Syntheses and reactions of heterometallic complexes of nickel and copper with tetrathiotungstates. The molecular structures of [Ph(4)P](2)[S2W(mu-S)(2)Ni(S-2)] and W(mu-S)(4)Cu-2(PPh(3))(4)center dot py

Reaction of [Ph(4)P]2WS4 With NiCl2 in methanol solution in the presence of NaOCH3 leads to the formation of [Ph(4)P](2) [S2W(mu-S)(2)Ni(S-2)] (I) A Similar reaction between (NH4)(2)WS4 and NiCl2 under O-2 atmosphere in the presence of Ph(4)PCl or (n)Bu(4)NCl affords [Ph(4)P](2)([(S-2)W(O)(mu-S)(2)]Ni-2] (IIa) and [(n)Bu(4)N](2)([(S-2)W(O)(mu-S)(2)]Ni-2} (IIb) Under argon the same reaction gives [Ph(4)P](2)[Ni(WS4)(2)] (IIIa) and [(n)Bu(4)N](2)[Ni(WS4)(2)] (IIIb). [Ph(4)P](2)[Ni(WOS3)(2)] (IV) and [Ph(4)P](2)[Ni(WO2S2)(2)] (V) can be prepared from the reaction of [Ph(4)P]2WOS3 and [Ph(4)P]2WO2S2 with NiCl2. Treatment of (NH4)(2)WS4 with CuCl in the presence of PPh(3) in boiling pyridine produces W(mu-S)(4)Cu-2(PPh(3))(3) (VI), which can further react with excess PPh(3) to give W(mu-S)(4)Cu-2(PPh(3))(4) . py (VII). Complex I crystallizes in the space group P2(1)/n with the cell parameters: a = 20.049(4), b = 17.010(4), c = 14.311(7) Angstrom; beta = 110.24(3)degrees and Z = 4; R = 0.058 for 4267 independent reflections. The structural study confirms that complex I contains two terminal sulfide ligands, two bridging sulfide ligands, a side-on disulfide ligand, and a planar central W(mu-S)(2)Ni four membered ring. Complex VII crystallizes in the space group C2/c with the cell parameters: a = 26.436(8), b = 20.542(6), c = 19.095(8) Angstrom; beta = 125.00(3)degrees and Z = 4; R = 0.080 for 3802 independent reflections. The structural study reveals a perfect linear arrangement of the three metal atoms Cu-W-Cu.

Determination of five pharmacologically active compounds extracted from Rhodiola for natural product drug discovery with HPLC-APCI-MS

A rapid and sensitive liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS) assay for the determination of five pharmacologically active compounds (PAC) extracted from the traditional Chinese medicine, Rhodiola , namely salidroside, tyrosol, rhodionin, gallic acid, and ethyl gallate has been developed. In this method, PAC could be baseline separated and detected with DAD at 275 nm. The validation of the method, including sensitivity, linearity, repeatability, and recovery, was examined. The linear calibration curves were acquired with correlation coefficient >0.999 and the limits of detection LOD (at a signal-to-noise ratio=3:1) were between 0.058 and 1.500 mu mol/L. It was found, that the amounts of PAC varied with different species of Rhodiola . The established method is rapid and reproducible for the separation of five natural pharmacologically active compounds from extracts of Rhodiola with satisfactory results.

河西走廊棘豆毒草中的硒及其与牲畜中毒关系研究

河西走廊地区草原生态环境,棘豆等毒草泛滥成灾,导致大量牲畜中毒死亡。棘豆毒草导致的牲畜中毒症状与历史上马可波罗记载的古代肃州牲畜毒草中毒症状及其相似。为了确定马可波罗所记载的肃州牲畜毒草中毒是否与硒有关,本项研究对河西走廊地区主要草原畜牧区肃南县草原发育的棘豆属植物及其土壤中的硒进行了测定,测定结果表明:土壤硒含量平均值为0.205±0.173mg/kg,与世界平均土壤硒含量相近。棘豆属植物小花棘豆根、茎叶的硒平均含量分别为0.112±0.038mg/kg(0.052～0.174mg/kg),0.102±0.027mg/kg(0.066～0.158 mg/kg);黄花棘豆全株硒平均含量为0.066±0.009mg/kg(0.058～0.078mg/kg),种子硒:0.107mg/kg。可见该区棘豆属毒草硒含量远低于能导致一般动物中毒的3mg/kg植物硒含量。根据肃南县棘豆毒草发育的地理位置、牲畜中毒症状调查及其硒含量测定的结果,本文认为马可波罗所记载的中国西部肃州牲畜毒草中毒是棘豆属毒草中毒,其主要毒素成分不是硒。

