A matter of time: delayed mate encounter postpones mating window initiation and reduces the strength of female choosiness

Reproductive success is determined by the presence and timing of encounter of mates. The latter depends on species-specific reproductive characteristics (e.g. initiation/duration of the mating window), season, and reproductive strategies (e.g. intensity of choosiness) that may potentially mitigate constraints imposed by mating windows. Despite their potentially crucial role for fitness and population dynamics, limited evidence exists about mating window initiation, duration and reproductive strategies. Here, we experimentally tested the mechanisms of initiation and the duration of the common lizard's Zootoca vivipara mating window, by manipulating the timing of mate encounter and analyzing its effect on (re-)mating probability. We furthermore tested treatment effects on female reproductive strategies, by measuring female choosiness. The timing of mate encounter and season did not significantly affect mating probability. However, a longer delay until mate encounter reduced female choosiness. Re-mating probability decreased with re-mating delay and was independent of mating delay. This indicates that mating window initiation depends on mate encounter, that its duration is fixed, and that plastic reproductive strategies exist. These findings contrast with previous beliefs and shows that mating windows per se may not necessarily constrain reproductive success, which is congruent with rapid range expansion and absence of positive density-effects on reproductive success (Allee effects). In summary, our results show that predicting the effect of mating windows on reproduction is complex and that experimental evidence is essential for evaluating their effect on reproduction and reproductive strategies, both being important determinants of population dynamics and the colonization of new habitats.

Investigation of classical epidemiological links between patients harbouring identical, non-predominant meticillin-resistant Staphylococcus aureus genotypes and lessons for epidemiological tracking.

According to molecular epidemiology theory, two isolates belong to the same chain of transmission if they are similar according to a highly discriminatory molecular typing method. This has been demonstrated in outbreaks, but is rarely studied in endemic situations. Person-to-person transmission cannot be established when isolates of meticillin-resistant Staphylococcus aureus (MRSA) belong to endemically predominant genotypes. By contrast, isolates of infrequent genotypes might be more suitable for epidemiological tracking. The objective of the present study was to determine, in newly identified patients harbouring non-predominant MRSA genotypes, whether putative epidemiological links inferred from molecular typing could replace classical epidemiology in the context of a regional surveillance programme. MRSA genotypes were defined using double-locus sequence typing (DLST) combining clfB and spa genes. A total of 1,268 non-repetitive MRSA isolates recovered between 2005 and 2006 in Western Switzerland were typed: 897 isolates (71%) belonged to four predominant genotypes, 231 (18%) to 55 non-predominant genotypes, and 140 (11%) were unique. Obvious epidemiological links were found in only 106/231 (46%) patients carrying isolates with non-predominant genotypes suggesting that molecular surveillance identified twice as many clusters as those that may have been suspected with classical epidemiological links. However, not all of these molecular clusters represented person-to-person transmission. Thus, molecular typing cannot replace classical epidemiology but is complementary. A prospective surveillance of MRSA genotypes could help to target epidemiological tracking in order to recognise new risk factors in hospital and community settings, or emergence of new epidemic clones.

Safety of a new algorithm for the management of childhood illness (Almanach) to improve quality of care and rational use of drugs

Introduction New evidence from randomized controlled and etiology of fever studies, the availability of reliable RDT for malaria, and novel technologies call for revision of the IMCI strategy. We developed a new algorithm based on (i) a systematic review of published studies assessing the safety and appropriateness of RDT and antibiotic prescription, (ii) results from a clinical and microbiological investigation of febrile children aged <5 years, (iii) international expert IMCI opinions. The aim of this study was to assess the safety of the new algorithm among patients in urban and rural areas of Tanzania.Materials and Methods The design was a controlled noninferiority study. Enrolled children aged 2-59 months with any illness were managed either by a study clinician using the new Almanach algorithm (two intervention health facilities), or clinicians using standard practice, including RDT (two control HF). At day 7 and day 14, all patients were reassessed. Patients who were ill in between or not cured at day 14 were followed until recovery or death. Primary outcome was rate of complications, secondary outcome rate of antibiotic prescriptions.Results 1062 children were recruited. Main diagnoses were URTI 26%, pneumonia 19% and gastroenteritis (9.4%). 98% (531/541) were cured at D14 in the Almanach arm and 99.6% (519/521) in controls. Rate of secondary hospitalization was 0.2% in each. One death occurred in controls. None of the complications was due to withdrawal of antibiotics or antimalarials at day 0. Rate of antibiotic use was 19% in the Almanach arm and 84% in controls.Conclusion Evidence suggests that the new algorithm, primarily aimed at the rational use of drugs, is as safe as standard practice and leads to a drastic reduction of antibiotic use. The Almanach is currently being tested for clinician adherence to proposed procedures when used on paper or a mobile phone

