574 research outputs found
Effects of hypnotic drugs on performance before and after sleep
The effects of various hypnotics on sleep stage parameters and on the parameters of effectiveness were evaluated along with the effects of several commonly used yet distinctly different hypnotics on daytime performance. The effects on daytime performance of two nonhypnotics commonly used in the space program were also examined
Attitude Determination from Single-Antenna Carrier-Phase Measurements
A model of carrier phase measurement (as carried out by a satellite
navigation receiver) is formulated based on electromagnetic theory. The model
shows that the phase of the open-circuit voltage induced in the receiver
antenna with respect to a local oscillator (in the receiver) depends on the
relative orientation of the receiving and transmitting antennas. The model
shows that using a {\it single} receiving antenna, and making carrier phase
measurements to seven satellites, the 3-axis attitude of a user platform (in
addition to its position and time) can be computed relative to an initial
point. This measurement model can also be used to create high-fidelity
satellite signal simulators that take into account the effect of platform
rotation as well as translation.Comment: 12 pages, and one figure. Published in J. Appl. Phys. vol. 91, No. 7,
April 1, 200
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Law enforcement duties and sudden cardiac death among police officers in United States: case distribution study
Objective: To assess the association between risk of sudden cardiac death and stressful law enforcement duties compared with routine/non-emergency duties. Design: Case distribution study (case series with survey information on referent exposures). Setting: United States law enforcement. Participants: Summaries of deaths of over 4500 US police officers provided by the National Law Enforcement Officers Memorial Fund and the Officer Down Memorial Page from 1984 to 2010. Main outcome measures Observed and expected sudden cardiac death counts and relative risks for sudden cardiac death events during specific strenuous duties versus routine/non-emergency activities. Independent estimates of the proportion of time that police officers spend across various law enforcement duties obtained from surveys of police chiefs and front line officers. Impact of varying exposure assessments, covariates, and missing cases in sensitivity and stability analyses. Results: 441 sudden cardiac deaths were observed during the study period. Sudden cardiac death was associated with restraints/altercations (25%, n=108), physical training (20%, n=88), pursuits of suspects (12%, n=53), medical/rescue operations (8%, n=34), routine duties (23%, n=101), and other activities (11%, n=57). Compared with routine/non-emergency activities, the risk of sudden cardiac death was 34-69 times higher during restraints/altercations, 32-51 times higher during pursuits, 20-23 times higher during physical training, and 6-9 times higher during medical/rescue operations. Results were robust to all sensitivity and stability analyses. Conclusions: Stressful law enforcement duties are associated with a risk of sudden cardiac death that is markedly higher than the risk during routine/non-emergency duties. Restraints/altercations and pursuits are associated with the greatest risk. Our findings have public health implications and suggest that primary and secondary cardiovascular prevention efforts are needed among law enforcement officers
Evaluation of the EndoPAT as a Tool to Assess Endothelial Function
Endothelial dysfunction is a potential target for (pharmaceutical) intervention of several systemic pathological conditions. We investigated the feasibility of the EndoPAT to evaluate acute changes in endothelial function with repeated noninvasive measurements and assessed its discriminating power in different populations.
