Defining and Meeting the Demand for Agricultural Machinery in China: A Case Study of John Deere

China, Machinery markets, John Deere, Agribusiness, Demand and Price Analysis, Marketing, Public Economics,

Closing the Divide: How Medical Homes Promote Equity in Health Care

Presents findings from the Commonwealth Fund 2006 Health Care Quality Survey, and demonstrates how having stable insurance, a regular provider and, in particular, a medical home, improves health care access and quality among vulnerable populations

What are the most practical primary care screens for post-traumatic stress disorder?

The 4-item Primary Care Post-Traumatic Stress Disorder screen (PC-PTSD) is a simple and effective tool to identify symptoms of post-traumatic stress disorder (PTSD) in primary care patients (strength of recommendation [SOR ]: B, 1 good-quality prospective cohort study and 1 good-quality retrospective cohort study). The 7-item Breslau screen also predictably identifies patients with PTSD symptoms (SOR : B, 1 good-quality prospective cohort study)

The Development and Evaluation of a Novel Thoracoscopic Diaphragmatic Hernia Repair Simulator

Background: Thoracoscopic diaphragmatic hernia (DH) repair has a high recurrence rate. Effective simulation modeling may improve technical performance for thoracoscopic DH repair. The study purpose was to evaluate measures of validity evidence for a low-cost thoracoscopic DH simulator. Materials and Methods: Synthetic diaphragm/intestine was connected to a to-scale left-sided neonatal rib cage and then covered with synthetic skin. Forty participants evaluated the DH repair simulator, using survey ratings that were analyzed for test content and internal structure validity evidence. Results: Observed averages (on a scale of 0?5) for the domains were 4.6 for Relevance, 4.5 for Value, 4.3 for Physical attributes, 4.0 for Realism of experience, 3.8 for Realism of materials, and 4.2 for Ability to perform. The highest observed averages were ?relevance to practice? and ?value, testing tool,? whereas the lowest ratings were realism, intestines and realism, diaphragm. The observed average of global opinion ratings was 2.84/4.0, indicating the simulator can be considered for teaching thoracoscopic DH repair but could be improved. Experienced surgeons (more than eight DH repairs, at least four thoracoscopic repairs) had higher overall ratings than inexperienced surgeons (4.4 versus 4.1, P=.001). Conclusions: We successfully created a thoracic space relevant to a thoracoscopic DH repair and completed the model using inexpensive, readily accessible materials. After participants performed a simulated thoracoscopic DH repair, their ratings indicated the simulator was relevant to clinical practice and valuable as a learning tool but still requires improvements. Improvements and additional evaluation of validity evidence (content, internal structure, response processes, and relationship to other variables) are necessary prior to full implementation of this model as an educational tool.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140147/1/lap.2013.0196.pd

The Development and Evaluation of a Novel Thoracoscopic Diaphragmatic Hernia Repair Simulator

Background: Thoracoscopic diaphragmatic hernia (DH) repair has a high recurrence rate. Effective simulation modeling may improve technical performance for thoracoscopic DH repair. The study purpose was to evaluate measures of validity evidence for a low-cost thoracoscopic DH simulator. Materials and Methods: Synthetic diaphragm/intestine was connected to a to-scale left-sided neonatal rib cage and then covered with synthetic skin. Forty participants evaluated the DH repair simulator, using survey ratings that were analyzed for test content and internal structure validity evidence. Results: Observed averages (on a scale of 0?5) for the domains were 4.6 for Relevance, 4.5 for Value, 4.3 for Physical attributes, 4.0 for Realism of experience, 3.8 for Realism of materials, and 4.2 for Ability to perform. The highest observed averages were ?relevance to practice? and ?value, testing tool,? whereas the lowest ratings were realism, intestines and realism, diaphragm. The observed average of global opinion ratings was 2.84/4.0, indicating the simulator can be considered for teaching thoracoscopic DH repair but could be improved. Experienced surgeons (more than eight DH repairs, at least four thoracoscopic repairs) had higher overall ratings than inexperienced surgeons (4.4 versus 4.1, P=.001). Conclusions: We successfully created a thoracic space relevant to a thoracoscopic DH repair and completed the model using inexpensive, readily accessible materials. After participants performed a simulated thoracoscopic DH repair, their ratings indicated the simulator was relevant to clinical practice and valuable as a learning tool but still requires improvements. Improvements and additional evaluation of validity evidence (content, internal structure, response processes, and relationship to other variables) are necessary prior to full implementation of this model as an educational tool.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140147/1/lap.2013.0196.pd

