643 research outputs found
Charged particle display
An optical shutter based on charged particles is presented. The output light
intensity of the proposed device has an intrinsic dependence on the
interparticle spacing between charged particles, which can be controlled by
varying voltages applied to the control electrodes. The interparticle spacing
between charged particles can be varied continuously and this opens up the
possibility of particle based displays with continuous grayscale.Comment: typographic errors corrected in Eqs (37) and (39); published in
Journal of Applied Physics; doi:10.1063/1.317648
Poly(benzyl ether) dendrimers with strongly fluorescent distyrylbenzene cores as the fluorophores for peroxyoxalate chemiluminescence: insulating effect of dendritic structures on fluorescent sites
ArticleTETRAHEDRON. 61(46): 11020-11026 (2005)journal articl
Forest harvesting impacts on microclimate conditions and sediment transport activities in a humid periglacial environment
Sediment transport activities in periglacial environments
are controlled by microclimate conditions (i.e., air and ground temperatures,
throughfall), which are highly affected by vegetation cover. Thus, there is
the possibility that forest harvesting, the most dramatic change to
vegetation cover in mountain areas, may severely impact sediment transport
activities in periglacial areas (i.e., soil creep, dry ravel). In this study,
we investigated changes in sediment transport activities following forest
harvesting in steep artificial forests located in a humid periglacial area of
the southern Japanese Alps. In the southern Japanese Alps, rainfall is
abundant in summer and autumn, and winter air temperatures frequently rise
above and fall below 0∘. Our monitoring by time lapse cameras
revealed that gravitational transport processes (e.g., frost creep and dry
ravel) dominate during the freeze–thaw season, while rainfall-induced
processes (surface erosion and soil creep) occur during heavy rainfall
seasons. Canopy removal by forest harvesting increased the winter diurnal
ground surface temperature range from 2.7 to 15.9 ∘C. Forest
harvesting also increased the diurnal range of net radiation and ground
temperature, and decreased the duration of snow cover. Such changes in the
microclimate conditions altered the type of winter soil creep from frost
creep to diurnal needle-ice creep. Winter creep velocity of ground surface
sediment in the harvested site (> 2 mm day−1 on the days
with frost heave) was significantly higher than that in the non-harvested
site (generally < 1 mm day−1). Meanwhile, sediment flux on
the hillslopes, as observed by sediment traps, decreased in the harvested
site. Branches of harvested trees left on the hillslopes captured sediment
moving downslope. In addition, the growth of understories after harvesting
possibly reduced surface erosion. Consequently, removal of the forest canopy
by forest harvesting directly impacts the microclimate conditions (i.e.,
diurnal range of ground temperature and net radiation, duration of snow
cover) and increases frequency and velocity of periglacial soil creep, while
sediment flux on hillslopes is decreased by branches left on the hillslopes
and recovery of understories. The impact of forest harvesting on sediment
transport activity is seasonally variable in humid periglacial areas, because
microclimate conditions relevant to both freeze–thaw processes and
precipitation-induced processes control sediment transport.</p
Artificial Neural Network Inference (ANNI): A Study on Gene-Gene Interaction for Biomarkers in Childhood Sarcomas
Objective: To model the potential interaction between previously identified biomarkers in children sarcomas using artificial neural network inference (ANNI).
Method: To concisely demonstrate the biological interactions between correlated genes in an interaction network map, only 2 types of sarcomas in the children small round blue cell tumors (SRBCTs) dataset are discussed in this paper. A backpropagation neural network was used to model the potential interaction between genes. The prediction weights and signal directions were used to model the strengths of the interaction signals and the direction of the interaction link between genes. The ANN model was validated using Monte Carlo cross-validation to minimize the risk of over-fitting and to optimize generalization ability of the model.
Results: Strong connection links on certain genes (TNNT1 and FNDC5 in rhabdomyosarcoma (RMS); FCGRT and OLFM1 in Ewing’s sarcoma (EWS)) suggested their potency as central hubs in the interconnection of genes with different functionalities. The results showed that the RMS patients in this dataset are likely to be congenital and at low risk of cardiomyopathy development. The EWS patients are likely to be complicated by EWS-FLI fusion and deficiency in various signaling pathways, including Wnt, Fas/Rho and intracellular oxygen.
