -/- • _____TRANSPORTE DO OVÓCITO -/- O ovócito que é liberado na ovulação, e que se encontra coberto pelas células do cumulus (figura 1), é capturado pela fímbria do infundíbulo ao aderir aos cílios. Esse processo é altamente eficaz, inclusive em espécies onde os ovários possuem várias formações globosas, por exemplo nas porcas, onde os ovidutos capturam entre 95 e 100% dos ovócitos que são ovulados. As contrações das camadas musculares do oviduto e o movimento intenso dos cílios da mucosa faz com que as secreções fluam em direção ao útero, transportando assim o complexo cumulus-ovócito. Esse transporte é relativamente rápido até alcançar a junção da ampola com o istmo (que é considerado o local de fertilização do espermatozoide e ovócito) a partir do qual se torna lento. Devido a fêmea estar em estro, o processo está sob controle endócrino, isto é, controle hormonal através do estradiol. Nas fêmeas domésticas, ao contrário das mulheres, o transporte ao longo do oviduto é extremamente eficiente, pois os embriões passam para o útero sem dificuldade, de modo que gestações ectópicas (tubárias ou em cavidade) são quase inexistentes. A égua, frequentemente, retém por muito tempo os ovócitos não fertilizados no oviduto, provavelmente devido a não secreção de substâncias (como a prostaglandina E) que poderiam favorecer sua passagem, como se propõe que aconteça com os embriões. A figura 2 apresenta um ovócito com suas respectivas estruturas. Figura 1: ovócitos de uma vaca madurados in vitro. Nota-se as células do cumulus que os recobre. -/- Figura 2: estruturas do ovócito de uma ovelha que se encontra na etapa de ovócito secundário, depois da ovulação. Elaborado pelo autor. • _____TRANSPORTE ESPERMÁTICO -/- Para que os espermatozoides sejam capazes de fertilizar o ovócito, deverão sofrer uma série de mudanças bioquímicas e morfológicas ao longo de sua passagem pelo aparelho reprodutor tanto masculino como feminino. Uma vez produzidos na parede do túbulo seminífero, os espermatozoides são liberados em direção ao lúmen tubular e transportados passivamente para uma estrutura ramificada conhecida como rede testicular (rete testis). Dessa rede são conduzidos em direção ao epidídimo passando através de 10 a 20 ductos eferentes localizados no polo superior do testículo. O epidídimo é dividido em três seções denominadas cabeça, corpo e cauda; é constituído por um só ducto longo e tortuoso que continua com o canal deferente. Ao final desemboca nas ampolas seminais, no ducto ejaculatório e na uretra. As funções do epidídimo são as de maduração, transporte e armazenamento dos espermatozoides. O transporte através do epidídimo é lento, aproximadamente de 10 dias em touros, e segue sendo passivo. Os espermatozoides tomados da cabeça do epidídimo são ainda imaturos e incapazes de fertilizar, enquanto os armazenados na cauda são completamente maduros. Durante o trânsito pelo epidídimo os espermatozoides adquirem motilidade e o potencial para fertilizar, o acrossomo é remodelado e a gota citoplasmática migra para o flagelo e é liberada. Quando um macho ejacula com muita frequência, é possível observar espermatozoides com gota citoplasmática no sêmen, já que não há tempo suficiente para que completem sua maduração. Os espermatozoides são expulsados fora do organismo durante a cópula, na masturbação ou em emissões espontâneas. Na ejaculação, os espermatozoides que se encontram suspensos nos fluidos do testículo e do epidídimo, misturam-se ao chegar na uretra com as secreções das glândulas acessórias para formar o sêmen. Essas secreções denominadas plasma seminal, proporcionam substâncias para manter o metabolismo energético das células espermáticas, e integram suas membranas elementos que impedem uma capacitação prematura. Durante a cópula, o sêmen é depositado na vagina ou no útero, variando entre as espécies (tabela 1). Na monta natural, geralmente, o serviço ocorre no momento propício, já que está definido pela fase do ciclo estral em que a fêmea é receptiva ao macho. No entanto, na inseminação artificial, é o macho que deverá determinar o momento ideal, e para isso é importante considerar a vida média dos gametas, ao qual é muito curta no caso dos ovócitos (tabela 1). -/- Tabela 1: local de depósito do sêmen, volume da ejaculação e vida média dos gametas. Espécie Local de deposição Volume (ml) Velocidade de ejaculação Vida média do ovócito Vida média do espermatozoide Bovinos Intravaginal 2 1 – 3 seg 8 h 30 – 48 h Caninos Intravaginal 2 – 30 (10 média) 6 – 45 min 48 – 72 h 9 – 11 d Equinos Intrauterina 50 – 200 20 – 60 seg 6 – 8 h 72 – 120 h Humanos Intravaginal 3 - - 5 – 6 d Ovinos Intravaginal 1 1 – 2 seg 16 – 24 h 30 – 48 h Suínos Intrauterina 200 – 400 5 – 20 min 8 – 10 h 24 – 48 h Onde d = dias; h = horas. A vida fértil do ovócito é muito curta, portanto, o momento do serviço é de grande importância para obter altos índices de fertilização. -/- Independentemente do local em que os espermatozoides sejam depositados no aparelho reprodutor feminino, serão expostos às secreções genitais e sofrem uma série de mudanças em seu trajeto até o local de fertilização antes de penetrar no ovócito. Nas espécies em que o sêmen é depositado na parte cranial da vagina, uma parte do mesmo penetra através da cérvix, enquanto outra parte é eliminada do aparelho genital da fêmea, em pouco tempo, através do fluxo retrógrado. O meio vaginal não é adequado e imobiliza os espermatozoides em pouco tempo, pelo qual deverão entrar no útero onde o ambiente é mais propício. O transporte espermático na fêmea é o resultado da alta contratilidade, do movimento ciliar e o fluido do aparelho genital durante o estro, ao qual está sob controle endócrino e do sistema nervoso. Esse transporte é favorecido pelas características especiais do muco estral, cujas moléculas formam uma espécie de canais que facilitam a passagem dos espermatozoides. Pelo contrário, durante a fase lútea seu transporte é dificultado. Além do meio vaginal, a cérvix também atua como barreira natural para limitar a passagem dos espermatozoides, diminuindo assim a possibilidade de polispermia. Funciona, também, como um filtro que seleciona os espermatozoides aptos dos que não o são, uma vez que somente os primeiros possuem uma motilidade vigorosa que lhes permite passar pelo muco altamente hidratado. Na vaca a cérvix é considerada como um reservatório espermático. Quando atravessam a cérvix, os espermatozoides seguem sua deslocação tanto por movimento próprio como pelas contrações uterinas e tubárias. Nas espécies em que o local de depósito do sêmen do macho na fêmea é intrauterino, como equinos, a principal barreira que os espermatozoides enfrentam é a união ou junção útero-tubárica. A união entre o útero e o oviduto (istmo do oviduto) serve como reservatório funcional dos espermatozoides nas espécies domésticas. Poucos minutos depois da cópula, é possível encontrar alguns espermatozoides no oviduto, que é conhecido como fase de transporte rápido. No entanto, esses espermato-zoides não são os que participam do processo de fertilização e podem apresentar certas anormalidades. Existe um segundo tipo de transporte denominado fase sustentada, a qual consiste na migração prolongada dos espermatozoides em direção as partes mais craniais do aparelho genital feminino, que conduzem à colonização do reservatório funcional e na liberação gradual dos espermatozoides dos reservatórios espermáticos, incluindo este último. O reservatório do istmo fornece aos espermatozoides um ambiente propício, protegendo-os contra a fagocitose, prolongando assim a sua viabilidade. Aqui os esper-matozoides permanecem aderidos a superfície das células ciliadas do epitélio até a finalização de sua capacitação, depois da qual são liberados quando alteram seu padrão de motilidade flagelada, fenômeno conhecido como hipermotilidade, e migram em ondas em direção ao local da fertilização. Dos milhões de espermatozoides ejaculados, somente alguns milhares alcançarão o istmo do oviduto e um número sumamente pequeno será encontrado nas imediações do ovócito no momento da fertilização. -/- • _____CAPACITAÇÃO ESPERMÁTICA E REAÇÃO ACROSSÔMICA -/- A capacitação é um processo gradual e essencial para a fertilização. Os espermato-zoides devem passar por um dado tempo de “incubação” no aparelho genital da fêmea e sofrer uma série de mudanças antes de serem capazes de fecundar o ovócito. A capacita-ção dos espermatozoides começa quando eles entram em contato com as secreções do aparelho genital da fêmea e termina no istmo do oviduto. Durante esse percurso a superfície da cabeça do espermatozoide se modifica já que algumas moléculas como o colesterol são removidas da membrana plasmática, aumentando sua fluidez e alterando suas propriedades bioquímicas. Entre outras coisas, essa reorganização dos lipídios facilita a entrada de cálcio extracelular pelos canais iônicos e ocasiona a desestabilização da membrana, tornando-a mais fusogênica. Também são eliminados outros fatores (conhecidos genericamente como fatores descapacitantes) que expõem receptores membranais indispensáveis para a realização da união entre o espermatozoide e o ovócito durante a fertilização. Os espermatozoides capacitados apresentam um padrão de hipermotilidade e uma maior atividade metabólica, características que devem obter para que sejam capazes de penetrar as camadas do ovócito. A capacitação é necessária para que ocorra a reação acrossômica. A reação acrossomal ou acrossômica (RA) é um fenômeno de exocitose que é desencadeada pela ligação entre as proteínas e receptores localizados na membrana do espermatozoide e a zona pelúcida do ovócito (figura 3). Envolve a fusão da membrana plasmática do espermatozoide com a membrana externa de seu acrossomo; formando, assim, pequenas vesículas, cujo conteúdo de enzimas hidrolíticas, como a hialuronidase e a acrosina, é liberado em direção ao seu exterior, facilitando a penetração da zona pelúcida. A adesão do espermatozoide à zona pelúcida é específica da espécie e depende de glicoproteínas presentes na membrana dos ovócitos maduros; a cabeça do espermatozoide se une com essas glicoproteínas mediante receptores específicos e atravessam em direção oblíqua a zona pelúcida até chegar ao espaço perivitelino. Nos mamíferos, particularmente em roedores e nos humanos, algumas dessas glicoproteínas são conhecidas como ZP1, ZP2 e ZP3. Pensa-se que a união da membrana espermática a esta última é o que desencadeia a reação acrossomal. Posteriormente, as vilosidades do ovócito entram em contato com o espermatozoide e a membrana presente na secreção equatorial da cabeça do espermatozoide, que tem proteínas fusogênicas específicas, une-se a membrana plasmática do ovócito, fusionando-se e permitindo a entrada do núcleo espermático ao citoplasma (figura 4). A capacitação dos espermatozoides é fundamental para o êxito da fertilização, uma vez que apenas os aptos estarão perfeitos e íntegros para que a união e percepção das glicoproteínas presentes nos mesmos possam ocorrer de forma ideal para a penetração deste no ovócito, fertilizá-lo e formar um zigoto. Figura 3: estrutura do espermatozoide. Nota: a membrana é acrossomal e não acrossonal. Elaborado pelo autor. -/- Figura 4: eventos que ocorrem durante a fertilização. A – depois de passar através das células do cumulus, o espermatozoide entra em contato com a zona pelúcida, onde receptores da membrana plasmática reconhecem as proteínas da zona pelúcida; B – é desencadeada, então, a reação acrossomal; C – para que o espermatozoide