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)

This study aimed to examine the lived experiences of multilingual students in online distance learning during the height of the COVID-19 pandemic. The study utilized the qualitative research design - transcendental phenomenology and employed purposive sampling. The study participants were ten (10) multilingual students among Senior High School Students. A researcher-made questionnaire was reviewed by research experts and was used in individual interviews with the participants. The collected data through interviews underwent thematic analyses and triangulation. Based on the findings, the (...) model was developed through thematic analyses, the Basic Instructional Strategies Aiming to Address the Problems of Multilingual Students in Online Distance Learning MODEL (in the Filipino language: Batayang Instruksiyong estratehiya na Naglalayong Tugunan at Alamin (BINTA) ang mga suliranin ng mga multilinggwal na mag-aaral sa online distance learning) was developed. The BINTA Model represents the lived experiences of multilingual students in online distance learning in terms of the themes that emerged: lack of interaction and communication, difficulty in understanding technical terms, consistency of internet connection, and effective communication. This implies that the model can help improve these students' educational outcomes and experiences by providing appropriate instructional strategies tailored to the needs of multilingual students. Educators can help mitigate these students' challenges and difficulties in an online distance learning environment. Through this, educators can help ensure that multilingual students can engage with the material, participate fully in online discussions and activities, and ultimately achieve their learning goals. (shrink)

Criticism can sometimes provoke defensive reactions, particularly when it implicates identities people hold dear. For instance, feminists told they are upholding rape culture might become angry or upset, since the criticism conflicts with an identity that is important to them. These kinds of defensive reactions are a primary focus of this paper. What is it to be defensive in this way, and why do some kinds of criticism, or implied criticism, tend to provoke this kind of response? What are the (...) connections between defensiveness, identity, and active ignorance? What are the social, political, and epistemic consequences of the tendency to defensiveness? Are there ways to improve the situation? (shrink)

Was ist Nachhaltigkeit, was ist ihr Wesen und was bedeutet Nachhaltigkeit für Mensch und Gesellschaft, für Natur und Kultur? Um diese Fragen zu beantworten, lädt Jürgen H. Franz seine Leser zu einer philosophischen Reise ein. Die Reise führt zu den begriflichen Wurzeln und den Grundbedingungen der Nachhaltigkeit und eröffnet dabei sowohl einen Blick auf ihre globale Relevanz als auch auf die vielfältigen Hindernisse, die sich ihrer Realisierung entgegenstellen. Sie führt etappenweise zu immer neuen Standpunkten und damit zu neuen Ansichten und (...) Einsichten. Die Reise schließt auch ein historisches Etappenziel ein. Es ist die Zeit des Philosophen und Theologen Cusanus, der sich als ein früher Wegbereiter der Nachhaltigkeit erweist. Schritt für Schritt offenbart sich dem Reisenden die humane, moralische, soziale, ökologische, ökonomische, technische und historische Dimension der Nachhaltigkeit. Er lernt ein neues Modell der Nachhaltigkeit kennen, die Crux des Denkens in Systemen und die Idee einer Hermeneutik der Natur. Und er lernt zwei ungleiche Verwandte kennen: die Menschlichkeit und die Scheinheiligkeit. Am Ende seiner Reise vermag er Sein und Schein der Nachhaltigkeit zu trennen und ein eigenes Bild nachhaltiger Entwicklungen zu zeichnen. Seine Reiseerfahrungen bereichern seinen Alltag, sein Berufsleben oder Studium. (shrink)

Historically, the Vienna Circle and the Dessau Bauhaus were related, with members of each group familiar with the ideas of the other. Peter Galison argues that their projects are related as well, through shared political views and methodological approach. The two main figures that connect the Vienna Circle to the Bauhaus—and the figures upon which Galison focuses—are Rudolf Carnap and Otto Neurath. Yet the connections that Galison develops do not properly capture the common themes between the Bauhaus and Neurath’s philosophical (...) projects. We demonstrate this by considering Neurath’s philosophical commitments. We suggest different connections between Neurath’s projects and the Bauhaus, connections that are both substantive and philosophically interesting. (shrink)

There are many good reasons to learn about the lives of people who have less social privilege than we do. We might want to understand their circumstances in order to have informed opinions on social policy, or to make our institutions more inclusive. We might also want to cultivate empathy for its own sake. Much of this knowledge is gained through social scientific or humanistic research into others' lives. The entitlement to theorize about or study the lives of marginalized others (...) is often granted under the presumption of academic freedom. This paper will not question whether academic freedom licenses us to do so in the first place ; instead, I will... (shrink)

Imperatives occur ubiquitously in natural languages. They produce forces which change the addressee’s cognitive state and regulate her actions accordingly. In real life we often receive conflicting orders, typically, issued by various authorities with different ranks. A new update semantics is proposed in this paper to formalize this idea. The general properties of this semantics, as well as its background ideas are discussed extensively. In addition, we compare our framework with other approaches of deontic logics in the context of normative (...) conflicts. (shrink)

In this paper, I attempt to show how Davidson’s anti-sceptical argument can respond to the closureRK-based radical scepticism. My approach will focus on the closureRK principle rather than the possibility that our beliefs could be massively wrong. I first review Davidson’s principle of charity and the triangulation argument, and then I extract his theory on content of a belief. According to this theory, content of a belief is determined by its typical cause and other relevant beliefs. With this constraint on (...) content, I argue that doubt must be local. Furthermore, since one cannot rationally believe that one’s commitment to the cause of beliefs could be false, our commitment to the denial of a sceptical hypothesis is not a knowledge-apt belief. Therefore, the closureRK principle is not applicable to rational evaluations of this commitment. As a result, the closureRK-based sceptical argument fails while the closureRK principle remains. (shrink)

