Conflict over resources generates conflict over mate choice: Reply to Smaldino and Newson

This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/doi:10.1016/j.evolhumbehav.2013.12.004Evolutionary computer simulations are an important part of the theoretical biologist's toolkit (Peck, 2004; DeAngelis & Mooij, 2005; Kokko, 2007), offering insights into a range of fundamental evolutionary processes, not least sexual selection (e.g. van Doorn & Weissing 2004, 2006; Fawcett et al., 2007, 2011; van Doorn et al., 2009; reviewed in Kuijper et al., 2012). Like all theoretical tools, they must be used with care (Hamblin, 2012). Smaldino & Newson (2013, henceforth S&N) have challenged our recent work on parent–offspring conflict over mate choice (Van den Berg et al., 2013), arguing that our simulations rely on unrealistic assumptions and that our conclusions are not supported. But all four points of criticism they present are misguided. (1) The accusation that the handicap principle cannot work in our model is wrong; Fig. 1a in Van den Berg et al. (2013) clearly demonstrates that a costly preference for a signal of male quality does evolve. (2) The assertion that mutation bias drove male quality close to zero in our model is wrong; in fact, male quality reached very high, stable levels in our simulations. (3) The assertion that overcompensation was responsible for our results is wrong; parent and offspring preferences also diverge in the absence of overcompensation. (4) The alternative explanation offered for our results is wrong, because it predicts the opposite pattern to that we actually observed in our simulations. Below we address each of these misunderstandings and consider two alternative hypotheses suggested by S&

Central adrenal insufficiency is rare in adults with Prader-Willi syndrome

CONTEXT: Prader-Willi syndrome (PWS) is associated with several hypothalamic-pituitary hormone deficiencies. There is no agreement on the prevalence of central adrenal insufficiency (CAI) in adults with PWS. In some countries, it is general practice to prescribe stress-dose hydrocortisone during physical or psychological stress in patients with PWS. Side effects of frequent hydrocortisone use are weight gain, osteoporosis, diabetes mellitus, and hypertension-already major problems in adults with PWS. However, undertreatment of CAI can cause significant morbidity-or even mortality. OBJECTIVE: To prevent both over- and undertreatment with hydrocortisone, we assessed the prevalence of CAI in a large international cohort of adults with PWS. As the synacthen test shows variable results in PWS, we only use the metyrapone test (MTP) and insulin tolerance test (ITT). DESIGN: Metyrapone test or ITT in adults with PWS (N = 82) and review of medical files for symptoms of hypocortisolism related to surgery (N = 645). SETTING: Outpatient clinic. PATIENTS OR OTHER PARTICIPANTS: Eighty-two adults with genetically confirmed PWS. MAIN OUTCOME MEASURE: For MTP, 11-deoxycortisol > 230 nmol/L was considered sufficient. For ITT, cortisol > 500 nmol/L (Dutch, French, and Swedish patients) or > 450 nmol/L (British patients) was considered sufficient. RESULTS: Central adrenal insufficiency was excluded in 81 of 82 patients. Among the 645 patients whose medical files were reviewed, 200 had undergone surgery without perioperative hydrocortisone treatment. None of them had displayed any features of hypocortisolism. CONCLUSIONS: Central adrenal insufficiency is rare (1.2%) in adults with PWS. Based on these results, we recommend against routinely prescribing hydrocortisone stress-doses in adults with PWS

PAHs, PCBs, PBDEs and Pesticides in Cold-Pressed Vegetable Oils

The aim of this study was to investigate levels of polychlorinated biphenyls (marker and dioxin-like congeners), polycyclic aromatic hydrocarbons (EPA 15 + 1), polybrominated diphenyl ethers (14 predominant congeners) and pesticides (74 compounds) in various cold-pressed vegetable oils. Poppy seed oil, rapeseed oil, sesame seed oil, pumpkinseed oil, hempseed oil, linaire oil, borage oil and evening star oil were investigated. Results of this study revealed that concentrations of PCBs, PBDEs and PAHs were low in majority of the investigated samples. However, high concentrations of organophosphorus insecticides were found. Chlorpyrifos methyl and pirimiphos methyl were the pesticide residues most commonly found in the studied oils. Concentration of 15 + 1 EPA PAHs was within the 17.85–37.16 μg kg−1 range, concentration of (marker) PCBs varied from 127 to 24,882 pg g−1, dioxin-like TEQ values were below 0.1 pg TEQ g−1. Concentration of PBDEs was below LOQ in most cases

Aerodynamics of the Hovering Hummingbird

Despite profound musculoskeletal differences, hummingbirds (Trochilidae) are widely thought to employ aerodynamic mechanisms similar to those used by insects. The kinematic symmetry of the hummingbird upstroke and downstroke has led to the assumption that these halves of the wingbeat cycle contribute equally to weight support during hovering, as exhibited by insects of similar size. This assumption has been applied, either explicitly or implicitly, in widely used aerodynamic models, and in a variety of empirical tests. Here we provide measurements of the wake of hovering rufous hummingbirds (Selasphorus rufus) obtained with digital particle image velocimetry that show force asymmetry: hummingbirds produce 75% of their weight support during the downstroke and only 25% during the upstroke. Some of this asymmetry is probably due to inversion of their cambered wings during upstroke. The wake of hummingbird wings also reveals evidence of leading-edge vortices created during the downstroke, indicating that they may operate at Reynolds numbers sufficiently low to exploit a key mechanism typical of insect hovering. Hummingbird hovering approaches that of insects, yet remains distinct because of effects resulting from an inherently dissimilar—avian—body plan

