17,406 research outputs found
Progenitors of Supernovae Type Ia and Chemical Enrichment in Hydrodynamical Simulations -I. The Single Degenerate Scenario
The nature of the Type Ia supernovae (SNIa) progenitors remains still
uncertain. This is a major issue for galaxy evolution models since both
chemical and energetic feedback play a major role in the gas dynamics, star
formation and therefore in the overall stellar evolution. The progenitor models
for the SNIa available in the literature propose different distributions for
regulating the explosion times of these events. These functions are known as
the Delay Time Distributions (DTDs). This work is the first one in a series of
papers aiming at studying five different DTDs for SNIa. Here, we implement and
analyse the Single Degenerate scenario (SD) in galaxies dominated by a rapid
quenching of the star formation, displaying the majority of the stars
concentrated in the bulge component. We find a good fit to both the present
observed SNIa rates in spheroidal dominated galaxies, and to the [O/Fe] ratios
shown by the bulge of the Milky Way. Additionally, the SD scenario is found to
reproduce a correlation between the specific SNIa rate and the specific star
formation rate, which closely resembles the observational trend, at variance
with previous works. Our results suggest that SNIa observations in galaxies
with very low and very high specific star formation rates can help to impose
more stringent constraints on the DTDs and therefore on SNIa progenitors.Comment: 19 pages, 6 figures, 1 table. Accepted for publication in Ap
Biomedical Informatics Applications for Precision Management of Neurodegenerative Diseases
Modern medicine is in the midst of a revolution driven by “big data,” rapidly advancing computing power, and broader integration of technology into healthcare. Highly detailed and individualized profiles of both health and disease states are now possible, including biomarkers, genomic profiles, cognitive and behavioral phenotypes, high-frequency assessments, and medical imaging. Although these data are incredibly complex, they can potentially be used to understand multi-determinant causal relationships, elucidate modifiable factors, and ultimately customize treatments based on individual parameters. Especially for neurodegenerative diseases, where an effective therapeutic agent has yet to be discovered, there remains a critical need for an interdisciplinary perspective on data and information management due to the number of unanswered questions. Biomedical informatics is a multidisciplinary field that falls at the intersection of information technology, computer and data science, engineering, and healthcare that will be instrumental for uncovering novel insights into neurodegenerative disease research, including both causal relationships and therapeutic targets and maximizing the utility of both clinical and research data. The present study aims to provide a brief overview of biomedical informatics and how clinical data applications such as clinical decision support tools can be developed to derive new knowledge from the wealth of available data to advance clinical care and scientific research of neurodegenerative diseases in the era of precision medicine
Dataset concerning the analytical approximation of the Ae3 temperature.
In this paper we present a new polynomial function for calculating the local phase transformation temperature (Ae3 ) between the austenite+ferrite and the fully austenitic phase fields during heating and cooling of steel:[Formula: see text] The dataset includes the terms of the function and the values for the polynomial coefficients for major alloying elements in steel. A short description of the approximation method used to derive and validate the coefficients has also been included. For discussion and application of this model, please refer to the full length article entitled "The role of aluminium in chemical and phase segregation in a TRIP-assisted dual phase steel" 10.1016/j.actamat.2016.05.046 (Ennis et al., 2016) [1]
University Housing: How Residence Halls Changed Student Life at Cal Poly
In 2014, Cal Poly President Jeffrey Armstrong submitted a “Letter to the Editor” in The Mustang News in which he described his vision for the future of Cal Poly housing. “As we contemplate our long-term vision for Cal Poly, we are shifting our culture to become a predominantly residential campus. In the foreseeable future, Cal Poly will house more than half — perhaps as many as two-thirds — of its students in university housing.”1 Armstrong continued, claiming that this move of opening up around 1,400 new spaces for freshman living on-campus was “good for students,” and that he hoped these living arrangements would foster more engaged students, better academic and behavior performance, as well as a “positive change for the residents of San Luis Obispo.”2
1 Jeffrey Armstrong, “Letters to the Editor,” Mustang News, April 28, 2014, accessed January 30, 2016, http://mustangnews.net/grand-avenue-housing-project-is-next-important-step/.
2 Armstrong, “Letters to the Editor.
A prospective observational study of mycophenolate mofetil treatment in progressive diffuse cutaneous systemic sclerosis of recent onset.
OBJECTIVE: A prospective observational study of mycophenolate mofetil (MMF) treatment in patients with diffuse progressive cutaneous systemic sclerosis (SSc) of recent onset.
METHODS: Twenty-five previously untreated consecutive patients with recent-onset (\u3c 24 mo) diffuse progressive cutaneous SSc received MMF as the only disease-modifying therapy. Modified Rodnan skin score (mRSS) and affected body surface area (BSA) were compared from initiation of MMF to study end. Pulmonary function tests performed at the same institution before therapy and at study end were available in 15 patients. Histopathology and real-time PCR assessment of fibrosis-related gene expression were performed before and after treatment in skin biopsies from 3 patients.
RESULTS: At 18.2 ± 8.73 months of MMF therapy (median 2000 mg/day) the mRSS decreased from 24.56 ± 8.62 to 14.52 ± 10.9 (p = 0.0004) and the affected BSA from 36% ± 16% to 14% ± 13.3% (p = 0.00001). Pulmonary function tests remained stable from initiation of MMF to the end of the study. Skin histopathology showed a remarkable reduction in accumulation of fibrotic tissue. Real-time PCR of skin biopsies demonstrated a marked decrease in expression of fibrosis-related genes.
CONCLUSION: Patients with diffuse progressive cutaneous SSc of recent onset treated with MMF experienced marked improvement in skin involvement and stabilization of pulmonary function. Skin biopsies from 3 patients demonstrated histopathological improvement and decreased expression of fibrosis-related genes
Nitrogen Incorporation in CH_4-N_2 Photochemical Aerosol Produced by Far Ultraviolet Irradiation
Nitrile incorporation into Titan aerosol accompanying hydrocarbon chemistry is thought to be driven by extreme UV wavelengths (λ120 nm is presently unaccounted for in atmospheric photochemical models. We suggest that reaction with CH radicals produced from CH_4 photolysis may provide a mechanism for incorporating N into the molecular structure of the aerosol. Further work is needed to understand the chemistry involved, as these processes may have significant implications for how we view prebiotic chemistry on early Earth and similar planets. Key Words: Titan—Photochemical aerosol—CH_4-N_2 photolysis—Far UV—Nitrogen activation
Neutral current (anti)neutrino scattering: relativistic mean field and superscaling predictions
We evaluate the neutral current quasi-elastic neutrino cross section within
two nuclear models: the SuSA model, based on the superscaling behavior of
electron scattering data, and the RMF model, based on relativistic mean field
theory. We also estimate the ratio and
compare with the MiniBooNE experimental data, performing a fit of the
parameters and within the two models. Finally, we present our
predictions for antineutrino scattering.Comment: 15 pages, 4 figure
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