3,721 research outputs found
Thermal effects on electron-phonon interaction in silicon nanostructures
Raman spectra from silicon nanostructures, recorded using excitation laser
power density of 1.0 kW/cm^2, is employed here to reveal the dominance of
thermal effects at temperatures higher than the room temperature. Room
temperature Raman spectrum shows only phonon confinement and Fano effects.
Raman spectra recorded at higher temperatures show increase in FWHM and
decrease in asymmetry ratio with respect to its room temperature counterpart.
Experimental Raman scattering data are analyzed successfully using theoretical
Raman line-shape generated by incorporating the temperature dependence of
phonon dispersion relation. Experimental and theoretical temperature dependent
Raman spectra are in good agreement. Although quantum confinement and Fano
effects persists, heating effects start dominating at higher temperatures than
room tempaerature.Comment: 9 Pages, 3 Figures and 1 Tabl
Determination of Pericardial Adipose Tissue Increases the Prognostic Accuracy of Coronary Artery Calcification for Future Cardiovascular Events
Objectives: Pericardial adipose tissue (PAT) is associated with coronary artery plaque accumulation and the incidence of coronary heart disease. We evaluated the possible incremental prognostic value of PAT for future cardiovascular events. Methods: 145 patients (94 males, age 60 10 years) with stable coronary artery disease underwent coronary artery calcification (CAC) scanning in a multislice CT scanner, and the volume of pericardial fat was measured. Mean observation time was 5.4 years. Results: 34 patients experienced a severe cardiac event. They had a significantly higher CAC score (1,708 +/- 2,269 vs. 538 +/- 1,150, p 400, 3.5 (1.9-5.4; p = 0.007) for scores > 800 and 5.9 (3.7-7.8; p = 0.005) for scores > 1,600. When additionally a PAT volume > 200 cm(3) was determined, there was a significant increase in the event rate and relative risk. We calculated a relative risk of 2.9 (1.9-4.2; p = 0.01) for scores > 400, 4.0 (2.1-5.0; p = 0.006) for scores > 800 and 7.1 (4.1-10.2; p = 0.005) for scores > 1,600. Conclusions:The additional determination of PAT increases the predictive power of CAC for future cardiovascular events. PAT might therefore be used as a further parameter for risk stratification. Copyright (C) 2012 S. Karger AG, Base
Activation of the innate immune receptor Dectin-1 upon formation of a 'phagocytic synapse'.
Innate immune cells must be able to distinguish between direct binding to microbes and detection of components shed from the surface of microbes located at a distance. Dectin-1 (also known as CLEC7A) is a pattern-recognition receptor expressed by myeloid phagocytes (macrophages, dendritic cells and neutrophils) that detects β-glucans in fungal cell walls and triggers direct cellular antimicrobial activity, including phagocytosis and production of reactive oxygen species (ROS). In contrast to inflammatory responses stimulated upon detection of soluble ligands by other pattern-recognition receptors, such as Toll-like receptors (TLRs), these responses are only useful when a cell comes into direct contact with a microbe and must not be spuriously activated by soluble stimuli. In this study we show that, despite its ability to bind both soluble and particulate β-glucan polymers, Dectin-1 signalling is only activated by particulate β-glucans, which cluster the receptor in synapse-like structures from which regulatory tyrosine phosphatases CD45 and CD148 (also known as PTPRC and PTPRJ, respectively) are excluded (Supplementary Fig. 1). The 'phagocytic synapse' now provides a model mechanism by which innate immune receptors can distinguish direct microbial contact from detection of microbes at a distance, thereby initiating direct cellular antimicrobial responses only when they are required
The formation of professional identity in medical students: considerations for educators
<b>Context</b> Medical education is about more than acquiring an appropriate level of knowledge and developing relevant skills. To practice medicine students need to develop a professional identity – ways of being and relating in professional contexts.<p></p>
<b>Objectives</b> This article conceptualises the processes underlying the formation and maintenance of medical students’ professional identity drawing on concepts from social psychology.<p></p>
<b>Implications</b> A multi-dimensional model of identity and identity formation, along with the concepts of identity capital and multiple identities, are presented. The implications for educators are discussed.<p></p>
<b>Conclusions</b> Identity formation is mainly social and relational in nature. Educators, and the wider medical society, need to utilise and maximise the opportunities that exist in the various relational settings students experience. Education in its broadest sense is about the transformation of the self into new ways of thinking and relating. Helping students form, and successfully integrate their professional selves into their multiple identities, is a fundamental of medical education
Labelling, Deviance and Media
Labelling theory is a perspective that emerged as a distinctive approach to criminology during the 1960s, and was a major seedbed of the radical and critical perspectives that became prominent in the 1970s. It represented the highpoint of an epistemological shift within the social sciences away from positivism – which had dominated criminological enquiry since the late-1800s – and toward an altogether more relativistic stance on the categories and concepts of crime and control. It inspired a huge amount of work throughout the 1960s and 1970s, and still resonates powerfully today. This short chapter maps out some of the ways in which labelling, deviance, media and justice interact at the levels of definition and process. It presents an overview and analysis of key mediatised labelling processes, such as the highly influential concept of moral panics. It discusses how the interconnections between labelling, crime and criminal justice are changing in a context of technological development, cultural change and media proliferation. The conclusion offers an assessment and evaluation of labelling theory’s long-term impact on criminology
Negative phenotypic and genetic associations between copulation duration and longevity in male seed beetles
