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An investigative laboratory course in human physiology using computer technology and collaborative writing.

Active investigative student-directed experiences in laboratory science are being encouraged by national science organizations. A growing body of evidence from classroom assessment supports their effectiveness. This study describes four years of implementation and assessment of an investigative laboratory course in human physiology for 65 second-year students in sports medicine and biology at a small private comprehensive college. The course builds on skills and abilities first introduced in an introductory investigations course and introduces additional higher-level skills and more complex human experimental models. In four multiweek experimental modules, involving neuromuscular, reflex, and cardiovascular physiology, by use of computerized hardware/software with a variety of transducers, students carry out self-designed experiments with human subjects and perform data collection and analysis, collaborative writing, and peer editing. In assessments, including standard course evaluations and the Salgains Web-based evaluation, student responses to this approach are enthusiastic, and gains in their skills and abilities are evident in their comments and in improved performance.

Computer-Assisted Instruction↗

Use of a moderated international Internet information exchange in the study of male reproduction.

It is clear that modern information technology is having a profound impact on the way researchers and clinicians exchange information. Use of the Internet is one example of how such change can be translated into scientific progress and improved patient care. Androlog, a moderated international information exchange, has proven to be very useful in the transfer of information pertaining to the study and treatment of male reproductive disorders. Allowing instantaneous dispersal of messages to members in 27 countries, this system has become a valuable source of scientific information, as well as an excellent forum for the discussion of a broad range of clinical and laboratory topics. Moderated-user groups such as Androlog are highly applicable to many other areas of urology. Establishment of such an information exchange requires only a modest investment in computer hardware and software and moderators who are willing to perform the necessary tasks of system administration and message review. Given the unique advantages provided by this method of communication, there is little doubt that systems such as Androlog will flourish in the future, providing a valuable tool in the advance of medical science.

Computer Communication Networks↗

Effects of tomographic motion, slice thickness, and object thickness on film density.

The experiment used the computer-aided CommCat model IS 2000 tomographic machine (Imaging Sciences International, Roebling, N.J.). The objective of the experiment was to study the influence of tomographic tube motion, tomographic slice thickness, and object thickness on film density. The experiment was conducted by x-radiating an aluminum step-wedge placed along the x-axis. Exposures were made for different tube motions and for different slice thicknesses. In linear horizontal and linear vertical motions, an increased slice thickness decreased film density. Slice thickness had a stronger effect on film density when the object to be x-radiated was thinner. In circular, elliptical, spiral, and hypocycloidal motions, changes in slice thickness had no noticeable effect on film density because the manufacturer had programmed the machine to produce approximately similar exposure times by increasing the x-ray tube velocity thickness had a greater effect on film density for circular, elliptical, spiral, and hypocycloidal tube motions than for linear horizontal and linear vertical tube motions. Clinical observation showed that except for the linear vertical motion (motion that was oriented in the same direction as that of the tube travel) all other motions produced a zone of diffusion along the edges of the steps of the step-wedge. An increase in slice thickness had an effect on film density. Slice thickness had a noticeable effect on film density in linear but not in multidirectional tomography. Object thickness had a greater effect on film density in multidirectional than in linear tomography.

Absorptiometry, Photon↗

A technology and nursing collaboration to help older adults age in place.

This is an account of an active collaboration between Computer Engineering, Health Informatics, and Nursing within an academic health science center to improve the quality of life of older adults as they "age in place." The Sinclair School of Nursing at the University of Missouri-Columbia has developed a licensed home health agency, Senior Care, to provide the care needed by residents of TigerPlace, a specially designed independent living center near the University. Technology has the potential to help address common problems encountered by older adults related to functional decline. Collaboration between Nursing, Computer Engineering, and Health Informatics is likely on a path to improve the quality of life of seniors.

Aged↗

Are computer-based educational materials recognized as publications? An analysis of promotion documents at American medical colleges.

A generalized perception exists that faculty will not be properly rewarded for efforts in developing computer-based educational materials. Faculty governed by traditional promotion and tenure systems thus may be reluctant to devote energies towards development of these materials. Recent national panels on educational reform have called for a reexamination of academic reward structures to insure that faculty receive appropriate scholarly recognition for materials developed in these new formats. A study of policy documents from accredited medical colleges in the United States was conducted to determine the extent to which academic health science institutions have adopted policies to grant recognition of computer-based materials equivalent to that accorded traditional print publications. Results revealed that while some progress has been made by leading-edge institutions, in three-quarters of the institutions, development of computer-based educational materials is considered evidence in support of teaching, not the more highly rewarded research or scholarly activity.

