662 research outputs found

    Ethyl Orthocarbonate [Orthocarbonic acid, tetrahethyl ester]

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    A solution of sodium ethoxide is prepared under nitrogen from 70 g. (3.04 g. atoms) of sodium and 2 l. of absolute ethanol (Note 1) in a 3-l. three-necked flask which is equipped with mechanical stirrer, efficient reflux condenser, dropping funnel, and a thermometer which dips below the level of the liquid in the flask. Chloropicrin (100 g., 0.61 mole) (Note 2) is placed in the dropping funnel, and the stirred solution is heated to 58–60° with a water bath. The chloropicrin is added at a rate of 30–35 drops per minute until the reaction becomes self-sustaining (about 20 minutes), at which point the water bath is removed and the balance of the chloropicrin is added at a rate sufficient to maintain the temperature at 58–60° (Note 3). When the addition, which requires nearly 2 hours, is complete, the stirrer is stopped and the mixture is allowed to stand overnight

    A Graphic Method For Depicting Horizontal Direction Data On Vertical Outcrop Photographs

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    Outcrop photographs which show two-dimensional representations of three-dimensionally dipping surfaces (e.g., bedding planes, cross-bed foresets) are commonly utilized in the description of sedimentary strata. In many instances, accurate depiction of the dip direction of such features is paramount for understanding their interpretation, and for visualizing the true form of three-dimensional bodies (e.g., conceptualizing the form of an architectural element in a cliff-face, preserved as a vertical slice that has been cut oblique to paleocurrent direction). However, as an outcrop photograph often presents information on a vertical plane and directional data refers to a horizontal plane, the accurate co-depiction of both sets of information may be challenging. There is presently no universal method for illustrating such measurements on outcrop photographs: techniques in common usage are often imprecise, and the lack of uniformity hinders comparison between different images. Here we present a method for accurately depicting horizontal direction data on vertical outcrop photographs which permits instant visualization of dip relative to the illustrated outcrop geometry. The method is simple to apply, does not compromise primary data, and is unobtrusive to other visual information within images; thus having utility across a broad spectrum of geological investigations

    997-90 Right (RV) and Left Ventricular (LV) Geometry and Myocyte Contractile Processes with Dilated Cardiomyopathy (DCM): Disparity Between Myocyte Growth and β-Adrenergic Responsiveness

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    The progression of DCM has been assumed to be a homogenous process for both the RV and LV. However, this assumption has never been tested. Accordingly, we measured myocyte contractile performance (velocity of shortening, VELSHORT; percent shortening, PERSHORT) at baseline (BASE) and after β-adrenergic receptor stimulation (βAR, 25 nM isoproterenol) of isolated myocytes taken from the RV and LV of 5 pigs with pacing induced DCM (240 bpm, 3 weeks) and 5 control pigs (CON). RV and LV mass/body weight (MASS) and myocyte length and cross-sectional area (CSA) were also determined.CON-RVCON-LVDCM-RVDCM-LVVELSHORT-BASE (μm/s)90±5+50±148±2*,+32±1*VELSHORT-βAR (μm/s)206±8+150±5123±8*111±9*PERSHORT-BASE (%)5.8±0.2+4.6±0.13.1±0.1*,+2.2±0.1*PERSHORT-βAR (%)11.5±0.3+10.2±0.359±0.3*5.2±0.4*Length (μm)150±2+137±1179±2*,+173±2*CSA (μm2)176±4+362±8232±4*,+292±5*Mass (gm/kg)0.8±0.1+2.8±0.11.6±0.1*,+2.9±0.2+p<0.05 vs LV*p<005 vS CONIn controls, RV myocytes were longer and had a smaller CSA, but enhanced contractile performance at baseline and with β-adrenergic stimulation. With DCM, no LV hypertrophy occurred. In contrast, RV chamber and cellular hypertrophy occurred and was associated with a persistent increase of RV myocyte baseline contractile function.SummaryThis study demonstrated, for the first time, that differences in RV and LV myocyte function and β-adrenergic responsiveness exist in normal and DCM states. More importantly, a disparity in RV and LV myocyte growth with DCM occurred. Thus, in this model of DCM, RV and LV growth and changes in contractile performance are not a homogenous process, and suggest that inherent differences exist in the response of RV and LV myocytes to stress

    Evolution of alluvial mudrock forced by early land plants.

