Probiotic Potential of Autochthonous Bacteria Isolated from the Gastrointestinal Tract of Four Freshwater Teleosts

In this study, a total of 121 bacterial strains were isolated from the gastrointestinal tract of four teleostean species, namely striped snakehead (Channa striatus), striped dwarf catfish (Mystus vittatus), orangefin labeo (Labeo calbasu) and mrigal carp (Cirrhinus mrigala), among which 8 isolates showed promising antibacterial activity against four potential fish pathogens, Aeromonas hydrophila, Aeromonas salmonicida, Aeromonas sobria and Pseudomonas fluorescens and were non-hemolytic. The isolates were further screened in response to fish bile tolerance and extracellular digestive enzyme activity. Two bacterial strains MVF1 and MVH7 showed highest tolerance and extracellular enzymes activities, and selected for further studies. Antagonistic activity of these two isolates was further confirmed by in vitro growth inhibition assay against four selected fish pathogens in liquid medium. Finally, these two bacterial strains MVF1 and MVH7 were selected as potential probiotic candidates and thus identification by partial 16S rRNA gene sequence analysis. The bacterial isolates MVF1 and MVH7 were identified as two strains of Bacillus sp.     

Disentangling complex fine‐scale ecological patterns by path modelling using GLMM and GIS

Question: How can statistical modelling tools (GLMM) and GIS be used as an aid in understanding complex ecological patterns? This general question was approached by using bryophyte demography data as an example. More specifically, we asked what is the contribution of terrain shape to explaining the performance and fate of plant individuals, controlling for all other known relationships? Location: Norway. Methods: Information on demography was obtained for 140 populations of the perennial clonal bryophyte Hylocomium splendens in Norway spruce forests during an 11‐year period (1992‐2002). Performance (size and branching pattern) was recorded for mature segments and fate was recorded for growing points. Positions of each of the more than 30 000 recorded bryophyte ramets were coupled with (micro‐) topographic characteristics (slope and convexity) derived from fine‐scale digital elevation models in a GIS framework. Carefully planned sequences of generalised linear mixed models (GLMM) were performed to test predictions from a conceptual path model. Results: We demonstrate strong dependence of size on branching, fate and on vertical position in the bryophyte carpet, and an effect of vertical position on branching pattern. Micro‐topography contributed to explaining plant performance by four different mechanisms: (1) a direct effect of slope on the segment's vertical position in the carpet; (2‐3) direct effects of both slope and convexity on fates of individuals via controls on risk of burial; and (4) an indirect effect of convexity on branching pattern via a direct effect on size. No indication of a direct effect of terrain on branching was found. Conclusions: Our study exemplifies the usefulness of GLMM for disentangling complex ecological relationships. Specifically, we recognise micro‐topography as a potentially important factor for plant demography in general and for performance and fate of individuals in particular.     

Long-term stability and effective population size in North Sea and Baltic Sea cod (Gadus morhua)

DNA from archived otoliths was used to explore the temporal stability of the genetic composition of two cod populations, the Moray Firth (North Sea) sampled in 1965 and 2002, and the Bornholm Basin (Baltic Sea) sampled in 1928 and 1997. We found no significant changes in the allele frequencies for the Moray Firth population, while subtle but significant genetic changes over time were detected for the Bornholm Basin population. Estimates of the effective population size ( N _e ) generally exceeded 500 for both populations when employing a number of varieties of the temporal genetic method. However, confidence intervals were very wide and N _e 's most likely range in the thousands. There was no apparent loss of genetic variability and no evidence of a genetic bottleneck for either of the populations. Calculations of the expected levels of genetic variability under different scenarios of N _e showed that the number of alleles commonly reported at microsatellite loci in Atlantic cod is best explained by N _e 's exceeding thousand. Recent fishery-induced bottlenecks can, however, not be ruled out as an explanation for the apparent discrepancy between high levels of variability and recently reported estimates of N _e  << 1000. From life history traits and estimates of survival rates in the wild, we evaluate the compatibility of the species' biology and extremely low N _e / N ratios. Our data suggest that very small N _e 's are not likely to be of general concern for cod populations and, accordingly, most populations do not face any severe threat of losing evolutionary potential due to genetic drift.     

Environmental forcing as a main determinant of bloom dynamics of the Chrysochromulina algae

In this paper, we demonstrate that the seasonal dynamics in the abiotic factors, without including seasonal changes in the biological relationships, can appropriately account for the seasonal dynamics of Chrysochromulina spp. This is through the analysis of data on the population dynamics of Chrysochromulina spp. off southern Norway that is evaluated in relation to environmental factors and season by the analyses of 12 year monthly time-series. Chrysochromulina spp. abundance, nutrient concentrations, hydrographical properties, as well as current and wind data were analysed on a monthly scale by means of autoregressive moving average models, principal component analyses (PCA), and linear and nonlinear regression models. Seasonal development of the Chrysochromulina assemblage was well predicted from regression models forced with two PCA components representing seasonal variation in nutrient and chlorophyll a levels and ratios, inflow of North Seawater to the Skagerrak and northeasterly wind along the Norwegian coast. Assuming these to be general results, we might hypothesis that marine algal communities are governed by seasonally varying abiotic factors to a large extent.     