Computer-Assisted Instruction↗

A brief individualized computer-delivered sexual risk reduction intervention increases HIV/AIDS preventive behavior.

PURPOSE: One objective of translational science is to identify elements of human immunodeficiency virus (HIV) risk-reduction interventions that have been shown to be effective and find new ways of delivering these interventions to the community to ensure that they reach the widest possible audience of at-risk individuals. The current study reports the development and evaluation of a computer-delivered, theory-based, individually tailored HIV risk-reduction intervention. METHODS: This study evaluated the effectiveness of a custom computerized HIV/AIDS risk reduction intervention at increasing HIV/AIDS preventive behaviors in a randomized trial with 157 college students. The intervention content and delivery were based on the Information-Motivation-Behavioral Skills Model of Health Behavior Change and used Motivational Interviewing techniques. Participants completed a baseline assessment of HIV prevention information, motivation, behavioral skills and behavior, attended two brief computer-delivered intervention sessions, and completed a follow-up assessment. RESULTS: As compared to the control group (a nutrition education tutorial), participants who interacted with the computer-delivered HIV/AIDS risk reduction intervention exhibited a significant increase in risk reduction behavior. Specifically, participants reported a greater frequency of keeping condoms available and displayed greater condom-related knowledge at a four-week follow-up session; among sexually active participants, there was a significant increase in self-reported condom use. CONCLUSIONS: Delivery of brief individually tailored HIV/AIDS risk reduction interventions via computer may be an effective HIV/AIDS prevention approach for adolescents. More research is needed to further support the effectiveness of this type of intervention and determine the generalizability of these findings to economically and educationally disadvantaged adolescents.

Acquired Immunodeficiency Syndrome↗

Fluoroscopy as an imaging means for computer-assisted surgical navigation.

OBJECTIVE: Intraoperative fluoroscopy is a valuable tool for visualizing underlying bone and surgical tool positions in orthopedic procedures. Disadvantages of this technology include the need for continued radiation exposure for visual control, and cumbersome means of alignment. The purpose of this article was to highlight a new concept for a computer-assisted freehand navigation system that uses single intraoperatively acquired fluoroscopic images as a basis for real-time navigation of surgical tools. MATERIALS AND METHODS: Optoelectronic markers are placed on surgical tools, a patient reference, and the fluoroscope to track their position in space. Projection properties of the fluoroscope are acquired through an initial precalibration procedure using a tracked radiopaque phantom grid. Corrections are applied to compensate for both the fluoroscope's image intensifier distortions and the mechanical bending of the C-arm frame. This enables real-time simulation of surgical tool positions simultaneously in several single-shot fluoroscopic images. In addition, through optoelectronically tracked digitization of a target viewpoint, the fluoroscope can be numerically aligned at precise angles relative to the patient without any X-ray exposure. RESULTS: This article shows the feasibility of this technology through its use in cadaver trials to perform the difficult task of distal locking of femoral nails.

Bone Nails↗

Bioinformatic assessment of mass spectrometric chemical derivatisation techniques for proteome database searching.

Identification of proteins from the mass spectra of peptide fragments generated by proteolytic cleavage using database searching has become one of the most powerful techniques in proteome science, capable of rapid and efficient protein identification. Using computer simulation, we have studied how the application of chemical derivatisation techniques may improve the efficiency of protein identification from mass spectrometric data. These approaches enhance ion yield and lead to the promotion of specific ions and fragments, yielding additional database search information. The impact of three alternative techniques has been assessed by searching representative proteome databases for both single proteins and simple protein mixtures. For example, by reliably promoting fragmentation of singly-charged peptide ions at aspartic acid residues after homoarginine derivatisation, 82% of yeast proteins can be unambiguously identified from a single typical peptide-mass datum, with a measured mass accuracy of 50 ppm, by using the associated secondary ion data. The extra search information also provides a means to confidently identify proteins in protein mixtures where only limited data are available. Furthermore, the inclusion of limited sequence information for the peptides can compensate and exceed the search efficiency available via high accuracy searches of around 5 ppm, suggesting that this is a potentially useful approach for simple protein mixtures routinely obtained from two-dimensional gels.

