2,898 research outputs found

    Chimpanzees in Laboratories: Distribution and Types of Research

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    This review presents the results of an informal 1993 survey of the distribution of chimpanzees (Pan troglodytes) in the world\u27s laboratories, and the types of research conducted on them. Based on the available information, there are over 2200 chimpanzees in.laboratories, most of which are located in several US facilities. Europe apparently has less than 200 chimpanzees housed in two facilities. Worldwide, an estimated 80% of the chimpanzees in laboratories are used in studies on AIDS and hepatitis. It is concluded that, if Europe terminated its use of chimpanzees in research, for either financial, moral or political reasons, the impact on experimental research would be relatively minor

    Alternative to Current Uses of Animals in Research, Safety Testing, and Education: A Layman\u27s Guide

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    https://www.wellbeingintlstudiesrepository.org/ebooks/1021/thumbnail.jp

    Clarifying Our Position

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    The HSUS is, and always has been, unequivocally opposed to violence in the name of animal protection. In speaking out against violent acts, we have questioned the perpetrators\u27 means of trying to advance their cause, but we have not questioned their commitment to animal protection. Animal-research advocates are already invoking the specter of violence to advance their agenda beyond simply discrediting animal protectionists

    History of the 3Rs in Toxicity Testing: From Russell and Burch to 21st Century Toxicology

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    Toxicity testing is a key part of the process of assessing the hazards, safety, or risk that chemicals and other substances pose to humans, animals, or the environment. Standardized methods for such testing, typically involving animals, began to emerge during the first half of the 20th century. In 1959, British scientists William Russell and Rex Burch proposed a framework for reducing, refining, or replacing animal use in toxicology and other forms of biomedical experimentation. This “3Rs” or “alternatives” approach emerged at a time of growing sensitivity to the use of animals in experimentation, and progress in its implementation has been spurred by a growing appreciation of the power of emerging science and technology and the limitations of animal-based approaches. The 3Rs approach, although slow to be embraced, increasingly become a framework for change in toxicity testing during the last quarter of the 20th century. These years saw measurable growth in research activity related to the 3Rs, along with the establishment of 3Rs-based organizations and centers, journals, websites, funding sources, and conferences. As the field matured, the principles for validating new and revised alternative tests were formulated and pioneered. The 3Rs framework reached a tipping point in 2007 with the emergence of a U.S. National Research Council report proposing a radically different, largely animal-free approach to toxicity testing, encapsulated in the phrase “21st Century Toxicology.” This chapter reviews these developments, examines 3Rs trends in the toxicological literature, presents measures of the impact of 3Rs activity, and concludes with a summary of some of the remaining challenges to the development, validation, regulatory acceptance, and implementation of 3Rs methods

    SKITTER foot design

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    A mechanical design team was formed to design a foot for the lunar utility vehicle SKITTER. The primary design was constrained to be a ski pole design compatible with the existing femur-tibia design legs. The lunar environment had several important effects on the foot design. Three materials were investigated for the SKITTER foot: aluminum alloys, cold worked stainless steel alloys, and titanium alloys. Thin film coatings were investigated as a method of wear reduction for the foot. The performance of the foot is dependent on the action of the legs. The range of motion for the legs was determined to be vertical to 15 degrees above horizontal. An impact analysis was performed for the foot movement, but the results were determined to be inconclusive due to unknown soil parameters. The initial foot design configuration consisted of an annulus attached to the pointed pole. The annulus was designed to prevent excess sinkage. Later designs call for a conical shaped foot with a disk at the point of the tibia attachment. The conical design was analyzed for strength and deflection by two different approaches. A deformable body analysis was performed for the foot under crane load in crane position, and also under actuator load in the vertical position. In both cases, the deflection of the foot was insignificant and the stresses well below the strength of the titanium alloy

    User’s Guide to C2R: A Set of C Language Output Routines Compatible with the R Statistics Language

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    C2R is a collection of C routines for saving complex data structures into a file that can be read in the R statistics environment with a single command.1 C2R provides both the means to transfer data structures significantly more complex than simple tables, and an archive mechanism to store data for future reference. We developed this software because we write and run computationally intensive numerical models in Fortran, C++, and AD Model Builder. We then analyse results with R. We desired to automate data transfer to speed diagnostics during working-group meetings. We thus developed the C2R interface to write an R data object (of type list) to a plain-text file. The master list can contain any number of matrices, values, dataframes, vectors or lists, all of which can be read into R with a single call to the dget function. This allows easy transfer of structured data from compiled models to R. Having the capacity to transfer model data, metadata, and results has sharply reduced the time spent on diagnostics, and at the same time, our diagnostic capabilities have improved tremendously. The simplicity of this interface and the capabilities of R have enabled us to automate graph and table creation for formal reports. Finally, the persistent storage in files makes it easier to treat model results in analyses or meta-analyses devised months—or even years—later. We offer C2R to others in the hope that they will find it useful. (PDF contains 27 pages

    User’s Guide to For2R: A Module of Fortran 95 Output Routines Compatible with the R Statistics Language

