From Demographic Strategies to Mathematical Models: Trends in Population Dynamics Studies of Aquatic Oligochaeta

The existence of a negative relationship between fine sediment infiltration during the incubation period and salmonid embryo survival has often been discussed in the literature. However, few studies have specifically addressed this relationship in the field. We conducted a field experiment to examine the relationship between survival of Atlantic salmon (Salmo salar) embryos contained in incubation baskets and the patterns of fine sediment infiltration into the baskets during the incubation period. The results indicate that survival to pre-eyed (STPE), eyed (STE) and hatched (STH) stages of development were all negatively correlated with the percentage of fine sediment entering the baskets. STPE and STE were most strongly affected by silts and clays (<0.063 mm) although this size class represented only a small fraction of the grain size distribution inside the incubation baskets (0.03–0.41%). STH was most strongly correlated with the infiltration of medium sand (0.25–0.50 mm) material. On average, 66% of the implanted embryos survived to the pre-eyed stage of development compared to 63% for the eyed and 48% for the hatched stages of development.     

Interactions of molybdocene dichloride with histidine- and methionine-containing peptides

The reaction behavior of the antitumor active metallocene dihalide Cp₂MoCl₂ (Cp = η⁵-cyclopentadienyl) towards AcHis, AcHis(1-Me), AcHis(3-Me), His-Gly, AcHis-Gly-His, AcMet, Gly-Met-Gly and cyclo-Met-Met has been studied in solution at 2.5 ? pD ? 7.4 by using ¹H NMR spectroscopy. The histidine-containing substrates were found to bind the Cp₂Mo²⁺ unit through the terminal carboxylate group or through the N1 nitrogen of the imidazole ring, depending on the pD value. At physiological pH, coordination takes place exclusively at the imidazole ring with the percentage of Cp₂Mo²⁺-His adducts in 1:1 mixtures being about 70%. By contrast, the thioether group in the side chain of methionine has a very low affinity for the Cp₂Mo²⁺ group. Monodentate S-coordination could not be detected. For AcMet, binding through the carboxylate group was observed as the only coordination mode, while in the case of Gly-Met-Gly Mo-S interaction occurs in combination with carboxylate coordination leading to a S,O-macrochelate in low yield. Coordination to methionine peptides only takes place at pD ? 6, while at physiological pH interactions with the weak donor sites are not observed due to predominating dimerization of [Cp₂Mo(H₂O)(OH)]⁺ to [Cp₂Mo(μ-OH)₂MoCp₂]²⁺. At c(Cl⁻) = 100 mM competitive Cl⁻ coordination reduces the amount of carboxylate and S,O-coordination significantly, while imidazole coordination is not affected.     

Effects of gap size and associated changes in light and soil moisture on the understorey vegetation of a Hungarian beech forest

In European beech forests windstorms often create canopy gaps and change the level of incident light, soil moisture and nutrient availability on the forest floor. Understanding the interrelations between gap size and environmental change, and the effects these have on regeneration processes is a prerequisite for developing techniques of nature-based forestry. The aims of this study were to investigate the effects of gap size on the resulting spatial distributions of key abiotic environmental variables (light and soil moisture) in gaps, and to study how light and soil moisture affect the abundance and distribution of herb layer species. To do this we used eight artificially created gaps – three large (diameter: 35–40 m) and five small (diameter: 10–15 m) – in a mesotrophic submontane beech forest. Data on species’ importance and substrate types were collected in systematically distributed 1 m×1 m quadrats before gap creation and on four occasions during the next two growing seasons. Hemispherical photographs were taken and analysed to estimate relative light intensity. Soil moisture was measured by frequency domain and capacitance probes. It was found that gap size had a profound effect on the environmental variables measured. While relative light intensity values in small gaps did not reach those in large gaps, soil moisture levels did reach similar maximum values in gap centres regardless of gap size. Richness, composition and total cover of herbaceous vegetation were different in small versus large gaps. Much of this difference was attributed to the presence of specific relative light intensities and also to the increased amount of available soil moisture in gaps. Species were differently affected by the combined effects of light and soil moisture, as well as by differences in available substrates. All this resulted in species-specific distribution patterns within gaps.     

