591 research outputs found
Olmstead v. L.C.: The Supreme Court Case
You have an incredible luxury here at Georgetown Law. You have faculty who are engaged in the world like two of my colleagues on this panel. To my immediate left is Professor Michael Gottesman (Georgetown University Law Center) who argued the case on behalf of Lois and Elaine, and to my next far left, Professor Irv Gornstein (Georgetown University Law Center) who argued the case on behalf of the United States. Between them is Jennifer Mathis (The Bazelon Center for Mental Health Law) who has spent, I think, most of her career at the Bazelon Center litigating, and organizing, and helping to coordinate folks on Olmsteadrelated issues. She played an important role in this case as it proceeded to the Supreme Court
Role of Leukotriene B4 Receptors in the Development of Atherosclerosis: Potential Mechanisms
Objective-Leukotriene B4 (LTB4), a potent leukocyte chemoattractant, is known to promote several inflammatory diseases, including atherosclerosis. We sought to determine mechanisms through which LTB 4 modulates atherosclerosis in cell lines expressing LTB4 receptors, BLT-1, and in mice deficient in BLT-1 as well as macrophage cell lines derived from BLT-1+/+ and BLT-/- mice. Methods and Results-Analysis of global changes in gene expression induced by LTB 4 in rat basophilic leukemia cells (RBL-2H3) expressing the human BLT-1 showed highest-fold increase in expression of fatty acid translocase/CD36 and the chemokine MCP1/JE/CCL2, which are critical in atherogenesis. To determine the importance of BLT-1 in atherogenesis, we crossed BLT-1-null mice with apolipoprotein (apo)-E-deficient mice, which develop severe atherosclerosis. Deletion of BLT-1 significantly reduced the lesion formation in apo-E-/- mice only during initiating stages (4 and 8 weeks) but had no effect on the lesion size in mice fed atherogenic diet for 19 weeks. Macrophage cell lines from BLT-1-deficient mice expressed the low-affinity LTB4 receptor, BLT-2, and exhibited chemotaxis to LTB4. Conclusions-The effects of LTB4 in atherosclerosis are likely mediated through the high-affinity BLT-1 and the low-affinity BLT-2 receptors. LTB4 promotes atherosclerosis by chemo-attracting monocytes, by providing an amplification loop of monocyte chemotaxis via CCL2 production, and by converting monocytes to foam cells by enhanced expression of CD36 and fatty acid accumulation
The Spectral Energy Distribution of Self-gravitating Interstellar Clouds I. Spheres
We derive the spectral energy distribution (SED) of dusty, isothermal, self
gravitating, stable and spherical clouds externally heated by the ambient
interstellar radiation field. For a given radiation field and dust properties,
the radiative transfer problem is determined by the pressure of the surrounding
medium and the cloud mass expressed as a fraction of the maximum stable cloud
mass above which the clouds become gravitational unstable.
To solve the radiative transfer problem a ray-tracing code is used to
accurately derive the light distribution inside the cloud. This code considers
both non isotropic scattering on dust grains and multiple scattering events.
The dust properties inside the clouds are assumed to be the same as in the
diffuse interstellar medium in our galaxy. We analyse the effect of the
pressure, the critical mass fraction, and the ISRF on the SED and present
brightness profiles in the visible, the IR/FIR and the submm/mm regime with the
focus on the scattered emission and the thermal emission from PAH-molecules and
dust grains.Comment: accepted for publication in ApJS, May 2008, v176n1 issu
IRAS03063+5735: A Bowshock Nebula Powered by an Early B Star
Mid-infrared images from the Spitzer Space Telescope Galactic Legacy Infrared
MidPlane Survey Extraordinaire program reveal that the infrared source IRAS
03063+5735 is a bowshock nebula produced by an early B star, 2MASS
03101044+5747035. We present new optical spectra of this star, classify it as a
B1.5 V, and determine a probable association with a molecular cloud complex at
V_LSR=-38 -- -42 km/s in the outer Galaxy near l=140.59 degr, b=-0.250 degr. On
the basis of spectroscopic parallax, we estimate a distance of 4.0 +/-1 kpc to
both the bowshock nebula and the molecular complex. One plausible scenario is
that this a high-velocity runaway star impinging upon a molecular cloud. We
identify the HII region and stellar cluster associated with IRAS 03064+5638 at
a projected distance of 64 pc as one plausible birth site. The
spectrophotometric distance and linkage to a molecular feature provides another
piece of data helping to secure the ill-determined rotation curve in the outer
Galaxy. As a by-product of spectral typing this star, we present empirical
spectral diagnostic diagrams suitable for approximate spectral classification
of O and B stars using He lines in the little-used yellow-red portion of the
optical spectrum.Comment: Accepted for publication in the Astronomical Journa
Harry Reid Center of Environmental Studies: Quality assurance program evaluation
The Quality Assurance (QA) Program is critical in the licensing of the Yucca Mountain Repository because it helps ensure that the information used to demonstrate the safer)\u27 of the repository is defensible and well documented. Through audits and surveillances the QA staff identifies areas of non-compliance within each task. The QA Program at the Harry Reid Center (HRC) for Environmental Studies can increase compliance with Quality /Assurance Procedures (QAPs) by improving the program\u27s process.
Through qualitative and quantitative research it was determined that reasons for non-compliance revolved around three key areas; process, communication and training. Communication and training are key components of the process for ensuring compliance. Therefore, our recommendations focus on process improvements.
