Influence of GABA and GABA-producing Lactobacillus brevis DPC 6108 on the development of diabetes in a streptozotocin rat model

peer-reviewedThe aim of this study was to investigate if dietary administration of γ-aminobutyric acid (GABA)-producing Lactobacillus brevis DPC 6108 and pure GABA exert protective effects against the development of diabetes in streptozotocin (STZ)-induced diabetic Sprague Dawley rats. In a first experiment, healthy rats were divided in 3 groups (n=10/group) receiving placebo, 2.6 mg/kg body weight (bw) pure GABA or L. brevis DPC 6108 (~109microorganisms). In a second experiment, rats (n=15/group) were randomised to five groups and four of these received an injection of STZ to induce type 1 diabetes. Diabetic and non-diabetic controls received placebo [4% (w/v) yeast extract in dH2O], while the other three diabetic groups received one of the following dietary supplements: 2.6 mg/kg bw GABA (low GABA), 200 mg/kg bw GABA (high GABA) or ~109 L. brevis DPC 6108. L. brevis DPC 6108 supplementation was associated with increased serum insulin levels (P0.05), compared with non-diabetic controls while all other diabetic groups displayed reduced diversity (P<0.05). L. brevis DPC 6108 attenuated hyperglycaemia induced by diabetes but additional studies are needed to understand the mechanisms involved in this reduction.The authors and their work were supported by the APC Microbiome Institute. The APC Microbiome Institute is funded by Science Foundation Ireland (SFI). This publication has emanated from research supported by a research grant from Science Foundation Ireland (SFI) under Grant Number SFI/12/RC/2273

Distinct amino acid compositional requirements for formation and maintenance of the [PSI+] prion in yeast

Multiple yeast prions have been identified that result from the structural conversion of proteins into a self-propagating amyloid form. Amyloid-based prion activity in yeast requires a series of discrete steps. First, the prion protein must form an amyloid nucleus that can recruit and structurally convert additional soluble proteins. Subsequently, maintenance of the prion during cell division requires fragmentation of these aggregates to create new heritable propagons. For the Saccharomyces cerevisiae prion protein Sup35, these different activities are encoded by different regions of the Sup35 prion domain. An N-terminal glutamine/asparagine-rich nucleation domain is required for nucleation and fiber growth, while an adjacent oligopeptide repeat domain is largely dispensable for prion nucleation and fiber growth but is required for chaperone-dependent prion maintenance. Although prion activity of glutamine/asparagine-rich proteins is predominantly determined by amino acid composition, the nucleation and oligopeptide repeat domains of Sup35 have distinct compositional requirements. Here, we quantitatively define these compositional requirements in vivo. We show that aromatic residues strongly promote both prion formation and chaperone-dependent prion maintenance. In contrast, nonaromatic hydrophobic residues strongly promote prion formation but inhibit prion propagation. These results provide insight into why some aggregation-prone proteins are unable to propagate as prions

Explaining lecture attendance behavior via structural equation modeling: Self-Determination Theory and the Theory of Planned Behavior

Some research suggests that university lecture attendance positively correlates with academic performance. Although there are several motivational pathways which may explain attendance, few studies have examined the psychosocial factors leading to student attendance intentions and behavior. Consequently, we evaluated via structural equation modeling (SEM) two prominent motivational theories to help explain lecture attendance: Self-Determination Theory (SDT) and The Theory of Planned Behavior (TPB). Undergraduates (N = 288) from two universities completed pre-semester motivation measurements and post-semester estimates of attendance. Student grades were also examined. SDT was not found to be an accurate model of attendance intentions or behavior. By contrast, TPB was found to be an adequate model to help explain attendance intentions and behavior. Lecture attendance did not significantly correlate with grades. If educators and students are committed to increasing lecture attendance rates, our findings suggest that the enhancement of perceived behavioral control, as well as optimistic intentions, may yield the greatest benefits with respect to students meeting their lecture attendance expectations

