Diets of Invasive Channel Catfish are Subsidized by Invasive Riparian Trees

Russian olive (Elaeagnus angustifolia) is an invasive, fruit- bearing riparian tree that dominates riparian zones of the San Juan River in the southwestern United States. Previous research in this river suggests olive fruit is common in diets of invasive channel catfish (Ictalurus punctatus), but its energetic importance is unknown (i.e. critical for catfish fitness vs. incidental consumption). We assessed Russian olive consumption in channel catfish diets bimonthly for 1 year, hypothesizing that olive consumption would be greatest during periods of high olive availability and low benthic aquatic invertebrate availability. We found that catfish consumed olive fruit throughout the year and that olive comprised up to 44% of total stomach contents by mass, with peaks in spring and fall. Regression models revealed the presence and mass of olive fruit in catfish stomachs were positively associated with catfish total length, with a significant interaction between water temperature and river discharge. Catfish were more likely to consume olive fruit during higher flows, regardless of temperature and at low discharge with higher temperature. Contrary to our hypothesis, neither olive nor benthic invertebrate availability were associated with olive presence in channel catfish diets. Nutrition analysis indicated that olive alone was a low-quality diet item but has the potential to provide a reliable energy source. We used seasonal data to estimate the energetic contribution of olive fruit to catfish populations using a bioen-ergetic model, which estimated that olive fruit accounted for 35.6% of energy (Joules) consumed by catfish populations and satisfied 38% of their metabolic demand. Our results suggest that Russian olive fruit is a significant subsidy to channel catfish in the San Juan River. However, more research is needed to determine the indirect effects of this interaction on native fishes and ecosystem function

A Diet Containing Soybean Oil Heated for Three Hours Increases Adipose Tissue Weight but Decreases Body Weight in C57BL/6 J Mice

Background: Our previous work showed that dietary oxidized linoleic acid given, as a single fatty acid, to LDL receptor knockout mice decreased weight gain as compared to control mice. Other studies have also reported that animals fed oils heated for 24 h or greater showed reduced weight gain. These observations, while important, have limited significance since fried foods in the typical human diet do not contain the extreme levels of oxidized lipids used in these studies. The main goal of this study was to investigate the effects of a diet containing soybean oil heated for 3 h on weight gain and fat pad mass in mice. Additionally, because PPARγ and UCP-1 mediate adipocyte differentiation and thermogenesis, respectively, the effect of this diet on these proteins was also examined. Findings: Four to six week old male C57BL/6 J mice were randomly divided into three groups and given either a low fat diet with heated soybean oil (HSO) or unheated soybean oil (USO) or pair fed for 16 weeks. Weight and food intake were monitored and fat pads were harvested upon the study’s termination. Mice consuming the HSO diet had significantly increased fat pad mass but gained less weight as compared to mice in the USO group despite a similar caloric intake and similar levels of PPARγ and UCP1. Conclusion: This is the first study to show that a diet containing soybean oil heated for a short time increases fat mass despite a decreased weight gain in C57BL/6 J mice. The subsequent metabolic consequences of this increased fat mass merits further investigation

Towards detecting super-GeV dark matter via annihilation to neutrinos

The next generation of neutrino telescopes will feature unprecedented sensitivities in the detection of neutrinos. Here we study the capabilities of a large-scale neutrino telescope, like the fully-operating KM3NeT experiment in the near future, for detecting dark matter annihilation signals from the Galactic Centre. We consider both ORCA and ARCA detectors, covering dark matter masses from a few GeV to 100 TeV. We obtain the sensitivities with a maximum-likelihood analysis method and present them as upper limits in the thermally averaged annihilation cross-section into Standard Model fermions. Our projections show that the sensitivity of such a neutrino telescope can reach the thermal relic line for $m_{\chi}\gtrsim 1\,{\rm TeV}$ and for $m_\chi \simeq$ few GeV, for the NFW dark matter density profile. This demonstrates that ORCA- and ARCA-like detectors will be able to perform competitive dark matter searches in a wide range of masses. The implications of these striking projections are investigated in a few selected dark matter particle models, where we show that neutrino telescopes are able to probe new parameter space

Lead zirconate titanate on base metal foils: An approach for embedded high-K passive components

An approach for embedding high-K dielectric thin films into polymer packages has been developed. Pb{sub 0.85}La{sub 0.15}(Zr{sub 0.52}Ti{sub 0.48}){sub 0.96}O{sub 3} thin films were prepared by chemical solution deposition on 50 {micro}m thick Ni-coated Cu foils. Sputter deposited Ni top electrodes completed the all base-metal capacitor stack. After high temperature N{sub 2} crystallization anneals, the PLZT composition showed reduction resistance while the base-metal foils remained flexible. Capacitance density and Loss tangent values range between 300 and 400 nF/cm{sup 2} and 0.01 and 0.02 from 1 to 1,000 kHz respectively. These properties represent a 2 to 3 order of magnitude improvement over available embedded capacitor technologies for polymeric packages

Classification of Protein Kinases on the Basis of Both Kinase and Non-Kinase Regions

