Humphrey Center News: Spring/Summer 1986 v. 2, no. 2

Newsletter of the Hubert H. Humphrey Cancer Research Center at Boston University School of Medicine

Online, interactive user guidance for high-dimensional, constrained motion planning

We consider the problem of planning a collision-free path for a high-dimensional robot. Specifically, we suggest a planning framework where a motion-planning algorithm can obtain guidance from a user. In contrast to existing approaches that try to speed up planning by incorporating experiences or demonstrations ahead of planning, we suggest to seek user guidance only when the planner identifies that it ceases to make significant progress towards the goal. Guidance is provided in the form of an intermediate configuration $\hat{q}$, which is used to bias the planner to go through $\hat{q}$. We demonstrate our approach for the case where the planning algorithm is Multi-Heuristic A* (MHA*) and the robot is a 34-DOF humanoid. We show that our approach allows to compute highly-constrained paths with little domain knowledge. Without our approach, solving such problems requires carefully-crafting domain-dependent heuristics

Implementing a mobile diagnostic unit to increase access to imaging and laboratory services in western Kenya.

Access to basic imaging and laboratory services remains a major challenge in rural, resource-limited settings in sub-Saharan Africa. In 2016, the Academic Model Providing Access to Healthcare programme in western Kenya implemented a mobile diagnostic unit (MDU) outfitted with a generator-powered X-ray machine and basic laboratory tests to address the lack of these services at rural, low-resource, public health facilities. The objective of this paper is to describe the design, implementation, preliminary impact and operational challenges of the MDU in western Kenya. Since implementing the MDU at seven rural health facilities serving a catchment of over half a million people, over 4500 chest radiographs have been performed, with one or more abnormalities detected in approximately 30% of radiographs. We observed favorable feedback and uptake of MDU services by healthcare workers and patients. However, various operational challenges in the design and construction of the MDU and the transmission and reporting of radiographs in remote areas were encountered. Our experience supports the feasibility of deploying an MDU to increase access to basic radiology and laboratory services in rural, resource-limited settings

Anthraquinone protects rice seed from birds

Application of bird-repellent chemicals to seed prior to planting is one possible approach to reducing bird damage to rice. Anthraquinone is a promising seed treatment compound, and in this paper we describe a sequence of tests evaluating a formulated commercial anthraquinone product. In l-cup cage tests, rice consumption by individual male red-winged blackbirds (Agelaius phoeniceus) and female boat-tailed grackles (Quiscalus major) was reduced 64-93% by 0.5 and 1.0% (g/g) anthraquinone treatments. Daily rice consumption by single male boat-tailed grackles tested in large enclosures was reduced from \u3e 14 g in pretreatment to \u3c 1 g by a 1.0% treatment. One of five test birds ate nothing during a 1 day post-treatment session. In a 7 day trial within a 0.2 ha flight pen, a group of four male grackles consumed 1.3% of anthraquinone-treated rice seed compared to 84.1% of sorghum, a nonpreferred alternate food. At two study sites in southwestern Louisiana, loss of rice sprouts in 2 ha plots sown with anthraquinone-treated seed was 0 and 12% compared to losses of 33% and 98% in nearby untreated plots. The formulation performed well at every stage of testing, and further development of anthraquinone products for bird-damage management is warranted

Amplification of Black Vulture (\u3ci\u3eCoragyps atratus\u3c/i\u3e) DNA from regurgitated food pellets

Studies that rely on noninvasive collection of DNA for birds often use feces or feathers. Some birds, such as vultures, regurgitate undigested matter in the form of pellets that are commonly found under roost sites. Our research demonstrates that regurgitated pellets are a viable, noninvasive source of DNA for molecular ecology studies of vultures. Our objectives were to amplify 5 microsatellite loci designed for distinguishing Turkey Vultures (Cathartes aura) and Black Vultures (Coragyps atratus) in a single, multiplexed PCR, and to determine how long the target nuclear DNA persists after a vulture pellet is regurgitated and exposed to the environment. We collected pellets from captive Black Vultures and placed them in an outdoor aviary for a maximum estimated total of 12, 24, 36, or 48 h. We swabbed pellet surfaces for extraction and amplified vulture DNA using the panel of markers. All amplified alleles fell within predicted ranges of Black Vultures for all 5 loci, supporting the use of this microsatellite panel for vulture species identification. Overall amplification success for samples collected 0–12 h after regurgitation was 82.3%. Pellets collected 12–24 h, 24–36 h, and 36–48 h after regurgitation had only 18%, 10.2%, and 4.5% amplification success, respectively, which may have been due to a rain event. Our approach will be useful for noninvasive genetic sampling targeting nuclear DNA. These results should encourage noninvasive genetic sampling studies of other species that regurgitate pellets, such as raptors, water birds, or shorebirds

Evaluation of the Maintainability of Object-Oriented Software

Empirical research is one way of testing software engineering methodologies. Many claims of the advantages of the object oriented paradigm have been made by research. Our work involves empirical projects in an attempt to validate these claims. This paper describes an experiment which compares the maintainability of the two functionally equivalent systems in order to explore the claim that systems developed with object-oriented languages are more easily maintained than those programmed with procedural languages. We found supporting evidence that programmers produce more maintainable code with an object-oriented language than with a standard procedural language. Another on-going research effort attempts to measure the reusability of objects (written in C++) versus the reusability of procedures (written in Pascal). These experiments involve students, but unlike other published reports, deal with large systems

CABLE-TO-POST ATTACHMENTS FOR A NON-PROPRIETARY HIGH-TENSION CABLE BARRIER – PHASE II

The research objectives reported herein were based on further development of cable-to-post attachment hardware for use in the non-proprietary high-tension cable barrier system. Specifically, this project aimed to develop and evaluate alternative attachment designs for the bolted, tabbed bracket and evaluate the use of a larger diameter, keeper rod for use in the top cable attachment. From a group of over 25 alternative attachment concepts, two tabbed bracket designs were selected for evaluation through dynamic component testing: 1) the lateral shear plate attachment and 2) the drop-in shear plate attachment. The drop-in shear plate concept did not perform as intended, as the vertical release load was too high and the lateral release loads were too low. Alternatively, the lateral shear plate design provided vertical and lateral release loads very similar to the original bolted, tabbed bracket V10. However, concerns were raised over the lack of rigidity in the attachment and the ease of installations of the shear plate. Thus, it was recommended that the lateral shear plate design be modified and reevaluated prior to use in the full-scale system. Dynamic bogie or component testing of the 3/16-in. (4.8-mm) diameter brass keeper rod provided a quick cable release similar to the previous design. The increased strength of the rod also showed promise in distributing impact loads more uniformly to adjacent posts and helping reduce system deflections. Thus, the 3/16-in. (4.8-mm) diameter brass rod was recommended for use in the new high-tension cable barrier system