Effects of Acidification in multiple stable Isotope Analyses

The effect of in situ acidification on the stable isotope ratios of carbon and nitrogen was tested in several invertebrates living in an eelgrass system. Dried and ground samples of individuals were weighted in silver cups and treated in situ with 10% HCl. Control samples were measured without acidification. This treatment to remove inorganic carbon significantly decreased the δ13C values. The δ15N values were not affected by this method of acidification. In contrast to the acid washing method the tested procedure seems suitable to remove inorganic carbon in small invertebrate species

Influence of molecular properties of SSBR and BR types on composite performance

Modern passenger car tire tread compounds usually consist of a polymer blend of Solution Styrene-Butadiene Rubber (SSBR) and Butadiene Rubber (BR) in combination with a silica/silane system. To further enhance the compatibility between the nonpolar polymer and the polar silica, different functional groups can be introduced at the end or along the polymer chains. The influence of such a polymer functionalization of SSBR and BR on the processing behavior as well as on mechanical and dynamic properties was investigated for silica-filled tire tread model compounds. Silica-filled functionalized SPRINTAN™ SLR 4602 was blended with non-functionalized SPRINTAN™ 363H and functionalized SPRINTAN™ 884 L in three ratios: 90/10, 80/20 and 70/30. The two BRs differ in five analytical properties: molecular weight, vinyl content, cis-content, glass transition temperature (Tg) and functionalization. All five properties influence the composite properties in a different way. The functionalization is the dominating influencing parameter in this study. The presence of the functionalization improves the rubber-filler-interaction. This leads to better dynamic and mechanical properties of the model tread compound: The reinforcement index is increased and the tan δ at 60 °C, as lab predictor for the tire rolling resistance, is reduced while the tan δ at 0 °C, as lab predictor for wet grip, is similar to the non-functionalized BR. Furthermore, the Tg of the whole blend compound dominates the dynamic-mechanical behavior, as expected. In the case of BR, the functionalization has the dominating influence on the tan δ, the effect of Tg plays a minor role. These new insights support the development of new functionalized polymers to improve the overall tire performance

Within-season temporal variation in bat counts.

<p>Relative abundance and approximate 95% confidence intervals during December-March for (A) <i>M. lucifugus</i>, (B) <i>P. subflavus</i>, (C) <i>M. sodalis</i>, and (D) <i>M. septentrionalis</i>. Relative abundance was set equal to 1.0 at the maximum expected value.</p

Improved Analysis of Long-Term Monitoring Data Demonstrates Marked Regional Declines of Bat Populations in the Eastern United States

<div><p>Bats are diverse and ecologically important, but are also subject to a suite of severe threats. Evidence for localized bat mortality from these threats is well-documented in some cases, but long-term changes in regional populations of bats remain poorly understood. Bat hibernation surveys provide an opportunity to improve understanding, but analysis is complicated by bats' cryptic nature, non-conformity of count data to assumptions of traditional statistical methods, and observation heterogeneities such as variation in survey timing. We used generalized additive mixed models (GAMMs) to account for these complicating factors and to evaluate long-term, regional population trajectories of bats. We focused on four hibernating bat species – little brown myotis (<i>Myotis lucifugus</i>), tri-colored bat (<i>Perimyotis subflavus</i>), Indiana myotis (<i>M. sodalis</i>), and northern myotis (<i>M. septentrionalis</i>) – in a four-state region of the eastern United States during 1999–2011.</p><p>Our results, from counts of nearly 1.2 million bats, suggest that cumulative declines in regional relative abundance by 2011 from peak levels were 71% (with 95% confidence interval of ±11%) in <i>M. lucifugus</i>, 34% (±38%) in <i>P. subflavus</i>, 30% (±26%) in <i>M. sodalis</i>, and 31% (±18%) in <i>M. septentrionalis</i>. The <i>M. lucifugus</i> population fluctuated until 2004 before persistently declining, and the populations of the other three species declined persistently throughout the study period. Population trajectories suggest declines likely resulted from the combined effect of multiple threats, and indicate a need for enhanced conservation efforts. They provide strong support for a change in the IUCN Red List conservation status in <i>M. lucifugus</i> from Least Concern to Endangered within the study area, and are suggestive of a need to change the conservation status of the other species. Our modeling approach provided estimates of uncertainty, accommodated non-linearities, and controlled for observation heterogeneities, and thus has wide applicability for evaluating population trajectories in other wildlife species.</p></div

Timing of hibernation surveys across years.

