A 2D/3D image analysis system to track fluorescently labeled structures in rod-shaped cells: application to measure spindle pole asymmetry during mitosis.

BACKGROUND: The yeast Schizosaccharomyces pombe is frequently used as a model for studying the cell cycle. The cells are rod-shaped and divide by medial fission. The process of cell division, or cytokinesis, is controlled by a network of signaling proteins called the Septation Initiation Network (SIN); SIN proteins associate with the SPBs during nuclear division (mitosis). Some SIN proteins associate with both SPBs early in mitosis, and then display strongly asymmetric signal intensity at the SPBs in late mitosis, just before cytokinesis. This asymmetry is thought to be important for correct regulation of SIN signaling, and coordination of cytokinesis and mitosis. In order to study the dynamics of organelles or large protein complexes such as the spindle pole body (SPB), which have been labeled with a fluorescent protein tag in living cells, a number of the image analysis problems must be solved; the cell outline must be detected automatically, and the position and signal intensity associated with the structures of interest within the cell must be determined. RESULTS: We present a new 2D and 3D image analysis system that permits versatile and robust analysis of motile, fluorescently labeled structures in rod-shaped cells. We have designed an image analysis system that we have implemented as a user-friendly software package allowing the fast and robust image-analysis of large numbers of rod-shaped cells. We have developed new robust algorithms, which we combined with existing methodologies to facilitate fast and accurate analysis. Our software permits the detection and segmentation of rod-shaped cells in either static or dynamic (i.e. time lapse) multi-channel images. It enables tracking of two structures (for example SPBs) in two different image channels. For 2D or 3D static images, the locations of the structures are identified, and then intensity values are extracted together with several quantitative parameters, such as length, width, cell orientation, background fluorescence and the distance between the structures of interest. Furthermore, two kinds of kymographs of the tracked structures can be established, one representing the migration with respect to their relative position, the other representing their individual trajectories inside the cell. This software package, called "RodCellJ", allowed us to analyze a large number of S. pombe cells to understand the rules that govern SIN protein asymmetry. CONCLUSIONS: "RodCell" is freely available to the community as a package of several ImageJ plugins to simultaneously analyze the behavior of a large number of rod-shaped cells in an extensive manner. The integration of different image-processing techniques in a single package, as well as the development of novel algorithms does not only allow to speed up the analysis with respect to the usage of existing tools, but also accounts for higher accuracy. Its utility was demonstrated on both 2D and 3D static and dynamic images to study the septation initiation network of the yeast Schizosaccharomyces pombe. More generally, it can be used in any kind of biological context where fluorescent-protein labeled structures need to be analyzed in rod-shaped cells. AVAILABILITY: RodCellJ is freely available under http://bigwww.epfl.ch/algorithms.html, (after acceptance of the publication).

Differential Gene Expression between Fall- and Spring-Run Chinook Salmon Assessed by Long Serial Analysis of Gene Expression

Of all Pacific salmonids, Chinook salmon Oncorhynchus tshawytscha display the greatest variability in return times to freshwater. The molecular mechanisms of these differential return times have not been well described. Current methods, such as long serial analysis of gene expression (LongSAGE) and microarrays, allow gene expression to be analyzed for thousands of genes simultaneously. To investigate whether differential gene expression is observed between fall- and spring-run Chinook salmon from California's Central Valley, LongSAGE libraries were constructed. Three libraries containing between 25,512 and 29,372 sequenced tags (21 base pairs/tag) were generated using messenger RNA from the brains of adult Chinook salmon returning in fall and spring and from one ocean-caught Chinook salmon. Tags were annotated to genes using complementary DNA libraries from Atlantic salmon Salmo salar and rainbow trout O. mykiss. Differentially expressed genes, as estimated by differences in the number of sequence tags, were found in all pairwise comparisons of libraries (freshwater versus saltwater = 40 genes; fall versus spring = 11 genes: and spawning versus nonspawning = 51 genes). The gene for ependymin, an extracellular glycoprotein involved in behavioral plasticity in fish, exhibited the most differential expression among the three groupings. Reverse transcription polymerase chain reaction analysis verified the differential expression of ependymin between the fall- and spring-run samples. These LongSAGE libraries, the first reported for Chinook salmon, provide a window of the transcriptional changes during Chinook salmon return migration to freshwater and spawning and increase the amount of expressed sequence data.

