Demonstration of the effectiveness of zinc in diarrhoea of children living in Switzerland.

We designed a double-blinded randomized clinical trial of zinc (10 or 20 mg of zinc sulphate for 2-5 month-old or 6-59 month-old children, respectively, during 10 days) vs. placebo in otherwise healthy children aged 2 months to 5 years who presented with acute diarrhoea (i.e. ≥3 stools/day for less than 72 h). Eighty-seven patients (median age 14 months; range 3.1-58.3) were analysed in an intention-to-treat approach. Forty-two patients took zinc and 45 placebo. There was no difference in the duration nor in the frequency of diarrhoea, but only 5% of the zinc group still had diarrhoea at 120 h of treatment compared to 20% in the placebo group (P = 0.05). Thirty-one patients (13 zinc and 18 placebo) were available for per-protocol analyses. The median (IQR) duration of diarrhoea in zinc-treated patients was 47.5 h (18.3-72) and differed significantly from the placebo group (median 76.3; IQR 52.8-137) (P = 0.03). The frequency of diarrhoea was also lower in the zinc group (P = 0.02). CONCLUSION: zinc treatment decreases the frequency and severity of diarrhoea in children aged 2 months to 5 years living in Switzerland. However, the intention-to-treat analysis reveals compliance issues that question the proper duration of treatment and the choice of optimal pharmaceutical formulation.

Bayesian Networks for the Age Classification of Living Individuals: a Study on Transition Analysis

Over the past few decades, age estimation of living persons has represented a challenging task for many forensic services worldwide. In general, the process for age estimation includes the observation of the degree of maturity reached by some physical attributes, such as dentition or several ossification centers. The estimated chronological age or the probability that an individual belongs to a meaningful class of ages is then obtained from the observed degree of maturity by means of various statistical methods. Among these methods, those developed in a Bayesian framework offer to users the possibility of coherently dealing with the uncertainty associated with age estimation and of assessing in a transparent and logical way the probability that an examined individual is younger or older than a given age threshold. Recently, a Bayesian network for age estimation has been presented in scientific literature; this kind of probabilistic graphical tool may facilitate the use of the probabilistic approach. Probabilities of interest in the network are assigned by means of transition analysis, a statistical parametric model, which links the chronological age and the degree of maturity by means of specific regression models, such as logit or probit models. Since different regression models can be employed in transition analysis, the aim of this paper is to study the influence of the model in the classification of individuals. The analysis was performed using a dataset related to the ossifications status of the medial clavicular epiphysis and results support that the classification of individuals is not dependent on the choice of the regression model.

Living with invasive plants in the Anthropocene : the importance of understanding practice and experience

The role of humans in facilitating the rapid spread of plants at a scale that is considered invasive is one manifestation of the Anthropocene, now framed as a geological period in which humans are the dominant force in landscape transformation. Invasive plant management faces intensified challenges, and can no longer be viewed in terms of 'eradication' or 'restoration of original landscapes'. In this perspectives piece, we focus on the practice and experience of people engaged in invasive plant management, using examples from Australia and Canada. We show how managers 1) face several pragmatic trade-offs; 2) must reconcile diverse views, even within stakeholder groups; 3) must balance competing temporal scales; 4) encounter tensions with policy; and 5) face critical and under-acknowledged labour challenges. These themes show the variety of considerations based on which invasive plant managers make complex decisions about when, where, and how to intervene. Their widespread pragmatic acceptance of small, situated gains (as well as losses) combines with impressive long-term commitments to the task of invasives management. We suggest that the actual practice of weed management challenges those academic perspectives that still aspire to attain pristine nature.

Précarité et problèmes cutanés [Skin problems associated with poor living conditions].

Les personnes vivant dans une situation de précarité sont susceptibles de développer un large éventail de problèmes médicaux et les atteintes cutanées sont très fréquentes. Nous présentons quatre situations cliniques de problèmes cutanés fréquemment retrouvés au sein des populations précaires. Leurs diagnostic et prise en charge précoces sont essentiels pour en prévenir l'ultérieure dissémination dans des contextes de promiscuité. People living in poor conditions are at high risk of developing different medical diseases of which dermatological diseases are very common. We present 4 clinical cases of skin diseases, which are the most prevalent amongst the majority of socially and economically vulnerable patients. Early diagnosis and appropriate treatment are of paramount importance, in order to avoid their spread in close- knit communities where these patients often live.

Probabilistic graphical models to deal with age estimation of living persons

Due to the rise of criminal, civil and administrative judicial situations involving people lacking valid identity documents, age estimation of living persons has become an important operational procedure for numerous forensic and medicolegal services worldwide. The chronological age of a given person is generally estimated from the observed degree of maturity of some selected physical attributes by means of statistical methods. However, their application in the forensic framework suffers from some conceptual and practical drawbacks, as recently claimed in the specialised literature. The aim of this paper is therefore to offer an alternative solution for overcoming these limits, by reiterating the utility of a probabilistic Bayesian approach for age estimation. This approach allows one to deal in a transparent way with the uncertainty surrounding the age estimation process and to produce all the relevant information in the form of posterior probability distribution about the chronological age of the person under investigation. Furthermore, this probability distribution can also be used for evaluating in a coherent way the possibility that the examined individual is younger or older than a given legal age threshold having a particular legal interest. The main novelty introduced by this work is the development of a probabilistic graphical model, i.e. a Bayesian network, for dealing with the problem at hand. The use of this kind of probabilistic tool can significantly facilitate the application of the proposed methodology: examples are presented based on data related to the ossification status of the medial clavicular epiphysis. The reliability and the advantages of this probabilistic tool are presented and discussed.

