2,234 research outputs found
Acute Treadmill Exercise Discriminately Improves the Skeletal Muscle Insulin-Stimulated Growth Signaling Responses in Mice Lacking REDD1
A loss of the regulated in development and DNA damage 1 (REDD1) hyperactivates mechanistic Target of Rapamycin Complex 1 (mTORC1) reducing insulinâstimulated insulin signaling, which could provide insight into mechanisms of insulin resistance. Although aerobic exercise acutely inhibits mTORC1 signaling, improvements in insulinâstimulated signaling are exhibited. The goal of this study was to determine if a single bout of treadmill exercise was sufficient to improve insulin signaling in mice lacking REDD1. REDD1 wildtype (WT) and REDD1 knockout (KO) mice were acutely exercised on a treadmill (30 min, 20 m/min, 5% grade). A within animal noninsulinâtoâinsulinâstimulated percent change in skeletal muscle insulinâstimulated kinases (IRSâ1, ERK1/2, Akt), growth signaling activation (4EâBP1, S6K1), and markers of growth repression (REDD1, AMPK, FOXO1/3A) was examined, following no exercise control or an acute bout of exercise. Unlike REDD1 KO mice, REDD1 WT mice exhibited an increase (P \u3c 0.05) in REDD1 following treadmill exercise. However, both REDD1 WT and KO mice exhibited an increase (P \u3c 0.05) AMPK phosphorylation, and a subsequent reduction (P \u3c 0.05) in mTORC1 signaling after the exercise bout versus nonexercising WT or KO mice. Exercise increased (P \u3c 0.05) the noninsulinâtoâinsulinâstimulated percent change phosphorylation of mTORC1, ERK1/2, IRSâ1, and Akt on S473 in REDD1 KO mice when compared to nonexercised KO mice. However, there was no change in the noninsulinâtoâinsulinâstimulated percent change activation of Akt on T308 and FOXO1/3A in the KO when compared to WT or KO mouse muscle after exercise. Our data show that a bout of treadmill exercise discriminately improves insulinâstimulated signaling in the absence of REDD1
Wage losses in the year after breast cancer: Extent and determinants among Canadian women
This article is available open access through the publisherâs website at the link below. © The Author 2008.Background - Wage losses after breast cancer may result in considerable financial burden. Their assessment is made more urgent because more women now participate in the workforce and because breast cancer is managed using multiple treatment modalities that could lead to long work absences. We evaluated wage losses, their determinants, and the associations between wage losses and changes for the worse in the family's financial situation among Canadian women over the first 12 months after diagnosis of early breast cancer.
Methods - We conducted a prospective cohort study among women with breast cancer from eight hospitals throughout the province of Quebec. Information that permitted the calculation of wage losses and information on potential determinants of wage losses were collected by three pretested telephone interviews conducted over the year following the start of treatment. Information on medical characteristics was obtained from medical records. The main outcome was the proportion of annual wages lost because of breast cancer. Multivariable analysis of variance using the general linear model was used to identify personal, medical, and employment characteristics associated with the proportion of wages lost. All statistical tests were two-sided.
Results - Among 962 eligible breast cancer patients, 800 completed all three interviews. Of these, 459 had a paying job during the month before diagnosis. On average, these working women lost 27% of their projected usual annual wages (median = 19%) after compensation received had been taken into account. Multivariable analysis showed that a higher percentage of lost wages was statistically significantly associated with a lower level of education (Ptrend = .0018), living 50 km or more from the hospital where surgery was performed (P = .070), lower social support (P = .012), having invasive disease (P = .086), receipt of chemotherapy (P < .001), self-employment (P < .001), shorter tenure in the job (Ptrend < .001), and part-time work (P < .001).
Conclusion - Wage losses and their effects on financial situation constitute an important adverse consequence of breast cancer in Canada.The Canadian Breast Cancer Research Alliance, Canadian
Institutes of Health Research, and Fondation de lâUniversitĂ© Laval
Phase transitions and the internal noise structure of nonlinear Schr\"odi nger equation solitons
We predict phase-transitions in the quantum noise characteristics of systems
described by the quantum nonlinear Schr\"odinger equation, showing them to be
related to the solitonic field transition at half the fundamental soliton
amplitude. These phase-transitions are robust with respect to Raman noise and
scattering losses. We also describe the rich internal quantum noise structure
of the solitonic fields in the vicinity of the phase-transition. For optical
coherent quantum solitons, this leads to the prediction that eliminating the
peak side-band noise due to the electronic nonlinearity of silica fiber by
spectral filtering leads to the optimal photon-number noise reduction of a
fundamental soliton.Comment: 10 pages, 5 figure
REDD1 deletion and treadmill running increase liver hepcidin and gluconeogenic enzymes in male mice
The iron-regulatory hormone hepcidin is transcriptionally up-regulated by gluconeogenic signals. Recent evidence suggeststhat increases in circulating hepcidin may decrease dietary iron absorption following prolonged exercise, however evidence is limited on whether gluconeogenic signals contribute to post-exercise increases in hepcidin. Mice with genetic knockout of regulated in development and DNA response-1 (REDD1) display greater glycogen depletion following exercise, possibly indicating greater gluconeogenesis. The objective of the present study was to determine liver hepcidin, markers of gluconeogenesis and iron metabolism in REDD1 knockout and wild-type mice following prolonged exercise. Twelve-week-old male REDD1 knockout and wild-type mice were randomised to rest or 60 min treadmill running with 1, 3 or 6 h recovery (n = 5â8/genotype/group). Liver gene expression of hepcidin (Hamp) and gluconeogenic enzymes (Ppargc1a, Creb3l3, Pck1, Pygl) were determined by qRT-PCR. Effects of genotype, exercise and their interaction were assessed by two-way ANOVAs with Tukey's post-hoc tests, and Pearson correlations were used to assess the relationships between Hamp and study outcomes. Liver Hamp increased 1- and 4-fold at 3 and 6 h post-exercise, compared to rest (P-adjusted < 0â
009 for all), and was 50% greater in REDD1 knockout compared to wild-type mice (P = 0â
0015). Liver Ppargc1a, Creb3l3 and Pck1 increased with treadmill running (P < 0â
0001 for all), and liver Ppargc1a, Pck1 and Pygl were greater with REDD1 deletion (P < 0â
02 for all). Liver Hamp was positively correlated with liver Creb3l3 (R = 0â
62, P < 0â
0001) and Pck1 (R = 0â
44, P = 0â
0014). In conclusion, REDD1 deletion and prolonged treadmill running increased liver Hamp and gluconeogenic regulators of Hamp, suggesting gluconeogenic signalling of hepcidin with prolonged exercise
Stability of stationary states in the cubic nonlinear Schroedinger equation: applications to the Bose-Einstein condensate
The stability properties and perturbation-induced dynamics of the full set of
stationary states of the nonlinear Schroedinger equation are investigated
numerically in two physical contexts: periodic solutions on a ring and
confinement by a harmonic potential. Our comprehensive studies emphasize
physical interpretations useful to experimentalists. Perturbation by stochastic
white noise, phase engineering, and higher order nonlinearity are considered.