Healthy, wealthy, wise, and happy? An exploratory analysis of the interplay between aging and subjective well-being in low and middle income countries

In this paper, we address the relationship between age and several dimension of subjective well-being. Whilst literature generally finds a U-shaped age-profile in subjective well-being, this age-pattern might only hold after controlling for objective life circumstances. The observed U-shaped age-profile might further not generalize to other dimensions of well-being and might vary across countries and cultures. Our study examines the relationship between age and several dimensions of well-being as well as the effect of objective life circumstances using the WHO Study on Global AGEing and Adult Health (SAGE). Our results suggest a decreasing age profile in the raw data associated with evaluative well-being, while experienced well-being shows a rather flat or slightly increasing pattern. However, age per se is not a cause of a decline in evaluative well-being. The negative age-profile in evaluative well-being is mainly explained by changes in life circumstances associated with aging. Controlling for socio-demographic factors, we find higher levels of well-being for older persons relative to their middle-aged counterparts. In contrast, we find that changes in life circumstances have a much smaller effect on experienced well-being.

Viability and Management of an Endangered Capercaillie (Tetrao urogallus) Metapopulation in the Jura Mountains, Western Switzerland

The populations of Capercaillie (Tetrao urogallus), the largest European grouse, have seriously declined during the last century over most of their distribution in western and central Europe. In the Jura mountains, the relict population is now isolated and critically endangered (about 500 breeding adults). We developed a simulation software (TetrasPool) that accounts for age and spatial structure as well as stochastic processes, to perform a viability analysis and explore management scenarios for this population, capitalizing on a 24 years-long series of field data. Simulations predict a marked decline and a significant extinction risk over the next century, largely due to environmental and demographic stochasticity (average values of life-history parameters would otherwise allow stability). Variances among scenarios mainly stem from uncertainties about the shape and intensity of density dependence. Uncertainty analyses suggest to focus conservation efforts on enhancing, not only adult survival (as often advocated for long-lived species), but also recruitment. The juvenile stage matters when local populations undergo extinctions, because it ensures connectivity and recolonization. Besides limiting human perturbations, a silvicultural strategy aimed at opening forest structure should improve the quality and surface of available patches, independent of their size and localization. Such measures are to be taken urgently, if the population is to be saved.

Predictors of leadership: The usual suspects and the suspect traits

In this chapter, I review literature on traits (i.e., individual differences) and their links to leader outcomes. I present an integrated model, the ascription-actuality trait theory, to explain two routes to leader outcomes that stem from traits: the route that objectively matters and the route that appears to matter but objectively may not. I discuss the history of trait research and provide criteria by which we should judge the validity of trait models. Finally, I review trait models that are the most predictive of leadership outcomes and identify those that are non-starters.

Incidence and types of illness when travelling to the tropics : a prospective controlled study of children and their parents

RESUME De plus en plus de familles se rendent vers des destinations tropicales, s'exposant à des agents infectieux et des maladies tropicales qu'ils ne rencontrent pas chez eux. Nous avons étudié 157 enfants (0-16 ans) et leurs parents partant pour les tropiques, qui ont tous consulté une clinique pré-voyage et qui étaient généralement compliants aux conseils prodigués. Les taux d'incidence de maladies communes chez les enfants et les adultes étaient respectivement de 16.9 (14.3-19.7) et 15.1 (12.7-17.8) épisodes/ 100 personnes-semaines. La diarrhée, les douleurs abdominales et la fièvre représentaient les plaintes les plus fréquentes. Il n'y avait pas de différence significative d'incidence des épisodes morbides entre les enfants et les adultes sauf pour la fièvre (plus fréquente chez les enfants). La plupart des épisodes avaient lieu dans les dix premiers jours du voyage. L'incidence de morbidité similaire chez les enfants et les adultes ainsi que l'aspect bénin des épisodes remet en question l'opinion selon laquelle il n'est pas sage de voyager avec des jeunes enfants.

