Applications of Euclidean constructions to computer graphics

This paper presents an interactive graphics system called L.E.G.O. The purpose of L.E.G.O. is to model two- and three-dimensional objects using Euclidean geometry constructions. L.E.G.O. has a layered structure which makes it convenient to use, both for the experienced programmer and the novice. The programs may be written in a compiled language (C), written interactively in an interpreted language (LISP) or developed using a graphical interface in a multiple-window environment. Applications of L.E.G.O. include computer-assisted instruction of geometry and computer graphics, geometric modeling, and kinematic analysis. The use of imperative constructions and the powerful interface based on the idea of graphical programming are the most distinctive features of the system.     

Spatial and temporal variation in indicator microbe sampling is influential in beach management decisions

Fecal indicator microbes, such as enterococci, are often used to assess potential health risks caused by pathogens at recreational beaches. Microbe levels often vary based on collection time and sampling location. The primary goal of this study was to assess how spatial and temporal variations in sample collection, which are driven by environmental parameters, impact enterococci measurements and beach management decisions. A secondary goal was to assess whether enterococci levels can be predictive of the presence of Staphylococcus aureus, a skin pathogen. Over a ten-day period, hydrometeorologic data, hydrodynamic data, bather densities, enterococci levels, and S. aureus levels including methicillin-resistant S. aureus (MRSA) were measured in both water and sand. Samples were collected hourly for both water and sediment at knee-depth, and every 6 h for water at waist-depth, supratidal sand, intertidal sand, and waterline sand. Results showed that solar radiation, tides, and rainfall events were major environmental factors that impacted enterococci levels. S. aureus levels were associated with bathing load, but did not correlate with enterococci levels or any other measured parameters. The results imply that frequencies of advisories depend heavily upon sample collection policies due to spatial and temporal variation of enterococci levels in response to environmental parameters. Thus, sampling at different times of the day and at different depths can significantly impact beach management decisions. Additionally, the lack of correlation between S. aureus and enterococci suggests that use of fecal indicators may not accurately assess risk for some pathogens.     

Can research on morality be "scientific"?

Proposes a particular ground for moral formulation that is consistent with the consensually based scientific ethic. Researchers' acts of formulating investigatory designs constitute moral values, but these assumptions of value often go unnoticed because they violate the positivist mandate that science should be value neutral. Only a special kind of consensus is "scientific" (as opposed to ideological) because the scientific ethic accepts knowledge as truthful only when it is openly achieved after evenhanded consideration and tested in debate. Since truth in science is a moral issue, close examination should be made of science's moral grounds. The kinds of analyses typically performed by philosophers are an essential part of this empirical search. The author concludes that moral research cannot be "scientific" if this means being value neutral, but it can be scientific in the sense of impartially submitting all formulations to the full reality of people's moral consensuses and interactions in everyday life. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simplified Approach for the Seismic Response of a Pile Foundation

Pseudostatic approaches for the seismic analysis of pile foundations are attractive for practicing engineers because they are simple when compared to difficult and more complex dynamic analyses. To evaluate the internal response of piles subjected to earthquake loading, a simplified approach based on the “p-y” subgrade reaction method has been developed. The method involves two main steps: first, a site response analysis is carried out to obtain the free-field ground displacements along the pile. Next, a static load analysis is carried out for the pile, subjected to the computed free-field ground displacements and the static loading at the pile head. A pseudostatic push over analysis is adopted to simulate the behavior of piles subjected to both lateral soil movements and static loadings at the pile head. The single pile or the pile group interact with the surrounding soil by means of hyperbolic p-y curves. The solution derived first for the single pile, was extended to the case of a pile group by empirical multipliers, which account for reduced resistance and stiffness due to pile-soil-pile interaction. Numerical results obtained by the proposed simplified approach were compared with experimental and numerical results reported in literature. It has been shown that this procedure can be used successfully for determining the response of a pile foundation to “inertial” loading caused by the lateral forces imposed on the superstructure and “kinematic” loading caused by the ground movements developed during an earthquake.     

Processes of moral development: Cognitive or social disequilibrium?

