654 research outputs found

    Work-life Events Theory: Making Sense of Shock Events in Dual-Earner Couples

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    Dual-earner couples are increasingly prevalent and encounter demands arising from each partner’s commitment to various work and life domains. Unfortunately, there has been little theoretical progress in explaining how dual-earner couples navigate work-life shock events, which we define as disruptive, novel, and critical events that require investment of a couple’s resources. Drawing from identity and sensemaking theories, we develop a theory of work-life shock events to explain how dual-earner couples perceive and respond to these events. We theorize that partners initially make sense of the event as individuals and then engage in couple-level sensemaking. We argue that each individual’s shock intensity perceptions are shaped by the shock event’s characteristics and the identity factors of role salience hierarchy and future self. A subsequent couple-level process of sensemaking ensues, influenced by the salience of the originating domain and partner role, as well as relational identity factors. Couple-level shock intensity perceptions result in the couple’s decision regarding resource investment in the shock event’s originating domain. We discuss implications for future research and for organizations

    Efficiency considerations in the construction of interpolated potential energy surfaces for the calculation of quantum observables by diffusion Monte Carlo

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    A modified Shepard interpolation scheme is used to construct global potential energy surfaces (PES) in order to calculate quantum observables--vibrationally averaged internal coordinates, fully anharmonic zero-point energies and nuclear radial distribution functions--for a prototypical loosely bound molecular system, the water dimer. The efficiency of PES construction is examined with respect to (a) the method used to sample configurational space, (b) the method used to choose which points to add to the PES data set, and (c) the use of either a one- or two-part weight function. The most efficient method for constructing the PES is found to require a quantum sampling regime, a combination of both h-weight and rms methods for choosing data points and use of the two-part weight function in the interpolation. Using this regime, the quantum diffusion Monte Carlo zero-point energy converges to the exact result within addition of 50 data points. The vibrationally averaged O-O distance and O-O radial distribution function, however, converge more slowly and require addition of over 500 data points. The methods presented here are expected to be applicable to both other loosely bound complexes as well as tightly bound molecular species. When combined with high quality ab initio calculations, these methods should be able to accurately characterize the PES of such species.D.L.C. would like to acknowledge the financial support of an Australian Postgraduate Research Award. This work has also been supported by Large Grant No. A00104447 from the Australian Research Council and by grants of computer time from the Australian Partnership in Advanced Computing (APAC) National Merit Allocation Scheme

    A classical trajectory study of the photodissociation of T₁ acetaldehyde: the transition from impulsive to statistical dynamics

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    Previous experimental and theoretical studies of the radical dissociation channel of T(1) acetaldehyde show conflicting behavior in the HCO and CH(3) product distributions. To resolve these conflicts, a full-dimensional potential-energy surface for the dissociation of CH(3)CHO into HCO and CH(3) fragments over the barrier on the T(1) surface is developed based on RO-CCSD(T)/cc-pVTZ(DZ) ab initio calculations. 20,000 classical trajectories are calculated on this surface at each of five initial excess energies, spanning the excitation energies used in previous experimental studies, and translational, vibrational, and rotational distributions of the radical products are determined. For excess energies near the dissociation threshold, both the HCO and CH(3) products are vibrationally cold; there is a small amount of HCO rotational excitation and little CH(3) rotational excitation, and the reaction energy is partitioned dominantly (>90% at threshold) into relative translational motion. Close to threshold the HCO and CH(3) rotational distributions are symmetrically shaped, resembling a Gaussian function, in agreement with observed experimental HCO rotational distributions. As the excess energy increases the calculated HCO and CH(3) rotational distributions are observed to change from a Gaussian shape at threshold to one more resembling a Boltzmann distribution, a behavior also seen by various experimental groups. Thus the distribution of energy in these rotational degrees of freedom is observed to change from nonstatistical to apparently statistical, as excess energy increases. As the energy above threshold increases all the internal and external degrees of freedom are observed to gain population at a similar rate, broadly consistent with equipartitioning of the available energy at the transition state. These observations generally support the practice of separating the reaction dynamics into two reservoirs: an impulsive reservoir, fed by the exit channel dynamics, and a statistical reservoir, supported by the random distribution of excess energy above the barrier. The HCO rotation, however, is favored by approximately a factor of 3 over the statistical prediction. Thus, at sufficiently high excess energies, although the HCO rotational distribution may be considered statistical, the partitioning of energy into HCO rotation is not.One of the authors D.L.C. acknowledges the financial support of an Australian Postgraduate Research Award. This work has also been supported in large by Grant No. A00104447 from the Australian Research Council and by grants of computer time from the Australian Partnership in Advanced Computing APAC National Merit Allocation Scheme

    The seasonal cycle of ocean-atmosphere CO2 Flux in Ryder Bay, West Antarctic Peninsula

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    Approximately 15 million km2 of the Southern Ocean is seasonally ice covered, yet the processes affecting carbon cycling and gas exchange in this climatically important region remain inadequately understood. Here, 3 years of dissolved inorganic carbon (DIC) measurements and carbon dioxide (CO2) fluxes from Ryder Bay on the west Antarctic Peninsula (WAP) are presented. During spring and summer, primary production in the surface ocean promotes atmospheric CO2 uptake. In winter, higher DIC, caused by net heterotrophy and vertical mixing with Circumpolar Deep Water, results in outgassing of CO2 from the ocean. Ryder Bay is found to be a net sink of atmospheric CO2 of 0.59–0.94 mol C m−2 yr−1 (average of 3 years). Seasonal sea ice cover increases the net annual CO2 uptake, but its effect on gas exchange remains poorly constrained. A reduction in sea ice on the WAP shelf may reduce the strength of the oceanic CO2 sink in this region

