926 resultados para night duty


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A number of observations have shown that Rayleigh scattering by aerosols dominates the transmission spectrum of HD 189733b at wavelengths shortward of 1 μm. In this study, we retrieve a range of aerosol distributions consistent with transmission spectroscopy between 0.3-24 μm that were recently re-analyzed by Pont et al. To constrain the particle size and the optical depth of the aerosol layer, we investigate the degeneracies between aerosol composition, temperature, planetary radius, and molecular abundances that prevent unique solutions for transit spectroscopy. Assuming that the aerosol is composed of MgSiO3, we suggest that a vertically uniform aerosol layer over all pressures with a monodisperse particle size smaller than about 0.1 μm and an optical depth in the range 0.002-0.02 at 1 μm provides statistically meaningful solutions for the day/night terminator regions of HD 189733b. Generally, we find that a uniform aerosol layer provide adequate fits to the data if the optical depth is less than 0.1 and the particle size is smaller than 0.1 μm, irrespective of the atmospheric temperature, planetary radius, aerosol composition, and gaseous molecules. Strong constraints on the aerosol properties are provided by spectra at wavelengths shortward of 1 μm as well as longward of 8 μm, if the aerosol material has absorption features in this region. We show that these are the optimal wavelengths for quantifying the effects of aerosols, which may guide the design of future space observations. The present investigation indicates that the current data offer sufficient information to constrain some of the aerosol properties of HD189733b, but the chemistry in the terminator regions remains uncertain.

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The present study explored the relationship between lucidity in dreams (awareness of dreams while dreaming) and mindfulness during wakefulness, also considering meditation as a possible moderating variable. An online survey was completed by 528 respondents, of whom 386 (73.1%) had lucid dream experiences. The reported frequency of lucid dreams was found to be positively related to higher dispositional mindfulness in wakefulness. This relationship was only present in those participants who reported acquaintance with meditation. Regarding the dimensions of mindfulness, lucid dream frequency was more strongly associated with mindful presence rather than acceptance. The findings support the notion of an existing relationship between lucidity in dreams and mindfulness during wakefulness, yet it remains unclear whether the relationship is influenced by actual meditation practice or whether it reflects some natural predispositions. Future studies should examine the role of different meditation practices, investigate personality variables that might influence the relationship, and explore how different facets of mindfulness and lucidity interrelate.

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BACKGROUND: Central and peripheral vision is needed for object detection. Previous research has shown that visual target detection is affected by age. In addition, light conditions also influence visual exploration. The aim of the study was to investigate the effects of age and different light conditions on visual exploration behavior and on driving performance during simulated driving. METHODS: A fixed-base simulator with 180 degree field of view was used to simulate a motorway route under daylight and night conditions to test 29 young subjects (25-40 years) and 27 older subjects (65-78 years). Drivers' eye fixations were analyzed and assigned to regions of interests (ROI) such as street, road signs, car ahead, environment, rear view mirror, side mirror left, side mirror right, incoming car, parked car, road repair. In addition, lane-keeping and driving speed were analyzed as a measure of driving performance. RESULTS: Older drivers had longer fixations on the task relevant ROI, but had a lower frequency of checking mirrors when compared to younger drivers. In both age groups, night driving led to a less fixations on the mirror. At the performance level, older drivers showed more variation in driving speed and lane-keeping behavior, which was especially prominent at night. In younger drivers, night driving had no impact on driving speed or lane-keeping behavior. CONCLUSIONS: Older drivers' visual exploration behavior are more fixed on the task relevant ROI, especially at night, when driving performance becomes more heterogeneous than in younger drivers.

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Leopard Complex spotting occurs in several breeds of horses and is caused by an incompletely dominant allele (LP). Homozygosity for LP is also associated with congenital stationary night blindness (CSNB) in Appaloosa horses. Previously, LP was mapped to a 6 cm region on ECA1 containing the candidate gene TRPM1 (Transient Receptor Potential Cation Channel, Subfamily M, Member 1) and decreased expression of this gene, measured by qRT-PCR, was identified as the likely cause of both spotting and ocular phenotypes. This study describes investigations for a mutation causing or associated with the Leopard Complex and CSNB phenotype in horses. Re-sequencing of the gene and associated splice sites within the 105 624 bp genomic region of TRPM1 led to the discovery of 18 SNPs. Most of the SNPs did not have a predictive value for the presence of LP. However, one SNP (ECA1:108,249,293 C>T) found within intron 11 had a strong (P < 0.0005), but not complete, association with LP and CSNB and thus is a good marker but unlikely to be causative. To further localize the association, 70 SNPs spanning over two Mb including the TRPM1 gene were genotyped in 192 horses from three different breeds segregating for LP. A single 173 kb haplotype associated with LP and CSNB (ECA1: 108,197,355- 108,370,150) was identified. Illumina sequencing of 300 kb surrounding this haplotype revealed 57 SNP variants. Based on their localization within expressed sequences or regions of high sequence conservation across mammals, six of these SNPs were considered to be the most likely candidate mutations. While the precise function of TRPM1 remains to be elucidated, this work solidifies its functional role in both pigmentation and night vision. Further, this work has identified several potential regulatory elements of the TRPM1 gene that should be investigated further in this and other species.

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Low quality of wireless links leads to perpetual transmission failures in lossy wireless environments. To mitigate this problem, opportunistic routing (OR) has been proposed to improve the throughput of wireless multihop ad-hoc networks by taking advantage of the broadcast nature of wireless channels. However, OR can not be directly applied to wireless sensor networks (WSNs) due to some intrinsic design features of WSNs. In this paper, we present a new OR solution for WSNs with suitable adaptations to their characteristics. Our protocol, called SCAD-Sensor Context-aware Adaptive Duty-cycled beaconless opportunistic routing protocol is a cross-layer routing approach and it selects packet forwarders based on multiple sensor context information. To reach a balance between performance and energy-efficiency, SCAD adapts the duty-cycles of sensors according to real-time traffic loads and energy drain rates. We compare SCAD against other protocols through extensive simulations. Evaluation results show that SCAD outperforms other protocols in highly dynamic scenarios.

