We study the modal logic M L r of the countable random frame, which is contained in and `approximates' the modal logic of almost sure frame validity, i.e. the logic of those modal principles which are valid with asymptotic probability 1 in a randomly chosen finite frame. We give a sound and complete axiomatization of M L r and show that it is not finitely axiomatizable. Then we describe the finite frames of that logic and show that it has the (...) finite frame property and its satisfiability problem is in EXPTIME. All these results easily extend to temporal and other multi-modal logics. Finally, we show that there are modal formulas which are almost surely valid in the finite, yet fail in the countable random frame, and hence do not follow from the extension axioms. Therefore the analog of Fagin's transfer theorem for almost sure validity in first-order logic fails for modal logic. (shrink)

The learning process of both students and teachers can be predicted based on the learning mode. Therefore, because of the COVID-19 pandemic, schools must start using online learning and abandon more traditional teaching techniques. Thus, this study investigates the relationship between self-efficacy and academic resilience among 150 senior high school students. Thus, the researchers employed General Self-Efficacy and Resilience Scale. Finally, the statistical analysis reveals that the r coefficient of 0.78 indicates a high positive correlation between the variables. The p-value (...) of 0.00, which is less than 0.05, leads to the decision to reject the null hypothesis. Hence, a significant relationship exists between self-efficacy and resilience among senior high school students. (shrink)

There are some arguments supporting the pessimistic meta-induction, coming from the direction of quantum theory (A. Kukla and J. Walmsley), from the direction of Laudan’s list with successful but false theories, and from the specific direction of the phlogiston theory (whom Kukla Walmsley, and S. Psillos consider to be false). Against these arguments we believe we can successfully oppose, in the first case the interactive quantum realism of I. Niiniluoto, in the second case the realism of the theoretical theoretical constituents (...) responsible for the empirical success of the theories of S. Psillos, and in the third case the analysis of the phlogiston theory done by V. Verronen, R. Vihalemm and E. McMullin (who suggested that this theory was simultaneously insufficiently mature and approximately true). Our conclusion does not necessary prove that the perspective of the scientific realism is true, but rather that the pessimistic meta-induction attack against it proves to be unconvincing. (shrink)

The paper deals with polymodal languages combined with standard semantics defined by means of some conditions on the frames. So, a notion of "polymodal base" arises which provides various enrichments of the classical modal language. One of these enrichments, viz. the base £(R,-R), with modalities over a relation and over its complement, is the paper's main paradigm. The modal definability (in the spirit of van Benthem's correspondence theory) of arbitrary and ~-elementary classes of frames in this base and in some (...) of its extensions, e.g., £(R,-R,R-1 ,_R-1), £(R,-R,=I=) etc., is described, and numerous examples of conditions definable there, as well as undefinable ones, are adduced. (shrink)

The focus of this study was to investigate "principals' administrative competence and teachers work performance" in Calabar Education zone. Four null hypotheses were tested in the course of the study. Correlational research design was adopted, while purposive sampling technique was used in selecting a sample of 800 teachers. Two instruments were used for data collection including "Principals' Administrative Competence Questionnaire (PACQ)," and Teachers' Work Performance Questionnaire (TWPQ)." Pearson Product Moment Correlation Analysis (r) and multiple regression (R) analysis were employed to (...) test the hypotheses at.05 level of significance were applicable, with the aid of SPSS v21. Findings from the study revealed that; principals' supervisory, leadership and communication competences are significantly related to teachers' work performance in terms of instructional delivery, attendance to classes, notes writing, and record keeping respectively. It was also revealed that; principals' supervisory, leadership and communication competences have significant composite influence on teachers' work performance in terms of instructional delivery (p <.05; F = 26.764), attendance to classes (p <.05; F = 109.122), notes writing (p <.05; F = 228.118), and record keeping (P <.05; F = 468.793). Based on these findings, it was recommended amongst others that; such techniques as close supervision of teachers, good leadership styles, and effective communication should be jointly practiced by secondary school principals in order to improve teachers' work performance. (shrink)

This study analyzed the utilization of social media platforms and university students' attitudes towards academic activities in Cross River State. A descriptive survey research design was adopted for the study. The population of this study comprised all the private and public university students in Cross River State. A sample of 1,600 students, which cuts across the three universities in the area of study, was selected using the convenience sampling technique. A questionnaire (r=.849) and a rating scale (r=.786) were used as (...) the instruments for data collection. Findings emerged amongst others that the utilization status of social media platforms by university students is generally high; the utilization of Facebook, WhatsApp, Instagram, Twitter, WeChat, Skype, Snapchat, Eskimi, Telegram and YouTube social media platforms has a significant composite influence (F=52.453, p<.05) on university students' attitudes towards academic activities. Relatively, utilization of Facebook was the highest predictor (t=11.222, β=.232, p<.05), followed by the utilization of WhatsApp (t=11.068, β=.229, p<.05), utilization of Twitter (t=5.977, β=.118, p<.05), and the utilization of Instagram (t=2.772, β=.056, p<.05), in that order. It was recommended that secondary school students should develop positive attitudes towards their academic activities and abhor activities that will lead to a decline in the learning outcomes. (shrink)

