1,262 research outputs found
Maturation of auditory temporal integration and inhibition assessed with event-related potentials (ERPs)
Background: We examined development of auditory temporal integration and inhibition by assessing electrophysiological responses to tone pairs separated by interstimulus intervals (ISIs) of 25, 50, 100, 200, 400, and 800 ms in 28 children aged 7 to 9 years, and 15 adults.Results: In adults a distinct neural response was elicited to tones presented at ISIs of 25 ms or longer, whereas in children this was only seen in response to tones presented at ISIs above 100 ms. In adults, late N1 amplitude was larger for the second tone of the tone pair when separated by ISIs as short as 100 ms, consistent with the perceptual integration of successive stimuli within the temporal window of integration. In contrast, children showed enhanced negativity only when tone pairs were separated by ISIs of 200 ms. In children, the amplitude of the P1 component was attenuated at ISIs below 200 ms, consistent with a refractory process.Conclusions: These results indicate that adults integrate sequential auditory information into smaller temporal segments than children. These results suggest that there are marked maturational changes from childhood to adulthood in the perceptual processes underpinning the grouping of incoming auditory sensory information, and that electrophysiological measures provide a sensitive, non-invasive method allowing further examination of these changes
Globular Cluster Distance Determinations
The present status of the distance scale to Galactic globular clusters is
reviewed. Six distance determination techniques which are deemed to be most
reliable are discussed in depth. These different techniques are used to
calibrate the absolute magnitude of the RR Lyrae stars. The various
calibrations fall into three groups. Main sequence fitting using Hipparcos
parallaxes, theoretical HB models and the RR Lyrae in the LMC all favor a
bright calibration, implying a `long' globular cluster distance scale. White
dwarf fitting and the astrometric distances yield a somewhat fainter RR Lyrae
calibration, while the statistical parallax solution yields faint RR Lyrae
stars implying a `short' distance scale to globular clusters. Various secondary
distance indicators discussed all favor the long distance scale. The `long' and
`short' distance scales differ by (0.31+/-0.16) mag. Averaging together all of
the different distance determinations yields Mv(RR) = (0.23+/-0.04)([Fe/H] +
1.6) + (0.56+/-0.12) mag.Comment: Invited review article to appear in: `Post-Hipparcos Cosmic Candles',
A. Heck & F. Caputo (Eds), Kluwer Academic Publ., Dordrecht, in pres
Understanding the acceptability, barriers and facilitators for chlamydia and gonorrhoea screening in technical colleges: qualitative process evaluation of the "Test n Treat" trial.
BACKGROUND: Low uptake of sexually transmitted infection testing by sexually active young people is a worldwide public health problem. Screening in non-medical settings has been suggested as a method to improve uptake. The "Test n Treat" feasibility trial offered free, on-site rapid chlamydia/gonorrhoea tests with same day treatment for chlamydia (and gonorrhoea treatment at a local clinic,) to sexually active students (median age 17 years) at six technical colleges in London. Despite high rates of chlamydia (6% prevalence), uptake of testing was low (< 15%). In a qualitative study we explored the acceptability, including barriers and facilitators to uptake, of on-site chlamydia screening. METHODS: In 2016-17 we conducted a qualitative study in the interpretative tradition using face to face or telephone semi-structured interviews with students (n = 26), teaching staff (n = 3) and field researchers (n = 4). Interviews were digitally recorded, transcribed and thematically analysed. RESULTS: From the student perspective, feelings of embarrassment and the potential for stigma were deterrents to sexually transmitted infection testing. While the non-medical setting was viewed as mitigating against stigma, for some students volunteering to be screened exposed them to detrimental judgements by their peers. A small financial incentive to be screened was regarded as legitimising volunteering in a non-discrediting way. Staff and researchers confirmed these views. The very low level of knowledge about sexually transmitted infections influenced students to not view themselves as candidates for testing. There were also suggestions that some teenagers considered themselves invulnerable to sexually transmitted infections despite engaging in risky sexual behaviours. Students and researchers reported the strong influence peers had on uptake, or not, of sexually transmitted infection testing. CONCLUSIONS: This study offers new insights into the acceptability of college-based sexually transmitted infection screening to young, multi-ethnic students. Future studies in similar high risk, hard to reach groups should consider linking testing with education about sexually transmitted infections, offering non stigmatising incentives and engaging peer influencers
'Test n Treat' (TnT): a cluster randomized feasibility trial of on-site rapid Chlamydia trachomatis tests and treatment in ethnically diverse, sexually active teenagers attending technical colleges.
Objectives
We conducted a cluster-randomized feasibility trial of 90-minute Chlamydia trachomatis tests and same day on-site treatment (‘Test n Treat/TnT’) in six technical colleges in London, England, to assess TnT uptake rates; follow-up rates; prevalence of C. trachomatis at baseline and 7 months; time to treatment; acceptability of TnT.