penetre na zona pelúcida; D – ao atravessar a zona pelúcida e entrar no espaço perivitelino, a cabeça do espermatozoide entra em contato com a membrana vitelina; ambas membranas se fusionam graças ao reconhecimento de proteínas fusogênicas que estão no segmento equatorial. E – ocorre, então, que o núcleo do espermatozoide penetra no citoplasma do ovócito; uma das consequências da fusão da membrana com a cabeça do espermatozoide é a reação cortical, em que os grânulos corticais do ovócito liberam seu conteúdo em direção ao espaço perivitelino, o que resulta na alteração da estrutura da zona pelúcida e da membrana vitelina para bloquear a polispermia. Elaborado pelo autor. • _____CONSEQUÊNCIAS DA PENETRAÇÃO -/- Bloqueio da polispermia -/- A fusão das membranas dos gametas durante a penetração permite a entrada da fosfolipase C zeta (PLCζ) – fator solúvel que provém do espermatozoide – que desencadeia liberação e oscilações de Ca2+ no retículo endoplasmático. Isso, por sua vez, provoca a migração e fusão dos grânulos corticais, com a consequente liberação de enzimas, que mudam tanto a estrutura da zona pelúcida (por exemplo a inativação de ZP3), como a da membrana vitelina. Desse modo, impede-se que outros espermatozoides as penetrem, evitando assim a polispermia (figura 5). -/- Figura 5: os grânulos corticais que encontram-se na periferia do citoplasma, debaixo da superfície da membrana do ovócito, migram e fusionam-se sobre a mesma, liberando seu conteúdo no espaço perivitelino imediatamente depois da penetração do espermatozoide. A – como conse-quência, tanto a membrana vitelina como a zona pelúcida são modificadas, impedindo a entrada de mais espermatozoides, o que evita a polispermia. B – o ovócito retoma, então, sua segunda divisão meiótica, que ocasiona a expulsão do segundo corpúsculo polar, e na formação dos pronúcleos feminino e masculino. C – continuando, os pronúcleos migram, suas membranas se dissolvem e os cromossomos de ambos se condensam e se unem. Completa-se, assim, a singamia e forma-se, então, o zigoto. Elaborado pelo autor baseado nos livros de embriologia e fisiologia da reprodução conforme vida bibliografia. -/- Ativação do ovócito e formação de pronúcleos -/- Na maioria das fêmeas domésticas, com exceção da cadela, o ovócito encontra-se suspenso na metáfase II da segunda meiose no momento da ovulação. A entrada da PLCζ do espermatozoide no citoplasma do ovócito, e a consequente liberação de Ca2+, faz com que o ovócito se ative, terminando a segunda divisão meiótica e expulse o segundo corpo polar. Posteriormente, o material nuclear do ovócito se reorganiza para formar o pronú-cleo feminino. Entretanto, a membrana nuclear do espermatozoide se dissolve, a cromatina descondensa-se, as protaminas são substituídas por histonas, e se forma uma nova membrana nuclear, dando lugar ao pronúcleo masculino. -/- Singamia -/- Uma vez que os pronúcleos feminino e masculino são formados, migram para o centro do ovócito, aproximam-se, suas membranas se dispersam e os cromossomos paternos e maternos se associam, com o qual recupera a condição diploide e dá origem ao zigoto (figura 5). -/- • _____DESENVOLVIMENTO EMBRIONÁRIO -/- Poucas horas após a fertilização ocorre a primeira divisão do zigoto em duas, depois em 4, 8, 16 e 32 células, denominadas blastômeros. Essas divisões mitóticas são conhecidas como divisões de segmentação ou clivagem (figura 6), uma vez que são realizadas sem aumento do citoplasma, de modo que com cada divisão os blastômeros se tornam menores. A partir das 16 células o embrião se chama mórula, e é visto como uma massa celular compacta. A compactação deve-se a informação de proteínas de ligação entre os blastômeros. O embrião acumula líquido em seu interior, formando uma cavidade denominada blastocele. Esse processo é conhecido como blastulação; o embrião, assim, passa a ser chamado de blastocisto. Nessa etapa é possível diferenciar duas populações de células embrionárias: a massa celular interna, embrioblasto ou botão embrionário (que dará origem ao embrião), e a massa celular externa, células superficiais ou trofoblasto, do qual se originam a maioria das membranas fetais. Ao continuar a multiplicação das células e a acumulação de líquido, o blastocisto aumenta de tamanho, convertendo-se em blastocisto expandido. A zona pelúcida torna-se mais fina e, finalmente, o embrião eclode; isto é, o embrião é liberado da zona pelúcida. -/- • _____FERTILIZAÇÕES ATÍPICAS -/- Polispermia -/- É a penetração de dois ou mais espermatozoides no óvulo. Esta condição é letal nos mamíferos, já que o número cromossômico desse zigoto é maior que 2n, o envelheci-mento do ovócito da porca, como consequência do serviço tardio, favorece a apresentação da polispermia, por isso, é comum ver números de nascimentos de média de 10 a 12 leitões por parição nessa espécie. Nas aves, no entanto, a penetração de mais de um espermatozoide é normal, embora apenas um pronúcleo masculino se formará, fundindo-se com o feminino. -/- Figura 6: etapas do processo de segmentação/clivagem. Fonte: aula de reprodução da professora Domenica Palomaris, UFT. -/- Ginogênese -/- É o desenvolvimento de um embrião a partir de um óvulo normal fecundado por um espermatozoide, mas sem a fusão dos cromossomos masculinos com os da fêmea. A função do espermatozoide, nesse caso, é a de ativação do ovócito para que este inicie seu desenvolvimento, mas não há fusão com o núcleo do espermatozoide. Ocorre em plantas, em nematódeos e em algumas espécies de peixes, por exemplo a Poecilia formosa, espécie em que os ovócitos das fêmeas são ativados por machos de outra espécie relacio-nada. -/- Partenogênese -/- Consiste no desenvolvimento do embrião sem a participação do espermatozoide. Ocorre em alguns insetos, o zangão, por exemplo, é partenogenético. Também pode apresentar-se em perus, cujos embriões são machos e, geralmente, morrem antes da eclosão. -/- • _____GÊMEOS -/- Existem dois tipos de gêmeos: idênticos ou monozigóticos e os não idênticos ou dizigóticos. -/- Idênticos ou monozigóticos -/- Originam-se do mesmo zigoto, sendo assim, possuem o mesmo genótipo e um fenótipo similar e, portanto, são do mesmo sexo. Em laboratório é possível gerá-los ao seccionar uma mórula em duas ou mais partes, por meio de um micromanipulador. Uma vez que possuem o mesmo genótipo, os produtos resultantes são clones. -/- Não idênticos ou dizigóticos -/- Provêm da fertilização de dois óvulos distintos por espermatozoides diferentes. Possuem, portanto, genótipos e fenótipos diferentes, e podem ser de sexo diferente. -/- REFERÊNCIAS BIBLIOGRÁFICAS -/- ALBERTS, Bruce et al. Biologia molecular da célula. Artmed Editora, 2010. AUSTIN, Colin Russell; SHORT, Roger Valentine. Reproduction in Mammals, Book I: Germ Cells and Fertilization. 1982. BEARDEN, Henry Joe et al. Reproducción animal aplicada. México: Manual Moderno, 1982. BOSCH, P.; WRIGHT JR, R. W. The oviductal sperm reservoir in domestic mammals. Archivos de medicina veterinaria, v. 37, n. 2, p. 95-105, 2005. CAPALLEJAS, Roberto Brito; RODRÍGUEZ, Lourdes Tagle. Fisiología de la reproducción animal: con elementos de biotecnología. Editorial Félix Varela, 2010. CROXATTO, Horacio B. Physiology of gamete and embryo transport through the fallopian tube. Reproductive biomedicine online, v. 4, n. 2, p. 160-169, 2002. CUPPS, Perry T. (Ed.). Reproduction in domestic animals. Elsevier, 1991. DIEDRICH, Smidt et al. Endocrinología y Fisiología de la Reproducción de los Animales Zootécnicos. 1972. DUKES, Henry Hugh; SWENSON, Melvin J.; REECE, William O. Dukes fisiologia dos animais domésticos. Editora Guanabara Koogan, 1996. FERREIRA, A. de M. Reprodução da fêmea bovina: fisiologia aplicada e problemas mais comuns (causas e tratamentos). Juiz de Fora: Minas Gerais–Brasil, p. 422, 2010. HAFEZ, Elsayed Saad Eldin; HAFEZ, Bahaa. Reprodução animal. São Paulo: Manole, 2004. HUNTER, Ronald Henry Fraser. The Fallopian tubes in domestic mammals: how vital is their physiological activity?. Reproduction Nutrition Development, v. 45, n. 3, p. 281-290, 2005. HUNTER, R. H. F.; RODRIGUEZ‐MARTINEZ, H. Capacitation of mammalian spermatozoa in vivo, with a specific focus on events in the Fallopian tubes. Molecular Reproduction and Development: Incorporating Gamete Research, v. 67, n. 2, p. 243-250, 2004. GALINA, Carlos; VALENCIA, Javier. Reproducción de los animales domésticos. 2006. HOPPER, Richard M. (Ed.). Bovine reproduction. John Wiley & Sons, 2014. HYTTEL, Poul; SINOWATZ, Fred; VEJLSTED, Morten. Embriologia veterinária. Elsevier Brasil, 2012. KÖLLE, Sabine; REESE, Sven; KUMMER, Wolfgang. New aspects of gamete transport, fertilization, and embryonic development in the oviduct gained by means of live cell imaging. Theriogenology, v. 73, n. 6, p. 786-795, 2010. MCKINNON, Angus O. et al. (Ed.). Equine reproduction. John Wiley & Sons, 2011. OLIVERA, Martha et al. El espermatozoide, desde la eyaculación hasta la fertilización. Revista Colombiana de Ciencias Pecuarias, v. 19, n. 4, p. 426-436, 2006. PLANT, Tony M.; ZELEZNIK, Anthony J. (Ed.). Knobil and Neill's physiology of reproduction. New York: Academic Press, 2014. RODRIGUEZ-MARTINEZ, Heriberto. Role of the oviduct in sperm capacitation. Theriogenology, v. 68, p. S138-S146, 2007. SAAVEDRA LEOS, María Dolores. Estudio de la composición de los gránulos corticales y del oolema de ovocitos porcinos y bovinos madurados y fecundados in vitro. Proyecto de investigación:, 2010. SENGER, Phillip L. et al. Pathways to pregnancy and parturition. Current Conceptions, Inc, 2004. SUAREZ, Susan S. The oviductal sperm reservoir in mammals: mechanisms of formation. Biology of Reproduction, v. 58, n. 5, p. 1105-1107, 1998. VALENCIA MÉNDEZ, Javier de J. Fisiología de la reproducción porcina. 1986. -/- FIXAÇÃO DO ASSUNTO -/- 1. Defina e diferencie fertilização e segmentação. -/- 2. Disserte sobre o transporte do ovócito. Por que no istmo o transporte do ovócito se torna lento? -/- 3. Fale sobre a eficiência do transporte do gameta no trato genital da fêmea e sobre a retenção de ovócitos pela égua. -/- 4. Defina as células do cumulus e explique seu papel sobre o ovócito. -/- 5. Quais as estruturas que compõem o ovócito? Qual a função de cada uma? -/- 6. Todos os ovócitos das fêmeas domésticas são iguais? Justifique. -/- 7. Disserte sobre o papel dos hormônios e das secreções sobre o transporte do ovócito no trato genital da fêmea. -/- 8. Disserte sobre o transporte do espermatozoide. Por que há transporte rápido e lento dos espermatozoides? -/- 9. Fale sobre o local de deposição do sêmen nas espécies domésticas e como esse influen-cia na eficiência da reprodução. -/- 10. Por que a vida média do espermatozoide canino é maior que as outras espécies? -/- 11. Quais as mudanças que os espermatozoides precisam sofrer para conseguir êxito na fertilização e por quê? -/- 12. Defina fase de transporte rápido, fase sustentada e hipermotilidade. Qual a importân-cia de cada um? -/- 13. Como ocorre a reação acrossômica? -/- 14. O que é polispermia e como ocorre seu bloqueio? 15. Como ocorre a ativação do ovócito e como se formam os pronúcleos? -/- 16. O que é e qual a importância da singamia? -/- 17. Disserte sobre as divisões de segmentação e qual a importância destas para o êxito da reprodução. -/- 18. Defina e diferencia mórula e blastocisto. -/- 19. Defina e diferencie ginogênese e partenogênese. -/- 20. Qual o papel endócrino e quais hormônios e enzimas atuam sobre o transporte de gametas, sobre a fertilização e sobre a segmentação? (shrink)