This study assessed human resource management and teachers’ job performance in secondary schools in Akamkpa Local Government Area of Cross River State. Three null hypotheses were formulated accordingly to guide the study. Census technique was adopted in selecting the entire population of 432 teachers. The instrument used for data collection was a questionnaire designed and administered by the researcher. Collected data were analyzed using descriptive statistics, while the null hypotheses were all tested at .05 level of significance using Pearson Product (...) Moment Correlation Analysis. Findings from the study revealed that there is significant relationship respectively between principals’ interpersonal relationship (r=0.364, p<. 05), teachers’ participation in decision-making (r=0.624, p< .05) and principals’ delegation of responsibilities (r = 0.538, p< .05) with teachers’ job performance in secondary schools. Based on these findings it was recommended among others that; principals should ensure that they create a conducive school climate by building a sound interpersonal relationship with teachers in order to improve their job performance; teachers should be actively involved in making certain decisions for the school especially those within their jurisdiction in order to foster unity and cooperation in the implementation of such decisions. (shrink)

This study evaluated school quality indicators and teachers job performance in Cross River State. One research question and four null hypotheses were raised following factorial research design. Proportionate random sampling technique was employed in selecting a sample of 1,463 teachers representing 30 percent from a population of 4,878 teachers distributed across 271 public secondary schools in Cross River State. “School Quality Indicators Questionnaire (SQIQ) and Teachers’ Job Performance Questionnaire (TJPQ)” were the instruments used for data collection. Prepared data were analyzed (...) using descriptive statistics; while the null hypotheses were all tested at .05 alpha level using Pearson Product Moment Correlation and Multiple regression analyses as appropriate with the aid of Minitab statistical software v18. Findings revealed that, quality of school facilities, leadership, and supervision jointly accounted for 90.6 percent (Pred. R2 = .9063) of the total variance of teachers’ job performance; there is significant relationship between quality of school facilities (r = .478, p< .05), quality of leadership (r = .928, p< .05) quality of supervision (r = .881, p< .05) respectively with secondary school teachers’ job performance; quality of school facilities, leadership, and supervision have significant composite influence (F=4800.58, p<.05) on secondary school teachers’ job performance; quality of leadership was the highest predictor (t=45.38, p< .05) of teachers’ job performance, followed by quality of school supervision (t = 27.29, p <.05). Based on these findings, conclusions and recommendations were made for improvement. Keywords:. (shrink)

This study assessed the administration of punishment, students’ test anxiety, and performance in mathematics in secondary schools of Cross River State. Three null hypotheses were formulated following a correlational research design. Proportionate stratified random sampling technique was employed in selecting a sample of 2,554 respondents representing 5% of the population of 51,097 junior secondary school students distributed across 271 public secondary schools in Cross River State. Administration of Punishment Questionnaire (APQ) designed by the researchers, Test Anxiety Inventory (TAI) developed by (...) Dawood et al., (2016), and Mathematics Achievement Test (MAT) designed by Owan (2012), were used as instruments for data collection. The null hypotheses were tested using one-way MANOVA), Pearson Product Moment Correlation, and Multiple regression analyses with the aid of SPSS v23. Findings revealed amongst others that administration of punishment has a significant influence on students’ test anxiety and performance in mathematics F (6, 5098) = 24.149, p<.05; Wilk’s Λ = 0.945, partial η2 = .028 on a joint basis; administration of punishment has a significant influence respectively on students’ test anxiety F (3, 2550) = 22.697, p<.0005, partial η2 =.026 and performance in mathematics F (3, 2550) = 23.090, P<.0005, partial η2 =.026; there is an inverse significant relationship (r= -339, p<0.05) between students’ tests anxiety and performance in mathematics. It was recommended that the use of corporal punishment should be totally abolished on strict grounds that it hurts the psychological disposition of learners resulting in a dip in their performance consequently. (shrink)

