Material Fatigue Testing System

A system for cyclicly applying a varying load to a material under test is described. It includes a load sensor which senses the magnitude of load being applied to a material, and, upon sensing a selected magnitude of loading, causes the load to be maintained for a predetermined time and then cause the system to resume cyclical loading

Microinjection of superior cervical ganglion neurons for studying axon degeneration

Primary cultures of neurons of the peripheral nervous system have been successfully used for studying many aspects of neuronal development and survival, including investigations into the mechanisms of axon degeneration. In this chapter we describe how to prepare and microinject dissociated cultures of sympathetic neurons of the superior cervical ganglion (SCG) specifically for use in highly controlled and targeted assays of axon survival and degeneration

‘White man’s disease’

Through critical reflection on the conspiracy theories told about the origins of HIV by American Indians, we learned that many community members refused the universalized aspects of AIDS prevention, education, and intervention. We found that standard HIV/AIDS-related prevention and treatment programs tend to universalize experiences with and responses to the AIDS epidemic and ignore – or push to the margin – alternative framings and understandings of this disease. Inspired by American Indians’ refusal to synthesize (in the Hegelian dialectical sense) their own experience into national and international AIDS knowledges, in this article we seek to engage with such marginal understandings, as well as their interactions with universal, individual, and community notions of care, AIDS, and health causality. The use of non-standard theories of the origins of AIDS by American Indians, we argue, disrupts the logic that attempts to universalize AIDS and community experiences. By making AIDS a ‘White Man’s disease’, Natives bring the epidemic in line with a history of social and health neglect by the settler state, and refuse to collapse their own, marginalized experiences and understandings of HIV/AIDS into dominant knowledges of the disease

Bird Friendly Beef: Exploring the Impacts of Regenerative Forage Production

In the eastern US, managed hayfields and pasturelands represent a significant portion of remaining available grassland bird habitat, hosting several declining species including the eastern meadowlark (Sturnella magna) and the grasshopper sparrow (Ammodramus savannarum). However, these working landscapes have deteriorated in their ability to support grassland birds in recent decades due to more frequent and early hay cuttings and intensive grazing. Since the conservation of grassland birds is inextricably linked to agricultural systems, for conservation to be effective, land management must aim to benefit both producers and birds. Regenerative agriculture is an emerging approach that incorporates land management practices that benefit agricultural ecosystems and increase efficiency and profitability. Regenerative grazing has demonstrated associations with greater bird abundance, but there is a significant gap in research that investigates whether these practices contribute to successful nesting. Collaborators from Smithsonian’s Virginia Working Landscapes, American Farmland Trust, and George Mason University set out to explore the effects of regenerative grazing practices on forage quality and the reproductive success of grassland birds. We established four experimental grazing and haying treatments on private working lands. For each treatment, we collected forage samples for nutrient analysis and quantified reproductive success using a combination of territory mapping and systematic nest searching. Our preliminary analysis suggests that grazing pastures early and stockpiling for fall and winter grazing results in standing forages suitable in quality for several different production classes of livestock while reducing producer reliance on harvested feeds such as hay. Our observations also identified this system to provide the greatest propensity for fledgling success of grassland birds due to the lack of disturbances during peak nesting periods which traditionally are due to trampling, haying, and predation

The MEK-ERK pathway negatively regulates bim expression through the 3' UTR in sympathetic neurons

Background: Apoptosis plays a critical role during neuronal development and disease. Developing sympathetic neurons depend on nerve growth factor (NGF) for survival during the late embryonic and early postnatal period and die by apoptosis in its absence. The proapoptotic BH3-only protein Bim increases in level after NGF withdrawal and is required for NGF withdrawal-induced death. The regulation of Bim expression in neurons is complex and this study describes a new mechanism by which an NGF-activated signalling pathway regulates bim gene expression in sympathetic neurons.Results: We report that U0126, an inhibitor of the prosurvival MEK-ERK pathway, increases bim mRNA levels in sympathetic neurons in the presence of NGF. We find that this effect is independent of PI3-K-Akt and JNK-c-Jun signalling and is not mediated by the promoter, first exon or first intron of the bim gene. By performing 3' RACE and microinjection experiments with a new bim-LUC+3'UTR reporter construct, we show that U0126 increases bim expression via the bim 3' UTR. We demonstrate that this effect does not involve a change in bim mRNA stability and by using PD184352, a specific MEK1/2-ERK1/2 inhibitor, we show that this mechanism involves the MEK1/2-ERK1/2 pathway. Finally, we demonstrate that inhibition of MEK/ERK signalling independently reduces cell survival in NGF-treated sympathetic neurons.Conclusions: These results suggest that in sympathetic neurons, MEK-ERK signalling negatively regulates bim expression via the 3' UTR and that this regulation is likely to be at the level of transcription. This data provides further insight into the different mechanisms by which survival signalling pathways regulate bim expression in neurons

