681 research outputs found
Psychological Underpinnings of the Work-Site Selection Process of Knowledge Workers
As a result of technological advances, knowledge workers have become increasingly mobile; people can perform work in a variety of new locations via an assortment of new working arrangements. Knowledge workers are now faced with the question of where to work. We argue that the process of work-site selection depends on the relationship between a variety of individual factors such as motivation, cognitive and affective evaluation, and regulatory focus as they interact with self-regulatory resources. Specifically, we use a dynamic interactionist perspective to integrate components of social exchange, self-determination, regulatory focus, and selfregulation theories. The resulting conceptual model contributes to the existing literature by integrating different theoretical sets of predictor variables and examining their effect on selfregulatory resources, which have implications for productivity and well-being. We discuss implications and avenues for future work exploring these relationships
The Multidimensional Role of Trust in Enabling Creativity within Virtual Communities of Practice: A Theoretical Model Integrating Swift, Knowledgebased, Institution-based, and Organizational Trust
Virtual communities of practice are gaining attention among scholars and practitioners as managers and high-level executives look for ways to adapt to an ever-increasing rate of environmental change. These communities have been recognized as a tool for generating new ideas by accessing geographically distributed expertise. As most expert knowledge is tacit and tacit knowledge exchange is what leads to creativity, an understanding of antecedents to tacit knowledge exchange is needed. This manuscript responds by examining the role of trust, a well-known antecedent of creativity, within the context of virtual communities of practice. An interdisciplinary approach led to the development of a multi-level, multi-dimensional model of trust. The authors propose that different dimensions of trust serve as both an antecedent and outcome of creativity in virtual communities of practice, by taking on various forms and roles in the creative process based on tenure of its members
Radiolytic H\u3csub\u3e2\u3c/sub\u3e Production in Martian Environments
Hydrogen, produced by water radiolysis, has been suggested to support microbial communities on Mars. We quantitatively assess the potential magnitude of radiolytic H2 production in wet martian environments (the ancient surface and the present subsurface) based on the radionuclide compositions of (1) eight proposed Mars 2020 landing sites, and (2) three sites that individually yield the highest or lowest calculated radiolytic H2 production rates on Mars. For the proposed landing sites, calculated H2 production rates vary by a factor of ∼1.6, while the three comparison sites differ by a factor of ∼6. Rates in wet martian sediment and microfractured rock are comparable with rates in terrestrial environments that harbor low concentrations of microbial life (e.g., subseafloor basalt). Calculated H2 production rates for low-porosity (M/year) are mostly higher than rates for South Pacific subseafloor basalt (∼0.02–0.6 nM/year). Production rates in martian high-porosity sediment (\u3e35%) and microfractured (1 μm) hard rock (0.03 toM/year) are generally similar to rates in South Pacific basalt, while yields for larger martian fractures (1 and 10 cm) are one to two orders of magnitude lower (M/year). If minerals or brine that amplify radiolytic H2 production rates are present, H2 yields exceed the calculated rates
A quantitative model of water radiolysis and chemical production rates near radionuclide-containing solids
We present a mathematical model that quantifies the rate of water radiolysis near radionuclide-containing solids. Our model incorporates the radioactivity of the solid along with the energies and attenuation properties for alpha (α), beta (β), and gamma (γ) radiation to calculate volume normalized dose rate profiles. In the model, these dose rate profiles are then used to calculate radiolytic hydrogen (H2) and hydrogen peroxide (H2O2) production rates as a function of distance from the solid–water interface. It expands on previous water radiolysis models by incorporating planar or cylindrical solid–water interfaces and by explicitly including γ radiation in dose rate calculations. To illustrate our model\u27s utility, we quantify radiolytic H2 and H2O2 production rates surrounding spent nuclear fuel under different conditions (at 20 years and 1000 years of storage, as well as before and after barrier failure). These examples demonstrate the extent to which α, β and γ radiation contributes to total absorbed dose rate and radiolytic production rates. The different cases also illustrate how H2 and H2O2 yields depend on initial composition, shielding and age of the solid. In this way, the examples demonstrate the importance of including all three types of radiation in a general model of total radiolytic production rates
