Causation and the Origin of Suboptimal Design in Biology

This paper seeks to demonstrate why the existence of suboptimal design in biology does not offer a reason for Christians to reject the biological case for Intelligent Design (ID). In it, I argue that Christians who critique ID based upon alleged deficiencies within biology fail to imagine the various ways in which a divine designer might bring about certain biological effects. That is, such critics presumably envision a simplistic notion of divine causation—where God either directly brings about every biological effect, or is not involved in any biological effect. Such either or thinking, I maintain, is theologically unnecessary.

Factoring in Societal Culture in Policy Transfer Design: the Proliferation of Private Sponsorship of Refugees

The Canadian model of private sponsorship schemes (PSS) for refugees is becoming an increasingly popular target for policy transfer in the field of migration. This article argues that the influence of societal culture on this transplanting process has played an underexplored role in the literature. We seek to provide original guidance for factoring in cultural elements into the policy transfer framework by demonstrating how specific design choices in PSS transfer display clear cultural associations. A tentative study of nine countries that have adopted different models of PSS corroborates this hypothesis empirically. Our preliminary findings suggest that cultural compatibility may indeed increase the effectiveness of a policy transfer in some instances, while culturally preferred choices being adopted in other cases may result in suboptimal design. This converse interplay indicates that cultural awareness constitutes a crucial element of successful transfer processes and stresses the need to adopt a culturally sensitive perspective more frequently and more explicitly.

Feasibility of cancer clinical trial enrollment goals based on cancer incidence.

20 Background: More than 20% of US clinical trials fail to accrue sufficient patients and terminate prematurely, impeding innovation and negating the valuable contributions of participating patients. The aim of this study is to estimate availability of patients for each trial opening in the national oncology clinical research portfolio to provide a benchmark for better understanding feasibility of clinical trial enrollment goals. Methods: The Database for Aggregate Analysis of ClinicalTrials.gov, up-to-date as of September 3, 2017, was used to identify actively-recruiting, interventional oncology trials at US sites. Observational studies were excluded as not all are registered. Trials were categorized via Medical Subject Headings or free text condition terms and sorted by cancer diagnosis. Trial slot availability was estimated between September 1, 2017, to August 31, 2018. Availability was estimated from total anticipated enrollment, assuming a constant recruitment rate. Estimates for studies with both foreign and US sites were pro-rated to calculate available enrollment in the US alone. The 2017 American Cancer Society cancer incidence estimates were used to approximate total US cancer diagnoses. Results: 4598 oncology trials were identified. Overall, an estimated 12.6 cancer patients are available for each clinical trial slot. The estimates by cancer diagnosis were: colorectal: 24.7 patients per trial slot; lung & bronchus: 20.1; prostate: 17.6; breast (female): 13.8; leukemia 11.6; and brain & other nervous system: 6.0. Conclusions: Across all diagnoses, 1 in 13 patients must enroll to meet accrual demands. This ratio varies by diagnosis. If cancer incidence is too low, trials with unrealistic accrual goals may be doomed at inception. In diagnoses with high disease burden, trial failure may be due to poor patient access or suboptimal design. [Table: see text]

A Separated Calibration Method for Inertial Measurement Units Mounted on Three-Axis Turntables

Inertial Measurement Unit (IMU) calibration accuracy is easily affected by turntable errors, so the primary aim of this study is to reduce the dependence on the turntable’s precision during the calibration process. Firstly, the indicated-output of the IMU considering turntable errors is constructed and with the introduction of turntable errors, the functional relationship between turntable errors and the indicated-output was derived. Then, based on a D-suboptimal design, a calibration method for simultaneously identifying the IMU error model parameters and the turntable errors was proposed. Simulation results showed that some turntable errors could thus be effectively calibrated and automatically compensated. Finally, the theoretical validity was verified through experiments. Compared with the traditional method, the method proposed in this paper can significantly reduce the influence of the turntable errors on the IMU calibration accuracy.

Causes of psychopathology

The causes of psychiatric and psychosomatic conditions can be categorized into two groups: proximate and ultimate (evolutionary) causes. Proximate causes comprise genetic factors, epigenetic modulation, childhood trauma and other life events, and senescence. Ultimate or evolutionary causes concern mismatch between adaptation and current environment, suboptimal design, and design compromises. Examples of evolutionary causes of dysfunction include cognitive and emotional adaptations to small-scale societies (mismatch), anxiety (suboptimal design), premature birth (design compromise), and other features associated with human life history. Furthermore, many ‘diseases of civilization’ fall under the category of mismatch, as well as immunological diseases that may arise from a lack of exposure to pathogens early in life. Prevention of psychopathology, though desirable, may not always be possible due to the fact that evolution does not select for emotional well-being. However, reducing the impact of early adversity and helping people develop alternative life-history strategies may be an attainable goal.

Enabling Decision-Based Design Using Solution Trajectory Correction and Backtracking Rules

Optimization is needed for effective decision based design (DBD). However, a utility function assessed a priori in DBD does not usually capture the preferences of the decision maker over the entire design space. As a result, when the optimizer searches for the optimal design, it traverses (or ends up) in regions where the preference order among different solutions is different from the actual order. For a highly non-convex design space, this can lead to convergence to a grossly suboptimal design depending on the initial design. In this article, we propose two approaches to alleviate this issue. First, we map the trajectory of the solution as generated by the optimizer and generate ranking questions that are presented to the designer to verify the correctness of the utility function. We then propose backtracking rules if a local utility function is very different from the initially assessed function. We demonstrate our methodology using a mathematical example and a welded beam design problem.

AN ANALYTIC APPROACH FOR EXACTLY DETERMINING CRITICAL LOADS OF BUCKLING OF NONUNIFORM COLUMNS

This paper studies buckling instability of columns with variable bending stiffness subjected to an axially compressive load. An analytic approach has been presented to determine critical buckling loads of a nonuniform column with or without continuous elastic restraint along its length. We transform this problem into a Fredholm equation, and then to a system of linear equations. The desired buckling loads can be easily obtained by solving the least positive eigenvalue of the resulting system. The validity and efficiency of the method is confirmed by comparing our numerical results with those available. The influences of variable cross-section or elastic restraint stiffness on the buckling loads of a simply-supported column are analyzed. A suboptimal design of a tapered cylindrical bar with fixed weight is given. The present results are of benefit to the optimal design of beam/column structures.

A New Generation of Aortic Valve Prosthesis: Design, Manufacture and Hydrodynamic Assessment

Aortic valve replacement (AVR) is the second most common cardiac procedure after coronary artery bypass grafting, accounting for more than 200,000 transplantations annually worldwide [1]. Currently available mechanical and bioprosthetic heart valve replacements are not ideal as they are associated with relevant complications. The tri-leaflet polymeric heart valves (PHVs) have been widely investigated as possible alternative to these substitutes. However, the clinical application of PHVs has been limited by their suboptimal design and poor durability of available polymeric materials. This study presents a new concept of surgical aortic valve using a novel nanocomposite polymer.

Suboptimal design of turbine governors for low head hydroturbines

The paper considers a low head hydro units control problem by using the modern control theory for turbine governor design. The design of optimal and suboptimal turbine governor is performed by using the optimal control theory and projective controls method. Implementation of modern control theory in contemporary turbine governors is fairly easy to obtain due their realisation in digital technology. Comparison for the closed-loop system dynamic performances, shows that better results are obtained with optimal and suboptimal governors as compared to conventional turbine governors.