376 research outputs found

    Diurnal ocean surface layer model validation

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    The diurnal ocean surface layer (DOSL) model at the Fleet Numerical Oceanography Center forecasts the 24-hour change in a global sea surface temperatures (SST). Validating the DOSL model is a difficult task due to the huge areas involved and the lack of in situ measurements. Therefore, this report details the use of satellite infrared multichannel SST imagery to provide day and night SSTs that can be directly compared to DOSL products. This water-vapor-corrected imagery has the advantages of high thermal sensitivity (0.12 C), large synoptic coverage (nearly 3000 km across), and high spatial resolution that enables diurnal heating events to be readily located and mapped. Several case studies in the subtropical North Atlantic readily show that DOSL results during extreme heating periods agree very well with satellite-imagery-derived values in terms of the pattern of diurnal warming. The low wind and cloud-free conditions necessary for these events to occur lend themselves well to observation via infrared imagery. Thus, the normally cloud-limited aspects of satellite imagery do not come into play for these particular environmental conditions. The fact that the DOSL model does well in extreme events is beneficial from the standpoint that these cases can be associated with the destruction of the surface acoustic duct. This so-called afternoon effect happens as the afternoon warming of the mixed layer disrupts the sound channel and the propagation of acoustic energy

    Synchronization of estrus and ovulation in dairy heifers using norgestomet, GnRH, and PGF2α

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    Two experiments were performed using the same treatments. All heifers received two injections of PGF2α 14 days apart. Controls then were inseminated after detected estrus. Heifers assigned to the two treatments also received 6 mg of norgestomet for 8 days beginning 7 days before the second of two PGF2α injections. The heifers in the last treatment also received GnRH 48 hr after the second PGF2α injection to induce ovulation in any heifer not observed in estrus before a fixed-time insemination at 72 hr after PGF2α. In Experiment 1, any control heifer or herifer in the two treatments not detected in estrus by 72 hr after PGF2α received a fixed-time insemination at 72 hr. Heifers receiving GnRH tended to have fewer standing events and a shorter duration of estrus. Fixed-time inseminations reduced conception compared to those after detected estrus. In Experiment 2, when inseminations were performed only after detected estrus, all measures of fertility were unaffected by treatments. These results indicated that addition of norgestomet and(or) GnRH did not improve measures of estrus synchronization or fertility of dairy heifers.; Dairy Day, 1997, Kansas State University, Manhattan, KS, 1997

    Forecasting Evaluation of WindSat in the Coastal Environment

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    WindSat has demonstrated that measurements from polarimetric space-based microwave radiometers can be used to retrieve global ocean surface vector winds. Since the date of launch in 2003, substantial incremental improvements have been made to WindSat data processing, calibration, and retrieval algorithms. The retrievals now have higher resolution, improved wind vector ambiguity removal, and enhanced capability to represent high winds. Utilization of WindSat retrievals (wind vectors, total precipitable water, rainrate and sea surface temperature) will be demonstrated in the context of operational weather forecasting applications, especially the monitoring of topographically-forced winds. Examples will be presented from various parts of the world, including inland seas, midlatitude oceans, the tropics, and the United States. We will illustrate retrievals in extreme high- and extreme low-wind regimes, both of which can be problematic. Rain contamination will be addressed. We will include a comparison of WindSat vector maps to corresponding maps from the QuikScat scatterometer. We will discuss how near-realtime data from WindSat is being transitioned to specific offices within the National Weather Service

    Integrated information increases with fitness in the evolution of animats

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    One of the hallmarks of biological organisms is their ability to integrate disparate information sources to optimize their behavior in complex environments. How this capability can be quantified and related to the functional complexity of an organism remains a challenging problem, in particular since organismal functional complexity is not well-defined. We present here several candidate measures that quantify information and integration, and study their dependence on fitness as an artificial agent ("animat") evolves over thousands of generations to solve a navigation task in a simple, simulated environment. We compare the ability of these measures to predict high fitness with more conventional information-theoretic processing measures. As the animat adapts by increasing its "fit" to the world, information integration and processing increase commensurately along the evolutionary line of descent. We suggest that the correlation of fitness with information integration and with processing measures implies that high fitness requires both information processing as well as integration, but that information integration may be a better measure when the task requires memory. A correlation of measures of information integration (but also information processing) and fitness strongly suggests that these measures reflect the functional complexity of the animat, and that such measures can be used to quantify functional complexity even in the absence of fitness data.Comment: 27 pages, 8 figures, one supplementary figure. Three supplementary video files available on request. Version commensurate with published text in PLoS Comput. Bio

    Comparison of Evaluations for Heart Transplant Before Durable Left Ventricular Assist Device and Subsequent Receipt of Transplant at Transplant vs Nontransplant Centers

