TRIM-NHL protein, NHL-2, modulates cell fate choices in the C. elegans germ line

Many tissues contain multipotent stem cells that are critical for maintaining tissue function. In Caenorhabditis elegans, germline stem cells allow gamete production to continue in adulthood. In the gonad, GLP-1/Notch signaling from the distal tip cell niche to neighboring germ cells activates a complex regulatory network to maintain a stem cell population. GLP-1/Notch signaling positively regulates production of LST-1 and SYGL-1 proteins that, in turn, interact with a set of PUF/FBF proteins to positively regulate the stem cell fate. We previously described sog (suppressor of glp-1 loss of function) and teg (tumorous enhancer of glp-1 gain of function) genes that limit the stem cell fate and/or promote the meiotic fate. Here, we show that sog-10 is allelic to nhl-2. NHL-2 is a member of the conserved TRIM-NHL protein family whose members can bind RNA and ubiquitinate protein substrates. We show that NHL-2 acts, at least in part, by inhibiting the expression of PUF-3 and PUF-11 translational repressor proteins that promote the stem cell fate. Two other negative regulators of stem cell fate, CGH-1 (conserved germline helicase) and ALG-5 (Argonaute protein), may work with NHL-2 to modulate the stem cell population. In addition, NHL-2 activity promotes the male germ cell fate in XX animals

Statistics of the main purse seine fleets fishing in the Indian Ocean (1981-2010).

This document presents a summary of the statistics of French, Spanish, Italian, Seychelles and EU related NEI purse seine fleets fishing in the Indian Ocean since 1981: effort, catch by species and fishing type (log and free swimming schools), catch per unit of effort, sampling and mean weights for the main species. Since 2002, data from the European fleet (France and Spain) are collected within the framework of the EU “Data Collection Regulation” (DCR, Reg. 1543/2000 and 1639/2001), followed in 2008 by the “Community framework for the collection, management and use of data in the fisheries sector and support for scientific advice regarding the Common Fisheries Policy” (DCF, Reg 199/2008 and 665/2008). Data from other fleets are collected by SFA (Seychelles Fishing Authority). Data processing (species composition and size distribution) is done collectively for the whole fishery

Statefinder diagnostic and w−w′w-w^{\prime} analysis for interacting polytropic gas dark energy model

The interacting polytropic gas dark energy model is investigated from the viewpoint of statefinder diagnostic tool and $w-w^{\prime}$ analysis. The dependency of the statefinder parameters on the parameter of the model as well as the interaction parameter between dark matter and dark energy is calculated. We show that different values of the parameters of model and different values of interaction parameter result different evolutionary trajectories in $s-r$ and $w-w^{\prime}$ planes. The polytropic gas model of dark energy mimics the standard $\Lambda$CDM model at the early time.Comment: 17 pages, 4 figures, ijtp accepte

Stable Isotope Biogeochemistry of Seabird Guano Fertilization: Results from Growth Chamber Studies with Maize (Zea Mays)

Stable isotope analysis is being utilized with increasing regularity to examine a wide range of issues (diet, habitat use, migration) in ecology, geology, archaeology, and related disciplines. A crucial component to these studies is a thorough understanding of the range and causes of baseline isotopic variation, which is relatively poorly understood for nitrogen (δ(15)N). Animal excrement is known to impact plant δ(15)N values, but the effects of seabird guano have not been systematically studied from an agricultural or horticultural standpoint.This paper presents isotopic (δ(13)C and δ(15)N) and vital data for maize (Zea mays) fertilized with Peruvian seabird guano under controlled conditions. The level of (15)N enrichment in fertilized plants is very large, with δ(15)N values ranging between 25.5 and 44.7‰ depending on the tissue and amount of fertilizer applied; comparatively, control plant δ(15)N values ranged between -0.3 and 5.7‰. Intraplant and temporal variability in δ(15)N values were large, particularly for the guano-fertilized plants, which can be attributed to changes in the availability of guano-derived N over time, and the reliance of stored vs. absorbed N. Plant δ(13)C values were not significantly impacted by guano fertilization. High concentrations of seabird guano inhibited maize germination and maize growth. Moreover, high levels of seabird guano greatly impacted the N metabolism of the plants, resulting in significantly higher tissue N content, particularly in the stalk.The results presented in this study demonstrate the very large impact of seabird guano on maize δ(15)N values. The use of seabird guano as a fertilizer can thus be traced using stable isotope analysis in food chemistry applications (certification of organic inputs). Furthermore, the fertilization of maize with seabird guano creates an isotopic signature very similar to a high-trophic level marine resource, which must be considered when interpreting isotopic data from archaeological material