Oncolytic Vesicular Stomatitis Virus in an Immunocompetent Model of MUC1-Positive or MUC1-Null Pancreatic Ductal Adenocarcinoma

Vesicular stomatitis virus (VSV) is a promising oncolytic agent against various malignancies. Here, for the first time, we tested VSV in vitro and in vivo in a clinically relevant, immunocompetent mouse model of pancreatic ductal adenocarcinoma (PDA). Our system allows the study of virotherapy against PDA in the context of overexpression (80% of PDA patients) or no expression of human mucin 1 (MUC1), a major marker for poor prognosis in patients. In vitro, we tested three VSV recombinants, wild-type VSV, VSV-green fluorescent protein (VSV-GFP), and a safe oncolytic VSV-ΔM51-GFP, against five mouse PDA cell lines that either expressed human MUC1 or were MUC1 null. All viruses demonstrated significant oncolytic abilities independent of MUC1 expression, although VSV-ΔM51-GFP was somewhat less effective in two PDA cell lines. In vivo administration of VSV-ΔM51-GFP resulted in significant reduction of tumor growth for tested mouse PDA xenografts (+MUC1 or MUC1 null), and antitumor efficacy was further improved when the virus was combined with the chemotherapeutic drug gemcitabine. The antitumor effect was transient in all tested groups. The developed system can be used to study therapies involving various oncolytic viruses and chemotherapeutics, with the goal of inducing tumor-specific immunity while preventing premature virus clearance.     

Meta-analysis of Gene-Level Associations for Rare Variants Based on Single-Variant Statistics

Meta-analysis of genome-wide association studies (GWASs) has led to the discoveries of many common variants associated with complex human diseases. There is a growing recognition that identifying “causal” rare variants also requires large-scale meta-analysis. The fact that association tests with rare variants are performed at the gene level rather than at the variant level poses unprecedented challenges in the meta-analysis. First, different studies may adopt different gene-level tests, so the results are not compatible. Second, gene-level tests require multivariate statistics (i.e., components of the test statistic and their covariance matrix), which are difficult to obtain. To overcome these challenges, we propose to perform gene-level tests for rare variants by combining the results of single-variant analysis (i.e., p values of association tests and effect estimates) from participating studies. This simple strategy is possible because of an insight that multivariate statistics can be recovered from single-variant statistics, together with the correlation matrix of the single-variant test statistics, which can be estimated from one of the participating studies or from a publicly available database. We show both theoretically and numerically that the proposed meta-analysis approach provides accurate control of the type I error and is as powerful as joint analysis of individual participant data. This approach accommodates any disease phenotype and any study design and produces all commonly used gene-level tests. An application to the GWAS summary results of the Genetic Investigation of ANthropometric Traits (GIANT) consortium reveals rare and low-frequency variants associated with human height. The relevant software is freely available.     

How the religious context affects the relationship between religiosity and attitudes towards immigration

This article approaches two shortcomings in previous research on religiosity and prejudice: (1) the lack of cross-country comparative studies; and (2) a failure to consider any moderating effects of religious contexts. We examine whether the relationship between religiosity and anti-immigration attitudes varies depending on religious contexts in Europe, and we find two things. First, strongly religious people are on average less likely to oppose immigration than non-religious people. Second, different religious contexts moderate the religiosity–attitude relationship in that religious people in Protestant countries and in countries with a low proportion of majority adherents are more tolerant than religious people in Catholic countries and in religiously homogenous countries. State policies also matter in that religious people are more negative where the government favours the majority religion. This calls into question the taken-for-granted understanding of religiosity and out-group attitudes found in the USA.