Intraspecific structure within three caviar-producing sturgeons (Acipenser gueldenstaedtii, A. stellatus, and Huso huso) based on mitochondrial DNA analysis

A survey of three mitochondrial DNA regions (control region, NADH5, cytochrome b) and comprehensive sequencing of the control region (631–646 bps) was conducted to examine whether subspecies and geographic populations within three species of Eurasian sturgeons, Acipenser gueldenstaedtii, A. stellatus, and Huso huso, are genetically distinct. Neither subspecies nor populations exhibited diagnostic distinction or reciprocal monophyly in any gene region examined. For the control region, molecular variance analyses (amova ) indicate that most of the variance is because of differences among haplotypes within subspecies (H. huso: 99.6%; A. stellatus: 95.0%; A. gueldenstaedtii: 81.0%) and populations (A. gueldenstaedtii: 76.1%). Significant pairwise F‐values were found for all pairwise comparisons except for Sea of Azov and Caspian Sea A. gueldenstaedtii and Caspian Sea and Black Sea A. stellatus and H. huso. Only weak genetic differentiation is apparent between select subspecies and populations, reflective of biogeographic and management history. High genetic diversity within A. gueldenstaedtii suggests the possibility of additional population structure. Future research and management projects should consider these results.     

5-Adamantan thiadiazole-based thiazolidinones as antimicrobial agents. Design,synthesis, molecular docking and evaluation

In continuation of our efforts to develop new compounds with antimicrobial properties we describe design, synthesis, molecular docking study and evaluation of antimicrobial activity of seventeen novel 2-{[5-(adamantan-1-yl)-1,3,4-thiadiazol-2-yl]-imino}-5-arylidene-1,3-thiazolidin-4-ones. All compounds showed antibacterial activity against eight Gram positive and Gram negative bacterial species. Twelve out of seventeen compounds were more potent than streptomycin and all compounds exhibited higher potency than ampicillin. Compounds were also tested against three resistant bacterial strains: MRSA, P. aeruginosa and E. coli. The best antibacterial potential against ATCC and resistant strains was observed for compound 8 (2-{[5-(adamantan-1-yl)-1,3,4-thiadiazol-2-yl]-imino}-5-(4-nitrobenzylidene)-1,3thiazolidin-4-one). The most sensitive bacterium appeared to be S. typhimirium, followed by B. cereus while L. monocitogenes and M. flavus were the most resistant. Compounds were also tested for their antifungal activity against eight fungal species. All compounds exhibited antifungal activity better than the reference drugs bifonazole and ketokonazole (3-115 times). It was found that compound 8 appeared again to be the most potent. Molecular docking studies on E. coli MurB, MurA as well as C. albicans CYP 51 and dihydrofolate reductase were used for the prediction of mechanism of antibacterial and antifungal activities confirming the experimental results.     

Molecular phylogeny of Acipenserinae and black caviar species identification.

The first phylogenetic tree for the Acipenserinae based on the combined sequence data for fragments of three mitochondrial genes, the cytochrome b (650 bp) gene, 12S (150 bp) and 16S (350 bp) rRNA genes is described. Three general conclusions are inferred from the tree: 1) Scaphirhynchus albus is the sister-species of all Acipenser and Huso species; 2) The two species of Huso are embedded within the genus Acipenser. Therefore, the genus Huso is not a separate taxonomic unit; and 3) There are three main clades within Acipenser: (a) A. sturio-A. oxyrinchus, (b) A. schrenckii-A. transmontanus, and (c) all Ponto-Caspian species plus A. dabryanus and A. brevirostrum. A method based on the identification of diagnostic nucleotide positions in the cytochrome b gene was developed and used to survey the United States and European caviar markets. The survey of 95 lots of caviar obtained at the American market suggests that in December 1995 and April 1996 17% of the designations made by caviar suppliers were mislabeled with respect to species identification. In December of 1996, this figure jumped to 32%. The main commercially harvested species (Huso huso, A. stellatus, A. gueldenstaedtii, A. schrenckii, and H. dauricus), as well as A. nudiventris, A. persicus, and A. baerii are threatened due to the increased demand of the international caviar market.     

Trophic relationships of nonnative brown trout, Salmo trutta, and native Bonneville cutthroat trout, Oncorhynchus clarkii utah, in a northern Utah, USA river

Nonnative trout invasions have caused the widespread decline of cutthroat trout populations in western North America. In contrast to other nonnative salmonids, the role of nonnative brown trout in native cutthroat trout decline is poorly understood. Specifically, the level of ecological similarity that occurs between these species and the importance of other trophic mechanisms (e.g., predation) in their interactions are key uncertainties. We evaluated the trophic relationships of brown trout and cutthroat trout in a northern Utah river using a combination of diet and stable isotope analyses. We compared the dietary habits of these two species using multiple and complementary measures. Based on both stomach contents and δ¹³C signatures, we found that these species consumed a similar and opportunistic diet (i.e., they were nonselective in their foraging patterns). However, at most sizes, brown trout ingested larger prey—including fishes—and occupied a higher relative trophic position (i.e., δ¹⁵N) than cutthroat trout. Overall, these results demonstrate a high degree of dietary similarity and therefore strengthen earlier conclusions regarding interspecific competition between these two species. Our study, when considered alongside the work of others, suggests there is potential for predatory interactions between these species (i.e., brown trout preying on small cutthroat trout). We believe that future research on brown trout–cutthroat trout interactions should consider predatory effects in greater detail.