The purpose of this research is to identify the extent of the efficiency of the internal control environment in the Palestinian higher educational institutions in Gaza Strip from the perspective of employees in the Palestinian universities in Gaza Strip, where researchers used in the study five universities. The researchers adopted in their study the descriptive and analytical approach. The research community consists of administrative employees and academic employees with administrative duties. Senior management or the University Council was excluded. The study (...) population compromises of (392) employees. A stratified random sample was chosen and (197) questionnaires were distributed. (160) questionnaires were received back with a return rate of (81.2%).The researchers used a questionnaire to collect that which then was analyzed using (SPSS) to get the results. The research found the following results: the absence of a fundamental difference between the responses of males and females. The lack of significant difference between the responses of the respondents attributed to the variable age. The lack of significant difference between the responses of the respondents attributed to the variable of years of service. And the existence of a fundamental difference between the responses of the respondents attributed to the university variable. The existence of a fundamental difference between the responses of the respondents attributed to the Qualification variable. The existence of a fundamental difference between the responses of the respondents attributed to the administrative level variable. The research found a group of recommendations including: the need to raise awareness of censorship as the basis for the protection of employees in all administrative levels from making mistake.Updating the systems and instructions of control periodically and parallel with the scientific progress and technology.Benefit from regional and international experiences in the application of internal control standards which commensurate with the administrative system of the institution. (shrink)

