1,166 research outputs found
The extension of variability properties in gamma-ray bursts to blazars
Both gamma-ray bursts (GRBs) and blazars have relativistic jets pointing at a
small angle from our line of sight. Several recent studies suggested that these
two kinds of sources may share similar jet physics. In this work, we explore
the variability properties for GRBs and blazars as a whole. We find that the
correlation between minimum variability timescale (MTS) and Lorentz factor,
, as found only in GRBs by Sonbas et al. can be extended to blazars
with a joint correlation of . The same
applies to the correlation as
found in GRBs, which can be well extended into blazars as well. These results
provide further evidence that the jets in these two kinds of sources are
similar despite of the very different mass scale of their central engines.
Further investigations of the physical origin of these correlations are needed,
which can shed light on the nature of the jet physics.Comment: 6 pages, 2 figures, accepted for publication in MNRA
Knowledge-Based Organization Evaluation
Knowledge has become the main value driver for organizations nowadays. In particular, knowledge-based organizations (KBOs) allocate resources for intangible assets (e.g., R&D) in the rapidly changing and highly competitive environment in order to gain competitive advantages. Therefore, how to evaluate knowledge-based organizations has become one of the most important issues in knowledge management. This paper aims to provide a framework for the evaluation of KBOs under uncertainty, using the state-ofthe- art methodology in Real Options. We specify the unique features of KBOs and explain their value drivers. This paper makes three contributions: (1) it bridges the gaps existent in the knowledge management literature on evaluating knowledge capital, (2) it provides a systematic application of Real Options models in the context of knowledge-based organization evaluation, (3) it uses a real world case to demonstrate the implications of the main findings for management
Management of ERP implementation
Implementation of Enterprise Resource Planning (ERP) solutions, which involve both technical and social uncertainties, is in practice a highly uncertain, risky endeavour. Traditional ERP practices address implementation of ERP as a static process; such practices focus on structure, not on ERP as something that will meet the needs of a changing organization. As a result, many relevant uncertainties that cannot be predefined are not easily accommodated. Options theory, which addresses uncertainties over time, resolves uncertainties in changing environments that cannot be predefined. In this paper, we propose an options perspective on the ERP implementation process with a focus on uncertainty. This perspective takes into consideration the often-changing nature of the companies that undertake ERP implementations. In addition, we present a practical example that demonstrates how to use options theory in context, enabling active management when implementing ERP. By actively managing ERP implementation, management can improve the flexibility of ERP implementation and can take appropriate actions to respond to the changing ERP implementation environment, to achieve more a successful ERP implementation that better meets the needs of the organization
SARS-CoV Regulates Immune Function-Related Gene Expressions in Human Monocytic Cells
Background: Severe Acute Respiratory Syndrome (SARS) is characterized by acute respiratory distress (ARDS) and pulmonary fibrosis, and the monocyte/macrophage is the key player in the pathogenesis of SARS.
 
Methods: In this study, we compared the transcriptional profiles of SARS coronavirus (SARS-CoV) infected monocytic cells against that infected by coronavirus 229E (CoV-229E). Total RNA was extracted from infected DC-SIGN transfected monocytes (THP-1-DC-SIGN) at 6 and 24 h after infection and the gene expression was profiled by oligonucleotide-based microarray. 

Results: Analysis of immune-related gene expression profiles showed that 24 h after SARS-CoV infection, (i) IFN-alpha/beta-inducible and cathepsin/proteosome genes were down-regulated; (ii) the hypoxia/hyperoxia-related genes were up-regulated; and (iii) the TLR/TLR-signaling, cytokine/cytokine receptor-related, chemokine/chemokine receptor-related, the lysosome-related, MHC/chaperon-related, and fibrosis-related genes were differentially regulated. 

Conclusion: These results elucidate that monocyte/macrophage dysfunction and dysregulation of fibrosis-related genes are two important pathogenic events of SARS. 

THE INFLUENCE OF EWOM AND EDITOR INFORMATION ON INFORMATION USEFULNESS IN VIRTUAL COMMUNITY
Information Usefulness, eWOM Information, Editor Information, Sense of Belonging
Sensitivity of Space-based Gravitational-Wave Interferometers to Ultralight Bosonic Fields and Dark Matter
Ultralight bosonic fields (ULBFs) are predicted by various theories beyond
the standard model of particle physics and are viable candidates of cold dark
matter. There have been increasing interests to search for the ULBFs in
physical and astronomical experiments. In this paper, we investigate the
sensitivity of several planned space-based gravitational-wave interferometers
to ultralight scalar and vector fields. Using time-delay interferometry (TDI)
to suppress the overwhelming laser frequency noise, we derive the averaged
transfer functions of different TDI combinations to scalar and vector fields,
and estimate the impacts of bosonic field's velocities. We obtain the
sensitivity curves for LISA, Taiji and TianQin, and explore their projected
constraints on the couplings between ULBFs and standard model particles,
illustrating with the ULBFs as dark matter.Comment: 33 pages, 8 figure
Functional recovery of older people with hip fracture: does malnutrition make a difference?
Aim To report a study of the effects of protein‐energy malnutrition on the functional recovery of older people with hip fracture who participated in an interdisciplinary intervention. Background It is not clear whether protein‐energy malnutrition is associated with worse functional outcomes or it affects the interdisciplinary intervention program on the functional recovery of older people with hip fracture. Design A randomized experimental design. Methods Data were collected between 2002–2006 from older people with hip fracture ( N = 162) in Taiwan. The generalized estimating equations approach was used to evaluate the effect of malnutrition on the functional recovery of older people with hip fracture. Results The majority of older patients with hip fracture were malnourished (48/80, 60% in the experimental group vs. 55/82, 67% in the control group) prior to hospital discharge. The results of the generalized estimating equations analysis demonstrated that subjects suffering from protein‐energy malnutrition prior to hospital discharge appeared to have significantly worse performance trajectories for their activities of daily living, instrumental activities of daily living, and recovery of walking ability compared with those without protein‐energy malnutrition. In addition, it was found that the intervention is more effective on the performance of activities of daily living and recovery of walking ability in malnourished patients than in non‐malnourished patients. Conclusion Healthcare providers should develop a nutritional assessment/management system in their interdisciplinary intervention program to improve the functional recovery of older people with hip fracture.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99041/1/jan12027.pd
Structural, Surface Morphology and Optical Properties of ZnS Films by Chemical Bath Deposition at Various Zn/S Molar Ratios
In this study, ZnS thin films were prepared on glass substrates by chemical bath deposition at various Zn/S molar ratios from 1/50 to 1/150. The effects of Zn/S molar ratio in precursor on the characteristics of ZnS films were demonstrated by X-ray diffraction, scanning electron microscopy, optical transmittance, X-ray photoelectron spectroscopy, and Fourier transform infrared spectrometry. It was found that more voids were formed in the ZnS film prepared using the precursor with Zn/S molar ratio of 1/50, and the other ZnS films showed the denser structure as the molar ratio was decreased from 1/75 to 1/150. From the analyses of chemical bonding states, the ZnS phase was indeed formed in these films. Moreover, the ZnO and Zn(OH)2 also appeared due to the water absorption on film surface during deposition. This would be helpful to the junction in cell device. With changing the Zn/S molar ratio from 1/75 to 1/150, the ZnS films demonstrate high transmittance of 75–88% in the visible region, indicating the films are potentially useful in photovoltaic applications
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