Methods
Participants completed questionnaires and provided genitourinary samples at baseline and 7 months. Participants were informed that baseline samples would not be tested for 7 months and were advised to get screened independently. Colleges were randomly allocated 1:1 to intervention (TnT) or control (no TnT).
One month and 4 months post recruitment, participants at intervention colleges were texted invitations for on-site free C. trachomatis tests. A purposive sample of students who did/did not attend for screening were interviewed (n = 26).
Results
Five hundred and nine sexually active students were recruited: median age 17.9 years, 47% male, 50% black ethnicity, 55% reporting two or more sexual partners in the previous year. TnT uptake was 13% (33/259; 95% CI 8.9–17.4%) at 1 month and 10% (26/259; 6.7–14.4%) at 4 months with overall C. trachomatis positivity 5.1% (3/59; 1.1–14.2%). Follow-up at 7 months was 62% (317/509) for questionnaires and 52% (264/509) for samples. C. trachomatis prevalence was 6.2% (31/503) at baseline and 6.1% (16/264) at 7 months. Median time from test to treatment was 15 h. Interviews suggested low test uptake was associated with not feeling at risk, perceptions of stigma, and little knowledge of sexually transmitted infections (STIs).
Conclusions
Despite high C. trachomatis rates at baseline and follow-up, uptake of testing was low. Like many countries, England urgently needs better sex education, including making STI testing routine/normal.
Trial registration ISRCTN5803879
'Test n Treat' (TnT): a cluster randomized feasibility trial of on-site rapid Chlamydia trachomatis tests and treatment in ethnically diverse, sexually active teenagers attending technical colleges.
Objectives
We conducted a cluster-randomized feasibility trial of 90-minute Chlamydia trachomatis tests and same day on-site treatment (‘Test n Treat/TnT’) in six technical colleges in London, England, to assess TnT uptake rates; follow-up rates; prevalence of C. trachomatis at baseline and 7 months; time to treatment; acceptability of TnT.
Methods
Participants completed questionnaires and provided genitourinary samples at baseline and 7 months. Participants were informed that baseline samples would not be tested for 7 months and were advised to get screened independently. Colleges were randomly allocated 1:1 to intervention (TnT) or control (no TnT).
One month and 4 months post recruitment, participants at intervention colleges were texted invitations for on-site free C. trachomatis tests. A purposive sample of students who did/did not attend for screening were interviewed (n = 26).
Results
Five hundred and nine sexually active students were recruited: median age 17.9 years, 47% male, 50% black ethnicity, 55% reporting two or more sexual partners in the previous year. TnT uptake was 13% (33/259; 95% CI 8.9–17.4%) at 1 month and 10% (26/259; 6.7–14.4%) at 4 months with overall C. trachomatis positivity 5.1% (3/59; 1.1–14.2%). Follow-up at 7 months was 62% (317/509) for questionnaires and 52% (264/509) for samples. C. trachomatis prevalence was 6.2% (31/503) at baseline and 6.1% (16/264) at 7 months. Median time from test to treatment was 15 h. Interviews suggested low test uptake was associated with not feeling at risk, perceptions of stigma, and little knowledge of sexually transmitted infections (STIs).
Conclusions
Despite high C. trachomatis rates at baseline and follow-up, uptake of testing was low. Like many countries, England urgently needs better sex education, including making STI testing routine/normal.
Trial registration ISRCTN5803879
Life satisfaction in coastal Kenya and Mozambique reflects culture, gendered relationships and security of basic needs: Implications for ecosystem services
This is the final version. Available from Elsevier via the DOI in this record. Data availability:
Data are published in https://reshare.ukdataservice.ac.ukLife satisfaction is both a desirable ‘end’ for sustainable development, and a means to understand the priorities, and behaviour of people towards local ecosystems. Ecosystem-services research on life satisfaction has focused on cultural services in wealthy, Western contexts, although ecosystem services are essential for poor people's livelihoods in the Global South. We examined reported life satisfaction from a survey of over 2000 people in rural and urban settings of coastal Kenya and Mozambique. We coded respondents’ open-ended reasons for their reported satisfaction, and used multiple correspondence analysis to explore the characteristics of people who mentioned different reasons. We tested associations between satisfaction and the meeting of basic needs and income, with binary logistic regression, accounting for site and gender. Life satisfaction was lower in Kenya, for men, and in the most urbanised site. Respondents explained high, and low, satisfaction in terms of social relationships, basic needs, money and employment. They rarely mentioned the ecosystem services and related livelihoods that underpin those, suggesting an instrumental relation to nature. Meeting basic needs, including economic security better predicted satisfaction than household income. Life satisfaction reflected material differences in people's lives but also different evaluative criteria and national cultures. For example, family reasons more commonly explained women's satisfaction, while money was more important for urban-dwelling men. We propose that the holistic perspective offered by life-satisfaction research can inform environmental management alongside more focused ecosystem-service research. For example, our results suggest that a) interventions should recognise immediate needs and social relationships, b) the role of ecosystem services for subjective wellbeing varies by local culture and individual identities and c) secure and fair access to ecosystem services may support life satisfaction better than high incomes that are insecure or inequitably distributed.Economic and Social Research Council (ESRC)Department for International Development (DFID)Natural Environment Research Council (NERC
Neutrino masses from new generations
We reconsider the possibility that Majorana masses for the three known
neutrinos are generated radiatively by the presence of a fourth generation and
one right-handed neutrino with Yukawa couplings and a Majorana mass term. We
find that the observed light neutrino mass hierarchy is not compatible with low
energy universality bounds in this minimal scenario, but all present data can
be accommodated with five generations and two right-handed neutrinos. Within
this framework, we explore the parameter space regions which are currently
allowed and could lead to observable effects in neutrinoless double beta decay,
conversion in nuclei and experiments. We
also discuss the detection prospects at LHC.Comment: 28 pages, 4 figures. Version to be published. Some typos corrected.