Abstract: Artificial Intelligence (AI) is transforming the agricultural sector, enhancing both productivity and sustainability. This paper delves into the impact of AI technologies on agriculture, emphasizing their application in precision farming, predictive analytics, and automation. AI-driven tools facilitate more efficient crop and resource management, leading to higher yields and a reduced environmental footprint. The paper explores key AI technologies, such as machine learning algorithms for crop monitoring, robotics for automated planting and harvesting, and data analytics for optimizing resource use. Additionally, (...) it discusses challenges like data privacy, barriers to technology adoption, and the ethical implications of AI in farming. Integrating AI into agricultural practices holds the promise of greater efficiency and sustainability, paving the way for future innovations. (shrink)

I argue for an account of grasping, or understanding that, on which we grasp via a higher‐order mental act of Husserlian fulfillment. Fulfillment is the act of matching up the objects of our phenomenally presentational experiences with those of our phenomenally representational thought. Grasping‐by‐fulfilling is importantly different from standard epistemic aims, in part because it is phenomenal rather than inferential. (I endorse Bourget's (2017) arguments to that effect.) I show that grasping‐by‐fulfilling cannot be a species of propositional knowledge or belief, (...) and that it is not essentially connected to justification. I motivate a revisionary epistemology on which achieving propositional knowledge and coming to grasp are dual epistemic aims. My account makes sense of a common occurrence—that we are often unmoved to act on our beliefs until we come to phenomenally experience them in some way. It also explains puzzling features of human inquiry. (shrink)

Coreferentialism refers to the common assumption in the literature that slurs and descriptors are coreferential expressions with precisely the same extension. For instance, Vallee recently writes that “If S is an ethnic slur in language L, then there is a non-derogatory expression G in L such that G and S have the same extension”. The non-derogatory expression G is commonly considered the nonpejorative correlate of the slur expression S and it is widely thought that every S has a coreferring G (...) that possesses precisely the same extension. Yet here I argue against this widespread assumption by first briefly introducing what slurs are and then considering four sources of supporting evidence showing that slurs and descriptors are in fact not coreferential expressions with precisely the same extension. I argue that since slurs and descriptors differ in their extension they thereby differ in their meaning or content also. This article additionally introduces the notion of a conceptual anchor in order to adequately account for the relationship between slurs and descriptors actually evidenced in the empirical data, and further considers the inadequacy of common dictionary definitions of slurs. This article therefore contributes to the literature on slurs by demonstrating that previous accounts operating on the assumption that slurs and descriptors are coreferential expressions with the same extension, and that they thereby have the same meaning or content, are inconsistent with empirical data and that an alternative account in accord with Croom better fits the facts concerning their actual meaning and use. (shrink)

Mango is an economically significant fruit crop cultivated in various tropical and subtropical regions around the world. However, the productivity and quality of mangoes can be severely impacted by a range of pests. This research paper introduces an innovative approach to identify mango pests using an expert system. The expert system integrates knowledge from entomology and plants to provide accurate identification of common mango pests. The paper outlines the development and implementation of the expert system using Clips shell, which utilizes (...) rule-based techniques to analyze symptoms associated with mango pests. By inputting observed symptoms, such as leaf spots, fruit damage, leaf mild and stem cankers the system can accurately identify the specific pest species affecting the mango tree. For each pest, the paper discusses their specific symptoms and Favorable conditions that affect the mango plant. By understanding the identification and symptoms of these pests, mango growers and agricultural professionals can implement appropriate pest management strategies to mitigate the economic losses caused by these insects. The research presented in this paper aims to contribute to the body of knowledge on mango pest management, facilitating sustainable mango production and ensuring the availability of high-quality mangoes in global markets. (shrink)

We provide a new interpretation of Zeno’s Paradox of Measure that begins by giving a substantive account, drawn from Aristotle’s text, of the fact that points lack magnitude. The main elements of this account are (1) the Axiom of Archimedes which states that there are no infinitesimal magnitudes, and (2) the principle that all assignments of magnitude, or lack thereof, must be grounded in the magnitude of line segments, the primary objects to which the notion of linear magnitude applies. Armed (...) with this account, we are ineluctably driven to introduce a highly constructive notion of (outer) measure based exclusively on the total magnitude of potentially infinite collections of line segments. The Paradox of Measure then consists in the proof that every finite or potentially infinite collection of points lacks magnitude with respect to this notion of measure. We observe that the Paradox of Measure, thus understood, troubled analysts into the 1880’s, despite their knowledge that the linear continuum is uncountable. The Paradox was ultimately resolved by Borel in his thesis of 1893, as a corollary to his celebrated result that every countable open cover of a closed line segment has a finite sub-cover, a result he later called the “First Fundamental Theorem of Measure Theory.” This achievement of Borel has not been sufficiently appreciated. We conclude with a metamathematical analysis of the resolution of the paradox made possible by recent results in reverse mathematics. (shrink)

In the Bayesian approach to quantum mechanics, probabilities—and thus quantum states—represent an agent’s degrees of belief, rather than corresponding to objective properties of physical systems. In this paper we investigate the concept of certainty in quantum mechanics. Particularly, we show how the probability-1 predictions derived from pure quantum states highlight a fundamental difference between our Bayesian approach, on the one hand, and Copenhagen and similar interpretations on the other. We first review the main arguments for the general claim that probabilities (...) always represent degrees of belief. We then argue that a quantum state prepared by some physical device always depends on an agent’s prior beliefs, implying that the probability-1 predictions derived from that state also depend on the agent’s prior beliefs. Quantum certainty is therefore always some agent’s certainty. Conversely, if facts about an experimental setup could imply agent-independent certainty for a measurement outcome, as in many Copenhagen-like interpretations, that outcome would effectively correspond to a preexisting system property. The idea that measurement outcomes occurring with certainty correspond to preexisting system properties is, however, in conflict with locality. We emphasize this by giving a version of an argument of Stairs [(1983). Quantum logic, realism, and value-definiteness. Philosophy of Science, 50, 578], which applies the Kochen–Specker theorem to an entangled bipartite system. (shrink)

In this paper, we argue that there are reasons to believe that an implicit bias for normalcy influences what are considered medically necessary treatments in psychiatry. First, we outline two prima facie reasons to suspect that this is the case. A bias for ‘the normal’ is already documented in disability studies; it is reasonable to suspect that it affects psychiatry too, since psychiatric patients, like disabled people, are often perceived as ‘weird’ by others. Secondly, psychiatry's explicitly endorsed values of well-being (...) and function are hard to measure directly, which is why we see simpler box-ticking conceptions of recovery used in large research studies. This need not be problematic, but might lead to researchers and clinicians focusing too much on treatments that promote easy-to-measure proxies for recovery, instead of what actually matters to psychiatric patients themselves. Next, we provide examples of treatments and treatment decisions within two areas – self-injury and psychosis – which are hard to explain unless we assume that an implicit and harmful normalcy bias is at work. We conclude with some suggestions for clinicians and future research. (shrink)

Does martial arts practice contribute to psychological well-being in professional martial artists? If so, what are the specific ways that martial arts practice accomplishes this? It has been a long-standing and widely held belief that martial arts practice can contribute to psychological well-being, however, there has been a lack of empirical research in the psychological literature focused on investigating the details of this hypothesis. The purpose of this research is therefore to investigate the impact of a paradigmatic martial arts practice—shadowboxing—on (...) the psychological well-being of professional martial artists. In this article I present the results from an original empirical study on professional Muay Thai practitioners (n = 14) that reveals how a martial arts practice (shadowboxing) contributes to their overall psychological well-being by contributing to their positive emotions, engagement, relationships, meaning, and accomplishment. I present general results for how shadowboxing contributes to the psychological well-being of these professional martial artists overall, as well as more specific results for how shadowboxing contributes to the psychological well-being of these professional martial artists based on factors such as their gender, fight experience, and training location. This article also provides qualitative first-person reports from professional Muay Thai practitioners (n = 14) about their use of visualization and mental imagery and their experience of flow while shadowboxing, offering unique insight into the minds of professional martial artists as they are actively engaged in their craft. Finally, this article discusses the value and limitations of the present study and outlines suggestions for future research. (shrink)

