225 research outputs found

    Street theatre : Critical pedagogy for social studies education

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    This paper aims at exploring the usefulness of street theatre as critical pedagogy in teaching of social studies education. It gives a brief background of street-theatre and its linkages with critical pedagogy. In the light of theoretical underpinnings of this arts-based pedagogy, the paper deliberates upon the relevance and efficacy of street theatre in a social studies classroom. This paper uses a street theatre performance case to look at the techniques such as: body motion, body work, props, use of visual and audio aids, etc.; processes such as: conscientization and catharsis; and dialogical approach employed by street theatre to bring awareness about socio-political and cultural issues prevalent in a society. The analysis of this performance act shows that street theatre successfully encourages spectators or the oppressed masses to reflect, and triggers action in them to come out of socio-political oppression. When looked at from educational perspective, street theatre encourages the employment of multiple-intelligences of both students and teachers; and therefore, it can be one innovative strategy to make students aware of the issues infecting their society and also to empower students for action

    Measurement of the Scintillation Efficiency of Na Recoils in NaI(Tl) down to 10 keV Nuclear Recoil Energy relevant to Dark Matter Searches

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    We present preliminary results of measurements of the quenching factor for Na recoils in NaI(Tl) at room temperature, made at a dedicated neutron facility at the University of Sheffield. Measurements have been performed with a 2.45 MeV mono-energetic neutron generator in the energy range from 10 keV to 100 keV nuclear recoil energy. A BC501A liquid scintillator detector was used to tag neutrons. Cuts on pulse-shape discrimination from the BC501A liquid scintillator detector and neutron time-of-flight were performed on pulses recorded by a digitizer with a 2 ns sampling time. Measured quenching factors range from 19% to 26%, in agreement with other experiments. From pulse-shape analysis, a mean time of pulses from electron and nuclear recoils are compared down to 2 keV electron equivalent energy.Comment: to appear in Proc. 6th Int. Workshop on the Identification of Dark Matter, 11-16 September 2006, Rhodes, Greece; 6 pages, 4 figures; corrected preliminary theoretical estimation curve plotted in figure

    Comparison of the Prevalence of Intestinal Parasites in HIV-Positive and AIDS Patients in Khorramabad City in 2006-2007

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    Abstract: Background & Aims: Immunodeficiency virus (HIV) may lead to acquired immunodeficiency syndrome (AIDS) in human. Parasites are one of the most important causes of infectious diseases in patients with AIDS. The prevalence of these parasites varies based on the condition of host’s immune system and the stage of disease (HIV/AIDS). To compare the prevalence of opportunistic intestinal parasites a cross-sectional study was carried out on 306 HIV positive and AIDS patients in Khorramabad city. Methods: After selecting the samples by census and availability sampling methods, planned questionnaires were completed and three stool samples were collected from patients. Then direct smear, formalin-ether concentration techniques and modified acid fast (Kinione) and modified trichorome staining methods were carried out on all samples during 2006-2007. Moreover the relationship between different variables and infection by intestinal parasites were examined. For description and statistical analysis t-test and Chi-square test were used. Results: The prevalence of intestinal parasites in HIV-positive and AIDS patients was 19.6% and 50% respectively. There was a significant relationship between HIV /AIDS and species of intestinal parasites (P< 0.001). Conclusion: Higher prevalence of intestinal parasites in patients with AIDS compared to HIV-positive individuals indicates higher immune system deficiency and more susceptibility to intestinal parasitic infections (specially opportunistic parasites) and reflects the necessity of prevention, screening, diagnosis and treatment programs for these patients. Keywords: Intestinal parasites, HIV, AIDS, Khorramaba

    Measurement of the quenching factor of Na recoils in NaI(Tl)

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    Measurements of the quenching factor for sodium recoils in a 5 cm diameter NaI(Tl) crystal at room temperature have been made at a dedicated neutron facility at the University of Sheffield. The crystal has been exposed to 2.45 MeV mono-energetic neutrons generated by a Sodern GENIE 16 neutron generator, yielding nuclear recoils of energies between 10 and 100 keVnr. A cylindrical BC501A detector has been used to tag neutrons that scatter off sodium nuclei in the crystal. Cuts on pulse shape and time of flight have been performed on pulses recorded by an Acqiris DC265 digitiser with a 2 ns sampling time. Measured quenching factors of Na nuclei range from 19% to 26% in good agreement with other experiments, and a value of 25.2 \pm 6.4% has been determined for 10 keV sodium recoils. From pulse shape analysis, the mean times of pulses from electron and nuclear recoils have been compared down to 2 keVee. The experimental results are compared to those predicted by Lindhard theory, simulated by the SRIM Monte Carlo code, and a preliminary curve calculated by Prof. Akira Hitachi.Comment: 21 pages, 13 figure

    Can muon-induced backgrounds explain the DAMA data?

