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Sample records for laboratory rodent studies

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

    USGS Publications Warehouse

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

    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 50 mg/(kg day), in laboratory exposures with mammalian model organisms. Many, but not all, effects of BPA are similar to effects seen in response to the model estrogens diethylstilbestrol and ethinylestradiol. For most effects, the potency of BPA is approximately 10–1000-fold less than that of diethylstilbestrol or ethinylestradiol. Based on our review of the literature, a consensus was reached regarding our level of confidence that particular outcomes occur in response to low dose BPA exposure. We are confident that adult exposure to BPA affects the male reproductive tract, and that long lasting, organizational effects in response to developmental exposure to BPA occur in the brain, the male reproductive system, and metabolic processes. We consider it likely, but requiring further confirmation, that adult exposure to BPA affects the brain, the female reproductive system, and the immune system, and that developmental effects occur in the female reproductive system.

  2. In Vivo Effects of Bisphenol A in Laboratory Rodent Studies

    PubMed Central

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

    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 50 mg/kg/day, in laboratory exposures with mammalian model organisms. Many, but not all, effects of BPA are similar to effects seen in response to the model estrogens diethylstilbestrol and ethinylestradiol. For most effects, the potency of BPA is approximately 10 to 1,000-fold less than that of diethylstilbestrol or ethinylestradiol. Based on our review of the literature, a consensus was reached regarding our level of confidence that particular outcomes occur in response to low-dose BPA exposure. We are confident that adult exposure to BPA affects the male reproductive tract, and that long-lasting, organizational effects in response to developmental exposure to BPA occur in the brain, the male reproductive system, and metabolic processes. We consider it likely, but requiring further confirmation, that adult exposure to BPA affects the brain, the female reproductive system, and the immune system, and that developmental effects occur in the female reproductive system. PMID:17683900

  3. Auditing laboratory rodent biosecurity programs.

    PubMed

    Porter, William P; Horn, Mandy J; Cooper, Dale M; Klein, Hilton J

    2013-10-22

    A rodent biosecurity program that includes periodic evaluation of procedures used in an institution's vivarium can be used to ensure that best practices are in place to prevent a microbial pathogen outbreak. As a result of an ongoing comprehensive biosecurity review within their North American and European production facilities, the authors developed a novel biosecurity auditing process and worksheet that could be useful in other animal care and use operations. The authors encourage other institutions to consider initiating similar audits of their biosecurity programs to protect the health of their laboratory animals. PMID:24150170

  4. A Hardware-and-Software System for Experimental Studies of the Acoustic Startle Response in Laboratory Rodents.

    PubMed

    Pevtsov, E F; Storozheva, Z I; Proshin, A T; Pevtsova, E I

    2016-02-01

    We developed and tested a novel hardware-and-software system for recording the amplitude of the acoustic startle response in rodents. In our experiments, the baseline indexes of acoustic startle response in laboratory rats and pre-stimulation inhibition under the standard delivery of acoustic stimulation were similar to those evaluated by other investigators on foreign devices. The proposed system is relatively cheap and provides the possibility of performing experiments on freely moving specimens. It should be emphasized that the results of studies can be processed with free-access software. PMID:26902348

  5. Susceptibility of Laboratory Rodents to Trichinella papuae

    PubMed Central

    Sadaow, Lakkhana; Intapan, Pewpan M.; Boonmars, Thidarut; Morakote, Nimit

    2013-01-01

    Members of the genus Trichinella are small nematodes that can infect a wide range of animal hosts. However, their infectivity varies depending on the parasite and host species combination. In this study, we examined the susceptibility of 4 species of laboratory rodents, i.e., mice, rats, hamsters, and gerbils to Trichinella papuae, an emerging non-encapsulated Trichinella species. Trichinella spiralis and Trichinella pseudospiralis were also included in this study for comparison. Fifteen animals of each rodent species were infected orally with 100 muscle larvae of each Trichinella species. Intestinal worm burden was determined at day 6 and 10 post-inoculation (PI). The numbers of muscle larvae were examined at day 45 PI. The reproductive capacity index (RCI) of the 3 Trichinella species in different rodent hosts was determined. By day 6 PI, 33.2-69.6% of the inoculated larvae of the 3 Trichinella species became adult worms in the small intestines of the host animals. However, in rats, more than 96% of adult worms of all 3 Trichinella species were expelled from the gut by day 10 PI. In gerbils, only 4.8-18.1% of adult worms were expelled by day 10 PI. In accordance with the intestinal worm burden and the persistence of adults, the RCI was the highest in gerbils with values of 241.5±41.0 for T. papuae, 432.6±48 for T. pseudospiralis, and 528.6±20.6 for T. spiralis. Hamsters ranked second and mice ranked third in susceptibility in terms of the RCI, Rats yielded the lowest parasite RCI for all 3 Trichinella species. Gerbils may be an alternative laboratory animal for isolation and maintenance of Trichinella spp. PMID:24516265

  6. Susceptibility of laboratory rodents to Trichinella papuae.

    PubMed

    Sadaow, Lakkhana; Intapan, Pewpan M; Boonmars, Thidarut; Morakote, Nimit; Maleewong, Wanchai

    2013-12-01

    Members of the genus Trichinella are small nematodes that can infect a wide range of animal hosts. However, their infectivity varies depending on the parasite and host species combination. In this study, we examined the susceptibility of 4 species of laboratory rodents, i.e., mice, rats, hamsters, and gerbils to Trichinella papuae, an emerging non-encapsulated Trichinella species. Trichinella spiralis and Trichinella pseudospiralis were also included in this study for comparison. Fifteen animals of each rodent species were infected orally with 100 muscle larvae of each Trichinella species. Intestinal worm burden was determined at day 6 and 10 post-inoculation (PI). The numbers of muscle larvae were examined at day 45 PI. The reproductive capacity index (RCI) of the 3 Trichinella species in different rodent hosts was determined. By day 6 PI, 33.2-69.6% of the inoculated larvae of the 3 Trichinella species became adult worms in the small intestines of the host animals. However, in rats, more than 96% of adult worms of all 3 Trichinella species were expelled from the gut by day 10 PI. In gerbils, only 4.8-18.1% of adult worms were expelled by day 10 PI. In accordance with the intestinal worm burden and the persistence of adults, the RCI was the highest in gerbils with values of 241.5±41.0 for T. papuae, 432.6±48 for T. pseudospiralis, and 528.6±20.6 for T. spiralis. Hamsters ranked second and mice ranked third in susceptibility in terms of the RCI, Rats yielded the lowest parasite RCI for all 3 Trichinella species. Gerbils may be an alternative laboratory animal for isolation and maintenance of Trichinella spp. PMID:24516265

  7. Euthanasia using gaseous agents in laboratory rodents.

    PubMed

    Valentim, A M; Guedes, S R; Pereira, A M; Antunes, L M

    2016-08-01

    Several questions have been raised in recent years about the euthanasia of laboratory rodents. Euthanasia using inhaled agents is considered to be a suitable aesthetic method for use with a large number of animals simultaneously. Nevertheless, its aversive potential has been criticized in terms of animal welfare. The data available regarding the use of carbon dioxide (CO2), inhaled anaesthetics (such as isoflurane, sevoflurane, halothane and enflurane), as well as carbon monoxide and inert gases are discussed throughout this review. Euthanasia of fetuses and neonates is also addressed. A table listing currently available information to ease access to data regarding euthanasia techniques using gaseous agents in laboratory rodents was compiled. Regarding better animal welfare, there is currently insufficient evidence to advocate banning or replacing CO2 in the euthanasia of rodents; however, there are hints that alternative gases are more humane. The exposure to a volatile anaesthetic gas before loss of consciousness has been proposed by some scientific studies to minimize distress; however, the impact of such a measure is not clear. Areas of inconsistency within the euthanasia literature have been highlighted recently and stem from insufficient knowledge, especially regarding the advantages of the administration of isoflurane or sevoflurane over CO2, or other methods, before loss of consciousness. Alternative methods to minimize distress may include the development of techniques aimed at inducing death in the home cage of animals. Scientific outcomes have to be considered before choosing the most suitable euthanasia method to obtain the best results and accomplish the 3Rs (replacement, reduction and refinement). PMID:26609130

  8. 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

  9. Neural changes induced by antipsychotic administration in adolescence: A review of studies in laboratory rodents.

    PubMed

    Moe, Aung Aung Kywe; Scott, James G; Burne, Thomas Hj; Eyles, Darryl W

    2016-08-01

    Adolescence is characterized by major remodelling processes in the brain. Use of antipsychotic drugs (APDs) in adolescents has increased dramatically in the last 20 years; however, our understanding of the neurobiological consequences of APD treatment on the adolescent brain has not kept the same pace and significant concerns have been raised. In this review, we examined currently available preclinical studies of the effects of APDs on the adolescent brain. In animal models of neuropsychiatric disorders, adolescent APD treatment appears to be protective against selected structural, behavioural and neurochemical phenotypes. In "neurodevelopmentally normal" adolescent animals, a range of short- and long-term alterations in behaviour and neurochemistry have been reported. In particular, the adolescent brain appears to be sensitive to long-term locomotor/reward effects of chronic atypical APDs in contrast with the outcomes in adults. Long-lasting changes in dopaminergic, glutamatergic and gamma-amino butyric acid-ergic systems induced by adolescent APD administration have been observed in the nucleus accumbens. A detailed examination of other potential target regions such as striatum, prefrontal cortex and ventral tegmental area is still required. Through identification of specific neural pathways targeted by adolescent APD treatment, future studies will expand the current knowledge on long-term neural outcomes which are of translational value. PMID:27413140

  10. Brain acetylcholinesterase activity recovery following acute methyl parathion intoxication in two feral rodent species: comparison to laboratory rodents

    SciTech Connect

    Roberts, D.K.; Silvey, N.J.; Bailey, E.M. Jr.

    1988-07-01

    Widespread use of organophosphorus insecticides (OPs) has produced both acute and chronic intoxication among nontarget organisms. Most such studies have included fish and birds as opposed to mammals. However, numerous OP toxicity studies have been conducted on laboratory rodents creating a temptation to apply this data to feral rodents. Chronic OP exposure has been reported to produce cholinergic adaptation which in turn lowers mortality rates following a subsequent acute anticholinesterase exposure. The relevance that these laboratory rodent studies have on feral rodents is subject to debate. Field studies involving OP exposure among nontarget feral mammals have produced contradictory results. Increased mortality as a result of repeated OP application has been reported. This observation may be of considerable importance to nontarget feral rodent populations due to the repetitive nature of OP application protocols. The ability of feral rodents to recover brain AChE activity (BAA) between OP application intervals undoubtedly promotes their survival. This study investigated and compared BAA recovery following acute oral methyl parathion intoxication among 2 feral rodent species and among 2 common laboratory rodent species.

  11. Field and Laboratory Studies Provide Insights into the Meaning of Day-Time Activity in a Subterranean Rodent (Ctenomys aff. knighti), the Tuco-Tuco

    PubMed Central

    Tomotani, Barbara M.; Flores, Danilo E. F. L.; Tachinardi, Patrícia; Paliza, José D.; Oda, Gisele A.; Valentinuzzi, Verônica S.

    2012-01-01

    South American subterranean rodents (Ctenomys aff. knighti), commonly known as tuco-tucos, display nocturnal, wheel-running behavior under light-dark (LD) conditions, and free-running periods >24 h in constant darkness (DD). However, several reports in the field suggested that a substantial amount of activity occurs during daylight hours, leading us to question whether circadian entrainment in the laboratory accurately reflects behavior in natural conditions. We compared circadian patterns of locomotor activity in DD of animals previously entrained to full laboratory LD cycles (LD12∶12) with those of animals that were trapped directly from the field. In both cases, activity onsets in DD immediately reflected the previous dark onset or sundown. Furthermore, freerunning periods upon release into DD were close to 24 h indicating aftereffects of prior entrainment, similarly in both conditions. No difference was detected in the phase of activity measured with and without access to a running wheel. However, when individuals were observed continuously during daylight hours in a semi-natural enclosure, they emerged above-ground on a daily basis. These day-time activities consisted of foraging and burrow maintenance, suggesting that the designation of this species as nocturnal might be inaccurate in the field. Our study of a solitary subterranean species suggests that the circadian clock is entrained similarly under field and laboratory conditions and that day-time activity expressed only in the field is required for foraging and may not be time-dictated by the circadian pacemaker. PMID:22649565

  12. Rodent Studies of Cardiovascular Deconditioning

    NASA Technical Reports Server (NTRS)

    Shoukas, Artin A.

    1999-01-01

    Changes in blood pressure can occur for two reasons: 1) A decrease in cardiac output resulting from the altered contractility of the heart or through changes in venous filling pressure via the Frank Starling mechanism or; 2) A change in systemic vascular resistance. The observed changes in cardiac output and blood pressure after long term space flight cannot be entirely explained through changes in contractility or heart rate alone. Therefore, alterations in filling pressure mediated through changes in systemic venous capacitance and arterial resistance function may be important determinants of cardiac output and blood pressure after long term space flight. Our laboratory and previous studies have shown the importance of veno-constriction mediated by the carotid sinus baroreceptor reflex system on overall circulatory homeostasis and in the regulation of cardiac output. Our proposed experiments test the overall hypothesis that alterations in venous capacitance function and arterial resistance by the carotid sinus baroreceptor reflex system are an important determinant of the cardiac output and blood pressure response seen in astronauts after returning to earth from long term exposure to microgravity. This hypothesis is important to our overall understanding of circulatory adjustments made during long term space flight. It also provides a framework for investigating counter measures to reduce the incidence of orthostatic hypotension caused by an attenuation of cardiac output. We continue to use hind limb unweighted (HLU) rat model to simulate the patho physiological effects as they relate to cardiovascular deconditioning in microgravity. We have used this model to address the hypothesis that microgravity induced cardiovascular deconditioning results in impaired vascular responses and that these impaired vascular responses result from abnormal alpha-1 AR signaling. The impaired vascular reactivity results in attenuated blood pressure and cardiac output responses to an

  13. Anaerobic threshold employed on exercise training prescription and performance assessment for laboratory rodents: A short review.

    PubMed

    Abreu, Phablo; Mendes, Sávio Victor Diogenes; Leal-Cardoso, José Henrique; Ceccatto, Vânia Marilande

    2016-04-15

    Several studies have generated numerous terms in the field of exercise training prescription and performance assessment that often do not match the information previously demonstrated by many other works, generating much debate and resulting in an immense pool of scientific results. Several protocols in exercise training prescription and performance assessment have been proposed for these purposes by many reasons. In the field of exercise science, the protocol must be thoroughly investigated and provide real tools to be reproducible. Many laboratories have been adapting and developing evaluation protocols and testing on physical training of rodents in different experimental conditions. In this context, mice, rats and rabbits are preferentially chosen due to easy manipulation and good response to exercise, and comparable at results obtained with humans in compatible effort intensities. But, the exercise training programs and aerobic-anaerobic transition assessment proposed for animal models vary extensively, depending on the species, gender, age, type of stimulus, type of exercise, type of method and also on the specific objectives of the program. This short review demonstrates the need in offering tools performed by invasive measurement to assess the anaerobic threshold by blood lactate employed on evolution of aerobic-anaerobic parameters of rodents. The objective of this short review was to present and to discuss physical evaluation protocols applications to rodents. The table submitted may give a basis for anaerobic threshold employed on exercise training prescription and performance assessment for laboratory rodents in future research. PMID:26860893

  14. A small rodent research facility for flight with Columbus laboratory.

    PubMed

    Adami, G; Falcetti, G

    2002-07-01

    During 2001 ESA has finalised the definition of an animal holding facility able to support experimentation with small rodent for the ISS International Space Station. The name of this facility is MISS or Mice on ISS. A facility Science Team is consolidating with ESA the MISS Requirement specification that is driving the Phase A/B Study, where Laben is acting as Prime contractor. In the frame of this Phase A/B that will last until the end 2003, Laben is working in co-operation with qualified European companies with recognised specific area of excellence and heritage. This article presents the Study heritage, the different scenarios under assessment, the critical areas to be explored and then preliminary candidates for bread boarding that is the final task of the Study to consolidate the final Facility Specification. PMID:15002605

  15. Problems in the study of rodent aggression.

    PubMed

    Blanchard, Robert J; Wall, Philip M; Blanchard, D Caroline

    2003-09-01

    Laboratory research has produced detailed descriptions of aggression and defense patterns in the rat, mouse, and hamster, showing strong similarities, but also some differences, across these species. Research on target sites for attack, in conjunction with analyses of the situational antecedents of attack behaviors and of responsivity of these to conditions that elicit fear, has also provided a strong basis for analysis of offensive and defensive aggression strategies and for identification of combinations of these modalities such as may occur in maternal aggression. These patterns have been empirically differentiated from phenomena such as play fighting or predation and compared for laboratory rodents and their wild ancestors. An array of tasks, suitable for use with pharmacological and experimental manipulations, is available for analysis of both aggression and defense. These developments should produce a firm basis for research using animal models to analyze a broad array of aggression-related phenomena, including systematic approaches to understanding the normal antecedents and consequences of each of several differentiable types of aggressive behavior. Despite this strong empirical and analytic background, laboratory animal aggression research has been in a period of decline, spanning several decades, relative to comparable research focusing on areas such as sexual behavior or stress. Problems that may have contributed to the relative neglect of aggression research include confusion about the interpretation of different tasks for eliciting aggression; difficulties and labor intensiveness of observational measures needed for an adequate differentiation of offensive and defensive behaviors; analytic difficulties stemming from the sensitivity of offensive aggression to the inhibitory effects of fear or defensiveness; lack of a clear relationship between categories of aggressive behavior as defined in animal studies and those used in human aggression research; and

  16. Estimation of Wildlife Hazard Levels Using Interspecies Correlation Models and Standard Laboratory Rodent Toxicity Data

    EPA Science Inventory

    Toxicity data from laboratory rodents are widely available and frequently used in human health assessments as an animal model. We explore the possibility of using single rodent acute toxicity values to predict chemical toxicity to a diversity of wildlife species and to estimate ...

  17. 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

  18. Neurogenetics of Aggressive Behavior – Studies in Rodents

    PubMed Central

    Takahashi, Aki; Miczek, Klaus A.

    2014-01-01

    Aggressive behavior is observed in many animal species, such as insects, fish, lizards, frogs, and most mammals including humans. This wide range of conservation underscores the importance of aggressive behavior in the animals’ survival and fitness, and the likely heritability of this behavior. Although typical patterns of aggressive behavior differ between species, there are several concordances in the neurobiology of aggression among rodents, primates, and humans. Studies with rodent models may eventually help us to understand the neurogenetic architecture of aggression in humans. However, it is important to recognize the difference between the ecological and ethological significance of aggressive behavior (species-typical aggression) and maladaptive violence (escalated aggression) when applying the findings of aggression research using animal models to human or veterinary medicine. Well-studied rodent models for aggressive behavior in the laboratory setting include the mouse (Mus musculus), rat (Rattus norvegicus), hamster (Mesocricetus auratus), and prairie vole (Microtus ochrogaster). The neural circuits of rodent aggression have been gradually elucidated by several techniques e.g. immunohistochemistry of immediate-early gene (c-Fos) expression, intracranial drug microinjection, in vivo microdialysis, and optogenetics techniques. Also, evidence accumulated from the analysis of gene-knockout mice shows the involvement of several genes in aggression. Here we review the brain circuits that have been implicated in aggression, such as the hypothalamus, prefrontal cortex (PFC), dorsal raphe nucleus (DRN), nucleus accumbens (NAc), and olfactory system. We then discuss the roles of glutamate and γ-aminobutyric acid (GABA), major inhibitory and excitatory amino acids in the brain, as well as their receptors, in controlling aggressive behavior, focusing mainly on recent findings. At the end of this chapter, we discuss how genes can be identified that underlie

  19. 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

  20. Human and laboratory rodent low response to alcohol: Is better consilience possible?

    PubMed Central

    Crabbe, John C.; Bell, Richard L.; Ehlers, Cindy L.

    2010-01-01

    If people are brought into the laboratory and given alcohol, there are pronounced differences among individuals in many responses to the drug. Some participants in alcohol challenge protocols show a cluster of “low level of responses to alcohol,” determined by observing post-drinking related changes in subjective, motor and physiological effects at a given dose level. Those individuals characterized as having low Level of Response (LR) to alcohol have been shown to be at increased risk for a lifetime diagnosis of alcohol dependence (AD), and this relationship between low LR and AD appears to be in part genetic. LR to alcohol is an area where achieving greater consilience between the human and rodent phenotypes would seem to be highly likely. However, despite extensive data from both human and rodent studies, few attempts have been made to evaluate the human and animal data systematically in order to understand which aspects of LR appear to be most directly comparable across species and thus the most promising for further study. We review four general aspects of LR that could be compared between humans and laboratory animals: 1) behavioral measures of subjective intoxication; 2) body sway; 3) endocrine responses; and 4) stimulant, autonomic and electrophysiological responses. None of these aspects of LR provide completely face-valid direct comparisons across species. Nevertheless, one of the most replicated findings in humans is the low subjective response, but, as it may reflect either aversively-valenced and/or positively-valenced responses to alcohol as usually assessed, it is unclear which rodent responses are analogous. Stimulated heart rate appears to be consistent in animal and human studies, although at-risk subjects appear to be more, rather than less sensitive to alcohol using this measure. The hormone and electrophysiological data offer strong possibilities of understanding the neurobiological mechanisms, but the rodent data in particular are rather

  1. Economic and technical considerations in the procurement of laboratory rodents.

    PubMed

    Lewis, L L

    1980-04-01

    Research cost effectiveness is an increasing fact of life in this climate of spiraling inflation, restricted budgets, advancing technology and increased regulatory complexities. Because rodent procurement is an easily identifiable cost center, it may become a target for budgetary restriction without judicious consideration of its impact on the total research effort. If such reductions compromise sound biologic, genetic or health principles, the result may be research delays or repetition, inefficient or ineffective use of scientific personnel and increased project costs. Procurement decisions should be based on the development of specific biologic, genetic and health parameters required by the project design. Potential sources of supply should be assessed to determine compliance with these criteria. Further analysis must include an evaluation of institutional resources to determine compatibility with procurement standards over the term of the project. Only then can procurement costs be placed in proper perspective. PMID:7052385

  2. Expression of a novel splicing variant of Pcp2 in closely related laboratory rodents.

    PubMed

    Przybyła, M A; Nowacka-Chmielewska, M M; Barski, J J

    2016-01-01

    Purkinje cell protein-2 (PCP2), also known as L7, is a member of the GoLoco protein family with highly cell-specific expression, being restricted to cerebellar Purkinje cells and retinal bipolar neurons in various species. However, its function in these tissues is unknown. Previous studies have suggested that PCP2 is a guanine nucleotide dissociation inhibitor, or a guanine nucleotide exchange factor. The Pcp2 gene is known to have many splice variants in both cerebellar Purkinje cells and retinal bipolar neurons. Here, we tested the hypothesis that a novel Pcp2 splice variant is conserved in closely related laboratory rodents (mice, rats, and hamsters). After analyzing alternative splicing of this gene in the Purkinje cells and retinas of these rodent species, we confirmed the presence of the novel longer transcript in mice. However, assessment of Pcp2 transcripts using polymerase chain reaction amplification of complementary DNA revealed this long splice variant containing the additional exon 3B to be absent from rats and hamsters. Thus, the novel Pcp2 transcript is particular to mouse cerebellar Purkinje cells and retinal bipolar neurons. It is likely to have arisen in this species, as a result of spontaneous mutation or de novo rearrangements. This gene presumably serves a very specific and, as yet, unknown function in the eyes and/or Purkinje cells of mice. PMID:27525924

  3. Can Rodent Longevity Studies be Both Short and Powerful?

    PubMed Central

    Robertson, Henry T.; Smith, Daniel L.; Pajewski, Nicholas M.; Weindruch, Richard H.; Garland, Theodore; Argyropoulos, George; Bokov, Alex

    2011-01-01

    Many rodent experiments have assessed effects of diets, drugs, genes, and other factors on life span. A challenge with such experiments is their long duration, typically over 3.5 years given rodent life spans, thus requiring significant time costs until answers are obtained. We collected longevity data from 15 rodent studies and artificially truncated them at 2 years to assess the extent to which one will obtain the same answer regarding mortality effects. When truncated, the point estimates were not significantly different in any study, implying that in most cases, truncated studies yield similar estimates. The median ratio of variances of coefficients for truncated to full-length studies was 3.4, implying that truncated studies with roughly 3.4 times as many rodents will often have equivalent or greater power. Cost calculations suggest that shorter studies will be more expensive but perhaps not so much to not be worth the reduced time. PMID:21051569

  4. 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.

  5. Design, construction, and validation of a large capacity rodent magnetic field exposure laboratory.

    PubMed

    Gauger, J R; Johnson, T R; Stangel, J E; Patterson, R C; Williams, D A; Harder, J B; McCormick, D L

    1999-01-01

    A magnetic field exposure laboratory has been constructed to support National Toxicology Program studies for the evaluation of the toxicity and carcinogenicity of pure, linearly polarized, 60 Hz magnetic fields in rodents. This dual corridor, controlled access facility can support the simultaneous exposure of 1200 rats and 1200 mice. The facility contains fully redundant electrical and environmental control systems and was constructed using non-metallic materials to maintain low levels of background (ambient), stray, and cross-talk magnetic fields. The exposure module design provides for large uniform exposure volumes with good control of stray and cross-talk fields, while allowing the use of roll-around cage racks for simplified animal husbandry. Stray fields and cross-talk have been further reduced by the inclusion of "steering coils" in each exposure module. Ambient 60 Hz fields (less cross-talk) in all exposure rooms are <0.1 microT (1 mG), and static magnetic fields have been mapped extensively. Magnetic field strength, waveform, temperature, relative humidity, light intensity, noise level, vibration, and air flow in all animal holding areas are tightly regulated, and are monitored continuously during all studies. Field uniformity in the animal exposure volumes is better than -/+l0%; a systematic program of cage, rack, and room rotation controls for possible positional effects within the exposure system. Magnetic fields are turned on and off over multiple cycles to prevent the induction of transients associated with abrupt field level changes. Total harmonic distortion is <3% at all field strengths. The facility has been used to study magnetic field bioeffects in rodent model systems in experiments ranging in duration from 8 weeks to 2 years. PMID:9915589

  6. The role of pheromonal responses in rodent behavior: future directions for the development of laboratory protocols.

    PubMed

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

    2013-03-01

    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

  7. 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...

  8. 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

  9. 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

  10. Early-stress regulates resilience, vulnerability and experimental validity in laboratory rodents through mother-offspring hormonal transfer.

    PubMed

    Macrì, Simone; Zoratto, Francesca; Laviola, Giovanni

    2011-06-01

    The role of early-life stressors in the calibration of individual responses to future challenges has long been investigated in laboratory rodents. Specifically, countless studies show that exposure to early-life stressors - in the form of various periods of maternal separation, administration of exogenous corticosterone and variable feeding conditions - modulate the regulation of defensive responses (e.g. behavioral fearfulness/anxiety and endocrine stress reactivity) in adulthood. Yet, the link between early-life stress and adult defensive responses is not linear. Specifically, while neonatal moderate stress is generally associated with adult subjects characterized by reduced stress reactivity, neonatal elevated stress is often reported to relate to opposite responses. Not only are these findings relevant to the understanding of individual plasticity to contextual features, but also they can have direct implications in the development of rodent models of human disorders. Specifically, these studies demonstrate that the experimental individual responds to early environmental cues with the consequence of adjusting its adaptation to the future environment. If neglected, this aspect may have detrimental consequences in laboratory animal experimentation. For example, neonatal conditions increasing adult responses to moderate stress may result in experimental subjects showing abnormal hypothalamic-pituitary-adrenocortical (HPA) activation to routine husbandry conditions, test environment and general laboratory procedures. The aim of the present review is threefold: (i) propose that neonatal circulating levels of corticosteroids may constitute a potential mediator connecting early and adult defensive systems; (ii) propose that the link between early and adult stress follows a U-shaped curve, with low levels down-regulating individual reactivity to external stressors and high levels exerting opposite effects; (iii) discuss the methodological implications of these

  11. 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...

  12. 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

  13. 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

  14. 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

  15. 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 (γHV68) 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 γHV68 and the primate gammaherpesviruses but is phylogenetically distinct from γHV68. RHVP establishes acute and latent infection in laboratory mice. Additionally, RHVP contains multiple open reading frames (ORFs) not present in γHV68 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

  16. 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

  17. Direct blood pressure monitoring in laboratory rodents via implantable radio telemetry.

    PubMed

    Huetteman, Daniel A; Bogie, Heather

    2009-01-01

    The ability to monitor and record precise blood pressure fluctuations in research animals is vital to research for human hypertension. Direct measurement of blood pressure via implantable radio telemetry devices is the preferred method for automatic collection of chronic, continuous blood pressure data. Two surgical techniques are described for instrumenting the two most commonly used laboratory rodent species with radiotelemetry devices. The basic rat procedure involves advancing a blood pressure catheter into the abdominal aorta and placing a radio transmitting device in the peritoneal cavity. The mouse technique involves advancing a thin, flexible catheter from the left carotid artery into the aortic arch and placing the telemetry device under the skin along the animal's flank. Both procedures yield a chronically instrumented model to provide accurate blood pressure data from an unrestrained animal in its home cage. PMID:19763922

  18. Rodent Brain Microinjection to Study Molecular Substrates of Motivated Behavior.

    PubMed

    Poland, Ryan S; Bull, Cecilia; Syed, Wahab A; Bowers, M Scott

    2015-01-01

    Brain microinjection can aid elucidation of the molecular substrates of complex behaviors, such as motivation. For this purpose rodents can serve as appropriate models, partly because the response to behaviorally relevant stimuli and the circuitry parsing stimulus-action outcomes is astonishingly similar between humans and rodents. In studying molecular substrates of complex behaviors, the microinjection of reagents that modify, augment, or silence specific systems is an invaluable technique. However, it is crucial that the microinjection site is precisely targeted in order to aid interpretation of the results. We present a method for the manufacture of surgical implements and microinjection needles that enables accurate microinjection and unlimited customizability with minimal cost. Importantly, this technique can be successfully completed in awake rodents if conducted in conjunction with other JoVE articles that covered requisite surgical procedures. Additionally, there are many behavioral paradigms that are well suited for measuring motivation. The progressive ratio is a commonly used method that quantifies the efficacy of a reinforcer to maintain responding despite an (often exponentially) increasing work requirement. This assay is sensitive to reinforcer magnitude and pharmacological manipulations, which allows reinforcing efficacy and/ or motivation to be determined. We also present a straightforward approach to program operant software to accommodate a progressive ratio reinforcement schedule. PMID:26437131

  19. Rodent Brain Microinjection to Study Molecular Substrates of Motivated Behavior

    PubMed Central

    Poland, Ryan S.; Bull, Cecilia; Syed, Wahab A.; Bowers, M. Scott

    2015-01-01

    Brain microinjection can aid elucidation of the molecular substrates of complex behaviors, such as motivation. For this purpose rodents can serve as appropriate models, partly because the response to behaviorally relevant stimuli and the circuitry parsing stimulus-action outcomes is astonishingly similar between humans and rodents. In studying molecular substrates of complex behaviors, the microinjection of reagents that modify, augment, or silence specific systems is an invaluable technique. However, it is crucial that the microinjection site is precisely targeted in order to aid interpretation of the results. We present a method for the manufacture of surgical implements and microinjection needles that enables accurate microinjection and unlimited customizability with minimal cost. Importantly, this technique can be successfully completed in awake rodents if conducted in conjunction with other JoVE articles that covered requisite surgical procedures. Additionally, there are many behavioral paradigms that are well suited for measuring motivation. The progressive ratio is a commonly used method that quantifies the efficacy of a reinforcer to maintain responding despite an (often exponentially) increasing work requirement. This assay is sensitive to reinforcer magnitude and pharmacological manipulations, which allows reinforcing efficacy and/ or motivation to be determined. We also present a straightforward approach to program operant software to accommodate a progressive ratio reinforcement schedule. PMID:26437131

  20. 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.

  1. 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

  2. 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...

  3. 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

  4. Building for the future: essential infrastructure for rodent ageing studies.

    PubMed

    Wells, Sara E; Bellantuono, Ilaria

    2016-08-01

    When planning ageing research using rodent models, the logistics of supply, long term housing and infrastructure provision are important factors to take into consideration. These issues need to be prioritised to ensure they meet the requirements of experiments which potentially will not be completed for several years. Although these issues are not unique to this discipline, the longevity of experiments and indeed the animals, requires a high level of consistency and sustainability to be maintained throughout lengthy periods of time. Moreover, the need to access aged stock or material for more immediate experiments poses many issues for the completion of pilot studies and/or short term intervention studies on older models. In this article, we highlight the increasing demand for ageing research, the resources and infrastructure involved, and the need for large-scale collaborative programmes to advance studies in both a timely and a cost-effective way. PMID:27221665

  5. 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.

  6. 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

  7. Arvicanthis ansorgei, a Novel Model for the Study of Sleep and Waking in Diurnal Rodents

    PubMed Central

    Hubbard, Jeffrey; Ruppert, Elisabeth; Calvel, Laurent; Robin-Choteau, Ludivine; Gropp, Claire-Marie; Allemann, Caroline; Reibel, Sophie; Sage-Ciocca, Dominique; Bourgin, Patrice

    2015-01-01

    Study Objectives: Sleep neurobiology studies use nocturnal species, mainly rats and mice. However, because their daily sleep/wake organization is inverted as compared to humans, a diurnal model for sleep studies is needed. To fill this gap, we phenotyped sleep and waking in Arvicanthis ansorgei, a diurnal rodent widely used for the study of circadian rhythms. Design: Video-electroencephalogram (EEG), electromyogram (EMG), and electrooculogram (EOG) recordings. Setting: Rodent sleep laboratory. Participants: Fourteen male Arvicanthis ansorgei, aged 3 mo. Interventions: 12 h light (L):12 h dark (D) baseline condition, 24-h constant darkness, 6-h sleep deprivation. Measurements and Results: Wake and rapid eye movement (REM) sleep showed similar electrophysiological characteristics as nocturnal rodents. On average, animals spent 12.9 h ± 0.4 awake per 24-h cycle, of which 6.88 h ± 0.3 was during the light period. NREM sleep accounted for 9.63 h ± 0.4, which of 5.13 h ± 0.2 during dark period, and REM sleep for 89.9 min ± 6.7, which of 52.8 min ± 4.4 during dark period. The time-course of sleep and waking across the 12 h light:12 h dark was overall inverted to that observed in rats or mice, though with larger amounts of crepuscular activity at light and dark transitions. A dominant crepuscular regulation of sleep and waking persisted under constant darkness, showing the lack of a strong circadian drive in the absence of clock reinforcement by external cues, such as a running wheel. Conservation of the homeostatic regulation was confirmed with the observation of higher delta power following sustained waking periods and a 6-h sleep deprivation, with subsequent decrease during recovery sleep. Conclusions: Arvicanthis ansorgei is a valid diurnal rodent model for studying the regulatory mechanisms of sleep and so represents a valuable tool for further understanding the nocturnality/diurnality switch. Citation: Hubbard J, Ruppert E, Calvel L, Robin-Choteau L, Gropp CM

  8. Anatomical features for an adequate choice of experimental animal model in biomedicine: II. Small laboratory rodents, rabbit, and pig.

    PubMed

    Lossi, Laura; D'Angelo, Livia; De Girolamo, Paolo; Merighi, Adalberto

    2016-03-01

    The anatomical features distinctive to each of the very large array of species used in today's biomedical research must be born in mind when considering the correct choice of animal model(s), particularly when translational research is concerned. In this paper we take into consideration and discuss the most important anatomical and histological features of the commonest species of laboratory rodents (rat, mouse, guinea pig, hamster, and gerbil), rabbit, and pig related to their importance for applied research. PMID:26527557

  9. 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%) ...

  10. Chemical-induced atrial thrombosis in NTP rodent studies.

    PubMed

    Yoshizawa, Katsuhiko; Kissling, Grace E; Johnson, Jo Anne; Clayton, Natasha P; Flagler, Norris D; Nyska, Abraham

    2005-01-01

    Cardiac thrombosis, one of the causes of sudden death throughout the world, plays a principal role in several cardiovascular diseases, such as myocardial infarction and stroke in humans. Data from studies of induction of chemical thrombosis in rodents help to identify substances in our environment that may contribute to cardiac thrombosis. Results for more than 500 chemicals tested in rodents in 2-year bioassays have been published as Technical Reports of the National Toxicology Program (NTP) http://ntp-server.niehs.nih.gov/index. We evaluated atrial thrombosis induced by these chemical exposures and compared it to similarly induced lesions reported in the literature. Spontaneous rates of cardiac thrombosis were determined for control Fischer 344 rats and B6C3F1 mice: 0% in rats and mice in 90-day studies and, in 2-year studies, 0.7% in both genders of mice, 4% in male rats, and 1% in female rats. Incidences of atrial thrombosis were increased in high-dosed groups involving 13 compounds (incidence rate: 20-100%): 2-butoxyethanol, C.I. Direct Blue 15, bis(2-chloroethoxy)methane, diazoaminobenzene, diethanolamine, 3,3'-dimethoxybenzidine dihydrochloride, hexachloroethane, isobutene, methyleugenol, oxazepam, C.I. Pigment Red 23, C.I. Acid Red 114, and 4,4'-thiobis(6-t-butyl-m-cresol). The main localization of spontaneously occurring and chemically induced thromboses occurred in the left atrium. The literature survey suggested that chemical-induced atrial thrombosis might be closely related to myocardial injury, endothelial injury, circulatory stasis, hypercoagulability, and impaired atrial mechanical activity, such as atrial fibrillation, which could cause stasis of blood within the left atrial appendage, contributing to left atrial thrombosis. Supplementary data referenced in this paper are not printed in this issue of Toxicologic Pathology. They are available as downloadable files at http://taylorandfrancis.metapress.com/openurl.asp?genre=journal&issn=0192-6233. To

  11. Carcinogenesis studies in rodents for evaluating risks associated with chemical carcinogens in aquatic food animals.

    PubMed Central

    Huff, J; Bucher, J; Yang, R

    1991-01-01

    Fish and shellfish caught in polluted waters contain potentially dangerous amounts of toxic and carcinogenic chemicals. Public concern was heightened when a large percentage of winter flounder taken from Boston Harbor was found to have visible cancer of the liver; winter flounder outside the estuary area had no liver lesions. Long-term chemical carcinogenesis studies could be easily and feasibly designed using laboratory rodents offered diets containing fish caught in polluted waters. Induced cancers in rodents would corroborate field observations in fish; positive results from these studies would provide further evidence about potential human health hazards from eating substantial amounts of chemically contaminated fish. Nonetheless, fish and aquatic organisms should be viewed as environmental biological monitors of pollution or of potential human health hazards, and authorities responsible for assuring clean and safe rivers, bodies of water, and biota should give more attention to these valid biological indicators or sentinels of environmental pollution. Consequently, fish and other sea creatures alone should serve as alarms regarding whether water areas constitute public health hazards. PMID:2050050

  12. Carcinogenesis studies in rodents for evaluating risks associated with chemical carcinogens in aquatic food animals

    SciTech Connect

    Huff, J.; Bucher, J.; Yang, R. )

    1991-01-01

    Fish and shellfish caught in polluted waters contain potentially dangerous amounts of toxic and carcinogenic chemicals. Public concern was heightened when a large percentage of winter flounder taken from Boston Harbor was found to have visible cancer of the liver; winter flounder outside the estuary area had no liver lesions. Long-term chemical carcinogenesis studies could be easily and feasibly designed using laboratory rodents offered diets containing fish caught in polluted waters. Induced cancers in rodents would corroborate field observations in fish; positive results from these studies would provide further evidence about potential human health hazards from eating substantial amounts of chemically contaminated fish. Nonetheless, fish and aquatic organisms should be viewed as environmental biological monitors of pollution or of potential human health hazards, and authorities responsible for assuring clean and safe rivers, bodies of water, and biota should give more attention to these valid biological indicators or sentinels of environmental pollution. Consequently, fish and other sea creatures alone should serve as alarms regarding whether water areas constitute public health hazards. 101 refs.

