109 research outputs found
Development of Forage Curriculum for Extension Educators in the Southeast USA
In the Southeast USA, livestock production is one of the largest agricultural activities, and forages are the primary feed source. Most livestock systems are highly dependent on off-farm inputs to support forage production and animal performance, which elevates production costs and the activity\u27s carbon footprint. There is a strong need to develop forage educational resources to enhance productivity, environmental sustainability, resilience, and profitability of agricultural systems in the region. This multi-disciplinary initiative was a collaboration among several land-grant Universities across the region. The objective was to develop decision tools and provide in-classroom training associated with hands-on demonstrations to Extension agents and agricultural educators in the Southeast. A textbook was developed for the two-day training, and the in-person program was held in Columbiana, AL, through a collaboration among 20 Specialists from several land-grant Universities. The book included basic concepts and management strategies for forages, livestock (e.g., beef, horse, small ruminants), soil, economics, nutrient management, animal genetics, and marketing strategies for forage-based systems. There were 62 participants from Alabama, Florida, Georgia, Louisiana, North Carolina, South Carolina, and Tennessee. The majority of the participants were Extension agents or educators, and close to half of them had been in the job position for less than five years (n= 28 participants). A significant emphasis was set on newer agents` participation aiming to allow them to address gaps in knowledge. The training sessions supported critical thinking and deepening of knowledge and network. Post-training surveys were applied to gather change in knowledge and feedback from participants and identify potential barriers to be used in structuring future curriculum development and trainings. Regional joint efforts can be a tool to address multi-disciplinary training while incentivizing collaboration across regions for Specialists and agents through their programming activities
Farmer Experiences With Alfalfa in the Southern U.S.A.
Alfalfa (Medicago sativa L.) is a forage crop of primary importance in the United States (USA); however, adoption and use in the southern USA region has been limited. The combination of adapted alfalfa cultivars and management strategies which demonstrate extended forage growing season length, improved forage nutritive value, and reduced N fertilizer inputs have renewed interest in forage-livestock farmers to consider planting alfalfa. A series of Extension-based educational strategies have been used in the southern USA to 1) create awareness on the use of alfalfa, 2) educate farmers regarding establishment and management practices, and 3) showcase opportunities and challenges of on-farm alfalfa use in the region. Educational initiatives included on-farm demonstrations and farmer testimonials, field days, integrated lecture and field-based workshops, and web-based content delivery. Across multiple educational methods, farmers reported increased awareness and understanding of management requirements to incorporate alfalfa into their operation. However, on-farm management challenges were also noted as the primary reason of hesitance towards adopting alfalfa in the region. Targeted education to farmers with a greater level of familiarity regarding stand management requirements, such as dedicated hay growers or row crop operators, were identified as audiences where alfalfa may be more readily adopted. Continuing education areas to demonstrate value of alfalfa include an emphasis on timeline for breakeven economic returns following establishment and ecosystem benefits of using legumes in forage management systems
In Vitro Methane Production from Heifers Offered Four Bermudagrass Cultivars
