110 research outputs found

    O1 haplotype diversity of the invasive colonial tunicate Didemnum vexillum in Drakes Estero and Bodega Bay

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    The colonial ascidian Didemnum vexillum is an invasive species with detrimental economic and ecological impacts on ecosystems where it is newly introduced. Populations of this recent marine pest are rapidly expanding along the North American coasts and provide the opportunity to assess whether population proximity and shared environmental factors influence genetic relatedness. The population in Tomales Bay, CA is the most diverse measured to date on the Northeast Pacific coast with the population composed of six different haplotypes; other locations are composed of three or four haplotypes. The diversity in Tomales Bay suggests it be an anomaly or possibly a matter associated to areas of limited diversity. D. vexillum populations in isolated areas such as Drakes Estero and Bodega Bay, CA are of close geographic range to Tomales. Drakes’ population is associated with aquaculture structures of the past and Bodega with fishing and recreational boat traffic. This study involved the genetic examination of these populations by barcoding the mitochondrial locus COI to determine haplotype distributions of Drakes Estero and Bodega Bay. From the ten Bodega and five Drakes sequences, there are at least two haplotypes represented. However, the results are preliminary; phylogenetic analysis of all sequences in comparison to the known haplotypes of D. vexillum is necessary before concluding which haplotypes are present in the populations

    Novel high performance small-scale thermoelectric power generation employing regenerative combustion systems

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    Hydrocarbon fuels have specific energy contents some two orders of magnitude greater than any electrical storage device. They therefore proffer an ideal source in the universal quest for compact, lightweight, long-lasting alternatives for batteries to power the ever-proliferating electronic devices. The motivation lies in the need to power, for example, equipment for infantry troops, for weather stations and buoys in polar regions which need to signal their readings intermittently to passing satellites, unattended over long periods, and many others. Fuel cells, converters based on miniaturized gas turbines, and other systems under intensive study, give rise to diverse practical difficulties. Thermoelectric devices are robust, durable and have no moving parts, but tend to be exceedingly inefficient. We propose regenerative combustion systems which mitigate this impediment and are likely to make high performance small-scale thermoelectric power generation applicable in practice. The efficiency of a thermoelectric generating system using preheat when operated between ambient and 1200 K is calculated to exceed the efficiency of the best present day thermoelectric conversion system by more than 20%

    How Is Physical Literacy Defined? A Contemporary Update

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    Physical literacy continues to gain global momentum, yet the definition and underlying concept of physical literacy remain contested in both research and practice. This lack of clarity has the potential to undermine the operationalization of physical literacy. This paper considers the various definitions of physical literacy that are currently adopted internationally. Physical literacy experts identified seven leading groups that have established physical literacy initiatives. Although each group is unified in using the term physical literacy, there are contrasting definitions and interpretations of the concept. Common themes were identified, including the (a) influence of physical literacy philosophy, (b) core elements of physical literacy, (c) lifelong nature of physical literacy, and (d) the need to scientifically pursue a robust operationalization of the concept. We conclude by recommending that programs relating to physical literacy should provide a definition, a clear philosophical approach, and transparency with how their actions align with this approach

    An examination of the reciprocal and concurrent relations between behavioral and cardiac indicators of acute pain in toddlerhood

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    The aim of this study was to examine the concurrent and predictive relations between healthy toddlers’ pain behavior and cardiac indicators (i.e., heart rate [HR], respiratory sinus arrhythmia [RSA]) during routine vaccinations. Caregiver-infant dyads were part of a longitudinal cohort observed during their 12- and 18-month vaccinations. Behavioral and cardiac data were simultaneously collected for 1-minute pre-needle and 3-minutes post-needle. Videotapes were coded for pain behaviors (FLACC; Merkel et al., 1996), and cardiac data were analyzed (HR, RSA) during sequential 30-second epochs. Four separate cross-lagged path models were estimated using data from the 12- (n= 147) and 18-month (n= 122) vaccinations. Across 12- and 18-month vaccinations, predictive within-measure relations were consistent for FLACC, HR and RSA, reflecting good stability of these pain indicators. Behavioral indicators predicted subsequent HR and RSA within the immediate post-needle period. Both baseline behavior and HR/RSA predicted future pain scores. Concurrent residual relations between behavioral and cardiac indicators were inconsistent across time and indicator. Results suggest that behavioral and cardiac indicators reflect unique aspects of the nociceptive response. As such, multi-modal assessment tools should be utilized and contextualized by child age, cardiac indicator, baseline behavior/physiology, and pain phase