Animals↗

Post-genomic virology: the impact of bioinformatics, microarrays and proteomics on investigating host and pathogen interactions.

Post-genomic research encompasses many diverse aspects of modern science. These include the two broad subject areas of computational biology (bioinformatics) and functional genomics. Laboratory based functional genomics aims to measure and assess either the messenger RNA (mRNA) levels (transcriptome studies) or the protein content (proteome studies) of cells and tissues. All of these methods have been applied recently to the study of host and pathogen interactions for both bacteria and viruses. A basic overview of the technology is given in this review together with approaches to data analysis. The wealth of information produced from even these preliminary studies has shown the generalities, subtleties and specificities of host-pathogen interactions. Such research should ultimately result in new methods for diagnosing and treating infectious diseases.

Amino Acid Sequence↗

Bioinformatics: harvesting information for plant and crop science.

Bioinformatics is an integral aspect of plant and crop science research. Developments in data management and analytical software are reviewed with an emphasis on applications in functional genomics. This includes information resources for Arabidopsis and crop species, and tools available for analysis and visualisation of comparative genomic data. Approaches used to explore relationships between plant genes and expressed sequences are compared, including use of ontologies. The impact of bioinformatics in forward and reverse genetics is described, together with the potential from data mining. The role of bioinformatics is explored in the wider context of plant and crop science.

Algorithms↗

Vision as Bayesian inference: analysis by synthesis?

We argue that the study of human vision should be aimed at determining how humans perform natural tasks with natural images. Attempts to understand the phenomenology of vision from artificial stimuli, although worthwhile as a starting point, can lead to faulty generalizations about visual systems, because of the enormous complexity of natural images. Dealing with this complexity is daunting, but Bayesian inference on structured probability distributions offers the ability to design theories of vision that can deal with the complexity of natural images, and that use 'analysis by synthesis' strategies with intriguing similarities to the brain. We examine these strategies using recent examples from computer vision, and outline some important implications for cognitive science.

Algorithms↗

The Draize eye test.

Hundreds of substances are used daily that can damage eyesight. People's eyes are open to accidental or intentional exposure during the production, transportation, use, and disposal of chemical preparations. Ensuring the safety of consumer products was born during the mid twentieth century in the aftermath of chemical warfare research, and was motivated by the hazards of unsafe cosmetics. Justified by an exigency for public protection, the Draize eye test became a governmentally endorsed method to evaluate the safety of materials meant for use in or around the eyes. The test involves a standardized protocol for instilling agents onto the cornea and conjunctiva of laboratory animals. A sum of ordinal-scale items of the outer eye gives an index of ocular morbidity. Advances in ocular toxicology are challenging the validity, precision, relevance, and need of the Draize eye test. Preclinical product-safety tests with rabbits and other mammals also raise ethical concerns of animal wellbeing. Some use the Draize test as a rallying point for how animals are treated in science and industry. A battery of cellular systems and computer models aim to reduce and ultimately to replace whole-animal testing. Molecular measures of ocular toxicity may eventually allow comprehensive screening in humans. The Draize eye test was created and refined for humanitarian reasons and has assuredly prevented harm. Its destiny is to be progressively supplanted as in vitro and clinical alternatives emerge for assessing irritancy of the ocular surface.

Animal Testing Alternatives↗

Similarity-based models of human visual recognition.

Seven models of human visual recognition from cognitive psychology, visual psychophysics and connectionism were compared. They were used to predict psychophysical classification data obtained via supervised learning with parametrised grey-level patterns (compound Gabor signals). Four sets of learning patterns, as well as foveal and extrafoveal viewing conditions, were applied. Model performance was determined by comparing observed and predicted data with respect to root mean square deviation and to signal reconstruction via multidimensional scaling. Results show that a psychophysical theory of classification requires a similarity concept that is based both on physical signal description and on cognitive bias. The latter is less pronounced in foveal recognition, where all seven models performed almost equally well, but matters in extrafoveal recognition. Virtual prototype models (Rentschler et al. (1994), Vision Research 34, 669-687), which best accommodate stimulus- and observer-dependencies, are then of advantage. Concerning computational efficiency, a hyperBF model (Poggio and Girosi (1990), Science 247, 978) was much faster, and generalized signal detection models were much slower than the average.

Cognition↗

Solvent abuse in pregnancy: a perinatal perspective.