Philosophers have relied on visual metaphors to analyse ideas and explain their theories at least since Plato. Descartes is famous for his system of axes, and Wittgenstein for his first design of truth table diagrams. Today, visualisation is a form of ‘computer-aided seeing’ information in data. Hence, information is the fundamental ‘currency’ exchanged through a visualisation pipeline. In this article, we examine the types of information that may occur at different stages of a general visualization pipeline. We do so from (...) a quantitative and a qualitative perspective. The quantitative analysis is developed on the basis of Shannon’s information theory. The qualitative analysis is developed on the basis of Floridi’s taxonomy in the philosophy of information. We then discuss in detail how the condition of the ‘data processing inequality’ can be broken in a visualisation pipeline. This theoretic finding underlines the usefulness and importance of visualisation in dealing with the increasing problem of data deluge. We show that the subject of visualisation should be studied using both qualitative and quantitative approaches, preferably in an interdisciplinary synergy between information theory and the philosophy of information. (shrink)

The ascription of desires or beliefs to other people is a milestone of human sociality. It allows us to understand, explain, and predict human behaviour. During the last years, research on children's knowledge about the mental world, better known as theory of mind research, has become a central topic in developmental psychology and the role of cultural impact is subject of various theoretical yet hitherto few empirical accounts. This book is the result of intensive collaboration between anthropologists and psychologists in (...) the field of cross-cultural research on social cognitive development. Five interdisciplinary research teams, coming from the University of Heidelberg, were investigating five Pacific Island societies. All together, they were interested in the question of how and when children in these different cultures come to assign mental states to others. This unique research project combines sound ethnography of different Pacific cultures with thoroughly conducted experimental work, done by developmental psychologists; it presents a shared, thoughtful analysis of the results and provides deeper insight into current debates on the ontogeny of theory of mind competencies. (shrink)

This paper aims to address the difficulties of high school students in bridging their computational understanding with their visualization skills in understanding the notion of the limits in their calculus class. This research used a pre-experimental one-group pretest-posttest design research on 62 grade 10 students enrolled in the Science, Technology, and Engineering Program (STEP) in one of the public high schools in Zamboanga del Sur, Philippines. A series of remedial sessions were given to help them understand the function values, one-sided (...) limits, limits of a function, and its discontinuities with the aid of the GeoGebra. Results revealed that there is a significant improvement in their mathematics performance before and after the remediation, t(61) = -19.99, p<.05. The real-time feedback provided by the drawing interface of GeoGebra has provided the students the insights into how objects behave in geometrical space, bridging their understanding in locating the values shown by the computational algebraic processes. Additionally, the significant difference in the achievement reveals a large effect size (Cohen’s =2.54) which could be accounted for by the remediation using interactive activities in the GeoGebra. (shrink)

This paper concerns “human symbolic output,” or strings of characters produced by humans in our various symbolic systems; e.g., sentences in a natural language, mathematical propositions, and so on. One can form a set that consists of all of the strings of characters that have been produced by at least one human up to any given moment in human history. We argue that at any particular moment in human history, even at moments in the distant future, this set is finite. (...) But then, given fundamental results in recursion theory, the set will also be recursive, recursively enumerable, axiomatizable, and could be the output of a Turing machine. We then argue that it is impossible to produce a string of symbols that humans could possibly produce but no Turing machine could. Moreover, we show that any given string of symbols that we could produce could also be the output of a Turing machine. Our arguments have implications for Hilbert’s sixth problem and the possibility of axiomatizing particular sciences, they undermine at least two distinct arguments against the possibility of Artificial Intelligence, and they entail that expert systems that are the equals of human experts are possible, and so at least one of the goals of Artificial Intelligence can be realized, at least in principle. (shrink)

Representing the kinetic state of a patient (posture, motion, and activity) during vital sign measurement is an important part of continuous monitoring applications, especially remote monitoring applications. In contextualized vital sign representation, the measurement result is presented in conjunction with salient measurement context metadata. We present an automated annotation system for vital sign measurements that uses ontologies from the Open Biomedical Ontology Foundry (OBO Foundry) to represent the patient’s kinetic state at the time of measurement. The annotation system is applied (...) to data generated by a wearable personal status monitoring (PSM) device. We demonstrate how annotated PSM data can be queried for contextualized vital signs as well as sensor algorithm configuration parameters. (shrink)

In this article, we explicate evidence-based nursing (EBN), critically appraise its framework and respond to nurses’ concern that EBN sidelines the caring elements of nursing practice. We use resources from care ethics, especially Vrinda Dalmiya’s work that considers care as crucial for both epistemology and ethics, to show how EBN is compatible with, and indeed can be enhanced by, the caring aspects of nursing practice. We demonstrate that caring can act as a bridge between ‘external’ evidence and the other pillars (...) of the EBN framework: clinical expertise; patient preferences and values. Drawing on an influential EBN handbook, section 1 presents the aims and features of EBN, including the normative principle that EBN should take place within a ‘context of caring’. We aim to understand this context and whether it can be neatly detached from the EBN framework, as the handbook seems to suggest. In section 2, we highlight the grounds for resistance to EBN from the nursing community, before mounting the argument that nursing practices can be understood fruitfully through feminist care ethics and/or virtue ethics lenses. In section 3, we deepen that analysis using Dalmiya’s concepts of care-knowing and care as a hybrid ethico-epistemic virtue, which are ideally suited to the complex practices of nursing. In section 4, we bring this rich understanding of care into conversation with EBN, showing that its framework cannot be adequately theorised without paying proper attention to care. Caring can be neither an innocuous background assumption of nor an afterthought to the EBN framework. (shrink)

This dissertation identifies and explains four major contributions of the Laws and related late dialogues to Plato's moral and political philosophy. -/- Chapter 1: I argue that Plato thinks the purpose of laws and other social institutions is the happiness of the city. A happy city is one in which the city's parts, i.e. the citizens, are unified under the rule of intelligence. Unlike the citizens of the Republic, the citizens of the Laws can all share the same true judgments (...) of value, and this unanimity explains the city's unity. Plato thinks that aiming at the city's happiness is justified, moreover, because a unified city contributes to the universe's order. -/- Chapter 2: In the Laws, Plato holds that the sick, poor, ugly, weak, but virtuous are happy, and that health, wealth, beauty, and strength benefit the virtuous but harm the vicious. Only in the Laws does Plato commit himself to all these claims simultaneously, and I explain how the moral psychology of the Laws permits Plato to maintain them coherently. -/- Chapter 3: I argue that, in the Laws, becoming virtuous is the same as becoming like God. Becoming like God does not require escape from the world of change as it does in the Theaetetus, however. Rather, becoming like God requires bringing "measure" or appropriate order to the world of change, especially to those entities over which we have the most control—our own souls. In the Laws, citizens achieve this order as they learn to be just and to understand the nature of reality. -/- Chapter 4: Unlike the Republic and Statesman, the Laws holds that obedience of the citizens to their laws should be effected, if possible, with rational persuasion. I argue that Plato wishes such persuasion to educate the citizens of the reasons for the laws. Understanding the laws' justification is the principal way in which citizens acquire the good judgment necessary for virtue. The city becomes more happy as the citizens progress in virtue, so rational persuasion is a necessary means to the lawgiver's overall aim. (shrink)