Synthesis and pharmacochemical study of novel polyfunctional molecules combining anti-inflammatory, antioxidant, and hypocholesterolemic properties

We have designed and synthesized a series of novel molecules having a residue of a classical NSAID and an antioxidant moiety, both attached through amide bonds to a known nootropic structure, an L-proline, trans-4-hydroxy-L-proline or DL-pipecolinic acid residue. The compounds were found to retain anti-inflammatory and antioxidant activities, to acquire hypocholesterolemic action, and to possess a greatly reduced gastrointestinal toxicity. The novel molecules could find useful applications, among others, in slowing the progression or delaying the onset of neurodegenerative diseases.     

Assessing conditions influencing the longitudinal distribution of exotic brown trout (<Emphasis Type="Italic">Salmo trutta</Emphasis>) in a mountain stream: a spatially-explicit modeling approach

Trout species often segregate along elevational gradients, yet the mechanisms driving this pattern are not fully understood. On the Logan River, Utah, USA, exotic brown trout (Salmo trutta) dominate at low elevations but are near-absent from high elevations with native Bonneville cutthroat trout (Onchorhynchus clarkii utah). We used a spatially-explicit Bayesian modeling approach to evaluate how abiotic conditions (describing mechanisms related to temperature and physical habitat) as well as propagule pressure explained the distribution of brown trout in this system. Many covariates strongly explained redd abundance based on model performance and coefficient strength, including average annual temperature, average summer temperature, gravel availability, distance from a concentrated stocking area, and anchor ice-impeded distance from a concentrated stocking area. In contrast, covariates that exhibited low performance in models and/or a weak relationship to redd abundance included reach-average water depth, stocking intensity to the reach, average winter temperature, and number of days with anchor ice. Even if climate change creates more suitable summer temperature conditions for brown trout at high elevations, our findings suggest their success may be limited by other conditions. The potential role of anchor ice in limiting movement upstream is compelling considering evidence suggesting anchor ice prevalence on the Logan River has decreased significantly over the last several decades, likely in response to climatic changes. Further experimental and field research is needed to explore the role of anchor ice, spawning gravel availability, and locations of historical stocking in structuring brown trout distributions on the Logan River and elsewhere.     

Nitric oxide releasing derivatives of tolfenamic acid with anti-inflammatory activity and safe gastrointestinal profile

Tolfenamic acid esters with nitrooxyalcohols are synthesized. They are anti-inflammatory agents reducing carrageenan rat paw edema, with low gastrointestinal and general toxicity. In vitro, they are nitric oxide donors, inhibitors of lipoxygenase and cyclooxygenases. A two to three carbon chain between carboxylic and nitric ester groups seems optimal for activity.     

An approach for hip joint center calculation for use in seated postures

In seated postures, such as those in office or automotive seats, locating the hip joint center (HJC) using three markers on the pelvis has been difficult if not impossible. A two-target approach by Bell et al. (J. Biomech. 23 (1990) 617) has been used, however, this method was shown to have inaccuracies when compared to the three-target method developed by Seidel et al. (J. Biomech. 28 (1995) 995). A new two-target method that is specific to the seated environment, has better accuracy than the Bell et al. approach, and is based on the Seidel et al. approach was developed and tested on 13 seated subjects. This new method used three targets and an initial reference file to estimate the HJC location. Once the HJC was located, assumptions were made that the magnitudes between the HJC and the respective anterior superior iliac spine, and the HJC and the respective lateral epicondyle remained constant. The primary concern when evaluating this new method was the affect of seated posture movement, in particular leg splay and spinal flexion on the assumptions. The results obtained with the new approach were compared to Seidel et al. and provided HJC locations with average differences of 3.8, 1.2 and 2.8mm for spinal flexion in the anterior/posterior, medial/lateral and superior/inferior directions, respectively, and 2.3, 1.0 and 1.4mm for knee splay. The proposed method provided better HJC estimation than the Bell et al. approach particularly in the superior/inferior dimensions.     

Comprehensive modeling of microRNA targets predicts functional non-conserved and non-canonical sites

mirSVR is a new machine learning method for ranking microRNA target sites by a down-regulation score. The algorithm trains a regression model on sequence and contextual features extracted from miRanda-predicted target sites. In a large-scale evaluation, miRanda-mirSVR is competitive with other target prediction methods in identifying target genes and predicting the extent of their downregulation at the mRNA or protein levels. Importantly, the method identifies a significant number of experimentally determined non-canonical and non-conserved sites.