Mismatches between breeding phenology and resource abundance of resident alpine ptarmigan negatively affect chick survival

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An overview of malaria transmission from the perspective of Amazon Anopheles vectors

In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.     

Intense photon emission induced by fracture of γ–irradiated Dy‐, Tm‐, Sm‐ and Mn‐doped CaSO4 single crystals

When an γ‐irradiated Dy‐, Tm‐, Sm‐ or Mn‐doped CaSO₄ crystal is impulsively deformed, two peaks appear in the ML intensity versus time curve, whereby the first ML peak is found in the deformation region and the second in the post‐deformation region of the crystals. In this study, intensities I_m1 and I_m2 corresponding to first and second ML peaks, respectively, increased linearly with an impact velocity v₀ of the piston used to deform the crystals, and times t_m1 and t_m2 corresponding to the first and second ML peaks, respectively, decreased with impact velocity. Total ML intensity initially increased with impact velocity and then reached a saturation value for higher values of impact velocity. ML intensity increased with increasing γ‐doses and size of crystals. Results showed that the electric field produced as a result of charging of newly‐created surfaces caused tunneling of electrons to the valence band of the hole‐trapping centres. The free holes generated moved in the valence band and their subsequent recombination with electron trapping centres released energy, thereby resulting in excitation of luminescent centres. Copyright © 2012 John Wiley & Sons, Ltd.     

Selected anthropometric variables and aerobic fitness as predictors of cardiovascular disease risk in children

The aim of this study was to assess the suitability of body mass index, waist circumference, waist-to-height ratio and aerobic fitness as predictors of cardiovascular risk factor clustering in children. A cross-sectional study was conducted with 290 school boys and girls from 6 to 10 years old, randomly selected. Blood was collected after a 12-hour fasting period. Blood pressure, waist circumference (WC), height and weight were evaluated according to international standards. Aerobic fitness (AF) was assessed by the 20-metre shuttle-run test. Clustering was considered when three of these factors were present: high systolic or diastolic blood pressure, high low-density lipoprotein (LDL) cholesterol, high triglycerides, high plasma glucose, high insulin concentrations and low high-density lipoprotein (HDL) cholesterol. A ROC curve identified the cut-off points of body mass index (BMI), WC, waist-to-height ratio (WHtR) and AF as predictors of risk factor clustering. BMI, WC and WHR resulted in significant areas under the ROC curves, which was not observed for AF. The anthropometric variables were good predictors of cardiovascular risk factor clustering in both sexes, whereas aerobic fitness should not be used to identify cardiovascular risk factor clustering in these children.     

Meta-analysis of Correlated Traits via Summary Statistics from GWASs with an Application in Hypertension

Genome-wide association studies (GWASs) have identified many genetic variants underlying complex traits. Many detected genetic loci harbor variants that associate with multiple—even distinct—traits. Most current analysis approaches focus on single traits, even though the final results from multiple traits are evaluated together. Such approaches miss the opportunity to systemically integrate the phenome-wide data available for genetic association analysis. In this study, we propose a general approach that can integrate association evidence from summary statistics of multiple traits, either correlated, independent, continuous, or binary traits, which might come from the same or different studies. We allow for trait heterogeneity effects. Population structure and cryptic relatedness can also be controlled. Our simulations suggest that the proposed method has improved statistical power over single-trait analysis in most of the cases we studied. We applied our method to the Continental Origins and Genetic Epidemiology Network (COGENT) African ancestry samples for three blood pressure traits and identified four loci (CHIC2, HOXA-EVX1, IGFBP1/IGFBP3, and CDH17; p < 5.0 × 10⁻⁸) associated with hypertension-related traits that were missed by a single-trait analysis in the original report. Six additional loci with suggestive association evidence (p < 5.0 × 10⁻⁷) were also observed, including CACNA1D and WNT3. Our study strongly suggests that analyzing multiple phenotypes can improve statistical power and that such analysis can be executed with the summary statistics from GWASs. Our method also provides a way to study a cross phenotype (CP) association by using summary statistics from GWASs of multiple phenotypes.     

