Sex allocation according to multiple sexually dimorphic traits of both parents in the barn swallow (Hirundo rustica).

Parents should differentially invest in sons or daughters depending on the sex-specific fitness returns from male and female offspring. In species with sexually selected heritable male characters, highly ornamented fathers should overproduce sons, which will be more sexually attractive than sons of less ornamented fathers. Because of genetic correlations between the sexes, females that express traits which are under selection in males should also overproduce sons. However, sex allocation strategies may consist in reaction norms leading to spatiotemporal variation in the association between offspring sex ratio (SR) and parental phenotype. We analysed offspring SR in barn swallows (Hirundo rustica) over 8 years in relation to two sexually dimorphic traits: tail length and melanin-based ventral plumage coloration. The proportion of sons increased with maternal plumage darkness and paternal tail length, consistently with sexual dimorphism in these traits. The size of the effect of these parental traits on SR was large compared to other studies of offspring SR in birds. Barn swallows thus manipulate offspring SR to overproduce 'sexy sons' and potentially to mitigate the costs of intralocus sexually antagonistic selection. Interannual variation in the relationships between offspring SR and parental traits was observed which may suggest phenotypic plasticity in sex allocation and provides a proximate explanation for inconsistent results of studies of sex allocation in relation to sexual ornamentation in birds.

With a little help from my kin: barn swallow nestlings modulate solicitation of parental care according to nestmates' need.

In altricial species, offspring competing for access to limiting parental resources (e.g. food) are selected to achieve an optimal balance between the costs of scrambling for food, the benefits of being fed and the indirect costs of subtracting food to relatives. As the marginal benefits of acquiring additional food decrease with decreasing levels of need, satiated offspring should be prone to favour access to food by their needy kin, thus enhancing their own indirect fitness, while concomitantly reducing costs of harsh competition with hungry broodmates. We tested this prediction in feeding trials of barn swallow (Hirundo rustica) nestlings by comparing begging behaviour and food intake of two similar-sized nestmates, one of which was food-deprived (FD). Non-food-deprived (NFD) offspring modulated begging intensity depending on their nestmate's need: when competing with FD nestmates, NFD nestlings reduced both the intensity and frequency of begging displays compared to themselves in the control trial before food deprivation. Hence, NFD nestlings reduced their competitiveness to the advantage of FD nestmates, which obtained more feedings and showed a threefold larger increase in body mass. Moderation of individual selfishness can therefore be adaptive in the presence of a needier kin, because the indirect fitness benefits of promoting its condition can outweigh the costs of forgoing being fed, and because it limits the cost of begging escalation against a vigorous competitor.

MHC genotype predicts mate choice in the ring-necked pheasant Phasianus colchicus.

Females of several vertebrate species selectively mate with males on the basis of the major histocompatibility complex (MHC) genes. As androgen-mediated maternal effects have long-lasting consequences for the adult phenotype, both mating and reproductive success may depend on the combined effect of MHC genotype and exposure to androgens during early ontogeny. We studied how MHC-based mate choice in ring-necked pheasants (Phasianus colchicus) was influenced by an experimental in ovo testosterone (T) increase. There was no conclusive evidence of in ovo T treatment differentially affecting mate choice in relation to MHC genotype. However, females avoided mating with males with a wholly different MHC genotype compared with males sharing at least one MHC allele. Females also tended to avoid mating with MHC-identical males, though not significantly so. These findings suggest that female pheasants preferred males with intermediate MHC dissimilarity. Male MHC heterozygosity or diversity did not predict the expression of ornaments or male dominance rank. Thus, MHC-based mating preferences in the ring-necked pheasant do not seem to be mediated by ornaments' expression and may have evolved mainly to reduce the costs of high heterozygosity at MHC loci for the progeny, such as increased risk of autoimmune diseases or disruption of coadapted gene pools.

Sex-related variation in migration phenology in relation to sexual dimorphism: a test of competing hypotheses for the evolution of protandry.

