224 research outputs found
Properties of pattern formation and selection processes in nonequilibrium systems with external fluctuations
We extend the phase field crystal method for nonequilibrium patterning to
stochastic systems with external source where transient dynamics is essential.
It was shown that at short time scales the system manifests pattern selection
processes. These processes are studied by means of the structure function
dynamics analysis. Nonequilibrium pattern-forming transitions are analyzed by
means of numerical simulations.Comment: 15 poages, 8 figure
Apresentação : a fortuna teórica e empírica de uma nova agenda de pesquisa : os múltiplos olhares sobre o domínio econômico
Resumo não disponíve
Climate-Related Risks and Management Issues Facing Agriculture in the Southeast: Interviews with Extension Professionals
To explore Extension professionals\u27 perceptions of the potential impact of climate variability and climate change on agriculture and to identify the top climate-related issues facing farmers, we conducted interviews with agricultural Extension personnel from Alabama, Florida, Georgia, and South Carolina. Of those interviewed, 92% believed climate change will affect agriculture a moderate amount or a great deal. Qualitative analyses revealed that the Extension professionals considered scarcity of water resources, temperature fluctuations, pest and disease pressures, forecast challenges, seasonal variability, and adaptation strategies as among the most important climate-related issues affecting agriculture in the Southeast
From Resistance to Receptiveness: Farmer Willingness to Participate in Extension Discussions About Climate Variability and Climate Change
Identifying what Extension professionals believe are the critical elements of a communication strategy that is most likely to encourage agricultural producers to participate in discussions of climate variability and climate change is pivotal to providing timely solutions to issues facing farmers. The current study involved interviews with 50 Extension professionals from four southeastern states (Alabama, Florida, Georgia, and South Carolina) who were engaged in ongoing work related to climate and agriculture. Respondents were asked to assess how best to engage farmers in conversations related to climate variability and climate change. Qualitative analysis showed that Extension professionals recommended avoiding content related to politics, attribution of climate change to human causes, and telling farmers what to do. Respondents recommended emphasizing adaptation strategies, climate variability over climate change, evidence that climate change exists, and the financial benefits for farmers. In addition, Extension professionals proposed several delivery methods they thought would be most effective with farmers, including delivery tailored to the characteristics of the audience, a positive overall tone, and an understanding that engagement should be viewed as a long-term process based on building relationships with farmers. The findings suggest that farmers are a potentially receptive audience on climate issues when properly approached
Profitability, Engaging Delivery, and Trust: How Extension Professionals Can Optimize Farmer Adoption of Climate-related Adaptation Strategies
This study examined Extension professionals’ perspectives on how to optimize the chances that farmers will adopt climate adaptation strategies designed to minimize risks associated with climate variability and climate change. In-depth interviews were conducted with Extension professionals in four southeastern states (Alabama, Florida, Georgia, and South Carolina). Responses were coded and analyzed, resulting in three recommendations. First, focus on profitability and issues of immediate concern to farmers. Second, use engaging delivery methods, especially field trials conducted under realistic conditions. Third, build trust with farmers, primarily by focusing on research-based information. This study has practical implications for how Extension professionals should approach the work of addressing climate issues in agriculture
“Your Body Feels Better When You Drink Water”: Parent and School-Age Children’s Sugar- Sweetened Beverage Cognitions