This paper examined the relationship between tertiary students’ social media management attitudes and their academic performance in Cross River State, with a specific focus on Facebook, WhatsApp, and Instagram. To achieve this purpose, three null hypotheses were formulated accordingly. The study adopted a correlational research design. Cluster and simple random sampling techniques were used to select a sample of 1000 students from the entire population. The instrument used for data collection was a questionnaire titled: Tertiary Students’ Social Media Management and (...) Academic Performance Questionnaire (TESSMMAPQ). The reliability of the instrument was established through Cronbach alpha and estimate of .93 was obtained indicating that the instrument was internally consistent in measuring what it purports to measure. Pearson Product Moment Correlation Analysis used to analyze data and to test the hypotheses at .05 level of significance. Findings revealed that there is no significant relationship between tertiary students Facebook management attitudes (r. cal.0.032 < crit. r.0.062), WhatsApp management attitudes (r. cal.0.038 < crit. r.0.062), and Instagram management attitudes (r. cal.-0.009 < crit. r.0.062) respectively, with their academic performance. Based on these findings it was recommended among others that; tertiary students' social media usage should be regulated by smartphones producers and internet service providers; in such a way that a maximum monthly login interval (MMLI) is provided that will restrict users to a limited number of login chances. This will ensure that students maintain focus when they have been barred. (shrink)

In an attempt to curtail examination malpractice, the Joint Admission and Matriculation Board (JAMB) has been generating different paper types with a different order of test items in the Unified Tertiary Matriculation Examination (UTME). However, the permutation of test items may compromise students’ performance unintentionally because constructive suggestions in theory and practice recommend that test items be sequenced in ascending order of difficulty. This study used data collected from a random sample of 1,226 SSIII students to ascertain whether the permutation (...) of test items has any effect on the performance of students in two different subjects (Use of English and Mathematics). The study adopted the Equivalent Groups Quasi-Experimental Research Design with three independent groups. Findings emerged, amongst others, that there is a significant difference in the performance scores of prospective university students' in use of English and Mathematics examintaions arranged in three different orders (ED, DE, R). There are no significant gender differences in the performance of students in Use of English and Mathematics based on test item permutation. However female students perform better than male students when test items are arranged in ascending order of difficulty while males perform better when test items are arranged in descending order of difficulty. It was concluded that the permutation of test items in UTME examination tends to affect the performance of students in Use of English and Mathematics. This finding has implications for the future conduct of UTME examinations and enrolment into higher education as the randomization of UTME test items changes the difficulty order of different paper types. It was recommended that other measures of curtailing examination malpractices that would not affect students’ academic performance should be adopted. (shrink)

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)

Does the visual system adapt to number? For more than fifteen years, most have assumed that the answer is an unambiguous “yes”. Against this prevailing orthodoxy, we recently took a critical look at the phenomenon, questioning its existence on both empirical and theoretical grounds, and providing an alternative explanation for extant results (the old news hypothesis). We subsequently received two critical responses. Burr, Anobile, and Arrighi rejected our critiques wholesale, arguing that the evidence for number adaptation remains overwhelming. Durgin questioned (...) our old news hypothesis — preferring instead a theory about density adaptation he has championed for decades — but also highlighted several ways in which our arguments do pose serious challenges for proponents of number adaptation. Here, we reply to both. We first clarify our position regarding number adaptation. Then, we respond to our critics’ concerns, highlighting seven reasons why we remain skeptical about number adaptation. We conclude with some thoughts about where the debate may head from here. (shrink)

Review of work on several debates, including Galileo vs. the Church, Bohr vs Einstein, Hoyle vs. Big Bang theory, Oppenheimer vs. Teller, N-rays, magnetic monopoles.

Conspiracy theories are typically thought to be examples of irrational beliefs, and thus unlikely to be warranted. However, recent work in Philosophy has challenged the claim that belief in conspiracy theories is irrational, showing that in a range of cases, belief in conspiracy theories is warranted. However, it is still often said that conspiracy theories are unlikely relative to non-conspiratorial explanations which account for the same phenomena. However, such arguments turn out to rest upon how we define what gets counted (...) both as a ‘conspiracy’ and a ‘conspiracy theory’, and such arguments rest upon shaky assumptions. It turns out that it is not clear that conspiracy theories are prima facie unlikely, and so the claim that such theories do not typically appear in our accounts of the best explanations for particular kinds of events needs to be reevaluated. (shrink)

