1,950 research outputs found

    Herbicide-Resistant Soybeans in Arkansas: Lessons Learned and Future Direction

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    In Arkansas Delta soybean production, glyphosate resistant (GR) Palmer amaranth has significantly impacted weed management. The incidence of herbicide resistant (HR) weeds has farreaching crop science, economic, and communications implications, which have been explored by the corresponding expertise of our research team members to form a comprehensive literature review. The review was used to develop policy recommendations to address current and future HR genetically modified (GM) crop use and the associated issues. The review of crop science research indicated an overall increase in herbicide application, as well as an increase in weed management programs focused around glyphosate rather than the application of multiple herbicides. The review also revealed some management methods have potential to resolve the problem, including alternating herbicide application, avoiding sub-lethal rates, using ā€œburn downā€ herbicides prior to planting, crop rotation, tillage, and zero tolerance weed policies. The use of fewer herbicides rather than multiple types creates a monopolistic edge for the companies producing those few herbicides, allowing greater market control. Crisis communication methods, including developing internal readiness, conducting needs assessments, developing a relevant message, and conveying the message through appropriate channels, can be used to develop a response to the issue that will best communicate necessary information to the target audience. The team used these findings to formulate policy recommendations, which include management, economic, and communication plans that may provide a starting point to address the issue

    Defining cell culture dynamics in response to growth factor provision for efficient optimization of cell based therapies

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    The design of processes to manufacture Cell Based Therapies (CBTs) is particularly challenging due to the dynamic cell culture environment and the complex response of the cell product. An approach to process design needs to achieve a balance between resource spent and process knowledge gained to meet manufacturing goals around cost, quality and risk. In order to address this, we developed a parsimonious mathematical modelling framework designed to allow representation of common mechanisms in cell culture, and associated process operations, that drive cell culture outcomes(1). We propose that this framework can be applied to generate widely applicable ā€˜template modelsā€™ and experimental strategies for process optimization. In this case we have demonstrated the application to define provision rates of elements that support cell growth in a hematopoietic culture system (erythroblasts). Building on a model that defined the influence of environmental change (incorporated as a single non-specific variable linked to cell growth and density) on population growth(2), we have defined the cell culture dynamics in response to specific elements such as growth factor provision. We have shown how achieving the correct combination of delivery rates of growth factors with other factors (e.g. metabolic) can ensure that each is used with maximal efficiency, significantly driving down volume use (more than 3-fold) and process supplementation costs. The models also define the corollary of such intensification in terms of increasingly demanding process control with respect to volume handling and process timing; however, an advantage of the level of intensification achieved is that the system oxygen demand increases to a level that oxygen input rates can be used to identify cell growth-inhibition in advance of reduced viability. This work demonstrates that models that appropriately represent common process dynamics will be a key tool to achieve the risk and cost reduction required for CBT manufacture. (1) AJ Stacey, EA Cheeseman, KE Glen, RLL Moore, RJ Thomas. Experimentally integrated dynamic modelling for intuitive optimization of cell-based processes and manufacture. Biochem Eng J. 2018. 132: 130-138 (2) KE Glen, EA Cheeseman, AJ Stacey, RJ Thomas. A mechanistic model of erythroblast growth inhibition providing a framework for optimization of cell therapy manufacturing. Biochem Eng J. 2018. 133:28-38

    Attitudes and Beliefs of African-Americans Toward Genetics, Genetic Testing, and Sickle Cell Disease Education and Awareness

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    Research among African-Americans indicates this population perceives sickle cell (SCD) to be a serious disease and sickle cell trait (SCT) screening an important intervention. However, studies have consistently demonstrated a lower than desired uptake of SCD education, inadequate knowledge regarding personal and family trait status, and a low perceived susceptibility of giving birth to a child with the disease. We examined general attitudes and beliefs regarding genetics and genetic testing including prenatal testing and newborn screening; we used this information as the foundation to more specifically assess attitudes and beliefs regarding SCD and perceived barriers to SCD education and awareness. Thirty-five African-American adult men and women participated in one of four focus groups. Thematic analysis identified that both prenatal testing and newborn screening are acceptable forms of genetic testing. Based largely on their personal experiences, participants possessed an understanding of the natural progression of SCD but had a limited understanding of the inheritance and probable risk of giving birth to a child with the disease. Barriers to education and greater awareness of SCD were classified as personal, familial, and societal. Community based interventions focused on sharing the stories of individuals with first-hand experiences with SCD should be considered

