151 research outputs found
Performance of the Producer Accumulator in Corn and Soybean Commodity Markets
This research quantifies risk reduction and performance of the producer accumulator contract in corn and soybean markets. To quantify performance, we use three alternative theoretical pricing models to estimate historical producer accumulator contract specifications in corn and soybean markets. We then compare the performance of the producer accumulator to eight alternative agricultural marketing strategy portfolios that are also used in new generation grain contracts. The performance measures we compare are: average bushel price that would be received by the producer, daily portfolio risk, and the Sharpe ratio. The period we examine performance was between 2008 and 2017. We investigate performance of the producer accumulator executed during each year, month, whether the contract was executed during the growing season or non-growing season, and beginning and following an uptrend, neutral trend, and downtrend ranging in length from 25 to 100-days. Specific to the producer accumulator, we also quantify bushels accumulated during the contract period. We find the average price the producer would expect to receive adopting an accumulator to slightly underperform the average price they would receive with a long futures portfolio in corn and slightly outperform long futures in soybeans. Nevertheless, the accumulator significantly reduces daily risk compared to the long futures portfolio. Indeed, producer accumulator portfolios produced average daily Sharpe ratios exceeding all other simulated risk management strategies in corn and soybeans on an average annual and average aggregate basis from 2008-2017. Consequently, the producer accumulator portfolio offered corn and soybean producers the best risk adjusted return to hedge production during this time-frame
Novel, Moon and Mars, partial gravity simulation paradigms and their effects on the balance between cell growth and cell proliferation during early plant development
Novel, Moon and Mars, partial gravity simulation paradigms and their effects on the balance between cell growth and cell proliferation during early plant development
Prospective randomized controlled trial to analyze the effects of intermittent pneumatic compression on edema following autologous femoropopliteal bypass surgery
A comparative study of 3D measuring methods for monitoring breast volume changes
Three-dimensional (3D) imaging techniques are promising new tools for measuring breast volume, for example in gender-affirming therapy. Transgender individuals can be treated with gender-affirming hormone therapy (GAHT). A robust method for monitoring breast volume changes is critical to be able to study the effects of feminizing GAHT. The primary aim of this study was to compare the accuracy of three 3D devices (Vectra XT, Artec LEO and iPhone XR) for measuring modest breast volume differences using a mannequin. The secondary aim of this study was to evaluate these methods in several performance domains. We used reference prostheses of increasing volumes and compared the volumes using GOM-inspect software. For Vectra XT 3D images, manufacturer-provided software was used to calculate volumes as well. The scanning methods were ranked based on their performance in a total of five categories: volume estimations, costs, user-friendliness, test subject- friendliness and technical aspects. The 3D models analyzed with GOM-inspect showed relative mean estimate differences from the actual volumes of 9.1% for the Vectra XT, 7.3% for the Artec LEO and 14% for the iPhone XR. For the Vectra XT models analyzed with the built-in software this was 6.2%. Root mean squared errors (RMSE) calculated based on the GOM-inspect volume analyses showed mean RMSEs of 2.27, 2.54 and 8.93 for the Vectra XT, Artec LEO and iPhone XR, respectively. The Vectra software had a mean RMSE of 3.00. In the combined performance ranking, the Vectra XT had the most favorable ranking, followed by the Artec LEO and the iPhone XR. The Vectra XT and Artec LEO are the preferred scanners to monitor breast development due to the combination of higher accuracy and overall performance. The current study shows that 3D techniques can be used to adequately measure modest breast volume differences and therefore will be useful to study for example breast changes in transgender individuals using feminizing GAHT. These observations may also be relevant in other fields of 3D imaging research.</p
Traumatic Anterior Dislocation of the Shoulder: Factors Affecting the Progress of the Traumatic Anterior Dislocation
Oncology Section EDGE Task Force on Urogenital Cancer Outcomes: Clinical Measures of Lymphedema—A Systematic Review
Background: Valid and reliable tools to assess lymphedema are necessary to accurately evaluate status and to objectively document and measure the results of interventions. Understanding the advantages and disadvantages of each measure can inform the clinician\u27s choice of the appropriate tool to be used in the clinic or research setting. Purpose: To identify reliable and valid measurement techniques that are sensitive to change for assessing edema volume or soft tissue change in the lower extremities or genital region of patients with lymphedema. Methods: A systematic review of the literature was conducted to assess the published psychometric properties and clinical feasibility of each method identified. Task Force members independently reviewed each measure using the Cancer EDGE Rating Form. Results: Both water displacement and circumferential measurement methods by tape measure were rated as Highly Recommended to quantify lower-extremity limb volume. Water displacement was determined to be the criterion standard by which all other assessments of volume are benchmarked. Both optoelectric volumetry and bioelectric impedance analysis were rated as Recommended, and ultrasound was rated Not Recommended. Conclusion: The Urogenital Cancer EDGE Task Force highly recommends water displacement and circumferential tape measurement for use as reliable methods for assessment and documentation of change of limb volume in this patient population. Early detection of subclinical lower-extremity lymphedema in this patient population remains challenging, as there is no “index” limb that can be proven to be uninvolved in a patient population with documented pelvic node dissection/irradiation. No articles were found to support valid and reliable genital lymphedema volume measurement
Prospective Randomized Controlled Trial to Analyze the Effects of Intermittent Pneumatic Compression on Edema Following Autologous Femoropopliteal Bypass Surgery
Background: Patients who undergo autologous femoropopliteal bypass surgery develop postoperative edema in the revascularized leg. The effects of intermittent pneumatic compression (IPC) to treat and to prevent postreconstructive edema were examined in this study. Methods: In a prospective randomized trial, patients were assigned to one of two groups. All patients suffered from peripheral arterial disease, and all were subjected to autologous femoropopliteal bypass reconstruction. Patients in group 1 used a compression stocking (CS) above the knee exerting 18 mmHg (class I) on the leg postoperatively for 1 week (day and night). Patients in group 2 used IPC on the foot postoperatively at night for 1 week. The lower leg circumference was measured preoperatively and at five postoperative time points. A multivariate analysis was done using a mixed model analysis of variance. Results: A total of 57 patients were analyzed (CS 28; IPC 29). Indications for operation were severe claudication (CS 13; IPC 13), rest pain (10/5), or tissue loss (7/11). Revascularization was performed with either a supragenicular (CS 13; IPC10) or an infragenicular (CS 15; IPC 19) autologous bypass. Leg circumference increased on day 1 (CS/IPC): 0.4%/2.7%, day 4 (2.1%/6.1%), day 7 (2.5%/7.9%), day 14 (4.7%/7.3%), and day 90 (1.0%/3.3%) from baseline (preoperative situation). On days 1, 4, and 7 there was a significant difference in leg circumference between the two treatment groups. Conclusions: Edema following femoropopliteal bypass surgery occurs in all patients. For the prevention and treatment of that edema the use of a class I CS proved superior to treatment with IPC. The use of CS remains the recommended practice following femoropopliteal bypass surgery
Survey on the management of acute first-time anterior shoulder dislocation amongst Dutch public hospitals
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