Sample records for laboratory rodent studies

  1. Recent Pacific Northwest Laboratory beagle and rodent studies

    SciTech Connect

    Gilbert, E.S.; Park, J.F.; Cross, F.C.; Dagle, G.E.

    1990-07-01

    Analyses based on data from two experimental studies conducted at Pacific Northwest Laboratory will be presented. The first is a lifespan study of beagle dogs exposed to inhaled plutonium. The objectives of this study are, first, to determine the biological effects in dogs of inhaled plutonium at various dose levels, and, second, to obtain dose-effect relationship data that can be used to estimate the risk of these effects in humans. In this study, eighteen-month-old beagle dogs were exposed through inhalation to six different levels and three different types of plutonium. The lowest level corresponds to the maximum permissible level for a plutonium worker, while the highest level is a level at which radiation pneumonitis is likely to cause early death. {sup 239}PuO{sub 2} was chosen because it is the form of plutonium to which people working in nuclear fuel processing and storage industries are likely to be exposed. {sup 238}PuO{sub 2} and {sup 239}Pu(NO{sub 3}){sub 4} were chosen because they result in different spatial and temporal distribution of radiation dose, and thus can provide information on the influence of these factors on risk. The second experiment is a lifespan study of rodents exposed through inhalation to radon and radon progeny. For the rodent experiments to be considered in this presentation, exposures were initiated at about 90 days of age at rates of 5, 50, and 500 WLM per week. Cumulative exposure levels were 320, 640, 1280, 2560, and 5120 WLM for animals exposed at 50 and 500 WLM per week, and 320 WLM for animals exposed at 5 WLM per week. 7 refs.

  2. In vivo effects of bisphenol A in laboratory rodent studies

    Microsoft Academic Search

    Catherine A. Richter; Linda S. Birnbaum; Francesca Farabollini; Retha R. Newbold; Beverly S. Rubin; Chris E. Talsness; John G. Vandenbergh; Debby R. Walser-Kuntz; Frederick S. vom Saal

    2007-01-01

    Concern is mounting regarding the human health and environmental effects of bisphenol A (BPA), a high-production-volume chemical used in synthesis of plastics. We have reviewed the growing literature on effects of low doses of BPA, below 50mg\\/(kgday), in laboratory exposures with mammalian model organisms. Many, but not all, effects of BPA are similar to effects seen in response to the

  3. Enrichment Strategies Rodents in the Laboratory

    E-print Network

    Bandettini, Peter A.

    enclosure such as "cage furniture, equipment for environmental enrichment, objects for manipulationEnrichment Strategies for Rodents in the Laboratory Endorsed by ARAC - 9/8/04 #12 of environmental enrichment on laboratory rats and mice. The development of enrichment programs for non

  4. Mycotoxins in laboratory rodent feed

    Microsoft Academic Search

    A Halldén Waldemarson; P Hedenqvist; A-C Salomonsson; P Häggblom

    2005-01-01

    Summary Twenty-one batches of fixed-formula rodent diets from three feed manufacturers were tested for the presence of five mycotoxins: deoxynivalenol (DON), nivalenol (NIV), HT-2 toxin, T-2 toxin and ochratoxin A (OTA). Five batches were also tested for the presence of zearalenone (ZEN) and six batches for aflatoxins. Detectable levels of DON (up to 298mg\\/kg), NIV (up to 118mg\\/kg), OTA (up

  5. Utility of Recycled Bedding for Laboratory Rodents

    PubMed Central

    Miyamoto, Toru; Li, Zhixia; Kibushi, Tomomi; Okano, Shinya; Yamasaki, Nakamichi; Kasai, Noriyuki

    2009-01-01

    Animal facilities generate a large amount of used bedding containing excrement as medical waste. We developed a recycling system for used bedding that involves soft hydrothermal processing. In this study, we examined the effects of bedding type on growth, hematologic and serum biochemical values, and organ weights of female and male mice reared on either recycled or fresh bedding from 3 to 33 wk of age. Neither growth nor physiology differed between mice housed on recycled bedding compared with fresh bedding. When 14-wk-old mice were bred, litter size and total number of weaned pups showed no significant differences between animals raised on recycled or fresh bedding. Because bedding type influences the environment within cages and animal rooms, we evaluated particulate and ammonia data from cages and animal rooms. Values were significantly lower from cages and rooms that used recycled bedding than from those using fresh bedding, thus indicating that recycled bedding has the potential to improve the environment within both cages and animal rooms. Overall, this study revealed that recycled bedding is an excellent material for use in housing laboratory rodents. Specifically, recycled bedding may reduce medical waste and maintain healthy environments within cages and animal rooms. PMID:19653951

  6. PERFLUOROOCTANE SULFONATE (PFOS) DISRUPTS THE THYROID STATUS IN LABORATORY RODENTS

    EPA Science Inventory

    PERFLUOROOCTANE SULFONATE (PFOS) DISRUPTS THE THYROID STATUS IN LABORATORY RODENTS. C. Lau, J.R. Thibodeaux, R.G. Hanson, B.E. Gray and J.M. Rogers. Reprod. Tox. Div. NHEERL, US EPA, Research Triangle Park, NC. PFOS is an environmental contaminant ubiquitously found in h...

  7. Estimation of wildlife hazard levels using interspecies correlation models and standard laboratory rodent toxicity data.

    PubMed

    Awkerman, Jill A; Raimondo, Sandy; Barron, Mace G

    2009-01-01

    Toxicity data from laboratory rodents are widely available and frequently used in human health assessments as animal model data. This study explores the possibility of using single rodent acute toxicity values to predict chemical toxicity to a diversity of wildlife species and estimate hazard levels from modeled species sensitivity distributions (SSD). Interspecies correlation estimation (ICE) models predict toxicity values for untested species using the sensitivity relationship between measured toxicity values of two species. Predicted toxicity values can subsequently populate SSD for application in ecological risk assessments. Laboratory mouse and rat toxicity values were used to estimate toxicity to wildlife and the predicted values then were used to derive SSD hazard dose levels. Toxicity values were predicted within fivefold of measured toxicity values for 78% of ICE models using laboratory rat or mouse toxicity as a surrogate value. Hazard dose levels (HD5) were within fivefold of measured estimates for 72% of SSD developed using laboratory rodent ICE models. Rodents were most often in the least sensitive quartile of species sensitivity distributions, and therefore toxicity values alone may not adequately represent the toxicity to many species of concern without appropriate safety or assessment factors. Laboratory rodent toxicity data offer an additional source of information that can be used to predict hazard levels for wildlife species, and thus offer a starting point for both health and ecological risk assessment. PMID:20077235

  8. Historical control data on developmental toxicity studies in rodents.

    PubMed

    Ema, Makoto; Endoh, Katsumi; Fukushima, Ryou; Fujii, Sakiko; Hara, Hiroaki; Hirata-Koizumi, Mutsuko; Hirose, Akihiko; Hojo, Hitoshi; Horimoto, Masao; Hoshino, Nobuhito; Hosokawa, Yoshinori; Imai, Yukari; Inada, Hiroshi; Inawaka, Kunifumi; Itoh, Keiichi; Katsumata, Yoshihiro; Izumi, Hiroyuki; Kato, Hirohito; Maeda, Maki; Matsumoto, Kiyoshi; Matsuo, Seiki; Matsuoka, Toshiki; Matsuura, Ikuo; Mineshima, Hiroshi; Miwa, Yoji; Nakano, Nao; Naya, Masato; Noyori, Hiroko; Ohta, Takafumi; Oku, Harutaka; Ono, Atsushi; Shimizu, Tatsuya; Shimomura, Kazuhiro; Takakura, Ikuro; Tanaka, Ryota; Tateishi, Taishi; Tominaga, Yuko; Uesugi, Tohru; Urakawa, Chizuru; Yabe, Kaoru; Yamashita, Akihito; Yamauchi, Toshiaki; Yokoi, Ryohei

    2014-08-01

    Historical control data on rodent developmental toxicity studies, performed between 1994 and 2010, were obtained from 19 laboratories in Japan, including 10 pharmaceutical and chemical companies and nine contract research organizations. Rats, mice, and hamsters were used for developmental toxicity studies. Data included maternal reproductive findings at terminal cesarean sections and fetal findings including the spontaneous incidences of external, visceral, and skeletal anomalies. No noticeable differences were observed in maternal reproductive data between laboratories. Inter-laboratory variations in the incidences of fetuses with anomalies appeared to be due to differences in the selection of observation parameters, observation criteria, classification of the findings, and terminology of fetal alterations. Historical control data are useful for the appropriate interpretation of experimental results and evaluation of the effects of chemical on reproductive and developmental toxicities. PMID:24666250

  9. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-wing; James, John T.; Taylor, Larry

    2008-01-01

    NASA will build an outpost on the lunar surface for long-duration human habitation and research. The surface of the Moon is covered by a layer of fine, reactive dust, and the living quarters in the lunar outpost are expected to be contaminated by lunar dust. NASA established the Lunar Airborne Dust Toxicity Advisory Group (LADTAG) to evaluate the risk of exposure to the dust and to establish safe exposure limits for astronauts working in the lunar habitat. Because the toxicity of lunar dust is not known, LADTAG has recommended investigating its toxicity in the lungs of laboratory animals. After receiving this recommendation, NASA directed the JSC Toxicology Laboratory to determine the pulmonary toxicity of lunar dust in exposed rodents. The rodent pulmonary toxicity studies proposed here are the same as those proposed by the LADTAG. Studies of the pulmonary toxicity of a dust are generally done first in rodents by intratracheal instillation (ITI). This toxicity screening test is then followed by an inhalation study, which requires much more of the test dust and is labor intensive. We succeeded in completing an ITI study on JSC-1 lunar dust simulant in mice (Lam et al., Inhalation Toxicology 14:901-916, 2002, and Inhalation Toxicology 14: 917-928, 2002), and have conducted a pilot ITI study to examine the acute toxicity of an Apollo lunar (highland) dust sample. Preliminary results obtained by examining lung lavage fluid from dust-treated mice show that lunar dust was somewhat toxic (more toxic than TiO2, but less than quartz dust). More extensive studies have been planned to further examine lung lavage fluid for biomarkers of toxicity and lung tissues for histopathological lesions in rodents exposed to aged and activated lunar dust samples. In these studies, reference dusts (TiO2 and quartz) of known toxicities and have industrial exposure limits will be studied in parallel so the relative toxicity of lunar dust can be determined. The ITI results will also be useful for choosing an exposure concentration for the animal inhalation study on a selected lunar dust sample, which is included as a part of this proposal. The animal inhalation exposure will be conducted with lunar dust simulant prior to the study with the lunar dust. The simulant exposure will ensure that the study techniques used with actual lunar dust will be successful. The results of ITI and inhalation studies will reveal the toxicological risk of exposures and are essential for setting exposure limits on lunar dust for astronauts living in the lunar habitat.

  10. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-wing; James, John T.

    2009-01-01

    NASA will build an outpost on the lunar surface for long-duration human habitation and research. The surface of the Moon is covered by a layer of fine, reactive dust, and the living quarters in the lunar outpost are expected to be contaminated by lunar dust. Because the toxicity of lunar dust is not known, NASA has tasked its toxicology laboratory to evaluate the risk of exposure to the dust and to establish safe exposure limits for astronauts working in the lunar habitat. Studies of the pulmonary toxicity of a dust are generally done first in rodents by intratracheal/intrapharyngeal instillation. This toxicity screening test is then followed by an inhalation study, which requires much more of the test dust and is labor intensive. Preliminary results obtained by examining lung lavage fluid from dust-treated mice show that lunar dust was somewhat toxic (more toxic than TiO2, but less than quartz dust). More extensive studies are in progress to further examine lung lavage fluid for biomarkers of toxicity and lung tissues for histopathological lesions in rodents exposed to aged and activated (ground) lunar dust samples. In these studies, reference dusts (TiO2 and quartz) of known toxicities and have industrial exposure limits will be studied in parallel so the relative toxicity of lunar dust can be determined. The results from the instillation studies will be useful for choosing exposure concentrations for the animal inhalation study. The animal inhalation exposure will be conducted with lunar dust simulant prior to the study with the lunar dust. The experiment with the simulate will ensure that the study techniques used with actual lunar dust will be successful. The results of instillation and inhalation studies will reveal the toxicological risk of exposures and are essential for setting exposure limits on lunar dust for astronauts living in the lunar habitat.

  11. The rodent estrous cycle: Characterization of vaginal cytology and its utility in toxicological studies

    EPA Science Inventory

    An evaluation of the estrous cycle in laboratory rodents can be a useful measure of the integrity of the hypothalamic-pituitary-ovarian reproductive axis. It can also serve as a way of insuring that animals exhibiting abnormal cycling patterns are disincluded from a study prior t...

  12. Diffusion MRI of Rodent Glioma at 21T National High Magnetic Field Laboratory

    E-print Network

    Weston, Ken

    Diffusion MRI of Rodent Glioma at 21T National High Magnetic Field Laboratory NMR Spectroscopy and Imaging Facility User Program, Florida State University In-vivo sodium and proton diffusion demonstrate with corresponding alterations of tumors' water diffusion is attracting particular attention in the efforts

  13. Rodents for comparative aging studies: from mice to beavers

    PubMed Central

    Bozzella, Michael J.; Seluanov, Andrei

    2008-01-01

    After humans, mice are the best-studied mammalian species in terms of their biology and genetics. Gerontological research has used mice and rats extensively to generate short- and long-lived mutants, study caloric restriction and more. Mice and rats are valuable model organisms thanks to their small size, short lifespans and fast reproduction. However, when the goal is to further extend the already long human lifespan, studying fast aging species may not provide all the answers. Remarkably, in addition to the fast-aging species, the order Rodentia contains multiple long-lived species with lifespans exceeding 20 years (naked mole-rat, beavers, porcupines, and some squirrels). This diversity opens great opportunities for comparative aging studies. Here we discuss the evolution of lifespan in rodents, review the biology of slow-aging rodents, and show an example of how the use of a comparative approach revealed that telomerase activity coevolved with body mass in rodents. PMID:19424861

  14. Rodents for comparative aging studies: from mice to beavers.

    PubMed

    Gorbunova, Vera; Bozzella, Michael J; Seluanov, Andrei

    2008-09-01

    After humans, mice are the best-studied mammalian species in terms of their biology and genetics. Gerontological research has used mice and rats extensively to generate short- and long-lived mutants, study caloric restriction and more. Mice and rats are valuable model organisms thanks to their small size, short lifespans and fast reproduction. However, when the goal is to further extend the already long human lifespan, studying fast aging species may not provide all the answers. Remarkably, in addition to the fast-aging species, the order Rodentia contains multiple long-lived species with lifespans exceeding 20 years (naked mole-rat, beavers, porcupines, and some squirrels). This diversity opens great opportunities for comparative aging studies. Here we discuss the evolution of lifespan in rodents, review the biology of slow-aging rodents, and show an example of how the use of a comparative approach revealed that telomerase activity coevolved with body mass in rodents. PMID:19424861

  15. The Role of Pheromonal Responses in Rodent Behavior: Future Directions for the Development of Laboratory Protocols

    PubMed Central

    Bind, Rebecca H; Minney, Sarah M; Rosenfeld, SaraJane; Hallock, Robert M

    2013-01-01

    Pheromones—chemical signals that can elicit responses in a conspecific—are important in intraspecies communication. Information conveyed by pheromones includes the location of an animal, the presence of food or a threat, sexual attraction, courtship, and dam–pup interactions. These chemical messages remain intact and volatile even when animals, such as rodents, are housed in laboratories rather than their natural environment. Laboratory protocols, such as the cage cleaning and sanitation processes, as well as general housing conditions can alter a rodent's normal production of pheromones in both amount and type and thus may affect behavior. In addition, some procedures induce the release of alarm pheromones that subsequently alter the behavior of other rodents. To prevent pheromonal interference and stress-induced pheromonal release in their research subjects, experimenters should assess current laboratory protocols regarding cage cleaning processes, housing designs, and behavioral assays. Here we discuss how the most commonly used laboratory procedures can alter pheromonal signaling and cause confounding effects. PMID:23562094

  16. CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS

    EPA Science Inventory

    CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS. WP Watkinson1, LB Wichers2, JP Nolan1, DW Winsett1, UP Kodavanti1, MCJ Schladweiler1, LC Walsh1, ER Lappi1, D Terrell1, R Slade1, AD Ledbetter1, and DL Costa1. 1USEPA, ORD/NHEERL/ETD/PTB, RTP, NC, US...

  17. Evaluation of individually ventilated cage systems for laboratory rodents: cage environment and animal health aspects.

    PubMed

    Höglund, A U; Renström, A

    2001-01-01

    The use of individually ventilated cage (IVC) systems has become an attractive housing regime of laboratory rodents. The benefits of IVC systems are, reportedly, a high degree of containment combined with relative ease of handling, and a high degree of protection from allergenes. In the present study we tested whether two IVC systems (BioZone VentiRack, IVC1 and Techniplast SealSafe, IVC2S), in which we held mature male NMRI mice, were constructed to maintain a constant differential pressure, positive or negative, during a prolonged period of time. We also measured ammonia (NH3) concentrations after about 2 weeks of use, and CO2 build-up during a 60 min simulated power failure situation. In addition, animal weight development and bite-wound frequency were recorded (Renström et al. 2000). From the present study it is concluded that the IVC1 air handling system provides a more uniform and balanced differential pressure than the IVC2S. Both systems effectively scavenge NH3 when bedding material is not soaked by urine. Although the IVCs are dependent on the continual function of the fans to work properly, it seems unlikely that CO2 concentrations increase to hazardous levels, as a result of a one hour power failure, with the type of cages used in this study. Differences in weight development and bite-wound occurrence were noted between the two IVC systems. Causes for these differences could not be established and need more investigation. PMID:11201288

  18. A Bead-Based Multiplex Assay for the Detection of DNA Viruses Infecting Laboratory Rodents

    PubMed Central

    Höfler, Daniela; Nicklas, Werner; Mauter, Petra; Pawlita, Michael; Schmitt, Markus

    2014-01-01

    The Federation of European Laboratory Animal Science Association (FELASA) recommends screening of laboratory rodents and biological materials for a broad variety of bacterial agents, viruses, and parasites. Methods commonly used to date for pathogen detection are neither cost-effective nor time- and animal-efficient or uniform. However, an infection even if silent alters experimental results through changing the animals’ physiology and increases inter-individual variability. As a consequence higher numbers of animals and experiments are needed for valid and significant results. We developed a novel high-throughput multiplex assay, called rodent DNA virus finder (rDVF) for the simultaneous identification of 24 DNA viruses infecting mice and rats. We detected all 24 DNA viruses with high specificity and reproducibility. Detection limits for the different DNA viruses varied between 10 and 1000 copies per PCR. The validation of rDVF was done with DNA isolated from homogenised organs amplified by pathogen specific primers in one multiplex PCR. The biotinylated amplicons were detected via hybridisation to specific oligonucleotide probes coupled to spectrally distinct sets of fluorescent Luminex beads. In conclusion, rDVF may have the potential to replace conventional testing and may simplify and improve routine detection of DNA viruses infecting rodents. PMID:24835244

  19. Sex Differences in Behavioral Circadian Rhythms in Laboratory Rodents

    PubMed Central

    Krizo, Jessica A.; Mintz, Eric M.

    2014-01-01

    There is a strong bias in basic research on circadian rhythms toward the use of only male animals in studies. Furthermore, of the studies that use female subjects, many use only females and do not compare results between males and females. This review focuses on behavioral aspects of circadian rhythms that differ between the sexes. Differences exist in the timing of daily onset of activity, responses to both photic and non-photic stimuli, and in changes across the lifespan. These differences may reflect biologically important traits that are ecologically relevant and impact on a variety of responses to behavioral and physiological challenges. Overall, more work needs to be done to investigate differences between males and females as well as differences that are the result of hormonal changes across the lifespan. PMID:25620955

  20. Housing conditions and stimulus females: a robust social discrimination task for studying male rodent social recognition

    PubMed Central

    Macbeth, Abbe H.; Edds, Jennifer Stepp; Young, W. Scott

    2010-01-01

    Social recognition (SR) enables rodents to distinguish between familiar and novel conspecifics, largely through individual odor cues. SR tasks utilize the tendency for a male to sniff and interact with a novel individual more than a familiar individual. Many paradigms have been used to study the roles of the neuropeptides oxytocin and vasopressin in SR. However, inconsistencies in results have arisen within similar mouse strains, and across different paradigms and laboratories, making reliable testing of social recognition difficult. The current protocol details a novel approach that is replicable across investigators and in different strains of mice. We created a protocol that utilizes gonadally intact, singly housed females presented within corrals to group-housed males. Housing females singly prior to testing is particularly important for reliable discrimination. This methodology will be useful for studying short-term social memory in rodents, and may also be applicable for longer-term studies. PMID:19816420

  1. Rodent models and imaging techniques to study liver regeneration.

    PubMed

    Wei, Weiwei; Dirsch, Olaf; Mclean, Anna Lawson; Zafarnia, Sara; Schwier, Michael; Dahmen, Uta

    2015-01-01

    The liver has the unique capability of regeneration from various injuries. Different animal models and in vitro methods are used for studying the processes and mechanisms of liver regeneration. Animal models were established either by administration of hepatotoxic chemicals or by surgical approach. The administration of hepatotoxic chemicals results in the death of liver cells and in subsequent hepatic regeneration and tissue repair. Surgery includes partial hepatectomy and portal vein occlusion or diversion: hepatectomy leads to compensatory regeneration of the remnant liver lobe, whereas portal vein occlusion leads to atrophy of the ipsilateral lobe and to compensatory regeneration of the contralateral lobe. Adaptation of modern radiological imaging technologies to the small size of rodents made the visualization of rodent intrahepatic vascular anatomy possible. Advanced knowledge of the detailed intrahepatic 3D anatomy enabled the establishment of refined surgical techniques. The same technology allows the visualization of hepatic vascular regeneration. The development of modern histological image analysis tools improved the quantitative assessment of hepatic regeneration. Novel image analysis tools enable us to quantify reliably and reproducibly the proliferative rate of hepatocytes using whole-slide scans, thus reducing the sampling error. In this review, the refined rodent models and the newly developed imaging technology to study liver regeneration are summarized. This summary helps to integrate the current knowledge of liver regeneration and promises an enormous increase in hepatological knowledge in the near future. PMID:25402256

  2. Two new rodent models for actinide toxicity studies. [/sup 237/Pu, /sup 241/Am

    SciTech Connect

    Taylor, G.N.; Jones, C.W.; Gardner, P.A.; Lloyd, R.D.; Mays, C.W.; Charrier, K.E.

    1981-04-01

    Two small rodent species, the grasshopper mouse (Onychomys leucogaster) and the deer mouse (Peromyscus maniculatus), have tenacious and high retention in the liver and skeleton of plutonium and americium following intraperitoneal injection of Pu and Am in citrate solution. Liver retention of Pu and Am in the grasshopper mouse is higher than liver retention in the deer mouse. Both of these rodents are relatively long-lived, breed well in captivity, and adapt suitably to laboratory conditions. It is suggested that these two species of mice, in which plutonium retention is high and prolonged in both the skeleton and liver, as it is in man, may be useful animal models for actinide toxicity studies.

  3. Comparison of Birth-and Conception-Based Definitions of Postnatal Age in Developmental and Reproductive Rodent Toxicity Studies: Influence of Gestation Length and Timing of Neonatal Examinations on Litter Data in Controls

    EPA Science Inventory

    Laboratories conducting developmental and reproductive toxicity studies with rodents use varied protocols for determining the timing of neonatal litter examinations and subsequent measurements. Most laboratories determine timing based on the day of birth (DOB); l.e., gestation le...

  4. Effect of Weak Acid Hypochlorous Solution on Selected Viruses and Bacteria of Laboratory Rodents

    PubMed Central

    Taharaguchi, Motoko; Takimoto, Kazuhiro; Zamoto-Niikura, Aya; Yamada, Yasuko K.

    2014-01-01

    Weak acid hypochlorous solution (WAHS) is known to have efficacy for inactivating pathogens and to be relatively safe with respect to the live body. Based on these advantages, many animal facilities have recently been introducing WAHS for daily cleaning of animal houses. In this study, we determined the effect of WAHS in inactivating specific pathogens of laboratory rodents and pathogens of opportunistic infection. WAHS with an actual chloride concentration of 60 ppm and a pH value of 6.0 was generated using purpose-built equipment. One volume of mouse hepatitis virus (MHV), Sendai virus, lymphocytic choriomeningitis virus, Bordetella bronchiseptica, Pasteurella pneumotropica, Corynebacterium kutscheri, Staphylococcus aureus, and Pseudomonas aeruginosa was mixed with 9 or 99 volumes of WAHS (×10 and ×100 reaction) for various periods (0.5, 1, and 5 min) at 25°C. After incubation, the remaining infectious viruses and live bacteria were determined by plaque assay or culture. In the ×100 reaction mixture, infectious viruses and live bacteria could not be detected for any of the pathogens examined even with the 0.5-min incubation. However, the effects for MHV, B. bronchiseptica, and P. aeruginosa were variable in the ×10 reaction mixture with the 0.5- and 1-min incubations. Sufficient effects were obtained by elongation of the reaction time to 5 min. In the case of MHV, reducing organic substances in the virus stock resulted in the WAHS being completely effective. WAHS is recommended for daily cleaning in animal facilities but should be used properly in order to obtain a sufficient effect, which includes such things as using a large enough volume to reduce effects of organic substances. PMID:24770639

  5. Comparative Studies of Diurnal and Nocturnal Rodents: Differences in Lifestyle Result in Alterations

    E-print Network

    Krubitzer, Leah A.

    organization of sensory cortex in four rodents: laboratory Norway rats (Long Evans; Rattus norvegicus), wild-caught Norway rats (Rattus norvegicus), wild-caught California ground squirrels (Spermophilus beecheyi

  6. Mammary gland neoplasia in long-term rodent studies.

    PubMed Central

    Russo, I H; Russo, J

    1996-01-01

    Breast cancer, the most frequent spontaneous malignancy diagnosed in women in the western world, is continuously increasing in incidence in industrialized nations. Although breast cancer develops in women as the result of a combination of external and endogenous factors such as exposure to ionizing radiation, diet, socioeconomic status, and endocrinologic, familial, or genetic factors, no specific etiologic agent(s) or the mechanisms responsible of the disease has been identified as yet. Thus, experimental models that exhibit the same complex interactions are needed for testing various mechanisms and for assessing the carcinogenic potential of given chemicals. Rodent mammary carcinomas represent such a model to a great extent because, in these species, mammary cancer is a multistep complex process that can be induced by either chemicals, radiation, viruses, or genetic factors. Long-term studies in rodent models have been particularly useful for dissecting the initiation, promotion, and progression steps of carcinogenesis. The susceptibility of the rodent mammary gland to develop neoplasms has made this organ a unique target for testing the carcinogenic potential of specific genotoxic chemicals and environmental agents. Mammary tumors induced by indirect- or direct-acting carcinogens such as 7, 12-dimethlbenz(a)anthracene or N-methyl-N-nitrosourea are, in general, hormone dependent adenocarcinomas whose incidence, number of tumors per animal, tumor latency, and tumor type are influenced by the age, reproductive history, and endocarinologic milieu of the host at the time of carcinogen exposure. Rodent models are informative in the absence of human data. They have provided valuable information on the dose and route of administration to be used and optimal host conditions for eliciting maximal tumorigenic response. Studies of the influence of normal gland development on the pathogenesis of chemically induced mammary carcinomas have clarified the role of differentiation in cancer initiation. Comparative studies with the development of the human breast and the pathogenesis of breast cancer have contributed to validate rodent-to-human extrapolations. However, it has not been definitively established what type of information is necessary for human risk assessment, whether currently toxicity testing methodologies are sufficient for fulfilling those needs, or whether treatment-induced tumorigenic responses in rodents are predictive of potential human risk. An alternative to the traditional bioassays are mechanism-based toxicology and molecular and cellular approaches, combined with comparative in vitro systems. These approaches might allow the rapid screen of chemicals for setting priorities for further studies to determine the dose-response relationship for chemical effects at low doses, to assess effects other than mutagenesis and/or tumorigenesis, or to establish qualitative and quantitative relationships of biomarkers to toxic effects. Until there is enough information on the predictive value of mechanism-based toxicology for risk assessment, this approach should be used in conjunction with and validated by the traditional in vivo long-term bioassays. Images Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. A Figure 7. B Figure 8. A Figure 8. B Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. PMID:8899375

  7. Identification and Sequencing of a Novel Rodent Gammaherpesvirus That Establishes Acute and Latent Infection in Laboratory Mice ?

    PubMed Central

    Loh, Joy; Zhao, Guoyan; Nelson, Christopher A.; Coder, Penny; Droit, Lindsay; Handley, Scott A.; Johnson, L. Steven; Vachharajani, Punit; Guzman, Hilda; Tesh, Robert B.; Wang, David; Fremont, Daved H.; Virgin, Herbert W.

    2011-01-01

    Gammaherpesviruses encode numerous immunomodulatory molecules that contribute to their ability to evade the host immune response and establish persistent, lifelong infections. As the human gammaherpesviruses are strictly species specific, small animal models of gammaherpesvirus infection, such as murine gammaherpesvirus 68 (?HV68) infection, are important for studying the roles of gammaherpesvirus immune evasion genes in in vivo infection and pathogenesis. We report here the genome sequence and characterization of a novel rodent gammaherpesvirus, designated rodent herpesvirus Peru (RHVP), that shares conserved genes and genome organization with ?HV68 and the primate gammaherpesviruses but is phylogenetically distinct from ?HV68. RHVP establishes acute and latent infection in laboratory mice. Additionally, RHVP contains multiple open reading frames (ORFs) not present in ?HV68 that have sequence similarity to primate gammaherpesvirus immunomodulatory genes or cellular genes. These include ORFs with similarity to major histocompatibility complex class I (MHC-I), C-type lectins, and the mouse mammary tumor virus and herpesvirus saimiri superantigens. As these ORFs may function as immunomodulatory or virulence factors, RHVP presents new opportunities for the study of mechanisms of immune evasion by gammaherpesviruses. PMID:21209105

  8. Genetic structure and inter-generic relationship of closed colony of laboratory rodents based on RAPD markers.

    PubMed

    Kumar, Mahadeo; Kumar, Sharad

    2014-11-01

    Molecular genetic analysis was performed using random amplified polymorphic DNA (RAPD) on three commonly used laboratory bred rodent genera viz. mouse (Mus musculus), rat (Rattus norvegicus) and guinea pig (Cavia porcellus) as sampled from the breeding colony maintained at the Animal Facility, CSIR-Indian Institute of Toxicology Research, Lucknow. In this study, 60 samples, 20 from each genus, were analyzed for evaluation of genetic structure of rodent stocks based on polymorphic bands using RAPD markers. Thirty five random primers were assessed for RAPD analysis. Out of 35, only 20 primers generated a total of 56.88% polymorphic bands among mice, rats and guinea pigs. The results revealed significantly variant and distinct fingerprint patterns specific to each of the genus. Within-genera analysis, the highest (89.0%) amount of genetic homogeneity was observed in mice samples and the least (79.3%) were observed in guinea pig samples. The amount of genetic homogeneity was observed very high within all genera. The average genetic diversity index observed was low (0.045) for mice and high (0.094) for guinea pigs. The inter-generic distances were maximum (0.8775) between mice and guinea pigs; and the minimum (0.5143) between rats and mice. The study proved that the RAPD markers are useful as genetic markers for assessment of genetic structure as well as inter-generic variability assessments. PMID:25074272

  9. Studying Autism in Rodent Models: Reconciling Endophenotypes with Comorbidities

    PubMed Central

    Argyropoulos, Andrew; Gilby, Krista L.; Hill-Yardin, Elisa L.

    2013-01-01

    Autism spectrum disorder (ASD) patients commonly exhibit a variety of comorbid traits including seizures, anxiety, aggressive behavior, gastrointestinal problems, motor deficits, abnormal sensory processing, and sleep disturbances for which the cause is unknown. These features impact negatively on daily life and can exaggerate the effects of the core diagnostic traits (social communication deficits and repetitive behaviors). Studying endophenotypes relevant to both core and comorbid features of ASD in rodent models can provide insight into biological mechanisms underlying these disorders. Here we review the characterization of endophenotypes in a selection of environmental, genetic, and behavioral rodent models of ASD. In addition to exhibiting core ASD-like behaviors, each of these animal models display one or more endophenotypes relevant to comorbid features including altered sensory processing, seizure susceptibility, anxiety-like behavior, and disturbed motor functions, suggesting that these traits are indicators of altered biological pathways in ASD. However, the study of behaviors paralleling comorbid traits in animal models of ASD is an emerging field and further research is needed to assess altered gastrointestinal function, aggression, and disorders of sleep onset across models. Future studies should include investigation of these endophenotypes in order to advance our understanding of the etiology of this complex disorder. PMID:23898259

  10. Laboratory Rodent Diets Contain Toxic Levels of Environmental Contaminants: Implications for Regulatory Tests

    PubMed Central

    Rocque, Louis-Marie; Spiroux de Vendômois, Joël; Séralini, Gilles-Eric

    2015-01-01

    The quality of diets in rodent feeding trials is crucial. We describe the contamination with environmental pollutants of 13 laboratory rodent diets from 5 continents. Measurements were performed using accredited methodologies. All diets were contaminated with pesticides (1-6 out of 262 measured), heavy metals (2-3 out of 4, mostly lead and cadmium), PCDD/Fs (1-13 out of 17) and PCBs (5-15 out of 18). Out of 22 GMOs tested for, Roundup-tolerant GMOs were the most frequently detected, constituting up to 48% of the diet. The main pesticide detected was Roundup, with residues of glyphosate and AMPA in 9 of the 13 diets, up to 370 ppb. The levels correlated with the amount of Roundup-tolerant GMOs. Toxic effects of these pollutants on liver, neurodevelopment, and reproduction are documented. The sum of the hazard quotients of the pollutants in the diets (an estimator of risk with a threshold of 1) varied from 15.8 to 40.5. Thus the chronic consumption of these diets can be considered at risk. Efforts toward safer diets will improve the reliability of toxicity tests in biomedical research and regulatory toxicology. PMID:26133768

  11. Laboratory Rodent Diets Contain Toxic Levels of Environmental Contaminants: Implications for Regulatory Tests.

    PubMed

    Mesnage, Robin; Defarge, Nicolas; Rocque, Louis-Marie; Spiroux de Vendômois, Joël; Séralini, Gilles-Eric

    2015-01-01

    The quality of diets in rodent feeding trials is crucial. We describe the contamination with environmental pollutants of 13 laboratory rodent diets from 5 continents. Measurements were performed using accredited methodologies. All diets were contaminated with pesticides (1-6 out of 262 measured), heavy metals (2-3 out of 4, mostly lead and cadmium), PCDD/Fs (1-13 out of 17) and PCBs (5-15 out of 18). Out of 22 GMOs tested for, Roundup-tolerant GMOs were the most frequently detected, constituting up to 48% of the diet. The main pesticide detected was Roundup, with residues of glyphosate and AMPA in 9 of the 13 diets, up to 370 ppb. The levels correlated with the amount of Roundup-tolerant GMOs. Toxic effects of these pollutants on liver, neurodevelopment, and reproduction are documented. The sum of the hazard quotients of the pollutants in the diets (an estimator of risk with a threshold of 1) varied from 15.8 to 40.5. Thus the chronic consumption of these diets can be considered at risk. Efforts toward safer diets will improve the reliability of toxicity tests in biomedical research and regulatory toxicology. PMID:26133768

  12. Teaching Laboratory Rodent Research Techniques under the Tenets of Situated Learning Improves Student Confidence and Promotes Collaboration

    PubMed Central

    Whitcomb, Tiffany L; Taylor, Edward W

    2014-01-01

    A targeted needs assessment at our institution revealed that the online system used to train researchers on performing techniques with animals did not provide opportunities to practice skills, introduce learners to animal care staff, nor satisfactorily support researchers’ needs to become comfortable with laboratory animal species. To correct these deficiencies, a series of hands-on training sessions, framed theoretically in situated learning, was developed. This theoretical framework asserts that learning for everyday living (in this case, performing laboratory animal techniques) happens when people interact within the community while using the ‘tools at hand’ (that is, the instruments and jargon of the field). From this perspective, the students work alongside the instructor as apprentices. The instructor creates increasingly challenging learning opportunities as students work toward independently performing techniques. To test our hypothesis that teaching from this perspective improves comfort levels with laboratory animals and promotes collaborative relationships between animal care and research personnel, a mixed-method design involving online surveys (first survey, n = 45; second survey, n = 35) and semistructured interviews (n = 10) was used. Quantitative results revealed that students became more comfortable with laboratory animals and were more likely to contact animal care personnel due to participating in the training program. The qualitative arm of the study identified specific features of the training program that improved comfort levels for students (seeing then doing, working in small groups, learning within a comfortable environment, and building collegial relationships). These results support teaching rodent research techniques from the practical and theoretical approach of situated learning. PMID:25199092

  13. ?-Cell Generation: Can Rodent Studies Be Translated to Humans?

    PubMed Central

    Carlotti, Françoise; Zaldumbide, Arnaud; Ellenbroek, Johanne H.; Spijker, H. Siebe; Hoeben, Rob C.; de Koning, Eelco J.

    2011-01-01

    ?-cell replacement by allogeneic islet transplantation is a promising approach for patients with type 1 diabetes, but the shortage of organ donors requires new sources of ? cells. Islet regeneration in vivo and generation of ?-cells ex vivo followed by transplantation represent attractive therapeutic alternatives to restore the ?-cell mass. In this paper, we discuss different postnatal cell types that have been envisaged as potential sources for future ?-cell replacement therapy. The ultimate goal being translation to the clinic, a particular attention is given to the discrepancies between findings from studies performed in rodents (both ex vivo on primary cells and in vivo on animal models), when compared with clinical data and studies performed on human cells. PMID:22007286

  14. Results from a Survey of Current Practices for Sampling of Nervous System in Rodents and Non-rodents in General Toxicity Studies

    EPA Science Inventory

    A survey of current practices for sampling and examination of the nervous system in rodents and non-rodents for general and neurotoxicity (NT) studies was conducted by the Nervous System Sampling Subcommittee of the STP. For general toxicity studies most of those surveyed (>63%) ...

  15. Survey of studies on how spaceflight affects rodent skeletal muscle.

    PubMed

    Fejtek, M B; Wassersug, R J

    1999-01-01

    Rodent muscles have been examined in more than 89 spaceflight studies over the last 25 years with much variation in the procedures and results. Mission duration ranged from four days to three weeks, postflight data collection ranged from a few hours to two days after landing, and there is great diversity in the number, size, and age of the rats that have flown. Several different types and sizes of animal enclosures have also been used--a significant factor because cage design affects animal activity and muscle loading. Only a small percentage (approximately 16%) of the total number of striated muscles in the rat have been examined. We have identified both substantial redundancy and inconsistencies in the results from studies to date. However, many of these appear unavoidable due to the great variation in experimental protocol of the different missions. Nevertheless these studies repeatedly confirm that exposure to spaceflight decreases the mass of limb muscles and leads to muscle atrophy. The majority of missions were flown by the former Soviet Union, but the majority of papers have been published by U.S. researchers. A relatively small number of investigators (about 50) clustered into fewer than 15 identifiable research groups worldwide account for most of the results to date. These groups have had access to rodent muscle tissue from two to seven spaceflights each. International cooperation in the post-cold war era and the publication of future work in peer-reviewed international journals should help greatly in reducing redundancy and enriching our knowledge of how gravity affects biological systems. PMID:10660771

  16. Anaesthesia and physiological monitoring during in vivo imaging of laboratory rodents: considerations on experimental outcomes and animal welfare

    PubMed Central

    2012-01-01

    The implementation of imaging technologies has dramatically increased the efficiency of preclinical studies, enabling a powerful, non-invasive and clinically translatable way for monitoring disease progression in real time and testing new therapies. The ability to image live animals is one of the most important advantages of these technologies. However, this also represents an important challenge as, in contrast to human studies, imaging of animals generally requires anaesthesia to restrain the animals and their gross motion. Anaesthetic agents have a profound effect on the physiology of the animal and may thereby confound the image data acquired. It is therefore necessary to select the appropriate anaesthetic regime and to implement suitable systems for monitoring anaesthetised animals during image acquisition. In addition, repeated anaesthesia required for longitudinal studies, the exposure of ionising radiations and the use of contrast agents and/or imaging biomarkers may also have consequences on the physiology of the animal and its response to anaesthesia, which need to be considered while monitoring the animals during imaging studies. We will review the anaesthesia protocols and monitoring systems commonly used during imaging of laboratory rodents. A variety of imaging modalities are used for imaging rodents, including magnetic resonance imaging, computed tomography, positron emission tomography, single photon emission computed tomography, high frequency ultrasound and optical imaging techniques such as bioluminescence and fluorescence imaging. While all these modalities are implemented for non-invasive in vivo imaging, there are certain differences in terms of animal handling and preparation, how the monitoring systems are implemented and, importantly, how the imaging procedures themselves can affect mammalian physiology. The most important and critical adverse effects of anaesthetic agents are depression of respiration, cardiovascular system disruption and thermoregulation. When anaesthetising rodents, one must carefully consider if these adverse effects occur at the therapeutic dose required for anaesthesia, if they are likely to affect the image acquisitions and, importantly, if they compromise the well-being of the animals. We will review how these challenges can be successfully addressed through an appropriate understanding of anaesthetic protocols and the implementation of adequate physiological monitoring systems. PMID:22877315

  17. Euthanasia by decapitation: evidence that this technique produces prompt, painless unconsciousness in laboratory rodents.

    PubMed

    Holson, R R

    1992-01-01

    Rapid euthanasia of laboratory rodents without the use of anesthesia is a necessary research technique whenever there is the likelihood of anesthesia or stress interfering with the chemistry of the tissues under investigation. Decapitation has long been the procedure of choice under such circumstances. Recently, however, the American Veterinary Medical Association (AVMA) panel on euthanasia recommended that decapitation be avoided on the grounds that the decapitated head may be conscious and suffering for as much as 15 seconds. The panel further recommended that if decapitation was scientifically necessary, the decapitated head be immediately immersed in liquid nitrogen. These AVMA guidelines now enjoy regulatory status; the recommendation that decapitation be avoided has thus caused considerable difficulty for all research requiring rapid, anesthesia-free collection of tissues. The scientific validity of these recommendations is consequently a matter of great practical as well as theoretical importance. The decision to discourage decapitation appears to have been based on a single literature report claiming that the EEG of the decapitated head revealed conscious suffering for more than 10 seconds (Mikeska and Klemm 1976). This review carefully examines the scientific literature on this subject. It is concluded that the report by Mikeska and Klemm of EEG activation in the decapitated head is correct, but that this phenomenon is also seen when the decapitated head is under deep anesthesia, and in normal brains under ether anesthesia or during REM sleep. Hence these findings do not demonstrate either consciousness or the perception of pain.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1522830

  18. Electromechanical design of a body weight support system for a therapeutic robot for rodent studies

    E-print Network

    Mayalu, Michaëlle Ntala

    2010-01-01

    As part of an ongoing effort to better understand and treat locomotor disorders, an over-ground therapeutic robot prototype to study recovery of locomotion after spinal cord injury in rodents is under development. One key ...

  19. Intracranial self-stimulation (ICSS) in rodents to study the neurobiology of motivation

    Microsoft Academic Search

    Elena H Chartoff; William A Carlezon

    2007-01-01

    It has become increasingly important to assess mood states in laboratory animals. Tests that reflect reward, reduced ability to experience reward (anhedonia) and aversion (dysphoria) are in high demand because many psychiatric conditions that are currently intractable in humans (e.g., major depression, bipolar disorder, addiction) are characterized by dysregulated motivation. Intracranial self-stimulation (ICSS) can be utilized in rodents (rats, mice)

  20. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    Tethered gravity laboratories study is presented. The following subject areas are covered: variable gravity laboratory; attitude tether stabilizer; configuration analysis (AIT); dynamic analysis (SAO); and work planned for the next reporting period.

  1. Lobe identity in the Mongolian gerbil prostatic complex: a new rodent model for prostate study.

    PubMed

    Rochel, Sabrina Santos; Bruni-Cardoso, Alexandre; Taboga, Sebastião Roberto; Vilamaior, Patricia Simone Leite; Góes, Rejane Maira

    2007-10-01

    Knowledge of structural and physiological differences among the prostatic lobes (PL) is the basis for development of experimental studies in traditional laboratory rodents. Although Mongolian gerbil reproductive organs have been increasingly investigated, its prostate structure is far from being properly known, and investigations of this organ focused on the ventral lobe (VL). Thus, the present study provides a thorough morphological description of prostatic complex in the male adult gerbil on the basis of topographic, histological, and ultrastructural analysis and ductal branching. Like other rodents, four pairs of PL were observed. However, in contrast to the rat and mouse, the VL is the least voluminous component and the dorsolateral lobe (DLL) is the most prominent and spatially isolated from remaining PL. The occurrence of a dorsal lobe (DL), hidden between bladder and insertion of seminal vesicles, has not been mentioned in previous reports with Mongolian gerbil. Collagenase digestion followed by microdissection revealed that, except for DL, which has a tubular-acinar organization, all PL exhibit tubular organization and variable ductal branching. Distinct histological and ultrastructural features such as secretory epithelium, aspect of luminal secretion and stromal organization are reported for each PL and are confirmed by morphometric and stereological methods. Histological sections showed at least three intralobar segments in VL and DL. Ultrastructural analysis evidenced that, although luminal epithelial cells of PL share typical features of exocrine secretory cells, there are striking lobe phenotypical variations. Both merocrine and apocrine pathways are observed in variable rates in all PL, with the predominance of the former in the DLL and the latter in the CG. The morphological observations presented herein point to distinct structural identities for each PL, which probably reflects specific functional compromise of seminal fluid secretion. These data also point to the gerbil as a good model for investigations concerning the regulation of prostate development and homeostasis, mainly with regard to the dorsal and dorsolateral PL. PMID:17724712

  2. Pulmonary Toxicity Studies of Lunar Dust in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-Wing; James, John T.

    2012-01-01

    NASA has been contemplating returning astronauts to the moon for long-duration habitation and research and using it as a stepping-stone to Mars. Other spacefaring nations are planning to send humans to the moon for the first time. The surface of the moon is covered by a layer of fine dust. Fine terrestrial dusts, if inhaled, are known to pose a health risk to humans. Some Apollo crews briefly exposed to moon dust that adhered to spacesuits and became airborne in the Lunar Module reported eye and throat irritation. The habitable area of any lunar landing vehicle or outpost would inevitably become contaminated with lunar dust. To assess the health risks of exposure of humans to airborne lunar dust, we evaluated the toxicity of Apollo 14 moon dust in animal lungs. Studies of the pulmonary toxicity of a dust are generally first done by intratracheal instillation (ITI) of aqueous suspensions of the test dust into the lungs of rodents. If a test dust is irritating or cytotoxic to the lungs, the alveolar macrophages, after phagocytizing the dust particles, will release cellular messengers to recruit white blood cells (WBCs) and to induce dilation of blood capillary walls to make them porous, allowing the WBCs to gain access to the alveolar space. The dilation of capillary walls also allows serum proteins and water entering the lung. Besides altering capillary integrity, a toxic dust can also directly kill the cells that come into contact with it or ingest it, after which the dead cells would release their contents, including lactate dehydrogenase (a common enzyme marker of cell death or tissue damage). In the treated animals, we lavaged the lungs 1 and 4 weeks after the dust instillation and measured the concentrations of these biomarkers of toxicity in the bronchioalveolar lavage fluids to determine the toxicity of the dust. To assess whether the inflammation and cellular injury observed in the biomarker study would lead to persistent or progressive histopathological changes, a similar study was conducted to microscopically examine rat lung tissue and the associated lymph nodes for lesions, including fibrosis, 1 or 3 months after the instillation. The results from this ITI study led us to select two concentrations (20 and 60 mg/cu m) for an inhalation study, in which rats were exposed to lunar dust 6 h daily for 4 weeks (5d/wk). Similar biochemical and histopathological assessments were carried out in these rats 1 day or 1, 4, or 13 weeks after the dust exposure. Rats exposed to lunar dust by ITI or inhalation showed effects indicating that the dust is moderately toxic. The data will be useful to establish safe exposure limits for astronauts working in a lunar habitat and also help engineers designing dust mitigation systems for lunar vehicles and habitats.

  3. Seroepidemiologic studies of hantavirus infection among wild rodents in California.

    PubMed Central

    Jay, M.; Ascher, M. S.; Chomel, B. B.; Madon, M.; Sesline, D.; Enge, B. A.; Hjelle, B.; Ksiazek, T. G.; Rollin, P. E.; Kass, P. H.; Reilly, K.

    1997-01-01

    A total of 4,626 mammals were serologically tested for antibodies to Sin Nombre virus. All nonrodent species were antibody negative. Among wild rodents, antibody prevalence was 8.5% in murids, 1.4% in heteromyids, and < 0.1% in sciurids. Of 1,921 Peromyscus maniculatus (deer mice), 226 (11.8%) were antibody positive, including one collected in 1975. The highest antibody prevalence (71.4% of 35) was found among P. maniculatus on Santa Cruz Island, off the southern California coast. Prevalence of antibodies among deer mice trapped near sites of human cases (26.8% of 164) was significantly higher than that of mice from other sites (odds ratio = 4.5; 95% confidence interval = 1.7, 11.6). Antibody prevalence increased with rising elevation (> 1,200 meters) and correlated with a spatial cluster of hantavirus pulmonary syndrome cases in the Sierra Nevada. PMID:9204301

  4. Why can't rodents vomit? A comparative behavioral, anatomical, and physiological study.

    PubMed

    Horn, Charles C; Kimball, Bruce A; Wang, Hong; Kaus, James; Dienel, Samuel; Nagy, Allysa; Gathright, Gordon R; Yates, Bill J; Andrews, Paul L R

    2013-01-01

    The vomiting (emetic) reflex is documented in numerous mammalian species, including primates and carnivores, yet laboratory rats and mice appear to lack this response. It is unclear whether these rodents do not vomit because of anatomical constraints (e.g., a relatively long abdominal esophagus) or lack of key neural circuits. Moreover, it is unknown whether laboratory rodents are representative of Rodentia with regards to this reflex. Here we conducted behavioral testing of members of all three major groups of Rodentia; mouse-related (rat, mouse, vole, beaver), Ctenohystrica (guinea pig, nutria), and squirrel-related (mountain beaver) species. Prototypical emetic agents, apomorphine (sc), veratrine (sc), and copper sulfate (ig), failed to produce either retching or vomiting in these species (although other behavioral effects, e.g., locomotion, were noted). These rodents also had anatomical constraints, which could limit the efficiency of vomiting should it be attempted, including reduced muscularity of the diaphragm and stomach geometry that is not well structured for moving contents towards the esophagus compared to species that can vomit (cat, ferret, and musk shrew). Lastly, an in situ brainstem preparation was used to make sensitive measures of mouth, esophagus, and shoulder muscular movements, and phrenic nerve activity-key features of emetic episodes. Laboratory mice and rats failed to display any of the common coordinated actions of these indices after typical emetic stimulation (resiniferatoxin and vagal afferent stimulation) compared to musk shrews. Overall the results suggest that the inability to vomit is a general property of Rodentia and that an absent brainstem neurological component is the most likely cause. The implications of these findings for the utility of rodents as models in the area of emesis research are discussed. PMID:23593236

  5. Why Can’t Rodents Vomit? A Comparative Behavioral, Anatomical, and Physiological Study

    PubMed Central

    Horn, Charles C.; Kimball, Bruce A.; Wang, Hong; Kaus, James; Dienel, Samuel; Nagy, Allysa; Gathright, Gordon R.; Yates, Bill J.; Andrews, Paul L. R.

    2013-01-01

    The vomiting (emetic) reflex is documented in numerous mammalian species, including primates and carnivores, yet laboratory rats and mice appear to lack this response. It is unclear whether these rodents do not vomit because of anatomical constraints (e.g., a relatively long abdominal esophagus) or lack of key neural circuits. Moreover, it is unknown whether laboratory rodents are representative of Rodentia with regards to this reflex. Here we conducted behavioral testing of members of all three major groups of Rodentia; mouse-related (rat, mouse, vole, beaver), Ctenohystrica (guinea pig, nutria), and squirrel-related (mountain beaver) species. Prototypical emetic agents, apomorphine (sc), veratrine (sc), and copper sulfate (ig), failed to produce either retching or vomiting in these species (although other behavioral effects, e.g., locomotion, were noted). These rodents also had anatomical constraints, which could limit the efficiency of vomiting should it be attempted, including reduced muscularity of the diaphragm and stomach geometry that is not well structured for moving contents towards the esophagus compared to species that can vomit (cat, ferret, and musk shrew). Lastly, an in situ brainstem preparation was used to make sensitive measures of mouth, esophagus, and shoulder muscular movements, and phrenic nerve activity–key features of emetic episodes. Laboratory mice and rats failed to display any of the common coordinated actions of these indices after typical emetic stimulation (resiniferatoxin and vagal afferent stimulation) compared to musk shrews. Overall the results suggest that the inability to vomit is a general property of Rodentia and that an absent brainstem neurological component is the most likely cause. The implications of these findings for the utility of rodents as models in the area of emesis research are discussed. PMID:23593236

  6. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, C.-W.; James, J. T.; Taylor, L.; Zeidler-Erdely, P. C.; Castranova, V.

    2009-01-01

    NASA will build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of fine, reactive dust. Astronauts on the Moon will go in and out of the base for various activities, and will inevitably bring some dust into the living quarters. Depressurizing the airlock so that astronauts can exit for outdoor activities could also bring dust inside the airlock to the habitable area. Concerned about the potential health effects on astronauts exposed to airborne lunar dust, NASA directed the JSC Toxicology Laboratory to determine the pulmonary toxicity of lunar dust. The toxicity data also will be needed by toxicologists to establish safe exposure limits for astronauts residing in the lunar habitat and by environmental engineers to design an appropriate dust mitigation strategy. We conducted a study to examine biomarkers of toxicity (inflammation and cytotoxicity) in lung lavage fluids from mice intrapharyngeally instilled with lunar dust samples; we also collected lung tissue from the mice for histopathological examination 3 months after the dust instillation. Reference dusts (TiO2 and quartz) having known toxicities and industrial exposure limits were studied in parallel with lunar dust so that the relative toxicity of lunar dust can be determined. A 6-month histopathology study has been planned. These instillation experiments will be followed by inhalation studies, which are more labor intensive and technologically difficult. The animal inhalation studies will be conducted first with an appropriate lunar dust simulant to ensure that the exposure techniques to be used with actual lunar dust will be successful. The results of these studies collectively will reveal the toxicological risk of exposures and enable us to establish exposure limits on lunar dust for astronauts living in the lunar habitat.

  7. Comparison of Birth-and Conception-Based Definitions of Postnatal Age in Developmental and Reproductive Rodent Toxicity Studies: lnfluence of Gestation Length on Measurements of Offspring Body Weight and Puberty in Controls

    EPA Science Inventory

    Most laboratories conducting developmental and reproductive toxicity studies in rodents assign age by defining postnatal day (PND) 0 or 1 as the day of birth (DOB); i.e., gestation length affects PND and the timing of postnatal measurements. Some laboratories, however, define age...

  8. AMPHETAMINE EFFECTS IN MICROTINE RODENTS: A COMPARATIVE STUDY USING MONOGAMOUS AND PROMISCUOUS VOLE SPECIES

    E-print Network

    Wang, Zuoxin

    AMPHETAMINE EFFECTS IN MICROTINE RODENTS: A COMPARATIVE STUDY USING MONOGAMOUS AND PROMISCUOUS VOLE in the nucleus accumbens of vole species that exhibit differing mating systems to examine potential interactions extracellular dopamine, however, monogamous voles had greater and longer-lasting increases in extracellular

  9. A study of vehicles for dosing rodent whole embryo culture with non aqueous soluble compounds

    Microsoft Academic Search

    Karen A Augustine-Rauch; Qin Zhang; Mark Kleinman; Richard Lawton; Michael J Welsh

    2004-01-01

    In rodent whole embryo culture (WEC), finding vehicles for non-aqueous-soluble compounds has been problematic due to developmental toxicity associated with many solvents. The purpose of this study was to identify alternative vehicles for insoluble compounds. In WEC, we evaluated carrier solutions containing bovine serum albumin (BSA) and glycerol as well as the solvents, formamide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and

  10. Epithelial Gaps in a Rodent Model of Inflammatory Bowel Disease: A Quantitative Validation Study

    E-print Network

    Alberta, University of

    Epithelial Gaps in a Rodent Model of Inflammatory Bowel Disease: A Quantitative Validation Study with accuracy comparable to CM and light microscopy. In a mouse model of inflammatory bowel disease online 9 June 2011 Subject Category: inflammatory bowel disease INTRODUCTION Epithelial cell shedding

  11. Issues in the Design and Interpretation of Chronic Toxicity and Carcinogenicity Studies in Rodents: Approaches to Dose Selection

    EPA Science Inventory

    For more than three decades chronic studies in rodents have been the benchmark for assessing the potential long-term toxicity, and particularly the carcinogenicity, of chemicals. With doses typically administered for about 2 years (18 months to lifetime), the rodent bioassay has ...

  12. A NEW METHOD TO QUANTIFY CORE TEMPERATURE INSTABILITY IN RODENTS.

    EPA Science Inventory

    Methods to quantify instability of autonomic systems such as temperature regulation should be important in toxicant and drug safety studies. Stability of core temperature (Tc) in laboratory rodents is susceptible to a variety of stimuli. Calculating the temperature differential o...

  13. Draft Genome Sequences of Eight Enterohepatic Helicobacter Species Isolated from Both Laboratory and Wild Rodents

    E-print Network

    Sheh, Alexander

    The draft genome sequences of eight enterohepatic Helicobacter species, H. muridarum, H. trogontum, H. typhlonius, and five unnamed helicobacters, are presented here. Using laboratory mice pervasively infected with ...

  14. Serological study of rickettsial diseases in human and rodent population in Chittoor dist. (A.P.).

    PubMed

    Prabhakaran, A; Lal, Sohan; Biswas, Shyamal; Vinoth, S; Asraf, Ali S; Mittal, Veena

    2010-09-01

    In India the presence of Rickettsial disease in human is documented in many states however, the data on presence of Rickettsial infection in Andhra Pradesh is very scare. Therefore, a study was undertaken in Chittoor district (A.P.) to see the prevalence of Rickettsial infection in human and rodent population. 3-5 ml of human blood samples were collected from the patients attending the nearest hospitals of Tirumala, Tirupathi, Palmner and Chittoor areas. Live rodents were trapped and blood samples were collected from them during January and February 2008. Sera was separated and tested by Weil Felix test. Two hundred human sera samples were tested. Of these 39 samples were found reactive with Weil Felix antigen. Of the 39 reactive, 31 were male and 8 female. All the human samples were showing reactivity at 1:20 dilution. Out of the 343 rodents samples tested, only 24 samples were showing reactivity. These were reactive at 1:20, 1:40 and 1:80 dilutions with different types of Weil Felix antigens. Eight rodent sera samples were having titer 1:80 with Proteus OXK which is suggestive of presence of Scrub typhus in this region. PMID:22471185

  15. MONITORING OF THE ESTROUS CYCLE IN THE LABORATORY RODENT BY VAGINAL LAVAGE

    EPA Science Inventory

    Ovarian cyclicity in a number of laboratory species can be monitored easily and noninvasively by observing changes in the vaginal cytology. his chapter describes the techniques used to collect data in the laboratory rat and mouse and how to interpret the lavages as they are obtai...

  16. Thirteen week rodent feeding study with processed fractions from herbicide tolerant (DP-Ø73496-4) canola.

    PubMed

    Delaney, Bryan; Appenzeller, Laura M; Roper, Jason M; Mukerji, Pushkor; Hoban, Denise; Sykes, Greg P

    2014-04-01

    The potential health effects of meal and oil processed from seed of genetically modified (GM) canola plants (OECD unique identifier: DP-Ø73496-4; hereafter referred to as 73496 canola) containing an insert that expresses the GAT4621 protein conferring tolerance to nonselective herbicidal ingredient glyphosate were evaluated in a subchronic rodent feeding study. Sprague-Dawley rats (12/sex/group) were administered diets containing dehulled, defatted toasted canola meal (DH meal) and refined/bleached/deodorized canola oil (RBD oil) processed from seed of plants that were untreated (73496), sprayed in-field with glyphosate (73496GLY), the non-transgenic near-isogenic (091; control), or one of four commercially available non-GM reference canola varieties (45H72, 45H73, 46A65, 44A89). All diets were formulated as a modification of the standard laboratory chow PMI® Nutrition International, LLC Certified Rodent LabDiet® 5002 (PMI® 5002). DH canola meal and RBD canola oil replaced all commodity soybean fractions typically incorporated in PMI® 5002. No toxicologically significant differences were observed between the test and control groups in this study. The results reported herein support the conclusion that DH meal and RBD oil processed from seed of 73496 canola are as safe and nutritious as DH meal and RBD oil processed from seed of non-GM canola. PMID:24491265

  17. Laboratory microfusion capability study

    NASA Astrophysics Data System (ADS)

    1993-05-01

    The purpose of this study is to elucidate the issues involved in developing a Laboratory Microfusion Capability (LMC) which is the major objective of the Inertial Confinement Fusion (ICF) program within the purview of the Department of Energy's Defense Programs. The study was initiated to support a number of DOE management needs: to provide insight for the evolution of the ICF program; to afford guidance to the ICF laboratories in planning their research and development programs; to inform Congress and others of the details and implications of the LMC; to identify criteria for selection of a concept for the Laboratory Microfusion Facility; and to develop a coordinated plan for the realization of an LMC. As originally proposed, the LMC study was divided into two phases. The first phase identifies the purpose and potential utility of the LMC, the regime of its performance parameters, driver independent design issues and requirements, its development goals and requirements, and associated technical, management, staffing, environmental, and other developmental and operational issues. The second phase addresses driver-dependent issues such as specific design, range of performance capabilities, and cost. The study includes four driver options: the neodymium-glass solid state laser, the krypton fluoride excimer gas laser, the light-ion accelerator, and the heavy-ion induction linear accelerator. The results of the Phase 2 study are described in the present report.

  18. Evaluation of individually ventilated cage systems for laboratory rodents: occupational health aspects.

    PubMed

    Renström, A; Björing, G; Höglund, A U

    2001-01-01

    New ventilated caging systems for laboratory animals were compared with conventional caging regarding allergen distribution, ergonomic suitability, cage environment and animal welfare. This paper presents occupational health evaluations. Mice were placed in individually ventilated cage (IVC) systems, a ventilated cabinet, and in cages on open shelves (conventional husbandry). The IVC systems were studied at negative and positive airflow. Aeroallergens were sampled on filters (n = 204, including controls) in undisturbed rooms and during cage changing. Concentrations of mouse urinary allergen (Mus m 1) in filter eluates were measured using sandwich ELISA. An ergonomic evaluation was performed with measurement of traction forces. Staff exposure during cage changing was high in all systems, range 116-4430 ng Mus m 1/m3. In undisturbed animal rooms, allergen levels were orders of magnitude higher when using conventional caging compared with ventilated systems; P < 0.001. At positive pressure both IVCs leaked allergen (median Mus m 1 concentration was < 0.08 ng/m3 at negative, but 6.5 ng/m3 (IVC1) and 0.8 ng/m3 (IVC2S) at positive pressure). The IVC systems had ergonomic disadvantages compared with the conventional husbandry and the ventilated cabinet, for instance with cages in unsuitable working heights. Ventilated husbandry solutions reduce levels of airborne allergen substantially at negative pressure, but are ergonomically less suitable. To prevent allergen exposure during cage changing, we propose that this procedure should be performed under ventilated conditions. Producers and users must cooperate in optimizing animal caging systems for both animals and staff. PMID:11201287

  19. Rodents for comparative aging studies: from mice to beavers

    Microsoft Academic Search

    Vera Gorbunova; Michael J. Bozzella; Andrei Seluanov

    2008-01-01

    After humans, mice are the best-studied mammalian species in terms of their biology and genetics. Gerontological research\\u000a has used mice and rats extensively to generate short- and long-lived mutants, study caloric restriction and more. Mice and\\u000a rats are valuable model organisms thanks to their small size, short lifespans and fast reproduction. However, when the goal\\u000a is to further extend the

  20. Assessing drug exposure in rodent toxicity studies without satellite animals

    Microsoft Academic Search

    Jerry R. Nedelman; Ekaterina Gibiansky; Francis L. S. Tse; Christine Babiuk I

    1993-01-01

    Five major objectives for pharmacokinetic investigations in support of toxicity studies are identified as follows: Assess whether animals exhibited measurable blood concentrations in a dose-dependent manner; estimate average area under the concentration- time curve (AUC)and maximal concentration (Cmax)for each treatment group; elucidate general patterns in the concentration-time (CxT)profile, and summarize relationships between CxTand treatment group; determine CxTdependence on day into

  1. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    Information on the Tethered Gravity Laboratory on the International Space Station is given in viewgraph form. Topics covered include active control, low gravity processes identification, systems analysis, tether interfaces with the Laboratory, elevator and payload configurations, elevator subsystems, and accelerometer technology requirements.