  13. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    Variable Gravity Laboratory studies are discussed. The following subject areas are covered: (1) conceptual design and engineering analysis; (2) control strategies (fast crawling maneuvers, main perturbations and their effect upon the acceleration level); and (3) technology requirements.

  14. Lung Function Measurements in Rodents in Safety Pharmacology Studies

    PubMed Central

    Hoymann, Heinz Gerd

    2012-01-01

    The ICH guideline S7A requires safety pharmacology tests including measurements of pulmonary function. In the first step – as part of the “core battery” – lung function tests in conscious animals are requested. If potential adverse effects raise concern for human safety, these should be explored in a second step as a “follow-up study”. For these two stages of safety pharmacology testing, both non-invasive and invasive techniques are needed which should be as precise and reliable as possible. A short overview of typical in vivo measurement techniques is given, their advantages and disadvantages are discussed and out of these the non-invasive head-out body plethysmography and the invasive but repeatable body plethysmography in orotracheally intubated rodents are presented in detail. For validation purposes the changes in the respective parameters such as tidal midexpiratory flow (EF50) or lung resistance have been recorded in the same animals in typical bronchoconstriction models and compared. In addition, the technique of head-out body plethysmography has been shown to be useful to measure lung function in juvenile rats starting from day two of age. This allows safety pharmacology testing and toxicological studies in juvenile animals as a model for the young developing organism as requested by the regulatory authorities (e.g., EMEA Guideline 1/2008). It is concluded that both invasive and non-invasive pulmonary function tests are capable of detecting effects and alterations on the respiratory system with different selectivity and area of operation. The use of both techniques in a large number of studies in mice and rats in the last years have demonstrated that they provide useful and reliable information on pulmonary mechanics in safety pharmacology and toxicology testing, in investigations of respiratory disorders, and in pharmacological efficacy studies. PMID:22973226

  15. Immunology in wild nonmodel rodents: an ecological context for studies of health and disease.

    PubMed

    Jackson, J A

    2015-05-01

    Transcriptomic methods are set to revolutionize the study of the immune system in naturally occurring nonmodel organisms. With this in mind, the present article focuses on ways in which the use of 'nonmodel' rodents (not the familiar laboratory species) can advance studies into the classical, but ever relevant, epidemiologic triad of immune defence, infectious disease and environment. For example, naturally occurring rodents are an interesting system in which to study the environmental stimuli that drive the development and homeostasis of the immune system and, by extension, to identify where these stimuli are altered in anthropogenic environments leading to the formation of immunopathological phenotypes. Measurement of immune expression may help define individual heterogeneity in infectious disease susceptibility and transmission and facilitate our understanding of infection dynamics and risk in the natural environment; furthermore, it may provide a means of surveillance that can filter individuals carrying previously unknown acute infections of potential ecological or zoonotic importance. Finally, the study of immunology in wild animals may reveal interactions within the immune system and between immunity and other organismal traits that are not observable under restricted laboratory conditions. Potentiating much of this is the possibility of combining gene expression profiles with analytical tools derived from ecology and systems biology to reverse engineer interaction networks between immune responses, other organismal traits and the environment (including symbiont exposures), revealing regulatory architecture. Such holistic studies promise to link ecology, epidemiology and immunology in natural systems in a unified approach that can illuminate important problems relevant to human health and animal welfare and production. PMID:25689683

  16. Primary gene structure and expression studies of rodent paracellin-1.

    PubMed

    Weber, S; Schlingmann, K P; Peters, M; Nejsum, L N; Nielsen, S; Engel, H; Grzeschik, K H; Seyberth, H W; Gröne, H J; Nüsing, R; Konrad, M

    2001-12-01

    The novel member of the claudin multigene family, paracellin-1/claudin-16, encoded by the gene PCLN1, is a renal tight junction protein that is involved in the paracellular transport of magnesium and calcium in the thick ascending limb of Henle's loop. Mutations in human PCLN1 are associated with familial hypomagnesemia with hypercalciuria and nephrocalcinosis, an autosomal recessive disease that is characterized by severe renal magnesium and calcium loss. The complete coding sequences of mouse and rat Pcln1 and the murine genomic structure are here presented. Full-length cDNAs are 939 and 1514 bp in length in mouse and rat, respectively, encoding a putative open-reading frame of 235 amino acids in both species with 99% identity. Exon-intron analysis of the human and mouse genes revealed a 100% homology of coding exon lengths and splice-site loci. By radiation hybrid mapping, the murine Pcln1 gene was assigned directly to marker D16Mit133 on mouse chromosome 16 (syntenic to a locus on human chromosome 3q27, which harbors the human PCLN1 gene). Mouse multiple-tissue Northern blot showed Pcln1 expression exclusively in the kidney. The expression profile along the nephron was analyzed by reverse transcriptase-PCR on microdissected nephron segments and immunohistochemistry of rat kidney. Paracellin-1 expression was restricted to distal tubular segments including the thick ascending limb of Henle's loop, the distal tubule, and the collecting duct. The identification and characterization of the rodent Pcln1 genes provide the basis for further studies of paracellin-1 function in suitable animal models. PMID:11729235

  17. Fear Extinction in Rodents

    PubMed Central

    Chang, Chun-hui; Knapska, Ewelina; Orsini, Caitlin A.; Rabinak, Christine A.; Zimmerman, Joshua M.; Maren, Stephen

    2009-01-01

    Pavlovian conditioning paradigms have become important model systems for understanding the neuroscience of behavior. In particular, studies of the extinction of Pavlovian fear responses are yielding important information about the neural substrates of anxiety disorders in humans. These studies are germane to understanding the neural mechanisms underlying behavioral interventions that suppress fear, including exposure therapy. This chapter described detailed behavioral protocols for examining the nature and properties of fear extinction in laboratory rodents. PMID:19340814

  18. 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

  19. Potential clinical translation of juvenile rodent inactivity models to study the onset of childhood obesity.

    PubMed

    Roberts, Michael D; Company, Joseph M; Brown, Jacob D; Toedebusch, Ryan G; Padilla, Jaume; Jenkins, Nathan T; Laughlin, M Harold; Booth, Frank W

    2012-08-01

    According to the latest data from the Center for Disease Control and Prevention 17%, or 12.5 million, of children and adolescents aged 2-19 years in the United States are obese. Physical inactivity is designated as one of the actual causes of US deaths and undoubtedly contributes to the obesity epidemic in children and adults. Examining the effects of inactivity on physiological homeostasis during youth is crucial given that 58% of children between the ages 6-11 yr old fail to obtain the recommended 60 min/day of physical activity and 92% of adolescents fail to achieve this goal [Troiano et al. Med Sci Sports Exerc. 40, 2008]. Nonetheless, invasive mechanistic studies in children linking diminished physical activity with metabolic maladies are lacking for obvious ethical reasons. The rodent wheel lock (WL) model was adopted by our laboratory and others to study how different organ systems of juvenile rats respond to a cessation of daily physical activity. Our WL model houses rats in cages equipped with voluntary running wheels starting at 28 days of age. After a certain period of voluntary running (3 to 6 wk), the wheels are locked, thus preventing the rats' primary source of physical activity. The studies discussed herein suggest that obesity-associated maladies including skeletal muscle insulin resistance, hypothalamic leptin resistance, fatty acid oxidation impairments in skeletal muscle and adipose tissue, nonalcoholic fatty liver disease, and endothelial dysfunction are initiated in juvenile animals that are restrained from voluntary exercise via WL. The use of the juvenile rodent WL or other inactivity models will continue to provide a powerful clinical translational tool that can be used for primordial prevention of human childhood obesity. PMID:22696577

  20. 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.

  1. Sublethal health effects in laboratory rodents from environmentally relevant exposures to oil sands contaminants.

    PubMed

    Rodríguez-Estival, Jaime; North, Michelle A; Smits, Judit E G

    2015-12-01

    Increasing activity of oil sands extraction and processing in northern Alberta is marked by ongoing controversy about the nature and extent of associated environmental impacts. Bitumen contains a mixture of toxic chemicals, including metals and residual polycyclic aromatic hydrocarbons (PAHs), whose release into the environment poses a distinct risk to the surrounding environment, plus wildlife and human health. In the present study, the authors evaluated several subclinical biomarkers of exposure and effect to mixtures of metals (Pb, Cd, and Hg) and/or PAHs (3 alkylated forms) at environmentally relevant concentrations (100-fold and 10-fold higher than the maximum dissolved concentrations found in snow, to simulate a worst-case scenario), using laboratory mice as a model for future studies of small mammals in the wild. Both metals and alkyl-PAHs exposure were associated with 1) increased relative liver, kidney, and spleen size; 2) alterations in the homeostasis of the antioxidant vitamins A and E in liver; and 3) compromised glutathione redox status in testes, with results also indicating synergistic interactions from co-exposure. The combination of morphometric and oxidative stress biomarkers provide reliable and sensitive measures of the response to contaminant exposure in a mammalian model, suggesting associated physiological costs. Based on the present experimental study, the authors propose that wild small mammals will prove to be valuable sentinel species reflecting sublethal health effects from oil sands-related contaminants. The present study's results also present a basis for the interpretation of future field data. PMID:26139097

  2. 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...

  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. New host, geographic records, and histopathologic studies of Angiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment.

    PubMed

    Robles, María del Rosario; Kinsella, John M; Galliari, Carlos; Navone, Graciela T

    2016-03-01

    To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis and Angiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylus species parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported. PMID:26982178

  5. New host, geographic records, and histopathologic studies of Angiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment

    PubMed Central

    Robles, María del Rosario; Kinsella, John M; Galliari, Carlos; Navone, Graciela T

    2016-01-01

    To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported. PMID:26982178

  6. The Effects of Prenatal Alcohol Exposure on Behavior: Rodent and Primate Studies

    PubMed Central

    Moore, Colleen F.; Adkins, Miriam M.

    2014-01-01

    The use of alcohol by women during pregnancy is a continuing problem. In this review the behavioral effects of prenatal alcohol from animal models are described and related to studies of children and adults with FASD. Studies with monkeys and rodents show that prenatal alcohol exposure adversely affects neonatal orienting, attention and motor maturity, as well as activity level, executive function, response inhibition, and sensory processing later in life. The primate moderate dose behavioral findings fill an important gap between human correlational data and rodent mechanistic research. These animal findings are directly translatable to human findings. Moreover, primate studies that manipulated prenatal alcohol exposure and prenatal stress independently show that prenatal stress exacerbates prenatal alcohol-induced behavioral impairments, underscoring the need to consider stress-induced effects in fetal alcohol research. Studies in rodents and primates show long-term effects of prenatal and developmental alcohol exposure on dopamine system functioning, which could underpin the behavioral effects. PMID:21499982

  7. Studies on the life history and development of Cuterebra polita (Diptera: Cuterebridae) in four species of rodents

    USGS Publications Warehouse

    Capelle, K.J.

    1970-01-01

    Cuterebra polita Coquillett is a primary parasite of the pocket gopher, Thomomys talpoides, in the western United States. It also occurs secondarily in other wild rodents that come into close contact with pocket gophers.Field studies disclosed pursuit, mating, and ovipositing at an aggregation site near Monte Cristo, Utah. Eggs were individually attached to fibrous roots suspended from the roof of shallow gopher burrows. This refinement of the host-parasite relationship has not previously been described for other North American cuterebrids.In the laboratory, 3 gravid females produced 186-357 viable eggs; about 85% were induced to hatch or hatched spontaneously after 12 days. Dissection of 1 of the females revealed another 886 eggs, for a total of 1243.Larvae were artificially introduced and developed in deer mice (Peromyscus maniculatus), domestic mice (Mus musculus), hamsters (Mesocricetus auratus), and meadow voles (Microtus montanus). The domestic rabbit (Orystolagus cuniculus) appeared refractory. The rate and success of development in the 4 rodent species was variable, but terminal larval development averaged about 22 days. Warbles appeared after 8 days in the rodents, and the majority of the cysts occurred in the posterior dorsal region.On the basis of larval characteristics, C. polita and C. thomomuris appear to be independent, valid species, though they share a common host.

  8. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1990-01-01

    The scope of the study is to investigate ways of controlling the microgravity environment of the International Space Station by means of a tethered system. Four main study tasks were performed. First, researchers analyzed the utilization of the tether systems to improve the lowest possible steady gravity level on the Space Station and the tether capability to actively control the center of gravity position in order to compensate for activities that would upset the mass distribution of the Station. The purpose of the second task was to evaluate the whole of the experiments performable in a variable gravity environment and the related beneficial residual accelerations, both for pure and applied research in the fields of fluid, materials, and life science, so as to assess the relevance of a variable g-level laboratory. The third task involves the Tethered Variable Gravity Laboratory. The use of the facility that would crawl along a deployed tether and expose experiments to varying intensities of reduced gravity is discussed. Last, a study performed on the Attitude Tether Stabilizer concept is discussed. The stabilization effect of ballast masses tethered to the Space Station was investigated as a means of assisting the attitude control system of the Station.

  9. 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.

  10. Eliminating Animal Facility Light-at-Night Contamination and Its Effect on Circadian Regulation of Rodent Physiology, Tumor Growth, and Metabolism: A Challenge in the Relocation of a Cancer Research Laboratory

    PubMed Central

    Dauchy, Robert T; Dupepe, Lynell M; Ooms, Tara G; Dauchy, Erin M; Hill, Cody R; Mao, Lulu; Belancio, Victoria P; Slakey, Lauren M; Hill, Steven M; Blask, David E

    2011-01-01

    Appropriate laboratory animal facility lighting and lighting protocols are essential for maintaining the health and wellbeing of laboratory animals and ensuring the credible outcome of scientific investigations. Our recent experience in relocating to a new laboratory facility illustrates the importance of these considerations. Previous studies in our laboratory demonstrated that animal room contamination with light-at-night (LAN) of as little as 0.2 lx at rodent eye level during an otherwise normal dark-phase disrupted host circadian rhythms and stimulated the metabolism and proliferation of human cancer xenografts in rats. Here we examined how simple improvements in facility design at our new location completely eliminated dark-phase LAN contamination and restored normal circadian rhythms in nontumor-bearing rats and normal tumor metabolism and growth in host rats bearing tissue-isolated MCF7(SR–) human breast tumor xenografts or 7288CTC rodent hepatomas. Reducing LAN contamination in the animal quarters from 24.5 ± 2.5 lx to nondetectable levels (complete darkness) restored normal circadian regulation of rodent arterial blood melatonin, glucose, total fatty and linoleic acid concentrations, tumor uptake of O2, glucose, total fatty acid and CO2 production and tumor levels of cAMP, triglycerides, free fatty acids, phospholipids, and cholesterol esters, as well as extracellular-signal-regulated kinase, mitogen-activated protein kinase, serine–threonine protein kinase, glycogen synthase kinase 3β, γ-histone 2AX, and proliferating cell nuclear antigen. PMID:21640027

  11. 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

  12. 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

  13. Analysis of arch-like bones: The rodent mandible as a case study.

    PubMed

    Vassallo, Aldo Iván

    2016-07-01

    Bone strength is determined by the mechanical properties of bone material, and the size and shape of the whole bone, i.e., its architecture. The mandible of vertebrates has been traditionally regarded as a beam oriented in relation to main masticatory loads, i.e., the longer dimension of its cross-section being parallel to the load. Rodents follow this pattern but, in addition, their mandible possesses an intriguing arch-like shape that is apparent when seen in the lateral view. Little attention was given to the structural capacity of this trait. The advantage of an arch is that it can withstand a greater load than a horizontal beam. The objective of this study was to model the rodent mandible like an arch to evaluate its structural strength. The bending moment in an arch-like mandible was 15-25% lower with respect to a beam-like mandible. Further, bending varies with mandible "slenderness" and incisor procumbency, a functionally relevant rodent trait. In the rodent Ctenomys talarum (Caviomorpha; Ctenomyidae), bone stress was substantially reduced when the mandible was modeled as an arch-like structure as compared with a beam-like structure, and safety factors were 15-34% higher. The shape of rodents' mandible might confer a functional advantage to high and repeatedly applied loads resulting from a unique feeding mode: gnawing. J. Morphol. 277:879-887, 2016. © 2016 Wiley Periodicals, Inc. PMID:27059294

  14. The Forgotten Lactogenic Activity of Growth Hormone: Important Implications for Rodent Studies

    PubMed Central

    Kopchick, John J.

    2015-01-01

    Studies of the effects of GH and the mechanisms of its actions frequently use rats or mice and various recombinant human GH preparations. Authors of many of these studies appear unaware of the fact that, in rodents, human GH signals through both GH and prolactin (PRL) receptors; thus, treatment with human GH is equivalent to a combined treatment with GH and PRL. GH receptors and PRL receptors are present in multiple cell types. Importantly, PRL exerts major effects on brain neuroendocrine action, female and male reproduction, metabolism, body composition, immune responses, and a host of other functions; thus, treatment of rodents with recombinant human GH could affect these important physiological parameters. PMID:25730109

  15. Carcinogenicity of airborne combustion products observed in subcutaneous tissue and lungs of laboratory rodents.

    PubMed Central

    Pott, F; Stöber, W

    1983-01-01

    Most air pollution in West Germany is caused by combustion products. Particulate organic matter released by incomplete combustion is suspected to contribute to the "urban factor" of lung cancer frequency in urban-industrial centers. The carcinogenic potential of single components, groups of compounds and total source emissions of combustion processes was investigated in laboratory animals by subcutaneous injection, intratracheal instillation or inhalation. Tests by subcutaneous injection of condensates of automobile exhaust, extracts of coal furnace emissions and of airborne particles and different fractions of these extracts showed that the polycyclic aromatic hydrocarbons (PAH) with four to six benzene rings have the strongest experimental carcinogenicity. However, polar compounds (heterocyclic nitrogen-containing PAH, phenols, and others) also show remarkable carcinogenic potency. There were large differences between the dose-response relationships of several PAHs. In the subcutaneous tissue, benzo(a)pyrene and dibenz(a,h)anthracene are the most carcinogenic of the tested airborne PAHs. Furthermore, they can induce high tumor rates in the lung after subcutaneous injection in newborn mice and after intratracheal instillation of mice or hamsters. The tumor rate of benzo(a)pyrene did not further increase after simultaneous instillation of carbon black, but lead chloride may have a promoting effect. Far more than 100 PAHs are found in the urban atmosphere. However, because of the remarkable similarity of the PAH profiles in the examined samples, it may be sufficient to measure just a few stable PAHs in the urban air in order to facilitate an assessment of the carcinogenic potency of the PAH content in the atmosphere. To examine the carcinogenic or cocarcinogenic effects of gas and vapor emissions, studies with a two-phase model were carried out: phase 1 relates to the induction of a basic tumor rate in the lung by a well known carcinogen, while phase 2 is

  16. Rodent-repellent studies. III. Advanced studies in the evaluation of chemical repellents

    USGS Publications Warehouse

    Bellack, E.; DeWitt, J.B.