Spatial Pattern Learning, Catastophic Forgetting and Optimal Rules of Synaptic Transmission

It is a neural network truth universally acknowledged, that the signal transmitted to a target node must be equal to the product of the path signal times a weight. Analysis of catastrophic forgetting by distributed codes leads to the unexpected conclusion that this universal synaptic transmission rule may not be optimal in certain neural networks. The distributed outstar, a network designed to support stable codes with fast or slow learning, generalizes the outstar network for spatial pattern learning. In the outstar, signals from a source node cause weights to learn and recall arbitrary patterns across a target field of nodes. The distributed outstar replaces the outstar source node with a source field, of arbitrarily many nodes, where the activity pattern may be arbitrarily distributed or compressed. Learning proceeds according to a principle of atrophy due to disuse whereby a path weight decreases in joint proportion to the transmittcd path signal and the degree of disuse of the target node. During learning, the total signal to a target node converges toward that node's activity level. Weight changes at a node are apportioned according to the distributed pattern of converging signals three types of synaptic transmission, a product rule, a capacity rule, and a threshold rule, are examined for this system. The three rules are computationally equivalent when source field activity is maximally compressed, or winner-take-all when source field activity is distributed, catastrophic forgetting may occur. Only the threshold rule solves this problem. Analysis of spatial pattern learning by distributed codes thereby leads to the conjecture that the optimal unit of long-term memory in such a system is a subtractive threshold, rather than a multiplicative weight.

Gamma-rays from heavy minimal dark matter

Motivated by the Minimal Dark Matter scenario, we consider the annihilation into gamma rays of candidates in the fermionic 5-plet and scalar 7-plet representations of SU(2)L, taking into account both the Sommerfeld effect and the internal bremsstrahlung. Assuming the Einasto profile, we show that present measurements of the Galactic Center by the H.E.S.S. instrument exclude the 5-plet and 7-plet as the dominant form of dark matter for masses between 1 TeV and 20 TeV, in particular, the 5-plet mass leading to the observed dark matter density via thermal freeze-out. We also discuss prospects for the upcoming Cherenkov Telescope Array, which will be able to probe even heavier dark matter masses, including the scenario where the scalar 7-plet is thermally produced.

Measurement of ratios of fragmentation fractions for bottom hadrons in pp̄ collisions at s=1.96TeV

This paper describes the first measurement of b-quark fragmentation fractions into bottom hadrons in Run II of the Tevatron Collider at Fermilab. The result is based on a 360pb-1 sample of data collected with the CDF II detector in pp̄ collisions at s=1.96TeV. Semileptonic decays of B̄0, B-, and B̄s0 mesons, as well as Λb0 baryons, are reconstructed. For an effective bottom hadron pT threshold of 7GeV/c, the fragmentation fractions are measured to be fu/fd=1.054±0.018(stat)-0.045+0.025(sys)±0. 058(B), fs/(fu+fd)=0.160±0.005(stat)-0.010+0.011(sys)-0.034+0.057(B), and fΛb/(fu+fd)=0.281±0.012(stat)-0.056+0.058(sys)-0.087+0.128(B), where the uncertainty B is due to uncertainties on measured branching ratios. The value of fs/(fu+fd) agrees within one standard deviation with previous CDF measurements and the world average of this quantity, which is dominated by LEP measurements. However, the ratio fΛb/(fu+fd) is approximately twice the value previously measured at LEP. The approximately 2σ discrepancy is examined in terms of kinematic differences between the two production environments. © 2008 The American Physical Society.