Stations, trains and small-world networks

The clustering coefficient, path length and average vertex degree of two urban train line networks have been calculated. The results are compared with theoretical predictions for appropriate random bipartite graphs. They have also been compared with one another to investigate the effect of architecture on the small-world properties.Comment: 6 pages, prepared in RevTe

Mirror, Mirror on the Wall: An International Update on the Comparative Performance of American Health Care

Using data from patient and physician surveys, finds that the U.S. healthcare system ranks last or next-to-last when comparing healthcare performance against that of five other nations -- Australia, Canada, Germany, New Zealand, the United Kingdom

Evaluation of Three Sources of Validity Evidence for a Laparoscopic Duodenal Atresia Repair Simulator

Purpose: Laparoscopic duodenal atresia (DA) repair is a relatively uncommon pediatric operation requiring advanced minimally invasive skills. Currently, there are no commercial simulators available that address surgeons' needs for refining skills associated with this procedure. The purposes of this study were (1) to create an anatomically correct, size-relevant model and (2) to evaluate the content validity of the simulator. Materials and Methods: Radiologic images were used to create an abdominal domain consistent with a full-term infant. Fetal bovine tissue was used to complete the simulator. Following Institutional Review Board exempt determination, 18 participants performed the simulated laparoscopic DA repair. Participants completed a self-report, six-domain, 24-item instrument consisting of 4-point rating scales (from 1=not realistic to 4=highly realistic). Validity evidence relevant to test content and response processes was evaluated using the many-facet Rasch model, and evidence of internal structure (inter-item consistency) was estimated using Cronbach's alpha. Results: The highest observed averages were for ?Value as a training and testing tool? (both observed averages=3.9), whereas the lowest ratings were ?Palpation of liver? (observed average=3.3) and ?Realism of skin? (observed average=3.2). The Global opinion rating was 3.2, indicating the simulator can be considered for use as is, but could be improved slightly. Inter-item consistency was high (α=0.89). Conclusions: We have successfully created a size-appropriate laparoscopic DA simulator. Participants agreed that the simulator was relevant and valuable as a learning/testing tool. Prior to implementing this simulator as a training tool, minor improvements should be made, with subsequent evaluation of additional validation evidence.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140148/1/lap.2014.0358.pd

Evaluation of Three Sources of Validity Evidence for a Synthetic Thoracoscopic Esophageal Atresia/Tracheoesophageal Fistula Repair Simulator

