287 research outputs found
Modeling long-range cross-correlations in two-component ARFIMA and FIARCH processes
We investigate how simultaneously recorded long-range power-law correlated
multi-variate signals cross-correlate. To this end we introduce a two-component
ARFIMA stochastic process and a two-component FIARCH process to generate
coupled fractal signals with long-range power-law correlations which are at the
same time long-range cross-correlated. We study how the degree of
cross-correlations between these signals depends on the scaling exponents
characterizing the fractal correlations in each signal and on the coupling
between the signals. Our findings have relevance when studying parallel outputs
of multiple-component of physical, physiological and social systems.Comment: 8 pages, 5 figures, elsart.cl
Concepts of threshold assessment for a first course in control engineering
This paper focuses on the combined challenge of encouraging students to engage with learning and assessment of their competence levels. A core challenge for many staff is the need to distinguish different levels of learning, and to evidence core competence clearly, especially for students with lower marks. This paper proposes a novel assessment strategy which separates core competencies from the more challenging application of the learning in engineering problem solving. The assessment design is efficient for staff and students and allows a reduction in student stress levels while simultaneously giving them strong incentives to adopt good working practices. Evaluation evidence is given to demonstrate the efficacy of the approach
Atmospheric Muon Flux at Sea Level, Underground, and Underwater
The vertical sea-level muon spectrum at energies above 1 GeV and the
underground/underwater muon intensities at depths up to 18 km w.e. are
calculated. The results are particularly collated with a great body of the
ground-level, underground, and underwater muon data. In the hadron-cascade
calculations, the growth with energy of inelastic cross sections and pion,
kaon, and nucleon generation in pion-nucleus collisions are taken into account.
For evaluating the prompt muon contribution to the muon flux, we apply two
phenomenological approaches to the charm production problem: the recombination
quark-parton model and the quark-gluon string model. To solve the muon
transport equation at large depths of homogeneous medium, a semi-analytical
method is used. The simple fitting formulas describing our numerical results
are given. Our analysis shows that, at depths up to 6-7 km w. e., essentially
all underground data on the muon intensity correlate with each other and with
predicted depth-intensity relation for conventional muons to within 10%.
However, the high-energy sea-level data as well as the data at large depths are
contradictory and cannot be quantitatively decribed by a single nuclear-cascade
model.Comment: 47 pages, REVTeX, 15 EPS figures included; recent experimental data
and references added, typos correcte
Understanding of sub-band gap absorption of femtosecond-laser sulfur hyperdoped silicon using synchrotron-based techniques
[[abstract]]The correlation between sub-band gap absorption and the chemical states and electronic and atomic structures of S-hyperdoped Si have been extensively studied, using synchrotron-based x-ray photoelectron spectroscopy (XPS), x-ray absorption near-edge spectroscopy (XANES), extended x-ray absorption fine structure (EXAFS), valence-band photoemission spectroscopy (VB-PES) and first-principles calculation. S 2p XPS spectra reveal that the S-hyperdoped Si with the greatest (~87%) sub-band gap absorption contains the highest concentration of S2− (monosulfide) species. Annealing S-hyperdoped Si reduces the sub-band gap absorptance and the concentration of S2− species, but significantly increases the concentration of larger S clusters [polysulfides (Sn2−, n > 2)]. The Si K-edge XANES spectra show that S hyperdoping in Si increases (decreased) the occupied (unoccupied) electronic density of states at/above the conduction-band-minimum. VB-PES spectra evidently reveal that the S-dopants not only form an impurity band deep within the band gap, giving rise to the sub-band gap absorption, but also cause the insulator-to-metal transition in S-hyperdoped Si samples. Based on the experimental results and the calculations by density functional theory, the chemical state of the S species and the formation of the S-dopant states in the band gap of Si are critical in determining the sub-band gap absorptance of hyperdoped Si samples.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]GB
The historical origins of corruption in the developing world: a comparative analysis of East Asia
A new approach has emerged in the literature on corruption in the developing world that breaks with the assumption that corruption is driven by individualistic self-interest and, instead, conceptualizes corruption as an informal system of norms and practices. While this emerging neo-institutionalist approach has done much to further our understanding of corruption in the developing world, one key question has received relatively little attention: how do we explain differences in the institutionalization of corruption between developing countries? The paper here addresses this question through a systematic comparison of seven developing and newly industrialized countries in East Asia. The argument that emerges through this analysis is that historical sequencing mattered: countries in which the "political marketplace" had gone through a process of concentration before universal suffrage was introduced are now marked by less harmful types of corruption than countries where mass voting rights where rolled out in a context of fragmented political marketplaces. The paper concludes by demonstrating that this argument can be generalized to the developing world as a whole