  2. A primer on rodent identification methods.

    PubMed

    Wang, Lotus

    2005-04-01

    Identifying laboratory rodents as a group may be sufficient if all the animals are to receive the same treatment and/or manipulation and if individual variations in response are not to be recorded separately. However, it is frequently necessary to be able to differentiate between individual animals used in a study. Identification of individual animals may also be necessary to maintain health records and to properly manage colonies of laboratory animals in compliance with regulatory agencies and research protocol requirements. PMID:15806093

  3. Examining lethality risk for rodent studies of primary blast lung injury.

    PubMed

    Hubbard, William Brad; Hall, Christina; Siva Sai Suijith Sajja, Venkata; Lavik, Erink; VandeVord, Pamela

    2014-01-01

    While protective measures have been taken to mitigate injury to the thorax during a blast exposure, primary blast lung injury (PBLI) is still evident in mounted/in vehicle cases during military conflicts. Moreover, civilians, who are unprotected from blast exposure, can be severely harmed by terrorist attacks that use improvised explosive devices (IEDs). Since the lungs are the most susceptible organ due to their air-filled nature, PBLI is one of the most serious injuries seen in civilian blast cases. Determining lethality threshold for rodent studies is crucial to guide experimental designs centered on therapies for survival after PBLI or mechanistic understanding of the injury itself. Using an Advanced Blast Simulator, unprotected rats were exposed to a whole body blast to induce PBLI. The one-hour survival rate was assessed to determine operating conditions for a 50% lethality rate. Macroscopic and histological analysis of lung was conducted using hematoxylin and eosin staining. Results demonstrated lethality risk trends based on static blast overpressure (BOP) for rodent models, which may help standardized animal studies and contribute to scaling to the human level. The need for a standardized method of producing PBLI is pressing and establishing standard curves, such as a lethality risk curve for lung blasts, is crucial for this condensing of BOP methods. PMID:25405409

  4. A Study on the Glycan Specificity of Natural Antibody Repertoires in Rodents

    PubMed Central

    Dai, Hui; Zhang, Yan; Lv, Ping; Gao, Xiao-Ming

    2009-01-01

    Inbred strains of mice and rats are widely used in preclinical investigations evaluating the effectiveness of glycan-based biomecines, however, the glycan specificity repertoires of serum Abs in rodents have not been fully characterized. In the present study, serum antibodies in naïve mice and rats of different inbred strains were analyzed for specificity against 4 representative carbohydrate structures including PGA (1,4-linked ?-D-galactopyranosyluronic acids), ?-glucan, mannan and ?-glucan (dextran). Mannan was not recognized by serum Abs from any of the mouse and rat strains. Serum IgM in naïve F344, BN and Lewis rats recognized PGA and ?-glucan and, less strongly, dextran. High titer circulating IgM against PGA were found in mice of BALB/c, C57BL/6, C3H/NeH and BXSB strains. C3H/NeH was the only strain which also produced low titer IgM against ?-glucan and dextran. Age-related production of high titer IgM, IgA and IgG Abs against ?-glucan was observed in BXSB mice. Intraperitoneal immunization of BALB/c and C57BL/6 mice with ?-glucan elicited strong IgM responses, while immunization with PGA also led to an increase of anti-PGA IgM Ab titers. These results provide useful information on the characteristics of glycan-specific natural antibody repertoires in rodents. PMID:20003821

  5. A Review of the Methods of Studies on Infant Ultrasound Production and Maternal Retrieval in Small Rodents

    Microsoft Academic Search

    Martin E. Hahn; Maria J. Lavooy

    2005-01-01

    Ultrasonic vocalizations or calls produced by young rodents have been associated with aspects of maternal behavior, in particular retrieving. We reviewed the methods of study used by investigators on each topic, focusing on intrinsic or subject variables and extrinsic or experimental variables. Intrinsic variables included the species studied, genotypes employed, number and sex composition of the litters, and the ages

  6. Ventilatory function assessment in safety pharmacology: Optimization of rodent studies using normocapnic or hypercapnic conditions

    SciTech Connect

    Goineau, Sonia; Rompion, Sonia; Guillaume, Philippe [Porsolt and Partners Pharmacology, Z.A. des Suhards, 53940 Le Genest-Saint-Isle (France); Picard, Sandra, E-mail: spicard@porsolt.co [Porsolt and Partners Pharmacology, Z.A. des Suhards, 53940 Le Genest-Saint-Isle (France)

    2010-09-15

    Although the whole body plethysmography for unrestrained animals is the most widely used method to assess the respiratory risk of new drugs in safety pharmacology, non-appropriate experimental conditions may mask deleterious side effects of some substances. If stimulant or bronchodilatory effects can be easily evidenced in rodents under standard experimental conditions, i.e. normal air breathing and diurnal phase, drug-induced respiratory depression remains more difficult to detect. This study was aimed at comparing the responsiveness of Wistar rats, Duncan Hartley guinea-pigs or BALB/c mice to the respiratory properties of theophylline (50 or 100 mg/kg p.o.) or morphine (30 mg/kg i.p.) under varying conditions (100% air versus 5% CO{sub 2}-enriched air, light versus dark day phase), in order to select the most appropriate experimental conditions to each species for safety airway investigations. Our results showed that under normocapnia the ventilatory depressant effects of morphine can be easily evidenced in mice, slightly observed in guinea-pigs and not detected in rats in any day phase. Slight hypercapnic conditions enhanced the responsiveness of rats to morphine but not that of guinea-pigs and importantly they did not blunt the airway responsiveness of rats to the stimulation and bronchodilation evoked by theophylline, the most widely used reference agent in safety pharmacology studies. In conclusion, hypercapnic conditions associated with the non-invasive whole body plethysmography should be considered for optimizing the assessment of both the ventilatory depressant potential of morphine-like substances or the respiratory stimulant effects of new drugs in the rat, the most extensively used species in rodent safety and toxicological investigations.

  7. CYTOKINE REGULATION OF HOST DEFENSE AGAINST PARASITIC GASTROINTESTINAL NEMATODES:Lessons from Studies with Rodent Models*1

    Microsoft Academic Search

    Fred D. Finkelman; Terez Shea-Donohue; Jon Goldhill; Carolyn A. Sullivan; Suzanne C. Morris; Kathleen B. Madden; William C. Gause

    1997-01-01

    Studies with rodents infected with Trichinella spiralis, Heligmosomoides poly- gyrus, Nippostrongylus brasiliensis, and Trichuris muris have provided consid- erable information about immune mechanisms that protect against parasitic gas- trointestinal nematodes. Four generalizations can be made: 1. CD4 C T cells are critical for host protection; 2. IL-12 and IFN- inhibit protective immunity; 3. IL-4 can: (a) be required for host

  8. Laboratory plasma studies

    NASA Astrophysics Data System (ADS)

    Fliflet, Arne

    1993-11-01

    The contents of the document are as follows: NIKE KrF Laser Support; Microwave and Millimeter Wave Experiments; Studies of Novel Accelerator Concepts and Free Electron Lasers; Studies for the Modified Betatron Accelerator (MBA); PHAROS 3 Studies; Electron Beam Diagnostics; Microwave Energy Deposition in the Upper Atmosphere; and Visualization Tools and Parallel Processing for Physics Applications.

  9. Comparative studies of diurnal and nocturnal rodents: differences in lifestyle result in alterations in cortical field size and number.

    PubMed

    Campi, Katharine L; Krubitzer, Leah

    2010-11-15

    In this study we examine and describe the neuroanatomical organization of sensory cortex in four rodents: laboratory Norway rats (Long Evans; Rattus norvegicus), wild-caught Norway rats (Rattus norvegicus), wild-caught California ground squirrels (Spermophilus beecheyi), and wild-caught Eastern gray squirrels (Sciurus carolinensis). Specifically, we examined the myeloarchitecture and cytochrome oxidase reactivity for several well-identified areas in visual cortex (areas 17, 18, and 19), somatosensory cortex (areas S1, S2 and PV), and auditory cortex [areas A1+AAF (R) and TA] and compared the percentage of dorsolateral cortex devoted to each of these areas. Our results demonstrate that squirrels have a larger mean percentage of dorsolateral cortex devoted to visual areas than rats. The difference is due to the greater percentage of cortex devoted to known areas such as area 17 and area 18 and not simply to a difference in the number of visual areas, which ultimately makes this distinction even more pronounced. Furthermore, both rat groups have a larger percentage of the dorsolateral cortex devoted to somatosensory and auditory cortical areas. Differences within groups were also observed. The arboreal squirrel had a larger mean percentage of dorsolateral cortex devoted to areas 17 and 18 compared with the terrestrial squirrel. The laboratory Norway rat had a larger percentage of dorsolateral cortex devoted to both somatosensory and auditory areas than the wild-caught Norway rat. Our results indicate that differences in sensory apparatus, use of sensory systems, and niche are reflected in the organization and size of cortical areas. PMID:20886618

  10. Validation study of OECD rodent uterotrophic assay for the assessment of estrogenic activity in Sprague-Dawley immature female rats.

    PubMed

    Kim, Hyung Sik; Kang, Tae Seok; Kang, Il Hyun; Kim, Tae Sung; Moon, Hyun Ju; Kim, In Young; Ki, Hoyun; Park, Kui Lea; Lee, Byung Mu; Yoo, Sun Dong; Han, Soon-Young

    2005-12-10

    The Organization for Economic Cooperation and Development (OECD) is developing a screening and testing method to identify estrogenic/antiestrogenic compounds. Based on these demands, phase 1 study for OECD uterotrophic assay was undertaken. The OECD is in the process of validating the assay results from international participating laboratories, which carried out this study with established environmental estrogenic compounds using designed protocols. The aim of this study was to provide data for validating the OECD uterotrophic assay using Sprague-Dawley immature female rats when testing with weak or partial estrogenic compounds. Ethinyl estradiol (EE) at 0.3 or 1 microg/kg/d, a positive control used in the present study, significantly increased both uterine wet and blotted weights. In the case of weak estrogenic compounds, the uterine wet weights were significantly increased by bisphenol A (BPA) at 300 mg/kg/d, nonylphenol (NP) at 80 mg/kg/d, genistein (GN) at 35 mg/kg/d, and methoxychlor (MXC) at 500 mg/kg/d. In addition, the increase in uterine blotted weights also showed a similar pattern to that of uterine wet weights. However, both 1,1,1-trichloro-2,2-bis(p-chlorphenyl)ethane (o,p-DDT) and dibutyl phthalate (DBP) did not affect uterus (wet and blotted) weights at doses of 100 and 500 mg/kg/d. These results suggest that the increase in uterine weights should be considered useful as a sensitive endpoint for detecting weak estrogenic compounds in 3-d rodent uterotrophic assay. However, further combination studies using surrogate biomarkers may be needed to improve the sensitivity of this assay for the detection of weak estrogenic compounds, such as o,p-DDT. PMID:16326438

  11. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    The use is studied of tether systems to improve the lowest possible steady gravity level on the Space Station. Particular emphasis is placed by the microgravity community on the achievement of high quality microgravity conditions. The tether capability is explored for active control of the center of gravity and the analysis of possible tethered configurations.

  12. Exercise, Obesity, and Cutaneous Wound Healing: Evidence from Rodent and Human Studies

    PubMed Central

    Pence, Brandt D.; Woods, Jeffrey A.

    2014-01-01

    Significance: Impaired cutaneous wound healing is a major health concern. Obesity has been shown in a number of studies to impair wound healing, and chronic nonhealing wounds in obesity and diabetes are a major cause of limb amputations in the United States. Recent Advances: Recent evidence indicates that aberrant wound site inflammation may be an underlying cause for delayed healing. Obesity, diabetes, and other conditions such as stress and aging can result in a chronic low-level inflammatory state, thereby potentially affecting wound healing negatively. Critical Issues: Interventions which can speed the healing rate in individuals with slowly healing or nonhealing wounds are of critical importance. Recently, physical exercise training has been shown to speed healing in both aged and obese mice and in older adults. Exercise is a relatively low-cost intervention strategy which may be able to be used clinically to prevent or treat impairments in the wound-healing process. Future Directions: Little is known about the mechanisms by which exercise speeds healing. Future translational studies should address potential mechanisms for these exercise effects. Additionally, clinical studies in obese humans are necessary to determine if findings in obese rodent models translate to the human population. PMID:24761347

  13. Tactile and non-tactile sensory paradigms for fMRI and neurophysiologic studies in rodents

    PubMed Central

    Sanganahalli, Basavaraju G.; Bailey, Christopher J.; Herman, Peter; Hyder, Fahmeed

    2013-01-01

    Functional magnetic resonance imaging (fMRI) has become a popular functional imaging tool for human studies. Future diagnostic use of fMRI depends, however, on a suitable neurophysiologic interpretation of the blood oxygenation level dependent (BOLD) signal change. This particular goal is best achieved in animal models primarily due to the invasive nature of other methods used and/or pharmacological agents applied to probe different nuances of neuronal (and glial) activity coupled to the BOLD signal change. In the last decade, we have directed our efforts towards the development of stimulation protocols for a variety of modalities in rodents with fMRI. Perception of the natural world relies on the formation of multi-dimensional representation of stimuli impinging on the different sensory systems, leading to the hypothesis that a sensory stimulus may have very different neurophysiologic outcome(s) when paired with a near simultaneous event in another modality. Before approaching this level of complexity, reliable measures must be obtained of the relatively small changes in the BOLD signal and other neurophysiologic markers (electrical, blood flow) induced by different peripheral stimuli. Here we describe different tactile (i.e., forepaw, whisker) and non-tactile (i.e., olfactory, visual) sensory paradigms applied to the anesthetized rat. The main focus is on development and validation of methods for reproducible stimulation of each sensory modality applied independently or in conjunction with one another, both inside and outside the magnet. We discuss similarities and/or differences across the sensory systems as well as advantages they may have for studying essential neuroscientific questions. We envisage that the different sensory paradigms described here may be applied directly to studies of multi-sensory interactions in anesthetized rats, en route to a rudimentary understanding of the awake functioning brain where various sensory cues presumably interrelate. PMID:18839094

  14. Differences in Ultrasonic Vocalizations between Wild and Laboratory California Mice (Peromyscus californicus)

    Microsoft Academic Search

    Matina C. Kalcounis-Rueppell; Radmila Petric; Jessica R. Briggs; Catherine Carney; Matthew M. Marshall; John T. Willse; Olav Rueppell; David O. Ribble; Janet P. Crossland

    2010-01-01

    BackgroundUltrasonic vocalizations (USVs) emitted by muroid rodents, including laboratory mice and rats, are used as phenotypic markers in behavioral assays and biomedical research. Interpretation of these USVs depends on understanding the significance of USV production by rodents in the wild. However, there has never been a study of muroid rodent ultrasound function in the wild and comparisons of USVs produced

  15. Imaging Neuronal Populations in Behaving Rodents: Paradigms for Studying Neural Circuits Underlying Behavior in the Mammalian Cortex

    PubMed Central

    Andermann, Mark L.; Keck, Tara; Xu, Ning-Long; Ziv, Yaniv

    2013-01-01

    Understanding the neural correlates of behavior in the mammalian cortex requires measurements of activity in awake, behaving animals. Rodents have emerged as a powerful model for dissecting the cortical circuits underlying behavior attributable to the convergence of several methods. Genetically encoded calcium indicators combined with viral-mediated or transgenic tools enable chronic monitoring of calcium signals in neuronal populations and subcellular structures of identified cell types. Stable one- and two-photon imaging of neuronal activity in awake, behaving animals is now possible using new behavioral paradigms in head-fixed animals, or using novel miniature head-mounted microscopes in freely moving animals. This mini-symposium will highlight recent applications of these methods for studying sensorimotor integration, decision making, learning, and memory in cortical and subcortical brain areas. We will outline future prospects and challenges for identifying the neural underpinnings of task-dependent behavior using cellular imaging in rodents. PMID:24198355

  16. Epithelial Gaps in a Rodent Model of Inflammatory Bowel Disease: A Quantitative Validation Study

    PubMed Central

    Liu, Julia J; Rudzinski, Jan K; Mah, Stephanie J; Thiesen, Aducio L; Bao, Haiyu; Wine, Eytan; Ogg, Stephen C; Boulanger, Pierre; Fedorak, Richard N; Madsen, Karen L

    2011-01-01

    OBJECTIVES: Confocal laser endomicroscopy (CLE) is a non-invasive imaging modality of the gastrointestinal tract. Epithelial gaps in the small intestine of patients and rodents have been demonstrated using CLE. The goal of this study was to quantitatively validate the findings of epithelial gap density observed with CLE against confocal microscopy (CM) and light microscopy. METHODS: Two strains of mice (control 129 Sv/Ev and interleukin 10 knockout (IL-10?/?)) underwent CLE of the terminal ileum. Adjacent ileal tissues were examined using CM and light microscopy. The total number of gaps and cells in the villi were manually counted from the three-dimensional reconstruction of cross-sectional CLE and CM images. The histology specimens were reviewed for epithelial gap and cell counts by a pathologist blinded to the study groups. The inter- and intra-observer variability for cell and gap counts were determined. RESULTS: For CLE, the gap densities (mean±s.d.) in the ileum for control and IL-10?/? mice were: 9.5±1.3 gaps per 1,000 cells and 20.6±2.1 gaps per 1,000 cells counted (P<0.001), respectively. For CM, the ileal gap densities were 7.3±1.3 gaps per 1,000 cells and 22.8±6.2 gaps per 1,000 cells (P=0.03), respectively. For light microscopy, the ileal gap densities were 29.2±5.9 gaps per 1,000 cells and 51.5±6.4 gaps per 1,000 cells for the two strains. CONCLUSION: CLE can be used to quantitatively assess epithelial cells and gaps with accuracy comparable to CM and light microscopy. In a mouse model of inflammatory bowel disease, the epithelial gap density in the terminal ileum is significantly increased when examined using all three modalities. PMID:23237881

  17. The rodent malaria lactate dehydrogenase assay provides a high throughput solution for in vivo vaccine studies.

    PubMed

    Otsuki, Hitoshi; Yokouchi, Yuki; Iyoku, Natsumi; Tachibana, Mayumi; Tsuboi, Takafumi; Torii, Motomi

    2015-08-01

    Rodent malaria is a useful model for evaluating the efficacy of malaria vaccine candidates; however, labor-intensive microscopic parasite counting hampers the use of an in vivo parasite challenge in high-throughput screening. The measurement of malaria parasite lactate dehydrogenase (pLDH) activity, which is commonly used in the in vitro growth inhibition assay of Plasmodium falciparum, may be the cheapest and simplest alternative to microscopic parasite counting. However, the pLDH assay has not been applied in the in vivo rodent malaria model. Here, we showed that the pLDH assay is reliable and accurately determines parasitemia in the rodent malaria model. pLDH activity measured using a chromogenic substrate reflects the parasite number in the blood; it allows fast and easy assessment using a conventional microplate reader. To validate this approach, we synthesized recombinant PyMSP1-19 protein (rPyMSP1-19) using a wheat germ cell-free protein synthesis system and immunized mice with rPyMSP1-19. The antisera showed specific reactivity on the surface of the Plasmodium yoelii merozoite and immunized mice were protected against a lethal P. yoelii 17 XL challenge. The pLDH assay quickly and easily demonstrated a significant reduction of the parasite numbers in the immunized mice. Accordingly, the pLDH assay proved to be an efficient alternative to rodent malaria parasite counting, and may therefore accelerate in vivo vaccine candidate screening. PMID:25701649

  18. Linking human behavior to environmental effects using a case study of urban rodent control

    EPA Science Inventory

    Pest control is common practice in many land use activities worldwide. Although often inadvertent, pest control can affect non-target species, sometimes fatally. Using social survey data about residential rodent control behavior in two areas in California, we applied a framewor...

  19. Biological and behavioural studies of rodents as a basis for control

    PubMed Central

    Jackson, W. B.

    1972-01-01

    Domestic rodents, particularly those living in urban populations, represent a serious public health problem, and effective control measures are required to deal with this threat to human health. Because of the characteristic interactions between individual animals, certain behaviour patterns occur in rodent populations that are of particular concern to control biologists. The genus Rattus is an extremely diverse group whose ecological requirements are variable and flexible, while the genus Mus, on account of its small size, limited range, and modest requirements in terms of food and water, is also very difficult to control. For any control operation a knowledge of the growth dynamics of domestic rodent populations is needed; after a period of logarithmic growth, population increases cease when the habitat is fully exploited. Consequently, control operations that merely remove some animals lead only to renewed population growth. Trapping, poisoning, and predation are traditional control measures of this kind. Environmental modification is a more certain, but more difficult, approach. The use of chemosterilants offers some hope of radical control in the future, but at present, although some field trials have been made, these substances are not available for general use, one reason being their lack of specificity. Another problem connected with the use of chemosterilants is that, on account of the sexual behaviour and physiology of domestic rodents, it would be necessary to reach nearly 100% of the population to obtain effective control. PMID:4539816

  20. Evaluation of NASA Foodbars as a Standard Diet for Use in Short-Term Rodent Space Flight Studies

    NASA Technical Reports Server (NTRS)

    Tou, Janet; Grindeland, Richard; Barrett, Joyce; Dalton, Bonnie; Mandel, Adrian; Wade, Charles

    2003-01-01

    A standard rodent diet for space flight must meet the unique conditions imposed by the space environment and must be nutritionally adequate since diet can influence the outcome of experiments. This paper evaluates the use of National Aeronautics and Space Administration (NASA) developed Foodbars as a standard space flight diet for rats. The Foodbar's semi-purified formulation permits criteria such as nutrient consistency, high nutrient bioavailability and flexibility of formulation to be met. Extrusion of the semi-purified diet produces Foodbars with the proper texture and a non-crumbing solid form for use in space. Treatment of Foodbar with 0.1% potassium sorbate prevents mold growth. Irradiation (15-25 kGy) prevents bacterial growth and in combination with sorbate-treatment provides added protection against mold for shelf-stability. However, during the development process, nutrient analyses indicated that extrusion and irradiation produced nutrient losses. Nutrients were adjusted accordingly to compensate for processing losses. Nutrient analysis of Foodbars continues to be performed routinely to monitor nutrient levels. It is important that the standard rodent diet provide nutrients that will prevent deficiency but also avoid excess that may mask physiological changes produced by space flight. All vitamins levels in the Foodbars, except for vitamin K conformed to or exceeded the current NRC (1995) recommendations. All indispensable amino acids in Foodbar conformed to or exceeded the NRC nutrient recommendation for mice growth and rat maintenance. However, some indispensable amino acids were slightly below recommendations for rat reproduction/growth. Short-term (18-20 d) animal feeding studies indicated that Foodbars were palatable, supported growth and maintained health in rats. Results indicated that NASA rodent Foodbars meet both the physical and nutritional criteria required to support rodents in the space environment and thus, may be used successfully as a standard diet for short-term space flight studies. However, nutritional adequacy of NASA Rodent Foodbars as a standard diet on longer duration (>20 d) space flight missions remains to be determined.

  1. A Guide to Research Rodent Housing

    Microsoft Academic Search

    William J. White

    BACKGROUND Laboratory rodents have been used in the United States as research animals since the late 1800s. In the past, housing of rodents used for research was designed primarily to prevent escape, to provide easy access to the animals by researchers, to allow the animals ready access to food and water, and to allow efficient dirty bedding removal and cage

  2. Short Retroposons of the B2 Superfamily: Evolution and Application for the Study of Rodent Phylogeny

    Microsoft Academic Search

    Irina M. Serdobova; Dmitri A. Kramerov

    1998-01-01

    .   Short retroposons can be used as natural phylogenetic markers. By means of hybridization and PCR analysis, we demonstrate\\u000a that B2 retroposon copies are present only in the three rodent families: Muridae, Cricetidae, and Spalacidae. This observation\\u000a highlights the close phylogenetic relation between these families. Two novel B2-related retroposon families, named DIP and\\u000a MEN elements, are described. DIP elements are

  3. Laboratory and Space Plasma Studies

    NASA Astrophysics Data System (ADS)

    Hyman, Ellis

    1996-08-01

    The work performed by Science Applications International Corporation (SAIC) on this contract, 'Laboratory and Space Plasma Studies,' Contract Number N00014-93-C-2178, SAIC Project Number 01-0157-03-6984, encompasses a wide range of topics in experimental, computational, and analytical laboratory and space plasma physics. The accomplishments described in this report have been in support of the programs of the Laser Plasma Branch (Code 6730) and other segments of the Plasma Physics Division at the Naval Research Laboratory (NRL) and cover the period 27 September 1993 to August 1, 1996. SAIC's efforts have been supported by subcontracts or consulting agreements with Pulse Sciences, Inc., Clark Richardson, and Biskup Consulting Engineers, Pharos Technical Enterprises, Plex Corporation, Cornell University, Stevens Institute of Technology, the University of Connecticut, Plasma Materials and Technologies, Inc., and GaSonics International, Inc. In the following discussions section we will describe each of the topics investigated and the results obtained. Much of the research work has resulted in journal publications and NRL Memorandum Reports in which the investigation is described in detail. These reports are included as Appendices to this Final Report.

  4. CLINICAL LABORATORY, VIROLOGIC, AND PATHOLOGIC CHANGES IN HAMSTERS EXPERIMENTALLY INFECTED WITH PIRITAL VIRUS (ARENAVIRIDAE): A RODENT MODEL OF LASSA FEVER

    Microsoft Academic Search

    ELENA SBRANA; ROSA I. MATEO; SHU-YUAN XIAO; VSEVOLOD L. POPOV; PATRICK C. NEWMAN; ROBERT B. TESH

    The clinical laboratory, virologic, and pathologic changes occurring in hamsters after infection with Pirital virus (Arenaviridae) are described. Pirital virus infection in the hamsters was characterized by high titered viremia, leukocytosis, coagulopathy, pulmonary hemorrhage and edema, hepatocellular and splenic necrosis, and marked eleva- tion of serum transaminase levels. All of the animals died within 9 days. The clinical and histopathological

  5. The Estrogenic Content of Rodent Diets, Bedding, Cages, and Water Bottles and Its Effect on Bisphenol A Studies

    PubMed Central

    Thigpen, Julius E; Setchell, Kenneth DR; Kissling, Grace E; Locklear, Jacqueline; Caviness, Gordon F; Whiteside, Tanya; Belcher, Scott M; Brown, Nadine M; Collins, Bradley J; Lih, Fred B; Tomer, Kenneth B; Padilla-Banks, Elizabeth; Camacho, Luísa; Adsit, Floyd G; Grant, Mary

    2013-01-01

    The lowest observed adverse effect level for bisphenol A (BPA) in mice and rats is currently poorly defined due to inconsistent study designs and results in published studies. The objectives of the current study were to (1) compare the estrogenic content of rodent diets, bedding, cages, and water bottles to evaluate their impact on the estrogenic activity of BPA and (2) review the literature on BPA to determine the most frequently reported diets, beddings, cages, and water bottles used in animal studies. Our literature review indicated that low-dose BPA animal studies have inconsistent results and that factors contributing to this inconsistency are the uses of high-phytoestrogen diets and the different routes of exposure. In 44% (76 of 172) of all reports, rodents were exposed to BPA via the subcutaneous route. Our literature review further indicated that the type of diet, bedding, caging, and water bottles used in BPA studies were not always reported. Only 37% (64 of 172) of the reports described the diet used. In light of these findings, we recommend the use of a diet containing low levels of phytoestrogen (less than 20 µg/g diet) and metabolizable energy (approximately 3.1 kcal/g diet) and estrogen-free bedding, cages, and water bottles for studies evaluating the estrogenic activity of endocrine-disrupting compounds such as BPA. The oral route of BPA exposure should be used when results are to be extrapolated to humans. PMID:23562095

  6. Ectoparasites of Rodents Captured in Bandar Abbas, Southern Iran

    PubMed Central

    Kia, EB; Moghddas-Sani, H; Hassanpoor, H; Vatandoost, H; Zahabiun, F; Akhavan, AA; Hanafi-Bojd, AA; Telmadarraiy, Z

    2009-01-01

    Background: Rodents play important role as host of ectoparasites and reservoir of different zoonotic diseases. The aim of this study was to asses the infestation of commensal rodents with ectoparasites in Bandar Abbas, a port city located in the northern part of the Persian Gulf in Iran. Methods: Rodents were captured using live traps during the study period in year 2007. After transferring the rodents to the laboratory, they were identified and then their ectoparasites were collected and mounted for species identification using appropriate systematic keys. Results: A total of 77 rodents were identified including Rattus norvegicus (74%), R. rattus (16.9%), Mus musculus (7.8%) and one hamster. Among all rodents, 40.3% were found infested with ectoparasites. A total of 69 ectoparasites were collected comprising flea, lice, mite and tick. Two species of fleas; Xenopsylla cheopis and X. astia were identified with higher index of X. astia. Two genera of ticks including Hyalomma sp. and Rhipicephalus sp. were identified. Laelaps nuttalli was the only mite found. The Polyplax spinulosa was considered as lice ectoparasite. Conclusion: Among all arthropods collected, flea and lice had the most and the least frequency, respectively. Nearly all rodent species were infested with Xenopsylla. These fleas are important due to their role in plague and murine typhus transmission. Ticks are important due to their role in CCHF (Crimean-Congo Hemorrhagic Fever), theileriosis, babesiosis, anaplasmosis and ehrlichiosis transmission .Monitoring of ectoparaiste infestation is important for preparedness and early warning preparation for possible control of arthropod-borne diseases. PMID:22808381

  7. Evaluation of three feed-through insecticides using two rodent and two sand fly species as models.

    PubMed

    Mascari, T M; Stout, R W; Foil, L D

    2012-09-01

    The efficacy of 3 rodent feed-through insecticides (novaluron, pyriproxyfen, and ivermectin) was determined against larvae of the sand flies Phlebotomus duboscqi and P. papatasi using Syrian hamsters (Mesocricetus auratus) and Mongolian gerbils (Meriones unguiculatus) as laboratory models. For each insecticide, there were no significant differences between the longevity or percentage survival of sand fly larvae that had been fed feces of treated rodents for each sand fly or rodent species pairing. The results of this study suggest that larvae of P. duboscqi and P. papatasi are equally susceptible to the concentrations of the rodent feed-through insecticides tested in this study and that these insecticides are pharmacologically compatible with different rodent/sand fly interactions. PMID:23833909

  8. Chemicals associated with site-specific neoplasia in 1394 long-term carcinogenesis experiments in laboratory rodents.

    PubMed Central

    Huff, J; Cirvello, J; Haseman, J; Bucher, J

    1991-01-01

    The carcinogenicity data base used for this paper originated in the late 1960s by the National Cancer Institute and since 1978 has been continued and made more comprehensive by the National Toxicology Program. The extensive files contain among other sets of information detailed pathology data on more than 400 long-term (most often 24 month) chemical carcinogenesis studies, comprised of nearly 1600 individual experiments having at least 10 million tissue sections that have been evaluated for toxicity and carcinogenicity. Using the current data set of 379 studies made up of 1394 experiments, we have compiled listings of chemicals having like carcinogenic target sites for each of the 34 organs or systems for which histopathology diagnoses have been recorded routinely. The most common tumor site is the liver (15% of all experiments), followed in rank order by: lung, hematopoietic system and kidneys, mammary glands, forestomach, thyroid glands, Zymbal glands, urinary bladder, skin and uterus/cervix, and circulatory system and adrenal glands. These compilations are most useful for maintaining a historic perspective when evaluating the carcinogenicity of contemporary experiments. Equally important, the chemical-tumor-organ connection permits an evaluation of how well chemically induced cancers in a particular organ in one sex or species will predict or correlate with the other sex or species. Using liver cancers as an example, the overall interspecies concordance is 80%. Likewise target site predictions can be made for chemicals selected for study that may be similar to those already evaluated; thereby experimental protocols could be adjusted to allow, for example, more extensive pathology on preselected target organs (i.e., serial sections of the kidney). Further from these observations, one could decide to use two strains of mice to evaluate a short-chain chlorinated aliphatic compound or to study a human carcinogen in a sex-species known to develop chemically induced tumors in the same site observed in humans. Structural classes of chemicals having a propensity for certain organs can be easily identified from these data. Sex-species responders to particular induced cancers become clearly evident, such as in the ovary of female mice or in the kidney of male rats. PMID:1773796

  9. Novel technology for modulating locomotor activity as an operant response in the mouse: implications for neuroscience studies involving “exercise” in rodents

    PubMed Central

    Fantegrossi, William E.; Xiao, Wenjie; Zimmerman, Sarah M.

    2012-01-01

    We have developed a novel, low-cost device designed to monitor and modulate locomotor activity in murine subjects. This technology has immediate application to the study of effects of physical exercise on various neurobiological endpoints, and will also likely be useful in the study of psychomotor sensitization and drug addiction. Here we demonstrate the capacity of these devices to establish locomotor activity as an operant response reinforced by food pellet presentations, and show that schedules of reinforcement can reliably control this behavior. Importantly, these data show that varying degrees of increased locomotor activity (in other words, “exercise”) can be elicited and maintained in mice by manipulating the schedule of reinforcement. Our findings argue that the present technology might reduce the imposition of stress and motivational bias inherent in more traditional procedures for establishing exercise in laboratory rodents, while allowing for true random assignment to experimental groups. As interest in physical exercise as a modulating factor in numerous clinical conditions continues to grow, technologies like the one proposed here are likely to become critical in conducting future experiments along these lines. PMID:23164960

  10. Non-invasive muscle contraction assay to study rodent models of sarcopenia

    PubMed Central

    2011-01-01

    Background Age-related sarcopenia is a disease state of loss of muscle mass and strength that affects physical function and mobility leading to falls, fractures, and disability. The need for therapies to treat age-related sarcopenia has attracted intensive preclinical research. To facilitate the discovery of these therapies, we have developed a non-invasive rat muscle functional assay system to efficiently measure muscle force and evaluate the efficacy of drug candidates. Methods The lower leg muscles of anesthetized rats are artificially stimulated with surface electrodes on the knee holders and the heel support, causing the lower leg muscles to push isometric pedals that are attached to force transducers. We developed a stimulation protocol to perform a fatigability test that reveals functional muscle parameters like maximal force, the rate of fatigue, fatigue-resistant force, as well as a fatigable muscle force index. The system is evaluated in a rat aging model and a rat glucocorticoid-induced muscle loss model Results The aged rats were generally weaker than adult rats and showed a greater reduction in their fatigable force when compared to their fatigue-resistant force. Glucocorticoid treated rats mostly lost fatigable force and fatigued at a higher rate, indicating reduced force from glycolytic fibers with reduced energy reserves. Conclusions The involuntary contraction assay is a reliable system to assess muscle function in rodents and can be applied in preclinical research, including age-related sarcopenia and other myopathy. PMID:22035016

  11. Evaluation of two rodent delayed-response memory tasks

    Microsoft Academic Search

    Alvin V Terry; William J Jackson; Jerry J Buccafusco

    2000-01-01

    The purpose of this study was to evaluate and compare two similar rodent memory tasks developed in our laboratory that employ stimulus discrimination and delayed response (light and tone stimuli and variable length delays) and to determine their sensitivity to the muscarinic-acetylcholine receptor (mAChR) antagonist, scopolamine hydrobromide (SCOP HBr), and its quaternary (methylbromide) analog (SCOP MBr). Male Wistar rats were

  12. Laboratory Studies of Astrophysical Ices

    NASA Astrophysics Data System (ADS)

    Dissly, Richard William

    1994-01-01

    This thesis reports the results of three laboratory studies, each concerned with some aspect of ices in an astrophysical environment, presented as independent papers water ice on interstellar grains demonstrate that amorphous water ice at 12 K can incorporate a substantial amount of H2, up to a mole ratio of H2/H2O = 0.53. We find that the physical behavior of approx. 80% of the hydrogen can be explained satisfactorily in terms of an equilibrium population, thermodynamically governed by a wide distribution of binding site energies. Such a description predicts that gas phase accretion could lead to mole fractions of H2 in interstellar grain mantles as high as 0.3. The possibility of interstellar grains that are rich in H2 could strongly affect our understanding of grain surface chemistry and gas-grain interactions. (2) Ultraviolet photolysis experiments on C2H4 ice were done to simulate its irradiation on Triton's surface. 0ur results show that C2H4 ice is readily dissociated by radiation of wavelengths less than ro equal to 1849A, with C2H2 ice as a primary product. Quantum yields for both the destruction of C2H4 and the formation of C2H2 are discussed, as functions of both irradiation wavelength and dilution in N2 ice. Applying these results to Triton, we find that the ambient UV flux reaching Triton's surface is more than adequate to prevent the build-up of an ethylene ice layer. (3) Thermal models of icy satellite surfaces that allow the scattering and absorption of incident sunlight at significant depths predict an enhancement of subsurface temperatures over the mean surface temperature known as the solid-state greenhouse effect. We verify that a solid-state greenhouse can readily be produced in a bed of evacuated glass beads, used as a crude analog for the surface of an icy body. Measurements of the thermal and radiative properties thought to govern the size of this temperature enhancement confirm that it can be reasonably predicted from these parameters.

  13. Does Nocturnality Drive Binocular Vision? Octodontine Rodents as a Case Study

    PubMed Central

    Vega-Zuniga, Tomas; Medina, Felipe S.; Fredes, Felipe; Zuniga, Claudio; Severín, Daniel; Palacios, Adrián G.; Karten, Harvey J.; Mpodozis, Jorge

    2013-01-01

    Binocular vision is a visual property that allows fine discrimination of in-depth distance (stereopsis), as well as enhanced light and contrast sensitivity. In mammals enhanced binocular vision is structurally associated with a large degree of frontal binocular overlap, the presence of a corresponding retinal specialization containing a fovea or an area centralis, and well-developed ipsilateral retinal projections to the lateral thalamus (GLd). We compared these visual traits in two visually active species of the genus Octodon that exhibit contrasting visual habits: the diurnal Octodon degus, and the nocturnal Octodon lunatus. The O. lunatus visual field has a prominent 100° frontal binocular overlap, much larger than the 50° of overlap found in O. degus. Cells in the retinal ganglion cell layer were 40% fewer in O. lunatus (180,000) than in O. degus (300,000). O. lunatus has a poorly developed visual streak, but a well developed area centralis, located centrally near the optic disk (peak density of 4,352 cells/mm2). O. degus has a highly developed visual streak, and an area centralis located more temporally (peak density of 6,384 cells/mm2). The volumes of the contralateral GLd and superior colliculus (SC) are 15% larger in O. degus compared to O. lunatus. However, the ipsilateral projections to GLd and SC are 500% larger in O. lunatus than in O. degus. Other retinorecipient structures related to ocular movements and circadian activity showed no statistical differences between species. Our findings strongly suggest that nocturnal visual behavior leads to an enhancement of the structures associated with binocular vision, at least in the case of these rodents. Expansion of the binocular visual field in nocturnal species may have a beneficial effect in light and contrast sensitivity, but not necessarily in stereopsis. We discuss whether these conclusions can be extended to other mammalian and non-mammalian amniotes. PMID:24391911

  14. Laboratory and Space Plasma Studies

    NASA Astrophysics Data System (ADS)

    Hyman, Ellis

    1996-08-01

    The work performed by Science Applications International Corporation (SAIC), encompasses a wide range of topics in experimental, computational, and analytical laboratory and space plasma physics. The accomplishments described in this report have been in support of the programs of the Laser Plasma Branch (Code 6730) and other segments of the Plasma Physics Division at the Naval Research Laboratory (NRL) and cover the period 27 September 1993 to August 1, 1996. SAIC's efforts have been supported by sub-contracts or consulting agreements with Pulse Sciences, Inc., Clark Richardson, and Biskup Consulting Engineers, Pharos Technical Enterprises, Plex Corporation, Cornell University, Stevens Institute of Technology, the University of Connecticut, Plasma Materials and Technologies, Inc., and GaSonics International, Inc. In the following discussions section we will describe each of the topics investigated and the results obtained. Much of the research work has resulted in journal publications and NRL Memorandum Reports in which the investigation is described in detail. These reports are included as Appendices to this Final Report.

  15. Probing perceptual decisions in rodents

    PubMed Central

    Carandini, Matteo; Churchland, Anne K

    2014-01-01

    The study of perceptual decision-making offers insight into how the brain uses complex, sometimes ambiguous information to guide actions. Understanding the underlying processes and their neural bases requires that one pair recordings and manipulations of neural activity with rigorous psychophysics. Though this research has been traditionally performed in primates, it seems increasingly promising to pursue it at least partly in mice and rats. However, rigorous psychophysical methods are not yet as developed for these rodents as they are for primates. Here we give a brief overview of the sensory capabilities of rodents and of their cortical areas devoted to sensation and decision. We then review methods of psychophysics, focusing on the technical issues that arise in their implementation in rodents. These methods represent a rich set of challenges and opportunities. PMID:23799475

  16. Ecological and Control Techniques for Sand Flies (Diptera: Psychodidae) Associated with Rodent Reservoirs of Leishmaniasis

    PubMed Central

    Mascari, Thomas M.; Hanafi, Hanafi A.; Jackson, Ryan E.; Ouahabi, Souâd; Ameur, Btissam; Faraj, Chafika; Obenauer, Peter J.; Diclaro, Joseph W.; Foil, Lane D.

    2013-01-01

    Background Leishmaniasis remains a global health problem because of the substantial holes that remain in our understanding of sand fly ecology and the failure of traditional vector control methods. The specific larval food source is unknown for all but a few sand fly species, and this is particularly true for the vectors of Leishmania parasites. We provide methods and materials that could be used to understand, and ultimately break, the transmission cycle of zoonotic cutaneous leishmaniasis. Methods and Findings We demonstrated in laboratory studies that analysis of the stable carbon and nitrogen isotopes found naturally in plant and animal tissues was highly effective for linking adult sand flies with their larval diet, without having to locate or capture the sand fly larvae themselves. In a field trial, we also demonstrated using this technique that half of captured adult sand flies had fed as larvae on rodent feces. Through the identification of rodent feces as a sand fly larval habitat, we now know that rodent baits containing insecticides that have been shown in previous studies to pass into the rodents' feces and kill sand fly larvae also could play a future role in sand fly control. In a second study we showed that rubidium incorporated into rodent baits could be used to demonstrate the level of bloodfeeding by sand flies on baited rodents, and that the elimination of sand flies that feed on rodents can be achieved using baits containing an insecticide that circulates in the blood of baited rodents. Conclusions Combined, the techniques described could help to identify larval food sources of other important vectors of the protozoa that cause visceral or dermal leishmaniasis. Unveiling aspects of the life cycles of sand flies that could be targeted with insecticides would guide future sand fly control programs for prevention of leishmaniasis. PMID:24069489

  17. Dietary administration in rodent studies distorts the tissue deposition profile of lanthanum carbonate; brain deposition is a contamination artefact?

    PubMed

    Damment, Stephen J P; Cox, Alan G; Secker, Roger

    2009-08-10

    Lanthanum carbonate is a non-calcium phosphate binder used to control hyperphosphataemia in patients with chronic kidney disease who are undergoing dialysis. Ultrastructurally, lanthanum ions are too large to traverse the tight junctions in the blood-brain barrier, yet tissue distribution studies using dietary administration have reported low concentrations in rodent brain, raising concern about accumulation. To investigate this, tissue lanthanum concentrations were measured in rats given the same lanthanum carbonate dose via powdered diet or oral gavage (838 and 863 mg/kg/day). Additional rats were dosed intravenously with lanthanum chloride (0.03 mg/kg/day), a route enabling much higher plasma lanthanum concentrations. After 28 days, median lanthanum concentrations in liver, bone, kidney and heart showed a direct relationship with those in plasma (highest after intravenous and lowest after dietary dosing). In contrast, brain concentrations were dramatically higher after dietary administration (< or =500 ng/g), compared to the other routes (LLOQ of 11 ng/g). An identical skewed pattern was noted for skin, a tissue readily contaminated in powdered diet studies. These data indicate that brain deposition is a contamination artefact caused by transfer of lanthanum from cranial skin to brain as animals are manipulated during autopsy. Dietary administration should be avoided in distribution studies of trace elements due to the high contamination risk. PMID:19464128

  18. LABORATORY SCALE STEAM INJECTION TREATABILITY STUDIES

    EPA Science Inventory

    Laboratory scale steam injection treatability studies were first developed at The University of California-Berkeley. A comparable testing facility has been developed at USEPA's Robert S. Kerr Environmental Research Center. Experience has already shown that many volatile organic...

  19. Radon transport: laboratory and model study.

    PubMed

    Catalano, R; Immé, G; Mangano, G; Morelli, D; Aranzulla, M

    2015-06-01

    In order to exploit radon profiles for geophysical purposes and also to estimate its entry indoors, it is necessary to study its transport through porous soils. The great number of involved parameters and processes affecting the emanation of radon from the soil grains and its transport in the source medium has led to many theoretical and/or laboratory studies. The authors report the first results of a laboratory study carried out at the Radioactivity Laboratory of the Department of Physics and Astronomy (University of Catania) by means of a facility for measuring radon concentrations in the sample pores at various depths under well-defined and controlled conditions of physical parameters. In particular, radon concentration vertical profiles extracted in low-moisture samples for different advective fluxes and temperatures were compared with expected concentrations, according to a three-phase transport model developed by Andersen (Risø National Laboratory, Denmark), showing, in general, a good agreement between measurements and model calculations. PMID:25977352

  20. [(11)C]5-HTP and microPET are not suitable for pharmacodynamic studies in the rodent brain.

    PubMed

    Visser, Anniek K D; Ramakrishnan, Nisha K; Willemsen, Antoon T M; Di Gialleonardo, Valentina; de Vries, Erik F J; Kema, Ido P; Dierckx, Rudi A J O; van Waarde, Aren

    2014-01-01

    The PET tracer [(11)C]5-hydroxytryptophan ([(11)C]5-HTP), which is converted to [(11)C]5-hydroxytryptamine ([(11)C]5-HT) by aromatic amino acid decarboxylase (AADC), is thought to measure 5-HT synthesis rates. But can we measure these synthesis rates by kinetic modeling of [(11)C]5-HTP in rat? Male rats were scanned with [(11)C]5-HTP (60 minutes) after different treatments. Scans included arterial blood sampling and metabolite analysis. 5-HT synthesis rates were calculated by a two-tissue compartment model (2TCM) with irreversible tracer trapping or Patlak analysis. Carbidopa (inhibitor peripheral AADC) dose-dependently increased [(11)C]5-HTP brain uptake, but did not influence 2TCM parameters. Therefore, 10?mg/kg carbidopa was applied in all subsequent study groups. These groups included treatment with NSD 1015 (general AADC inhibitor) or p-chlorophenylalanine (PCPA, inhibitor of tryptophan hydroxylase, TPH). In addition, the effect of a low-tryptophan (Trp) diet was investigated. NSD 1015 or Trp depletion did not affect any model parameters, but PCPA reduced [(11)C]5-HTP uptake, and the k3. This was unexpected as NSD 1015 directly inhibits the enzyme converting [(11)C]5-HTP to [(11)C]5-HT, suggesting that trapping of radioactivity does not distinguish between parent tracer and its metabolites. As different results have been acquired in monkeys and humans, [(11)C]5-HTP-PET may be suitable for measuring 5-HT synthesis in primates, but not in rodents. PMID:24084697

  1. Preparation and Biodistribution Studies of a Radiogallium-Acetylacetonate Bis (Thiosemicarbazone) Complex in Tumor-Bearing Rodents

    PubMed Central

    Jalilian, Amir Reza; Yousefnia, Hassan; Shafaii, Kamaleddin; Novinrouz, Aytak; Rajamand, Amir Abbas

    2012-01-01

    Various radiometal complexes have been developed for tumor imaging, especially Ga-68 tracer. In the present study, the development of a radiogallium bis-thiosemicarbazone complex has been reported. [67Ga] acetylacetonate bis(thiosemicarbazone) complex ([67Ga] AATS) was prepared starting [67Ga]Gallium acetate and freshly prepared acetylacetonate bis (thiosemicarbazone) (AATS) in 30 min at 90°C. The partition co-efficient and the stability of the tracer were determined in final solution (25°C) and the presence of human serum (37°C) up to 24 h. The biodistribution of the labeled compound in wild-type and fibrosarcoma-bearing rodents were determined up to 72 h. The radiolabled Ga complex was prepared in high radiochemical purity (> 97%, HPLC) followed by initial biodistribution data with the significant tumor accumulation of the tracer in 2 h which is far higher than free Ga-67 cation while the compound wash-out is significantly faster. Above-mentioned pharmacokinetic properties suggest an interesting radiogallium complex while prepared by the PET Ga radioisotope, 68Ga, in accordance with the physical half life, for use in fibrosarcoma tumors, and possibly other malignancies. PMID:24250475

  2. Laboratory Studies of DIB Carriers

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.

    1995-01-01

    Spectroscopic studies of the following potential diffuse interstellar band (DIB) carriers are reviewed: unspecified organics, carbon chains, polycyclic aromatic hydrocarbons (PAHs), fullerenes and derivatives, as well as porphyrins and related material. An assessment of each is given, along with suggestions for further experimental studies needed to fully test each candidate. Of the experimental techniques in common use matrix isolation spectroscopy with neon matrices is the most appropriate for the DIBs. The low vapor pressure and high reactivity of these materials preclude gas phase studies on many of these species. At this point, given the type and quality of published data available, carbon chains and PARs are the most promising candidates for a number of the DIBs.

  3. Some studies on spontaneous Hymenolepis diminuta infection in laboratory rats.

    PubMed

    Ahmad, Azza K; Abdel-Hafeez, Ekhlas H; Kamal, Amany M

    2015-04-01

    Hymenolepis diminuta is a tapeworm that occurs worldwide. It is known to be found commonly in areas where large amounts of food grains or other dry feed products, which are the favorite foods for rats. Transmission of disease to human is uncommon; however, it may be a serious threat for population who are living in rural areas which are suffering from excessive rodents. Here, this study had done on spontaneous H. diminuta infection in laboratory rats as a model. Out of thirty five adult laboratory rats investigated for parasitic diseases only nine (25.71%) were diagnosed positive for spontaneous H. diminuta infection. Four of them (44.44%) were found losing of weight and lacking of motility, while the others were normal. On microscopic examination, H. diminuta eggs had been found in their stool. On autopsy, small intestines were found to contain from 5-6 multi-segmented tapeworms in each rat. Histopathologically, intestinal lumen showed varying sections of H. diminuta segments with serrated borders. H. diminuta infection caused multiple mucosal ulcers with absence of intestinal villi from the surface epithelium and excessive mucin. Moreover, inflammatory cells infiltration in the connective tissue core of the villi. Furthermore, the Toluidine blue stain showed that there are Mastiocytosis. Additionally, there were goblet cells hyperplasia on using PAS. Moreover, there were high expression of cyclooxygenase 2 (COX-2), tumor necrosis factor-? (TNF-?) and inducible Nitric-Oxide Synthase (iNOs). This implicate, strong correlation between COX-2, TNF-? and iNOs expression and inflammation induced by H. diminuta. PMID:26012226

  4. Trimethoprim: laboratory and clinical studies

    Microsoft Academic Search

    J. H. Darrell; L. P. Garrod; Pamela M. Waterworth

    1968-01-01

    Trimethoprim is a synthetic compound which arrests the step in bacterial purine synthesis immediately succeeding that interfered with by sulphonamides.Acting alone it inhibits the growth of a wide range of bacteria in generally much lower concentrations than sulphonamides. Its action with a sulphonamide is strongly synergic and bactericidal.Studies are described of suitable cultural conditions, methods of testing sensitivity, and acquired

  5. NIH POLICY MANUAL 3043-1 -Introduction of Rodents, Rodent Products and Rodent Pathogens

    E-print Network

    Bandettini, Peter A.

    NIH POLICY MANUAL 3043-1 - Introduction of Rodents, Rodent Products and Rodent Pathogens Issuing from sources other than those approved by the NIH Rodent Import Officer are introduced into NIH, and Isolation Area; to clarify NIH excluded pathogens and other terms; and to include the handling of rodent

  6. Laboratory studies of lean combustion

    NASA Technical Reports Server (NTRS)

    Sawyer, R. F.; Schefer, R. W.; Ganji, A. R.; Daily, J. W.; Pitz, R. W.; Oppenheim, A. K.; Angeli, J. W.

    1977-01-01

    The fundamental processes controlling lean combustion were observed for better understanding, with particular emphasis on the formation and measurement of gas-phase pollutants, the stability of the combustion process (blowout limits), methods of improving stability, and the application of probe and optical diagnostics for flow field characterization, temperature mapping, and composition measurements. The following areas of investigation are described in detail: (1) axisymmetric, opposed-reacting-jet-stabilized combustor studies; (2) stabilization through heat recirculation; (3) two dimensional combustor studies; and (4) spectroscopic methods. A departure from conventional combustor design to a premixed/prevaporized, lean combustion configuration is attractive for the control of oxides of nitrogen and smoke emissions, the promotion of uniform turbine inlet temperatures, and, possibly, the reduction of carbon monoxide and hydrocarbons at idle.

  7. Laboratory studies of heavy ozone

    NASA Technical Reports Server (NTRS)

    Morton, J.; Barnes, J.; Schueler, B.; Mauersberger, K.

    1990-01-01

    Dissociation of ozone in the Chappuis bands has been used as an O atom source to study isotope effects occurring in the O(3P) + O2(3 Sigma g) recombination reaction. The ozone produced was found to be enriched in both of its heavy isotopes. The pressure dependence (5-1000 torr) and temperature dependence (127-360 K) of this isotope effect have been investigated. The enrichment is approximately constant from 5 torr to 100 torr and decreases at higher pressures. It increases with temperature, with O3-50 showing a slightly faster rate of increase than O3-45. The results of this experiment have clearly isolated the source of the isotope effect to the gas phase O(3P) + O2(3 Sigma g) recombination reaction.

  8. Vasovagal Syncope Case Study/Laboratory Supplement

    NSDL National Science Digital Library

    PhD Jan Foster (North Greenville University Biology)

    2012-05-01

    This is a case study emphasizing neural control of the cardiovascular system. This study was designed to be completed during an undergraduate anatomy and physiology laboratory period on the study of blood pressure and hemodynamics. This case study involves guided student exploration in understanding of the autonomic nervous system, heart rate, total peripheral resistance, cardiac output, blood pressure, and autoregulatory range. This study also includes an optional section on cardiovascular responses in pregnancy.

  9. Extrapolation of Rodent Studies on Amniotic Fluid Contaminatnts to Human Populations

    Microsoft Academic Search

    Claude Hughes; Warren Foster; Siu Chan; Lawrence Platt; Stephanie Thompson; Slade Hubbard; Alison DuBose; Lee Tyrey

    2001-01-01

    If endocrine active chemicals (EACs) adversely affect human development, then there must be evidence of effects in animal models at properly scaled levels of exposure during pertinent sensitive periods as derived from quantified exposures of the human fetus. Our recent studies attempt to address both effects and exposures. First Study: Dams were gavaged from Gestation Day (GD) 14 through weaning

  10. Rapid field test for detection of hantavirus antibodies in rodents.

    PubMed Central

    Sirola, H.; Kallio, E. R.; Koistinen, V.; Kuronen, I.; Lundkvist, A.; Vaheri, A.; Vapalahti, O.; Henttonen, H.; Närvänen, A.

    2004-01-01

    Puumala virus (PUUV) is the causative agent of nephropathia epidemica, a mild form of haemorrhagic fever with renal syndrome. PUUV is transmitted to humans via aerosolized excreta of the infected bank vole (Clethrionomys glareolus). Current methods for screening of the PUUV prevalence among bank vole populations are laborious, combining sampling in the field and subsequent analyses in the laboratory. In order to facilitate animal testing, a new serological immunochromatographic rapid test was developed. The test uses PUUV nucleocapsid protein as antigen, and it detects anti-PUUV IgG antibodies in rodents. With fresh and undiluted bank-vole blood samples (n = 105) the efficacy of the test was 100%, and with frozen and diluted samples (n = 78) the efficacy was 91%. The test was also shown to detect related hantavirus infections in Norway lemmings and sibling voles (n = 31) with 99% efficacy. The test provides an applicable tool for studying PUUV and related hantavirus infections in arvicoline rodents. PMID:15188724

  11. Applications of schedule-induced polydipsia in rodents for the study of an excessive ethanol intake phenotype

    PubMed Central

    Ford, Matthew M.

    2014-01-01

    Schedule-induced polydipsia (SIP) is generated by subjecting a highly motivated animal to a sub-optimal rate of food reinforcement while also providing access to a fluid. SIP is one of several adjunctive (or displacement) behaviors that are expressed in an exaggerated form that is deemed ‘excessive’. This feature makes SIP an attractive model for studying an excessive ethanol drinking phenotype in rodents. Multiple experimental variables are crucial for the full manifestation of adjunctive drinking, including the degree of food deprivation, the inter-pellet interval selected, and the size of the food reward offered. Although these variables were extensively studied and optimized for water polydipsia in rats, a similarly customized approach to ethanol SIP and application of the procedure in mice have largely been curtailed in favor of the default variable values historically used for water SIP in rats. Further, ethanol SIP also requires careful consideration of variables such as taste and ethanol concentration. Investigation of the stress axis and neurochemical systems such as dopamine and serotonin in mediating adjunctive drinking stemmed from two leading hypotheses regarding the underlying mechanisms of SIP generation: 1) SIP as a coping strategy to mitigate stress associated with the aversive environmental condition, and 2) SIP as a displacement of reward in a highly motivated animal. Ethanol SIP is a powerful model of excessive intake because it can generate an ethanol-dependent state and sustain frequent and intoxicating levels of blood ethanol with voluntary oral consumption. The required food deprivation and the loss of the excessive drinking phenotype following removal of the generator schedule are the two main limitations of the model. Future utility of ethanol SIP will be enhanced by more fully dissecting the underlying hormonal and neurochemical mechanisms and optimizing experimental variables for ethanol SIP on a per species and strain basis. PMID:24680665

  12. Two new rodent models for actinide toxicity studies. [²³⁷Pu, ²⁴¹Am

    Microsoft Academic Search

    G. N. Taylor; C. W. Jones; P. A. Gardner; R. D. Lloyd; C. W. Mays; K. E. Charrier

    1981-01-01

    Two small rodent species, the grasshopper mouse (Onychomys leucogaster) and the deer mouse (Peromyscus maniculatus), have tenacious and high retention in the liver and skeleton of plutonium and americium following intraperitoneal injection of Pu and Am in citrate solution. Liver retention of Pu and Am in the grasshopper mouse is higher than liver retention in the deer mouse. Both of

  13. HEART RATE VARIABILITY IN RODENTS ? USES AND CAVEATS IN TOXICOLOGICAL STUDIES

    EPA Science Inventory

    Heart rate variability (HRV) is a measure of cardiac pacing dynamics that has recently garnered a great deal of interest in environmental health studies. While the use of these measures has become popular, much uncertainty remains in the interpretation of results, both in terms ...

  14. Regulation of Wheal and Flare by Tea Tree Oil: Complementary Human and Rodent Studies

    Microsoft Academic Search

    Zeinab Khalil; Annette L. Pearce; Narmatha Satkunanathan; Emma Storer; John J. Finlay-Jones; Prue H. Hart

    2004-01-01

    When applied 20 min after injection of histamine into human forearm skin, tea tree oil (TTO) reduces the developing cutaneous vascular response. In this study, the effect of TTO on inflammatory microvascular changes was dissected at the base of an experimental blister on rat skin. 1,8-Cineole, representing 2% of TTO, reduced vascular changes induced by sensory neuropeptides released when the

  15. Local application of fluvastatin improves peri-implant bone quantity and mechanical properties: A rodent study

    Microsoft Academic Search

    Yasuko Moriyama; Yasunori Ayukawa; Yoichiro Ogino; Ikiru Atsuta; Mitsugu Todo; Yoshihiro Takao; Kiyoshi Koyano

    2010-01-01

    Statins are known to stimulate osteoblast activity and bone formation. This study examines whether local application of fluvastatin enhances osteogenesis around titanium implants in vivo. Ten-week-old rats received a vehicle gel (propylene glycol alginate (PGA)) or PGA containing fluvastatin (3, 15, 75 or 300?g) in their tibiae just before insertion of the implants. For both histological and histomorphometric evaluations undecalcified

  16. Acute and sub-chronic oral toxicity study of black tea in rodents

    PubMed Central

    Sur, Tapas Kumar; Chatterjee, Suparna; Hazra, Alok Kumar; Pradhan, Richeek; Chowdhury, Supriyo

    2015-01-01

    Objectives: Systematic oral toxicity study for black tea (Camellia sinensis), the most commonly consumed variety of tea, is lacking. The present study was undertaken to assess the iron load on black tea (Camellia sinensis) and its safety aspects in animals. Materials and Methods: The analysis of iron was done in six tea samples as per American Public Health Association method using flame atomic absorption spectrophotometer. Maximum physical iron-loaded tea sample was identified on black tea sample 2 (BTS-2), and this was further studied for acute and 90-day sub-chronic toxicity following Organisation for Economic Co-operation and Development guidelines. Results: Black tea sample 2 did not show any signs of toxicity or mortality at up to 2 g/kg per oral dose in Swiss albino mice. 90-day toxicity studies in Wistar rats did not reveal any evidence of toxicity at up to 250 mg/kg/day (2.5% infusion of BTS-2) oral dose as exhibited by regular observations, body weight, food consumption, hematology, serum chemistry, organ weights, and histopathology. Further, serum iron, total iron binding capacity, unsaturated iron binding capacity, and ferritin were not altered after 90 days of treatment. Masson trichrome staining and Perls’ staining did not reveal any abnormalities in hepatic tissue following 90-day treatment of high iron-loaded BTS-2. Conclusions: This safety study provides evidence that BTSs, in spite of relatively high iron content, show no significant iron-related toxicity on acute or sub-chronic oral administration in animals. PMID:25878375

  17. Biochemical and toxicological studies of aqueous extract of Syzigium aromaticum (L.) Merr. & Perry (Myrtaceae) in rodents.

