2,008 research outputs found
Prolactin stimulates precursor cells in the adult mouse hippocampus
In the search for ways to combat degenerative neurological disorders, neurogenesis-stimulating factors are proving to be a promising area of research. In this study, we show that the hormonal factor prolactin (PRL) can activate a pool of latent precursor cells in the adult mouse hippocampus. Using an in vitro neurosphere assay, we found that the addition of exogenous PRL to primary adult hippocampal cells resulted in an approximate 50% increase in neurosphere number. In addition, direct infusion of PRL into the adult dentate gyrus also resulted in a significant increase in neurosphere number. Together these data indicate that exogenous PRL can increase hippocampal precursor numbers both in vitro and in vivo. Conversely, PRL null mice showed a significant reduction (approximately 80%) in the number of hippocampal-derived neurospheres. Interestingly, no deficit in precursor proliferation was observed in vivo, indicating that in this situation other niche factors can compensate for a loss in PRL. The PRL loss resulted in learning and memory deficits in the PRL null mice, as indicated by significant deficits in the standard behavioral tests requiring input from the hippocampus. This behavioral deficit was rescued by direct infusion of recombinant PRL into the hippocampus, indicating that a lack of PRL in the adult mouse hippocampus can be correlated with impaired learning and memory
The Shapes of Cooperatively Rearranging Regions in Glass Forming Liquids
The shapes of cooperatively rearranging regions in glassy liquids change from
being compact at low temperatures to fractal or ``stringy'' as the dynamical
crossover temperature from activated to collisional transport is approached
from below. We present a quantitative microscopic treatment of this change of
morphology within the framework of the random first order transition theory of
glasses. We predict a correlation of the ratio of the dynamical crossover
temperature to the laboratory glass transition temperature, and the heat
capacity discontinuity at the glass transition, Delta C_p. The predicted
correlation agrees with experimental results for the 21 materials compiled by
Novikov and Sokolov.Comment: 9 pages, 6 figure
Discovery of a Brown Dwarf Companion to Gliese 570ABC: A 2MASS T Dwarf Significantly Cooler than Gliese 229B
We report the discovery of a widely separated (258\farcs3\pm0\farcs4) T
dwarf companion to the Gl 570ABC system. This new component, Gl 570D, was
initially identified from the Two Micron All Sky Survey (2MASS). Its
near-infrared spectrum shows the 1.6 and 2.2 \micron CH absorption bands
characteristic of T dwarfs, while its common proper motion with the Gl 570ABC
system confirms companionship. Gl 570D (M = 16.470.07) is nearly a
full magnitude dimmer than the only other known T dwarf companion, Gl 229B, and
estimates of L = (2.80.3)x10 L_{\sun} and T = 75050
K make it significantly cooler and less luminous than any other known brown
dwarf companion. Using evolutionary models by Burrows et al. and an adopted age
of 2-10 Gyr, we derive a mass estimate of 5020 M for this object.Comment: 13 pages, 2 figures, 2 tables, accepted by ApJ
Low Energy Nuclear Reaction Aircraft- 2013 ARMD Seedling Fund Phase I Project
This report serves as the final written documentation for the Aeronautic Research Mission Directorate (ARMD) Seedling Fund's Low Energy Nuclear Reaction (LENR) Aircraft Phase I project. The findings presented include propulsion system concepts, synergistic missions, and aircraft concepts. LENR is a form of nuclear energy that potentially has over 4,000 times the energy density of chemical energy sources. It is not expected to have any harmful emissions or radiation which makes it extremely appealing. There is a lot of interest in LENR, but there are no proven theories. This report does not explore the feasibility of LENR. Instead, it assumes that a working system is available. A design space exploration shows that LENR can enable long range and high speed missions. Six propulsion concepts, six missions, and four aircraft concepts are presented. This report also includes discussion of several issues and concerns that were uncovered during the study and potential research areas to infuse LENR aircraft into NASA's aeronautics research
Accessibility, sustainability, excellence: how to expand access to research publications. Executive summary
This article is a summary, by the authors, of a 140-page report prepared in 2012 by the UK Working Group on Expanding Access to Published Research Findings, chaired by British sociologist and academic administrator Janet Finch, DBE. The Working Group was charged with recommending how to develop a model that would be effective and sustainable over time, for expanding access to the published fi ndings of research. The whole report, which can be accessed at http://www.researchinfonet.org/wp-content/uploads/2012/06/Finch-Group-report-FINAL-VERSION.pdf [http://tinyurl.com/d2lxqks], has been published under a Creative Commons License Attribution 3.0 Unported. This is the fi rst of a series of Perspectives articles devoted to the Open Access Initiative that will be published in INTERNATIONAL MICROBIOLOGY. Our journal already published an Editorial on the topic in 2004 (Guerrero R & Piqueras M, Int Microbiol 7:157-161), and strongly supports open access. [Int Microbiol 2013; 16(2):125-132
