Attentional Bias towards Positive Emotion Predicts Stress Resilience

There is extensive evidence for an association between an attentional bias towards emotionally negative stimuli and vulnerability to stress-related psychopathology. Less is known about whether selective attention towards emotionally positive stimuli relates to mental health and stress resilience. The current study used a modified Dot Probe task to investigate if individual differences in attentional biases towards either happy or angry emotional stimuli, or an interaction between these biases, are related to self-reported trait stress resilience. In a nonclinical sample (N = 43), we indexed attentional biases as individual differences in reaction time for stimuli preceded by either happy or angry (compared to neutral) face stimuli. Participants with greater attentional bias towards happy faces (but not angry faces) reported higher trait resilience. However, an attentional bias towards angry stimuli moderated this effect: The attentional bias towards happy faces was only predictive for resilience in those individuals who also endorsed an attentional bias towards angry stimuli. An attentional bias towards positive emotional stimuli may thus be a protective factor contributing to stress resilience, specifically in those individuals who also endorse an attentional bias towards negative emotional stimuli. Our findings therefore suggest a novel target for prevention and treatment interventions addressing stress-related psychopathology.     

Bio-seismic and sequence stratigraphy of the Neogene of the Northwest Damietta Concession,Nile Delta,Egypt

The stratigraphic framework of the Neogene sequence drilled by two offshore wells located in the north-eastern shore of the Nile Delta (the wells Sekhmet-1 and Sekhmet-2) has been established. The lithostratigraphic units with their sequences, from older to younger, are as follows: the Sidi Salim Formation (including Sr1 SB, Sr2 SB, Sr2 MFS, Sr3 SB and Sr3 MFS), a sequence representing the uppermost part of the Sidi Salim and most of the lower part of the Qawasim Formations (including Tor 1.1 SB, Tor 1.2 SB, Tor 1.3 SB, Tor 1.4 SB and ?Tor 2 SB), a sequence representing the uppermost part of Qawasim and the lower part of the Abu Madi Formations (including ?Me1 SB, Me2 SB and Me2 MFS), the Kafr El Sheikh Formation (including alternatively Za 1 and 2 SB and MFS and Ge 1 SB and MFS), the El Wastani Formation (including Ge 2 SB and MFS) and a Quaternary sequence represented by the topmost part of El Wastani and Mit Ghamr/Bilqas Formation (including alternatively ?Cala 1 and 2 SB and MFS and ?Io 2 SB). The lower part of the Qawasim in well Sekhmet-2 includes two LST: Tor 2 LST and Me 1 LST.     

The Impact of Short-Term,Intensive Antifolate Treatment (with Pyrimethamine and Sulfadoxine) and Antibiotics Followed by Long-Term,Secondary Antifolate Prophylaxis on the Rate of Toxoplasmic Retinochoroiditis Recurrence

PurposeTo assess the impact of intensive antifolate treatment, followed by secondary antifolate prophylaxis (A-SP) on the recurrence rate of toxoplasmic retinochoroiditis (TRC). To investigate whether there are any other factors potentially predisposing for recurrence.ResultsWhen secondary antifolate prophylaxis (A-SP) was instituted immediately after the treatment for TRC, the probability of 3-year recurrence–free survival after the first course of A-SP was 90.9%. A recurrence was most likely approximately 3.5 years after the first treatment. A univariate Cox regression model demonstrated that a risk for recurrence was 2.82 times higher (p = 0.02) in patients with retinal scars. In the multivariate analysis, the risk for recurrence was 2.41 higher (p = 0.06). In patients with haemorrhagic lesions the risk for recurrence was lower, aRR = 0.17 (approaching borderline statistical significance p = 0.08).ConclusionsWith the institution of A-SP of immediately after the intensive treatment for TRC, i.e. when a reactivation was most likely, there was no recurrence during A-SP. Following A-SP the recurrence rates were low and recurrence-free periods tended to be longer. The treatment regimen employed had a beneficial effect on the recurrence interval as it reduced and delayed the highest probability of recurrence.     