Are living organisms--as Descartes argued--just machines? Or is the nature of life such that it can never be fully explained by mechanistic models? In this thought-provoking and controversial book, eminent geophysicist Walter M. Elsasser argues that the behavior of living organisms cannot be reduced to physico-chemical causality. Suggesting that molecular biology today is at the same point as Newtonian physics on the eve of the quantum revolution, Elsasser lays the foundation for a theoretical biology that points the way toward a (...) natural philosophy of organic life. Explicitly repudiating "vitalism" (the notion that the laws of nature need to be modified when applied to living organisms), Elsasser argues instead that the structural complexity of even a single living cell is "transcomputational"--that is, beyond the power of any imaginable system to compute. Beginning from this insight, Elsasser leads the reader through a step-by-step process that ultimately arrives at the conclusion that living and non-living matter are separated by "a no-man's land of irrationality." Trained in Germany as a physicist, Elsasser first pondered the implications of quantum mechanics for biology as early as 1951. The more closely he studied the inherent complexity of life, the more skeptical he became of the reductionist view of organisms as tiny machines. "An organism," he concluded, "is a source of causal chains which cannot be traced beyond a terminal point because they are lost in the unfathomable complexity of the organism." Like the physicist who works within the bounds of an unfathomable universe, Elsasser argues, the biologist must seek answers within a system that is no less unfathomable. (shrink)

Batı’da teorik felsefe; Analitik Felsefe (AF), Kıta Felsefesi (KF) ve Felsefe Tarihi (FT) olmak üzere üçe ayrılır. Fakat üçünde de işler yolunda değildir. AF, felsefenin bir bilim olabileceği iddiasından kuşku duyduğu için gerçek dünyayla ilgilenmiyorken başından beri uygun bir teorik yöntem izlemeyen Kıta Felsefesinin uygulanışı, belirli politik ve etik yargılara hizmet edecek şekilde özelleştirilmiştir. FT çalışmalarının gidişatı ise eldeki eserin nesnel değerinden daha çok ilgili filozofun ait olduğu ulus veya kültüre göre bölgesel bir temelde gelişmiştir. Felsefede ilerleme sağlanacaksa bu ancak (...) bahsi geçen tuzaklardan kaçınılarak gerçekleşebilir. (shrink)

This study aims to detect the starting point of the crises that happened in Education and Culture by the philosophical analysis which Hannah Arendt (1906 - 1975) had discussed. In Arendt's account, we can understand the genesis of the crisis as a pre-strategy to fix it. In fact, thinking is the fundamental solution to these crises and to renew our common world. Prosperity in society is related genuinely to education and culture. Regarding human capability for development, education is considered an (...) inalienable civic right which is imposed on society insofar as seeking growth. This study seeks to discover failure in these two spheres. Methods: This study relies on three methodologies; the analytical method used for discussing Arendts' terms, the historical method to explain the development of each term, and the critic method to determine the reasons behind these crises. Conclusions: The results illustrated there is a serious relation between misunderstanding the concepts of education and learning and the emptiness of their aims. (shrink)

Francis Bacon (15611626) wrote that good scientists are not like ants (mindlessly gathering data) or spiders (spinning empty theories). Instead, they are like bees, transforming nature into a nourishing product. This essay examines Bacon's "middle way" by elucidating the means he proposes to turn experience and insight into understanding. The human intellect relies on "machines" to extend perceptual limits, check impulsive imaginations, and reveal nature's latent causal structure, or "forms." This constructivist interpretation is not intended to supplant inductivist or experimentalist (...) interpretations, but is designed to explicate Bacon's account of science as a collaborative project with several interdependent methodological goals. (shrink)

A priori theories of justification of logic based on meaning often lead to trouble, in particular to issues concerning circularity. First, I present Boghossian’s a prioriview. Boghossian maintains the rule-circular justifications from a conceptual role semantics. However, rule-circular justifications are problematic. Recently, Boghossian (Boghossian, 2015) has claimed that rules should be thought of as contents and contents as abstract objects. In this paper, I discuss Boghossian’s view. My argumentation consists of three main parts. First, I analyse several arguments to show (...) that in fact, Boghossian’s inferentialist solution is not fully satisfying. Second, I discuss the matter further, if one accepts that basic logical rules are constitutive of meaning, that is, they constitute the logical concepts and the content of a rule is an abstract object, then abstract objects — like, for example, rules — could be constitutive of meaning. The question is whether conceptual priority is in the judgment or in the object and what theory of content is pursued. Grasping content as a matter of knowing how a word or concept behaves in inferences is not completely explicative. Finally, I contend that rules come to exist as a result of certain kinds of mental action. These actions function as constitutive norms. Logical rules are not abstract objects but ideal. What one construes as norms or rules of content may involve idealization, but this is because we share a language. (shrink)

Is shadowboxing an effective form of functional exercise? What physiological and morphological changes result from an exercise program based exclusively on shadowboxing for 3 weeks? To date, no empirical research has focused specifically on addressing these questions. Since mixed martial arts (MMA) is the fastest growing sport in the world, and since boxing and kickboxing fitness classes are among the most popular in gyms and fitness clubs worldwide, the lack of research on shadowboxing and martial arts-based fitness programs in the (...) extant literature is a shortcoming that the present article aims to address. This case study involved a previously sedentary individual engaging in an exercise program based exclusively on shadowboxing for 3 weeks. Body composition and heart rate data were collected before, throughout, and upon completion of the 3-week exercise program to determine the effectiveness of shadowboxing for functional fitness purposes. An original shadowboxing program prepared by an Everlast Master Instructor and NASM Certified Personal Trainer (NASM-CPT) and Performance Enhancement Specialist (NASM-PES) was used for this 3-week period. The original shadowboxing program with goals, techniques, and combinations to work on throughout the 3-week program is included in this article. This case study demonstrates that a 3-week exercise program based exclusively on shadowboxing can increase aerobic capacity, muscle mass, bone mass, basal metabolic rate, and daily calorie intake, and decrease resting heart rate, fat mass, body fat percentage, and visceral fat rating in a previously sedentary individual. The results of this research demonstrate that shadowboxing can be a safe and effective form of exercise leading to morphological and physiological improvements including fat loss and increased aerobic capacity. The results of this research also demonstrate that the Tanita BC-1500 is a reliable tool for individuals to evaluate their own fitness progress over time. (shrink)

In this article, we consider Wittgenstein’s approach to non-inferential knowledge, its relation to special propositions, and the nature of the justification of these propositions. According to Wittgenstein, there is a kind of non-inferential knowledge whose rational status is not the result of basic beliefs (in a foundational sense) that justify it. In Wittgenstein’s rule-following analysis, Frege’s theory is criticized. This theory is based on the idea that having a conceptual repertoire prior to the understanding of any rule, requires having grasped (...) the conditions of verification of a rule, which is a source of problems. Following Wright’s construing of Wittgenstein’s ideas, we maintain that understanding concepts cannot be prior to the linguistic ability. RIFL (2018) Vol. 12, n. 2: 70-82. DOI: 10.4396/20180204. (shrink)

Dance is intimately connected to both Kierkegaard’s personal life and his life in writing, as exemplified in his famous nightly attendance at the dance-filled theater, and his invitation to the readers of “A First and Last Explanation” to “dance with” his pseudonyms. The present article’s acceptance of that dance invitation proceeds as follows: the first section surveys the limited secondary literature on dance in Kierkegaard, focusing on the work of M. Ferreira and Edward Mooney. The second section explores the hidden (...) dancing dimensions of Kierkegaard’s “leap” and “shadow-dance”. And the third section reinterprets the pseudonymous works richest in dance, Repetition and Postscript, concluding that the religious for him is the lighthearted dance of a comic actor through the everyday theater of the world. (shrink)

This article proposes an alternative approach to social epistemology – a comprehensive approach. It argues that the dominant approaches to social epistemology, which it identifies as communitarian and veritistic, are inadequate. It observes that the nature of the emphasis that the communitarian approach places on the epistemic community foster mindless tolerance in epistemology, which makes the pursuit of the cognitive goal of truth difficult to attain. It also observes that the veritistic approach that seeks to refocus social epistemology on the (...) pursuit of the cognitive goal of obtaining truth does this at the expense of the affective goals of social epistemology. To overcome the inadequacies of the communitarian and the veritistic approaches and to ensure that social epistemology effectively pursues its cognitive and affective goals, this article offers the comprehensive approach. This approach absorbs the virtues of the communitarian and the veritistic approaches while avoiding their errors. Hence, it thrives on a view of truth that posits an objective and a subjective dimension of truth. The objective dimension ensures that the community only fosters and never impedes social epistemological projects such that social epistemology continues to pursue the cognitive goal of truth. The subjective dimension guarantees that the concern for truth does not lead to the neglect or abandonment of the pursuit of the affective goals of social epistemology. The rationale behind this approach is that for social epistemological projects and practices to remain truly epistemological and social, they must always take into consideration the cognitive and affective features of knowledge and knowers. (shrink)