Making sense of risk. Donor risk communication in families considering living liverdonation to a child
This paper contributes to the growing line of thought in bioethics that respect for autonomy should not be equated to the facilitation of individualistic self determination through standard requirements of informed consent in all healthcare contexts. The paper describes how in the context of donation for living related liver transplantation (LRLT) meaningful, responsible decision making is often embedded within family processes and its negotiation. We suggest that good donor risk communication in families promote “conscientious autonomy” and “reflective trust”. From this, the paper offers the suggestion that transplant teams and other relevant professionals have to broaden their role and responsibility for risk communication beyond proper disclosure by addressing the impact of varied psychosocial conditions on risk interpretation and assessment for potential donors and family stakeholders. In conclusion, we suggest further research questions on how professional responsibility and role-taking in risk communication should be morally understood
Recommended from our members
The effects of market economy and foreign MNE subsidiaries on the convergence and divergence of HRM
This study explores patterns of human resource management (HRM) practices across market economies, and between indigenous firms and foreign MNE subsidiary operations, offering a novel perspective on convergence and divergence. Applying institutional theorizing to improve our understanding of convergence/ divergence as a process and an outcome, data collected from nine countries at three points in time over a decade confirm that convergence and divergence occur to different extents in a non-linear fashion, and vary depending on the area of HRM practice observed. Patterns of adoption and convergence/ divergence are explained through the effect of institutional constraints, which vary between liberal and coordinated market economies, and between indigenous firms and foreign MNE subsidiaries. The study contributes a more graded conceptualization of convergence/ divergence, which reflects the complex dynamic reality of international business
Transforming Post-Secondary Education in Mathematics
In this manuscript, I introduce and describe the work of mathematicians and
mathematics educators in the group Transforming Post-Secondary Education in
Mathematics (TPSE Math or TPSE, pronounced "tipsy", for short). TPSE aims to
coordinate and drive constructive change in education in the mathematical
sciences at two-year colleges, four-year colleges, and universities across the
nation. It seeks to build on the successes of the entire mathematical sciences
community.
This manuscript reviews the events that led to the founding of TPSE Math and
articulates its vision and mission. In its first phase with national events,
TPSE found broad consensus with the mathematical sciences community on the
challenges facing the community. Learning from educational transformations
experiences in other scientific fields, and with the support of the
Mathematical Advisory Group of 34 mathematical sciences department chairs and
leaders, TPSE moves into a second phase focused on action. This is a snapshot
in time, and TPSE's ongoing activities will continue to be documented and
disseminated. The piece concludes with a reflection of the impact that my
involvement in this work has had on my career.Comment: 17 page
C-Jun N-terminal kinase controls TDP-43 accumulation in stress granules induced by oxidative stress
<p>Abstract</p> <p>Background</p> <p>TDP-43 proteinopathies are characterized by loss of nuclear TDP-43 expression and formation of C-terminal TDP-43 fragmentation and accumulation in the cytoplasm. Recent studies have shown that TDP-43 can accumulate in RNA stress granules (SGs) in response to cell stresses and this could be associated with subsequent formation of TDP-43 ubiquinated protein aggregates. However, the initial mechanisms controlling endogenous TDP-43 accumulation in SGs during chronic disease are not understood. In this study we investigated the mechanism of TDP-43 processing and accumulation in SGs in SH-SY5Y neuronal-like cells exposed to chronic oxidative stress. Cell cultures were treated overnight with the mitochondrial inhibitor paraquat and examined for TDP-43 and SG processing.</p> <p>Results</p> <p>We found that mild stress induced by paraquat led to formation of TDP-43 and HuR-positive SGs, a proportion of which were ubiquitinated. The co-localization of TDP-43 with SGs could be fully prevented by inhibition of c-Jun N-terminal kinase (JNK). JNK inhibition did not prevent formation of HuR-positive SGs and did not prevent diffuse TDP-43 accumulation in the cytosol. In contrast, ERK or p38 inhibition prevented formation of both TDP-43 and HuR-positive SGs. JNK inhibition also inhibited TDP-43 SG localization in cells acutely treated with sodium arsenite and reduced the number of aggregates per cell in cultures transfected with C-terminal TDP-43 162-414 and 219-414 constructs.</p> <p>Conclusions</p> <p>Our studies are the first to demonstrate a critical role for kinase control of TDP-43 accumulation in SGs and may have important implications for development of treatments for FTD and ALS, targeting cell signal pathway control of TDP-43 aggregation.</p
- …
