253 research outputs found

    Volatile chemicals in glands of the carpenter ant, Camponotus arminius

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    Camponotus arminius is a large black carpenter ant that occurs in tropical and sub-tropical Africa and has extensive foraging trails both in trees and on the ground. Analysis of excised mandibular glands has confirmed The presence of pentane-2,4-dione, n-hexanal, 4-methyl-3-heptanone, and mellein. Pentane-2,4-dione has not been reported from insects. The postpharyngeal gland contains n-heneicosane, n-tricosene, n-tricosane, n-pentacosene, n-pentacosane, and a significant amount of 11-methyl- n-tricosaneand 11-methyl- n-pentacosane. Dufours glands contain mainly n-undecane, n-tridecane, and two terpenoid compounds that are unknown in the genus Camponotus. These latter two compounds are geranyllinalool and probably geranylfarnesol

    The Composition of Fatty Materials from a Thule Eskimo Site on Herschel Island

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    Analysis of midden material from a Thule Eskimo dwelling site on the shore of Herschel Island showed it to contain a high proportion of fatty material. Chemical analysis shows this to consist of a mixture of fatty acids from the fats and oils of marine animals which has been partially, but far from completely, converted to adipocere. The lack of complete conversion is attributed to anaerobic conditions, low ambient temperature, and lack of bacterial action. The results are consistent with, but not a proof that the debris is from a mixture of harbour, ringed, and bearded seal, which is the conclusion from the bone fragments found.Key words: Thule dwelling, midden, fat and oil, adipocere, anaerobic decay, whale fat, seal fatMots clés: résidence Thulé, amas d'ordures, gras et huile, adipocire, décomposition anaérobique, gras de baleine, gras de phoqu

    Reconstruction of a radiation point source’s radial location using goodness-of-fit test on spectra obtained from an HPGe detector

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    High purity germanium (HPGe) detectors are ubiquitous in nuclear physics experiments and are also used in numerous low radioactive background detectors. The effect of the position of 60Co and 137Cs point sources on the shape of spectra were studied with Monte Carlo and HPGe detector measurements. We briefly con firm previous work on the position dependence of relative heights of peaks. Spectra taken with the radiation sources placed at locations around the detector were then compared using the Kolmogorov-Smirnov (K-S) goodness-of- t test. We demonstrate that with this method the Compton continuum spectral shape has good sensitivity to the radial location of a point-source, but poor angular resolution. We conclude with a study of the position reconstruction accuracy as a function of the number of counts from the source

    Plasmonic excitations in noble metals: The case of Ag

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    The delicate interplay between plasmonic excitations and interband transitions in noble metals is described by means of {\it ab initio} calculations and a simple model in which the conduction electron plasmon is coupled to the continuum of electron-hole pairs. Band structure effects, specially the energy at which the excitation of the dd-like bands takes place, determine the existence of a subthreshold plasmonic mode, which manifests itself in Ag as a sharp resonance at 3.8 eV. However, such a resonance is not observed in the other noble metals. Here, this different behavior is also analyzed and an explanation is provided.Comment: 9 pages, 8 figure

    Sustainable change: long-term efforts toward developing a learning organization

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    Globalization and intensified competition require organizations to change and adapt to dynamic environments in order to stay competitive. This article describes a longitudinal action research study supporting the strategic change of a trading company. The strategic change was accompanied by planned changes in organizational structures and processes, management systems, emerging changes in leadership, and organization members’ attitudes and behaviors, and it was supported by management development activities. Longitudinal data over a 4-year period including participant observation and interviews reveal that a systemic approach, a learning and becoming perspective toward change, trust, an appropriate role perception, and the specific use of management instruments contribute to sustained change that resulted in performance improvements and a move toward a learning organization. We conclude with implications for strategic change and suggestions for further research in this area

    Study of two dose regimens of ticagrelor compared with clopidogrel in patients undergoing percutaneous coronary intervention for stable coronary artery disease