<p>Box plots showing date of hibernacula surveys during 1999–2011.</p

Long-term population trajectories.

<p>Expected relative abundance and approximate 95% confidence intervals during 1999–2011 for (A) <i>M. lucifugus</i>, (B) <i>P. subflavus</i>, (C) <i>M. sodalis</i>, and (D) <i>M. septentrionalis</i>. Relative abundance was set equal to 1.0 at the maximum expected value. Two trajectories are shown for each bat species: the trajectory with abundance estimates corrected for survey date of bat counts (in blue), and the uncorrected trajectory (red).</p

Model selection.

<p>Shown are information criteria for fit of models including the fixed and random effects of (A) <i>M. lucifugus</i>, (B) <i>P. subflavus</i>, (C) <i>M. sodalis</i>, and (D) <i>M. septentrionalis</i>. Fixed effects are <i>Day</i>, smoothed <i>Day</i>, <i>Year</i>, and smoothed <i>Year</i>, and the random effects are <i>Route</i> and <i>Route</i> nested in <i>Location</i>. Best models were selected on the basis of Akaike's Information Criterion (AIC). DF are the degrees of freedom, Δ<i>_i</i> is the difference in AIC between the top-ranked and listed model, and <i>w_i</i> is the Akaike weight, the weight of evidence for each model in the set given the data (where 1.00 represents the highest likelihood of the model relative to other models). The number of models examined varied for each species because some random effects were not applicable for some species, due to the particular survey routes used.</p

Deficient EBV-specific B- and T-cell response in patients with chronic fatigue syndrome.

Epstein-Barr virus (EBV) has long been discussed as a possible cause or trigger of Chronic Fatigue Syndrome (CFS). In a subset of patients the disease starts with infectious mononucleosis and both enhanced and diminished EBV-specific antibody titers have been reported. In this study, we comprehensively analyzed the EBV-specific memory B- and T-cell response in patients with CFS. While we observed no difference in viral capsid antigen (VCA)-IgG antibodies, EBV nuclear antigen (EBNA)-IgG titers were low or absent in 10% of CFS patients. Remarkably, when analyzing the EBV-specific memory B-cell reservoir in vitro a diminished or absent number of EBNA-1- and VCA-antibody secreting cells was found in up to 76% of patients. Moreover, the ex vivo EBV-induced secretion of TNF-α and IFN-γ was significantly lower in patients. Multicolor flow cytometry revealed that the frequencies of EBNA-1-specific triple TNF-α/IFN-γ/IL-2 producing CD4(+) and CD8(+) T-cell subsets were significantly diminished whereas no difference could be detected for HCMV-specific T-cell responses. When comparing EBV load in blood immune cells, we found more frequently EBER-DNA but not BZLF-1 RNA in CFS patients compared to healthy controls suggesting more frequent latent replication. Taken together, our findings give evidence for a deficient EBV-specific B- and T-cell memory response in CFS patients and suggest an impaired ability to control early steps of EBV reactivation. In addition the diminished EBV response might be suitable to develop diagnostic marker in CFS

CFS patients show reduced EBV-specific memory T-cell response.

<p>(A) Comparison of cytokine producing CD4⁺ (upper panels) and CD8⁺ T cells (lower panels) of CFS patients and healthy controls after 10 days of stimulation with EBNA-1 (left panel, Control n = 17, CFS n = 23). Boolean gating strategy was applied to analyze IFN-γ/TNF-α/IL-2 triple, IFN-γ/TNF-α double, and IFN-γ and TNF-α single cytokine producing T cells after intracellular staining of isolated PBMCs incubated with Brefeldin A for 16 h. Stimulation with CMV pp65 (right panel, Control n = 7, CFS n = 5) is shown for IFN-γ/TNF-α/IL-2 triple, and IFN-γ single cytokine producing T cells. (B) Frequencies of PD-1 expression were analyzed for IFN-γ/TNF-α double producing CD4⁺ and CD8⁺ T cells after 10 days of stimulation with EBNA-1 or pp65 (n = 8). Statistical analysis was performed using the two-tailed Mann-Whitney-U test with ** p<0.01.</p