Melanin-based colouration predicts natal dispersal in the barn owl, Tyto alba

Searching for a suitable breeding site is an important decision in the life of most animals. The decisions where to settle and how far to travel before doing so depend on many factors. Individual differences in dispersal distance could result from different strategies (e.g. specialists versus generalists), which might result in similar reproductive success in different habitats, or different competitive abilities to acquire a territory close to the natal site. The barn owl is polymorphic in melanic coloration, which is associated with many physiological and behavioural traits such as habitat choice, stress response and docility, raising the possibility that the coloration is also related to dispersal. We studied natal dispersal (from rearing site to site of first breeding attempt) and breeding dispersal (from one breeding site to the next) in barn owls using a long-term data set. Darker reddish individuals moved further than paler individuals during natal dispersal, but not during breeding dispersal. A cross-fostering experiment showed that the colour of the biological and foster parents had no influence on dispersal distance. The distance dispersed by parents and same-sex offspring was correlated, whereas natal and breeding dispersal were not repeatable within individuals, indicating that they are two different processes. Given that the distance travelled in natal dispersal appears to be heritable, the underlying genes might be coupled to those related to coloration. We discuss hypotheses to explain the potential adaptive function of the link between coloration and natal dispersal.

Risk of cardiovascular disease in a traditional African population with a high infectious load: a population-based study.

BACKGROUND: To test the inflammatory origin of cardiovascular disease, as opposed to its origin in western lifestyle. Population-based assessment of the prevalences of cardiovascular risk factors and cardiovascular disease in an inflammation-prone African population, including electrocardiography and ankle-arm index measurement. Comparison with known prevalences in American and European societies. METHODOLOGY/PRINCIPAL FINDINGS: Traditional population in rural Ghana, characterised by adverse environmental conditions and a high infectious load. Population-based sample of 924 individuals aged 50 years and older. Median values for cardiovascular risk factors, including waist circumference, BMI, blood pressure, and markers of glucose and lipid metabolism and inflammation. Prevalence of myocardial infarction detected by electrocardiography and prevalence of peripheral arterial disease detected by ankle-arm index. When compared to western societies, we found the Ghanaians to have more proinflammatory profiles and less cardiovascular risk factors, including obesity, dysglycaemia, dyslipidaemia, and hypertension. Prevalences of cardiovascular disease were also lower. Definite myocardial infarction was present in 1.2% (95%CI: 0.6 to 2.4%). Peripheral arterial disease was present in 2.8% (95%CI: 1.9 to 4.1%). CONCLUSIONS/SIGNIFICANCE: Taken together, our data indicate that for the pathogenesis of cardiovascular disease inflammatory processes alone do not suffice and additional factors, probably lifestyle-related, are mandatory.

Assessment of a new MRI classification of spinal stenosis based on cross-sectional morphology of the dural sac : FM2

Introduction: Quantitative measures of degree of lumbar spinal stenosis (LSS) such as antero-posterior diameter of the canal or dural sac cross sectional area vary widely and do not correlate with clinical symptoms or results of surgical decompression. In an effort to improve quantification of stenosis we have developed a grading system based on the morphology of the dural sac and its contents as seen on T2 axial images. The grading comprises seven categories ranging form normal to the most severe stenosis and takes into account the ratio of rootlet/CSF content. Material and methods: Fifty T2 axial MRI images taken at disc level from twenty seven symptomatic lumbar spinal stenosis patients who underwent decompressive surgery were classified into seven categories by five observers and reclassified 2 weeks later by the same investigators. Intra- and inter-observer reliability of the classification were assessed using Cohen's and Fleiss' kappa statistics, respectively. Results: Generally, the morphology grading system itself was well adopted by the observers. Its success in application is strongly influenced by the identification of the dural sac. The average intraobserver Cohen's kappa was 0.53 ± 0.2. The inter-observer Fleiss' kappa was 0.38 ± 0.02 in the first rating and 0.3 ± 0.03 in the second rating repeated after two weeks. Discussion: In this attempt, the teaching of the observers was limited to an introduction to the general idea of the morphology grading system and one example MRI image per category. The identification of the dimension of the dural sac may be a difficult issue in absence of complete T1 T2 MRI image series as it was the case here. The similarity of the CSF to possibly present fat on T2 images was the main reason of mismatch in the assignment of the cases to a category. The Fleiss correlation factors of the five observers are fair and the proposed morphology grading system is promising.