    1949-01-01

    In order to bridge the gap between preliminary screening of chemicals for potential rodent repellency and the application ofthese compounds to paper cartons, more advanced studies in the evaluation ofpromising materials have been carried out. These studies have resulted in: (1) a modification of the food acceptance technique which eliminates doubtful compounds and also provides a closer analogy to the ultimate goal, and (2) a method for rapidly testing chemicals incorporated in paper. When the results of these latter tests are expressed as a function of time, it can be shown that a distinct correlation exists between the deterrency exhibited by treated paper and the repellency of treated food.

  17. An epidemiological comparative study on diagnosis of rodent leptospirosis in Mazandaran Province, northern Iran

    PubMed Central

    Esfandiari, Behzad; Pourshafie, Mohammad Reza; Gouya, Mohammad Mehdi; Khaki, Pejvak; Mostafavi, Ehsan; Darvish, Jamshid; Bidhendi, Soheila Moradi; Hanifi, Hamed; Nahrevanian, Hossein

    2015-01-01

    OBJECTIVES: Leptospirosis is a zoonosis caused by leptospires, in which transmission occurs through contact with contaminated biological fluids from infected animals. Rodents can act as a source of infection for humans and animals. The disease has a global distribution, mainly in humid, tropical and sub-tropical regions. The aim of this study was to compare culture assays, the microscopic agglutination test (MAT), polymerase chain reaction (PCR), and nested PCR (n-PCR), for the diagnosis of leptospirosis in rodents in Mazandaran Province, northern Iran. METHODS: One hundred fifty-one rodents were trapped alive at 10 locations, and their urine and kidney samples were collected and used for the isolation of live Leptospira. The infecting serovars were identified and the antibody titres were measured by MAT, using a panel of 20 strains of live Leptospira species as antigens. The presence of leptospiral DNA was evaluated in urine and kidney samples using PCR and n-PCR. RESULTS: No live leptospires were isolated from the kidney and urine samples of the rodents. Different detection rates of leptospirosis were observed with MAT (21.2%), PCR (11.3%), and n-PCR (3.3%). The dominant strain was Leptospira serjoehardjo (34.4%, p=0.28), although other serotypes were also found. The prevalence of positive leptospirosis tests in rodents was 15.9, 2.6, and 2.6% among Rattus norvegicus, R. rattus, and Apodemus sylvaticus, respectively. CONCLUSIONS: Leptospirosis was prevalent in rodents in Mazandaran Province, northern Iran. MAT was able to detect leptospires more frequently than culture or PCR. The kidney was a more suitable site for identifying leptospiral DNA by n-PCR than urine. Culture was not found to be an appropriate technique for clinical diagnosis. PMID:25773440

  18. 40 CFR 799.9305 - TSCA Repeated dose 28-day oral toxicity study in rodents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 33 2013-07-01 2013-07-01 false TSCA Repeated dose 28-day oral toxicity study in rodents. 799.9305 Section 799.9305 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS Health...

  19. 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...

  20. 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 ...

  1. Studies on rodents role as reservoir hosts of leishmaniasis with specical reference to their ectoparasites in Suez Governorate.

    PubMed

    Shoukry, Nahla M; El-Naggar, Mostafa H; Darwish, Ahmed B; Soliman, Belal A; El-Sawaf, Bahira M

    2006-04-01

    The distribution of rodents was studied in three different habitats. Seven rodent species were identified: Rattus norvegicus, R. alexandrinus, R. frugivorous, Mus musculus, Acomys russatus, Meriones sacramenti and Gerbillus pyramidum. The species distribution varied with the habitat type. The highest density of rodents was in July and August and the lowest one was in January. However, some species were collected all the year round. The rodents were investigated for the endo- and ecto-parasites. No Leishmania parasites were found. The ectoparasites were: Xenopsylla cheopis, Leptopsylla segnis and Ctenocephalides felis, Polyplax spinulos, Hyalomma dromedarii (nymph) and Echinolaelaps echidninus and Hemolaelaps glassgowi. Ecto-parasites were on rodents all year-round in domestic habitat and peridomestic habitats. In wild one, ecto-parasites activity was from March to December. The rodents' role as reservoir for L. major was experimentally studied. Rodents inoculated with L. major together with hamster and BALB-c mice developed cutaneous lesions. The active lesions, the rodents' ecological habitats and the presence of insect-vector may pave the way to an epidemic zoonotic leishmaniasis role. PMID:16605103

  2. 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...

  3. A new exposure model to evaluate smoked illicit drugs in rodents: A study of crack cocaine.

    PubMed

    Hueza, Isis M; Ponce, Fernando; Garcia, Raphael C T; Marcourakis, Tânia; Yonamine, Maurício; Mantovani, Cínthia de C; Kirsten, Thiago B

    2016-01-01

    The use of smoked illicit drugs has spread dramatically, but few studies use proper devices to expose animals to inhalational abused drugs despite the availability of numerous smoking devices that mimic tobacco exposure in rodents. Therefore, the present study developed an inexpensive device to easily expose laboratory animals to smoked drugs. We used crack cocaine as the drug of abuse, and the cocaine plasma levels and the behaviors of animals intoxicated with the crack cocaine were evaluated to prove inhaled drug absorption and systemic activity. We developed an acrylic device with two chambers that were interconnected and separated by a hatch. Three doses of crack (100, 250, or 500 mg), which contained 63.7% cocaine, were burned in a pipe, and the rats were exposed to the smoke for 5 or 10 min (n=5/amount/period). Exposure to the 250-mg dose for 10 min achieved cocaine plasma levels that were similar to those of users (170 ng/mL). Behavioral evaluations were also performed to validate the methodology. Rats (n=10/group) for these evaluations were exposed to 250 mg of crack cocaine or air for 10 min, twice daily, for 28 consecutive days. Open-field evaluations were performed at three different periods throughout the experimental design. Exposed animals exhibited transient anorexia, increased motor activity, and shorter stays in central areas of the open field, which suggests reduced anxiety. Therefore, the developed model effectively exposed animals to crack cocaine, and this model may be useful for the investigation of other inhalational abused drugs. PMID:26391341

  4. Evidence for a relationship between cage stereotypies and behavioural disinhibition in laboratory rodents.

    PubMed

    Garner, Joseph P; Mason, Georgia J

    2002-10-17

    Cage stereotypies-abnormal, repetitive, unvarying and apparently functionless behaviours-are common in many captive animals, sometimes resulting in self-injury or decreased reproductive success. However, a general mechanistic or neurophysiological understanding of cage stereotypies has proved elusive. In contrast, stereotypies in human mental disorder, or those induced by drugs or brain lesions, are well understood, and are thought to result from the disinhibition of behavioural selection by the basal ganglia. In this study, we found that the cage stereotypies of captive bank voles also correlate with signs of altered response selection by the basal ganglia. Stereotypic bar-mouthing in the caged voles correlated with inappropriate responding in extinction learning, impairments of response timing, evidence of a knowledge-action dissociation, increased rates of behavioural activation, and hyperactivity. Furthermore, all these signs intercorrelated, implicating a single underlying deficit consistent with striatal disinhibition of response selection. Bar-mouthing thus appears fundamentally similar to the stereotypies of autists, schizophrenics, and subjects treated with amphetamine or basal ganglial lesions. These results represent the first evidence for a neural substrate of cage stereotypy. They also suggest that stereotypic animals may experience novel forms of psychological distress, and that stereotypy might well represent a potential confound in many behavioural experiments. PMID:12385793

  5. Rodent Control

    ERIC Educational Resources Information Center

    Indian Journal of Adult Education, 1975

    1975-01-01

    Strategies for rodent control in crop fields, threshing yards, and rural residential areas are presented together with an operational plan for implementing a program for rodent control at the national level. Training personnel in rodent control procedures and procedures for educating the public in the necessity for control are covered. (EC)

  6. Rodent models of cardiopulmonary disease: their potential applicability in studies of air pollutant susceptibility.

    PubMed Central

    Kodavanti, U P; Costa, D L; Bromberg, P A

    1998-01-01

    The mechanisms by which increased mortality and morbidity occur in individuals with preexistent cardiopulmonary disease following acute episodes of air pollution are unknown. Studies involving air pollution effects on animal models of human cardiopulmonary diseases are both infrequent and difficult to interpret. Such models are, however, extensively used in studies of disease pathogenesis. Primarily they comprise those developed by genetic, pharmacologic, or surgical manipulations of the cardiopulmonary system. This review attempts a comprehensive description of rodent cardiopulmonary disease models in the context of their potential application to susceptibility studies of air pollutants regardless of whether the models have been previously used for such studies. The pulmonary disease models include bronchitis, emphysema, asthma/allergy, chronic obstructive pulmonary disease, interstitial fibrosis, and infection. The models of systemic hypertension and congestive heart failure include: those derived by genetics (spontaneously hypertensive, Dahl S. renin transgenic, and other rodent models); congestive heart failure models derived by surgical manipulations; viral myocarditis; and cardiomyopathy induced by adriamycin. The characteristic pathogenic features critical to understanding the susceptibility to inhaled toxicants are described. It is anticipated that this review will provide a ready reference for the selection of appropriate rodent models of cardiopulmonary diseases and identify not only their pathobiologic similarities and/or differences to humans but also their potential usefulness in susceptibility studies. Images Figure 2 PMID:9539009

  7. Considerations for resting state functional MRI and functional connectivity studies in rodents

    PubMed Central

    Pan, Wen-Ju; Billings, Jacob C. W.; Grooms, Joshua K.; Shakil, Sadia; Keilholz, Shella D.

    2015-01-01

    Resting state functional MRI (rs-fMRI) and functional connectivity mapping have become widely used tools in the human neuroimaging community and their use is rapidly spreading into the realm of rodent research as well. One of the many attractive features of rs-fMRI is that it is readily translatable from humans to animals and back again. Changes in functional connectivity observed in human studies can be followed by more invasive animal experiments to determine the neurophysiological basis for the alterations, while exploratory work in animal models can identify possible biomarkers for further investigation in human studies. These types of interwoven human and animal experiments have a potentially large impact on neuroscience and clinical practice. However, impediments exist to the optimal application of rs-fMRI in small animals, some similar to those encountered in humans and some quite different. In this review we identify the most prominent of these barriers, discuss differences between rs-fMRI in rodents and in humans, highlight best practices for animal studies, and review selected applications of rs-fMRI in rodents. Our goal is to facilitate the integration of human and animal work to the benefit of both fields. PMID:26300718

  8. 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.

  9. Rodent repellency

    USGS Publications Warehouse

    DeWitt, J.B.; Welch, J.F.; Bellack, E.

    1950-01-01

    In the course of studies involving more than 2,500 chemical repellents, it has been found that certain groups of- compounds containing nitrogen or sulfur are repellent to rats under the , test conditions and it appears probable that some of these compounds might be used for the protection of packaged goods against rodent attacks. Additional tests to determine optimum methods of application will be necessary before final evaluation of these compounds will be possible and extensive field trials will be required to establish the degree of protection which may be afforded by the use of these materials. Pending such final evaluation, it may be assumed that the results,to date offer a means of selecting the most promising types of'materials for further trial....On the basis of the test data, it appears that some amine derivative, such as a salt of some organic, acid, or a complex with trinitrobenzene or with a metallic salt of a dialkyl dithiocarbamic acid might offer promise of protection of packaging materials against rodent attacks....Protection might be obtained through the use of certain 'physical deterrents' such as plastics, waxes or drying oils.

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

    PubMed

    Carlezon, William A; Chartoff, Elena H

    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) to understand how pharmacological or molecular manipulations affect the function of brain reward systems. Although many different methodologies are possible, we will describe in this protocol the use of medial forebrain bundle (MFB) stimulation together with the 'curve-shift' variant of analysis. This combination is particularly powerful because it produces a highly reliable behavioral output that enables clear distinctions between the treatment effects on motivation and the treatment effects on the capability to perform the task. PMID:18007634

  11. Microscale Immune Studies Laboratory.

    SciTech Connect

    Poschet, Jens Fredrich; Carroll-Portillo, Amanda; Wu, Meiye; Manginell, Ronald Paul; Herr, Amy Elizabeth; Martino, Anthony A.; Perroud, Thomas D.; Branda, Catherine; Srivastava, Nimisha; Sinclair, Michael B.; Moorman, Matthew Wallace; Apblett, Christopher Alan; Sale, Kenneth L.; James, Conrad D.; Carles, Elizabeth L.; Lidke, Diane S.; Van Benthem, Mark Hilary; Rebeil, Roberto; Kaiser, Julie; Seaman, William; Rempe, Susan; Brozik, Susan Marie; Jones, Howland D. T.; Gemperline, Paul; Throckmorton, Daniel J.; Misra, Milind; Murton, Jaclyn K.; Carson, Bryan D.; Zhang, Zhaoduo; Plimpton, Steven James; Renzi, Ronald F.; Lane, Todd W.; Ndiaye-Dulac, Elsa; Singh, Anup K.; Haaland, David Michael; Faulon, Jean-Loup Michel; Davis, Ryan W.; Ricken, James Bryce; Branda, Steven S.; Patel, Kamlesh D.; Joo, Jaewook; Kubiak, Glenn D.; Brennan, James S.; Martin, Shawn Bryan; Brasier, Allan

    2009-01-01

    The overarching goal is to develop novel technologies to elucidate molecular mechanisms of the innate immune response in host cells to pathogens such as bacteria and viruses including the mechanisms used by pathogens to subvert/suppress/obfuscate the immune response to cause their harmful effects. Innate immunity is our first line of defense against a pathogenic bacteria or virus. A comprehensive 'system-level' understanding of innate immunity pathways such as toll-like receptor (TLR) pathways is the key to deciphering mechanisms of pathogenesis and can lead to improvements in early diagnosis or developing improved therapeutics. Current methods for studying signaling focus on measurements of a limited number of components in a pathway and hence, fail to provide a systems-level understanding. We have developed a systems biology approach to decipher TLR4 pathways in macrophage cell lines in response to exposure to pathogenic bacteria and their lipopolysaccharide (LPS). Our approach integrates biological reagents, a microfluidic cell handling and analysis platform, high-resolution imaging and computational modeling to provide spatially- and temporally-resolved measurement of TLR-network components. The Integrated microfluidic platform is capable of imaging single cells to obtain dynamic translocation data as well as high-throughput acquisition of quantitative protein expression and phosphorylation information of selected cell populations. The platform consists of multiple modules such as single-cell array, cell sorter, and phosphoflow chip to provide confocal imaging, cell sorting, flow cytomtery and phosphorylation assays. The single-cell array module contains fluidic constrictions designed to trap and hold single host cells. Up to 100 single cells can be trapped and monitored for hours, enabling detailed statistically-significant measurements. The module was used to analyze translocation behavior of transcription factor NF-kB in macrophages upon activation by E

  12. Animal Models for the Study of Rodent-Borne Hemorrhagic Fever Viruses: Arenaviruses and Hantaviruses

    PubMed Central

    Golden, Joseph W.; Hammerbeck, Christopher D.; Mucker, Eric M.; Brocato, Rebecca L.

    2015-01-01

    Human pathogenic hantaviruses and arenaviruses are maintained in nature by persistent infection of rodent carrier populations. Several members of these virus groups can cause significant disease in humans that is generically termed viral hemorrhagic fever (HF) and is characterized as a febrile illness with an increased propensity to cause acute inflammation. Human interaction with rodent carrier populations leads to infection. Arenaviruses are also viewed as potential biological weapons threat agents. There is an increased interest in studying these viruses in animal models to gain a deeper understating not only of viral pathogenesis, but also for the evaluation of medical countermeasures (MCM) to mitigate disease threats. In this review, we examine current knowledge regarding animal models employed in the study of these viruses. We include analysis of infection models in natural reservoirs and also discuss the impact of strain heterogeneity on the susceptibility of animals to infection. This information should provide a comprehensive reference for those interested in the study of arenaviruses and hantaviruses not only for MCM development but also in the study of viral pathogenesis and the biology of these viruses in their natural reservoirs. PMID:26266264

  13. Neuroimmune pathways in alcohol consumption: evidence from behavioral and genetic studies in rodents and humans.

    PubMed

    Robinson, Gizelle; Most, Dana; Ferguson, Laura B; Mayfield, Jody; Harris, R Adron; Blednov, Yuri A

    2014-01-01

    Immune or brain proinflammatory signaling has been linked to some of the behavioral effects of alcohol. Immune signaling appears to regulate voluntary ethanol intake in rodent models, and ethanol intake activates the immune system in multiple models. This bidirectional link raises the possibility that consumption increases immune signaling, which in turn further increases consumption in a feed-forward cycle. Data from animal and human studies provide overlapping support for the involvement of immune-related genes and proteins in alcohol action, and combining animal and human data is a promising approach to systematically evaluate and nominate relevant pathways. Based on rodent models, neuroimmune pathways may represent unexplored, nontraditional targets for medication development to reduce alcohol consumption and prevent relapse. Peroxisome proliferator-activated receptor agonists are one class of anti-inflammatory medications that demonstrate antiaddictive properties for alcohol and other drugs of abuse. Expression of immune-related genes is altered in animals and humans following chronic alcohol exposure, and the regulatory influences of specific mRNAs, microRNAs, and activated cell types are areas of intense study. Ultimately, the use of multiple datasets combined with behavioral validation will be needed to link specific neuroimmune pathways to addiction vulnerability. PMID:25175860

  14. 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

  15. Optimal decision-making in mammals: insights from a robot study of rodent texture discrimination

    PubMed Central

    Lepora, Nathan F.; Fox, Charles W.; Evans, Mathew H.; Diamond, Mathew E.; Gurney, Kevin; Prescott, Tony J.

    2012-01-01

    Texture perception is studied here in a physical model of the rat whisker system consisting of a robot equipped with a biomimetic vibrissal sensor. Investigations of whisker motion in rodents have led to several explanations for texture discrimination, such as resonance or stick-slips. Meanwhile, electrophysiological studies of decision-making in monkeys have suggested a neural mechanism of evidence accumulation to threshold for competing percepts, described by a probabilistic model of Bayesian sequential analysis. For our robot whisker data, we find that variable reaction-time decision-making with sequential analysis performs better than the fixed response-time maximum-likelihood estimation. These probabilistic classifiers also use whatever available features of the whisker signals aid the discrimination, giving improved performance over a single-feature strategy, such as matching the peak power spectra of whisker vibrations. These results cast new light on how the various proposals for texture discrimination in rodents depend on the whisker contact mechanics and suggest the possibility of a common account of decision-making across mammalian species. PMID:22279155

  16. Optimal decision-making in mammals: insights from a robot study of rodent texture discrimination.

    PubMed

    Lepora, Nathan F; Fox, Charles W; Evans, Mathew H; Diamond, Mathew E; Gurney, Kevin; Prescott, Tony J

    2012-07-01

    Texture perception is studied here in a physical model of the rat whisker system consisting of a robot equipped with a biomimetic vibrissal sensor. Investigations of whisker motion in rodents have led to several explanations for texture discrimination, such as resonance or stick-slips. Meanwhile, electrophysiological studies of decision-making in monkeys have suggested a neural mechanism of evidence accumulation to threshold for competing percepts, described by a probabilistic model of Bayesian sequential analysis. For our robot whisker data, we find that variable reaction-time decision-making with sequential analysis performs better than the fixed response-time maximum-likelihood estimation. These probabilistic classifiers also use whatever available features of the whisker signals aid the discrimination, giving improved performance over a single-feature strategy, such as matching the peak power spectra of whisker vibrations. These results cast new light on how the various proposals for texture discrimination in rodents depend on the whisker contact mechanics and suggest the possibility of a common account of decision-making across mammalian species. PMID:22279155

  17. Rodent models of cerebral ischemia

    SciTech Connect

    Ginsberg, M.D.; Busto, R. )

    1989-12-01

    The use of physiologically regulated, reproducible animal models is crucial to the study of ischemic brain injury--both the mechanisms governing its occurrence and potential therapeutic strategies. Several laboratory rodent species (notably rats and gerbils), which are readily available at relatively low cost, are highly suitable for the investigation of cerebral ischemia and have been widely employed for this purpose. We critically examine and summarize several rodent models of transient global ischemia, resulting in selective neuronal injury within vulnerable brain regions, and focal ischemia, typically giving rise to localized brain infarction. We explore the utility of individual models and emphasize the necessity for meticulous experimental control of those variables that modulate the severity of ischemic brain injury.169 references.