We treat both attractive and repulsive nonlinearity and illustrate the
soliton-train nature of the stationary states.Comment: 9 pages, 11 figure
Formation and Propagation of Matter Wave Soliton Trains
Attraction between atoms in a Bose-Einstein-Condensate renders the condensate
unstable to collapse. Confinement in an atom trap, however, can stabilize the
condensate for a limited number of atoms, as was observed with 7Li, but beyond
this number, the condensate collapses. Attractive condensates constrained to
one-dimensional motion are predicted to form stable solitons for which the
attractive interactions exactly compensate for the wave packet dispersion. Here
we report the formation or bright solitons of 7Li atoms created in a quasi-1D
optical trap. The solitons are created from a stable Bose-Einstein condensate
by magnetically tuning the interactions from repulsive to attractive. We
observe a soliton train, containing many solitons. The solitons are set in
motion by offsetting the optical potential and are observed to propagate in the
potential for many oscillatory cycles without spreading. Repulsive interactions
between neighboring solitons are inferred from their motion
Knowledge Management of Historical Data: Ontology Development for Chemical Reactions
Knowledge management of the literature and historical data is critical to accelerated drug and materials discovery. Currently, literature knowledge is scattered in journal articles in various formats: diagrams, texts, plots, etc. Historical data from past experiments are saved in a number of local computers under confusing folder structures with ambiguous file names. To manage and organize historical data and knowledge, our group (SDLE) at CWRU follows FAIR (Findable, Accessible, Interoperable, Reusable) principles, which outline the best practices for data stewardship and data provenance, and ontology, a formal representation of terms and concepts and their relationships, as a tool to improve interoperability. Knowledge graphs, constructed from graph data structure, are built from historical knowledge and domain ontology, which acts as a schema layer, and are capable of inductive reasoning via graph traversal. In this project, an ontology for conducting a chemical reaction or synthesis is developed by mapping terms from multiple common mid-level ontologies from the chemistry domain such as Chemical Entities with Biological Interest (ChEBI), National Cancer Institute thesaurus (NCIt), Chemical Method Ontology (CHMO), etc. The ontology is built using FAIRmaterials, a package available in R and Python developed by SDLE students. The resulting ontology will be used to build a knowledge graph on the nitration of aromatic compounds with flow chemistry
Self-consistent model of ultracold atomic collisions and Feshbach resonances in tight harmonic traps
We consider the problem of cold atomic collisions in tight traps, where the
absolute scattering length may be larger than the trap size. As long as the
size of the trap ground state is larger than a characteristic length of the van
der Waals potential, the energy eigenvalues can be computed self-consistently
from the scattering amplitude for untrapped atoms. By comparing with the exact
numerical eigenvalues of the trapping plus interatomic potentials, we verify
that our model gives accurate eigenvalues up to milliKelvin energies for single
channel s-wave scattering of Na atoms in an isotropic harmonic trap,
even when outside the Wigner threshold regime. Our model works also for
multi-channel scattering, where the scattering length can be made large due to
a magnetically tunable Feshbach resonance.Comment: 7 pages, 4 figures (PostScript), submitted to Physical Review
Materials Data Science Ontology (MDS-Onto): Unifying Domain Knowledge in Materials and Applied Data Science
Ontologies have gained popularity in the scientific community as a means of standardizing concepts and terminology used in metadata across different institutions to facilitate data comprehension, sharing, and reuse. Despite the existence of frameworks and guidelines for building ontologies, the processes and standards used to develop ontologies still differ significantly, particularly in Materials Science. Our goal with the MDS-Onto Framework is to provide a unified and automated system for ontology development in the Materials and Data Sciences. This framework offers recommendations on where to publish ontologies online, how to best integrate them within the semantic web, and which formats to store and share ontologies. The framework aims to enhance the findability and interoperability of these ontologies. One critical component of the MDS-Onto Framework is the bilingual FAIRmaterials Python and R package, a practical and user-friendly tool for scientists to create and visualize ontologies effectively. We also present two domain ontologies created with our framework, X-ray diffraction and Photovoltaics(PV), to demonstrate the practical application and steps for implementing materials in ontology creation and merging. These cases highlight our framework\u27s feasibility and efficiency
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