    Protective effects of antiâ C5a peptide antibodies in experimental sepsis

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    We evaluated antibodies to different peptide regions of rat C5a in the sepsis model of cecal ligation and puncture (CLP) for their protective effects in rats. Rabbit polyclonal antibodies were developed to the following peptide regions of rat C5a: aminoâ terminal region (A), residues 1â 16; middle region (M), residues 17â 36; and the carboxylâ terminal region (C), residues 58â 77. With rat neutrophils, the chemotactic activity of rat C5a was significantly inhibited by antibodies with the following rank order: antiâ C > antiâ M â « antiâ A. In vivo, antibodies to the M and C (but not A) regions of C5a were protective in experimental sepsis, as determined by survival over a 10â day period, in a doseâ dependent manner. The relative protective efficacies of antiâ C5a preparations (in descending order of efficacy) were antiâ C â ¥ antiâ M â « antiâ A. In CLP rats, a delay in infusion of antibodies, which were injected at 6 or 12 h after CLP, still resulted in significant improvement in survival rates. These in vivo and in vitro data suggest that there are optimal targets on C5a for blockade during sepsis and that delayed infusion of antiâ C5a antibody until after onset of clinical evidence of sepsis still provides protective effects.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154417/1/fsb2fj000653fje-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154417/2/fsb2fj000653fje.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154417/3/fsb2fj000653fje-sup-0002.pd

    Biochemical and genetic characterization of <em>Trypanosoma cruzi N</em>-myristoyltransferase

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    Co- and post-translational N-myristoylation is known to play a role in the correct subcellular localization of specific proteins in eukaryotes. The enzyme that catalyses this reaction, NMT (N-myristoyltransferase), has been pharmacologically validated as a drug target in the African trypanosome, Trypanosoma brucei. In the present study, we evaluate NMT as a potential drug target in Trypanosoma cruzi, the causative agent of Chagas’ disease, using chemical and genetic approaches. Replacement of both allelic copies of TcNMT (T. cruzi NMT) was only possible in the presence of a constitutively expressed ectopic copy of the gene, indicating that this gene is essential for survival of T. cruzi epimastigotes. The pyrazole sulphonamide NMT inhibitor DDD85646 is 13–23-fold less potent against recombinant TcNMT than TbNMT (T. brucei NMT), with K(i) values of 12.7 and 22.8 nM respectively, by scintillation proximity or coupled assay methods. DDD85646 also inhibits growth of T. cruzi epimastigotes (EC(50)=6.9 μM), but is ~1000-fold less potent than that reported for T. brucei. On-target activity is demonstrated by shifts in cell potency in lines that over- and under-express NMT and by inhibition of intracellular N-myristoylation of several proteins in a dose-dependent manner. Collectively, our findings suggest that N-myristoylation is an essential and druggable target in T. cruzi

    Understanding scientific study via process modeling

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    This paper argues that scientific studies distinguish themselves from other studies by a combination of their processes, their (knowledge) elements and the roles of these elements. This is supported by constructing a process model. An illustrative example based on Newtonian mechanics shows how scientific knowledge is structured according to the process model. To distinguish scientific studies from research and scientific research, two additional process models are built for such processes. We apply these process models: (1) to argue that scientific progress should emphasize both the process of change and the content of change; (2) to chart the major stages of scientific study development; and (3) to define “science”

    Lipid rescue: small trials and animal research

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    What is a Pharm.D.?

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