In the Summa Theologiae, I, q. 5, art. 4, Thomas argues that the good has the ratio of the final cause.1 This thesis is problematic because there seems to be a difference between the definitions and uses of “good” and “final cause.” If Thomas is arguing that the good and the final cause are in no way distinct, then why might we plausibly describe something as good even if it has no causal role? If not, then what does it mean (...) for the ratio of goodness to be the same as that of final causality? Later Thomists disagree over the precise relationship between goodness and final causality, and their disagreement is reflected in their different interpretations of the argument and conclusion of this text. Few hold that Thomas merely means to say that goodness is the fundament of being an end, or that being an end is something like a proper passion of goodness. But they disagree over what the additional connection between the two might be. (shrink)

The first purpose of this series of articles is to introduce case studies on how current AI models can be used in the development of a possible theory of quantum gravity, their limitations, and the role the researcher has in steering the development in the right direction, even highlighting the errors, weaknesses and strengths of the whole process. The second is to introduce the new Presentist Fragmentalist ontology as a framework and use it for developing theories of quantum gravity and (...) speculate on achieving a TOE. We emphasize it is necessary for the researcher to check everything in these articles for themselves. While there are many good ideas in this series of papers, the AI is known to make even arithmetic and algebraic mistakes. To select just five apparently good ideas, there is a causal interaction tensor Cαβγδ(F1, F2) that encodes the causal relationship and the strength of the (possibly non-local) interaction between two fragments of reality (formed by each quantum system). There is a quantitative prediction for a testable table-top experiment. There is an explanation of how spacetime emerges from the fragments and their interactions. There is an explicit account of the double-slit experiment. And there is an explanation how this theory accommodates dark matter and dark energy simultaneously. We explore ideas, equations they lead to, concrete calculations, and give corrections along the way. While these are generally morally right within this framework they must be checked by the researcher. Given this caveat, we believe we have made significant progress with the PF interpretation in developing a theory of quantum gravity and pointing out a possible path to a TOE. (shrink)

In §201 of Philosophical Investigations, Ludwig Wittgenstein puts forward his famous "rule-following paradox". The paradox is how can one follow in accord with a rule - the applications of which are potentially infinite - when the instances from which one learns the rule and the instances in which one displays that one has learned the rule are only finite? How can one be certain of rule-following at all? In Wittgenstein: On Rules and Private Language, Saul Kripke concedes the skeptical position (...) that there are no facts that we follow a rule but that there are still conditions under which we are warranted in asserting of others that they are following a rule. In this paper, I explain why Kripke's solution to the rule-following paradox fails. I then offer an alternative. (shrink)

Most of human-robot interaction (HRI) research relies on an implicit assumption that seems to drive experimental work in interaction studies: the more anthropomorphism we can reach in robots, the more effective the robot will be in 'being social.' The notion of 'sociomorphing' was developed in order to challenge the assumption of ubiquitous anthropomorphizing. This paper aims to explore the notion of sociomorphing by analysing the possibilities offered by actor-network theory (ANT). We claim that ANT is a valid framework to re-think (...) the conceptual couple anthropomorphizing / sociomorphing and answer the following question: What kind of negotiation process and social practices can be developed in HRI, given the notion of sociomorph interactional networks? (shrink)

INTERNATIONAL STUDIES IN THE PHILOSOPHY OF SCIENCE Vol. 10, number 2, 1996, pp. 127-140. R.M. Nugayev. Why did the new physics force out the old ? Abstract. The aim of my paper is to demonstrate that special relativity and the early quantum theory were created within the same programme of statistical mechanics, thermodynamics and Maxwellian electrodynamics reconciliation. I’ll try to explain why classical mechanics and classical electrodynamics were “refuted” almost simultaneously or, in other words, why the quantum revolution and the (...) relativistic one both took place at the beginning of the 20th century. I’ll argue that the quantum and relativistic revolutions were simultaneous since they had a common origin – the clash beyween the mature theories of the second half of the 19th century that constituted the “body” of classical physics. The revolution’s most dramatic point was Einstein’s 1905 photon paper that laid the foundations of both special relativity and the old quantum theory. Hence the dialectic of the old theories is crucial for theory change. Later, classical physics was forced out by the joint development of quantum and relativistic subprogrammes. The title of my paper can be reformulated in Bruno Latour’s terms: The Einstein Revolution or Drawing Models Together. -/- . (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Hume Studies Volume 30, Number 2, November 2004, pp. 213-236 Pleased and Afflicted: Hume on the Paradox of Tragic Pleasure E. M. DADLEZ How fast can you run? As fast as a leopard. How fast are you going to run? A whistle sounds the order that sends Archie Hamilton and his comrades over the top of the trench to certain death. Racing to circumvent that order and arriving seconds (...) too late, Archie's friend Frank screams in rage and despair. Archie is cut down before he has run twenty yards. Peter Weir's film Gallipoli is a chronicle of the disastrous Dardanelles campaign of the first World War, but it is also a film about racing. Archie is trained by his uncle Jack to run "as fast as a leopard." The film begins as it ends, with Archie sprinting in response to a whistle. Frank is first shown racing after a train, along with friends who are on their way to enlist. Archie and Frank meet while competing in a race, they race in Cairo once they have enlisted, and they finally race death. From the beginning, Archie has been faster; even at the end he is the first to die. And from the beginning he has swept Frank along in his wake, encouraging him, pushing him, inspiring him, and helping him to positions for which he is inadequately qualified. In the end, Archie's compassion and kindness prompt a decision which has grim consequences both for himself and for hundreds of others. Knowing that his friend fears death in the trenches, Archie recommends Frank as a substitute for himself, a designated message runner. But Frank is not fast enough, and falls short by mere seconds which Archie would not have lost. This is what leads to the failure of the one real effort to countermand the fatal charge. E. M. Dadlez is Professor of Humanities and Philosophy, University of Central Oklahoma, Edmond, OK 73034, USA. e-mail: [email protected] 214 E. M. Dadlez I am an emotional wreck by the time the movie is over, though I should admit that most of my tears are the result of sheer rage. Both my dogs exited the room in some haste once I began to shout at the television and the unpardonably dimwitted British officers who sat sipping tea at a comfortable distance as they gave the order for soldiers to commit suicide. But it isn't just the scope of the real human disaster, or the enormity of the blunder, or the pointlessness of the entire enterprise, or even my renewed conviction that stupidity is, in fact, evil, that is so unsettling. The film unnerves with respect to personal as well as global concerns, focusing attention on the chance of vanity's leading one to undertake responsibilities beyond one's competence, the possibility of advancement or security being achievable only at the expense of another, and the realization of how easy it might be to let those things happen. Gallipoli is a sad, disturbing film, and the spectator is grieved and disturbed in the course of watching it. Yet, having said that, I must own to having a copy in my possession, and to having watched it more than once. I recommend it to friends, offering to lend them my videotape. In fact, I press it on them. I say that it is a terrific, rewarding work which they should take the time to see. How is it that I can describe my experience of the film in such glowing terms and at the same time acknowledge the extreme distress I felt in the course of watching it? How can I reconcile the discordant aspects of my experience? David Hume explores some possible answers in his essay "Of Tragedy."1 He begins by calling attention to the paradox of tragic pleasure: It seems an unaccountable pleasure, which the spectators of a well written tragedy receive from sorrow, terror... and other passions, which are in themselves disagreeable and uneasy. The more they are touched and affected, the more are they delighted with the spectacle.... The whole art of the poet is employed in rousing and supporting the compassion and... (shrink)