This evaluation contains recommendations related to improving processes within the QA Program. In particular, the QA Program should enhance its current training program by making it more hands on, utilising pre/post-tests, requiring mandatory annual training, creating an easy to use reference manual and hiring a full time trainer. In addition, communication can be improved by increasing the number of meetings between Pis and researchers, having mandatory regularly scheduled meetings with QA staff in the Reno area, and creating and maintaining a database for all statt associated with every task. Finally, the QA Program should create incentives for compliance and consequences for noncompliance
GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire), a SIRTF
Legacy Science Program, will be a fully sampled, confusion-limited infrared
survey of the inner two-thirds of the Galactic disk with a pixel resolution of
\~1.2" using the Infrared Array Camera (IRAC) at 3.6, 4.5, 5.8, and 8.0
microns. The survey will cover Galactic latitudes |b| <1 degree and longitudes
|l|=10 to 65 degrees (both sides of the Galactic center). The survey area
contains the outer ends of the Galactic bar, the Galactic molecular ring, and
the inner spiral arms. The GLIMPSE team will process these data to produce a
point source catalog, a point source data archive, and a set of mosaicked
images. We summarize our observing strategy, give details of our data products,
and summarize some of the principal science questions that will be addressed
using GLIMPSE data. Up-to-date documentation, survey progress, and information
on complementary datasets are available on the GLIMPSE web site:
www.astro.wisc.edu/glimpse.Comment: Description of GLIMPSE, a SIRTF Legacy project (Aug 2003 PASP, in
press). Paper with full res.color figures at
http://www.astro.wisc.edu/glimpse/glimpsepubs.htm
Cationic group VI metal imido alkylidene N‐heterocyclic carbene nitrile complexes : bench‐stable, functional‐group‐tolerant olefin metathesis catalysts
Despite their excellent selectivities and activities, Mo‐and W‐based catalysts for olefin metathesis have not gained the same widespread use as Ru‐based systems, mainly due to their inherent air sensitivity. Herein, we describe the synthesis of air‐stable cationic‐at‐metal molybdenum and tungsten imido alkylidene NHC nitrile complexes. They catalyze olefin metathesis reactions of substrates containing functional groups such as (thio‐) esters, (thio‐) ethers and alcohols without the need for prior activation, for example, by a Lewis acid. The presence of a nitrile ligand was found to be essential for their stability towards air, while no decrease in activity and productivity could be observed upon coordination of a nitrile. Variations of the imido and anionic ligand revealed that alkoxide complexes with electron‐withdrawing imido ligands offer the highest reactivities and excellent stability compared to analogous triflate and halide complexes.Deutsche ForschungsgemeinschaftProjekt DEA
Dual catalysis with an N‐heterocyclic carbene and a Lewis acid : thermally latent precatalyst for the polymerization of ε‐caprolactam
So far, the earlier reported strong correlation between basicity of an N‐heterocyclic carbene (NHC) and its reactivity in poly(ε‐caprolactam) (PA6) synthesis resulted in a substantial limitation of applicable carbenes. Here, to overcome this issue, 1,3‐dimethylimidazolium‐2‐carboxylate, an easily accessible, air and moisture‐stable NHC, was applied as thermally latent initiator. In order to compensate for its low basicity, reactivity was enhanced by the addition of both a Lewis acid and an activator to ease the initial polymerization step. The resulting mixtures of ε‐caprolactam, the CO2‐protected NHC, a Lewis acid and N‐acylazepan‐2‐one constitute homogeneous, thermally fully latent “single‐component” blends for the anionic polymerization‐based synthesis of PA6. They can be stored both in the liquid and solid state for days and months, respectively, without any loss in activity. The role of the Lewis acid as well as technical implications of the prolonged pot‐times are discussed.Projekt DEA
Reversible N‐heterocyclic carbene‐induced α‐H abstraction in Tungsten(VI) imido dialkyl dialkoxide complexes
The first reversible N‐heterocyclic carbene (NHC) induced α‐H abstraction in tungsten(VI) imido‐dialkyl dialkoxide complexes is reported. Treatment of W(NAr)(CH2Ph)2(OtBu)2 (Ar=2,6‐dichlorophenyl, 2,6‐dimethylphenyl, 2,6‐diisopropylphenyl) with different NHCs leads to the formation of complexes of the type W(NAr)(CHPh)(NHC)(CH2Ph)(OtBu) in excellent isolated yields of up to 96 %. The highly unusual release of the tert‐butoxide ligand as tBuOH in the course of the reaction was observed. The formed alkylidene complexes and tBuOH are in an equilibrium with the NHC and the dialkyl complexes. Reaction kinetics were monitored by 1H NMR spectroscopy. A correlation between the steric and electronic properties of the NHC and the reaction rates was observed. Kinetics of a deuterium‐labeled complex in comparison to its non‐deuterated counterpart revealed the presence of a strong primary kinetic isotope effect (KIE) of 4.2, indicating that α‐H abstraction is the rate‐determining step (RDS) of the reaction.Deutsche Forschungsgemeinschaf
Fast fluorescence microscopy for imaging the dynamics of embryonic development
Live imaging has gained a pivotal role in developmental biology since it increasingly allows real-time observation of cell behavior in intact organisms. Microscopes that can capture the dynamics of ever-faster biological events, fluorescent markers optimal for in vivo imaging, and, finally, adapted reconstruction and analysis programs to complete data flow all contribute to this success. Focusing on temporal resolution, we discuss how fast imaging can be achieved with minimal prejudice to spatial resolution, photon count, or to reliably and automatically analyze images. In particular, we show how integrated approaches to imaging that combine bright fluorescent probes, fast microscopes, and custom post-processing techniques can address the kinetics of biological systems at multiple scales. Finally, we discuss remaining challenges and opportunities for further advances in this field
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