Improved figures 3 and
Cloning, expression and characterization of alcohol dehydrogenases in the silkworm Bombyx mori
Alcohol dehydrogenases (ADH) are a class of enzymes that catalyze the reversible oxidation of alcohols to corresponding aldehydes or ketones, by using either nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP), as coenzymes. In this study, a short-chain ADH gene was identified in Bombyx mori by 5′-RACE PCR. This is the first time the coding region of BmADH has been cloned, expressed, purified and then characterized. The cDNA fragment encoding the BmADH protein was amplified from a pool of silkworm cDNAs by PCR, and then cloned into E. coli expression vector pET-30a(+). The recombinant His-tagged BmADH protein was expressed in E. coli BL21 (DE3), and then purified by metal chelating affinity chromatography. The soluble recombinant BmADH, produced at low-growth temperature, was instrumental in catalyzing the ethanol-dependent reduction of NAD+, thereby indicating ethanol as one of the substrates of BmADH
The R-Process Alliance: Fourth Data Release from the Search for R-process-enhanced Stars in the Galactic Halo
This compilation is the fourth data release from the R-Process Alliance (RPA) search for r-process-enhanced stars and the second release based on "snapshot" high-resolution (R ~ 30,000) spectra collected with the du Pont 2.5 m Telescope. In this data release, we propose a new delineation between the r-I and r-II stellar classes at , instead of the empirically chosen level previously in use, based on statistical tests of the complete set of RPA data released to date. We also statistically justify the minimum level of [Eu/Fe] for definition of the r-I stars, [Eu/Fe] > +0.3. Redefining the separation between r-I and r-II stars will aid in the analysis of the possible progenitors of these two classes of stars and determine whether these signatures arise from separate astrophysical sources at all. Applying this redefinition to previous RPA data, the number of identified r-II and r-I stars changes to 51 and 121, respectively, from the initial set of data releases published thus far. In this data release, we identify 21 new r-II, 111 new r-I (plus 3 re-identified), and 7 new (plus 1 re-identified) limited-r stars out of a total of 232 target stars, resulting in a total sample of 72 new r-II stars, 232 new r-I stars, and 42 new limited-r stars identified by the RPA to date
The high-energy Sun - probing the origins of particle acceleration on our nearest star
As a frequent and energetic particle accelerator, our Sun provides us with an excellent astrophysical laboratory for understanding the fundamental process of particle acceleration. The exploitation of radiative diagnostics from electrons has shown that acceleration operates on sub-second time scales in a complex magnetic environment, where direct electric fields, wave turbulence, and shock waves all must contribute, although precise details are severely lacking. Ions were assumed to be accelerated in a similar manner to electrons, but γ-ray imaging confirmed that emission sources are spatially separated from X-ray sources, suggesting distinctly different acceleration mechanisms. Current X-ray and γ-ray spectroscopy provides only a basic understanding of accelerated particle spectra and the total energy budgets are therefore poorly constrained. Additionally, the recent detection of relativistic ion signatures lasting many hours, without an electron counterpart, is an enigma. We propose a single platform to directly measure the physical conditions present in the energy release sites and the environment in which the particles propagate and deposit their energy. To address this fundamental issue, we set out a suite of dedicated instruments that will probe both electrons and ions simultaneously to observe; high (seconds) temporal resolution photon spectra (4 keV – 150 MeV) with simultaneous imaging (1 keV – 30 MeV), polarization measurements (5–1000 keV) and high spatial and temporal resolution imaging spectroscopy in the UV/EUV/SXR (soft X-ray) regimes. These instruments will observe the broad range of radiative signatures produced in the solar atmosphere by accelerated particles
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