    PubMed

    Agbaje, E O; Adeneye, A A; Daramola, A O

    2009-01-01

    The effects of long-term administration of boiled aqueous extract of Syzigium aromaticum (SYZ), commonly known as clove (which has been locally employed for treating gastrointestinal tract diseases and also used as food spices), on some biochemical indices, such as body weight, liver functions and blood parameters were studied in adult albino rats of both sexes. Selected doses of 300 and 700 mg kg(-1) were given orally through cannular to groups of animals for a period of 90 days, while the control group received distilled water throughout the duration of study via the same route. Blood samples collected after therapy and assayed for activities of some liver enzymes recorded a significant (p<0.05) and prominent effect on ALP and AST. Measurement of haematological parameters also revealed significant effects (p<0.05; p<0.001) on Hb, RBC (p<0.05), PCV (p<0.001), platelets (p<0.001) and granulocytes (p<0.001). An insignificant reduction was recorded for total WBC. The histopathological study conducted was in consonance with the results of the biochemical investigations that the aqueous extract of SYZ even at moderate doses, significantly affects body organs, their enzymes as well as the various functions. LD(50) for both intraperitoneal and oral routes of SYZ were 263 and 2500 mg kg(-1) respectively. The present work has revealed the toxicity of sub chronic administration of SYZ, which suggests that its prolonged usage must be avoided. PMID:20448849

  18. Evaluation of an operant successive negative contrast task as a method to study affective state in rodents.

    PubMed

    Mitchell, Emma N; Marston, Hugh M; Nutt, David J; Robinson, Emma S J

    2012-10-01

    Successive negative contrast (SNC) describes a change in an animal's behaviour following a downshift in the quantitative or qualitative value of a reward. Previous studies suggest both consummatory and instrumental paradigms have the potential to provide an objective measure of affective state in rodents. We first investigated whether an SNC effect is observed in an operant task based on the 5 choice serial reaction time task. We then tested whether this SNC effect was sensitive to differences in affective state induced by manipulating the home cage environment. In animals trained to receive a four pellet food reward, reinforcer downshift to a single reward pellet induced a significant slowing of both correct response and collection latencies to levels below that of animals which had only ever received the lower value reward, indicating a SNC effect. Home cage environmental enrichment resulted in a paradoxical effect on responses in this SNC task where animals housed in a barren environment showed faster baseline response times and the SNC effect was significantly attenuated. These data suggest that the animals housed in the barren conditions were in a more positive affective and/or motivational state during testing than animals housed in enriched cages. Although opposite to the effects of housing conditions in a runway SNC task, these data could be explained by the enriching effects of daily training in an operant task. Rather than inducing a negative affective state in rats, the barren housing conditions resulted in a relatively more positive affective state in the chamber when compared to animals living in a highly enriched environment. PMID:22732261

  19. Anthocyanins do not influence long-chain n-3 fatty acid status: studies in cells, rodents and humans.

    PubMed

    Vauzour, David; Tejera, Noemi; O'Neill, Colette; Booz, Valeria; Jude, Baptiste; Wolf, Insa M A; Rigby, Neil; Silvan, Jose Manuel; Curtis, Peter J; Cassidy, Aedin; de Pascual-Teresa, Sonia; Rimbach, Gerald; Minihane, Anne Marie

    2015-03-01

    Increased tissue status of the long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular and cognitive benefits. Limited epidemiological and animal data suggest that flavonoids, and specifically anthocyanins, may increase EPA and DHA levels, potentially by increasing their synthesis from the shorter-chain n-3 PUFA, ?-linolenic acid. Using complimentary cell, rodent and human studies we investigated the impact of anthocyanins and anthocyanin-rich foods/extracts on plasma and tissue EPA and DHA levels and on the expression of fatty acid desaturase 2 (FADS2), which represents the rate limiting enzymes in EPA and DHA synthesis. In experiment 1, rats were fed a standard diet containing either palm oil or rapeseed oil supplemented with pure anthocyanins for 8 weeks. Retrospective fatty acid analysis was conducted on plasma samples collected from a human randomized controlled trial where participants consumed an elderberry extract for 12 weeks (experiment 2). HepG2 cells were cultured with ?-linolenic acid with or without select anthocyanins and their in vivo metabolites for 24 h and 48 h (experiment 3). The fatty acid composition of the cell membranes, plasma and liver tissues were analyzed by gas chromatography. Anthocyanins and anthocyanin-rich food intake had no significant impact on EPA or DHA status or FADS2 gene expression in any model system. These data indicate little impact of dietary anthocyanins on n-3 PUFA distribution and suggest that the increasingly recognized benefits of anthocyanins are unlikely to be the result of a beneficial impact on tissue fatty acid status. PMID:25573539

  20. Anthocyanins do not influence long-chain n-3 fatty acid status: studies in cells, rodents and humans?

    PubMed Central

    Vauzour, David; Tejera, Noemi; O'Neill, Colette; Booz, Valeria; Jude, Baptiste; Wolf, Insa M.A.; Rigby, Neil; Silvan, Jose Manuel; Curtis, Peter J.; Cassidy, Aedin; de Pascual-Teresa, Sonia; Rimbach, Gerald; Minihane, Anne Marie

    2015-01-01

    Increased tissue status of the long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular and cognitive benefits. Limited epidemiological and animal data suggest that flavonoids, and specifically anthocyanins, may increase EPA and DHA levels, potentially by increasing their synthesis from the shorter-chain n-3 PUFA, ?-linolenic acid. Using complimentary cell, rodent and human studies we investigated the impact of anthocyanins and anthocyanin-rich foods/extracts on plasma and tissue EPA and DHA levels and on the expression of fatty acid desaturase 2 (FADS2), which represents the rate limiting enzymes in EPA and DHA synthesis. In experiment 1, rats were fed a standard diet containing either palm oil or rapeseed oil supplemented with pure anthocyanins for 8 weeks. Retrospective fatty acid analysis was conducted on plasma samples collected from a human randomized controlled trial where participants consumed an elderberry extract for 12 weeks (experiment 2). HepG2 cells were cultured with ?-linolenic acid with or without select anthocyanins and their in vivo metabolites for 24 h and 48 h (experiment 3). The fatty acid composition of the cell membranes, plasma and liver tissues were analyzed by gas chromatography. Anthocyanins and anthocyanin-rich food intake had no significant impact on EPA or DHA status or FADS2 gene expression in any model system. These data indicate little impact of dietary anthocyanins on n-3 PUFA distribution and suggest that the increasingly recognized benefits of anthocyanins are unlikely to be the result of a beneficial impact on tissue fatty acid status. PMID:25573539

  1. Evidence for rodent-common and species-typical limb and digit use in eating, derived from a comparative analysis of ten rodent species.

    PubMed

    Whishaw, I Q; Sarna, J R; Pellis, S M

    1998-11-01

    Order Rodentia comprises a vast portion of mammalian species (1814 species), which occupy extremely diverse habitats requiring very distinct motor specializations (e.g. burrowing, hopping, climbing, flying and swimming). Although early classification of paw use ability suggests rodents are impoverished relative to primates and make little use of their paws, there have been no systematic investigations of paw use in rodents. The present study was undertaken to describe limb/paw movements in a variety of common rodents. The movements used for handling sunflower seeds and other foods were videorecorded and analyzed in the guinea pig (Cavia porcellus), Mongolian gerbil (Meriones unguiculatus), Syrian hamster (Mesocricetus auratus), laboratory mouse (Mus musculus), laboratory rat (Rattus norvegicus), gray squirrel (Sciurus carolinensis), red squirrel (Tamiasciurus hudsonicus), Richardson's ground squirrel (Spermophilus richardsonni), prairie dog (Cynomus parvidens), and Canadian beaver (Castor americanus). The results suggested five order-common movements of food handling: (1) locating food by sniffing, (2) grasping food by mouth, (3) sitting back on the haunches to eat, (4) grasping the food using an elbow-in movement, and (5) manipulate the food with the digits. Different species displayed species-typical specializations including (1) bilateral grasping with the paws (gerbil), (2) unilateral grasping with a paw (beaver), (3) unilateral holding (ground squirrels), (4) various grip and digit postures (all species), (5) unilateral object removal from the mouth (gerbil), (6) bilateral thumb holding (squirrels), and (7) simultaneous holding/manipulation of two objects (squirrels). Only the guinea pig did not handle food with its paws, suggesting its behavior is regressive. The existence of a core pattern of paw and digit use in rodents suggests that skilled limb and paw movements originate at least with the common ancestors of the rodent, and likely the common ancestor to rodent and primate lineages, while species-typical movements suggest specialization/regression of limb use has occurred in a number of mammalian orders. PMID:9821545

  2. Lassa fever or lassa hemorrhagic fever risk to humans from rodent-borne zoonoses.

    PubMed

    El-Bahnasawy, Mamdouh M; Megahed, Laila Abdel-Mawla; Abdalla Saleh, Hala Ahmed; Morsy, Tosson A

    2015-04-01

    Viral hemorrhagic fevers (VHFs) typically manifest as rapidly progressing acute febrile syndromes with profound hemorrhagic manifestations and very high fatality rates. Lassa fever, an acute hemorrhagic fever characterized by fever, muscle aches, sore throat, nausea, vomiting, diarrhea and chest and abdominal pain. Rodents are important reservoirs of rodent-borne zoonosis worldwide. Transmission rodents to humans occur by aerosol spread, either from the genus Mastomys rodents' excreta (multimammate rat) or through the close contact with infected patients (nosocomial infection). Other rodents of the genera Rattus, Mus, Lemniscomys, and Praomys are incriminated rodents hosts. Now one may ask do the rodents' ectoparasites play a role in Lassa virus zoonotic transmission. This paper summarized the update knowledge on LHV; hopping it might be useful to the clinicians, nursing staff, laboratories' personals as well as those concerned zoonoses from rodents and rodent control. PMID:26012219

  3. Ultrastructural features of masseter muscle exhibiting altered occlusal relationship—a study in a rodent model

    NASA Astrophysics Data System (ADS)

    Lisboa, Marcio V.; Aciole, Gilberth T. S.; Oliveira, Susana C. P. S.; Marques, Aparecida M. C.; Baptista, Abrahão F.; Pinheiro, Antonio L. B.; Aguiar, Marcio C.; Santos, Jean N.

    2010-05-01

    The role of occlusion on Tempormandibular Disorders (TMD) is still unclear, mainly regarding muscular function. The aim of this study was to evaluate the occlusion highlights on masseter ultra morphology. Twenty Wistar rats were randomly divided in four groups: 10 for control group, 10 for occlusal alteration group (CCO). Rats underwent unilateral amputation of the left inferior and superior molar cusps to simulate an occlusal wear situation. The rats of control group had no occlusal wear. Half of the animals of each group was sacrificed in 14 days after the occlusal consuming and half 30 days after the occlusal consuming. The masseter muscles ipsilateral to the amputated molars were excised and processed for light microscopy, electron microscopy. The light microscopy did not show differences between the groups. The electron microscopy was able to detect a degree of intracellular damage in muscle fibers of CCO group: swollen mitochondria with disrupted cristae and cleared matrix, signs of hypercontraction of I bands and myofibril disorganization.

  4. Comparative study between open ended laboratory and traditional laboratory

    Microsoft Academic Search

    Norliza Abd. Rahman; Noorhisham Tan Kofli; Mohd Sobri Takriff; Siti Rozaimah Sheikh Abdullah

    2011-01-01

    The traditional laboratory work based on guided assignment will not be adequate within the outcome based learning environment. Innovative approaches that require active involvement of the students in the learning activities are necessary in ensuring that the targeted learning outcomes are achieved. The Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, introduced open ended laboratory work in 2008 as

  5. PRELIMINARY GASTROINTESTINAL STUDIES OF METHANOL EXTRACT OF INDIGOFERA PULCHRA WILLD IN RODENTS

    PubMed Central

    Sule, M.I.; Haruna, A. K.; Ilyas, M.; Iliya, I.; Yaro, A. H.; Magaji, M.G.

    2010-01-01

    In this study, the effect of the methanol extract of Indigofera pulchra Willd. (Papillionaceae) was investigated against castor oil induced diarrheoa. Its effects on perfused isolated rabbit jejunum and guinea pig ileum were also evaluated. The extract produced a dose-dependent protection against the castor oil-induced diarrheoa in mice with the highest protection (100%), obtained at 200 mgkg?1 comparable to that of loperamide (5 mgkg?1), a standard antidiarrhoeal drug. The extract (0.4 – 6.4 mgml?1) produced a concentration relaxation of the rabbit jejunum. However, no observable effect was noticed when the guinea pig ileum was treated. The extract blocked the contractile effect of acetylcholine (2 × 10?8 gml?1) and histamine (4 × 10?7 gml?1) on both rabbit jejunum and guinea pig ileum. Phytochemical screening revealed the presence of flavonoids, tannins, saponins and steroids. The intraperitoneal median lethal dose (LD50) value for the extract was found to be 2154.0 mgkg?1. The results obtained revealed that the extract possesses pharmacologically active compounds with gastrointestinal relaxant and antidiarrhoeal activities and may possibly explain the use of the plant in traditional medicine for the treatment of gastrointestinal disorder. PMID:21197141

  6. Local application of fluvastatin improves peri-implant bone quantity and mechanical properties: a rodent study.

    PubMed

    Moriyama, Yasuko; Ayukawa, Yasunori; Ogino, Yoichiro; Atsuta, Ikiru; Todo, Mitsugu; Takao, Yoshihiro; Koyano, Kiyoshi

    2010-04-01

    Statins are known to stimulate osteoblast activity and bone formation. This study examines whether local application of fluvastatin enhances osteogenesis around titanium implants in vivo. Ten-week-old rats received a vehicle gel (propylene glycol alginate (PGA)) or PGA containing fluvastatin (3, 15, 75 or 300 microg) in their tibiae just before insertion of the implants. For both histological and histomorphometric evaluations undecalcified ground sections were obtained and the bone-implant contact (BIC), peri-implant osteoid volume and mineralized bone volume (MBV) were calculated after 1, 2 and 4 weeks. Using the same models mechanical push-in tests were also performed to evaluate the implant fixation strength. After 1 week the MBV and push-in strength were significantly lower in the 300 microg fluvastatin-treated group than in the other groups (P<0.01). At 2 weeks, however, the BIC and MBV were both significantly higher in the 75 microg fluvastatin-treated group than in the non-fluvastatin-treated groups (P<0.01). Similar tendencies were observed at week 4. Furthermore, the data showed a good correlation between the MBV and the push-in strength. These results demonstrate positive effects of locally applied fluvastatin on the bone around titanium implants and suggest that this improvement in osseointegration may be attributed to calcification of the peri-implant bone. PMID:19887121

  7. [Role of endoparasites of fleas of wild rodents in plague enzootia].

    PubMed

    Chumakova, I V; Tokhov, Iu M

    2013-01-01

    Laboratory studies of fleas for gregarines have established that it is the latter inhabiting the intestine and stomach of the fleas of wild rodents which are of much interest as protozoa, in whose organism, parasitic species of bacteria can survive. Penetration of plague bacteria into the endoplasm ofgregarines and their possible survival in the cysts may create an additional component in the chain of an epizootic process, which ensures its function, without involving the rodents at the nesting biocenotic level following the pattern: flea imagoes - nesting litter infected with gregarine spores, cysts - flea larvae - flea imagoes infected with cysts, with the plague pathogen emerging into a rodent population through the imago of blocked fleas. PMID:23805483

  8. Laboratory studies with some recent anticoccidials.

    PubMed

    Ryley, J F; Wilson, R G

    1975-04-01

    The activities of monensin, lasalocid and halofuginone against Eimeria tenella, E. brunetti and E. necatrix have been studied under laboratory conditions. Complete control of experimental infections in the chick, separable from toxicity, was not obtained with monensin, but was achieved with the other two compounds at levels of 150 and 6 ppm in the food respectively. All three compounds appear to inhibit coccidial development very early in the life-cycle, and to have a fairly rapid lethal effect, monensin and lasalocid more so than the febrifugine derivative. In vivo observations have been supplemented with in vitro studies. Some discussion of the difficulties of relating laboratory experiments to field performance is given. PMID:1128923

  9. Spontaneous expression of magnetic compass orientation in an epigeic rodent: the bank vole, Clethrionomys glareolus.

    PubMed

    Oliveriusová, Ludmila; N?mec, Pavel; Pavelková, Zuzana; Sedlá?ek, František

    2014-07-01

    Magnetoreception has been convincingly demonstrated in only a few mammalian species. Among rodents, magnetic compass orientation has been documented in four species of subterranean mole rats and two epigeic (i.e. active above ground) species-the Siberian hamster and the C57BL/6J mouse. The mole rats use the magnetic field azimuth to determine compass heading; their directional preference is spontaneous and unimodal, and their magnetic compass is magnetite-mediated. By contrast, the primary component of orientation response is learned in the hamster and the mouse, but both species also exhibit a weak spontaneous bimodal preference in the natural magnetic field. To determine whether the magnetic compass of wild epigeic rodents features the same functional properties as that of laboratory rodents, we investigated magnetic compass orientation in the bank vole Clethrionomys glareolus (Cricetidae, Rodentia). The voles exhibited a robust spontaneous bimodal directional preference, i.e. built nests and slept preferentially along the north-south axis, and deflected their directional preference according to a shift in the direction of magnetic north, clearly indicating that they were deriving directional information from the magnetic field. Thus, bimodal, axially symmetrical directional choice seems to be a common feature shared by epigeic rodents. However, spontaneous directional preference in the bank vole appeared to be more pronounced than that reported in the hamster and the mouse. These findings suggest that bank voles are well suited for future studies investigating the adaptive significance and mechanisms of magnetic orientation in epigeic rodents. PMID:24913128

  10. Spontaneous expression of magnetic compass orientation in an epigeic rodent: the bank vole, Clethrionomys glareolus

    NASA Astrophysics Data System (ADS)

    Oliveriusová, Ludmila; N?mec, Pavel; Pavelková, Zuzana; Sedlá?ek, František

    2014-07-01

    Magnetoreception has been convincingly demonstrated in only a few mammalian species. Among rodents, magnetic compass orientation has been documented in four species of subterranean mole rats and two epigeic (i.e. active above ground) species—the Siberian hamster and the C57BL/6J mouse. The mole rats use the magnetic field azimuth to determine compass heading; their directional preference is spontaneous and unimodal, and their magnetic compass is magnetite-mediated. By contrast, the primary component of orientation response is learned in the hamster and the mouse, but both species also exhibit a weak spontaneous bimodal preference in the natural magnetic field. To determine whether the magnetic compass of wild epigeic rodents features the same functional properties as that of laboratory rodents, we investigated magnetic compass orientation in the bank vole Clethrionomys glareolus (Cricetidae, Rodentia). The voles exhibited a robust spontaneous bimodal directional preference, i.e. built nests and slept preferentially along the north-south axis, and deflected their directional preference according to a shift in the direction of magnetic north, clearly indicating that they were deriving directional information from the magnetic field. Thus, bimodal, axially symmetrical directional choice seems to be a common feature shared by epigeic rodents. However, spontaneous directional preference in the bank vole appeared to be more pronounced than that reported in the hamster and the mouse. These findings suggest that bank voles are well suited for future studies investigating the adaptive significance and mechanisms of magnetic orientation in epigeic rodents.

  11. All Rodents Are Not the Same: A Modern Synthesis of Cortical Organization

    PubMed Central

    Krubitzer, Leah; Campi, Katharine L.; Cooke, Dylan F.

    2011-01-01

    Rodents are a major order of mammals that is highly diverse in distribution and lifestyle. Five suborders, 34 families, and 2,277 species within this order occupy a number of different niches and vary along several lifestyle dimensions such as diel pattern (diurnal vs. nocturnal), terrain niche, and diet. For example, the terrain niche of rodents includes arboreal, aerial, terrestrial, semi-aquatic, burrowing, and rock dwelling. Not surprisingly, the behaviors associated with particular lifestyles are also highly variable and thus the neocortex, which generates these behaviors, has undergone corresponding alterations across species. Studies of cortical organization in species that vary along several dimensions such as terrain niche, diel pattern, and rearing conditions demonstrate that the size and number of cortical fields can be highly variable within this order. The internal organization of a cortical field also reflects lifestyle differences between species and exaggerates behaviorally relevant effectors such as vibrissae, teeth, or lips. Finally, at a cellular level, neuronal number and density varies for the same cortical field in different species and is even different for the same species reared in different conditions (laboratory vs. wild-caught). These very large differences across and within rodent species indicate that there is no generic rodent model. Rather, there are rodent models suited for specific questions regarding the development, function, and evolution of the neocortex. PMID:21701141

  12. Laboratory and field studies in rotational spectroscopy at the Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Drouin, Brian J.

    2004-01-01

    Rotational spectroscopy of atmospheric molecules has long been a hallmark of laboratory and field studies at the Jet Propulsion Laboratory. in addition to maintenance of the millimeter and submillimeter spectral line catalog, the laboratory has actively purued the challenging laboratory tasks of quantitative linewidth measurements and transient species identification.

  13. Department of Geosciences Environmental Studies Laboratory

    NSDL National Science Digital Library

    This Web site depicts the research efforts in environmental variability and change by the Environmental Studies Laboratory at the University of Arizona. Students and educators can learn about the group's current paleoenvironmental research throughout the world including Arctic System Variability, Atlantic Variability, and Northern African Climate Dynamics. Researchers can learn how to obtain copies of the lab's publications as well as the data associated with them. The Web site also exhibits the group's educational outreach programs for primary and secondary school students.

  14. Effect of chronic antipsychotic treatment on striatal phosphodiesterase 10A levels: a [¹¹C]MP-10 PET rodent imaging study with ex vivo confirmation.

    PubMed

    Natesan, S; Ashworth, S; Nielsen, J; Tang, S-P; Salinas, C; Kealey, S; Lauridsen, J B; Stensbøl, T B; Gunn, R N; Rabiner, E A; Kapur, S

    2014-01-01

    A number of phosphodiesterase 10A (PDE10) inhibitors are about to undergo clinical evaluation for their efficacy in treating schizophrenia. As phosphodiesterases are in the same signalling pathway as dopamine D2 receptors, it is possible that prior antipsychotic treatment could influence these enzyme systems in patients. Chronic, in contrast to acute, antipsychotic treatment has been reported to increase brain PDE10A levels in rodents. The aim of this study was to confirm these findings in a manner that can be translated to human imaging studies to understand its consequences. Positron emission tomography (PET) scanning was used to evaluate PDE10A enzyme availability, after chronic haloperidol administration, using a specific PDE10A ligand ([(11)C]MP-10). The binding of [(11)C]MP-10 in the striatum and the cerebellum was measured in rodents and a simplified reference tissue model (SRTM) with cerebellum as the reference region was used to determine the binding potential (BPND). In rats treated chronically with haloperidol (2 mg kg(-1) per day), there was no significant difference in PDE10A levels compared with the vehicle-treated group (BPND±s.d.: 3.57 ± 0.64 versus 2.86 ± 0.71). Following PET scans, ex vivo analysis of striatal brain tissue for PDE10A mRNA (Pde10a) and PDE10A enzyme activity showed no significant difference. Similarly, the PDE10A protein content determined by western blot analysis was similar between the two groups, contrary to an earlier finding. The results of the study indicate that prior exposure to antipsychotic medication in rodents does not alter PDE10A levels. PMID:24690597

  15. Effect of chronic antipsychotic treatment on striatal phosphodiesterase 10A levels: a [11C]MP-10 PET rodent imaging study with ex vivo confirmation

    PubMed Central

    Natesan, S; Ashworth, S; Nielsen, J; Tang, S-P; Salinas, C; Kealey, S; Lauridsen, J B; Stensbøl, T B; Gunn, R N; Rabiner, E A; Kapur, S

    2014-01-01

    A number of phosphodiesterase 10A (PDE10) inhibitors are about to undergo clinical evaluation for their efficacy in treating schizophrenia. As phosphodiesterases are in the same signalling pathway as dopamine D2 receptors, it is possible that prior antipsychotic treatment could influence these enzyme systems in patients. Chronic, in contrast to acute, antipsychotic treatment has been reported to increase brain PDE10A levels in rodents. The aim of this study was to confirm these findings in a manner that can be translated to human imaging studies to understand its consequences. Positron emission tomography (PET) scanning was used to evaluate PDE10A enzyme availability, after chronic haloperidol administration, using a specific PDE10A ligand ([11C]MP-10). The binding of [11C]MP-10 in the striatum and the cerebellum was measured in rodents and a simplified reference tissue model (SRTM) with cerebellum as the reference region was used to determine the binding potential (BPND). In rats treated chronically with haloperidol (2?mg?kg?1 per day), there was no significant difference in PDE10A levels compared with the vehicle-treated group (BPND±s.d.: 3.57±0.64 versus 2.86±0.71). Following PET scans, ex vivo analysis of striatal brain tissue for PDE10A mRNA (Pde10a) and PDE10A enzyme activity showed no significant difference. Similarly, the PDE10A protein content determined by western blot analysis was similar between the two groups, contrary to an earlier finding. The results of the study indicate that prior exposure to antipsychotic medication in rodents does not alter PDE10A levels. PMID:24690597

  16. Polycystic echinococcosis in Colombia: the larval cestodes in infected rodents.

    PubMed

    Morales, G A; Guzman, V H; Wells, E A; Angel, D

    1979-07-01

    Described are the characteristics of the polycystic larval cestodes found in an endemic area of echinococcosis in the Easter Plains of Colombia and the tissue reaction evoked in infected rodents. Of 848 free-ranging animals examined, polycystic hydatids were found in 44/93 Cuniculus paca and 1/369 Proechimys sp. None of 20 Dasyprocta fuliginosa examined was infected, but hunters provided a heart with hydatid cysts and information about two additional animals with infected livers. Recognition of an endemic area of polycystic echinococcosis provides a means to investigate the life cycle of the parasites and to study the histogenesis of the larval cestodes in susceptible laboratory animals. PMID:501848

  17. Laboratory studies of radionuclide migration in tuff

    SciTech Connect

    Rundberg, R.S.; Mitchell, A.J.; Ott, M.A.; Thompson, J.L.; Triay, I.R.

    1989-10-01

    The movement of selected radionuclides has been observed in crushed tuff, intact tuff, and fractured tuff columns. Retardation factors and dispersivities were determined from the elution profiles. Retardation factors have been compared with those predicted on the basis of batch sorption studies. This comparison forms a basis for either validating distribution coefficients or providing evidence of speciation, including colloid formation. Dispersivities measured as a function of velocity provide a means of determining the effect of sorption kinetics or mass transfer on radionuclide migration. Dispersion is also being studied in the context of scaling symmetry to develop a basis for extrapolating from the laboratory scale to the field. 21 refs., 6 figs., 2 tabs.

  18. Laboratory Studies of Interstellar PAH Analogs

    NASA Technical Reports Server (NTRS)

    Salama, Farid; DeVincenzi, Donald (Technical Monitor)

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a closer simulation of space environments and a better support to space missions.

  19. DNA metabarcoding diet analysis for species with parapatric vs sympatric distribution: a case study on subterranean rodents.

    PubMed

    Lopes, C M; De Barba, M; Boyer, F; Mercier, C; da Silva Filho, P J S; Heidtmann, L M; Galiano, D; Kubiak, B B; Langone, P; Garcias, F M; Gielly, L; Coissac, E; de Freitas, T R O; Taberlet, P

    2015-05-01

    Closely related sympatric species commonly develop different ecological strategies to avoid competition. Ctenomys minutus and C. flamarioni are subterranean rodents parapatrically distributed in the southern Brazilian coastal plain, showing a narrow sympatric zone. To gain understanding on food preferences and possible competition for food resources, we evaluated their diet composition performing DNA metabarcoding analyzes of 67 C. minutus and 100 C. flamarioni scat samples, collected along the species geographical ranges. Thirteen plant families, mainly represented by Poaceae, Araliaceae, Asteraceae and Fabaceae, were identified in the diet of C. minutus. For C. flamarioni, 10 families were recovered, with a predominance of Poaceae, Araliaceae and Asteraceae. A significant correlation between diet composition and geographical distance was detected in C. minutus, whereas the diet of C. flamarioni was quite homogeneous throughout its geographical distribution. No significant differences were observed between males and females of each species. However, differences in diet composition between species were evident according to multivariate analysis. Our results suggest some level of diet partitioning between C. flamarioni and C. minutus in the sympatric region. While the first species is more specialized on few plant items, the second showed a more varied and heterogeneous diet pattern among individuals. These differences might have been developed to avoid competition in the region of co-occurrence. Resource availability in the environment also seems to influence food choices. Our data indicate that C. minutus and C. flamarioni are generalist species, but that some preference for Poaceae, Asteraceae and Araliaceae families can be suggested for both rodents. PMID:25649502

  20. The largest fossil rodent

    PubMed Central

    Rinderknecht, Andrés; Blanco, R. Ernesto

    2008-01-01

    The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000?kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene–Pleistocene (4–2?Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities. PMID:18198140

  1. Laboratory studies of petal-shaped occulters

    NASA Astrophysics Data System (ADS)

    Schindhelm, E.; Shipley, A.; Oakley, P.; Leviton, D.; Cash, W.; Card, G.

    2007-09-01

    We present laboratory studies of scaled occulting starshades for the New Worlds Observer (NWO). A deep reactive ion etched silicon starshade has been fabricated by NIST, designed to cover the same number of Fresnel zones as in the proposed mission. The broadband shadow is mapped with a photometer in a dark vacuum tunnel fed by a heliostat at HAO. CCD images provide direct contrast measurements of different features around the starshade. Preliminary measurements reach 5x10 -6 suppression in the center of the shadow at the focal plane. The two-dimensional structure of the starshade diffraction pattern is compared to that produced by the Fresnel integral.

  2. Microbiological monitoring of laboratory mice and biocontainment in individually ventilated cages: a field study

    Microsoft Academic Search

    M Brielmeier; E Mahabir; J R Needham; C Lengger; P Wilhelm; J Schmidt

    2006-01-01

    Summary Over recent years, the use of individually ventilated cage (IVC) rack systems in laboratory rodent facilities has increased. Since every cage in an IVC rack may be assumed to be a separate microbiological unit, comprehensive microbiological monitoring of animals kept in IVCs has become a challenging task, which may be addressed by the appropriate use of sentinel mice. Traditionally,

  3. TECHNIQUES IN ASEPTIC RODENT SURGERY

    PubMed Central

    Hoogstraten-Miller, Shelley L.; Brown, Patricia A.

    2008-01-01

    Performing aseptic survival surgery in rodents can be challenging. This unit describes some basic principles to assist clinicians, researchers, and technicians in becoming proficient in performing aseptic rodent surgery. PMID:18729061

  4. Study of Fast Reconnection in Laboratory Plasmas

    NASA Astrophysics Data System (ADS)

    Yamada, M.; Ji, H.; Terry, S.; Kulsrud, R.

    2002-12-01

    With abundant data from space satellites and the recently developed laboratory experiments, there exist many opportunities for collaborative study between space and laboratory experimental research. In this talk, we highlight the recent laboratory experimental data from the MRX device [1] in comparison with the space observations [2] as well as with the recent numerical simulations[3] addressing a major question why the observed reconnection rates are much faster than predictions by the classical theories, such as the Sweet-Parker model. There exist two leading theories for the underlying physics: one based on laminar 2D structures due to the Hall terms in the generalized Ohm's law and another based on resistivity enhancement (or the so-called anomalous resistivity) due to the inherently 3D micro-instabilities. Experimental efforts are under way to study both mechanisms in MRX, where the fast reconnection rates have been regularly observed in the low collisionality regime. A fine structure probe with spatial resolution of 1 mm (2-3 electron skin depth) is being installed. Also a special focus will be put on the electrostatic and magnetic turbulence which have recently been identified in the neutral sheet. The details of the characteristics of the turbulence measured by Hodogram probe and internal pick-up probes will be presented along with theoretical interpretations and discussions on its relation with the observed fast reconnection in space. Work supported by DOE, NASA And NSF. 1. M. Yamada et al., Phys. Plasmas 4, 1936, (1997) 2. F. Mozer et al, Phys. Rev. Letts. 15002, 1, (2002) 3. M.A. Shay et al J. Geophys. Res. 103, 9165 (1998)

  5. Effect of cage-change frequency on rodent breeding performance

    Microsoft Academic Search

    Heather M. Multari; Jeffrey J. Lohmiller; Samuel R. Boutin; Amy E. Sanderson

    2010-01-01

    Many people who work in laboratory rodent breeding facilities believe that disrupting certain sensitive rodent lines will result in increased breeding failures and loss of newborn pups. To evaluate this hypothesis, the authors assessed the effect of cage-change frequency on the breeding performances of a mouse strain (C57BL\\/6NTac) and a rat stock (NTac:NIH-Whn) that were thought to be sensitive to

  6. LABORATORY SIMULATION METHODS FOR STUDYING COMPLEX COLLABORATIVE TASKS

    E-print Network

    McCrickard, Scott

    LABORATORY SIMULATION METHODS FOR STUDYING COMPLEX COLLABORATIVE TASKS William D. Humphries, Dennis. Carroll Penn State University State College, PA This paper describes a new laboratory model developed for studying complex CSCW phenomena. In our prior work a more ecological laboratory approach was developed

  7. Endoparasites of Wild Rodents in Southeastern Iran

    PubMed Central

    Nateghpour, Mehdi; Motevalli-Haghi, Afsaneh; Akbarzadeh, Kamran; Akhavan, Amir Ahmad; Mohebali, Mehdi; Mobedi, Iraj; Farivar, Leila

    2015-01-01

    Background: This study was aimed to collect wild rodents for endoparasites determination in some parts of Sistan and Baluchistan Province, southeastern Iran nearby Pakistan and Afghanistan countries. Methods: A total of 100 wild rodents were captured alive with cage traps. Various samples were collected from blood and feces, also impression smear prepared from different organs. The samples were prepared by formalin-ether or stained with Giemsa, after that were examined under microscope. Results: All the caught rodents (47 Tatera indica, 44 Meriones hurriana, 5 Gerbilus nanus and 4 Meriones libycus) were studied for endoparasites emphasizing to their zoonotic aspects. Endoparasites including Spirurida, Hymenolepis diminuta, Hymenolepis nana feraterna, Trichuris trichiura, Skerjabino taenia, Trichostrongylus spp, Entamoeba muris, Chilomastix mesnili and Leishmania spp were parasitologically identified. Conclusion: Among 9 genera or species of the identified parasites at least 5 of them have zoonotic and public health importance.

  8. Glycosylphosphatidylinositols of Plasmodium chabaudi chabaudi: a basis for the study of malarial glycolipid toxins in a rodent model.

    PubMed Central

    Gerold, P; Vivas, L; Ogun, S A; Azzouz, N; Brown, K N; Holder, A A; Schwarz, R T

    1997-01-01

    Free and protein-bound glycosylphosphatidylinositols (GPIs) of the blood stages of the rodent malarial parasite Plasmodium chabaudi chabaudi AS were identified and characterized. TLC analysis of material extracted by organic solvents from metabolically labelled parasites revealed a distinct set of glycolipids. These glycolipids were identified as GPIs by specific chemical and enzymic treatments and by structural analysis of their glycan and hydrophobic parts. These analyses revealed that P.c.chabaudi AS synthesizes a set of GPI-biosynthesis intermediates and two potential GPI-anchor precursors exhibiting the following structures: ethanolamine-phosphate [(alpha1-2)mannose]mannose (alpha 1-2) mannose (alpha 1-6) mannose (alpha 1-4) glucosamine - (acyl) inositol-phosphate-diacylglycerol (P.ch. alpha) and ethanolamine-phosphate - mannose (alpha 1-2) mannose (alpha 1-6) mannose (alpha 1-4) glucosamine-(acyl)inositol-phosphate-diacylglycerol (P.ch. beta). One of these GPI-anchor precursors (P.ch. alpha) possesses the same carbohydrate structure as the GPI membrane anchor of merozoite surface protein-1 from P.c.chabaudi AS. PMID:9396737

  9. Vehicle and positive control values from the in vivo rodent comet assay and biomonitoring studies using human lymphocytes: historical database and influence of technical aspects.

    PubMed

    Pant, Kamala; Springer, S; Bruce, S; Lawlor, T; Hewitt, N; Aardema, M J

    2014-10-01

    There is increased interest in the in vivo comet assay in rodents as a follow-up approach for determining the biological relevance of chemicals that are genotoxic in in vitro assays. This is partly because, unlike other assays, DNA damage can be assessed in this assay in virtually any tissue. Since background levels of DNA damage can vary with the species, tissue, and cell processing method, a robust historical control database covering multiple tissues is essential. We describe extensive vehicle and positive control data for multiple tissues from rats and mice. In addition, we report historical data from control and genotoxin-treated human blood. Technical issues impacting comet results are described, including the method of cell preparation and freezing. Cell preparation by scraping (stomach and other GI tract organs) resulted in higher % tail DNA than mincing (liver, spleen, kidney etc) or direct collection (blood or bone marrow). Treatment with the positive control genotoxicant, ethyl methanesulfonate (EMS) in rats and methyl methanesulfonate in mice, resulted in statistically significant increases in % tail DNA. Background DNA damage was not markedly increased when cell suspensions were stored frozen prior to preparing slides, and the outcome of the assay was unchanged (EMS was always positive). In conclusion, historical data from our laboratory for the in vivo comet assay for multiple tissues from rats and mice, as well as human blood show very good reproducibility. These data and recommendations provided are aimed at contributing to the design and proper interpretation of results from comet assays. PMID:24957907

  10. Vitamin K Contents of Rodent Diets: A Review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adequate nutrient intake is critical in the maintenance of normal physiological activity of rodents in biomedical studies. Vitamin K is an essential nutrient in rodent diets and functions as a cofactor for the y-carboxylation of certain proteins involved in blood coagulation and bone metabolism. Dif...

  11. Microdialysis in Rodents

    PubMed Central

    Zapata, Agustin; Chefer, Vladimir I.; Shippenberg, Toni S.

    2010-01-01

    Microdialysis is an in vivo sampling technique that permits the quantification of various substances (e.g., neurotransmitters, peptides, electrolytes) in blood and tissue. It is also used to infuse substances into the brain and spinal cord. This unit describes methods for the construction and stereotaxic implantation of microdialysis probes into discrete brain regions of the rat and mouse. Procedures for the conduct of conventional and quantitative microdialysis experiments in the awake and anesthetized rodent are also provided. PMID:19340813

  12. Rodent models for human diseases.

    PubMed

    Vandamme, Thierry F

    2015-07-15

    One of the factors limiting the translation of knowledge from preclinical studies to the clinic has been the limitations of in vivo diseases models. Except in the case of highly controlled and regulated clinical trials, geneticists and scientists do not use humans for their experimental investigations because of the obvious risk to life. Instead, they use various animal, fungal, bacterial, and plant species as model organisms for their studies. Amongst these model organisms, rodent models are the most used due to the easiness for the experiments and the possibility to modify genetically these model animals. Nevertheless, due to the fact that animal models typically do not contract the same genetic diseases as people, so scientists must alter their genomes to induce human disease states and to know what kind of mutation causes the disease. In this brief review, we will discuss the interests of rodent models that have been developed to simulate human pathologies, focusing in models that employ xenografts and genetic modification. Within the framework of genetically engineered mouse (GEM) models, we will review some of the current genetic strategies for modeling diseases. PMID:25823811

  13. A Study of Mathematics Needed for Dental Laboratory Technology, Medical Laboratory Technology, and Respiratory Therapy.

    ERIC Educational Resources Information Center

    Roberts, Keith J.

    A study was conducted to determine what mathematics skills were needed for Dental Laboratory Technology, Medical Laboratory Technology, and Respiratory Therapy. Data obtained from studies, course outlines, textbooks, and reports were used to construct a 79-item mathematics skill questionnaire. This questionnaire was administered to employers,…

  14. Rocket and laboratory studies in astronomy

    NASA Technical Reports Server (NTRS)

    Feldman, Paul D.

    1994-01-01

    This report covers the period from September 1, 1993 to August 31, 1994. During the reporting period we launched the Faint Object Telescope to measure the absolute flux of a hot white dwarf star in the spectral range below 1200 A. This experiment was not successful due to a failure of an electronics unit in the onboard TV acquisition system. The source of the failure has been identified and corrected and is described in detail below. The payload was recovered in excellent condition and we are planning to refurbish it for flight during the November 1995 Australia campaign. We have continued our laboratory studies of the ultraviolet performance of charge-coupled-detector (CCD) arrays and plan to include a UV-sensitive CCD in a new payload that was assembled during the current period. The objective of the experiment is the ultraviolet imaging of Jupiter and we are scheduled to launch the payload, 36.115UG, in May-June 1995. We have also begun the design of a high-resolution FUV spectrograph for a future flight of the FOT and have just recently received a high line density grating fabricated by Jobin-Yvon, S.A. (France) for evaluation. Work has continued on the analysis of data from previous rocket experiments.

  15. Laboratory Study of Shock Wave Precursors

    NASA Astrophysics Data System (ADS)

    Burris, R.; Grun, J.; Manka, C.; Fisher, A.; Evans, K.

    1996-11-01

    When a shock wave propagates over a heated layer of gas, the shock wave will refract and its velocity will increase. A precursor shock wave will form which precedes the original shock wave along the surface. A highly structured, complicated vortex flow region develops under the precursor shock wave which can result in greatly enhanced dynamic pressure conditions. We report here on a laboratory experimental simulation of the phenomenon. A shock wave in 1 atm. of Argon is generated by focusing the NRL Pharos III Laser (1.5 kJ, 5 nsec, 1054 nm) through an evacuated path onto a thin metal foil at the gas/vacuum interface. The shock wave spherically expands over a thin heated layer above a 5cm by 5cm tantalum foil which was preheated up to 3000K (corresponding to > 3x sound speed at room temperature) with a fast rise-time current pulse (> 50 ?sec). The formation, propagation, and cleanup (or decay) of the shock wave precursor, caused by the thin layer of hot gas on the foil surface, was studied with a combined folded-wave interferometry/dark-field shadowgraphy diagnostic. The results of these experiments will be presented.

  16. Laboratory Studies in Support of Planetary Science

    NASA Astrophysics Data System (ADS)

    Dalton, James B.; Castillo, J.; Hodyss, R.; Spilker, T.; Brown, L.; Orton, G.; Gudipati, M.; Mastrapa, R.; Atreya, S.; Nimmo, F.; Blankenship, D.; Durham, B.; Khurana, K.; others

    2009-09-01

    Scientific understanding in several fields within Planetary Science could enter a period of rapid progress and discovery once certain laboratory investigations are performed to provide valuable constraints on fundamental properties of radiation and matter, the physics and chemistry of atmospheric, surface and subsurface compounds, and dynamic interactions within the Solar System. Much theoretical work at present is based upon rough estimates of basic parameters that could be measured under carefully controlled laboratory conditions. Due to the exotic nature of many planetary environments, these investigations are unique, challenging, and generally expensive for the individual researchers. Traditionally, funding for laboratory work has lagged behind that of missions; at present, there is sufficient mission data already recorded to justify a sustained investment in laboratory activities over the coming decade that would result in an exponential return in scientific progress. Specific laboratory investigations are needed to provide fundamental physical, chemical, and biological parameters for theoretical models and observational interpretations that will drive the entire field of Planetary Science forward, particularly with regard to atmospheric dynamics, chemistry, and composition; celestial dynamics, surface chemistry and composition, planetary formation, geology, and geophysics; plasmas and magnetospheres; and applications of astrobiology and astrophysics for Solar System bodies. A series of topical white papers addressing each of these are being submitted to the Planetary Science Decadal Survey and highlighting the areas most in need of supporting laboratory work.

  17. Geomagnetic field detection in rodents

    SciTech Connect

    Olcese, J.; Reuss, S.; Semm, P.

    1988-01-01

    In addition to behavioral evidence for the detection of earth-strength magnetic fields (MF) by rodents, recent investigations have revealed that electrophysiological and biochemical responses to MF occur in the pineal organ and retina of rodents. In addition, ferrimagnetic deposits have been identified in the ethmoidal regions of the rodent skull. These findings point to a new sensory phenomenon, which interfaces with many fields of biology, including neuroscience, psychophysics, behavioral ecology, chronobiology and sensory physiology.

  18. The Touchscreen Cognitive Testing Method for Rodents: How to Get the Best out of Your Rat

    ERIC Educational Resources Information Center

    Bussey, Timothy J.; Padain, Tina L.; Skillings, Elizabeth A.; Winters, Boyer D.; Morton, A. Jennifer; Saksida, Lisa M.

    2008-01-01

    The touchscreen testing method for rodents is a computer-automated behavioral testing method that allows computer graphic stimuli to be presented to rodents and the rodents to respond to the computer screen via a nose-poke directly to the stimulus. The advantages of this method are numerous; however, a systematic study of the parameters that…

  19. Hindlimb unloading rodent model: technical aspects.

    PubMed

    Morey-Holton, Emily R; Globus, Ruth K

    2002-04-01

    Since its inception at the National Aeronautics and Space Administration (NASA) Ames Research Center in the mid-1970s, many laboratories around the world have used the rat hindlimb unloading model to simulate weightlessness and to study various aspects of musculoskeletal loading. In this model, the hindlimbs of rodents are elevated to produce a 30 degrees head-down tilt, which results in a cephalad fluid shift and avoids weightbearing by the hindquarters. Although several reviews have described scientific results obtained with this model, this is the first review to focus on the technical aspects of hindlimb unloading. This review includes a history of the technique, a brief comparison with spaceflight data, technical details, extension of the model to mice, and other important technical considerations (e.g., housing, room temperature, unloading angle, the potential need for multiple control groups, age, body weight, the use of the forelimb tissues as internal controls, and when to remove animals from experiments). This paper is intended as a reference for researchers, reviewers of manuscripts, and institutional animal care and use committees. Over 800 references, related to the hindlimb unloading model, can be accessed via the electronic version of this article. PMID:11895999

  20. 222-S LABORATORY FUME HOOD TESTING STUDY

    SciTech Connect

    RUELAS, B.H.

    2007-03-26

    The 222-S Laboratory contains 155 active fume hoods that are used to support analytical work with radioactive and/or toxic materials. The performance of a fume hood was brought into question after employees detected odors in the work area while mixing chemicals within the subject fume hood. Following the event, testing of the fume hood was conducted to assess the performance of the fume hood. Based on observations from the testing, it was deemed appropriate to conduct performance evaluations of other fume hoods within the laboratory.

  1. Jet Deflection via Crosswinds: Laboratory Astrophysical Studies

    Microsoft Academic Search

    S. V. Lebedev; D. Ampleford; A. Ciardi; S. N. Bland; J. P. Chittenden; M. G. Haines; A. Frank; E. G. Blackman; A. Cunningham

    2004-01-01

    We present new data from high energy density laboratory experiments designed to explore the interaction of a heavy hypersonic radiative jet with a crosswind. The jets are generated with the MAGPIE pulsed power machine, where converging conical plasma flows are produced from a cylindrically symmetric array of inclined wires. Radiative hypersonic jets emerge from the convergence point. The crosswind is

  2. Biological effects of magnetic fields: laboratory studies

    Microsoft Academic Search

    Larry E. Anderson

    1998-01-01

    There is now a reasonable battery of evidence from a large number of laboratories, that exposure to extremely low frequency magnetic and electric fields (EMF) produces biological responses in animals. Many of the observed effects appear to be directly or indirectly associated with the neural or neuroendocrine systems. Such effects include increased neuronal excitability, chemical and hormonal changes in the

  3. Cellular Inductive Powering System for Weakly-Linked Resonant Rodent Implants

    E-print Network

    Genov, Roman

    delivery system shown in Fig. 1 for neural interfaces implanted in laboratory rodents. The designCellular Inductive Powering System for Weakly-Linked Resonant Rodent Implants Nima Soltani, Miaad S-- This paper presents a cellular inductive powering system for neural interface devices to facilitate chronic

  4. Roles of dental development and adaptation in rodent evolution.

    PubMed

    Rodrigues, Helder Gomes; Renaud, Sabrina; Charles, Cyril; Le Poul, Yann; Solé, Floréal; Aguilar, Jean-Pierre; Michaux, Jacques; Tafforeau, Paul; Headon, Denis; Jernvall, Jukka; Viriot, Laurent

    2013-01-01

    In paleontology, many changes affecting morphology, such as tooth shape in mammals, are interpreted as ecological adaptations that reflect important selective events. Despite continuing studies, the identification of the genetic bases and key ecological drivers of specific mammalian dental morphologies remains elusive. Here we focus on the genetic and functional bases of stephanodonty, a pattern characterized by longitudinal crests on molars that arose in parallel during the diversification of murine rodents. We find that overexpression of Eda or Edar is sufficient to produce the longitudinal crests defining stephanodonty in transgenic laboratory mice. Whereas our dental microwear analyses show that stephanodonty likely represents an adaptation to highly fibrous diet, the initial and parallel appearance of stephanodonty may have been facilitated by developmental processes, without being necessarily under positive selection. This study demonstrates how combining development and function can help to evaluate adaptive scenarios in the evolution of new morphologies. PMID:24051719

  5. A Study of Key Communicators in Research and Development Laboratories

    ERIC Educational Resources Information Center

    Chakrabarti, Alok K.; O'Keefe, Robert D.

    1977-01-01

    The purposes of this study were to identify key communicators within a sample of Research and Development laboratories, to explore those factors which motivate individuals to assume and maintain the role of key communicators, and to derive implications for further study of the characteristics of key communicators in R & D laboratories. (Author)

  6. ACCURACY OF LABORATORY REPORTING IN EPAS WET INTERLABORATORY VARIABILITY STUDY

    EPA Science Inventory

    In 1999 and 2000, EPA conducted an interlaboratory variability study of whole effluent toxicity (WET) test methods. This study provided an excellent opportunity to evaluate the accuracy with which laboratories analyzed and reported WET test data. Twenty-eight laboratories reporte...

  7. Laboratory combustion tube studies. Part II. Report SUPRI TR10

    Microsoft Academic Search

    W. E. Brigham; M. R. Fassihi; A. Satman; R. L. Williams; P. Pettit; J. Grim; H. J. Jr. Ramey

    1981-01-01

    To promote a better understanding of the problems and mechanisms involved in dry in-situ combustion of crude oils in porous media, continuing laboratory studies are carried out at SUPRI. The report about the first two experiments was submitted earlier to the Department of Energy. This report describes the results of the last three tube runs. Three laboratory combustion tube studies

  8. Field, Laboratory, and Modeling Study of Reactive Transport of

    E-print Network

    Field, Laboratory, and Modeling Study of Reactive Transport of Groundwater Arsenic in a Coastal. Accepted May 22, 2009. A field, laboratory, and modeling study of As in groundwater discharging to Waquoit of As in a coastal aquifer. Dissolved Fe(II) and As(III) in a reducing groundwater plume bracketed by an upper

  9. Chemical Grouting - Laboratory Study of Chemical Grouts and Geocomposites Properties

    Microsoft Academic Search

    K. Soucek; Stas J. Scucka; P. Martine

    The paper presents important laboratory methods and techniques that are used for properties study of chemical grouts and geocomposites. Geocomposites are specific materials created in the field of grouting technologies by pressure grouting of chemical grouts into soils, disturbed rocks or into damaged building structures. The paper focuses on some mechanical properties of studied geocomposites and cured grouts. (standard laboratory

  10. Photochemistry of OIO: Laboratory study and atmospheric implications

    E-print Network

    Ashworth, Stephen H.

    Photochemistry of OIO: Laboratory study and atmospheric implications Juan C. Go´mez Marti´n,1 in the marine boundary layer. The photochemistry of iodine dioxide (OIO) plays a key role in both (2009), Photochemistry of OIO: Laboratory study and atmospheric implications, Geophys. Res. Lett., 36, L

  11. Thirteen week rodent feeding study with grain from molecular stacked trait lepidopteran and coleopteran protected (DP-ØØ4114-3) maize.

    PubMed

    Delaney, Bryan; Karaman, Sule; Roper, Jason; Hoban, Denise; Sykes, Greg; Mukerji, Pushkor; Frame, Steven R

    2013-03-01

    The results from a subchronic feeding study conducted in Sprague–Dawley rats fed with diets containing grain from 4114 (OECD unique identifier: DP-ØØ4114-3) maize that was untreated (4114) or sprayed in field with glufosinate ammonium (4114GLU) in a design similar to previous studies are reported. The test material, 4114 maize, is a hybrid maize produced by transformation with a DNA construct encoding 4 different transgenic proteins for resistance to lepidopteran pests, coleopteran pests, and tolerance to the herbicidal active ingredient glufosinate ammonium. There were a total of 144 rats divided into 12 groups of 12 rats/sex/group. All experimental diets were formulated by Purina Mills, LLC (St. Louis, MO) in accordance with the standards of Purina Mills Labdiet® Certified Rodent LabDiet® 5002. The incorporation rate of maize grain in all diets was 32% (wt/wt). No biologically significant, treatment related differences in body weight, food consumption, clinical pathology parameters (hematology, blood chemistry, urinalysis, or organ weight) were observed in rats consuming the diets containing 4114 maize grain compared with rats fed conventional maize diets. A number of histologic observations were noted in this study but were background lesions and representative of what would be expected for rats of this age and strain. An independent panel of experts determined certain observations to be spontaneous and not related to the test diet. Accordingly, these results support the conclusion that 4114 maize grain is as safe and nutritious as conventional maize grain. PMID:23261672

  12. Inoculation of Infectious Agents in Laboratory Rodents

    E-print Network

    Manning, Sturt

    , and date of inoculation. 3.3 Medical Surveillance 3.3.1 Participate in the Animal Users Health and Safety or physical restraint device. If the procedure or conditions of inoculation pose too high a risk with an awake 1 of 4 The most recent version of this document is available electronically at: http

  13. Complementary use of inter-laboratory certification study data

    Microsoft Academic Search

    W. Hässelbarth

    1999-01-01

    The agreed purpose of an inter-laboratory certification study is to characterise a certified reference material (CRM). In\\u000a addition to this, any (successful) certification study may also be utilised as a laboratory\\/method performance study by the\\u000a participants. The intention of this note is to emphasise the complementary use of certification study data by the participants\\u000a of the certification study and to

  14. Mortality study of pathologists and medical laboratory technicians

    Microsoft Academic Search

    J M Harrington; H S Shannon

    1975-01-01

    Membership lists of professional bodies were used to establish study populations of British pathologists (1955-73) and medical laboratory technicians (1963-73). The standardised mortality ratio (SMR) for pathologists was 60 and for medical laboratory technicians 67. Twenty-seven of the 310 deaths were due to suicide. These numbers gave SMRs of 250 for pathologists and 243 for medical laboratory technicians. Suicide was

  15. 21 CFR 58.185 - Reporting of nonclinical laboratory study results.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Records and Reports... Reporting of nonclinical laboratory study results. (a) A...prepared for each nonclinical laboratory study and shall include...shall include the number of animals used, sex, body...

  16. Sero-Prevalence of Rodent Pathogens in India

    PubMed Central

    Manjunath, Shrruthi; Kulkarni, Prachet G.; Nagavelu, Krishnaveni; Samuel, Rosa J.; Srinivasan, Sandhya; Ramasamy, Nandhini; Hegde, Nagendra R.; Gudde, Ramachandra S.

    2015-01-01

    Health monitoring is an integral part of laboratory animal quality standards. However, current or past prevalence data as well as regulatory requirements dictate the frequency, type and the expanse of health monitoring. In an effort to understand the prevalence of rodent pathogens in India, a preliminary study was carried out by sero-epidemiology. Sera samples obtained from 26 public and private animal facilities were analyzed for the presence of antibodies against minute virus of mice (MVM), ectromelia virus (ECTV), lymphocytic choriomeningitis virus (LCMV), mouse hepatitis virus (MHV), Sendai virus (SeV), and Mycoplasma pulmonis in mice, and SeV, rat parvo virus (RPV), Kilham’s rat virus (KRV) and sialodacryoadenitis virus (SDAV) in rats, by sandwich ELISA. It was observed that MHV was the most prevalent agent followed by Mycoplasma pulmonis and MVM in mice, and SDAV followed by RPV were prevalent in rats. On the other hand, none of the samples were positive for ECTV in mice, or SeV or KRV in rats. Multiple infections were common in both mice and rats. The incidence of MHV and Mycoplasma pulmonis was higher in facilities maintained by public organizations than in vivaria of private organizations, although the difference was not statistically different. On the other hand the prevalence of rodent pathogens was significantly higher in the northern part of India than in the South. These studies form the groundwork for detailed sero-prevalence studies which should further lay the foundations for country-specific guidelines for health monitoring of laboratory animals. PMID:26158453

  17. Receiving of emotional signal of pain from conspecifics in laboratory rats.

    PubMed

    Nakashima, Satoshi F; Ukezono, Masatoshi; Nishida, Hiroshi; Sudo, Ryunosuke; Takano, Yuji

    2015-04-01

    Though recent studies have shown that rodents express emotions with their face, whether emotional expression in rodents has a communicative function between conspecifics is still unclear. Here, we demonstrate the ability of visual recognition of emotional expressions in laboratory rats. We found that Long-Evans rats avoid images of pain expressions of conspecifics but not those of neutral expressions. The results indicate that rats use visual emotional signals from conspecifics to adjust their behaviour in an environment to avoid a potentially dangerous place. Therefore, emotional expression in rodents, rather than just a mere 'expression' of emotional states, might have a communicative function. PMID:26064632

  18. Receiving of emotional signal of pain from conspecifics in laboratory rats

    PubMed Central

    Nakashima, Satoshi F.; Ukezono, Masatoshi; Nishida, Hiroshi; Sudo, Ryunosuke; Takano, Yuji

    2015-01-01

    Though recent studies have shown that rodents express emotions with their face, whether emotional expression in rodents has a communicative function between conspecifics is still unclear. Here, we demonstrate the ability of visual recognition of emotional expressions in laboratory rats. We found that Long-Evans rats avoid images of pain expressions of conspecifics but not those of neutral expressions. The results indicate that rats use visual emotional signals from conspecifics to adjust their behaviour in an environment to avoid a potentially dangerous place. Therefore, emotional expression in rodents, rather than just a mere ‘expression’ of emotional states, might have a communicative function.

  19. Airborne and laboratory studies of interstellar PAHs

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.; Sandford, S. A.; Hudgins, D. M.; Witteborn, Fred C.

    1995-01-01

    A brief history of the observations which have led to the hypothesis that polycyclic aromatic hydrocarbons (PAH's) are the carriers of the widespread interstellar emission features near 3050, 1615, '1300' and 890 cm(exp -1) (3.29, 6.2, '7.7', and 11.2 mu m) is presented. The central role of airborne spectroscopy is stressed. The principal reason for the assignment to PAH's was the resemblance of the interstellar emission spectrum to the laboratory absorption spectra of PAH's and PAH-like materials. Since precious little information was available on the properties of PAH's in the forms that are thought to exist under interstellar conditions -isolated and ionized in the emission zones, with the smallest PAH's being dehydrogenated- there was a need for a spectral data base on PAH's taken in these states. Here, the relevant infrared spectroscopic properties of PAH's will be reviewed. These laboratory spectra show that relative band intensities are severely altered and that band frequencies shift. It is shown that these new data alleviate several of the spectroscopic criticisms previously leveled at the hypothesis.

  20. How Stress has been Studied: In the Laboratory

    E-print Network

    Meagher, Mary

    How Stress has been Studied: In the Laboratory ! Acute Stress Paradigm ! People are taken into the laboratory ! Exposed to a short-term stressful event ! Counting backward by 7s/give speech ! The impact of the stress is observed ! Physiological responses ! Neuroendocrine responses ! Psychological responses #12;How

  1. Extremely low frequency fields and cancer: laboratory studies

    Microsoft Academic Search

    Larry Anderson; Larry E

    1998-01-01

    There is now convincing evidence from a large number of laboratories, that exposure to extremely low frequency (ELF) magnetic and electric fields produces biological responses in animals. However, no animal studies clearly demonstrate deleterious effects of ELF fields, although several are suggestive of potential health impacts. A major current emphasis in laboratory research is to determine whether or not the

  2. Microbiological monitoring of laboratory mice and biocontainment in individually ventilated cages: a field study.

    PubMed

    Brielmeier, M; Mahabir, E; Needham, J R; Lengger, C; Wilhelm, P; Schmidt, J

    2006-07-01

    Over recent years, the use of individually ventilated cage (IVC) rack systems in laboratory rodent facilities has increased. Since every cage in an IVC rack may be assumed to be a separate microbiological unit, comprehensive microbiological monitoring of animals kept in IVCs has become a challenging task, which may be addressed by the appropriate use of sentinel mice. Traditionally, these sentinels have been exposed to soiled bedding but more recently, the concept of exposure to exhaust air has been considered. The work reported here was aimed firstly at testing the efficiency of a sentinel-based microbiological monitoring programme under field conditions in a quarantine unit and in a multi-user unit with frequent imports of mouse colonies from various sources. Secondly, it was aimed at determining biocontainment of naturally infected mice kept in an IVC rack, which included breeding of the mice. Sentinels were exposed both to soiled bedding and to exhaust air. The mice which were used in the study carried prevalent infectious agents encountered in research animal facilities including mouse hepatitis virus (MHV), mouse parvovirus (MPV), intestinal flagellates and pinworms. Our data indicate that the sentinel-based health monitoring programme allowed rapid detection of MHV, intestinal flagellates and pinworms investigated by a combination of soiled bedding and exhaust air exposure. MHV was also detected by exposure to exhaust air only. The IVC rack used in this study provided biocontainment when infected mice were kept together with non-infected mice in separate cages in the same IVC rack. PMID:16803642

  3. Rocket and laboratory studies in astronomy

    NASA Technical Reports Server (NTRS)

    Feldman, P. D.

    1993-01-01

    This report covers the period from September 1, 1992 to August 31, 1993. During the reporting period we launched the Faint Object Telescope to measure absolute fluxes of two hot dwarf stars in the spectral range below 1200 A. Although all systems worked normally, a higher than anticipated pressure in the detector led to ion-feedback that masked the useable data from the source. We have identified the source of the problem and are preparing for a reflight in the Fall of 1993. Our laboratory program for the evaluation of the ultraviolet performance of charge-coupled-detector (CCD) arrays continued with the aim of including a UV-sensitive CCD in a payload to be flown in 1994, and we have begun the assembly of this payload. Work has continued on the analysis of data from previous rocket experiments and from the UVX experiment which flew on STS-61C in January 1986.

  4. Laboratory studies of imbibition flooding using carbonated brine 

    E-print Network

    Sharif, Qamar Javaid

    1991-01-01

    LABORATORY STUDIES OF IMBIBITION FLOODING USING CARBONATED BRINE A Thesis by QAMAR JAVAID SHARIF Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1991 Major Subject: Petroleum Engineering LABORATORY STUDIES OF IMBIBITION FLOODING USING CARBONATED BRINE A Thesis by QAMAR JA VAID SHARIF Appmved as to style and content by: S. W. Poston (Chair of committee) J. S. Osoba...

  5. Dual captures of Colorado rodents: implications for transmission of hantaviruses.

    PubMed Central

    Calisher, C. H.; Childs, J. E.; Sweeney, W. P.; Canestrop, K. M.; Beaty, B. J.

    2000-01-01

    We analyzed dual-capture data collected during longitudinal studies monitoring transmission and persistence of Sin Nombre virus in rodents in Colorado. Our data indicate that multiple captures (two or more rodents captured in a single trap) may not be random, as indicated by previous studies, but rather the result of underlying, species-specific social behavior or cohesiveness. In the pairs we captured, most often, rodents were of the same species, were male, and could be recaptured as pairs. Therefore, dual captures of rodents, which are unusual but not rare, tend to occur among certain species, and appear to be nonrandom, group-foraging encounters. These demographic and ecologic characteristics may have implications for the study of the transmission of hantaviruses. PMID:10970147

  6. Incorporation of analgesics into rodent embryo transfer protocols: assessing the effects on reproductive outcomes 

    E-print Network

    Burckhardt, Heather Ann

    2009-05-15

    Surgical embryo transfer in rodents is a common procedure in today’s research laboratory, although little is known of the effect analgesics may have on not only the recipient female but also the embryos. Two perioperative analgesics, ketoprofen...

  7. Sources of Variance in Baseline Gene Expression in the Rodent Liver

    PubMed Central

    Corton, J. Christopher; Bushel, Pierre R.; Fostel, Jennifer; O'Lone, Raegan B.

    2012-01-01

    The use of gene expression profiling in both clinical and laboratory settings would be enhanced by better characterization of variation due to individual, environmental, and technical factors. Analysis of microarray data from untreated or vehicle-treated animals within the control arm of toxicogenomics studies has yielded useful information on baseline fluctuations in liver gene expression in the rodent. Here, studies which highlight contributions of different factors to gene expression variability in the rodent liver are discussed including a large meta-analysis of rat liver, which identified genes that vary in control animals in the absence of chemical treatment. Genes and their pathways that are the most and least variable were identified in a number of these studies. Life stage, fasting, sex, diet, circadian rhythm and liver lobe source can profoundly influence gene expression in the liver. Recognition of biological and technical factors that contribute to variability of background gene expression can help the investigator in the design of an experiment that maximizes sensitivity and reduces the influence of confounders that may lead to misinterpretation of genomic changes. The factors that contribute to variability in liver gene expression in rodents are likely analogous to those contributing to human interindividual variability in drug response and chemical toxicity. Identification of batteries of genes that are altered in a variety of background conditions could be used to predict responses to drugs and chemicals in appropriate models of the human liver. PMID:22230429

  8. Overall Type I Error Rate and Power of Multiple Dunnett's Tests on Rodent Body Weights in Toxicology Studies

    Microsoft Academic Search

    Wherly P. Hoffman; Justin Recknor; Cindy Lee

    2008-01-01

    Body weight data are routinely collected in in vivo general toxicology studies, including 2-year carcinogenicity studies, to help assess the overall health of animals. The effect of the compound on body weight is statistically evaluated for each sex separately using a linear trend test or a many-to-one test by Dunnett. These tests are performed either in the framework of a

  9. Heterogeneous processes: Laboratory, field, and modeling studies

    NASA Technical Reports Server (NTRS)

    Poole, Lamont R.; Kurylo, Michael J.; Jones, Rod L.; Wahner, Andreas; Calvert, Jack G.; Leu, M.-T.; Fried, A.; Molina, Mario J.; Hampson, Robert F.; Pitts, M. C.

    1991-01-01

    The efficiencies of chemical families such as ClO(x) and NO(x) for altering the total abundance and distribution of stratospheric ozone are controlled by a partitioning between reactive (active) and nonreactive (reservoir) compounds within each family. Gas phase thermodynamics, photochemistry, and kinetics would dictate, for example, that only about 1 percent of the chlorine resident in the lower stratosphere would be in the form of active Cl or ClO, the remainder existing in the reservoir compounds HCl and ClONO2. The consistency of this picture was recently challenged by the recognition that important chemical transformations take place on polar regions: the Airborne Antarctic Ozone Experiment (AAOE) and the Airborne Arctic Stratospheric Expedition (AASA). Following the discovery of the Antarctic ozone hole, Solomon et al. suggested that the heterogeneous chemical reaction: ClONO2(g)+HCl(s) yields Cl2(g)+HNO3(s) could play a key role in converting chlorine from inactive forms into a species (Cl2) that would rapidly dissociate in sunlight to liberate atomic chlorine and initiate ozone depletion. The symbols (s) and (g) denote solid phase, or adsorbed onto a solid surface, and gas phase, respectively, and represent the approach by which such a reaction is modeled rather than the microscopic details of the reaction. The reaction was expected to be most important at altitudes where PSC's were most prevalent (10 to 25 km), thereby extending the altitude range over which chlorine compounds can efficiently destroy ozone from the 35 to 45 km region (where concentrations of active chlorine are usually highest) to lower altitudes where the ozone concentration is at its peak. This chapter will briefly review the current state of knowledge of heterogeneous processes in the stratosphere, emphasizing those results obtained since the World Meteorological Organization (WMO) conference. Sections are included on laboratory investigations of heterogeneous reactions, the characteristics and climatology of PSC's, stratospheric sulfate aerosols, and evidence of heterogeneous chemical processing.

  10. Selection and validation of reference genes for real-time RT-PCR studies in the non-model species Delomys sublineatus, an endemic Brazilian rodent.