Though bermudagrass (Cynodon dactylon [L.] Pers.) is one of the predominant warm-season perennial forage supporting the southeastern United States livestock production systems, little is known about its influence on parameters of ruminal metabolism, including carbon loss as methane. With the multitude of cultivars of this grass that have been developed and released, one may question whether the physiological cultivar differences will manifest varying results in digestive efficiency and subsequent methane emissions. Thus, the objective of this study was to evaluate in vitro methane (CH4) production as influenced by four bermudagrass cultivars. Ruminally-fistulated heifers (n = 4) were assigned randomly to one of four bermudagrass cultivars (Coastal [COS], Russell [RUS], Tifton 44 [T44], or Tifton 85 [T85]) for four 30-d in vivo periods in a Latin square design. On d 28 of each period, rumen fluid was collected from each heifer for use in CH4 production evaluation. Samples of each bermudagrass, corresponding to the cultivar fed, were weighed into duplicate 10-mL serum bottles and incubated at 39°C for 0, 2, 4, and 24 h. Following incubation, headspace samples were assayed for CH4 concentrations by gas chromatography. There was an interaction of cultivar and time (P \u3c 0.01). There was no difference among cultivars (P \u3c 0.05) at 0, 2, or 4 h of incubation. After 24 h of incubation, however, CH4 concentrations were greater (P \u3c 0.05) from T44 and T85 (7.7 and 6.2 mmol/L, respectively) than from RUS and COS (3.4 and 3.0 mmol/L, respectively). Results are interpreted to mean that cultivar type has an influence on the potential CH4 production of bermudagrass
Public Good Overprovision by a Manipulative Provider
We study contracting between a public good provider and users with private valuations of the good. We show that, once the provider extracts the users' private information, she benefits from manipulating the collective information received from all users when communicating with them. We derive conditions under which such manipulation determines the direction of distortions in public good provision. If the provider is non-manipulative, the public good is always underprovided, whereas overprovision occurs with a manipulative provider. With overprovision, not only high-valuation users, but also low-valuation users may obtain positive rents—users may prefer facing a manipulative provider.Peer Reviewe
Tribute to Professor Doug Rendleman
A tribute to Professor Doug Rendleman, who served on the faculty of the Washington and Lee University School of Law from 1988 to 2020. Rendleman became Professor of Law, Emeritus in 2020
Judge Jack B. Weinstein, Tort Litigation, and the Public Good: A Roundtable Discussion to Honor One of America\u27s Great Trial Judges on the Occasion of his 80th Birthday
Herbage Accumulation and Nutritive Value of Limpograss Breeding Lines Under Stockpiling Management.
Supplements or conserved forage are often used to overcome forage quantity deficits for beef cattle, but stockpiled forage can be more economical. Limpograss [Hemarthria altissima (Poir.) Stapf & C.E. Hubb.] is the best available species for stockpiling in Florida because it is productive in autumn and maintains greater digestibility than other grasses at advanced stages of maturity. New limpograss hybrid breeding lines have been developed, but they have not been tested under stockpiling. Three limpograss breeding lines (1, 4F, and 10) and the most-used cultivar, Floralta, received 50 or 100 kg N ha?1 at initiation of stockpiling and herbage accumulated for 8, 12, or 16 wk. Entry 4F had greater herbage accumulation (7.3 Mg ha?1) than Entries 10, 1, and Floralta (6.1, 6.0, and 5.4 Mg ha?1, respectively). Entry 4F also had greater in vitro digestible organic matter (IVDOM) concentration (530?594 g kg?1) than Entries 1 and Floralta, but 4F was not different from Entry 10 (519?531 g kg?1) after 12 and 16 wk of accumulation. As stockpiling period increased from 8 to 16 wk, herbage accumulation increased from 5.3 to 7.4 Mg ha?1, dead material proportion increased from 1 to 10%, and herbage crude protein (CP) decreased from 44 to 32 g kg?1. Limpograss hybrids 4F and 10 are superior to Floralta for stockpiling, stockpiling period should not be longer than 12 wk, and protein supplement will be required to achieve satisfactory animal performance on stockpiled limpograss
Deletion of L-Selectin Increases Atherosclerosis Development in ApoE−/− Mice