IFNγ Response to Mycobacterium tuberculosis,Risk of Infection and Disease in Household Contacts of Tuberculosis Patients in Colombia

Objectives

Household contacts (HHCs) of pulmonary tuberculosis patients are at high risk of Mycobacterium tuberculosis infection and early disease development. Identification of individuals at risk of tuberculosis disease is a desirable goal for tuberculosis control. Interferon-gamma release assays (IGRAs) using specific M. tuberculosis antigens provide an alternative to tuberculin skin testing (TST) for infection detection. Additionally, the levels of IFNγ produced in response to these antigens may have prognostic value. We estimated the prevalence of M. tuberculosis infection by IGRA and TST in HHCs and their source population (SP), and assessed whether IFNγ levels in HHCs correlate with tuberculosis development.

Methods

A cohort of 2060 HHCs was followed for 2–3 years after exposure to a tuberculosis case. Besides TST, IFNγ responses to mycobacterial antigens: CFP, CFP-10, HspX and Ag85A were assessed in 7-days whole blood cultures and compared to 766 individuals from the SP in Medellín, Colombia. Isoniazid prophylaxis was not offered to child contacts because Colombian tuberculosis regulations consider it only in children under 5 years, TST positive without BCG vaccination.

Results

Using TST 65.9% of HHCs and 42.7% subjects from the SP were positive (OR 2.60, p<0.0001). IFNγ response to CFP-10, a biomarker of M. tuberculosis infection, tested positive in 66.3% HHCs and 24.3% from the SP (OR = 6.07, p<0.0001). Tuberculosis incidence rate was 7.0/1000 person years. Children <5 years accounted for 21.6% of incident cases. No significant difference was found between positive and negative IFNγ responders to CFP-10 (HR 1.82 95% CI 0.79–4.20 p = 0.16). However, a significant trend for tuberculosis development amongst high HHC IFNγ producers was observed (trend Log rank p = 0.007).

Discussion

CFP-10-induced IFNγ production is useful to establish tuberculosis infection prevalence amongst HHC and identify those at highest risk of disease. The high tuberculosis incidence amongst children supports administration of chemoprohylaxis to child contacts regardless of BCG vaccination.     

Direct determination of the enantiomeric purity of (R)- and (S)-2-hydroxy-4-phenylbutyric acid

The determination of enantiomeric purity of (R)- and (S)-2-hydroxy-4-phenylbutyric acid by chiral HPLC is described. Good resolution has been obtained on covalently bonded L-hydroxyproline saturated with Cu(II) ions. The method makes possible the determination of enantiomeric purity in media containing growing cells. © 1994 Wiley-Liss, Inc.     

Responses of native and migrant desert residents to arid heat

Four groups of Sonoran Desert residents were compared in three studies of heat tolerance. In the first two studies the task involved walking in arid heat at a moderate rate (5 km/hour) for two hours per day over a period of seven consecutive days. The first study compared seven Yaqui Indians with ten Mestizos, all lifelong residents of the same neighborhood in Hermosillo, Sonora. The groups showed no significant differences in physiological responses. The second study compared five Papago Indian students with five White students from Tucson, Arizona. The Papago showed significantly lower sweat rates and significantly lower rectal temperatures. None of the groups showed sequential changes which could be called acclimatization. The lower sweat rate of the Papago is partially the result of their smaller size, but their lower rectal temperatures may represent a more effective heat dissipating mechanism. The third study compared naturally acclimatized Yaquis and Mestizos in hot, humid conditions established by other investigators. These well acclimatized subjects responded in a manner intermediate between the unacclimatized and artificially acclimatized Caucasians reported in the literature. Thus desert acclimatization does not confer maximal acclimatization to humid heat.     

