19 research outputs found
Motivations for Participating in Community-Supported Agriculture and Their Relationship with Community Attachment and Social Capital
The social fabric of rural communities is continuing to change as we move toward a more globalized society and food economy, and the vitality of rural agricultural communities in particular may be declining (Berry 1999). In response to these changes, efforts are underway in many parts of the United States to counteract this global, industrial food system and by implication, increase the vitality and sustainability of rural communities. One effort that is gaining momentum is the Community Supported Agriculture (CSA) movement, which involves local farmers and community members working together as partners to create a sustainable local food system. It has been argued that one measure of a community’s vitality and sustainability is the longterm health of its food system, and CSAs provide a locally-based approach to community revitalization that also incorporates the benefit of such a healthy food system (Feenstra 1997). Using quantitative data from the memberships of CSA operations in both Central Illinois and New Hampshire, this research identifies the perceived benefits of CSA involvement, the motivations CSA members identify as important to their involvement, and the effects of CSA activity on community social capital. Analyses reveal that CSA member motivations are similar to those found in past empirical work, with concerns over quality of food being the strongest motivators. The importance of community building and development of social capital are not considered significant motivators for joining a CSA, nor are they perceived to be particularly important benefits of membership. However, the importance of community attachment in enhancing certain motivating factors like a desire to develop a stronger sense of community and a desire to support local growers is significant
Beryllium isotopes in central Arctic Ocean sediments over the past 12.3 million years: Stratigraphic and paleoclimatic implications
The upper 200 m of the sediments recovered during IODP Leg 302, the Arctic Coring Expedition (ACEX), to the Lomonosov Ridge in the central Arctic Ocean consist almost exclusively of detrital material. The scarcity of biostratigraphic markers severely complicates the establishment of a reliable chronostratigraphic framework for these sediments, which contain the first continuous record of the Neogene environmental and climatic evolution of the Arctic region. Here we present profiles of cosmogenic 10Be together with the seawater-derived fraction of stable 9Be obtained from the ACEX cores. The down-core decrease of 10Be/9Be provides an average sedimentation rate of 14.5 ± 1 m/Ma for the uppermost 151 m of the ACEX record and allows the establishment of a chronostratigraphy for the past 12.3 Ma. The age-corrected 10Be concentrations and 10Be/9Be ratios suggest the existence of an essentially continuous sea ice cover over the past 12.3 Ma
Imaging biomarker roadmap for cancer studies.
Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET and ultrasonography biomarkers are used extensively in cancer research and drug development. New IBs need to be established either as useful tools for testing research hypotheses in clinical trials and research studies, or as clinical decision-making tools for use in healthcare, by crossing 'translational gaps' through validation and qualification. Important differences exist between IBs and biospecimen-derived biomarkers and, therefore, the development of IBs requires a tailored 'roadmap'. Recognizing this need, Cancer Research UK (CRUK) and the European Organisation for Research and Treatment of Cancer (EORTC) assembled experts to review, debate and summarize the challenges of IB validation and qualification. This consensus group has produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical (assay) validation, biological/clinical validation and assessment of cost-effectiveness; the need for IB standardization and accreditation systems; the need to continually revisit IB precision; an alternative framework for biological/clinical validation of IBs; and the essential requirements for multicentre studies to qualify IBs for clinical use.Development of this roadmap received support from Cancer Research UK and the Engineering and Physical Sciences Research Council (grant references A/15267, A/16463, A/16464, A/16465, A/16466 and A/18097), the EORTC Cancer Research Fund, and the Innovative Medicines Initiative Joint Undertaking (grant agreement number 115151), resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007-2013) and European Federation of Pharmaceutical Industries and Associations (EFPIA) companies' in kind contribution
Spectral and kinetic measurements on a series of persistent iminoxyl radicals
