Evaluation and Demonstration of BMPs for Cattle on Grazing Lands for the Lone Star Healthy Streams Program

According to the 2008 Texas Water Quality Inventory and 303(d) List, recreation is impaired in 274 waterbody segments and oyster harvest is impaired in another 21 due to bacteria. One of the primary strategies for reducing bacteria in many of these waterbodies is to provide technical and financial assistance to implement best management practices (BMPs) to reduce bacteria runoff from cattle on grazing lands. In order to inspire behavior change, evaluations and demonstrations of BMP effectiveness are needed to encourage voluntary implementation of BMPs and participation in federal and state technical and financial assistance programs designed to reduce bacterial runoff ultimately improve water quality. The goal of this project was to reduce bacterial contamination caused by grazing livestock in Texas waterbodies through evaluation and demonstration of BMP effectiveness in reducing bacteria runoff from grazing lands. This BMP effectiveness data then served as the scientific-basis for the Lone Star Healthy Streams education program (grazing cattle component). Lone Star Healthy Streams programs and other outreach and technology transfer were utilized to increase voluntary implementation of BMPs and participation in federal and state technical and financial assistance programs by providing landowners with feasible options for addressing sources of bacteria through education programs based on the evaluation and demonstration of BMP effectiveness

Using Stockpiled Warm-Season Perennial Grasses for Fall and Winter Grazing in East Texas

Last updated: 6/12/200

Yield estimates for alfalfa following four years of on-farm production research

Last updated: 6/1/200

Lucerne Production and Economics on Stakeholder Ranches on Coastal Plain Acid Soils

Research using small plots determined factors restricting lucerne (Medicago sativa) production on Coastal Plain soils of the southern USA. These acid soils, primarily Ultisols and Alfisols, become deficient in B when limed to pH 6.8 or 7.0 for lucerne. Other production-limiting soil problems include poor drainage and aeration, subsoil acidity, and low natural fertility. The objective of this study was to evaluate stand longevity on hectare-size stakeholder fields when growth-limiting factors were eliminated by site selection and soil treatment

Environmental Management of Grazing Lands

Bacteria levels are the number one cause of water quality impairment in Texas. Several recent Total Maximum Daily Loads (TMDLs) in Texas, such as those implemented in the Peach Creek and Leon River watersheds, have identified grazing cattle as a contributor to bacterial water quality impairments in those watersheds through both direct deposition and runoff of their fecal matter to streams. To address this issue, the Texas State Soil and Water Conservation Board (TSSWCB) and the Natural Resources Conservation Service (NRCS) funded this project to assist with development and delivery of technical information and support to ranchers on protection and enhancement of the functions and values of grasslands. A number of best management practices (BMPs) have been identified to reduce bacteria runoff from grazing lands and direct deposition into streams. The primary focus of these BMPs is to maintain adequate ground cover and minimize concentrated livestock areas, especially on sensitive areas such as riparian areas. Maintaining adequate ground cover and plant density improves the filtering capacity of the vegetation and enhances water infiltration into the soil. Minimizing concentrated livestock areas, trailing, and trampling reduces soil compaction, reduces excess runoff and subsequent soil erosion, and enhances fecal matter distribution and ground cover. Specific BMPs identified include grazing management, fencing, alternate water sources, hardened watering points, controlled access, supplemental feed placement, and shade or cover manipulation (NRCS 2007). This project accomplished several objectives, including: 1) compiling existing information on environmental management of grazing lands, 2) evaluating and demonstrating the effectiveness of proper grazing management in reducing bacterial runoff from grazing lands, 3) initiating evaluation of the effect of complementary practices (i.e. alternative water supplies and shade) on cattle behavior and stream water quality, and 4) promoting adoption of appropriate grazing land management practices. Evaluation and demonstration of the effect of grazing management on bacteria runoff at the USDA-ARS Riesel Watersheds has produced some interesting results. The site mean concentration of E. coli (i.e. flow weighted concentration) at the ungrazed native prairie site was surprisingly high (1.0E+04 cfu/100 ml), greatly exceeding the Texas Surface Water Quality Standards single sample standard for E. coli (394 cfu/100 ml) as well as the geometric mean (126 cfu/100 ml). It is important to note that these standards apply to waterbodies, such as streams and reservoirs, but not to edge-of-field runoff as described here. Also, the E. coli concentration seen in the runoff from the moderately grazed bermudagrass site (2.3E+04 cfu/100 ml) was significantly higher (more than double) than that observed at the native prairie site. These levels, however, are consistent with the findings of other researchers. The pre-BMP implementation evaluation of the effectiveness of alternative water supplies and shade on cattle behavior and stream water quality (E. coli) has been completed at the 2S Ranch, near Lockhart. This evaluation showed that when alternative water was not available, E. coli levels increased as the stream flowed through the ranch. Quarterly evaluation of cattle behavior using GPS collars indicated cattle spent only 4.5% of the time within 35 feet of the stream when alternative water was not available. When alternative water was provided, however, this percent time that cattle spent within 35 feet of the stream was reduced to 1.1%, a 75% reduction. This reduction is consistent with the findings of other researchers. Post-BMP evaluation has been initiated and will continue for another year now that alternative water and shade has been provided. Much was done through this project to increase awareness of the bacteria issue and BMPs to address them. AgriLife Extension and TWRI developed fact sheets, provided posters and presentations, conducted site tours, and developed a Web site to help disseminate information. These outreach activities reached local, state, and national audiences. The Web site alone has reached 539 unique visitors during the project. Much is left to do, however. Evaluation of grazing management, alternative water supplies, and shade will continue. Data on other practices (i.e. using rip-rap to reduce access to riparian areas, providing controlled access points, etc.) and groups of practices is still needed to provide cattlemen with a “toolbox” for addressing the bacteria issue. Modification of water quality standards may also be appropriate to address the high levels of E. coli found in runoff from ungrazed sites. Education programs need to be conducted state- and nation-wide to assist cattlemen in addressing bacteria issues