Everyone thinks they know who Prince Zuko is and can be. His father, Fire Lord Ozai, and sister, Azula, think him weak, disobedient, and undeserving of the crown. His Uncle Iroh thinks him good, if troubled, but ultimately worthy of his faith. The kids initially think him a villain, but eventually come to see him as a person – neither monster nor saint – someone who can choose to go in a new way. Zuko himself shows great ambivalence between these (...) conflicting stories about who he is, though each one helps to craft his own self-understanding. In this paper, we apply Hilde Lindemann’s narrative account of the self to explore the ways that others “hold” Zuko in one identity or “let him go” from others. According to Lindemann, our personal identities consist of the first- and third-person stories that cluster around significant acts, relationships, and commitments in our lives. Our identities are fundamentally relational, formed by the interaction between our own self-conception and the ways in which others see us. As such, others’ stories can enable or prevent us from imaginatively projecting ourselves into a particular future. This can lead us to becoming trapped in our identities; without the possibility of being perceived differently by others, we might find ourselves unable to try different ways of being or acting. The converse is also true, in that others can open up new possible identities by seeing things in us that we have trouble seeing in ourselves. If others in our moral community see us as wicked, beyond redemption and unable to repair our wrongs, we are held in the role of the villain and might come to live into that role without question. Zuko’s story is a perfect illustration of Jean Harvey’s reminder that, “it is just not true that once a thief, always a thief” and that agents can choose to go in a new way, can choose to change. How does Zuko change? We argue that Zuko’s redemption is enabled by those in his moral community holding him in identities in which he is a good person, capable and deserving of care, friendship, and love. While the identity he has in relation to his father and sister closes down many possible futures, his uncle Iroh in particular persists in holding him in an identity in which he is loved and worthy of love. And in doing so - in holding this space for him - Iroh opens up a way for Zuko to exercise agency and choose to become a different kind of person than the one he thought he was destined to be. (shrink)

Liver transplantation (LT) activities during the COVID-19 pandemic have been curtailed in many countries. The impact of various policies restricting LT on outcomes of potential LT candidates is unclear. We studied all patients on the nationwide LT waitlists in Hong Kong and Singapore between January 2016 and May 2020. We used continuous time Markov chains to model the effects of different scenarios and varying durations of disruption on LT candidates.

Is the societal-level of analysis sufficient today to understand the values of those in the global workforce? Or are individual-level analyses more appropriate for assessing the influence of values on ethical behaviors across country workforces? Using multi-level analyses for a 48-society sample, we test the utility of both the societal-level and individual-level dimensions of collectivism and individualism values for predicting ethical behaviors of business professionals. Our values-based behavioral analysis indicates that values at the individual-level make a more significant contribution to (...) explaining variance in ethical behaviors than do values at the societal-level. Implicitly, our findings question the soundness of using societal-level values measures. Implications for international business research are discussed. (shrink)

On the basis of PM2.5 data of the national air quality monitoring sites, local population data, and baseline all-cause mortality rate, PM2.5-related health economic benefits of the Air Improvement Action Plan implemented in Wuhan in 2013–2017 were investigated using health-impact and valuation functions. Annual avoided premature deaths driven by the average concentration of PM2.5 decrease were evaluated, and the economic benefits were computed by using the value of statistical life (VSL) method. Results showed that the number of avoided premature deaths (...) in Wuhan are 21,384 (95% confidence interval (CI): 15,004 to 27,255) during 2013–2017, due to the implementation of the Air Improvement Action Plan. According to the VSL method, the obtained economic benefits of Huangpi, Wuchang, Hongshan, Xinzhou, Jiang’an, Hanyang, Jiangxia, Qiaokou, Jianghan, Qingshan, Caidian, Dongxihu, and Hannan District were 8.55, 8.19, 8.04, 7.39, 5.78, 4.84, 4.37, 4.04, 3.90, 3.30, 2.87, 2.42, and 0.66 billion RMB (1 RMB = 0.1417 USD On 14 October 2019), respectively. These economic benefits added up to 64.35 billion RMB (95% CI: 45.15 to 82.02 billion RMB), accounting for 4.80% (95% CI: 3.37% to 6.12%) of the total GDP of Wuhan in 2017. Therefore, in the process of formulating a regional air quality improvement scheme, apart from establishing hierarchical emission-reduction standards and policies, policy makers should give integrated consideration to the relationship between regional economic development, environmental protection and residents’ health benefits. Furthermore, for improving air quality, air quality compensation mechanisms can be established on the basis of the status quo and trends of air quality, population distribution, and economic development factors. (shrink)

Is the societal-level of analysis sufficient today to understand the values of those in the global workforce? Or are individual-level analyses more appropriate for assessing the influence of values on ethical behaviors across country workforces? Using multi-level analyses for a 48-society sample, we test the utility of both the societal-level and individual-level dimensions of collectivism and individualism values for predicting ethical behaviors of business professionals. Our values-based behavioral analysis indicates that values at the individual-level make a more significant contribution to (...) explaining variance in ethical behaviors than do values at the societal-level. Implicitly, our findings question the soundness of using societal-level values measures. Implications for international business research are discussed. (shrink)

Entrepreneurship education is among the key drivers of the country’s economy, and teachers are primarily responsible for its integration into teaching and finding the best and most useful method. The purpose of this research is to determine the level of entrepreneurial competence and teaching methods among entrepreneurship education teachers. Focusing on the concept of entrepreneurial competencies combining conceptual, human relations, strategic, commitment, opportunity, organizational and strategic competencies. Using quantitative – descriptive survey, the study tested its significant difference and relationship when (...) grouped with the profile variables. The findings indicate a significant correlation between the variables particularly, with the technical competence which has the strongest correlation. The paper sheds some light concerning the status of the current entrepreneurial competence of the teachers in the division and recommends training curriculum to develop their competencies in handling the subject. (shrink)

