1,491 research outputs found
Exploring interdisciplinarity through the prism of research objects
Whereas articles about the rhetoric of interdisciplinarity abound, empirical evidence substantiating the value of its practices remains limited, at best conflicting. While most studies have focused on the natural and medical sciences, very few studies have focused on the social sciences and humanities. To better understand interdisciplinarity patterns observed in those disciplines, this paper explores how research objects can serve as a bridge between disciplines and specialties in the social sciences and humanities. Our results shows that certain social sciences disciplines, such as economics and management, and, to a lesser extent, education and literature, have objects, concepts and their own methods, that are not shared with other disciplines. In contrast, sociology and history have few specific objects, and are positioned at the heart of the network of undisciplined objects. On the whole, our results suggest that disciplines of the social sciences and humanities are not monolithic blocks and a strong interdisciplinarity is expressed through a wide selection of objects
Predicting Cell Death and Mutation Frequency for a Wide Spectrum of LET by Assuming DNA Break Clustering Inside Repair Domains
Cosmic radiation, which is composed of high charged and energy (HZE) particles, is responsible for cell death and mutation, which may be involved in cancer induction. Mutations are consequences of mis-repaired DNA breaks especially double-strand breaks (DSBs) that induce inter- and intra-chromosomal rearrangements (translocations, deletions, inversion). In this study, a computer simulation model is used to investigate the clustering of DSBs in repair domains, previously evidenced by our group in human breast cells [1]. This model is calibrated with experimental data measuring persistent 53BP1 radiation-induced foci (RIF) and is used to explain the high relative biological effectiveness (RBE) of HZE for both cell death and DNA mutation frequencies. We first validate our DSB cluster model using a new track structure model deployed on a simple geometrical configuration for repair domains in the nucleus; then we extend the scope from cell death to mutation induction. This work suggests that mechanism based on DSB repair process can explain several biological effects induced by HZE particles on different type of living cell
AF-algebras and topology of mapping tori
A covariant functor from the category of mapping tori to a category of
AF-algebras is constructed; the functor takes continuous maps between such
manifolds to stable homomorphisms between the corresponding AF-algebras. We use
this functor to develop an obstruction theory for the torus bundles of
dimension 2, 3 and 4.Comment: to appear Czechoslovak Math.
Contact complete integrability
Complete integrability in a symplectic setting means the existence of a
Lagrangian foliation leaf-wise preserved by the dynamics. In the paper we
describe complete integrability in a contact set-up as a more subtle structure:
a flag of two foliations, Legendrian and co-Legendrian, and a
holonomy-invariant transverse measure of the former in the latter. This turns
out to be equivalent to the existence of a canonical
structure on the leaves of the co-Legendrian foliation. Further, the above
structure implies the existence of contact fields preserving a special
contact 1-form, thus providing the geometric framework and establishing
equivalence with previously known definitions of contact integrability. We also
show that contact completely integrable systems are solvable in quadratures. We
present an example of contact complete integrability: the billiard system
inside an ellipsoid in pseudo-Euclidean space, restricted to the space of
oriented null geodesics. We describe a surprising acceleration mechanism for
closed light-like billiard trajectories
Study of nuclear recoils in liquid argon with monoenergetic neutrons
For the development of liquid argon dark matter detectors we assembled a
setup in the laboratory to scatter neutrons on a small liquid argon target. The
neutrons are produced mono-energetically (E_kin=2.45 MeV) by nuclear fusion in
a deuterium plasma and are collimated onto a 3" liquid argon cell operating in
single-phase mode (zero electric field). Organic liquid scintillators are used
to tag scattered neutrons and to provide a time-of-flight measurement. The
setup is designed to study light pulse shapes and scintillation yields from
nuclear and electronic recoils as well as from {\alpha}-particles at working
points relevant to dark matter searches. Liquid argon offers the possibility to
scrutinise scintillation yields in noble liquids with respect to the
populations of the two fundamental excimer states. Here we present experimental
methods and first results from recent data towards such studies.Comment: 9 pages, 8 figures, proceedings of TAUP 2011, to be published in
Journal of Physics: Conference Series (JCPS
Assessing the Effect of Cold Weather on Rural Cardiovascular Disease Deaths in Vermont
Objective: To study Vermont mortality and temperature data to determine if there is an increased incidence of cardiovascular disease related death on categorically cold streak days among rural residents.
Methods: A retrospective study was conducted using a cohort of Vermont CVD deaths between 2009-2017 subset with corresponding daily temperature data. CVD deaths that occurred on a categorical cold streak day were then identified and analyzed using a Poisson Regression to assess the relationship between ambient temperature changes, CVD mortality, and rurality.
Results: As compared to non-cold streak days, risk of CVD mortality was 4% higher on cold streak days (P (P\u3c0.001). However, when controlling for cold streak days, rurality, and tobacco use, the excess risk of CVD deaths was 4.5% lower for each successive year of age.