Endothelial function was stable over a longer period of time in renally impaired patients (coefficient of variation 13%). Endothelial function in renally impaired and type 2 diabetic patients was not decreased compared to healthy volunteers (2.9 ± 1.4 and 1.8 ± 0.3, resp., versus 1.8 ± 0.5, P > 0.05). The EndoPAT did not detect an effect of robust interventions on endothelial function in healthy volunteers (glucose load: change from baseline 0.08 ± 0.50, 95% confidence interval −0.44 to 0.60; smoking: change from baseline 0.49 ± 0.92, 95% confidence interval −0.47 to 1.46). This suggests that at present the EndoPAT might not be suitable to assess (changes in) endothelial function in early-phase clinical pharmacology studies. Endothelial function as measured by the EndoPAT could be physiologically different from endothelial function as measured by conventional techniques. This should be investigated carefully before the EndoPAT can be considered a useful tool in drug development or clinical practice
Commercial Driver Medical Exams: Relationships Between Body Mass Index and Comorbid Conditions
There are an estimated 5.7 million Commercial Motor Vehicle (CMV) drivers in the United States in 2012. Health and Safety of CMV drivers are of high consequence group because of: occupational risks from the size and speed of their vehicles, frequently poor health status, poor health care utilization, and the large impact of truck crashes on public health and safety. CMV drivers pass a commercial driver medical examination (CDME) to maintain licensure. CDME examiners document multiple potentially disqualifying health conditions. CMV drivers reportedly have poor health status, which may be attributed to lifestyle and occupational factors (e.g., improper diet, inadequate physical activity, poor sleep hygiene, shift work), yet few data are reported analyzing relative importance and relationships of these factors. Methods- CDMEs conducted between 2005 and 2012 among 88,246 commercial drivers were analyzed. Associations between measured Body Mass Index (BMI) categories and CDME findings, as well as driver certification were examined. Results- 53.3% of drivers were obese (BMI\u3e30.0 kg/m2 ) with half of those being morbidly obese (BMI\u3e35.0 kg/m2 ). After adjustment for age and gender, obese drivers were statistically significantly less likely to be certified for the full 2 year period and significantly more likely to report many factors including heart disease, hypertension, diabetes mellitus, nervous disorders, sleep disorders, and chronic low back pain (all p\u3c0.0001). ConclusionsBMI is related to many factors, some of which have been associated with increased crash risk. BMI screening may be a useful tool. Interventions for BMI reduction may have an impact on comorbidities
A mixed-methods feasibility study of a goal-focused manualised intervention to support people with dementia to stay living independently at home with support from family carers: NIDUS (New Interventions for Independence in Dementia Study) Family
Objectives:
To examine the feasibility and acceptability of NIDUS-Family, a 6–8 session manualised, individually tailored, modular intervention supporting independence at home for people with dementia; and explore participants’ and facilitators’ experiences of the intervention. /
Method:
In this single group multi-site feasibility study, trained, supervised non-clinically qualified graduates (facilitators) delivered NIDUS-Family to family carer and people living with dementia dyads. We recruited participants from GP practices and memory services in London and Bradford. We completed quantitative outcomes pre- and post-intervention; and conducted qualitative interviews with participants and facilitators. Our pre-specified main outcomes were proportion of potential participants approached who agreed to participate, intervention adherence and acceptability to family carers, and facilitator fidelity to the manual. /
Results:
We recruited 16 dyads (57% of those approached); 12 (75%) completed the intervention. Of 12 participants rating intervention acceptability, 9 (75%) agreed or strongly agreed that it had helped; 2 (18%) neither agreed nor disagreed and 1 (8%) disagreed. Mean facilitator fidelity was high (81.5%). Dyads set on average 3.9 goals; these most commonly related to getting out and about and increasing activity/hobby participation (n = 10); carer wellbeing (n = 6), managing physical complaints (n = 6); meal preparation/cooking (n = 5); and reducing irritability, frustration or aggression (n = 5). Almost all secondary outcomes changed in a direction indicating improvement. In our qualitative analysis we identified three overarching themes; relationships facilitate change, goal-focused versus manualised approach and balancing the needs of carers and people with dementia. /
Conclusion:
NIDUS-Family was feasible and acceptable to participants. Following refinements, testing in a pragmatic trial is underway
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Nut consumption on all-cause, cardiovascular, and cancer mortality risk: a systematic review and meta-analysis of epidemiologic studies
