946 research outputs found
Independent and relative effects of stress, depressive symptoms, and affect on college students' daily health behaviors.
Stress and depressive symptoms are associated with maladaptive health behavior practices such as unhealthy eating, sedentary behavior, insufficient sleep, and substance use. The relative and interactive effects of stress and depressive symptoms on health behavior practices are less well understood. The present study examined these processes in a daily diary study of 127 college students. Results from hierarchical generalized linear models indicated that depressive symptoms, and chronic and daily stress, but not acute stressful life events, were significantly associated with a composite score of daily maladaptive health behavior engagement (depressive symptoms b = .01, SE= .00, p < .01; chronic stress, b = .03, SE= .01, p < .01; daily stress, b = .01, SE= .01, p = .02); unexpectedly, the effect of stress on health behaviors was not moderated by depressive symptoms. Additionally, results demonstrated that the effect of depressive symptoms on health behaviors was mediated by fluctuations in daily negative affect. These results bear implications for intervention during a crucial period in the development of mental and physical health
Long-Term Trends in Calcifying Plankton and pH in the North Sea
Relationships between six calcifying plankton groups and pH are explored in a highly biologically productive and data-rich area of the central North Sea using time-series datasets. The long-term trends show that abundances of foraminiferans, coccolithophores, and echinoderm larvae have risen over the last few decades while the abundances of bivalves and pteropods have declined. Despite good coverage of pH data for the study area there is uncertainty over the quality of this historical dataset; pH appears to have been declining since the mid 1990s but there was no statistical connection between the abundance of the calcifying plankton and the pH trends. If there are any effects of pH on calcifying plankton in the North Sea they appear to be masked by the combined effects of other climatic (e.g. temperature), chemical (nutrient concentrations) and biotic (predation) drivers. Certain calcified plankton have proliferated in the central North Sea, and are tolerant of changes in pH that have occurred since the 1950s but bivalve larvae and pteropods have declined. An improved monitoring programme is required as ocean acidification may be occurring at a rate that will exceed the environmental niches of numerous planktonic taxa, testing their capacities for acclimation and genetic adaptation
Ground-State Electromagnetic Moments of Calcium Isotopes
High-resolution bunched-beam collinear laser spectroscopy was used to measure
the optical hyperfine spectra of the Ca isotopes. The ground state
magnetic moments of Ca and quadrupole moments of Ca were
measured for the first time, and the Ca ground state spin was
determined in a model-independent way. Our results provide a critical test of
modern nuclear theories based on shell-model calculations using
phenomenological as well as microscopic interactions. The results for the
neutron-rich isotopes are in excellent agreement with predictions using
interactions derived from chiral effective field theory including three-nucleon
forces, while lighter isotopes illustrate the presence of particle-hole
excitations of the Ca core in their ground state.Comment: Accepted as a Rapid Communication in Physical Review
Spins, Electromagnetic Moments, and Isomers of 107-129Cd
The neutron-rich isotopes of cadmium up to the N=82 shell closure have been
investigated by high-resolution laser spectroscopy. Deep-UV excitation at 214.5
nm and radioactive-beam bunching provided the required experimental
sensitivity. Long-lived isomers are observed in 127Cd and 129Cd for the first
time. One essential feature of the spherical shell model is unambiguously
confirmed by a linear increase of the 11/2- quadrupole moments. Remarkably,
this mechanism is found to act well beyond the h11/2 shell
Toward an automated signature recognition toolkit for mission operations
Signature recognition is the problem of identifying an event or events from its time series. The generic problem has numerous applications to science and engineering. At NASA's Johnson Space Center, for example, mission control personnel, using electronic displays and strip chart recorders, monitor telemetry data from three-phase electrical buses on the Space Shuttle and maintain records of device activation and deactivation. Since few electrical devices have sensors to indicate their actual status, changes of state are inferred from characteristic current and voltage fluctuations. Controllers recognize these events both by examining the waveform signatures and by listening to audio channels between ground and crew. Recently the authors have developed a prototype system that identifies major electrical events from the telemetry and displays them on a workstation. Eventually the system will be able to identify accurately the signatures of over fifty distinct events in real time, while contending with noise, intermittent loss of signal, overlapping events, and other complications. This system is just one of many possible signature recognition applications in Mission Control. While much of the technology underlying these applications is the same, each application has unique data characteristics, and every control position has its own interface and performance requirements. There is a need, therefore, for CASE tools that can reduce the time to implement a running signature recognition application from months to weeks or days. This paper describes our work to date and our future plans
Syngenetic sand veins and anti-syngenetic sand wedges, Tuktoyaktuk Coastlands, western Arctic Canada