Does the Ship of Theseus present a genuine puzzle about persistence due to conflicting intuitions based on “continuity of form” and “continuity of matter” pulling in opposite directions? Philosophers are divided. Some claim that it presents a genuine puzzle but disagree over whether there is a solution. Others claim that there is no puzzle at all since the case has an obvious solution. To assess these proposals, we conducted a cross-cultural study involving nearly 3,000 people across twenty-two countries, speaking eighteen (...) different languages. Our results speak against the proposal that there is no puzzle at all and against the proposal that there is a puzzle but one that has no solution. Our results suggest that there are two criteria—“continuity of form” and “continuity of matter”— that constitute our concept of persistence and these two criteria receive different weightings in settling matters concerning persistence. (shrink)

Climate change and decarbonization raise complex justice questions that researchers and policymakers must address. The distributions of greenhouse gas emissions rights and mitigation efforts have dominated justice discourses within scenario research, an integrative element of the IPCC. However, the space of justice considerations is much larger. At present, there is no consistent approach to comprehensively incorporate and examine justice considerations. Here we propose a conceptual framework grounded in philosophical theory for this purpose. We apply this framework to climate mitigation scenarios (...) literature as proof of concept, enabling a more holistic and multidimensional investigation of justice. We identify areas of future research, including new metrics of service provisioning essential for human well-being. [Can be freely read by clicking the ReadCube link below.]. (shrink)

In written and spoken communications, metaphors are often used as an aid to help convey abstract or less tangible concepts. However, the benefits of using visual metaphors in visualization have so far been inconclusive. In this work, we report an empirical study to evaluate hypotheses that visual metaphors may aid memorization, visual search and concept comprehension. One major departure from previous metaphor-related experiments in the literature is that we make use of a dual-task methodology in our experiment. This design offers (...) an abstraction of typical situations where viewers do not have their full attention focused on visualization (e.g., in meetings and classes). The use of the secondary task introduces “divided attention”, and makes the effects of visual metaphors more observable. In addition, it also serves as additional masking in memory-based trials. The results of this study show that visual metaphors can help participants better remember the information depicted in visualization. On the other hand, visual metaphors can have a negative impact on the speed of visual search. The results also show a complex pattern as to the benefits of visual metaphors in helping participants grasp key concepts from visualization. (shrink)

Nelson Goodman (1906-2007) approached the arts and other kinds of knowledge as forms of symbolism. His principal aim in philosophy was to advance understanding and remove confusions by verbal analysis and logical constructions. Goodman's philosophical theories encompass nominalism, constructivism and a version of radical relativism. In his Languages of Art, Goodman sets forth distinctions among the various art according to differences in the forms of symbols employed. He contributed as well to arts education and to philosophy of the museum. His (...) performance work, "Hockey Seen: A Nightmare in Three Periods and Sudden Death embodies his aesthetic theories. (shrink)

Introduction: During the COVID-19 pandemic, adolescents have increasingly suffered from online problem behaviors and mental disorders. But little research has paid attention to the protective factors among adolescents. Therefore, the present study attempted to investigate the role of positive youth development (PYD) attributes in adolescents’ depression, internet gaming disorder (IGD) and cyberbullying/victimization (CBV). -/- Methods: A total of 995 Chinese adolescents (Mage = 15.97 years, SD = 0.77, 325 boys) from two public high schools in Hubei province were recruited to (...) participate in the three-wave longitudinal study over the span of 1 year during the pandemic (Time 1: November, 2020; Time 2: May, 2021; Time 3: November, 2021). -/- Results: T1 PYD attributes negatively predicted T2 depression and T3 online problematic behaviors. T2 depression positively predicted IGD at T3. T3 IGD significantly predicted greater involvement in T3 CBV, and vice versa. Moreover, depression and one online problem behavior mediated the relationships between PYD attributes and the other online problem behavior, separately and sequentially. (shrink)

This research explores the effects of globalization to the Malaysian architectural practice in the current situation. The research explores three issues, firstly what are the reasons local architects are taking projects locally (localization) only, and, secondly, what are the factors which motivate local architects to venture into international projects (termed as globalization). It also explores, thirdly, what are the factors which influence foreign architects coming to Malaysia to practice. Research was qualitative in nature using semi-structured interviews. The interviews were transcribed (...) and a thematic analysis was carried out. An online survey was conducted towards the end to a different group from the architecture fraternity to supplement the research and findings. Overall, the reasons uncovered for the first issue are the total lack of opportunities and insufficient capacity due to small practices. Reasons for the second issue are due to the more lucrative fees and the experience and technology transfer which are advancements to their practices. For the third issue, the factors were found to more personal reasons based rather than solely applying to practice. In summary, to go global or stay local is actually up to the individual preference of the architect and also the capacity of their practices. The findings can be used as a resource for architects and architectural students who are still deciding whether to globalize or localize their careers. As it currently the case, many architects are practicing in other countries to replicate architectural styles which may be more conducive to sustainable tourism, for example, hotel designs. (shrink)

Allelopathy is an important biological phenomenon in exotic plant invasions. Studies about this phenomenon can help us to understand how plant interactions influence plant colony and ecosystem functioning. Both alligator weed (Alternanthera philoxeroides, Ap) and crofton weed (Eupatorium adenophorum, Ea) are important destructive exotic species in China. Their allelopathic effects on native plant species are well documented. However, whether alligator weed and crofton weed antagonize each other regarding plant growth? There is largely unknown currently. Here we report that the leaf (...) extract from crofton weed possesses the negative effect on the growth of alligator weed. The results showed that root growth of alligator weed could be seriously inhibited by aqueous extract from crofton weed, exhibited as no root or a few roots if only. Consistent with the inhibition of root growth, we observed changes of physiological and biochemical parameters in treated alligator weed. The chlorophyll content, the root activity and the acetolactate synthase (ALS) activity were significantly decreased; while the rate of superoxide anion (O2-), the malondialdehyde (MDA) content, the peroxidase (POD) activity, and the shikimic acid content were remarkably increased in the treated alligator weed plants. These physiological analyzes suggested that the main allelopathic effects of crofton weed were mainly through affecting the integrity of cell membrane and the activity of the key enzymes. Further, these data also imply that one exotic species has the potential value to be used in bio-control of the other exotic species. (shrink)

