636 research outputs found
Directional responses following recombinant cytokine stimulation of rainbow trout (Oncorhynchus mykiss) RTS-11 macrophage cells as revealed by transcriptome profiling
Peer reviewedPublisher PD
Starvation alters the liver transcriptome of the innate immune response in Atlantic salmon (Salmo salar)
Peer reviewedPublisher PD
Electron and Hole Dynamics of InAs∕GaAsInAs∕GaAs Quantum Dot Semiconductor Optical Amplifiers
Single-color and two-color pump-probe measurements are used to analyze carrier dynamics in InAs∕GaAs quantum dot amplifiers. The study reveals that hole recovery and intradot electron relaxation occur on a picosecond time scale, while the electron capture time is on the order of 10ps. A longer time scale of hundreds of picoseconds is associated with carrier recovery in the wetting layer, similar to that observed in quantum well semiconductor amplifiers
Delay Induced Excitability
We analyse the stochastic dynamics of a bistable system under the influence
of time-delayed feedback. Assuming an asymmetric potential, we show the
existence of a regime in which the systems dynamic displays excitability by
calculating the relevant residence time distributions and correlation times.
Experimentally we then observe this behaviour in the polarization dynamics of a
vertical cavity surface emitting laser with opto-electronic feedback. Extending
these observations to two-dimensional systems with dispersive coupling we
finally show numerically that delay induced excitability can lead to the
appearance of propagating wave-fronts and spirals.Comment: 5 pages, 6 figure
The tuberculosis challenge in a rural South African HIV programme.
BACKGROUND: South Africa remains the country with the greatest burden of HIV-infected individuals and the second highest estimated TB incidence per capita worldwide. Within South Africa, KwaZulu-Natal has one of the highest rates of TB incidence and an emerging epidemic of drug-resistant tuberculosis. METHODS: Review of records of consecutive HIV-infected people initiated onto ART between 1st January 2005 and 31st March 2006. Patients were screened for TB at initiation and incident episodes recorded. CD4 counts, viral loads and follow-up status were recorded; data was censored on 5th August 2008. Geographic cluster analysis was performed using spatial scanning. RESULTS: 801 patients were initiated. TB prevalence was 25.3%, associated with lower CD4 (AHR 2.61 p = 0.01 for CD4 25 copies/ml (OR 1.75 p = 0.11). A low-risk cluster for incident TB was identified for patients living near the local hospital in the geospatial analysis. CONCLUSION: There is a large burden of TB in this population. Rate of incident TB stabilises at a rate higher than that of the overall population. These data highlight the need for greater research on strategies for active case finding in rural settings and the need to focus on strengthening primary health care
Rapid acquisition of HPV around the time of sexual debut in adolescent girls in Tanzania.
BACKGROUND: No reports exist on genotype-specific human papillomavirus (HPV) acquisition in girls after first sex in sub-Saharan Africa, despite high HPV prevalence and cervical cancer incidence. METHODS: We followed 503 HP-unvaccinated girls aged 15-16 years in Mwanza, Tanzania, 3-monthly for 18 months with interviews and self-administered vaginal swabs. Swabs were tested for 13 higHRisk and 24 low-risk HPV genotypes. Incidence, clearance and duration of overall HPV and genotype-specific infections were calculated and associated factors evaluated. RESULTS: A total of 106 participants reported first sex prior to enrolment (N = 29) or during follow-up (N = 77). One was HIV-positive at the final visit. The remaining 105 girls contributed 323 adequate specimens. Incidence of any new HPV genotype was 225/100 person-years (pys), and incidence of vaccine types HPV-6, -11, -16 and -18 were 12, 2, 2 and 7/100 pys, respectively. Reporting sex in the past 3 months and knowing the most recent sexual partner for a longer period before sex were associated with HPV acquisition. Median time from reported sexual debut to first HPVinfection was 5 months, and infection duration was 6 months. CONCLUSION: This is the first description of HPV acquisition after first sex in sub-Saharan Africa where the incidence of cervical cancer is amongst the highest in the world. HPV incidence was very high after first sex, including some vaccine genotypes, and infection duration was short. This very high HPV incidence may help explain high cervical cancer rates, and supports recommendations that the HPV vaccine should be given to girls before first sex
Dangerous liaisons: youth sport, citizenship and intergenerational mistrust
This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Sport Policy and Politics on 24/3/2014, available online: DOI 10.1080/19406940.2014.896390This paper reflects on and offers a critical analysis of the relationship between youth sport and citizenship development, in practice and in the UK policy context of sports coaching and physical education. While deploying data and insights from a recently completed research project in England, which identified substantial tensions in intergenerational relationships in sport and coaching, the argument and analysis also invokes wider international concerns and more generally applicable implications for policy and practice. Drawing heuristically upon the philosophy of Dewey (2007 [1916]), it is recognised that the concept of citizenship as a form of social practice should seek to encourage the development of complementary traits and dispositions in young people. To develop socially and educationally thus entails engagement in meaningful social and cultural activity, of which one potentially significant component is participation in youth sport, both within and outside formal education. However, it is argued that any confident assumption that sporting and coaching contexts will necessarily foster positive traits and dispositions in young people should be considered dubious and misplaced. Deploying a Lacanian (1981) perspective to interpret our data, we contend that ‘liaisons’ and interactions between coaches and young people are often treated suspiciously, and regarded as potentially ‘dangerous’
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