1,380 research outputs found

    Comparison of Best Management Practice Adoption Between Virginia\u27s Chesapeake Bay Basin and Southern Rivers Watersheds

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    Producers in two regions of Virginia (Chesapeake Bay basin and Southern Rivers region) were surveyed to compare farming practices and agricultural best management practice (BMP) adoption. Objectives were to assess farming operations and determine the extent of cost-share and non-cost-share BMP implementation and gain insight into the impact of selected socioeconomic factors on the BMP adoption. Although farming characteristics and producer attitudes toward pollution and water quality were similar, BMP implementation differed between the two regions. Differences in BMP implementation may be due to a more focused, longer-term NPS pollution control educational effort in the Bay basin

    Herbicide Movement and Dissipation at Four Midwestern Sites

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    This study was conducted to evaluate atrazine (2‐chloro‐4‐ethylamino‐6‐isopropyl‐1, 3, 5‐triazine) and alachlor (2‐chIoro‐N‐(methoxymethyl)acetamide) dissipation and movement to shallow aquifers across the Northern Sand Plains region of the United States. Sites were located at Minnesota on a Zimmerman fine sand, North Dakota on Hecla sandy loam, South Dakota on a Brandt silty clay loam, and Wisconsin on a Sparta sand. Herbicide concentrations were determined in soil samples taken to 90 cm four times during the growing season and water samples taken from the top one m of aquifer at least once every three months. Herbicides were detected to a depth of 30 cm in Sparta sand and 90 cm in all other soils. Some aquifer samples from each site contained atrazine with the highest concentration in the aquifer beneath the Sparta sand (1.28 μg L‐1). Alachlor was detected only once in the aquifer at the SD site. The time to 50% atrazine dissipation (DT50) in the top 15 cm of soil averaged about 21 d in Sparta and Zimmerman sands and more than 45 d for Brandt and Hecla soils. Atrazine DT50 was correlated positively with % clay and organic carbon (OC), and negatively with % fine sand. Alachlor DT50 ranged from 12 to 32 d for Zimmerman and Brandt soils, respectively, and was correlated negatively with % clay and OC and positively with % sand

    Proteomics Analysis and Protein Expression during Sporozoite Excystation of Cryptosporidium parvum (Coccidia, Apicomplexa)

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    Cryptosporidiosis, caused by coccidian parasites of the genus Cryptosporidium, is a major cause of human gastrointestinal infections and poses a significant health risk especially to immunocompromised patients. Despite intensive efforts for more than 20 years, there is currently no effective drug treatment against these protozoa. This study examined the zoonotic species Cryptosporidium parvum at two important stages of its life cycle: the non-excysted (transmissive) and excysted (infective) forms. To increase our understanding of the molecular basis of sporozoite excystation, LC-MS/MS coupling with a stable isotope N-terminal labeling strategy using iTRAQ (TM) reagents was used on soluble fractions of both non-excysted and excysted sporozoites, i.e. sporozoites both inside and outside oocysts were examined. Sporozoites are the infective stage that penetrates small intestinal enterocytes. Also to increase our knowledge of the C. parvum proteome, shotgun sequencing was performed on insoluble fractions from both non-excysted and excysted sporozoites. In total 303 C. parvum proteins were identified, 56 of which, hitherto described as being only hypothetical proteins, are expressed in both excysted and non-excysted sporozoites. Importantly we demonstrated that the expression of 26 proteins increases significantly during excystation. These excystation-induced proteins included ribosomal proteins, metabolic enzymes, and heat shock proteins. Interestingly three Apicomplexa-specific proteins and five Cryptosporidium-specific proteins augmented in excysted invasive sporozoites. These eight proteins represent promising targets for developing vaccines or chemotherapies that could block parasite entry into host cells

    Identification of a bone morphogenetic protein type 2 receptor neutralizing antibody

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    The bone morphogenetic protein (BMP) signaling pathway comprises the largest subdivision of the transforming growth factor (TGFβ) superfamily. BMP signaling plays essential roles in both embryonic development and postnatal tissue homeostasis. Dysregulated BMP signaling underlies human pathologies ranging from pulmonary arterial hypertension to heterotopic ossification. Thus, understanding the basic mechanisms and regulation of BMP signaling may yield translational opportunities. Unfortunately, limited tools are available to evaluate this pathway, and genetic approaches are frequently confounded by developmental requirements or ability of pathway components to compensate for one another. Specific inhibitors for type 2 receptors are poorly represented. Thus, we sought to identify and validate an antibody that neutralizes the ligand-binding function of BMP receptor type 2 (BMPR2) extracellular domain (ECD)

    Loss of the Nutrient Sensor Tas1R3 Leads to Reduced Bone Resorption

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    Background: The Taste receptor, type 1 (TAS1R) family of heterotrimeric G protein-coupled receptors participates in monitoring energy and nutrient needs. TAS1R member 3 (TAS1R3) either recognizes amino acids such as glycine and L-glutamate or sweet molecules such as sucrose and fructose when dimerized with TAS1R member 1 (TAS1R1) or TAS1R member 2 (TAS1R2), respectively. Loss of TAS1R3 expression can cause impaired mTORC1 signaling and increased autophagy, indicating that signaling through this receptor is critical for assessing nutrient needs. Recently, it was reported that global deletion of TAS1R3 expression in Tas1R3 mutant mice leads to increased cortical bone mass and trabecular remodeling but the underlying cellular mechanism leading to this phenotype remains unclear. Results: To address this open question, we quantified bone turnover markers in serum from 20-week-old wild type and Tas1R3 mutant mice and found that levels of the resorption marker Collagen Type I C-telopeptide (CTx) were reduced on average by \u3e60% in the absence of TAS1R3 expression. Levels of the bone formation marker Procollagen Type I N-terminal Propeptide (P1NP) tend to be higher in Tas1R3 mutant mice but this finding did not reach statistical significance (
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