The In Vitro Mass-Produced Model Mycorrhizal Fungus, Rhizophagus irregularis, Significantly Increases Yields of the Globally Important Food Security Crop Cassava.

The arbuscular mycorrhizal symbiosis is formed between arbuscular mycorrhizal fungi (AMF) and plant roots. The fungi provide the plant with inorganic phosphate (P). The symbiosis can result in increased plant growth. Although most global food crops naturally form this symbiosis, very few studies have shown that their practical application can lead to large-scale increases in food production. Application of AMF to crops in the tropics is potentially effective for improving yields. However, a main problem of using AMF on a large-scale is producing cheap inoculum in a clean sterile carrier and sufficiently concentrated to cheaply transport. Recently, mass-produced in vitro inoculum of the model mycorrhizal fungus Rhizophagus irregularis became available, potentially making its use viable in tropical agriculture. One of the most globally important food plants in the tropics is cassava. We evaluated the effect of in vitro mass-produced R. irregularis inoculum on the yield of cassava crops at two locations in Colombia. A significant effect of R. irregularis inoculation on yield occurred at both sites. At one site, yield increases were observed irrespective of P fertilization. At the other site, inoculation with AMF and 50% of the normally applied P gave the highest yield. Despite that AMF inoculation resulted in greater food production, economic analyses revealed that AMF inoculation did not give greater return on investment than with conventional cultivation. However, the amount of AMF inoculum used was double the recommended dose and was calculated with European, not Colombian, inoculum prices. R. irregularis can also be manipulated genetically in vitro, leading to improved plant growth. We conclude that application of in vitro R. irregularis is currently a way of increasing cassava yields, that there is a strong potential for it to be economically profitable and that there is enormous potential to improve this efficiency further in the future.

Phase-based manganese enhanced MRI, a new methodology to enhance brain cytoarchitectural contrast and study manganese uptake.

PURPOSE: As the magnetic susceptibility induced frequency shift increases linearly with magnetic field strength, the present work evaluates manganese as a phase imaging contrast agent and investigates the dose dependence of brain enhancement in comparison to T1 -weighted imaging after intravenous administration of MnCl2 . METHODS: Experiments were carried out on 12 Sprague-Dawley rats. MnCl2 was infused intravenously with the following doses: 25, 75, 125 mg/kg (n=4). Phase, T1 -weighted images and T1 maps were acquired before and 24h post MnCl2 administration at 14.1 Tesla. RESULTS: Manganese enhancement was manifested in phase imaging by an increase in frequency shift differences between regions rich in calcium gated channels and other tissues, together with local increase in signal to noise ratio (from the T1 reduction). Such contrast improvement allowed a better visualization of brain cytoarchitecture. The measured T1 decrease observed across different manganese doses and in different brain regions were consistent with the increase in the contrast to noise ratio (CNR) measured by both T1 -weighted and phase imaging, with the strongest variations being observed in the dentate gyrus and olfactory bulb. CONCLUSION: Overall from its high sensitivity to manganese combined with excellent CNR, phase imaging is a promising alternative imaging protocol to assess manganese enhanced MRI at ultra high field. Magn Reson Med 72:1246-1256, 2014. © 2013 Wiley Periodicals, Inc.

Combined analysis of grey matter voxel-based morphometry and white matter tract-based spatial statistics in late-life bipolar disorder.

Background: Previous magnetic resonance imaging (MRI) studies in young patients with bipolar disorder indicated the presence of grey matter concentration changes as well as microstructural alterations in white matter in various neocortical areas and the corpus callosum. Whether these structural changes are also present in elderly patients with bipolar disorder with long-lasting clinical evolution remains unclear. Methods: We performed a prospective MRI study of consecutive elderly, euthymic patients with bipolar disorder and healthy, elderly controls. We conducted a voxel-based morphometry (VBM) analysis and a tract-based spatial statistics (TBSS) analysis to assess fractional anisotropy and longitudinal, radial and mean diffusivity derived by diffusion tensor imaging (DTI). Results: We included 19 patients with bipolar disorder and 47 controls in our study. Fractional anisotropy was the most sensitive DTI marker and decreased significantly in the ventral part of the corpus callosum in patients with bipolar disorder. Longitudinal, radial and mean diffusivity showed no significant between-group differences. Grey matter concentration was reduced in patients with bipolar disorder in the right anterior insula, head of the caudate nucleus, nucleus accumbens, ventral putamen and frontal orbital cortex. Conversely, there was no grey matter concentration or fractional anisotropy increase in any brain region in patients with bipolar disorder compared with controls. Limitations: The major limitation of our study is the small number of patients with bipolar disorder. Conclusion: Our data document the concomitant presence of grey matter concentration decreases in the anterior limbic areas and the reduced fibre tract coherence in the corpus callosum of elderly patients with long-lasting bipolar disorder.