A series of new iminoxyl radicals, Et3C(C=NO•)Bu-tert (1), tert-C5H11(C=NO•) Bu-tert (2), (tert-C5H11)2C = NO• (3), Et3C(C=NO•)Ph (4), PhCH2CMe2(C=NO•)Bu-tert (5), PhMe2(C=NO•)Bu-tert (6) and Me2CH(C=NO•)C5H11-tert (7), was characterized by EPR and in some cases visible spectra and decay kinetics in solution. Isolation of 1H and 3-tert-butyl-4,4-diethyl-5-methyl-4,5-dihydro-5-isoxazolol (9) among the decomposition products of 1 was consistent with a previously unrecognized mode of iminoxyl reaction in which the initial step is an internal β-H abstraction. Molecular orbital calculations on H2C=NO• indicate a C-N-O angle of about 140° and a 10 kcal mol-1 barrier to inversion. Rate constants for the reaction of tert-Bu2C=NO• (8) with a series of olefins were measured
Scoring system predictive of survival for patients undergoing stereotactic body radiation therapy for liver tumors
<p>Abstract</p> <p>Background</p> <p>Stereotactic body radiation therapy (SBRT) is an emerging treatment option for liver tumors. This study evaluated outcomes after SBRT to identify prognostic variables and to develop a novel scoring system predictive of survival.</p> <p>Methods</p> <p>The medical records of 52 patients with a total of 85 liver lesions treated with SBRT from 2003 to 2010 were retrospectively reviewed. Twenty-four patients had 1 lesion; 27 had 2 or more. Thirteen lesions were primary tumors; 72 were metastases. Fiducials were placed in all patients prior to SBRT. The median prescribed dose was 30 Gy (range, 16 – 50 Gy) in a median of 3 fractions (range, 1–5).</p> <p>Results</p> <p>With median follow-up of 11.3 months, median overall survival (OS) was 12.5 months, and 1 year OS was 50.8%. In 42 patients with radiographic follow up, 1 year local control was 74.8%. On univariate analysis, number of lesions (p = 0.0243) and active extralesional disease (p < 0.0001) were predictive of OS; Karnofsky Performance Status (KPS) approached statistical significance (p = 0.0606). A scoring system for predicting survival was developed by allocating 1 point for each of the three following factors: active extralesional disease, 2 or more lesions, and KPS ≤ 80%. Score was associated with OS (p < 0.0001). For scores of 0, 1, 2 and 3, median survival intervals were 34, 12.5, 7.6, and 2.8 months, respectively.</p> <p>Conclusions</p> <p>SBRT offers a safe and feasible treatment option for liver tumors. A prognostic scoring system based on the number of liver lesions, activity of extralesional disease, and KPS predicts survival following SBRT and can be used as a guide for prospective validation and ultimately for treatment decision-making.</p
Biodiversity increases the resistance of ecosystem productivity to climate extremes
It remains unclear whether biodiversity buffers ecosystems against climate extremes, which are becoming increasingly frequent worldwide. Early results suggested that the ecosystem productivity of diverse grassland plant communities was more resistant, changing less during drought, and more resilient, recovering more quickly after drought, than that of depauperate communities. However, subsequent experimental tests produced mixed results. Here we use data from 46 experiments that manipulated grassland plant diversity to test whether biodiversity provides resistance during and resilience after climate events. We show that biodiversity increased ecosystem resistance for a broad range of climate events, including wet or dry, moderate or extreme, and brief or prolonged events. Across all studies and climate events, the productivity of low-diversity communities with one or two species changed by approximately 50% during climate events, whereas that of high-diversity communities with 16-32 species was more resistant, changing by only approximately 25%. By a year after each climate event, ecosystem productivity had often fully recovered, or overshot, normal levels of productivity in both high- and low-diversity communities, leading to no detectable dependence of ecosystem resilience on biodiversity. Our results suggest that biodiversity mainly stabilizes ecosystem productivity, and productivity-dependent ecosystem services, by increasing resistance to climate events. Anthropogenic environmental changes that drive biodiversity loss thus seem likely to decrease ecosystem stability, and restoration of biodiversity to increase it, mainly by changing the resistance of ecosystem productivity to climate events.Isbell, Forest; Craven, Dylan; Connolly, John; Loreau, Michel; Schmid, Bernhard; Beierkuhnlein, Carl; Bezemer, T. Martijn; Bonin, Catherine; Bruelheide, Helge; de Luca, Enrica; Ebeling, Anne; Griffin, John N; Guo, Qinfeng; Hautier, Yann; Hector, Andy; Jentsch, Anke; Kreyling, Jürgen; Lanta, Vojtěch; Manning, Pete; Meyer, Sebastian T; Mori, Akira S.; Naeem, Shahid; Niklaus, Pascal A; Polley, H. Wayne; Reich, Peter B; Roscher, Christiane; Seabloom, Eric W; Smith, Melinda D; Thakur, Madhav P; Tilman, David; Tracy, Benjamin F; van der Putten, Wim H; van Ruijven, Jasper; Weigelt, Alexandra; Weisser, Wolfgang W; Wilsey, Brian; Eisenhauer, Nico. (2015). Biodiversity increases the resistance of ecosystem productivity to climate extremes. Retrieved from the University Digital Conservancy, 10.1038/nature15374
Extreme drought impacts have been underestimated in grasslands and shrublands globally.
Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought