18 research outputs found
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Modeling information technology impacts in clerical work environments
The industrialization of white collar work via information technology (IT) is a key indicator of the emerging post-industrial economy (Hirschhorn, 1988). A conceptual model linking clerical work environments to effective IT impacts such as IT utilization, IT\u27s perceived ease of use and performance impact was developed and empirically tested. Underlying the model is the premise that clerical job structure is a facilitator of IT impacts (Weber, 1988). The results indicate that clerical job structure factors such as typing, composing or editing, and bookkeeping were significantly related to IT impacts in clerical work settings. A job holder\u27s IT competence and top management commitment to IT were also found to be significantly related to IT impacts in clerical work settings. Antecedent relationships among the IT impacts also contributed to understanding the IT impacts - for example, IT utilization affected perceived ease of use and perceived performance impact, and perceived ease of use affected perceived performance impact
Spatial variation in exhumation rates across Ladakh and the Karakoram: New apatite fission track data from the Eastern Karakoram, NW India
Characterization of low-temperature cooling histories and associated exhumation rates is critical for deciphering the recent evolution of orogenic regions. However, these may vary significantly over relatively short distances within orogens. It is pertinent therefore to constrain cooling histories and hence exhumation rates across major tectonic boundaries. We report the first apatite fission track ages from the Karakoram Fault Zone in the Eastern Karakoram range, which forms part of the western margin of the Tibetan Plateau. Ten samples, from elevations of 3477–4875m, have apatite fission track dates from 3.3 ± 0.3 Ma to 7.4± 1.1Ma. The ages correspond to modeled average erosional exhumation rates of 0.67+ 0.27-0.18mm/yr across the Eastern Karakoram. The results are consistent with a trend northward from the Indus suture zone, across the Ladakh terrane and into the Karakoram, in which tectonic uplift associated with crustal thickening increases toward the north, raising elevation and promoting glaciation and generation of extreme relief. As a result, erosion and exhumation rates increase south to north. Present-day precipitation on the other hand varies little within the study area and on a larger scale decreases southwest to northeast across this portion of the orogen. The Eastern Karakoram results highlight the diverse patterns of exhumation driven by regional variations in tectonic response to collision along the western margin of Tibet
The Cytosolic Domain of Fis1 Binds and Reversibly Clusters Lipid Vesicles
Every lipid membrane fission event involves the association of two apposing bilayers, mediated by proteins that can promote membrane curvature, fusion and fission. We tested the hypothesis that Fis1, a tail-anchored protein involved in mitochondrial and peroxisomal fission, promotes changes in membrane structure. We found that the cytosolic domain of Fis1 alone binds lipid vesicles, which is enhanced upon protonation and increasing concentrations of anionic phospholipids. Fluorescence and circular dichroism data indicate that the cytosolic domain undergoes a membrane-induced conformational change that buries two tryptophan side chains upon membrane binding. Light scattering and electron microscopy data show that membrane binding promotes lipid vesicle clustering. Remarkably, this vesicle clustering is reversible and vesicles largely retain their original shape and size. This raises the possibility that the Fis1 cytosolic domain might act in membrane fission by promoting a reversible membrane association, a necessary step in membrane fission