Robust response transformations based on optimal prediction

Nonlinear regression problems can often be reduced to linearity by transforming the response variable (e.g., using the Box-Cox family of transformations). The classic estimates of the parameter defining the transformation as well as of the regression coefficients are based on the maximum likelihood criterion, assuming homoscedastic normal errors for the transformed response. These estimates are nonrobust in the presence of outliers and can be inconsistent when the errors are nonnormal or heteroscedastic. This article proposes new robust estimates that are consistent and asymptotically normal for any unimodal and homoscedastic error distribution. For this purpose, a robust version of conditional expectation is introduced for which the prediction mean squared error is replaced with an M scale. This concept is then used to develop a nonparametric criterion to estimate the transformation parameter as well as the regression coefficients. A finite sample estimate of this criterion based on a robust version of smearing is also proposed. Monte Carlo experiments show that the new estimates compare favorably with respect to the available competitors.

Intraoperative angiography reloaded: a new hybrid operating theater for combined endovascular and surgical treatment of cerebral arteriovenous malformations: a pilot study on 25 patients.

BACKGROUND: Multimodality treatment suites for patients with cerebral arteriovenous malformations (AVM) have recently become available. This study was designed to evaluate feasibility, safety and impact on treatment of a new intraoperative flat-panel (FP) based integrated surgical and imaging suite for combined endovascular and surgical treatment of cerebral AVM. METHODS: Twenty-five patients with AVMs to treat with combined endovascular and surgical interventions were prospectively enrolled in this consecutive case series. The hybrid suite allows combined endovascular and surgical approaches with intraoperative scanner-like imaging (XperCT®) and intraoperative 3D rotational angiography (3D-RA). The impact of intraoperative multimodal imaging on feasibility, workflow of combined interventions, surgery, and unexpected imaging findings were analyzed. RESULTS: Twenty-five patients (mean age 38 ± 18.6 year) with a median Spetzler-Martin grade 2 AVM (range 1-4) underwent combined endovascular and surgical procedures. Sixteen patients presented with a ruptured AVM and nine with an unruptured AVM. In 16 % (n = 4) of cases, intraoperative imaging visualized AVM remnants ≤3 mm and allowed for completion of the resections in the same sessions. Complete resection was confirmed in all n = 16 patients who had follow-up angiography one year after surgery so far. All diagnostic and therapeutical steps, including angiographic control, were performed without having to move the patients CONCLUSION: The hybrid neurointerventional suite was shown to be a safe and useful setup which allowed for unconstrained combined microsurgical and neuroradiological workflow. It reduces the need for extraoperative angiographic controls and subsequent potential surgical revisions a second time, as small AVM remnants can be detected with high security.

Impact and cost of a 2-week community-based screening and awareness program for diabetes and cardiovascular risk factors in a Swiss canton.