    Limitation of Life-Sustaining Care in the Critically Ill: A Systematic Review of the Literature

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    When life-sustaining treatments (LST) are no longer effective or consistent with patient preferences, limitations may be set so that LSTs are withdrawn or withheld from the patient. Many studies have examined the frequency of limitations of LST in intensive care unit (ICU) settings in the past 30 years. This systematic review describes variation and patient characteristics associated with limitations of LST in critically ill patients in all types of ICUs in the United States. A comprehensive search of the literature was performed by a medical librarian between December 2014 and April 2017. A total of 1,882 unique titles and abstracts were reviewed, 113 were selected for article review, and 36 studies were fully reviewed. Patient factors associated with an increased likelihood of limiting LST included white race, older age, female sex, poor preadmission functional status, multiple comorbidities, and worse illness severity score. Based on several large, multicenter studies, there was a trend toward a higher frequency of limitation of LST over time. However, there is large variability between ICUs in the proportion of patients with limitations and on the proportion of deaths preceded by a limitation. Increases in the frequency of limitations of LST over time suggests changing attitudes about aggressive end-of-life-care. Limitations are more common for patients with worse premorbid health and greater ICU illness severity. While some differences in the frequency of limitations of LST may be explained by personal factors such as race, there is unexplained wide variability between units

    Determination of vancomycin and gentamicin clearance in an in vitro, closed loop dialysis system

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    Background\ud The purpose of this study was to evaluate the feasibility of utilizing an in-vitro, closed loop hemodialysis system as a method to assess drug clearance. Secondarily, this study tested the influence of variables (blood flow rate, dialysate flow rate, and type of filter) in the hemodialysis procedure on the clearance of vancomycin and gentamicin.\ud \ud Methods\ud An in-vitro, closed loop hemodialysis system was constructed. The vancomycin (30 mg/L) and gentamicin (25 mg/L) were added to a simulated blood system (SBS). Four conditions (C1-C4) were tested by defining the filter (Polyflux 170H or F180) and the blood and dialysate flow rates (BFR and DFR). All hemodialysis sessions were 3 hours in length and each condition was completed in duplicate. Dialysate effluent was collected in a 50 gallon polyethylene drum. Samples were collected (in duplicate) from the SBS and the dialysate effluent at baseline and at the end of the hemodialysis session. Samples were analyzed for vancomycin and gentamicin with an ultrahigh performance liquid chromatography/tandem mass spectrometry method.\ud \ud Results\ud A total of eight 3-hour hemodialysis sessions were conducted. For all tested conditions (C1-C4), vancomycin was undetectable in the SBS at the end of dialysis. However, total vancomycin recovery in the dialysis effluent was 85Ā±18%, suggesting that up to 15% may have adsorbed to the dialysis filter or tubing. Gentamicin clearance from SBS was >98% in all tested conditions. Average gentamicin recovery in the dialysate effluent was 99Ā±15%.\ud \ud Conclusion\ud Both vancomycin and gentamicin were readily removed by high-flux hemodialysis under all conditions studied. No significant differences in drug clearance were observed between conditions used in this in vitro study. The clinical implications of changing these hemodialysis parameters are unknown

    Development and initial application of a blade design methodology for overspeed power-regulated tidal turbines

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    The range and variability of flow velocities in which horizontal axis tidal stream turbines operate introduces the requirement for a power regulation method in the system. Overspeed power regulation (OSPR) has the potential to improve the structural robustness and decrease the complexity associated with active pitch power regulation methods, while removing the difficulties of operating in stalled flow. This paper presents the development of a methodology for the design of blades to be used in such systems. The method requires a site depth, maximum flow velocity and rated power or flow speed as input parameters. The pitch setting, twist and chord distribution were set as input parameters, variable through the use of alteration functions. Rotor performance has been broken down into OSPR performance metrics which consider coefficients of power and thrust, and cavitation inception. Three visual-numerical tools have been developed: the OSPR performance metrics were used in conjunction with a one-at-a-time sensitivity analysis approach to develop a design space; cavitation inception analyses gave plots of converging cavitation and pressure terms for each blade section; the local angle of attack and torque distribution across the blade designs were plotted at key turbine operation states. Alterations to pitch setting and twist distribution are shown to have most impact upon the design requirement of increased gradient in the rotor speed-efficiency relationship in the overspeed region; coupled with such alterations, targeted changes to the chord distribution have been shown to increase the maximum efficiency. The prevention of cavitation has been highlighted as a driver for speed-limiting design alterations. While facilitating blade design, the methodology also produces experiential knowledge which can be stored, and shared in graphical format