Purpose: Thoracoscopic esophageal atresia (EA)/tracheoesophageal fistula (TEF) repair is technically challenging. We have previously reported our experiences with a high-fidelity hybrid model for simulation-based educational instruction in thoracoscopic EA/TEF, including the high cost of the tissue for these models. The purposes of this study were (1) to create a low-cost synthetic tissue EA/TEF repair simulation model and (2) to evaluate the content validity of the synthetic tissue simulator. Materials and Methods: Review of the literature and computed tomography images were used to create computer-aided drawings (CAD) for a synthetic, size-appropriate EA/TEF tissue insert. The inverse of the CAD image was then printed in six different sections to create a mold that could be filled with platinum-cured silicone. The silicone EA/TEF insert was then placed in a previously described neonatal thorax and covered with synthetic skin. Following institutional review board?exempt determination, 47 participants performed some or all of a simulated thoracoscopic EA/TEF during two separate international meetings (International Pediatric Endosurgery Group [IPEG] and World Federation of Associations of Pediatric Surgeons [WOFAPS]). Participants were identified as ?experts,? having 6?50 self-reported thoracoscopic EA/TEF repairs, and ?novice,? having 0?5 self-reported thoracoscopic EA/TEF repairs. Participants completed a self-report, six-domain, 24-item instrument consisting of 23 5-point rating scales and one 4-point Global Rating Scale. Validity evidence relevant to test content and response processes was evaluated using the many-facet Rasch model, and evidence of internal structure (interitem consistency) was estimated using Cronbach's alpha. Results: A review of the participants' ratings indicates there were no overall differences across sites (IPEG versus WOFAPS, P=.84) or experience (expert versus novice, P=.17). The highest observed averages were 4.4 (Value of Simulator as a Training Tool), 4.3 (Physical Attributes?chest circumference, chest depth, and intercostal space), and 4.3 (Realism of Experience?fistula location). The lowest observed averages were 3.5 (Ability to Perform?closure of fistula), 3.7 (Ability to Perform?acquisition target trocar sites), 3.8 (Physical Attributes?landmark visualization), 3.8 (Ability to Perform?anastomosis and dissection of upper pouch), and 3.9 (Realism of Materials?skin). The Global Rating Scale was 2.9, coinciding with a response of ?this simulator can be considered for use in neonatal TEF repair training, but could be improved slightly.? Material costs for the synthetic EA/TEF inserts were less than $2 U.S. per insert. Conclusions: We have successfully created a low-cost synthetic EA/TEF tissue insert for use in a neonatal thoracoscopic EA/TEF repair simulator. Analysis of the participants' ratings of the synthetic EA/TEF simulation model indicates that it has value and can be used to train pediatric surgeons, especially those early in their learning curve, to begin to perform a thoracoscopic EA/TEF repair. Areas for model improvement were identified, and these areas will be the focus for future modifications to the synthetic EA/TEF repair simulator.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140150/1/lap.2014.0370.pd

Preliminary Evaluation of a Novel Thoracoscopic Infant Lobectomy Simulator

Purpose: Thoracoscopic lobectomy in infants requires advanced minimally invasive skills. Simulation-based education has the potential to improve complex procedural skills without exposing the patient to undue risks. The study purposes were (1) to create a size-appropriate infant lobectomy simulator and (2) to evaluate validity evidence to support or refute its use in surgical education. Materials and Methods: In this Institutional Review Board-exempt study, a size-appropriate rib cage for a 3-month-old infant was created. Fetal bovine tissue completed the simulator. Thirty-three participants performed the simulated thoracoscopic lobectomy. Participants completed a self-report, 26-item instrument consisting of 25 4-point rating scales (from 1=not realistic to 4=highly realistic) and a one 4-point Global Rating Scale. Validity evidence relevant to test content and response processes was evaluated using the many-facet Rasch model, and evidence of internal structure (inter-item consistency) was estimated using Cronbach's alpha. Results: Experienced surgeons (observed average=3.6) had slightly higher overall rating than novice surgeons (observed average=3.4, P=.001). The highest combined observed averages were for the domain Physical Attributes (3.7), whereas the lowest ratings were for the domains Realism of Experience and Ability to Perform Tasks (3.4). The global rating was 2.9, consistent with ?this simulator can be considered for use in infant lobectomy training, but could be improved slightly.? Inter-item consistency for items used to evaluate the simulator's quality was high (α=0.90). Conclusions: With ratings consistent with high physical attributes and realism, we successfully created an infant lobectomy simulator, and preliminary evidence relevant to test content, response processes, and internal structure was supported. Participants rated the model as realistic, relevant to clinical practice, and valuable as a learning tool. Minor improvements were suggested prior to its full implementation as an educational and testing tool.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140149/1/lap.2014.0364.pd