  18. Clinical laboratory, virologic, and pathologic changes in hamsters experimentally infected with Pirital virus (Arenaviridae): a rodent model of Lassa fever.

    PubMed

    Sbrana, Elena; Mateo, Rosa I; Xiao, Shu-Yuan; Popov, Vsevolod L; Newman, Patrick C; Tesh, Robert B

    2006-06-01

    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 elevation of serum transaminase levels. All of the animals died within 9 days. The clinical and histopathological findings in the Pirital virus-infected hamsters were very similar to those reported in severe human cases of Lassa fever, suggesting that this new animal model could serve as a low-cost and relatively safe alternative for studying the pathogenesis and therapy of Lassa fever. PMID:16760527

  19. Current Status of Laboratory Studies.

    ERIC Educational Resources Information Center

    Liberty, Paul; And Others

    General information on the studies currently underway by the Southwestern Cooperative Educational Laboratory (SECEL) is presented in this report. Module A is concerned with investigating the relationships between a variety of cultural-psychological factors and language development in grade 1. Testing and home interviews play a major part in this…

  20. How well can in vitro data predict in vivo effects of chemicals? Rodent carcinogenicity as a case study.

    PubMed

    Anthony Tony Cox, Louis; Popken, Douglas A; Kaplan, A Michael; Plunkett, Laura M; Becker, Richard A

    2016-06-01

    A recent research article by the National Center for Computational Toxicology (NCCT) (Kleinstreuer et al., 2013), indicated that high throughput screening (HTS) data from assays linked to hallmarks and presumed pathways of carcinogenesis could be used to predict classification of pesticides as either (a) possible, probable or likely rodent carcinogens; or (b) not likely carcinogens or evidence of non-carcinogenicity. Using independently developed software to validate the computational results, we replicated the majority of the results reported. We also found that the prediction model correlating cancer pathway bioactivity scores with in vivo carcinogenic effects in rodents was not robust. A change of classification of a single chemical in the test set was capable of changing the overall study conclusion about the statistical significance of the correlation. Furthermore, in the subset of pesticide compounds used in model validation, the accuracy of prediction was no better than chance for about three quarters of the chemicals (those with fewer than 7 positive outcomes in HTS assays representing the 11 histopathological endpoints used in model development), suggesting that the prediction model was not adequate to predict cancer hazard for most of these chemicals. Although the utility of the model for humans is also unclear because a number of the rodent responses modeled (e.g., mouse liver tumors, rat thyroid tumors, rat testicular tumors, etc.) are not considered biologically relevant to human responses, the data examined imply the need for further research with HTS assays and improved models, which might help to predict classifications of in vivo carcinogenic responses in rodents for the pesticide considered, and thus reduce the need for testing in laboratory animals. PMID:26879462

  1. β-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

    β-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 β cells. Islet regeneration in vivo and generation of β-cells ex vivo followed by transplantation represent attractive therapeutic alternatives to restore the β-cell mass. In this paper, we discuss different postnatal cell types that have been envisaged as potential sources for future β-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

  2. Rodent repellent studies. IV. Preparation and properties of trinitrobenzene-aryl amine complexes

    USGS Publications Warehouse

    DeWitt, J.B.; Bellack, E.; Welch, J.F.

    1953-01-01

    Data are presented on methods of preparation, chemical arid physical characteristics, toxicity, and repellency to rodents of complexes of symmetrical trinitrohenzene with various aromatic amines: When applied in suitable carriers or incorporated in plastic .films, members of this series ofmaterials were shown to offer significant increases in time required by wild rodents to damage common packaging materials.

  3. A Novel Method of Head Fixation for the Study of Rodent Facial Function

    PubMed Central

    Hadlock, Tessa; Kowaleski, Jeffrey; Mackinnon, Susan; Heaton, James T.

    2007-01-01

    The rodent vibrissial system offers an excellent model for the study of both sensory and motor function. It has been widely employed to gather data pertaining to sensory and motor function involving the 5th and 7th cranial nerves and the central nervous system. Existing methods of head fixation for precise measurements of ocular and vibrissial function involve exposing the cranium and applying dental cement from which two or more threaded rods emerge. This common approach is suboptimal, requiring a relatively complicated implantation procedure, and results in a large, chronic interface between the scalp and environmentally-exposed implant material attached to the skull. Here we describe a head fixation device that is inexpensive, easy to build, less prone to infection, preserves access to the cranial midline, and permits repeated measurements over many months. PMID:17397835

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

    SciTech Connect

    Goineau, Sonia; Rompion, Sonia; Guillaume, Philippe; Picard, Sandra

    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.

  5. Surfaces and spaces: troubleshooting the study of dietary niche space overlap between North American stem primates and rodents

    NASA Astrophysics Data System (ADS)

    Prufrock, Kristen A.; López-Torres, Sergi; Silcox, Mary T.; Boyer, Doug M.

    2016-06-01

    Dental topographic metrics provide quantitative, biologically meaningful data on the three-dimensional (3D) form of teeth. In this study, three dental topographic metrics (Dirichlet normal energy (DNE), relief index (RFI), and orientation patch count rotated (OPCR)) are used to evaluate the presence of dietary niche overlap between North American plesiadapoid primates (Plesiadapidae, Carpolestidae, and Saxonellidae) and early rodents. Calculation of these metrics requires researchers to modify the 3D surface models of the teeth by cropping them to a region of interest and/or orienting them. The current study therefore also examines the error introduced by cropping and orientation, and evaluates the contribution of these metrics to the niche overlap hypothesis. Our results indicate that cropping creates significantly more variation in RFI than DNE. Furthermore, orientation is an even larger source of variation in the calculation of RFI than cropping. Orientation does not strongly influence OPCR values. However, none of these sources of error are significant enough to undermine the extent to which these metrics can speak to the niche overlap hypothesis. The DNE and RFI results suggest that carpolestids and saxonellids had very different molar morphologies from early rodents, and thus these groups were not adapted to consume the same resources. Some plesiadapids show similar levels of occlusal curvature, relief, and complexity to early rodents. The plesiadapid Chiromyoides, which has distinctively low cusps and weak shearing crest development, has molars that are the most rodent-like of all taxa compared. This suggests that Chiromyoides had a dietary niche that overlapped with early rodents and would have been the most likely to be competing over food resources. Results from the plesiadapoid-rodent dental topographic analysis highlight the utility of DNE for detecting more fine-scaled differences in occlusal surface morphology than OPCR, whereas RFI provided valuable

  6. Using the Activity-based Anorexia Rodent Model to Study the Neurobiological Basis of Anorexia Nervosa

    PubMed Central

    Chowdhury, Tara Gunkali; Chen, Yi-Wen; Aoki, Chiye

    2015-01-01

    Anorexia nervosa (AN) is a psychiatric illness characterized by excessively restricted caloric intake and abnormally high levels of physical activity. A challenging illness to treat, due to the lack of understanding of the underlying neurobiology, AN has the highest mortality rate among psychiatric illnesses. To address this need, neuroscientists are using an animal model to study how neural circuits may contribute toward vulnerability to AN and may be affected by AN. Activity-based anorexia (ABA) is a bio-behavioral phenomenon described in rodents that models the key symptoms of anorexia nervosa. When rodents with free access to voluntary exercise on a running wheel experience food restriction, they become hyperactive – running more than animals with free access to food. Here, we describe the procedures by which ABA is induced in adolescent female C57BL/6 mice. On postnatal day 36 (P36), the animal is housed with access to voluntary exercise on a running wheel. After 4 days of acclimation to the running wheel, on P40, all food is removed from the cage. For the next 3 days, food is returned to the cage (allowing animals free food access) for 2 hr daily. After the fourth day of food restriction, free access to food is returned and the running wheel is removed from the cage to allow the animals to recover. Continuous multi-day analysis of running wheel activity shows that mice become hyperactive within 24 hr following the onset of food restriction. The mice run even during the limited time during which they have access to food. Additionally, the circadian pattern of wheel running becomes disrupted by the experience of food restriction. We have been able to correlate neurobiological changes with various aspects of the animals’ wheel running behavior to implicate particular brain regions and neurochemical changes with resilience and vulnerability to food-restriction induced hyperactivity. PMID:26555618

  7. Using the Activity-based Anorexia Rodent Model to Study the Neurobiological Basis of Anorexia Nervosa.

    PubMed

    Chowdhury, Tara Gunkali; Chen, Yi-Wen; Aoki, Chiye

    2015-01-01

    Anorexia nervosa (AN) is a psychiatric illness characterized by excessively restricted caloric intake and abnormally high levels of physical activity. A challenging illness to treat, due to the lack of understanding of the underlying neurobiology, AN has the highest mortality rate among psychiatric illnesses. To address this need, neuroscientists are using an animal model to study how neural circuits may contribute toward vulnerability to AN and may be affected by AN. Activity-based anorexia (ABA) is a bio-behavioral phenomenon described in rodents that models the key symptoms of anorexia nervosa. When rodents with free access to voluntary exercise on a running wheel experience food restriction, they become hyperactive - running more than animals with free access to food. Here, we describe the procedures by which ABA is induced in adolescent female C57BL/6 mice. On postnatal day 36 (P36), the animal is housed with access to voluntary exercise on a running wheel. After 4 days of acclimation to the running wheel, on P40, all food is removed from the cage. For the next 3 days, food is returned to the cage (allowing animals free food access) for 2 hr daily. After the fourth day of food restriction, free access to food is returned and the running wheel is removed from the cage to allow the animals to recover. Continuous multi-day analysis of running wheel activity shows that mice become hyperactive within 24 hr following the onset of food restriction. The mice run even during the limited time during which they have access to food. Additionally, the circadian pattern of wheel running becomes disrupted by the experience of food restriction. We have been able to correlate neurobiological changes with various aspects of the animals' wheel running behavior to implicate particular brain regions and neurochemical changes with resilience and vulnerability to food-restriction induced hyperactivity. PMID:26555618

  8. Urban Market Gardening and Rodent-Borne Pathogenic Leptospira in Arid Zones: A Case Study in Niamey, Niger

    PubMed Central

    Dobigny, Gauthier; Garba, Madougou; Tatard, Caroline; Loiseau, Anne; Galan, Max; Kadaouré, Ibrahima; Rossi, Jean-Pierre; Picardeau, Mathieu; Bertherat, Eric

    2015-01-01

    Leptospirosis essentially affects human following contact with rodent urine-contaminated water. As such, it was mainly found associated with rice culture, recreational activities and flooding. This is also the reason why it has mainly been investigated in temperate as well as warm and humid regions, while arid zones have been only very occasionally monitored for this disease. In particular, data for West African countries are extremely scarce. Here, we took advantage of an extensive survey of urban rodents in Niamey, Niger, in order to look for rodent-borne pathogenic Leptospira species presence and distribution across the city. To do so, we used high throughput bacterial 16S-based metabarcoding, lipL32 gene-targeting RT-PCR, rrs gene sequencing and VNTR typing as well as GIS-based multivariate spatial analysis. Our results show that leptospires seem absent from the core city where usual Leptospira reservoir rodent species (namely R. rattus and M. natalensis) are yet abundant. On the contrary, L. kirschneri was detected in Arvicanthis niloticus and Cricetomys gambianus, two rodent species that are restricted to irrigated cultures within the city. Moreover, the VNTR profiles showed that rodent-borne leptospires in Niamey belong to previously undescribed serovars. Altogether, our study points towards the importance of market gardening in maintain and circulation of leptospirosis within Sahelian cities. In Africa, irrigated urban agriculture constitutes a pivotal source of food supply, especially in the context of the ongoing extensive urbanization of the continent. With this in mind, we speculate that leptospirosis may represent a zoonotic disease of concern also in arid regions that would deserve to be more rigorously surveyed, especially in urban agricultural settings. PMID:26437456

  9. Urban Market Gardening and Rodent-Borne Pathogenic Leptospira in Arid Zones: A Case Study in Niamey, Niger.

    PubMed

    Dobigny, Gauthier; Garba, Madougou; Tatard, Caroline; Loiseau, Anne; Galan, Max; Kadaouré, Ibrahima; Rossi, Jean-Pierre; Picardeau, Mathieu; Bertherat, Eric

    2015-01-01

    Leptospirosis essentially affects human following contact with rodent urine-contaminated water. As such, it was mainly found associated with rice culture, recreational activities and flooding. This is also the reason why it has mainly been investigated in temperate as well as warm and humid regions, while arid zones have been only very occasionally monitored for this disease. In particular, data for West African countries are extremely scarce. Here, we took advantage of an extensive survey of urban rodents in Niamey, Niger, in order to look for rodent-borne pathogenic Leptospira species presence and distribution across the city. To do so, we used high throughput bacterial 16S-based metabarcoding, lipL32 gene-targeting RT-PCR, rrs gene sequencing and VNTR typing as well as GIS-based multivariate spatial analysis. Our results show that leptospires seem absent from the core city where usual Leptospira reservoir rodent species (namely R. rattus and M. natalensis) are yet abundant. On the contrary, L. kirschneri was detected in Arvicanthis niloticus and Cricetomys gambianus, two rodent species that are restricted to irrigated cultures within the city. Moreover, the VNTR profiles showed that rodent-borne leptospires in Niamey belong to previously undescribed serovars. Altogether, our study points towards the importance of market gardening in maintain and circulation of leptospirosis within Sahelian cities. In Africa, irrigated urban agriculture constitutes a pivotal source of food supply, especially in the context of the ongoing extensive urbanization of the continent. With this in mind, we speculate that leptospirosis may represent a zoonotic disease of concern also in arid regions that would deserve to be more rigorously surveyed, especially in urban agricultural settings. PMID:26437456

  10. Laboratory Studies Towards Understanding Comets

    NASA Astrophysics Data System (ADS)

    Gudipati, Murthy S.; Abou Mrad, Ninette; Blum, Jürgen; Charnley, Steven B.; Chiavassa, Thierry; Cordiner, Martin A.; Mousis, Olivier; Danger, Grégoire; Duvernay, Fabrice; Gundlach, Bastian; Hartogh, Paul; Marboeuf, Ulysse; Simonia, Irakli; Simonia, Tsitsino; Theulé, Patrice; Yang, Rui

    2015-12-01

    This review presents some of the recent advancements in our understanding of comets facilitated by laboratory studies, need for new laboratory simulations, and predictions for future explorations. With the spacecraft Rosetta at the comet 67P/Churyumov-Gerasimenko, a large volume of science data is expected to follow early results that have been published recently. The most surprising of them being hard ice shell that bounced the lander Philae a couple of times before settling on the comet. Long evaded molecular nitrogen has now been detected in the comet 67P/CG. The observed density of 470 kg m^{- 3} is in line with other comet observations, whereas the nature and composition of hydrocarbons detected on the surface are still a puzzle. Observation of D/H ratio that deviates significantly from Earth's water D/H ratio brings back to the table the long-standing question whether or not water on Earth was delivered by comet impacts. Our review summarizes some of the critical laboratory work that helps improve our understanding of cometary interior (whether amorphous or crystalline or containing clathrates), cometary surface (rich of complex organics), cometary coma and tail (D/H ratio, negative ions, and photoluminescence). Outstanding questions are also discussed.

  11. 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.

  12. Laboratory study of cometary analogues

    NASA Astrophysics Data System (ADS)

    Colangeli, L.; Brucato, J.; Mennella, V.; Palumbo, P.

    In situ exploration (e.g., GIOTTO mission) and astronomical observations (e.g., ISO) of comets have provided fundamental information about the structure, chemistry and physical properties of materials present in such primordial bodies of the Solar System. Moreover, it is known that cosmic materials evolve, depending on the efficiency of active processes (e.g., thermal annealing, UV irradiation, ion bombardment, gassolid interactions) in different space environments. Thus, the properties of cometary constituents must be considered in a wider perspective, including cosmic dust formation around cold stars and evolution in the interstellar medium until the formation of proto-planetary nebulae. In this scenario, laboratory experiments provide important hints to clarify the status of cometary compounds. The laboratory work is aimed at both reproducing material properties and at simulating their evolution based on the most effective mechanisms active in space. Several techniques are used to synthesise "analogues" of cometary compounds with controlled chemical and physical characteristics. The study of optical properties, complemented by other analytical techniques, is applied to investigate the products of synthesis in the experiments. The monitoring of the effects produced by processing methods, similar to those active in space, provides information both on the reactivity of materials and on the efficiency of treatments. Such an approach is able to provide quantitative information on chemical and structural modifications produced on organic and refractory materials. The comparison of laboratory results with data coming from space observations and in situ measurements provides a powerful tool to understand the real nature of comets and to place constraints on formation and evolution pathways. The laboratory experiments on analogues gain even more relevance as a sort of training in the future perspective of analysing cometary samples returned to Earth by space missions (e

  13. A Novel Water Delivery System for Administering Volatile Chemicals while Minimizing Chemical Waste in Rodent Toxicity Studies

    EPA Science Inventory

    Rodent toxicity studies typically use water bottles to administer test chemicals via drinking water. However, water bottles provide inconsistent exposure of volatile chemicals due to varying headspace, as well as lead to excessive waste of test material. In order to refine drin...