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Objective. The objective of this study was to determine the prevalence of unintended pregnancy and the association between social and demographic factors among a population of active duty women in the U.S. Army giving birth to viable infants at a U.S. Army hospital at Fort Hood, Texas. Prevalence of unintended pregnancy in this group was 50.9% (95% CI 44.0 to 57.9) with 36.3% being mistimed (95% CI 29.8 to 33.2) and 14.6% being unwanted (95% CI 10.2 to 20.1). A further 14.2% of the women experienced ambivalence (95% CI 9.8 to 19.6). ^ The study population was a cross-sectional group of active duty pregnant women who represent the target population of all female soldiers that deliver viable infants in the Army. Using a survey based on previous studies, intendedness of pregnancy at conception was retrospectively determined. Unintended births are further characterized as mistimed or unwanted. Demographic and other exposures were described bivariately. Associations were evaluated using measures of relative risk and chi-square analysis. ^ The results of the research indicate that in the study population, race/ethnicity is not associated with unintended pregnancy and non-commissioned officers had a lower rate of unintended pregnancy than other rank groupings. ^

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by E. D. Morel

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Previous research has shown an association between mental health status and cigarette smoking. This study examined four specific mental health predictors and the outcome variable any smoking, defined as smoking one or more cigarettes in the past 30 days. The population included active duty military members serving in the United States Army, Air Force, Navy and Marine Corps. The data was collected during the 2005 Department of Defense Survey of Health Related Behaviors Among Active Duty Military Personnel, a component of the Defense Lifestyle Assessment Program. The sample size included 13,603 subjects. This cross sectional prevalence study consisted of descriptive statistics, univariate analysis, and multivariate logistic regression analysis of the four mental health predictors and the any smoking outcome variable. Multivariate adjustment showed an association between the four mental health predictors and any smoking. This association is consistent with previous literature and can help guide public health officials in the development of smoking prevention and cessation programs.^

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A life table methodology was developed which estimates the expected remaining Army service time and the expected remaining Army sick time by years of service for the United States Army population. A measure of illness impact was defined as the ratio of expected remaining Army sick time to the expected remaining Army service time. The variances of the resulting estimators were developed on the basis of current data. The theory of partial and complete competing risks was considered for each type of decrement (death, administrative separation, and medical separation) and for the causes of sick time.^ The methodology was applied to world-wide U.S. Army data for calendar year 1978. A total of 669,493 enlisted personnel and 97,704 officers were reported on active duty as of 30 September 1978. During calendar year 1978, the Army Medical Department reported 114,647 inpatient discharges and 1,767,146 sick days. Although the methodology is completely general with respect to the definition of sick time, only sick time associated with an inpatient episode was considered in this study.^ Since the temporal measure was years of Army service, an age-adjusting process was applied to the life tables for comparative purposes. Analyses were conducted by rank (enlisted and officer), race and sex, and were based on the ratio of expected remaining Army sick time to expected remaining Army service time. Seventeen major diagnostic groups, classified by the Eighth Revision, International Classification of Diseases, Adapted for Use In The United States, were ranked according to their cumulative (across years of service) contribution to expected remaining sick time.^ The study results indicated that enlisted personnel tend to have more expected hospital-associated sick time relative to their expected Army service time than officers. Non-white officers generally have more expected sick time relative to their expected Army service time than white officers. This racial differential was not supported within the enlisted population. Females tend to have more expected sick time relative to their expected Army service time than males. This tendency remained after diagnostic groups 580-629 (Genitourinary System) and 630-678 (Pregnancy and Childbirth) were removed. Problems associated with the circulatory system, digestive system and musculoskeletal system were among the three leading causes of cumulative sick time across years of service. ^

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Background. Infant colic is a common condition that is thought to put infants at risk for Shaken Baby Syndrome, a particularly devastating form of child abuse. However, little research has been done on techniques parents can use to deal with infant colic. This pilot study was conducted to assess the equipment that will be used in a randomized control trial that will compare the results for two different techniques that parents can use to reduce crying in infants with colic. ^ Methods. A total of 11 healthy infants, between one and five months of age, were recruited into this pilot study. All infants had a dosimeter, actiwatch and maternal log placed into the home and a subset of infants (N=3) were also recorded by a video camera. The equipment recorded between 6pm and 6am for at least two and up to five nights. The maternal log and video log were compared with one another to determine if the maternal log provides an accurate representation of the infant's night-time activities (i.e. sleep, awake, crying, feeding). The maternal log was then compared to the dosimeter and actiwatch data to determine if the dosimeter/actiwatch accurately reproduce the maternal log. ^ Results. Data from 10 infants were included in the analyses. The maternal log and video log were in full or partial agreement 90% of the time. When comparing events noted by the mother, the maternal log and dosimeter data were in agreement 84% of the time, and the maternal log and actiwatch data were in agreement 87% of the time. In combination, the dosimeter and/or actiwatch data agreed with the maternal log 90% of the time. ^ Conclusions. Our preliminary analyses of these data suggest the dosimeter and actiwatch will be useful tool for defining infant sleep patterns relative to the maternal log. However further analysis will be required to develop threshold values that can be used to objectively define events in the proposed RCT. Such analyses will need to integrate data from multiple dosimeters and deal with the shifting baselines observed for both the dosimeter and actiwatch.^