BACKGROUND: Protein phosphorylation is a generic way to regulate signal transduction pathways in all kingdoms of life. In many organisms, it is achieved by the large family of Ser/Thr/Tyr protein kinases which are traditionally classified into groups and subfamilies on the basis of the amino acid sequence of their catalytic domains. Many protein kinases are multi-domain in nature but the diversity of the accessory domains and their organization are usually not taken into account while classifying kinases into groups or subfamilies. METHODOLOGY: Here, we present an approach which considers amino acid sequences of complete gene products, in order to suggest refinements in sets of pre-classified sequences. The strategy is based on alignment-free similarity scores and iterative Area Under the Curve (AUC) computation. Similarity scores are computed by detecting common patterns between two sequences and scoring them using a substitution matrix, with a consistent normalization scheme. This allows us to handle full-length sequences, and implicitly takes into account domain diversity and domain shuffling. We quantitatively validate our approach on a subset of 212 human protein kinases. We then employ it on the complete repertoire of human protein kinases and suggest few qualitative refinements in the subfamily assignment stored in the KinG database, which is based on catalytic domains only. Based on our new measure, we delineate 37 cases of potential hybrid kinases: sequences for which classical classification based entirely on catalytic domains is inconsistent with the full-length similarity scores computed here, which implicitly consider multi-domain nature and regions outside the catalytic kinase domain. We also provide some examples of hybrid kinases of the protozoan parasite Entamoeba histolytica. CONCLUSIONS: The implicit consideration of multi-domain architectures is a valuable inclusion to complement other classification schemes. The proposed algorithm may also be employed to classify other families of enzymes with multi-domain architecture

Conserved phosphoryl transfer mechanisms within kinase families and the role of the C8 proton of ATP in the activation of phosphoryl transfer

<p>Abstract</p> <p>Background</p> <p>The kinome is made up of a large number of functionally diverse enzymes, with the classification indicating very little about the extent of the conserved kinetic mechanisms associated with phosphoryl transfer. It has been demonstrated that C8-H of ATP plays a critical role in the activity of a range of kinase and synthetase enzymes.</p> <p>Results</p> <p>A number of conserved mechanisms within the prescribed kinase fold families have been identified directly utilizing the C8-H of ATP in the initiation of phosphoryl transfer. These mechanisms are based on structurally conserved amino acid residues that are within hydrogen bonding distance of a co-crystallized nucleotide. On the basis of these conserved mechanisms, the role of the nucleotide C8-H in initiating the formation of a pentavalent intermediate between the γ-phosphate of the ATP and the substrate nucleophile is defined. All reactions can be clustered into two mechanisms by which the C8-H is induced to be labile via the coordination of a backbone carbonyl to C6-NH₂of the adenyl moiety, namely a "push" mechanism, and a "pull" mechanism, based on the protonation of N7. Associated with the "push" mechanism and "pull" mechanisms are a series of proton transfer cascades, initiated from C8-H, via the tri-phosphate backbone, culminating in the formation of the pentavalent transition state between the γ-phosphate of the ATP and the substrate nucleophile.</p> <p>Conclusions</p> <p>The "push" mechanism and a "pull" mechanism are responsible for inducing the C8-H of adenyl moiety to become more labile. These mechanisms and the associated proton transfer cascades achieve the proton transfer via different family-specific conserved sets of amino acids. Each of these mechanisms would allow for the regulation of the rate of formation of the pentavalent intermediate between the ATP and the substrate nucleophile. Phosphoryl transfer within kinases is therefore a specific event mediated and regulated via the coordination of the adenyl moiety of ATP and the C8-H of the adenyl moiety.</p

Neutrophil cannibalism – a back up when the macrophage clearance system is insufficient

BACKGROUND: During a lipopolysaccharide-induced lung inflammation, a massive accumulation of neutrophils occurs, which is normally cleared by macrophage phagocytosis following neutrophil apoptosis. However, in cases of extensive apoptosis the normal clearance system may fail, resulting in extensive neutrophil secondary necrosis. The aim of this study was to explore the hypothesis that neutrophils, in areas of the lung with extensive cellular infiltration, contribute to clearance by phagocytosing apoptotic cells and/or cell debris derived from secondary necrosis. METHODS: Intranasal lipopolysaccharide administration was used to induce lung inflammation in mice. The animals were sacrificed at seven time points following administration, bronchoalveolar lavage was performed and tissue samples obtained. Electron microscopy and histochemistry was used to assess neutrophil phagocytosis. RESULTS: Electron microscopic studies revealed that phagocytosing neutrophils was common, at 24 h after LPS administration almost 50% of the total number of neutrophils contained phagosomes, and the engulfed material was mainly derived from other neutrophils. Histochemistry on bronchoalvolar lavage cells further showed phagocytosing neutrophils to be frequently occurring. CONCLUSION: Neutrophils are previously known to phagocytose invading pathogens and harmful particles. However, this study demonstrates that neutrophils are also able to engulf apoptotic neutrophils or cell debris resulting from secondary necrosis of neutrophils. Neutrophils may thereby contribute to clearance and resolution of inflammation, thus acting as a back up system in situations when the macrophage clearance system is insufficient and/or overwhelmed