364 research outputs found
Exploring Urban Food Desert Polices in the United States Through the Water-Food-Energy Nexus
Climate change is shifting the distribution and availability of resources around the world. The impacts of climate change are felt significantly within the Water-Food-Energy Nexus, which aims to explore the interconnected impacts on both the natural and human environment. As changes to the climate affect access to resources many societies continue to face the challenge of supporting their human populations while others continue to use resources in excess. Even within industrialized countries like the United States, people face serious resource poverty, clearly seen in food insecurity. Food deserts have arisen in urban areas within the United States and are influenced by a variety of economic, environmental, and social factors. People living in these communities lack the ability to access nutritious, culturally appropriate, and sustainable food options, negatively impacting their health. The ongoing COVID-19 pandemic has only exacerbated the food insecurity felt in urban environments. In this project, I examine case studies of policies that have been implemented on the local level by government and community organizations to combat the growing urban food insecurity. In looking at these local policies through the Water-Food-Energy Nexus I explore the connections between each resource type and the root causes of urban food deserts. Using the Water-Food-Energy Nexus perspective allows for more sustainable approaches to food insecurity, especially as communities begin to experience more significant impacts to natural resources due to climate change and face the unpredictability of resources in their future environment
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Effects of partner separation time on pair bond behaviors and partner-elicited neuronal activation
Resistance traits and AFLP characterization of diploid primitive tuber-bearing potatoes.
ISSN: 0925-986
Does sentence diagraming help seventh grade language art students understand sentence structure?
Sentence diagraming could be an appropriate strategy used in teaching and reinforcing the concept of sentence structure to seventh grade language arts students. The goal of using appropriate teaching-learning strategies has been important to educators for many years (Levin, 1986). In pursuing this goal, there needs to be matching between the strategy selected and the characteristics of the learner at a given developmental stage; the match must be appropriate if the learner is to receive benefit from the teaching technique (Levin, 1986). According to Levin\u27s study, both the specific skills and the competencies of the learner should be the central focus in selecting and developing teaching strategies
Quantum entropy of two-dimensional extreme charged dilaton black hole
By using Hawking's treatment as well as Zaslavskii's treatment respectively
and the brick wall model, two different values of classical entropy and quantum
entropy of scalar fields in the two-dimensional extreme charged dilaton black
hole backgrounds have been obtained. A new divergent term emerges in the
quantum entropy under the extreme limit for Zaslavskii's treatment and its
connection with the phase transition has been addressed.Comment: Latex version, to be published on Phys.Lett.
Coexpression gene network analysis of cold-tolerant Solanum commersonii reveals new insights in response to low temperatures
Among abiotic stressors, cold is one of the most harmful for the cultivated potato (Solanum tuberosum L.), a frost-sensitive crop. RNA sequencing (RNA-seq) profiling of two different clones of wild potato (S. commersonii Dun.) contrasting in their capacity to withstand low temperatures revealed a higher number of differentially expressed genes (DEGs) under nonacclimated conditions (NAC) in tolerant clone cmm1T vs. the susceptible cmm6-6 (1,002 and 8,055 DEGs, respectively). By contrast, the number of DEGs was much more comparable when both genotypes were under acclimated conditions (AC). Indeed, a total of 5,650 and 8,936 DEGs were detected in the tolerant genotype vs. the susceptible. Gene ontology (GO) classification under NAC showed a significant role for transcription regulation, lignin catabolic genes, and regulation of plant type secondary cell wall in the cold-tolerant genotypes, suggesting an important role in conferring tolerance response. By contrast, response to stress and response to stimuli were enriched GO categories in both clones under AC. Unsigned weighted correlation networks analysis (WGCNA) allowed identification of coexpressed hub genes with possible main regulatory functions and major impacts on the phenotype. Among those identified, we clarified the role of CBF4. This gene showed contrasting expression profiles in the two clones under NAC, being induced in cold-tolerant cmm1T but suppressed in susceptible cmm6-6. By contrast, under AC, CBF4 was upregulated in both clones. Our study provides a global understanding of mechanisms involved following exposure to NAC and AC in S. commersonii. The mechanisms described here will inform future investigations for detailed validation in studies regarding cold tolerance in plants
Fertilization fitness and offspring ploidy in 3x x 2x matings in potato.