Reproduction can be costly and is predicted to trade-off against other characters. However, while these trade-offs are well documented for females, there has been less focus on aspects of male reproduction. Furthermore, those studies that have looked at males typically only investigate phenotypic associations, with the underlying genetics often ignored. Here, we report on phenotypic and genetic trade-offs in male reproductive effort in the seed beetle, Callosobruchus maculatus. We find that the duration of a male's first copulation is negatively associated with subsequent male survival, phenotypically and genetically. Our results are consistent with life-history theory and suggest that like females, males trade-off reproductive effort against longevity
The Use of NVivo in the Different Stages of Qualitative Research
When researchers take their first steps in qualitative research, they face the great lack of models to follow regarding the method to use in the analysis of data, on some occasions falling into the temptation of coveting the high level of systematisation employed by researchers working with quantitative data. This article offers a basic theoretical contribution that allows researcher to approach qualitative data analysis and the use of the NVivo software, highlighting its advantages and describing the main functions at each moment of a qualitative investigation, placing particular emphasis on the analysis process
Poor youths and ‘pacification’:dilemmas between discourse and practice from the perspective of young people about policing in Rio de Janeiro’s favelas
This article explores the social representations of youngsters from favelas in Rio de Janeiro on
police practices in the context of the implementation of ‘Pacifying Police Units’. Drawing from
fieldwork, participant observation and interviews, the authors analyse the narratives and practices
which influence relations between young people and the police in the Complexo do Alemão
area of the city. The interviewees expressed a demand for further public security and social
services. Young people noted some progress in police practices, although these changes appear
to be unstable. The permanence of violent practices and prejudice by the police was verified in
youngsters’ narratives. Any change in this scenario should be based on the replacement of the
war logic of ‘pacification’ for another logic, that of participation.2030-01-0
Diverse tick-borne microorganisms identified in free-living ungulates in Slovakia
Background: Free-living ungulates are hosts of ixodid ticks and reservoirs of tick-borne microorganisms in central Europe and many regions around the world. Tissue samples and engorged ticks were obtained from roe deer, red deer, fallow deer, mouflon, and wild boar hunted in deciduous forests of south-western Slovakia. DNA isolated from these samples was screened for the presence of tick-borne microorganisms by PCR-based methods. Results: Ticks were found to infest all examined ungulate species. The principal infesting tick was Ixodes ricinus, identified on 90.4% of wildlife, and included all developmental stages. Larvae and nymphs of Haemaphysalis concinna were feeding on 9.6% of wildlife. Two specimens of Dermacentor reticulatus were also identified. Ungulates were positive for A. phagocytophilum and Theileria spp. Anaplasma phagocytophilum was found to infect 96.1% of cervids, 88.9% of mouflon, and 28.2% of wild boar, whereas Theileria spp. was detected only in cervids (94.6%). Importantly, a high rate of cervids (89%) showed mixed infections with both these microorganisms. In addition to A. phagocytophilum and Theileria spp., Rickettsia helvetica, R. monacensis, unidentified Rickettsia sp., Coxiella burnetii, "Candidatus Neoehrlichia mikurensis", Borrelia burgdorferi (s.l.) and Babesia venatorum were identified in engorged I. ricinus. Furthermore, A. phagocytophilum, Babesia spp. and Theileria spp. were detected in engorged H. concinna. Analysis of 16S rRNA and groEL gene sequences revealed the presence of five and two A. phagocytophilum variants, respectively, among which sequences identified in wild boar showed identity to the sequence of the causative agent of human granulocytic anaplasmosis (HGA). Phylogenetic analysis of Theileria 18S rRNA gene sequences amplified from cervids and engorged I. ricinus ticks segregated jointly with sequences of T. capreoli isolates into a moderately supported monophyletic clade. Conclusions: The findings indicate that free-living ungulates are reservoirs for A. phagocytophilum and Theileria spp. and engorged ixodid ticks attached to ungulates are good sentinels for the presence of agents of public and veterinary concern. Further analyses of the A. phagocytophilum genetic variants and Theileria species and their associations with vector ticks and free-living ungulates are required.Fil: Kazimírová, Mária. Slovak Academy of Sciences. Institute of Zoology; EslovaquiaFil: Hamšíková, Zuzana. Slovak Academy of Sciences. Institute of Zoology; EslovaquiaFil: Spitalská, Eva. Slovak Academy of Sciences. Institute of Virology. Biomedical Research Center,; EslovaquiaFil: Minichová, Lenka. Slovak Academy of Sciences. Institute of Virology. Biomedical Research Center,; EslovaquiaFil: Mahríková, Lenka. Slovak Academy of Sciences. Institute of Zoology; EslovaquiaFil: Caban, Radoslav. Široká ; EslovaquiaFil: Sprong, Hein. National Institute for Public Health and Environment.Laboratory for Zoonoses and Environmental Microbiology; Países BajosFil: Fonville, Manoj. National Institute for Public Health and Environment.Laboratory for Zoonoses and Environmental Microbiology; Países BajosFil: Schnittger, Leonhard. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kocianová, Elena. Slovak Academy of Sciences. Institute of Virology. Biomedical Research Center,; Eslovaqui
A multidimensional view? Evaluating the different and combined contributions of diaries and interviews in an exploration of asexual identities and intimacies
This article evaluates the relative contributions of diaries and interviews in multiple methods qualitative research exploring asexual identities and intimacies. Differentiated by three core differences: reflective time-frame (the day just had/lifetime), context (alone/with researcher) and mode (written/verbal), these methods had the potential to generate a multidimensional view of our topics. Using five cases in which data from both interviews and diaries were collected, this article explores how the intermeshed issues of identity and intimacy were constructed in each method, as well as reflecting on what was gained by their combination. Our analysis leads us to conclude that multiple methods do not always produce a fuller or a more rounded picture of individual participants’ lives. Nevertheless, the decision to collect data using different strategies did increase our chances of finding a method that suited individual participants, whether in style or focus
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