How could we go beyond the conventional categorization of the five senses and find out a sixth sense in the observation of a building? Let’s call such a sense atmospheric one. Humans are rooted in the atmosphere, generated by things and space, just as the roots of plants in the soil. To observe novel experiences, we aimed to prioritize the atmosphere and affective encounters in space. First, archive photographs and technical drawings were compiled and examined, parallel with the historical evaluation (...) of the building (Eskişehir Esnaf Sarayı) and its context. However, this reading was not only about the mere transfer of archive data but also their affective engagements of them. Further, the atmosphere and its affects were unveiled through the inherent (and personal) experiences of the space. (shrink)

Filmmaking with Artificial Intelligence Image Generation Models In just about one year, OpenAI’s release of ChatGPT 4 has caused panic in our daily lives. After a year, OpenAI introduced Sora, a moving image-generating model from text, similar to DALL-E for still images. Even though Sora is not yet available to the public, the very potential itself has raised issues in film production from the perspectives of producers and studios, as well as directors, actors, writers, and editors. In this chapter, the (...) role and expected impact of AI video generation technologies, such as OpenAI Sora and Stable Diffusion 3, will be considered in regard to filmmaking. To discuss these issues, it is necessary to further analyze the concept of artificial intelligence, what it means, and how it is misunderstood by the general public. These misunderstandings also lead to sci-fi fantasy and doomsday talk, adding nothing valuable to the debate. Once this concept is defined, the argument of why an artificial general intelligence akin to a human being is unlikely will be set, mostly referring to Hubert Dreyfus and David Chalmers. However, even though the good old-fashioned AI seems impossible, the AI tools we have now seem to be enough to cause many of the problems that the thought of a complete artificial intelligence also brings forth. It is important to treat these tools as tools and not entities in their current forms to focus on the more practical problems regarding human labor, interaction, and experience in the world. In this regard, it is important to look back in history to see how technology has shifted ways of making films. When thought of as such, it becomes clearer that these tools will likely not end human involvement in the practice of creating art but transform the methods and aesthetics of film production, challenging conventions in both artistic and commercial works in some ways and exaggerating them in others. Furthermore, the chapter will consist of the investigation of the impact of various AI tools on human creativity. Regarding human creativity, commercial films will most likely go through a paradigm shift. Production companies will most likely regard this shift as a way of improving performance and production. However, this advancement poses dire questions in the field and pursuit of creating art. AI tools help automate and accelerate the filmmaking process at the cost of filmmaking as an art form. The discussion will address why commercial filmmaking will see a paradigm shift and loss of some human labor, but in an optimistic world of philosophical thought, film as fine art will gain much in return. This is because AI tools in their current and foreseeable state are not capable of willing to make art due to their limitations regarding embodied cognition, experience, unconsciousness, and intuition. These things make us what we are more than we think. There is no better way to explain why human beings make art than to show how tools do not matter but the ideas and the will to do it. -/- . (shrink)

Originally published in 1927, John Dewey’s The Public and Its Problems is a landmark work in pragmatist political philosophy. Today many commentators appreciate it as the mature expression of the American pragmatist’s democratic theory (though at least two later essays are perhaps more representative). It is also considered a classic text for students of twentieth-century American political thought. The book was originally a series of lectures given at Kenyon College in 1926. Many of its central ideas grew out of debate (...) Dewey had with a fellow public intellectual, Walter Lippmann. Besides its inclusion in the collected works (1996, edited by Larry Hickman), the only other edition to be released was by Swallow Press in 1954, containing Dewey’s half-page foreword (1927) and his twelve-page afterword (1946). With the arrival of Penn State Press’ new edition, introduced and edited by Melvin L. Rogers, The Public and Its Problems receives a monumental facelift. It includes a chronology of Dewey’s life events, an editorial note, and Rogers’ introduction to the work, subtitled ‘Revisiting the Public and Its Problems’. (shrink)

Gözlemlenenlerden gözlemlen(e)meyenlere diğer bir deyişle genel yasalara ulaşma imkânı veren çıkarım yöntemi olarak tümevarımsal ya da endüktif akıl yürütmenin rasyonel olarak temellendirilmesinin imkanına yönelik soruşturma tarih içerisinde tümevarım sorunu ya da endüksiyon problemi olarak tezahür etmiştir. Bu sorunun temel argümanı tarihsel okumalara baktığımızda İskoç ampirist filozof David Hume tarafından öne sürülmüştür. Hume, tümevarımsal çıkarımlar temelinde, gözlenmeyen meseleler hakkındaki inançlarımıza hangi gerekçelerle ulaştığımızı soruşturmaktadır. Hume soruşturmasının sonucunda gözlemlenenden gözlemlen(e)meyen durumlara ilişkin yapılan olgu meseleleri ile ilgili bütün tümevarımsal akıl yürütmelerin dolaylı ya (...) da dolaysız olarak nedensellik ilişkisine ve bu ilişkinin temelinde yer alan doğanın düzenliliği ilkesi ya da “gelecek her zaman geçmişe benzer” önermesine dayandığını ifade ederek bütün tümevarımsal akıl yürütmelerde ortak olan geleceğin her zaman geçmişe benzeyeceği ifadesinin rasyonel olarak temellendirilmesinin mümkün olmadığını belirtmektedir. Bu bağlamda, çalışmada tümevarımsal akıl yürütme sonucunda ulaşılan sonuca inanmanın hiçbir rasyonel temelinin olamayacağı yönündeki Hume’un görüşü argüman formunda yeniden yapılandırılarak ortaya konulacaktır. (shrink)