The main objective of the current research was to study the reproductive behaviour of artificial triploid potato hybrids between wild Solanum commersonii and the cultivated potato Solanum tuberosum. When used in 3x 6 2x crosses, triploids gave aneuploid progenies with somatic chromosome number ranging from 29 to 36. Fertilization fitness data suggested that the survival rate of gametes produced by the triploid parents may be related to their chromosome number. In addition, consistent with molecular data, our results indicated that fitness of gametes and chromosome number of progenies are influenced by the genome dosage of interspecific triploids. Since a main route to polyploidy formation is via 2n gametes and triploids, our study may contribute to a better understanding of polyploid plant reproduction, evolution and breeding
Coexpression gene network analysis of cold-tolerant Solanum commersonii reveals new insights in response to low temperatures
AbstractAmong abiotic stressors, cold is one of the most harmful for the cultivated potato (Solanum tuberosum L.), a frost‐sensitive crop. RNA sequencing (RNA‐seq) profiling of two different clones of wild potato (S. commersonii Dun.) contrasting in their capacity to withstand low temperatures revealed a higher number of differentially expressed genes (DEGs) under nonacclimated conditions (NAC) in tolerant clone cmm1T vs. the susceptible cmm6‐6 (1,002 and 8,055 DEGs, respectively). By contrast, the number of DEGs was much more comparable when both genotypes were under acclimated conditions (AC). Indeed, a total of 5,650 and 8,936 DEGs were detected in the tolerant genotype vs. the susceptible. Gene ontology (GO) classification under NAC showed a significant role for transcription regulation, lignin catabolic genes, and regulation of plant type secondary cell wall in the cold‐tolerant genotypes, suggesting an important role in conferring tolerance response. By contrast, response to stress and response to stimuli were enriched GO categories in both clones under AC. Unsigned weighted correlation networks analysis (WGCNA) allowed identification of coexpressed hub genes with possible main regulatory functions and major impacts on the phenotype. Among those identified, we clarified the role of CBF4. This gene showed contrasting expression profiles in the two clones under NAC, being induced in cold‐tolerant cmm1T but suppressed in susceptible cmm6‐6. By contrast, under AC, CBF4 was upregulated in both clones. Our study provides a global understanding of mechanisms involved following exposure to NAC and AC in S. commersonii. The mechanisms described here will inform future investigations for detailed validation in studies regarding cold tolerance in plants
Changes in Disease Resistance Phenotypes Associated With Plant Physiological Age Are Not Caused by Variation in R Gene Transcript Abundance
Foliar late blight is one of the most important diseases of potato. Foliar blight resistance has been shown to change as a plant ages. In other pathosystems, resistance (R) gene transcript levels appear to be correlated to disease resistance. The cloning of the broad-spectrum, foliar blight resistance gene RB provided the opportunity to explore how foliar blight resistance and R-gene transcript levels vary with plant age. Plants of Solanum bulbocastanum PT29, from which RB, including the native promoter and other flanking regions, was cloned, and S. tuberosum cv. Dark Red Norland (nontransformed and RB-transformed) representing three different developmental stages were screened for resistance to late blight and RB transcript levels. Preflowering plants of all genotypes exhibited the highest levels of resistance, followed by postflowering and near-senescing plants. The RB transgene significantly affected resistance, enhancing resistance levels of all RB-containing lines, especially in younger plants. RB transgene transcripts were detected at all plant ages, despite weak correlation with disease resistance. Consistent transcript levels in plants of different physiological ages with variable levels of disease resistance demonstrate that changes in disease-resistance phenotypes associated with plant age cannot be attributed to changes in R-gene transcript abundance
Higher copy numbers of the potato RB transgene correspond to enhanced transcript and late blight resistance levels.
Late blight of potato ranks among the costliest of crop diseases worldwide. Host resistance offers the best means for controlling late blight, but previously deployed single resistance genes have been short-lived in their effectiveness. The foliar blight resistance gene RB, previously cloned from the wild potato Solanum bulbocastanum, has proven effective in greenhouse tests of transgenic cultivated potato. In this study, we examined the effects of the RB transgene on foliar late blight resistance in transgenic cultivated potato under field production conditions. In a two-year replicated trial, the RB transgene, under the control of its endogenous promoter, provided effective disease resistance in various genetic backgrounds, including commercially prominent potato cultivars, without fungicides. RB copy numbers and transcript levels were estimated with transgene-specific assays. Disease resistance was enhanced as copy numbers and transcript levels increased. The RB gene, like many other disease resistance genes, is constitutively transcribed at low levels. Transgenic potato lines with an estimated 15 copies of the RB transgene maintain high RB transcript levels and were ranked among the most resistant of 57 lines tested. We conclude that even in these ultra–high copy number lines, innate RNA silencing mechanisms have not been fully activated. Our findings suggest resistance-gene transcript levels may have to surpass a threshold before triggering RNA silencing. Strategies for the deployment of RB are discussed in light of the current research
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