  14. Wentworth Institute Mechanical Engineering Laboratory Manual. Laboratory Study Guide.

    ERIC Educational Resources Information Center

    Avakian, Harry; And Others

    This publication is a laboratory study guide designed for mechanical engineering students. All of the experiments (with the exception of experiment No. 1) contained in the Mechanical Engineering Laboratory Manual have been included in this guide. Brief theoretical backgrounds, examples and their solutions, charts, graphs, illustrations, and…

  15. Comparative Studies of Diurnal and Nocturnal Rodents: Differences in Lifestyle Result in Alterations in Cortical Field Size and Number

    PubMed Central

    Campi, Katharine L.; Krubitzer, Leah

    2012-01-01

    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

  16. The role of the hippocampus in approach-avoidance conflict decision-making: Evidence from rodent and human studies.

    PubMed

    Ito, Rutsuko; Lee, Andy C H

    2016-10-15

    The hippocampus (HPC) has been traditionally considered to subserve mnemonic processing and spatial cognition. Over the past decade, however, there has been increasing interest in its contributions to processes beyond these two domains. One question is whether the HPC plays an important role in decision-making under conditions of high approach-avoidance conflict, a scenario that arises when a goal stimulus is simultaneously associated with reward and punishment. This idea has its origins in rodent work conducted in the 1950s and 1960s, and has recently experienced a resurgence of interest in the literature. In this review, we will first provide an overview of classic rodent lesion data that first suggested a role for the HPC in approach-avoidance conflict processing and then proceed to describe a wide range of more recent evidence from studies conducted in rodents and humans. We will demonstrate that there is substantial, converging cross-species evidence to support the idea that the HPC, in particular the ventral (in rodents)/anterior (in humans) portion, contributes to approach-avoidance conflict decision making. Furthermore, we suggest that the seemingly disparate functions of the HPC (e.g. memory, spatial cognition, conflict processing) need not be mutually exclusive. PMID:27457133

  17. An Experimental Approach for Selecting Appropriate Rodent Diets for Research Studies on Metabolic Disorders

    PubMed Central

    Sasidharan, Suja Rani; Joseph, Joshua Allan; Anandakumar, Senthilkumar; Venkatesan, Vijayabalaji; Ariyattu Madhavan, Chandrasekharan Nair; Agarwal, Amit

    2013-01-01

    Diverse high energy diets have been utilized to precipitate obesity and related metabolic disorders in rodent models, though the dietary intervention has not absolutely been standardized. The present study established usage of a customized semipurified normal control diet (NCD) and high fat diet (HFD), for research studies on diet-induced metabolic disorders in albino rats. Male Wistar rats were fed with normal pellet diet (NPD) or customized NCDs I, II, III or HFDs I, II, III for 12 weeks and parameters, namely, body weight, visceral adiposity, serum triglycerides, cholesterol, and glucose were evaluated to select an appropriate NCD and HFD. The selected HFD was further evaluated for induction of fatty liver, whilst type 2 diabetes (T2D) induction was confirmed in HFD and streptozotocin (STZ) induced diabetes model in Wistar rats. Amongst different diets tested, NCD-I and HFD-I were selected, since NCD-I exhibited close resemblance to NPD, whereas HFD-I induced metabolic alterations, particularly obesity and dyslipidemia consistently. Moreover, HFD-I elevated terminal hepatic lipids, while HFD-I/STZ treatment augmented insulin resistance index and serum glucose levels significantly indicating effective induction of fatty liver and T2D, respectively. Therefore, customized semipurified NCD-I and HFD-I can be recommended for research studies on diet-induced metabolic disorders in albino Wistar rats. PMID:24151620

  18. Gnotobiotic Rodents: An In Vivo Model for the Study of Microbe–Microbe Interactions

    PubMed Central

    Martín, Rebeca; Bermúdez-Humarán, Luis G.; Langella, Philippe

    2016-01-01

    Germ-free rodents have no microorganisms living in or on them, allowing researchers to specifically control an animal’s microbiota through the direct inoculation of bacteria of interest. This strategy has been widely used to decipher host–microbe interactions as well as the role of microorganisms in both (i) the development and function of the gut barrier (mainly the intestinal epithelium) and (ii) homeostasis and its effects on human health and disease. However, this in vivo model also offers a more realistic environment than an assay tube in which to study microbe–microbe interactions, without most of the confounding interactions present in the intestinal microbiota of conventionally raised mice. This review highlights the usefulness of controlled-microbiota mice in studying microbe–microbe interactions. To this end, we summarize current knowledge on germ-free animals as an experimental model for the study of the ecology and metabolism of intestinal bacteria as well as of microbe–microbe interactions. PMID:27065973

  19. In vivo longitudinal study of rodent skeletal muscle atrophy using ultrasonography

    PubMed Central

    Mele, Antonietta; Fonzino, Adriano; Rana, Francesco; Camerino, Giulia Maria; De Bellis, Michela; Conte, Elena; Giustino, Arcangela; Conte Camerino, Diana; Desaphy, Jean-François

    2016-01-01

    Muscle atrophy is a widespread ill condition occurring in many diseases, which can reduce quality of life and increase morbidity and mortality. We developed a new method using non-invasive ultrasonography to measure soleus and gastrocnemius lateralis muscle atrophy in the hindlimb-unloaded rat, a well-accepted model of muscle disuse. Soleus and gastrocnemius volumes were calculated using the conventional truncated-cone method and a newly-designed sinusoidal method. For Soleus muscle, the ultrasonographic volume determined in vivo with either method was linearly correlated to the volume determined ex-vivo from excised muscles as muscle weight-to-density ratio. For both soleus and gastrocnemius muscles, a strong linear correlation was obtained between the ultrasonographic volume and the muscle fiber cross-sectional area determined ex-vivo on muscle cryosections. Thus ultrasonography allowed the longitudinal in vivo evaluation of muscle atrophy progression during hindlimb unloading. This study validates ultrasonography as a powerful method for the evaluation of rodent muscle atrophy in vivo, which would prove useful in disease models and therapeutic trials. PMID:26832124

  20. Experiment K-7-29: Connective Tissue Studies. Part 3; Rodent Tissue Repair: Skeletal Muscle

    NASA Technical Reports Server (NTRS)

    Stauber, W.; Fritz, V. K.; Burkovskaya, T. E.; Ilyina-Kakueva, E. I.

    1994-01-01

    Myofiber injury-repair was studied in the rat gastrocnemius following a crush injury to the lower leg prior to flight in order to understand if the regenerative responses of muscles are altered by the lack of gravitational forces during Cosmos 2044 flight. After 14 days of flight, the gastrocnemius muscle was removed from the 5 injured flight rodents and various Earth-based treatment groups for comparison. The Earth-based animals consisted of three groups of five rats with injured muscles from a simulated, tail-suspended, and vivarium as well as an uninjured basal group. The gastrocnemius muscle from each was evaluated by histochemical and immunohistochemical techniques to document myofiber, vascular, and connective tissue alterations following injury. In general the repair process was somewhat similar in all injured muscle samples with regard to extracellular matrix organization and myofiber regeneration. Small and large myofibers were present with a newly organized extracellular matrix indicative of myogenesis and muscle regeneration. In the tail-suspended animals, a more complete repair was observed with no enlarged area of non-muscle cells or matrix material visible. In contrast, the muscle samples from the flight animals were less well differentiated with more macrophages and blood vessels in the repair region but small myofibers and proteoglycans, nevertheless, were in their usual configuration. Thus, myofiber repair did vary in muscles from the different groups, but for the most part, resulted in functional muscle tissue.

  1. Recommended Methods for Brain Processing and Quantitative Analysis in Rodent Developmental Neurotoxicity Studies.

    PubMed

    Garman, Robert H; Li, Abby A; Kaufmann, Wolfgang; Auer, Roland N; Bolon, Brad

    2016-01-01

    Neuropathology methods in rodent developmental neurotoxicity (DNT) studies have evolved with experience and changing regulatory guidance. This article emphasizes principles and methods to promote more standardized DNT neuropathology evaluation, particularly procurement of highly homologous brain sections and collection of the most reproducible morphometric measurements. To minimize bias, brains from all animals at all dose levels should be processed from brain weighing through paraffin embedding at one time using a counterbalanced design. Morphometric measurements should be anchored by distinct neuroanatomic landmarks that can be identified reliably on the faced block or in unstained sections and which address the region-specific circuitry of the measured area. Common test article-related qualitative changes in the developing brain include abnormal cell numbers (yielding altered regional size), displaced cells (ectopia and heterotopia), and/or aberrant differentiation (indicated by defective myelination or synaptogenesis), but rarely glial or inflammatory reactions. Inclusion of digital images in the DNT pathology raw data provides confidence that the quantitative analysis was done on anatomically matched (i.e., highly homologous) sections. Interpreting DNT neuropathology data and their presumptive correlation with neurobehavioral data requires an integrative weight-of-evidence approach including consideration of maternal toxicity, body weight, brain weight, and the pattern of findings across brain regions, doses, sexes, and ages. PMID:26296631

  2. Value of water mazes for assessing spatial and egocentric learning and memory in rodent basic research and regulatory studies.

    PubMed

    Vorhees, Charles V; Williams, Michael T

    2014-01-01

    Maneuvering safely through the environment is central to survival of all animals. 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 sometimes proximal cues, egocentric navigation. Allocentric navigation involves the hippocampus, entorhinal cortex, and surrounding structures (e.g., subiculum); in humans this system encodes declarative memory (allocentric, semantic, and episodic, i.e., memory for people, places, things, and events). This form of memory is assessed in laboratory animals by many methods, but predominantly 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 over-learned becomes implicit or procedural memory. Several allocentric methods for rodents are reviewed and compared with the MWM with particular focus on the Cincinnati water maze (CWM). MWM advantages include minimal training, no food deprivation, ease of testing, reliable learning, insensitivity to differences in body weight and appetite, absence of non-performers, control methods for performance effects, repeated testing capability and other factors that make this test well-suited for regulatory studies. MWM limitations are also reviewed. Evidence-based MWM design and testing methods are presented. On balance, the MWM is arguably the preferred test for assessing learning and memory in basic research and regulatory studies and the CWM is recommended if two tests can be accommodated so that both allocentric (MWM) and egocentric (CWM) learning and memory can be effectively and efficiently assessed. PMID:25116937

  3. Laboratory studies of volcanic jets

    NASA Astrophysics Data System (ADS)

    Kieffer, Susan Werner; Sturtevant, Bradford

    1984-09-01

    The study of the fluid dynamics of violent volcanic eruptions by laboratory experiment is described, and the important fluid-dynamic processes that can be examined in laboratory models are discussed in detail. In preliminary experiments, pure gases are erupted from small reservoirs. The gases used are Freon 12 and Freon 22, two gases of high molecular weight and high density that are good analogs of heavy and particulate-laden volcanic gases; nitrogen, a moderate molecular weight, moderate density gas for which the thermodynamic properties are well known; and helium, a low molecular weight, lowdensity gas that is used as a basis for comparison with the behavior of the heavier gases and as an analog of steam, the gas that dominates many volcanic eruptions. Transient jets erupt from the reservoir into the laboratory upon rupture of a thin diaphragm at the exit of a convergent nozzle. The gas accelerates from rest in the reservoir to high velocity in the jet. Reservoir pressures and geometries are such that the fluid velocity in the jets is initially supersonic and later decays to subsonic. The measured reservoir pressure decreases as the fluid expands through repetitively reflecting rarefaction waves, but for the conditions of these experiments, a simple steady-discharge model is sufficient to explain the pressure decay and to predict the duration of the flow. Density variations in the flow field have been visualized with schlieren and shadowgraph photography. The observed structure of the jet is correlated with the measured pressure history. The starting vortex generated when the diaphragm ruptures becomes the head of the jet. Though the exit velocity is sonic, the flow head in the helium jet decelerates to about one-third of sonic velocity in the first few nozzle diameters, the nitrogen head decelerates to about three-fourths of sonic velocity, while Freon maintains nearly sonic velocity. The impulsive acceleration of reservoir fluid into the surrounding atmosphere

  4. Rodent models of osteoporosis

    PubMed Central

    Sophocleous, Antonia; Idris, Aymen I

    2014-01-01

    The aim of this protocol is to provide a detailed description of male and female rodent models of osteoporosis. In addition to indications on the methods of performing the surgical procedures, the choice of reliable and safe anaesthetics is also described. Post-operative care, including analgesia administration for pain management, is also discussed. Ovariectomy in rodents is a procedure where ovaries are surgically excised. Hormonal changes resulting from ovary removal lead to an oestrogen-deprived state, which enhances bone remodelling, causes bone loss and increases bone fracture risk. Therefore, ovariectomy has been considered as the most common preclinical model for understanding the pathophysiology of menopause-associated events and for developing new treatment strategies for tackling post-menopausal osteoporosis. This protocol also provides a detailed description of orchidectomy, a model for androgen-deficient osteoporosis in rodents. Endocrine changes following testes removal lead to hypogonadism, which results in accelerated bone loss, increasing osteoporosis risk. Orchidectomised rodent models have been proposed to mimic male osteoporosis and therefore remain a valuable tool for understanding androgen deficiency in aged men. Although it would have been particularly difficult to assemble an internationally acceptable description of surgical procedures, here we have attempted to provide a comprehensive guide for best practice in performing ovariectomy and orchidectomy in laboratory rodents. Research scientists are reminded that they should follow their own institution's interpretation of such guidelines. Ultimately, however, all animal procedures must be overseen by the local Animal Welfare and Ethical Review Body and conducted under licences approved by a regulatory ethics committee. PMID:25852854

  5. 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...

  6. Rodent-repellent studies. I. Method for the evaluation of chemical repellents

    USGS Publications Warehouse

    Bellack, E.; DeWitt, J.B.

    1949-01-01

    A biological assay procedure and a method for the numerical expression of results have been devised for the determination of the repellency to rodents of different chemical compounds. The procedure is based upon the degree of acceptability of foods containing the candidate repellents,. and has been shown. to offer a rapid, reliable measure of repellent activIty.

  7. Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals

    PubMed Central

    Jun, Sang Beom; Cuzon Carlson, Verginia; Ikeda, Stephen; Lovinger, David

    2011-01-01

    Mechanical dissociation of neurons from the central nervous system has the advantage that presynaptic boutons remain attached to the isolated neuron of interest. This allows for examination of synaptic transmission under conditions where the extracellular and postsynaptic intracellular environments can be well controlled. A vibration-based technique without the use of proteases, known as vibrodissociation, is the most popular technique for mechanical isolation. A micropipette, with the tip fire-polished to the shape of a small ball, is placed into a brain slice made from a P1-P21 rodent. The micropipette is vibrated parallel to the slice surface and lowered through the slice thickness resulting in the liberation of isolated neurons. The isolated neurons are ready for study within a few minutes of vibrodissociation. This technique has advantages over the use of primary neuronal cultures, brain slices and enzymatically isolated neurons including: rapid production of viable, relatively mature neurons suitable for electrophysiological and imaging studies; superior control of the extracellular environment free from the influence of neighboring cells; suitability for well-controlled pharmacological experiments using rapid drug application and total cell superfusion; and improved space-clamp in whole-cell recordings relative to neurons in slice or cell culture preparations. This preparation can be used to examine synaptic physiology, pharmacology, modulation and plasticity. Real-time imaging of both pre- and postsynaptic elements in the living cells and boutons is also possible using vibrodissociated neurons. Characterization of the molecular constituents of pre- and postsynaptic elements can also be achieved with immunological and imaging-based approaches. PMID:21654624

  8. CAVEATS REGARDING THE USE OF THE LABORATORY RATS AS A MODEL FOR ACUTE TOXICOLOGICAL STUDIES: MODULATION OF THE TOXIC RESPONSE VIA PHYSIOLOGICAL AND BEHAVIORAL MECHANISMS

    EPA Science Inventory

    The rodent, specifically the inbred laboratory rat, is the primary experimental animal used in toxicology testing. Despite its popularity, recent studies from our laboratory and others raise a number of questions concerning the rat's appropriateness as an animal model for toxicol...

  9. Adipose tissue macrophages in non-rodent mammals: a comparative study.

    PubMed

    Ampem, Grace; Azegrouz, Hind; Bacsadi, Árpád; Balogh, Lajos; Schmidt, Susanne; Thuróczy, Julianna; Röszer, Tamás

    2016-02-01

    The stromal vascular fraction (SVF) of adipose tissue in rodents and primates contains mesenchymal stem cells and immune cells. SVF cells have complex metabolic, immune and endocrine functions with biomedical impact. However, in other mammals, the amount of data on SVF stem cells is negligible and whether the SVF hosts immune cells is unknown. In this study, we show that the SVF is rich in immune cells, with a dominance of adipose tissue macrophages (ATMs) in cattle (Bos primigenius taurus), domestic goat (Capra aegagrus hircus), domestic sheep (Ovis aries), domestic cat (Felis catus) and domestic dog (Canis familiaris). ATMs of these species are granulated lysosome-rich cells with lamellipodial protrusions and express the lysosome markers acid phosphatase 5 (ACP-5) and Mac-3/Lamp-2. Using ACP-5 and Mac-3/Lamp-2 as markers, we additionally detected ATMs in other species, such as the domestic horse (Equus ferus caballus), wild boar (Sus scrofa) and red fox (Vulpes vulpes). Feline and canine ATMs also express the murine macrophage marker F4/80 antigen. In the lean condition, the alternative macrophage activation marker CD206 is expressed by feline and canine ATMs and arginase-1 by feline ATMs. Obesity is associated with interleukin-6 and interferon gamma expression and with overt tyrosine nitration in both feline and canine ATMs. This resembles the obesity-induced phenotype switch of murine and human ATMs. Thus, we show, for the first time, that the presence of ATMs is a general trait of mammals. The interaction between the adipose cells and SVF immune cells might be evolutionarily conserved among mammals. PMID:26239911

  10. 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

  11. 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

  12. Analgesic and anti-inflammatory properties of the leaf extracts of Anacardium occidentalis in the laboratory rodents.

    PubMed

    Onasanwo, S A; Fabiyi, T D; Oluwole, F S; Olaleye, S B

    2012-06-01

    Anacardium occidentalis (family: Anacardiaceae) is a plant of the tropical climate widely used by folklore to treat pain and inflammation. This study was conducted to evaluate the analgesic and anti-inflammatory effects of the leaf extracts in rat and mice using different models in other to confirm folkloric claims. The aqueous, hexane, dichloromethane and methanol extracts (AEAO, HEAO, DEAO and MEAO respectively) were investigated for analgesic effects in acetic acid induced pain in mice. They significantly reduced the number of writhing (p<0.001) and the highest analgesic effect was seen in DEAO extract. DEAO was further studied on various analgesic and anti-inflammatory models in graded doses. The extract significantly reduced writhing induced by acetic acid and the number and time of paw licking induced by formalin in a dose related manner. It inhibited the neurogenic and inflammatory phases of formalin. Analgesia was shown in the inhibition of nociception induced by tail immersion in 55oC hot water. The extract prolonged the latencies of tail withdrawal to a similar degree as pentazocine. The extract caused significant inhibition of carrageenan induced paw oedema in rats in a dose dependent manner. These findings suggest that the leaf extracts of Anacardium occidentalis are highly potent analgesic and anti-inflammatory agents. Phytochemical analysis showed that the leaf extracts contain alkaloids, tannins, saponins and cardenolides. PMID:23235310

  13. Meal-feeding rodents and toxicology research.

    PubMed

    Carey, Gale B; Merrill, Lisa C

    2012-08-20

    Most laboratory rodents used for toxicology studies are fed ad libitum, with unlimited access to food. As a result, ad libitum-fed rodents tend to overeat. Research demonstrates that ad libitum-fed rodents are physiologically and metabolically different from rodents fed controlled amounts of food at scheduled times (meal-fed). Ad libitum-fed rodents can develop hypertriglyceridemia, hypercholesterolemia, diet-induced obesity, nephropathy, cardiomyopathy, and pituitary, pancreatic, adrenal, and thyroid tumors, conditions likely to affect the results of toxicology research studies. In contrast, meal-feeding synchronizes biological rhythms and leads to a longer life span, lower body weight, lower body temperature, hypertrophy of the small intestine, and synchronization of hepatic and digestive enzymes. The circadian rhythms present in nearly all living organisms are entrained by light intensity and food intake, and peripheral clocks in all organs of the body, especially the GI tract and liver, are particularly sensitive to food intake. Feeding schedule has been demonstrated to alter the toxicity and metabolism of drugs including sodium valproate, chloral hydrate, acetaminophen, gentamicin, and methotrexate. Feeding schedule alters the expression of genes that code for Phase I, II, and III proteins, thereby altering the rate and amplitude of drug disposition. Rhythms of plasma insulin and glucagon that fluctuate with food ingestion are also altered by feeding schedule; ad libitum feeding promotes hyperinsulinemia which is a precursor for developing diabetes. The emerging field of chronopharmacology, the interaction of biological rhythms and drugs, will lead to optimizing the design and delivery of drugs in a manner that matches biological rhythms, but it is wise for toxicology researchers to consider feeding schedule when designing these experiments. It has been 10 years since the Society for Toxicologic Pathology voiced its position that feeding schedule is an

  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. Assessment of attention and inhibitory control in rodent developmental neurotoxicity studies.