    PubMed

    Weyrich, Alexandra; Axtner, Jan; Sommer, Simone

    2010-02-01

    Quantitative real-time RT-PCR (qRT-PCR) is a sensitive technique for gene expression analysis. A critical factor for creating reliable data in relative quantification is the normalization of the expression data of genes of interest. Therefore the needed normalization factor is calculated out of the expression data of co-amplified genes that are stable expressed in the certain sample material, the so-called reference genes. In this study, we demonstrate the important process of validating potential reference genes using a non-model species. As there are almost no sequences known of the Pallid Atlantic Forest Rat (Delomys sublineatus), a rodent used as indicator species in conservation studies of the endangered Brazilian rainforest, suitable primer sets are more problematic to find than in model species. Out of nine tested primer sets designed for the fully sequenced Mus musculus, five could be used for the establishment of a proper running SYBR-Green assay and validation of their constant expression. qRT-PCR results of 12 cDNAs of Delomys livers were analyzed with three different validation software programs: BestKeeper, NormFinder and geNorm. Our approach showed that out of the five (Sdha, Canx, Pgk1, Actb and Actg1) potential reference genes, the first four should be used for accurate normalization in further relative quantification analyses. Transferring data from close-by model organisms makes high sensitive real-time RT-PCR applicable even to free-ranging non-model organisms. Our approach might be suitable for other non-model organisms. PMID:20059981

  11. RODENT MODELS OF SLEEP APNEA

    PubMed Central

    Davis, Eric M.; O’Donnell, Christopher P.

    2014-01-01

    Rodent models of sleep apnea have long been used to provide novel insight into the generation and predisposition to apneas as well as to characterize the impact of sleep apnea on cardiovascular, metabolic, and psychological health in humans. Given the significant body of work utilizing rodent models in the field of sleep apnea, the aims of this review are three-fold: first, to review the use of rodents as natural models of sleep apnea; second, to provide an overview of the experimental interventions employed in rodents to simulate sleep apnea; third, to discuss the refinement of rodent models to further our understanding of breathing abnormalities that occur during sleep. Given mounting evidence that sleep apnea impairs cognitive function, reduces quality of life, and exacerbates the course of multiple chronic diseases, rodent models will remain a high priority as a tool to interrogate both the pathophysiology and sequelae of breathing related abnormalities during sleep and to improve approaches to diagnosis and therapy. PMID:23722067

  12. A Mechanistic Basis for the Beneficial Effects of Caloric Restriction On Longevity and Disease: Consequences for the Interpretation of Rodent Toxicity Studies

    Microsoft Academic Search

    Julian E. A. Leakey; John E. Seng; Crissy R. Barnas; Vanessa M. Baker; Ronald W. Hart

    1998-01-01

    Caloric restriction in rodents has been repeatedly shown to increase life span while reducing the severity and retarding the onset of both spontaneous and chemically induced neoplasms. These effects of caloric restriction are associated with a spectrum of biochemical and physiological changes that characterize the organism's adaptation to reduced caloric intake and provide the mechanistic basis for caloric restriction's effect

  13. Rat Brain Endothelial Cell Lines for the Study of Blood–Brain Barrier Permeability and Transport Functions

    Microsoft Academic Search

    Françoise Roux; Pierre-Olivier Couraud

    2005-01-01

    Summary  1. In vitro models of the BBB have been developed from cocultures between bovine, porcine, rodent or human brain capillary endothelial cells with rodent or human astrocytes. Since most in vivo BBB studies have been performed with small laboratory animals, especially rats, it is important to establish a rat brain endothelial (RBE) cell culture system that will allow correlations between

  14. Basic toxicology and metabolism studies of 1,5-anhydro- d-fructose using bacteria, cultured mammalian cells, and rodents

    Microsoft Academic Search

    Shukun Yu; Jie Mei; Bo Ahrén

    2004-01-01

    1,5-Anhydro-d-fructose (AF) is a monosaccharide occurring in edible morels, red seaweeds and certain mammalian tissues. It can be formed directly from starch and glycogen in vivo by ?-1,4-glucan lyase (EC 4.2.2.13). In this study, the toxicity, absorption and metabolism of AF using bacteria, mammalian cells, rat and mouse models were examined. In Ames test, AF showed no genotoxicity using five

  15. The safety of PolyGlycopleX® (PGX®) as shown in a 90-day rodent feeding study

    Microsoft Academic Search

    Ray A Matulka; Michael R Lyon; Simon Wood; Palma Ann Marone; Daniel J Merkel; George A Burdock

    2009-01-01

    BACKGROUND: This study was designed to evaluate the safety of PolyGlycopleX® (PGX®), a novel viscous dietary polysaccharide (fiber), when administered to Sprague Dawley® rats in the diet for 90 days. METHODS: Groups of ten male and ten female rats each consumed PGX mixed in the diet at levels of 0, 1.25, 2.5 or 5.0% for 90 days, then evaluated for

  16. Bone morphology of the hind limbs in two caviomorph rodents.

    PubMed

    de Araújo, F A P; Sesoko, N F; Rahal, S C; Teixeira, C R; Müller, T R; Machado, M R F

    2013-04-01

    In order to evaluate the hind limbs of caviomorph rodents a descriptive analysis of the Cuniculus paca (Linnaeus, 1766) and Hydrochoerus hydrochaeris (Linnaeus, 1766) was performed using anatomical specimens, radiography, computed tomography (CT) and full-coloured prototype models to generate bone anatomy data. The appendicular skeleton of the two largest rodents of Neotropical America was compared with the previously reported anatomical features of Rattus norvegicus (Berkenhout, 1769) and domestic Cavia porcellus (Linnaeus, 1758). The structures were analyzed macroscopically and particular findings of each species reported. Features including the presence of articular fibular projection and lunulae were observed in the stifle joint of all rodents. Imaging aided in anatomical description and, specifically in the identification of bone structures in Cuniculus paca and Hydrochoerus hydrochaeris. The imaging findings were correlated with the anatomical structures observed. The data may be used in future studies comparing these animals to other rodents and mammalian species. PMID:22731111

  17. Old World Hantaviruses in Rodents in New Orleans, Louisiana

    PubMed Central

    Cross, Robert W.; Waffa, Bradley; Freeman, Ashley; Riegel, Claudia; Moses, Lina M.; Bennett, Andrew; Safronetz, David; Fischer, Elizabeth R.; Feldmann, Heinz; Voss, Thomas G.; Bausch, Daniel G.

    2014-01-01

    Seoul virus, an Old World hantavirus, is maintained in brown rats and causes a mild form of hemorrhagic fever with renal syndrome (HFRS) in humans. We captured rodents in New Orleans, Louisiana and tested them for the presence of Old World hantaviruses by reverse transcription polymerase chain reaction (RT-PCR) with sequencing, cell culture, and electron microscopy; 6 (3.4%) of 178 rodents captured—all brown rats—were positive for a Seoul virus variant previously coined Tchoupitoulas virus, which was noted in rodents in New Orleans in the 1980s. The finding of Tchoupitoulas virus in New Orleans over 25 years since its first discovery suggests stable endemicity in the city. Although the degree to which this virus causes human infection and disease remains unknown, repeated demonstration of Seoul virus in rodent populations, recent cases of laboratory-confirmed HFRS in some US cities, and a possible link with hypertensive renal disease warrant additional investigation in both rodents and humans. PMID:24639295

  18. Chronic Toxicity and Carcinogenicity Studies of the Long-Acting GLP-1 Receptor Agonist Dulaglutide in Rodents.

    PubMed

    Byrd, Richard A; Sorden, Steven D; Ryan, Thomas; Pienkowski, Thomas; LaRock, Richard; Quander, Ricardo; Wijsman, John A; Smith, Holly W; Blackbourne, Jamie L; Rosol, Thomas J; Long, Gerald G; Martin, Jennifer A; Vahle, John L

    2015-07-01

    The tumorigenic potential of dulaglutide was evaluated in rats and transgenic mice. Rats were injected sc twice weekly for 93 weeks with dulaglutide 0, 0.05, 0.5, 1.5, or 5 mg/kg corresponding to 0, 0.5, 7, 20, and 58 times, respectively, the maximum recommended human dose based on plasma area under the curve. Transgenic mice were dosed sc twice weekly with dulaglutide 0, 0.3, 1, or 3 mg/kg for 26 weeks. Dulaglutide effects were limited to the thyroid C-cells. In rats, diffuse C-cell hyperplasia and adenomas were statistically increased at 0.5 mg/kg or greater (P ? .01 at 5 mg/kg), and C-cell carcinomas were numerically increased at 5 mg/kg. Focal C-cell hyperplasia was higher compared with controls in females given 0.5, 1.5, and 5 mg/kg. In transgenic mice, no dulaglutide-related C-cell hyperplasia or neoplasia was observed at any dose; however, minimal cytoplasmic hypertrophy of C cells was observed in all dulaglutide groups. Systemic exposures decreased over time in mice, possibly due to an antidrug antibody response. In a 52-week study designed to quantitate C-cell mass and plasma calcitonin responses, rats received twice-weekly sc injections of dulaglutide 0 or 5 mg/kg. Dulaglutide increased focal C-cell hyperplasia; however, quantitative increases in C-cell mass did not occur. Consistent with the lack of morphometric changes in C-cell mass, dulaglutide did not affect the incidence of diffuse C-cell hyperplasia or basal or calcium-stimulated plasma calcitonin, suggesting that diffuse increases in C-cell mass did not occur during the initial 52 weeks of the rat carcinogenicity study. PMID:25860029

  19. Geometric Morphometrics of Rodent Sperm Head Shape

    PubMed Central

    Varea Sánchez, María; Bastir, Markus; Roldan, Eduardo R. S.

    2013-01-01

    Mammalian spermatozoa, particularly those of rodent species, are extremely complex cells and differ greatly in form and dimensions. Thus, characterization of sperm size and, particularly, sperm shape represents a major challenge. No consensus exists on a method to objectively assess size and shape of spermatozoa. In this study we apply the principles of geometric morphometrics to analyze rodent sperm head morphology and compare them with two traditional morphometry methods, that is, measurements of linear dimensions and dimensions-derived parameters calculated using formulae employed in sperm morphometry assessments. Our results show that geometric morphometrics clearly identifies shape differences among rodent spermatozoa. It is also capable of discriminating between size and shape and to analyze these two variables separately. Thus, it provides an accurate method to assess sperm head shape. Furthermore, it can identify which sperm morphology traits differ between species, such as the protrusion or retraction of the base of the head, the orientation and relative position of the site of flagellum insertion, the degree of curvature of the hook, and other distinct anatomical features and appendices. We envisage that the use of geometric morphometrics may have a major impact on future studies focused on the characterization of sperm head formation, diversity of sperm head shape among species (and underlying evolutionary forces), the effects of reprotoxicants on changes in cell shape, and phenotyping of genetically-modified individuals. PMID:24312234

  20. Efficacy of rodenticide baits for the control of three invasive rodent species in Hawaii.

    PubMed

    Pitt, William C; Driscoll, Laura C; Sugihara, Robert T

    2011-04-01

    We tested the efficacy and palatability of nine commercial rodenticide bait formulations on Polynesian rats (Rattus exulans), roof rats (R. rattus), and house mice (Mus musculus). Efficacy varied by rodenticide tested and rodent species. Generally, rodenticides were more effective against mice than for either of the rat species, and mice tended to consume more rodenticide bait than the laboratory chow alternative food. Efficacy was generally highest for the second-generation anticoagulants tested; however, this varied across products and one-first-generation rodenticide had similar effectiveness. Bait acceptance (palatability) also varied both by rodenticide and by rodent species. Acceptance was the lowest for the acute rodenticides. Bait acceptance appeared to substantially affect the efficacy of rodenticides; materials that were not well accepted produced lower mortality rates. Rodenticide products currently registered for use in Hawaii performed less effectively in this study than other available products not yet registered. Although markets for rodent control products for use on islands are limited, there are advantages to having additional products registered for island use in agriculture, conservation, and public health. PMID:20552335

  1. Laboratory studies of refractory metal oxide smokes

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph A.; Nelson, R. N.; Donn, Bertram

    1989-01-01

    Studies of the properties of refractory metal oxide smokes condensed from a gas containing various combinations of SiH4, Fe(CO)5, Al(CH3)3, TiCl4, O2 and N2O in a hydrogen carrier stream at 500 K greater than T greater than 1500 K were performed. Ultraviolet, visible and infrared spectra of pure, amorphous SiO(x), FeO(x), AlO(x) and TiO(x) smokes are discussed, as well as the spectra of various co-condensed amorphous oxides, such as FE(x)SiO(y) or Fe(x)AlO(y). Preliminary studies of the changes induced in the infrared spectra of iron-containing oxide smokes by vacuum thermal annealing suggest that such materials become increasingly opaque in the near infrared with increased processing: hydration may have the opposite effect. More work on the processing of these materials is required to confirm such a trend: this work is currently in progress. Preliminary studies of the ultraviolet spectra of amorphous Si2O3 and MgSiO(x) smokes revealed no interesting features in the region from 200 to 300 nm. Studies of the ultraviolet spectra of both amorphous, hydrated and annealed SiO(x), TiO(x), AlO(x) and FeO(x) smokes are currently in progress. Finally, data on the oxygen isotopic composition of the smokes produced in the experiments are presented, which indicate that the oxygen becomes isotopically fractionated during grain condensation. Oxygen in the grains is as much as 3 percent per amu lighter than the oxygen in the original gas stream. The authors are currently conducting experiments to understand the mechanism by which fractionation occurs.

  2. Laboratory study of avalanches in magnetized plasmas.

    PubMed

    Van Compernolle, B; Morales, G J; Maggs, J E; Sydora, R D

    2015-03-01

    It is demonstrated that a novel heating configuration applied to a large and cold magnetized plasma allows the study of avalanche phenomena under controlled conditions. Intermittent collapses of the plasma pressure profile, associated with unstable drift-Alfvén waves, exhibit a two-slope power-law spectrum with exponents near -1 at lower frequencies and in the range of -2 to -4 at higher frequencies. A detailed mapping of the spatiotemporal evolution of a single avalanche event is presented. PMID:25871044

  3. To investigate antihyperglycemic and antihyperlipidemic potential of safrole in rodents by in-vivo and in-vitro study.

    PubMed

    Rani, S; Sharma, S; Kumar, S

    2014-06-01

    In the present investigation anti-diabetic and in-vitro antioxidant potential of safrole were evaluated (100 and 200?mg/kg p.o.) in acute and chronic Streptozotocin-nicotinamide (STZ) induced antihyperglycemic rat model. The oral administration of safrole for 30 days affects the level of blood glucose, glycosylated hemoglobin (HbA1C), total cholesterol (TC), triglycerides (TG), phospholipids, high density lipoprotein (HDL), body weight, insulin level, liver glycogen content, antioxidant parameters, lipase, ?-amylase in normal and STZ induced diabetic rats. The oral administration of safrole at dose 100 & 200?mg/kg p.o. significantly improve the diabetic condition in Streptozotocin-induced diabetic rats. In enzymatic assay, the IC50 value of the safrole for ?-amylase and lipase was found to be 702.78 and 861.35??g/ml respectively which was found comparable with the standard drug (ascorbic acid) as 252.12??g/ml. Further studies can be performed on safrole for mechanistic and toxicological aspects so that it can be investigated as a new substance for the management of various diseases. PMID:24132706

  4. In vitro and in vivo effects of two coconut oils in comparison to monolaurin on Staphylococcus aureus: rodent studies.

    PubMed

    Manohar, Vijaya; Echard, Bobby; Perricone, Nicholas; Ingram, Cass; Enig, Mary; Bagchi, Debasis; Preuss, Harry G

    2013-06-01

    Since monolaurin, a monoglyceride formed in the human body in small quantities, has proven effective both in vitro and in vivo against certain strains of Staphylococcus aureus, an important question arises whether consuming a substance high in lauric acid content, such as coconut oil could increase intrinsic monolaurin production to levels that would be successful in overcoming staphylococcal and other microbial invaders. Both a cup plate method and a microdilution broth culture system were employed to test bacteriostatic and bactericidal effects of the test agents in vitro. To test effectiveness in vivo, female C3H/he mice (10-12 per group) were orally administered sterile saline (regular control), vancomycin (positive control), aqueous monolaurin, or two varieties of coconut oil (refined, bleached, deodorized coconut oil and virgin coconut oil) for 1 week before bacterial challenge and 30 days after. A final group received both monolaurin and vancomycin. In contrast to monolaurin, the coconut oils did not show bactericidal activity in vitro. In vivo, the groups receiving vancomycin, monolaurin, or the combination showed some protection--50-70% survival, whereas the protection from the coconut oils were virtually the same as control--0-16% survival. Although we did not find that the two coconut oils are helpful to overcome S. aureus infections, we corroborated earlier studies showing the ability of monolaurin to do such. PMID:23767861

  5. The role of mode of delivery on elastic fiber architecture and vaginal vault elasticity: a rodent model study

    PubMed Central

    Downing, Keith; Billah, Mubashir; Raparia, Eva; Shah, Anup; Silverstein, Moshe; Ahmad, Amanda; Boutis, Gregory S.

    2013-01-01

    We report on an experimental study of the role of mode of delivery and pregnancy on the architecture of vaginal elastic fibers and vaginal vault elasticity in female Sprague-Dawley rats. In primiparous rats submitted to spontaneous or Cesarean delivery and virgin rats submitted to simulated delivery, the tortuosity of elastic fibers (defined as the ratio of length to end-to-end distance) was observed to decrease when measured two days to two weeks postpartum. In addition, the measured tortuosity of elastic fibers in multiparous rats was greater than that of virgin rats. The tortuosity of elastic fibers of all rats measured at two days postpartum were found to be similar to that of multiparous rats. At two weeks postpartum the measured tortuosity of vaginal elastic fibers was indistinguishable from virgin rats, regardless of the delivery method. Borrowing from the field of polymer physics, a model is suggested that connects elastic fiber tortuosity to the resulting tension under an applied stress; fibers having high tortuosity are expected to provide less structural support than more linear, low tortuosity fibers. To probe the macroscopic effects in elasticity due to architectural changes observed in elastic fibers, we have measured the stiffness of the vaginal vault in each cohort using a pressure-infusion system. The vaginal vault stiffness of all primiparous rats measured two weeks postpartum was greater than that measured two days postpartum. In addition, the vaginal vault of virgin rats was stiffer than that of multiparous rats. These observations confirmed that vaginal vault elastic fibers undergo significant remodeling due to pregnancy and parturition, and that the complex remodeling may be a significant contributor to tissue elasticity. Remarkably, regardless of the mode of delivery or simulated tissue trauma, elastic fiber tortuosity is observed to decrease from two days to two weeks postpartum indicating the onset of repair and recovery of tissue stiffness. PMID:24099948

  6. The safety of PolyGlycopleX® (PGX®) as shown in a 90-day rodent feeding study

    PubMed Central

    Matulka, Ray A; Lyon, Michael R; Wood, Simon; Ann Marone, Palma; Merkel, Daniel J; Burdock, George A

    2009-01-01

    Background This study was designed to evaluate the safety of PolyGlycopleX® (PGX®), a novel viscous dietary polysaccharide (fiber), when administered to Sprague Dawley® rats in the diet for 90 days. Methods Groups of ten male and ten female rats each consumed PGX mixed in the diet at levels of 0, 1.25, 2.5 or 5.0% for 90 days, then evaluated for toxicological effects on parameters that included neuromotor activity, body weight, clinical chemistry, urinalysis, hematology, and histopathology. Results Mean body weight, mean feed consumption and food efficiency in the treated groups were generally comparable to controls for both male and female rats. No changes were noted in neuromotor behavior, and histopathological analysis revealed no significant changes between treated and control animals. There were no differences in mean organ weight, organ-to-body weight or organ-to-brain weight values between controls and treated animals. Decreased red blood cell count occurred in the high dose males and increases in aspartate and alanine aminotransferase enzyme levels and triglycerides, while significant decreases in serum sodium, potassium and chloride concentrations were observed in the females fed 5.0% PGX. However, the decreased mineral concentrations may be the result of significantly increased urinary volume in both males and females at the high dose, with a concomitant decrease in urinary specific gravity (males and females) and protein concentration (females). These results were within historical control values, did not correlate with any histopathological changes, and were not considered adverse. Conclusion The results indicate a no observed adverse effect level (NOAEL) for PGX at 5.0% of the diet, corresponding to an average daily intake of 3219 and 3799 mg/kg bw/day in male and female rats, respectively. PMID:19149876

  7. Infrared laboratory studies of synthetic planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Williams, D.

    1974-01-01

    Research involving a test of multiplicative transmittance for mixed absorbing gases when their lines are broadened by H2 and He, which are constituents of the atmospheres of the major planets was conducted. The results indicate that the multiplicative law as originally formulated can be applied with confidence. The broadening of individual lines in the CO fundamental by various gases has been investigated. The results indicate that the ratio of the self-broadening ability of CO to the line-broadening ability of foreign gases is greater for lines in the band wings than for lines near the band center when the molecular mass of the broadener is less than that of CO. The results have been interpreted in terms of a phenomenological theory. Studies of the relative line broadening abilities of foreign gases have provided information that can be used to provide optical collision cross sections for individual lines in the CO fundamental.

  8. Systematic studies of Oryzomyine rodents (Muridae, Sigmodontinae): diagnoses and distributions of species formerly assigned to Oryzomys 'capito'

    USGS Publications Warehouse

    Musser, G.G.; Carleton, M.D.; Brothers, E.M.; Gardner, A.L.

    1998-01-01

    We describe the morphological species-boundaries and geographic distributions of ten Neotropical Oryzomys based on analyses of museum specimens (skins and skulls, examples preserved in fluid, chromosomal spreads, and information about collection sites from skin tags, field catalogs, and other sources). These species have been regarded as members of an Oryzomys capito complex and for a long time were consolidated into a single entity identified as O. capito. Our study documents the following: 1. Defining the limits of species within the O. capito complex first requires a comprehensive review and rigorous definition of O. capito itself. We consider Fischer's (1814) Mus megacephalus to be valid and available, designate a neotype to bear the name, and reinstate it as a senior synonym of capito Olfers (1818). We then provide a working definition of O. megacephalus and its close relative, O. laticeps, derived from analyses of morphometric variation, estimates of geographic distributions, and evaluations of synonyms. In our view, O. megacephalus occurs in Amazonia but also extends into eastern Paraguay; its synonyms are capito Olfers (1818), cephalotes Desmarest (1819), velutinus Allen and Chapman (1893), goeldi Thomas (1897), modestus Allen (1899), and perenensis Allen (1901). Oryzomys laticeps Lund (1840) occurs in the Atlantic Forest region of eastern Brazil. We designate a lectotype for laticeps and allocate the names saltator Winge (1887) and oniscus Thomas (1904) as synonyms. 2. We provide the first comprehensive taxonomic revision of Oryzomys yunganus Thomas (1902). Its range covers tropical evergreen rainforest formations in the Guiana region and the Amazon Basin where, as documented by voucher specimens, it has been collected at the same localities as O. megacephalus, O. nitidus, and O. tern of carotid arterial circulation, occlusal patterns of second upper and lower molars, cranial proportions, and chromosomal features. Appreciable intraspecific geographic variation occurs in diploid number of chromosomes and frequency of occurrence of the hypothenar plantar pad, but sampling inadequacies obscure the significance of this variation. Large body size is characteristic of populations in the western Amazon Basin and in the tepui region of eastern Venezuela; smaller size characterizes populations in the Guianas and along the eastern margin of the Amazon Basin. No other scientific name has been correctly associated with the species. Samples from Mirador, Palmera, and Mera in the western Andean foothills of central Ecuador possess a combination of pelage, cranial, and dental traits that distinguish them from all samples of O. yunganus. These specimens are the basis for a new species we describe here, one that is more closely related to O. yunganus than to any other member of the former O. 'capito' complex. 3. We redescribe Oryzomys bolivaris (reviewed by Pine, 1971, under the name O. bombycinus), amplify its geographic range, and contrast it with O. talamancae and O. alfaroi, two sympatric congeners often confused with it. A distinctive set of morphological traits allows unambiguous identification of specimens belonging to O. bolivaris. It is a trans-Andean species recorded from very wet tropical evergreen rainforests extending from eastern Honduras and Nicaragua through Costa Rica and Panama to western Colombia and Ecuador. Allen's (1901) bolivaris is the oldest name for this species; castaneus Allen (1901), rivularis Allen (1901), bombycinus Goldman (1912), alleni Goldman (1915), and orinus Pearson (1939) are synonyms. 4. We revise the definition of Oryzomys talamancae Allen (1891) provided by Musser and Williams (1985), document additional specimens, describe karyotypes from Ecuadoran and Venezuelan samples, and contrast its morphology, chromosomes, and distribution with those of O. alfaroi and O. megacephalus. The geographic distribution of O. talamancae is also trans-Andean, but it inh

  9. Laboratory studies on the El Tor vibrio

    PubMed Central

    Sayamov, R. M.

    1963-01-01

    The identity of the El Tor vibrio is a controversial question that the usual methods of bacteriological investigation have as yet failed to settle. In this paper, the author presents the results of a study of the interrelationships between El Tor vibrios, true cholera vibrios and water vibrios, as revealed by the behaviour of the vibrios in the bile system and in the small intestine of experimental animals. The vibrios investigated included two strains isolated at the El Tor quarantine station on the Sinai Peninsula in 1934, two strains isolated at Makassar, Celebes, during a cholera epidemic in 1937 and identified as “El Tor” vibrios, four strains of true cholera vibrios and five strains of water vibrios. On the whole, the behaviour of the El Tor and Makassar vibrios was similar, closely resembling that of the cholera vibrios and differing markedly from that of the water vibrios. The author therefore considers that the strains of El Tor and Makassar vibrios examined are varieties of Vibrio cholerae and suggests that carriers of such strains should be subjected to the same measures as carriers of true cholera vibrios. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 8 PMID:13986981

  10. Serologic survey of orthopoxvirus infection among rodents in hungary.

    PubMed

    Oldal, Miklós; Sironen, Tarja; Henttonen, Heikki; Vapalahti, Olli; Madai, Mónika; Horváth, Gy?z?; Dallos, Bianka; Kutas, Anna; Földes, Fanni; Kemenesi, Gábor; Németh, Viktória; Bányai, Krisztián; Jakab, Ferenc

    2015-05-01

    As a result of discontinuing vaccination against smallpox after the late 1970s, different orthopoxviruses (OPVs), such as cowpox virus (CPXV), have become a re-emerging healthcare threat among zoonotic pathogens. In Hungary, data on OPV prevalence among its rodent host species have been absent. Here, rodents belonging to four species, i.e., striped field mouse (Apodemus agrarius), yellow-necked mouse (A. flavicollis), wood mouse (A. sylvaticus) and bank vole (Myodes glareolus), were live trapped at 13 sampling plots on a 149-ha area in the Mecsek Mountains, Hungary, from March to September in 2011 and 2012. Rodent sera were collected and screened for OPV-reactive antibodies with an immunfluorescence assay (IFA). Among the 1587 tested rodents, 286 (18.0%) harbored OPV-specific antibodies. Seroprevalence was the highest for the bank vole (71.4%) and the striped field mouse (66.7%). Due to a masting event in the autumn of 2011 across Central Europe, the abundance of bank voles increased drastically in the 2012 season, raising the overall OPV seroprevalence. We provide the first data on OPV occurrence and seroprevalence in rodents in Hungary. The circulation of OPV in rodents in densely populated areas warrants further studies to elucidate the zoonotic potential of OPV in humans. PMID:25988441

  11. Immunological Mechanisms Mediating Hantavirus Persistence in Rodent Reservoirs

    PubMed Central

    Easterbrook, Judith D.; Klein, Sabra L.

    2008-01-01

    Hantaviruses, similar to several emerging zoonotic viruses, persistently infect their natural reservoir hosts, without causing overt signs of disease. Spillover to incidental human hosts results in morbidity and mortality mediated by excessive proinflammatory and cellular immune responses. The mechanisms mediating the persistence of hantaviruses and the absence of clinical symptoms in rodent reservoirs are only starting to be uncovered. Recent studies indicate that during hantavirus infection, proinflammatory and antiviral responses are reduced and regulatory responses are elevated at sites of increased virus replication in rodents. The recent discovery of structural and non-structural proteins that suppress type I interferon responses in humans suggests that immune responses in rodent hosts could be mediated directly by the virus. Alternatively, several host factors, including sex steroids, glucocorticoids, and genetic factors, are reported to alter host susceptibility and may contribute to persistence of hantaviruses in rodents. Humans and reservoir hosts differ in infection outcomes and in immune responses to hantavirus infection; thus, understanding the mechanisms mediating viral persistence and the absence of disease in rodents may provide insight into the prevention and treatment of disease in humans. Consideration of the coevolutionary mechanisms mediating hantaviral persistence and rodent host survival is providing insight into the mechanisms by which zoonotic viruses have remained in the environment for millions of years and continue to be transmitted to humans. PMID:19043585

  12. Challenges in Using Cultured Primary Rodent Hepatocytes or Cell Lines to Study Hepatic HDL Receptor SR-BI Regulation by Its Cytoplasmic Adaptor PDZK1

    PubMed Central

    Tsukamoto, Kosuke; Buck, Lorenna; Inman, Walker; Griffith, Linda; Kocher, Olivier; Krieger, Monty

    2013-01-01

    Background PDZK1 is a four PDZ-domain containing cytoplasmic protein that binds to a variety of membrane proteins via their C-termini and can influence the abundance, localization and/or function of its target proteins. One of these targets in hepatocytes in vivo is the HDL receptor SR-BI. Normal hepatic expression of SR-BI protein requires PDZK1 - <5% of normal hepatic SR-BI is seen in the livers of PDZK1 knockout mice. Progress has been made in identifying features of PDZK1 required to control hepatic SR-BI in vivo using hepatic expression of wild-type and mutant forms of PDZK1 in wild-type and PDZK1 KO transgenic mice. Such in vivo studies are time consuming and expensive, and cannot readily be used to explore many features of the underlying molecular and cellular mechanisms. Methodology/Principal Findings Here we have explored the potential to use either primary rodent hepatocytes in culture using 2D collagen gels with newly developed optimized conditions or PDZK1/SR-BI co-transfected cultured cell lines (COS, HEK293) for such studies. SR-BI and PDZK1 protein and mRNA expression levels fell rapidly in primary hepatocyte cultures, indicating this system does not adequately mimic hepatocytes in vivo for analysis of the PDZK1 dependence of SR-BI. Although PDZK1 did alter SR-BI protein expression in the cell lines, its influence was independent of SR-BI’s C-terminus, and thus is not likely to occur via the same mechanism as that which occurs in hepatocytes in vivo. Conclusions/Significance Caution must be exercised in using primary hepatocytes or cultured cell lines when studying the mechanism underlying the regulation of hepatic SR-BI by PDZK1. It may be possible to use SR-BI and PDZK1 expression as sensitive markers for the in vivo-like state of hepatocytes to further improve primary hepatocyte cell culture conditions. PMID:23936087

  13. A Laboratory Analogue for the Study of Peer Sexual Harassment

    ERIC Educational Resources Information Center

    Mitchell, Damon; Hirschman, Richard; Angelone, D. J.; Lilly, Roy S.

    2004-01-01

    The purpose of this study was to develop a laboratory analogue for the study of peer sexual harassment, and to examine person and situational factors associated with male on female peer sexual harassment. One hundred twenty-two male participants were given the opportunity to tell jokes to a female confederate from a joke list that included…

  14. Chromosome damage in wild rodents inhabiting a site contaminated with Aroclor 1254

    SciTech Connect

    Shaw-Allen, P.L.; McBee, K. (Oklahoma State Univ., Stillwater (United States))

    1993-04-01

    An in situ investigation of structural chromosomal damage in wild rodents from a site contaminated with Aroclor 1254 was undertaken to compare effects observed in nature to those documented in previous laboratory studies. Laboratory assays indicate that Aroclor 1254 does not cause structural damage to chromosomes. However, the many variables at work in actual waste-site environments and receptor populations led the authors to question whether exposures under natural conditions could potentially lead to different results using the same assay systems. Individuals of three rodent species, Peromyscus leucopus, Sigmodon hispidus, and Reithrodontomys fulvescens, were collected from the contaminated site and three matched, pristine reference sites. Standard somatic metaphase chromosome preparations from bone marrow were examined for chromosomes lesions. Comparisons were made between conspecifics from the Aroclor-contaminated site and the reference sites. Significant increases in chromosome damage were not observed in animals from the Aroclor-contaminated site, indicating agreement between laboratory assays and an in situ application of this assay system.

  15. A collagen-based nerve guide conduit for peripheral nerve repair: an electrophysiological study of nerve regeneration in rodents and nonhuman primates.

    PubMed

    Archibald, S J; Krarup, C; Shefner, J; Li, S T; Madison, R D

    1991-04-22

    When a peripheral nerve is severed and left untreated, the most likely result is the formation of an endbulb neuroma; this tangled mass of disorganized nerve fibers blocks functional recovery following nerve injury. Although there are several different approaches for promoting nerve repair, which have been greatly refined over recent years, the clinical results of peripheral nerve repair remain very disappointing. In this paper we compare the results of a collagen nerve guide conduit to the more standard clinical procedure of nerve autografting to promote repair of transected peripheral nerves in rats and nonhuman primates. In rats, we tested recovery from sciatic nerve transection and repair by 1) direct microsurgical suture, 2) 4 mm autograft, or 3) entubulation repair with collagen-based nerve guide conduits. Evoked muscle action potentials (MAP) were recorded from the gastrocnemius muscle at 4 and 12 weeks following sciatic nerve transection. At 4 weeks the repair group of direct suture demonstrated a significantly greater MAP, compared to the other surgical repair groups. However, at 12 weeks all four surgical repair groups displayed similar levels of recovery of the motor response. In six adult male Macaca fascicularis monkeys the median nerve was transected 2 cm above the wrist and repaired by either a 4 mm nerve autograft or a collagen-based nerve guide conduit leaving a 4 mm gap between nerve ends. Serial studies of motor and sensory fibers were performed by recording the evoked MAP from the abductor pollicis brevis muscle (APB) and the sensory action potential (SAP) evoked by stimulation of digital nerves (digit II), respectively, up to 760 days following surgery. Evoked muscle responses returned to normal baseline levels in all cases. Statistical analysis of the motor responses, as judged by the slope of the recovery curves, indicated a significantly more rapid rate of recovery for the nerve guide repair group. The final level of recovery of the MAP amplitudes was not significantly different between the groups. In contrast, the SAP amplitude only recovered to the low normal range and there were no statistically significant differences between the two groups in terms of sensory recovery rates. The rodent and primate studies suggest that in terms of recovery of physiological responses from target muscle and sensory nerves, entubulation repair of peripheral nerves with a collagen-based nerve guide conduit over a short nerve gap (4 mm) is as effective as a standard nerve autograft.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2071700

  16. Graduate StudieS 2014 National Superconducting Cyclotron Laboratory

    E-print Network

    by NASA. National Superconducting Cyclotron Laboratory Michigan State University 640 South Shaw Lane, East in accelerator technology and experimental equipment. During the past half-century, nuclear science research result as NSCL and subsequently FRIB push the envelope at the sensitivity frontier of field. Progress

  17. Rodent nutrition: digestive comparisons of 4 common rodent species.

    PubMed

    Grant, Kerrin

    2014-09-01

    This article summarizes the literature regarding digestive strategies and captive diets of common rodent pocket pets. A comparison is made between the 2 suborders in which chinchillas, guinea pigs, hamsters, and gerbils occur, highlighting digestive anatomy and dietary adaptations. Recommended captive diets are provided, as well as common nutritionally related health issues that may be presented to veterinary clinics. PMID:25155666

  18. Short- and long-term effects of litter size manipulation in a small wild-derived rodent

    PubMed Central

    Lehto Hürlimann, Mikko; Stier, Antoine; Scholly, Olivier; Criscuolo, François; Bize, Pierre

    2014-01-01

    Iteroparous organisms maximize their overall fitness by optimizing their reproductive effort over multiple reproductive events. Hence, changes in reproductive effort are expected to have both short- and long-term consequences on parents and their offspring. In laboratory rodents, manipulation of reproductive efforts during lactation has however revealed few short-term reproductive adjustments, suggesting that female laboratory rodents express maximal rather than optimal levels of reproductive investment as observed in semelparous organisms. Using a litter size manipulation (LSM) experiment in a small wild-derived rodent (the common vole; Microtus arvalis), we show that females altered their reproductive efforts in response to LSM, with females having higher metabolic rates and showing alternative body mass dynamics when rearing an enlarged rather than reduced litter. Those differences in female reproductive effort were nonetheless insufficient to fully match their pups’ energy demand, pups being lighter at weaning in enlarged litters. Interestingly, female reproductive effort changes had long-term consequences, with females that had previously reared an enlarged litter being lighter at the birth of their subsequent litter and producing lower quality pups. We discuss the significance of using wild-derived animals in studies of reproductive effort optimization. PMID:24671828

  19. When allowed, females prefer novel males in the polygynous subterranean rodent Ctenomys talarum (tuco-tuco).

    PubMed

    Fanjul, Maria Sol; Zenuto, Roxana Rita

    2013-01-01

    The ability to recognize familiar conspecifics plays an important role at the time of choosing a mating partner in rodents. A laboratory study using preference test was used in order to test the hypothesis that, in the polygynous subterranean rodent Ctenomys talarum, females prefer novel males when offered two odors, or individuals (one familiar and one novel) limited in their movements so that male aggression is prevented. Our findings show that females prefer novel tuco-tucos at three levels of male assessment: odor samples (consisting of shavings soiled with urine, feces, and presumably, other body secretions collected from the male home cage), confined males behind a wire mesh, and full contact with tethered males. Previous studies of this species demonstrated that in the wild, male-male competition and male coercion severely limit the possibility of females mating non-neighbors, i.e. novel males. Females mating neighbors to whom they are familiarized, obtain high quality mating since they are territorial, highly competitive males. Nonetheless, when females have the opportunity, as shown in the two-choice experiments, they choose novel males, probably benefiting their progeny from novel genetic combinations. Hence, combining evidence from laboratory and field studies in C. talarum, it is possible to better understand female preferences in modeling individual reproductive strategies. PMID:23164625

  20. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  1. 21 CFR 58.185 - Reporting of nonclinical laboratory study results.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Records and Reports §...

  2. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  3. 21 CFR 58.185 - Reporting of nonclinical laboratory study results.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Records and Reports §...

  4. 21 CFR 58.185 - Reporting of nonclinical laboratory study results.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Records and Reports §...

  5. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  6. 21 CFR 58.185 - Reporting of nonclinical laboratory study results.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Records and Reports §...

  7. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  8. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  9. The Coso Geothermal Area: A Laboratory for Advanced MEQ Studies

    E-print Network

    Foulger, G. R.

    - 1 - The Coso Geothermal Area: A Laboratory for Advanced MEQ Studies for Geothermal Monitoring-Dinger Geothermal Program Office, U. S. Navy, China Lake, CA 93555-6001 Keith.Richards-Dinge@navy.mil Keywords of three-component digital seismometers at the Coso geothermal area, California, supplemented by 14

  10. SEWER SEDIMENT GATE AND VACUUM FLUSHING TANKS: LABORATORY FLUME STUDIES

    EPA Science Inventory

    The objective of this study was to test the performance of a traditional gate-flushing device and a newly designed vacuum-flushing device in removing sediments from combined sewers and CSO storage tanks. A laboratory hydraulic flune was used to simulate a reach of sewer or storag...

  11. LABORATORY STUDY OF LIMESTONE REGENERATION IN DUAL ALKALI SYSTEMS

    EPA Science Inventory

    The report describes a series of open- and closed-loop laboratory bench scale experiments which were carried out to study parameters which affect the reaction of limestone with dual alkali flue gas desulfurization system process liquors. It gives details of several sets of operat...

  12. Experimental studies on methane-fuel laboratory scale ram combustor

    Microsoft Academic Search

    Y. Kinoshita; J. Kitajima; Y. Seki; A. Tatara

    1995-01-01

    The laboratory scale ram combustor test program has been investigating fundamental combustion characteristics of a ram combustor, which operates from Mach 2.5 to 5 for the super\\/hypersonic transport propulsion system. In the previous study, combustion efficiency had been found poor, less than 70 percent, due to a low inlet air temperature and a high velocity at Mach 3 condition. To

  13. Developing Medicare Competitive Bidding: A Study of Clinical Laboratories

    PubMed Central

    Hoerger, Thomas J.; Meadow, Ann

    1997-01-01

    Competitive bidding to derive Medicare fees promises several advantages over administered fee systems. The authors show how incentives for cost savings, quality, and access can be incorporated into bidding schemes, and they report on a study of the clinical laboratory industry conducted in preparation for a bidding demonstration. The laboratory industry is marked by variable concentration across geographic markets and, among firms themselves, by social and economic heterogeneity. The authors conclude that these conditions can be accommodated by available bidding design options and by careful selection of bidding markets. PMID:10180003

  14. COMPARATIVE MEDICINE LABORATORY ANIMAL FACILITIES

    E-print Network

    Krovi, Venkat

    for obtaining cage cards. 2.0 Scope: This procedure applies to all animal caretakers, and researchers breeding1.B.33 COMPARATIVE MEDICINE LABORATORY ANIMAL FACILITIES STANDARD OPERATING PROCEDURE for RODENT WEANING 1.0 Purpose: This procedure details breeding density and the timeline for weaning rodents

  15. Pathology of Rodent Models of Intestinal Cancer: Progress Report and Recommendations

    PubMed Central

    Washington, Mary Kay; Powell, Anne E.; Sullivan, Ruth; Sundberg, John; Wright, Nicholas; Coffey, Robert J.; Dove, William F.

    2013-01-01

    In October 2010, a pathology review of rodent models of intestinal neoplasia was held at The Jackson Laboratory. This review complemented 2 other concurrent events: a workshop on methods of modeling colon cancer in rodents and a conference on current issues in murine and human colon cancer. We summarize the results of the pathology review and the committee’s recommendations for tumor nomenclature. A virtual high-resolution image slide box of these models has been developed. This report discusses significant recent developments in rodent modeling of intestinal neoplasia, including the role of stem cells in cancer and the creation of models of metastatic intestinal cancer. PMID:23415801

  16. Petrochemical-related DNA damage in wild rodents detected by flow cytometry

    SciTech Connect

    McBee, K.; Bickham, J.W.

    1988-03-01

    The need for quick, reliable, in situ tests of environmental mutagenicity is evidenced by increasing public concern about potential health effects of pollutants. Conventional tests of clastogenicity usually involve treatment of laboratory test systems with pure samples of suspect compounds followed by scoring numerous metaphase cells for chromosome aberrations. There are at least two shortcomings of these test protocols. They are very time consumptive and are generally restricted to controlled laboratory situations which may not realistically indicate the effects of environmental pollution. The use of flow cytometry to study resident rodent species as bioindicators provides a system by which cytogenetic effects of environmental pollutants upon exposed organisms rapidly and accurately can be ascertained. The authors found that two species of wild rodents (Peromyscus leucopus and Sigmodon hispidus) living at a dump site polluted with a complex mixture of oil, grease, polychlorinated biphenols, hexachlorobenzene, zinc, manganese, cadmium, chromium, copper, and lead had significantly higher frequencies of chromosomal aberrations than did animals from two unpolluted control sites. These data suggest that resident small mammals may be useful as in situ monitors of the presence and action of mutagenic pollutants in the environment. This study was conducted to determine if changes in patterns of DNA content indicative of the action of mutagens could be detected by flow cytometric analysis of tissues from these same animals.

  17. Maintaining plethodontid salamanders in the laboratory for regeneration studies.

    PubMed

    Arenas, Claudia Marcela; Gómez-Molina, Andrea; Delgado, Jean Paul

    2015-01-01

    Limb regeneration studies have been extensively carried out in species of Ambystomatidae and Salamandridae families. So far limited research has been conducted in species belonging to the Plethodontidae family, where some of the species differs from other salamander families due to their direct development, thus absence of a larval life. Here, we describe a protocol to maintain the plethodontid salamanders of genus Bolitoglossa species under laboratory conditions to perform regeneration studies. PMID:25740477

  18. Perampanel, an antagonist of ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, for the treatment of epilepsy: studies in human epileptic brain and nonepileptic brain and in rodent models.

    PubMed

    Zwart, R; Sher, E; Ping, X; Jin, X; Sims, J R; Chappell, A S; Gleason, S D; Hahn, P J; Gardinier, K; Gernert, D L; Hobbs, J; Smith, J L; Valli, S N; Witkin, J M

    2014-10-01

    Perampanel [Fycompa, 2-(2-oxo-1-phenyl-5-pyridin-2-yl-1,2-dihydropyridin-3-yl)benzonitrile hydrate 4:3; Eisai Inc., Woodcliff Lake, NJ] is an AMPA (?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor antagonist used as an adjunctive treatment of partial-onset seizures. We asked whether perampanel has AMPA receptor antagonist activity in both the cerebral cortex and hippocampus associated with antiepileptic efficacy and also in the cerebellum associated with motor side effects in rodent and human brains. We also asked whether epileptic or nonepileptic human cortex is similarly responsive to AMPA receptor antagonism by perampanel. In rodent models, perampanel decreased epileptic-like activity in multiple seizure models. However, doses of perampanel that had anticonvulsant effects were within the same range as those engendering motor side effects. Perampanel inhibited native rat and human AMPA receptors from the hippocampus as well as the cerebellum that were reconstituted into Xenopus oocytes. In addition, with the same technique, we found that perampanel inhibited AMPA receptors from hippocampal tissue that had been removed from a patient who underwent surgical resection for refractory epilepsy. Perampanel inhibited AMPA receptor-mediated ion currents from all the tissues investigated with similar potency (IC50 values ranging from 2.6 to 7.0 ?M). Cortical slices from the left temporal lobe derived from the same patient were studied in a 60-microelectrode array. Large field potentials were evoked on at least 45 channels of the array, and 10 ?M perampanel decreased their amplitude and firing rate. Perampanel also produced a 33% reduction in the branching parameter, demonstrating the effects of perampanel at the network level. These data suggest that perampanel blocks AMPA receptors globally across the brain to account for both its antiepileptic and side-effect profile in rodents and epileptic patients. PMID:25027316

  19. d- chiro-Inositol is absorbed but not synthesised in rodents.

    PubMed

    Lin, Xiaobo; Ma, Lina; Gopalan, Chaya; Ostlund, Richard E

    2009-11-01

    d-chiro-inositol (DCI) and pinitol (1d-3-O-methyl-chiro-inositol) are distinctive inositols reported to possess insulin-mimetic properties. DCI-containing compounds are abundant in common laboratory animal feed. By GC-MS of 6 m-HCl hydrolysates, Purina Laboratory Rodent Diet 5001 (diet 5001) contained 0.23 % total DCI by weight with most found in the lucerne and soya meal components. In contrast, only traces of l-chiro-inositol were observed. The DCI moiety was present in a water-soluble non-ionic form of which most was shown to be pinitol. To measure the absorption of dietary inositols, rats were fed diet 5001 in a balance study or given purified pinitol or [2H6]DCI. More than 98 % of the total DCI fed to rats as diet 5001, purified pinitol or [2H6]DCI was absorbed from the gastrointestinal tract. Rats chronically on diet 5001 consumed 921 mumol total DCI/kg body weight per d but excreted less than 5.3 % in the stools and urine, suggesting that the bulk was metabolised. The levels of pinitol or DCI in plasma, stools or urine remained relatively stable in mice fed Purina PicoLab Rodent Diet 20 5053 over a 5-week period, whereas these values declined to very low levels in mice fed a pinitol/DCI-deficient chemically defined diet. To test whether DCI was synthesised or converted from myo-inositol, mice were treated with heavy water or [2H6]myo-inositol. DCI was neither synthesised endogenously from 2H-labelled water nor converted from [2H6]myo-inositol. DCI and pinitol in rodents appear to be derived solely from the diet. PMID:19586572

  20. Characteristics associated with contact with rodents in, around, and outside homes in Khon Kaen Province, Thailand.

    PubMed

    Suwannarong, Kanokwan; Chapman, Robert S

    2015-04-01

    Rodents are an important reservoir for zoonotic diseases. To enhance the evidence on the human-rodent interface, this cross-sectional study was conducted in 2011 to investigate characteristics associated with rodent contact in Khon Kaen Province, Thailand. A standardized, interviewer-administered questionnaire elicited information from 201 adults (101 males and 100 females). Overall, 86.6% of participants reported encountering or seeing evidence of rodents in or near the home, whereas 57.2% encountered rodents while working with crops. Encountering rodents in or near the home was positively associated with the number of agricultural activities, whereas encountering rodents during crop work was positively associated with perceiving that disease can be acquired from rodents, the number of food crops grown, the number of agricultural activities, and living in a house with wooden walls. Surprisingly, neither outcome was associated appreciably with gender, age, or setting (urban, forest, or agricultural). These results provide information on the potential risk of rodent-borne zoonoses; this evidence has implications for risk communication strategies in this province and likely elsewhere. PMID:25646260

  1. Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

    PubMed Central

    Mercier, Aurélien; Garba, Madougou; Bonnabau, Henri; Kane, Mamadou; Rossi, Jean-Pierre; Dardé, Marie-Laure; Dobigny, Gauthier

    2013-01-01

    A serological survey of Toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of Niamey, Niger. A low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. However, differences between species were important, ranging from less than 2% in truly commensal Mastomys natalensis, Rattus rattus and Mus musculus, while garden-associated Arvicanthis niloticus displayed 9.1% of seropositive individuals. This is in line with previous studies on tropical rodents - that we reviewed here - which altogether show that Toxoplasma seroprevalence in rodent is highly variable, depending on many factors such as locality and/or species. Moreover, although we were not able to decipher statistically between habitat or species effect, such a contrast between Nile grass rats and the other rodent species points towards a potentially important role of environmental toxoplasmic infection. This would deserve to be further scrutinised since intra-city irrigated cultures are extending in Niamey, thus potentially increasing Toxoplasma circulation in this yet semi-arid region. As far as we are aware of, our study is one of the rare surveys of its kind performed in Sub-Saharan Africa and the first one ever conducted in the Sahel. PMID:23828008

  2. Laboratory Studies of Fundamental Physics Processes in Space Astrophysical Plasmas

    NASA Astrophysics Data System (ADS)

    Yamada, Masaaki

    2003-10-01

    Despite the enormous difference in physical scales, there are striking similarities in the behavior of laboratory and space plasmas. In the recent decade, a fruitful cross fertilization has been initiated between laboratory plasma physicists and space-astrophysicists in multidisciplinary meetings. The advances in laboratory plasma physics, along with the recent surge of space astrophysical data from satellites, have made collaborative research very useful for obtaining new understanding of key space and astrophysical phenomena. The recent rapid advance of numerical simulations has played an important role to bridge laboratory data with space-astrophysical observations. Many common plasma physics mechanisms have been identified in our research fields that study plasma waves, particle acceleration, magnetic reconnection, dynamos, transport and, more generally, plasma's self-organization phenomena. For example, the magnetic reconnection phenomenon is considered to be a key process in the evolution of solar flares, in the dynamics of the earth's magnetosphere and in the formation process of stars. It is also one of the most important self-organization processes in fusion research plasmas. It is crucial for both fields to understand the basic physics of magnetic reconnection. The present talk presents examples of common plasma physics issues which are extensively investigated among laboratory and space astrophysics research. Special focus is put on magnetic self-organization phenomena [1] which include magnetic reconnection [2] and dynamos [3]. During the past decade, many "physics-issue-dedicated" laboratory experiments have been constructed to address the specified physics mechanisms of space-astrophysical phenomena. They can generate fundamental physics processes in a controlled manner and provide well-correlated data of plasma parameters simultaneously at multiple locations. This talk reviews the most recent progress of these dedicated laboratory experiments as well as comparison of the data with space astrophysical observations and numerical simulation results. The talk also covers the goals and principles of the recent new initiatives to attack the common frontier of both laboratory and space astrophysics research. [1] J.B. Taylor, Rev. Modern phys.,vol.58, 741 (1986) [2] M. Yamada, Earth Planets Space, vol.53, 539 (2001) [3] H. Ji and S. Prager, Magnetohydrodynamics, vol.38,191 (2002)

  3. Distant healing intention: definitions and evolving guidelines for laboratory studies.

    PubMed

    Schlitz, Marilyn; Radin, Dean; Malle, Bertram F; Schmidt, Stefan; Utts, Jessica; Yount, Garret L

    2003-01-01

    This paper provides definitions and a discussion of evolving guidelines for conducting research on the effects of distant healing intention (DHI) on living systems in the laboratory. We consider the relevance of DHI laboratory research to applied healing, special theoretical challenges, and other considerations that distinguish DHI research from other domains of laboratory science. Two sample protocols for investigating DHI are provided, one involving the human autonomic nervous system as the "target" of distant intention, and the other involving cell cultures. In essence, DHI differs from other alternative healing modalities because it postulates that mental intention alone can affect living systems at a distance, unbounded by the usual constraints of both space and time. This postulate challenges scientific assumptions that often go unexamined, including the nature of causality, the distinction between subjective and objective states, and the efficacy of double-blind protocols in controlling for experimenters' intentions. Previous laboratory research in this domain suggests that DHI effects warrant serious study, but most scientists and funding agencies are unaware of the evidence or the relevant literature. By following these evolving guidelines, researchers' designs and their ultimate publications will conform more closely to the quality standards expected by scientific journals, and such publications will in turn attract the attention of a broader range of scientists. This seems especially important for alternative healing research in general and for distant healing in particular; both realms enjoy broad public support but have largely eluded serious attention by mainstream science. PMID:12776463

  4. Thieving rodents as substitute dispersers of megafaunal seeds

    PubMed Central

    Jansen, Patrick A.; Hirsch, Ben T.; Emsens, Willem-Jan; Zamora-Gutierrez, Veronica; Wikelski, Martin; Kays, Roland

    2012-01-01

    The Neotropics have many plant species that seem to be adapted for seed dispersal by megafauna that went extinct in the late Pleistocene. Given the crucial importance of seed dispersal for plant persistence, it remains a mystery how these plants have survived more than 10,000 y without their mutualist dispersers. Here we present support for the hypothesis that secondary seed dispersal by scatter-hoarding rodents has facilitated the persistence of these large-seeded species. We used miniature radio transmitters to track the dispersal of reputedly megafaunal seeds by Central American agoutis, which scatter-hoard seeds in shallow caches in the soil throughout the forest. We found that seeds were initially cached at mostly short distances and then quickly dug up again. However, rather than eating the recovered seeds, agoutis continued to move and recache the seeds, up to 36 times. Agoutis dispersed an estimated 35% of seeds for >100 m. An estimated 14% of the cached seeds survived to the next year, when a new fruit crop became available to the rodents. Serial video-monitoring of cached seeds revealed that the stepwise dispersal was caused by agoutis repeatedly stealing and recaching each other’s buried seeds. Although previous studies suggest that rodents are poor dispersers, we demonstrate that communities of rodents can in fact provide highly effective long-distance seed dispersal. Our findings suggest that thieving scatter-hoarding rodents could substitute for extinct megafaunal seed dispersers of tropical large-seeded trees. PMID:22802644

  5. Laboratory Studies on the Role of PAHs as DIB Carriers

    NASA Astrophysics Data System (ADS)

    Huisken, F.; Rouillé, G.; Steglich, M.; Carpentier, Y.; Jäger, C.; Henning, Th.

    2014-02-01

    The electronic spectroscopy of various polycyclic aromatic hydrocarbon (PAH) molecules has been studied in the laboratory at low temperatures using both molecular beam and matrix isolation spectroscopy techniques. While molecular beam spectra can be readily compared to astronomical observations, the band positions measured in Ne and Ar matrices are extrapolated to obtain rather good estimates for the same transitions in the gas phase. Absolute absorption cross sections are determined for gas-phase and matrix spectra by comparing them with calibrated solution spectra. All laboratory results are analyzed and discussed in view of the role that PAHs can play as carriers of the diffuse interstellar bands (DIBs). Our studies suggest that regular neutral PAHs are not responsible for any of the known strong DIBs.

  6. Mycobiota and Ochratoxin A in laboratory mice feed: preliminary study

    Microsoft Academic Search

    Inês Almeida; H. Marina Martins; Marta F. Marques; Salomé Magalhães; Fernando Bernardo

    2010-01-01

    The occurrence of mycotoxin-producing moulds in animal feed is a hazard for animals. When these undesirable substances contaminate\\u000a laboratory animal feed, convey an additional problem in experimental animal assays confidence levels. The aim of this study\\u000a was to evaluate fungal contamination and to determine natural occurrence of Ochratoxin A (OTA) in 31 samples. OTA is a mycotoxin\\u000a produced by fungi

  7. Toxicity studies with Sesbania spp. in domestic and laboratory animals 

    E-print Network

    Whall, Jeffrey DePass

    1982-01-01

    Miscellaneous Phase. Cattle Phase Analysis of Data 15 17 20 21 28 RESULTS 31 Rat Phase. Rabbit Phase Miscellaneous Phase. Cattle Phase 31 33 35 37 DISCUSSION. Toxicity Clinical Syndrome. Lesions. Blood Parameters Laboratory Experiments... Sesbania, were studied for their effects on cattle, rabbits, and rats. LD50 determina- tion was made for these animals, for both species of plant gastric intubation of finely ground seed. In rats the LD&0 for S. vesicaria was calculated to be 1. 09...

  8. Laboratory studies of air stripping of VOC?contaminated soils

    Microsoft Academic Search

    F. H. Shah; H. A. Hadim; G. P. Korfiatis

    1995-01-01

    Bench?scale laboratory experiments were conducted to evaluate the effectiveness of air stripping for in situ remediation of benzene?contaminated soils. Several parametric studies were performed to evaluate the effect of soil grain size, air injection flow rate, and air inlet temperature on the benzene recovery efficiency.An increase in soil grain size produced a significant increase in benzene recovery efficiency especially during

  9. Laboratory aging studies for the HERA-B muon chambers

    Microsoft Academic Search

    M. Danilov; I. Tikhomirov; M. Titov; Yu. Zaitsev

    2002-01-01

    The severe radiation environment of the HERA-B experiment leads to a maximum accumulated charge on a wire, within the muon detector, of 200mC\\/cmwire. For operation in this high-intensity environment, the main criteria for the gas choice turned out to be stability against aging. We report recent results of laboratory aging studies performed by irradiating proportional wire chambers filled with Ar\\/CF4\\/CH4

  10. Design of dietary treatment: humans versus rodents.

    PubMed

    Eagles, Douglas A

    2008-11-01

    Ketogenic diets (KDs) are designed to create the metabolic conditions of fasting, which was among the earliest therapies discovered for epilepsy. The major measures used to evaluate dietary effectiveness have been the levels of urinary ketone bodies and the successful reduction of seizure activity. Modifications of the "classical" animal fat KD have been used in an attempt to boost ketonuria or ketonemia, increase palatability and compliance, and reduce side effects. Studies of KDs in experimental animals have been largely confined to rodents (mice and rats) for reasons of cost and convenience, and both have been found to be protected against experimentally induced seizures following consumption of KDs. Most of these studies have been designed to test hypotheses about the mechanism(s) by which reductions in carbohydrate or increases in fat result in elevated seizure threshold, decreased seizure duration, and decreased seizure severity. So far, underlying mechanisms have proven elusive. Rodent studies have led to a degree of general agreement that ketone levels per se do not correlate well with seizure protection, that reduction of glucose levels is fundamentally important, and that calorie restriction is additive to high fat diets in providing seizure protection. PMID:19049590

  11. In Vivo Rodent Micronucleus Assay

    Microsoft Academic Search

    Makoto Hayashi

    Genotoxicity plays an important role for the safety evaluation of chemicals. Chromosomal aberration is one of two major end\\u000a points of genotoxicity. The rodent haematopoietic cell micronucleus assay is most widely used as an in vivo test to evaluate\\u000a structural and numerical chromosomal aberrations. The historical aspects of the development of the in vivo micronucleus test,\\u000a the mechanism of micronucleus

  12. Antenatal maternal hypoxia: criterion for fetal growth restriction in rodents

    PubMed Central

    Jang, Eeun Amy; Longo, Lawrence D.; Goyal, Ravi

    2015-01-01

    Rodents are a useful model for life science research. Accumulating evidence suggests that the offspring of mice and rats suffer from similar disorders as humans when exposed to hypoxia during pregnancy. Importantly, with antenatal hypoxic exposure, human neonates demonstrate low birth weight or growth restriction. Similarly, with antenatal hypoxic exposure rodents also demonstrate the fetal growth restriction (FGR). Surprisingly, there is no consensus on the minimum duration or degree of hypoxic exposure required to cause FGR in rodents. Thus, we have reviewed the available literature in an attempt to answer these questions. Based on studies in rats, birth weight reduction of 31% corresponded to 10th percentile reduction in birth weight curve. With the similar criterion (10th percentile), in mice 3 days or more and in rats 7 days or more of 14% or lower hypoxia administration was required to produce statistically significant FGR.

  13. Anatomy and Histology of Rodent and Human Major Salivary Glands

    PubMed Central

    Amano, Osamu; Mizobe, Kenichi; Bando, Yasuhiko; Sakiyama, Koji

    2012-01-01

    Major salivary glands of both humans and rodents consist of three pairs of macroscopic glands: parotid, submandibular, and sublingual. These glands secrete serous, mucous or mixed saliva via the proper main excretory ducts connecting the glandular bodies with the oral cavity. A series of discoveries about the salivary ducts in the 17th century by Niels Stensen (1638–1686), Thomas Wharton (1614–1673), and Caspar Bartholin (1655–1738) established the concept of exocrine secretion as well as salivary glands. Recent investigations have revealed the endocrine functions of parotin and a variety of cell growth factors produced by salivary glands. The present review aims to describe macroscopic findings on the major salivary glands of rodents and the microscopic differences between those of humans and rodents, which review should be of interest to those researchers studying salivary glands. PMID:23209333

  14. Can shrub cover increase predation risk for a desert rodent?

    USGS Publications Warehouse

    Schooley, R.L.; Sharpe, Peter B.

    1996-01-01

    Previous research indicates that predation risk may influence activity patterns, habitat partitioning, and community structure of nocturnal desert rodents. Shrub microhabitat is typically considered safer than open microhabitat for these small mammals. We investigated predation risk for Townsend's ground squirrels (Spermophilus townsendii), which are diurnal desert rodents that detect predators visually and use burrows for refuge. Our results suggested that shrub cover may increase risk for these squirrels by decreasing their ability to escape from predators. Our field experiment indicated that running speeds of juvenile squirrels were lower in shrub (Ceratoides lanata) habitat than in open areas. Shrub cover was also associated with shorter predator-detection distances (mammalian and avian) and fewer refuges (burrow entrances per hectare) than in open areas in one year but not in another. Our study demonstrated that the visual and locomotive obstruction of vegetative cover may increase predation risk for diurnal desert rodents and that elements of habitat-dependent risk may be temporally dynamic.

  15. Teasing Apart the Effects of Seed Size and Energy Content on Rodent Scatter-Hoarding Behavior

    PubMed Central

    Wang, Bo; Yang, Xiaolan

    2014-01-01

    Scatter-hoarding rodents are known to play a crucial role in the seed dispersal of many plant species. Numerous studies have indicated that both seed size and the energy content of seeds can affect rodent foraging behavior. However, seed size is usually associated with energy content per seed, making it difficult to isolate how seed size and energy affect rodent foraging preferences. This study used 99 treatments of artificial seeds (11 seed sizes×9 levels of energy content) to tease apart the effect of seed size and energy content on rodent seed-caching behavior. Both seed traits showed significant effects, but their details depended on the stage of the rodent foraging process. Seeds with higher energy content were harvested more rapidly while seed size only had a modest effect on harvest rate. However, after harvesting, seed size showed a much stronger effect on rodent foraging behavior. Rodents’ choice of which seeds to remove and cache, as well as seed dispersal distance, seemed to reflect an optimal seed size. Our findings could be adapted in future studies to gain a better understanding of scatter-hoarding rodent foraging behavior, and the co-evolutionary dynamics between plant seed production and seed dispersers. PMID:25350369

  16. Comparison of the potency of three Brazilian Bothrops antivenoms using in vivo rodent and in vitro assays. BIASG (Butantan Institute Antivenom Study Group).

    PubMed

    Laing, G D; Theakston, R D; Leite, R P; da Silva, W D; Warrell, D A

    1992-10-01

    Three Brazilian polyspecific Bothrops antivenoms were compared using standard W.H.O. rodent in vivo and in vitro assays of their ability to neutralize the principal venom activities of pooled whole Bothrops jararaca venom. On a volume basis, the antivenoms were equally effective in neutralizing lethal activity in mice, and there were only minor differences in their ability to neutralize venom-induced haemorrhage, necrosis and procoagulant activity. Antivenom efficacy in neutralizing defibrinogenation varied. However, when equal amounts of antivenom IgG were compared, it was found that the FUNED antivenom best neutralized lethality, haemorrhage, necrosis and fibrinogen clotting activity. Vital Brazil and FUNED antivenoms were equally effective in neutralizing plasma coagulant activity but Vital Brazil antivenom was the more effective in neutralizing defibrinogenation. PMID:1440628

  17. Synanthropic rodents as possible reservoirs of shigatoxigenic Escherichia coli strains

    PubMed Central

    Blanco Crivelli, Ximena; Rumi, María V.; Carfagnini, Julio C.; Degregorio, Osvaldo; Bentancor, Adriana B.

