Abstract. We hypothesized that Neotropical passerines would invest more in costly immune function relative to north-temperate passerines, due to differences in their respective life histories. We further hypothesized that latitudinal variation in immune activity would persist in common-garden conditions. To test these hypotheses, we compared immune function, measured via phytohemagglutinin (PHA)-induced wing-web swelling in both wild House Sparrows (Passer domesticus) and House Sparrows kept under common-garden conditions for 18 months. We found that wild Neotropical sparrows had relatively stable immune responses across the year, whereas wild north-temperate sparrows showed substantial seasonal variation in immune activity, having lower responses than Neotropical birds during the early breeding season and significantly higher responses than Neotropical birds during the late and nonbreeding seasons. Latitudinal differences in immune responses were not related to mass, sex, or body condition, but were influenced by mass change 24 hours after immune challenge. Under common-garden conditions, birds from both populations first decreased (after five months) and then increased (after 18 months) their nonbreeding immune responses relative to wild values, indicating condition dependence in the PHA response. Relative differences in the PHA response between the populations, however, were maintained in captivity: after 18 months in common gardens, north-temperate sparrows exhibited stronger nonbreeding immune responses than Neotropical sparrows.
Sex chromosomes in mammals are about 300 million years old and typically have a highly degenerated Y chromosome. The sex chromosomes in the dioecious plant Silene latifolia in contrast, represent an early stage of evolution in which functional X-Y gene pairs are still frequent. In this study, we characterize a novel tandem repeat called TRAYC, which has accumulated on the Y chromosome in S. latifolia. Its presence demonstrates that processes of satellite accumulation are at work even in this early stage of sex chromosome evolution. The presence of TRAYC in other species of the Elisanthe section suggests that this repeat had spread after the sex chromosomes evolved but before speciation within this section. TRAYC possesses a palindromic character and a strong potential to form secondary structures, which could play a role in satellite evolution. TRAYC accumulation is most prominent near the centromere of the Y chromosome. We propose a role for the centromere as a starting point for the cessation of recombination between the X and Y chromosomes.
The foreskin is a complex structure that protects and moisturizes the head of the penis, and, being the most densely innervated and sensitive portion of the penis, is essential to providing the complete sexual response. Circumcision-the removal of this structure-is non-therapeutic, painful, irreversible surgery that also risks serious physical injury, psychological sequelae, and death. Men rarely volunteer for it, and increasingly circumcised men are expressing their resentment about it.Circumcision is usually performed for religious, cultural and personal reasons. Early claims about its medical benefits have been proven false. The American Academy of Pediatrics and the Centers for Disease Prevention and Control have made many scientifically untenable claims promoting circumcision that run counter to the consensus of Western medical organizations.Circumcision violates the cardinal principles of medical ethics, to respect autonomy (self-determination), to do good, to do no harm, and to be just. Without a clear medical indication, circumcision must be deferred until the child can provide his own fully informed consent.In 2012, a German court held that circumcision constitutes criminal assault. Under existing United States law and international human rights declarations as well, circumcision already violates boys› absolute rights to equal protection, bodily integrity, autonomy, and freedom to choose their own religion. A physician has a legal duty to protect children from unnecessary interventions. Physicians who obtain parental permission through spurious claims or omissions, or rely on the American Academy of Pediatrics' position, also risk liability for misleading parents about circumcision.
Bioethics committees have issued guidelines that medical interventions should be permissible only in cases of clinically verifiable disease, deformity, or injury. Furthermore, once the existence of one or more of these requirements has been proven, the proposed therapeutic procedure must reasonably be expected to result in a net benefit to the patient. As an exception to this rule, some prophylactic interventions might be performed on individuals “in their best interests” or with the aim of averting an urgent and potentially calamitous public health danger. In order to invoke these exceptions, a stringent set of criteria must first be satisfied. Additionally, where the proposed prophylactic intervention is intended for children, who are unlikely to be able to provide a meaningfully informed consent, a heightened scrutiny of any such measures is required. We argue that children should not be subjected to prophylactic interventions “in their best interests” or for public health reasons when there exist effective and conservative alternative interventions, such as behavioural modification, that individuals could employ as competent adolescents or adults to avoid adverse health outcomes. Applying these criteria, we consider the specific examples of prophylactic mastectomy, immunisations, cosmetic ear surgery, and circumcision.
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