Timing of arrival/emergence to the breeding grounds is under contrasting natural and sexual selection pressures. Because of differences in sex roles and physiology, the balance between these pressures on either sex may differ, leading to earlier male (protandry) or female (protogyny) arrival. We test several competing hypotheses for the evolution of protandry using migration data for 22 bird species, including for the first time several monochromatic ones where sexual selection is supposedly less intense. Across species, protandry positively covaried with sexual size dimorphism but not with dichromatism. Within species, there was weak evidence that males migrate earlier because, being larger, they are less susceptible to adverse conditions. Our results do not support the 'rank advantage' and the 'differential susceptibility' hypotheses, nor the 'mate opportunity' hypothesis, which predicts covariation of protandry with dichromatism. Conversely, they are compatible with 'mate choice' arguments, whereby females use condition-dependent arrival date to assess mate quality.

Maternal allocation strategies and differential effects of yolk carotenoids on the phenotype and viability of yellow-legged gull (Larus michahellis) chicks in relation to sex and laying order.

Egg quality may mediate maternal allocation strategies according to progeny sex. In vertebrates, carotenoids have important physiological roles during embryonic and post-natal life, but the consequences of variation in yolk carotenoids for offspring phenotype in oviparous species are largely unknown. In yellow-legged gulls, yolk carotenoids did not vary with embryo sex in combination with egg laying date, order and mass. Yolk lutein supplementation enhanced the growth of sons from first eggs but depressed that of sons from last eggs, enhanced survival of daughters late in the season, and promoted immunity of male chicks and chicks from small eggs. Lack of variation in egg carotenoids in relation to sex and egg features, and the contrasting effects of lutein on sons and daughters, do not support the hypothesis of optimal sex-related egg carotenoid allocation. Carotenoids transferred to the eggs may rather result from a trade-off between opposing effects on sons or daughters.

Prevalence of arterial and venous thromboembolic events in diabetic patients with and without the metabolic syndrome: a cross sectional study.

BACKGROUND: Metabolic syndrome (MS) is associated with an increased risk of cardiovascular events. Recent studies have found a higher prevalence of the MS in patients with idiopathic venous thromboembolic events (VTE) compared to controls suggesting a role of the MS in the pathogenesis of VTE. The presence of MS was shown to further increase the risk of arterial cardiovascular diseases (CVD) in diabetic patients. Conversely, there are no studies that have compared the risk of VTE in diabetic patients with and without the MS. METHODS: A cross sectional study comparing the prevalence of arterial cardiovascular events and VTE in diabetic patients with and without the MS was conducted. RESULTS: Nine hundred and fifty three patients were included in the study; 85.7% of patients had MS. Patients with the MS had an increased prevalence of CVD as compared with those without (23.4% vs. 11.8%) and the MS was an independent predictor of CVD in diabetic patients (OR 3.16, 95%CI 1.78, 5.59) after multiple logistic regression analysis. The prevalence of VTE was higher in patients with the MS in comparison to patients without the MS, but this association was not statistically significant (3,43% vs 1.47%; OR 2.38, 95% CI 0.56, 10.10%). CONCLUSION: Our study confirms the role of MS as an adjunctive cardiovascular risk factor in patients with diabetes. There is insufficient evidence to evaluate the role of the as an adjunctive risk factor for VTE in these patients. Further studies are necessary to confirm or refute these preliminary findings.

Safety of tumor necrosis factor alpha blockers in hepatitis B virus occult carriers (hepatitis B surface antigen negative/anti-hepatitis B core antigen positive) with rheumatic diseases.

OBJECTIVE: To assess the safety of anti-tumor necrosis factor alpha (anti-TNFalpha) therapy on the course of hepatitis B virus (HBV) infection in carriers of antibodies to hepatitis B core antigen (anti-HBc) affected by chronic inflammatory arthropathies. METHODS: From January 2001 to December 2008, HBV markers were determined before the first administration of anti-TNFalpha agents in all 732 patients affected by inflammatory arthropathies treated with anti-TNFalpha at 2 outpatient rheumatologic clinics in Northern Italy. Anti-HBc-positive patients were prospectively evaluated and HBV markers and HBV DNA were assessed every 6 months, in case of aminotransferase elevation, and at the end of the study. RESULTS: At the time of recruitment, 72 patients were anti-HBc carriers, 5 of whom were positive for hepatitis B surface antigen (HBsAg) and not included in the study. The ratio of men:women was 26:41 and the mean +/- SD followup was 42.52 +/- 21.33 months. Of the patients, 25 were treated with infliximab, 23 with etanercept, and 19 with adalimumab. Fifty-one patients were treated also with methotrexate, 52 with nonsteroidal antiinflammatory drugs, and 43 with prednisone (3 with a dosage >7.5 mg/day). All anti-HBc patients were HBV DNA negative at the first observation. During followup, no patient presented HBV reactivation with viral load increase and no patient became HBsAg positive. CONCLUSION: Anti-HBc positivity in HBsAg-negative patients is a sign of previous HBV infection and does not indicate chronic hepatitis. In these patients, anti-TNFalpha therapy appears to be quite safe, as no HBV reactivation was found in our study. Nevertheless, careful monitoring is necessary.

