231 research outputs found

    African-American Activist Mary Church Terrell and the Brownsville Disturbance

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    Mary Church Terrell (1863–1954) demonstrated the philosophy of calm courage many times in a long life of activism. In the middle of her life, when three companies of African-American soldiers in Brownsville, Texas, were dismissed without honor and without a hearing in 1906, she readily came to their defense. Their dismissals followed a racial disturbance during which one white man was killed and several others wounded in Brownsville. Terrell, at the urging of some African-American leaders, went to see Secretary of War William Howard Taft to request that the action against the black troops be rescinded until they received a fair hearing. Her request was granted after Taft appealed to President Theodore Roosevelt, and the Constitution League, a civil rights organization, sent in lawyers to hear the soldiers’ side of the story

    Site-Specific Effects of PECAM-1 on Atherosclerosis in LDL Receptor-Deficient Mice

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    Objective—Atherosclerosis is a vascular disease that involves lesion formation at sites of disturbed flow under the influence of genetic and environmental factors. Endothelial expression of adhesion molecules that enable infiltration of immune cells is important for lesion development. Platelet/endothelial cell adhesion molecule-1 (PECAM-1; CD31) is an adhesion and signaling receptor expressed by many cells involved in atherosclerotic lesion development. PECAM-1 transduces signals required for proinflammatory adhesion molecule expression at atherosusceptible sites; thus, it is predicted to be proatherosclerotic. PECAM-1 also inhibits inflammatory responses, on which basis it is predicted to be atheroprotective. Methods and Results—We evaluated herein the effect of PECAM-1 deficiency on development of atherosclerosis in LDL receptor– deficient mice. We found that PECAM-1 has both proatherosclerotic and atheroprotective effects, but that the former dominate in the inner curvature of the aortic arch whereas the latter dominate in the aortic sinus, branching arteries, and descending aorta. Endothelial cell expression of PECAM-1 was sufficient for its atheroprotective effects in the aortic sinus but not in the descending aorta, where the atheroprotective effects of PECAM-1 also required its expression on bone marrow–derived cells. Conclusion—We conclude that PECAM-1 influences initiation and progression of atherosclerosis both positively and negatively, and that it does so in a site-specific manner. (Arterioscler Thromb Vasc Biol. 2008;28:1996-2002

    Regional Anesthesia for Bilateral Carpal Tunnel Release

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    Carpal Tunnel Syndrome is the most common nerve entrapment neuropathy with over 60% of diagnosed patients presenting with bilateral median nerve involvement. Bilateral upper extremity surgery presents unique anesthesia challenges, yet surgeons are increasingly interested in performing simultaneous bilateral carpal tunnel release (BCTR) procedures. Regional anesthesia techniques traditionally employed for unilateral hand procedures are impractical, and general anesthesia is expensive and incurs added risk. A cost effective and efficient anesthesia plan for BCTR is therefore needed. Objective: Conduct a literature search to support the administration of an efficient and safe anesthesia technique for BCTR utilizing local infiltration and median nerve block. Methods: Electronic searches were conducted for current pertinent information published in anesthesia, hand surgery and plastic surgery journals within the past 5 years. Information gathered was assimilated to make an evidence based recommendation for a BCTR anesthesia technique. Results: BCTR is a more cost effective and time efficient treatment for bilateral carpal tunnel syndrome than a staged unilateral approach. Local anesthesia with median nerve block with or without sedation is a cost efficient and safe anesthesia strategy for BCTR

    Use of Foliar Chemical Treatments to Induce Disease Resistance in Rhododendrons Inoculated with Phytophthora ramorum

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    A field study was conducted at the National Ornamental Research Site at Dominican University California (NORS-DUC). The study goal was to evaluate three chemical inducers applied as foliar treatments for controlling Phytophthora ramorum, on Rhododendron x ‘Cunningham’s White’ nursery plants. The inducers were chlorine dioxide (ElectroBiocide), hydrogen peroxide (OxiDate 2.0), and acibenzolar-s methyl (Actigard). Water samples from the electrostatic sprayer were measured for three physicochemical water properties. Visual assessment of plant foliage, based on the Horsfall- Barratt scale, was conducted at three and five months after chemical treatments. Foliar fluorescence (Fv/Fm) was measured over three dates. The success of P. ramorum inoculations were determined using qPCR methods. Visual assessment across both months showed no signs of P. ramorum infection or chemical injury symptoms. However, P. ramorum infection vis-à-vis qPCR analysis was confirmed. The September Fv/Fm results revealed that all the chemical inducer treatments were equivalent to the water treatment, except for Actigard. The qPCR results were in general agreement with the Fv/Fm results indicating that the rhododendrons were successfully inoculated with P. ramorum but were non-symptomatic. The electrostatic sprayer ionized the water droplets, resulting in increased Fv/Fm values for the water treatments 90 days after application. There was a three-month delay in fluorescence responses to the most effective chemical applications, indicating that woody plants may need to be monitored over the long term to determine accurate responses to foliar treatments

    CryoEM structure of the human SLC4A4 sodium-coupled acid-base transporter NBCe1.