Improved determination of hadron matrix elements using the variational method

The extraction of hadron form factors in lattice QCD using the standard two- and three-point correlator functions has its limitations. One of the most commonly studied sources of systematic error is excited state contamination, which occurs when correlators are contaminated with results from higher energy excitations. We apply the variational method to calculate the axial vector current gA and compare the results to the more commonly used summation and two-exponential fit methods. The results demonstrate that the variational approach offers a more efficient and robust method for the determination of nucleon matrix elements.Comment: 7 pages, 6 figures, talk presented at Lattice 2015, PoS (LATTICE2015

Vegetation studies on Vandenberg Air Force Base, California

Vandenburg Air Force Base, located in coastal central California with an area of 98,400 ac, contains resources of considerable biological significance. Available information on the vegetation and flora of Vandenburg is summarized and new data collected in this project are presented. A bibliography of 621 references dealing with vegetation and related topics related to Vanderburg was compiled from computer and manual literature searches and a review of past studies of the base. A preliminary floristic list of 642 taxa representing 311 genera and 80 families was compiled from past studies and plants identified in the vegetation sampling conducted in this project. Fifty-two special interest plant species are known to occur or were suggested to occur. Vegetation was sampled using permanent plots and transects in all major plant communities including chaparral, Bishop pine forest, tanbark oak forest, annual grassland, oak woodland, coastal sage scrub, purple sage scrub, coastal dune scrub, coastal dunes, box elder riparian woodland, will riparian woodland, freshwater marsh, salt marsh, and seasonal wetlands. Comparison of the new vegetation data to the compostie San Diego State University data does not indicate major changes in most communities since the original study. Recommendations are made for additional studies needed to maintain and extend the environmental data base and for management actions to improve resource protection

Pilot’s Evaluation of the Usefulness of Full Mission IFR Simulator Flights for General Aviation Pilot Training

Professional pilots, including flight instructors, who had participated in multiple session line-oriented flight training (LOFT) Instrument Flight Rules (IFR) simulator flights differing in task difficulty evaluated the value of such flights for the training of general aviation pilots. These flights, which employed a relatively low cost simulator (Frasca 141), were judged to be quite useful for instrument student flight training, for instrument rated pilots with moderate instrument experience, and for experienced pilots. The aspects of flight that were seen as receiving the greatest benefit from the flight scenarios were practicing responses to problem situations, attitude instrument flying, practicing instrument approaches under varying weather conditions, and navigation and communications for student pilots. In contrast, the simulator was not seen as useful for Visual Flight Rules (VFR) recurrent training

Strategies Employed by Community-Based Service Providers to Address HIV-Associated Neurocognitive Challenges: A Qualitative Study

Background: HIV-associated neurocognitive disorders and other causes of neurocognitive challenges experienced by people living with HIV (PLWH) persist as public health concerns in developed countries. Consequently, PLWH who experience neurocognitive challenges increasingly require social support and mental health services from community-based providers in the HIV sector. Methods: Thirty-three providers from 22 AIDS service organizations across Ontario, Canada, were interviewed to determine the strategies they used to support PLWH experiencing neurocognitive difficulties. Thematic analysis was conducted to determine key themes from the interview data. Results: Three types of strategies were identified: (a) intrapersonal, (b) interpersonal, and (c) organizational. Intrapersonal strategies involved learning and staying informed about causes of neurocognitive challenges. Interpersonal strategies included providing practical assistance, information, counseling, and/or referrals to PLWH. Organizational strategies included creating dedicated support groups for PLWH experiencing neurocognitive challenges, partnering with other organizations with services not available within their own organization, and advocating for greater access to services with expertise and experience working with PLWH. Conclusion: Through concerted efforts in the future, it is likely that empirically investigating, developing, and customizing these strategies specifically to address HIV-associated neurocognitive challenges will yield improved social support and mental health outcomes for PLWH