Background: Recent pooled analyses supported a beneficial impact of nut consumption on health, but to our knowledge, whether nuts are associated with overall decreased mortality has not been previously reviewed. Objectives: We aimed to systematically review prospective studies that explored the effects of nut consumption on all-cause, cardiovascular disease (CVD), and cancer mortality and quantify the size effect through a meta-analysis. We also reviewed confounding factors associated with nut consumption to assess potential clustering with other covariates. Design: We searched PubMed and EMBASE for studies published up to June 2014. Study characteristics, HRs, and 95% CIs were generated on the basis of quantitative analyses. A dose-response analysis was performed when data were available. Results: Seven studies for all-cause mortality, 6 studies for CVD mortality, and 2 studies for cancer mortality were included in the meta-analysis with a total of 354,933 participants, 44,636 cumulative incident deaths, and 3,746,534 cumulative person-years. Nut consumption was associated with some baseline characteristics such as lower body mass index and smoking status as well as increased intakes of fruit, vegetables, and alcohol. One-serving of nuts per week and per day resulted in 4% (RR: 0.96; 95% CI: 0.93, 0.98) and 27% (RR: 0.73; 95% CI: 0.60, 0.88) decreased risk of all-cause mortality, respectively, and decreased risk of CVD mortality [RR: 0.93 (95% CI: 0.88, 0.99) and 0.61 (95% CI: 0.42, 0.91), respectively]. Effects were primarily driven by decreased coronary artery disease deaths rather than stroke deaths. Nut consumption was also associated with decreased risk of cancer deaths when highest compared with lowest categories of intake were compared (RR: 0.86; 95% CI: 0.75, 0.98), but no dose-effect was shown. Conclusion: Nut consumption is associated with lower risk of allcause, CVD, and cancer mortality, but the presence of confounding factors should be taken into account when considering such findings
Social connectedness and dementia prevention: Pilot of the APPLE-Tree video-call intervention during the Covid-19 pandemic
BACKGROUND AND OBJECTIVES: The Covid-19 pandemic reduced access to social activities and routine health care that are central to dementia prevention. We developed a group-based, video-call, cognitive well-being intervention; and investigated its acceptability and feasibility; exploring through participants’ accounts how the intervention was experienced and used in the pandemic context. RESEARCH DESIGN AND METHOD: We recruited adults aged 60+ years with memory concerns (without dementia). Participants completed baseline assessments and qualitative interviews/focus groups before and after the 10-week intervention. Qualitative interview data and facilitator notes were integrated in a thematic analysis. RESULTS: 12/17 participants approached completed baseline assessments, attended 100/120 (83.3%) intervention sessions and met 140/170 (82.4%) of goals set. Most had not used video calling before. In the thematic analysis, our overarching theme was social connectedness. Three sub-themes were as follows: Retaining independence and social connectedness: social connectedness could not be at the expense of independence; Adapting social connectedness in the pandemic: participants strived to compensate for previous social connectedness as the pandemic reduced support networks; Managing social connections within and through the intervention: although there were tensions, for example, between sharing of achievements feeling supportive and competitive, participants engaged with various lifestyle changes; social connections supported group attendance and implementation of lifestyle changes. DISCUSSION AND IMPLICATIONS: Our intervention was acceptable and feasible to deliver by group video-call. We argue that dementia prevention is both an individual and societal concern. For more vulnerable populations, messages that lifestyle change can help memory should be communicated alongside supportive, relational approaches to enabling lifestyle changes
Social connectedness and dementia prevention: Pilot of the APPLE-Tree video-call intervention during the Covid-19 pandemic.
BACKGROUND AND OBJECTIVES: The Covid-19 pandemic reduced access to social activities and routine health care that are central to dementia prevention. We developed a group-based, video-call, cognitive well-being intervention; and investigated its acceptability and feasibility; exploring through participants' accounts how the intervention was experienced and used in the pandemic context. RESEARCH DESIGN AND METHOD: We recruited adults aged 60+ years with memory concerns (without dementia). Participants completed baseline assessments and qualitative interviews/focus groups before and after the 10-week intervention. Qualitative interview data and facilitator notes were integrated in a thematic analysis. RESULTS: 12/17 participants approached completed baseline assessments, attended 100/120 (83.3%) intervention sessions and met 140/170 (82.4%) of goals set. Most had not used video calling before. In the thematic analysis, our overarching theme was social connectedness. Three sub-themes were as follows: Retaining independence and social connectedness: social connectedness could not be at the expense of independence; Adapting social connectedness in the pandemic: participants strived to compensate for previous social connectedness as the pandemic reduced support networks; Managing social connections within and through the intervention: although there were tensions, for example, between sharing of achievements feeling supportive and competitive, participants engaged with various lifestyle changes; social connections supported group attendance and implementation of lifestyle changes. DISCUSSION AND IMPLICATIONS: Our intervention was acceptable and feasible to deliver by group video-call. We argue that dementia prevention is both an individual and societal concern. For more vulnerable populations, messages that lifestyle change can help memory should be communicated alongside supportive, relational approaches to enabling lifestyle changes
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