Results of An International Study of Quantitative BCR/ABL Assays Using Defined RNA Samples

Molecular monitoring of BCR/ABL transcripts by real time quantitative reverse transcription PCR (qRT-PCR) is an essential technique for clinical management of patients with BCR/ABL-positive CML and ALL. Though quantitative BCR/ABL assays are performed in hundreds of laboratories worldwide, results among these laboratories cannot be reliably compared due to heterogeneity in test methods, data analysis, reporting, and lack of quantitative standards. Recent efforts towards standardization have been limited in scope. Aliquots of RNA were sent to clinical test centers worldwide in order to evaluate methods and reporting for e1a2, b2a2, and b3a2 transcript levels using their own qRT-PCR assays. Total RNA was isolated from tissue culture cells that expressed each of the different BCR/ABL transcripts. Serial log dilutions were prepared, ranging from 100 to 10-5, in RNA isolated from HL60 cells. Laboratories performed 5 independent qRT-PCR reactions for each sample type at each dilution. In addition, 15 qRT-PCR reactions of the 10-3 b3a2 RNA dilution were run to assess reproducibility within and between laboratories. Participants were asked to run the samples following their standard protocols and to report cycle threshold (Ct), quantitative values for BCR/ABL and housekeeping genes, and ratios of BCR/ABL to housekeeping genes for each sample RNA. Thirty-seven (n=37) participants have submitted qRT-PCR results for analysis (36, 37, and 34 labs generated data for b2a2, b3a2, and e1a2, respectively). The limit of detection for this study was defined as the lowest dilution that a Ct value could be detected for all 5 replicates. For b2a2, 15, 16, 4, and 1 lab(s) showed a limit of detection at the 10-5, 10-4, 10-3, and 10-2 dilutions, respectively. For b3a2, 20, 13, and 4 labs showed a limit of detection at the 10-5, 10-4, and 10-3 dilutions, respectively. For e1a2, 10, 21, 2, and 1 lab(s) showed a limit of detection at the 10-5, 10-4, 10-3, and 10-2 dilutions, respectively. Log %BCR/ABL ratio values provided a method for comparing results between the different laboratories for each BCR/ABL dilution series. Linear regression analysis revealed concordance among the majority of participant data over the 10-1 to 10-4 dilutions. The overall slope values showed comparable results among the majority of b2a2 (mean=0.939; median=0.9627; range (0.399 - 1.1872)), b3a2 (mean=0.925; median=0.922; range (0.625 - 1.140)), and e1a2 (mean=0.897; median=0.909; range (0.5174 - 1.138)) laboratory results (Fig. 1-3)). Thirty-four (n=34) out of the 37 laboratories reported Ct values for all 15 replicates and only those with a complete data set were included in the inter-lab calculations. Eleven laboratories either did not report their copy number data or used other reporting units such as nanograms or cell numbers; therefore, only 26 laboratories were included in the overall analysis of copy numbers. The median copy number was 348.4, with a range from 15.6 to 547,000 copies (approximately a 4.5 log difference); the median intra-lab %CV was 19.2% with a range from 4.2% to 82.6%. While our international performance evaluation using serially diluted RNA samples has reinforced the fact that heterogeneity exists among clinical laboratories, it has also demonstrated that performance within a laboratory is overall very consistent. Accordingly, the availability of defined BCR/ABL RNAs may facilitate the validation of all phases of quantitative BCR/ABL analysis and may be extremely useful as a tool for monitoring assay performance. Ongoing analyses of these materials, along with the development of additional control materials, may solidify consensus around their application in routine laboratory testing and possible integration in worldwide efforts to standardize quantitative BCR/ABL testing.

Prognostic significance of nailfold capillary microscopy in patients with Raynaud's phenomenon and scleroderma-pattern abnormalities. A six-year follow-up study.