Nihilism, Nietzsche and the Doppelganger Problem Was Nietzsche a nihilist? Yes, because, like J. L. Mackie, he was an error-theorist about morality, including the elitist morality to which he himself subscribed. But he was variously a diagnostician, an opponent and a survivor of certain other kinds of nihilism. Schacht argues that Nietzsche cannot have been an error theorist, since meta-ethical nihilism is inconsistent with the moral commitment that Nietzsche displayed. Schacht’s exegetical argument parallels the substantive argument (advocated in recent years (...) by Wright and Blackburn) that Mackie’s error theory can’t be true because if it were, we would have to give up morality or give up moralizing. I answer this argument with a little bit of help from Nietzsche. I then pose a problem, the Doppelganger Problem, for the meta-ethical nihilism that I attribute to Mackie and Nietzsche. (If A is a moral proposition then not-A is a moral proposition: hence not all moral propositions can be false.) I solve the problem by reformulating the error theory and also deal with a variant of the problem, the Reinforced Doppelganger, glancing at a famous paper of Ronald Dworkin’s. Thus, whatever its demerits, the error theory, is not self-refuting, nor does it require us to give up morality. (shrink)

According to ‘orthodox’ epistemology, it has recently been said, whether or not a true belief amounts to knowledge depends exclusively on truth-related factors: for example, on whether the true belief was formed in a reliable way, or was supported by good evidence, and so on. Jason Stanley refers to this as the ‘intellectualist’ component of orthodox epistemology, and Jeremy Fantl and Matthew McGrath describe it as orthodox epistemology’s commitment to a ‘purely epistemic’ account of knowledge — that is, an account (...) of knowledge where only truth-related factors figure in whether or not a person knows. In the first part of this paper I try to clarify the intellectualist thesis and to distinguish what I take to be its two main strains. In the remainder of the paper I then take a more critical turn and argue that even if, as a matter of fact, traditional epistemology has endorsed intellectualism in both of its strains, this is a mistake on the part of the tradition. At least one way of understanding intellectualism should be rejected and its practicalist counterpart should be accepted instead. (shrink)

What is it to be a woman? What is it to be a man? We start by laying out desiderata for an analysis of 'woman' and 'man': descriptively, it should link these gender categories to sex biology without reducing them to sex biology, and politically, it should help us explain and combat traditional sexism while also allowing us to make sense of the activist view that gendering should be consensual. Using a Putnam-style 'Twin Earth' example, we argue that none of (...) the existing analyses in the feminist literature succeeds in meeting all of our desiderata. Finally, we propose a positive account that we believe can satisfy all the desiderata outlined. According to our theory, the genders 'woman' and 'man' are individuated not by their contemporary connections to sex biology, but by their historical continuity with classes that were originally closely connected to sex biology. (shrink)

Deontological evidentialism is the claim that we ought to form and maintain our beliefs in accordance with our evidence. In this paper, I criticize two arguments in its defense. I begin by discussing Berit Broogard’s use of the distinction between narrow-scope and wide-scope requirements against W.K. Clifford’s moral defense of. I then use this very distinction against a defense of inspired by Stephen Grimm’s more recent claims about the moral source of epistemic normativity. I use this distinction once again to (...) argue that Hilary Kornblith’s criticism of Richard Feldman’s defense of is incomplete. Finally, I argue that Feldman’s defense is insensitive to the relation between normative requirements and privileged values: values that have normative authority over us. (shrink)

Philosophers of experiment have acknowledged that experiments are often more than mere hypothesis-tests, once thought to be an experiment's exclusive calling. Drawing on examples from contemporary biology, I make an additional amendment to our understanding of experiment by examining the way that `wide' instrumentation can, for reasons of efficiency, lead scientists away from traditional hypothesis-directed methods of experimentation and towards exploratory methods.

For a period of several years the philosopher of science Hasok Chang has promoted various inter-related views including pluralism, pragmatism, and an associated view of natural kinds. He has also argued for what he calls the persistence of everyday terms in the scientific view. Chang claims that terms like phlogiston were never truly abandoned but became transformed into different concepts that remain useful. On the other hand, Chang argues that some scientific terms such as acidity have suffered a form of (...) “rupture”, especially in the case of the modern Lewis definition of acids. Chang also complains that the degree of acidity of a Lewis acid cannot be measured using a pH meter and seems to regard this as a serious problem. The present paper examines some of these views, especially what Chang claims to be a rupture in the definition of acidity. It is suggested that there has been no such rupture but a genuine generalization, on moving from the Brønsted-Lowry theory to the Lewis theory of acidity. It will be shown how the quantification and measurement of Lewis acidity can easily be realized through the use of equilibrium theory and the use of stability constants. (shrink)

This article analyses what it means for the attribution of responsibility to adopt a structural perspective on macro-social phenomena. To this end, a specific form of responsibility, namely ‘structural responsibility’, is distinguished from and placed in relation to personal and interpersonal moral responsibility. It is argued that only with the attribution of structural responsibility can we appropriately take account of macro-social problems including those that are predominant in international relations. Using the example of climate responsibility, the article explains in a (...) final step what happens when structural responsibility is overlooked, trivialised or even negated. (shrink)

