1,075 research outputs found
Investigation of Unusual Mineral Occurrences in Southern Ohio and Their Possible Relation to the Mineralization of Serpent Mound
This project focuses on a mine prospect site I recently located in Ross County, Ohio,
dating back to the 1930's, which is an area of unusual and heretofore undocumented
mineralization. Limestone concretions and samples of crystalline quartz and pyrite occur in
sizes and quantities which are quite uncommon in the state of Ohio.
The goals of the project were, through field observation and laboratory analysis, to
identify the nature and extent of mineralization in the study area, find its relation to other
mineral localities in south-central Ohio, and determine what role unrecognized faults and/or
hydrothermal activity in the area have played in the genesis of the unusual mineralization.
The area lies along the unconformable contact between upper Silurian and middle
Devonian bedrock, and also includes ground and end moraines from both the Wisconsinan
and Illinoian glaciations. Sulfide mineralization in the middle Devonian Ohio Shale occurs as
nodules of pyrite and marcasite, with trace barite, up to ten centimeters in diameter embedded
in black shale. This unit has also yielded crystalline quartz lining contorted cavities in large
limestone concretions up to one meter across. Traces of barite, marcasite, pyrite, galena, and
glacial gold have been found in stream sediments throughout the area.
Aerial photographs, verified in the field, show a lineation extending northward
through the study area in Ross County, which may be related to radiating faults from the
Serpent Mound Disturbance in Adams County, 30km to the south.No embargoAcademic Major: Geological Science
Targeted Deletion of a High-Affinity GATA-binding Site in the GATA-1 Promoter Leads to Selective Loss of the Eosinophil Lineage In Vivo
Transcription factor GATA-1 reprograms immature myeloid cells to three different hematopoietic lineages-erythroid cells, megakaryocytes, and eosinophils. GATA-1 is essential for maturation of erythroid and megakaryocytic precursors, as revealed by gene targeting in mice. Here we demonstrate that deletion of a high-affinity GATA-binding site in the GATA-1 promoter, an element presumed to mediate positive autoregulation of GATA-1 expression, leads to selective loss of the eosinophil lineage. These findings suggest that GATA-1 is required for specification of this lineage during hematopoietic development. Mice lacking the ability to produce eosinophils should prove useful in ascertaining the role of eosinophils in a variety of inflammatory or allergic disorders
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Status of the LBNL normal-conducting CW VHF electron photo-gun
The fabrication and installation at the Lawrence Berkeley National Laboratory of a high-brightness high-repetition rate photo-gun, based on a normal conducting 187 MHz (VHF) RF cavity operating in CW mode, is in an advanced phase. The cavity will generate an electric field at the cathode plane of ∼ 20 MV/m to accelerate the electron bunches up to ∼ 750 keV, with peak current, energy spread and transverse emittance suitable for FEL and ERL applications. The gun vacuum system has been designed for achieving pressures compatible with the use of "delicate" high quantum efficiency semiconductor cathodes to generate up to a nC bunches at MHz repetition rate with present laser technology. Several photo-cathode/laser systems are under consideration, and in particular photo-cathodes based on K CsSb are being developed for the gun and have already achieved a QE of 8% at 532 nm wavelength, or close to 20% including the Schottky barrier lowering. The cathode will be operated by a μJ fiber laser in conjunction with refractive transverse beam shaping to create a flat top transverse profile, as well as a birefringent pulse stacker to create a flat top temporal profile. The present status and the plan for future activities are presented.
GRACE Gravity Data Target Possible Mega-impact in North Central Wilkes Land, Antarctica
A prominent positive GRACE satellite-measured free-air gravity anomaly over regionally depressed subglacial topography may identify a mascon centered on (70 deg S, 120 deg E) between the Gamburtsev and Transantarctic Mountains of East Antarctica. Being more than twice the size of the Chicxulub crater, the inferred Wilkes Land impact crater is a strong candidate for a Gondwana source of the greatest extinction of life at the end of the Permian. Its ring structure intersects the coastline and thus may have strongly influenced the Cenozoic rifting of East Antarctica from Australia that resulted in the enigmatic lack of crustal thinning on the conjugate Australian block
Detecting depressive and anxiety disorders in distressed patients in primary care; comparative diagnostic accuracy of the Four-Dimensional Symptom Questionnaire (4DSQ) and the Hospital Anxiety and Depression Scale (HADS)
