12 research outputs found
Critical research needs for successful food systems adaptation to climate change
There is a growing sense of the fragility of agricultural production in the Global North and South and of increasing risks to food security, as scientific observations confirm significant changes in the Gulf Stream, polar ice, atmospheric CO2, methane release, and other measures of climate change. This sense is heightened as each of us experiences extreme weather, such as the increasing frequency of droughts, floods, unseasonal temperatures, and erratic seasonality. The central research challenge before us is how global, national, regional, and local food systems may adapt to accelerating climate change stresses and uncertainties to ensure the availability, access, consumption, and stability of healthy food for and by all people. Missing aspects of research fall into two broad categories: the impacts of rapid climate change on the environmental systems supporting food production, and climate change’s impact on the predominantly human systems that influence food security. Of particular concern is how different policy and governance mechanisms can support or hinder the collective decision-making needed to promote a swift adaptive response to increase and sustain food security. Human systems research is needed to investigate food system activities beyond production (processing, distribution, consumption, and waste management). It also must consider political, cultural, and regulatory factors that influence behavior and facilitate positive behavioral changes. To accurately envision future scenarios, research is needed to characterize risk comprehensively throughout the food system, assess barriers to and opportunities for changing food systems, and evaluate novel and traditional approaches that may lead to greater food security
Resorption Protection. Anthocyanins Facilitate Nutrient Recovery in Autumn by Shielding Leaves from Potentially Damaging Light Levels
The resorption protection hypothesis, which states that anthocyanins protect foliar nutrient resorption during senescence by shielding photosynthetic tissues from excess light, was tested using wild-type (WT) and anthocyanin-deficient mutants of three deciduous woody species, Cornus sericea, Vaccinium elliottii (Chapmn.), and Viburnum sargentii (Koehne). WT Betula papyrifera (Marsh) was included to compare the senescence performance of a species that does not produce anthocyanins in autumn. Plants were subjected to three environmental regimes during senescence: an outdoor treatment; a 5-d high-stress (high light and low temperature) treatment followed by transfer to a low-stress environment and a low-stress treatment that served as control. In the outdoor treatment, the appearance of anthocyanins in senescing leaves of WT plants was concomitant with the development of photo-inhibition in mutant plants of all three anthocyanin-producing species. In the high-stress environment, WT plants maintained higher photochemical efficiencies than mutants and were able to recover when transferred to the low-stress environment, whereas mutant leaves dropped while still green and displayed signs of irreversible photooxidative damage. Nitrogen resorption efficiencies and proficiencies of all mutants in both stressful treatments were significantly lower than the WT counterparts. B. papyrifera displayed photochemical efficiencies and nitrogen resorption performance comparable with the highest of the anthocyanin-producing species in all three senescing environments, indicating a photoprotective strategy divergent from the other species studied. These results strongly support the resorption protection hypothesis of anthocyanins in senescing leaves
A rat pancreatic ribonuclease fused to a late cotton pollen promoter severely reduces pollen viability in tobacco plants
The effects of an animal RNase fused to the late cotton pollen-specific promoter G9 in a plant system were investigated. Expression of
the chimeric genes G9-uidA and G9-RNase in tobacco plants showed that the 1.2-kb promoter fragment of the G9 gene was sufficient
to maintain tissue and temporal specificity in a heterologous system. GUS (beta-glucuronidase) expression was detected only in pollen
from anther stage 6 through anthesis, with maximal GUS activity in pollen from stage 10 anthers. Investigating the effects of the rat RNase
on pollen viability at stage 10, we found that pollen viability was reduced from 79 to 8% and from 89 to 40%, in pollen germination and
fluoresceine diacetate assays, respectively, in one G9-RNase transgenic line, suggesting a lethal effect of the RNase gene. This indicates
that the rat RNase produces deleterious effects in this plant system and may be useful for engineering male sterility
Food Webs and Food Sovereignty: Research Agenda for Sustainability
Future food production will be constrained by the scarcity of fossil fuel and fresh water as well as increasing intensity and unpredictability of weather events and climate changes. The assurance of food security and equity for many consumers is complicated by concentration of ownership of land and other production resources, as well as a global corporate food systems model that is driven by profit at the expense of people and the environment. To assess potential alternatives to the contemporary global food chain, well focused research is needed on local food production and food webs where small- and midscale family farms provide economic viability for rural communities and their regions. We suggest multiple and integrative research priorities in production, enterprise, and farm economics, environmental impacts of farming at different scales, and social and community consequences of value adding and economic multipliers in local food webs and systems as well as the structure of agriculture. Research into key questions on food security and how it relates to increased food sovereignty is clearly needed to assess creative food system alternatives for the future
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Thiazolides as novel antiviral agents. 2. Inhibition of Hepatitis C virus replication
We report the activities of a number of thiazolides [2-hydroxyaroyl-N-(thiazol-2-yl)amides] against hepatitis C virus (HCV) genotypes IA and IB, using replicon assays. The structure–activity relationships (SARs) of thiazolides against HCV are less predictable than against hepatitis B virus (HBV), though an electron-withdrawing group at C(5′) generally correlates with potency. Among the related salicyloylanilides, the m-fluorophenyl analogue was most promising; niclosamide and close analogues suffered from very low solubility and bioavailability. Nitazoxanide (NTZ) 1 has performed well in clinical trials against HCV. We show here that the 5′-Cl analogue 4 has closely comparable in vitro activity and a good cell safety index. By use of support vector analysis, a quantitative structure–activity relationship (QSAR) model was obtained, showing good predictive models for cell safety. We conclude by updating the mode of action of the thiazolides and explain the candidate selection that has led to compound 4 entering preclinical development