Field tests of cis-regulatory variation at the prairie vole avpr1a locus: association with V1aR abundance but not sexual or social fidelity

The neuropeptide vasopressin and its receptor V1aR are broadly implicated in social behavior and play a central role in several key aspects of male mating tactics in voles. In the prairie vole, a microsatellite in the cis-regulatory region of the gene encoding V1aR (avpr1a) provides a potential genetic basis for individual variation in neural phenotype and behavior; recent studies found that allele length predicts V1aR expression and male social attachment in the laboratory. Here, we explore the relationship between avpr1a microsatellite length, V1aR neural phenotype, and field measures of monogamy and fitness in male prairie voles. We found significant effects of allele length on V1aR expression in structures integral to pairbond formation. These effects did not, however, translate to differences in mating tactics or reproductive success. Together, these data suggest that, while length polymorphism in the avpr1a microsatellite influences neuronal phenotype, this variation does not contribute significantly to male reproductive success and field behavior. We propose that previously reported behavioral effects may be mediated primarily by sequence variation at this locus, for which allele length is an imperfect proxy. By combining genetic, neuronal and ecological approaches, these data provide novel insights into the contribution of genotype to natural diversity in brain and behavior.     

Sperm head morphology is associated with sperm swimming speed: A comparative study of songbirds using electron microscopy

Sperm exhibit extraordinary levels of morphological diversification across the animal kingdom. In songbirds, sperm have a helically shaped head incorporating a distinct acrosomal membrane or “helical keel,” the form and extent of which varies across species. The functional significance of this helical shape, however, remains unknown. Using scanning electron microscopy, we quantified inter‐ and intraspecific variation in sperm head morphology across 36 songbird species (Passeriformes: Passerida). Using phylogenetic comparative methods, we investigated the relationship between sperm head morphology and both sperm swimming speed and the frequency of extra‐pair young (EPY). We found that species whose sperm had a relatively more pronounced helical form (i.e., long acrosome, short nucleus, wide helical membrane, and a more pronounced waveform along the sperm head “core”) had faster‐swimming sperm. We found no evidence of a relationship between interspecific variation in sperm head morphology and EPY, although we did find that among‐ and within‐male variation in sperm head traits were negatively correlated with EPY. Applying principles of fluid mechanics, we discuss how the helical form of the sperm head may influence swimming speed, and suggest that further studies considering aspects of sperm morphology beyond sperm length are needed to improve our understanding of sperm structure‐function relationships.     

Enriched partial correlations in genome-wide gene expression profiles of hybrids (A. thaliana): a systems biological approach towards the molecular basis of heterosis

Heterosis is a well-known phenomenon but the underlying molecular mechanisms are not yet established. To contribute to the understanding of heterosis at the molecular level, we analyzed genome-wide gene expression profile data of Arabidopsis thaliana in a systems biological approach. We used partial correlations to estimate the global interaction structure of regulatory networks. Our hypothesis states that heterosis comes with an increased number of partial correlations which we interpret as increased numbers of regulatory interactions leading to enlarged adaptability of the hybrids. This hypothesis is true for mid-parent heterosis for our dataset of gene expression in two homozygous parental lines and their reciprocal crosses. For the case of best-parent heterosis just one hybrid is significant regarding our hypothesis based on a resampling analysis. Summarizing, both metabolome and gene expression level of our illustrative dataset support our proposal of a systems biological approach towards a molecular basis of heterosis.     

Oligovalent Fab Display on M13 Phage Improved by Directed Evolution

Efficient display of antibody on filamentous phage M13 coat is crucial for successful biopanning selections. We applied a directed evolution strategy to improve the oligovalent display of a poorly behaving Fab fragment fused to phage gene-3 for minor coat protein (g3p). The Fab displaying clones were enriched from a randomly mutated Fab gene library with polyclonal anti-mouse IgG antibodies. Contribution of each mutation to the improved phenotype of one selected mutant was studied. It was found out that two point mutations had significant contribution to the display efficiency of Fab clones superinfected with hyperphage. The most dramatic effect was connected to a start codon mutation, from AUG to GUG, of the PelB signal sequence preceding the heavy chain. The clone carrying this mutation, FabM_GUG, displayed Fab 19-fold better and yielded twofold higher phage titers than the original Fab.