    PubMed

    Driscoll, Lori L; Strupp, Barbara J

    2015-01-01

    In designing screens to assess potential neurotoxicants, the paramount goal is that the selected assessment tools detect dysfunction if it exists. This goal is particularly challenging in the case of cognitive assessments. Cognition is not a unitary phenomenon, and indeed there is growing evidence that different aspects of cognitive functioning are subserved by distinct neural systems. As a result, if a particular neurotoxicant selectively damages certain neural systems but not others, it can impair some cognitive, sensory, or affective functions, but leave many others intact. Accordingly, studies with human subjects use batteries of cognitive tests, cognizant of the fact that no one test is capable of detecting all forms of cognitive dysfunction. In contrast, assessment of cognitive functioning in non-human animal developmental neurotoxicity (DNT) studies typically consists of a single, presumably representative, "learning and memory" task that is expected to detect all potential effects on cognitive functioning. Streamlining the cognitive assessment in these studies saves time and money, but these shortcuts can have serious consequences if the aspect of cognitive functioning that is impaired is not tapped by the single selected task. In particular, executive functioning - a constellation of cognitive functions which enables the organism to focus on multiple streams of information simultaneously, and revise plans as necessary - is poorly assessed in most animal DNT studies. The failure to adequately assess these functions - which include attention, working memory, inhibitory control, and planning - is particularly worrisome in light of evidence that the neural systems that subserve these functions may be uniquely vulnerable to early developmental insults. We illustrate the importance of tapping these areas of functioning in DNT studies by describing the pattern of effects produced by early developmental Pb exposure. Rats exposed to lead (Pb) early in development

  16. 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

  17. SURVEILLANCE OF TRYPANOSOMA SPP OF RODENTS AND STUDIES IN THEIR TRANSMISSION PROBABILITY BY FLEAS IN SOME RURAL EGYPTIAN AREAS.

    PubMed

    Dahesh, Salwa M A; Mikhail, Micheal W

    2016-04-01

    A new public health problem arises from animal trypanosomes that afflict human by a disease called atypical human trypanosomiasis. Although humans have an innate protection against most Trypanosoma species, nineteen cases of atypical human trypanosomiasis caused by the animal trypanosome as T. b. brucei, T. vivax, T. congolense, T. evansi and T. lewisi have been recorded. Some of theserecorded cases were transient, six required trypanocidal treatments however two patients died. Rodent trypanosome, T. lewisi is transmitted via ingestion of fleas or their feces containing the infective stage, the metacyclic trypomastigote. Because of the high densities of various species of rodents and their distribution all over the country especially in rural areas, the present work aimed to evaluate the trypanosomiasis among rodents collected from November to March 2016 and study transmission probability by their fleas in some rural areas in Abu Alnomros Center, Giza. The overall trypanosomiasis prevalence among the different rodent species was (21 rats) 24.7%. All the infected rats belonged to Rattus r. spp where the prevalence of infection with Trypanosoma lewisi among that species was very high 51.2% while none of rats belonged to Rattus norvegicus were infected. That may be attributed to the solid immunity gained by the R. norvegicus where most of the collected norvegicus were aged and weighed more than 200 grams. There was an inverse significant correlation between the densities of parasites and the weights of the losts. The rat which recorded the highest parasite density (60,000 parasites/microliter) was a female Rattus r. captured indoor (inside house). As to sex of Rattus rattus spp no significant difference was found between males and females in trypanosomiasis. Also there was no significant correlation between the densities of parasites and the number of white blood cells among Rattus rattus spp. All positive rats were collected indoors (from houses) and all the rats

  18. 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.

  19. 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...

  20. Simulated Laboratory/Field Study of Evolution.

    ERIC Educational Resources Information Center

    Dubowsky, Nathan; Hartman, Elliott M., Jr.

    1986-01-01

    Immediately following a lecture discussion on early hominid characteristics and behavior, students participate in a laboratory study of bipedal locomotion based on an analysis of footprints. The development and use of this simulation are described. (JN)

  1. 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.

  2. Photographic laboratory studies of explosions.

    NASA Technical Reports Server (NTRS)

    Kamel, M. M.; Oppenheim, A. K.

    1973-01-01

    Description of a series of cinematographic studies of explosions made with a high-speed rotating-mirror streak camera which uses a high-frequency stroboscopic ruby laser as the light source. The results obtained mainly concern explosions initiated by focused laser irradiation from a pulsed neodymium laser in a detonating gas consisting essentially of an equimolar mixture of acetylene and oxygen at an initial pressure of 100 torr at room temperature. Among the most significant observations were observations of a spherical blast wave preceded by a Chapman-Jouguet detonation which is stabilized immediately after initiation, the merging of a spherical flame with a shock front of the blast wave in which the flame is propagating, the division of a spherical detonation front into a shock wave and flame, and the generation of shock waves by a network of spherical flames.

  3. Colonisation and shedding of Lawsonia intracellularis in experimentally inoculated rodents and in wild rodents on pig farms.

    PubMed

    Collins, A M; Fell, S; Pearson, H; Toribio, J-A

    2011-06-01

    Lawsonia intracellularis is an intracellular bacterium causing proliferative enteropathy in various animal species, and is considered an economically important pathogen of pigs. Rats and mice have been implicated as external vectors for a wide range of pig pathogens, including L. intracellularis. Previous studies have demonstrated L. intracellularis infection and proliferative enteropathy in rodents, but did not show the duration of shedding or the number of L. intracellularis shed by infected rodents, and therefore the infection risk that rodents pose to pigs. In this study, the number of L. intracellularis shed in the faeces and intestinal mucosa of wild rats trapped on pig farms was determined by a quantitative real time polymerase chain reaction assay. The prevalence of L. intracellularis in wild rats trapped on pig farms with endemic proliferative enteropathy (PE) was very high (≥ 70.6%), and large numbers of L. intracellularis were shed (10(10)/g of faeces) in a small proportion of wild rats. The duration of colonisation in laboratory rats and mice challenged with porcine isolates of L. intracellularis was also shown. Faecal shedding of L. intracellularis persisted for 14-21 days in rats and mice that were mildly affected with histological lesions of PE. The humoral immune response to L. intracellularis persisted for 40 days in both species. This study demonstrates that rodents may be an important reservoir of L. intracellularis on piggeries, and hence rodent control is important in disease eradication programs on pig farms. PMID:21349664

  4. Genetic strategies to study TDP-43 in rodents and to develop preclinical therapeutics for amyotrophic lateral sclerosis.

    PubMed

    Wang, David B; Gitcho, Michael A; Kraemer, Brian C; Klein, Ronald L

    2011-10-01

    The neuropathological hallmark of the majority of amyotrophic lateral sclerosis (ALS) and a class of frontotemporal lobar degeneration is ubiquitinated cytoplasmic aggregates composed of transactive response DNA binding protein 43 kDa (TDP-43). Genetic manipulation of TDP-43 in animal models has been used to study the protein's role in pathogenesis. Transgenic rodents for TDP-43 have recapitulated key aspects of ALS such as paralysis, loss of spinal motor neurons and muscle atrophy. Viral vectors are an alternate approach to express pathological proteins in animals. Use of the recombinant adeno-associated virus vector serotype 9 has permitted widespread transgene expression throughout the central nervous system after intravenous administration. Expressing TDP-43 in rats with this method produced a phenotype that was consistent with and similar to TDP-43 transgenic lines. Increased levels of TDP-43 in the nucleus are toxic to neurons and sufficient to produce ALS-like symptoms. Animal models based on TDP-43 will address the relationships between TDP-43 expression levels, pathology, neuronal loss, muscle atrophy, motor function and causative mechanisms of disease. New targets that modify TDP-43 function, or targets from previous ALS models and other models of spinal cord diseases, could be tested for efficacy in the recent rodent models of ALS based on TDP-43. The vector approach could be an important therapeutic channel because the entire spinal cord can be affected from a one-time peripheral administration. PMID:21777407

  5. Intravital two-photon microscopy for studying the uptake and trafficking of fluorescently conjugated molecules in live rodents

    PubMed Central

    Masedunskas, Andrius; Weigert, Roberto

    2009-01-01

    Here we describe an experimental system based on intravital two-photon microscopy for studying endocytosis in live animals. The rodent submandibular glands were chosen as model organs since they can be exposed easily, imaged without compromising their function and, furthermore, they are amenable to pharmacological and genetic manipulations. We show that the fibroblasts within the stroma of the glands readily internalize systemically injected molecules such as fluorescently conjugated dextran and bovine serum albumin, providing a robust model to study endocytosis. We dynamically image the trafficking of these probes from the early endosomes to the late endosomes and lysosomes while also visualizing homotypic fusion events between early endosomes. Finally, we demonstrate that pharmacological agents can be delivered specifically to the submandibular salivary glands thus providing a powerful tool to study the molecular machinery regulating endocytosis in a physiological context. PMID:18647170

  6. 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

  7. Rodents And Other Gnawers.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Presents information about rodents and lagomorphs, including definitions and the characteristics of these animals. Contains teaching activities such as "Habitats for Hoppers,""Cartoon Gnawers," and "The Great Rodent Expedition." Reproducible handouts for two of the activities are provided. (TW)

  8. 40 CFR 799.9305 - TSCA Repeated dose 28-day oral toxicity study in rodents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... section 3 of TSCA and in 40 CFR Part 792—Good Laboratory Practice Standards apply to this section. The... aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma glutamyl transpeptidase, and...

  9. 40 CFR 799.9305 - TSCA Repeated dose 28-day oral toxicity study in rodents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... section 3 of TSCA and in 40 CFR Part 792—Good Laboratory Practice Standards apply to this section. The... aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma glutamyl transpeptidase, and...

  10. Molecular and Integrative Physiological Effects of Isoflurane Anesthesia: The Paradigm of Cardiovascular Studies in Rodents using Magnetic Resonance Imaging

    PubMed Central

    Constantinides, Christakis; Murphy, Kathy

    2016-01-01

    To-this-date, the exact molecular, cellular, and integrative physiological mechanisms of anesthesia remain largely unknown. Published evidence indicates that anesthetic effects are multifocal and occur in a time-dependent and coordinated manner, mediated via central, local, and peripheral pathways. Their effects can be modulated by a range of variables, and their elicited end-effect on the integrative physiological response is highly variable. This review summarizes the major cellular and molecular sites of anesthetic action with a focus on the paradigm of isoflurane (ISO) – the most commonly used anesthetic nowadays – and its use in prolonged in vivo rodent studies using imaging modalities, such as magnetic resonance imaging (MRI). It also presents established evidence for normal ranges of global and regional physiological cardiac function under ISO, proposes optimal, practical methodologies relevant to the use of anesthetic protocols for MRI and outlines the beneficial effects of nitrous oxide supplementation. PMID:27525256

  11. Two-photon microscopy as a tool to study blood flow and neurovascular coupling in the rodent brain

    PubMed Central

    Shih, Andy Y; Driscoll, Jonathan D; Drew, Patrick J; Nishimura, Nozomi; Schaffer, Chris B; Kleinfeld, David

    2012-01-01

    The cerebral vascular system services the constant demand for energy during neuronal activity in the brain. Attempts to delineate the logic of neurovascular coupling have been greatly aided by the advent of two-photon laser scanning microscopy to image both blood flow and the activity of individual cells below the surface of the brain. Here we provide a technical guide to imaging cerebral blood flow in rodents. We describe in detail the surgical procedures required to generate cranial windows for optical access to the cortex of both rats and mice and the use of two-photon microscopy to accurately measure blood flow in individual cortical vessels concurrent with local cellular activity. We further provide examples on how these techniques can be applied to the study of local blood flow regulation and vascular pathologies such as small-scale stroke. PMID:22293983

  12. 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

  13. 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-α (TNF-α) and inducible Nitric-Oxide Synthase (iNOs). This implicate, strong correlation between COX-2, TNF-α and iNOs expression and inflammation induced by H. diminuta. PMID:26012226

  14. 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

  15. [Caucasian cryptic species of rodents as models for studying the problem of species and speciation].

    PubMed

    Baskevich, M I; Potapov, S G; Mironova, T A

    2015-01-01

    The problem of species and speciation is considered using as a model the cryptic species of rodents inhabiting the Caucasus, the mountain chain with prominent altitude environmental gradient and insular pattern of mountain habitats. These circumstances open additional possibilities for the choice of species conception (biological or phylogenetic), exploration of ancestry pathways (sympatric or allopatric speciation) of model cryptic species groups, and testing the 'refuge' hypothesis. As model species, sibling-species Sicista from the group 'caucasica' (a group of unstriped birch mice) and representatives of the vole subspecies Terricola (Microtus, Arvicolinae) were used. Based on the new data on karyology, nucleotide sequences of mitochondrial gene cytb, multivariate statistical analysis of odontologic traits, and biogeography of sibling-species Sicista from the group 'caucasica' and voles from subspecies Terricola (Microtus, Arvicolinae), their evolutionary history is reconstructed and applicable species concepts are examined. For the present sibling-species Sicista from the group 'caucasica' the allopatric dispersion is typical, which agrees with the hypothesis of speciation in refuges. The sympatry of Terricola sibling-species in the Caucasus is considered as being secondary, and their phenotypic likeness--as an adaptation to similar environmental conditions. Affirmed coexistence of sibling-species Microtus (Terricola) majori and Microtus (Terricola) daghestanicus in the Caucasus (without their hybridization) supports the biological conception of species. The existence of Sicista allospecies from the group of Caucasian unstriped birch mice is best conformed to the phylogenetic conception. However, the high level of chromosomal differences between sibling-species and, in particular, between extreme variants of common evolutionary line (Sicista kazbegica, Sicista kluchorica) does not contradict the biological conception of species. PMID:26353399

  16. 40 CFR 799.9305 - TSCA Repeated dose 28-day oral toxicity study in rodents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... section 3 of TSCA and in 40 CFR Part 792—Good Laboratory Practice Standards apply to this section. The... concentration, erythrocyte count, total and differential leukocyte count, platelet count and a measure of blood clotting time/potential. (ii) Blood samples should be taken from a named site just prior to or as part...

  17. 40 CFR 799.9305 - TSCA Repeated dose 28-day oral toxicity study in rodents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... section 3 of TSCA and in 40 CFR Part 792—Good Laboratory Practice Standards apply to this section. The... concentration, erythrocyte count, total and differential leukocyte count, platelet count and a measure of blood clotting time/potential. (ii) Blood samples should be taken from a named site just prior to or as part...

  18. Reflections on Rodent Implantation.

    PubMed

    Cha, Jeeyeon M; Dey, Sudhansu K

    2015-01-01

    Embryo implantation is a complex process involving endocrine, paracrine, autocrine, and juxtacrine modulators that span cell-cell and cell-matrix interactions. The quality of implantation is predictive for pregnancy success. Earlier observational studies formed the basis for genetic and molecular approaches that ensued with emerging technological advances. However, the precise sequence and details of the molecular interactions involved have yet to be defined. This review reflects briefly on aspects of our current understanding of rodent implantation as a tribute to Roger Short's lifelong contributions to the field of reproductive physiology. PMID:26450495

  19. Human Laboratory Studies on Cannabinoids and Psychosis.

    PubMed

    Sherif, Mohamed; Radhakrishnan, Rajiv; D'Souza, Deepak Cyril; Ranganathan, Mohini

    2016-04-01

    Some of the most compelling evidence supporting an association between cannabinoid agonists and psychosis comes from controlled laboratory studies in humans. Randomized, double-blind, placebo-controlled, crossover laboratory studies demonstrate that cannabinoid agonists, including phytocannabinoids and synthetic cannabinoids, produce a wide range of positive, negative, and cognitive symptoms and psychophysiologic deficits in healthy human subjects that resemble the phenomenology of schizophrenia. These effects are time locked to drug administration, are dose related, and are transient and rarely necessitate intervention. The magnitude of effects is similar to the effects of ketamine but qualitatively distinct from other psychotomimetic drugs, including ketamine, amphetamine, and salvinorin A. Cannabinoid agonists have also been shown to transiently exacerbate symptoms in individuals with schizophrenia in laboratory studies. Patients with schizophrenia are more vulnerable than healthy control subjects to the acute behavioral and cognitive effects of cannabinoid agonists and experience transient exacerbation of symptoms despite treatment with antipsychotic medications. Furthermore, laboratory studies have failed to demonstrate any "beneficial" effects of cannabinoid agonists in individuals with schizophrenia-challenging the cannabis self-medication hypothesis. Emerging evidence suggests that polymorphisms of several genes related to dopamine metabolism (e.g., COMT, DAT1, and AKT1) may moderate the effects of cannabinoid agonists in laboratory studies. Cannabinoid agonists induce dopamine release, although the magnitude of release does not appear to be commensurate to the magnitude and spectrum of their acute psychotomimetic effects. Interactions between the endocannabinoid, gamma-aminobutyric acid, and glutamate systems and their individual and interactive effects on neural oscillations provide a plausible mechanism underlying the psychotomimetic effects of

  20. 75 FR 80011 - Good Laboratory Practice for Nonclinical Laboratory Studies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-21

    ..., 1978 (43 FR 60013). As stated in its scope (Sec. 58.1), this regulation prescribes good laboratory..., sponsors have requested the ability to cite compliance with the applicable good manufacturing requirements... be required under a revised part 58, subpart F or the relevant good manufacturing requirements....

  1. Rodent Research-1 Validation of Rodent Hardware

    NASA Technical Reports Server (NTRS)

    Globus, Ruth; Beegle, Janet

    2013-01-01

    To achieve novel science objectives, validation of a rodent habitat on ISS will enable - In-flight analyses during long duration spaceflight- Use of genetically altered animals- Application of modern analytical techniques (e.g. genomics, proteomics, and metabolomics)

  2. Spatial Segregation between Invasive and Native Commensal Rodents in an Urban Environment: A Case Study in Niamey, Niger

    PubMed Central

    Garba, Madougou; Dalecky, Ambroise; Kadaoure, Ibrahima; Kane, Mamadou; Hima, Karmadine; Veran, Sophie; Gagare, Sama; Gauthier, Philippe; Tatard, Caroline; Rossi, Jean-Pierre; Dobigny, Gauthier

    2014-01-01

    Invasive rodents have been responsible for the diffusion worldwide of many zoonotic agents, thus representing major threats for public health. Cities are important hubs for people and goods exchange and are thus expected to play a pivotal role in invasive commensal rodent dissemination. Yet, data about urban rodents' ecology, especially invasive vs. native species interactions, are dramatically scarce. Here, we provide results of an extensive survey of urban rodents conducted in Niamey, Niger, depicting the early stages of rodent bioinvasions within a city. We explore the species-specific spatial distributions throughout the city using contrasted approaches, namely field sampling, co-occurrence analysis, occupancy modelling and indicator geostatistics. We show that (i) two species (i.e. rural-like vs. truly commensal) assemblages can be identified, and that (ii) within commensal rodents, invasive (Rattus rattus and Mus musculus) and native (Mastomys natalensis) species are spatially segregated. Moreover, several pieces of arguments tend to suggest that these exclusive distributions reflect an ongoing native-to-invasive species turn over. The underlying processes as well as the possible consequences for humans are discussed. PMID:25379785

  3. STUDY OF THE PREVALENCE OF Capillaria hepatica IN HUMANS AND RODENTS IN AN URBAN AREA OF THE CITY OF PORTO VELHO, RONDÔNIA, BRAZIL

    PubMed Central

    da Rocha, Elierson José Gomes; Basano, Sérgio de Almeida; de Souza, Márcia Maria; Honda, Eduardo Resende; de Castro, Márcio Botelho; Colodel, Edson Moleta; Silva, Jéssica Carolinne Damasceno e; Barros, Lauro Prado; Rodrigues, Elisa Sousa; Camargo, Luís Marcelo Aranha

    2015-01-01

    Introduction: Hepatic capillariosis, caused by Capillaria hepatica (Calodium hepaticum) (Bancroft, 1893), Travassos, 1915 (Nematoda, Trichinelloidea, Capillariidae), is a common zoonosis in rodents but is rare in humans. Seventy-two cases in humans have been reported worldwide since the first case was described by MACARTHUR in 192417,27. This study aimed to determine the prevalence of Capillaria hepatica in humans and rodents in an urban area of Porto Velho, the capital of Rondônia, in Brazil. Methods: After conducting a census of the area, 490 residents were randomly selected, and, after signing a term of consent, provided blood samples that were screened for anti-Capillaria hepatica antibodies. Simultaneously, rats were captured to assess the prevalence of this parasite in rodents by histopathological examination in liver sections. Results: A prevalence of 1.8% was found among residents who had specific antibodies at a dilution of 1:150, indicating exposure to parasite eggs; 0.8% of the subjects also had positive titers at a dilution of 1:400, indicating true infection. The prevalence in rats was 2%. Conclusions: The prevalence of infection with this parasite among humans and rats was low. While the prevalence encountered among humans was within the limits reported in the literature, the prevalence among rodents was much lower. PMID:25651325

  4. The prosocial effects of 3,4-methylenedioxymethamphetamine (MDMA): Controlled studies in humans and laboratory animals.