Axon degeneration assays in Superior Cervical Ganglion explant cultures

The ability of peripheral nervous system neurons to extend long, axon-like neurites in vitro makes them ideally suited for studies on mechanisms of axon survival and degeneration. In this chapter we describe how to prepare explant cultures of sympathetic neurons of the superior cervical ganglion (SCG). We also describe how to induce and assess axon degeneration with an injury or a chemical insult

Inducing Increased Bioplastic Production in \u3ci\u3eR. palustris\u3c/i\u3e CGA009

PHA’s (polyhydroxyalkanoates) are important bio polymers in different industries such as petroleum, medicine, and nano technology. In the microorganisms in which they are produced, they serve as an energy storage material by storing both carbon and usable electrons. This is useful in environments where the organisms are nutrient starved. PHA’s have a practical use especially in the medical field as bio-plastics because they are biodegradable and bio-compatible. Rhodopseudomonas. palustris, a common soil bacterium, is notable for its uncommon metabolic flexibility. Its diverse metabolism means that it can fix CO 2 and grow on many lignin based monomers in both aerobic and anaerobic environments. Currently, R. palustris already produces PHB (polyhydroxybutyrate), but there are other PHA’s and co polymers that have superior processing characteristics and applications. Our research will investigate the effect of the PHA production genes from Paraburkholderia sacchari DSM 17165 and Cupriavidus necator DSM 545 when introduced into R. palustris and potentially R. palustris strains with their native PHA production genes knocked out Both P. sacchari and C. necator produce higher titers of PHA’s as well as co polymers with improved processing characteristics and more applications than R. palustris ’ current PHB production. Our research will work to combine the metabolic flexibility of R. palustris with the higher PHA and co polymer production of P sacchari and C. necator by introducing genes for PhaA, PhaB, and PhaC production into R. palustris

Managing Manure Phosphorus

Manure, a renewable resource, contains nutrients that are needed for plant growth. Phosphorus in manure can be utilized for crop production as a substitute for synthetic fertilizers. Phosphorus in manure can also be a source of surface or ground water contamination if not used properly. Increased P concentration can lead to eutrophication of surface waters. Management systems need to be developed to utilize manure P effectively without adverse effects on the environment

LOW PRESSURE CENTER PIVOT AND SOIL MANAGEMENT EFFECTS ON RUNOFF

The objective of this research was to determine the influence center-pivot sprinkler irrigation methods in combination with tillage practices for corn (Zea mays L.) have on surface runoff of irrigation and rainfall. A center pivot irrigation machine was redesigned to apply water by high-pressure-impact (HPI), low-pressure-impact (LPI), and low-pressure-spray (LPS) nozzles. The center-pivot was a standard 10-tower machine, 395 meters in length and 38.4 meters tower spacing. Three tillage systems were used -- till-plant (T), disk (D), and subtill (S) which was till-plant with subsoiling between rows with straight single shanks, 360 mm deep, after last cultivation. The soil was a Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic Argiudolls). Runoff was measured from two plots representing each tillage system under the span between towers 9 and 10 for HPI, LPI, and LPS. Hand samples of water were taken at specific time intervals during runoff events for sediment and nutrient analysis. The greatest average annual sediment yield within each irrigation system was for D tillage treatment (148 kg ha-1) and smallest was for S tillage treatment (2 kg ha-1). Total nitrogen in runoff followed a pattern similar to sediment with a range from 0.86 to 0.01 kg ha-I for D and S tillage, respectively. Runoff as a percentage of irrigation water applied for irrigation systems ranked LPS \u3e LPI \u3e HPI. Tractor wheel trafficked rows accounted for majority of the runoff

FOXO transcription factors directly activate bim gene expression and promote apoptosis in sympathetic neurons

Developing sympathetic neurons die by apoptosis when deprived of NGF. BIM, a BH3-only member of the BCL-2 family, is induced after NGF withdrawal in these cells and contributes to NGF withdrawal–induced death. Here, we have investigated the involvement of the Forkhead box, class O (FOXO) subfamily of Forkhead transcription factors in the regulation of BIM expression by NGF. We find that overexpression of FOXO transcription factors induces BIM expression and promotes death of sympathetic neurons in a BIM-dependent manner. In addition, we find that FKHRL1 (FOXO3a) directly activates the bim promoter via two conserved FOXO binding sites and that mutation of these sites abolishes bim promoter activation after NGF withdrawal. Finally, we show that FOXO activity contributes to the NGF deprivation–induced death of sympathetic neurons