A comparative analysis of multidimensional features of objects resembling sets of graphs

In the present paper, we introduce a notion of a style representing abstract, complex objects having characteristics that can be represented as structured objects. Furthermore, we provide some mathematical properties of such styles. As a main result, we present a novel approach to perform a meaningful comparative analysis of such styles by defining and using graph-theoretic measures. We compare two styles by comparing the underlying feature sets representing sets of graph structurally. To determine the structural similarity between the underlying graphs, we use graph similarity measures that are computationally efficient. More precisely, in order to compare styles, we map each feature set to a so-called median graph and compare the resulting median graphs. As an application, we perform an experimental study to compare special styles representing sets of undirected graphs and present numerical results thereof. (C) 2007 Elsevier Inc. All rights reserved.

Eclipsing Binary Science via the Merging of Transit and Doppler Exoplanet Survey Data—A Case Study with the MARVELS Pilot Project and SuperWASP

Exoplanet transit and Doppler surveys discover many binary stars during their operation that can be used to conduct a variety of ancillary science. Specifically, eclipsing binary stars can be used to study the stellar mass-radius relationship and to test predictions of theoretical stellar evolution models. By cross-referencing 24 binary stars found in the MARVELS Pilot Project with SuperWASP photometry, we find two new eclipsing binaries, TYC 0272-00458-1 and TYC 1422-01328-1, which we use as case studies to develop a general approach to eclipsing binaries in survey data. TYC 0272-00458-1 is a single-lined spectroscopic binary for which we calculate a mass of the secondary and radii for both components using reasonable constraints on the primary mass through several different techniques. For a primary mass of M 1 = 0.92 ± 0.1 M sun, we find M 2 = 0.610 ± 0.036 M sun, R 1 = 0.932 ± 0.076 R sun, and R 2 = 0.559 ± 0.102 R sun, and find that both stars have masses and radii consistent with model predictions. TYC 1422-01328-1 is a triple-component system for which we can directly measure the masses and radii of the eclipsing pair. We find that the eclipsing pair consists of an evolved primary star (M 1 = 1.163 ± 0.034 M sun, R 1 = 2.063 ± 0.058 R sun) and a G-type dwarf secondary (M 2 = 0.905 ± 0.067 M sun, R 2 = 0.887 ± 0.037 R sun). We provide the framework necessary to apply this analysis to much larger data sets.

Job strain and adverse health behaviors: The Finnish public sector study

Objective: The objective of this study was to explore the association between job strain and the co-occurrence of adverse health behaviors, smoking; heavy drinking; obesity, and physical inactivity. Methods. The authors studied cross-sectional data of 34,058 female and 8154 male public sector employees. Results: Multinomial logistic regression models adjusted for sex, age, basic education, marital status, and type of job contract showed that high job strain and passive jobs were associated with 1.3 to 1.4 times higher odds of having >= 3 (vs 0) adverse health behaviors. Among men, low job control was associated with a 1.3 fold likelihood and amon women active jobs were associated with a 1.2 fold likelihood of having >= 3 (vs 0) adverse behaviors. High demands were associated with a higher likelihood of co-occurrence of one to two (vs 0) adverse behav irs among women. Conclusions. b strain conditions may be associated with the co-occurrence of adverse health behaviors that contribute to preventable chronic diseases. Clinical Significance. Adversejob conditions may increase the likelihood of co-occurring health risk behaviors. Reducing work stress by increasingl ob control and decreasing psychologic demands might help efforts to promote healthy 1 festyles.

A computational model of cellular response to modulated radiation fields

Purpose:
To develop a model to describe the response of cell populations to spatially modulated radiation exposures of relevance to advanced radiotherapies.

Materials and Methods:
A Monte Carlo model of cellular radiation response was developed. This model incorporated damage from both direct radiation and intercellular communication including bystander signaling. The predictions of this model were compared to previously measured survival curves for a normal human fibroblast line (AGO1522) and prostate tumor cells (DU145) exposed to spatially modulated fields.