Microtubule-associated nuclear envelope proteins in interphase and mitosis

The LINC (linker of nucleoskeleton and cytoskeleton) complex forms a transcisternal bridge across the NE (nuclear envelope) that connects the cytoskeleton with the nuclear interior. This enables some proteins of the NE to communicate with the centrosome and the microtubule cytoskeleton. The position of the centrosome relative to the NE is of vital importance for many cell functions, such as cell migration and division, and centrosomal dislocation is a frequent phenotype in laminopathic disorders. Also in mitosis, a small group of transmembrane NE proteins associate with microtubules when they concentrate in a specific membrane domain associated with the mitotic spindle. The present review discusses structural and functional aspects of microtubule association with NE proteins and how this association may be maintained over the cell cycle.     

An exploratory trial of cyclooxygenase type 2 inhibitor in HIV-1 infection: downregulated immune activation and improved T cell-dependent vaccine responses

Chronic HIV infection is characterized by chronic immune activation and dysfunctional T cells with elevated intracellular cyclic AMP (cAMP), which inhibits the T cell activation capability. cAMP may be induced by prostaglandin E(2) following lipopolysaccharide (LPS)-induced upregulation of cyclooxygenase type 2 (COX-2) in monocytes due to the elevated LPS levels in patients with chronic HIV infection. This hypothesis was tested using celecoxib, a COX-2 inhibitor, for 12 weeks in HIV-infected patients without antiretroviral treatment in a prospective, open, randomized exploratory trial. Thirty-one patients were randomized in the trial; 27 completed the study, including 13 patients on celecoxib. Celecoxib reduced chronic immune activation in terms of CD38 density on CD8(+) T cells (-24%; P = 0.04), IgA levels (P = 0.04), and a combined score for inflammatory markers (P < 0.05). Celecoxib further reduced the inhibitory surface receptor programmed death 1 (PD-1) on CD8(+) T cells (P = 0.01), including PD-1 on the HIV Gag-specific subset (P = 0.02), enhanced the number of CD3(+) CD4(+) CD25(+) CD127(lo/-) Treg or activated cells (P = 0.02), and improved humoral memory recall responses to a T cell-dependent vaccine (P = 0.04). HIV RNA (P = 0.06) and D dimers (P = 0.07) tended to increase in the controls, whereas interleukin-6 (IL-6) possibly decreased in the treatment arm (P = 0.10). In conclusion, celecoxib downmodulated the immune activation related to clinical progression of chronic HIV infection and improved T cell-dependent functions in vivo.     

An institutional analysis of EPD programs and a global PCR registry

Purpose

A Product Category Rules (PCR) document specifies the quantification method and communication format of environmental impacts of a product category. To ensure neutrality and credibility of quantitative environmental information, the development of PCR documents is defined in ISO 14025. Hence, the rules are preconditions for comparative considerations and modular application of information entities and Environmental Product Declarations (EPD). However, with the growing number of EPD programs, the producers, purchasers, and consumers feel increasingly alienated in relation to the validity and legitimacy of the environmental information presented by EPDs. This results in a need for enhanced transparency of PCR development and EPD program compatibility. This article offers navigational assistance in this respect.

Methods

To identify harmonization potential, we compare PCR development regarding two aspects: quantitatively by mapping existing PCR and EPD documents, and qualitatively by comparing existing institutional structures with normative guidance. Information was gathered through an internet search and through direct correspondence with program operators.

Results and discussion

We identified 27 programs, 556 PCR documents, and 3614 EPD declarations (May 2013). There were significant differences in activity level between programs and sectors. Furthermore, the institutional structures differ widely from each other and from normative guidance on PCR development.

Conclusions

This first global PCR register guides practitioners in the search for PCR documents. The analysis of program institutional structures for PCR development and EPD verification indicates the involvement of different stakeholders on Type III environmental declarations. Regarding PCR compatibility and newly released guidance documents from the European Commission and the PCR Guidance Development Initiative, we recommend that operators (1) settle on a common (sector) categorization system, (2) implement a Stakeholder Identification Worksheet, (3) consider the mandatory involvement of consumer and environmental interests in the PCR review panel, (4) require PCR reviewers to declare potential conflicts of interest, and (5) consider installing mandatory third party verification of declarations for any external use.     

Outlier SNP markers reveal fine‐scale genetic structuring across European hake populations (Merluccius merluccius)

Shallow population structure is generally reported for most marine fish and explained as a consequence of high dispersal, connectivity and large population size. Targeted gene analyses and more recently genome‐wide studies have challenged such view, suggesting that adaptive divergence might occur even when neutral markers provide genetic homogeneity across populations. Here, 381 SNPs located in transcribed regions were used to assess large‐ and fine‐scale population structure in the European hake (Merluccius merluccius), a widely distributed demersal species of high priority for the European fishery. Analysis of 850 individuals from 19 locations across the entire distribution range showed evidence for several outlier loci, with significantly higher resolving power. While 299 putatively neutral SNPs confirmed the genetic break between basins (F_CT = 0.016) and weak differentiation within basins, outlier loci revealed a dramatic divergence between Atlantic and Mediterranean populations (F_CT range 0.275–0.705) and fine‐scale significant population structure. Outlier loci separated North Sea and Northern Portugal populations from all other Atlantic samples and revealed a strong differentiation among Western, Central and Eastern Mediterranean geographical samples. Significant correlation of allele frequencies at outlier loci with seawater surface temperature and salinity supported the hypothesis that populations might be adapted to local conditions. Such evidence highlights the importance of integrating information from neutral and adaptive evolutionary patterns towards a better assessment of genetic diversity. Accordingly, the generated outlier SNP data could be used for tackling illegal practices in hake fishing and commercialization as well as to develop explicit spatial models for defining management units and stock boundaries.