OBJECTIVE: To review the scope and sequelae of solvent abuse in women presenting to a Manitoba teaching hospital. METHODS: Fifty-six patient charts with a diagnosis of solvent abuse in pregnancy were identified through computer search in the medical records of Winnipeg Health Sciences Centre, General Hospital. These charts were reviewed and data obtained from birthing records and associated pediatric charts. RESULTS: Renal tubular acidosis was diagnosed in three patients (5.3%). Two patients (3.6%) had adverse neurological sequelae. One patient was diagnosed with brain damage, including expressive aphasia. Twelve patients (21.4%) delivered preterm infants. Nine infants (16.1%) had major anomalies. Seven infants (12.5%) had fetal alcohol syndrome (FAS)-like facial features. Six neonates (10.7%) had hearing loss. CONCLUSION: Substance abuse in pregnancy is associated with severe maternal and neonatal sequelae. Physicians must be aware of this increasing problem in the obstetrical population and assistance should be offered to each woman, ideally before a woman becomes pregnant, but at least at the first contact a pregnant woman makes with the health care community.

Acidosis, Renal Tubular↗

Electronic structure, vibrational stability, and predicted infrared-Raman spectra of the As20, As @ Ni12, and As @ Ni12 @ As20 clusters.

Recently an inorganic fullerine-like [As@Ni(12)@As(20)](3-) onion with near-perfect icosahedral symmetry in the crystalline phase was reported [M. J. Moses, J. C. Fettinger, and B. W. Eichhorn, Science 300, 778 (2003)]. This paper presents a detailed computational study in the framework of density functional theory on various aspects of this molecule. The electronic structure of the As@Ni(12)@As(20) is investigated in its neutral as well as -3 charged state together with its subunits As(20) and As@Ni(12) by the all electron linear combination of Gaussian-type orbitals method. The bonding is studied by examining the integrated charge within atomic sphere, the electron localization function, changes in the electron density distribution, and from vibrational modes. We find that strong covalent As-As bonds seen in isolated As(20) become weaker in the As@Ni(12)@As(20) and strong covalent As-Ni bonds are formed. The structural stability of all four clusters is examined by analyzing the energetics and by calculating the vibrational frequencies. Further, the infrared and Raman spectra is predicted for both the neutral and charged As@Ni(12)@As(20) clusters. Finally, the energy barrier for removal of a single arsenic atom is calculated for the neutral As@Ni(12)@As(20) cluster.

Journal Article↗

Optimal sum-of-pairs multiple sequence alignment using incremental Carrillo and Lipman bounds.

Alignment of sequences is an important routine in various areas of science, notably molecular biology. Multiple sequence alignment is a computationally hard optimization problem which involves the consideration of different possible alignments in order to find an optimal one, given a measure of goodness of alignments. Dynamic programming algorithms are generally well suited for the search of optimal alignments, but are constrained by unwieldy space requirements for large numbers of sequences. Carrillo and Lipman devised a method that helps to reduce the search space for an optimal alignment under a sum-of-pairs measure using bounds on the scores of its pairwise projections. In this paper, we generalize Carrillo and Lipman bounds and demonstrate a novel approach for finding optimal sum-of-pairs multiple alignments that allows incremental pruning of the optimal alignment search space. This approach can result in a drastic pruning of the final search space polytope (where we search for the optimal alignment) when compared to Carrillo and Lipman's approach and hence allows many runs that are not feasible with the original method.

Algorithms↗

The neurobiology of visual-saccadic decision making.

Over the past two decades significant progress has been made toward understanding the neural basis of primate decision making, the biological process that combines sensory data with stored information to select and execute behavioral responses. The most striking progress in this area has been made in studies of visual-saccadic decision making, a system that is becoming a model for understanding decision making in general. In this system, theoretical models of efficient decision making developed in the social sciences are beginning to be used to describe the computations the brain must perform when it connects sensation and action. Guided in part by these economic models, neurophysiologists have been able to describe neuronal activity recorded from the brains of awake-behaving primates during actual decision making. These recent studies have examined the neural basis of decisions, ranging from those made in predictable sensorimotor tasks to those unpredictable decisions made when animals are engaged in strategic conflict. All of these experiments seem to describe a surprisingly well-integrated set of physiological mechanisms that can account for a broad range of behavioral phenomena. This review presents many of these recent studies within the emerging neuroeconomic framework for understanding primate decision making.

Animals↗