1,979 research outputs found

    Improvement of Tractor Performance

    Get PDF
    Improvement of agricultural tractor performance was analyzed using the data from 926 diesel tractors tested at the Nebraska Tractor Test Laboratory from 1959 through 2002. The performance analysis included the specific volumetric fuel consumption, power per unit weight, traction coefficient, maximum torque rise, and sound level. They were evaluated based on the PTO power level and chassis type of tractor. Some of the results are: (1) The average specific volumetric fuel consumptions for the maximum PTO and drawbar powers increased by 20.5% and 23.4% to 3.47 kW•h/L and 3.01 kW•h/L, respectively, from 1959 through 2002. (2) The average maximum PTO and drawbar powers per unit weight of ballasted tractors increased 72.1% and 66.2% to 1.48 and 1.28 kW/kN from 1959 through 2002. (3) The traction coefficient increased 24.4% for 4WD tractors and 27.4% for standard tractors from 1959 through 2002, resulting in 1.02 and 0.94 for 2001-2002 respectively. In the 2001-2002 period, the average torque rise of the tractors in a PTO power range of 37-75 kW was 27.7%, which was 18.4% increase from 1992 through 2002. The tractors with greater PTO power than 187 kW had an average torque rise of 50.8%, which was 30.9% increase over the same period. The maximum sound level within the cab in the early 1970’s ranged from 83.0 to 93.6 dBA and reduced to 73.5 to 88.5 dBA in the 2001-2002 period, which was about 9.3% to 21.5% reduction from 1972 through 2002

    Improvement of Tractor Performance

    Get PDF
    Improvement of agricultural tractor performance was analyzed using the data from 926 diesel tractors tested at the Nebraska Tractor Test Laboratory from 1959 through 2002. The performance analysis included the specific volumetric fuel consumption, power per unit weight, traction coefficient, maximum torque rise, and sound level. They were evaluated based on the PTO power level and chassis type of tractor. Some of the results are: (1) The average specific volumetric fuel consumptions for the maximum PTO and drawbar powers increased by 20.5% and 23.4% to 3.47 kW•h/L and 3.01 kW•h/L, respectively, from 1959 through 2002. (2) The average maximum PTO and drawbar powers per unit weight of ballasted tractors increased 72.1% and 66.2% to 1.48 and 1.28 kW/kN from 1959 through 2002. (3) The traction coefficient increased 24.4% for 4WD tractors and 27.4% for standard tractors from 1959 through 2002, resulting in 1.02 and 0.94 for 2001-2002 respectively. In the 2001-2002 period, the average torque rise of the tractors in a PTO power range of 37-75 kW was 27.7%, which was 18.4% increase from 1992 through 2002. The tractors with greater PTO power than 187 kW had an average torque rise of 50.8%, which was 30.9% increase over the same period. The maximum sound level within the cab in the early 1970’s ranged from 83.0 to 93.6 dBA and reduced to 73.5 to 88.5 dBA in the 2001-2002 period, which was about 9.3% to 21.5% reduction from 1972 through 2002

    In Silico Derivation of HLA-Specific Alloreactivity Potential from Whole Exome Sequencing of Stem Cell Transplant Donors and Recipients: Understanding the Quantitative Immuno-biology of Allogeneic Transplantation

