151 research outputs found

    System And Process For Integrative Computational Soil Mapping

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    An integrative computational soil mapping system and process that reduces the required number of soil property measurements without jeopardizing the statistical precision of the resulting digital soil maps. The integrative computational soil mapping system and process saves monetary resources and time by reducing the number of soil property measurements required to produce digital soil maps and by offering soil sample locations which capture the maximum amount of representativeness of the soil characteristics in a determined area. In addition, the inventive system and process are integrative computational soil mapping that utilize algorithms based on state-of-the-art computational statistics and machine learning methods for the production of digital soil property maps and also provides soil sampling locations to collect new soil property measurements. These soil property measurements can be used to update and potentially improve previous versions of digital soil property maps, produced by the computational process

    System And Process For Integrative Computational Soil Mapping

    Get PDF
    An integrative computational soil mapping system and process that reduces the required number of soil property measurements without jeopardizing the statistical precision of the resulting digital soil maps. The integrative computational soil mapping system and process saves monetary resources and time by reducing the number of soil property measurements required to produce digital soil maps and by offering soil sample locations which capture the maximum amount of representativeness of the soil characteristics in a determined area. In addition, the inventive system and process are integrative computational soil mapping that utilize algorithms based on state-of-the-art computational statistics and machine learning methods for the production of digital soil property maps and also provides soil sampling locations to collect new soil property measurements. These soil property measurements can be used to update and potentially improve previous versions of digital soil property maps, produced by the computational process

    Microparticles in Hemostasis and Thrombosis

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    Blood contains microparticles (MPs) derived from a variety of cell types, including platelets, monocytes and endothelial cells. In addition, tumors release MPs into the circulation. MPs are formed from membrane blebs that are released from the cell surface by proteolytic cleavage of the cytoskeleton. All MPs are procoagulant because they provide a membrane surface for the assembly of components of the coagulation protease cascade. Importantly, the procoagulant activity is increased by the presence of anionic phospholipids, particularly phosphatidylserine (PS), and the procoagulant protein tissue factor (TF), which is the major cellular activator of the clotting cascade. High levels of platelet-derived PS+ MPs are present in healthy individuals, whereas the number of TF+,PS+ MPs is undetectable or very low. However, levels of PS+, TF+ MPs are readily detected in a variety of diseases and monocytes appear to be the primary cellular source. In cancer, PS+, TF+ are derived from tumors and may serve as a useful biomarker to identify patients at risk for venous thrombosis. This review will summarize our current knowledge on the role of procoagulant MPs in hemostasis and thrombosis

    Tissue factor and thrombosis: The clot starts here

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    Thrombosis, or complications from thrombosis, currently occupies the top three positions in the cardiovascular causes of morbidity and mortality in the developed world. There are a limited number of safe and effective drugs to prevent and treat thrombosis. Animal models of thrombosis are necessary to better understand the complex components and interactions involved in the formation of a clot. Tissue factor (TF) is required for the initiation of blood coagulation and likely plays a key role in both arterial and venous thrombosis. Understanding the role of TF in thrombosis may permit the development of new antithrombotic drugs. This review will focus on the role of TF in in vivo models of thrombosis

    Regional Variation in Aortic AT1b Receptor mRNA Abundance Is Associated with Contractility but Unrelated to Atherosclerosis and Aortic Aneurysms

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    BACKGROUND: Angiotensin II (AngII), the main bioactive peptide of the renin angiotensin system, exerts most of its biological actions through stimulation of AngII type 1 (AT1) receptors. This receptor is expressed as 2 structurally similar subtypes in rodents, termed AT1a and AT1b. Although AT1a receptors have been studied comprehensively, roles of AT1b receptors in the aorta have not been defined. METHODOLOGY/RESULTS: We initially compared the regional distribution of AT1b receptor mRNA with AT1a receptor mRNA in the aorta. mRNA abundance of both subtypes increased from the proximal to the distal aorta, with the greatest abundance in the infra-renal region. Corresponding to the high mRNA abundance for both receptors, only aortic rings from the infra-renal aorta contracted in response to AngII stimulation. Despite the presence of both receptor transcripts, deletion of AT1b receptors, but not AT1a receptors, diminished AngII-induced contractility. To determine whether absence of AT1b receptors influenced aortic pathologies, we bred AT1b receptor deficient mice into an LDL receptor deficient background. Mice were fed a diet enriched in saturated fat and infused with AngII (1,000 ng/kg/min). Parameters that could influence development of aortic pathologies, including systolic blood pressure and plasma cholesterol concentrations, were not impacted by AT1b receptor deficiency. Absence of AT1b receptors also had no effect on size of aortic atherosclerotic lesions and aortic aneurysms in both the ascending and abdominal regions. CONCLUSIONS/SIGNIFICANCE: Regional abundance of AT1b receptor mRNA coincided with AngII-induced regional contractility, but it was not associated with AngII-induced aortic pathologies