Antibody levels against GLURP R2, MSP1 block 2 hybrid and AS202.11 and the risk of malaria in children living in hyperendemic (Burkina Faso) and hypo-endemic (Ghana) areas.

Differences in parasite transmission intensity influence the process of acquisition of host immunity to Plasmodium falciparum malaria and ultimately, the rate of malaria related morbidity and mortality. Potential vaccines being designed to complement current intervention efforts therefore need to be evaluated against different malaria endemicity backgrounds. The associations between antibody responses to the chimeric merozoite surface protein 1 block 2 hybrid (MSP1 hybrid), glutamate-rich protein region 2 (GLURP R2) and the peptide AS202.11, and the risk of malaria were assessed in children living in malaria hyperendemic (Burkina Faso, n = 354) and hypo-endemic (Ghana, n = 209) areas. Using the same reagent lots and standardized protocols for both study sites, immunoglobulin (Ig) M, IgG and IgG sub-class levels to each antigen were measured by ELISA in plasma from the children (aged 6-72 months). Associations between antibody levels and risk of malaria were assessed using Cox regression models adjusting for covariates. There was a significant association between GLURP R2 IgG3 and reduced risk of malaria after adjusting age of children in both the Burkinabe (hazard ratio 0.82; 95 % CI 0.74-0.91, p < 0.0001) and the Ghanaian (HR 0.48; 95 % CI 0.25-0.91, p = 0.02) cohorts. MSP1 hybrid IgM was associated (HR 0.85; 95 % CI 0.73-0.98, p = 0.02) with reduced risk of malaria in Burkina Faso cohort while IgG against AS202.11 in the Ghanaian children was associated with increased risk of malaria (HR 1.29; 95 % CI 1.01-1.65, p = 0.04). These findings support further development of GLURP R2 and MSP1 block 2 hybrid, perhaps as a fusion vaccine antigen targeting malaria blood stage that can be deployed in areas of varying transmission intensity.

Predator or prey? Chlamydophila abortus infections of a free-living amoebae, Acanthamoeba castellani 9GU.

Limited evidence exists to suggest that the ability to invade and escape protozoan host cell bactericidal activity extends to members of the Chlamydiaceae, intracellular pathogens of humans and animals and evolutionary descendants of amoeba-resisting Chlamydia-like organisms. PCR and microscopic analyses of Chlamydophila abortus infections of Acanthamoeba castellani revealed uptake of this chlamydial pathogen but, unlike the well-described inhabitant of A. castellani, Parachlamydia acanthamoebae, Cp. abortus did not appear to propagate and is likely digested by its amoebal host. These data raise doubts about the ability of free-living amoebae to serve as hosts and vectors of pathogenic members of the Chlamydiaceae but reveal opportunities, via comparative genomics, to understand virulence mechanisms used by Chlamydia-like organisms to avoid amoebal digestion.

Condition-dependence, pleiotropy and the handicap principle of sexual selection in melanin-based colouration.

The signalling function of melanin-based colouration is debated. Sexual selection theory states that ornaments should be costly to produce, maintain, wear or display to signal quality honestly to potential mates or competitors. An increasing number of studies supports the hypothesis that the degree of melanism covaries with aspects of body condition (e.g. body mass or immunity), which has contributed to change the initial perception that melanin-based colour ornaments entail no costs. Indeed, the expression of many (but not all) melanin-based colour traits is weakly sensitive to the environment but strongly heritable suggesting that these colour traits are relatively cheap to produce and maintain, thus raising the question of how such colour traits could signal quality honestly. Here I review the production, maintenance and wearing/displaying costs that can generate a correlation between melanin-based colouration and body condition, and consider other evolutionary mechanisms that can also lead to covariation between colour and body condition. Because genes controlling melanic traits can affect numerous phenotypic traits, pleiotropy could also explain a linkage between body condition and colouration. Pleiotropy may result in differently coloured individuals signalling different aspects of quality that are maintained by frequency-dependent selection or local adaptation. Colouration may therefore not signal absolute quality to potential mates or competitors (e.g. dark males may not achieve a higher fitness than pale males); otherwise genetic variation would be rapidly depleted by directional selection. As a consequence, selection on heritable melanin-based colouration may not always be directional, but mate choice may be conditional to environmental conditions (i.e. context-dependent sexual selection). Despite the interest of evolutionary biologists in the adaptive value of melanin-based colouration, its actual role in sexual selection is still poorly understood.