In The Birthright Lottery, Ayelet Shachar subjects the institution of birthright citizenship to close scrutiny by applying to citizenship the historical and philosophical critique of hereditary ownership built up over four centuries of liberal and democratic theory, and proposing compelling alternatives drawn from the theory of private law to the usual modes of conveyance of membership. Nonetheless, there are some difficulties with this critique. First, the analogy between entailed property and birthright citizenship is not as illustrative as Shachar intends it (...) to be; second, the mechanism of the birthright privilege levy is insufficient for addressing structural impediments to growth; and third, the principle of ius nexi, while an important corrective to currently dominant principles of nationality, will likely have effects both unnecessary and insufficient to correct the injustices that Shachar identifies. In the end, the most significant improvements in the lives of the neediest persons on the planet are more likely advanced through conventional arguments for the lowering of barriers to the circulation of goods, labor, and capital. This shift in attention from opening borders to extending citizenship risks being a distraction from more effective means of addressing the injustices associated with global inequality.Dans son livre The Birthright Lottery, Ayelet Shachar soumet l’institution de la citoyenneté par droit de naissance à un examen rigoureux, en appliquant à la citoyenneté la critique philosophique et historique de la propriété héritée construite pendant quatre siècles de théorie démocratique libérale, et en proposant aux modes habituels d’attribution de la citoyenneté une alternative séduisante tirée de la théorie du droit privé. Néanmoins, cette critique comporte certaines difficultés. Premièrement, l’analogie entre la transmission de la propriété par l’institution de la taille et la citoyenneté par droit de naissance n’est pas aussi éclairante que le soutient Shachar ; deuxièmement, le mécanisme de la taxe sur le privilège du droit de naissance est insuffisant pour s’attaquer aux obstacles structurels à la croissance ; et troisièmement, le principe du jus nexi, bien qu’on puisse le considérer comme un important correctif du principe de nationalité actuellement dominant, aura vraisemblablement des effets à la fois non nécessaires et insuffisants pour corriger les injustices que Shachar identifie. En fin de compte, les améliorations les plus significatives dans la vie des personnes les plus démunies de la planète sont vraisemblablement mieux défendues à l’aide des arguments conventionnels en faveur d’une baisse des barrières à la circulation des biens, du travail et du capital. Ce déplacement de l’attention de l’ouverture des frontières à l’extension de la citoyenneté risque de nous distraire des moyens plus efficaces de nous attaquer aux injustices associées à l’inégalité globale. (shrink)

One of the most influential and controversial schools of 20th century Thomism—especially in North America—is the “River Forest School” or “River Forest Thomism”. And one of the most influential and controversial theses associated with that school is the thesis that metaphysics cannot be established as a distinct and autonomous science unless one has already proven the existence of a positively immaterial being. The purpose of this paper is to show that River Forest Thomism cannot and should not be reduced to (...) that controversial thesis. As such, rejection of the thesis cannot and should not constitute a rejection of the school. Indeed, as soon as we understand what River Forest Thomism was really about, it will become clear that all Thomists should be River Forest Thomists. (shrink)

There are extensive discussions of the 5D AdS metric that arises naturally from a metric that accounts for the A-series, the B-series, and x^a; black holes, including their information, entropy, temperature, energy, and energy density; the Big Bang; the finitude of singularities here; inflation; AdS/CFT and dS; symmetry groups of this theory of gravity not including and including those of the standard model, with evaluations of how integrated and how plausible they are; how the theory of quantum gravity here gives (...) general relativity in one limit and quantum mechanics in another limit; and much more. -/- Of particular interest is the physics based argument for the continuation of awareness after death, which starts on about page 196 and spans several pages. (shrink)

We can ask, (1) given the state of the universe at the big bang, what is the probability that the universe would have ended up in its current actual state? What is the probability distribution for the possible states the universe could have evolved into? We can ask, (2) given the current actual state of the universe, what is the probability the big bang would have been in the state it was? What is the probability distribution over different possible states (...) at the big bang? Both the Fine-Tuning argument and the Anthropic argument are confused versions of (2). This settles the issues once and for all. (shrink)

General Introduction: In [1] a Calculus of Qualia (CQ) was proposed. The key idea is that, for example, blackness is radically different than █. The former term, “blackness” refers to or is about a quale, whereas the latter term, “█” instantiates a quale in the reader’s mind and is non-referential; it does not even refer to itself. The meaning and behavior of these terms is radically different. All of philosophy, from Plato through Descartes through Chalmers, including hieroglyphics and emojis, used (...) referential terms up until CQ. This paper in this series of papers includes a relatively short but comprehensive discussion with the AI Claude 3.5 Sonnet on how the CQ impacts various theories of consciousness, including Materialism, Dualism, Idealism, and 14 others. (shrink)

General Introduction: In [1] a Calculus of Qualia (CQ) was proposed. The key idea is that, for example, blackness is radically different than █. The former term, “blackness” refers to or is about a quale, whereas the latter term, “█” instantiates a quale in the reader’s mind and is non-referential; it does not even refer to itself. The meaning and behavior of these terms is radically different. All of philosophy, from Plato through Descartes through Chalmers, including hieroglyphics and emojis, used (...) referential terms up until CQ. This paper in this series of papers addresses the question of why is there something rather than nothing, at length, and gives a radical new answer. It has to do with the fact in CQ that, while blackness is contingently possible, █ is necessarily actual, as it was in this sentence. (shrink)

Walter Reese-Schäfer, Karl-Otto Apel, Zur Einführung (with an Afterword by Jürgen Habermas), Junis Verlag GmbH, Hamburg 1990, 176pp. DM 17.80 -/- The author, presently a freelance writer published in the newspaper “Die Zeit” and the magazine “Stern,” pro­vides in this small book a clear and concise introduction to sources, themes and conclusions in the philosophy of Karl-Otto Apel. Apel, Emeritus Pro­fessor at Frank­furt, and close colleague of Habermas, characterizes his viewpoint as a “transcen­dental pragmatism” in which a Kantian concern (...) for question regarding “the conditions for the possi­bility of some­thing,” (p.10) mixes with deontological discourse-ethics, semeiotic themes from Peirce, an ap­proach to fallibilism, the demand for “final justifica­tions” (Letzt­begründung) and German her­meneutics. In view of the “den­sity and concentration” of Apel’s texts, which often have a “deterrent effect” upon those not already at home with “the phil­osophical language game,” it is the announced aim of this book to provide a work of translation and clarification of Apel’s special­ized efforts --in effect an orientation to Apel’s work. The book divides into an Introduction, 8 chapters and a summary conclusion --with Habermas’ appreciation, “A Master Builder with Hermeneutic Feeling --The Way of Philosopher Karl-Otto Apel,” bringing up the rear. There is also a bibliography of primary and secondary sources and a short table outlining highlights of Apel’s career. The “Introduction” provides a good overview of the aims of the book and gets one started on central themes. (shrink)

The word "green" refers to the color green, which could more precisely refer to the wavelength of green photons, green paint, green light, or green qualia. But in this 12-page paper, as in this abstract, it is written in black. Thus its referential meaning(s) is different than its non-referential or presentational meaning, which is the actual quale of blackness arising in the actual reader's mind. Philosophy has discussed--but never employed--non-referential terms before. That is like discussing swimming but never employing a (...) swimming ability. It can be done, but it misses the whole point. This paper discusses non-referential terms, poetry, painting, music, swimming, counterfactuals, and how this distinction is deeper than the 1st-person / 3rd-person divide. (shrink)