Atherosclerosis is an inflammatory disease characterized by accumulation of leukocytes in the arterial intima. Members of the selectin family of adhesion molecules are important mediators of leukocyte extravasation. However, it is unclear whether L-selectin (L-sel) is involved in the pathogenesis of atherosclerosis. In the present study, mice deficient in L-selectin (L-sel−/−) animals were crossed with mice lacking Apolipoprotein E (ApoE−/−). The development of atherosclerosis was analyzed in double-knockout ApoE/L-sel (ApoE−/− L-sel−/−) mice and the corresponding ApoE−/− controls fed either a normal or a high cholesterol diet (HCD). After 6 weeks of HCD, aortic lesions were increased two-fold in ApoE−/− L-sel−/− mice as compared to ApoE−/− controls (2.46%±0.54% vs 1.28%±0.24% of total aortic area; p<0.05). Formation of atherosclerotic lesions was also enhanced in 6-month-old ApoE−/− L-sel−/− animals fed a normal diet (10.45%±2.58% vs 1.87%±0.37%; p<0.05). In contrast, after 12 weeks of HCD, there was no difference in atheroma formation between ApoE−/− L-sel−/− and ApoE−/− mice. Serum cholesterol levels remained unchanged by L-sel deletion. Atherosclerotic plaques did not exhibit any differences in cellular composition assessed by immunohistochemistry for CD68, CD3, CD4, and CD8 in ApoE−/− L-sel−/− as compared to ApoE−/− mice. Leukocyte rolling on lesions in the aorta was similar in ApoE−/− L-sel−/− and ApoE−/− animals. ApoE−/− L-sel−/− mice exhibited reduced size and cellularity of peripheral lymph nodes, increased size of spleen, and increased number of peripheral lymphocytes as compared to ApoE−/− controls. These data indicate that L-sel does not promote atherosclerotic lesion formation and suggest that it rather protects from early atherosclerosis
Serum IgE Reactivity Profiling in an Asthma Affected Cohort
BACKGROUND: Epidemiological evidence indicates that atopic asthma correlates with high serum IgE levels though the contribution of allergen specific IgE to the pathogenesis and the severity of the disease is still unclear. METHODS: We developed a microarray immunoassay containing 103 allergens to study the IgE reactivity profiles of 485 asthmatic and 342 non-asthmatic individuals belonging to families whose members have a documented history of asthma and atopy. We employed k-means clustering, to investigate whether a particular IgE reactivity profile correlated with asthma and other atopic conditions such as rhinitis, conjunctivitis and eczema. RESULTS: Both case-control and parent-to-siblings analyses demonstrated that while the presence of specific IgE against individual allergens correlated poorly with pathological conditions, particular reactivity profiles were significantly associated with asthma (p<10E-09). An artificial neural network (ANN)-based algorithm, calibrated with the profile reactivity data, correctly classified as asthmatic or non-asthmatic 78% of the individual examined. Multivariate statistical analysis demonstrated that the familiar relationships of the study population did not affect the observed correlations. CONCLUSIONS: These findings indicate that asthma is a higher-order phenomenon related to patterns of IgE reactivity rather than to single antibody reactions. This notion sheds new light on the pathogenesis of the disease and can be readily employed to distinguish asthmatic and non-asthmatic individuals on the basis of their serum reactivity profile
Utility of Survival Motor Neuron ELISA for Spinal Muscular Atrophy Clinical and Preclinical Analyses
Genetic defects leading to the reduction of the survival motor neuron protein (SMN) are a causal factor for Spinal Muscular Atrophy (SMA). While there are a number of therapies under evaluation as potential treatments for SMA, there is a critical lack of a biomarker method for assessing efficacy of therapeutic interventions, particularly those targeting upregulation of SMN protein levels. Towards this end we have engaged in developing an immunoassay capable of accurately measuring SMN protein levels in blood, specifically in peripheral blood mononuclear cells (PBMCs), as a tool for validating SMN protein as a biomarker in SMA.A sandwich enzyme-linked immunosorbent assay (ELISA) was developed and validated for measuring SMN protein in human PBMCs and other cell lysates. Protocols for detection and extraction of SMN from transgenic SMA mouse tissues were also developed.The assay sensitivity for human SMN is 50 pg/mL. Initial analysis reveals that PBMCs yield enough SMN to analyze from blood volumes of less than 1 mL, and SMA Type I patients' PBMCs show ∼90% reduction of SMN protein compared to normal adults. The ELISA can reliably quantify SMN protein in human and mouse PBMCs and muscle, as well as brain, and spinal cord from a mouse model of severe SMA.This SMN ELISA assay enables the reliable, quantitative and rapid measurement of SMN in healthy human and SMA patient PBMCs, muscle and fibroblasts. SMN was also detected in several tissues in a mouse model of SMA, as well as in wildtype mouse tissues. This SMN ELISA has general translational applicability to both preclinical and clinical research efforts
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