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    Background—Ticagrelor has superior efficacy to clopidogrel in the management of acute coronary syndromes but has not been assessed in patients undergoing percutaneous coronary intervention (PCI) for stable coronary artery disease (CAD). We compared the pharmacodynamic effects of ticagrelor and clopidogrel in this stable population. Methods—180 aspirin-treated stable CAD patients, who were planned to undergo elective PCI in a single center, were randomized 1:1:1 to either a standard clopidogrel regimen or one of two regimens of ticagrelor, either 90mg (T90) or 60mg twice-daily (T60), both with 180mg loading dose. Cellular adenosine uptake was assessed, at the time of the procedure and pre- and post-dose at 1 month, by adding adenosine 1 μmol/L to aliquots of anticoagulated whole blood and mixing with a stop solution at 0, 15, 30 and 60 seconds then measuring residual plasma adenosine concentration by high-performance liquid chromatography. Systemic plasma adenosine concentration and platelet reactivity were assessed at the same timepoints. High-sensitivity troponin T (hsTnT) was measured pre- and 18-24 hours post-PCI. Results—174 patients underwent an invasive procedure, of which 162 patients received PCI (mean age 65 years, 18% female, 21% with diabetes mellitus). No effect on in vitro adenosine uptake was seen post-dose at 1 month for either ticagrelor dose compared with clopidogrel (residual adenosine at 15s, mean ± SD: clopidogrel 0.274 ± 0.101 μmol/L; T90 0.278 ± 0.134 μmol/L; T60 0.288 ± 0.149 μmol/L; P = 0.37). Similarly no effect of ticagrelor on in vitro adenosine uptake was seen at other timepoints, nor was plasma adenosine concentration affected (all P > 0.1). Both maintenance doses of ticagrelor achieved more potent and consistent platelet inhibition than clopidogrel (VerifyNow PRU, 1 month, mean ± SD: pre-dose, T60: 62 ± 47, T90: 40 ± 38, clopidogrel 181 ± 44; post-dose, T60: 34 ± 30, T90: 24 ± 21, clopidogrel 159 ± 57; all P 208, 1-month post-dose: 0%, 0% and 21%, respectively). Median (IQR) hsTnT increase was 16.9 (6.5-46.9) ng/l for clopidogrel, 22.4 (5.5-53.8) ng/L for T60 and 17.7 (8.1-43.5) ng/L for T90 (P = 0.95). There was a trend towards less dyspnea with T60 versus T90 (7.1% vs 19.0%; P = 0.09). Conclusions—Maintenance therapy with T60 or T90 had no detectable effect on cellular adenosine uptake at 1 month, nor was there any effect on systemic plasma adenosine levels. Both regimens of ticagrelor achieved greater and more consistent platelet inhibition than clopidogrel but did not appear to affect troponin release after percutaneous coronary interventio

    CSF1R inhibitor JNJ-40346527 attenuates microglial proliferation and neurodegeneration in P301S mice

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    Neuroinflammation and microglial activation are significant processes in Alzheimer's disease pathology. Recent genome-wide association studies have highlighted multiple immune-related genes in association with Alzheimer's disease, and experimental data have demonstrated microglial proliferation as a significant component of the neuropathology. In this study, we tested the efficacy of the selective CSF1R inhibitor JNJ-40346527 (JNJ-527) in the P301S mouse tauopathy model. We first demonstrated the anti-proliferative effects of JNJ-527 on microglia in the ME7 prion model, and its impact on the inflammatory profile, and provided potential CNS biomarkers for clinical investigation with the compound, including pharmacokinetic/pharmacodynamics and efficacy assessment by TSPO autoradiography and CSF proteomics. Then, we showed for the first time that blockade of microglial proliferation and modification of microglial phenotype leads to an attenuation of tau-induced neurodegeneration and results in functional improvement in P301S mice. Overall, this work strongly supports the potential for inhibition of CSF1R as a target for the treatment of Alzheimer's disease and other tau-mediated neurodegenerative diseases
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