138 research outputs found

    Two-Higgs-Doublet type-II and -III models and tcht\to c h at the LHC

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    We study the constraints of the generic two-Higgs-doublet model (2HDM) type-III and the impacts of the new Yukawa couplings. For comparisons, we revisit the analysis in the 2HDM type-II. To understand the influence of all involving free parameters and to realize their correlations, we employ χ\chi-square fitting approach by including theoretical and experimental constraints, such as S, T, and U oblique parameters, the production of standard model Higgs and its decay to γγ\gamma\gamma, WW/ZZWW^*/ZZ^*, τ+τ\tau^+\tau^-, etc. The errors of analysis are taken at 68%68\%, 95.5%95.5\%, and 99.7%99.7\% confidence levels. Due to the new Yukawa couplings being associated with cos(βα)\cos(\beta-\alpha) and sin(βα)\sin(\beta -\alpha), we find that the allowed regions for sinα\sin\alpha and tanβ\tan\beta in the type-III model can be broader when the dictated parameter χF\chi_F is positive; however, for negative χF\chi_F, the limits are stricter than those in the type-II model. By using the constrained parameters, we find that the deviation from the SM in the hZγh\to Z\gamma can be of O(10%){\cal O}(10\%). Additionally, we also study the top-quark flavor-changing processes induced at the tree level in the type-III model and find that when all current experimental data are considered, we get Br(tc(h,H))<103Br(t\to c(h, H) )< 10^{-3} for mh=125.36m_h=125.36 and mH=150m_H=150 GeV and Br(tcA)Br(t\to cA) slightly exceeds 10310^{-3} for mA=130m_A =130 GeV.Comment: 22 pages, 11 figures. v3: Slight change in the abstract, Figure.1 added and commented, the conclusion remains unchange

    Van der Waals induced polarization of molecules adsorbed on small metallic spheres : anisotropy and nonlocality effects

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    The calculation of Van der Waals induced polarization of molecules interacting with small metallic spheres is based on the spherical-tensor theory by using the response field susceptibility of the sphere. The first Euler angle appearing in the expression giving this polarization exhibits the anisotropy of the molecule. In order to illustrate the non locality and anisotropy effects as well as the importance of the metallic sphere curvature on the induced polarization magnitudes, we present numerical results for typical systems (HF, HCl) on (Ag, Al and Cu).The calculation of Van der Waals induced polarization of molecules interacting with small metallic spheres is based on the spherical-tensor theory by using the response field susceptibility of the sphere. The first Euler angle appearing in the expression giving this polarization exhibits the anisotropy of the molecule. In order to illustrate the non locality and anisotropy effects as well as the importance of the metallic sphere curvature on the induced polarization magnitudes, we present numerical results for typical systems (HF, HCl) on (Ag, Al and Cu)

    Reponses Of A Metallic Bubble: A Self-Consistent Calculation Including Correlation And Exchange Effects

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    The Van der Waals energy of molecules interacting with metallic bubbles is determined from spherical-tensor theory by using the response field susceptibility of the spherical bubble. The correlation and exchange effects of the electron response inside the metal are included by using the local density approximation (LDA). The dependence of the Van der Waals energy on the first Euler angle is manifestation of the anisotropy of the interaction. In order to illustrate the non-locality and the correlation and exchange effects as well as the importance of the spherical bubble curvature and anisotropy of the interaction on the potential magnitudes, we present numerical results for typical systems (HF,HCl) molecules on (Ag,Al) surfaces.The Van der Waals energy of molecules interacting with metallic bubbles is determined from spherical-tensor theory by using the response field susceptibility of the spherical bubble. The correlation and exchange effects of the electron response inside the metal are included by using the local density approximation (LDA). The dependence of the Van der Waals energy on the first Euler angle is manifestation of the anisotropy of the interaction. In order to illustrate the non-locality and the correlation and exchange effects as well as the importance of the spherical bubble curvature and anisotropy of the interaction on the potential magnitudes, we present numerical results for typical systems (HF,HCl) molecules on (Ag,Al) surfaces

    Risk factors caused by scorpion stings and envenomations in the province of Kelâa Des Sraghna (Morocco)

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    The present study aims to elucidate the risk factors involved in deaths caused by scorpion envenomation. A retrospective study was carried out in the province of Kelâa des Sraghna from 2003 to 2004. The hospital charts of scorpion envenomation cases treated in the Essalama Hospital in Kelâa des Sraghna were exhaustively analyzed. Our study contains 31 cases of death among 470 hospitalization cases. Most stings had occurred during the hot period peaking in July and August (54.6%). Moreover, the scorpion stings occurred at night in 60.1% of the cases, between 6:00 pm and 6:00 am. In addition, all age groups were affected by envenomation, with a higher frequency in children aged less than 15 years (68.3%). The envenomation rate (class II + class III) was 70.9%. The statistical analysis of the data shows that being less than 15 years old, having been stung during the night and belonging to class III are risk factors that aggravate vital prognosis of hospitalized patients. Furthermore, clinical severity factors, elicited by relative risk analysis, are cardiovascular, respiratory and neurological vital distresses, with relative risks of 14.84, 11.92 and 48.33, respectively. The results of our study clearly displayed the severity and extent of the scorpion envenomation problem. Thus, great attention must be paid to this region of Morocco by the national health authorities

    Three dimensional structure prediction of fatty acid binding site on human transmembrane receptor CD36