In the mid-seventeenth century a movement of self-styled experimental philosophers emerged in Britain. Originating in the discipline of natural philosophy amongst Fellows of the fledgling Royal Society of London, it soon spread to medicine and by the eighteenth century had impacted moral and political philosophy and even aesthetics. Early modern experimental philosophers gave epistemic priority to observation and experiment over theorising and speculation. They decried the use of hypotheses and system-building without recourse to experiment and, in some quarters, developed a (...) philosophy of experiment. The movement spread to the Netherlands and France in the early eighteenth century and later impacted Germany. Its important role in early modern philosophy was subsequently eclipsed by the widespread adoption of the Kantian historiography of modern philosophy, which emphasised the distinction between rationalism and empiricism and had no place for the historical phenomenon of early modern experimental philosophy. The re-emergence of interest in early modern experimental philosophy roughly coincided with the development of contemporary x-phi and there are some important similarities between the two. (shrink)

The revival of analytic metaphysics in the latter half of the twentieth century is typically understood as a consequence of the critiques of logical positivism, Quine’s naturalization of ontology, Kripke’s Naming and Necessity, clarifications of modal notions in logic, and the theoretical exploitation of possible worlds. However, this explanation overlooks the work of metaphysicians at the height of positivism and linguisticism that affected metaphysics of the late twentieth century. Donald C. Williams is one such philosopher. In this paper I explain (...) how Williams’s fundamental ontology and philosophy of time influenced in part the early formation of David Lewis’s metaphysics. Thus, Williams played an important role in the revival of analytic metaphysics. (shrink)

We introduce and study hierarchies of extensions of the propositional modal and temporal languages with pairs of new syntactic devices: point of reference-reference pointer which enable semantic references to be made within a formula. We propose three different but equivalent semantics for the extended languages, discuss and compare their expressiveness. The languages with reference pointers are shown to have great expressive power (especially when their frugal syntax is taken into account), perspicuous semantics, and simple deductive systems. For instance, Kamp's and (...) Stavi's temporal operators, as well as nominals (names, clock variables), are definable in them. Universal validity in these languages is proved undecidable. The basic modal and temporal logics with reference pointers are uniformly axiomatized and a strong completeness theorem is proved for them and extended to some classes of their extensions. (shrink)

In the literature on supervaluationism, a central source of concern has been the acceptability, or otherwise, of its alleged logical revisionism. I attack the presupposition of this debate: arguing that when properly construed, there is no sense in which supervaluational consequence is revisionary. I provide new considerations supporting the claim that the supervaluational consequence should be characterized in a ‘global’ way. But pace Williamson (1994) and Keefe (2000), I argue that supervaluationism does not give rise to counterexamples to familiar inference-patterns (...) such as reductio and conditional proof. (shrink)

We generalize and extend the class of Sahlqvist formulae in arbitrary polyadic modal languages, to the class of so called inductive formulae. To introduce them we use a representation of modal polyadic languages in a combinatorial style and thus, in particular, develop what we believe to be a better syntactic approach to elementary canonical formulae altogether. By generalizing the method of minimal valuations à la Sahlqvist–van Benthem and the topological approach of Sambin and Vaccaro we prove that all inductive formulae (...) are elementary canonical and thus extend Sahlqvist’s theorem over them. In particular, we give a simple example of an inductive formula which is not frame-equivalent to any Sahlqvist formula. Then, after a deeper analysis of the inductive formulae as set-theoretic operators in descriptive and Kripke frames, we establish a somewhat stronger model-theoretic characterization of these formulae in terms of a suitable equivalence to syntactically simpler formulae in the extension of the language with reversive modalities. Lastly, we study and characterize the elementary canonical formulae in reversive languages with nominals, where the relevant notion of persistence is with respect to discrete frames. (shrink)

This paper deals with, prepositional calculi with strong negation (N-logics) in which the Craig interpolation theorem holds. N-logics are defined to be axiomatic strengthenings of the intuitionistic calculus enriched with a unary connective called strong negation. There exists continuum of N-logics, but the Craig interpolation theorem holds only in 14 of them.

Complete deductive systems are constructed for the non-valid (refutable) formulae and sequents of some propositional modal logics. Thus, complete syntactic characterizations in the sense of Lukasiewicz are established for these logics and, in particular, purely syntactic decision procedures for them are obtained. The paper also contains some historical remarks and a general discussion on refutation systems.