    Prognostic Value of D-Dimer and Markers of Coagulation for Stratification of Abdominal Aortic Aneurysm growth

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    Abdominal aortic aneurysm (AAA) is associated with high morbidity and mortality and is an established cause of unbalanced hemostasis. A number of hemostatic biomarkers have been associated with AAA; however, the utility of hemostatic biomarkers in AAA diagnosis and prognosis is unclear. The aim of the present study was to characterize the potential prognostic value of D-dimer and markers of altered hemostasis in a large cohort of patients with AAAs characterized by either fast or slow aneurysm growth (frequency matched for baseline diameter) and subaneurysmal dilations. We measured plasma concentrations of thrombin-antithrombin (TAT) complex, platelet factor 4 (PF4), and D-dimer in 352 patients with either fast-growing AAAs (.2 mm/y), slow-growing AAAs (,2 mm/y), subaneurysmal aortic dilations, or nonaneurysmal aortas. Plasma D-dimer and TAT were significantly elevated in both AAA and subaneurysmal dilation patients compared with controls. Individuals with D-dimer levels $500 ng/mL had 3.09 times the odds of subaneurysms, 6.23 times the odds of slow-growing AAAs, and 7.19 times the odds of fast-growing AAAs than individuals with D-dimer level,500 ng/mL. However, no differences in D-dimer concentration were noted between fast- and slow-growing aneurysms. Plasma D-dimer and TAT were strong independent predictors of AAA growth rate with multivariate analysis revealing a 500-ng/mL increase in D-dimer or 1-mg/mL increase in TAT led to additional 0.21-mm and 0.24-mm changes in aortic diameter per year, respectively. Rising levels of plasma TAT, in addition to D-dimer, may predict disease progression and aneurysm growth in patients with AAA or subaneurysmal dilation

    Dietary Choline Supplementation Attenuates High-Fat-Diet-Induced Hepatocellular Carcinoma in Mice

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    Background: Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death in the world. Choline deficiency has been well studied in the context of liver disease; however, less is known about the effects of choline supplementation in HCC. Objective: The objective of this study was to test whether choline supplementation could influence the progression of HCC in a high-fat-diet (HFD)-driven mouse model. Methods: Four-day-old male C57BL/6J mice were treated with the chemical carcinogen, 7,12-dimethylbenz[a]anthracene, and were randomly assigned at weaning to a cohort fed an HFD (60% kcal fat) or an HFD with supplemental choline (60% kcal fat, 1.2% choline; HFD+C) for 30 wk. Blood was isolated at 15 and 30 wk to measure immune cells by flow cytometry, and glucose-tolerance tests were performed 2 wk prior to killing. Overall tumor burden was quantified, hepatic lipids were measured enzymatically, and phosphatidylcholine species were measured by targeted MS methods. Gene expression and mitochondrial DNA were quantified by quantitative PCR. Results: HFD+C mice exhibited a 50-90% increase in both circulating choline and betaine concentrations in the fed state (P ≤ 0.05). Choline supplementation resulted in a 55% decrease in total tumor numbers, a 67% decrease in tumor surface area, and a 50% decrease in hepatic steatosis after 30 wk of diet (P ≤ 0.05). Choline supplementation increased the abundance of mitochondria and the relative expression of β-oxidation genes by 21% and ∼75-100%, respectively, in the liver. HFD+C attenuated circulating myeloid-derived suppressor cells at 15 wk of feeding (P ≤ 0.05). Conclusions: Choline supplementation attenuated HFD-induced HCC and hepatic steatosis in male C57BL/6J mice. These results suggest a therapeutic benefit of choline supplementation in blunting HCC progression

    Hepatocyte tissue factor contributes to the hypercoagulable state in a mouse model of chronic liver injury

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    Patients with chronic liver disease and cirrhosis have a dysregulated coagulation system and are prone to thrombosis. The basis for this hypercoagulable state is not completely understood. Tissue factor (TF) is the primary initiator of coagulation in vivo. Patients with cirrhosis have increased TF activity in white blood cells and circulating microparticles. The aim of our study was to determine the contribution of TF to the hypercoagulable state in a mouse model of chronic liver injury

    Endothelial Shc Regulates Arteriogenesis Through Dual Control of Arterial Specification and Inflammation via the Notch and Nuclear Factor- -Light-Chain-Enhancer of Activated B-Cell Pathways

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    Arteriogenesis, the shear stress-driven remodeling of collateral arteries, is critical in restoring blood flow to ischemic tissue following a vascular occlusion. Our previous work has shown that the adaptor protein Shc mediates endothelial responses to shear stress in vitro
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