The aim of this study was to assess the prognostic significance of scleroderma capillary pattern (SD-pattern) in patients with Raynaud's phenomenon. Thirty patients with a capillaroscopy examination suggestive of scleroderma (megacapillaries and/or avascularity) but without clinical criteria of scleroderma (ARA criteria) were reevaluated 6 years after the initial clinical and capillaroscopy examinations. SD-pattern abnormalities were classified according to a semiquantitative method. Eight out of the 28 evaluated patients (28%) developed a scleroderma spectrum disorder (SDS). The presence of avascularity and/or a mean of more than two megacapillaries digit greatly enhanced the percentage of evolution toward SDS (70%/88% respectively). Most of the patients with few enlarged capillaries and no capillary rarefaction at entry had primary acrocyanosis (11/15). None of them developed SDS. The microangiopathy disappeared during the follow-up period in most of these patients (14/15). These results confirm the prognostic value of SD-pattern capillary abnormalities for SDS. Primary acrocyanosis, a benign clinical entity should be considered in presence of few megacapillaries and without capillary rarefaction.

Bioreporters and biosensors for arsenic detection. Biotechnological solutions for a world-wide pollution problem.

A wide variety of whole cell bioreporter and biosensor assays for arsenic detection has been developed over the past decade. The assays permit flexible detection instrumentation while maintaining excellent method of detection limits in the environmentally relevant range of 10-50 μg arsenite per L and below. New emerging trends focus on genetic rewiring of reporter cells and/or integration into microdevices for more optimal detection. A number of case studies have shown realistic field applicability of bioreporter assays.

Trophic resource partitioning and competition between the two sibling bat species Myotis myotis and Myotis blythii

1. Niche theory predicts that the stable coexistence of species within a guild should be associated, if resources are limited, with a mechanism of resource partitioning. Using extensive data on diets, the present study attempts: (i) to test the hypothesis that, in sympatry, the interspecific overlap between the trophic niches of the sibling bat species Myotis myotis and M. blythii-which coexist intimately in their roosts-is effectively lower than the two intraspecific overlaps; (ii) to assess the role played by interspecific competition in resource partitioning through the study of trophic niche displacement between several sympatric and allopatric populations. 2. Diets were determined by the analysis of faecal samples collected in the field from individual bats captured in various geographical areas. Trophic niche overlaps were calculated monthly for all possible intraspecific and interspecific pairs of individuals from sympatric populations. Niche breadth was estimated from: (i) every faecal sample; (ii) all the faecal samples collected per month in a given population (geographical area). 3. In every population, the bulk of the diets of M. myotis and M. blythii consisted of, respectively, terrestrial (e.g. carabid beetles) and grass-dwelling (mostly bush crickets) prey. All intraspecific trophic niche overlaps were significantly greater than the interspecific one, except in Switzerland in May when both species exploited mass concentrations of cockchafers, a non-limiting food source. This clearcut partitioning of resources may allow the stable, intimate coexistence observed under sympatric conditions. 4. Relative proportions of ground-and grass-dwelling prey, as well as niche breadths (either individual or population), did not differ significantly between sympatry and allopatry, showing that, under allopatric conditions, niche expansion does not take place. This suggests that active interspecific competition is not the underlying mechanism responsible for the niche partitioning which is currently observed between M. myotis and M. blythii.

Ionotropic receptors (IRs): chemosensory ionotropic glutamate receptors in Drosophila and beyond.

Ionotropic Receptors (IRs) are a recently characterized family of olfactory receptors in the fruit fly, Drosophila melanogaster. IRs are not related to insect Odorant Receptors (ORs), but rather have evolved from ionotropic glutamate receptors (iGluRs), a conserved family of synaptic ligand-gated ion channels. Here, we review the expression and function of IRs in Drosophila, highlighting similarities and differences with iGluRs. We also briefly describe the organization of the neuronal circuits in which IRs function, comparing and contrasting them with the sensory pathways expressing ORs. Finally, we summarize the bioinformatic identification and initial characterization of IRs in other species, which imply an evolutionarily conserved role for these receptors in chemosensation in insects and other protostomes.

Diagnostic accuracy of body mass index, body fat and waist in defining low aerobic fitness in adolescents