    2012-01-01

    Shigatoxigenic Escherichia coli (STEC) strains are worldwide zoonotic pathogen responsible for different cases of human disease including hemolytic uremic syndrome (HUS). Transmission of STEC to humans occurs through the consumption of food and water contaminated by faeces of carriers and by person-to-person contact. The objective of this study was two-fold: (1) to investigate whether synanthropic rodents are possible reservoirs of STEC in the urban area and (2) whether a particular genus out of synanthropic rodent is the principal carrier of STEC. One hundred and forty-five rodents were captured in Buenos Aires City. Screening for stx1/stx2 and rfbO157 was done by PCR from the confluence zone. STEC isolates were further characterized with biochemical tests by standard methods. Additional virulence factors (eae, ehxA, and saa) were also determined by PCR. Forty-one of the rodents were necropsied and sample of kidney and small and large intestine were taken for histopathological diagnosis. The samples sections were stained with hematoxylin-eosin, and observed by light microscopy to evaluate the systemic involvement of these species in natural infections. STEC was isolated from seven out of 27 suspect animals at screening. The following genotypes were found in the STEC strains: stx1/stx2/ehxA (1), stx2 (4), stx2/ehxA (1), stx2/ehxA/eae (1). Neither gross nor microscopic lesions compatible with those produced by Shiga toxin were observed in the studied organs of necropsied rodents. The bivariate analysis including the 145 rodent's data showed that the isolation of STEC is associated positively to Rattus genus. This synanthropic species may play a role in the transmissibility of the agent thus being a risk to the susceptible population. Their control should be included specifically in actions to dismiss the contamination of food and water by STEC in the urban area, as additional strategies for epidemiological control. PMID:23125967

  18. Molecular evolution of the nuclear von Willebrand factor gene in mammals and the phylogeny of rodents.

    PubMed

    Huchon, D; Catzeflis, F M; Douzery, E J

    1999-05-01

    Nucleotide sequences of exon 28 of the von Willebrand Factor (vWF) were analyzed for a representative sampling of rodent families and eutherian orders, with one marsupial sequence as outgroup. The aim of this study was to test if inclusion of an increased taxonomic diversity in molecular analyses would shed light on three uncertainties concerning rodent phylogeny: (1) relationships between rodent families, (2) Rodentia monophyly, and (3) the sister group relationship of rodents and lagomorphs. The results did not give evidence of any particular rodent pattern of molecular evolution relative to a general eutherian pattern. Base compositions and rates of evolution of vWF sequences of rodents were in the range of placental variation. The 10 rodent families studied here cluster in five clades: Hystricognathi, Sciuridae and Aplodontidae (Sciuroidea), Muridae, Dipodidae, and Gliridae. Among hystricognaths, the following conclusions are drawn: a single colonization event in South America by Caviomorpha, a paraphyly of Old World and New World porcupines, and an African origin for Old World porcupines. Despite a broader taxonomic sampling diversity, we did not obtain a robust answer to the question of Rodentia monophyly, but in the absence of any other alternative, we cannot reject the hypothesis of a single origin of rodents. Moreover, the phylogenetic position of Lagomorpha remains totally unsettled. PMID:10335651

  19. Prospects for biological control of rodent populations*

    PubMed Central

    Wodzicki, Kazimierz

    1973-01-01

    Pathogens and predatory animals are the main agents used for the biological control of rodents. The pathogens that have been used are of the genus Salmonella; none is rodent-specific and all can cause severe infection in man and domestic animals. Furthermore, rodents frequently develop immunity to, and become carriers of, these organisms, and there is little to commend their use, except in lightly populated areas where control is infrequently applied. The relationships of five predator species with their rodent prey have been examined. The monitor lizard, mongoose, and ferret were for different reasons found to be unsatisfactory, and there is not yet sufficient evidence to warrant further releases of the Japanese weasel. Domestic and feral cats control rodents well in some situations but only after some other agent has removed a large part of the rodent population. PMID:4587482

  20. The AIN-76A defined rodent diet accelerates the development of heart failure in SHHF rats: a cautionary note on its use in cardiac studies.

    PubMed

    Rees, M L; Gioscia-Ryan, R A; McCune, S A; Browder, J C; Zachman, D K; Chicco, A J; Johnson, C A; Murphy, R C; Moore, R L; Sparagna, G C

    2014-02-01

    Previous studies from our laboratory have shown positive benefits of linoleic acid (LA) feeding for attenuation of rat heart failure (HF). However, another research group concluded LA feeding was detrimental to cardiac function, using the American Institute of Nutrition 76A (AIN) diet as a background diet for the experimental animals only. To reconcile these conflicting results and determine whether (i) AIN has effects on cardiovascular function, and (ii) AIN reverses the positive effects of LA feeding, studies were performed using spontaneously hypertensive heart failure (SHHF) rats in both a survival study with lifetime feeding of AIN (control: Purina 5001) and a 2 × 2 factorial design for 6 weeks in young male SHHF rats with background diet and LA as variables. During a lifetime of AIN feeding, mortality from heart failure is significantly accelerated, cardiolipin altered and triglycerides increased. In young rats, 6 weeks on the AIN diet promoted increased systolic and diastolic blood pressure, increased fed and fasting blood glucose, increased serum inflammatory eicosanoids, decreased docosahexanoic acid, increased posterior wall thickness in diastole and an altered cardiolipin subspecies profile. The addition of LA to the AIN diet was able to rescue blood pressure. However, the combination increased retroperitoneal fat mass, body weight and fed blood glucose beyond the levels with the AIN diet alone. Because the AIN diet has wide ranging effects on cardiovascular parameters, our results suggest that it should not be used in animal studies involving the cardiovascular system unless induction of cardiac dysfunction is the desired outcome. PMID:23298172

  1. Pet Rodents and Fatal Lymphocytic Choriomeningitis in Transplant Patients

    PubMed Central

    Pavlin, Boris I.; Albariño, Cesar G.; Comer, James A.; Erickson, Bobbie R.; Oliver, Jennifer B.; Sealy, Tara K.; Vincent, Martin J.; Nichol, Stuart T.; Paddock, Christopher D.; Tumpey, Abbigail J.; Wagoner, Kent D.; Glauer, R. David; Smith, Kathleen A.; Winpisinger, Kim A.; Parsely, Melody S.; Wyrick, Phil; Hannafin, Christopher H.; Bandy, Utpala; Zaki, Sherif; Rollin, Pierre E.; Ksiazek, Thomas G.

    2007-01-01

    In April 2005, 4 transplant recipients became ill after receiving organs infected with lymphocytic choriomeningitis virus (LCMV); 3 subsequently died. All organs came from a donor who had been exposed to a hamster infected with LCMV. The hamster was traced back through a Rhode Island pet store to a distribution center in Ohio, and more LCMV-infected hamsters were discovered in both. Rodents from the Ohio facility and its parent facility in Arkansas were tested for the same LCMV strain as the 1 involved in the transplant-associated deaths. Phylogenetic analysis of virus sequences linked the rodents from the Ohio facility to the Rhode Island pet store, the index hamster, and the transplant recipients. This report details the animal traceback and the supporting laboratory investigations. PMID:17553250

  2. Susceptibility of selected rodent species from Colorado to Borrelia burgdorferi.

    PubMed

    Ubico, S R; McLean, R G; Cooksey, L M

    1996-04-01

    To determine the susceptibility of some common Colorado (USA) rodent species to Borrelia burgdorferi, pregnant Peromyscus maniculatus, Tamias minimus, and Spermophilus lateralis were trapped in May 1990 and kept in quarantine until their young were old enough to be used in the experiment. Six to eight 8-wk-old individuals of each of the Colorado species and, for comparison, eight laboratory raised P. leucopus were subcutaneously inoculated with > or = 10(5) spirochetes in 0.1 ml in July 1990. Tissue specimens were collected for isolation from these animals through April 1991. Spirochetes were isolated from blood, ear, bladder, kidney, spleen, liver, and eye in Barbour-Stoener-Kelly (BSK) medium from P. maniculatus, P. leucopus and T. minimus. Spirochetes were isolated from at least one tissue from all of these animals and no isolations were obtained from any of the S. lateralis. Thus, three of the four rodent species tested are susceptible to, and could harbor, B. burgdorferi. PMID:8722268

  3. Variable effects of cyclophosphamide in rodent models of experimental allergic encephalomyelitis

    PubMed Central

    Mangano, K; Nicoletti, A; Patti, F; Donia, M; Malaguarnera, L; Signorelli, S; Magro, G; Muzio, V; Greco, B; Zaratin, P; Meroni, P; Zappia, M; Nicoletti, F

    2010-01-01

    In this study, we have evaluated the effects of cyclophosphamide on the development of experimental allergic encephalomyelitis (EAE) in four EAE rodent models: monophasic EAE in Lewis rats, protracted relapsing (PR)-EAE in DA rats, myelin oligodendrocyte protein (MOG)-induced EAE in C57Bl/6 mice and proteolipid protein (PLP)-induced EAE in Swiss/Jackson Laboratory (SJL) mice. Cyclophosphamide, administered either prophylactically or therapeutically, suppressed most strongly the clinical symptoms of PR-EAE in DA rats. Treated rats in this group also exhibited the lowest degree of inflammatory infiltration of the spinal cord, as well as the lowest levels of nuclear factor kappa B, interleukin-12 and interferon-gamma. Cyclophosphamide prophylactically, but not therapeutically, also delayed significantly the onset of EAE in Lewis rats. In contrast, regardless of the treatment regimen used, was unable to influence the clinical course of EAE in either MOG-induced EAE in C57Bl/6 mice or PLP-induced EAE in SJL mice. This heterogeneous pharmacological response to cyclophosphamide suggests that significant immunopathogenic differences exist among these EAE rodent models that must be considered when designing preclinical studies. In addition, the effectiveness of cyclophosphamide in dark Agouti (DA) rats with PR-EAE suggests that this may be a particularly useful model for studying novel therapeutic approaches for refractory and rapidly worsening multiple sclerosis in human patients. PMID:19922500

  4. Prediction of rodent carcinogenicity for 30 chemicals.

    PubMed Central

    Ashby, J

    1996-01-01

    Predictions of carcinogenic activity are made for 30 chemicals currently being assessed for rodent carcinogenicity by the U.S. National Toxicology Program. The predictions are based upon the chemical structure, the anticipated or reported mutagenicity, and the reported sub-chronic toxicity of each chemical. It is predicted that 13 chemicals will be noncarcinogenic to rodents, that 7 will be genotoxic carcinogens, and that 10 may show some evidence of presumed nongenotoxic rodent carcinogenesis. PMID:8933060

  5. The use of a running wheel to measure activity in rodents: Relationship to energy balance, general activity, and reward

    PubMed Central

    Levine, James A.

    2015-01-01

    Running wheels are commonly employed to measure rodent physical activity in a variety of contexts, including studies of energy balance and obesity. There is no consensus on the nature of wheel-running activity or its underlying causes, however. Here, we will begin by systematically reviewing how running wheel availability affects physical activity and other aspects of energy balance in laboratory rodents. While wheel running and physical activity in the absence of a wheel commonly correlate in a general sense, in many specific aspects the two do not correspond. In fact, the presence of running wheels alters several aspects of energy balance, including body weight and composition, food intake, and energy expenditure of activity. We contend that wheel-running activity should be considered a behavior in and of itself, reflecting several underlying behavioral processes in addition to a rodent's general, spontaneous activity. These behavioral processes include defensive behavior, predatory aggression, and depression- and anxiety-like behaviors. As it relates to energy balance, wheel running engages several brain systems—including those related to the stress response, mood, and reward, and those responsive to growth factors—that influence energy balance indirectly. We contend that wheel-running behavior represents factors in addition to rodents' tendency to be physically active, engaging additional neural and physiological mechanisms which can then independently alter energy balance and behavior. Given the impact of wheel-running behavior on numerous overlapping systems that influence behavior and physiology, this review outlines the need for careful design and interpretation of studies that utilize running wheels as a means for exercise or as a measurement of general physical activity. PMID:22230703

  6. Geographic variation in rodent-flea relationships in the presence of black-tailed prairie dog colonies.

    PubMed

    Thiagarajan, Bala; Cully, Jack F; Loughin, Thomas M; Montenieri, John A; Gage, Kenneth L

    2008-06-01

    We characterized the relationship between fleas and their rodent hosts in the presence of prairie dog colonies and compared them to adjacent assemblages away from colonies. We evaluated the rodent-flea relationship by quantifying prevalence, probability of infestation, flea load, and intensity of fleas on rodents. As prairie dog burrows provide refugia for fleas, we hypothesized that prevalence, flea load, and intensity would be higher for rodents that are associated with black-tailed prairie dog colonies. Rodents were trapped at off- and on-colony grids, resulting in the collection of 4,509 fleas from 1,430 rodents in six study areas. The rodent community composition varied between these study areas. Flea species richness was not different between prairie dog colonies and the surrounding grasslands (p = 0.883) but was positively correlated with rodent species richness (p = 0.055). Prairie dog colonies did not increase the prevalence of fleas (p > 0.10). Flea loads on rodents did not vary between off- and on-colony grids at three of the study areas (p > 0.10). Based on the prevalence, infestation rates, and flea loads, we identified Peromyscus maniculatus, Onychomys leucogaster, and two Neotoma species as important rodent hosts for fleas and Aetheca wagneri, Orchopeus leucopus, Peromyscopsylla hesperomys, Pleochaetis exilis, and Thrassisfotus as the most important fleas associated with these rodents. Prairie dog colonies did not seem to facilitate transmission of fleas between rodent hosts, and the few rodent-flea associations exhibited significant differences between off- and on-colony grids. PMID:18697322

  7. Diversity of gastrointestinal helminths among murid rodents from northern and northeastern Thailand.

    PubMed

    Chaisiri, Kittipong; Chaeychomsri, Win; Siruntawineti, Jindawan; Ribas, Alexis; Herbreteau, Vincent; Morand, Serge

    2012-01-01

    The presence of gastrointestinal helminths (GI helminths) was investigated among 725 murid rodents, trapped in various habitats of Nan, Loei and Buri Ram Provinces, Thailand. The study revealed 17 species of rodents infected with 21 species or taxonomic groups of parasites (3 trematodes, 3 cestodes, 14 nematodes and 1 acanthocephalan). The overall prevalence of infection was 57.7% (418/725). Of the gastrointestinal (GI) helminths, the dominant parasitic group was members of the family Trichostrongylidae (24.3%), followed by the cestodes Raillietina sp (17.1%) and Hymenolepis diminuta (8.6%) and the nematode Syphacia muris (8.6%). The GI helminthic infection rates were highest in Mus caroli (81.8%), Mus cervicolor (76.5%), Leopoldamys edwardsi (75.0%), Bandicota indica (71.5%) and Bandicota savilei (71.4%). Highest rodent species richness (RSR) and helminth species richness (HSR) rates were found in Loei, followed by Nan and Buri Ram. The helminth prevalence rate was higher in rodents from Nan, followed by rodents from Loei and Buri Ram. Rodents from irrigated fields had the highest infection rates followed by rodents from upland or dry agricultural areas, forests and domestic habitats. Raillietina sp, Rodentolepis nana (syn. Hymenolepis nana), Hymenolepis diminuta, Moniliformis moniliformis and Cyclodontostomum purvisi, considered zoonotic parasites, were mainly found in rodents from domestic habitats and lowland irrigated fields. PMID:23082550

  8. Factors determining the abundance and distribution of rodents in a shrub-steppe ecosystem: the role of shrubs

    Microsoft Academic Search

    Robert R. Parmenter; James A. MacMahon

    1983-01-01

    This study addressed the relative importances of shrub “resources” on a rodent community in a sagebrush dominated shrub-steppe ecosystem in southwestern Wyoming. Direct effects of shrubs (i.e., providing rodents with “food and cover”) were assessed by removing shrubs from a 1.25 ha study plot and monitoring both rodent populations and their food resources. Shrub architecture and shrub-related food resources were

  9. COMPLEMENTARITY OF GENOTOXIC AND NONGENOTOXIC PREDICTORS OF RODENT CARCINOGENICITY

    EPA Science Inventory

    Twenty-one chemicals known to be carcinogenic in rodent bioassays were selected for study. he chemicals were administered by gavage in two dose levels to female Sprague-Dawley rats. he effects of these 21 chemicals on four biochemical assays (hepatic DNA damage by alkaline elutio...

  10. OPPOSING EFFECTS OF DHEA REPLACEMENT IN ELDERLY SUBJECTS ON DECLARATIVE MEMORY AND ATTENTION AFTER EXPOSURE TO A LABORATORY STRESSOR

    Microsoft Academic Search

    Oliver T. Wolf; Brigitte M. Kudielka; Dirk H. Hellhammer; Juliane Hellhammer; Clemens Kirschbaum

    1998-01-01

    Aging is accompanied by a continuous decline of the adrenal steroid hormone DHEA and its ester DHEAS. Results from studies in rodents have demonstrated that DHEA(S) administration can enhance memory in several test paradigms. However studies from this laboratory did not find positive effects of DHEA treatment on cognitive performance in young and elderly humans. With respect to a possible

  11. Neutrino Nuclear Responses for Neutrino Studies in Nuclear Femto Laboratories

    SciTech Connect

    Ejiri, Hiroyasu [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Nuclear Science, Czech Technical University, Brehova, Prague (Czech Republic)

    2010-11-24

    Fundamental properties of neutrinos and neutrino nuclear interactions are of great interest from particle and astro-nuclear physics view points. They are well studied in nuclear femto laboratories, where neutrino nuclear responses are crucial. Neutrino masses and neutrino natures are studied by neutrino-less double beta decays (0{nu}{beta}{beta}) in nuclei. Here neutrino nuclear responses are required to extract neutrino properties from 0{nu}{beta}{beta} rates. Neutrino nuclear responses are sensitive to nuclear spin isospin correlations and nuclear structures. They are experimentally studied by nuclear probes for charge exchange nuclear reactions, photon EM probes for photo-nuclear reactions, and lepton probes for muon and neutrino capture reactions.

  12. Clinical Laboratory Stressors Used to Study Alcohol–Stress Relationships

    PubMed Central

    Thomas, Suzanne; Bacon, Amy K.; Sinha, Rajita; Uhart, Magdalena; Adinoff, Bryon

    2012-01-01

    Understanding the biologic systems that underlie the relationship between stress and alcohol consumption may lead to better prevention efforts and more effective treatments for alcoholism. Clinical laboratory studies offer a unique opportunity to examine these relationships by using a controlled environment to study how an acute stressor affects alcohol drinking and alcohol craving, how individuals in recovery or those at risk for alcoholism may respond differently to stressors relative to control subjects, and how alcohol differentially affects stress reactivity in these groups. This article reviews some of the most common physical, psychological, and pharmacological stressors used in stress-induction studies designed to reveal details about the relationship between stress reactivity and alcohol use and abuse. PMID:23584112

  13. Robust reproducible resting state networks in the awake rodent brain.

    PubMed

    Becerra, Lino; Pendse, Gautam; Chang, Pei-Ching; Bishop, James; Borsook, David

    2011-01-01

    Resting state networks (RSNs) have been studied extensively with functional MRI in humans in health and disease to reflect brain function in the un-stimulated state as well as reveal how the brain is altered with disease. Rodent models of disease have been used comprehensively to understand the biology of the disease as well as in the development of new therapies. RSN reported studies in rodents, however, are few, and most studies are performed with anesthetized rodents that might alter networks and differ from their non-anesthetized state. Acquiring RSN data in the awake rodent avoids the issues of anesthesia effects on brain function. Using high field fMRI we determined RSNs in awake rats using an independent component analysis (ICA) approach, however, ICA analysis can produce a large number of components, some with biological relevance (networks). We further have applied a novel method to determine networks that are robust and reproducible among all the components found with ICA. This analysis indicates that 7 networks are robust and reproducible in the rat and their putative role is discussed. PMID:22028788

  14. Laboratory combustion tube studies. Part II. Report SUPRI TR-10

    SciTech Connect

    Brigham, W.E.; Fassihi, M.R.; Satman, A.; Williams, R.L.; Pettit, P.; Grim, J.; Ramey, H.J. Jr.

    1981-03-01

    To promote a better understanding of the problems and mechanisms involved in dry in-situ combustion of crude oils in porous media, continuing laboratory studies are carried out at SUPRI. The report about the first two experiments was submitted earlier to the Department of Energy. This report describes the results of the last three tube runs. Three laboratory combustion tube studies were made with unconsolidated core material, and Lombardi Zone crude oil from the San Ardo field, California. After preparation, the material was packed into the combustion tube. Conditions employed during the steady burning phase of each run were about constant. Injection pressure for all of them was 100 Psig (6.8 Atm.). Burning front velocities ranged from 7.22 cm/hr (5.68 ft/day) to 12.96 cm/hr (10.2 ft/day) while the stream front velocities ranged from 10.4 cm/hr to 13.48 cm/hr. The air flux was between 88.33 SCF/hr-ft/sup 2/ and 122.7SCF/hr-ft/sup 2/. Observed fuel ration ranged from 162.54 SCF/lb to 169.33 SCF/lb of fuel burned. The detailed analysis of these experiments accompanied with their field application will be presented later.

  15. Rodent Control: Seal Up! Trap Up! Clean Up!

    MedlinePLUS

    ... successfully trapping rodents in and around the home. Seal Up! Seal up holes inside and outside the home to ... infested areas. Before cleaning, trap the rodents and seal up any entryways to ensure that no rodents ...

  16. Assessment of the use of selected rodents in ecological monitoring

    NASA Astrophysics Data System (ADS)

    Douglass, Richard J.

    1989-05-01

    Rodents can be useful in detecting environmental impacts because they are easy to study (easy to capture and handle), they can occur in densities adequate for statistical analysis, and they are ecologically important. In this study the usefulness of rodent populations for ecological monitoring was investigated by examining the effect of variation on the possibility of detecting differences among populations of rodents on 10 trapping grids. The effects of sampling frequencies and dispersal on detecting differences in population parameters among grids was also investigated, as was the possibility of inferring population parameters from correlations with habitat data. Statistically significant differences as small as 4.3 Peromyscus maniculatus/ha were detected between grids. Of 10 populations, this comprised 12% of the highest-density population and 44% of the lowest-density population. Smaller and more differences among grids were found by examining only animals surviving from previous months. Dispersal confounds detection of direct impacts to populations, especially during the breeding season. Infrequent sampling fails to detect impacts that occur between sampling periods and will indicate impacts when observed changes result from natural variation. Correlations between population parameters and habitat variables exist but should only be used in predicting, not measuring, impacts. It is concluded that some rodent populations can be used in ecological monitoring. However, intensive sampling is required to account for variation and dispersal.

  17. Laboratory Study of Angular Momentum Transport in Astrophysical Accretion Disks

    NASA Astrophysics Data System (ADS)

    Ji, Hantao

    2014-10-01

    Studying astrophysical processes in the lab becomes increasingly possible and exciting, as one of Stirling's favorite subjects throughout his scientific career. In this talk, I will describe experimental efforts to study mechanisms of rapid angular momentum transport required to occur in accretion disks to explain a wide range of phenomena from star formation, energetic activity of cataclysmic variables, to powering quasars, the most luminous steady sources in the Universe. By carefully isolating effects due to artificial boundaries, which are inherent to terrestrial experiments, certain astrophysical questions regarding hydrodynamic and magnetohydrodynamic stabilities are being addressed in the laboratory. Inspirations from Stirling as well as scientific exchanges with him will be mentioned during this talk as part of my scientific journey on this subject.

  18. Laboratory Studies of Ice Nucleation on Volcanic Ash

    NASA Astrophysics Data System (ADS)

    Tolbert, M. A.; Schill, G. P.; Genareau, K. D.

    2014-12-01

    Ice nucleation on volcanic ash controls both ash aggregation and cloud glaciation, which affect human respiratory health, atmospheric transport, and global climate. We have performed laboratory studies of the depositional and immersion freezing efficiency of three distinct samples of volcanic ash using Raman Microscopy coupled to an environmental cell. Ash from the Fuego (Basaltic Ash, Guatemala), Soufriere Hills (Andesetic Ash, Montserrat), and Taupo (Rhyolitic Ash, New Zealand) volcanoes were chosen to represent different geographical locations and silica content. All ash samples were quantitatively analyzed for both percent crystallinity and mineralogy using X-ray diffraction. We find that all three samples of volcanic ash are excellent depositional ice nuclei, nucleating ice at ice saturation ratios of 1.05 ± 0.1. For immersion freezing, however, only the Taupo ash exhibited efficient heterogeneous ice nucleation activity. Similar to recent studies on mineral dust, we suggest that the mineralogy of volcanic ash may dictate its ice nucleation activity in the immersion mode.

  19. Rorschach measures of aggression: a laboratory-based validity study.

    PubMed

    Kivisto, Aaron J; Swan, Scott A

    2013-01-01

    This study sought to complement the archival research designs that have established the empirical foundations of Rorschach aggression scores, including Exner's ( 2003 ) Aggressive Movement (AG) score and Meloy and Gacono's ( 1992 ) Aggressive Content (AgC), Aggressive Past (AgPast), and Aggressive Potential (AgPot) variables. Utilizing a highly controlled laboratory-based aggression paradigm and self-report measures of violence history in a sample of 35 undergraduate males with an average age of 19.38 (SD = 2.11), this study found that only AgC was positively associated with in vivo aggression (r = .40, p = .02). None of the Rorschach measures of aggression were significantly associated with self-reported violence history, although there were several trends approaching significance. Theoretical and methodological implications are discussed. PMID:22906090

  20. Laboratory studies of actinide partitioning relevant to 244Pu chronometry

    NASA Technical Reports Server (NTRS)

    Benjamin, T.; Heuser, W. R.; Burnett, D. S.

    1978-01-01

    Actinide partitioning and light lanthanide fractionation have been studied to gain an understanding of Pu chemistry under meteoritic and lunar conditions. The goal of the study was to identify conditions and samples from which chronological information can be retrieved. The laboratory investigations involved particle track radiography of the crystal/liquid partitioning of Th, U and Pu among diopsidic clinopyroxene, whitlockite and liquid. It is found that trivalent Pu plays an important role in partitioning for lunar and most meteoritic conditions. The use of Pu/Nd for relative age assessments is supported to some extent by the investigations; samples with unfractionated U, Th and Nd abundances (relative to average solar system values) may be suitable for Pu chronometry.

  1. Coupled laboratory and numerical studies of impacts into planetary regolith

    NASA Astrophysics Data System (ADS)

    Dove, A.; Li, Y.; Curtis, J.; Colwell, J. E.

    2014-12-01

    We present the initial results from coupled experimental and numerical study of the response of particles to low-velocity impacts. In this study, laboratory experiments are used to validate and tune a new DEM capable of handling complex particle shapes for simulation of the behavior of planetary regolith. These studies have fundamental applications to granular material science, as well as broader applications to the response to low-energy impacts of surface layers on other planetary bodies, including planetesimals, asteroids, small moons, and planetary ring particles. Knowledge of the velocities and mass distributions of dust knocked off of planetary surfaces is necessary to understand the evolution of the upper layers of the soil, the plasma environment, and to develop mitigation strategies for transported dust. In addition, the fine particles in the regolith pose an engineering and safety hazard for equipment, experiments, and astronauts working in severe environments. Our laboratory experiments consist of impacting a spherical impactor into a bed of particles and tracking the subsequent mass loss and trajectories of the ejected particles. We begin with spherical particles and then we will expand to elongated rods, flake-like particles, and well-characterized aggregates. Complementary discrete element method (DEM) simulations are validated by these experimental studies; in the DEM simulations, the non-spherical nature of these particles will be described using a glued-sphere approach. An initial comparison between the particle ejection velocities observed in the experiments and simulations for spherical particles is shown in the figure. Discrepancies at low velocities are due to the fact that the trajectories of particles with such low ejection speeds are not observable in this setup. The simulations will then be used to gain physical insight and to evaluate a broader range of scenarios than can be easily explored experimentally, such as conditions similar to those present on lunar or small-body surfaces.

  2. Mathematical Models for Hantavirus Infection in Rodents

    Microsoft Academic Search

    Linda J. S. Allen; Robert K. McCormack; Colleen B. Jonsson

    2006-01-01

    Hantavirus pulmonary syndrome is an emerging disease of humans that is carried by wild rodents. Humans are usually exposed to the virus through geographically isolated outbreaks. The driving forces behind these outbreaks is poorly understood. Certainly, one key driver of the emergence of these viruses is the virus population dynamics within the rodent population. Two new mathematical models for hantavirus

  3. CONTROLLING RODENTS IN COMMERCIAL POULTRY FACILITIES

    E-print Network

    Ginzel, Matthew

    CONTROLLING RODENTS IN COMMERCIAL POULTRY FACILITIES Judy Loven, Animal Damage Management and Ralph in and around livestock and farm facilities. Enclosed and insulated commercial poultry facilities provide ideal problems to a poultry manager. Rodents consume and contaminate feed, gnaw on struc- tural, mechanical

  4. Rodents as agents of ecological change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rodents have the potential to exert a wide array of ecological pressures in any given ecosystem. The negative impacts to plant communities in general, especially cultivated crops, are typically cited as examples of rodent grazing pressure. Considerable research has been conducted on the negative imp...

  5. Interactions between multiple helminths and the gut microbiota in wild rodents.

    PubMed

    Kreisinger, Jakub; Bastien, Géraldine; Hauffe, Heidi C; Marchesi, Julian; Perkins, Sarah E

    2015-08-19

    The gut microbiota is vital to host health and, as such, it is important to elucidate the mechanisms altering its composition and diversity. Intestinal helminths are host immunomodulators and have evolved both temporally and spatially in close association with the gut microbiota, resulting in potential mechanistic interplay. Host-helminth and host-microbiota interactions are comparatively well-examined, unlike microbiota-helminth relationships, which typically focus on experimental infection with a single helminth species in laboratory animals. Here, in addition to a review of the literature on helminth-microbiota interactions, we examined empirically the association between microbiota diversity and composition and natural infection of multiple helminth species in wild mice (Apodemus flavicollis), using 16S rRNA gene catalogues (metataxonomics). In general, helminth presence is linked with high microbiota diversity, which may confer health benefits to the host. Within our wild rodent system variation in the composition and abundance of gut microbial taxa associated with helminths was specific to each helminth species and occurred both up- and downstream of a given helminth's niche (gut position). The most pronounced helminth-microbiota association was between the presence of tapeworms in the small intestine and increased S24-7 (Bacteroidetes) family in the stomach. Helminths clearly have the potential to alter gut homeostasis. Free-living rodents with a diverse helminth community offer a useful model system that enables both correlative (this study) and manipulative inference to elucidate helminth-microbiota interactions. PMID:26150661

  6. Rodent Models for Metabolic Syndrome Research

    PubMed Central

    Panchal, Sunil K.; Brown, Lindsay

    2011-01-01

    Rodents are widely used to mimic human diseases to improve understanding of the causes and progression of disease symptoms and to test potential therapeutic interventions. Chronic diseases such as obesity, diabetes and hypertension, together known as the metabolic syndrome, are causing increasing morbidity and mortality. To control these diseases, research in rodent models that closely mimic the changes in humans is essential. This review will examine the adequacy of the many rodent models of metabolic syndrome to mimic the causes and progression of the disease in humans. The primary criterion will be whether a rodent model initiates all of the signs, especially obesity, diabetes, hypertension and dysfunction of the heart, blood vessels, liver and kidney, primarily by diet since these are the diet-induced signs in humans with metabolic syndrome. We conclude that the model that comes closest to fulfilling this criterion is the high carbohydrate, high fat-fed male rodent. PMID:21253582

  7. Responses of herbivorous rodents to habitat disturbance on the North Slope of Alaska: Final report, July 1984 to 31 December 1986

    SciTech Connect

    Batzli, G.O.

    1987-05-01

    Herbivorous rodents were studied in the vicinity of Toolik Lake on the North Slope of Alaska. Results indicate that herbivorous microtine rodents (lemmings and voles) respond to disturbance of their habitats in predictable ways in relation to changes in the availability of high-quality food. The quality of natural foods was determined by feeding trials. Preferences of voles for different plants in the field matched their performance (measured by change in body mass) when fed the same plants in the laboratory. Stepwise multiple regression successfully predicted the relative densities of the two most common species of voles based upon the availability of preferred food items. Preliminary results from field experiments indicate that densities of voles increase in response to supplements of high-quality food in natural habitats. 13 refs., 8 figs., 8 tabs.

  8. Lassa serology in natural populations of rodents and horizontal transmission.

    PubMed

    Fichet-Calvet, Elisabeth; Becker-Ziaja, Beate; Koivogui, Lamine; Günther, Stephan

    2014-09-01

    Lassa virus causes hemorrhagic fever in West Africa. Previously, we demonstrated by PCR screening that only the multimammate mouse, Mastomys natalensis, hosts Lassa virus in Guinea. In the present study, we used the same specimen collection from 17 villages in Coastal, Upper, and Forest Guinea to investigate the Lassa virus serology in the rodent population. The aim was to determine the dynamics of antibody development in M. natalensis and to detect potential spillover infections in other rodent species. Immunoglobulin G (IgG) antibody screening was performed using the indirect immunofluorescence assay with the Guinean Lassa virus strain Bantou 289 as antigen. The overall seroprevalence was 8% (129/1551) with the following rodents testing positive: 109 M. natalensis, seven Mastomys erythroleucus, four Lemniscomys striatus, four Praomys daltoni, three Mus minutoides, and two Praomys rostratus. Nearly all of them (122/129) originated from Bantou, Tanganya, and Gbetaya, where Lassa virus is highly endemic in M. natalensis. The antibody seroprevalence in M. natalensis from this high-endemic area (27%; 108/396) depended on the village, habitat, host age, and host abundance. A main positive factor was age; the maximum seroprevalence reached 50% in older animals. Our data fit with a model implicating that most M. natalensis rodents become horizontally infected, clear the virus within a period significantly shorter than their life span, and develop antibodies. In addition, the detection of antibodies in other species trapped in the habitats of M. natalensis suggests spillover infections. PMID:25229705

  9. Response of brown treesnakes to reduction of their rodent prey

    USGS Publications Warehouse

    Gragg, J.E.; Rodda, G.H.; Savidge, J.A.; White, G.C.; Dean-Bradley, K.; Ellingson, A.R.

    2007-01-01

    Trapping brown treesnakes (Boiga irregularis; BTS) with live-mouse (Mus domesticus) lures is the principal control technique for this invasive species on Guam. Lure-based trapping is also used on other islands as a precaution against undetected arrivals and in response to verified BTS sightings. However, the effectiveness of lure-based trapping on other islands is questionable, as it has yielded no BTS despite other evidence of their presence. Some evidence suggests that high rodent numbers may interfere with BTS control. To test the relationship between rodent abundance and snake trappability, we conducted a controlled, replicated field experiment incorporating a rodenticide treatment during a BTS mark-recapture study. Using open population modeling in Program MARK, we estimated BTS apparent survival and recapture probabilities. Rodent reduction increased BTS recapture probabilities by 52-65% in 2002 and 22-36% in 2003, and it decreased apparent survival by <1% both years. This appears to be the first published instance of manipulating wild prey to influence snake behavior. Rodent reduction may enhance detection and control of BTS with traps on Guam and other islands. It may also amplify the effectiveness of oral toxicants against BTS.

  10. Experimental transmission of Hepatozoon americanum to rodents.

    PubMed

    Johnson, Eileen M; Allen, Kelly E; Breshears, Melanie A; Panciera, Roger J; Little, Susan E; Ewing, Sidney A

    2008-02-14

    Laboratory-raised cotton rats (Sigmodon hispidus), outbred white mice (Mus musculus), and C57BL/6J-Lystbg-J/J mice (M. musculus) that were administered approximately 50 sporulated oocysts of Hepatozoon americanum (AF176836) by gavage developed inflammatory lesions containing parasitic cystozoites in cardiac and skeletal muscle, kidney, and lung. Sprague-Dawley rats (Rattus norvegicus) similarly exposed showed no evidence of infection. Cystozoites were first detected by histopathologic examination four weeks after exposure to oocysts. Globular, PAS-positive material accumulated around the cystozoites as the duration of infection lengthened. Nested PCR analysis of tissues collected 16 weeks post-exposure was positive for the 18S rRNA Hepatozoon sp. gene and the DNA sequence of the fragment amplified was 99.6% and 99.8% identical to H. americanum sequences previously reported from naturally-infected dogs (AF176836 and AY864676, respectively). Merogonous and gamontogonous stages of the parasite were not detected in any of the cystozoite-infected rodents. PMID:18055118

  11. Assessing spatial learning and memory in rodents.

    PubMed

    Vorhees, Charles V; Williams, Michael T

    2014-01-01

    Maneuvering safely through the environment is central to survival of almost all species. The ability to do this depends on learning and remembering locations. This capacity is encoded in the brain by two systems: one using cues outside the organism (distal cues), allocentric navigation, and one using self-movement, internal cues and nearby proximal cues, egocentric navigation. Allocentric navigation involves the hippocampus, entorhinal cortex, and surrounding structures; in humans this system encodes allocentric, semantic, and episodic memory. This form of memory is assessed in laboratory animals in many ways, but the dominant form of assessment is the Morris water maze (MWM). Egocentric navigation involves the dorsal striatum and connected structures; in humans this system encodes routes and integrated paths and, when overlearned, becomes procedural memory. In this article, several allocentric assessment methods for rodents are reviewed and compared with the MWM. MWM advantages (little training required, no food deprivation, ease of testing, rapid and reliable learning, insensitivity to differences in body weight and appetite, absence of nonperformers, control methods for proximal cue learning, and performance effects) and disadvantages (concern about stress, perhaps not as sensitive for working memory) are discussed. Evidence-based design improvements and testing methods are reviewed for both rats and mice. Experimental factors that apply generally to spatial navigation and to MWM specifically are considered. It is concluded that, on balance, the MWM has more advantages than disadvantages and compares favorably with other allocentric navigation tasks. PMID:25225309

  12. Laboratory study of methane production from broiler-chicken litter

    SciTech Connect

    Shih, J.C.H.; Huang, J.J.H.

    1980-01-01

    North Carolina is one of the largest poultry-production states in the United States. Although a considerable amount of work has been done on methane production from livestock, brewery, and municipal wastes, little is known concerning poultry waste. Consequently, a laboratory study was conducted to delineate the potential for thermophilic (60/sup 0/C) methane generation from broiler litter. Broiler litter was chosen as the substrate for the following reasons: first, it is the most abundant waste of poultry production in North Carolina; second, wood chips which are used as the bedding material could be a potential source of carbon for methane biosynthesis; and third, it has a desirable nitrogen content of 3 to 4%, a level similar to that of the cattle waste..

  13. Nutritional Evaluation of NASA's Rodent Food Bar Diet

    NASA Technical Reports Server (NTRS)

    Barrett, Joyce E.; Yu, Diane S.; Dalton, Bonnie P.

    2000-01-01

    Tests are being conducted on NASA's rodent Food Bar in preparation for long-term use as the rat and mouse diet aboard the International Space Station. Nutritional analyses are performed after the bars are manufactured and then repeated periodically to determine nutritional stability. The primary factors analyzed are protein, ash, fat, fiber, moisture, amino acids, fatty acids, and minerals. Nutrient levels are compared to values published in the National Research Council's dietary requirements for rodents, and also to those contained in several commonly used commercial rodent lab diets. The Food Bar is manufactured from a powdered diet to which moisture is added as it is processed through an extruder. The bars are dipped into potassium sorbate, vacuum-sealed, and irradiated. In order to determine nutrient changes during extrusion and irradiation, the powdered diet, the non-irradiated bars, and the irradiated bars are all analyzed. We have observed lower values for some nutrients (iodine, vitamin K, and iron) in the Food Bars compared with NRC requirements. Many nutrients in the Food Bars are contained at a higher level than levels in the NRC requirements. An additional factor we are investigating is the 26% moisture level in the Food Bars, which drops to about 15% within a week, compared to a stable 10% moisture in many standard lab chow diets. In addition to the nutritional analyses, the food bar is being fed to several strains of rats and mice, and feeding study and necropsy results are being observed (Barrett et al, unpublished data). Information from the nutritional analyses and from the rodent studies will enable us to recommend the formulation that will most adequately meet the rodent Food Bar requirements for long-term use aboard the Space Station.

  14. Qualitative and quantitative study on drainage networks at laboratory scale

    NASA Astrophysics Data System (ADS)

    Oliveto, G.; Palma, D.; di Domenico, A.

    2009-04-01

    Although simulated drainage networks at the laboratory scale would represent highly-simplified models of natural drainages, they would provide a significant contribute to the comprehension of the complex dynamics governing the fluvial systems. Laboratory experiments also give the advantage to detect transient growth phases shedding some light on the knowledge of temporal and spatial landform evolution. Perhaps, pioneering laboratory experiments on drainage network evolution were carried out in 1977 at REF (Rainfall Erosion Facility) of Colorado State University by Schumm and co-workers. This study deals with an analysis of physical experiments simulating the evolution and the development of drainage networks. To this purpose, some experiments were carried out at University of Basilicata by using a 1.5 m by 1.5 m box-basin-simulator with an outlet incised in the middle of the downslope-end side. The experimental landscape was made of a weakly cohesive soil mainly constituted by clay and silt. A system of microsprinklers generated an almost uniform artificial precipitation. Simulations were performed at a constant rainfall rate with intensity of 100 mm/h. In total four experiments were carried out. Three of those were conducted by ensuring consistent initial conditions except for the initial landscape planar slope of 9%, 5%, and 0.6%, respectively. The remaining experiment was performed with a landscape slope of 9% again, but with the (surface) base-level coinciding with the base of the outlet (i.e. streams could not erode below the base-level). Despite the central outlet constraint, the generated stream system for the 9% plane exhibited trellis-like drainage patterns with many short tributaries joining the main stream at nearly right angles. For the 5% experiment still sub-parallel drainage patterns were formed but mainly in the centre of the watershed. Channels were clearly shallower than those of the 9% experiment. For the gentler slope of 0.6% dendritic drainage patterns developed with tributaries entering the main channel at acute angles (less than 90Ë? ). Digital elevation models (DEM) of the evolving landscape were achieved through detailed soil surveys with a laser pointer or a laser scanner. Then, the drainage networks were extracted from the DEMs by using the D8 algorithm. Based on the data collected, the scaling properties of the simulated networks are analysed and compared with those of natural basins. Findings are provided mainly in terms of Hortonian laws, fractal dimensions and informational entropy. Scaling properties and space filling tendencies are discussed and peculiar differences between quasi-equilibrium and transient stages are also highlighted. Experimental evidences are also provided on the interaction between the base-level and growing mechanisms.

  15. Partnering at the National Laboratories: Catalysis as a Case Study

    SciTech Connect

    JACKSON,NANCY B.

    1999-09-14

    The role of the national laboratories, particularly the defense program laboratories, since the end of the cold war, has been a topic of continuing debate. The relationship of national laboratories to industry spurred debate which ranged from designating the labs as instrumental to maintaining U.S. economic competitiveness to concern over the perception of corporate welfare to questions regarding the industrial globalization and the possibility of U.S. taxpayer dollars supporting foreign entities. Less debated, but equally important, has been the national laboratories' potential competition with academia for federal research dollars and discussions detailing the role of each in the national research enterprise.

  16. Automatic cortical thickness analysis on rodent brain

    NASA Astrophysics Data System (ADS)

    Lee, Joohwi; Ehlers, Cindy; Crews, Fulton; Niethammer, Marc; Budin, Francois; Paniagua, Beatriz; Sulik, Kathy; Johns, Josephine; Styner, Martin; Oguz, Ipek

    2011-03-01

    Localized difference in the cortex is one of the most useful morphometric traits in human and animal brain studies. There are many tools and methods already developed to automatically measure and analyze cortical thickness for the human brain. However, these tools cannot be directly applied to rodent brains due to the different scales; even adult rodent brains are 50 to 100 times smaller than humans. This paper describes an algorithm for automatically measuring the cortical thickness of mouse and rat brains. The algorithm consists of three steps: segmentation, thickness measurement, and statistical analysis among experimental groups. The segmentation step provides the neocortex separation from other brain structures and thus is a preprocessing step for the thickness measurement. In the thickness measurement step, the thickness is computed by solving a Laplacian PDE and a transport equation. The Laplacian PDE first creates streamlines as an analogy of cortical columns; the transport equation computes the length of the streamlines. The result is stored as a thickness map over the neocortex surface. For the statistical analysis, it is important to sample thickness at corresponding points. This is achieved by the particle correspondence algorithm which minimizes entropy between dynamically moving sample points called particles. Since the computational cost of the correspondence algorithm may limit the number of corresponding points, we use thin-plate spline based interpolation to increase the number of corresponding sample points. As a driving application, we measured the thickness difference to assess the effects of adolescent intermittent ethanol exposure that persist into adulthood and performed t-test between the control and exposed rat groups. We found significantly differing regions in both hemispheres.

  17. ELF electric and magnetic fields: Pacific Northwest Laboratory studies

    NASA Astrophysics Data System (ADS)

    Anderson, L. E.

    1992-06-01

    Studies were conducted at Battelle, Pacific Northwest Laboratory, to examine extremely-low-frequency (ELF) electromagnetic fields for possible biological effects in animals. Three areas of investigation are reported here: (1) studies on the nervous system, including behavior and neuroendocrine function; (2) experiments on cancer development in animals; and (3) measurements of currents and electric fields induced in animal models by exposure to external magnetic fields. In behavioral experiments, rats were shown to be responsive to ELF electric field exposure. Furthermore, experimental data indicate that short-term memory may be affected in albino rats exposed to combined ELF and static magnetic fields. Neuroendocrine studies were conducted to demonstrate an apparent stress-related response in rats exposed to 60-Hz electric fields. Nighttime pineal melatonin levels were shown to be significantly depressed in animals exposed to either electric or magnetic fields. A number of animal tumor models are currently under investigation to examine possible relationships between ELF exposure and carcinogenesis. Finally, theoretical and experimental measurements were performed which form the basis for animals and human exposure comparisons.

  18. Molecular Carbon in the Galaxy: Laboratory and Observational Studies

    NASA Technical Reports Server (NTRS)

    Saykally, Richard James

    2003-01-01

    In a collaboration with the Mats Larsson group from Stockholm, we carried out a new measurement of the rate of dissociative recombination of H(sup *, sub j), using a new pulsed supersonic beam source of rotationally cold H(sup *, sub j). This source was first designed and characterized in our lab by IR cavity ringdown spectroscopy, determining a rotationaYtranslationa1 temperature of 20-60K, depending on conditions. This new source was then taken to Stockholm for the recombination rate studies at the CRYRING storage ring. The recombination rate constant measured against temperature yields values consistent with the most recent calculations, whereas previous experimental measurements varied over a range of 10(exp 4) and were poor agreement with theory. This is a crucial achievement for understanding the ion chemistry of diffuse clouds. Moreover, this result in combination with recent observations implies a greatly enhanced (factor of 40) cosmic ray ionization rate in a diffuse cloud (zeta Persei) relative to previous studies. The implications of this are discussed in our recent Nature paper. An enhanced cosmic-ray flux towards zeta Persei inferred from a laboratory study of the H(sup *, sub j)-e(sup -) recombination rate.

  19. PREDICTING RODENT CARCINOGENICITY OF HALOGENATED HYDROCARBON BY IN VIVO BIOCHEMICAL PARAMETERS

    EPA Science Inventory

    Forty halogenated hydrocarbons of known rodent carcinogenicity (24 carcinogens, 16 noncarcinogens), including many promoters of carcinogenesis, nongenotoxic carcinogens and hepatocarcinogens were selected for study. he effects of these 40 chemicals on four biochemical assays (hep...

  20. Methods and modeling for the reduced platen compression of cancellous bone in the rodent proximal tibia

    E-print Network

    Rogers, William Elliott

    2002-01-01

    This study focused on the reduced platen compression (RPC) test of cancellous bone in the rodent proximal tibia. The objective was to improve methods for this mechanical test, specifically in the areas of specimen location, specimen preparation...

  1. Past and Future Work on Radiobiology Mega-Studies: A Case Study At Argonne National Laboratory

    Microsoft Academic Search

    Benjamin Haley; Qiong Wang; Beau Wanzer; Stefan Vogt; Lydia Finney; Ping Liu Yang; Tatjana Paunesku; Gayle Woloschak

    2011-01-01

    Between 1952 and 1992, more than 200 large radiobiology studies were conducted in research institutes throughout Europe, North America, and Japan to determine the effects of external irradiation and internal emitters on the lifespan and tissue toxicity development in animals. At Argonne National Laboratory, 22 external beam studies were conducted on nearly 700 beagle dogs and 50,000 mice between 1969

  2. Anti-dementia drugs and hippocampal-dependent memory in rodents

    PubMed Central

    Yuede, Carla M.; Dong, Hongxin; Csernansky, John G.

    2009-01-01

    Abnormalities in hippocampal structure and function are characteristics of early Alzheimer's disease (AD). Behavioral tests measuring hippocampal-dependent memory in rodents are often used to evaluate novel treatments for AD and other dementias. In this study, we review the effects of drugs marketed for the treatment of AD, such as the acetylcholinesterase inhibitors, donepezil, rivastigmine, galantamine and the N-methyl-d-aspartic acid antagonist, memantine, in rodent models of memory impairment. We also briefly describe the effects of novel treatments for cognitive impairment in rodent models of memory impairment, and discuss issues concerning the selection of the animal model and behavioral tests. Suggestions for future research are offered. PMID:17762506

  3. Seed removal by scatter-hoarding rodents: the effects of tannin and nutrient concentration.

    PubMed

    Wang, Bo; Yang, Xiaolan

    2015-04-01

    The mutualistic interaction between scatter-hoarding rodents and seed plants have a long co-evolutionary history. Plants are believed to have evolved traits that influence the foraging behavior of rodents, thus increasing the probability of seed removal and caching, which benefits the establishment of seedlings. Tannin and nutrient content in seeds are considered among the most essential factors in this plant-animal interaction. However, most previous studies used different species of plant seeds, rendering it difficult to tease apart the relative effect of each single nutrient on rodent foraging behavior due to confounding combinations of nutrient contents across seed species. Hence, to further explore how tannin and different nutritional traits of seed affect scatter-hoarding rodent foraging preferences, we manipulated tannin, fat, protein and starch content levels, and also seed size levels by using an artificial seed system. Our results showed that both tannin and various nutrients significantly affected rodent foraging preferences, but were also strongly affected by seed size. In general, rodents preferred to remove seeds with less tannin. Fat addition could counteract the negative effect of tannin on seed removal by rodents, while the effect of protein addition was weaker. Starch by itself had no effect, but it interacted with tannin in a complex way. Our findings shed light on the effects of tannin and nutrient content on seed removal by scatter-hoarding rodents. We therefore, believe that these and perhaps other seed traits should interactively influence this important plant-rodent interaction. However, how selection operates on seed traits to counterbalance these competing interests/factors merits further study. PMID:25625425

  4. Efficacy of Rodenticide Baits for the Control of Three Invasive Rodent Species in Hawaii

    Microsoft Academic Search

    William C. PittLaura; Laura C. Driscoll; Robert T. Sugihara

    2011-01-01

    We tested the efficacy and palatability of nine commercial rodenticide bait formulations on Polynesian rats (Rattus exulans), roof rats (R. rattus), and house mice (Mus musculus). Efficacy varied by rodenticide tested and rodent species. Generally, rodenticides were more effective against mice than\\u000a for either of the rat species, and mice tended to consume more rodenticide bait than the laboratory chow

  5. A qualitative case study of instructional support for web-based simulated laboratory exercises in online college chemistry laboratory courses

    NASA Astrophysics Data System (ADS)

    Schulman, Kathleen M.

    This study fills a gap in the research literature regarding the types of instructional support provided by instructors in online introductory chemistry laboratory courses that employ chemistry simulations as laboratory exercises. It also provides information regarding students' perceptions of the effectiveness of that instructional support. A multiple case study methodology was used to carry out the research. Two online introductory chemistry courses were studied at two community colleges. Data for this study was collected using phone interviews with faculty and student participants, surveys completed by students, and direct observation of the instructional designs of instructional support in the online Blackboard web sites and the chemistry simulations used by the participating institutions. The results indicated that the instructors provided multiple types of instructional support that correlated with forms of effective instructional support identified in the research literature, such as timely detailed feedback, detailed instructions for the laboratory experiments, and consistency in the instructional design of lecture and laboratory course materials, including the chemistry lab simulation environment. The students in one of these courses identified the following as the most effective types of instructional support provided: the instructor's feedback, opportunities to apply chemistry knowledge in the chemistry lab exercises, detailed procedures for the simulated laboratory exercises, the organization of the course Blackboard sites and the chemistry lab simulation web sites, and the textbook homework web sites. Students also identified components of instructional support they felt were missing. These included a desire for more interaction with the instructor, more support for the simulated laboratory exercises from the instructor and the developer of the chemistry simulations, and faster help with questions about the laboratory exercises or experimental calculations. Students believed that having this additional instructional support would lead to increased understanding of the laboratory exercises, allowing them to complete them with less difficulty, and giving them increased access to the instructor. Recommendations for the instructors of these two courses include: increased participation in the online course environment, increased emphasis on laboratory safety, and increased emphasis on the differences between simulated and real life chemistry laboratory experiments.

  6. A human laboratory pilot study with baclofen in alcoholic individuals

    PubMed Central

    Leggio, Lorenzo; Zywiak, William H.; McGeary, John E.; Edwards, Steven; Fricchione, Samuel R.; Shoaff, Jessica R.; Addolorato, Giovanni; Swift, Robert M.; Kenna, George A.

    2015-01-01

    Preclinical and clinical studies show that the GABAB receptor agonist baclofen may represent a pharmacotherapy for alcohol dependence (AD). However, the mechanisms by which baclofen affects drinking are not well characterized; thus this pilot study investigated possible baclofen’s biobehavioral mechanisms. The design was a double-blind controlled randomized human laboratory pilot study. Fourteen non-treatment seeking alcohol-dependent heavy drinking subjects received either baclofen 10 mg t.i.d. or an active placebo (cyproheptadine 2 mg t.i.d., to control for sedation) for a 7-day period. At day 8, participants performed an alcohol cue-reactivity (CR) followed by an alcohol self-administration (ASA). Additionally, we explored possible moderators that might guide future larger studies, i.e. anxiety, family history and onset of alcoholism, and D4 dopamine receptor (DRD4) and 5-HTTLPR polymorphisms. The main results were a significant effect of baclofen for increasing stimulation (p=.001) and sedation (p<.01). Furthermore, when drinking during the ASA and the 2 days before was analyzed as a composite variable, there was a significant effect of baclofen to reduce alcohol consumption (p<.01). As for the exploratory analyses, baclofen’s effects to increase alcohol sedation and to reduce alcohol consumption were limited to those individuals with DRD4 ?7 repeats (DRD4L). Yet, baclofen’s effects on alcohol consumption were also moderated by 5-HTTLPR LL genotype. In conclusion, baclofen’s ability to reduce alcohol drinking may be related to its effects on the biphasic effects of alcohol, but larger studies are needed to confirm these preliminary findings. PMID:23262301

  7. Leaving home: A study of laboratory mouse pup independence

    Microsoft Academic Search

    Allison Bechard; Georgia Mason

    2010-01-01

    Juvenile wild house mice leave their mothers at 8 weeks (+). In contrast, laboratory strains of mice (lab mice) are typically ‘weaned’ at postnatal day (PND) 21. Lab mice might mature faster than their wild forebears; but if they do not, standard laboratory weaning likely involves maternal deprivation. We therefore investigated when lab mice voluntarily leave their mothers. C57BL\\/6J families

  8. Laboratory study of selected personal inhalable aerosol samplers.

    PubMed

    Görner, Peter; Simon, Xavier; Wrobel, Richard; Kauffer, Edmond; Witschger, Olivier

    2010-03-01

    Assessment of inhalable dust exposure requires reliable sampling methods in order to measure airborne inhalable particles' concentrations. Many inhalable aerosol samplers can be used but their performances widely vary and remain unknown in some cases. The sampling performance of inhalable samplers is strongly dependent on particle size and ambient air velocity. Five inhalable aerosol samplers have been studied in two laboratory wind tunnels using polydisperse glass-beads' test aerosol. Samplers tested were IOM sampler (UK), two versions of CIP 10-I sampler, v1 and v2 (F), 37-mm closed face cassette sampler (USA), 37-mm cassette fitted up with an ACCU-CAP insert (USA), and Button sampler (USA). Particle size-dependent sampling efficiencies were measured in a horizontal wind tunnel under a 1 m s(-1) wind velocity and in a vertical tunnel under calm air, using a specific method with Coulter(R) counter particle size number distribution determinations. Compared with CEN-ISO-ACGIH sampling criteria for inhalable dust, the experimental results show fairly high sampling efficiency for the IOM and CIP 10-I v2 samplers and slightly lower efficiencies for the Button and CIP 10-I v1 samplers. The closed face cassette (4-mm orifice) produced the poorest performances of all the tested samplers. This can be improved by using the ACCU-CAP internal capsule, which prevents inner wall losses inside the cassette. Significant differences between moving air and calm air sampling efficiency were observed for all the studied samplers. PMID:20147627

  9. Fretting fatigue characteristics of shim pack materials: A laboratory study

    SciTech Connect

    Dorning, R.E. II

    1983-09-30

    Premature shim pack failures have been experienced in improved/ uprated equipment at all three diffusion plants. Shim packs are the flexible part of the coupling connecting axial flow compressors and motors. A three-plant QA committee was established to investigate the premature shim pack failures. Several possible contributing factors were identified including design, material, alignment, and installation practices. At Portsmouth, laboratory studies were made to determine if change of the shim pack materials from Tomaloy (a proprietary alloy) to 301 stainless steel contributed to the premature failures. The investigation included determination of fretting resistance differences and the fretting fatigue endurance limit differences between the various materials. Little or no differences in fretting resistance were observed between Tomaloy, 301 half-hard stainless steel, and 301 full-hard stainless steel. The fretting fatigue endurance limits for the three materials were found to be comparable. No differences between the test materials significant enough to be a contributing factor in shim pack failure were found in these studies. 4 refs., 6 figs., 4 tabs.

  10. Knowledge Retention for Computer Simulations: A study comparing virtual and hands-on laboratories

    NASA Astrophysics Data System (ADS)

    Croom, John R., III

    The use of virtual laboratories has the potential to change physics education. These low-cost, interactive computer activities interest students, allow for easy setup, and give educators a way to teach laboratory based online classes. This study investigated whether virtual laboratories could replace traditional hands-on laboratories and whether students could retain the same long-term knowledge in virtual laboratories as compared to hands-on laboratories. This study is a quantitative quasi-experiment that used a multiple posttest design to determine if students using virtual laboratories would retain the same knowledge as students who performed hands-on laboratories after 9 weeks. The study was composed of 336 students from 14 school districts. Students had their performances on the laboratories and their retention of the laboratories compared to a series of factors that might have affected their retention using a pretest and two posttests, which were compared using a t test. The results showed no significant difference in short-term learning between the hands-on laboratory groups and virtual laboratory groups. There was, however, a significant difference (p = .005) between the groups in long-term retention; students in the hands-on laboratory groups retained more information than those in the virtual laboratory groups. These results suggest that long-term learning is enhanced when a laboratory contains a hands-on component. Finally, the results showed that both groups of students felt their particular laboratory style was superior to the alternative method. The findings of this study can be used to improve the integration of virtual laboratories into science curriculum.

  11. Urban resident attitudes toward rodents, rodent control products, and environmental effects

    Microsoft Academic Search

    Anita T. Morzillo; Angela G. Mertig

    2011-01-01

    Rodent control in urban areas can result in the inadvertent mortality of non-target species (e.g., bobcats). However, there\\u000a is little detailed information from urban residents about rodent control practices. We evaluated urban rodent control behaviors\\u000a in two areas of California (southwestern Bakersfield and in proximity to Santa Monica Mountains National Recreation Area (SAMO))\\u000a where biologists have observed non-target mortality among

  12. ER-2: Flying Laboratory for Earth Science Studies

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    2007-01-01

    The National Aeronautics and Space Administration (NASA) Dryden Flight Research Center (DFRC), (Edwards, California, USA) has two Lockheed Martin Corporation (Bethesda, Maryland) Earth Research-2 (ER-2) aircraft that serve as high-altitude and long-range flying laboratories. The ER-2 has been utilized to conduct scientific studies of stratospheric and tropospheric chemistry, land-use mapping, disaster assessment, preliminary testing and calibration and validation of satellite sensors. The ER-2 aircraft provides experimenters with a wide array of payload accommodation areas with suitable environment control with required electrical and mechanical interfaces. Missions may be flown out of DFRC or from remote bases worldwide. The NASA ER-2 is utilized by a variety of customers, including U.S. Government agencies, civilian organizations, universities, and state governments. The combination of the ER-2 s range, endurance, altitude, payload power, payload volume and payload weight capabilities complemented by a trained maintenance and operations team provides an excellent and unique platform system to the science community.

  13. Factors influencing repeated seed movements by scatter-hoarding rodents in an alpine forest

    PubMed Central

    Wang, Bo; Chen, Jin; Corlett, Richard T.

    2014-01-01

    Scatter-hoarding rodents are effective dispersal agents for many plant species. Several studies have shown that rodents repeatedly re-cache seeds. The re-caching process often has a significant impact on final seedling establishment, but the factors determining its occurrence are poorly understood. In this study, we followed the fate of 3564 artificial seeds that varied in size, nutrient content and tannin content. Seeds cached closer to their original releasing plots were more likely to be re-cached, and to a further distance. Larger seeds were more likely to be re-cached than smaller ones, while nutrient and tannin content had little effect. Most plant species that depend on scatter-hoarding rodents for seed dispersal bear relatively large seeds, and large seeds are usually more likely to be dispersed and to establish seedlings, suggesting that the caching preferences of scatter-hoarding rodents may have played an important role in the evolution of large seeds. PMID:24759374

  14. Factors influencing repeated seed movements by scatter-hoarding rodents in an alpine forest.

    PubMed

    Wang, Bo; Chen, Jin; Corlett, Richard T

    2014-01-01

    Scatter-hoarding rodents are effective dispersal agents for many plant species. Several studies have shown that rodents repeatedly re-cache seeds. The re-caching process often has a significant impact on final seedling establishment, but the factors determining its occurrence are poorly understood. In this study, we followed the fate of 3564 artificial seeds that varied in size, nutrient content and tannin content. Seeds cached closer to their original releasing plots were more likely to be re-cached, and to a further distance. Larger seeds were more likely to be re-cached than smaller ones, while nutrient and tannin content had little effect. Most plant species that depend on scatter-hoarding rodents for seed dispersal bear relatively large seeds, and large seeds are usually more likely to be dispersed and to establish seedlings, suggesting that the caching preferences of scatter-hoarding rodents may have played an important role in the evolution of large seeds. PMID:24759374

  15. Rearing and Maintaining Midge Cultures (Chironomus tentans) for Laboratory Studies.

    ERIC Educational Resources Information Center

    Hein, John; Mahadeva, Madhu N.

    1992-01-01

    The life history of the Chironomus tentans can be observed in easily established and maintained laboratory cultures. Projects for the classroom include observing hydration of an egg mass; embryonic development, hatching and larval feeding; larval activity; and mating activity. (MDH)

  16. The Study of a Cobalt Complex--A Laboratory Project.

    ERIC Educational Resources Information Center

    Loehlin, James H.; And Others

    1982-01-01

    Describes an 8-week project involving the synthesis of cobalt compounds. Once synthesized, compounds are qualitatively and quantitatively analyzed. Background information, laboratory procedures, and results/discussion are provided for three project experiments. (Author/JN)

  17. A laboratory study of the friction behavior of granular materials

    E-print Network

    Frye, Kevin M. (Kevin Michael), 1972-

    2002-01-01

    I report on laboratory experiments designed to investigate the microphysical processes that result in rate- and state-dependent friction behavior and experiments designed to match the boundary conditions used by numerical ...

  18. Case Study- Steam System Improvements at Dupont Automotive Marshall Laboratory 

    E-print Network

    Larkin, A.

    2002-01-01

    Dupont's Marshall Laboratory is an automotive paint research and development facility in Philadelphia, Pennsylvania. The campus is comprised of several buildings that are served by Trigen-Philadelphia Energy Corporation's district steam loop...