Southward expansion: The myth of the West in the promotion of Florida, 1876–1900
This article examines the ways in which promoters and developers of Florida, in the decades after Reconstruction, engaged with a popular myth of the West as a means of recasting and selling their state to prospective settlers in the North and Midwest. The myth envisaged a cherished region to the west where worthy Americans could migrate and achieve social and economic independence away from the crowded confines of the East, or Europe. According to state immigration agents, land-promoters and other booster writers, Florida, although a Southern ex-Confederate state, offered precisely these 'western' opportunities for those hard-working Northerners seeking land and an opening for agrarian prosperity. However, the myth, which posited that, in the west, an individual's labour and thrift were rewarded with social and economic improvement, meshed awkwardly with the contemporary emergence of Florida as a popular winter destination for wealthy tourists and invalids seeking leisure and healthfulness away from the North. Yet it also reflected and reinforced promotional notions of racial improvement which would occur with an influx of enterprising Anglo-Americans, who would effectively displace the state's large African American population. In Florida, the myth of the West supported the linked post-Reconstruction processes of state development and racial subjugation
Determination of in situ dissolved inorganic carbon concentration and alkalinity for marine sedimentary porewater
Dissolved inorganic carbon (DIC) concentration and total alkalinity in marine sediment vary with biological activity, mineral diagenesis and past bottom ocean water composition. Reliable interpretation of this data is often compromised due to precipitation of calcium carbonate (CaCO3) during sediment recovery, processing and sample storage. Here we present and test a method that corrects for this precipitation and consequently allows quantification of in situ carbonate system chemistry. Our method relies on the over-determination of the dissolved carbonate system by (i) measuring DIC, alkalinity and calcium, and (ii) explicitly assuming CaCO3 saturation in the sediment. We experimentally tested this method using data from Integrated Ocean Drilling Program (IODP) Site U1368 in the South Pacific Gyre. Our results show that we can accurately reproduce in situ aqueous carbonate system chemistry if DIC, alkalinity and calcium concentration are measured simultaneously. At Site U1368, the correction for sampling associated precipitation is equivalent to 4.5 and 8.9% of the measured DIC and alkalinity, respectively. The method is well suited for any sediment porewater that is saturated with respect to calcium carbonate; consequently, it is applicable for approximately 50% of the global oceanic seafloor
Subseafloor life and its biogeochemical impacts
Subseafloor microbial activities are central to Earth’s biogeochemical cycles. They control Earth’s surface oxidation and major aspects of ocean chemistry. They affect climate on long timescales and play major roles in forming and destroying economic resources. In this review, we evaluate present understanding of subseafloor microbes and their activities, identify research gaps, and recommend approaches to filling those gaps. Our synthesis suggests that chemical diffusion rates and reaction affinities play a primary role in controlling rates of subseafloor activities. Fundamental aspects of subseafloor communities, including features that enable their persistence at low catabolic rates for millions of years, remain unknown
Reconstruction of Pacific Ocean Bottom Water Salinity During the Last Glacial Maximum
Knowledge of salinity in the deep ocean is important for understanding past ocean circulation and climate. Based on sedimentary pore fluid chloride measurements of a single Pacific site, Adkins et al. (2002) suggested that, during the Last Glacial Maximum (LGM), the Pacific deep bottom water was saltier than expected based on lower sea level alone. Here we present high-resolution salinity profiles from five sites in the South, Equatorial, and North Pacific Ocean. Our study greatly constrains understanding of LGM salinity in the Pacific Ocean. Our results show that LGM chloride concentrations of deep Pacific bottom water were 4.09 ± 0.4% greater than today\u27s values. Pacific Ocean bottom water salinity was also indistinguishable from being homogeneous across the wide range of latitudes studied here. These LGM salinity reconstructions are on average slightly higher (~1.4 to 1% higher) than expected from sea level of the time, which is generally inferred to have been ~120 to ~135 m lower than today
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