Considering that the visual dimension of anatomy cannot be ignored and an anatomy education without the visual part will make a doctor imperfect in their profession, it may be seen that pictorial anatomy books written in previous periods are highly valuable. The purpose of this study is to investigate the spinal nerve anatomy included in the work titled Teşrihü’l-Ebdan min e’t-Tıb written in the XIVth century and compare the information at that period to the information of our time. The nervous (...) system was analyzed under a separate title in the book. Firstly, general information was provided about nerves, and then cranial and spinal nerves were described. The author stated in his work that there are two differences between humans and animals as feeling and movement. He stated that the center for feeling and movement is the brain and all nerves converge in the brain. Although there are insufficient or incorrect information in historical books of medicine, such books are highly valuable as they show the scientific progress. It is apparent that Mansur’s work titled Teşrihü’l-Ebdan min e’t-Tıb has a significant place in the history of anatomy, and its influence was reflected in the following periods. Despite the occasions of insufficient or incorrect information in the piece, we think it contributed to the historical development of anatomy. (shrink)

Marx’ın yapıtlarında ahlaki bir kaygı taşıdığı ve bu doğrultuda bir etik teorisine sahip olduğu düşüncesi günümüzde tartışılmaya devam eden bir meseledir. Bu tartışma genellikle Marx'ın yabancılaşma, insan doğası ve kapitalizm hakkında ileri sürmüş olduğu düşünceleri üzerinden yürütülmektedir. Bu kapsamda, ilk olarak, makalede Marx’ın yabancılaşma teorisi ve bu kavramın nasıl ortaya çıktığına ilişkin tarihsel arka plan verilmektedir. Daha sonra yabancılaşma ile insan doğası arasındaki ilişkiyi kurarak, Marx'ın insan doğası anlayışının ona bir etik teorisi imkânı sağlayıp sağlamadığı tartışılmaktadır. Bu bağlamda, Marx'ın etik (...) teorisine hizmet eden evrensel bir insan doğası anlayışına sahip olduğu fikri, Louis Althusser ve Norman Geras'ın analizi ile irdelenmektedir. Yapılan tartışmalar doğrultusunda, nihai olarak, makalede Marx’ın bir etik teorisine ve ahlak anlayışına sahip olduğu sonucu desteklenmektedir. (shrink)

İnsanın dış dünyadan bilgiyi elde etme şekli tarih boyunca tüm çağlarda ve toplumlarda insanların üzerinde düşündükleri bir olgu olmuştur. Düşünürler bunun için çeşitli iddialar ileri sürmüşlerdir. Bu iddialardan biri, bilginin kaynağının kalp olduğudur. Kalp ise duygu kavramıyla ilişkilendirilmiş ve bilginin kaynağı bu şekilde duygu temelli açıklanmaya çalışılmıştır. Duygu ise ‘sezgisel bir yetenek’ olarak tanımlanmış ve duygunun sezgiyle ilişkisine vurgu yapılmıştır. Antik Yunan’da Homeros ve Sokrat öncesi düşünürler ve Aristoteles düşünmenin ve bilincin merkezi olarak kalbi kabul etmiştir. Eski Mısır medeniyetinde de (...) kalp ön plandadır ve ölen firavunların kalbi çıkarılarak özel bir kâsede muhafaza edilmiştir. Kutsal kitaplarda bilgi verici bir organ olarak kalbe vurgu yapılmıştır. İbn Sina ve Farabi, Aristoteles’ten etkilendikleri için kalbe ağırlık veren açıklamalar yapmıştır. İbn Sina, kalbin beyne önceliği olduğunu söyler: “Kalbin duyusu, özellikle de dokunmanın duyusu, bizatihi beynin duyusundan daha büyüktür. Bu yüzden de kalbin ağrılarına tahammül edilemez.. Sonuç olarak kalp kendisinden güçlerin beyne feyezan ettiği ilk ilkedir. Bu güçlerin bazılarının fiilleri de beyinde ve beynin parçalarında tamam olur.” . (shrink)

An extensive literature about pictorial representation discusses what is involved when a two-dimensional image represents some specific object or type of object. A smaller literature addresses parallel issues in sculptural representation. But little has been said about the role played by the sculptural material itself in determining the meanings of the sculptural work. Appealing to Nelson Goodman and Catherine Elgin’s discussions of literal and metaphorical exemplification, I argue that the material of which a sculpture is constituted plays key roles in (...) what is represented and how it is represented, in part because we have bodily and emotional responses to the real possibilities the sculptural material creates for us. I discuss examples of contemporary artworks by Melvin Edwards, Kara Walker, Willie Cole, Marc Quinn, Ai Weiwei, Janine Antoni, El Anatsui, Zoe Leonard, and others. (shrink)

Çin anakarasında yirminci yüzyılın başları; dilden edebiyata, geleneksel düşünceden eğitim sistemine ve hatta siyasal rejime dek pek çok alanda modernleşmeye gidilen süreci kapsar. Kültürel çaptaki bu yenilikçi hareketler arasında; antik çağa tarihlenen, Konfuçyüs (MÖ 479-551) tarafından ilkeleştirilen ve Mengzi’nın (MÖ 372-289) insan doğası görüşü sayesinde geniş kitlelerce benimsenen düşünce akımının “Yeni Konfuçyanizm” adı altında kurulması oldukça mühimdir. Konfuçyüs’ün normatif ahlak anlayışının aksine bu yeni akım, Mengzi’nın doğuştancı kuramına daha yakın durmaktadır. Yeni Konfuçyanizm’in temellerini atan Xiong Shili (1885-1968), Mengzi öğretisinde okunabilen (...) ve akılkalp ilgileşimi karşılığını verebilen “benlik” kavramını merkeze alır. Akımın sonraki temsilcilerinden Mou Zongsan (1909-1995) ise, gerek akıl-kalp ilgileşimine gerekse benliğin beslenmesine getirdiği çarpıcı yorumlarıyla dönemin en etkili fikir adamı olarak dikkatleri üzerine çekmektedir. Mou felsefesi; Mengzi’nın bütünleşik kabul ettiği bilişsel ve duyuşsal süreçleri tamamen farklı aşamalarda açıklayan, bu aşamaları benliğin iki katmanlı yapısıyla eşleştiren ve varoluşsal özü insan doğasının özüne özdeş sayan bazı varsayımsal yargılar içermektedir. Bu çalışmada, Mou felsefesinin onto-kozmolojik yaklaşımından hareketle benlik algısının nasıllığı incelenecek; doğuştan var olduğu farzındaki bilginin ve erdemin özümsenmesinde bilişsel farkındalığa karşı çıkan önermenin ayrıntıları analiz edilecektir. (shrink)

