oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 34 )

2018 ( 240 )

2017 ( 242 )

2016 ( 335 )

Custom range...

Search Results: 1 - 10 of 192436 matches for " Evan D. Rosen "
All listed articles are free for downloading (OA Articles)
Page 1 /192436
Display every page Item
Regulation of Early Adipose Commitment by Zfp521
Sona Kang,Peter Akerblad,Riku Kiviranta,Rana K. Gupta,Shingo Kajimura,Michael J. Griffin,Jie Min,Roland Baron,Evan D. Rosen
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.1001433
Abstract: While there has been significant progress in determining the transcriptional cascade involved in terminal adipocyte differentiation, less is known about early events leading to lineage commitment and cell fate choice. It has been recently discovered that zinc finger protein 423 (Zfp423) is an early actor in adipose determination. Here, we show that a close paralog of Zfp423, Zfp521, acts as a key regulator of adipose commitment and differentiation in vitro and in vivo. Zfp521 exerts its actions by binding to early B cell factor 1 (Ebf1), a transcription factor required for the generation of adipocyte progenitors, and inhibiting the expression of Zfp423. Overexpression of Zfp521 in cells greatly inhibits adipogenic potential, whereas RNAi-mediated knock-down or genetic ablation of Zfp521 enhances differentiation. In addition, Zfp521?/? embryos exhibit increased mass of interscapular brown adipose tissue and subcutaneous white adipocytes, a cell autonomous effect. Finally, Ebf1 participates in a negative feedback loop to repress Zfp521 as differentiation proceeds. Because Zfp521 is known to promote bone development, our results suggest that it acts as a critical switch in the commitment decision between the adipogenic and osteogenic lineages.
Regulation of Early Adipose Commitment by Zfp521
Sona Kang,Peter Akerblad equal contributor,Riku Kiviranta equal contributor,Rana K. Gupta,Shingo Kajimura,Michael J. Griffin,Jie Min,Roland Baron,Evan D. Rosen
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.1001433
Abstract: While there has been significant progress in determining the transcriptional cascade involved in terminal adipocyte differentiation, less is known about early events leading to lineage commitment and cell fate choice. It has been recently discovered that zinc finger protein 423 (Zfp423) is an early actor in adipose determination. Here, we show that a close paralog of Zfp423, Zfp521, acts as a key regulator of adipose commitment and differentiation in vitro and in vivo. Zfp521 exerts its actions by binding to early B cell factor 1 (Ebf1), a transcription factor required for the generation of adipocyte progenitors, and inhibiting the expression of Zfp423. Overexpression of Zfp521 in cells greatly inhibits adipogenic potential, whereas RNAi-mediated knock-down or genetic ablation of Zfp521 enhances differentiation. In addition, Zfp521?/? embryos exhibit increased mass of interscapular brown adipose tissue and subcutaneous white adipocytes, a cell autonomous effect. Finally, Ebf1 participates in a negative feedback loop to repress Zfp521 as differentiation proceeds. Because Zfp521 is known to promote bone development, our results suggest that it acts as a critical switch in the commitment decision between the adipogenic and osteogenic lineages.
Mammalian Stem Cells Reprogramming in Response to Terahertz Radiation
Jonathan Bock,Yayoi Fukuyo,Sona Kang,M. Lisa Phipps,Ludmil B. Alexandrov,Kim ?. Rasmussen,Alan R. Bishop,Evan D. Rosen,Jennifer S. Martinez,Hou-Tong Chen,George Rodriguez,Boian S. Alexandrov,Anny Usheva
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0015806
Abstract: We report that extended exposure to broad-spectrum terahertz radiation results in specific changes in cellular functions that are closely related to DNA-directed gene transcription. Our gene chip survey of gene expression shows that whereas 89% of the protein coding genes in mouse stem cells do not respond to the applied terahertz radiation, certain genes are activated, while other are repressed. RT-PCR experiments with selected gene probes corresponding to transcripts in the three groups of genes detail the gene specific effect. The response was not only gene specific but also irradiation conditions dependent. Our findings suggest that the applied terahertz irradiation accelerates cell differentiation toward adipose phenotype by activating the transcription factor peroxisome proliferator-activated receptor gamma (PPARG). Finally, our molecular dynamics computer simulations indicate that the local breathing dynamics of the PPARG promoter DNA coincides with the gene specific response to the THz radiation. We propose that THz radiation is a potential tool for cellular reprogramming.
