1,464 research outputs found

    The association between life events, social support, and antibody status following thymus-dependent and thymus-independent vaccinations in healthy young adults

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    This study determined whether stressful life events and social support were related to antibody status following both thymus-dependent and thymus-independent vaccinations. Life events in the previous year and customary social support were measured in 57 healthy students at baseline. Antibody status was also assessed at baseline and at five weeks and five months following vaccination with the trivalent influenza vaccine and the meningococcal A+C polysaccharide vaccine. Taking into account baseline antibody titre, high life events scores prior to vaccination were associated with lower responses to the B/Shangdong influenza strain at both five weeks and five months and meningococcal C at five weeks. Life events scores were not associated with response to the other two influenza viral strains nor response to meningococcal A. Those with high social support scores had stronger 5-week and 5-month antibody responses to the A/Panama influenza strain, but not to any of the other strains. These associations could not be accounted for by demographic or health behaviour factors, and also emerged from analyses comparing those who exhibited a four-fold increase in antibody titre from baseline with those who did not. Life events and social support were related to antibody status following influenza vaccination in distinctive ways that may be partly determined by vaccine novelty and prior naturalistic exposure. Life events also predicted poor antibody response to meningococcal C polysaccharide vaccination after previous meningococcal C conjugate vaccination. Neither psychosocial factor was associated with response to primary meningococcal A polysaccharide vaccination

    Primary deposition and early diagenetic effects on the high saturation accumulation of gas hydrate in a silt dominated reservoir in the Gulf of Mexico

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    On continental margins, high saturation gas hydrate systems (\u3e60% pore volume) are common in canyon and channel environments within the gas hydrate stability zone, where reservoirs are dominated by coarse-grained, high porosity sand deposits. Recent studies, including the results presented here, suggest that rapidly deposited, silt-dominated channel-levee environments can also host high saturation gas hydrate accumulations. Here we present several sedimentological data sets, including sediment composition, biostratigraphic age from calcareous nannofossils, grain size, total organic carbon (TOC), C/N elemental ratio, δ13C-TOC, CaCO3, total sulfur (TS), and δ34S-TS from sediments collected with pressure cores from a gas hydrate rich, turbidite channel-levee system in the Gulf of Mexico during the 2017 UT-GOM2-1 Hydrate Pressure Coring Expedition. Our results indicate the reservoir is composed of three main lithofacies, which have distinct sediment grain size distributions (type A-silty clay to clayey silt, type B-clayey silt, and type C-sandy silt to silty sand) that are characteristic of variable turbidity current energy regimes within a Pleistocene (\u3c 0.91 Ma) channel-levee environment. We document that the TOC in the sediments of the reservoir is terrestrial in origin and contained within the fine fraction of each lithofacies, while the CaCO3 fraction is composed of primarily reworked grains, including Cretaceous calcareous nannofossils, and part of the detrital load. The lack of biogenic grains within the finest grained sediment intervals throughout the reservoir suggests interevent hemipelagic sediments are not preserved, resulting in a reservoir sequence of silt dominated, stacked turbidites. We observe two zones of enhanced TS at the top and bottom of the reservoir that correspond with enriched bulk sediment δ34S, indicating stalled or slowly advancing paleo-sulfate-methane transition zone (SMTZ) positions likely driven by relative decreases in sedimentation rate. Despite these two diagenetic zones, the low abundance of diagenetic precipitates throughout the reservoir allowed the primary porosity to remain largely intact, thus better preserving primary porosity for subsequent pore-filling gas hydrate. In canyon, channel, and levee environments, early diagenesis may be regulated via sedimentation rates, where high rates result in rapid progression through the SMTZ and minimal diagenetic mineralization and low rates result in the stalling of the SMTZ, enhancing diagenetic mineralization. Here, we observed some enhanced pyritization to implicate potential sedimentation rate changes, but not enough to consume primary porosity, resulting in a high saturation gas hydrate reservoir. These results emphasize the important implications of sedimentary processes, sedimentation rates, and early diagenesis on the distribution of gas hydrate in marine sediments along continental margins

    Low temperature characterization of modulation doped SiGe grown on bonded silicon-on-insulator

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    Modulation doped pseudomorphic Si0.87Ge0.13 strained quantum wells were grown on bonded silicon-on-insulator (SOI) substrates. Comparison with similar structures grown on bulk Si(100) wafers shows that the SOI material has higher mobility at low temperatures with a maximum value of 16 810 cm 2/V s for 2.05 × 1011 cm – 2 carries at 298 mK. Effective masses obtained from the temperature dependence of Shubnikov–de Haas oscillations have a value of (0.27 ± 0.02) m0 compared to (0.23 ± 0.02) m0 for quantum wells on Si(100) while the cyclotron resonance effective masses obtained at higher magnetic fields without consideration for nonparabolicity effects have values between 0.25 and 0.29 m0. Ratios of the transport and quantum lifetimes, tau/tau q=2.13 ± 0.10, were obtained for the SOI material that are, we believe, the highest reported for any pseudomorphic SiGe modulation doped structure and demonstrates that there is less interface roughness or charge scattering in the SOI material than in metal–oxide–semiconductor field effect transistors or other pseudomorphic SiGe modulation doped quantum wells

    Antipsychotic adherence, switching, and health care service utilization among Medicaid recipients with schizophrenia