Cryptogenic cerebral infarction in a young patient with very high lipoprotein(a) serum level as the only risk factor.

Lipoprotein(a) [Lp(a)] is a plasma lipoprotein that consists of a low-density lipoprotein (LDL)-like particle containing APO B-100 and apolipoprotein(a), linked by a disulphide bridge. There is evidence that higher serum level of Lp(a) is a predictor of various vascular diseases, such as myocardial infarction, coronary stenosis, re-occlusion of aortocoronary bypass vein grafts, peripheral atherosclerosis and cerebral infarction [1-4]. We describe a young man with a cryptogenic stroke with very high serum level of Lp(a) as the only vascular risk factor.

Atherosclerotic adult Moya-Moya disease in a patient with hyperhomocysteinaemia.

Moya-Moya is a rare cerebrovascular occlusive disease characterized by bilateral stenosis or occlusion at the terminal portion of the internal carotid artery and abnormal vascular network at the base of the brain, named "moya-moya". In children, Moya-Moya disease usually presents with ischemic cerebrovascular events, mainly TIA or lacunar stroke, leading to mental deterioration. In adults, especially in females, it presents with intracranial haemorrhages. We describe the case of an adult patient with an atherosclerotic Moya-Moya disease which presented with a cerebral borderzone infarction.

Microgravity and hypergravity effect on survival and reproduction of microinvertebrates.

Preliminary to carry out long-term experiments on the International Space Station (ISS) using living orgainisms, the capacity of the experimental organisms to cope with perturbations of gravity should be tested. Actually, animals have evolved under gravity, because on earth gravity force cannot be eluded, and several features that influence life-history traits may be affected by the presence of gravity. Among the other features, feeding efficiency may be affected by gravity if the animals feed by filtering suspended particles, creating currents that carry the particulate food to their mouth opening. In presence of gravity the food particles tend to sink to the bottom and filter-feeders must be able to suspend and collect the particles with some apparatus such as ciliary wreaths. It can be predicted that hypergravity, increasing the particle sedimentation rate, will reduce the animal filtering efficiency, while microgravity will increase filtering rate. Differently, some bacteriophagous animals do not possess structures to collect their food, but commonly live and move into sediment and feed on the bacteria upon encounter. Hypergravity will apply higher pressure on their bodies, and could force them to adhere to some surface and to reduce their displacement, and microgravity could impede adhesion to the surface and make food item encounters improbable. Thus, gravity perturbations may affect animal life-history traits, such as survival or fecundity, by influencing their feeding efficiency. In this study we exposed a filter-feeding organism (Macrotrachela quadricornifera, Rotifera Bdelloidea) and a bacteriophagous one (Panagrolaimus rigidus, Nematoda) to both microgravity and hypergravity to test their reproduction capacity under such stressful conditions, and their suitability as models for experiments on the ISS.

Automated culture system experiments hardware: developing test results and design solutions.

The experiment proposed by Prof. Ricci University of Milan is funded by ASI with Laben as industrial Prime Contractor. ACS-EH (Automated Culture System-Experiment Hardware) will support the multigenerational experiment on weightlessness with rotifers and nematodes within four Experiment Containers (ECs) located inside the European Modular Cultivation System (EMCS) facility..Actually the Phase B is in progress and a concept design solution has been defined. The most challenging aspects for the design of such hardware are, from biological point of view the provision of an environment which permits animal's survival and to maintain desiccated generations separated and from the technical point of view, the miniaturisation of the hardware itself due to the reduce EC provided volume (160mmx60mmx60mm). The miniaturisation will allow a better use of the available EMCS Facility resources (e.g. volume. power etc.) and to fulfil the experiment requirements. ACS-EH, will be ready to fly in the year 2005 on boar the ISS.