Abū Hāmid al-Ghazālī (1058–1111 c.e .) is well known, among other things, for his account, in al-Munqidh min al-ḍalāl (Deliverance from error), of a struggle with philosophical skepticism that bears a striking resemblance to that described by Descartes in the Meditations . This essay aims to give a close comparative analysis of these respective accounts, and will concentrate solely on the processes of invoking or entertaining doubt that al-Ghazālī and Descartes describe, respectively. In the process some subtle differences between them (...) in this regard will be brought to light that are relevant to the comparative issue of the respective solutions at which they arrive. The latter issue will not be touched upon here, although the present discussion is intended as a prelude to a future treatment of that topic. (shrink)

Bilime ve bilimsel bilgiye yönelik yaygın görüş, bilimin objektif bir faaliyet olduğudur. Bu görüş bilimsel bilginin elde edilmesinde, bilim insanlarının nesnel bir tavır sergilediğini ve onların sosyal faktörlerden etkilenmediğini varsaymaktadır. Yirminci yüzyılın ikinci çeyreğinde, Viyana Çevresi ve Karl Popper’ın düşünceleri ile bilimde sosyolojik ve psikolojik unsurların keşif bağlamı içerisinde görülebileceği, bilimsel kuramların ve araştırmaların gerekçelendirilmesine yönelik girişimlerin ise yalnızca nesnel, epistemik çalışmalardan oluştuğu ileri sürülmektedir. Keşif bağlamı ve gerekçelendirme bağlamı adı altında yapılan bu ayrıma ilişkin iddialar, Thomas Kuhn’un 1962 yılında (...) yayımlanmış olan ‘Bilimsel Devrimlerin Yapısı’ adlı kitabında vurguladığı argümanlar ile sekteye uğramaktadır. Kuhn, sosyal ve psikolojik etkenlerin her iki bağlamda da yer aldığını ifade etmekte ve bu sebeple keşif ve gerekçelendirme ayrımına karşı çıkmaktadır. Bu çerçevede makalede, Kuhn’un ulaşmış olduğu sonuçlar Güçlü Program’ın öne sürmüş olduğu argümanlar çerçevesinde desteklenerek ortaya konulmaktadır. (shrink)

The objective of the paper is to implement and validate diagnosis in the medical field via refined neutrosophic fuzzy logic (RNFL). As such, we have proposed a Max-Min composition (MMC) method in RNFL. This method deals with the diagnosis under certain constraints like uncertainty and indeterminacy. Further, we have considered the diagnosis problems to validate the sensitivity analysis of the novel multi attribute decision-making technique. Finally, we gave the graphical representations and compared the obtained results with other existing measures in (...) refined neutrosophic fuzzy sets. (shrink)

Sleep onset is associated with marked changes in behavioral, physiological, and subjective phenomena. In daily life though subjective experience is the main criterion in terms of which we identify it. But very few studies have focused on these experiences. This study seeks to identify the subjective variables that reflect sleep onset. Twenty young subjects took an afternoon nap in the laboratory while polysomnographic recordings were made. They were awakened four times in order to assess subjective experiences that correlate with the (...) (1) appearance of slow eye movement, (2) initiation of stage 1 sleep, (3) initiation of stage 2 sleep, and (4) 5 min after the start of stage 2 sleep. A logistic regression identified control over and logic of thought as the two variables that predict the perception of having fallen asleep. For sleep perception, these two variables accurately classified 91.7% of the cases; for the waking state, 84.1%. (shrink)

Bu çalışmada bilginin kazandığı doğru nitelemesi ve bilimsel bilgide doğrunun bir dogma haline gelmesi, kökenleriyle birlikte tartışılacaktır. Bu hususta Karl Popper'ın yanlışlamacı bilim imgesinin anlatıldığı bu çalışmada ikili bir yol izlenecektir. İlki; Popper'ın neye, neden karşı çıktığı üzerine, ikincisi ise bu karşı çıkış sonucunda açılan boşluğun nasıl doldurulduğudur. Dolayısıyla birinci aşama Popper açısından geleneksel imgeye yapılan bir kritik niteliğinde olurken, ikinci aşama ise Poppercı bilim imgesinin serimlendiği bölümü oluşturacaktır. Nihayetinde Popper yenilikleriyle bilimsel düşünüşe yeni bir soluk getirirken, son bölümde sisteminin (...) ne gibi eksiklikler barındırdığı tartışılacaktır. Bu eksiklikler ise Ayer ve Duhem-Quine tezi ile sırasıyla yanlışlamanın mantıksal olarak imkânsızlığı ve kuramın yanlışlanmasında holistik yaklaşımın gerekliliğini kapsayacaktır. (shrink)

I have argued that political values are beliefs informed, more or less well, by the evidence of experience and that, where relevant and well-supported by evidence, the inclusion of political values in scientific theorizing can increase the objectivity of research. The position I endorse has been called the “values-as-evidence” approach. In this essay I respond to three kinds of resistance to this approach, using examples of feminist political values. Solomon questions whether values are beliefs that can be tested, Alcoff argues (...) that even if our values are beliefs that can be tested, testing them might not be desirable because doing so assigns these important values a contingency that weakens their normative force, and Yap argues that the approach is too idealistic in its articulation of the role of evidence in our political deliberations. In response, I discuss the ways that values can be tested, I analyze the evidential strength of feminist values in science, and I argue that the evidence-based nature of these values is neither a weakness nor an idealization. Problems with political values affecting science properly concern the dogmatic ways that evaluative beliefs are sometimes held—a problem that arises with dogmatism toward descriptive beliefs as well. I conclude that scientists, as with the rest of us, ought to adopt a pragmatically-inclined appreciation of the fallible, inductive process by which we gather evidence in support of any of our beliefs, whether they are described as evaluative or descriptive. (shrink)

