544 research outputs found

    Adjustment of interaural-time-difference analysis to sound level

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    To localize low-frequency sound sources in azimuth, the binaural system compares the timing of sound waves at the two ears with microsecond precision. A similarly high precision is also seen in the binaural processing of the envelopes of high-frequency complex sounds. Both for low- and high-frequency sounds, interaural time difference (ITD) acuity is to a large extent independent of sound level. The mechanisms underlying this level-invariant extraction of ITDs by the binaural system are, however, only poorly understood. We use high-frequency pip trains with asymmetric and dichotic pip envelopes in a combined psychophysical, electrophysiological, and modeling approach. Although the dichotic envelopes cannot be physically matched in terms of ITD, the match produced perceptually by humans is very reliable, and it depends systematically on the overall sound level. These data are reflected in neural responses from the gerbil lateral superior olive and lateral lemniscus. The results are predicted in an existing temporal-integration model extended with a level-dependent threshold criterion. These data provide a very sensitive quantification of how the peripheral temporal code is conditioned for binaural analysis

    Family-led rehabilitation after stroke in India (ATTEND): a randomised controlled trial

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    Background: Most people with stroke in India have no access to organised rehabilitation services. The effectiveness of training family members to provide stroke rehabilitation is uncertain. Our primary objective was to determine whether family-led stroke rehabilitation, initiated in hospital and continued at home, would be superior to usual care in a low-resource setting. Methods: The Family-led Rehabilitation after Stroke in India (ATTEND) trial was a prospectively randomised open trial with blinded endpoint done across 14 hospitals in India. Patients aged 18 years or older who had had a stroke within the past month, had residual disability and reasonable expectation of survival, and who had an informal family-nominated caregiver were randomly assigned to intervention or usual care by site coordinators using a secure web-based system with minimisation by site and stroke severity. The family members of participants in the intervention group received additional structured rehabilitation training—including information provision, joint goal setting, carer training, and task-specific training—that was started in hospital and continued at home for up to 2 months. The primary outcome was death or dependency at 6 months, defined by scores 3–6 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) as assessed by masked observers. Analyses were by intention to treat. This trial is registered with Clinical Trials Registry-India (CTRI/2013/04/003557), Australian New Zealand Clinical Trials Registry (ACTRN12613000078752), and Universal Trial Number (U1111-1138-6707). Findings: Between Jan 13, 2014, and Feb 12, 2016, 1250 patients were randomly assigned to intervention (n=623) or control (n=627) groups. 33 patients were lost to follow-up (14 intervention, 19 control) and five patients withdrew (two intervention, three control). At 6 months, 285 (47%) of 607 patients in the intervention group and 287 (47%) of 605 controls were dead or dependent (odds ratio 0·98, 95% CI 0·78–1·23, p=0·87). 72 (12%) patients in the intervention group and 86 (14%) in the control group died (p=0·27), and we observed no difference in rehospitalisation (89 [14%]patients in the intervention group vs 82 [13%] in the control group; p=0·56). We also found no difference in total non-fatal events (112 events in 82 [13%] intervention patients vs 110 events in 79 [13%] control patients; p=0·80). Interpretation: Although task shifting is an attractive solution for health-care sustainability, our results do not support investment in new stroke rehabilitation services that shift tasks to family caregivers, unless new evidence emerges. A future avenue of research should be to investigate the effects of task shifting to health-care assistants or team-based community care. Funding: The National Health and Medical Research Council of Australia

    Increased dynamics in the 40-57 Ω-loop of the G41S variant of human cytochrome c promote its pro-apoptotic conformation

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    Thrombocytopenia 4 is an inherited autosomal dominant thrombocytopenia, which occurs due to mutations in the human gene for cytochrome c that results in enhanced mitochondrial apoptotic activity. The Gly41Ser mutation was the first to be reported. Here we report stopped-flow kinetic studies of azide binding to human ferricytochrome c and its Gly41Ser variant, together with backbone amide H/D exchange and 15N-relaxation dynamics using NMR spectroscopy, to show that alternative conformations are kinetically and thermodynamically more readily accessible for the Gly41Ser variant than for the wild-type protein. Our work reveals a direct conformational link between the 40-57 Ω-loop in which residue 41 resides and the dynamical properties of the axial ligand to the heme iron, Met80, such that the replacement of glycine by serine promotes the dissociation of the Met80 ligand, thereby increasing the population of a peroxidase active state, which is a key non-native conformational state in apoptosis

    Comparative study of vectis versus manual method for extraction of fetal head during lower segment cesarean section

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    Background: Delivery of fetal head through uterine incision is often the major technical problem during low transverse cesarean section when the presenting part is unengaged. Techniques to deliver head under special circumstances are traumatic to both mother and fetus. This study aims to establish the role of vectis in extraction of fetal head during lower segment cesarean section (LSCS) and to assess associated difficulties or untoward effects of use of vectis over manual method.Methods: The study was undertaken in PESIMSR, Kuppam, Andhra Pradesh over two years. Vectis was used in extraction of fetal head in LSCS in 100 cases of full term pregnancy and maternal and neonatal outcomes were compared with 100 cases of manual extraction.Results: Incision-delivery time interval was similar in both vectis and manual extraction method (p value of 0.390). Vectis group did not require any fundal pressure for extraction of head where as 100% of women in manual extraction group required fundal pressure (p value: <0.001) which is statistically significant. The length of abdominal incision for majority of cases in vectis group was smaller and statistically significant compared to manual extraction group (p value of 0.001). Neonatal outcomes were similar in both the groups.Conclusions: As per our study, usage of vectis has shown significant advantage in reducing maternal discomfort caused due to fundal pressure and length of abdominal incision required, with negligible difference in neonatal and other maternal outcomes in comparison to manual method of extraction