Genetic Mapping in Escherichia coli K-12 by Radiation-Induced Crossing-Over

Conventional methods for chromosomal mapping in Escherichia coli are (i) interruption of matings to obtain minimum marker entry times, (ii) linkage analysis of recombinants, and (iii) cotransduction. Method (i) has a resolution of about 0.5 min (5 x 10(4) nucleotides) and is not useful for distances less than about 1 min; methods (ii) and (iii) are capable of better resolution but are generally not very reproducible and no general theory is available for translating crossing-over and cotransduction frequencies into physical chromosomal distances. We found that when merozygotes are irradiated (X rays or ultraviolet light) soon after marker transfer, high linkage values (0.8 to 1.0) between nearby marker pairs decrease with radiation dose to 0.5. Our results are quantitatively consistent with the idea that radiations induce crossing-over lesions proportional to dose, and the number of such lesions between two markers is proportional to the physical separation of the markers in the range that can also be measured by interruption of mating (0.5 to 4.0 min). Additivity relations among markers are also satisfied. We used this technique to measure the distances (0.1 to 1.0 min) between several pairs of closely linked markers.     

Celecoxib after the onset of reperfusion reduces apoptosis in the amygdala

Reperfused myocardial infarction induces an inflammatory response that is responsible for local and systemic alterations. Among these, apoptosis observed in the amygdala following myocardial infarction has been pointed out as a consequence of such an inflammatory process. We hypothesized that inhibition of the inducible inflammatory enzyme Cox-2 during the reperfusion period may attenuate the apoptotic process in the amygdala. Anaesthetized rats were subjected to left anterior descending coronary artery occlusion for 40 min, followed by reperfusion. The Cox-2 antagonist Celecoxib (3 mg/kg i.p.) was administered 10 min after the onset of the reperfusion period. After 72 h of reperfusion, infarct size was determined and the lateral and medial amygdala were dissected from the brain. Infarct size was similar between untreated and Celecoxib-treated animals (40–45% of the area at risk). Cox-2 expression was significantly reduced in both parts of the amygdala in the Celecoxib group. Apoptosis regression was observed in the amygdala of the Celecoxib group as shown by decreased number of TUNEL positive cells and by decreased of caspase-3 activation. Bax/Bcl-2 ratio was not significantly altered by Celecoxib while Akt activation was increased in the lateral amygdala but not in the medial amygdala. This data indicates that inhibition of Cox-2 by Celecoxib is associated with regression of apoptosis in the amygdala following myocardial infarction.     

Fermentation product butane 2,3-diol induces Ca2+ transients in E. coli through activation of lanthanum-sensitive Ca2+ channels

The results here are the first demonstration of a physiological agonist opening Ca2+ channels in bacteria. Bacteria in the gut ferment glucose and other substrates, producing alcohols, diols, ketones and acids, that play a key role in lactose intolerance, through the activation of Ca2+ and other ion channels in host cells and neighbouring bacteria. Here we show butane 2,3-diol (5-200mM; half maximum 25mM) activates Ca2+ transients in E. coli, monitored by aequorin. Ca2+-transient magnitude depended on external Ca2+ (0.1-10mM). meso-Butane 2,3-diol was approximately twice as potent as 2R,3R (-) and 2S,3S (+) butane 2,3-diol. There were no detectable effects on cytosolic free Ca2+ of butane 1,3-diol, butane 1,4-diol and ethylene glycol. The glycerol fermentation product propane 1,3-diol only induced significant Ca2+ transients in 10mM external Ca2. Ca2+ butane 2,3-diol Ca2+ transients were due to activation of Ca2+ influx, followed by activation of Ca2+ efflux. The effect of butane 2,3-diol was abolished by La3+, and markedly reduced as a function of growth phase. These results were consistent with butane 2,3-diol activating a novel La3+-sensitive Ca2+ channel. They have important implications for the role of butane 2,3-diol and Ca2+ in bacterial-host cell signalling.