Thomas Reid (1710–96) is increasingly being seen as a highly significant philosopher and a central figure in the Scottish Enlightenment. This new edition of Reid's classic philosophical text in the philosophy of mind at long last gives scholars a complete, critically edited text of the Inquiry. The critical text is based on the fourth life-time edition (1785). A selection of related documents showing the development of Reid's thought, textual notes, bibliographical details of previous editions and a full introduction by the (...) editor makes this an important contribution to the study of this increasingly respected philosopher. -/- Key Features - Complete, critically edited text of the Inquiry accompanied by a judicious selection of manuscript evidence relating to its composition - Comprehensive Introduction providing an historical and philosophical account of the formation of the Inquiry - Detailed textual notes which include bibliographical details and allusions, translations, references to secondary literature and selected passages from Reid's manuscripts. (shrink)

This paper defends a novel account of how to determine the intrinsic value of possible worlds. Section 1 argues that a highly intuitive and widely accepted account leads to undesirable consequences. Section 2 takes the first of two steps towards a novel account by clarifying and defending a view about value-contribution that is based on some of W. D. Ross’ claims about the value of pleasure. Section 3 takes the second step by clarifying and defending a view about value-suppression that (...) is based on Ross’ claims about the interplay between prima-facie duties. Section 4 states and defends the account that I call Rossian Totalism. According to this account, the atoms of intrinsic value within a world only sometimes contribute their intrinsic value to the value of that world. (shrink)

Philosophical discussions of species have focused on multicellular, sexual animals and have often neglected to consider unicellular organisms like bacteria. This article begins to fill this gap by considering what species concepts, if any, apply neatly to the bacterial world. First, I argue that the biological species concept cannot be applied to bacteria because of the variable rates of genetic transfer between populations, depending in part on which gene type is prioritized. Second, I present a critique of phylogenetic bacterial species, (...) arguing that phylogenetic bacterial classification requires a questionable metaphysical commitment to the existence of essential genes. I conclude by considering how microbiologists have dealt with these biological complexities by using more pragmatic and not exclusively evolutionary accounts of species. I argue that this pragmatism is not borne of laziness but rather of the substantial conceptual problems in classifying bacteria based on any evolutionary standard. (shrink)

The values-based approach to welfare holds that it is good for one to realize goals, activities, and relationships with which one strongly (and stably) identifies. This approach preserves the subjectivity of welfare while affirming that a life well lived must be active, engaged, and subjectively meaningful. As opposed to more objective theories, it is unified, naturalistic, and ontologically parsimonious. However, it faces objections concerning the possibility of self-sacrifice, disinterested and paradoxical values, and values that are out of sync with physical (...) and emotional needs. This paper revises the values-based approach, emphasizing the important—but limited—role consciously held values play in human agency. The additional components of human agency in turn explain why it is important for one’s values to cohere with one’s fixed drives, hard-wired emotional responses, and nonvolitionally guided cognitive pro- cesses. This affords promising responses to the objections above. (shrink)

This study used a partial least squares structural equation modelling (PLS-SEM) to estimate curriculum management's direct and indirect effects on university graduate programmes' viability. The study also examined the role of institutional effectiveness in mediating the nexus between the predictor and response variables. This is a correlational study with a factorial research design. The study's participants comprised 149 higher education administrators (23 Faculty Deans and 126 HODs) from two public universities in Nigeria. A structured questionnaire designed by the researchers was (...) used for data collection. The questionnaire was duly validated with an acceptable scale and item content validity indices. The dimensionality of the instrument was determined using exploratory factor analysis (EFA). Convergent validity was based on Average Variance Extracted (AVE), whereas discriminant validity was based on Fornell-Lacker criteria and the Hetero-Trait Mono-Trait (HTMT) ratio. Acceptable composite reliability estimates of internal consistency were reached for the three sub-scales. Following ethical practices, the questionnaire was physically administered to respondents and retrieved afterwards. Smart PLS (version 3.2.9) and SPSS (version 26.0) programs were used for all the statistical analyses. This study uncovered significant direct and indirect effects of curriculum management on the viability of graduate programmes. Institutional effectiveness significantly impacted graduate programmes’ viability while mediating the nexus between curriculum management and graduate programmes’ viability. Curriculum management and institutional effectiveness jointly explained a significant proportion of graduate programmes’ viability variance. The result of this study proved that graduate programmes’ viability depends, to a great extent, on how much curriculum is managed and how effective institutions are with their services. The result of this study can enable institutions seeking to run viable graduate programmes to re-evaluate their curriculum management practices and the effectiveness of their services. (shrink)

For years now, unionization has been under vigorous attack. Membership has been steadily declining, and with it union bargaining power. As a result, unions may soon lose their ability to protect workers from economic and personal abuse, as well as their significance as a political force. In the Name of Liberty responds to this worrying state of affairs by presenting a new argument for unionization, one that derives an argument for universal unionization in both the private and public sector from (...) concepts of liberty that we already accept. In short, In the Name of Liberty reclaims the argument for liberty from the political right, and shows how liberty not only requires the unionization of every workplace as a matter of background justice, but also supports a wide variety of other progressive policies. (shrink)

Exploitation and Economic Justice in the Liberal Capitalist State offers the first new, liberal theory of economic justice to appear in more than 30 years. The theory presented is designed to offer an alternative to the most popular liberal egalitarian theories of today and aims to be acceptable to both right and left libertarians too.