    Firesetting Reoffending: A Meta-Analysis

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    Despite the significant adverse consequences of deliberate firesetting, it has been unclear what proportion of individuals repeat this problematic behavior, owing to methodological differences and large variability in reported reoffending rates. A meta-analysis of 25 samples of untreated adults and children with a history of firesetting, examining reoffending over a follow-up period, was conducted. The base rates of reoffending from this meta-analysis indicated that between 57% and 66% of untreated firesetters engage in general reoffending, between 8% and 10% engage in criminal arson, and around 20% engage in deliberate firesetting behavior. The odds of firesetting during the follow-up period were 5 times greater for known firesetters in comparison with other offenders. Clinical and criminological correlates of reoffending, including age, are examined. Implications for enabling evidence-based practice with this population, including defensible risk assessments and treatment provision, are discussed

    Developing a core outcome set for periodontal trials

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    Acknowledgments The authors wish to thank all patients and professionals who took part in the Delphi process and face-to-face consensus meeting. We wish to thank Jillian Sutherland, Shirley Bell, Margaret Mooney and Lorna Barnsley for helping to organise the face-to-face consensus meeting. Patient participant recruitment to this study was facilitated by SHAREā€“the Scottish Health Research Register. SHARE is supported by NHS Research Scotland and the Chief Scientists Office Funding: TL received research funding for the core outcome set development for the prevention and management of periodontal diseases which was provided by the Tattershall fund, Dundee Dental School. This grant provided funds for the e-Delphi software, SHARE services and the face-to-face consensus meeting travel and catering costs. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptPeer reviewedPublisher PD

    Mindfulness training for depressed older adults using smartphone technology: Protocol for a fully remote precision clinical trial

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    BACKGROUND: Precision medicine, optimized interventions, and access to care are catchphrases for the future of behavioral treatments. Progress has been slow due to the dearth of clinical trials that optimize interventions\u27 benefits, individually tailor interventions to meet individual needs and preferences, and lead to rapid implementation after effectiveness is demonstrated. Two innovations have emerged to meet these challenges: fully remote trials and precision clinical trials. OBJECTIVE: This paper provides a detailed description of Mindful MyWay, a study designed to test online mindfulness training in older adults with depression. Consistent with the concept of fully remote trials using a smartphone app, the study requires no in-person contact and can be conducted with participants anywhere in the United States. Based upon the precision medicine framework, the study assesses participants using high-frequency assessments of symptoms, cognitive performance, and patient preferences to both understand the individualized nature of treatment response and help individually tailor the intervention. METHODS: Mindful MyWay is an open-label early-phase clinical trial for individuals 65 years and older with current depression. A smartphone app was developed to help coordinate the study, deliver the intervention, and evaluate the acceptability of the intervention, as well as predictors and outcomes of it. The curriculum for the fully remote intervention parallels the mindfulness-based stress reduction curriculum, a protocolized group-based mindfulness training that is typically provided in person. After consent and screening, participants download The Healthy Mind Lab mobile health smartphone app from the Apple App Store, allowing them to complete brief smartphone-based assessments of depressive symptoms and cognitive performance 4 times each day for 4 weeks prior to and after completing the intervention. The intervention consists of an introduction video and 10 weekly mindfulness training sessions, with the expectation to practice mindfulness at home daily. The app collects participant preference data throughout the 10-week intervention period; these high-frequency assessments identify participants\u27 individually dynamic preferences toward the goal of optimizing the intervention in future iterations. RESULTS: Participant recruitment and data collection began in March 2019. Final end point assessments will be collected in May 2022. The paper describes lessons learned regarding the critical role of early-phase testing prior to moving to a randomized trial. CONCLUSIONS: The Mindful MyWay study is an exemplar of innovative clinical trial designs that use smartphone technology in behavioral and neuropsychiatric conditions. These include fully remote studies that can recruit throughout the United States, including hard-to-access areas, and collect high-frequency data, which is ideal for idiographic assessment and individualized intervention optimization. Our findings will be used to modify our methods and inform future randomized controlled trials within a precision medicine framework. TRIAL REGISTRATION: ClinicalTrials.gov NCT03922217; https://clinicaltrials.gov/ct2/show/NCT03922217. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/39233
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