Winter habitat selection by marsh tits Poecile palustris in a British woodland

Capsule: Radio-tracking and remote sensing showed Marsh Tits selected for English Oak Quercus robur trees within large winter home-ranges. Aims: To investigate winter habitat selection by Marsh Tits in a British wood, testing for preferences in tree species and woodland structure. Methods: Thirteen Marsh Tits were radio-tracked during the winter, and home-ranges were derived. Lidar and hyperspectral data were used to compare the vegetation structure and tree species composition of entire home-ranges and the core areas of intensive use within. Instantaneous sampling observations provided further information for tree species utilization. Results: The mean home-range was very large (39 ha, n=13). There were no significant differences in mean tree height, canopy closure, understorey height, or shrub volume between full home-ranges and the core areas of use. Core areas contained a significantly greater proportion of English Oak relative to availability in the full home-ranges. Instantaneous sampling confirmed that English Oak was used significantly more than other trees. Conclusion: Selection for English Oak during winter contrasted with previous studies of breeding territories, indicating that habitat usage varies seasonally and demonstrating the need for habitat selection studies throughout the year. Large home-ranges help to explain the Marsh Tit’s sensitivity to habitat fragmentation

Differences in transcription between free-living and CO_2-activated third-stage larvae of Haemonchus contortus

Background: The disease caused by Haemonchus contortus, a blood-feeding nematode of small ruminants, is of major economic importance worldwide. The infective third-stage larva (L3) of this gastric nematode is enclosed in a cuticle (sheath) and, once ingested with herbage by the host, undergoes an exsheathment process that marks the transition from the free-living (L3) to the parasitic (xL3) stage. This study explored changes in gene transcription associated with this transition and predicted, based on comparative analysis, functional roles for key transcripts in the metabolic pathways linked to larval development. Results: Totals of 101,305 (L3) and 105,553 (xL3) expressed sequence tags (ESTs) were determined using 454 sequencing technology, and then assembled and annotated; the most abundant transcripts encoded transthyretin-like, calcium-binding EF-hand, NAD(P)-binding and nucleotide-binding proteins as well as homologues of Ancylostoma-secreted proteins (ASPs). Using an in silico-subtractive analysis, 560 and 685 sequences were shown to be uniquely represented in the L3 and xL3 stages, respectively; the transcripts encoded ribosomal proteins, collagens and elongation factors (in L3), and mainly peptidases and other enzymes of amino acid catabolism (in xL3). Caenorhabditis elegans orthologues of transcripts that were uniquely transcribed in each L3 and xL3 were predicted to interact with a total of 535 other genes, all of which were involved in embryonic development. Conclusion: The present study indicated that some key transcriptional alterations taking place during the transition from the L3 to the xL3 stage of H. contortus involve genes predicted to be linked to the development of neuronal tissue (L3 and xL3), formation of the cuticle (L3) and digestion of host haemoglobin (xL3). Future efforts using next-generation sequencing and bioinformatic technologies should provide the efficiency and depth of coverage required for the determination of the complete transcriptomes of different developmental stages and/or tissues of H. contortus as well as the genome of this important parasitic nematode. Such advances should lead to a significantly improved understanding of the molecular biology of H. contortus and, from an applied perspective, to novel methods of intervention

Prevalence and Risk Factors for Methicillin-Resistant Staphylococcus aureus in an HIV-Positive Cohort

Background: Persons living with HIV (PLWH) are disproportionately burdened with methicillin-resistant Staphylococcus aureus (MRSA). Our objective was to evaluate prevalence and risks for MRSA colonization in PLWH. Methods: Adults were recruited from Johns Hopkins University AIDS Service in Baltimore, Maryland. A risk questionnaire and specimen collection from anatomic sites with culture susceptibility and genotyping were completed. Generalized estimating equation modeling identified MRSA colonization risk factors. Results: Of 500 participants,mostwere black (69%), on antiretroviral therapy (ART) (87%),with undetectable viral loads (73.4%). Median CD4 count was 487 cells/mm3 (interquartile range, 316-676.5 cells/mm3). MRSA prevalence was 15.4%, predominantly from the nares (59.7%). Forty percent were nares negative but were colonized elsewhere. Lower odds for colonizationwere associatedwith recent sexual activity (adjusted odds ratio [AOR]¼0.84, P$75,000; AOR ¼ 2.68, P \u3c .001), recent hospitalization (AOR ¼ 1.54, P \u3c .001), incarceration (AOR ¼ 1.55,