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    For2R is a collection of Fortran routines for saving complex data structures into a file that can be read in the R statistics environment with a single command.1 For2R provides both the means to transfer data structures significantly more complex than simple tables, and an archive mechanism to store data for future reference. We developed this software because we write and run computationally intensive numerical models in Fortran, C++, and AD Model Builder. We then analyse results with R. We desired to automate data transfer to speed diagnostics during working-group meetings. We thus developed the For2R interface to write an R data object (of type list) to a plain-text file. The master list can contain any number of matrices, values, dataframes, vectors or lists, all of which can be read into R with a single call to the dget function. This allows easy transfer of structured data from compiled models to R. Having the capacity to transfer model data, metadata, and results has sharply reduced the time spent on diagnostics, and at the same time, our diagnostic capabilities have improved tremendously. The simplicity of this interface and the capabilities of R have enabled us to automate graph and table creation for formal reports. Finally, the persistent storage in files makes it easier to treat model results in analyses or meta-analyses devised months—or even years—later. We offer For2R to others in the hope that they will find it useful. (PDF contains 31 pages

    Polarized light transmission through skin using video reflectometry: toward optical tomography of superficial tissue layers

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    The movement of polarized light through the superficial layers of the skin was visualized using a video camera with a polarizing filter. This study constitutes a description of the impulse response to a point source of incident collimated linearly polarized light. Polarization images reject unwanted diffusely backscattered light from deeper in the tissue and the specular reflectance from the air/tissue interface. Two experiments were conducted: (1) Video polarization reflectometry used a polarized HeNe laser (633 nm) pointing perpendicularly down onto a phantom medium (0.900-”m dia. polystyrene spheres in water). The video camera was oriented 10° off the vertical axis and viewed the irradiation site where the laser beam met the phantom. Video images were acquired through a polarizing filter that was either parallel or perpendicular with the reference plane defined by the source, camera, and irradiation site on the phantom medium's surface. The source polarization was parallel to the reference plane. The two images (parallel and perpendicular) were used to calculate a polarization image which indicated the attenuation of polarization as a function of distance between the source and point of photon escape from the phantom. Results indicated a strong polarization pattern within approximately 0.35 cm (approximately 2.2 mfp') from source. [mfp' = 1/(”_a + ”_s')]. (2) Optical fiber reflectometry using a polarized diode laser (792 nm) coupled to a polarization-maintaining single-mode fiber, and a multi-mode fiber collector to collect regardless of polarization. Reflectance as a function of fiber separation was measured for the source fiber oriented parallel and perpendicular with the reference plane. Results indicated that the strongest polarization propagated within approximately 0.43 cm (2.2 mfp') from source. The polarization survived ~2.2 mfp', which for skin at 630 - 800 nm (mfp' ≈ 0.066 cm) corresponds to 1.5 mm (or 6.4 ps of travel at the speed of light). Using 6.4 ps as a maximum time of survival, classical paths of photon transport (Feynman paths) were calculated to illustrate the expected depth of interrogation by polarized imaging. The expected mean depth of photons is about 0.36 mm at these longer wavelengths. Shorter wavelengths would result in a shorter mfp' and therefore more superficial imaging of the skin. Polarization images offer an inexpensive approach toward 2-D acquisition of time- gated images based on the early light escaping the tissue. Polarization imaging is an opportunity for a new form of optical image especially useful for dermatology

    The First Forty Years of the Alternatives Approach: Refining, Reducing, and Replacing the Use of Laboratory Animals

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    The concept of the Three Rs— reduction, refinement, and replacement of animal use in biomedical experimentation—stems from a project launched in 1954 by a British organization, the Universities Federation for Animal Welfare (UFAW). UFAW commissioned William Russell and Rex Burch to analyze the status of humane experimental techniques involving animals. In 1959 these scientists published a book that set out the principles of the Three Rs, which came to be known as alternative methods. Initially, Russell and Burch’s book was largely ignored, but their ideas were gradually picked up by the animal protection community in the 1960s and early ’70s. In the ’80s, spurred by public pressure, the alternatives approach was incorporated into national legislation throughout the developed countries and embraced by industry in Europe and America. Government centers devoted to the validation and regulatory acceptance of alternative methods were established during the ’90s. By 2000 the use of animals in research had fallen by up to fifty percent from its high in the 1970s

    Possibilities for Refinement and Reduction: Future Improvements Within Regulatory Testing

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    Approaches and challenges to refining and reducing animal use in regulatory testing are reviewed. Regulatory testing accounts for the majority of animals reported in the most painful and/or distressful categories in the United States and Canada. Refinements in testing, including the use of humane endpoints, are of increasing concern. Traditional approaches to reduction (e.g., improving experimental design) are being supplemented with complementary approaches, such as the use of tier testing to eliminate some chemicals prior to in vivo testing. Technological advances in telemetry and noninvasive techniques will help decrease either the demand for animals in testing or animal suffering. Further decreases in animal use will stem from international harmonization and coordination of testing programs. Progress in refinement and reduction faces a variety of broad challenges, including limited funding for research. In the specific area of refinement, a key challenge is the issue of distress (as distinct from pain). In the area of reduction, the practice of using unjustifiably high numbers of animals from small species (e.g., rodents) should be challenged. One case study of the use of carbon dioxide as a euthanasia agent illustrates the need for further analysis and research. Notwithstanding the complexities and challenges, the potential for refinement and reduction in regulatory testing is encouraging
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