    Get PDF
    Donor T cell mediated graft vs. host effects may result from the aggregate alloreactivity to minor histocompatibility antigens (mHA) presented by the HLA in each donor-recipient pair (DRP) undergoing stem cell transplantation (SCT). Whole exome sequencing has demonstrated extensive nucleotide sequence variation in HLA-matched DRP. Non-synonymous single nucleotide polymorphisms (nsSNPs) in the GVH direction (polymorphisms present in recipient and absent in donor) were identified in 4 HLA-matched related and 5 unrelated DRP. The nucleotide sequence flanking each SNP was obtained utilizing the ANNOVAR software package. All possible nonameric-peptides encoded by the non-synonymous SNP were then interrogated in-silico for their likelihood to be presented by the HLA class I molecules in individual DRP, using the Immune-Epitope Database (IEDB) SMM algorithm. The IEDB-SMM algorithm predicted a median 18,396 peptides/DRP which bound HLA with an IC50 of <500nM, and 2254 peptides/DRP with an IC50 of <50nM. Unrelated donors generally had higher numbers of peptides presented by the HLA. A similarly large library of presented peptides was identified when the data was interrogated using the Net MHCPan algorithm. These peptides were uniformly distributed in the various organ systems. The bioinformatic algorithm presented here demonstrates that there may be a high level of minor histocompatibility antigen variation in HLA-matched individuals, constituting an HLA-specific alloreactivity potential. These data provide a possible explanation for how relatively minor adjustments in GVHD prophylaxis yield relatively similar outcomes in HLA matched and mismatched SCT recipients.Comment: Abstract: 235, Words: 6422, Figures: 7, Tables: 3, Supplementary figures: 2, Supplementary tables:

    Managing hyperglycaemia during antenatal steroid administration, labour and birth in pregnant women with diabetes

    Get PDF
    Optimal glycaemic control before and during pregnancy improves both maternal and fetal outcomes. This article summarizes the recently published guidelines on the management of glycaemic control in pregnant women with diabetes on obstetric wards and delivery units produced by the Joint British Diabetes Societies for Inpatient Care and available in full at www.diabetes.org.uk/joint-british-diabetes-society and https://abcd.care/joint-british-diabetes-societies-jbds-inpatient-care-group. Hyperglycaemia following steroid administration can be managed by variable rate intravenous insulin infusion (VRIII) or continuous subcutaneous insulin infusion (CSII) in women who are willing and able to safely self‐manage insulin dose adjustment. All women with diabetes should have capillary blood glucose (CBG) measured hourly once they are in established labour. Those who are found to be higher than 7 mmol/l on two consecutive occasions should be started on VRIII. If general anaesthesia is used, CBG should be monitored every 30 min in the theatre. Both the VRIII and CSII rate should be reduced by at least 50% once the placenta is delivered. The insulin dose needed after delivery in insulin‐treated Type 2 and Type 1 diabetes is usually 25% less than the doses needed at the end of first trimester. Additional snacks may be needed after delivery especially if breastfeeding. Stop all anti‐diabetes medications after delivery in gestational diabetes. Continue to monitor CBG before and 1 h after meals for up to 24 h after delivery to pick up any pre‐existing diabetes or new‐onset diabetes in pregnancy. Women with Type 2 diabetes on oral treatment can continue to take metformin after birth

    Manifolds with 1/4-pinched flag curvature

    Get PDF
    We say that a nonnegatively curved manifold (M,g)(M,g) has quarter pinched flag curvature if for any two planes which intersect in a line the ratio of their sectional curvature is bounded above by 4. We show that these manifolds have nonnegative complex sectional curvature. By combining with a theorem of Brendle and Schoen it follows that any positively curved manifold with strictly quarter pinched flag curvature must be a space form. This in turn generalizes a result of Andrews and Nguyen in dimension 4. For odd dimensional manifolds we obtain results for the case that the flag curvature is pinched with some constant below one quarter, one of which generalizes a recent work of Petersen and Tao

    Review of the Tuberous Sclerosis Renal Guidelines from the 2012 Consensus Conference: Current Data and Future Study.