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    CD36 is an integral membrane protein which is thought to have a hairpin-like structure with alpha-helices at the C and N terminals projecting through the membrane as well as a larger extracellular loop. This receptor interacts with a number of ligands including oxidized low density lipoprotein and long chain fatty acids (LCFAs). It is also implicated in lipid metabolism and heart diseases. It is therefore important to determine the 3D structure of the CD36 site involved in lipid binding. In this study, we predict the 3D structure of the fatty acid (FA) binding site [127–279 aa] of the CD36 receptor based on homology modeling with X-ray structure of Human Muscle Fatty Acid Binding Protein (PDB code: 1HMT). Qualitative and quantitative analysis of the resulting model suggests that this model was reliable and stable, taking in consideration over 97.8% of the residues in the most favored regions as well as the significant overall quality factor. Protein analysis, which relied on the secondary structure prediction of the target sequence and the comparison of 1HMT and CD36 [127–279 aa] secondary structures, led to the determination of the amino acid sequence consensus. These results also led to the identification of the functional sites on CD36 and revealed the presence of residues which may play a major role during ligand-protein interactions

    Talking about chronic pain in family settings: a glimpse of older persons' everyday realities.

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    The expression of chronic pain remains a delicate matter for those older persons who suffer from this condition. If many studies highlight the difficulties of putting pain into words, scarce are those that take into account how given social networks can facilitate or prevent its expression. Based on a qualitative study that explores the communication about chronic pain in older persons' social network, this article reports on this key issue of talking about health in later life within family settings and provides clinicians with information about the way older persons with chronic conditions perceive their everyday realities and social relations. A multidisciplinary research team (medicine, linguistics and psychology) interviewed 49 persons with chronic pain, all from the French-speaking part of Switzerland, aged 75 and older, without any major cognitive or auditory impairments. After transcription, the interviews were analyzed by combining content and discourse analysis with social network theories. Communication about chronic pain depends significantly on the position of the interlocutors within the family structure, with a preference for direct relatives or individuals with similar difficulties. In social networks, the ability to communicate about chronic pain is both a resource (by allowing older persons to get help or by strengthening interpersonal relations) and a challenge (by threatening their autonomy, social relations or self-esteem). The study shows the predominance of the nuclear family (partner, children) in communication relating specifically to the everyday management of chronic pain. This state of affairs is, nevertheless, balanced by issues of (loss of) autonomy. These findings, in line with current trends in geriatrics, could benefit future reflections on the scope and limits of including relatives in the care of older patients with chronic conditions

    Communication About Chronic Pain in Older Persons' Social Networks: Study Protocol of a Qualitative Approach.

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    A lack of social relations appears to impact on health and life expectancy among the older persons. The quality and diversity of social relations are correlated with good health and well-being in later life. Chronic pain is a crucial issue in aging population. Effective communication between the older persons with chronic pain, their relatives and the actors of the healthcare system facilitates the management of this condition. Studies on communication in later life generally do not consider the older persons' social network as a whole, focusing only a specific segment (e.g., family or medical staff). This lack of scientific data prevents the actors of the healthcare system from offering solutions to bridge clinically relevant communication gaps. As a consequence, our study has three objectives: (1) to identify how the older persons perceive communication about chronic pain with their social network; (2) to identify their unmet communication needs; (3) to develop recommendations that improve communication about chronic pain in later life. The study will be divided into two phases. The first phase will meet objectives 1 and 2. It will involve individual interviews with about 50 people over 75 years old suffering from chronic pain and without major cognitive or auditory troubles. In this phase, we will apply a multi-layered analysis. We will map the older persons' personal network and identify their communication practices and needs, by combining content and discourse analysis with social network theories. The second phase of the study will aim at recommendations based on the results of the first phase (objective 3). It will require focus groups with different sets of stakeholders (older persons, relative caregivers, health professionals, decision-makers). In the second phase, we will use content analysis to pinpoint the concerns and suggestions for action. The results will be disseminated on three levels: (1) to the scientific world (specialists in the field of health and aging and health communication); (2) to health practitioners working with older persons; (3) to society at large, with a focus on institutions and groups directly concerned by the issue

    Fractionation of lead in soil by isotopic dilution and sequential extraction

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    ‘Reactivity’ or ‘lability’ of lead is difficult to measure using traditional methods. We investigated the use of isotopic dilution with 204Pb to determine metal reactivity in four soils historically contaminated with contrasting sources of Pb, including (i) petrol-derived Pb, (ii) Pb/Zn minespoil, (iii) long-term sewage sludge application and (iv) 19th century urban waste disposal; total soil Pb concentrations ranged from 217 to 13 600 mg kg–1. A post-spike equilibration period of 3 days and suspension in 5.0 × 10–4 M ethylenediaminetetraacetic acid provided reasonably robust conditions for measuring isotopically exchangeable Pb. However, in acidic organic soils a dilute Ca(NO3)2 electrolyte may be preferable to avoid mobilisation of ‘non-labile’ Pb. Results showed that the reactive pool of soil Pb can be a large proportion of the total soil lead content but varies with the original Pb source. A comparison of isotopic exchangeability with the results of a sequential extraction procedure showed that (isotopically) ‘non-labile’ Pb may be broadly equated with ‘residual’ Pb in organic soils. However, in mineral soils the ‘carbonate’ and ‘oxide-bound’ Pb fractions included non-labile forms of Pb. The individual isotopic signatures of labile and non-labile Pb pools suggested that, despite prolonged contact with soil, differences between the lability of the original contaminant and the native soil Pb may remain
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