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    Mudrocks are a primary archive of Earth's history from the Archean eon to recent times, and their source-to-sink production and deposition play a central role in long-term ocean chemistry and climate regulation. Using original and published stratigraphic data from all 704 of Earth's known alluvial formations from the Archean eon (3.5 billion years ago) to the Carboniferous period (0.3 billion years ago), we prove contentions of an upsurge in the proportion of mud retained on land coeval with vegetation evolution. We constrain the onset of the upsurge to the Ordovician-Silurian and show that alluvium deposited after land plant evolution contains a proportion of mudrock that is, on average, 1.4 orders of magnitude greater than the proportion contained in alluvium from the preceding 90% of Earth's history. We attribute this shift to the ways in which vegetation revolutionized mud production and sediment flux from continental interiors

    799-2 Left Ventricular (LV) and Myocyte Electrophysiology with the Development of Dilated Cardiomyopathy (DCM); Effects of Angiotensin II Receptor (AT1 AT-II) Blockade

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    Ventricular arrhythmias are a significant cause of morbidity and mortality with DCM, and AT1 AT-II receptor activation has been implicated to play a role in arrhythmogenesis. However, the effects of AT1, AT-II receptor activation on changes in LV function and myocyte electrophysiology during the progression of DCM remain unexplored. Accordingly, this study measured weekly changes in LV function (ejection fraction, LVEF; peak systolic wall stress, LVWS) and surface electrocardiography (R-R interval, QRS duration, QTc interval), and myocyte action potentials (resting membrane, RM; upstroke velocity, Vmax; duration at 90% repolarization, APD90) at terminal study in 3 groups of dogs (n=6/group): DCM, chronic pace (216 bpm, 4 weeks); DCM/AT-BLOCK, chronic pace and treatment with a specific non-peptide AT1 AT-II antagonist (SR 47436 (BMS 186295); 30mg/kg BID); and control (CON). All measurements were made with the pacemaker deactivated.LVEF (%)LVWS (g/cm2)R-R (ms).QRS (ms).QTc (ms)Week 2:CON68.7±3.2133±14646±9958.4±1.3291±13DCM40.9±4.1*184±16*519±4060.7±1.9316±9DCM/AT-Block44.1±3.7*138±10+540±566.32±1.2*325±9Week4:CON73.1±2.4127±10629±4557.6±1.4314±9DCM35.2±3.5*223±16*505±41*62.0±1.9313±9DCM/AT-Block35.2±2.7*160±13*+578±4865.7±1.5*296±6*p<0.05 vs CON+p<0.05 vs DCMWith DCM, RM (-71±l* vs -78±1mV) and APD90 (257±9* vs 226±7ms) increased, and Vmax decreased (121±5* vs 158±9V/s) compared to CON. In contrast, with AT-BLOCK, RM became more negative (-76±1+mV), APD90 was reduced (183±14*+) and Vmax increased (165±13+).SummaryAT1 AT-II receptor blockade during the progression of DCM caused significant changes in LV myocardial conduction and myocyte action potentials. These results suggest that AT1 AT-II receptor activation plays a contributory role toward the changes in LV electrophysiology with DCM

    Developmental differences in myocyte contractile response after cardioplegic arrest

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    AbstractAlthough developmental differences in left ventricular function after cardioplegic arrest and rewarming have been postulated, whether differences exist at the level of the myocyte remains unexplored. This project tested the hypothesis that there is a differential effect of hypothermic hyperkalemic cardioplegic arrest with subsequent rewarming on contractile function of immature compared with adult ventricular myocytes. Myocytes were isolated from the left ventricular free wall of five immature and five adult rabbits and incubated for 2 hours in hyperkalemic modified Ringer's solution at 4° C (cardioplegia) or for 2 hours in cell culture medium at 37° C (normothermia). Myocytes were resuspended (“rewarmed”) in 37° C cell culture medium after the incubation protocol. Normothermic baseline contractile performance was lower in immature, compared with adult, myocytes. Specifically, myocyte shortening velocity was 62 ± 4 μm/sec in immature and 112 ± 6 μm/sec in adult myocytes (p < 0.01). After cardioplegia and rewarming, immature myocyte contractile function was unchanged, whereas adult myocyte contractile function was significantly diminished. For example, myocyte shortening velocity was 65 ± 4 μm/sec in immature and 58 ± 3 μm/sec in adult myocytes (p < 0.01 versus normothermic). Myocyte surface area, which reflects myocyte volume, was increased after cardioplegia and rewarming in adults (3582 ± 55 versus 3316 ± 46 μm2, p < 0.01), but remained unchanged in immature myocytes (2212 ± 27 versus 2285 ± 28 μm2, p = not significant). These unique findings demonstrate a preservation of myocyte contractile function and volume regulation in immature myocytes after cardioplegic arrest and rewarming. Thus this study directly demonstrates that developmental differences exist in myocyte responses to hypothermic hyperkalemic cardioplegic arrest with subsequent rewarming. (J THORAC CARDIOVASC SURG 1996;111:1257-66

    Genome-wide linkage using the Social Responsiveness Scale in Utah autism pedigrees

