Economics of Experimental Design: Finding the Optimal Design of a Whole Field Randomized Experiment

An April 2017 Cornhusker Economics article Getting to Know Your Yield Response Better through Whole-field Randomized Experiments discussed a case study detailing a whole-field randomized agronomic experiment (nitrogen and seed rate). The study was conducted in Kentucky and funded through the USDA-NIFA Data Intensive Farm Management (DIFM) project. The project has so far resulted in more than 50 experiments across several states, including Illinois, Nebraska, Kansas, and Washington. The overarching goal of the project is to provide agricultural producers with the best input rate, variable or uniform, which maximizes their farm profits. This involves statistically estimating the crop response function and then the mathematical optimization to identify the best input rate based on the estimated response function

Toward an effective approach for on‑farm experimentation: lessons learned from a case study of fertilizer application optimization in Japan

On-farm experimentation (OFE) is increasing worldwide. Appropriate OFE procedures may differ depending on the characteristics and circumstances surrounding farms, such as climate, field conditions, farm size, degree of agricultural digitalization, and a farmer’s socioeconomic background. This study aims to guide the future development of OFE in Japanese grain farming by examining the experimental setup, data analysis, and farmers’ activities within their socioeconomic and institutional communication and learning networks. The results of this typical OFE case study, which estimates a field’s economicallyoptimal fertilizer variable-rate application map for winter wheat production, are reported. The outcomes of the case study, which are intended to guide the direction of OFE development in Japan, were used as reference materials for a survey taken while interviewing farmers who had never been involved in OFE. Farmers’ answers showed that the economic return of site-specific management depends on farm and field size and exhibits economies of scale. A very high share of the profit increases provided by OFE data came from improvements in field-specific uniform rate management, not from within-field site-specific management. The interviews revealed that farmers open to OFE are more interested in increasing rice crop quality to earn price premiums than in increasing yield. Increased engagement with farmers in conducting OFEs could play a key role not only in generating data to guide farmers’ input management but also in fostering farmer collaboration to develop marketing strategies. This study is the first to propose future orientations of OFE research that target typical moderately-sized Japanese grain farms

Ultrastrong Stationary Double Layers in a Nondischarge Magnetoplasma

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String Sanitization Under Edit Distance: Improved and Generalized

Let W be a string of length n over an alphabet Σ, k be a positive integer, and S be a set of length-k substrings of W. The ETFS problem asks us to construct a string XED such that: (i) no string of S occurs in XED; (ii) the order of all other length-k substrings over Σ is the same in W and in XED; and (iii) XED has minimal edit distance to W. When W represents an individual's data and S represents a set of confidential patterns, the ETFS problem asks for transforming W to preserve its privacy and its utility [Bernardini et al., ECML PKDD 2019]. ETFS can be solved in O(n2k) time [Bernardini et al., CPM 2020]. The same paper shows that ETFS cannot be solved in O(n2−δ) time, for any δ>0, unless the Strong Exponential Time Hypothesis (SETH) is false. Our main results can be summarized as follows: (i) an O(n2log2k)-time algorithm to solve ETFS; and (ii) an O(n2log2n)-time algorithm to solve AETFS, a generalization of ETFS in which the elements of S can have arbitrary lengths. Our algorithms are thus optimal up to polylogarithmic factors, unless SETH fails. Let us also stress that our algorithms work under edit distance with arbitrary weights at no extra cost. As a bonus, we show how to modify some known techniques, which speed up the standard edit distance computation, to be applied to our problems. Beyond string sanitization, our techniques may inspire solutions to other problems related to regular expressions or context-free grammars

Acid-suppressive effects of generic omeprazole: Comparison of three brands of generic omeprazole with original omeprazole

Background: Generic omeprazole contains the same active ingredient as original omeprazole and require verification of the bioequivalence with original omeprazole. However, very few clinical studies have been reported. Aims: A prospective, randomised, open-label, crossover study to compare acid-suppressive effect of generic omeprazole with that of original omeprazole. Subjects: Seven healthy Helicobacter pylori-negative subjects of CYP2C19 extensive metaboliser. Methods: Intragastric pH was measured for 24 h without medications (placebo) and on day 7 of repeated administration of 10 mg once daily after breakfast of original omeprazole, Omeprazon, or three brands of generic omeprazole, Omeprazole-Towa, Ovulanze or Omerap. Results: Median values of intragastric pH and percentages of time with pH > 4 for 24 h were significantly higher with administration of any omeprazole formulation compared with placebo (P 4 with Omeprazole-Towa and Omerap were not significantly higher than placebo. Compared with Omeprazon, these two parameters for 24 h showed significantly greater inter-subject variations with Omeprazole-Towa (P < 0.05 and P < 0.01, F-test) and Ovulanze (P < 0.05). Conclusions: Acid-suppressive effects of some brands of generic omeprazole are not the same as original omeprazole. These differences might be reflected in clinical outcomes