    Screening and Optimization of Physical Parameters for Enhanced Alkaline Protease Production by Alkaliphilic Bacillus Subtilis SH2 Isolate

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    The present investigations dealt with the optimization of the physical parameters for production of alkaline protease by alkaliphilic Bacillus subtilis SH-2 isolated from slaughter house soil of Warangal, Telangana State, India. Primary screening of four different samples revealed one potent isolate. Morphological and Biochemical characterization followed by Molecular signature of 16s rRNA homology confirmed that the isolate SH-2 belongs to Bacillus subtilis. Bacillus subtilis SH-2 was screened on four different reported mediums (M1213, M660, Horikoshi and Halophilic Bacillus medium) under shake culture conditions. Maximum alkaline protease production (500 EU/ml) obtained on M1213 and Horikoshi mediums. Further optimization of physical parameters by OVAT method revealed that mean generation time (41.18 min), 4% level inoculum, incubation time 72 hrs, pH 10, temperature 350C and agitation 150 rpm are ideal for enzyme production. OVAT method resulted in 2.2 fold increased production of alkaline protease production (1100 EU/ml)

    Chromium removal from aqueous solution by a PEI-silica nanocomposite

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    It is essential and important to determine the adsorption mechanism as well as removal efficiency when using an adsorption technique to remove toxic heavy metals from wastewater. In this research, the removal efficiency and mechanism of chromium removal by a silica-based nanoparticle were investigated. A PEI-silica nanoparticle was synthesized by a one-pot technique and exhibited uniformly well-dispersed PEI polymers in silica particles. The adsorption capacity of chromium ions was determined by a batch adsorption test, with the PEI-silica nanoparticle having a value of 183.7 mg/g and monolayer sorption. Adsorption of chromium ions was affected by the solution pH and altered the nanoparticle surface chemically. First principles calculations of the adsorption energies for the relevant adsorption configurations and XPS peaks of Cr and N showed that Cr(VI), [HCrO4](-) is reduced to two species, Cr(III), CrOH2+ and Cr3+, by an amine group and that Cr(III) and Cr(VI) ions are adsorbed on different functional groups, oxidized N and NH3+

    Advances in the use of biological stabilisers and hyper-compaction for sustainable earthen construction materials.

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    In the majority of cases, earthen construction materials for real buildings require amendment to deliver suitable material properties, which could be some additional strength or resilience to erosion. In modern earthen construction, in India, Australia and other parts of the world, cement and lime have been successfully used as stabilisers, providing both strength and durability benefits. However, the use of cement is detrimental to the green credentials of earthen construction materials, due to the large carbon footprint of that material’s manufacture and, for some time, researchers have been motivated to find more appropriate stabilisers and manufacturing methods. In this paper, we present recent findings from two projects that are linked by this motivation, and involve the study of bio-based stabilisers and alternative manufacturing methods for insitu and unit-based materials. Results are presented from laboratory testing of strength and durability of a range of materials, bio-stabilisers and manufacturing processes, indicating that there could be viable alternatives to cement and lime, certainly for many current uses of earthen construction materials

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

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    BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

    What's in a message? Delivering sexual health promotion to young people in Australia via text messaging

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    <p>Abstract</p> <p>Background</p> <p>Advances in communication technologies have dramatically changed how individuals access information and communicate. Recent studies have found that mobile phone text messages (SMS) can be used successfully for short-term behaviour change. However there is no published information examining the acceptability, utility and efficacy of different characteristics of health promotion SMS. This paper presents the results of evaluation focus groups among participants who received twelve sexual health related SMS as part of a study examining the impact of text messaging for sexual health promotion to on young people in Victoria, Australia.</p> <p>Methods</p> <p>Eight gender-segregated focus groups were held with 21 males and 22 females in August 2008. Transcripts of audio recordings were analysed using thematic analysis. Data were coded under one or more themes.</p> <p>Results</p> <p>Text messages were viewed as an acceptable and 'personal' means of health promotion, with participants particularly valuing the informal language. There was a preference for messages that were positive, relevant and short and for messages to cover a variety of topics. Participants were more likely to remember and share messages that were funny, rhymed and/or tied into particular annual events. The message broadcasting, generally fortnightly on Friday afternoons, was viewed as appropriate. Participants said the messages provided new information, a reminder of existing information and reduced apprehension about testing for sexually transmitted infections.</p> <p>Conclusions</p> <p>Mobile phones, in particular SMS, offer health promoters an exciting opportunity to engage personally with a huge number of individuals for low cost. The key elements emerging from this evaluation, such as message style, language and broadcast schedule are directly relevant to future studies using SMS for health promotion, as well as for future health promotion interventions in other mediums that require short formats, such as social networking sites.</p
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