263 research outputs found
Herbicide Presistence in Soil
Herbicides are applied directly to soils or plant foliage. Interaction of a herbicide with various living and non-living components of the environment ultimately determines how quickly it dissipates or degrades. Dissipation can be defined as the disappearance or loss of herbicide from the target site through a number of processes. Herbicide may move from the target site via processes such as runoff or leaching, or gradually degrade to undetectable or insignificant levels. Degradation, or alteration of the herbicide molecule by primarily chemical and biological processes, is thus one component of dissipation. Alternatively, we can distinguish between the transfer of herbicide molecules in soil due to processes such as runoff and leaching, and the transformation of the herbicide molecule, due to various degradation pathways. Degradation usually results in deactivation of the herbicide, while herbicide is not deactivated in transfer processes. Processes involved in herbicide dissipation include adsorption, degradation through chemical reaction, microbial degradation, photodecomposition, leaching, runoff, volatilization, and plant uptake
Determining Herbicide Carryover Risk- How Close Can We Come?
Crop injury resulting from herbicide carryover is a function of four variables: 1) the herbicide residue persisting from one year or crop to the next (or the herbicide concentration in soil at the time of planting); 2) the availability of the herbicide for uptake by the germinating seed, emerging seedling, or young plant; 3) the sensitivity of the follow crop to the herbicide; and 4) the environmental conditions in the early part of the growing season. These four factors interact to determine the potential for or the severity of injury due to carryover
Professional experience, motivation and preparedness for practice with older adults : implications for the MSW curriculum
This quantitative study explores Smith College School for Social Work (SCSSW) Master of Social Work (MSW) alumni perceptions of the SCSSW curriculum in the area of agingrelated practice, and the contribution of their educational experience to their preparedness, motivation, and decision to work with older adults. SCSSW MSW alumni from the years 2007 to 2011 (N = 77) comprised the study sample. The 50-item online survey, including two openended questions, was emailed to participants based on contact information they had provided to the alumni office of the School. Questions included original items developed by the author of this study and selected items from the UCLA Geriatric Attitudes Scale (GAS) and the Geriatric Social Work Competency Scale (GSWCS) II. Findings indicate that while recent graduates of SCSSW hold generally positive attitudes toward older adults and recognize the importance of serving this population, on the whole they feel underprepared to carry out professional work with the older adult population and are generally not seeking employment in this field. Alumni feel more competent in their clinical skills than in skills involved in navigating systems and identifying resources; they also felt less prepared in their understanding of the medical issues related to the aging population. Finally, participants express a desire for greater integration of older adult coursework in the curriculum. Considerations for enhancements to MSW curriculums and further research are provided
Differences in effectiveness and use of laparoscopic surgery in locally advanced colon cancer patients
AGMIAL: implementing an annotation strategy for prokaryote genomes as a distributed system
We have implemented a genome annotation system for prokaryotes called AGMIAL. Our approach embodies a number of key principles. First, expert manual annotators are seen as a critical component of the overall system; user interfaces were cyclically refined to satisfy their needs. Second, the overall process should be orchestrated in terms of a global annotation strategy; this facilitates coordination between a team of annotators and automatic data analysis. Third, the annotation strategy should allow progressive and incremental annotation from a time when only a few draft contigs are available, to when a final finished assembly is produced. The overall architecture employed is modular and extensible, being based on the W3 standard Web services framework. Specialized modules interact with two independent core modules that are used to annotate, respectively, genomic and protein sequences. AGMIAL is currently being used by several INRA laboratories to analyze genomes of bacteria relevant to the food-processing industry, and is distributed under an open source license
Context matters: Construct framing in measures of physical activity engagement among African American women
Assessment of psychosocial factors influencing health behavior typically privileges conceptual consistency (framing constructs similarly across contexts) over conceptual specificity (context-specific framing). Modest statistical relationships between these factors and health behaviors, and persistent racial disparities in health outcomes raise questions about whether conceptually consistent framing fully captures relevant predictors. Ethnographic studies suggest not - that perceptions influencing health behaviors are multifaceted and contextual. To test this, we added items querying contextualized predictors of intention to engage in leisure-time physical activity (LTPA) to a Theory of Planned Behavior (TPB)-based survey and examined the psychometrics of the adapted subscales. We measured internal consistency (Cronbach’s alpha) and construct validity (exploratory factor analysis using polychoric correlations for ordinal data). Participants were a convenience sample of 200 African American women in a Midwestern, suburban University-affiliated family medicine practice.