  19. Community composition and size structure of murid rodents in relation to the biogeography of the Japanese archipelago

    Microsoft Academic Search

    Virginie Millien-Parra; Michel Loreau

    2000-01-01

    We investigated the geographical patterns of community composition and size structure of murid rodent assemblages in Japan. Rodent faunal composition showed three biogeographic zones in the studied area (Hokkaido, northern Honshu and southern Honshu), which are characterized by endemic species or genera. There was a large discrepancy between distribution patterns of murine species, which are generalist and widespread in Japan,

  20. Hantavirus Infection in Humans and Rodents, Northwestern Argentina

    PubMed Central

    Levis, Silvana; Calderón, Gladys; Ramirez, Josefina; Bravo, Daniel; Lozano, Elena; Ripoll, Carlos; St. Jeor, Stephen; Ksiazek, Thomas G.; Barquez, Ruben M.; Enria, Delia

    2003-01-01

    We initiated a study to elucidate the ecology and epidemiology of hantavirus infections in northern Argentina. The northwestern hantavirus pulmonary syndrome (HPS)–endemic area of Argentina comprises Salta and Jujuy Provinces. Between 1997 and 2000, 30 HPS cases were diagnosed in Jujuy Province (population 512,329). Most patients had a mild clinical course, and the death rate (13.3%) was low. We performed a serologic and epidemiologic survey in residents of the area, in conjunction with a serologic study in rodents. The prevalence of hantavirus antibodies in the general human population was 6.5%, one of the highest reported in the literature. No evidence of interhuman transmission was found, and the high prevalence of hantavirus antibody seemed to be associated with the high infestation of rodents detected in domestic and peridomestic habitats. PMID:14519242

  1. Experimental infections by Brucella suis type 4 in Alaskan rodents.

    PubMed

    Miller, L G; Neiland, K A

    1980-10-01

    The susceptibility of nine species of rodents and one species of lagomorph to Brucella suis type 4 was studied experimentally. The rodent species included: guinea pig (Cavia porcellus), Scandinavian lemming (Lemmus lemmus), brown lemming (L. sibiricus), northern red-backed vole (Clethrionomys rutilis), varying lemmings (Dicrostonyx stevensoni and D. rubricatus), yellow-cheeked vole (Microtus xanthognathus), flying squirrel (Glaucomys sabrinus) and ground squirrel (Citellus parryii). The lagomorph, Lepus americanus (varying hare), was also studied. All of these species were readily infected by intraperitoneal inoculations of brucellae. Pathologic responses were not marked in most of these species. However, both species of varying lemmings responded dramatically to infections initiated by about as few as two cfu. All individuals of both species that were not killed eventually died from the infection. PMID:7463596

  2. Influence of Rock Fabric on Hydraulic Fracture Propagation: Laboratory Study

    NASA Astrophysics Data System (ADS)

    Stanchits, S. A.; Desroches, J.; Burghardt, J.; Surdi, A.; Whitney, N.

    2014-12-01

    Massive hydraulic fracturing is required for commercial gas production from unconventional reservoirs. These reservoirs are often highly fractured and heterogeneous, which may cause significant fracture complexity and also arrest propagation of hydraulic fractures, leading to production decrease. One of the goals of our study was to investigate the influence of rock fabric features on near-wellbore fracture geometry and complexity. We performed a series of laboratory tests on Niobrara outcrop shale blocks with dimensions of 30 x 30 x 36 inches in a true-triaxial loading frame. Acoustic Emission (AE) technique was applied to monitor hydraulic fracture initiation and dynamics of fracture propagation. After the tests, the shape of the created hydraulic fracture was mapped by goniometry technique. To estimate fracture aperture, particles of different sizes were injected with fracturing fluid. In all tests, AE analysis indicated hydraulic fracture initiation prior to breakdown or the maximum of wellbore pressure. In most tests, AE analysis revealed asymmetrical hydraulic fracture shapes. Post-test analysis demonstrated good correspondence of AE results with the actual 3D shape of the fracture surface map. AE analysis confirmed that in some of these tests, the hydraulic fracture approached one face of the block before the maximum wellbore pressure had been reached. We have found that in such cases the propagation of hydraulic fracture in the opposite direction was arrested by the presence of mineralized interfaces. Mapping the distribution of injected particles confirmed the creation of a narrow-width aperture in the vicinity of pre-existing interfaces, restricting fracture conductivity. Based on the results of our study, we concluded that the presence of planes of weakness, such as mineralized natural fractures, can result in the arrest of hydraulic fracture propagation, or in poor fracture geometries with limited aperture, that in turn could lead to high net pressure and low fracture conductivity, restricted proppant delivery, and decreased production.

  3. Los Alamos National Laboratory W76 Pit Tube Lifetime Study

    SciTech Connect

    Abeln, Terri G. [Los Alamos National Laboratory

    2012-04-25

    A metallurgical study was requested as part of the Los Alamos National Laboratory (LANL) W76-1 life-extension program (LEP) involving a lifetime analysis of type 304 stainless steel pit tubes subject to repeat bending loads during assembly and disassembly operations at BWXT/Pantex. This initial test phase was completed during the calendar years of 2004-2006 and the report not issued until additional recommended tests could be performed. These tests have not been funded to this date and therefore this report is considered final. Tubes were reportedly fabricated according to Rocky Flats specification P14548 - Seamless Type 304 VIM/VAR Stainless Steel Tubing. Tube diameter was specified as 0.125 inches and wall thickness as 0.028 inches. A heat treat condition is not specified and the hardness range specification can be characteristic of both 1/8 and 1/4 hard conditions. Properties of all tubes tested were within specification. Metallographic analysis could not conclusively determine a specified limit to number of bends allowable. A statistical analysis suggests a range of 5-7 bends with a 99.95% confidence limit. See the 'Statistical Analysis' section of this report. The initial phase of this study involved two separate sets of test specimens. The first group was part of an investigation originating in the ESA-GTS [now Gas Transfer Systems (W-7) Group]. After the bend cycle test parameters were chosen (all three required bends subjected to the same amount of bend cycles) and the tubes bent, the investigation was transferred to Terri Abeln (Metallurgical Science and Engineering) for analysis. Subsequently, another limited quantity of tubes became available for testing and were cycled with the same bending fixture, but with different test parameters determined by T. Abeln.

  4. Rodents as potential couriers for bioterrorism agents.

    PubMed

    Lõhmus, Mare; Janse, Ingmar; van de Goot, Frank; van Rotterdam, Bart J

    2013-09-01

    Many pathogens that can cause major public health, economic, and social damage are relatively easily accessible and could be used as biological weapons. Wildlife is a natural reservoir for many potential bioterrorism agents, and, as history has shown, eliminating a pathogen that has dispersed among wild fauna can be extremely challenging. Since a number of wild rodent species live close to humans, rodents constitute a vector for pathogens to circulate among wildlife, domestic animals, and humans. This article reviews the possible consequences of a deliberate spread of rodentborne pathogens. It is relatively easy to infect wild rodents with certain pathogens or to release infected rodents, and the action would be difficult to trace. Rodents can also function as reservoirs for diseases that have been spread during a bioterrorism attack and cause recurring disease outbreaks. As rats and mice are common in both urban and rural settlements, deliberately released rodentborne infections have the capacity to spread very rapidly. The majority of pathogens that are listed as potential agents of bioterrorism by the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases exploit rodents as vectors or reservoirs. In addition to zoonotic diseases, deliberately released rodentborne epizootics can have serious economic consequences for society, for example, in the area of international trade restrictions. The ability to rapidly detect introduced diseases and effectively communicate with the public in crisis situations enables a quick response and is essential for successful and cost-effective disease control. PMID:23971813

  5. Can rodents conceive hyperbolic spaces?

    PubMed

    Urdapilleta, Eugenio; Troiani, Francesca; Stella, Federico; Treves, Alessandro

    2015-06-01

    The grid cells discovered in the rodent medial entorhinal cortex have been proposed to provide a metric for Euclidean space, possibly even hardwired in the embryo. Yet, one class of models describing the formation of grid unit selectivity is entirely based on developmental self-organization, and as such it predicts that the metric it expresses should reflect the environment to which the animal has adapted. We show that, according to self-organizing models, if raised in a non-Euclidean hyperbolic cage rats should be able to form hyperbolic grids. For a given range of grid spacing relative to the radius of negative curvature of the hyperbolic surface, such grids are predicted to appear as multi-peaked firing maps, in which each peak has seven neighbours instead of the Euclidean six, a prediction that can be tested in experiments. We thus demonstrate that a useful universal neuronal metric, in the sense of a multi-scale ruler and compass that remain unaltered when changing environments, can be extended to other than the standard Euclidean plane. PMID:25948611

  6. Molecular and Paleontological Evidence for a Post-Cretaceous Origin of Rodents

    PubMed Central

    Wu, Shaoyuan; Wu, Wenyu; Zhang, Fuchun; Ye, Jie; Ni, Xijun; Sun, Jimin; Edwards, Scott V.; Meng, Jin; Organ, Chris L.

    2012-01-01

    The timing of the origin and diversification of rodents remains controversial, due to conflicting results from molecular clocks and paleontological data. The fossil record tends to support an early Cenozoic origin of crown-group rodents. In contrast, most molecular studies place the origin and initial diversification of crown-Rodentia deep in the Cretaceous, although some molecular analyses have recovered estimated divergence times that are more compatible with the fossil record. Here we attempt to resolve this conflict by carrying out a molecular clock investigation based on a nine-gene sequence dataset and a novel set of seven fossil constraints, including two new rodent records (the earliest known representatives of Cardiocraniinae and Dipodinae). Our results indicate that rodents originated around 61.7–62.4 Ma, shortly after the Cretaceous/Paleogene (K/Pg) boundary, and diversified at the intraordinal level around 57.7–58.9 Ma. These estimates are broadly consistent with the paleontological record, but challenge previous molecular studies that place the origin and early diversification of rodents in the Cretaceous. This study demonstrates that, with reliable fossil constraints, the incompatibility between paleontological and molecular estimates of rodent divergence times can be eliminated using currently available tools and genetic markers. Similar conflicts between molecular and paleontological evidence bedevil attempts to establish the origination times of other placental groups. The example of the present study suggests that more reliable fossil calibration points may represent the key to resolving these controversies. PMID:23071573

  7. Rodent and Ruminant Ingestive Response to Flavonoids in Euphorbia esula

    Microsoft Academic Search

    F. Halaweish; S. Kronberg; J. A. Rice

    2003-01-01

    Euphorbia esula, common name leafy spurge, was chemically evaluated for aversive phytochemicals that appear to minimize herbivory by rodents and cattle. A middle-layer extract elicited food aversions in rats as did the petroleum ether extract of the initial methanol extract. Kaempferol-3-0-ß- glucuronic acid and quercetin-3-0-ß-glucuronic acid were separated and identified from the middle-layer residue. This study is the first report

  8. The past, present, and future of National Aeronautics and Space Administration spaceflight diet in support of microgravity rodent experiments.

    PubMed

    Sun, Gwo-Shing; Tou, Janet C; Yu, Diane; Girten, Beverly E; Cohen, Jacob

    2014-02-01

    Rodents have been the most frequently flown animal model used to study physiological responses to the space environment. In support of future of space exploration, the National Aeronautics and Space Administration (NASA) envisions an animal research program focused on rodents. Therefore, the development of a rodent diet that is suitable for the spaceflight environment including long duration spaceflight is a high priority. Recognizing the importance of nutrition in affecting spaceflight physiological responses and ensuring reliable biomedical and biological science return, NASA developed the nutrient-upgraded rodent food bar (NuRFB) as a standard diet for rodent spaceflight. Depending on future animal habitat hardware and planned spaceflight experiments, modification of the NuRFB or development of a new diet formulation may be needed, particularly for long term spaceflights. Research in this area consists primarily of internal technical reports that are not readily accessible. Therefore, the aims of this contribution are to provide a brief history of the development of rodent spaceflight diets, to review the present diet used in rodent spaceflight studies, and to discuss some of the challenges and potential solutions for diets to be used in future long-term rodent spaceflight studies. PMID:24012282

  9. Prevalence and Diversity of Bartonella Species in Commensal Rodents and Ectoparasites from Nigeria, West Africa

    PubMed Central

    Kamani, Joshua; Morick, Danny; Mumcuoglu, Kosta Y.; Harrus, Shimon

    2013-01-01

    Background Bartonellae are fastidious bacteria causing persistent bacteremia in humans and a wide variety of animals. In recent years there is an increasing interest in mammalian bartonelloses in general and in rodent bartonelloses in particular. To date, no studies investigating the presence of Bartonella spp. in rodents and ectoparasites from Nigeria were carried out. Methodology/Principal Findings The aim of the current study was to investigate the presence of Bartonella spp. in commensal rodents and their ectoparasites in Nigeria. We report, for the first time, the molecular detection of Bartonella in 26% (46/177) of commensal rodents (Rattus rattus, R. norvegicus and Cricetomys gambianus) and 28% (9/32) of ectoparasite pools (Xenopsylla cheopis, Haemolaelaps spp., Ctenophthalmus spp., Hemimerus talpoides, and Rhipicephalus sanguineus) from Nigeria. Sequence analysis of the citrate synthase gene (gltA) revealed diversity of Bartonella spp. and genotypes in Nigerian rodents and their ectoparasites. Bartonella spp. identical or closely related to Bartonella elizabethae, Bartonella tribocorum and Bartonella grahamii were detected. Conclusions/Significance High prevalence of infection with Bartonella spp. was detected in commensal rodents and ectoparasites from Nigeria. The Bartonella spp. identified were previously associated with human diseases highlighting their importance to public health. Further studies need to be conducted to determine whether the identified Bartonella species could be responsible for human cases of febrile illness in Nigeria. PMID:23738028

  10. Behavioral Assessment of Intermittent Wheel Running and Individual Housing in Mice in the Laboratory

    Microsoft Academic Search

    Therese M. Pham; Stefan Brené; Vera Baumans

    Physical cage enrichment—exercise devices for rodents in the laboratory—often in- cludes running wheels. This study compared responses of mice in enriched physical and social conditions and in standard social conditions to wheel running, individual housing, and open-field test. The study divided into 6 groups, 48 female BALB\\/c mice group housed in enriched and standard conditions. On alternate days, the study

  11. 6Mercaptopurine reverses experimental vasospasm and alleviates the production of endothelins in NO-independent mechanism—a laboratory study

    Microsoft Academic Search

    Chih-Zen Chang; Shu-Chuan Wu; Aij-Lie Kwan; Chih-Long Lin; Shiuh-Lin Hwang

    2011-01-01

    Introduction  Increased endothelin-1 (ET-1) production and diminished nitric oxide synthase (NOS) bioavailability has been observed in aneurysmal\\u000a subarachnoid hemorrhage (SAH). The authors previously found that 6-mercaptopurine (6-mp) is effective in preventing and reversing\\u000a arterial narrowing in a rodent SAH model. This present study is of interest to examine the effect of 6-mp on ET-1\\/endothelial\\u000a nitric oxide synthase (eNOS) in this animal

  12. The effect of area size and predation on the time to extinction of prairie vole populations. simulation studies via SERDYCA: a Spatially-Explicit Individual-Based Model of Rodent Dynamics

    SciTech Connect

    Kostova, T; Carlsen, T

    2003-11-21

    We present a spatially-explicit individual-based computational model of rodent dynamics, customized for the prairie vole species, M. Ochrogaster. The model is based on trophic relationships and represents important features such as territorial competition, mating behavior, density-dependent predation and dispersal out of the modeled spatial region. Vegetation growth and vole fecundity are dependent on climatic components. The results of simulations show that the model correctly predicts the overall temporal dynamics of the population density. Time-series analysis shows a very good match between the periods corresponding to the peak population density frequencies predicted by the model and the ones reported in the literature. The model is used to study the relation between persistence, landscape area and predation. We introduce the notions of average time to extinction (ATE) and persistence frequency to quantify persistence. While the ATE decreases with decrease of area, it is a bell-shaped function of the predation level: increasing for 'small' and decreasing for 'large' predation levels.

  13. Towards an integrative model of sociality in caviomorph rodents

    PubMed Central

    Hayes, Loren D.; Burger, Joseph Robert; Soto-Gamboa, Mauricio; Sobrero, Raúl; Ebensperger, Luis A

    2012-01-01

    In the late 1990s and early 2000s it was recognized that behavioral ecologists needed to study the sociality of caviomorph rodents (New World hystricognaths) before generalizations about rodent sociality could be made. Researchers identified specific problems facing individuals interested in caviomorph sociality, including a lack of information on the proximate mechanisms of sociality, role of social environment in development, and geographical or intraspecific variation in social systems. Since then researchers have described the social systems of many previously understudied species, including some with broad geographical ranges. Researchers have done a good job of determining the role of social environments in development and identifying the costs and benefits of social living. However, relatively little is known about the proximate mechanisms of social behavior and fitness consequences, limiting progress toward the development of integrative (evolutionary-mechanistic) models for sociality. To develop integrative models behavioral ecologists studying caviomorph rodents must generate information on the fitness consequences of different types of social organization, brain mechanisms, and endocrine substrates of sociality. We review our current understanding and future directions for research in these conceptual areas. A greater understanding of disease ecology, particularly in species carrying Old World parasites, is needed before we can identify potential links between social phenotypes, mechanism, and fitness. PMID:22328791

  14. Laboratory studies of heterogeneous processes relevant to Mars

    NASA Astrophysics Data System (ADS)

    Gough, Raina V.

    Heterogeneous (gas-surface) processes may play an important role in both the atmospheric and surface chemistry of Mars. Atmospheric species may be affected by the chemistry and physical properties of the planetary surface and the surface material may be affected by the components and properties of the atmosphere. In this thesis, several laboratory studies are described which experimentally investigate two types of atmosphere-surface systems likely to exist on Mars. First, experiments were performed to better understand the spatial and temporal variability of atmospheric methane (CH4) on Mars. Reported CH4 plumes in the atmosphere of Mars are difficult to explain using known chemical or physical processes. The observations imply a strong, present-day source and also a rapid yet unknown CH4 sink. We have investigated the potential role of mineral dust in CH4 variability. First, using a Knudsen cell capable of simulating Martian temperature and pressure conditions, we have studied the adsorption of CH4 to a Martian mineral analog as a function of temperature. An uptake coefficient was determined and then applied to the Martian surface-atmosphere system. Our results suggest that adsorption to soil grains could possibly affect the CH4 mixing ratio on a seasonal time scale especially at mid-latitude regions. Additionally, chemical oxidation of CH4 by oxidants thought to exist in the Martian regolith was studied. The Viking mission in the 1970's found Martian soil was able to oxidize complex organic compounds to CO 2. The identity of the oxidant is unknown, but has been proposed to be either hydrogen peroxide or perchlorate salts. We used a gas chromatograph to determine if simulated Mars soil containing these oxidants was able to oxidize CH4 to CO2. However, no CH4 was oxidized within the detection limit of the instrument and only an upper limit reaction coefficient could be reported. Even these upper limit values suggest CH 4 could not be removed from the Martian atmosphere rapidly enough to cause variability. We have also studied the interactions of another important trace gas on Mars, water vapor, with perchlorate, a highly deliquescent salt recently discovered in polar soil. A Raman microscope equipped with an environmental cell was used to study phase transitions of the salts. The relative humidity (RH) at which deliquescence (absorption of water vapor by the solid to become an aqueous solution) and efflorescence (crystallization of the aqueous solution) occur were determined as a function of temperature, hydration state and associated cation. We show that the deliquescence RH for perchlorate salts can be low (˜40% RH for anhydrous sodium perchlorate, for example). Thermodynamics can predict deliquescence; however, the kinetic inhibition of crystallization causes efflorescence to occur at much lower RH values than deliquescence which allows supersaturated salt solutions to exist in a metastable state. Based on the diurnal RH and temperature cycles on Mars, aqueous solutions could be stable or metastable for several hours a day at the Phoenix landing site. The astrobiological implications of potential liquid H2O on Mars are significant.

  15. Laboratory Studies of Predation by Euphausiid Shrimps on Fish Larvae

    Microsoft Academic Search

    G. H. Theilacker; R. Lasker

    Our experiments were designed to determine whether euphausiids could capture fish larvae, and if so, how many and under what conditions. We have combined our laboratory findings with the field data given by Brinton (1967 and unpublished) to estimate the mortality of northern anchovy larvae that may be caused by co-occurring E. pacifica. Of the oceanic zooplankters which frequent the

  16. Studies: Educational Laboratory Theatre Project, 1966-70. Final Report.

    ERIC Educational Resources Information Center

    Hoetker, James; And Others

    This second volume of four which comprise the final report on the Educational Laboratory Theatre Project (1966-1970) is composed of the following chapters: (1) The End-of-the-Project Questionnaire: Additional Analyses; (2) Alumni Clubs; (3) The Curriculum Portfolios and Teachers' Uses of Them; (4) Drama in the Secondary English Class; Actor and…

  17. TROPICAL CENTER FOR EARTH AND SPACE STUDIES SPACE INFORMATION LABORATORY

    E-print Network

    Gilbes, Fernando

    BY FERNANDO GILBES Period: October 2004 to September 2005 The Geological and Environmental Remote Sensing spatial resolution of the available images and lack of appropriate equipment for field validation. A GER in the laboratory to determine the composition. Results indicate a change in magnitude in the reflectance curve

  18. Tethered variable gravity laboratory study: Low gravity process identification report

    NASA Technical Reports Server (NTRS)

    Briccarello, M.

    1989-01-01

    Experiments are described performable in the variable gravity environment, and the related compatible/beneficial residual accelerations, both for pure and applied research in the fields of Fluid Mechanics (static and dynamic), Materials Sciences (Crystal Growth, Metal and Alloy Solidification, Glasses, etc.), and Life Sciences, so as to assess the relevance of a variable G-level laboratory.

  19. Waste management study: Process development at Lawrence Livermore National Laboratory

    SciTech Connect

    Not Available

    1984-12-01

    This report presents the results of an evaluation of the present Toxic Waste Control Operations at the Lawrence Livermore National Laboratory, evaluates the technologies most applicable to the treatment of toxic and hazardous wastes and presents conceptual designs of processes for the installation of a new decontamination and waste treatment facility (DWTF) for future treatment of these wastes.

  20. A Study of the Effectiveness of the Instructional Systems Laboratory.

    ERIC Educational Resources Information Center

    Philipson, Will D.; Chan-Tam, Pik Wai

    A survey examined perception and use of the services of the Instructional Systems Laboratory (ISL) by the faculty of the University of Minnesota's College of Education. The questionnaire, mailed to all College of Education faculty members, emphasized faculty perception of instructional systems in the following areas: (1) instructional commitment:…

  1. Pollination Systems of Colchicum (Colchicaceae) in Southern Africa: Evidence for Rodent Pollination

    PubMed Central

    Kleizen, Ciara; Midgley, Jeremy; Johnson, Steven D.

    2008-01-01

    Background and Aims Plants adapted for pollination by rodents tend to exhibit a distinct floral syndrome that includes dull coloured and geoflorous inflorescences and nocturnal anthesis and nectar production. On the basis of their floral traits, it was predicted that two African Colchicum species (C. scabromarginatum and C. coloratum) are rodent-pollinated. Methods Field studies were carried out in the semi-arid Succulent Karoo region of South Africa. Live trapping of rodents was conducted and pollen loads on the rodents were quantified. The daily periodicity of nectar production was determined. Selective exclusion and controlled pollination experiments were also conducted. Key Results Live-trapped rodents were found to carry large amounts of Colchicum pollen on the fur of their snouts, and in their faeces. Birds were occasional pollinators of flowers of C. coloratum. During the evening, nectar volume and concentration increased for both species. When vertebrates were excluded from C. scabromarginatum and C. coloratum plants, there was a significant decrease in seed set compared with open control plants. By contrast, vertebrate exclusion did not significantly affect seed production of a congener, C. hantamense, which has floral traits associated with insect pollination. Breeding system experiments revealed that both C. scabromarginatum and C. coloratum require pollinators for seed production. Colchicum scabromarginatum is strictly self-incompatible, whereas C. coloratum is partially self-compatible. Conclusions Pollination by rodents occurs in two African Colchicum species. C. scabromarginatum appears to depend exclusively on rodents for seed production, while birds and autonomous selfing may contribute to seed production in C. coloratum. These are the first records of rodent pollination in the Colchicaceae. PMID:18723860

  2. Trypanosoma from rodents as potential source of infection in human-shaped landscapes of South-East Asia.

    PubMed

    Pumhom, Pornpan; Morand, Serge; Tran, Annelise; Jittapalapong, Sathaporn; Desquesnes, Marc

    2015-03-15

    Reports of atypical human cases of Trypanosoma lewisi or T. lewisi-like and Trypanosoma evansi infections have increased in South-East Asia, urging to investigate the possible links between humans, animal reservoirs and habitats. We tested how habitat structure affects the infection by Trypanosoma species of common murine rodents, inhabiting human-dominated landscapes in South East Asia. For this, we used geo-referenced data of rodents investigated for Trypanosoma infection and land cover maps produced for seven study sites in Thailand, Cambodia and Lao PDR. High prevalence of infection by T. lewisi was observed in rodents living near human settlement and in areas with high cover of built-up habitat, while the infection of rodents by T. evansi was explained by increased landscape patchiness and high cover of rain-fed agriculture lands. These results suggest a likely role of wild rodents as reservoir and possible source of atypical human infection by animal trypanosomes. PMID:25613476

  3. Isolating human DNA repair genes using rodent-cell mutants

    SciTech Connect

    Thompson, L.H.; Weber, C.A.; Brookman, K.W.; Salazar, E.P.; Stewart, S.A.; Mitchell, D.L.

    1987-03-23

    The DNA repair systems of rodent and human cells appear to be at least as complex genetically as those in lower eukaryotes and bacteria. The use of mutant lines of rodent cells as a means of identifying human repair genes by functional complementation offers a new approach toward studying the role of repair in mutagenesis and carcinogenesis. In each of six cases examined using hybrid cells, specific human chromosomes have been identified that correct CHO cell mutations affecting repair of damage from uv or ionizing radiations. This finding suggests that both the repair genes and proteins may be virtually interchangeable between rodent and human cells. Using cosmid vectors, human repair genes that map to chromosome 19 have cloned as functional sequences: ERCC2 and XRCC1. ERCC1 was found to have homology with the yeast excision repair gene RAD10. Transformants of repair-deficient cell lines carrying the corresponding human gene show efficient correction of repair capacity by all criteria examined. 39 refs., 1 fig., 1 tab.

  4. Joshua tree (Yucca brevifolia) seeds are dispersed by seed-caching rodents

    USGS Publications Warehouse

    Vander Wall, S. B.; Esque, T.; Haines, D.; Garnett, M.; Waitman, B.A.

    2006-01-01

    Joshua tree (Yucca brevifolia) is a distinctive and charismatic plant of the Mojave Desert. Although floral biology and seed production of Joshua tree and other yuccas are well understood, the fate of Joshua tree seeds has never been studied. We tested the hypothesis that Joshua tree seeds are dispersed by seed-caching rodents. We radioactively labelled Joshua tree seeds and followed their fates at five source plants in Potosi Wash, Clark County, Nevada, USA. Rodents made a mean of 30.6 caches, usually within 30 m of the base of source plants. Caches contained a mean of 5.2 seeds buried 3-30 nun deep. A variety of rodent species appears to have prepared the caches. Three of the 836 Joshua tree seeds (0.4%) cached germinated the following spring. Seed germination using rodent exclosures was nearly 15%. More than 82% of seeds in open plots were removed by granivores, and neither microsite nor supplemental water significantly affected germination. Joshua tree produces seeds in indehiscent pods or capsules, which rodents dismantle to harvest seeds. Because there is no other known means of seed dispersal, it is possible that the Joshua tree-rodent seed dispersal interaction is an obligate mutualism for the plant.

  5. Seven Principles of Instructional Content Design for a Remote Laboratory: A Case Study on ERRL

    ERIC Educational Resources Information Center

    Cagiltay, N. E.; Aydin, E.; Aydin, C. C.; Kara, A.; Alexandru, M.

    2011-01-01

    This paper discusses the results of a study of the requirements for developing a remote radio frequency (RF) laboratory for electrical engineering students. It investigates students' preferred usage of the technical content of a state-of-the-art RF laboratory. The results of this study are compared to previous findings, which dealt with other user…

  6. Rodent models of neuroinflammation for Alzheimer's disease.

    PubMed

    Nazem, Amir; Sankowski, Roman; Bacher, Michael; Al-Abed, Yousef

    2015-01-01

    Alzheimer's disease remains incurable, and the failures of current disease-modifying strategies for Alzheimer's disease could be attributed to a lack of in vivo models that recapitulate the underlying etiology of late-onset Alzheimer's disease. The etiology of late-onset Alzheimer's disease is not based on mutations related to amyloid-? (A?) or tau production which are currently the basis of in vivo models of Alzheimer's disease. It has recently been suggested that mechanisms like chronic neuroinflammation may occur prior to amyloid-? and tau pathologies in late-onset Alzheimer's disease. The aim of this study is to analyze the characteristics of rodent models of neuroinflammation in late-onset Alzheimer's disease. Our search criteria were based on characteristics of an idealistic disease model that should recapitulate causes, symptoms, and lesions in a chronological order similar to the actual disease. Therefore, a model based on the inflammation hypothesis of late-onset Alzheimer's disease should include the following features: (i) primary chronic neuroinflammation, (ii) manifestations of memory and cognitive impairment, and (iii) late development of tau and A? pathologies. The following models fit the pre-defined criteria: lipopolysaccharide- and PolyI:C-induced models of immune challenge; streptozotocin-, okadaic acid-, and colchicine neurotoxin-induced neuroinflammation models, as well as interleukin-1?, anti-nerve growth factor and p25 transgenic models. Among these models, streptozotocin, PolyI:C-induced, and p25 neuroinflammation models are compatible with the inflammation hypothesis of Alzheimer's disease. PMID:25890375

  7. Studies with a laboratory atmospheric fluidized bed combustor system

    SciTech Connect

    Orndorff, W.W.; Su, Shi; Napier, J. [Western Kentucky Univ., Bowling Green, KY (United States)] [and others

    1996-12-31

    Growing public concerns over acid rain and municipal solid waste problems have created interest in the development of atmospheric fluidized bed combustion systems. A computer controlled 12-inch laboratory atmospheric fluidized bed combustor (AFBC) system has been developed at Western Kentucky University. On-line analysis by gas chromatography, Fourier-transform infrared (FTIR) spectrometry, and mass spectrometry (MS) allows extensive analysis of the flux gases. Laboratory experiments with a thermogravimetric analyzer (TGA) interfaced with FTIR and MS systems are used to screen fuel blends for runs in the AFBC system. Current experiments being conducted include co-firing blends of refuse derived fuels with coal and extended burns with coals containing different levels of chlorine.

  8. Oral treatment of rodents with insecticides for control of sand flies (Diptera: Psychodidae) and the fluorescent tracer technique (FTT) as a tool to evaluate potential sand fly control methods.

    PubMed

    Mascari, T M; Clark, J; Gordon, S; Mitchell, M A; Rowton, E D; Stout, R; Foil, L D

    2011-03-01

    In laboratory studies, insecticides (diflubenzuron, novaluron, methoprene and, pyriproxyfen) that have been incorporated into rodent diets were effective as feed-throughs against sand fly larvae. Novaluron also was effective against sand fly larvae at low concentrations and under simulated field conditions. Ivermectin has been shown to be effective as a systemic insecticide, killing 100% of blood-feeding sand flies for up to seven d after rodents were treated. The fluorescent tracer technique (FTT) is the use of certain fluorescent dyes (rhodamine B or uranine O) as feed-through transtadial biomarkers for phlebotomine sand flies, systemic biomarkers for blood-feeding sand flies, and permanent markers for nectar-feeding sand flies. The results of these laboratory studies provide proof of concept for the FTT and indicate that the FTT could be used to delineate specific foci with rodent/sand fly associations that would be susceptible to control by using feed-through or systemic insecticides, or foci where insecticide-treated sugar baits could be used against sand flies. PMID:21366765

  9. Laboratory Studies of Organic Compounds With Reflectance Spectroscopy

    Microsoft Academic Search

    J. M. Curchin; R. N. Clark; T. M. Hoefen

    2007-01-01

    In order to properly interpret reflectance spectra of any solar system surface from the earth to the Oort cloud, laboratory spectra of candidate materials for comparative analysis are needed. Although the common cosmochemical species (H2O, CO2, CO, NH3, and CH4) are well represented in the spectroscopic literature, comparatively little reflectance work has been done on organics from room to cryogenic

  10. The MAM rodent model of schizophrenia

    PubMed Central

    Lodge, Daniel J.

    2013-01-01

    Rodent models of human disease are essential to obtain a better understanding of disease pathology, the mechanism of action underlying conventional treatments, as well as for the generation of novel therapeutic approaches. There are a number of rodent models of schizophrenia based on either genetic manipulations, acute or sub-chronic drug administration, or developmental disturbances. The prenatal methylazoxymethanol acetate (MAM) rodent model is a developmental disruption model gaining increased attention because it displays a number of histological, neurophysiological and behavioral deficits analogous to those observed in schizophrenia patients. This unit describes the procedures required to safely induce the MAM phenotype in rats. In addition, we describe a simple behavioral procedure, amphetamine-induced hyper-locomotion, which can be utilized to verify the MAM phenotype. PMID:23559309

  11. A SURVEY OF LABORATORY AND STATISTICAL ISSUES RELATED TO FARMWORKER EXPOSURE STUDIES

    EPA Science Inventory

    Developing internally valid, and perhaps generalizable, farmworker exposure studies is a complex process that involves many statistical and laboratory considerations. Statistics are an integral component of each study beginning with the design stage and continuing to the final da...

  12. Chemical carcinogenesis: too many rodent carcinogens.

    PubMed Central

    Ames, B N; Gold, L S

    1990-01-01

    The administration of chemicals at the maximum tolerated dose (MTD) in standard animal cancer tests is postulated to increase cell division (mitogenesis), which in turn increases rates of mutagenesis and thus carcinogenesis. The animal data are consistent with this mechanism, because a high proportion--about half--of all chemicals tested (whether natural or synthetic) are indeed rodent carcinogens. We conclude that at the low doses of most human exposures, where cell killing does not occur, the hazards to humans of rodent carcinogens may be much lower than is commonly assumed. Images PMID:2217209

  13. Evaluation of bioaccumulation using in vivo laboratory and field studies.

    PubMed

    Weisbrod, Annie V; Woodburn, Kent B; Koelmans, Albert A; Parkerton, Thomas F; McElroy, Anne E; Borgå, Katrine

    2009-10-01

    A primary consideration in the evaluation of chemicals is the potential for substances to be absorbed and retained in an organism's tissues (i.e., bioaccumulated) at concentrations sufficient to pose health concerns. Substances that exhibit properties that enable biomagnification in the food chain (i.e., amplification of tissue concentrations at successive trophic levels) are of particular concern due to the elevated long-term exposures these substances pose to higher trophic organisms, including humans. Historically, biomarkers of in vivo chemical exposure (e.g., eggshell thinning, bill deformities) retrospectively led to the identification of such compounds, which were later categorized as persistent organic pollutants. Today, multiple bioaccumulation metrics are available to quantitatively assess the bioaccumulation potential of new and existing chemicals and identify substances that, upon or before environmental release, may be characterized as persistent organic pollutants. This paper reviews the various in vivo measurement approaches that can be used to assess the bioaccumulation of chemicals in aquatic or terrestrial species using laboratory-exposed, field-deployed, or collected organisms. Important issues associated with laboratory measurements of bioaccumulation include appropriate test species selection, test chemical dosing methods, exposure duration, and chemical and statistical analyses. Measuring bioaccumulation at a particular field site requires consideration of which test species to use and whether to examine natural populations or to use field-deployed populations. Both laboratory and field methods also require reliable determination of chemical concentrations in exposure media of interest (i.e., water, sediment, food or prey, etc.), accumulated body residues, or both. The advantages and disadvantages of various laboratory and field bioaccumulation metrics for assessing biomagnification potential in aquatic or terrestrial food chains are discussed. Guidance is provided on how to consider the uncertainty in these metrics and develop a weight-of-evidence evaluation that supports technically sound and consistent persistent organic pollutant and persistent, bioaccumulative, and toxic chemical identification. Based on the bioaccumulation information shared in 8 draft risk profiles submitted for review under the United Nations Stockholm Convention, recommendations are given for the information that is most critical to aid transparency and consistency in decision making. PMID:19552500

  14. Toxicological study of plant extracts on termite and laboratory animals.

    PubMed

    Rahman, I; Gogoi, Inee; Dolui, A K; Handique, Ruma

    2005-04-01

    Toxic activity of leaf extracts of Polygonum hydropiper L. and Pogostemon parviflorus Benth. were tested in the laboratory against tea termite, Odontotermes assamensis Holm. Both the tested extracts caused mortality of the termite. The highest toxic activity (100%) was found in the 2.0% chloroform extracts of P. hydropiper. The chloroform extract of P. hydropiper was explored for possible mammalian toxicological effects. The LD50 was 758.58 mg/kg in male albino mice. Subcutaneous injection of sub-lethal dose of extract into male mice once a week for 6 weeks failed to express any significant influence on WBC, RBC count and blood cholesterol. PMID:16161979

  15. A laboratory study of the activities of dried rumen microorganisms 

    E-print Network

    Harbers, Leniel Henry

    1958-01-01

    the yrslncubatlon time vas Iengthened, the values in Table 4 are all insignificantly lov ln comparison vith those obtained by the use of' fresh rumen liquid as an inoculum. The use of dry milk solids or cellulose as protective agents during the lyoyhlllsatlon... for the cellulose digestion experiments. cPrepared in the laboratory. TAELE 4 ~ EPPES OP PHEINOUBATION WITH OABBO3GNETHYL -ELLULO. "&E ON ~ ~ ~ELLULOGE DIGEETION HY DRIED RZfZN ~P. PGANIGK~ Lyophiliaed remen liquid ?O l. l 0. $ Presh rumen fluid (control...

  16. Helicobacter acinonychis: Genetic and Rodent Infection Studies of a Helicobacter pylori-Like Gastric Pathogen of Cheetahs and Other Big Cats

    Microsoft Academic Search

    Daiva Dailidiene; Giedrius Dailide; Keiji Ogura; Maojun Zhang; Asish K. Mukhopadhyay; Kathryn A. Eaton; Giovanni Cattoli; Johannes G. Kusters; Douglas E. Berg

    2004-01-01

    Insights into bacterium-host interactions and genome evolution can emerge from comparisons among related species. Here we studied Helicobacter acinonychis (formerly H. acinonyx), a species closely related to the human gastric pathogen Helicobacter pylori. Two groups of strains were identified by randomly amplified polymorphic DNA fingerprinting and gene sequencing: one group from six cheetahs in a U.S. zoo and two lions

  17. [Tuberculosis Laboratory Surveillance Network (TuLSA) study group. The fi rst step for national tuberculosis laboratory surveillance: Ankara, 2011].

    PubMed

    Sezen, Figen; Albayrak, Nurhan; Özkara, ?eref; Karagöz, Alper; Alp, Alpaslan; Duyar A?ca, Filiz; ?nan Süer, Asiye; Müderris, Tuba; Ceyhan, ?smail; Durmaz, R?za; Ertek, Mustafa; Tüberküloz Laboratuvar Sürveyans A?? Tulsa Çal??ma Grubu, Tulsa

    2015-04-01

    The most effective method for monitoring country-level drug resistance frequency and to implement the necessary control measures is the establishment of a laboratory-based surveillance system. The aim of this study was to summarize the follow up trend of the drug-resistant tuberculosis (TB) cases, determine the load of resistance and evaluate the capacities of laboratories depending on laboratory quality assurance system for the installation work of National Tuberculosis Laboratory Surveillance Network (TuLSA) which has started in Ankara in 2011. TuLSA studies was carried out under the coordination of National Tuberculosis Reference Laboratory (NRL) with the participation of TB laboratories and dispensaries. Specimens of TB patients, reported from health institutions, were followed in TB laboratories, and the epidemiological information was collected from the dispensaries. One isolate per patient with the drug susceptibility test (DST) results were sent to NRL from TB laboratories and in NRL the isolates were rechecked with the genotypical (MTBDRplus, Hain Lifescience, Germany) and phenotypical (MGIT 960, BD, USA) DST methods. Molecular epidemiological analysis were also performed by spoligotyping and MIRU/VNTR. Second-line DST was applied to the isolates resistant to rifampin. A total of 1276 patients were reported between January 1st to December 31th 2011, and 335 cases were defined as "pulmonary TB from Ankara province". The mean age of those patients was 43.4 ± 20 years, and 67.5% were male. Three hundred seventeen (94.6%) patients were identified as new cases. The average sample number obtained from pulmonary TB cases was 3.26 ± 2.88, and 229 (68.3%) of them was culture positive. DST was applied to all culture positive isolates; 90.4% (207/229) of cases were susceptible to the five drugs tested (ethambutol, isoniazid, pyrazinamide, rifampicin, streptomycin). Eight (3.5%) of the isolates were multidrug-resistant (MDR-TB), while no extensively drug-resistant strains were detected. MDR-TB is likely to occur in 63.3 times more among previously treated cases, and 73.3 times more in legal aliens. The achievement of therapy among pulmonary TB cases was 91.9%. Spoligotyping performed for 221 M.tuberculosis complex isolates, showed that all strains were clustered in nine groups. SIT 41 (105/221; 47.5%) was the most frequent spoligotype detected, and clustering rate based on MIRU-VNTR results were found as 16.3%. All of the clustered strains were sensitive while all of MDR-TB isolates showed specific MIRU-VNTR profiles. In conclusion, TuLSA studies started in Ankara in 2011 and the system is still expanding in the country. Our data obtained with TuLSA have been published as a regional surveillance data in the WHO Global Tuberculosis Report 2011, and as a national surveillance data in Global Tuberculosis Report 2012. PMID:26167815

  18. Mammalogy Laboratory 6 -Rodents II: Castoridae, Geomyidae, Heteromyidae, Dipodidae, Muridae

    E-print Network

    Sullivan, Jack

    Heteromyidae (Pocket mice, Kangaroo rats, Kangaroo mice) Diagnosis: External fur-lined cheek pouches (Desert pocket mouse)* Dipodomys ordii (Ord's kangaroo rat) D. microps (Chisel-toothed kangaroo rat) D. heermani (Heerman's kangaroo rat)* Microdipodops megacephalus (Dark kangaroo mouse) *Not an Idaho species

  19. Mammalogy Laboratory 5 -Rodents I: Hystricognathi, Sciuridae, Aplodontidae

    E-print Network

    Sullivan, Jack

    : Erethizon dorsatum (Porcupine) #12;3 Family Myocastoridae (Nutria or Coypu) Diagnosis: Robust; pes much; nocturnal. Range: North, Central and South America Representative Genera: Erethizon, Coendu Material in Lab

  20. Forest rodents provide directed dispersal of Jeffrey pine seeds

    USGS Publications Warehouse

    Briggs, J.S.; Wall, S.B.V.; Jenkins, S.H.

    2009-01-01

    Some species of animals provide directed dispersal of plant seeds by transporting them nonrandomly to microsites where their chances of producing healthy seedlings are enhanced. We investigated whether this mutualistic interaction occurs between granivorous rodents and Jeffrey pine (Pinus Jeffreyi) in the eastern Sierra Nevada by comparing the effectiveness of random abiotic seed dispersal with the dispersal performed by four species of rodents: deer mice (Peromyscus maniculatus), yellow-pine and long-eared chipmunks (Tamias amoenus and T. quadrimaculatus), and golden-mantled ground squirrels (Spermophilus lateralis). We conducted two caching studies using radio-labeled seeds, the first with individual animals in field enclosures and the second with a community of rodents in open forest. We used artificial caches to compare the fates of seeds placed at the range of microsites and depths used by animals with the fates of seeds dispersed abiotically. Finally, we examined the distribution and survival of naturally establishing seedlings over an eight-year period. Several lines of evidence suggested that this community of rodents provided directed dispersal. Animals preferred to cache seeds in microsites that were favorable for emergence or survival of seedlings and avoided caching in microsites in which seedlings fared worst. Seeds buried at depths typical of animal caches (5-25 mm) produced at least five times more seedlings than did seeds on the forest floor. The four species of rodents differed in the quality of dispersal they provided. Small, shallow caches made by deer mice most resembled seeds dispersed by abiotic processes, whereas many of the large caches made by ground squirrels were buried too deeply for successful emergence of seedlings. Chipmunks made the greatest number of caches within the range of depths and microsites favorable for establishment of pine seedlings. Directed dispersal is an important element of the population dynamics of Jeffrey pine, a dominant tree species in the eastern Sierra Nevada. Quantifying the occurrence and dynamics of directed dispersal in this and other cases will contribute to better understanding of mutualistic coevolution of plants and animals and to more effective management of ecosystems in which directed dispersal is a keystone process. ?? 2009 by the Ecological society of America.

  1. Forest rodents provide directed dispersal of Jeffrey pine seeds.

    PubMed

    Briggs, Jennifer S; Vander Wall, Stephen B; Jenkins, Stephen H

    2009-03-01

    Some species of animals provide directed dispersal of plant seeds by transporting them nonrandomly to microsites where their chances of producing healthy seedlings are enhanced. We investigated whether this mutualistic interaction occurs between granivorous rodents and Jeffrey pine (Pinus jeffreyi) in the eastern Sierra Nevada by comparing the effectiveness of random abiotic seed dispersal with the dispersal performed by four species of rodents: deer mice (Peromyscus maniculatus), yellow-pine and long-eared chipmunks (Tamias amoenus and T. quadrimaculatus), and golden-mantled ground squirrels (Spermophilus lateralis). We conducted two caching studies using radio-labeled seeds, the first with individual animals in field enclosures and the second with a community of rodents in open forest. We used artificial caches to compare the fates of seeds placed at the range of microsites and depths used by animals with the fates of seeds dispersed abiotically. Finally, we examined the distribution and survival of naturally establishing seedlings over an eight-year period. Several lines of evidence suggested that this community of rodents provided directed dispersal. Animals preferred to cache seeds in microsites that were favorable for emergence or survival of seedlings and avoided caching in microsites in which seedlings fared worst. Seeds buried at depths typical of animal caches (5-25 mm) produced at least five times more seedlings than did seeds on the forest floor. The four species of rodents differed in the quality of dispersal they provided. Small, shallow caches made by deer mice most resembled seeds dispersed by abiotic processes, whereas many of the large caches made by ground squirrels were buried too deeply for successful emergence of seedlings. Chipmunks made the greatest number of caches within the range of depths and microsites favorable for establishment of pine seedlings. Directed dispersal is an important element of the population dynamics of Jeffrey pine, a dominant tree species in the eastern Sierra Nevada. Quantifying the occurrence and dynamics of directed dispersal in this and other cases will contribute to better understanding of mutualistic coevolution of plants and animals and to more effective management of ecosystems in which directed dispersal is a keystone process. PMID:19341138

  2. Subsite Awareness in Neuropathology Evaluation of National Toxicology Program (NTP) Studies: A Review of Select Neuroanatomical Structures with their Functional Significance in Rodents

    PubMed Central

    Rao, Deepa B.; Little, Peter B.; Sills, Robert

    2013-01-01

    This review manuscript is designed to serve as an introductory guide in neuroanatomy for toxicologic pathologists evaluating general toxicity studies. The manuscript provides an overview of approximately 50 neuroanatomical subsites and their functional significance across seven coronal sections of the brain. Also reviewed are three sections of the spinal cord, cranial and peripheral nerves (trigeminal and sciatic respectively), and intestinal autonomic ganglia. The review is limited to the evaluation of hematoxylin and eosin (H&E) stained tissue sections, as light microscopic evaluation of these sections is an integral part of the first-tier toxicity screening of environmental chemicals, drugs, and other agents. Prominent neuroanatomical sites associated with major neurological disorders are noted. This guide, when used in conjunction with detailed neuroanatomic atlases may aid in an understanding of the significance of functional neuroanatomy, thereby improving the characterization of neurotoxicity in general toxicity and safety evaluation studies. PMID:24135464

  3. Role of Macrophage Migration Inhibitory Factor in Obesity, Insulin Resistance, Type 2 Diabetes, and Associated Hepatic Co-Morbidities: A Comprehensive Review of Human and Rodent Studies

    PubMed Central

    Morrison, Martine C.; Kleemann, Robert

    2015-01-01

    Obesity is associated with a chronic low-grade inflammatory state that drives the ­development of obesity-related co-morbidities such as insulin resistance/type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular disease. This metabolic inflammation is thought to originate in the adipose tissue, which becomes inflamed and insulin resistant when it is no longer able to expand in response to excess caloric and nutrient intake. The production of inflammatory mediators by dysfunctional adipose tissue is thought to drive the development of more complex forms of disease such as type 2 diabetes and NAFLD. An important factor that may contribute to metabolic inflammation is the cytokine macrophage migration inhibitory factor (MIF). Increasing evidence suggests that MIF is released by adipose tissue in obesity and that it is also involved in metabolic and inflammatory processes that underlie the development of obesity-related pathologies. This review provides a comprehensive summary of our current knowledge on the role of MIF in obesity, its production by adipose tissue, and its involvement in the development of insulin resistance, type 2 diabetes, and NAFLD. We discuss the main findings from recent clinical studies in obese subjects and weight-loss intervention studies as well as results from clinical studies in patients with insulin resistance and type 2 diabetes. Furthermore, we summarize findings from experimental disease models studying the contribution of MIF in obesity and insulin resistance, type 2 diabetes, and hepatic lipid accumulation and fibrosis. Although many of the findings support a pro-inflammatory role of MIF in disease development, recent reports also provide indications that MIF may exert protective effects under certain conditions.

  4. Occurrence of ectoparasitic arthropods associated with rodents in Hail region northern Saudi Arabia.

    PubMed

    Asiry, Khalid A; Fetoh, Badr El-Sabah A

    2014-09-01

    Ectoparasitic arthropods are a diverse element of the Saudi fauna. Due to this, a survey of ectoparasites associated with rodents was conducted as a preliminary study in five districts of Hail region of northern Saudi Arabia for the first time. Ectoparasites extracted from 750 rodents were sampled and identified by recording their frequency of appearance. Results revealed that 1,287 ectoparasites infested 316 of the captured rodent hosts. These ectoparasites parasitized on four species of rodents including three species of rats Rattus rattus rattus, Rattus rattus frugivorus, and Rattus rattus alexandrinus and one species of mouse Acomys dimidiatus (Rodentia: Muridae). The ectoparasites belong to four different groups: ticks, fleas, lice, and mites. Ticks were the highest in the number, while fleas were the lowest among all the extracted ectoparasite groups. The collected ectoparasitic arthropods consisted of seven species. Ticks were of two species: Rhipicephalus turanicus and Rhipicephalus sanguineus (Acari: Ixodidae), fleas were of two species: Xenopsylla cheopis and Xenopsyllus conformis mycerini (Siphonaptera: Pulicidae), lice was a single species: Polyplax serrata (Anoplura: Hoplopleuridae), and mites were of two species: Laelaps nuttali and Laelaps echidninus (Mesostigmata: Laelapidae). The findings of the study showed that the intensity of infestation was varied between rodent host sexes, wherein females had the highest rate of parasitic infestation, and the parasitic index of appearance was very high for one group of parasites (i.e., ticks). The parasitic prevalence was 42.13 % on rodents, and mites were the most prevalent parasite species. Overall, this study was carried out to establish baseline data for ectoparasite-infested rodents in Hail region, Saudi Arabia, and may help for appropriate planning to control zoonotic diseases in this area. PMID:24838257

  5. Rough-legged buzzards, Arctic foxes and red foxes in a tundra ecosystem without rodents.

    PubMed

    Pokrovsky, Ivan; Ehrich, Dorothée; Ims, Rolf A; Kondratyev, Alexander V; Kruckenberg, Helmut; Kulikova, Olga; Mihnevich, Julia; Pokrovskaya, Liya; Shienok, Alexander

    2015-01-01

    Small rodents with multi-annual population cycles strongly influence the dynamics of food webs, and in particular predator-prey interactions, across most of the tundra biome. Rodents are however absent from some arctic islands, and studies on performance of arctic predators under such circumstances may be very instructive since rodent cycles have been predicted to collapse in a warming Arctic. Here we document for the first time how three normally rodent-dependent predator species-rough-legged buzzard, arctic fox and red fox - perform in a low-arctic ecosystem with no rodents. During six years (in 2006-2008 and 2011-2013) we studied diet and breeding performance of these predators in the rodent-free Kolguev Island in Arctic Russia. The rough-legged buzzards, previously known to be a small rodent specialist, have only during the last two decades become established on Kolguev Island. The buzzards successfully breed on the island at stable low density, but with high productivity based on goslings and willow ptarmigan as their main prey - altogether representing a novel ecological situation for this species. Breeding density of arctic fox varied from year to year, but with stable productivity based on mainly geese as prey. The density dynamic of the arctic fox appeared to be correlated with the date of spring arrival of the geese. Red foxes breed regularly on the island but in very low numbers that appear to have been unchanged over a long period - a situation that resemble what has been recently documented from Arctic America. Our study suggests that the three predators found breeding on Kolguev Island possess capacities for shifting to changing circumstances in low-arctic ecosystem as long as other small - medium sized terrestrial herbivores are present in good numbers. PMID:25692786

  6. Helicobacter acinonychis: Genetic and Rodent Infection Studies of a Helicobacter pylori-Like Gastric Pathogen of Cheetahs and Other Big Cats

    PubMed Central

    Dailidiene, Daiva; Dailide, Giedrius; Ogura, Keiji; Zhang, Maojun; Mukhopadhyay, Asish K.; Eaton, Kathryn A.; Cattoli, Giovanni; Kusters, Johannes G.; Berg, Douglas E.

    2004-01-01

    Insights into bacterium-host interactions and genome evolution can emerge from comparisons among related species. Here we studied Helicobacter acinonychis (formerly H. acinonyx), a species closely related to the human gastric pathogen Helicobacter pylori. Two groups of strains were identified by randomly amplified polymorphic DNA fingerprinting and gene sequencing: one group from six cheetahs in a U.S. zoo and two lions in a European circus, and the other group from a tiger and a lion-tiger hybrid in the same circus. PCR and DNA sequencing showed that each strain lacked the cag pathogenicity island and contained a degenerate vacuolating cytotoxin (vacA) gene. Analyses of nine other genes (glmM, recA, hp519, glr, cysS, ppa, flaB, flaA, and atpA) revealed a ?2% base substitution difference, on average, between the two H. acinonychis groups and a ?8% difference between these genes and their homologs in H. pylori reference strains such as 26695. H. acinonychis derivatives that could chronically infect mice were selected and were found to be capable of persistent mixed infection with certain H. pylori strains. Several variants, due variously to recombination or new mutation, were found after 2 months of mixed infection. H. acinonychis ' modest genetic distance from H. pylori, its ability to infect mice, and its ability to coexist and recombine with certain H. pylori strains in vivo should be useful in studies of Helicobacter infection and virulence mechanisms and studies of genome evolution. PMID:14702304

  7. Follow-Up Study of Graduates of the Medical Laboratory Technician Program.

    ERIC Educational Resources Information Center

    Kupel, Claudia

    A follow-up study to discover to what extent the education provided by the Medical Laboratory Technician program at Western Wisconsin Technical Institute has benefited the graduates and their employers was conducted. It was determined that 17 of the first 22 graduates were working successfully as medical laboratory technicians in eight states;…

  8. A laboratory study to determine the effect of iron oxides on proton NMR measurements

    E-print Network

    Knight, Rosemary

    in the laboratory, or in the field using a well-logging device or a system deployed at the earth's surface. NMRA laboratory study to determine the effect of iron oxides on proton NMR measurements Kristina and mineralogic form of iron on measured proton nuclear magnetic resonance NMR relaxation rates. Five samples

  9. Laboratory Practices of Beginning Secondary Science Teachers: A Five-Year Study

    ERIC Educational Resources Information Center

    Wong, Sissy S.; Firestone, Jonah B.; Luft, Julie A.; Weeks, Charles B.

    2013-01-01

    During the beginning years of teaching, science teachers develop the knowledge and skills needed to design and implement science laboratories. In this regard, this quantitative study focused on the reported laboratory practices of 61 beginning secondary science teachers who participated in four different induction programs. The results…

  10. Tested Studies for Laboratory Teaching Proceedings of the Association for Biology Laboratory Education

    E-print Network

    Aguirre, Windsor E.

    Education Vol. 34, 361-371, 2013 361 Landmark-Based Geometric Morphometrics: What Fish Shapes Can Tell Us are emphasized. Firstpage36 Keywords: threespine stickleback, morphometrics, body shape, foraging morphology Link Morphometrics is the study of size and shape of living organisms, which has traditionally been accomplished us

  11. Helicobacter acinonychis: genetic and rodent infection studies of a Helicobacter pylori-like gastric pathogen of cheetahs and other big cats.

    PubMed

    Dailidiene, Daiva; Dailide, Giedrius; Ogura, Keiji; Zhang, Maojun; Mukhopadhyay, Asish K; Eaton, Kathryn A; Cattoli, Giovanni; Kusters, Johannes G; Berg, Douglas E

    2004-01-01

    Insights into bacterium-host interactions and genome evolution can emerge from comparisons among related species. Here we studied Helicobacter acinonychis (formerly H. acinonyx), a species closely related to the human gastric pathogen Helicobacter pylori. Two groups of strains were identified by randomly amplified polymorphic DNA fingerprinting and gene sequencing: one group from six cheetahs in a U.S. zoo and two lions in a European circus, and the other group from a tiger and a lion-tiger hybrid in the same circus. PCR and DNA sequencing showed that each strain lacked the cag pathogenicity island and contained a degenerate vacuolating cytotoxin (vacA) gene. Analyses of nine other genes (glmM, recA, hp519, glr, cysS, ppa, flaB, flaA, and atpA) revealed a approximately 2% base substitution difference, on average, between the two H. acinonychis groups and a approximately 8% difference between these genes and their homologs in H. pylori reference strains such as 26695. H. acinonychis derivatives that could chronically infect mice were selected and were found to be capable of persistent mixed infection with certain H. pylori strains. Several variants, due variously to recombination or new mutation, were found after 2 months of mixed infection. H. acinonychis ' modest genetic distance from H. pylori, its ability to infect mice, and its ability to coexist and recombine with certain H. pylori strains in vivo should be useful in studies of Helicobacter infection and virulence mechanisms and studies of genome evolution. PMID:14702304

  12. Preclinical acute toxicity studies and rodent-based dosimetry estimates of the novel sigma-1 receptor radiotracer [ 18F]FPS

    Microsoft Academic Search

    Rikki N Waterhouse; Michael G Stabin; John G Page

    2003-01-01

    [18F]1-(Fluoropropyl)-4-[(4-cyanophenoxy)methyl]piperidine ([18F]FPS) is a novel high affinity (KD = 0.5 nM) sigma receptor radioligand that exhibits saturable and selective in vivo binding to sigma receptors in rats, mice and non-human primates. In order to support an IND application for the characterization of [18F]FPS through PET imaging studies in humans, single organ and whole body radiation adsorbed doses associated with [18F]FPS

  13. Dose and time-dependent sub-chronic toxicity study of hydroethanolic leaf extract of Flabellaria paniculata Cav. (Malpighiaceae) in rodents

    PubMed Central

    Akindele, Abidemi J.; Adeneye, Adejuwon A.; Salau, Oluwole S.; Sofidiya, Margaret O.; Benebo, Adokiye S.

    2014-01-01

    Flabellaria paniculata Cav. (Malpighiaceae) is a climbing shrub, the preparations of which are used in the treatment of wounds and ulcers in Nigeria and Ghana. This study investigated the sub-chronic toxicity profile of the hydroethanolic leaf extract of F. paniculata (HLE-FP). HLE-FP was administered p.o. (20, 100, and 500 mg/kg) for 30 and 60 days to different groups of rats. Control animals received 10 ml/kg distilled water. In the group of animals for reversibility study, HLE-FP administration ceased on the 60th day and animals were monitored for a further 15 days. Results showed that oral treatment with HLE-FP for 30 days caused significant (p < 0.05) reductions in weight gain pattern compared to control. These changes were sustained with 60 days treatment. However, no significant (p > 0.05) differences in relative organ weights between control and treatment groups were observed. HLE-FP-treated rats showed significant (p < 0.05) increases in Hb, PCV and RBC on day 30 and significant (p < 0.05) increases in MCV and MCH indices on day 60 compared to control. There were significant (p < 0.05) elevations in serum K+, urea and creatinine compared to control. The liver function tests showed slight but non-significant alterations in relevant parameters when compared to control. Biochemical findings were supported by histopathological observations of vital organs including the kidney and liver. Toxicities observed in respect of kidney function were irreversible at 15 days of stoppage of treatment. In the acute toxicity study, HLE-FP given p.o. caused no lethality at 5000 mg/kg but behavioral manifestations like restlessness, generalized body tremor, feed, and water refusal were observed. The i.p. LD50 was estimated to be 2951.2 mg/kg. Findings in this study showed that HLE-FP is relatively non-toxic on acute exposure and generally safe on sub-chronic administration, but could be deleterious on the kidneys on prolonged oral exposure at a high dose. Thus, caution should be exercised with its long-term usage. PMID:24795634

  14. Dose and time-dependent sub-chronic toxicity study of hydroethanolic leaf extract of Flabellaria paniculata Cav. (Malpighiaceae) in rodents.

    PubMed

    Akindele, Abidemi J; Adeneye, Adejuwon A; Salau, Oluwole S; Sofidiya, Margaret O; Benebo, Adokiye S

    2014-01-01

    Flabellaria paniculata Cav. (Malpighiaceae) is a climbing shrub, the preparations of which are used in the treatment of wounds and ulcers in Nigeria and Ghana. This study investigated the sub-chronic toxicity profile of the hydroethanolic leaf extract of F. paniculata (HLE-FP). HLE-FP was administered p.o. (20, 100, and 500 mg/kg) for 30 and 60 days to different groups of rats. Control animals received 10 ml/kg distilled water. In the group of animals for reversibility study, HLE-FP administration ceased on the 60th day and animals were monitored for a further 15 days. Results showed that oral treatment with HLE-FP for 30 days caused significant (p < 0.05) reductions in weight gain pattern compared to control. These changes were sustained with 60 days treatment. However, no significant (p > 0.05) differences in relative organ weights between control and treatment groups were observed. HLE-FP-treated rats showed significant (p < 0.05) increases in Hb, PCV and RBC on day 30 and significant (p < 0.05) increases in MCV and MCH indices on day 60 compared to control. There were significant (p < 0.05) elevations in serum K(+), urea and creatinine compared to control. The liver function tests showed slight but non-significant alterations in relevant parameters when compared to control. Biochemical findings were supported by histopathological observations of vital organs including the kidney and liver. Toxicities observed in respect of kidney function were irreversible at 15 days of stoppage of treatment. In the acute toxicity study, HLE-FP given p.o. caused no lethality at 5000 mg/kg but behavioral manifestations like restlessness, generalized body tremor, feed, and water refusal were observed. The i.p. LD50 was estimated to be 2951.2 mg/kg. Findings in this study showed that HLE-FP is relatively non-toxic on acute exposure and generally safe on sub-chronic administration, but could be deleterious on the kidneys on prolonged oral exposure at a high dose. Thus, caution should be exercised with its long-term usage. PMID:24795634

  15. Complete Genome Sequences of Novel Anelloviruses from Laboratory Rats

    PubMed Central

    Nishiyama, Shoko; Dutia, Bernadette M.

    2015-01-01

    Anelloviruses are nonenveloped single-stranded DNA viruses infecting a wide range of mammals. We report three complete genomes of novel anelloviruses detected in laboratory rats. Phylogenetic analysis demonstrates that these viruses are related to but distinct from recently described rodent Torque teno viruses (RoTTVs) found in wild rodent species. PMID:25657264

  16. Preclinical study of the systemic toxicity and pharmacokinetics of 5-iodo-2-deoxypyrimidinone-2'-deoxyribose as a radiosensitizing prodrug in two, non-rodent animal species: implications for phase I study design.

