关键词： Cropping   sustainability   organic   soybean   cover crop   reduced-tillage   no-till  

摘要： Organic grain producers are interested in reducing tillage to conserve soil and decrease labor and fuel costs. We examined agronomic and economic tradeoffs associated with alternative strategies for reducing tillage frequency and intensity in a cover crop-soybean (Glycine max L. Merr.) sequence within a corn (Zea mays L.)-soybean-spelt (Triticum spelta L.) organic cropping system experiment in Pennsylvania. Tillage-based soybean production preceded by a cover crop mixture of annual ryegrass (Lolium perenne L. ssp. multiflorum), orchardgrass (Dactylis glomerata L.) and forage radish (Raphanus sativus L.) interseeded into corn grain (Z. mays L.) was compared with reduced-tillage soybean production preceded by roller-crimped cereal rye (Secale cereale L.) that was sown after corn silage. Total aboveground weed biomass did not differ between soybean production strategies. Each strategy, however, was characterized by high inter-annual variability in weed abundance. Tillage-based soybean production marginally increased grain yield by 0.28 Mg ha(-1) compared with reduced-tillage soybean. A path model of soybean yield indicated that soybean stand establishment and weed biomass were primary drivers of yield, but soybean production strategy had a measurable effect on yields due to factors other than within-season weed-crop competition. Cumulative tillage frequency and intensity were quantified for each cover crop-sequence using the Soil Tillage Intensity Rating (STIR) index. The reduced-tillage soybean sequence resulted in 50% less soil disturbance compared to tillage-based soybean sequence across study years. Finally, enterprise budget comparisons showed that the reduced-tillage soybean sequence resulted in lower input costs than the tillage-based soybean sequence but was approximately $114 ha(-1) less profitable because of lower average yields.

关键词： MBD   FEA   SEM   RC   Plough-shank  

摘要： Plough-breast is the crucial soil-engaging component of horizontally reversible plough (HRP). The unique merit of HRP, in comparison to regular mouldboard ploughs, is the use of remote cylinder (RC) to drive its plough-body to implement alternative shifting tillage operations. A major technical challenge in the shifting operation is violent soil-tool interaction, caused by varying RC speeds, appearing on the plough-breast, particularly along its cutting edge, i.e. plough-shank. Still, the question of whether this interaction affects the plough-breast performance remains to be answered. In this study the interaction between soil and plough-breast was simulated using a combination of multi-body dynamics (MBD) and finite element analysis (FEA) and results were compared to wear rates measured in the field. It was found that for the cases examined herein the varying RC speeds can produce the maximum stress, e.g. 602.3 Pa and the most severe wear rate, e.g. 7.17 x 10(-8) m(2) along the ploughshank. But, the results are so small compared to the past findings as to have negligible effects on the plough-breast performance. Closer comparison of the experimental and numerical results confirms that sliding & rubbing, interrupted cutting and irregular soil flow, due to the varying RC speeds, result in the maximum stress and the most severe wear rate along the plough-shank.

关键词： Benign prostatic hyperplasia   Lower urinary tract symptoms   Quality of life   Phytotherapy   Physical therapy  

摘要： Benign prostatic hyperplasia (BPH) is a common disease that can cause uncomfortable lower urinary tract symptoms. The occurrence of symptomatic BPH develops after the age of 40 years and increases gradually with age to reach more than 50% at the age of 60 years and severely disturbs the quality of life of the patients. Alpha-blockers and 5-alpha reductase inhibitors are first-line agents used for the treatment of BPH. Due to the adverse effects of these conventional therapies, many patients turn to phytotherapy and other alternative therapies. This review covers alternative therapies, i.e., phytotherapy (cernilton, eviprostat, quercetin, saw palmetto and pumpkin seed) and physical therapy (acupuncture, aquablation, pulsed electromagnetic field, prostate urethral lift, radial extracorporeal shock wave therapy, thermobalancing therapy, and transurethral needle ablation) commonly used in the management of BPH.

摘要： Clerkship grades (like money) are a social construct that function as the currency through which value exchanges in medical education are negotiated between the system's various stakeholders. They provide a widely recognizable and efficient medium through which learner development can be assessed, tracked, compared, and demonstrated and are commonly used to make decisions regarding progression, distinction, and selection for residency. However, substantial literature has demonstrated how grades imprecisely and unreliably reflect the value of learners. In this article, the authors suggest that challenges with clerkship grades are fundamentally tied to their role as currency in the medical education system. Associations are drawn between clerkship grades and the history of the U.S. economy;2 major concepts are highlighted: regulation and stock prices. The authors describe the history of these economic concepts and how they relate to challenges in clerkship grading. Using lessons learned from the history of the U.S. economy, the authors then propose a 2-step solution to improve upon grading for future generations of medical students: (1) transition from grades to a federally regulated competency-based assessment model and (2) development of a departmental competency letter that incorporates competency-based assessments rather than letter grades and meets the needs of program directors.