    Weddell Sea Export Pathways from Surface Drifters

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    The complex export pathways that connect the surface waters of the Weddell Sea with the Antarctic Circumpolar Current influence water mass modification, nutrient fluxes, and ecosystem dynamics. To study this exchange, 40 surface drifters, equipped with temperature sensors, were released into the northwestern Weddell Sea’s continental shelf and slope frontal system in late January 2012. Comparison of the drifter trajectories with a similar deployment in early February 2007 provides insight into the interannual variability of the surface circulation in this region. Observed differences in the 2007 and 2012 drifter trajectories are related to a variable surface circulation responding to changes in wind stress curl over the Weddell Gyre. Differences between northwestern Weddell Sea properties in 2007 and 2012 include 1) an enhanced cyclonic wind stress forcing over the Weddell Gyre in 2012; 2) an acceleration of the Antarctic Slope Current (ASC) and an offshore shift of the primary drifter export pathway in 2012; and 3) a strengthening of the Coastal Current (CC) over the continental shelf in 2007. The relationship between wind stress forcing and surface circulation is reproduced over a longer time period in virtual drifter deployments advected by a remotely sensed surface velocity product. The mean offshore position and speed of the drifter trajectories are correlated with the wind stress curl over the Weddell Gyre, although with different temporal lags. The drifter observations are consistent with recent modeling studies suggesting that Weddell Sea boundary current variability can significantly impact the rate and source of exported surface waters to the Scotia Sea, a process that determines regional chlorophyll distributions

    Nest location preferences in zoo-housed orangutans

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    Nest building is an advanced and complex activity that wild orangutans engage in, yet they do so on a daily basis and with potential safety consequences. Like their wild counterparts, zoo-housed orangutans also make nests when given adequate materials, yet comparatively little research has documented the nesting habits of captive orangutans, including potential social and environmental influences of nest site selections. We documented the night nesting behavior of six adult orangutans housed at the Smithsonian's National Zoological Park (NZP), identifying preferred nest locations and proximity to conspecifics, comparing observed patterns to those reported in a nest behavior survey of orangutan facilities throughout the Association of Zoos and Aquariums (AZA). Survey results reveal that in addition to several universal patterns of nesting behaviors, as in the wild, the sharing of night nests by captive adult orangutans occurs only rarely (2 of 31 surveyed facilities). Data collected at NZP indicate that night nearest neighbor associations among nesting conspecifics may be a useful proxy for actual nearest neighbor data taken during daytime social interactions and may offer a more feasible alternative for determining social relationships among large groups of socially housed orangutans

    Establishing haematological and biochemical reference intervals for free-ranging Scottish golden eagle nestlings (Aquila chrysaetos)

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    Health assessment of individuals is an important aspect of monitoring endangered wildlife populations. Haematological and biochemical values are a common health assessment tool, and whilst reference values are well established for domestic species, they are often not available for wild animal species. This study established 31 haematological and biochemical reference intervals for golden eagle (Aquila chrysaetos) nestlings in Scotland, in order to improve the understanding of the species’ health and support conservation efforts. Reference intervals were created from 47 nestlings (ages 2–7.5 weeks old) across 37 nests, to date, the largest sample of wild individuals of this species and age cohort sampled for these purposes. Upper reference intervals for concentrations of lymphocytes, total protein, cholesterol, triglycerides, uric acid, and monocytes, calculated in this study, are higher than those found for adult raptors and the interval span is higher than that observed in adult raptors for concentrations of AST, albumin, eosinophil, LDH, and monocyte count. Statistically significant positive correlations were found with age and concentrations of haemoglobin, lymphocytes, serum pH, and creatine kinase, and significant negative correlations with age for concentrations of thrombocytes, heterophils, total protein, globulin, and lactate dehydrogenase. Packed cell volume was significantly higher for females than males, and concentration of calcium and eosinophils were higher for individuals in good body condition than those in moderate body condition. The reference intervals produced by this study will be of important use to the veterinary and conservation management communities and will aid the long-term monitoring of the Scottish golden eagle population health

    Numerical Simulation of an EUV Coronal Wave Based on the February 13, 2009 CME Event Observed by STEREO

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    On 13 February 2009, a coronal wave -- CME -- dimming event was observed in quadrature by the STEREO spacecraft. We analyze this event using a three-dimensional, global magnetohydrodynamic (MHD) model for the solar corona. The numerical simulation is driven and constrained by the observations, and indicates where magnetic reconnection occurs between the expanding CME core and surrounding environment. We focus primarily on the lower corona, extending out to 3R⊙3R_{\odot}; this range allows simultaneous comparison with both EUVI and COR1 data. Our simulation produces a diffuse coronal bright front remarkably similar to that observed by STEREO/EUVI at 195 \AA. It is made up of \emph{two} components, and is the result of a combination of both wave and non-wave mechanisms. The CME becomes large-scale quite low (<< 200 Mm) in the corona. It is not, however, an inherently large-scale event; rather, the expansion is facilitated by magnetic reconnection between the expanding CME core and the surrounding magnetic environment. In support of this, we also find numerous secondary dimmings, many far from the initial CME source region. Relating such dimmings to reconnecting field lines within the simulation provides further evidence that CME expansion leads to the "opening" of coronal field lines on a global scale. Throughout the CME expansion, the coronal wave maps directly to the CME footprint. Our results suggest that the ongoing debate over the "true" nature of diffuse coronal waves may be mischaracterized. It appears that \emph{both} wave and non-wave models are required to explain the observations and understand the complex nature of these events
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