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    Objective: To evaluate health care resource utilization in patients with schizophrenia who continued newly prescribed antipsychotic medications, compared with those switching to different treatments. Methods: Adults with schizophrenia in the California Medicaid (MediCal) database who initiated treatment with index medications in 1998–2001, were classified as having: 1) abandoned antipsychotic medications; 2) switched to another medication; or 3) continued with the index antipsychotic, for up to 6 months after the index date. Results: Of 2300 patients meeting eligibility criteria, 1382 (60.1%) continued index medications, 480 (20.9%) switched, and 438 (19.0%) abandoned antipsychotic treatment. Utilization in several resource categories occurred significantly more frequently among patients whose regimens were switched (vs those continuing index medications). These included using psychiatric (24.2% vs 14.5%; P \u3c 0.001) or nonpsychiatric (31.5% vs 24.3%; P \u3c 0.05) emergency services; being admitted to a hospital (10.6% vs 7.4%; P \u3c 0.05); making nonpsychiatric outpatient hospital visits (43.3% vs 36.4%; P \u3c 0.05) or nonpsychiatric physician visits (62.7% vs 56.4%; P \u3c 0.05); and using other outpatient psychiatric (53.3% vs 40.7%; P \u3c 0.001) or nonpsychiatric (82.7% vs 74.6%; P \u3c 0.001) services. Conclusions: Switching antipsychotic medications is associated with significantly increased health care resource utilization (vs continuing treatment)

    Effectiveness and cost-effectiveness of a universal parenting skills programme in deprived communities : multicentre randomised controlled trial

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    Objective: To evaluate the effectiveness and cost utility of a universally provided early years parenting programme. Design: Multicentre randomised controlled trial with cost-effectiveness analysis. Setting: Early years centres in four deprived areas of South Wales. Participants: Families with children aged between 2 and 4 years. 286 families were recruited and randomly allocated to the intervention or waiting list control. Intervention: The Family Links Nurturing Programme (FLNP), a 10-week course with weekly 2 h facilitated group sessions. Main outcome measures: Negative and supportive parenting, child and parental well-being and costs assessed before the intervention, following the course (3 months) and at 9 months using standardised measures. Results: There were no significant differences in primary or secondary outcomes between trial arms at 3 or 9 months. With ‘+’ indicating improvement, difference in change in negative parenting score at 9 months was +0.90 (95%CI −1.90 to 3.69); in supportive parenting, +0.17 (95%CI −0.61 to 0.94); and 12 of the 17 secondary outcomes showed a non-significant positive effect in the FLNP arm. Based on changes in parental well-being (SF-12), the cost per quality-adjusted life year (QALY) gained was estimated to be £34 913 (range 21 485–46 578) over 5 years and £18 954 (range 11 664–25 287) over 10 years. Probability of cost per QALY gained below £30 000 was 47% at 5 years and 57% at 10 years. Attendance was low: 34% of intervention families attended no sessions (n=48); only 47% completed the course (n=68). Also, 19% of control families attended a parenting programme before 9-month follow-up. Conclusions: Our trial has not found evidence of clinical or cost utility for the FLNP in a universal setting. However, low levels of exposure and contamination mean that uncertainty remains. Trial registration: The trial is registered with Current Controlled Trials ISRCTN13919732

    Cardiovascular activity and the antibody response to vaccination

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    Objective To examine the relationship between cardiovascular activity in response to acute psychological stress and the antibody response to vaccination. Methods Fifty-seven healthy participants were vaccinated with the trivalent influenza vaccine and meningococcal A+C polysaccharides. Antibody levels were measured at baseline and 5-weeks post-vaccination. Cardiovascular activity was measured at rest, during, and following a mental arithmetic stress task in 54 participants. Results Participants demonstrating a fourfold increase in antibody titre to the A/Panama and B/Shangdong influenza strains and to meningococcal A showed greater blood pressure reactions toward the end of the acute stress task. In addition, there was some evidence of delayed diastolic blood pressure recovery in those who were responders to A/Panama and B/Shangdong influenza strains. Conclusion The present results suggest that heightened cardiovascular reactivity to stress and delayed recovery may not necessarily be detrimental to all aspects of health and may be associated with an enhanced immune response to antigen challenge

    Bereavement and marriage are associated with antibody response to influenza vaccination in the elderly

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    Stressful life events exposure including bereavement, an event commonly experienced by elderly people, social support, marital status and satisfaction were examined in relation to antibody response to the annual trivalent influenza vaccination in an elderly community sample (N = 184). Antibody response was assessed at baseline, and at one and 12 months following vaccination. Taking into account baseline antibody titer, overall life events exposure and social support were not associated with response to any of the influenza strains. However, bereavement in the year prior to vaccination was negatively associated with the one-month response to the A/Panama and B/Shangdong strains. Being married and having higher marital satisfaction was also associated with higher peak responses to the A/Panama influenza strain at one month. The positive association between marital satisfaction and A/Panama response was particularly evident in the younger half of the married sample. These associations largely withstood adjustment for potential confounders. Thus, in the elderly, peak antibody response was associated with bereavement and marriage, and not the more general factors, life events and social support, related to antibody response in student samples. This suggests the importance of taking a life course approach to examining relationships between psychosocial factors and immunity, and that interventions to modify the impact of these factors should address those most salient for each age group
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