Results:
The model was found to be able to accurately reproduce cell survival both in populations which were directly exposed to radiation and those which were outside the primary treatment field. The model predicts that the bystander effect makes a significant contribution to cell killing even in uniformly irradiated cells. The bystander effect contribution varies strongly with dose, falling from a high of 80% at low doses to 25% and 50% at 4 Gy for AGO1522 and DU145 cells, respectively. This was verified using the inducible nitric oxide synthase inhibitor aminoguanidine to inhibit the bystander effect in cells exposed to different doses, which showed significantly larger reductions in cell killing at lower doses.

Conclusions:
The model presented in this work accurately reproduces cell survival following modulated radiation exposures, both in and out of the primary treatment field, by incorporating a bystander component. In addition, the model suggests that the bystander effect is responsible for a significant portion of cell killing in uniformly irradiated cells, 50% and 70% at doses of 2 Gy in AGO1522 and DU145 cells, respectively. This description is a significant departure from accepted radiobiological models and may have a significant impact on optimization of treatment planning approaches if proven to be applicable in vivo.

Plasma HDL cholesterol and risk of myocardial infarction: A mendelian randomisation study

Background: High plasma HDL cholesterol is associated with reduced risk of myocardial infarction, but whether this association is causal is unclear. Exploiting the fact that genotypes are randomly assigned at meiosis, are independent of non-genetic confounding, and are unmodified by disease processes, mendelian random isation can be used to test the hypothesis that the association of a plasma biomarker with disease is causal.
Methods: We performed two mendelian randomisation analyses. First, we used as an instrument a single nucleotide polymorphism (SNP) in the endothelial lipase gene (LIPG Asn396Ser) and tested this SNP in 20 studies (20 913 myocardial infarction cases, 95 407 controls). Second, we used as an instrument a genetic score consisting of 14 common SNPs that exclusively associate with HDL cholesterol and tested this score in up to 12 482 cases of myocardial infarction and 41 331 controls. As a positive control, we also tested a genetic score of 13 common SNPs exclusively associated with LDL cholesterol.
Findings: Carriers of the LIPG 396Ser allele (2·6% frequency) had higher HDL cholesterol (0·14 mmol/L higher p=8×10-13) but similar levels of other lipid and non-lipid risk factors for myocardial infarction compared with noncarriers. This difference in HDL cholesterol is expected to decrease risk of myocardial infarction by 13% (odds ratio [OR] 0·87, 95% CI 0·84-0·91). However, we noted that the 396Ser allele was not associated with risk of myocardial infarction (OR 0·99, 95% CI 0·88-1·11, p=0·85). From observational epidemiology, an increase of 1 SD in HDL cholesterol was associated with reduced risk of myocardial infarction (OR 0·62, 95% CI 0·58-0·66). However, a 1 SD increase in HDL cholesterol due to genetic score was not associated with risk of myocardial infarction (OR 0·93 95% CI 0·68-1·26, p=0·63). For LDL cholesterol, the estimate from observational epidemiology (a 1 SD increase in LDL cholesterol associated with OR 1·54, 95% CI 1·45-1·63) was concordant with that from genetic score (OR 2·13 95% CI 1·69-2·69, p=2×10 -10).
Interpretation: Some genetic mechanisms that raise plasma HDL cholesterol do not seem to lower risk of myocardial infarction. These data challenge the concept that raising of plasma HDL cholesterol will uniformly translate into reductions in risk of myocardial infarction.

Integrating textual analysis and evidential reasoning for decision making in Engineering design

Decision making is an important element throughout the life-cycle of large-scale projects. Decisions are critical as they have a direct impact upon the success/outcome of a project and are affected by many factors including the certainty and precision of information. In this paper we present an evidential reasoning framework which applies Dempster-Shafer Theory and its variant Dezert-Smarandache Theory to aid decision makers in making decisions where the knowledge available may be imprecise, conflicting and uncertain. This conceptual framework is novel as natural language based information extraction techniques are utilized in the extraction and estimation of beliefs from diverse textual information sources, rather than assuming these estimations as already given. Furthermore we describe an algorithm to define a set of maximal consistent subsets before fusion occurs in the reasoning framework. This is important as inconsistencies between subsets may produce results which are incorrect/adverse in the decision making process. The proposed framework can be applied to problems involving material selection and a Use Case based in the Engineering domain is presented to illustrate the approach. © 2013 Elsevier B.V. All rights reserved.