Studied the processes of development in 2 moral systems—L. Kohlberg's (1981) and an interactional formulation by N. Haan (1983)—by comparing the effects of 2 curricular experiences. The 2 curricular experiences involved (1) a discussion of hypothetical dilemmas, which was designed to promote cognitive disequilibrium and the playing of moral games, (2) which in turn was designed to promote social disequilibrium. Ss were 119 university students who were members of 15 naturally existing friendship groups of 8 members each. 10 friendship groups played moral games during 5 3-hr sessions; 5 groups discussed hypothetical dilemmas for the same length of time. Individual interviews, held before, immediately after, and 3 mo after these group sessions, provided the bases for constructing developmental indices. Eight moral scores for each moral system—3 interview and 5 session-based—were thereby secured. Other data collected before the session began included measures of characteristic ego functioning and friends' sociometric evaluations, and during the sessions, measures of students' situational ego functioning and the behavior of friendship groups. Development in both moral systems was generally and strongly predicted by positive interactions between individual S's characteristic ego coping and their friendship group's social disequilibrium. Cognitive disequilibrium only occasionally and weakly facilitated moral development in both systems. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antibody response to Engerix-B and Recombivax-HB hepatitis B vaccination in end-stage renal disease

Recombivax-HB (REC) and Engerix-B (ENG) are FDA-approved vaccines for hepatitis B virus (HBV) in end-stage renal disease (ESRD). This study compares antibody response rates between them in routine clinical practice. Patients completing the recommended 40 mug dose of REC (3 doses) or ENG (4 doses) between January 1, 2000 to April 30, 2003 were eligible. Patients with prior positive HBV surface antigen (HBsAg) or antibody (HBsAb) test results were excluded. The conversion rate and persistence of protective titer (HBsAb titer>or=10 IU/mL) were tracked for 1 year. A supplemental analysis of a one-to-one matched patient sample was also performed. REC patients (N=885) were older, had longer dialysis vintage, and had a larger proportion of whites than ENG patients (N=13,661). Cumulative conversion response was greater in ENG (58%) than REC (40%) at 1 year (p<0.0001). The odds ratio for response to ENG compared with REC was 1.96 (95% limits: 1.56, 2.45; p<0.0001) adjusted for age, gender, race, diabetes, vintage, BSA, hemoglobin, and eKt/V. Persistent protective HBsAb after 1 year was 77% (ENG) vs. 53% (REC). HBsAg was positive in 208 ENG patients (1.5%) with all but 1 because of transient, vaccine-related antigenemia. The difference in conversion response favoring ENG persisted in a one-to-one sample matched for age, gender, race, modality, and dialysis vintage. The study found higher seroconversion response to ENG compared with REC at several time points up to 1 year. Protective HBsAb disappeared in 23-47% of patients 1 year later, validating CDC recommendations to re-test HBsAb yearly. The observed difference in response rates may be related to the extra ENG dose given at the second month (0, 1, 2, 6 regimen). The study raises a hypothesis that requires confirmation in a prospective clinical trial.     

Preschoolers' moral actions and emotions in Prisoner's Dilemma.

The moral acts of 19 dyads of 4-yr-olds in a cognitively simplified version of Prisoner's Dilemma game were analyzed in relationship to their friendship, emotions, and processes of conflict resolution. Degree of friendship was rated by teachers; 2 sociologists used a Q-sort of group processes to describe the dyads' interactions. The emotions of each S were coded from videotape independently of his/her partner's and with the sound turned off. Moral acts were categorically identified as equalization, reparation, stalemate, default, and betrayal. These acts were also assigned scale scores on a dimension of moral sensitivity that was independently derived from separate work with 143 undergraduates, who judged the 5 acts in all possible paired comparisons and then rated the moral difference between each pair. These data almost perfectly fitted a model of increasing monotonic function. The degree of friendship between the dyads and their interactive processes—group orientation, positive emotional tone, and active involvement—were positively related to sensitive moral action. Their emotions were related to concurrent acts, and more importantly, predicted their subsequent acts even though they seldom talked about morality. Results suggest that if social scientists' search for practical morality is to be successful, emotional communication needs to be considered. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterization of nanocellulose‐ reinforced shape memory polyurethanes

BACKGROUND: Shape memory polymers are capable of fixing a transient shape and of recovering their original dimensions by the application of an external stimulus. Their major drawback is their low stiffness compared to smart materials based on metals and ceramics. To overcome this disadvantage, nanocellulose was utilized as reinforcement. RESULTS: Composites were prepared by casting stable nanocellulose/segmented polyurethane suspensions. The heat of melting of the polyurethane soft segment phase increased on cellulose addition. Composites showed higher tensile modulus and strength than unfilled films (53% modulus increase at 1 wt% nanocellulose), with higher elongation at break. Creep deformation decreased as cellulose concentration increased (36% decrease in 60‐minute creep by addition of 1 wt% nanocellulose). The nanocomposites displayed shape memory properties equivalent to those of the neat polyurethane, with recoveries of the order of 95% (referred to second and further cycles). CONCLUSIONS: It is possible to markedly improve the rigidity of shape memory polymers by adding small amounts of well‐dispersed nanocellulose. However, this improvement did not have substantial effects on the material shape fixity or recovery. Shape memory behavior seems to continue to be controlled by the polymer properties. Copyright © 2007 Society of Chemical Industry