摘要： Feedback pedagogies and research tend to focus on immediate corrective actions rather than learning for the longer term. This approach means that feedback may not support trainees who are managing complex, competing, and ambiguous practice situations, often with limited supervision. There is an opportunity to consider how feedback can help medical trainees sustain their own development into the future, including when they have completed formal training. This article explores how feedback pedagogies can facilitate medical trainees' abilities to develop challenging aspects of practice across multiple clinical environments to eventually practice without supervision. From a sociocultural perspective, clinical training takes place within a practice curriculum;each clinical environment offers varying opportunities, which the trainees may choose to engage with. The authors propose feedback as an interpersonal process that helps trainees make sense of both formal training requirements and performance relevant information, including workplace cues such as patient outcomes or colleagues' comments, found within any practice curriculum. A significant pedagogic strategy may be to develop trainees' evaluative judgment or their capability to identify and appraise the qualities of good practice in both themselves and others. In this way, feedback processes may help trainees surmount complex situations and progressively gain independence from supervision.

摘要： After the closure of pill mills and implementation of Florida's Prescription Drug Monitoring Program in 2010, high demand for opioids was met with counterfeit pills, heroin, and fentanyl. In response, medical students at the University of Miami Miller School of Medicine embarked on a journey to bring syringe services programs (SSPs) to Florida through an innovative grassroots approach. Working with the Florida Medical Association, students learned patient advocacy, legislation writing, and negotiation within a complex political climate. Advocacy over 4 legislative sessions (2013-2016) included committee testimony and legislative visit days, resulting in the authorization of a 5-year SSP pilot. The University of Miami's Infectious Disease Elimination Act (IDEA) SSP opened on December 1, 2016. Students identified an urgent need for expanded health care for program participants and founded a weekly free clinic at the SSP. Students who rotate through the clinic learn medicine and harm reduction through the lens of social justice, with exposure to people who use drugs, sex workers, individuals experiencing homelessness, and other vulnerable populations. The earliest success of the IDEA SSP was the distribution of over 2,000 boxes of nasal naloxone, which the authors believe positively contributed to a decrease in the number of opioid-related deaths in Miami-Dade County for the first time since 2013. The second was the early identification of a cluster of acute human immunodeficiency virus infections among program participants. Inspired by these successes, students from across the state joined University of Miami students and met with legislators in their home districts, wrote op-eds, participated in media interviews, and traveled to the State Capitol to advocate for decisive action to mitigate the opioid crisis. The 2019 legislature passed legislation authorizing SSPs statewide. In states late to adopt SSPs, medical schools have a unique opportunity to address the opioid

关键词： Tabular olivine   Morphological transition   Serpentinite dehydration   Surfactant   Inhibited growth   Subduction zone  

摘要： Crystal morphologies are essential for deciphering the reaction history of igneous and metamorphic rocks because they often record the interplay between nucleation and growth rates controlled by the departure from equilibrium. Here, we report an exceptional record of the morphological transition of olivine formed during subduction metamorphism and high- pressure dehydration of antigorite-serpentinite to prograde chlorite-harzburgite in the Almirez ultramafic massif (Nevado-Filabride Complex, Betic Cordillera, SE Spain). In this massif, rare varied-textured chlorite-harzburgite (olivine+enstantite+chlorite+oxides)-formed after high-P dehydration of antigorite-serpentinite-exhibits large olivine porphyroblasts made up of rounded cores mantled by coronas of tabular olivine grains, similar to single tabular olivines occurring in the matrix. The correlative X-ray mu-CT and EBSD study of two varied-textured chlorite-harzburgite samples show that tabular olivine in coronas is tabular on (100)(Ol) with c > b >> a, and grew in nearly the same crystallographic orientation as the rounded olivine cores of the porphyroblast. Quantitative textural analysis and mass balance indicate that varied-textured chlorite-harzburgite is the result of a two-stage nucleation and growth of olivine during the progress of the high-P dehydration of antigorite-serpentinite to chlorite-harzburgite reaction. The first stage occurred under a low affinity (Delta G(r)) and affinity rate (Delta G(r)/dt) of the antigorite dehydration reaction that resulted in a low time-integrated nucleation rate and isotropic growth of olivine, forming rounded olivine porphyroblasts. With further progress of the dehydration reaction, a second stage of relatively higher affinity and affinity rate resulted in a higher time-integrated nucleation rate of olivine coeval with a shift from isotropic to anisotropic olivine growth, leading to tabular olivines. The two-stage evolution resulted in olivine porphyroblasts made up of

摘要： The iconic Miller's pyramid, proposed in 1989, characterizes 4 levels of assessment in medical education ("knows," "knows how," "shows how," "does"). The frame work has created a worldwide awareness of the need to have different assessment approaches for different expected outcomes of education and training. At the time, Miller stressed the innovative use of simulation techniques, geared at the third level ("shows how");however, the "does" level, assessment in the workplace, remained a largely uncharted area. In the 30 years since Miller's conference address and seminal paper, much attention has been devoted to procedures and instrument development for workplace-based assessment. With the rise of competency-based medical education (CBME), the need for approaches to determine the competence of learners in the clinical workplace has intensified. The proposal to use entrustable professional activities as a framework of assessment and the related entrustment decision making for clinical responsibilities at designated levels of supervision of learners (e.g., direct, indirect, and no supervision) has become a recent critical innovation of CBME at the "does" level. Analysis of the entrustment concept reveals that trust in a learner to work without assistance or supervision encompasses more than the observation of "doing" in practice (the "does" level). It implies the readiness of educators to accept the inherent risks involved in health care tasks and the judgment that the learner has enough experience to act appropriately when facing unexpected challenges. Earning this qualification requires qualities beyond observed proficiency, which led the authors to propose adding the level "trusted" to the apex of Miller's pyramid.