Invasive Aspergillus fumigatus infection after Plasmodium falciparum malaria in an immuno-competent host: Case report and review of literature

Invasive fungal infection is rarely reported in association with malaria, even though malaria-associated inhibition of phagocyte function is a well-known condition. Invasive aspergillosis is frequently found in severely immuno-compromised patients but not in healthy individuals. Here, a case of pulmonary invasive aspergillosis in a previously healthy patient with severe P. falciparum malaria is presented, who was successfully treated with voriconazol and caspofungin. This is the first survival of malaria-associated invasive aspergillosis

Clinicoradiological manifestations of paraganglioma syndromes associated with succinyl dehydrogenase enzyme mutation

BACKGROUND: Paragangliomas are rare tumours derived from the autonomic nervous system that have increasingly been recognised to have a genetic predisposition. Mutations of the enzyme succinyl dehydrogenase (SDH) have proven to result in paraganglioma formation. There are four subunits (A through D) that form the enzyme complex and are associated with different genophenotypic expressions of disease. SDHB and SDHD mutations are more common, whereas SDHA and SDHC mutations are rare. Patients with SDHB mutations are prone to extra-adrenal pheochromocytomas, malignant disease and extra-paraganglial neoplasia, whereas SDHD mutations have a greater propensity for multiple, benign head and neck paragangliomas. METHODS: Diagnosis of a sporadic paraganglioma or pheochromocytoma should lead to a full genetic workup of the patient and family if SDH mutations are found. RESULTS: Further annual screening will be required depending on the mutation, which can have a significant impact on radiologists and the resources of the radiology department. CONCLUSION: We present our imaging experience with a series of patients with proven SDH mutations resulting in paragangliomas with a review of the literature

Genetic screening and democracy: lessons from debating genetic screening criteria in the Netherlands

Recent decades have witnessed increasing possibilities for genetic testing and screening. In clinical genetics, the doctor’s office defined a secluded space for discussion of sensitive reproductive options in cases of elevated risk for genetic disorders in individuals or their offspring. When prenatal screening for all pregnant women became conceivable, the potential increase in scale made social and ethical concerns relevant for the whole of society. Whereas genetic testing in clinical genetic practice was widely accepted, prenatal screening at a population level met with unease. Concerns were raised regarding social pressure to screen: the sum of individual choice might result in a ‘collective eugenics’. The government’s involvement also raised suspicion: actively offering screening evoked associations with eugenic population policies from the first half of the 20th century. By reconstructing elements of policy and public debate on prenatal screening in the Netherlands from the past 30 years, this article discusses how the government has gradually changed its role in balancing the interest of the individual and the collective on genetic reproductive issues. Against a background of increasing knowledge about and demand for prenatal screening among the population, governmental policy changed from focusing on protection by banning screening toward facilitating screening in a careful and ethically sound way by providing adequate information, decision aids and quality assessment instruments. In the meanwhile, invigorating democracy in public debate may entail discussing concepts of ‘the good life’ in relation to living with or without impairments and dealing with genetic information about oneself or one’s offspring

CMV infection of liver transplant recipients: comparison of antigenemia and molecular biology assays

BACKGROUND: CMV is a major clinical problem in transplant recipients. Thus, it is important to use sensitive and specific diagnostic techniques to rapidly and accurately detect CMV infection and identify patients at risk of developing CMV disease. In the present study, CMV infection after liver transplantation was monitored retrospectively by two molecular biology assays - a quantitative PCR assay and a qualitative NASBA assay. The results were compared with those obtained by prospective pp65 antigenemia determinations. MATERIALS AND METHODS: 87 consecutive samples from 10 liver transplanted patients were tested for CMV by pp65 antigenemia, and CMV monitor and NASBA pp67 mRNA assay. RESULTS: CMV infection was detected in all patients by antigenemia and CMV monitor, whereas NASBA assay identified only 8/10 patients with viremia. Furthermore, CMV infection was never detected earlier by molecular biology assays than by antigenemia. Only 5/10 patients with CMV infection developed CMV disease. Using a cut off value of 8 cells/50,000, antigenemia was found to be the assay that better identified patients at risk of developing CMV disease. However, the kinetics of the onset of infection detected by NASBA and CMV monitor seemed to have better identified patients at risk of developing CMV disease. Furthermore, before onset of disease, CMV pp67 mRNA was found to have similar or better negative and positive predictive values for the development of CMV disease. CONCLUSIONS: The present data, suggests that the concomitant use of antigenemia and pp67 mRNA assay gives the best identification of patients at risk of developing CMV disease