Objective: to assess the diagnostic accuracy of different anthropometric markers in defining low aerobic fitness among adolescents. Methods: cross-sectional study on 2,331 boys and 2,366 girls aged 10 - 18 years. Body mass index (BMI) was measured using standardized methods; body fat (BF) was assessed by bioelectrical impedance. Low aerobic fitness was assessed by the 20-meter shuttle run using the FITNESSGRAMR criteria. Waist was measured in a subsample of 1,933 boys and 1,897 girls. Overweight, obesity and excess fat were defined according to the International Obesity Task Force (IOTF) or FITNESSGRAMR criteria. Results: 38.5% of boys and 46.5% of girls were considered as unfit according to the FITNESSGRAMR criteria. In boys, the area under the ROC curve (AUC) and 95% confidence interval were 66.7 (64.1 - 69.3), 67.1 (64.5 - 69.6) and 64.6 (61.9 - 67.2) for BMI, BF and waist, respectively (P<0.02). In girls, the values were 68.3 (65.9 - 70.8), 63.8 (61.3 - 66.3) and 65.9 (63.4 - 68.4), respectively (P<0.001). In boys, the sensitivity and specificity to diagnose low fitness were 13% and 99% for obesity (IOTF); 38% and 86% for overweight + obesity (IOTF); 28% and 94% for obesity (FITNESSGRAMR) and 42% and 81% for excess fat (FITNESSGRAMR). For girls, the values were 9% and 99% for obesity (IOTF); 33% and 82% for overweight + obesity (IOTF); 22% and 94% for obesity (FITNESSGRAMR) and 26% and 90% for excess fat (FITNESSGRAMR). Conclusions: BMI, not body fat or waist, should be used to define low aerobic fitness. The IOTF BMI cut-points to define obesity have a very low screening capacity and should not be used.

Recurrent Macular Edema in Central Retinal Vein Occlusion Treated with Intravitreal Ranibizumab using a Modified Treat and Extend Regimen.

Background: The aim of this study was to evaluate the stability over time of the individually defined interval of intravitreal ranibizumab injection (IVR) for the treatment of recurrent macular edema (ME) in central retinal vein occlusion (CRVO). Patients and Methods: A case series of treatment naïve patients followed in the Jules Gonin Eye Hospital for macular edema due to central retinal vein occlusion is presented. Patients were treated monthly with IVR until complete absence of fluid on qualitative SD-OCT with a minimum of 5 monthly IVR. Thereafter, they were followed according to a modified treat and extend regimen (mTER). Results: Twelve eyes (12 patients) with ME due to CRVO were included. The mean follow-up period was 31.3 months. Analysis showed that best corrected visual acuity (BCVA), central macular thickness and qualitative spectral domain optical coherence tomography (SD-OCT) showed comparable results under monthly interval, after titration of an individualized interval and when performed in a series. 78 % of treating intervals were within ± 2 weeks of the first individually adjusted interval. The mean first defined interval was 4.3 weeks and the mean interval over time was 5.5 weeks (p = 0.003). There was a trend towards longer interval over time. Conclusion: The adjusted interval of retreatment of patients with ME due to CRVO showed a high stability with a trend toward longer duration over time. An mTER regimen seems to be valuable to follow patients with ME with good stabilization of VA.

A formin-nucleated actin aster concentrates cell wall hydrolases for cell fusion in fission yeast.

Cell-cell fusion is essential for fertilization. For fusion of walled cells, the cell wall must be degraded at a precise location but maintained in surrounding regions to protect against lysis. In fission yeast cells, the formin Fus1, which nucleates linear actin filaments, is essential for this process. In this paper, we show that this formin organizes a specific actin structure-the actin fusion focus. Structured illumination microscopy and live-cell imaging of Fus1, actin, and type V myosins revealed an aster of actin filaments whose barbed ends are focalized near the plasma membrane. Focalization requires Fus1 and type V myosins and happens asynchronously always in the M cell first. Type V myosins are essential for fusion and concentrate cell wall hydrolases, but not cell wall synthases, at the fusion focus. Thus, the fusion focus focalizes cell wall dissolution within a broader cell wall synthesis zone to shift from cell growth to cell fusion.

A modular tethering complex for endosomal recycling.

How proteins migrate through the interconnected organelles of the endolysosomal system is poorly understood. A piece of the puzzle has been added with the identification of a complex of tethering factors that functions in the recycling of proteins towards the cell surface.

Role of Chlamydia trachomatis and emerging Chlamydia-related bacteria in ectopic pregnancy in Vietnam.

In this case-control study, we investigated the seroprevalence and molecular evidence of Chlamydia trachomatis and Waddlia chondrophila in ectopic pregnancies (EP) and uneventful control pregnancies in 343 women from Vietnam. Whereas presence of C. trachomatis IgG was strongly associated with EP [adjusted odds ratio (aOR) 5·41, 95% confidence interval (CI) 2·58-11·32], its DNA remained undetected in all tubal lesions. We confirmed an independent association between antibodies against Waddlia and previous miscarriage (aOR 1·87, 95% CI 1·02-3·42). Further investigations are needed to understand the clinical significance of Waddlia's high seroprevalence (25·9% in control pregnancies) in this urban population.