Proinflammatory Cytokines Activate the Intrinsic Apoptotic Pathway in β-Cells

OBJECTIVE:Proinflammatory cytokines are cytotoxic to beta-cells and have been implicated in the pathogenesis of type 1 diabetes and islet graft failure. The importance of the intrinsic mitochondrial apoptotic pathway in cytokine-induced beta-cell death is unclear. Here, cytokine activation of the intrinsic apoptotic pathway and the role of the two proapoptotic Bcl-2 proteins, Bad and Bax, were examined in beta-cells.RESEARCH DESIGN AND METHODS:Human and rat islets and INS-1 cells were exposed to a combination of proinflammatory cytokines (interleukin-1beta, interferon-gamma, and/or tumor necrosis factor-alpha). Activation of Bad was determined by Ser136 dephosphorylation, mitochondrial stress by changes in mitochondrial metabolic activity and cytochrome c release, downstream apoptotic signaling by activation of caspase-9 and -3, and DNA fragmentation. The inhibitors FK506 and V5 were used to investigate the role of Bad and Bax activation, respectively. [...

Polar cap hot patches: enhanced density structures different from the classical patches in the ionosphere

Based on in situ and ground-based observations, a new type of “polar cap hot patch” has been identified that is different from the classical polar cap enhanced density structure (cold patches). Comparing with the classical polar cap patches, which are transported from the dayside sunlit region with dense and cold plasma, the polar cap hot patches are associated with particle precipitations (therefore field-aligned currents), ion upflows, and flow shears. The hot patches may have the same order of density enhancement as classical patches in the topside ionosphere, suggesting that the hot patches may be produced by transported photoionization plasma into flow channels. Within the flow channels, the hot patches have low-energy particle precipitation and/or ion upflows associated with field-aligned currents and flow shears. Corresponding Global Navigation Satellite System (GNSS) signal scintillation measurements indicate that hot patches may produce slightly stronger radio signal scintillation in the polar cap region than classical patches. A new type of polar cap patches, “polar cap hot patches,” is identified to differentiate enhanced density structures from classical patches. Hot patches are associated with particle precipitations, ion upflows, field-aligned currents, and shear flows in the polar cap. Hot patches may lead to slightly stronger ionospheric scintillations of GNSS signals in the polar cap region than classical patches

Transgenic Overexpression of Active Calcineurin in β-Cells Results in Decreased β-Cell Mass and Hyperglycemia

BACKGROUND:Glucose modulates beta-cell mass and function through an initial depolarization and Ca(2+) influx, which then triggers a number of growth regulating signaling pathways. One of the most important downstream effectors in Ca(2+) signaling is the calcium/Calmodulin activated serine threonine phosphatase, calcineurin. Recent evidence suggests that calcineurin/NFAT is essential for beta-cell proliferation, and that in its absence loss of beta-cells results in diabetes. We hypothesized that in contrast, activation of calcineurin might result in expansion of beta-cell mass and resistance to diabetes. METHODOLOGY/PRINCIPAL FINDINGS:To determine the role of activation of calcineurin signaling in the regulation of pancreatic beta-cell mass and proliferation, we created mice that expressed a constitutively active form of calcineurin under the insulin gene promoter (caCn(RIP)). To our surprise, these mice exhibited glucose intolerance. In vitro studies demonstrated that while the second phase of Insulin secretion is enhanced, the overall insulin secretory response was conserved. Islet morphometric studies demonstrated decreased beta-cell mass suggesting that this was a major component responsible for altered Insulin secretion and glucose intolerance in caCn(RIP) mice. The reduced beta-cell mass was accompanied by decreased proliferation and enhanced apoptosis. CONCLUSIONS:Our studies identify calcineurin as an important factor in controlling glucose homeostasis and indicate that chronic depolarization leading to increased calcineurin activity may contribute, along with other genetic and environmental factors, to beta-cell dysfunction and diabetes