BACKGROUND: Depressive and anxiety disorders often go unrecognized in distressed primary care patients, despite the overtly psychosocial nature of their demand for help. This is especially problematic in more severe disorders needing specific treatment (e.g. antidepressant pharmacotherapy or specialized cognitive behavioural therapy). The use of a screening tool to detect (more severe) depressive and anxiety disorders may be useful not to overlook such disorders. We examined the accuracy with which the Four-Dimensional Symptom Questionnaire (4DSQ) and the Hospital Anxiety and Depression Scale (HADS) are able to detect (more severe) depressive and anxiety disorders in distressed patients, and which cut-off points should be used. METHODS: Seventy general practitioners (GPs) included 295 patients on sick leave due to psychological problems. They excluded patients with recognized depressive or anxiety disorders. Patients completed the 4DSQ and HADS. Standardized diagnoses of DSM-IV defined depressive and anxiety disorders were established with the Composite International Diagnostic Interview (CIDI). Receiver Operating Characteristic (ROC) analyses were performed to obtain sensitivity and specificity values for a range of scores, and area under the curve (AUC) values as a measure of diagnostic accuracy. RESULTS: With respect to the detection of any depressive or anxiety disorder (180 patients, 61%), the 4DSQ and HADS scales yielded comparable results with AUC values between 0.745 and 0.815. Also with respect to the detection of moderate or severe depressive disorder, the 4DSQ and HADS depression scales performed comparably (AUC 0.780 and 0.739, p 0.165). With respect to the detection of panic disorder, agoraphobia and social phobia, the 4DSQ anxiety scale performed significantly better than the HADS anxiety scale (AUC 0.852 versus 0.757, p 0.001). The recommended cut-off points of both HADS scales appeared to be too low while those of the 4DSQ anxiety scale appeared to be too high. CONCLUSION: In general practice patients on sick leave because of psychological problems, the 4DSQ and the HADS are equally able to detect depressive and anxiety disorders. However, for the detection of cases severe enough to warrant specific treatment, the 4DSQ may have some advantages over the HADS, specifically for the detection of panic disorder, agoraphobia and social phobi
Study of Constrained Minimal Supersymmetry
Taking seriously phenomenological indications for supersymmetry, we have made
a detailed study of unified minimal SUSY, including effects at the few percent
level in a consistent fashion. We report here a general analysis without
choosing a particular unification gauge group. We find that the encouraging
SUSY unification results of recent years do survive the challenge of a more
complete and accurate analysis. Taking into account effects at the 5-10% level
leads to several improvements of previous results, and allows us to sharpen our
predictions for SUSY in the light of unification. We perform a thorough study
of the parameter space. The results form a well-defined basis for comparing the
physics potential of different facilities. Very little of the acceptable
parameter space has been excluded by LEP or FNAL so far, but a significant
fraction can be covered when these accelerators are upgraded. A number of
initial applications to the understanding of the SUSY spectrum, detectability
of SUSY at LEP II or FNAL, BR(), Width(), dark
matter, etc, are included in a separate section. We formulate an approach to
extracting SUSY parameters from data when superpartners are detected. For small
tan(beta) or large both and are entirely bounded from
above at O(1 tev) without having to use a fine-tuning constraint.Comment: Michigan preprint UM-TH-93-24, LaTeX, 60 pages without figures.
Complete paper with inline figures available by anonymous ftp to
williams.physics.lsa.umich.edu in /pub/preprints/UM-TH-93-24.ps.Z
(uncompresses to 10MB / 77 pages), or by e-mailing reques
Search for the Supersymmetric Partner of the Top-Quark in Collisions at
We report on a search for the supersymmetric partner of the top quark (stop)
produced in events using of
collisions at recorded with the Collider Detector at
Fermilab. In the case of a light stop squark, the decay of the top quark into
stop plus the lightest supersymmetric particle (LSP) could have a significant
branching ratio. The observed events are consistent with Standard Model production and decay. Hence, we set limits on the branching ratio of
the top quark decaying into stop plus LSP, excluding branching ratios above 45%
for a LSP mass up to 40 {\rm GeV/c}.Comment: 11 pages, 4 figure
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
The Overlap of Small Molecule and Protein Binding Sites within Families of Protein Structures
Protein–protein interactions are challenging targets for modulation by small molecules. Here, we propose an approach that harnesses the increasing structural coverage of protein complexes to identify small molecules that may target protein interactions. Specifically, we identify ligand and protein binding sites that overlap upon alignment of homologous proteins. Of the 2,619 protein structure families observed to bind proteins, 1,028 also bind small molecules (250–1000 Da), and 197 exhibit a statistically significant (p<0.01) overlap between ligand and protein binding positions. These “bi-functional positions”, which bind both ligands and proteins, are particularly enriched in tyrosine and tryptophan residues, similar to “energetic hotspots” described previously, and are significantly less conserved than mono-functional and solvent exposed positions. Homology transfer identifies ligands whose binding sites overlap at least 20% of the protein interface for 35% of domain–domain and 45% of domain–peptide mediated interactions. The analysis recovered known small-molecule modulators of protein interactions as well as predicted new interaction targets based on the sequence similarity of ligand binding sites. We illustrate the predictive utility of the method by suggesting structural mechanisms for the effects of sanglifehrin A on HIV virion production, bepridil on the cellular entry of anthrax edema factor, and fusicoccin on vertebrate developmental pathways. The results, available at http://pibase.janelia.org, represent a comprehensive collection of structurally characterized modulators of protein interactions, and suggest that homologous structures are a useful resource for the rational design of interaction modulators
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