Reliability of the adapted subscales was notably lower than the original subscales. A two-factor model fit best for the attitudes subscale, but explained slightly less than 50% of the variance. The new items loaded strongly on one factor. A three-factor model best fit the norms subscale and accounted for around 57% of the variance. Two of the three new items loaded strongly on one factor. Factor analysis for the perceived control subscale was not possible due to low number of items; however, two of the three new items were highly correlated (.73). Including context-specific factors may improve assessment of intention to engage in LTPA. Further study of this question with a larger, representative sample is warranted
Issues in Assessing Environmental Exposures to Manufactured Nanomaterials
Manufactured nanomaterials (MNs) are commonly considered to be commercial products possessing at least one dimension in the size range of 10−9 m to 10−7 m. As particles in this size range represent the smaller fraction of colloidal particles characterized by dimensions of 10−9 m to 10−6 m, they differ from both molecular species and bulk particulate matter in the sense that they are unlikely to exhibit significant settling under normal gravitational conditions and they are also likely to exhibit significantly diminished diffusivities (when compared to truly dissolved species) in environmental media. As air/water, air/soil, and water/soil intermedium transport is governed by diffusive processes in the absence of significant gravitational and inertial impaction processes in environmental systems, models of MN environmental intermedium transport behavior will likely require an emphasis on kinetic approaches. This review focuses on the likely environmental fate and transport of MNs in atmospheric and aquatic systems. Should significant atmospheric MNs emission occur, previous observations suggest that MNs may likely exhibit an atmospheric residence time of ten to twenty days. Moreover, while atmospheric MN aggregates in a size range of 10−7 m to 10−6 m will likely be most mobile, they are least likely to deposit in the human respiratory system. An examination of various procedures including the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal particle suspension stability in water indicates that more sophisticated approaches may be necessary in order to develop aquatic exposure models of acceptable uncertainty. In addition, concepts such as Critical Coagulation Concentrations and Critical Zeta Potentials may prove to be quite useful in environmental aquatic exposure assessments
Evaluating Herbicides for the Control of Multiflora Rose and Autumn Olive in Eastern Ohio
Invasive plants cause billions of dollars annually in damage, displace desirable plants, and reduce available land area for livestock grazing. Multiflora rose and autumn olive are two such species prevalent across the Eastern United States. Originally introduced for livestock containment and erosion control, these plants have become widespread, resulting in reduced animal grazing. The Eastern Agricultural Research Station (EARS) is located in Southeast Ohio and is owned by The Ohio State University. Much of the more than 2,000 acres has a history of surface mining and was reclaimed with the planting of multiflora rose and autumn olive. These plants have invaded significant portions of the property and have reduced land available to support the commercial beef research herd. Our study included a replicated trial of multiflora rose and autumn olive plants. We categorized plants into small and medium/large sizes across the study area. Six herbicide treatments were applied to plants using a handheld sprayer. Herbicide treatments were applied randomly in August and an assessment was completed approximately six weeks to rate effectiveness of the applications as compared to the control plants. There were four replicates per treatment. The initial results of the first year of the study indicate each of the products tested provided acceptable control of the treated plants
AGMIAL: implementing an annotation strategy for prokaryote genomes as a distributed system
We have implemented a genome annotation system for prokaryotes called AGMIAL. Our approach embodies a number of key principles. First, expert manual annotators are seen as a critical component of the overall system; user interfaces were cyclically refined to satisfy their needs. Second, the overall process should be orchestrated in terms of a global annotation strategy; this facilitates coordination between a team of annotators and automatic data analysis. Third, the annotation strategy should allow progressive and incremental annotation from a time when only a few draft contigs are available, to when a final finished assembly is produced. The overall architecture employed is modular and extensible, being based on the W3 standard Web services framework. Specialized modules interact with two independent core modules that are used to annotate, respectively, genomic and protein sequences. AGMIAL is currently being used by several INRA laboratories to analyze genomes of bacteria relevant to the food-processing industry, and is distributed under an open source license
The HMGB1/RAGE inflammatory pathway promotes pancreatic tumor growth by regulating mitochondrial bioenergetics
Tumor cells require increased adenosine triphosphate (ATP) to support anabolism and proliferation. The precise mechanisms regulating this process in tumor cells are unknown. Here, we show that the receptor for advanced glycation endproducts (RAGE) and one of its primary ligands, high-mobility group box 1 (HMGB1), are required for optimal mitochondrial function within tumors. We found that RAGE is present in the mitochondria of cultured tumor cells as well as primary tumors. RAGE and HMGB1 coordinately enhanced tumor cell mitochondrial complex I activity, ATP production, tumor cell proliferation and migration. Lack of RAGE or inhibition of HMGB1 release diminished ATP production and slowed tumor growth in vitro and in vivo. These findings link, for the first time, the HMGB1-RAGE pathway with changes in bioenergetics. Moreover, our observations provide a novel mechanism within the tumor microenvironment by which necrosis and inflammation promote tumor progression
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