Genetic, Morphometric, and Behavioral Factors Linked to the Midsagittal Area of the Corpus Callosum
Glenn D. Rosen
Frontiers in Genetics , 2012, DOI: 10.3389/fgene.2012.00091
Abstract: The corpus callosum is the main commissure connecting left and right cerebral hemispheres, and varies widely in size. Differences in the midsagittal area of the corpus callosum (MSACC) have been associated with a number of cognitive and behavioral phenotypes, including obsessive-compulsive disorders, psychopathy, suicidal tendencies, bipolar disorder, schizophrenia, autism, and attention deficit hyperactivity disorder. Although there is evidence to suggest that MSACC is heritable in normal human populations, there is surprisingly little evidence concerning the genetic modulation of this variation. Mice provide a potentially ideal tool to dissect the genetic modulation of MSACC. Here, we use a large genetic reference panel – the BXD recombinant inbred line – to dissect the natural variation of the MSACC. We estimated the MSACC in over 300 individuals from nearly 80 strains. We found a 4-fold difference in MSACC between individual mice, and a 2.5-fold difference among strains. MSACC is a highly heritable trait (h2 = 0.60), and we mapped a suggestive QTL to the distal portion of Chr 14. Using sequence data and neocortical expression databases, we were able to identify eight positional and plausible biological candidate genes within this interval. Finally, we found that MSACC correlated with behavioral traits associated with anxiety and attention.
Social Vulnerability and Ecological Fragility: Building Bridges between Social and Natural Sciences Using the Irish Potato Famine as a Case Study
Evan D. G. Fraser
Ecology and Society , 2003,
Abstract: Between 1845 and 1850, a potato blight triggered a famine that killed or displaced 25% of the Irish population. Aside from its historical and cultural significance, the Irish Potato Famine illustrates how social and economic forces can create vulnerability to environmental disturbance. Therefore, studying the famine contributes to the on-going academic debate on theories to combine social and environmental data. This paper explores the conditions leading to the Irish famine using the “Entitlement” framework of Sen (1980) and the “Panarchy” model proposed by Gunderson and Holling (2002). Entitlement theory allows us to better understand how community food security may become vulnerable over time as different social and economic forces eliminate or restrict avenues to obtain food. In Ireland, a host of economic, demographic, and social pressures marked the decades leading to the famine and meant that the Irish peasantry had no food options when the potato crop failed. Panarchy provides a way of characterizing ecological systems that are vulnerable to disruptions. The agro-ecosystem that developed in Ireland prior to the famine had characteristics typical of vulnerable environments: fields were close together, biodiversity was low, and a large amount of biomass made this ecosystem attractive to opportunistic pests. Neither framework, however, provides an adequate way of examining the totality of human–environmental relations. By combining entitlements with panarchy, we can explore both the social and environmental characteristics of vulnerability. Entitlements and panarchy can be coupled by first assessing the extent to which communities depend on the natural environment for livelihoods, and the options available if the environment changes. Once a dependency on the environment has been ascertained, the characteristics of the specific ecosystems in question must then be assessed to determine their vulnerability to external shocks and disturbances. The panarchy framework makes this possible.
Magnetic resonance imaging technology in evaluating the presence and integrity of the anterior oblique ligament of the thumb
Evan D. Collins
Orthopedic Reviews , 2012, DOI: 10.4081/or.2012.e23
Abstract: The investigation examines the reliability and reproducibility of magnetic resonance imaging (MRI) technology in evaluating the anterior oblique ligament (AOL) of the trapeziometacarpal joint (TMC) of the thumb, in order to establish an effective imaging protocol to use in the early identification of conditions leading to degenerative arthritis. We used cadaver specimens, three hand surgeons independently rated from X-rays each specimen. The specimens were then scanned in a General Electric MRI machine with a standard wrist coil. An effort was made to reproduce the image of the AOL - with a unique technique to obtain images of the obliquely oriented thumb and its ligaments. Following the MRI, the specimens were dissected