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    <p>Abstract</p> <p>Background</p> <p>Autism Spectrum Disorder<b>s </b>(ASD) are phenotypically heterogeneous, characterized by impairments in the development of communication and social behaviour and the presence of repetitive behaviour and restricted interests. Dissecting the genetic complexity of ASD may require phenotypic data reflecting more detail than is offered by a categorical clinical diagnosis. Such data are available from the Social Responsiveness Scale (SRS) which is a continuous, quantitative measure of social ability giving scores that range from significant impairment to above average ability.</p> <p>Methods</p> <p>We present genome-wide results for 64 multiplex and extended families ranging from two to nine generations. SRS scores were available from 518 genotyped pedigree subjects, including affected and unaffected relatives. Genotypes from the Illumina 6 k single nucleotide polymorphism panel were provided by the Center for Inherited Disease Research. Quantitative and qualitative analyses were done using MCLINK, a software package that uses Markov chain Monte Carlo (MCMC) methods to perform multilocus linkage analysis on large extended pedigrees.</p> <p>Results</p> <p>When analysed as a qualitative trait, linkage occurred in the same locations as in our previous affected-only genome scan of these families, with findings on chromosomes 7q31.1-q32.3 [heterogeneity logarithm of the odds (HLOD) = 2.91], 15q13.3 (HLOD = 3.64), and 13q12.3 (HLOD = 2.23). Additional positive qualitative results were seen on chromosomes 6 and 10 in regions that may be of interest for other neuropsychiatric disorders. When analysed as a quantitative trait, results replicated a peak found in an independent sample using quantitative SRS scores on chromosome 11p15.1-p15.4 (HLOD = 2.77). Additional positive quantitative results were seen on chromosomes 7, 9, and 19.</p> <p>Conclusions</p> <p>The SRS linkage peaks reported here substantially overlap with peaks found in our previous affected-only genome scan of clinical diagnosis. In addition, we replicated a previous SRS peak in an independent sample. These results suggest the SRS is a robust and useful phenotype measure for genetic linkage studies of ASD. Finally, analyses of SRS scores revealed linkage peaks overlapping with evidence from other studies of neuropsychiatric diseases. The information available from the SRS itself may, therefore, reveal locations for autism susceptibility genes that would not otherwise be detected.</p

    Integration of highly probabilistic sources into optical quantum architectures: perpetual quantum computation

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    In this paper we introduce a design for an optical topological cluster state computer constructed exclusively from a single quantum component. Unlike previous efforts we eliminate the need for on demand, high fidelity photon sources and detectors and replace them with the same device utilised to create photon/photon entanglement. This introduces highly probabilistic elements into the optical architecture while maintaining complete specificity of the structure and operation for a large scale computer. Photons in this system are continually recycled back into the preparation network, allowing for a arbitrarily deep 3D cluster to be prepared using a comparatively small number of photonic qubits and consequently the elimination of high frequency, deterministic photon sources.Comment: 19 pages, 13 Figs (2 Appendices with additional Figs.). Comments welcom

    Genome-wide parametric linkage analyses of 644 bipolar pedigrees suggest susceptibility loci at chromosomes 16 and 20

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    OBJECTIVE: Our aim is to map chromosomal regions that harbor loci that increase susceptibility to bipolar disorder. METHODS: We analyzed 644 bipolar families ascertained by the National Institute of Mental Health Human Genetics Initiative for bipolar disorder. The families have been genotyped with microsatellite loci spaced every approximately 10 cM or less across the genome. Earlier analyses of these pedigrees have been limited to nonparametric (model-free) methods and thus, information from unaffected subjects with genotypes was not considered. In this study, we used parametric analyses assuming dominant and recessive transmission and specifying a maximum penetrance of 70%, so that information from unaffecteds could be weighed in the linkage analyses. As in previous linkage analyses of these pedigrees, we analyzed three diagnostic categories: model 1 included only bipolar I and schizoaffective, bipolar cases (1565 patients of whom approximately 4% were schizoaffective, bipolar); model 2 included all individuals in model 1 plus bipolar II patients (1764 total individuals); and model 3 included all individuals in model 2 with the addition of patients with recurrent major depressive disorder (2046 total persons). RESULTS: Assuming dominant inheritance the highest genome-wide pair-wise logarithm of the odds (LOD) score was 3.2 with D16S749 using model 2 patients. Multipoint analyses of this region yielded a maximum LOD score of 4.91. Under recessive transmission a number of chromosome 20 markers were positive and multipoint analyses of the area gave a maximum LOD of 3.0 with model 2 cases. CONCLUSION: The chromosome 16p and 20 regions have been implicated by some studies and the data reported herein provide additional suggestive evidence of bipolar susceptibility genes in these regions
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