We discuss arguments against the thesis that the world itself can be vague. The first section of the paper distinguishes dialectically effective from ineffective arguments against metaphysical vagueness. The second section constructs an argument against metaphysical vagueness that promises to be of the dialectically effective sort: an argument against objects with vague parts. Firstly, cases of vague parthood commit one to cases of vague identity. But we argue that Evans' famous argument against will not on its own enable one to (...) complete the reductio in the present context. We provide a metaphysical premise that would complete the reductio, but note that it seems deniable. We conclude by drawing general morals from our case study. (shrink)

This article examines how Quine and Sellars develop informatively contrasting responses to a fundamental tension in Carnap’s semantics ca. 1950. Quine’s philosophy could well be styled ‘Essays in Radical Empiricism’; his assay of radical empiricism is invaluable for what it reveals about the inherent limits of empiricism. Careful examination shows that Quine’s criticism of Carnap’s semantics in ‘Two Dogmas of Empiricism’ fails, that at its core Quine’s semantics is for two key reasons incoherent and that his hallmark Thesis of Extensionalism (...) is untenable. The tension in Carnap’s semantics together with Quine’s exposure of the severe limits of radical empiricism illuminate central features of Sellars’s philosophy: the fully general form of the myth of givenness, together with Sellars’s alternative Kantian characterisation of understanding; the full significance of Carnap’s distinction between conceptual analysis and conceptual explication, and its important methodological implications; the specifically pragmatic character of Sellars’s realism; and Sellars’s methodological reasons for holding that philosophy must be systematic and that systematic philosophy must be deeply historically and textually informed. This paper thus re-examines this recent episode of philosophical history for its philosophical benefits and systematic insights. (shrink)

This book is the first comprehensive study of the meaning and measure of enforceability. While we have long debated what restraints should govern the conduct of our social life, we have paid relatively little attention to the question of what it means to make a restraint enforceable. Focusing on the enforceability of legal rights but also addressing the enforceability of moral rights and social conventions, Mark Reiff explains how we use punishment and compensation to make restraints operative in the world. (...) After describing the various means by which restraints may be enforced, Reiff explains how the sufficiency of enforcement can be measured, and he presents a unified theory of deterrence, retribution, and compensation that shows how these aspects of enforceability are interconnected. Reiff then applies his theory of enforceability to illuminate a variety of real-world problem situations. (shrink)

This paper outlines Lewis’s favoured foundational account of linguistic representation, and outlines and briefly evaluates variations and modifications. Section 1 gives an opinionated exegesis of Lewis’ work on the foundations of reference—his interpretationism. I look at the way that the metaphysical distinction between natural and non-natural properties came to play a central role in his thinking about language. Lewis’s own deployment of this notion has implausible commitments, so in section 2 I consider variations and alternatives. Section 3 briefly considers a (...) buck-passing strategy involving fine-grained linguistic conventions. (shrink)

This paper presents an attempt to integrate theories of causal processes—of the kind developed by Wesley Salmon and Phil Dowe—into a theory of causal models using Bayesian networks. We suggest that arcs in causal models must correspond to possible causal processes. Moreover, we suggest that when processes are rendered physically impossible by what occurs on distinct paths, the original model must be restricted by removing the relevant arc. These two techniques suffice to explain cases of late preëmption and other cases (...) that have proved problematic for causal models. (shrink)

I apply the notion of truthmaking to the topic of fundamentality by articulating a truthmaker theory of fundamentality according to which some truths are truth-grounded in certain entities while the ones that don't stand in a metaphysical-semantic relation to the truths that do. I motivate this view by critically discussing two problems with Ross Cameron's truthmaker theory of fundamentality. I then defend this view against Theodore Sider's objection that the truthmaking approach to fundamentality violates the purity constraint. Truthmaker theorists can (...) have a trouble-free theory of fundamentality. (shrink)

