3,143 research outputs found

    Grappling with Emerging Adulthoods

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    __Abstract__ This study is about subjectivities of young people and about coming of age in a frontier town, Beitbridge, in southern Zimbabwe. The study is motivated by the growing attention to African youth as a social-demographic group and a social phenomenon since the late 1990s in the context of unprecedented economic dislocation. The latter has seen young people resorting to livelihoods largely seen as illicit, immoral and anti-establishment such as activities in the grey economy and sex work. As young people take matters into their own hands, policy makers have tended to use essentialist arguments according to which young people’s behaviour can be understood as a result of age and hormonal changes. This study uses a constructivist and interpretivist approach in which youth is socially created and the behaviour of young people is understood as embedded on its socio-economic, cultural and political context. These approaches are complementary and allow us to question what is taken for granted such as what is assumed about youth and also account for the dissonance between norms and deeds (Yanow 2006:19, Gergen 2000:50). By studying young people’s subjectivities in growing up, the study sought to capture lived experiences of the young and how economic instability impinges on growing up

    Youth lyrics, street language and the politics of age: Contextualising the youth question in the Third Chimurenga in Zimbabwe

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    Debates about the effects of the 'cultural nationalism' that has accompanied the so-called 'Third Chimurenga' in Zimbabwe since 2000, often portray youth as pawns of officials - for example, as national youth service trainees or as government sponsored artists - rather than as among the worst affected by recent developmental crises, who are struggling against the odds to survive. Yet concern about youth restlessness did, in part, lead to policies, such as the requirement of '75 per cent local content' for public broadcasters, which created opportunities for youth action and led, in turn, to the development of a new musical style known as 'urban grooves'. However, in 2007, Zimbabwean public radio and television banned the airplay of certain 'urban grooves' songs because of their unsavoury lyrics. In this article I analyse the lyrics of these songs in order to argue that together, the songs' lyrics, and their ban fromairtime, point to emergent intergenerational tensions. Some of these tensions revolve around emerging forms, uses andmeanings of vernacular languages. Whereas the 75 per cent local content policy imposed by the government in 2001 envisaged an anti-imperialist popular culture through the use of vernacular languages and local media products, youths used vernacular languages to highlight intergenerational sex differences in heterosexual behaviour. They used street language not ordinarily accessible to adults, to deliver an incisive critique of adult sexual excesses. As observed elsewhere in sub-Saharan Africa, not only do the banned songs provide an insight into youth subjectivities amidst the social contradictions of Zimbabwe's socio-economic and political crises, they also illustrate how popular music can be a form of civic participation

    Observations of rotationally resolved C3 in translucent sight lines

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    The rotationally resolved spectrum of the A ^1Pi_u <- X ^1Sigma^+_g 000-000 transition of C3, centered at 4051.6A, has been observed along 10 translucent lines of sight. To interpret these spectra, a new method for the determination of column densities and analysis of excitation profiles involving the simulation and fitting of observed spectra has been developed. The populations of lower rotational levels (J<14) in C3 are best fit by thermal distributions that are consistent with the kinetic temperatures determined from the excitation profile of C2. Just as in the case of C2, higher rotational levels (J>14) of C3 show increased nonthermal population distributions in clouds which have been determined to have total gas densities below ~500 cm-3.Comment: 12 pages, 4 figures, accepted for publication in The Astrophysical Journa