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    Na+-coupled acid-base transporters play essential roles in human biology. Their dysfunction has been linked to cancer, heart, and brain disease. High-resolution structures of mammalian Na+-coupled acid-base transporters are not available. The sodium-bicarbonate cotransporter NBCe1 functions in multiple organs and its mutations cause blindness, abnormal growth and blood chemistry, migraines, and impaired cognitive function. Here, we have determined the structure of the membrane domain dimer of human NBCe1 at 3.9 Å resolution by cryo electron microscopy. Our atomic model and functional mutagenesis revealed the ion accessibility pathway and the ion coordination site, the latter containing residues involved in human disease-causing mutations. We identified a small number of residues within the ion coordination site whose modification transformed NBCe1 into an anion exchanger. Our data suggest that symporters and exchangers utilize comparable transport machinery and that subtle differences in their substrate-binding regions have very significant effects on their transport mode

    Platelet PECAM-1 Inhibits Thrombus Formation In Vivo

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    Platelet endothelial cell adhesion molecule-1 (PECAM-1) is a cell surface glycoprotein receptor expressed on a range of blood cells including platelets, and is also on vascular endothelial cells. PECAM-1 possesses adhesive and signalling properties, the latter being mediated by an Immunoreceptor Tyrosine-based Inhibitory Motif present on the cytoplasmic tail of the protein. Recent studies in vitro have demonstrated that PECAM-1 signalling inhibits the aggregation of platelets. In the present study we have utilised PECAM-1 deficient mice and radiation chimeras to investigate the function of this receptor in the regulation of thrombus formation. Using intravital microscopy and laser induced injury to cremaster muscle arterioles, we show that thrombi formed in PECAM-1 deficient mice were larger, formed more rapidly than in control mice and were more stable. Larger thrombi were also formed in control mice transplanted with PECAM-1 deficient bone marrow, in comparison to control-transplanted mice. A ferric chloride model of thrombosis was used to investigate thrombus formation in carotid arteries. In PECAM-1 deficient mice the time to 75% vessel occlusion was significantly shorter than in control mice. These data provide evidence for the involvement of platelet PECAM-1 in the negative regulation of thrombus formation

    Hot Disks And Delayed Bar Formation

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    We present observational evidence for the inhibition of bar formation in dispersion-dominated (dynamically hot) galaxies by studying the relationship between galactic structure and host galaxy kinematics in a sample of 257 galaxies between 0.1 << z ≤\leq 0.84 from the All-Wavelength Extended Groth Strip International Survey (AEGIS) and the Deep Extragalactic Evolutionary Probe 2 (DEEP2) survey. We find that bars are preferentially found in galaxies that are massive and dynamically cold (rotation-dominated) and on the stellar Tully-Fisher relationship, as is the case for barred spirals in the local Universe. The data provide at least one explanation for the steep (×\times3) decline in the overall bar fraction from z=0 to z=0.84 in L∗^* and brighter disks seen in previous studies. The decline in the bar fraction at high redshift is almost exclusively in the lower mass (10 << log M∗_{*}(\Msun)<< 11), later-type and bluer galaxies. A proposed explanation for this "downsizing" of the bar formation / stellar structure formation is that the lower mass galaxies may not form bars because they could be dynamically hotter than more massive systems from the increased turbulence of accreting gas, elevated star formation, and/or increased interaction/merger rate at higher redshifts. The evidence presented here provides observational support for this hypothesis. However, the data also show that not every disk galaxy that is massive and cold has a stellar bar, suggesting that mass and dynamic coldness of a disk are necessary but not sufficient conditions for bar formation -- a secondary process, perhaps the interaction history between the dark matter halo and the baryonic matter, may play an important role in bar formation.Comment: In press, ApJ, 13 pages, 5 figures (3 color

    Regional Anesthesia for Bilateral Carpal Tunnel Release

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    Carpal Tunnel Syndrome is the most common nerve entrapment neuropathy with over 60% of diagnosed patients presenting with bilateral median nerve involvement.&nbsp; Bilateral upper extremity surgery presents unique anesthesia challenges, yet surgeons are increasingly interested in performing simultaneous bilateral carpal tunnel release (BCTR) procedures. Regional anesthesia techniques traditionally employed for unilateral hand procedures are impractical, and general anesthesia is expensive and incurs added risk.&nbsp; A cost effective and efficient anesthesia plan for BCTR is therefore needed. Objective: &nbsp;Conduct a literature search to support the administration of an efficient and safe anesthesia technique for BCTR utilizing local infiltration and median nerve block.&nbsp; Methods: Electronic searches were conducted for current pertinent information published in anesthesia, hand surgery and plastic surgery journals within the past 5 years. &nbsp;Information gathered was assimilated to make an evidence based recommendation for a BCTR anesthesia technique.&nbsp; Results: BCTR is a more cost effective and time efficient treatment for bilateral carpal tunnel syndrome than a staged unilateral approach.&nbsp; Local anesthesia with median nerve block with or without sedation is a cost efficient and safe anesthesia strategy for BCTR

    Intercomparability of X_(CO_2) and X_(CH_4) from the United States TCCON sites

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    The Total Carbon Column Observing Network (TCCON) has become the standard for long-term column-averaged measurements of CO_2 and CH_4. Here, we use a pair of portable spectrometers to test for intra-network bias among the four currently operating TCCON sites in the United States (US). A previous analytical error analysis has suggested that the maximum 2σ site-to-site relative (absolute) bias of TCCON should be less than 0.2% (0.8ppm) in X_(CO_2) and 0.4% (7ppb) in X_(CH_4). We find here experimentally that the 95% confidence intervals for maximum pairwise site-to-site bias among the four US TCCON sites are 0.05–0.14% for X_(CO_2) and 0.08–0.24% for X_(CH_4). This is close to the limit of the bias we can detect using this methodology
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