Conclusions: The ANN network inference approach and the examination of identified genes in the published literature within the context of the disease highlights the substantial influence of certain genes in sarcomas
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A framework for comparative institutional research on HRM
This article argues that awareness of institutional context has been singularly lacking in the most influential areas of HRM. This lack of attention to external context has resulted in findings that fail to reflect reality. We offer a layered contextual framework embedded in economic institutional theory. We propose that it forms the basis of a comparative research agenda for HRM. We validate the framework using extant publications on institutionally based comparative HRM, drawing on findings from the Cranet research network published in the decade 2007–2017
High-performance work system and employee performance: the mediating roles of social exchange and thriving and the moderating effect of employee proactive personality
Research on high-performance work system (HPWS) has primarily drawn from social exchange theory and human capital theory to unlock the underlying mechanisms in relation to employee performance. In addition to social exchange theory and human capital theory, a personal resources perspective can also be used to explain the effects of HPWS. In this cross-level research, we examined the mediating roles of social exchange and thriving, and the moderating role of proactive personality in the relationships between HPWS and task performance and organizational citizenship behavior (OCB) by analyzing a sample of 391 employees and 84 supervisors from 21 firms in China. Using multilevel analyses, social exchange and thriving were found to mediate the effects of HPWS on employee task performance and OCB. Furthermore, proactive personality attenuated HPWS’s direct effect on thriving and indirect effects on employee task performance and OCB through thriving. Finally, we discuss theoretical contributions, and practical implications of the study, as well as future research directions
The Effect of Proprioceptive Feedback on the Distribution of Sensory Information in a Model of an Undulatory Organism
In an animal, a crucial factor concerning the arrival of information at the sensors and subsequent transmission to the effectors, is how it is distributed. At the same time, higher animals also employ proprioceptive feedback so that their respective neural circuits have information regarding the state of the animal body. In order to disseminate what this practically means for the distribution of sensory information, we have modeled a segmented swimming organism (animat) coevolving its nervous system and body plan morphology. In a simulated aquatic environment, we find that animats artificially endowed with proprioceptive feedback are able to evolve completely decoupled central pattern generators (CPGs) meaning that they emerge without any connections made to neural circuits in adjacent body segments. Without such feedback however, we also find that the distribution of sensory information from the head of the animat becomes far more important, with adjacent CPG circuits becoming interconnected. Crucially, this demonstrates that where proprioceptive mechanisms are lacking, more effective delivery of sensory input is essential
Maintenance of bone mineral density after implantation of a femoral neck hip prosthesis
<p>Abstract</p> <p>Background</p> <p>Stress shielding of the proximal femur has been observed in a number of conventional cementless implants used in total hip arthroplasty. Short femoral-neck implants are claiming less interference with the biomechanics of the proximal femur. The goal of this study was to investigate the changes of bone-mineral density in the proximal femur and the clinical outcome after implantation of a short femoral-neck prosthesis.</p> <p>Methods</p> <p>We prospectively assessed the clinical outcome and the changes of bone mineral density of the proximal femur up to one year after implantation of a short femoral neck prosthesis in 20 patients with a mean age of 47 years (range 17 to 65). Clinical outcome was assessed using the Harris Hip Score. The WOMAC was used as a patient-relevant outcome-measure. The bone mineral density was determined using dual energy x-ray absorptiometry, performed 10 days, three months and 12 months after surgery.</p> <p>Results</p> <p>The Harris Hip Score improved from an average preoperative score of 46 to a postoperative score at 12 months of 89 points, the global WOMAC index from 5,3 preoperatively to 0,8 at 12 months postoperatively. In contrast to conventional implants, the DEXA-scans overall revealed a slight increase of bone mineral density in the proximal femur in the 12 months following the implantation.</p> <p>Conclusion</p> <p>The short femoral neck stem lead to a distinct bone reaction. This was significantly different when compared to the changes in bone mineral density reported after implantation of conventional implants.</p
Detection of a circadian enhancer in the mDbp promoter using prokaryotic transposon vector-based strategy
In mammals, the expression of 5–10% of genes occurs with circadian fluctuation in various organs and tissues. This cyclic transcription is thought to be directly or indirectly regulated through circadian transcriptional/translational feedback loops consisting of a set of clock genes. Among the clock genes in mammals, expression of the Dbp mRNA robustly oscillates both in vivo and in culture cells. Here, we present circadian enhancer detection strategy using prokaryotic transposon system. The mDbp promoter drives reporter gene expression in robust circadian cycles in rat-1 fibroblasts. To identify the circadian enhancer generating this robust rhythm, we developed a prokaryotic transposon-based enhancer detecting vector for in vitro transposition. Using this system, we identified a strong circadian enhancer region containing the CATGTG sequence in the 5′ flanking region of the mDbp gene; this enhancer region is critical for the ability of the mDbp promoter to drive robust oscillation in living cells. This enhancer is classified as a CANNTG type non-canonical E-box. These findings strongly suggest that CANNTG-type non-canonical E-boxes may contribute, at least in part, to the regulation of robust circadian gene expression. Furthermore, these data may help explain the wider effects of the CLOCK/BMAL1 complex in control of clock output genes
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