Recherches nouvelles sur les "Evangiles latins de l'enfance" de M. R. James et sur un récit apocryphe mal connu de la naissance de Jésus

Les Evangiles latins de l'enfance ont été peu étudiés depuis l'édition de M. R. James en 1927. La prochaine publication dans la Series apocryphorum des Évangiles irlandais de l'enfance jette un éclairage nouveau sur cette compilation latine qui combine le Protévangile de Jacques, l'Évangile du Pseudo-Matthieu et une 3e Source non identifiée racontant la naissance de Jésus. Les récits irlandais du Leabar Breac et du Liber Flavus Fergusiorum permettent de remonter à un état antérieur à la compilation, pas encore influencé par le Pseudo-Matthieu. Ils conservent parfois des éléments du texte de la Source qui ont disparu dans le latin. Le récit original de cette source inconnue est indépendant du Protévangile de Jacques et pourrait être aussi ancien que lui. C'est ce qui ressort de l'étude par l'A. de quelques motifs caractéristiques : l'impôt lié au recensement, la pauvreté de Joseph, le rôle des fils de Joseph, le lieu de la nativité, l'épisode de la sage-femme.

Das Auerhuhn im Jura: Qualität des Lebensraum, Demographie, Habitatwahl und nicht-invasive genetische Untersuchungen

Most Central European Capercaillie populations have been declining during the last century. In the Jura Mountains, at the border between Switzerland and France, remaining Capercaillie populations are now isolated and endangered. In this study, land-use and Capercaillie presence data were used to identify key landscape parameters by logistic regression modelling. We found that Capercaillie prefers areas at the highest altitude in the Jura Mountains that are characterised by continous forests and stands with intermediate canopy cover. At the local scale, winter habitat selection revealed a preference for open forests with a sparse canopy cover dominated by spruce and fir. Capercaillie avoided dense undercanopy and understorey, especially when dominated by beech. Population viability and sensitivity analyses underlined the crucial importance of adult female survival, chick survival and breeding success for populations maintenance. Legal bases, scientific knowledge and technical measures are now available to conserve the flagship species Capercaillie within Jura Mountains. Capercaillie-adapted forestry requires a mosaic distribtution of habitat types, with a matrix of open forests where fir is favoured, and understorey kept sparse. Preliminary essays indicate that grouse-adapted forestry costs are similar or even lower than present costs. To increase survival and breeding sucess, one option is to diminish human distrubance by limiting access to Capercailllie breeding and wintering areas. An action plan for the species should avoid more costly and intensive approaches such as the reintroduction of birds from other populations. Capercaillie conservaiton represents a major challenge rising from various and contradictory leisure, tourist and rural development activities. Collaborations with different stakeholders and state agencies for forestry with an effective protection from human distrubance.

Discriminating Irritable Bowel Syndrome fromInflammatory Bowel Disease: what is the Role of Biomarkers in Daily Practice?

Background a nd A ims: D iscriminating irritable bowelsyndrome (IBS) from inflammatory bowel disease (IBD) can bea clinical c hallenge as s ymptoms c an overlap. We a nd othershave recently shown that fecal c alprotectin ( FC) is moreaccurate for d iscriminating IBS f rom IBD compared to C -reactive p rotein ( CRP) and b lood leukocytes. We a imed toassess which b iomarkers are used by g astroenterologists intheir daily practice for discriminating IBS from IBD.Methods: A q uestionnaire was sent to all board certifiedgastroenterologists in Switzerland in July 2010.Results: Response rate was 57% (153/270). Mean physician'sage was 50±9years, mean duration o f gastroenterologicpractice 1 4±8years, 52% of them were working in p rivatepractice a nd 48% in h ospitals. T he following biomarkers weredetermined for discriminating IBS from IBD: CRP 100%, FC79%, hematogram (red blood cells and leukocytes) 70%, ironstatus ( ferritin, t ransferrin s aturation) 59%, e rythrocytesedimentation rate 2.7%, protein electrophoresis 0.7%, andalpha-1 antitrypsin clearance 0.7%. There was a trend for usingFC more often in p rivate practice t han in h ospital ( P = 0.08).Eighty-nine percent of gastroenterologists considered FC to besuperior to CRP for discriminating IBS from IBD, 8 7% thoughtthat patient's compliance for fecal sampling is high, and 51%judged the fee of USD 60 for a FC test as appropriate.Conclusions: F C is widely used in c linical practice t odiscriminate IBS from IBD. In accordance with the scientificevidence, the majority of gastroenterologists consider FC to bemore accurate than CRP for discriminating IBS from IBD.