Adam Smith is respected as the father of contemporary economics for his work on systemizing classical economics as an independent field of study in The Wealth of Nations. But he was also a significant moral philosopher of the Scottish Enlightenment, with its characteristic concern for integrating sentiments and rationality. This article considers Adam Smith as a key moral philosopher of commercial society whose critical reflection upon the particular ethical challenges posed by the new pressures and possibilities of commercial society remains (...) relevant today. The discussion has three parts. First I address the artificial separation between self-interest and morality often attributed to Smith, in which his work on economics is stripped of its ethical context. Second I outline Smith’s ethical approach to economics, focusing on his vigorous but qualified defence of commercial society for its contributions to prosperity, justice, and freedom. Third I outline Smith’s moral philosophy proper as combining a naturalistic account of moral psychology with a virtue ethics based on propriety in commercial society. (shrink)

Accusations of hypocrisy are a recurring theme in the public debate on climate change, but their significance remains poorly understood. Different motivations are associated with this accusation, which is leveled by proponents and opponents of climate action. In this article, I undertake a systematic assessment of climate hypocrisy, with a focus on lifestyle and political hypocrisy. I contextualize the corresponding accusation, introduce criteria for the conceptual analysis of climate hypocrisy, and develop an evaluative framework that allows us to determine its (...) moral significance. I argue that different instances of climate hypocrisy are problematic to different degrees, depending on how detrimental they are to an agent's attainment of environmental integrity. The resulting framework helps clear the confusion caused by disinformation campaigners, by distinguishing objectionable uses of the climate hypocrisy charge from constructive ones motivated by genuine concern for integrity. (shrink)

Consumer boycotts have become a frequent form of social protest in the digital age. The corporate malpractices motivating them are varied, including environmental pollution, lack of minimum labour standards, severe mistreatment of animals, lobbying and misinformation campaigns, collaboration or complicity with illegitimate political regimes, and systematic tax evasion and tax fraud. In this article, I argue that organised consumer boycotts should be regarded as a legitimate and purposeful instrument for structural change, provided they conform to a number of normative criteria. (...) In order to show this, the practice and empirical context of consumer boycotts are first outlined. I then lay out and refute three general objections to this practice. Although each of these objections fails, their discussion generates insights concerning the normative standards with which boycotters must comply if they want their campaigns to be both legitimate and successful. These normative criteria are detailed along the lines of two guiding principles, proportionality and transparency. In the final step, I elaborate on structural change as the deeper purpose of consumer boycotts. (shrink)

A certain type of inference rules in modal logics, generalizing Gabbay's Irreflexivity rule, is introduced and some general completeness results about modal logics axiomatized with such rules are proved.

This paper addresses several questions related to the nature, production, and use of animal-human (a-h) chimeras. At the heart of the issue is whether certain types of a-h chimeras should be brought into existence, and, if they are, how we should treat such creatures. In our current research environment, we recognize a dichotomy between research involving nonhuman animal subjects and research involving human subjects, and the classification of a research protocol into one of these categories will trigger different ethical standards (...) as to the moral permissibility of the research in question. Are a-h chimeras entitled to the more restrictive and protective ethical standards applied to human research subjects? We elucidate an Aristotelian-Thomistic metaphysical framework in which to argue how such chimeras ought to be defined ontologically. We then examine when the creation of, and experimentation upon, certain types of a-h chimeras may be morally permissible. (shrink)

The claim that ordinary ethical discourse is typically true and that ethical facts are typically knowable seems in tension with the claim that ordinary ethical discourse is about features of reality friendly to a scientific worldview. Cornell Realism attempts to dispel this tension by claiming that ordinary ethical discourse is, in fact, discourse about the same kinds of things that scientific discourse is about: natural properties. We offer two novel arguments in reply. First, we identify a key assumption that we (...) find unlikely to be true. Second, we identify two features of typical natural properties that ethical properties lack. We conclude that Cornell Realism falls short of dispelling the tension between ethical conservativism and ethical naturalism. (shrink)

In this article, I critically reassess Iris Marion Young's late works, which centre on the distinction between liability and social connection responsibility. I concur with Young's diagnosis that structural injustices call for a new conception of responsibility, but I reject several core assumptions that underpin her distinction between two models and argue for a different way of conceptualising responsibility to address structural injustices. I show that Young's categorical separation of guilt and responsibility is not supported by the writings of Hannah (...) Arendt, which Young draws on, and that it is also untenable on independent systematic grounds. Furthermore, I argue that several of Young's other criteria fail to clearly demarcate two distinct phenomena. I therefore propose to transcend Young's distinction between two models in favour of a related, but conceptually different distinction between two forms of responsibility: interactional and structural. Embracing this terminology facilitates the conceptualisation of the general features of responsibility that are shared by both forms, including their retrospective and prospective time-direction and their applicability to individual, joint and group agency. The distinction between interactional and structural responsibility also yields a more compelling general account of the role of background structures, and of blame within ascriptions of political responsibility. (shrink)