    Prompt emission polarimetry of Gamma Ray Bursts with ASTROSAT CZT-Imager

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    X-ray and Gamma-ray polarization measurements of the prompt emission of Gamma-ray bursts (GRBs) are believed to be extremely important for testing various models of GRBs. So far, the available measurements of hard X-ray polarization of GRB prompt emission have not significantly constrained the GRB models, particularly because of the difficulty of measuring polarization in these bands. The CZT Imager (CZTI) onboard {\em AstroSat} is primarily an X-ray spectroscopic instrument that also works as a wide angle GRB monitor due to the transparency of its support structure above 100 keV. It also has experimentally verified polarization measurement capability in the 100 - 300 keV energy range and thus provides a unique opportunity to attempt spectro-polarimetric studies of GRBs. Here we present the polarization data for the brightest 11 GRBs detected by CZTI during its first year of operation. Among these, 5 GRBs show polarization signatures with \gtrapprox3σ\sigma, and 1 GRB shows \>2σ\sigma detection significance. We place upper limits for the remaining 5 GRBs. We provide details of the various tests performed to validate our polarization measurements. While it is difficult yet to discriminate between various emission models with the current sample alone, the large number of polarization measurements CZTI expects to gather in its minimum lifetime of five years should help to significantly improve our understanding of the prompt emission.Comment: Accepted for Publication in ApJ ; a figure has been update

    Atomic Scale Sliding and Rolling of Carbon Nanotubes

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    A carbon nanotube is an ideal object for understanding the atomic scale aspects of interface interaction and friction. Using molecular statics and dynamics methods different types of motion of nanotubes on a graphite surface are investigated. We found that each nanotube has unique equilibrium orientations with sharp potential energy minima. This leads to atomic scale locking of the nanotube. The effective contact area and the total interaction energy scale with the square root of the radius. Sliding and rolling of nanotubes have different characters. The potential energy barriers for sliding nanotubes are higher than that for perfect rolling. When the nanotube is pushed, we observe a combination of atomic scale spinning and sliding motion. The result is rolling with the friction force comparable to sliding.Comment: 4 pages (two column) 6 figures - one ep

    The InfraRed Imaging Spectrograph (IRIS) for TMT: latest science cases and simulations

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    The Thirty Meter Telescope (TMT) first light instrument IRIS (Infrared Imaging Spectrograph) will complete its preliminary design phase in 2016. The IRIS instrument design includes a near-infrared (0.85 - 2.4 micron) integral field spectrograph (IFS) and imager that are able to conduct simultaneous diffraction-limited observations behind the advanced adaptive optics system NFIRAOS. The IRIS science cases have continued to be developed and new science studies have been investigated to aid in technical performance and design requirements. In this development phase, the IRIS science team has paid particular attention to the selection of filters, gratings, sensitivities of the entire system, and science cases that will benefit from the parallel mode of the IFS and imaging camera. We present new science cases for IRIS using the latest end-to-end data simulator on the following topics: Solar System bodies, the Galactic center, active galactic nuclei (AGN), and distant gravitationally-lensed galaxies. We then briefly discuss the necessity of an advanced data management system and data reduction pipeline.Comment: 15 pages, 7 figures, SPIE (2016) 9909-0

    Prognostic value of replication errors on chromosomes 2p and 3p in non-small-cell lung cancer

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    As chromosomes 2p and 3p are frequent targets for genomic instability in lung cancer, we have addressed whether alterations of simple (CA)n DNA repeats occur in non-small-cell lung cancer (NSCLC) at early stages. We have analysed by polymerase chain reaction (PCR) assay replication errors (RER) and loss of heterozygosity (LOH) at microsatellites mapped on chromosomes 2p and 3p in 64 paired tumour-normal DNA samples from consecutively resected stage I, II or IIIA NSCLC. DNA samples were also examined for K-ras and p53 gene mutations by PCR-single-stranded conformational polymorphism (PCR-SSCP) analysis and cyclic sequencing, as well as their relationship with clinical outcome. Forty-two of the 64 (66%) NSCLC patients showed RER at single or multiple loci. LOH was detected in 23 tumours (36%). Among patients with stage I disease, the 5-year survival rate was 80% in those whose tumours had no evidence of RER and 26% in those with RER (P = 0.005). No correlation was established between RER phenotype and LOH, K-ras or p53 mutations. RER remained a strong predictive factor (hazard ratio for death, 2.89; 95% confidence interval, 2.23-3.79; P = 0.002) after adjustment for all other evaluated factors, including p53, K-ras, LOH, histological type, tumour differentiation and TNM stage, suggesting that microsatellite instability on chromosomes 2p and 3p may play a role in NSCLC progression through a different pathway from the traditional tumour mechanisms of oncogene activation and/or tumour-suppressor gene inactivation
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