Preface/Introduction: The question under discussion is metaphysical and truly elemental. It emerges in two aspects — how did we come to be conscious of our own existence, and, as a deeper corollary, do existence and awareness necessitate each other? I am bold enough to explore these questions and I invite you to come along; I make no claim to have discovered absolute answers. However, I do believe I have created here a compelling interpretation. You’ll have to judge for yourself. -/- (...) What follows is the presentation of three essays I have worked on over the past several years seeing publication for the first time. “Hollows of Experience” was written first as an invited chapter for a collection on the ontology of consciousness. However, when cuts became necessary, my chapter got the knife. Its length has prohibited it from publication in any print journal. “Myth and Mind” was written next as a journal article, but as my involvement with it grew so did its length, so it has also idled on my websty awaiting its call. “From Panexperientialism to Conscious Experience” was written most recently, but it is the only one to have been available to the public elsewhere than my own website. Under the name, “The Continuum of Experience”, it was Target Article #95 on the recently closed Karl Jaspers Forum (for discussion purposes only). -/- I have put them in a different sequence here, for reasons of logical sense. Up first, “Panexperientialism” deals with an idea difficult for many to accept, namely that conscious experience is a particular mode of symbolically reflected experience that is largely unique to our species. However, I aver that experienced sensation in itself (as found, for example, in autonomic sensory response systems) goes “all the way down” into nature, and thus the title, panexperientialism. -/- Understanding this idea is helpful to dealing with the focus on language in Part I of “Hollows”, next, since here speech and general symbolic interaction in general are found to be the catalysts for the creation of our consciously experienced world (our “lived reality”). In Part II, however, I explore how experienced sensations must be coeval with existence, and, with even greater temerity, how all this sensational existence might have arisen within some literally inconceivable background of awareness-in-itself that yet has a dynamism that occasionally breaks into existence as experiential events and entities. (The latter may sound wacky, but physicists and cosmologists are themselves attempting to come to terms with that which seethes with vast potential energy in what they refer to as the quantum vacuum.) -/- “Myth and Mind” was put third since it deals with a major lacuna in “Hollows” — that presumed prehistoric period when members of our species made the painful crossing of the symbolic threshold into the beginnings of cultural consciousness. Speech plays a central role here, too, but I look more at narrative structures from the dawn of self-awareness when ritual and myth became vital to human survival. Why would fantastic stories and bizarre rituals be necessary? I speculate that growing foresight led to the unavoidable realization of certain mortality, from which, in turn, emerged the secondary realization that we were now alive. In contrast to our yet-to-come death, we have life here and now, and by ritually identifying with a symbolically expanded mythic, i.e., sacred, reality, we may continue to live on after bodily death, just as our ancestors and loved ones must also do. Language and mythmaking are necessary to avoid mortal despair and they remain at the core of human consciousness. -/- As Ernst Cassirer (1944) has noted, language and myth are “twin creatures”, both metaphoric webs over a reality we can never wholly comprehend. We live in the symbolic and construct our works of imagination and wars of conquest to make life meaningful, to feel immortal, and to sense that we ourselves participate in a reality greater than ourselves. No doubt we do, but this does not mean our culturally constructed self-identities survive the death of our bodies, and it does not imply that our symbolic concepts can ever indicate the ultimate truth. We simply must symbolize an extended reality that was sacred to our ancestors: “Is it not our way, as illusory as it may be, to force continuance on our world and our life in the face of their inevitable ending? Are we not compelled to extend those imaginary horizons as far as we can despite the terror and the sometime joy their extension incites? Is their closure not a form of death?” (Crapanzano, p. 210) -/- Of course, this leaves me in the uncomfortable position of being forced to admit that this venture of mine must inevitably be another attempt at meaningful mythmaking. But what else could it be? This is certainly not a scientific proof though it is indeed an academically rigorous exploration. (Just try to count the citations!) I hope the reader will judge my thesis on the basis of its coherence, the sense of meaning it evokes, my intellectual responsibility, and, finally, the engagement it inspires. If you have read my expositions and found yourself immersed in the timeless questions I here call forth, I would call these writings successful (even if you violently disagree with my answers). -/- I am very grateful to Huping Hu for granting me this special issue of JCER in which to present my ideas in some detail. He has patiently dealt with my exuberant approach and allowed the many changes I kept coming up with right until the final publication date. I also wish to thank the many potential commentators who politely replied to my invitation, and, even more, I thank those who made time to write actual commentaries. -/- References -/- Cassirer, E. (1944). An Essay on Man: An Introduction to a Philosophy of Human Culture. New Haven/London: Yale UP. -/- Crapanzano, V. (2004). Imaginative Horizons: An Essay in Literary-Philosophical Anthropology. Chicago: U of Chicago Press. -/- Gregory M. Nixon University of Northern British Columbia Prince George, British Columbia, Canada Email: [email protected] Websty: http://members.shaw.ca/doknyx. (shrink)

El presente trabajo de tesis se centra en el estoicismo, en la obra titulada Disertaciones que recoge las enseñanzas de Epicteto pero que fue recopilada por Arriano. Es en tal texto en el que principalmente basamos la presente tesis. Analizamos las enseñanzas de Epicteto, filósofo nacido en Hierópolis (Frigia) hacia el 55 d.C., que fue un liberto que se adentró en el estoicismo tras asistir a las clases del filósofo Musonio Rufo; gracias al permiso de su amo Epafrodito pudo asistir (...) a las pláticas de tal erudito. Los dos temas a tratar, el poder y el amor, que forman parte de la ética y de la filosofía política –estoicas-, así como de la epistemología, la física y la metafísica, por ser el sistema estoico uno que está estrecha y racionalmente interconectado, han sido abordados por investigadores recientes desde distintos ámbitos y perspectivas. El poder y el amor son conceptos que deben de ser explicados y analizados a partir de los conceptos mencionados de “sentimiento”, “inclinación”, “pasión”, “bueno”, “malo”, además de los de “virtud”, “vicio”, “indiferente”, “oikéiosis”, “deber”, “sabio”, “libertad”, etc. Por lo que ambas categorías han sido abordadas desde su vinculación con, o a partir de su explicación a través de, uno o varios de los conceptos mencionados. (shrink)

Joint remembering relies on the successful interweaving of multiple cognitive, linguistic, bodily, social and material resources, anchored in specific cultural ecosystems. Such systems for joint remembering in social interactions are composed of processes unfolding over multiple but complementary timescales which we distinguish for analytic purposes with the terms ‘coordination’, ‘collaboration’, ‘cooperation’, and ‘culture’, so as better to study their interanimation in practice. As an illustrative example of the complementary timescales involved in joint remembering in a real-world activity, we present a (...) micro-qualitative analysis of an interactional sequence in which two members of a fourperson team of video designers crafted a memory- scaffolding tool. In order to find the temporal structure of the crafting of the memory-scaffolding tool, we used software for pattern recognition. The analysis suggests that coordination, collaboration, cooperation, and culture reveal complementary aspects of interacting to remember, which should be considered as complex phenomenon unfolding at multiple interanimating timescales. (shrink)

Criteria of the growth of knowledge proposed in modern philosophy of science are considered. It is argued that the model of growth that fits the peculiarities of social sciences&humanities is provided by the methodology of scientific research programmes. Yet one has to correct some drawbacks. The author concludes that the real growth of knowledge consists in the growth of causal explanations and in the corresponding growth of empirical content of the theories from superseeding scientific research programmes. -/- Key words: R.Rorty, (...) M.Weber,N.Cartwright -/- . (shrink)

In this short informal note we consider four Gedankenexperiments that show A-theories of time are compelling and can be leveraged to give a Presentist Fragmentalist realist interpretation of quantum mechanics. Each of these four involve roles for manifest time, relativistic time, and quantum mechanical time. The point is to give simple everyday situations where a new point of view leads to the consistency of all three. This is the MO of the early Einstein. Einstein's Train is one of the Gedankenexperiments (...) considered. (shrink)

Scientists regularly invoke broadly aesthetic properties like elegance and simplicity when evaluating theories, but why should we expect aesthetic pleasure to signal an epistemic good? I argue that aesthetic judgements in science are best understood as a special case of affective cognition, and that the feelings on which these judgements are based are the upshots of metacognitive monitoring of the quality of our engagement with theory and evidence. Finding a theory beautiful fallibly signals that it fits well with our background (...) knowledge and that it’s neither artificially adjusted to accommodate otherwise disconfirming evidence nor fitted to noise in the data, which makes aesthetic pleasure a good heuristic for theory evaluation. (shrink)

This paper proposes a novel theoretical framework for reconciling quantum mechanics with relativity that leads to a theory of quantum gravity by examining the fundamental nature of time. In the first section we argue that it is possible to perform an experiment for oneself in which, with enough ‘internal technology’ it is possible to distinguish between one’s experience of time on the one hand, and one’s thoughts about one’s experience of time on the other hand. The former gives McTaggart's A-series (...) (future/present/past) and the latter gives McTaggart’s B-series (earlier/simultaneous/later). Several arguments are then given for why this should work, and several Gedankenexperiments, including Einstein’s Train, are explored and it is shown how they can be solved using this notion of time. These series lead directly to the Presentist Fragmentalist interpretation of quantum mechanics [Merriam 2022a]. To a first approximation, quantum mechanics primarily operates in the A-series and relativity operates in the B-series. The interpretation is used to propose a theory of quantum gravity, where the A-series and the B-series become mixed. It is then shown how this theory leads to the Schrodinger equation in one limit and General Relativity in another limit. (shrink)

This note outlines a Theory of Everything consistent with the PF interpretation of quantum mechanics.

Presentist Fragmentalism is a novel interpretation of quantum mechanics. This paper develops the resulting theory of Quantum Gravity.

This paper presents a falsifiable prediction based on A-theories of time, which require both an A-series (future/present/past) and B-series (earlier/simultaneous/later) of time. We make an unusual argument based on the temporal search parameters of YouTube videos, which requires *two* parameters. We make the falsifiable prediction that no interface with just *one* parameter can be made that has the same functionality (as would be asserted in B-theories). This circumstance applies to many areas of human endeavor. We extend this analysis to clocks, (...) showing how sundials, analog clocks, digital clocks, and atomic clocks all fundamentally operate using both temporal series. The progression from hardware to software clocks in computers reveals how both series persist through increasing levels of abstraction. These findings suggest that physics, being fundamentally based on clock measurements, must incorporate both temporal series rather than attempting to reduce one to the other. This approach offers new insights into the relationship between quantum mechanics and relativity, suggesting that quantum mechanics primarily operates in A-series time while relativity operates in B-series time, potentially illuminating why their unification has proven challenging. (shrink)

Einstein's relativity emerged from his resolution of three key thought experiments. We show that Presentist Fragmentalism can systematically resolve eight fundamental paradoxes, including Einstein's classic train scenario and Schrodinger’s Cat.