    Get PDF
    Renal-related disease is the most common cause of tuberous sclerosis complex (TSC)-related death in adults, and renal angiomyolipomas can lead to complications that include chronic kidney disease (CKD) and hemorrhage. International TSC guidelines recommend mammalian target of rapamycin (mTOR) inhibitors as first-line therapy for management of asymptomatic, growing angiomyolipomas >3 cm in diameter. This review discusses data regarding patient outcomes that were used to develop current guidelines for embolization of renal angiomyolipomas and presents recent data on 2 available mTOR inhibitors - sirolimus and everolimus - in the treatment of angiomyolipoma. TSC-associated renal angiomyolipomas can recur after embolization. Both sirolimus and everolimus have shown effectiveness in reduction of angiomyolipoma volume, with an acceptable safety profile that includes preservation of renal function with long-term therapy. The authors propose a hypothesis for mTORC1 haploinsufficiency as an additional mechanism for CKD and propose that preventive therapy with mTOR inhibitors might have a role in reducing the number of angiomyolipoma-related deaths. Because mTOR inhibitors target the underlying pathophysiology of TSC, patients might benefit from treatment of multiple manifestations with one systemic therapy. Based on recent evidence, new guidelines should be considered that support the earlier initiation of mTOR inhibitor therapy for the management of renal angiomyolipomas to prevent future serious complications, rather than try to rescue patients after the complications have occurred

    The Morphometric Synthesis for landmarks and edge-elements in images

    Full text link
    Over the last decade, techniques from mathematical statistics, multivariate biometrics, non-Euclidean geometry, and computer graphics have been combined in a coherent new system of tools for the biometric analysis of landmarks , or labelled points, along with the biological images in which they are seen. Multivariate analyses of samples for all the usual scientific purposes - description of mean shapes, of shape variation, and of the covariation of shape with size, group, or other causes or effects - may be carried out very effectively in the tangent space to David Kendall's shape space at the Procrustes average shape. For biometric interpretation of such analyses, we need a basis for the tangent space that is Procrustes-orthonormal, and we need graphics for visualizing mean shape differences and other segments and vectors there; both of these needs are managed by the thin-plate spline. The spline also links the biometrics of landmarks to deformation analysis of curves in the images from which the landmarks originally arose. This article reviews the principal tools of this synthesis in a typical study design involving landmarks and edge information from a microfossil.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75091/1/j.1365-3121.1995.tb00535.x.pd

    Clinical practice. Diagnosis and treatment of cow’s milk allergy

    Get PDF
    Introduction Cow's milk allergy (CMA) is thought to affect 2-3% of infants. The signs and symptoms are nonspecific and may be difficult to objectify, and as the diagnosis requires cow's milk elimination followed by challenge, often, children are considered cow's milk allergic without proven diagnosis. Diagnosis Because of the consequences, a correct diagnosis of CMA is pivotal. Open challenges tend to overestimate the number of children with CMA. The only reliable way to diagnose CMA is by double-blind, placebo-controlled challenge (DBPCFC). Therapy At present, the only proven treatment consists of elimination of cow's milk protein from the child's diet and the introduction of formulas based on extensively hydrolysed whey protein or casein; amino acid-based formula is rarely indicated. The majority of children will regain tolerance to cow's milk within the first 5 years of life. Conclusions Open challenges can be used to reject CMA, but for adequate diagnosis, DBPCFC is mandatory. In most children, CMA can be adequately treated with extensively hydrolysed whey protein or casein formulas

    Analytic frameworks for assessing dialogic argumentation in online learning environments

    Get PDF
    Over the last decade, researchers have developed sophisticated online learning environments to support students engaging in argumentation. This review first considers the range of functionalities incorporated within these online environments. The review then presents five categories of analytic frameworks focusing on (1) formal argumentation structure, (2) normative quality, (3) nature and function of contributions within the dialog, (4) epistemic nature of reasoning, and (5) patterns and trajectories of participant interaction. Example analytic frameworks from each category are presented in detail rich enough to illustrate their nature and structure. This rich detail is intended to facilitate researchers’ identification of possible frameworks to draw upon in developing or adopting analytic methods for their own work. Each framework is applied to a shared segment of student dialog to facilitate this illustration and comparison process. Synthetic discussions of each category consider the frameworks in light of the underlying theoretical perspectives on argumentation, pedagogical goals, and online environmental structures. Ultimately the review underscores the diversity of perspectives represented in this research, the importance of clearly specifying theoretical and environmental commitments throughout the process of developing or adopting an analytic framework, and the role of analytic frameworks in the future development of online learning environments for argumentation
    corecore