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    IMPORTANCE: In 2020, the Centers for Medicare & Medicaid Services revised its national coverage determination, removing the requirement to obtain review from a Medicare-approved heart transplant center to implant a durable left ventricular assist device (LVAD) for bridge-to-transplant (BTT) intent at an LVAD-only center. The association between center-level transplant availability and access to heart transplant, the gold-standard therapy for advanced heart failure (HF), is unknown. OBJECTIVE: To investigate the association of center transplant availability with LVAD implant strategies and subsequent heart transplant following LVAD implant before the Centers for Medicare & Medicaid Services policy change. DESIGN, SETTING, AND PARTICIPANTS: A retrospective cohort study of the Society of Thoracic Surgeons Intermacs multicenter US registry database was conducted from April 1, 2012, to June 30, 2020. The population included patients with HF receiving a primary durable LVAD. EXPOSURES: LVAD center transplant availability (LVAD/transplant vs LVAD only). MAIN OUTCOMES AND MEASURES: The primary outcomes were implant strategy as BTT and subsequent transplant by 2 years. Covariates that might affect listing strategy and outcomes were included (eg, patient demographic characteristics, comorbidities) in multivariable models. Parameters for BTT listing were estimated using logistic regression with center-level random effects and for receipt of a transplant using a Cox proportional hazards regression model with death as a competing event. RESULTS: The sample included 22 221 LVAD recipients with a median age of 59.0 (IQR, 50.0-67.0) years, of whom 17 420 (78.4%) were male and 3156 (14.2%) received implants at LVAD-only centers. Receiving an LVAD at an LVAD/transplant center was associated with a 79% increased adjusted odds of BTT LVAD designation (odds ratio, 1.79; 95% CI, 1.35-2.38; P \u3c .001). The 2-year transplant rate following LVAD implant was 25.6% at LVAD/transplant centers and 11.9% at LVAD-only centers. There was an associated 33% increased rate of transplant at LVAD/transplant centers compared with LVAD-only centers (adjusted hazard ratio, 1.33; 95% CI, 1.17-1.51) with a similar hazard for death at 2 years (adjusted hazard ratio, 0.99; 95% CI, 0.90-1.08). CONCLUSIONS AND RELEVANCE: Receiving an LVAD at an LVAD-transplant center was associated with increased odds of BTT intent at implant and subsequent transplant receipt for patients at 2 years. The findings of this study suggest that Centers for Medicare & Medicaid Services policy change may have the unintended consequence of further increasing inequities in access to transplant among patients at LVAD-only centers

    Discovery of Novel MicroRNAs in Female Reproductive Tract Using Next Generation Sequencing

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    MicroRNAs (miRNAs) are small non-coding RNAs that mediate post-transcriptional gene silencing. Over 700 human miRNAs have currently been identified, many of which are mutated or de-regulated in diseases. Here we report the identification of novel miRNAs through deep sequencing the small RNAome (<30 nt) of over 100 tissues or cell lines derived from human female reproductive organs in both normal and disease states. These specimens include ovarian epithelium and ovarian cancer, endometrium and endometriomas, and uterine myometrium and uterine smooth muscle tumors. Sequence reads not aligning with known miRNAs were each mapped to the genome to extract flanking sequences. These extended sequence regions were folded in silico to identify RNA hairpins. Sequences demonstrating the ability to form a stem loop structure with low minimum free energy (<−25 kcal) and predicted Drosha and Dicer cut sites yielding a mature miRNA sequence matching the actual sequence were considered putative novel miRNAs. Additional confidence was achieved when putative novel hairpins assembled a collection of sequences highly similar to the putative mature miRNA but with heterogeneous 3′-ends. A confirmed novel miRNA fulfilled these criteria and had its “star” sequence in our collection. We found 7 distinct confirmed novel miRNAs, and 51 additional novel miRNAs that represented highly confident predictions but without detectable star sequences. Our novel miRNAs were detectable in multiple samples, but expressed at low levels and not specific to any one tissue or cell type. To date, this study represents the largest set of samples analyzed together to identify novel miRNAs

    ExCyto PCR Amplification

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    ExCyto PCR cells provide a novel and cost effective means to amplify DNA transformed into competent bacterial cells. ExCyto PCR uses host E. coli with a chromosomally integrated gene encoding a thermostable DNA polymerase to accomplish robust, hot-start PCR amplification of cloned sequences without addition of exogenous enzyme.Because the thermostable DNA polymerase is stably integrated into the bacterial chromosome, ExCyto cells can be transformed with a single plasmid or complex library, and then the expressed thermostable DNA polymerase can be used for PCR amplification. We demonstrate that ExCyto cells can be used to amplify DNA from different templates, plasmids with different copy numbers, and master mixes left on ice for up to two hours. Further, PCR amplification with ExCyto cells is comparable to amplification using commercial DNA polymerases. The ability to transform a bacterial strain and use the endogenously expressed protein for PCR has not previously been demonstrated.ExCyto PCR reduces pipetting and greatly increases throughput for screening EST, genomic, BAC, cDNA, or SNP libraries. This technique is also more economical than traditional PCR and thus broadly useful to scientists who utilize analysis of cloned DNAs in their research

    Colors of 2625 Quasars at 0<z<5 Measured in the Sloan Digital Sky Survey Photometric System

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    We present an empirical investigation of the colors of quasars in the Sloan Digital Sky Survey (SDSS) photometric system. The sample studied includes 2625 quasars with SDSS photometry. The quasars are distributed in a 2.5 degree wide stripe centered on the Celestial Equator covering 529\sim529 square degrees. Positions and SDSS magnitudes are given for the 898 quasars known prior to SDSS spectroscopic commissioning. New SDSS quasars represent an increase of over 200% in the number of known quasars in this area of the sky. The ensemble average of the observed colors of quasars in the SDSS passbands are well represented by a power-law continuum with αν=0.5\alpha_{\nu} = -0.5 (fνναf_{\nu} \propto \nu^{\alpha}). However, the contributions of the 3000A˚3000 {\rm \AA} bump and other strong emission lines have a significant effect upon the colors. The color-redshift relation exhibits considerable structure, which may be of use in determining photometric redshifts for quasars. The range of colors can be accounted for by a range in the optical spectral index with a distribution αν=0.5±0.65\alpha_{\nu}=-0.5\pm0.65 (95% confidence), but there is a red tail in the distribution. This tail may be a sign of internal reddening. Finally, we show that there is a continuum of properties between quasars and Seyfert galaxies and we test the validity of the traditional division between the two classes of AGN.Comment: 66 pages, 15 figures (3 color), accepted by A
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