Recension : Les pédagogies de ré-imagination et de désapprentissage : Les dommages du décolonialisme au sein/contre les tenants du colonialisme au Canada
This book review is a close reading of three book-length works by key, contemporary scholars in the field of settler colonial studies: Walter Mignolo and Catherine Walsh's On Decoloniality; Adam Dahl's The Empire of the People; and Emma Battell Lowman and Adam Barker's Settler: Identity and Colonialism in 21st Century Canada. This review provides a critical account of the significance of navigating the complexities of modern settler colonial practices and frameworks within Western settler societies to better inform and navigate our own decolonizing processes. We identify settler logics, perspectives and foundational frameworks as key factors in our current educative practices. Through this, we debate the significance of unsettling our/selves to consider extensions of our identities through a decolonial lens and how we, as a society, contribute to ongoing colonial processes. The review also provides approaches to how these resources may be used to deepen our anti-colonial lens by considering these texts as an underlying basis to reflect upon current educative curricula.Ce travail est une analyse minutieuse sur les critiques des trois ouvrages écrits par des universitaires contemporains de référence dans le domaine des études décoloniales : La Décolonisation (On Decoloniality) de Walter Mignolo et Catherine Walsh; L’Empire du Peuple (The Empire of the People) de Adam Dahl; et Les Colons : Identité et colonialisme en 21ème siècle au Canada (Settler: Identity and Colonialism in 21st Century Canada) de Emma Battell Lowman et Adam Barker. Cette étude fournit un compte rendu critique de l’importance d’explorer les éléments complexes constituant les structures et les pratiques du système colonialisme moderne à l’intérieur des sociétés occidentales coloniales afin de mieux nous informer et nous diriger dans nos propres processus de décolonisation. Nous identifions les logiques, les perspectives et les cadres référentiels des colons qui sont des facteurs clés de nos pratiques éducatives actuelles. A travers cette analyse, nous discutons de l’importance de nous défaire nous-mêmes en considérant les héritages de nos identités sous un angle décolonial et comment nous, en tant que société, contribuons aux processus du système colonialisme actuel. L’analyse fournit aussi une approche sur la façon dont ces ressources peuvent être utilisées pour approfondir notre vision anticoloniale en considérant ces écrits comme un fondement sur lequel se reposent les curricula actuels
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Growth rate of clinically diagnosed superficial basal cell carcinoma and changes in dermoscopic features over time
BACKGROUND/OBJECTIVES: Basal cell carcinoma (BCC) is the most commonly occurring skin cancer. BCCs have been found to generally grow slowly. Data are limited on how the dermoscopic characteristics of BCCs evolve. We set out to determine the growth rate of superficial BCCs (sBCC) and assess the change in dermoscopic features over time. METHODS: A retrospective review was performed of clinically diagnosed sBCC. Images, demographic and dermoscopic data were collected by a melanographer. Mixed effects linear regression models were used to investigate sBCC growth and associations between size and dermoscopic/demographic variables. We tested differences in trends over time in dermoscopic features using non-parametric trend tests. RESULTS: 100 individual sBCC were evaluated in 70 patients (mean age 62; 59% male), 69% had Fitzpatrick skin phototype 1 or 2, and 81% had some degree of actinic damage. sBCC were present on the back in 58% and 22% of men and women, respectively. The median surface area was 41.9 mm2 with a growth rate of 0.81 mm2 /month. Males had larger sBCC than females. There was no association between sBCC size and Fitzpatrick skin phototype, history of skin cancer or family history of melanoma. There is some evidence larger sBCC gain shiny white structures (P = 0.053) over time. CONCLUSIONS: sBCC grow at a rate unlikely to adversely affect patient outcomes associated with long wait times. Our data suggest that dermoscopy can aid in appropriate treatment selection for sBCC
The Grizzly, October 12, 2023
Meet the New Professors on Campus • Center for Career and Post-Graduate Events • Professor Feature: Dr. Andy Davis • Let\u27s Do the (Rocky Horror: A Breakaway Student Production) Again • The Captivating Collegeville Diner • Crossword Puzzle • Ursinus Field is Keeping the Program\u27s Legacy Alive • Sports Shout-outs!https://digitalcommons.ursinus.edu/grizzlynews/2018/thumbnail.jp
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