String Sanitization Under Edit Distance: Improved and Generalized

Let W be a string of length n over an alphabet Σ, k be a positive integer, and S be a set of length-k substrings of W. The ETFS problem asks us to construct a string XED such that: (i) no string of S occurs in XED; (ii) the order of all other length-k substrings over Σ is the same in W and in XED; and (iii) XED has minimal edit distance to W. When W represents an individual's data and S represents a set of confidential patterns, the ETFS problem asks for transforming W to preserve its privacy and its utility [Bernardini et al., ECML PKDD 2019]. ETFS can be solved in O(n2k) time [Bernardini et al., CPM 2020]. The same paper shows that ETFS cannot be solved in O(n2−δ) time, for any δ>0, unless the Strong Exponential Time Hypothesis (SETH) is false. Our main results can be summarized as follows: (i) an O(n2log2k)-time algorithm to solve ETFS; and (ii) an O(n2log2n)-time algorithm to solve AETFS, a generalization of ETFS in which the elements of S can have arbitrary lengths. Our algorithms are thus optimal up to polylogarithmic factors, unless SETH fails. Let us also stress that our algorithms work under edit distance with arbitrary weights at no extra cost. As a bonus, we show how to modify some known techniques, which speed up the standard edit distance computation, to be applied to our problems. Beyond string sanitization, our techniques may inspire solutions to other problems related to regular expressions or context-free grammars

Intrapericardial migration of dislodged sternal struts as late complication of open pectus excavatum repairs

<p>Abstract</p> <p>We present a case of sternal steel strut dislodgement and migration in a patient undergoing Ravitch repair for pectus excavatum (PE) 37 years ago. Broken struts perforated the right ventricle and right ventricular outflow tract (RVOT) and additionally migrated into the left upper lobar bronchus.</p> <p>Dislodged sternal struts represent rare complications after surgical repair of patients suffering from pectus excavatum. Reviewing the literature, only five cases of intrapericardial migration of dislodged sternal struts or wires have been reported so far.</p> <p>In our case, the first strut was removed from the airways through a left antero-lateral thoracotomy. Using cardiopulmonary bypass, a second strut was removed via ventriculotomy. These life-threatening sequelae underscore the importance of postoperative follow-up and early removal of osteosynthetic materials used in open PE repair. Accurate preoperative localization of migrated materials and availability of CPB support are crucial for successful surgical removal.</p> <p>Introduction</p> <p>The migration of dislodged sternal steel struts or wires into the pericardium and cardiac cavities is a rare but life-threatening complication of open pectus excavatum (PE) repair <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>. Removal of these materials poses a challenge for cardiothoracic surgeons. Herein, the authors report a case of migration of dislodged steel struts through the right ventricle and right ventricular outflow tract (RVOT) into the left upper lobar bronchus in a patient who underwent Ravitch repair 37 years ago.</p

Domestic Water Demand During Droughts in Temperate Climates: Synthesising Evidence for an Integrated Framework

In the upcoming years, as the population is growing and ageing, as lifestyle changes create the need for more water and as fewer people live in each household, the UK water sector will have to deal with challenges in the provision of adequate water services. Unless critical action is taken, every area in the UK may face a supply-demand gap by the 2080s. Extreme weather events and variations that alter drought and flood frequency add to these pressures. However, little evidence is available about householders’ response to drought and there are few if any studies incorporating this evidence into models of demand forecasting. The present work lays the groundwork for modelling domestic water demand response under drought conditions in temperate climates. After discussing the current literature on estimating and forecasting domestic water consumption under both ‘normal’ and drought conditions, this paper identifies the limited ability of current domestic demand forecasting techniques to include the many different and evolving factors affecting domestic consumption and it stresses the need for the inclusion of inter and intra household factors as well as water use practices in future demand forecasting models

Low Lipoprotein(a) Concentration Is Associated with Cancer and All-Cause Deaths: A Population-Based Cohort Study (The JMS Cohort Study)

Background: Experimental studies support the anti-neoplastic effect of apo(a), but several clinical studies have reported contradictory results. The purpose of this study was to determine whether a low lipoprotein(a) [Lp(a)] concentration is related to mortality from major causes of death, especially cancer. Methods The subjects were 10,413 participants (4,005 men and 6,408 women) from a multi-center population-based cohort study in Japan (The Jichi Medical School cohort study). The average age at registration was 55.0 years, and the median observation period was 4,559 days. As the estimated hazard ratio was high for both the low and very high Lp(a) levels, we defined two Lp(a) groups: a low Lp(a) group [Lp(a)<80 mg/L] and an intermediate-to-high Lp(a) group [Lp(a)≥80]. Participants who died from malignant neoplasms (n = 316), cardiovascular disease (202), or other causes (312) during the observation period were examined. Results: Cumulative incidence plots showed higher cumulative death rates for the low Lp(a) group than for the intermediate-to-high Lp(a) group for all-cause, cancer, and miscellaneous-cause deaths (p<0.001, p = 0.03, and p = 0.03, respectively). Cox proportional hazards analyses with the sex and age of the participants, body mass index, and smoking and drinking histories as covariates showed that a low Lp(a) level was a significant risk for all-cause, cancer, and miscellaneous-cause deaths (p<0.001, p = 0.003, and p = 0.01, respectively). The hazard ratio (95% CI) [1.48, 1.15–1.92] of a low Lp(a) level for cancer deaths was almost the same as that for a male sex (1.46, 1.00–2.13). Conclusions: This is the first report to describe the association between a low Lp(a) level and all-cause or cancer death, supporting the anti-neoplastic effect of Lp(a). Further epidemiological studies are needed to confirm the present results