    PubMed

    Kinsella, T J; Schupp, J E; Davis, T W; Berry, S E; Hwang, H S; Warren, K; Balis, F; Barnett, J; Sands, H

    2000-09-01

    We have demonstrated previously an improved therapeutic index for oral 5-iodo-2-deoxypyrimidinone-2'-deoxyribose (IPdR) compared with oral and continuous infusion of 5-iodo-2'-deoxyuridine (IUdR) as a radiosensitizing agent using three different human tumor xenografts in athymic mice. IPdR is a prodrug that is efficiently converted to IUdR by a hepatic aldehyde oxidase, resulting in high IPdR and IUdR plasma levels in mice for > or =1 h after p.o. IPdR. Athymic mice tolerated oral IPdR at up to 1500 mg/kg/day given four times per day for 6-14 days without significant systemic toxicities. In anticipation of an investigational new drug application for the first clinical Phase I and pharmacology study of oral IPdR in humans, we studied the drug pharmacokinetics and host toxicities in two non-rodent, animal species. For the IPdR systemic toxicity and toxicology study, twenty-four male or female ferrets were randomly assigned to four IPdR dosage groups receiving 0, 15, 150, and 1500 mg/kg/day by oral gavage x 14 days prior to sacrifice on study day 15. All ferrets survived the 14-day treatment. Ferrets receiving 1500 mg/kg/day showed observable systemic toxicities with diarrhea, emesis, weight loss, and decreased motor activity beginning at days 5-8 of the 14-day schedule. Overall, both male and female ferrets receiving IPdR at 1500 mg/kg/day experienced significant weight loss (9 and 19%, respectively) compared with controls after the 14-day treatment. No weight loss or other systemic toxicities were observed in other IPdR dosage groups. Grossly, no anatomical lesions were noted at complete necropsy, although liver weights were increased in both male and female ferrets in the two higher IPdR dosage groups. Histologically, IPdR-treated animals showed dose-dependent microscopic changes in liver consisting of minimal to moderate cytoplasmic vacuolation of hepatocytes, which either occurred in the periportal area (high dosage group) or diffusely throughout the liver (lower dosage groups). Female ferrets in the highest IPdR dose group also showed decreased kidney and uterus weights at autopsy without any associated histological changes. No histological changes were found in central nervous system tissues. No significant abnormalities in blood cell counts, liver function tests, kidney function tests, or urinalysis were noted. Hepatic aldehyde oxidase activity was decreased to approximately 50 and 30% of control ferrets in the two higher IPdR dosage groups, respectively, after the 14-day treatment period. The % IUdR-DNA incorporation in ferret bone marrow at the completion of IPdR treatment was < or =0.05% in the two lower dosage groups and approximately 2% in the 1500 mg/kg/day dosage group. The % IUdR-DNA in normal liver was < or =0.05% in all IPdR dosage groups. In a pharmacokinetic study in four Rhesus monkeys, we determined the plasma concentrations of IPdR after a single i.v. bolus of 50 mg/kg over 20 min. Using a two-compartment model to fit the plasma pharmacokinetic data, we found that IPdR was cleared in these non-human primates in a biexponential manner with an initial rapid distributive phase (mean T1/2alpha = 6.5 min), followed by an elimination phase with a mean T1/2 of 63 min. The mean maximum plasma concentration of IPdR was 124+/-43 microM with a mean total body clearance of 1.75+/-0.95 l/h/kg. IPdR was below detection (<0.5 microM) in the cerebrospinal fluid. We conclude that there are dose-limiting systemic toxicities to a 14-day schedule of p.o. IPdR at 1500 mg/kg/day in ferrets that were not found previously in athymic mice. However, no significant hematological, biochemical, or histopathological changes were found. Hepatic aldehyde oxidase activity was reduced in a dose-dependent in ferret liver, suggesting partial enzyme saturation by this IPdR schedule. The plasma pharmacokinetic profile in Rhesus monkeys showing biexponential clearance is similar to our published data in athymic mice. These data are being applied PMID:10999760

  17. Strength of surgical wire fixation. A laboratory study.

    PubMed

    Guadagni, J R; Drummond, D S

    1986-08-01

    Because of the frequent use of stainless steel wire in spinal surgery and to augment fracture fixation, several methods of securing wire fixation were tested in the laboratory to determine the relative strength of fixation. Any method of fixation stronger than the yield strength of the wire is sufficient. Square knots, knot twists, symmetric twists, and the AO loop-tuck techniques afforded acceptable resistance against tension loads, but the wire wrap and AO loop technique were unacceptable. The double symmetric twist, which is frequently used for tension banding, was barely acceptable. The symmetric twist technique was the most practical because it is strong enough, efficient in maintaining tension applied during fixation, and least likely to cause damage to the wire. To optimize the fixation strength of the symmetrical twist, at least two twists are required at a reasonably tight pitch. PMID:3731592

  18. Renewable Energy Laboratory Development for Biofuels Advanced Combustion Studies

    SciTech Connect

    Soloiu, Valentin

    2012-03-31

    The research advanced fundamental science and applied engineering for increasing the efficiency of internal combustion engines and meeting emissions regulations with biofuels. The project developed a laboratory with new experiments and allowed investigation of new fuels and their combustion and emissions. This project supports a sustainable domestic biofuels and automotive industry creating economic opportunities across the nation, reducing the dependence on foreign oil, and enhancing U.S. energy security. The one year period of research developed fundamental knowledge and applied technology in advanced combustion, emissions and biofuels formulation to increase vehicle's efficiency. Biofuelsâ?? combustion was investigated in a Compression Ignition Direct Injection (DI) to develop idling strategies with biofuels and an Indirect Diesel Injection (IDI) intended for auxiliary power unit.

  19. [Liver cell function test based on selective laboratory studies].

    PubMed

    Sliwi?ska-Przyjemska, H; Pilawska, H

    1981-01-01

    Laboratory tests have been carried out in 517 workers of a Chemical Fibres Plant. This was aimed at the detection of the changes resulting from cumulative exposure to caprolactam, dowtherm and physical factors. There have been performed hematological investigations, uninalyses and biochemical tests: total protein level, activity of enzymes: ASPAT, ALAT, PA, ChE, thymol test. The results have been analysed as the mean values for particular divisions and workstands; then they have been compared with standards. In order to evaluate the degree of occupational exposure of particular groups of workers, an index of the liver cell damage has been calculated. It was expressed in % of the results exceeding the standards in relation to all results in a given group of workers. The highest values of the index were those in the group employed at the polymerization division. The authoresses promote the advisability of special care for this group of workers. PMID:7289867

  20. Feasibility study of an orbiting laboratory for testing CSI technology

    NASA Technical Reports Server (NTRS)

    Bicos, Andrew S.; Loboda, Gregory G.

    1993-01-01

    A concept for an orbiting laboratory for testing Controls-Structures Integration (CSI) technology is described. The CSI-Star concept reflects a lower cost, higher risk approach. The concept supports demonstration and validation testing for critical CSI technologies at a cost of $20M to $26M with a 1-year reliability of approximately 0.9. The Ball Aerospace QuickStar bus is the carrier for the CSI test article. QuickStar is launched as a secondary payload on the McDonnell Douglas Delta 2. The QuickStar/Delta 2 approach is flight proven. The CSI test article is a 20 foot, 1 Hz, truss beam which is deployed from the QuickStar bus. The test article is well instrumented for quality system identification. The laboratory provides three layers of active control consisting of global vibration suppression along the truss beam, vibration isolation between the beam and instrument platforms, and vibration compensation through the use of gimbaled platforms which point lasers relative to optical sensor targets. The configuration simulates the dynamics of multi-instrument science platforms such as those of the Earth Observation System (EOS) while maintaining strong ties to astrophysics missions such as the Optical Interferometer. Uplink/downlink services and a reprogrammable computer provide flexibility for long-term investigations by members of the CSI community (NASA, DoD, academia, and industry). CSI-Star fills the gap between short-term experiments, which have been conducted primarily on the Shuttle, and future science missions which require the technology. The on-orbit maturity of CSI technology must be established to obtain acceptance by project managers and to promote injection of the technology into future science missions.

  1. Pilot-Scale Fermentation and Laboratory Nutrient Studies on Mixed-Acid Fermentation

    E-print Network

    Smith, Aaron Douglas

    2011-08-08

    PILOT-SCALE FERMENTATION AND LABORATORY NUTRIENT STUDIES ON MIXED-ACID FERMENTATION A Dissertation by AARON DOUGLAS SMITH Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2011 Major Subject: Chemical Engineering PILOT-SCALE FERMENTATION AND LABORATORY NUTRIENT STUDIES ON MIXED-ACID FERMENTATION A Dissertation by AARON DOUGLAS SMITH...

  2. Chemical carcinogenesis: Too many rodent carcinogens

    Microsoft Academic Search

    B. N. Ames; L. S. Gold

    1990-01-01

    The administration of chemicals at the maximum tolerated dose (MTD) in standard animal cancer tests is postulated to increase cell division (mitogenesis), which in turn increases rates of mutagenesis and thus carcinogenesis. The animal data are consistent with this mechanism, because a high proportionâabout halfâof all chemicals tested (whether natural or synthetic) are indeed rodent carcinogens. The authors conclude that

  3. Too many rodent carcinogens: Mitogenesis increases mutagenesis

    Microsoft Academic Search

    B. N. Ames; L. S. Gold

    1990-01-01

    A clarification of the mechanism of carcinogenesis is developing at a rapid rate. This new understanding undermines many assumptions of current regulatory policy toward rodent carcinogens and necessitates rethinking the utility and meaning of routine animal cancer tests. At a recent watershed meeting on carcinogenesis, much evidence was presented suggesting that mitogenesis plays a dominant role in carcinogenesis. Our own

  4. Mycoplasmas and their role as rodent pathogens

    Microsoft Academic Search

    R. J. Fallon

    1967-01-01

    SUMMARY Mycoplasmas are the smallest known free-living form of life, and differ from bacteria in a number of characteristics. They are widely distributed in the animal kingdom and may give rise to both acute and latent infections as well as being present as normal flora. The three principal rodent pathogens so far described are Mycoplasma pulmonis, Mycoplasma arthritidis and Mycoplasma

  5. Object Recognition Memory and the Rodent Hippocampus

    ERIC Educational Resources Information Center

    Broadbent, Nicola J.; Gaskin, Stephane; Squire, Larry R.; Clark, Robert E.

    2010-01-01

    In rodents, the novel object recognition task (NOR) has become a benchmark task for assessing recognition memory. Yet, despite its widespread use, a consensus has not developed about which brain structures are important for task performance. We assessed both the anterograde and retrograde effects of hippocampal lesions on performance in the NOR…

  6. Effects of rodent poisoning on Powelliphanta traversi

    Microsoft Academic Search

    Shaun J. Bennett; Rachel J. Standish; Ian A. N. Stringer

    Rat predation is a threat to lowland Powelliphanta traversi (giant predatory land snail), and we have shown that 'press' poisoning of rodents (rats and mice) using brodifacoum baits significantly reduces rat abundance relative to non- poisoned areas. The effect on P. t. traversi was evident by the increase in population size, mainly due to adult migration, and a decrease in

  7. Learning Style and Laboratory Preference: A Study of Middle School Technology Education Teachers in Virginia

    NSDL National Science Digital Library

    Reed, Philip A.

    Laboratory instruction has long been a cornerstone of technology education pedagogy. The French realized the potential for technical laboratory instruction within general education in 1865 (Bennett, 1926). By the 1880s, the United States also realized the benefits of the technical laboratory for general education (Anderson, 1926). Despite these early roots and the continued practice of utilizing laboratory instruction within technology education, there is little research to support this teaching method. McCrory (1987) noted that there were no studies on laboratories (excluding machine safety) or new technology education equipment during the period 1980-1986. Laboratory studies during the period 1987-1993 concentrated on curriculum and did not focus on new instructional methods and strategies (Zuga, 1994). The adoption of modular technology education has only heightened the need for research on laboratory instructional methods. Since the middle of the 1980s, modular technology education has grown considerably. Brusic and LaPorte (2000) found that almost half of the technology education teachers they surveyed in Virginia taught in some type of modular lab. Despite such emerging research, opinions concerning the merit of modular technology education, especially commercially created packages, dominate the field of technology education. To address these opinions, this study investigated whether the preference for a conventional or modular laboratory is influenced by the learning style of the teacher. Target Audience: Middle School Faculty/Administrators

  8. Combining Methods in Evaluating Information Systems: Case Study of a Clinical Laboratory Information System

    PubMed Central

    Kaplan, Bonnie; Duchon, Dennis

    1989-01-01

    This paper reports how quantitative and qualitative methods were combined in a case study of a clinical laboratory information system. The study assessed effects of the system on work in the laboratories, as reported by laboratory technologists seven months post implementation. Primary changes caused by the computer system were increases in the amount of paperwork performed by technologists and improvements in laboratory results reporting. Individual technologists, as well as laboratories, differed in their assessments of the system according to their perceptions of how it affected their jobs. The combination of qualitative and quantitative data led to the development of a theoretical explanatory model of these differences. The paper discusses methodological implications and the need for an approach to evaluating medical computer systems that takes into account the inter-relationships and processes of which the system is a part.

  9. Effect of laser (? 660 nm) and LED (? 630 nm) photobiomodulation on formocresol-induced oral ulcers: a clinical and histological study on rodents.

    PubMed

    de Carvalho, Fabiola Bastos; Andrade, Aline Silva; Rasquin, Luis Cardoso; de Castro, Isabele Vieira; Cangussu, Maria Cristina Teixeira; Pinheiro, Antônio Luiz Barbosa; dos Santos, Jean Nunes

    2015-01-01

    The aim of this study was to evaluate, clinically and histologically, the influence of laser and LED photobiomodulation in the healing of formocresol-induced oral mucosa ulcers of rats. We used 60 Wistar rats in which oral ulcers were induced on the gingiva of the lower incisors. Forty-eight hours after inducing the ulcers, the animals were divided into three groups: laser, LED, and untreated. Animals from the laser group received irradiation with GaAlAs, 660 nm, CW, 40 mW, ? 4 mm(2), 4.8 J/cm(2). Animals from the LED group received irradiation with InGaAIP, 630 nm, 150 mW, 4.8 J/cm(2), 0.8 cm spot. Forty-eight hours after oral ulcer induction, both irradiations were applied in a punctuate manner in the center of the ulcer at 48-h interval until the end of the experimental period. The animals were killed at 3, 5, 7, and 11 days after day 0. The results of the clinical evaluation showed that the laser and LED phototherapies were able to accelerate the healing of formocresol-induced oral ulcers, which occurred first in the laser group (ANOVA, p?

  10. Performance testing of radiobioassay laboratories: In vitro measurements, fecal study report

    SciTech Connect

    MacLellan, J.A.

    1988-09-01

    This study evaluated nine radiobioassay laboratories; performances in analyzing fecal samples to determine the samples' levels of radioactivity. A total of 135 artificial fecal samples were sent to nine laboratories. Each laboratory received five samples spiked with 9. 58 pCi of /sup 239/Pu, five samples spiked with 1.13 pCi /sup 239/Pu, and five unspiked blank samples. Four of the laboratories returned data for all samples; four reported they were unable to complete the analyses; one analyzed six samples (three blanks and three of the lower activity samples). Results reported by the laboratories were analyzed by statistical methods specified in the draft standard for relative bias, relative precision, and minimum detectable activity (MDA). The calculated relative biases of all laboratories were well within the criteria of the standard (/minus/0.25 to +0.5). Biases for three laboratories were about 5% and the two others were within +-20%. Relative precision statistics for all participating laboratories were lower than the acceptance criteria of the standard (40%). Relative precision was less than 15% for one laboratory; for two others, it was less than 10%; and for the remaining two, it was less than 5% of the acceptance criteria. For the MDA criterion, four of the five laboratories passed. For all four of the passing laboratories, the entire 90% confidence interval was less than the specified acceptable minimum detectable amount (acceptable MDA) of 1 pCi. for the fifth laboratory, the MDA was 80% above the acceptable MDA specified in the draft standard. 16 refs., 3 figs., 3 tabs.

  11. Evidence from studies in rodents and in isolated adipocytes that agonists of the chemerin receptor CMKLR1 may be beneficial in the treatment of type 2 diabetes

    PubMed Central

    Wargent, Edward T.; Zaibi, Mohamed S.; O’Dowd, Jacqueline F.; Cawthorne, Michael A.; Wang, Steven J.; Stocker, Claire J.

    2015-01-01

    The literature is unclear on whether the adipokine chemerin has pro- or anti-inflammatory properties or plays any role in the aetiology of type 2 diabetes or obesity. To address these questions, and in particular the potential of agonists or antagonists of the chemerin receptor CMKLR1 in the treatment of type 2 diabetes and obesity, we studied the metabolic phenotypes of both male and female, CMKLR1 knockout and heterozygote mice. We also investigated changes in plasma chemerin levels and chemerin gene mRNA content in adipose tissue in models of obesity and diabetes, and in response to fasting or administration of the insulin sensitizing drug rosiglitazone, which also has anti-inflammatory properties. The effects of murine chemerin and specific C-terminal peptides on glucose uptake in wild-type and CMKLR1 knockout adipocytes were investigated as a possible mechanism by which chemerin affects the blood glucose concentration. Both male and female CMKLR1 knockout and heterozygote mice displayed a mild tendency to obesity and impaired glucose homeostasis, but only when they were fed on a high-fat died, rather than a standard low-fat diet. Obesity and impaired glucose homeostasis did not occur concurrently, suggesting that obesity was not the sole cause of impaired glucose homeostasis. Picomolar concentrations of chemerin and its C15- and C19-terminal peptides stimulated glucose uptake in the presence of insulin by rat and mouse wild-type epididymal adipocytes, but not by murine CMKLR1 knockout adipocytes. The insulin concentration-response curve was shifted to the left in the presence of 40 pM chemerin or its C-15 terminal peptide. The plasma chemerin level was raised in diet-induced obesity and ob/ob but not db/db mice, and was reduced by fasting and, in ob/ob mice, by treatment with rosiglitazone. These findings suggest that an agonist of CMKLR1 is more likely than an antagonist to be of value in the treatment of type 2 diabetes and to have associated anti-obesity and anti-inflammatory activities. One mechanism by which an agonist of CMKLR1 might improve glucose homeostasis is by increasing insulin-stimulated glucose uptake by adipocytes. PMID:25699203

  12. Investigating neural correlates of behavior in freely behaving rodents using inertial sensors.

    PubMed

    Venkatraman, Subramaniam; Jin, Xin; Costa, Rui M; Carmena, Jose M

    2010-07-01

    Simultaneous behavior and multielectrode neural recordings in freely behaving rodents holds great promise to study the neural bases of behavior and disease models in combination with genetic manipulations. Here, we introduce the use of three-axis accelerometers to characterize the behavior of rats and mice during chronic neural recordings. These sensors were small and light enough to be worn by rodents and were used to record three-axis acceleration during freely moving behavior. A two-layer neural network-based pattern recognition algorithm was developed to extract the natural behavior of mice from the acceleration data. Successful recognition of resting, eating, grooming, and rearing are shown using this approach. The inertial sensors were combined with continuous 24-h recordings of neural data from the striatum of mice to characterize variations in neural activity with circadian cycles and to study the neural correlates of spontaneous action initiation. Finally, accelerometers were used to study the performance of rodents in traditional operant conditioning, where they were used to extract the reaction time of rodents. Thus the addition of accelerometer recordings of rodents to chronic multielectrode neural recordings provides great value for a number of neuroscience applications. PMID:20427622

  13. Partial Rodent Genetic Models for Bipolar Disorder

    PubMed Central

    Chen, Guang; Henter, Ioline D.; Manji, Husseini K.

    2015-01-01

    Bipolar disorder (BPD) is a complex clinical phenomenon. This episodic illness comprises at least four features/components: depression, mania, vulnerability to mood swings in euthymic BPD patients, and spontaneous cyclicity in at least some BPD patients. Currently, there is no rodent genetic model capable of encompassing the whole phenotype of BPD exists; however, recent genetic-behavioral studies have delineated partial models for some components of BPD, namely, depression, mania, and vulnerability or resilience to mood swings. p11 knockout (KO), vesicular monoamine transporter 2 (VMAT2) heterozygous KO, and neural cell adhesion molecule (NCAM) KO mice display anhedonia-like symptoms, and treatment with antidepressants rescues this anhedonia-related phenotype. Mutant CLOCK, glutamate receptor 6 (GluR6) KO, and extracellular signal-regulated kinase 1 (ERK1) KO mice exhibit mania-like behavioral clusters referred to as excessive behavioral excitement; at least some of the exhibited behaviors can be rescued through treatment with mood stabilizers or atypical antipsychotics. Neuronal glucocorticoid receptor (GR) overexpressing, B-cell lymphoma 2 (Bcl-2) heterozygous KO, and Bcl-2-associated athanogene (BAG1) heterozygous KO mice show vulnerability to mood swings. In contrast, neuronal BAG1 overexpressing mice display resilience to mood swings. These mutant mouse strains and the behavioral approaches used to characterize these strains offer an emerging set of research tools for the comprehensive understanding of various components of BPD, and the interrelation of these components at the molecular, cellular, and neuronal circuitry levels. These partial genetic models can also be used as complementary tools to augment other existing behavioral tests and paradigms in drug development for BPD. PMID:25236551

  14. The hip adductor muscle group in caviomorph rodents: anatomy and homology.

    PubMed

    García-Esponda, César M; Candela, Adriana M

    2015-06-01

    Anatomical comparative studies including myological data of caviomorph rodents are relatively scarce, leading to a lack of use of muscular features in cladistic and morphofunctional analyses. In rodents, the hip adductor muscles constitute an important group of the hindlimb musculature, having an important function during the beginning of the stance phase. These muscles are subdivided in several distinct ways in the different clades of rodents, making the identification of their homologies hard to establish. In this contribution we provide a detailed description of the anatomical variation of the hip adductor muscle group of different genera of caviomorph rodents and identify the homologies of these muscles in the context of Rodentia. On this basis, we identify the characteristic pattern of the hip adductor muscles in Caviomorpha. Our results indicate that caviomorphs present a singular pattern of the hip adductor musculature that distinguishes them from other groups of rodents. They are characterized by having a single m. adductor brevis that includes solely its genicular part. This muscle, together with the m. gracilis, composes a muscular sheet that is medial to all other muscles of the hip adductor group. Both muscles probably have a synergistic action during locomotion, where the m. adductor brevis reinforces the multiple functions of the m. gracilis in caviomorphs. Mapping of analyzed myological characters in the context of Rodentia indicates that several features are recovered as potential synapomorphies of caviomorphs. Thus, analysis of the myological data described here adds to the current knowledge of caviomorph rodents from anatomical and functional points of view, indicating that this group has features that clearly differentiate them from other rodents. PMID:25911542

  15. Estimating the duration of sexual behavior: a laboratory analog study.

    PubMed

    Levitt, E E

    1983-08-01

    Estimate of male orgasm latency, a common parameter of the sex history, is hypothetically subject to retrospective distortion. This investigation attempted to assess the degree and direction of the distortion using a laboratory analog procedure. Groups of sophomore medical students were shown a movie depicting a couple engaging in continuous foreplay and coitus. About half were asked to estimate the length of the foreplay and coitus periods in minutes. The other half were required to judge whether time periods were average, below average, or above average in duration for people of their own age. Subjects tended to overestimate the length of the coitus period in the film, but not the foreplay period. Females tended to estimate both periods as significantly longer than males. Nearly half of the group judged the foreplay period to be average, and over 60% judged the coital period to be average. Less than 23% thought that the coital period was below average. Married subjects tended to regard both time periods as above average, compared to single subjects. A possible inference from this investigation is that the mean young adult male orgasm latency is probably in the range of 2-3 minutes. PMID:6639328

  16. Laboratory studies of molecular growth in the Titan ionosphere.

    PubMed

    Thissen, Roland; Vuitton, Veronique; Lavvas, Panayotis; Lemaire, Joel; Dehon, Christophe; Dutuit, Odile; Smith, Mark A; Turchini, Stefano; Catone, Daniele; Yelle, Roger V; Pernot, Pascal; Somogyi, Arpad; Coreno, Marcello

    2009-10-22

    Experimental simulations of the initial steps of the ion-molecule reactions occurring in the ionosphere of Titan were performed at the synchrotron source Elettra in Italy. The measurements consisted of irradiating gas mixtures with a monochromatic photon beam, from the methane ionization threshold at 12.6 eV, up to and beyond the molecular nitrogen dissociative ionization threshold at 24.3 eV. Three gas mixtures of increasing complexity were used: N(2)/CH(4) (0.96/0.04), N(2)/CH(4)/C(2)H(2) (0.96/0.04/0.001), and N(2)/CH(4)/C(2)H(2)/C(2)H(4) (0.96/0.04/0.001/0.001). The resulting ions were detected with a high-resolution (1 T) FT-ICR mass spectrometer as a function of time and VUV photon energy. In order to interpret the experimental results, a Titan ionospheric model was adapted to the laboratory conditions. This model had previously allowed the identification of the ions detected in the Titan upper atmosphere by the ion neutral mass spectrometer (INMS) onboard the Cassini spacecraft. Comparison between observed and modeled ion densities validates the kinetic model (reactions, rate constants, product branching ratios) for the primary steps of molecular growth. It also reveals differences that we attribute to an intense surface chemistry. This result implies that heterogeneous chemistry on aerosols might efficiently produce HCN and NH(3) in the Titan upper atmosphere. PMID:19769328

  17. Laboratory Studies of Cometary Materials - Continuity Between Asteroid and Comet

    NASA Technical Reports Server (NTRS)

    Messenger, Scott; Walker, Robert M.

    2015-01-01

    Laboratory analysis of cometary samples have been enabled by collection of cometary dust in the stratosphere by high altitude aircraft and by the direct sampling of the comet Wild-2 coma by the NASA Stardust spacecraft. Cometary materials are composed of a complex assemblage of highly primitive, unprocessed interstellar and primordial solar system materials as well as a variety of high temperature phases that must have condensed in the inner regions of the protoplanetary disk. These findings support and contradict conclusions of comet properties based solely on astronomical observations. These sample return missions have instead shown that there is a continuity of properties between comets and asteroids, where both types of materials show evidence for primitive and processed materials. Furthermore, these findings underscore the importance and value of direct sample return. There will be great value in comparing the findings of the Stardust cometary coma sample return mission with those of future asteroid surface sample returns OSIRIS-REx and Hayabusa II as well as future comet nucleus sample returns.

  18. Study of a Bordetella hinzii Isolate from a Laboratory Mouse

    PubMed Central

    Hayashimoto, Nobuhito; Yasuda, Masahiko; Goto, Kazuo; Takakura, Akira; Itoh, Toshio

    2008-01-01

    Bordetella hinzii isolated from the trachea and lungs of a laboratory mouse with a respiratory infection was identified based on its phenotypic and genetic traits. The mouse showed sneezing with a chattering sound but without nasal discharge, and histopathologic examination revealed rhinitis, tracheitis, and bronchopneumonia. The isolate was a gram-negative, oxidase- and catalase-positive, short rod-shaped organism that produced alkali from malonate. The results of biochemical identification, an alkali production test from malonate, and partial sequence analysis of the 16S rRNA gene (1523 bp) were consistent with those reported previously for B. hinzii. The isolate induced sneezing in ICR mice and sneezing and slight to severe dyspnea in NOD-SCID mice after experimental infection. Histopathologic examination revealed catarrhal rhinitis and bronchopneumonia in both strains of mice and interstitial pneumonia in NOD-SCID mice. In light of these findings, B. hinzii was deemed to be a novel causative agent of respiratory disease in mice. This report describes the first isolation of B. hinzii from a mouse and confirms the organism's pathogenicity in mice. PMID:19004369

  19. Laboratory studies of the aqueous-phase oxidation of polyols: submicron particles vs. bulk aqueous solution

    E-print Network

    Daumit, Kelly Elizabeth

    Oxidation in the atmospheric aqueous phase (cloud droplets and deliquesced particles) has received recent attention as a potential pathway for the formation of highly oxidized organic aerosol. Most laboratory studies of ...

  20. CHARACTERIZATION AND LABORATORY SOIL TREATABILITY STUDIES FOR CREOSOTE AND PENTACHLOROPHENOL SLUDGES AND CONTAMINATED SOIL

    EPA Science Inventory

    Information is presented from characterization and laboratory treatability phases of a 3-phase study pertaining to on-site treatability potential of soils containing hazardous constituents from wood-treatment waste. Specific information includes: (1) literature assessment of soil...

  1. NASA ER-2: Flying Laboratory for Earth Science Studies and Remote Sensing

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    2007-01-01

    This viewgraph presentation shows views of the ER-2, NASA's Flying Laboratory for Earth Science Studies and Remote Sensing. The presentation briefly reviews the successes of the ER-2, and what the facility provides.

  2. Survey for hantaviruses, tick-borne encephalitis virus, and Rickettsia spp. in small rodents in Croatia.

    PubMed

    Svoboda, Petra; Dobler, Gerhard; Markoti?, Alemka; Kurolt, Ivan-Christian; Speck, Stephanie; Habuš, Josipa; Vucelja, Marko; Krajinovi?, Lidija Cvetko; Tadin, Ante; Margaleti?, Josip; Essbauer, Sandra

    2014-07-01

    In Croatia, several rodent- and vector-borne agents are endemic and of medical importance. In this study, we investigated hantaviruses and, for the first time, tick-borne encephalitis virus (TBEV) and Rickettsia spp. in small wild rodents from two different sites (mountainous and lowland region) in Croatia. In total, 194 transudate and tissue samples from 170 rodents (A. flavicollis, n=115; A. agrarius, n=2; Myodes glareolus, n=53) were tested for antibodies by indirect immunofluorescence assays (IIFT) and for nucleic acids by conventional (hantaviruses) and real-time RT-/PCRs (TBEV and Rickettsia spp.). A total of 25.5% (24/94) of the rodents from the mountainous area revealed specific antibodies against hantaviruses. In all, 21.3% (20/94) of the samples from the mountainous area and 29.0% (9/31) from the lowland area yielded positive results for either Puumala virus (PUUV) or Dobrava-Belgrade virus (DOBV) using a conventional RT-PCR. All processed samples (n=194) were negative for TBEV by IIFT or real-time RT-PCR. Serological evidence of rickettsial infection was detected in 4.3% (4/94) rodents from the mountainous region. Another 3.2% (3/94) rodents were positive for Rickettsia spp. by real-time PCR. None of the rodents (n=76) from the lowland area were positive for Rickettsia spp. by real-time PCR. Dual infection of PUUV and Rickettsia spp. was found in one M. glareolus from the mountainous area by RT-PCR and real-time PCR, respectively. To our knowledge, this is the first detection of Rickettsia spp. in small rodents from Croatia. Phylogenetic analyses of S- and M-segment sequences obtained from the two study sites revealed well-supported subgroups in Croatian PUUV and DOBV. Although somewhat limited, our data showed occurrence and prevalence of PUUV, DOBV, and rickettsiae in Croatia. Further studies are warranted to confirm these data and to determine the Rickettsia species present in rodents in these areas. PMID:24866325

  3. Prevalence and genetic diversity of Bartonella strains in rodents from northwestern Mexico.

    PubMed

    Rubio, André V; Ávila-Flores, Rafael; Osikowicz, Lynn M; Bai, Ying; Suzán, Gerardo; Kosoy, Michael Y

    2014-12-01

    Bartonella infections were investigated in wild rodents from northwestern Chihuahua, Mexico. A total of 489 rodents belonging to 14 species were surveyed in four areas. Bartonella bacteria were cultured from 50.1% of rodent samples (245/489). Infection rates ranged from 0% to 83.3% per rodent species, with no significant difference between sites except for Cynomys ludovicianus. Phylogenetic analyses of the citrate synthase gene (gltA) of the Bartonella isolates revealed 23 genetic variants (15 novel and 8 previously described), clustering into five phylogroups. Three phylogroups were associated with Bartonella vinsonii subsp. vinsonii, B. vinsonii subsp. arupensis, and B. washoensis, respectively. The other two phylogroups were not genetically related to any known Bartonella species. The genetic variants and phylogenetic groups exhibited a high degree of host specificity, mainly at the genus and family levels. This is the first study that describes the genetic diversity of Bartonella strains in wild rodents from Mexico. Considering that some variants found in this study are associated with Bartonella species that have been reported as zoonotic, more investigations are needed to further understand the ecology of Bartonella species in Mexican wildlife and their implications for human health. PMID:25514119

  4. Rodent Models and Behavioral Outcomes of Cervical Spinal Cord Injury

    PubMed Central

    Geissler, Sydney A.; Schmidt, Christine E.; Schallert, Timothy

    2014-01-01

    Rodent spinal cord injury (SCI) models have been developed to examine functional and physiological deficits after spinal cord injury with the hope that these models will elucidate information about human SCI. Models are needed to examine possible treatments and to understand histopathology after SCI; however, they should be considered carefully and chosen based on the goals of the study being performed. Contusion, compression, transection, and other models exist and have the potential to reveal important information about SCI that may be related to human SCI and the outcomes of treatment and timing of intervention. PMID:25309824

  5. Analyzing short time series data from periodically fluctuating rodent populations by threshold models: A nearest block bootstrap approach

    Microsoft Academic Search

    Kung-Sik Chan; Howell Tong; Nils Chr Stenseth

    2009-01-01

    The study of the rodent fluctuations of the North was initiated in its modern form with Elton’s pioneering work. Many scientific\\u000a studies have been designed to collect yearly rodent abundance data, but the resulting time series are generally subject to\\u000a at least two “problems”: being short and non-linear. We explore the use of the continuous threshold autoregressive (TAR) models\\u000a for

  6. Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

    PubMed Central

    PENICHE-LARA, Gaspar; DZUL-ROSADO, Karla; PÉREZ-OSORIO, Carlos; ZAVALA-CASTRO, Jorge

    2015-01-01

    Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán. PMID:25923891

  7. A glimpse on the pattern of rodent diversification: a phylogenetic approach

    PubMed Central

    2012-01-01

    Background Development of phylogenetic methods that do not rely on fossils for the study of evolutionary processes through time have revolutionized the field of evolutionary biology and resulted in an unprecedented expansion of our knowledge about the tree of life. These methods have helped to shed light on the macroevolution of many taxonomic groups such as the placentals (Mammalia). However, despite the increase of studies addressing the diversification patterns of organisms, no synthesis has addressed the case of the most diversified mammalian clade: the Rodentia. Results Here we present a rodent maximum likelihood phylogeny inferred from a molecular supermatrix. It is based on 11 mitochondrial and nuclear genes that covers 1,265 species, i.e., respectively 56% and 81% of the known specific and generic rodent diversity. The inferred topology recovered all Rodentia clades proposed by recent molecular works. A relaxed molecular clock dating approach provided a time framework for speciation events. We found that the Myomorpha clade shows a greater degree of variation in diversification rates than Sciuroidea, Caviomorpha, Castorimorpha and Anomaluromorpha. We identified a number of shifts in diversification rates within the major clades: two in Castorimorpha, three in Ctenohystrica, 6 within the squirrel-related clade and 24 in the Myomorpha clade. The majority of these shifts occurred within the most recent familial rodent radiations: the Cricetidae and Muridae clades. Using the topological imbalances and the time line we discuss the potential role of different diversification factors that might have shaped the rodents radiation. Conclusions The present glimpse on the diversification pattern of rodents can be used for further comparative meta-analyses. Muroid lineages have a greater degree of variation in their diversification rates than any other rodent group. Different topological signatures suggest distinct diversification processes among rodent lineages. In particular, Muroidea and Sciuroidea display widespread distribution and have undergone evolutionary and adaptive radiation on most of the continents. Our results show that rodents experienced shifts in diversification rate regularly through the Tertiary, but at different periods for each clade. A comparison between the rodent fossil record and our results suggest that extinction led to the loss of diversification signal for most of the Paleogene nodes. PMID:22697210

  8. What happens to mood, performance and sleep in a laboratory study with no sleep deprivation?

    PubMed Central

    Paterson, Jessica L; Dorrian, Jill; Ferguson, Sally A; Jay, Sarah M; Dawson, Drew

    2014-01-01

    There are few studies examining changes in waking function in a laboratory environment with no sleep deprivation and mood has been largely overlooked in this context. The present study examined changes in mood, performance, sleep and sleepiness in the laboratory study with no sleep deprivation. Nineteen participants (10M, 9F; 22y ± 4.2y) were given nine 9h sleep opportunities (2300-0800). Every two hours during wake, participants completed the Mood Scale II, a 10-minute Psychomotor Vigilance Task and measures of sleepiness and fatigue. Sleep was monitored using an electroencephalographic montage. Findings revealed significant negative mood change, performance impairment, reduced total sleep time and sleep efficiency (all p < .05). These findings suggest that the laboratory environment or procedural factors may impair mood, performance and sleep. These findings may have implications for interpreting impairments in mood, performance and sleep when observed in laboratory environments. PMID:24839396

  9. Laboratory infrared studies of molecules of atmospheric and astrophysical interest

    NASA Technical Reports Server (NTRS)

    Rao, N. N.

    1982-01-01

    Nineteen reprints on the molecular species are compiled. Much of the work was done by using the Doppler-limited resolution provided by diode lasers. The diode laser was used as a source to a grating spectrometer which has been used earlier for high resolution studies. This technique provided many advantages. Wherever possible, the studies have been directed to intensity determinations of infrared bands.

  10. Scientometric Study of Doctoral Theses of the Physical Research Laboratory

    NASA Astrophysics Data System (ADS)

    Anilkumar, N.

    2010-10-01

    This paper presents the results of a study of bibliographies compiled from theses submitted in the period 2001-2005. The bibliographies have been studied to find out how research carried out at PRL is being used by the doctoral students. Resources are categorized by type of resource — book, journal article, proceedings, doctoral thesis, etc., to understand the usage of content procured by the library. The period of the study, 2001-2005, has been chosen because technology is changing so fast and so are the formats of scholarly communications. For the sake of convenience, only the "e-journals period" is considered for the sample.

  11. Genotyping and subtyping of Giardia and Cryptosporidium isolates from commensal rodents in China.

    PubMed

    Zhao, Z; Wang, R; Zhao, W; Qi, M; Zhao, J; Zhang, L; Li, J; Liu, A

    2015-05-01

    Cryptosporidium and Giardia are two important zoonotic intestinal parasites responsible for diarrhoea in humans and other animals worldwide. Rodents, as reservoirs or carriers of Cryptosporidium and Giardia, are abundant and globally widespread. In the present study, we collected 232 fecal specimens from commensal rodents captured in animal farms and farm neighbourhoods in China. We collected 33 Asian house rats, 168 brown rats and 31 house mice. 6.0% (14/232) and 8.2% (19/232) of these rodents were microscopy-positive for Giardia cysts and Cryptosporidium oocysts, respectively. All 14 Giardia isolates were identified as Giardia duodenalis assemblage G at a minimum of one or maximum of three gene loci (tpi, gdh and bg). By small subunit rRNA (SSU rRNA) gene sequencing, Cryptosporidium parvum (n = 12) and Cryptosporidium muris (n = 7) were identified. The gp60 gene encoding the 60-kDa glycoprotein was successfully amplified and sequenced in nine C. parvum isolates, all of which belonged to the IIdA15G1 subtype. Observation of the same IIdA15G1 subtype in humans (previously) and in rodents (here) suggests that rodents infected with Cryptosporidium have the potential to transmit cryptosporidiosis to humans. PMID:25579244

  12. Two-phase seed dispersal: linking the effects of frugivorous birds and seed-caching rodents.

    PubMed

    Vander Wall, Stephen B; Kuhn, Kellie M; Gworek, Jennifer R

    2005-09-01

    Frugivorous birds disperse the seeds of many fruit-bearing plants, but the fate of seeds after defecation or regurgitation is often unknown. Some rodents gather and scatter hoard seeds, and some of these may be overlooked, germinate, and establish plants. We show that these two disparate modes of seed dispersal are linked in some plants. Rodents removed large (>25 mg) seeds from simulated bird feces (pseudofeces) at rates of 8-50%/day and scatter hoarded them in soil. Ants (Formica sibylla) also harvested some seeds and carried them to their nests. Rodents carried seeds 2.5+/-3.2 m to cache sites (maximum 12 m) and buried seeds at 8+/-7 mm depth. Enclosure studies suggest that yellow pine chipmunks (Tamias amoenus) and deer mice (Peromyscus maniculatus) made the caches. In spring, some seeds germinated from rodent caches and established seedlings, but no seedlings established directly from pseudofeces. This form of two-phase seed dispersal is important because each phase offers different benefits to plants. Frugivory by birds permits relatively long-range dispersal and potential colonization of new sites, whereas rodent caching moves seeds from exposed, low-quality sites (bird feces on the ground surface) to a soil environment that may help maintain seed viability and promote successful seedling establishment. PMID:15959820

  13. Laboratory Studies of Ion Chemistry in the Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Bierbaum, V. M.

    2014-02-01

    Studies of gas phase ion-neutral reactions provide insight into many areas of astrochemistry, including the elusive characterization of the Diffuse Interstellar Bands (DIBs). This presentation gives an overview of our experimental studies of several classes of positive and negative ions, using the flowing afterglow-selected ion flow tube and a newly modified ion trap. Earlier studies of carbon chain anions and polycyclic aromatic hydrocarbon (PAH) cations, both of which have been suggested as carriers of the DIBs, are described. More recent work including isomeric PAHs, nitrogen-containing PAHs, negative ions of PAHs, and negative ions of 5-membered heterocyclic rings are discussed. Finally, the study of quantitative thermochemistry by coupling our results with data from Photoelectron Spectroscopy is described.

  14. FIELD AND LABORATORY OPERATIONS REPORT FOR THE OREGON WETLANDS STUDY

    EPA Science Inventory

    The Oregon Wetlands Study (OWS) was designed to provide detailed characterizations of natural, created, and restored freshwater wetlands which is located in the urban environment of Portland, Oregon. his document discusses training the elementary, middle and high school teachers ...

  15. Genotoxic changes to rodent cells exposed in vitro to tungsten, nickel, cobalt and iron.

    PubMed

    Bardack, Stephanie; Dalgard, Clifton L; Kalinich, John F; Kasper, Christine E

    2014-03-01

    Tungsten-based materials have been proposed as replacements for depleted uranium in armor-penetrating munitions and for lead in small-arms ammunition. A recent report demonstrated that a military-grade composition of tungsten, nickel, and cobalt induced a highly-aggressive, metastatic rhabdomyosarcoma when implanted into the leg muscle of laboratory rats to simulate a shrapnel wound. The early genetic changes occurring in response to embedded metal fragments are not known. In this study, we utilized two cultured rodent myoblast cell lines, exposed to soluble tungsten alloys and the individual metals comprising the alloys, to study the genotoxic effects. By profiling cell transcriptomes using microarray, we found slight, yet distinct and unique, gene expression changes in rat myoblast cells after 24 h metal exposure, and several genes were identified that correlate with impending adverse consequences of ongoing exposure to weapons-grade tungsten alloy. These changes were not as apparent in the mouse myoblast cell line. This indicates a potential species difference in the cellular response to tungsten alloy, a hypothesis supported by current findings with in vivo model systems. Studies examining genotoxic-associated gene expression changes in cells from longer exposure times are warranted. PMID:24619124

  16. Genotoxic Changes to Rodent Cells Exposed in Vitro to Tungsten, Nickel, Cobalt and Iron

    PubMed Central

    Bardack, Stephanie; Dalgard, Clifton L.; Kalinich, John F.; Kasper, Christine E.

    2014-01-01

    Tungsten-based materials have been proposed as replacements for depleted uranium in armor-penetrating munitions and for lead in small-arms ammunition. A recent report demonstrated that a military-grade composition of tungsten, nickel, and cobalt induced a highly-aggressive, metastatic rhabdomyosarcoma when implanted into the leg muscle of laboratory rats to simulate a shrapnel wound. The early genetic changes occurring in response to embedded metal fragments are not known. In this study, we utilized two cultured rodent myoblast cell lines, exposed to soluble tungsten alloys and the individual metals comprising the alloys, to study the genotoxic effects. By profiling cell transcriptomes using microarray, we found slight, yet distinct and unique, gene expression changes in rat myoblast cells after 24 h metal exposure, and several genes were identified that correlate with impending adverse consequences of ongoing exposure to weapons-grade tungsten alloy. These changes were not as apparent in the mouse myoblast cell line. This indicates a potential species difference in the cellular response to tungsten alloy, a hypothesis supported by current findings with in vivo model systems. Studies examining genotoxic-associated gene expression changes in cells from longer exposure times are warranted. PMID:24619124

  17. Rodent reservoirs of future zoonotic diseases.

    PubMed

    Han, Barbara A; Schmidt, John Paul; Bowden, Sarah E; Drake, John M

    2015-06-01

    The increasing frequency of zoonotic disease events underscores a need to develop forecasting tools toward a more preemptive approach to outbreak investigation. We apply machine learning to data describing the traits and zoonotic pathogen diversity of the most speciose group of mammals, the rodents, which also comprise a disproportionate number of zoonotic disease reservoirs. Our models predict reservoir status in this group with over 90% accuracy, identifying species with high probabilities of harboring undiscovered zoonotic pathogens based on trait profiles that may serve as rules of thumb to distinguish reservoirs from nonreservoir species. Key predictors of zoonotic reservoirs include biogeographical properties, such as range size, as well as intrinsic host traits associated with lifetime reproductive output. Predicted hotspots of novel rodent reservoir diversity occur in the Middle East and Central Asia and the Midwestern United States. PMID:26038558

  18. Transplantation tolerance: lessons from experimental rodent models

    PubMed Central

    Kingsley, Cherry I; Nadig, Satish N; Wood, Kathryn J

    2007-01-01

    Immunological tolerance or functional unresponsiveness to a transplant is arguably the only approach that is likely to provide long-term graft survival without the problems associated with life-long global immunosuppression. Over the past 50 years, rodent models have become an invaluable tool for elucidating the mechanisms of tolerance to alloantigens. Importantly, rodent models can be adapted to ensure that they reflect more accurately the immune status of human transplant recipients. More recently, the development of genetically modified mice has enabled specific insights into the cellular and molecular mechanisms that play a key role in both the induction and maintenance of tolerance to be obtained and more complex questions to be addressed. This review highlights strategies designed to induce alloantigen specific immunological unresponsiveness leading to transplantation tolerance that have been developed through the use of experimental models. PMID:17711408

  19. Cage allocation designs for rodent carcinogenicity experiments.

    PubMed Central

    Herzberg, A M; Lagakos, S W

    1992-01-01

    Cage allocation designs for rodent carcinogenicity experiments are discussed and presented with the goal of avoiding dosage group biases related to cage location. Considerations in selecting a cage design are first discussed in general terms. Specific designs are presented for use in experiments involving three, four, and five dose groups and with one, four, and five rodents per cage. Priorities for balancing treatment groups include horizontal position on shelf and shelf of rack, nearest neighbor balance, and male-female balance. It is proposed that these balance criteria be considered together with practical issues, such as the ability to accurately conform to a design and to determine a sensible and efficient design for each experiment. PMID:1295494

  20. Rodent reservoirs of future zoonotic diseases

    PubMed Central

    Han, Barbara A.; Schmidt, John Paul; Bowden, Sarah E.; Drake, John M.

    2015-01-01

    The increasing frequency of zoonotic disease events underscores a need to develop forecasting tools toward a more preemptive approach to outbreak investigation. We apply machine learning to data describing the traits and zoonotic pathogen diversity of the most speciose group of mammals, the rodents, which also comprise a disproportionate number of zoonotic disease reservoirs. Our models predict reservoir status in this group with over 90% accuracy, identifying species with high probabilities of harboring undiscovered zoonotic pathogens based on trait profiles that may serve as rules of thumb to distinguish reservoirs from nonreservoir species. Key predictors of zoonotic reservoirs include biogeographical properties, such as range size, as well as intrinsic host traits associated with lifetime reproductive output. Predicted hotspots of novel rodent reservoir diversity occur in the Middle East and Central Asia and the Midwestern United States. PMID:26038558

  1. Site study plan for routine laboratory rock mechanics, Deaf Smith County Site, Texas: Revision 1

    SciTech Connect

    Not Available

    1987-12-01

    This Site Study Plan for Routine Laboratory Rock Mechanics describes routine laboratory testing to be conducted on rock samples collected as part of the characterization of the Deaf Smith County site, Texas. This study plan describes the early laboratory testing. Additional testing may be required and the type and scope of testing will be dependent upon the results of the early testing. This study provides for measurements of index, hydrological, mechanical, and chemical properties with tests which are standardized and used widely in geotechnical investigations. Another Site Study Plan for Nonroutine Laboratory Rock Mechanics describes laboratory testing of samples from the site to determine mechanical, thermomechanical, and thermal properties by less widely used methods, many of which have been developed specifically for characterization of the site. Data from laboratory tests will be used for characterization of rock strata, design of shafts and underground facilities, and modeling of repository behavior in support of resolution of both preclosure and postclosure issues. A tentative testing schedule and milestone log are given. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that appropriate documentation is maintained. 18 refs., 8 figs., 3 tabs.

  2. A study of divergent TA teaching styles in inquiry-based laboratory education

    NASA Astrophysics Data System (ADS)

    Little, James H.

    This dissertation is a study of the divergent behaviors evidenced by different TAs teaching inquiry based physics laboratories with minimal preparation on how to use techniques such as Socratic dialogue, wait time, and time management. The revised physics laboratory curricula, a four semester laboratory sequence, were studied over the course of two years and one of the laboratory manuals was rewritten and new techniques of TA training developed in order to align TA behavior with the ideals of inquiry based education. This revision was only partially successful, aiding TAs dramatically in improving their time management skills and use of their time, however not yielding dramatic improvements in their use of Socratic dialogue or leading questions.

  3. Evolution of the spermatozoon in muroid rodents.

    PubMed

    Breed, William G

    2005-09-01

    In the rodent superfamily Muroidea, a model for the evolution of sperm form has been proposed in which it is suggested that a hook-shaped sperm head and long tail evolved from a more simple, nonhooked head and short tail in several different subfamilies. To test this model the shape of the sperm head, with particular emphasis on its apical region, and length of sperm tail were matched to a recent phylogeny based on the nucleotide sequence of several protein-coding nuclear genes from 3 families and 10 subfamilies of muroid rodents. Data from the two other myomorph superfamilies, the Dipodoidea and kangaroo rats in the Geomyoidea, were used for an outgroup comparison. In most species in all 10 muroid subfamilies, apart from in the Murinae, the sperm head has a long rostral hook largely composed of acrosomal material, although its length and cross-sectional shape vary across the various subfamilies. Nevertheless, in a few species of various lineages a very different sperm morphology occurs in which an apical hook is lacking. In the outgroups the three species of dipodid rodents have a sperm head that lacks a hook, whereas in the heteromyids an acrosome-containing apical hook is present. It is concluded that, as the hook-shaped sperm head and long sperm tail occur across the muroid subfamilies, as well as in the heteromyid rodents, it is likely to be the ancestral condition within each of the subfamilies with the various forms of nonhooked sperm heads, that are sometimes associated with short tails, being highly derived states. These findings thus argue against a repeated evolution in various muroid lineages of a complex, hook-shaped sperm head and long sperm tail from a more simple, nonhooked sperm head and short tail. An alternative proposal for the evolution of sperm form within the Muroidea is presented in the light of these data. PMID:16037955

  4. Global Inter-Laboratory Fecal Source Identification Methods Comparison Study

    EPA Science Inventory

    Source tracking is key to identifying sources of fecal contamination for remediation as well as risk assessment. Previous intra- and inter-lab studies have investigated the performance of human and cow-associated source tracking markers, as well as library-dependent fecal source ...

  5. An Innovative Method to Study Stokes' Law in the Laboratory

    ERIC Educational Resources Information Center

    Wadhwa, Ajay

    2008-01-01

    A new method is introduced to study the behaviour of the falling spherical ball in a viscous liquid using the well known Stokes' law. Experimental results are compared with those obtained by numerical calculations. Upper limits on the size and mass of the spherical balls of different materials used in the experiment are presented. (Contains 5…

  6. Review of epidemiologic studies at Los Alamos National Laboratory

    SciTech Connect

    Voelz, G.L.; Wilkinson, G.S.; Acquavella, J.F.; Reyes, M.; McInroy, J.F.

    1982-01-01

    Epidemiologic studies at Los Alamos are directed toward understanding potential health risks associated with activities pertaining to national energy and defense needs. Currently this research focuses on evaluating the effects of plutonium exposure in man. The major programs consist of (1) epidemiologic studies of the incidence of disease and mortality among plutonium and other workers at six Department of Energy (DOE) contractor facilities (Los Alamos, Rocky Flats, Mound, Savannah River, Hanford, and Oak Ridge), and (2) measurement of plutonium and other radionuclides in human tissues. Currently, investigations of mortality for Pantex workers and the surrounding general population are also being conducted for DOE in support of an Environment Impact Statement. This paper places emphasis on the activities of the national epidemiologic study of plutonium workers. The purpose of the plutonium workers study is to: (1) investigate whether adverse health effects are associated with exposures to plutonium, (2) explore whether adverse health effects are associated with exposure to transuranic elements, other radioisotopes, and hazardous substances that are found in nuclear facilities making routine use of plutonium, and (3) to describe in detail the nature of such health effects should they be discovered.

  7. CHARGED DROPLET SCRUBBER FOR FINE PARTICLE CONTROL: LABORATORY STUDY

    EPA Science Inventory

    The report gives results of a feasibility study of the application of charged droplet scrubbing for fine particle control. Results, using the TRW charged droplet scrubber, indicated that the method is feasible and applicable over a wide range of conditions. In the charged droplet...

  8. Laboratory Studies of Solar Flux Loops in MRX

    Microsoft Academic Search

    Erdem Oz; Masaaki Yamada; Brendan McGeehan; Seth Dorfman; Hantao Ji; Nate Williams; Stewart Zweben

    2008-01-01

    Energetic solar phenomena such as solar flares occur as a result of interplay between solar magnetic fields and plasma. The physics of these events is unexplained because of the scarcity of experimental data which can only be obtained using remote sensing. We will present an experimental study of the dynamics of half-toroidal plasma arcs relevant to solar coronal activities in

  9. Systems studies department FY78 activity report. Vol. I. Computing and applied mathematics. [Sandia Laboratories, Livermore

    Microsoft Academic Search

    Gold

    1979-01-01

    The Systems Studies Department at Sandia Laboratories, Livermore, has two primary responsibilities: to provide computational and mathematical services and to perform ''systems analysis'' studies. The computational services include applied mathematics, numerical analysis, programming, computer graphics, and management information systems, as well as operation, maintenance, and enhancement of the SLL computer center. The systems analysis studies attempt to evaluate the relative

  10. A Review of Published Quantitative Experimental Studies on Factors Affecting Laboratory Fume Hood Performance

    Microsoft Academic Search

    Kwangseog Ahn; Susan Woskie; Louis DiBerardinis; Michael Ellenbecker

    2008-01-01

    This study attempted to identify the important factors that affect the performance of a laboratory fume hood and the relationship between the factors and hood performance under various conditions by analyzing and generalizing the results from other studies that quantitatively investigated fume hood performance. A literature search identified 43 studies that were published from 1966 to 2006. For each of

  11. Dissociated vertical deviation-a clinical and laboratory study.

    PubMed Central

    Helveston, E M

    1980-01-01

    The previously reported nomenclature and clinical characteristics of dissociated vertical deviation have been recorded. The incidence and characteristics of DVD have been determined by evaluation of 1,000 consecutive strabismus or nystagmus patients, and with selected chart study carried out on the 111 DVD patients found in this series. Electro-oculographic studies of selected patients with DVD provided objective evidence of the speed and amplitude of the ocular movements in DVD. Bell phenomenon, strabismus sursoadductorius and the Bielschowsky phenomenon were recorded and compared to clinical findings of strabismus patients with DVD. The technique for the results of surgery for DVD were described. Dissociated vertical deviation was characterized as a component of the overall strabismus picture. Images FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 1 D FIGURE 1 E FIGURE 2 A FIGURE 2 B FIGURE 2 C FIGURE 3 A FIGURE 3 B FIGURE 3 C FIGURE 4 A FIGURE 4 B PMID:7020216

  12. Hypergravity Effects on Rodent Pregnancy and Parturition

    NASA Technical Reports Server (NTRS)

    Ronca, A. E.; Baer, L. A.; Mills, N. A.; Wade, C. E.; Dalton, Bonnie (Technical Monitor)

    2002-01-01

    No mammal has yet undergone birth, or parturition, in the microgravity of space. Previous studies (Ronco & Alberts, 2000) have shown that mid-pregnant rat dams exposed to spaceflight (0-g) and landed 48-72 hrs before term successfully delivered robust, healthy offspring Microgravity-exposed dams exhibited twice the expected numbers of labor contractions whereas length of pregnancy, duration of labor, fetal wastage, number of neonates born and litter gender ratios were identical to controls. In the present study, we report the results of rodent pregnancy and parturition at the opposite end of the gravity spectrum, in hypergravity. Dams exposed to either: 1.0-g, 1.5-g, 1.75-g or 2.0-g from Gestational day (G) 11 and throughout the births of their litters had comparable pregnancy and labor durations, fetal wastage, numbers of neonates born and litter Tender ratios. During parturition, hypergravity-exposed dams exhibited significantly fewer labor contractions as compared to 1.0-g controls. Dams that underwent birth in hypergravity had significantly fewer offspring surviving the immediate postpartum period (P1: 1.0-g, 11.92 +/- 2.84; 1.5-g, 10.88 +/- 2.17; 1.75-g, 9.22 +/-1.99; 2.0-g, 8.83 +/- 3.31). Within 24 hrs postpartum, neonatal survival was further diminished in hypergravity [P2: 100% (1.0-g); 96% (1.5-g); 96% (1.75-g); 73% (2.0-g)] and continued to decline (P10: 100%(1.0-g.); 90%(1.5-g); 87%(1.75-g), 40%(2.0-g)]. Neonatal losses stabilized by P5 for the 1.5-g andl.75-g conditions but continued until P9 for the 2.0-g condition. Together, these findings show that postnatal, but not prenatal, survival is compromised following birth in hypergravity, Maternal and neonatal factors that contribute to peri-parturitional vulnerability to altered gravity environments will be discussed.

  13. Laboratory studies on secondary organic aerosol formation from terpenes

    Microsoft Academic Search

    Yoshiteru Iinuma; O Boge; Yunkun Miao; Berko Sierau; Thomas Gnauk; Hartmut Herrmann

    2005-01-01

    The formation of secondary organic aerosol (SOA) following the\\u000a ozonolysis of terpene has been investigated intensively in recent years.\\u000a The enhancement of SOA yields from the acid catalysed reactions of\\u000a organics on aerosol surfaces or in the bulk particle phase has been\\u000a receiving great attention. Recent studies show that the presence of\\u000a acidic seed particles increases the SOA yield significantly

  14. Laboratory Studies of Total Load and Apparent Bed Load

    Microsoft Academic Search

    Richard A. Stein

    1965-01-01

    This paper is an analysis of the results of 59 flume experiments conducted in a 100-foot recirculating flume at the U.S. Department of Agriculture Sedimentation Labora- tory. Studies were made of total bed material transport as determined by fractionM sampling, static and dynamic dune properties, and head losses encountered by flow over an alluvial bed. Under the conditions of these

  15. Competition between two boll weevil parasitoids: a laboratory study

    E-print Network

    O'Neil, Robert James

    1980-01-01

    parasitoids of the cotton boll weevil, (Antho- comus Brandis Boheman) were cultured alone and together to deter- mine the effects of competition on their population growth rate and maintenance. It was found that Catolaccus grandis (Burke) out- competed... produced by B. mellitor and C. ~zandfs in the 2nd replicate of the population-competition study. 16, Breakdown of the number pupae produced by B. mellitor and C. grandis when both inhabit the same host in the 2nd replicate of the population...

  16. Skeletogenesis and sequence heterochrony in rodent evolution, with particular emphasis on the African striped mouse, Rhabdomys pumilio (Mammalia)

    Microsoft Academic Search

    Laura A. B. Wilson; Carsten Schradin; Christian Mitgutsch; Fernando C. Galliari; Andrea Mess; Marcelo R. Sánchez-Villagra

    2010-01-01

    Data documenting skeletal development in rodents, the most species-rich ‘order’ of mammals, are at present restricted to a\\u000a few model species, a shortcoming that hinders exploration of the morphological and ecological diversification of the group.\\u000a In this study we provide the most comprehensive sampling of rodent ossification sequences to date, with the aim of exploring\\u000a whether heterochrony is ubiquitous in

  17. Mode of Action Profiles for Pesticide Compounds with Rodent Liver Tumor Outcomes

    EPA Science Inventory

    Mode of action (MOA) provides a central framework for assessing human relevance of adverse health outcomes observed in nonclinical safety studies. The goal of this study was to characterize MOA profiles for known rodent liver tumorigens identified from a database of pesticides as...

  18. Effect of body size on the abundance of ectoparasitic mites on the wild rodent Oligoryzomys nigripes.

    PubMed

    Fernandes, Fernanda Rodrigues; Cruz, Leonardo Dominici; Linhares, Arício Xavier; Zuben, Claudio José Von

    2015-09-01

    The abundance of parasites on a host can be affected by several factors; in this study, we investigated the influence of sex and body size of the host rodent Oligoryzomys nigripes on the abundance of ectoparasitic mites (Acari: Mesostigmata). The generalized linear model indicated that body size (indicative of age) of the host rodent O. nigripes significantly contributed to the variation in the abundance of mites on host rodents at the Experimental Station of Itirapina. This trend of increased parasitism on hosts with larger body sizes may be linked to the fact that larger individuals are able to support the coexistence of a larger number of parasites, and being more mobile, are more exposed to infection by parasites. PMID:26204011

  19. Ketene Formation in Interstellar Ices: A Laboratory Study

    NASA Technical Reports Server (NTRS)

    Hudson, Reggie L.; Loeffler, Mark Josiah

    2013-01-01

    The formation of ketene (H2CCO, ethenone) in polar and apolar ices was studied with in situ 0.8 MeV proton irradiation, far-UVphotolysis, and infrared spectroscopic analyses at 10-20 K. Using isotopically enriched reagents, unequivocal evidencewas obtained for ketene synthesis in H2O-rich and CO2-rich ices, and several reaction products were identified. Results from scavenging experiments suggested that ketene was formed by free-radical pathways, as opposed to acid-base processes or redox reactions. Finally, we use our results to draw conclusions about the formation and stability of ketene in the interstellar medium.

  20. Laboratory Study of Hall Reconnection in Partially Ionized Plasmas

    SciTech Connect

    Lawrence, Eric E.; Ji, Hantao; Yamaada, Masaaki; Yoo, Jongsoo

    2012-05-15

    The effects of partial ionization (ni/nn ? 1%) on magnetic reconnection in the Hall regime have been studied systematically in the Magnetic Reconnection Experiment (MRX). It is shown that, when neutrals are added the Hall quadrupole field pattern and thus electron flow is unchanged while the ion outflow speed is reduced due to ion-neutral drag. However, in constrast to theoretical predictions, the ion diffusion layer width does not change appreciably. Therefore, the total ion outflow flux and the normalized reconnection rate are reduced.

  1. Laboratory study of Hall reconnection in partially ionized plasmas.

    PubMed

    Lawrence, Eric E; Ji, Hantao; Yamada, Masaaki; Yoo, Jongsoo

    2013-01-01

    The effects of partial ionization (n(i) / n(n) ? 1%) on magnetic reconnection in the Hall regime have been studied systematically in the Magnetic Reconnection Experiment. It is shown that, when neutrals are added, the Hall quadrupole field pattern and thus electron flow are unchanged while the ion outflow speed is reduced due to ion-neutral drag. However, in contrast to theoretical predictions, the ion diffusion layer width does not change appreciably. Therefore, the total ion outflow flux and the normalized reconnection rate are reduced. PMID:23383799

  2. Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance

    NASA Technical Reports Server (NTRS)

    Molina, Mario J.

    2004-01-01

    The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HCl vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow-chemical ionization mass spectrometry and optical ellipsometry, among others.

  3. Deep brain stimulation with simultaneous FMRI in rodents.

    PubMed

    Younce, John Robert; Albaugh, Daniel L; Shih, Yen-Yu Ian

    2014-01-01

    In order to visualize the global and downstream neuronal responses to deep brain stimulation (DBS) at various targets, we have developed a protocol for using blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) to image rodents with simultaneous DBS. DBS fMRI presents a number of technical challenges, including accuracy of electrode implantation, MR artifacts created by the electrode, choice of anesthesia and paralytic to minimize any neuronal effects while simultaneously eliminating animal motion, and maintenance of physiological parameters, deviation from which can confound the BOLD signal. Our laboratory has developed a set of procedures that are capable of overcoming most of these possible issues. For electrical stimulation, a homemade tungsten bipolar microelectrode is used, inserted stereotactically at the stimulation site in the anesthetized subject. In preparation for imaging, rodents are fixed on a plastic headpiece and transferred to the magnet bore. For sedation and paralysis during scanning, a cocktail of dexmedetomidine and pancuronium is continuously infused, along with a minimal dose of isoflurane; this preparation minimizes the BOLD ceiling effect of volatile anesthetics. In this example experiment, stimulation of the subthalamic nucleus (STN) produces BOLD responses which are observed primarily in ipsilateral cortical regions, centered in motor cortex. Simultaneous DBS and fMRI allows the unambiguous modulation of neural circuits dependent on stimulation location and stimulation parameters, and permits observation of neuronal modulations free of regional bias. This technique may be used to explore the downstream effects of modulating neural circuitry at nearly any brain region, with implications for both experimental and clinical DBS. PMID:24561922

  4. Radiation ecology issues associated with murine rodents and shrews in the Chernobyl exclusion zone.

    PubMed

    Gaschak, Sergey P; Maklyuk, Yulia A; Maksimenko, Andrey M; Bondarkov, Mikhail D; Jannik, G Timothy; Farfán, Eduardo B

    2011-10-01

    This article describes major studies performed by the Chernobyl Center's International Radioecology Laboratory (Slavutich, Ukraine) on radioecology of murine rodents and shrews inhabiting the Chernobyl Exclusion Zone. The article addresses the long-term (1986-2005) and seasonal dynamics of radioactive contamination of animals and reviews interspecies differences in radionuclide accumulations and factors affecting the radionuclide accumulations. It is shown that bioavailability of radionuclides in the "soil-to-plant" chain and a trophic specialization of animals play key roles in determining their actual contamination levels. The total absorbed dose rates in small mammals significantly reduced during the years following the Chernobyl Nuclear Power Plant accident. In 1986, the absorbed dose rate reached 1.3-6.0 Gy h(-1) in the central areas of the Chernobyl Exclusion Zone (the "Red Forest"). In 1988 and 1990, the total absorbed dose rates were 1.3 and 0.42 Gy h(-1), respectively. In 1995, 2000, and 2005, according to the present study, the total absorbed dose rates rarely exceeded 0.00023, 0.00018, and 0.00015 Gy h(-1), respectively. Contributions of individual radiation sources into the total absorbed dose are described. PMID:21878767

  5. Nucleobases in Space: Laboratory Studies of Polycyclic Aromatic Nitrogen Heterocycles

    NASA Technical Reports Server (NTRS)

    Elsila, Jamie; Mattioda, Andy; Bernstein, Max; Sandford, Scott; Hudgins, Doug

    2005-01-01

    Polycyclic Aromatic Nitrogen Heterocycles (PANHs) are heterocyclic aromatics Le., PAHs with carbon atoms replaced by a nitrogen atom. These molecules have been detected in meteorite extracts, and in general these nitrogen heterocycles are of astrobiological interest since this class of molecules include nucleobases, basic components of our nucleic acids. These compounds are predicted to be present in the interstellar medium and in Titan tholin, but have received relatively little attention. We will present spectra and reactions of PANHs, frozen in solid H2O at 12 K, conditions germane to astronomical observations. In contrast to simple PAHs, that do not interact strongly with solid H2O, the nitrogen atoms in PANHs are potentially capable of hydrogen bonding with H20 changing their spectra, complicating their remote detection on the surfaces of icy bodies. Moreover, we have studied the photo-chemistry of these interesting compounds under astrophysical conditions and will use our lab studies to assess a potential interstellar heritage of these compounds in carbonaceous chondrites.