BACKGROUND: Community-based diabetes screening programs can help sensitize the population and identify new cases. However, the impact of such programs is rarely assessed in high-income countries, where concurrent health information and screening opportunities are common place. INTERVENTION AND METHODS: A 2-week screening and awareness campaign was organized as part of a new diabetes program in the canton of Vaud (population of 697,000) in Switzerland. Screening was performed without appointment in 190 out of 244 pharmacies in the canton at the subsidized cost of 10 Swiss Francs per participant. Screening included questions on risk behaviors, measurement of body mass index, blood pressure, blood cholesterol, random blood glucose (RBG), and A1c if RBG was >/=7.0 mmol/L. A mass media campaign promoting physical activity and a healthy diet was channeled through several media, eg, 165 spots on radio, billboards in 250 public places, flyers in 360 public transport vehicles, and a dozen articles in several newspapers. A telephone survey in a representative sample of the population of the canton was performed after the campaign to evaluate the program. RESULTS: A total of 4222 participants (0.76% of all persons aged >/=18 years) underwent the screening program (median age: 53 years, 63% females). Among participants not treated for diabetes, 3.7% had RBG >/= 7.8 mmol/L and 1.8% had both RBG >/= 7.0 mmol/L and A1c >/= 6.5. Untreated blood pressure >/=140/90 mmHg and/or untreated cholesterol >/=5.2 mmol/L were found in 50.5% of participants. One or several treated or untreated modifiable risk factors were found in 78% of participants. The telephone survey showed that 53% of all adults in the canton were sensitized by the campaign. Excluding fees paid by the participants, the program incurred a cost of CHF 330,600. CONCLUSION: A community-based screening program had low efficiency for detecting new cases of diabetes, but it identified large numbers of persons with elevated other cardiovascular risk factors. Our findings suggest the convenience of A1c for mass screening of diabetes, the usefulness of extending diabetes screening to other cardiovascular risk factors, and the importance of a robust background communication campaign.

Political representation in Switzerland : democratic or plutocratic ?

Les inégalités économiques se traduisent-elles dans des inégalités politiques à travers le processus de représentation électorale? Telle est la question centrale de cette thèse qui s'attache, par ailleurs, à investiguer les mécanismes qui tendent à produire une représentation biaisée des préférences politiques des citoyens en fonction de leur statut économique. Focalisé sur le cas de la Suisse et faisant usage des données de l'enquête postélectorale Selects de 2007, ce travail démontre que sur les rares sujets qui divisent les citoyens selon des clivages économiques - la redistribution des richesses et la sécurité sociale en particulier - les élus à l'Assemblée fédérale ont des préférences qui reflètent mieux les opinions des citoyens les plus riches. Cette sous-représentation des opinions des citoyens modestes et de ceux faisant partie du centre de la distribution des revenus peut en partie être attribuée à des différences dans les taux de participation et de connaissance politiques entre ces groupes de citoyens. La thèse met également en évidence le rôle joué par la représentation descriptive - autrement dit, la similitude en termes de statut économique entre les représentants et les représentés - dans la représentation des opinions et intérêts des citoyens. Par ailleurs, la structure du système partisan en Suisse ne reflétant pas la multidimensionnalité des préférences politiques des citoyens, les électeurs ne parviennent pas à traduire la complexité de leurs préférences politiques dans un choix de vote, ce qui, dans la configuration actuelle des forces politiques, tend à favoriser l'élection de représentants aux opinions proches de la droite sur les questions économiques. Enfin, une analyse de la représentation politique au niveau cantonal tend à soutenir la thèse selon laquelle le manque de régulation en matière de financement des partis en Suisse pourrait partiellement expliquer les inégalités dans la représentation des opinions politiques des citoyens aux revenus distincts. - Do economic inequalities translate into political inequalities through electoral representation? This is the central research question of this thesis, which also investigates the mechanisms that lead to potential economically based inequalities in the representation of citizens' policy preferences. Focusing on the case of Switzerland and making use of data provided by the post- electoral survey Selects 2007, this research demonstrates that regarding the rare policy domains in which the preferences of citizens are clearly linked to economic cleavages - redistribution and social security in particular - members of the Federal Assembly have policy preferences that best reflect the policy preferences of richer citizens. The under-representation of the opinions of relatively poor citizens and of those being the in the middle of the income distribution can be to some extent be explained by differences in political participation and political information across income groups. The thesis also puts forward the role played by descriptive representation - the similarity between representatives and represented in terms of their socioeconomic status - for the representation of citizens' preferences and interests. In addition, the structure of the party system in Switzerland does not reflect the multidimensionality of policy preferences among citizens who, as a result, have a hard time translating their complex preferences into a vote choice. Given the configuration of political actors, this tends to favour the election of representatives from the right who do not represent the preferences of their voters on economic issues. Finally, an analysis of representation at the cantonal level tends to confirm that the lack of party finance regulations in Switzerland may partially explain inequalities in the representation of citizens with different levels of income.