Engaging Rural Nevadans in Participatory Research to Explore and Explain the Community Food and Physical Activity Context

The purpose of this study was to engage residents of four rural Nevada communities to explain local resources and readiness to address environmental challenges to weight healthy lifestyles. Residents engaged in HEAL MAPPS™, a participatory research approach using photomapping and community conversations to document lived experiences of place-based resources as supports or barriers. Data were triangulated to scale community readiness-to-change. This study focuses on a description of methods and qualitative findings. Healthy food unavailability emerged consistently among communities as a barrier; produce options were limited and many residents relied on convenience foods. Physical activity opportunities were available, yet access was a barrier. Transportation-related issues emerged as barriers to healthy eating and physical activity. Communities ranged between “vague awareness” and “preplanning” on readiness-to-change. Local data and shared knowledge of the obesogenic context can inform community policy and environmental improvements that promote health and enhance quality of life for rural populations

Medicago truncatula contains a second gene encoding a plastid located glutamine synthetase exclusively expressed in developing seeds

<p>Abstract</p> <p>Background</p> <p>Nitrogen is a crucial nutrient that is both essential and rate limiting for plant growth and seed production. Glutamine synthetase (GS), occupies a central position in nitrogen assimilation and recycling, justifying the extensive number of studies that have been dedicated to this enzyme from several plant sources. All plants species studied to date have been reported as containing a single, nuclear gene encoding a plastid located GS isoenzyme per haploid genome. This study reports the existence of a second nuclear gene encoding a plastid located GS in <it>Medicago truncatula</it>.</p> <p>Results</p> <p>This study characterizes a new, second gene encoding a plastid located glutamine synthetase (GS2) in <it>M. truncatula</it>. The gene encodes a functional GS isoenzyme with unique kinetic properties, which is exclusively expressed in developing seeds. Based on molecular data and the assumption of a molecular clock, it is estimated that the gene arose from a duplication event that occurred about 10 My ago, after legume speciation and that duplicated sequences are also present in closely related species of the Vicioide subclade. Expression analysis by RT-PCR and western blot indicate that the gene is exclusively expressed in developing seeds and its expression is related to seed filling, suggesting a specific function of the enzyme associated to legume seed metabolism. Interestingly, the gene was found to be subjected to alternative splicing over the first intron, leading to the formation of two transcripts with similar open reading frames but varying 5' UTR lengths, due to retention of the first intron. To our knowledge, this is the first report of alternative splicing on a plant GS gene.</p> <p>Conclusions</p> <p>This study shows that <it>Medicago truncatula </it>contains an additional GS gene encoding a plastid located isoenzyme, which is functional and exclusively expressed during seed development. Legumes produce protein-rich seeds requiring high amounts of nitrogen, we postulate that this gene duplication represents a functional innovation of plastid located GS related to storage protein accumulation exclusive to legume seed metabolism.</p

Soil respiration in northern forests exposed to elevated atmospheric carbon dioxide and ozone

The aspen free-air CO 2 and O 3 enrichment (FACTS II–FACE) study in Rhinelander, Wisconsin, USA, is designed to understand the mechanisms by which young northern deciduous forest ecosystems respond to elevated atmospheric carbon dioxide (CO 2 ) and elevated tropospheric ozone (O 3 ) in a replicated, factorial, field experiment. Soil respiration is the second largest flux of carbon (C) in these ecosystems, and the objective of this study was to understand how soil respiration responded to the experimental treatments as these fast-growing stands of pure aspen and birch + aspen approached maximum leaf area. Rates of soil respiration were typically lowest in the elevated O 3 treatment. Elevated CO 2 significantly stimulated soil respiration (8–26%) compared to the control treatment in both community types over all three growing seasons. In years 6–7 of the experiment, the greatest rates of soil respiration occurred in the interaction treatment (CO 2  + O 3 ), and rates of soil respiration were 15–25% greater in this treatment than in the elevated CO 2 treatment, depending on year and community type. Two of the treatments, elevated CO 2 and elevated CO 2  + O 3 , were fumigated with 13 C-depleted CO 2 , and in these two treatments we used standard isotope mixing models to understand the proportions of new and old C in soil respiration. During the peak of the growing season, C fixed since the initiation of the experiment in 1998 (new C) accounted for 60–80% of total soil respiration. The isotope measurements independently confirmed that more new C was respired from the interaction treatment compared to the elevated CO 2 treatment. A period of low soil moisture late in the 2003 growing season resulted in soil respiration with an isotopic signature 4–6‰ enriched in 13 C compared to sample dates when the percentage soil moisture was higher. In 2004, an extended period of low soil moisture during August and early September, punctuated by a significant rainfall event, resulted in soil respiration that was temporarily 4–6‰ more depleted in 13 C. Up to 50% of the Earth’s forests will see elevated concentrations of both CO 2 and O 3 in the coming decades and these interacting atmospheric trace gases stimulated soil respiration in this study.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45867/1/442_2006_Article_381.pd

Research achievements in plant resistance to insect pests of cool season food legumes

Plant resistance to at least 17 field and storage insect pests of cool season food legumes has been identified. For the most part, this resistance was located in the primary gene pools of grain legumes via conventional laboratory, greenhouse, and field screening methods. The use of analytical techniques (i.e., capillary gas chromatography) to characterize plant chemicals that mediate the host selection behavior of pest insects offers promise as a new, more rapid way to differentiate between insect-resistant and susceptible plant material. Examples of research achievements in mechanisms of resistance and host-plant resistance within the context of integrated control programs are discussed. Accelerating the development and subsequent releases of insect-resistant cultivars to pulse farmers requires more involvement from interdisciplinary teams of plant breeders, entomologists, plant pathologists, plant chemists, molecular biologists, and other scientist