  6. The utility of rodent models of autism spectrum disorders

    PubMed Central

    Lazaro, Maria; Golshani, Peyman

    2015-01-01

    Purpose of Review This review discusses the ways rodent models of autism spectrum disorders (ASDs) have been used to gain critical information convergent molecular pathways, the mechanisms underlying altered microcircuit structure and function, and as a screen for potential cutting edge-treatments. Recent Findings There is convergent evidence that impaired developmental pruning of connections may be a common finding among several mouse models of ASDs. Recent studies have uncovered impaired autophagy by pathological mTOR activation as a potential contributor to microcircuit dysfunction and behavior. ASD related disinhibition and exaggerated synaptic plasticity in multiple distinct circuits in cortex and reward circuits in striatum also contribute to social dysfunction and repetitive behaviors. New exciting molecular therapeutic techniques have reversed cognitive deficits in models of ASD, indicating that mouse models could be used for preclinical translational studies of new treatments. Summary Rodent models of ASDs coupled to new emerging technologies for genome editing, cell-specific functional and structural imaging, and neuronal activity manipulation will yield critical insights into ASD pathogenesis and fuel the emergence of new treatments. PMID:25734952

  7. The diversity of microparasites of rodents: a comparative analysis that helps in identifying rodent-borne rich habitats in Southeast Asia

    PubMed Central

    Bordes, Frédéric; Herbreteau, Vincent; Dupuy, Stéphane; Chaval, Yannick; Tran, Annelise; Morand, Serge

    2013-01-01

    Background Predicting habitats prone to favor disease transmission is challenging due to confounding information on habitats, reservoirs, and diseases. Comparative analysis, which aims at investigating ecological and evolutionary patterns among species, is a tool that may help. The emergence of zoonotic pathogens is a major health concern and is closely linked to habitat modifications by human activities. Risk assessment requires a better knowledge of the interactions between hosts, parasites, and the landscape. Methods We used information from a field spatial study that investigated the distribution of murid rodents, in various habitats of three countries in Southeast Asia, in combination with their status of infection by 10 taxa of microparasites obtained from the literature. Microparasite species richness was calculated by rodent species on 20,272 rodents of 13 species. Regression tree models and generalized linear models were used to explain microparasite diversity by the average distance between the trapping site and five categories of land cover: forest, steep agriculture land, flat agriculture land, water, and built-up surfaces. Another variable taken into account was the slope. Results We found that microparasite diversity was positively associated with flat agriculture land, in this context mainly rice fields, and negatively associated with slope. Microparasite diversity decreased sharply a 100 m or less from flat agriculture land. Conclusion We conclude that there is high microparasite circulation in rodents of flooded farmlands, meaning possibly a higher risk of disease for human inhabitants. PMID:23577229

  8. EFFECTS OF FOOD AVAILABILITY ON SURVIVAL, GROWTH, AND REPRODUCTION OF THE GRASS SHRIMP PALAEMONETES PUGIO: A LABORATORY STUDY

    EPA Science Inventory

    Grass shrimp are abundant, ecologically important inhabitants of estuarine ecosystems; adults and embryos have been used extensively in laboratory experiments, including studies of the impacts of environmental toxicants. However, optimal laboratory feeding conditions for grass sh...

  9. Laboratory methods for volatile organic compounds evolved in mineralization studies

    SciTech Connect

    Hickey, W.J.; Arnold, S.M.; Moran, B.N. [Univ. of Wisconsin, Madison, WI (United States)

    1995-11-01

    A system to study mineralization of volatile organic compounds (VOCs) was developed using commercially available solid-phase VOC traps and impingers to collect CO{sub 2} as well as VOCs breaking out from the solid-phase trap. The efficiencies of VOC traps containing activated charcoal (AC) or graphitized carbon black (GCB) for absorbing [{sup 14}C]trichloroethylene ([{sup 14}C]TCE) and {sup 14}CO{sub 2} were evaluated, and approaches for minimizing VOC losses from reaction vessels were established. Mass balances showed AC and GCB absorbed similar amounts of [{sup 14}C]TCE. However, GCB had no detectable {sup 14}CO{sub 2} retention, whereas AC absorbed about 7% of the {sup 14}CO{sub 2}. Because {sup 14}CO{sub 2} absorption could influence the interpretation of mineralization experiments, GCB was concluded to be the better VOC-trapping matrix.

  10. KETENE FORMATION IN INTERSTELLAR ICES: A LABORATORY STUDY

    SciTech Connect

    Hudson, Reggie L.; Loeffler, Mark J., E-mail: Reggie.Hudson@NASA.gov [Astrochemistry Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2013-08-20

    The formation of ketene (H{sub 2}CCO, ethenone) in polar and apolar ices was studied with in situ 0.8 MeV proton irradiation, far-UV photolysis, and infrared spectroscopic analyses at 10-20 K. Using isotopically enriched reagents, unequivocal evidence was obtained for ketene synthesis in H{sub 2}O-rich and CO{sub 2}-rich ices, and several reaction products were identified. Results from scavenging experiments suggested that ketene was formed by free-radical pathways, as opposed to acid-base processes or redox reactions. Finally, we use our results to draw conclusions about the formation and stability of ketene in the interstellar medium.

  11. Alcohol consumption in arthritic patients: clinical and laboratory studies.

    PubMed Central

    Bradlow, A; Mowat, A G

    1985-01-01

    In popular belief patients with chronic arthritis take alcohol for its analgesic effect. To test this we studied by validated questionnaire the past and present alcohol consumption of 103 patients with primary osteoarthritis of the hip (OA), 95 patients with rheumatoid arthritis (RA), and 90 orthopaedic non-arthritic controls. OA men were most likely and RA men least likely to have been heavy drinkers at any time of their lives. Mean red corpuscular volume (MCV), gamma-glutamyltransferase (GGT), and serum uric acid (SUA) levels did not correlate with reported alcohol consumption. Two of 93 OA femoral heads examined had avascular change; both were from heavy drinkers. The abstemiousness of RA men compared with their OA counterparts was due to a striking increase in joint pain after drinking alcohol (p = 0.004), fear of adverse drug reactions with alcohol, and a widespread belief not expressed by OA men that 'alcohol and arthritis do not mix'. PMID:2858181

  12. Habitat-specific shaping of proliferation and neuronal differentiation in adult hippocampal neurogenesis of wild rodents

    PubMed Central

    Cavegn, Nicole; van Dijk, R. Maarten; Menges, Dominik; Brettschneider, Helene; Phalanndwa, Mashudu; Chimimba, Christian T.; Isler, Karin; Lipp, Hans-Peter; Slomianka, Lutz; Amrein, Irmgard

    2013-01-01

    Daily life of wild mammals is characterized by a multitude of attractive and aversive stimuli. The hippocampus processes complex polymodal information associated with such stimuli and mediates adequate behavioral responses. How newly generated hippocampal neurons in wild animals contribute to hippocampal function is still a subject of debate. Here, we test the relationship between adult hippocampal neurogenesis (AHN) and habitat types. To this end, we compare wild Muridae species of southern Africa [Namaqua rock mouse (Micaelamys namaquensis), red veld rat (Aethomys chrysophilus), highveld gerbil (Tatera brantsii), and spiny mouse (Acomys spinosissimus)] with data from wild European Muridae [long-tailed wood mice (Apodemus sylvaticus), pygmy field mice (Apodemus microps), yellow-necked wood mice (Apodemus flavicollis), and house mice (Mus musculus domesticus)] from previous studies. The pattern of neurogenesis, expressed in normalized numbers of Ki67- and Doublecortin(DCX)-positive cells to total granule cells (GCs), is similar for the species from a southern African habitat. However, we found low proliferation, but high neuronal differentiation in rodents from the southern African habitat compared to rodents from the European environment. Within the African rodents, we observe additional regulatory and morphological traits in the hippocampus. Namaqua rock mice with previous pregnancies showed lower AHN compared to males and nulliparous females. The phylogenetically closely related species (Namaqua rock mouse and red veld rat) show a CA4, which is not usually observed in murine rodents. The specific features of the southern environment that may be associated with the high number of young neurons in African rodents still remain to be elucidated. This study provides the first evidence that a habitat can shape adult neurogenesis in rodents across phylogenetic groups. PMID:23616743

  13. Laboratory studies on secondary organic aerosol formation from terpenes.

    PubMed

    Iinuma, Yoshiteru; Böge, Olaf; Miao, Yunkun; Sierau, Berko; Gnauk, Thomas; Herrmann, Hartmut

    2005-01-01

    The formation of secondary organic aerosol (SOA) following the ozonolysis of terpene has been investigated intensively in recent years. The enhancement of SOA yields from the acid catalysed reactions of organics on aerosol surfaces or in the bulk particle phase has been receiving great attention. Recent studies show that the presence of acidic seed particles increases the SOA yield significantly (M. S. Jang and R. M. Kamens, Environ. Sci. Technol., 2001, 35, 4758, ref. 1; M. S. Jang, N. M. Czoschke, S. Lee and R. M. Kamens, Science, 2002, 298, 814, ref. 2; N. M. Czoschke, M. Jang and R. M. Kamens, Atmos. Environ., 2003, 37, 4287, ref. 3; M. S. Jang, B. Carroll, B. Chandramouli and R. M. Kamens, Environ. Sci. Technol., 2003, 37, 3828, ref. 4; Y. Iinuma, O. Böge, T. Gnauk and H. Herrmann, Atmos. Environ., 2004, 38, 761, ref. 5; S. Gao, M. Keywood, N. L. Ng, J. Surratt, V. Varutbangkul, R. Bahreini, R. C. Flagan and J. H. Seinfeld, J. Phys. Chem. A, 2004, 108, 10147, ref. 6). More detailed studies report the formation of higher molecular weight products in SOA (refs. 5 and 6; M. P. Tolocka, M. Jang, J. M. Ginter, F. J. Cox, R. M. Kamens and M. V. Johnston, Environ. Sci. Technol., 2004, 38, 1428, ref. 7; S. Gao, N. L. Ng, M. Keywood, V. Varutbangkul, R. Bahreini, A. Nenes, J. He, K. Y. Yoo, J. L. Beauchamp, R. P. Hodyss, R. C. Flagan and J. H. Seinfeld, Environ. Sci. Technol., 2004, 38, 6582, ref. 8) which could result in a non-reversible uptake of organics into the particle phase. Most of the past studies concentrated on the characterisation of the yields of enhanced SOA and its composition from ozonolysis of terpenes in the presence or absence of acidic and neutral seed particles. Recent findings from cyclohexene ozonolysis show that the presence of OH scavengers can also significantly influence the SOA yield. Our new results from the IfT chemistry department aerosol chamber on terpene ozonolysis in the presence of OH scavengers show that the presence of hydroxyl radical scavengers clearly reduces the amount of formed SOA. The OH scavenger strongly depletes the formation of oligomeric compounds in the particle phase in contrast to previous findings (M. D. Keywood, J. H. Kroll, V. Varatbangkul, R. Bahreini, R. C. Flagan and J. H. Seinfeld, Environ. Sci. Technol., 2004, 38, 3343, ref. 9). This result indicates that hydroxyl radicals play an important role in the formation of precursor compounds (e.g., hydroxy pinonaldehyde) for the particle phase heterogeneous acid catalysed reactions leading to the higher molecular weight compounds and thus the enhancement of SOA yields. Better understanding of the role of hydroxyl radicals in the formation of SOA is necessary to distinguish between the contribution of ozonolysis and hydroxyl radicals to the SOA yield. If the recent findings are a ubiquitous phenomenon in the atmosphere, current atmospheric and climate models might underestimate SOA formation yields, particle phase OC contents and its impact on the atmospheric radiation budget. PMID:16161789

  14. Microseismicity Induced by Fluid Pressure Drop (Laboratory Study)

    NASA Astrophysics Data System (ADS)

    Turuntaev, Sergey; Zenchenko, Evgeny; Melchaeva, Olga

    2013-04-01

    Pore pressure change in saturated porous rocks may result in its fracturing (Maury et Fourmaintraux, 1993) and corresponding microseismic event occurrences. Microseismicity due to fluid injection is considered in numerous papers (Maxwell, 2010, Shapiro et al., 2005). Another type of the porous medium fracturing is related with rapid pore pressure drop at some boundary. The mechanism of such fracturing was considered by (Khristianovich, 1985) as a model of sudden coal blowing and by (Alidibirov, Panov, 1998) as a model of volcano eruptions. If the porous saturated medium has a boundary where it directly contacted with fluid under the high pressure (in a hydraulic fracture or in a borehole), and the pressure at that boundary is dropped, the conditions for tensile cracks can be achieved at some distance from the boundary. In the paper, the results of experimental study of saturated porous sample fracturing due to pore pressure rapid drop are discussed. The samples (82 mm high, ?60 mm) were made of quartz sand, which was cemented by "liquid glass" glue with mass fraction 1%. The sample (porosity 35%, uniaxial unconfined compression strength 2.5 MPa) was placed in a mould and saturated by oil. The upper end of the sample contacted with the mould upper lid, the lower end contacted with fluid. The fluid pressure was increased to 10 MPa and then discharged through the bottom nipple. The pressure increases/drops were repeated 30-50 times. Pore pressure and acoustic emission (AE) were registered by transducers mounted into upper and bottom lids of the mould. It was found, that AE sources (corresponded to microfracturing) were spreading from the open end to the closed end of the sample, and that maximal number of AE events was registered at some distance from the opened end. The number of AE pulses increased with every next pressure drop, meanwhile the number of pulses with high amplitudes diminished. It was found that AE maximal rate corresponded to the fluid pressure gradient maximal values. The model of AE relation with the pore pressure gradient was considered based on the following assumptions: AE event occurred when the pore pressure gradient reaches some critical value; the critical value varies and can be described by Weibull distribution. Permeability variation during the fluid pressure drop was estimated by means of fluid pressure data and pore-elastic equation solution for small time intervals (0.01 sec). The study showed possibility to solve both a direct problem of microseismicity variation relation with fluid pressure changes and an inverse problem of defining permeability by registering microseismic activity variation in particular volume of porous medium alongside with pore pressure measurements at some point.

  15. Pertinent case studies illustrating the need for laboratory accessibility for Doctors of Chiropractic: a clinical conundrum

    PubMed Central

    Crawford, John P; Gotlib, Allan C; Injeyan, H Stephen

    1997-01-01

    Current provincial legislation in various jurisdictions across Canada, serves to impede the utilization of the diagnostic laboratory by doctors of chiropractic. Chiropractic students both in Canada and the United States, are required to successfully complete an intensive course of study in the area of laboratory diagnosis, as a necessary aspect of the undergraduate educational curriculum. Unfortunately, Canadian graduate doctors of chiropractic and their patients, are not currently afforded the privilege of direct referral to a community diagnostic laboratory. Rather, chiropractors must enlist the assistance of other health care providers, namely medical doctors, to acquire various laboratory testing procedures. The premise of this paper is intended to demonstrate the necessity of revising such laws, in order to address the needs of those health care consumers who seek the services of the rapidly growing profession of chiropractic. Two clinical cases are presented as illustrative examples.

  16. Seismic hazard studies for the High Flux Beam Reactor at Brookhaven National Laboratory

    SciTech Connect

    Costantino, C.J.; Heymsfield, E. (City Coll., New York, NY (United States). Dept. of Civil Engineering); Park, Y.J.; Hofmayer, C.H. (Brookhaven National Lab., Upton, NY (United States))

    1991-01-01

    This paper presents the results of a calculation to determine the site specific seismic hazard appropriate for the deep soil site at Brookhaven National Laboratory (BNL) which is to be used in the risk assessment studies being conducted for the High Flux Beam Reactor (HFBR). The calculations use as input the seismic hazard defined for the bedrock outcrop by a study conducted at Lawrence Livermore National Laboratory (LLNL). Variability in site soil properties were included in the calculations to obtain the seismic hazard at the ground surface and compare these results with those using the generic amplification factors from the LLNL study. 9 refs., 8 figs.

  17. Laboratory Studies on the Effects of Shear on Fish

    SciTech Connect

    Neitzel, Duane A.; Richmond, Marshall C.; Dauble, Dennis D.; Mueller, Robert P.; Moursund, Russell A.; Abernethy, Cary S.; Guensch, Greg R.

    2000-09-20

    The overall objective of our studies was to specify an index describing the hydraulic force that fish experience when subjected to a shear environment. Fluid shear is a phenomenon that is important to fish. However, elevated levels of shear may result in strain rates that injure or kill fish. At hydroelectric generating facilities, concerns have been expressed that strain rates associated with passage through turbines, spillways, and fish bypass systems may adversely affect migrating fish. Development of fish friendly hydroelectric turbines requires knowledge of the physical forces (injury mechanisms) that impact entrained fish and the fish's tolerance to these forces. It requires up-front, pre-design specifications for the environmental conditions that occur within the turbine system, in other words, determining or assuming that those conditions known to injure fish will provide the descriptions of conditions that engineers must consider in the design of a turbine system. These biological specifications must be carefully and thoroughly documented throughout the design of a fish friendly turbine. To address the development of biological specifications, we designed and built a test facility where juvenile fish could be subjected to a range of shear environments and quantified their biological response.

  18. Atmospheric stability of levoglucosan: a detailed laboratory and modeling study.

    PubMed

    Hoffmann, D; Tilgner, A; Iinuma, Y; Herrmann, H

    2010-01-15

    Levoglucosan, an important molecular marker for biomass burning, represents an important fraction of the water-soluble organic carbon in atmospheric particles influenced by residential wood burning and wildfires. However, particle phase oxidation processes of levoglucosan by free radicals are not well-known. Hence, detailed kinetic studies on the reactivity of levoglucosan with OH, NO(3), and SO(4)(-) radicals in aqueous solutions were performed to better understand the levoglucosan oxidation in the deliquescent particles. The data obtained were implemented into a parcel model with detailed microphysics and complex multiphase chemistry to investigate the degradation fluxes of levoglucosan in cloud droplets and in deliquescent particles. The model calculations show that levoglucosan can be oxidized readily by OH radicals during daytime with mean degradation fluxes of about 7.2 ng m(-3) h(-1) in summer and 4.7 ng m(-3) h(-1) in winter for a polluted continental plume. This indicates that the oxidation of levoglucosan in atmospheric deliquescent particles is at least as fast as that of other atmospherically relevant organic compounds and levoglucosan may not be as stable as previously thought in the atmosphere, especially under high relative humidity conditions. PMID:20000815

  19. Rodents and risk in the Mekong Delta of Vietnam: seroprevalence of selected zoonotic viruses in rodents and humans.

    PubMed

    Van Cuong, Nguyen; Carrique-Mas, Juan; Vo Be, Hien; An, Nguyen Ngoc; Tue, Ngo Tri; Anh, Nguyet Lam; Anh, Pham Hong; Phuc, Nguyen The; Baker, Stephen; Voutilainen, Liina; Jääskeläinen, Anne; Huhtamo, Eili; Utriainen, Mira; Sironen, Tarja; Vaheri, Antti; Henttonen, Heikki; Vapalahti, Olli; Chaval, Yannick; Morand, Serge; Bryant, Juliet E

    2015-01-01

    In the Mekong Delta in southern Vietnam, rats are commonly traded in wet markets and sold live for food consumption. We investigated seroprevalence to selected groups of rodent-borne viruses among human populations with high levels of animal exposure and among co-located rodent populations. The indirect fluorescence antibody test (IFAT) was used to determine seropositivity to representative reference strains of hantaviruses (Dobrava virus [DOBV], Seoul virus [SEOV]), cowpox virus, arenaviruses (lymphocytic choriomeningitis virus [LCMV]), flaviviruses (tick-borne encephalitis virus [TBEV]), and rodent parechoviruses (Ljungan virus), using sera from 245 humans living in Dong Thap Province and 275 rodents representing the five common rodent species sold in wet markets and present in peridomestic and farm settings. Combined seropositivity to DOBV and SEOV among the rodents and humans was 6.9% (19/275) and 3.7% (9/245), respectively; 1.1% (3/275) and 4.5% (11/245) to cowpox virus; 5.4% (15/275) and 47.3% (116/245) for TBEV; and exposure to Ljungan virus was 18.8% (46/245) in humans, but 0% in rodents. Very little seroreactivity was observed to LCMV in either rodents (1/275, 0.4%) or humans (2/245, 0.8%). Molecular screening of rodent liver tissues using consensus primers for flaviviruses did not yield any amplicons, whereas molecular screening of rodent lung tissues for hantavirus yielded one hantavirus sequence (SEOV). In summary, these results indicate low to moderate levels of endemic hantavirus circulation, possible circulation of a flavivirus in rodent reservoirs, and the first available data on human exposures to parechoviruses in Vietnam. Although the current evidence suggests only limited exposure of humans to known rodent-borne diseases, further research is warranted to assess public health implications of the rodent trade. PMID:25629782

  20. Clinical and Laboratory Studies of the Fate of Intranasal Allergen

    PubMed Central

    Rimmer, Janet; Santos, Conceição; Yli-Panula, Eija; Noronha, Virginia; Viander, Markku

    2015-01-01

    Background The precise way in which allergen is handled by the nose is unknown. The objective of this study was to determine recovery of Der p 1 allergen following nasal administration and to determine whether Der p 1 can be detected in nasal biopsies after natural exposure and nasal challenge to allergen. Methods (1) 20 nonatopic non-rhinitics were challenged with Der p 1 and recovery was measured by ELISA in the nasal wash, nasal mucus and induced sputum up to 30 minutes. Particulate charcoal (<40 ?m) served as control. (2) In 8 subjects (5 atopics), 30 to 60 minutes after challenge histological localisation of Der p 1 in the nasal mucosal epithelium, subepithelial mucous glands and lamina propria was performed. Co-localisation of Der p 1 with macrophages and IgE-positive cells was undertaken. Results (1) Less than 25% of total allergen was retrievable after aqueous or particulate challenge, most from the nasal mucus during 1-5 min after the challenge. The median of carbon particles recovered was 9%. (2) Prechallenge Der p 1 staining was associated with the epithelium and subepithelial mucous glands. After challenge there was a trend for greater Der p 1 deposition in atopics, but both atopics and nonatopics showed increases in the number of Der p 1 stained cells and stained tissue compartments. In atopics, increased eosinophils, macrophages and IgE positive cells co-localized with Der p 1 staining. Conclusions Der p 1 allergen is detected in nasal tissue independent of atopic status after natural exposure. After challenge the nose effectively retains allergen, which remains mucosally associated; in atopics there is greater Der p 1 deposition and inflammatory response than in nonatopics. These results support the hypothesis that nasal mucus and tissue act as a reservoir for the inhaled Der p 1 allergen leading to a persistent allergic inflammatory response in susceptible individuals. PMID:25969994

  1. Coronagraphic phase diversity: performance study and laboratory demonstration

    NASA Astrophysics Data System (ADS)

    Paul, B.; Sauvage, J.-F.; Mugnier, L. M.

    2013-04-01

    Context. The final performance of current and future instruments dedicated to exoplanet detection and characterization (such as SPHERE on the European Very Large Telescope, GPI on Gemini North, or future instruments on Extremely Large Telescopes) is limited by uncorrected quasi-static aberrations. These aberrations create long-lived speckles in the scientific image plane, which can easily be mistaken for planets. Aims: Common adaptive optics systems require dedicated components to perform wave-front analysis. The ultimate wave-front measurement performance is thus limited by the unavoidable differential aberrations between the wave-front sensor and the scientific camera. To reach the level of detectivity required by high-contrast imaging, these differential aberrations must be estimated and compensated for. In this paper, we characterize and experimentally validate a wave-front sensing method that relies on focal-plane data. Methods: Our method, called COFFEE (for COronagraphic Focal-plane wave-Front Estimation for Exoplanet detection), is based on a Bayesian approach, and it consists in an extension of phase diversity to high-contrast imaging. It estimates the differential aberrations using only two focal-plane coronagraphic images recorded from the scientific camera itself. Results: We first present a thorough characterization of COFFEE's performance by means of numerical simulations. This characterization is then compared with an experimental validation of COFFEE using an in-house adaptive optics bench and an apodized Roddier & Roddier phase mask coronagraph. An excellent match between experimental results and the theoretical study is found. Lastly, we present a preliminary validation of COFFEE's ability to compensate for the aberrations upstream of a coronagraph.

  2. Emissions of tar-containing binders: a laboratory study.

    PubMed

    Hugener, Martin; Emmenegger, Lukas; Mattrel, Peter

    2007-02-15

    In Switzerland, hot recycling of tar-containing pavements is a subject of much dispute between environmentalists, road authorities and constructors. The main reason for this controversy comes from a lack of knowledge about the amount of hazardous compounds emitted, especially polycyclic aromatic hydrocarbons (PAHs), and the resulting health risk for road workers. On this background we decided to initiate a research project to study the emission behaviour of tar-containing materials. Mixtures of tar and bitumen with variable PAH content were heated in an open reactor flask at different temperatures to identify and quantify the key parameters of PAH emissions. The expected linear correlation between PAH concentration in the fumes and in the binder was found only for binder mixtures with PAH concentrations above 5000 ppm. This was traced back to the problem that a change of the PAH content in the binder was always accompanied by a change of other parameters, like viscosity. In the experiments with temperature variation, emissions of individual PAHs correlated well with vapor pressure. However, for Naphthalene and, in a lesser degree, for 3-ring PAHs too, a partial depletion of these compounds in the vapour was observed in some experiments. The effect is a slower increase with temperature for these compounds compared to 4-6-ring PAHs. This is one reason why the commonly used set of EPA-PAHs, which includes naphthalene and 3-ring PAHs, is considered inappropriate for the assessment of the health hazard in the case of tar-containing materials in hot recycling. PMID:17365290

  3. Leptospira and Rodents in Cambodia: Environmental Determinants of Infection

    PubMed Central

    Ivanova, Svilena; Herbreteau, Vincent; Blasdell, Kim; Chaval, Yannick; Buchy, Philippe; Guillard, Bertrand; Morand, Serge

    2012-01-01

    We investigated infection of rodents and shrews by Leptospira spp. in two localities of Cambodia (Veal Renh, Kaev Seima) and in four types of habitat (forests, non-flooded lands, lowland rain-fed paddy fields, houses) during the wet and the dry seasons. Habitat preference was common, and rodent and shrew species were found only in houses or in rain-fed paddy fields or in forests. Among 649 small mammals trapped belonging to 12 rodent species and 1 shrew species, 71 of 642 animals tested were carriers of Leptospira according to the 16S ribosomal RNA marker used. Rodent infection was higher in low-slope locations, corresponding to rain-fed paddy fields, especially in the rainy season and in Kaev Seima. Rodents (Rattus exulans) and shrews (Suncus murinus) inhabiting households showed significantly low levels of infections, whereas rodents living in and near to forests (shrubby wasteland, orchards) showed high levels of infection. PMID:22665613

  4. Implementation of automated reporting of estimated glomerular filtration rate among Veterans Affairs laboratories: a retrospective study

    PubMed Central

    2012-01-01

    Background Automated reporting of estimated glomerular filtration rate (eGFR) is a recent advance in laboratory information technology (IT) that generates a measure of kidney function with chemistry laboratory results to aid early detection of chronic kidney disease (CKD). Because accurate diagnosis of CKD is critical to optimal medical decision-making, several clinical practice guidelines have recommended the use of automated eGFR reporting. Since its introduction, automated eGFR reporting has not been uniformly implemented by U. S. laboratories despite the growing prevalence of CKD. CKD is highly prevalent within the Veterans Health Administration (VHA), and implementation of automated eGFR reporting within this integrated healthcare system has the potential to improve care. In July 2004, the VHA adopted automated eGFR reporting through a system-wide mandate for software implementation by individual VHA laboratories. This study examines the timing of software implementation by individual VHA laboratories and factors associated with implementation. Methods We performed a retrospective observational study of laboratories in VHA facilities from July 2004 to September 2009. Using laboratory data, we identified the status of implementation of automated eGFR reporting for each facility and the time to actual implementation from the date the VHA adopted its policy for automated eGFR reporting. Using survey and administrative data, we assessed facility organizational characteristics associated with implementation of automated eGFR reporting via bivariate analyses. Results Of 104 VHA laboratories, 88% implemented automated eGFR reporting in existing laboratory IT systems by the end of the study period. Time to initial implementation ranged from 0.2 to 4.0 years with a median of 1.8 years. All VHA facilities with on-site dialysis units implemented the eGFR software (52%, p<0.001). Other organizational characteristics were not statistically significant. Conclusions The VHA did not have uniform implementation of automated eGFR reporting across its facilities. Facility-level organizational characteristics were not associated with implementation, and this suggests that decisions for implementation of this software are not related to facility-level quality improvement measures. Additional studies on implementation of laboratory IT, such as automated eGFR reporting, could identify factors that are related to more timely implementation and lead to better healthcare delivery. PMID:22788730

  5. ORGANOTIN TOXICITY STUDIES CONDUCTED WITH SELECTED MARINE ORGANISMS AT EPA'S ENVIRONMENTAL RESEARCH LABORATORY, GULF BREEZE, FLORIDA

    EPA Science Inventory

    Studies on effect of bis(tri-n-butyltin)oxide (TBTO) and other organotins on marine species have been conducted at the U.S. Environmental Protection Agency's laboratory at Gulf Breeze, Florida, since 1983. First studies were done on two species of algae, Skeletonema costatum and ...

  6. Laboratory Studies on Surface Sampling of Bacillus anthracis Contamination: Summary, Gaps, and Recommendations

    Microsoft Academic Search

    Gregory F. Piepel; Brett G. Amidan; Rebecca Hu

    2011-01-01

    This report summarizes previous laboratory studies to characterize the performance of methods for collecting, storing\\/transporting, processing, and analyzing samples from surfaces contaminated by Bacillus anthracis or related surrogates. The focus is on plate culture and count estimates of surface contamination for swab, wipe, and vacuum samples of porous and nonporous surfaces. Summaries of the previous studies and their results were

  7. Use of the LITEE Lorn Manufacturing Case Study in a Senior Chemical Engineering Unit Operations Laboratory

    ERIC Educational Resources Information Center

    Abraham, Nithin Susan; Abulencia, James Patrick

    2011-01-01

    This study focuses on the effectiveness of incorporating the Laboratory for Innovative Technology and Engineering Education (LITEE) Lorn Manufacturing case into a senior level chemical engineering unit operations course at Manhattan College. The purpose of using the case study is to demonstrate the relevance of ethics to chemical engineering…

  8. Effect of material aging on parachute pack life: a synopsis of Sandia National Laboratories studies

    Microsoft Academic Search

    I. Auerbach; J. W. Mead; K. E. Mead; R. H. Ericksen; F. B. Burns; C. L. Renschler

    1984-01-01

    A systematic study of the effects of environmental factors on nylon 66 and Kevlar 29 strength degradation in parachute components is being conducted at Sandia National Laboratories. It includes: (1) accelerated aging studies in air, inert environments, humidity, ozone, and smog; (2) a 25-year surveillance program of parachutes in a variety of natural climatic environments; (3) moisture absorption as a

  9. The Effectiveness of Laboratory Photomicrography for Studying Microbiology in Nigerian Secondary Schools.

    ERIC Educational Resources Information Center

    Ali, Anthony

    1984-01-01

    Investigated effects of using laboratory photomicrography as a motivational technique in the teaching/learning processes involved in the study of microbiology in Nigerian schools. Of the 720 students participating in the study, those taught using the photomicrographs scored highest on posttests and indicated that they were highly motivated by the…

  10. Ancient DNA and the tropics: a rodent's tale

    PubMed Central

    Gutiérrez-García, Tania A.; Vázquez-Domínguez, Ella; Arroyo-Cabrales, Joaquín; Kuch, Melanie; Enk, Jacob; King, Christine; Poinar, Hendrik N.

    2014-01-01

    Most genetic studies of Holocene fauna have been performed with ancient samples from dry and cold regions, in which preservation of fossils is facilitated and molecular damage is reduced. Ancient DNA work from tropical regions has been precluded owing to factors that limit DNA preservation (e.g. temperature, hydrolytic damage). We analysed ancient DNA from rodent jawbones identified as Ototylomys phyllotis, found in Holocene and Late Pleistocene stratigraphic layers from Loltún, a humid tropical cave located in the Yucatan peninsula. We extracted DNA and amplified six short overlapping fragments of the cytochrome b gene, totalling 666 bp, which represents an unprecedented success considering tropical ancient DNA samples. We performed genetic, phylogenetic and divergence time analyses, combining sequences from ancient and modern O. phyllotis, in order to assess the ancestry of the Loltún samples. Results show that all ancient samples fall into a unique clade that diverged prior to the divergence of the modern O. phyllotis, supporting it as a distinct Pleistocene form of the Ototylomys genus. Hence, this rodent's tale suggests that the sister group to modern O. phyllotis arose during the Miocene–Pliocene, diversified during the Pleistocene and went extinct in the Holocene. PMID:24899682

  11. Molecular detection of bacterial contamination in gnotobiotic rodent units

    PubMed Central

    Packey, Christopher D; Shanahan, Michael T; Manick, Sayeed; Bower, Maureen A; Ellermann, Melissa; Tonkonogy, Susan L; Carroll, Ian M; Sartor, R Balfour

    2013-01-01

    Gnotobiotic rodents provide an important technique to study the functional roles of commensal bacteria in host physiology and pathophysiology. To ensure sterility, these animals must be screened frequently for contamination. The traditional screening approaches of culturing and Gram staining feces have inherent limitations, as many bacteria are uncultivable and fecal Gram stains are difficult to interpret. Thus, we developed and validated molecular methods to definitively detect and identify contamination in germ-free (GF) and selectively colonized animals. Fresh fecal pellets were collected from rodents housed in GF isolators, spontaneously contaminated ex-GF isolators, selectively colonized isolators and specific pathogen-free (SPF) conditions. DNA isolated from mouse and rat fecal samples was amplified by polymerase chain reaction (PCR) and subjected to quantitative PCR (qPCR) using universal primers that amplify the 16S rRNA gene from all bacterial groups. PCR products were sequenced to identify contaminating bacterial species. Random amplification of polymorphic DNA (RAPD) PCR profiles verified bacterial inoculation of selectively colonized animals. These PCR techniques more accurately detected and identified GF isolator contamination than current standard approaches. These molecular techniques can be utilized to more definitively screen GF and selectively colonized animals for bacterial contamination when Gram stain and/or culture results are un-interpretable or inconsistent. PMID:23887190

  12. Preparing undercut model of posttraumatic epileptogenesis in rodents.

    PubMed

    Xiong, Wenhui; Ping, Xingjie; Gao, Jianhua; Jin, Xiaoming

    2011-01-01

    Partially isolated cortex ("undercut") is an animal model of posttraumatic epileptogenesis. The surgical procedure involves cutting through the sensorimotor cortex and the underneath white matter (undercut) so that a specific region of the cerebral cortex is largely isolated from the neighboring cortex and subcortical regions(1-3). After a latency of two or more weeks following the surgery, epileptiform discharges can be recorded in brain slices from rodents(1); and electrical or behavior seizures can be observed in vivo from other species such as cat and monkey(4-6). This well established animal model is efficient to generate and mimics several important characteristics of traumatic brain injury. However, it is technically challenging attempting to make precise cortical lesions in the small rodent brain with a free hand. Based on the procedure initially established in Dr. David Prince's lab at the Stanford University(1), here we present an improved technique to perform a surgery for the preparation of this model in mice and rats. We demonstrate how to make a simple surgical device and use it to gain a better control of cutting depth and angle to generate more precise and consistent results. The device is easy to make, and the procedure is quick to learn. The generation of this animal model provides an efficient system for study on the mechanisms of posttraumatic epileptogenesis. PMID:21946525

  13. New Insights from Rodent Models of Fatty Liver Disease

    PubMed Central

    2011-01-01

    Abstract Rodent models of fatty liver disease are essential research tools that provide a window into disease pathogenesis and a testing ground for prevention and treatment. Models come in many varieties involving dietary and genetic manipulations, and sometimes both. High-energy diets that induce obesity do not uniformly cause fatty liver disease; this has prompted close scrutiny of specific macronutrients and nutrient combinations to determine which have the greatest potential for hepatotoxicity. At the same time, diets that do not cause obesity or the metabolic syndrome but do cause severe steatohepatitis have been exploited to study factors important to progressive liver injury, including cell death, oxidative stress, and immune activation. Rodents with a genetic predisposition to overeating offer yet another model in which to explore the evolution of fatty liver disease. In some animals that overeat, steatohepatitis can develop even without resorting to a high-energy diet. Importantly, these models and others have been used to document that aerobic exercise can prevent or reduce fatty liver disease. This review focuses primarily on lessons learned about steatohepatitis from manipulations of diet and eating behavior. Numerous additional insights about hepatic lipid metabolism, which have been gained from genetically engineered mice, are also mentioned. Antioxid. Redox Signal. 15, 535–550. PMID:21126212

  14. Chromosomal instability in rodents caused by pollution from Baikonur cosmodrome.

    PubMed

    Kolumbayeva, Saule; Begimbetova, Dinara; Shalakhmetova, Tamara; Saliev, Timur; Lovinskaya, Anna; Zhunusbekova, Benazir

    2014-09-01

    An assessment of the health status of ecosystems exposed to man-made pollution is a vital issue for many countries. Particularly it concerns the consequences of contamination caused by the activity of the space industry. Each rocket launch is accompanied by the introduction of parts of the rocket propellant into the environment. This study aims to scrutinize the effect of the components of rocket fuel on the induction of lipid peroxidation and chromosomal aberrations on rodents inhabiting the area exposed to pollution from Baikonur cosmodrome. The results showed the increase of the level of lipid hydroperoxide and malondialdehyde in the livers of Citellus pygmaeus Pallas and Mus musculus L., which indicates an augmentation of free radical activity and DNA damage. The cytogenetic analysis of bone marrow cells revealed that the frequency of chromosomal aberrations was a few times higher in the rodents from contaminated territory. The signs of oxidative stress and high level of chromosomal aberrations indicate the environmental impact of the cosmodrome, and its possible toxic and mutagenic effects on ecosystems. PMID:24990120

  15. Causal evidence between monsoon and evolution of rhizomyine rodents.

    PubMed

    López-Antoñanzas, Raquel; Knoll, Fabien; Wan, Shiming; Flynn, Lawrence J

    2015-01-01

    The modern Asian monsoonal systems are currently believed to have originated around the end of the Oligocene following a crucial step of uplift of the Tibetan-Himalayan highlands. Although monsoon possibly drove the evolution of many mammal lineages during the Neogene, no evidence thereof has been provided so far. We examined the evolutionary history of a clade of rodents, the Rhizomyinae, in conjunction with our current knowledge of monsoon fluctuations over time. The macroevolutionary dynamics of rhizomyines were analyzed within a well-constrained phylogenetic framework coupled with biogeographic and evolutionary rate studies. The evolutionary novelties developed by these rodents were surveyed in parallel with the fluctuations of the Indian monsoon so as to evaluate synchroneity and postulate causal relationships. We showed the existence of three drops in biodiversity during the evolution of rhizomyines, all of which reflected elevated extinction rates. Our results demonstrated linkage of monsoon variations with the evolution and biogeography of rhizomyines. Paradoxically, the evolution of rhizomyines was accelerated during the phases of weakening of the monsoons, not of strengthening, most probably because at those intervals forest habitats declined, which triggered extinction and progressive specialization toward a burrowing existence. PMID:25759260

  16. Light-induced Fos expression in the suprachiasmatic nucleus of the four-striped field mouse, Rhabdomys pumilio: A southern African diurnal rodent.

    PubMed

    Schumann, D M; Cooper, H M; Hofmeyr, M D; Bennett, N C

    2006-10-16

    Previous studies have suggested that nocturnal and diurnal species of rodents differ in their circadian responses to light including phase shifts and early gene expression. Rhabdomys pumilio, the four-striped field mouse, is diurnal both in nature and in the laboratory. We studied in this species the response of the suprachiasmatic nucleus (SCN) to light stimuli at different time periods using light-induced expression of Fos as marker of neuronal activity. Fos induction in the SCN was investigated using immunohistochemistry and quantitative image analysis. The animals were exposed to a 15 min light pulse with monochromatic green light at different circadian times throughout a 24-h cycle. Animals maintained in constant darkness served as controls. R. pumilio exhibited an endogenous Fos rhythm in the SCN during constant darkness with highest expression during the subjective day at circadian time (CT) 2 and CT10. Photic stimulation resulted in significant Fos induction in the SCN at CT6, CT14, CT18 and CT22, compared to controls kept in constant darkness, with a peak of expression at CT22, i.e. during late subjective night, mainly due to expression in the ventral SCN. In tract tracing experiments based on the use of cholera toxin subunit B, we found that retinal fibres innervate mainly the contralateral ventral SCN. The intergeniculate leaflet received bilateral retinal innervation with overlap between ipsilateral and contralateral fibres. Altogether the data show that the rodent R. pumilio is a unique diurnal model for chronobiological studies. PMID:17027762

  17. Control of Domestic Rats & Mice, Training Guide--Rodent Control Series.

    ERIC Educational Resources Information Center

    Bjornson, Bayard F.; And Others

    As one booklet in a series on rodent control, this training guide has been developed to assist administrators, rodent-control operators, and others responsible for rodent-control operations in the training of employees in this field. Topics covered include rodents and human welfare, description and habits of domestic rats and mice, rodent-borne…

  18. Ecology, Genetic Diversity, and Phylogeographic Structure of Andes Virus in Humans and Rodents in Chile?

    PubMed Central

    Medina, Rafael A.; Torres-Perez, Fernando; Galeno, Hector; Navarrete, Maritza; Vial, Pablo A.; Palma, R. Eduardo; Ferres, Marcela; Cook, Joseph A.; Hjelle, Brian

    2009-01-01

    Andes virus (ANDV) is the predominant etiologic agent of hantavirus cardiopulmonary syndrome (HCPS) in southern South America. In Chile, serologically confirmed human hantavirus infections have occurred throughout a wide latitudinal distribution extending from the regions of Valparaíso (32 to 33°S) to Aysén (46°S) in southern Patagonia. In this study, we found seropositive rodents further north in the Coquimbo region (30°S) in Chile. Rodent seroprevalence was 1.4%, with Oligoryzomys longicaudatus displaying the highest seroprevalence (5.9%), followed by Abrothrix longipilis (1.9%) and other species exhibiting ?0.6% seropositivity. We sequenced partial ANDV small (S) segment RNA from 6 HCPS patients and 32 rodents of four different species collected throughout the known range of hantavirus infection in Chile. Phylogenetic analyses showed two major ANDV South (ANDV Sout) clades, congruent with two major Chilean ecoregions, Mediterranean (Chilean matorral [shrubland]) and Valdivian temperate forest. Human and rodent samples grouped according to geographic location. Phylogenetic comparative analyses of portions of S and medium segments (encoding glycoproteins Gn and Gc) from a subset of rodent specimens exhibited similar topologies, corroborating two major ANDV Sout clades in Chile and suggesting that yet unknown factors influence viral gene flow and persistence throughout the two Chilean ecoregions. Genetic algorithms for recombination detection identified recombination events within the S segment. Molecular demographic analyses showed that the virus is undergoing purifying selection and demonstrated a recent exponential growth in the effective number of ANDV Sout infections in Chile that correlates with the increased number of human cases reported. Although we determined virus sequences from four rodent species, our results confirmed O. longicaudatus as the primary ANDV Sout reservoir in Chile. While evidence of geographic differentiation exists, a single cosmopolitan lineage of ANDV Sout remains the sole etiologic agent for HCPS in Chile. PMID:19116256

  19. Mosaic Convergence of Rodent Dentitions

    PubMed Central

    Lazzari, Vincent; Charles, Cyril; Tafforeau, Paul; Vianey-Liaud, Monique; Aguilar, Jean-Pierre; Jaeger, Jean-Jacques; Michaux, Jacques; Viriot, Laurent

    2008-01-01

    Background Understanding mechanisms responsible for changes in tooth morphology in the course of evolution is an area of investigation common to both paleontology and developmental biology. Detailed analyses of molar tooth crown shape have shown frequent homoplasia in mammalian evolution, which requires accurate investigation of the evolutionary pathways provided by the fossil record. The necessity of preservation of an effective occlusion has been hypothesized to functionally constrain crown morphological changes and to also facilitate convergent evolution. The Muroidea superfamily constitutes a relevant model for the study of molar crown diversification because it encompasses one third of the extant mammalian biodiversity. Methodology/Principal Findings Combined microwear and 3D-topographic analyses performed on fossil and extant muroid molars allow for a first quantification of the relationships between changes in crown morphology and functionality of occlusion. Based on an abundant fossil record and on a well resolved phylogeny, our results show that the most derived functional condition associates longitudinal chewing and non interlocking of cusps. This condition has been reached at least 7 times within muroids via two main types of evolutionary pathways each respecting functional continuity. In the first type, the flattening of tooth crown which induces the removal of cusp interlocking occurs before the rotation of the chewing movement. In the second type however, flattening is subsequent to rotation of the chewing movement which can be associated with certain changes in cusp morphology. Conclusion/Significance The reverse orders of the changes involved in these different pathways reveal a mosaic evolution of mammalian dentition in which direction of chewing and crown shape seem to be partly decoupled. Either can change in respect to strong functional constraints affecting occlusion which thereby limit the number of the possible pathways. Because convergent pathways imply distinct ontogenetic trajectories, new Evo/Devo comparative studies on cusp morphogenesis are necessary. PMID:18974837

  20. Protection against esophageal cancer in rodents with lyophilized berries: potential mechanisms.

    PubMed

    Stoner, Gary D; Chen, Tong; Kresty, Laura A; Aziz, Robeena M; Reinemann, Tiffany; Nines, Ronald

    2006-01-01

    For several years, our laboratory has been evaluating the ability of lyophilized (freeze-dried) black raspberries (Rubus occidentalis, BRBs), blackberries (R. fructicosus, BBs), and strawberries (Fragaria ananasia, STRWs) to inhibit carcinogen-induced cancer in the rodent esophagus. To assure "standardized" berry preparations for study, each berry type is of the same cultivar, picked at about the same degree of ripeness, washed and frozen within 2-4 h of the time of picking, and freeze-dried under conditions that preserve the components in the berries. Some of the known chemopreventive agents in berries include vitamins A, C, and E and folic acid; calcium and selenium; beta-carotene, alpha-carotene, and lutein; polyphenols such as ellagic acid, ferulic acid, p-coumaric acid, quercetin, and several anthocyanins; and phytosterols such as beta-sitosterol, stigmasterol, and kaempferol. In initial bioassays, freeze-dried STRW, BRB, and BB powders were mixed into AIN-76A synthetic diet at concentrations of 5% and 10% and fed to Fischer 344 rats before, during, and after treatment with the esophageal carcinogen N-nitrosomethylbenzylamine (NMBA). At 25 wk of the bioassay, all three berry types were found to inhibit the number of esophageal tumors (papillomas) in NMBA-treated animals by 24-56% relative to NMBA controls. This inhibition correlated with reductions in the formation of the NMBA-induced O6-methylguanine adduct in esophageal DNA, suggesting that the berries influenced the metabolism of NMBA leading to reduced DNA damage. Studies are ongoing to determine the mechanisms by which berries influence NMBA metabolism and DNA adduct formation. BRBs and STRWs were also tested in a postinitiation scheme and were found to inhibit NMBA-induced esophageal tumorigenesis by 31-64% when administered in the diet following treatment of the animals with NMBA. Berries, therefore, inhibit tumor promotion and progression events as well as tumor initiation. In vivo mechanistic studies with BRBs indicate that they reduce the growth rate of premalignant esophageal cells, in part, through down-regulation of cyclooxygenase-2 leading to reduced prostaglandin production and of inducible nitric oxide synthase leading to reduced nitrate/nitrite levels in the esophagus. Based upon the preclinical data on rodents, we have initiated prevention trials in humans to determine if berries might exhibit chemopreventive effects in the esophagus. PMID:16800771

  1. Comparative Effects of Dieldrin on Hepatic Ploidy, Cell Proliferation, and Apoptosis in Rodent Liver

    Microsoft Academic Search

    Lisa M. Kamendulis; Kyle L. Kolaja; Donald E. Stevenson; Earl F. Walborg Jr; James E. Klaunig

    2001-01-01

    Dieldrin-induced hepatocarcinogenesis, which is seen only in the mouse, apparently occurs through a nongenotoxic mechanism. Previous studies have demonstrated that dieldrin induces hepatic DNA synthesis in mouse, but not rat liver. A number of nongenotoxic hepatocarcinogens have been shown to increase hepatocyte nuclear ploidy following acute and subchronic treatment in rodents, suggesting that an induction of hepatocyte DNA synthesis may

  2. Prediction of Chemical Carcinogenicity in Rodents from in vitro Genetic Toxicity Assays

    Microsoft Academic Search

    Raymond W. Tennant; Barry H. Margolin; Michael D. Shelby; Errol Zeiger; Joseph K. Haseman; Judson Spalding; William Caspary; Michael Resnick; Stanley Stasiewicz; Beth Anderson; Robert Minor

    1987-01-01

    Four widely used in vitro assays for genetic toxicity were evaluated for their ability to predict the carcinogenicity of selected chemicals in rodents. These assays were mutagenesis in Salmonella and mouse lymphoma cells and chromosome aberrations and sister chromatid exchanges in Chinese hamster ovary cells. Seventy-three chemicals recently tested in 2-year carcinogenicity studies conducted by the National Cancer Institute and

  3. Spatial distribution of commensal rodents in regions with high and low Lassa fever prevalence in Guinea

    Microsoft Academic Search

    Elisabeth Fichet-Calvet; Kékoura Koulémou; Lamine Koivogui; Barré Soropogui; Oumar Sylla; Emilie Lecompte; Stéphane Daffis; Allali Kouadio; Stéphane Kouassi; Chantal Akoua-Koffi; Christiane Denys

    Lassa fever is a hemorrhagic fever caused by an arenavirus, which affects approximately 150,000 per- sons per year in West Africa. It is principally transmitted by rodents of the genus Mastomys, which serve as both reservoir and vector of the virus. This study tested the hypothesis that human Lassa fever in Guinea is related to the occurrence rate of the

  4. Geometric morphometrics of the scapula of South American caviomorph rodents (Rodentia: Hystricognathi): Form, function and phylogeny

    Microsoft Academic Search

    Cecilia C. Morgan

    2009-01-01

    The scapula of the ecomorphologically diverse South American caviomorph rodents was studied through geometric morphometric techniques, using landmarks and semilandmarks to capture the shape of this complex morphological structure. Representatives of 33 species from all caviomorph superfamilies, as well as Hystrix cristata for comparisons, were analyzed. Marked differences in scapular shape were found among the major caviomorph lineages analyzed, particularly

  5. Successional processes in a Texas savanna woodland: the role of birds and rodents 

    E-print Network

    Huebotter, Neal Harvey

    1991-01-01

    at the Ls Copita Research Area 19 5 Number of each microhabitst selected, number of traps placed in each microhabitat, and mean(SE) trap density on the rodent study ares 6 Capture locations for individual white-footed mice and short-tailed grasshopper...

  6. Arrival and diversification of caviomorph rodents and platyrrhine primates in America

    Microsoft Academic Search

    Céline Poux; Pascale Chevret; Dorothée Huchon; Wilfried W. de Jong; Emmanuel J. P. Douzery

    2006-01-01

    Platyrrhine primates and caviomorph rodents are clades of mammals that colonized South America during its period of isolation from the other continents, between 100 and 3 million years ago (Mya). Until now, no molecular study investigated the timing of the South American colonization by these two lineages with the same molecular data set. Using sequences from three nuclear genes (ADRA2B,

  7. PREDICTING RODENT CARCINOGENICITY OF AMES TEST "FALSE POSITIVES" BY IN VIVO BIOCHEMICAL PARAMETERS

    EPA Science Inventory

    Twenty-eight chemicals known to be mutagenic in the Ames test but not carcinogenic in rodent bioassays were selected for study. The effects of these chemicals on four biochemical assays (hepatic DNA damage by alkaline elution (DD), hepatic ornithine decarboxylase activity (ODC), ...

  8. Effect of plant cover on seed removal by rodents in the Monte Desert (Mendoza, Argentina)

    Microsoft Academic Search

    Paula A. Taraborelli; Mariana Dacar; Stella M. Giannoni

    2003-01-01

    In desert areas, predation risk is one of the highest costs of foraging and is a major influence on animal behaviour. Several strategies are used by foragers for surviving and reproducing in desert areas. The foraging strategies of the small mammals of South American deserts are still poorly known. In this study, we investigated the foraging strategies of rodents of

  9. Vigilance and foraging behaviour in a social desert rodent, Microcavia australis (Rodentia Caviidae)

    Microsoft Academic Search

    Paula Taraborelli

    2008-01-01

    Microcavia australis is a social species, diurnal and native to South America. This rodent provides an opportunity for analyzing the relationship between group size and the vigilance and foraging behaviour of the lesser cavy in two populations inhabiting two risky sites (El Leoncito and Ñacuñán). The study should reveal the mechanisms used by M. australis to reduce predation risk (many-eyes

  10. Edges effects on seed predation by rodents in deciduous forests of northern Switzerland

    Microsoft Academic Search

    Johannes Kollmann; Marco Buschor

    2003-01-01

    Seed predation by rodents affects plant population dynamics and it mayrespond to changes in vegetation structure at forest edges. This studyinvestigates the magnitude and direction of a potential edge effect intemperatedeciduous forests, and it seeks possible explanations based on predatorabundance and vegetation structure. The study was conducted at twelve forestedges in northern Switzerland; in six sites all shrubs at the

  11. Iris-Derived Cells from Adult Rodents and Primates Adopt Photoreceptor-Specific Phenotypes

    Microsoft Academic Search

    Tadamichi Akagi; Joe Akita; Masatoshi Haruta; Takuya Suzuki; Yoshihito Honda; Tomoyuki Inoue; Shigeki Yoshiura; Ryoichiro Kageyama; Takaaki Yatsu; Masahiro Yamada; Masayo Takahashi

    2005-01-01

    PURPOSE. The purpose of this study was to investigate the effects of various genes related to photoreceptor development on rodent and primate iris cells and the potential of iris cells as donor cells for retinal transplantation. METHODS. Adult rat and monkey iris tissue were cultured in serum-free medium containing basic fibroblast growth factor. Gene deliveries of Crx, Nrl, NeuroD and

  12. Repetitive DNA sequence homologies and amplifications in South American cricetid rodents

    Microsoft Academic Search

    D. Corach; Facultad Farmacia

    1990-01-01

    The extent of conservation of repetitive DNA sequences in five species of South American cricetid rodents, belonging to three tribes and genera, exhibiting clear karyological differences has been investigated. Dot blot evaluation of interspecific hybridization percentages underscored sharp discrepancies in some reciprocal assays, suggesting sequence amplification events might have taken place since the evolutionary divergence of the species studied. Southern

  13. Common Genetic Mechanisms of Blood Pressure Elevation in Two Independent Rodent Models of Human Essential Hypertension

    Microsoft Academic Search

    Ryan S. Friese; Payam Mahboubi; Nitish R. Mahapatra; Sushil K. Mahata; Nicholas J. Schork; Geert W. Schmid-Schönbein; Daniel T. O’Connor

    2005-01-01

    Genetic studies of essential hypertension, a complex, polygenic, and age-dependent disorder, have not been able to completely elucidate the genes responsible for development of the trait. We used a novel strategy to compare gene expression in the adrenal gland of two independent rodent models of human essential hypertension (the spontaneously hypertensive rat, SHR, and the blood pressure high mouse, BPH),

  14. Site Study Plan for laboratory soil mechanics, Deaf Smith County site, Texas: Revision 1

    SciTech Connect

    Not Available

    1987-12-01

    This Site Study Plan for laboratory soil mechanics describes the laboratory testing to be conducted on soil samples collected as part of the characterization of the Deaf Smith County site, Texas. This study provides for measurements of index, mechanical, thermal, hydrologic, chemical, and mineral properties of soils from boring throughout the site. Samples will be taken from Playa Borings/Trenching, Transportation/Utilities Foundation Borings, Repository Surface Facilities Design Foundation Borings, and Exploratory Shaft Facilities Design Foundation Borings. Data from the laboratory tests will be used for soil strata characterization, design of foundations for surface structures, design of transportation facilities and utility structures, design of impoundments, design of shaft lining, design of the shaft freeze wall, shaft permitting, performance assessment calculations, and other program requirements. A tentative testing schedule and milestone log are given. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that appropriate documentation is maintained. 18 refs., 6 figs., 3 tabs.

  15. The potential importance of nut removal by rodents from Australian macadamia orchards.

    PubMed

    Elmouttie, David; Wilson, John

    2005-10-01

    Extensive crop damage due to rodents, predominantly the black rat (Rattus rattus) is a major concern to both the Hawaiian and Australian macadamia industries. Within Australian systems, indicated the importance of adjacent non-crop habitats in the damage process with damage being directly related to the size and temporal stability of these habitats. It was also suggested that the current estimates of crop loss might be underestimates as R. rattus may remove nuts into adjacent non-crop habitats, however, the economic significance of nut removal was not investigated. This study has determined that the crop loss due to nut removal is equivalent to the crop loss due to in-crop feeding within the first row of the orchard, with nuts being removed and consumed under the cover provided by weedy adjacent habitats. Previous studies (White et al.,1997; Horskins et al.,1998; White et al.,1998) investigating the impact of rodents on crop damage have ignored the nut removal component of the damage process and hence rodents have a far greater impact on the Australian macadamia industry than previously suggested. This study also indicates that the cost-benefit of habitat manipulation as a rodent management strategy is much greater than that suggested by . Habitat manipulation is not only a cost-effective means of damage control but is also sustainable, having none of the potentially adverse public health and environmental effects of continual rodenticide use. PMID:15950371

  16. Review of experimental attempts of islet allotransplantation in rodents: Parameters involved and viability of the procedure

    PubMed Central

    Iuamoto, Leandro Ryuchi; Meyer, Alberto; Chaib, Eleazar; D’Albuquerque, Luiz Augusto Carneiro

    2014-01-01

    The purpose of the present study was to organize the parameters involved in experimental allotransplantation in rodents to elaborate the most suitable model to supply the scarcity of islet donors. We used the PubMed database to systematically search for published articles containing the keywords “rodent islet transplantation” to review. We included studies that involved allotransplantation experiments with rodents’ islets, and we reviewed the reference lists from the eligible publications that were retrieved. We excluded articles related to isotransplantation, autotransplantation and xenotransplantation, i.e., transplantation in other species. A total of 25 studies related to allotransplantation were selected for systematic review based on their relevance and updated data. Allotransplantation in rodents is promising and continues to develop. Survival rates of allografts have increased with the discovery of new immunosuppressive drugs and the use of different graft sites. These successes suggest that islet transplantation is a promising method to overcome the scarcity of islet donors and advance the treatment options for type 1 diabetes. PMID:25309081

  17. RNAVLab: A virtual laboratory for studying RNA secondary structures based on grid computing technology

    PubMed Central

    Taufer, Michela; Leung, Ming-Ying; Solorio, Thamar; Licon, Abel; Mireles, David; Araiza, Roberto; Johnson, Kyle L.

    2009-01-01

    As ribonucleic acid (RNA) molecules play important roles in many biological processes including gene expression and regulation, their secondary structures have been the focus of many recent studies. Despite the computing power of supercomputers, computationally predicting secondary structures with thermodynamic methods is still not feasible when the RNA molecules have long nucleotide sequences and include complex motifs such as pseudoknots. This paper presents RNAVLab (RNA Virtual Laboratory), a virtual laboratory for studying RNA secondary structures including pseudoknots that allows scientists to address this challenge. Two important case studies show the versatility and functionalities of RNAVLab. The first study quantifies its capability to rebuild longer secondary structures from motifs found in systematically sampled nucleotide segments. The extensive sampling and predictions are made feasible in a short turnaround time because of the grid technology used. The second study shows how RNAVLab allows scientists to study the viral RNA genome replication mechanisms used by members of the virus family Nodaviridae. PMID:19885376

  18. Behavioral Effects of Developmental Methylmercury Drinking Water Exposure in Rodents

    PubMed Central

    Bisen-Hersh, Emily B.; Farina, Marcelo; Barbosa, Fernando; Rocha, Joao BT; Aschner, Michael

    2013-01-01

    Early methylmercury (MeHg) exposure can have long-lasting consequences likely arising from impaired developmental processes, the outcome of which has been exposed in several longitudinal studies of affected populations. Given the large number of newborns at an increased risk of learning disabilities associated with in utero MeHg exposure, it is important to study neurobehavioral alterations using ecologically valid and physiologically relevant models. This review highlights the benefits of using the MeHg drinking water exposure paradigm and outlines behavioral outcomes arising from this procedure in rodents. Combination treatments that exacerbate or ameliorate MeHg-induced effects, and possible molecular mechanisms underlying behavioral impairment are also discussed. PMID:24210169

  19. [Structural characteristics of certain Rodents spines (Rodentia: Myomorpha, Hystricomorpha)].

    PubMed

    Chernova, O F; Kuznetsov, G V

    2001-01-01

    The architectonics of spines and hair was studied in Neacomys spinosus, Arvicanthis somalicus, Leopoldamys sabanus, L. edwardsi, Maxomys moi, M. surifer, Niviventer fulvescens, N. confucianus, N. cremoriventer, Acomys cahirinus, A. somalica, Hystrix indica, H. cristata, Atherurus macrourus, Erethizon dorsatum, Proechimys steerei, and Lonchotrix emiliae. The presence of a dorsal longitudinal furrow covered by a modified cuticle is a common structural feature of spines in all studied species except E. dorsatum, H. indica, and the frontal surface of the mosaic (scales located side by side) and terrace cuticle (steps between scales) varies in different species from smooth to rib-folded. A terminology has been proposed to describe the main structures of spine and hair. The adaptive significance of the spine architectonics in rodents is discussed. PMID:11525125

  20. Laboratory work and pregnancy outcomes: a study within the National Birth Cohort in Denmark

    PubMed Central

    Zhu, J L; Knudsen, L E; Andersen, A?M N; Hjollund, N H; Olsen, J

    2006-01-01

    Aims To examine pregnancy outcomes in women doing laboratory work. Methods Using data from the Danish National Birth Cohort (1997–2003), the authors conducted a prospective cohort study of 1025 female laboratory technicians and 8037 female teachers (as reference). The laboratory technicians were asked about laboratory work tasks during pregnancy in an interview (at around 16?weeks of gestation). Pregnancy outcomes were obtained by linking the cohort to the national registers. Hazard ratios (HRs) of late fetal loss and diagnosing of congenital malformations were calculated by using Cox regression, and odds ratios (ORs) of preterm birth and small for gestational age were calculated by using logistic regression. Results Overall, there were no significant differences in pregnancy outcomes between laboratory technicians and teachers. However, we found that laboratory technicians working with radioimmunoassay or radiolabelling had an increased risk of preterm birth (OR?=?2.2, 95% CI 0.8 to 6.2 for radioimmunoassay, and OR?=?1.9, 95% CI 0.8 to 4.6 for radiolabelling) and “major” malformations (HR?=?2.1, 95% CI 1.0 to 4.7 for radioimmunoassay, and HR?=?1.8, 95% CI 0.9 to 3.7 for radiolabelling). The ORs of preterm birth doubled for women working with these tasks every day or several times a week. When an exposure matrix was applied, an increased risk of “major” malformations for exposure to organic solvents was seen. Conclusions The results did not indicate any high risk of reproductive failures in laboratory technicians in general. Exposure to radioisotopes may carry a high risk of preterm birth and congenital malformations. This finding deserves further investigation. PMID:16361406