2,693 research outputs found
A mini-array for large air showers
A mini-array that utilizes the Linsley effect is proposed for the measurement of large air showers. An estimate of the detectable shower rates for various shower sizes is made. Details of the detection and data collection systems are also described
Stabilization, pointing and command control of a balloon-borne 1-meter telescope
A 1-meter balloon-borne telescope has been constructed and flown to observe far-infrared radiation from celestial sources. The attitude control systems must perform to the diffraction limit of the telescope for stabilization and have positioning capability for source acquisition. These and associated systems are discussed in detail, as is the command control of the payload as a whole
Suite of simple metrics reveals common movement syndromes across vertebrate taxa
ecause empirical studies of animal movement are most-often site- and species-specific, we lack understanding of the level of consistency in movement patterns across diverse taxa, as well as a framework for quantitatively classifying movement patterns. We aim to address this gap by determining the extent to which statistical signatures of animal movement patterns recur across ecological systems. We assessed a suite of movement metrics derived from GPS trajectories of thirteen marine and terrestrial vertebrate species spanning three taxonomic classes, orders of magnitude in body size, and modes of movement (swimming, flying, walking). Using these metrics, we performed a principal components analysis and cluster analysis to determine if individuals organized into statistically distinct clusters. Finally, to identify and interpret commonalities within clusters, we compared them to computer-simulated idealized movement syndromes representing suites of correlated movement traits observed across taxa (migration, nomadism, territoriality, and central place foraging)
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‘If you look the part you’ll get the job’: should career professionals help clients to enhance their career image?
This article presents a critical exploration of the role of career professionals in supporting people to reflect on and enhance their appearance, attractiveness and self-presentation (career image). The article is conceptual and based on a review of the broader literature on career success, appearance and attractiveness. It explores the evidence for a relationship between attractiveness and career, and the authors propose a conceptual framework in which career image is comprised of three elements (interpersonal skills, aesthetic presentation and beauty). The paper examines a possible role for career professionals in relation to this and then critically examines this role and concludes with the proposition of a research agenda in this area
Complete homochirality induced by the nonlinear autocatalysis and recycling
A nonlinear autocatalysis of a chiral substance is shown to achieve
homochirality in a closed system, if the back-reaction is included. Asymmetry
in the concentration of two enantiomers or the enantiometric excess increases
due to the nonlinear autocatalysis. Furthermore, when the back-reaction is
taken into account, the reactant supplied by the decomposition of the
enantiomers is recycled to produce more and more the dominant one, and
eventually the homochirality is established.Comment: 4 pages, 2 figure
Advances in the study of marine mammal predator-prey interactions: a novel real-time visualization of independently collected echosounder data using GeoZui4D
Identification of Critical Paraoxonase 1 Residues Involved in High Density Lipoprotein Interaction
Paraoxonase 1 (PON1) is a high density lipoprotein (HDL)-associated protein with atherosclerosis-protective and systemic anti-oxidant functions. We recently showed that PON1, myeloperoxidase, and HDL bind to one another in vivo forming a functional ternary complex (Huang, Y., Wu, Z., Riwanto, M., Gao, S., Levison, B. S., Gu, X., Fu, X., Wagner, M. A., Besler, C., Gerstenecker, G., Zhang, R., Li, X. M., Didonato, A. J., Gogonea, V., Tang, W. H., et al. (2013) J. Clin. Invest. 123, 3815–3828). However, specific residues on PON1 involved in the HDL-PON1 interaction remain unclear. Unambiguous identification of protein residues involved in docking interactions to lipid surfaces poses considerable methodological challenges. Here we describe a new strategy that uses a novel synthetic photoactivatable and click chemistry-taggable phospholipid probe, which, when incorporated into HDL, was used to identify amino acid residues on PON1 that directly interact with the lipoprotein phospholipid surface. Several specific PON1 residues (Leu-9, Tyr-185, and Tyr-293) were identified through covalent cross-links with the lipid probes using affinity isolation coupled to liquid chromatography with on-line tandem mass spectrometry. Based upon the crystal structure for PON1, the identified residues are all localized in relatively close proximity on the surface of PON1, defining a domain that binds to the HDL lipid surface. Site-specific mutagenesis of the identified PON1 residues (Leu-9, Tyr-185, and Tyr-293), coupled with functional studies, reveals their importance in PON1 binding to HDL and both PON1 catalytic activity and stability. Specifically, the residues identified on PON1 provide important structural insights into the PON1-HDL interaction. More generally, the new photoactivatable and affinity-tagged lipid probe developed herein should prove to be a valuable tool for identifying contact sites supporting protein interactions with lipid interfaces such as found on cell membranes or lipoproteins