Sugar-sweetened beverages (SSBs) are a leading source of added sugar in the American diet. Further, ingestion of added sugars from SSBs exceeds recommendations. Thus, interventions that effectively reduce SSB consumption are needed. Focus group discussions with parents (n = 37) and school-aged children between the ages of 6 and 11 years (n = 41) from Florida, New Jersey, and West Virginia were led by trained moderators using Social Cognitive Theory as a guide. Trends and themes that emerged from the content analysis of the focus group data indicated that both parents and children felt that limiting SSBs was important to health and weight control. However, parents and children reported consuming an average of 1.85 ± 2.38 SD and 2.13 ± 2.52 SD SSB servings/week, respectively. Parents and children were aware that parent behaviors influenced kids, but parents reported modeling healthy SSB behaviors was difficult. Busy schedules, including more frequent parties and events as children get older, were another barrier to limiting SSBs. Parents were most successful at limiting SSBs when they were not in the house. This qualitative research provides novel insights into parents’ and children’s cognitions (e.g., beliefs, attitudes), barriers, and facilitators related to SSB ingestion. Consideration of these insights during nutrition intervention development has the potential to improve intervention effectiveness in reducing SSB intake
Spatial and temporal spectra of noise driven stripe patterns
Spatial and temporal noise power spectra of stripe patterns are investigated,
using as a model a Swift-Hohenberg equation with a stochastic term. In
particular, the analytical and numerical investigations show: 1) the temporal
noise spectra are of 1/f^alpha form, where alpha=1+(3-D)/4 with D the spatial
dimension of the system; 2) that the stochastic fluctuations of the stripe
position are sub-diffusive.Comment: Submitted to PR
Brain and blood biomarkers of tauopathy and neuronal injury in humans and rats with neurobehavioral syndromes following blast exposure
Traumatic brain injury (TBI) is a risk factor for the later development of neurodegenerative diseases that may have various underlying pathologies. Chronic traumatic encephalopathy (CTE) in particular is associated with repetitive mild TBI (mTBI) and is characterized pathologically by aggregation of hyperphosphorylated tau into neurofibrillary tangles (NFTs). CTE may be suspected when behavior, cognition, and/or memory deteriorate following repetitive mTBI. Exposure to blast overpressure from improvised explosive devices (IEDs) has been implicated as a potential antecedent for CTE amongst Iraq and Afghanistan Warfighters. In this study, we identified biomarker signatures in rats exposed to repetitive low-level blast that develop chronic anxiety-related traits and in human veterans exposed to IED blasts in theater with behavioral, cognitive, and/or memory complaints. Rats exposed to repetitive low-level blasts accumulated abnormal hyperphosphorylated tau in neuronal perikarya and perivascular astroglial processes. Using positron emission tomography (PET) and the [18F]AV1451 (flortaucipir) tau ligand, we found that five of 10 veterans exhibited excessive retention of [18F]AV1451 at the white/gray matter junction in frontal, parietal, and temporal brain regions, a typical localization of CTE tauopathy. We also observed elevated levels of neurofilament light (NfL) chain protein in the plasma of veterans displaying excess [18F]AV1451 retention. These findings suggest an association linking blast injury, tauopathy, and neuronal injury. Further study is required to determine whether clinical, neuroimaging, and/or fluid biomarker signatures can improve the diagnosis of long-term neuropsychiatric sequelae of mTBI
Advanced Fluorescence Microscopy Techniques-FRAP, FLIP, FLAP, FRET and FLIM
Fluorescence microscopy provides an efficient and unique approach to study fixed and living cells because of its versatility, specificity, and high sensitivity. Fluorescence microscopes can both detect the fluorescence emitted from labeled molecules in biological samples as images or photometric data from which intensities and emission spectra can be deduced. By exploiting the characteristics of fluorescence, various techniques have been developed that enable the visualization and analysis of complex dynamic events in cells, organelles, and sub-organelle components within the biological specimen. The techniques described here are fluorescence recovery after photobleaching (FRAP), the related fluorescence loss in photobleaching (FLIP), fluorescence localization after photobleaching (FLAP), Forster or fluorescence resonance energy transfer (FRET) and the different ways how to measure FRET, such as acceptor bleaching, sensitized emission, polarization anisotropy, and fluorescence lifetime imaging microscopy (FLIM). First, a brief introduction into the mechanisms underlying fluorescence as a physical phenomenon and fluorescence, confocal, and multiphoton microscopy is given. Subsequently, these advanced microscopy techniques are introduced in more detail, with a description of how these techniques are performed, what needs to be considered, and what practical advantages they can bring to cell biological research
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