Kant’ın (ö.1804) felsefesi eklektik bir felsefedir ve Aydınlanma felsefesinin devamı niteliğindedir. Aydınlanma felsefesine benzer şekilde felsefesinin temeli akıldır ve aklın sınırları ve kullanımı hakkında fikirler ileri sürmüştür. Kant, dini ele alırken Tanrı’nın varlığının saf akılla ispatlanamayacağı sonucuna varmıştır. Çünkü akılla yapılan ispatlarda Tanrı’nın varlığına getirilen deliller kadar yokluğuna da eşit derecede deliller getirilebilir. O nedenle Tanrı’nın varlığının ispatında saf aklın değil pratik aklın önemli olduğunu ve ahlâksal yasaların bizi Tanrı’nın varlığına götüreceğini ileri sürer. Bu görüşünü desteklemek için eserlerinde teistik delillerin (...) akla uygun olmadığını ve akılla bilinemeyeceğini ispatlamaya çalışmıştır. Ona göre ontolojik, kozmolojik, teleolojik.. vb. teistik delillerin işlevi zihni tanrıbilim için hazırlamaktan ibarettir. Fakat tek başına Tanrı’nın varlığını ispat etmekten uzaktır. Ontolojik delili Tanrı’nın varlığının ispatı ile ilgili belli bir felsefi delilin adı olarak kullanan ilk kişi 18.yy. filozoflarından Christian Wolff’tur (ö.1754). Ontolojik delil, diğer deliler gibi ‘olgulara dayalı’ değildir. Bu delil tamamen kavramsal ve a priori önermelere dayanır. Delil, Tanrı’nın doğrudan doğruya ve hiçbir vasıtaya gerek kalmadan bilineceği üzerine kurgulanmıştır. Tanrı’nın mükemmelliği, ‘Tanrı vardır’ önermesinin sadece düşünsel bir önerme mi yoksa dış varlığa karşılık gelen bir önerme mi olduğu, Tanrı’nın varlığının zorunluluğu meselesi ontolojik delil içinde tartışılan konulardır. Ontolojik delilde ‘Tanrı vardır’ önermesi a priori ve analitik bir önerme olarak kabul edilmektedir. Analitik önermeler ise Tanrı’nın varlığının zorunluluğunu gösterir. Kant’ın eleştirisine göre a priori kavramlar yoluyla her şeyi olanaklı düşünebiliriz ve bunun için zihnimizde herhangi bir sınırlama olamaz. Tanrı ve zorunlu varlık kavramlarını zihnimizde düşündüğümüz gibi Anka Kuşu, Kaf dağı, Pamuk Prenses..vb. kavramların da var olduğu düşünülebilir ve bizim düşünmemiz bunları zorunlu yapmaz, tıpkı Tanrı’yı düşündüğümüzde Tanrı’yı zorunlu var kılmadığı gibi. Bu bildiride Kant’ın düşüncesi ortaya konulduktan sonra onun düşüncesindeki tutarlılık ve tutarsızlıklara değinilecektir. Anka Kuşu, Kaf Dağı, Pamuk Prenses ..vb. gibi hayali kavramlarla Tanrı kıyaslanabilir mi? Biz hayali varlıkları zihnimizde oluştururken yine duyu verilerinden yararlanır ve dış dünyada gözlemlediğimiz canlılara benzer ‘hayali varlıklar’ üretiriz. Dış dünyada, kuş, dağ ve prenses vardır. Bizim tek yaptığımız bunu hayali adlar takmaktır. Fakat Tanrı söz konusu olduğunda dış dünyada gözlem yaparak bir Tanrı’ya şahit olmayız ve bu şahit olduğumuz Tanrı’ya benzer bir Tanrı’yı hayal ederek zihnimizde hayali bir varlık oluşturmayız. Tam tersine Tanrı kavramını zihnimizde oluştururken hiçbir şeye benzemeyen, sebebi olmayan, her şeyi varlığa getiren, mükemmel bir varlık çıkarımını akıl ve mantığımızın bizi götürdüğü sonuçla ortaya koyarız. Çünkü insan olarak biz birbirimize benzeriz, bizim bir sebebimiz vardır, hiçbir şey yaratamayız ve mükemmel değilizdir. Ve evrenin sonsuzluğu, yıldızlar, gezegenler, insanın biyolojik yapısı, matematiksel düzen bizi zorunlu olarak ‘sebebi olmayan mükemmel bir sebep’ aramaya iter. Ve Ontolojik Delil ortaya çıkar. Bu bakımdan Kant’ın eleştirisini kabul etmek mümkün değildir. (shrink)

Den här boken handlar om invasiva främmande växter. I det föregående kapitlet reflekterade Niklas Vareman om vad som läggs i begreppet ‘invasiv’, men vad gäller då för den andra termen i begreppet – alltså ordet ‘främmande’? Vid första påseende kan det verka som att ’främmande’ borde vara ett enklare ord att definiera. Det är ju vanligare och inte så tekniskt jämfört med ‘invasiv’. Frågan är dock om inte just dessa två egenskaper gör ordet ’främmande’ mer svårdefinierat. Ord som är både (...) vanligare och mer vardagliga används av fler personer och på fler olika sätt. (shrink)

«Demokrasi, insani varoluşa içkin olanakları hem pozitif hem de negatif özgürlükler bağlamında hayata geçirme ve her tekil insanın kendisini ne ise o olarak algılama arzusuna eşlik edecek “ontolojik haysiyet eşitliği” talebinin sesidir. Dile getirdiğim eşitliğe dayalı demokrasi talebi, aynı zamanda, egemenlik ilişkilerinin hiyerarşik yapılanmasına karşı bir direnişi de temsil eder. Bu kitaptaki her bir bölüm bu direnişe açılan yeni bir pencere olarak okunursa kitap amacına ulaşmış olacaktır». (editör) Eray Yağanak -/- Ülkemizin çeşitli üniversitelerinden on bir yazarın kaleme aldığı bu kitapta, (...) çağdaş felsefenin Mill, Nietzsche, Popper, Rawls, Habermas, Dworkin, Laclau, Mouffe, Badiou, Rancière ve Pettit gibi önemli figürlerinin demokrasi anlayışları incelenmektedir. (shrink)