Sand-sheet deposits of full-glacial age in the Tuktoyaktuk Coastlands, western Arctic Canada, contain syngenetic sand veins 1-21 cm wide and sometimes exceeding 9 m in height. Their tall and narrow, chimney-like morphology differs from that of known syngenetic ice wedges and indicates an unusually close balance between the rate of sand-sheet aggradation and the frequency of thermal-contraction cracking. The sand sheets also contain rejuvenated (syngenetic) sand wedges that have grown upward from an erosion surface. By contrast, sand sheets of postglacial age contain few or sometimes no intraformational sand veins and wedges, suggesting that the climatic conditions were unfavourable for thermal-contraction cracking. Beneath a postglacial sand sheet near Johnson Bay, sand wedges with unusually wide tops (3.9 m) extend down from a prominent erosion surface. The wedges grew vertically downward during deflation of the ground surface, and represent anti-syngenetic wedges. The distribution of sand veins and wedges within the sand sheets indicates that the existence of continuous permafrost during sand-sheet aggradation can be inferred confidently only during full-glacial conditions
Early Adversity and the Prospective Prediction of Depressive and Anxiety Disorders in Adolescents
The current study was a prospective exploration of the specificity of early childhood adversities as predictors of anxiety and depressive disorders in adolescents. Participants were 816 adolescents (414 males, 402 females) with diagnostic information collected at age 15; information on early adversities had been collected from the mothers during pregnancy, at birth, age 6 months, and age 5 years for a related study. Adolescents with "pure" anxiety disorders were compared with adolescents with "pure" depressive disorders (major depressive disorder, dysthymia), and these groups were compared to never-ill controls. Analyses controlled for gender and maternal depression and anxiety disorders. Results indicated that adolescents with anxiety disorders were more likely than depressed youth to have been exposed to various early stressors, such as maternal prenatal stress, multiple maternal partner changes, and more total adversities, whereas few early childhood variables predicted depressive disorders. Even when current family stressors at age 15 were controlled, early adversity variables again significantly predicted anxiety disorders. Results suggest that anxiety disorders may be more strongly related to early strees exposure, while depressive disorders may be related to more proximal stressors or to early stressors not assessed in the current study
Validating New Summary Indices for the Childhood Trauma Interview: Associations with First Onsets of Major Depressive Disorder and Anxiety Disorders
Childhood and adolescent adversity is of great interest in relation to risk for psychopathology, and interview measures of adversity are thought to be more reliable and valid than their questionnaire counterparts. One interview measure, the Childhood Trauma Interview (CTI; Fink et al., 1995), has been positively evaluated relative to similar measures, but there are some psychometric limitations to an existing scoring approach that limit the full potential of this measure. We propose several new summary indices for the CTI that permit examination of different types of adversity and different developmental periods. Our approach creates several summary indices: one sums the severity scores of adversities endorsed; another utilizes the number of minor and major (moderate to severe) adversities. The new indices were examined in association with first onsets of major depressive disorder (MDD) and anxiety disorders across a 5-year period using annual clinical diagnostic interviews (Structured Clinical Interview for DSM–IV–TR). Summary scores derived with the previously used approach were also examined for comparison. Data on 332 participants came from the Youth Emotion Project, a longitudinal study of risk for emotional disorders. Results support the predictive validity of the proposed summary scoring methods and indicate that several forms of major (but typically not minor) adversity are significantly associated with first onsets of MDD and anxiety disorders. Finally, multivariate regression models show that, in many instances, the new indices contributed significant unique variance predicting disorder onsets over and above the previously used summary indices
Stress sensitization and adolescent depressive severity as a function of childhood adversity: A link to anxiety disorders
The goal of the present study was to determine whether exposure to adversity in childhood contributes to a differential threshold at which stressful life events provoke depressive reactions in adolescence. In addition, to address empirical and conceptual questions about stress effects, the moderating effect of anxiety disorder history was also explored. This examination was conducted in a sample of 816 children of depressed and nondepressed mothers, who were followed from birth to age 15. Information on adversities experienced in childhood was collected both from mothers during the first five years of their youth's life and from the youths themselves at age 15, and included information on the mother's relationship with her partner, maternal psychopathology, as well as youth-reported abuse. Results indicated that youths with both greater exposure to adversity in childhood and a history of an anxiety disorder displayed increased depressive severity following low levels of episodic stress compared to youths with only one or neither of these risk factors. The results are speculated to reflect the possibility that early anxiety disorders associated with exposure to adversity in childhood may be a marker of dysregulated stress responses, and may help to account for the comorbidity of depression and anxiety in some individuals
- …