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    We present an accurate simulation of the muon-induced background in the DAMA/LIBRA experiment. Muon sampling underground has been performed using the MUSIC/MUSUN codes and subsequent interactions in the rock around the DAMA/LIBRA detector cavern and the experimental setup including shielding, have been simulated with GEANT4.9.6. In total we simulate the equivalent of 20 years of muon data. We have calculated the total muon-induced neutron flux in the DAMA/LIBRA detector cavern as Φμn = 1.0 ×10-9 cm-2s-1, which is consistent with other simulations. After selecting events which satisfy the DAMA/LIBRA signal criteria, our simulation predicts 3.49 ×10-5 cpd/kg/keV which accounts for less than 0.3% of the DAMA/LIBRA modulation amplitude. We conclude from our work that muon-induced backgrounds are unable to contribute to the observed signal modulation

    Self-Reported Occupational Exposure to HIV and Factors Influencing its Management Practice: A Study of Healthcare Workers in Tumbi and Dodoma Hospitals, Tanzania.

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    Blood borne infectious agents such as hepatitis B virus (HBV), hepatitis C virus (HCV) and human immune deficiency virus (HIV) constitute a major occupational hazard for healthcare workers (HCWs). To some degree it is inevitable that HCWs sustain injuries from sharp objects such as needles, scalpels and splintered bone during execution of their duties. However, in Tanzania, there is little or no information on factors that influence the practice of managing occupational exposure to HIV by HCWs. This study was conducted to determine the prevalence of self-reported occupational exposure to HIV among HCWs and explore factors that influence the practice of managing occupational exposure to HIV by HCWs in Tanzania. Self-administered questionnaire was designed to gather information of healthcare workers' occupational exposures in the past 12 months and circumstances in which these injuries occurred. Practice of managing occupational exposure was assessed by the following questions: Nearly half of the HCWs had experienced at least one occupational injury in the past 12 months. Though most of the occupational exposures to HIV were experienced by female nurses, non-medical hospital staff received PEP more frequently than nurses and doctors. Doctors and nurses frequently encountered occupational injuries in surgery room and labor room respectively. HCWs with knowledge on the possibility of HIV transmission and those who knew whom to contact in event of occupational exposure to HIV were less likely to have poor practice of managing occupational exposure. Needle stick injuries and splashes are common among HCWs at Tumbi and Dodoma hospitals. Knowledge of the risk of HIV transmission due to occupational exposure and knowing whom to contact in event of exposure predicted practice of managing the exposure. Thus provision of health education on occupational exposure may strengthen healthcare workers' practices to manage occupational exposure

    Asymmetric Inelastic Inert Doublet Dark Matter from Triplet Scalar Leptogenesis

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    The nature of dark matter (DM) particles and the mechanism that provides their measured relic abundance are currently unknown. In this paper we investigate inert scalar and vector like fermion doublet DM candidates with a charge asymmetry in the dark sector, which is generated by the same mechanism that provides the baryon asymmetry, namely baryogenesis-via-leptogenesis induced by decays of scalar triplets. At the same time the model gives rise to neutrino masses in the ballpark of oscillation experiments via type II seesaw. We discuss possible sources of depletion of asymmetry in the DM and visible sectors and solve the relevant Boltzmann equations for quasi-equilibrium decay of triplet scalars. A Monte-Carlo-Markov-Chain analysis is performed for the whole parameter space. The survival of the asymmetry in the dark sector leads to inelastic scattering off nuclei. We then apply bayesian statistic to infer the model parameters favoured by the current experimental data, in particular the DAMA annual modulation and Xenon100 exclusion limit. The latter strongly disfavours asymmetric scalar doublet DM of mass \mathcal{O}(\TeV) as required by DM-DMˉ\bar{\rm DM} oscillations, while an asymmetric vector like fermion doublet DM with mass around 100 GeV is a good candidate for DAMA annual modulation yet satisfying the constraints from Xenon100 data.Comment: 35 pages and 15 figures, references adde

    Brexit: Its Passing and Reverberations

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    The most significant financial and economic news story in 2016 was the June 23 decision of the British public to terminate the U.K.’s membership in the European Union. Polls and bookmakers in the days leading up to the vote had constantly maintained that, while the vote would be close, a “Brexit” was unlikely. As we now know, that position proved false. Financial markets around the world reacted quickly and sharply to the unexpected news

    Dark Matter attempts for CoGeNT and DAMA

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    Recently, the CoGeNT collaboration presented a positive signal for an annual modulation in their data set. In light of the long standing annual modulation signal in DAMA/LIBRA, we analyze the compatibility of both of these signal within the hypothesis of dark matter (DM) scattering on nuclei, taking into account existing experimental constraints. We consider the cases of elastic and inelastic scattering with either spin-dependent or spin-independent coupling to nucleons. We allow for isospin violating interactions as well as for light mediators. We find that there is some tension between the size of the modulation signal and the time-integrated event excess in CoGeNT, making it difficult to explain both simultaneously. Moreover, within the wide range of DM interaction models considered, we do not find a simultaneous explanation of CoGeNT and DAMA/LIBRA compatible with constraints from other experiments. However, in certain cases part of the data can be made consistent. For example, the modulation signal from CoGeNT becomes consistent with the total rate and with limits from other DM searches at 90% CL (but not with the DAMA/LIBRA signal) if DM scattering is inelastic spin-independent with just the right couplings to protons and neutrons to reduce the scattering rate on xenon. Conversely the DAMA/LIBRA signal (but not CoGeNT) can be explained by spin-dependent inelastic DM scattering.Comment: 20 pages, 9 figure
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