Identification of Critical Paraoxonase 1 Residues Involved in High Density Lipoprotein Interaction
Paraoxonase 1 (PON1) is a high density lipoprotein (HDL)-associated protein with atherosclerosis-protective and systemic anti-oxidant functions. We recently showed that PON1, myeloperoxidase, and HDL bind to one another in vivo forming a functional ternary complex (Huang, Y., Wu, Z., Riwanto, M., Gao, S., Levison, B. S., Gu, X., Fu, X., Wagner, M. A., Besler, C., Gerstenecker, G., Zhang, R., Li, X. M., Didonato, A. J., Gogonea, V., Tang, W. H., et al. (2013) J. Clin. Invest. 123, 3815–3828). However, specific residues on PON1 involved in the HDL-PON1 interaction remain unclear. Unambiguous identification of protein residues involved in docking interactions to lipid surfaces poses considerable methodological challenges. Here we describe a new strategy that uses a novel synthetic photoactivatable and click chemistry-taggable phospholipid probe, which, when incorporated into HDL, was used to identify amino acid residues on PON1 that directly interact with the lipoprotein phospholipid surface. Several specific PON1 residues (Leu-9, Tyr-185, and Tyr-293) were identified through covalent cross-links with the lipid probes using affinity isolation coupled to liquid chromatography with on-line tandem mass spectrometry. Based upon the crystal structure for PON1, the identified residues are all localized in relatively close proximity on the surface of PON1, defining a domain that binds to the HDL lipid surface. Site-specific mutagenesis of the identified PON1 residues (Leu-9, Tyr-185, and Tyr-293), coupled with functional studies, reveals their importance in PON1 binding to HDL and both PON1 catalytic activity and stability. Specifically, the residues identified on PON1 provide important structural insights into the PON1-HDL interaction. More generally, the new photoactivatable and affinity-tagged lipid probe developed herein should prove to be a valuable tool for identifying contact sites supporting protein interactions with lipid interfaces such as found on cell membranes or lipoproteins
Human myocardial cytosolic Ca2+-independent phospholipase A2 is modulated by ATP. Concordant ATP-induced alterations in enzyme kinetics and mechanism-based inhibition
Intestinal Microbiota-Generated Metabolite Trimethylamine-N-Oxide and 5-Year Mortality Risk in Stable Coronary Artery Disease: The Contributory Role of Intestinal Microbiota in A COURAGE-Like Patient Cohort
Background: Trimethylamine-N-oxide (TMAO), a metabolite derived from gut microbes and dietary phosphatidylcholine, is linked to both coronary artery disease pathogenesis and increased cardiovascular risks. The ability of plasma TMAO to predict 5-year mortality risk in patients with stable coronary artery disease has not been reported. This study examined the clinical prognostic value of TMAO in patients with stable coronary artery disease who met eligibility criteria for a patient cohort similar to that of the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial. Methods and Results: We examined the relationship between fasting plasma TMAO and all-cause mortality over 5-year follow-up in sequential patients with stable coronary artery disease (n=2235) who underwent elective coronary angiography. We identified the COURAGE-like patient cohort as patients who had evidence of significant coronary artery stenosis and who were managed with optimal medical treatment. Higher plasma TMAO levels were associated with a 4-fold increased mortality risk. Following adjustments for traditional risk factors, high-sensitivity C-reactive protein, and estimated glomerular filtration rate, elevated TMAO levels remained predictive of 5-year all-cause mortality risk (quartile 4 versus 1, adjusted hazard ratio 1.95, 95% CI 1.33–2.86; P=0.003). TMAO remained predictive of incident mortality risk following cardiorenal and inflammatory biomarker adjustments to the model (adjusted hazard ratio 1.71, 95% CI 1.11–2.61; P=0.0138) and provided significant incremental prognostic value for all-cause mortality (net reclassification index 42.37%, P\u3c0.001; improvement in area under receiver operator characteristic curve 70.6–73.76%, P\u3c0.001). Conclusions: Elevated plasma TMAO levels portended higher long-term mortality risk among patients with stable coronary artery disease managed with optimal medical treatment
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