Conclusion: Our findings highlight an increased risk of CVD death among rural residents on cold-streak days. However, further research is needed to understand why CVD death on cold-streak days was less likely with every year increase in age among our sample
DNA Repair Domain Modeling Can Predict Cell Death and Mutation Frequency for Wide Range Spectrum of Radiation
Exploration missions to Mars and other destinations raise many questions about the health of astronauts. The continuous exposure of astronauts to galactic cosmic rays is one of the main concerns for long-term missions. Cosmic ionizing radiations are composed of different ions of various charges and energies notably, highly charged energy (HZE) particles. The HZE particles have been shown to be more carcinogenic than low-LET radiation, suggesting the severity of chromosomal aberrations induced by HZE particles is one possible explanation. However, most mathematical models predicting cell death and mutation frequency are based on directly fitting various HZE dose response and are in essence empirical approaches. In this work, we assume a simple biological mechanism to model DNA repair and use it to simultaneously explain the low- and high-LET response using the exact same fitting parameters. Our work shows that the geometrical position of DNA repair along tracks of heavy ions are sufficient to explain why high-LET particles can induce more death and mutations. Our model is based on assuming DNA double strand breaks (DSBs) are repaired within repair domain, and that any DSBs located within the same repair domain cluster into one repair unit, facilitating chromosomal rearrangements and increasing the probability of cell death. We introduced this model in 2014 using simplified microdosimetry profiles to predict cell death. In this work, we collaborated with NASA Johnson Space Center to generate more accurate microdosimetry profiles derived by Monte Carlo techniques, taking into account track structure of HZE particles and simulating DSBs in realistic cell geometry. We simulated 224 data points (D, A, Z, E) with the BDSTRACKS model, leading to a large coverage of LET from ~10 to 2,400 keV/m. This model was used to generate theoretical RBE for various particles and energies for both cell death and mutation frequencies. The RBE LET dependence is in agreement with experimental data known in human and murine cells. It suggests that cell shape and its orientation with respect to the HZE particle beam can modify the biological response to radiation. Such discovery will be tested experimentally and, if proven accurate, will be another strong supporting evidence for DNA repair domains and their critical role in interpreting cosmic radiation sensitivity
Maturity and Well-Being: Consistent Associations Across Samples and Measures
Introduction: Researchers have noted an association between maturity and well-being. However, this body of research uses different measures and conceptualizations of maturity (e.g., ego development, psychosocial maturity) and often only a few indicators of well-being. In the present research, we examined associations between a single self-rated measure of maturity and a variety of different indicators of well-being. Furthermore, we examined this association across a variety of samples. We hypothesized that maturity will show a positive relationship with measures related to well-being.
Methods: Samples of college students (Studies 1, 3, 4), Star Wars fans (Study 2), and individuals in the U.S., Canada, Brazil, Vietnam, and India (Study 5) completed a short measure of maturity and measures related to well-being.
Results: Across the studies, self-rated maturity was consistently positively correlated with various indicators of well-being (e.g., psychological, physical) and related constructs (e.g., self-compassion, empathy).
Conclusion: The results highlight the association between maturity and well-being. Furthermore, the results address the fragmented nature of this association in the literature by showing consistent relationships with a variety of well-being indicators with a single measure of maturity. Assessments of maturity may be beneficial in hiring decisions and student evaluation in the healthcare profession
Religious faith and psychosocial adaptation among stroke patients in Kuwait: A mixed method study
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2012 Springer Science+Business Media.Religious faith is central to life for Muslim patients in Kuwait, so it may influence adaptation and rehabilitation. This study explored quantitative associations among religious faith, self-efficacy, and life satisfaction in 40 female stroke patients and explored the influence of religion within stroke rehabilitation through qualitative interviews with 12 health professionals. The quantitative measure of religious faith did not relate to life satisfaction or self-efficacy in stroke patients. However, the health professionals described religious coping as influencing adaptation post-stroke. Fatalistic beliefs were thought to have mixed influences on rehabilitation. Measuring religious faith among Muslims through a standardized scale is debated. The qualitative accounts suggest that religious beliefs need to be acknowledged in stroke rehabilitation in Kuwait
Self-directed growth of AlGaAs core-shell nanowires for visible light applications
Al(0.37)Ga(0.63)As nanowires (NWs) were grown in a molecular beam epitaxy
system on GaAs(111)B substrates. Micro-photoluminescence measurements and
energy dispersive X-ray spectroscopy indicated a core-shell structure and Al
composition gradient along the NW axis, producing a potential minimum for
carrier confinement. The core-shell structure formed during the growth as a
consequence of the different Al and Ga adatom diffusion lengths.Comment: 20 pages, 7 figure
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