to expose the AOL and visualize the TMC joint. A standard MRI fiducial was sewn to the proximal and distal extent of the volar side of the AOL. The soft tissues were replaced and the skin was closed. They were then rescanned following the same protocol, and pre and post-dissection ligamentlabeled specimens were compared. Following dissection and tagging of the AOL ligament, a repeat MRI confirmed its location and validated the protocol in all cases. The open dissection and ligament tagging confirmed that what was visualized was in fact the structure of interest. This investigation demonstrated that with an appropriate MRI protocol it is feasible to guide the scanner to catch appropriate images of a ligament that is closely correlated with degenerative arthritis.
Reionization and the Fate of Dwarf Galaxies
Evan D. Skillman
Revista mexicana de astronomía y astrofísica , 2005,
Abstract:
Observational constraints on dwarf galaxy evolution: a retrospective of lequeux et al. (1979)
Evan D. Skillman
Revista mexicana de astronomía y astrofísica , 2002,
Abstract: Las contribuciones de los Peimbert han sido fundamentales para establecer ideas concernientes tanto a las propiedades como a la evoluci on de las galaxias enanas. Revisar e brevemente estas ideas dentro del contexto de una retrospectiva del art culo hist orico Chemical Composition and Evolution of Irregular and Blue Compact Galaxies" de Lequeux, Peimbert, Rayo, Serrano, & Torres-Peimbert, 1979, A&A, 80, 155. Este art culo aport o observaciones espectrosc opicas pioneras de regiones H II en 6 galaxias enanas y proporcion o muchas de las bases de nuestra visi on moderna de las galaxias enanas. La mayor a de las conclusiones e inferencias permanecen v alidas hoy, a dos d ecadas de su publicaci on.
Systems Genetics of the Lateral Septal Nucleus in Mouse: Heritability, Genetic Control, and Covariation with Behavioral and Morphological Traits
Alexander Talishinsky, Glenn D. Rosen
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0044236
Abstract: The lateral septum has strong efferent projections to hypothalamic and midbrain regions, and has been associated with modulation of social behavior, anxiety, fear conditioning, memory-related behaviors, and the mesolimbic reward pathways. Understanding natural variation of lateral septal anatomy and function, as well as its genetic modulation, may provide important insights into individual differences in these evolutionarily important functions. Here we address these issues by using efficient and unbiased stereological probes to estimate the volume of the lateral septum in the BXD line of recombinant inbred mice. Lateral septum volume is a highly variable trait, with a 2.5-fold difference among animals. We find that this trait covaries with a number of behavioral and physiological phenotypes, many of which have already been associated with behaviors modulated by the lateral septum, such as spatial learning, anxiety, and reward-seeking. Heritability of lateral septal volume is moderate (h2 = 0.52), and much of the heritable variation is caused by a locus on the distal portion of chromosome (Chr) 1. Composite interval analysis identified a secondary interval on Chr 2 that works additively with the Chr 1 locus to increase lateral septum volume. Using bioinformatic resources, we identified plausible candidate genes in both intervals that may influence the volume of this key nucleus, as well as associated behaviors.
Simulations of Evolving or Outbursting Molecular Protostellar Jets
Alexander Rosen,Michael D. Smith
Physics , 2003, DOI: 10.1046/j.1365-8711.2003.06654.x
Abstract: The kinematic and radiative power of molecular jets is expected to change as a protostar undergoes permanent or episodal changes in the rate at which it accretes. We study here the consequences of evolving jet power on the spatial and velocity structure, as well as the fluxes, of molecular emission from the bipolar outflow. We consider a jet of rapidly increasing density and a jet in which the mass input is abruptly cut off. We perform three dimensional hydrodynamic simulations with atomic and molecular cooling and chemistry. In this work, highly collimated and sheared jets are assumed. We find that position-velocity diagrams, velocity-channel maps and the relative H$_2$ and CO fluxes are potentially the best indicators of the evolutionary stage. In particular, the velocity width of the CO lines may prove most reliable although the often-quoted mass-velocity power-law index is probably not. We demonstrate how the relative H$_2$ 1--0 S(1) and CO J=1--0 fluxes evolve and apply this to interpret the phase of several outflows.
Page 1 /192436
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.