    PubMed

    Kamilar-Britt, Philip; Bedi, Gillinder

    2015-10-01

    Users of ±3,4-methylenedioxymethamphetamine (MDMA; 'ecstasy') report prosocial effects such as sociability and empathy. Supporting these apparently unique social effects, data from controlled laboratory studies indicate that MDMA alters social feelings, information processing, and behavior in humans, and social behavior in rodents. Here, we review this growing body of evidence. In rodents, MDMA increases passive prosocial behavior (adjacent lying) and social reward while decreasing aggression, effects that may involve serotonin 1A receptor mediated oxytocin release interacting with vasopressin receptor 1A. In humans, MDMA increases plasma oxytocin and produces feelings of social affiliation. It decreases identification of negative facial expressions (cognitive empathy) and blunts responses to social rejection, while enhancing responses to others' positive emotions (emotional empathy) and increasing social approach. Thus, consistent with drug folklore, laboratory administration of MDMA robustly alters social processing in humans and increases social approach in humans and animals. Effects are consistent with increased sociability, with mixed evidence about enhanced empathy. These neurobiologically-complex prosocial effects likely motivate recreational ecstasy use. PMID:26408071

  5. 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.

  6. Robertsonian fusions, pericentromeric repeat organization and evolution: a case study within a highly polymorphic rodent species, Gerbillus nigeriae.

    PubMed

    Gauthier, Philippe; Hima, Karmadine; Dobigny, Gauthier

    2010-06-01

    Pericentromeric repeats have been claimed to mediate centric fusions through heterologous recombination of arrays of tandemly repeated and highly homogenized motifs. However, mammalian case studies are essentially restricted to pathologic fusions in human, or to the house mouse Roberstonian (Rb) races. We here provide an example in a wild gerbil rodent, Gerbillus nigeriae, which displays an extensive Rb polymorphism, with 2n ranging between 2n = 60 and 74. The distribution of two closely related repeats, GERB1 and GERB2 that were previously isolated by Volobouev et al. (Chromosoma 104:252-259, 1995) in this African species, were investigated in the genomes of seven individuals with various diploid numbers. Our results clearly show that GERB1 and GERB2 are organized in a non-random manner, with GERB2 and GERB1 being clearly juxtacentromeric and centromeric, respectively. Finally, cloning and sequencing revealed that, unlike GERB2, GERB1 monomers display a more homogeneous organization at both the nucleotide and structural levels. Altogether, our results point toward a pivotal role of GERB1 repeats in the mediation of Rb fusions through heterologous recombination, with some evidence of subsequent loss of repeats after the Rb fusion during the course of evolution of metacentric elements. Moreover, the repeat pattern observed in G. nigeriae closely matches the organization and sequence structure of satellite DNAs described in human acrocentrics. Consequently, G. nigeriae appears as an additional model for the study of repeat evolution and its role in centric fusions and their consequences in mammals. PMID:20361248

  7. Laboratory studies in ultraviolet solar physics

    NASA Technical Reports Server (NTRS)

    Parkinson, W. H.; Kohl, J. L.; Gardner, L. D.; Raymond, J. C.; Smith, P. L.

    1991-01-01

    The research activity comprised the measurement of basic atomic processes and parameters which relate directly to the interpretation of solar ultraviolet observations and to the development of comprehensive models of the component structures of the solar atmosphere. The research was specifically directed towards providing the relevant atomic data needed to perform and to improve solar diagnostic techniques which probe active and quiet portions of the solar chromosphere, the transition zone, the inner corona, and the solar wind acceleration regions of the extended corona. The accuracy with which the physical conditions in these structures can be determined depends directly on the accuracy and completeness of the atomic and molecular data. These laboratory data are used to support the analysis programs of past and current solar observations (e.g., the Orbiting solar Observatories, the Solar Maximum Mission, the Skylab Apollo Telescope Mount, and the Naval Research Laboratory's rocket-borne High Resolution Telescope and Spectrograph). In addition, we attempted to anticipate the needs of future space-borne solar studies such as from the joint ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft. Our laboratory activities stressed two categories of study: (1) the measurement of absolute rate coefficients for dielectronic recombination and electron impact excitation; and (2) the measurement of atomic transition probabilities for solar density diagnostics. A brief summary of the research activity is provided.

  8. Rat-atouille: A Mixed Method Study to Characterize Rodent Hunting and Consumption in the Context of Lassa Fever.

    PubMed

    Bonwitt, Jesse; Kelly, Ann H; Ansumana, Rashid; Agbla, Schadrac; Sahr, Foday; Saez, Almudena Mari; Borchert, Matthias; Kock, Richard; Fichet-Calvet, Elisabeth

    2016-06-01

    Lassa fever is a zoonotic hemorrhagic illness predominant in areas across Nigeria, Sierra Leone, Guinea, Liberia, and southern Mali. The reservoir of Lassa virus is the multimammate mouse (Mastomys natalensis), a highly commensal species in West Africa. Primary transmission to humans occurs through direct or indirect contact with rodent body fluids such as urine, feces, saliva, or blood. Our research draws together qualitative and quantitative methods to provide a fuller and more nuanced perspective on these varied points of human-animal contact. In this article, we focus on the hunting, preparation, and consumption of rodents as possible routes of exposure in Bo, Sierra Leone. We found that the consumption of rodents, including the reservoir species, is widespread and does not neatly tally against generational or gender lines. Further, we found that the reasons for rodent consumption are multifactorial, including taste preferences, food security, and opportunistic behavior. We argue that on certain topics, such as rodent consumption, establishing trust with communities, and using qualitative research methods, is key to investigate sensitive issues and situate them in their wider context. To conclude, we recommend ways to refine sensitization campaigns to account for these socio-cultural contexts. PMID:26895631

  9. 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

  10. [(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

  11. Investigating the underlying mechanisms of aberrant behaviors in bipolar disorder from patients to models: Rodent and human studies.

    PubMed

    van Enkhuizen, Jordy; Geyer, Mark A; Minassian, Arpi; Perry, William; Henry, Brook L; Young, Jared W

    2015-11-01

    Psychiatric patients with bipolar disorder suffer from states of depression and mania, during which a variety of symptoms are present. Current treatments are limited and neurocognitive deficits in particular often remain untreated. Targeted therapies based on the biological mechanisms of bipolar disorder could fill this gap and benefit patients and their families. Developing targeted therapies would benefit from appropriate animal models which are challenging to establish, but remain a vital tool. In this review, we summarize approaches to create a valid model relevant to bipolar disorder. We focus on studies that use translational tests of multivariate exploratory behavior, sensorimotor gating, decision-making under risk, and attentional functioning to discover profiles that are consistent between patients and rodent models. Using this battery of translational tests, similar behavior profiles in bipolar mania patients and mice with reduced dopamine transporter activity have been identified. Future investigations should combine other animal models that are biologically relevant to the neuropsychiatric disorder with translational behavioral assessment as outlined here. This methodology can be utilized to develop novel targeted therapies that relieve symptoms for more patients without common side effects caused by current treatments. PMID:26297513

  12. 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

  13. Reprint of "Value of water mazes for assessing spatial and egocentric learning and memory in rodent basic research and regulatory studies".

    PubMed

    Vorhees, Charles V; Williams, Michael T

    2015-01-01

    Maneuvering safely through the environment is central to survival of all animals. 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 sometimes proximal cues, egocentric navigation. Allocentric navigation involves the hippocampus, entorhinal cortex, and surrounding structures (e.g., subiculum); in humans this system encodes declarative memory (allocentric, semantic, and episodic, i.e., memory for people, places, things, and events). This form of memory is assessed in laboratory animals by many methods, but predominantly 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 over-learned becomes implicit or procedural memory. Several allocentric methods for rodents are reviewed and compared with the MWM with particular focus on the Cincinnati water maze (CWM). MWM advantages include minimal training, no food deprivation, ease of testing, reliable learning, insensitivity to differences in body weight and appetite, absence of non-performers, control methods for performance effects, repeated testing capability and other factors that make this test well-suited for regulatory studies. MWM limitations are also reviewed. Evidence-based MWM design and testing methods are presented. On balance, the MWM is arguably the preferred test for assessing learning and memory in basic research and regulatory studies and the CWM is recommended if two tests can be accommodated so that both allocentric (MWM) and egocentric (CWM) learning and memory can be effectively and efficiently assessed. PMID:26071087

  14. Confounding effects of anesthesia on functional activation in rodent brain: a study of halothane and alpha-chloralose anesthesia.

    PubMed

    Austin, V C; Blamire, A M; Allers, K A; Sharp, T; Styles, P; Matthews, P M; Sibson, N R

    2005-01-01

    Functional magnetic resonance imaging (fMRI) in animal models provides a platform for more extensive investigation of drug effects and underlying physiological mechanisms than is possible in humans. However, it is usually necessary for the animal to be anesthetized. In this study, we have used a rat model of direct cortical stimulation to investigate the effects of anesthesia in rodent fMRI. Specifically, we have sought to answer two questions (i) what is the relationship between baseline neuronal activity and the BOLD response to stimulation under halothane anesthesia? And (ii) how does the BOLD response change after transferring from halothane to the commonly used anesthetic alpha-chloralose? In the first set of experiments, we found no significant differences in the amplitude of the BOLD response at the different halothane doses studied, despite electroencephalography (EEG) recordings indicating a dose-dependent reduction in baseline neuronal activity with increasing halothane levels. In the second set of experiments, a reduction in the spatial extent of the BOLD response was apparent immediately after transfer from halothane to alpha-chloralose anesthesia, although no change in the peak signal change was evident. However, several hours after transfer to alpha-chloralose, a significant increase in both the spatial extent and peak height of the BOLD response was observed, as well as an increased sensitivity to secondary cortical and subcortical activation. These findings suggest that, although alpha-chloralose anesthesia is associated with a greater BOLD response for a fixed stimulus relative to halothane, there is substantial variation in the extent and magnitude of the response over time that could introduce considerable variability in studies using this anesthetic. PMID:15588600

  15. Rodent models to study the metabolic effects of shiftwork in humans

    PubMed Central

    Opperhuizen, Anne-Loes; van Kerkhof, Linda W. M.; Proper, Karin I.; Rodenburg, Wendy; Kalsbeek, Andries

    2015-01-01

    Our current 24-h society requires an increasing number of employees to work nightshifts with millions of people worldwide working during the evening or night. Clear associations have been found between shiftwork and the risk to develop metabolic health problems, such as obesity. An increasing number of studies suggest that the underlying mechanism includes disruption of the rhythmically organized body physiology. Normally, daily 24-h rhythms in physiological processes are controlled by the central clock in the brain in close collaboration with peripheral clocks present throughout the body. Working schedules of shiftworkers greatly interfere with these normal daily rhythms by exposing the individual to contrasting inputs, i.e., at the one hand (dim)light exposure at night, nightly activity and eating and at the other hand daytime sleep and reduced light exposure. Several different animal models are being used to mimic shiftwork and study the mechanism responsible for the observed correlation between shiftwork and metabolic diseases. In this review we aim to provide an overview of the available animal studies with a focus on the four most relevant models that are being used to mimic human shiftwork: altered timing of (1) food intake, (2) activity, (3) sleep, or (4) light exposure. For all studies we scored whether and how relevant metabolic parameters, such as bodyweight, adiposity and plasma glucose were affected by the manipulation. In the discussion, we focus on differences between shiftwork models and animal species (i.e., rat and mouse). In addition, we comment on the complexity of shiftwork as an exposure and the subsequent difficulties when using animal models to investigate this condition. In view of the added value of animal models over human cohorts to study the effects and mechanisms of shiftwork, we conclude with recommendations to improve future research protocols to study the causality between shiftwork and metabolic health problems using animal models

  16. Rodent models to study the metabolic effects of shiftwork in humans.

    PubMed

    Opperhuizen, Anne-Loes; van Kerkhof, Linda W M; Proper, Karin I; Rodenburg, Wendy; Kalsbeek, Andries

    2015-01-01

    Our current 24-h society requires an increasing number of employees to work nightshifts with millions of people worldwide working during the evening or night. Clear associations have been found between shiftwork and the risk to develop metabolic health problems, such as obesity. An increasing number of studies suggest that the underlying mechanism includes disruption of the rhythmically organized body physiology. Normally, daily 24-h rhythms in physiological processes are controlled by the central clock in the brain in close collaboration with peripheral clocks present throughout the body. Working schedules of shiftworkers greatly interfere with these normal daily rhythms by exposing the individual to contrasting inputs, i.e., at the one hand (dim)light exposure at night, nightly activity and eating and at the other hand daytime sleep and reduced light exposure. Several different animal models are being used to mimic shiftwork and study the mechanism responsible for the observed correlation between shiftwork and metabolic diseases. In this review we aim to provide an overview of the available animal studies with a focus on the four most relevant models that are being used to mimic human shiftwork: altered timing of (1) food intake, (2) activity, (3) sleep, or (4) light exposure. For all studies we scored whether and how relevant metabolic parameters, such as bodyweight, adiposity and plasma glucose were affected by the manipulation. In the discussion, we focus on differences between shiftwork models and animal species (i.e., rat and mouse). In addition, we comment on the complexity of shiftwork as an exposure and the subsequent difficulties when using animal models to investigate this condition. In view of the added value of animal models over human cohorts to study the effects and mechanisms of shiftwork, we conclude with recommendations to improve future research protocols to study the causality between shiftwork and metabolic health problems using animal models

  17. 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 ...

  18. Automatic system for analysis of locomotor activity in rodents--a reproducibility study.

    PubMed

    Aragão, Raquel da Silva; Rodrigues, Marco Aurélio Benedetti; de Barros, Karla Mônica Ferraz Teixeira; Silva, Sebastião Rogério Freitas; Toscano, Ana Elisa; de Souza, Ricardo Emmanuel; Manhães-de-Castro, Raul

    2011-02-15

    Automatic analysis of locomotion in studies of behavior and development is of great importance because it eliminates the subjective influence of evaluators on the study. This study aimed to develop and test the reproducibility of a system for automated analysis of locomotor activity in rats. For this study, 15 male Wistar were evaluated at P8, P14, P17, P21, P30 and P60. A monitoring system was developed that consisted of an open field of 1m in diameter with a black surface, an infrared digital camera and a video capture card. The animals were filmed for 2 min as they moved freely in the field. The images were sent to a computer connected to the camera. Afterwards, the videos were analyzed using software developed using MATLAB® (mathematical software). The software was able to recognize the pixels constituting the image and extract the following parameters: distance traveled, average speed, average potency, time immobile, number of stops, time spent in different areas of the field and time immobile/number of stops. All data were exported for further analysis. The system was able to effectively extract the desired parameters. Thus, it was possible to observe developmental changes in the patterns of movement of the animals. We also discuss similarities and differences between this system and previously described systems. PMID:21182870

  19. Overview of reproductive and developmental toxicity studies of 1,3-butadiene in rodents.

    PubMed Central

    Morrissey, R E; Schwetz, B A; Hackett, P L; Sikov, M R; Hardin, B D; McClanahan, B J; Decker, J R; Mast, T J

    1990-01-01

    A series of studies to further evaluate the developmental and reproductive toxicity of inhaled 1,3-butadiene was sponsored by the National Toxicology Program. Pregnant Sprague-Dawley rats (24-28/group) and Swiss (CD-1) mice (18-22/group) were exposed to atmospheric concentrations of 0, 40, 200, or 1000 ppm 1,3-butadiene for 6 hr/day on days 6 through 15 of gestation (dg) and killed on dg 18 (mice) or dg 20 (rats). Subsequently, the uterine contents were evaluated; individual fetal body weights were recorded; and external, visceral, and skeletal examinations were performed. In rats, maternal toxicity was observed in the 1000-ppm group in the form of reduced extragestational weight gain and, during the first week of treatment, decreased body weight gain. Under these conditions, there was no evidence of developmental toxicity in rats. In contrast, results of the mouse developmental toxicity study indicated that the fetus may be more susceptible than the dam to inhaled 1,3-butadiene. Maternal toxicity was observed in mice at the 200- and 1000-ppm 1,3-butadiene exposure levels, whereas 40 ppm and higher concentrations of 1,3-butadiene caused significant exposure-related reductions in the mean body weights of male fetuses. Mean body weights of female fetuses were also reduced at the 200- and 1000-ppm exposure levels. No increased incidence of malformations was observed in either study. Other studies addressing male reproductive and mutagenesis end points were performed with B6C3F1 mice (sperm-head morphology) and Swiss (CD-1) mice (dominant lethal study).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2205495

  20. Preliminary studies on model development for rodent toxicity and its interspecies correlation with aquatic toxicities of pharmaceuticals.

    PubMed

    Das, Rudra Narayan; Sanderson, Hans; Mwambo, Andrew E; Roy, Kunal

    2013-03-01

    Environmental toxicity due to pharmaceuticals has been an issue of serious concern for long time. Development of chemometric models with reliable predictive power has been considered as an effective tool for the design of new drug agents with reduced or without ecotoxic potential. Considering a higher degree of similarity in genetic homology towards drug receptor with mammals, we have used a dataset of 194 compounds with reported rodent, fish, daphnia and algae toxicity data for extrapolation of their toxicity towards humans. Allowing for rodents as the most surrogate to human physiology, attempts have also been made to develop interspecies correlation models keeping rodent toxicity as dependent variable so that any drug without reported rodent toxicity can be predicted using fish, daphnia or algae toxicity data which can be consequently extrapolated to human toxicity. The developed models have been subjected to multiple validation strategies. Acceptable results have been obtained in both cases of direct and interspecies extrapolation quantitative structure-activity relationship models. PMID:23238824

  1. Perspectives on opioid tolerance from basic research: behavioural studies after spinal administration in rodents.

    PubMed

    Stevens, C W

    1994-01-01

    For tolerance development studies, computer modelling and statistical tests suggested that the equation which best described the decrement of analgesic effect was best served by an exponential decay function. Further analysis of the time course data led to the tentative conclusion that all groups of animals became tolerant at the same rate, regardless of drug or dose. A literature search revealed then, as it does now, that although there are many statements regarding the rate of opioid tolerance, there has been little systematic investigation of this. The Holy Grail of obtaining the rates of tolerance for a number of opioid agents in a systematic study is well within grasp. This information will be needed in clinical practice for the rational choice of opioid with regard to rate of the development of tolerance. The working hypothesis that emerges for the magnitude of opioid tolerance is that more potent agonists produce less tolerance. Further confirmation of this hypothesis has been forthcoming. This suggests that clinical use of more potent opioids, such as fentanyl, should be considered as a substitute for morphine in long term treatment regimens. The working hypothesis for cross-tolerance is that agents acting on the same receptors will show cross-tolerance. Cross-tolerance will also be observed among agents acting on different receptors, but only those that exhibit pharmacological synergy after short term administration. Asymmetry of cross-tolerance can occur, as the magnitude of this cross-tolerance is determined by the relative potency of the toleragen with regard to that of the probe agent. Given the additional factor of receptor selectivity with agents of different receptor classes, types and subtypes, new studies need to be designed combining the toleragen with a selective antagonist to determine the precise receptor mediation of the magnitude of tolerance, and thus cross-tolerance. For example, the delta opioid DADLE infused with a mu selective opioid

  2. Laboratory Studies Of Circumstellar Carbonaceous Grain Formation

    NASA Astrophysics Data System (ADS)

    Contreras, Cesar; Sciamma-O'Brien, Ella; Salama, Farid

    2014-06-01

    The study of the formation processes of dust is essential to understand the budget of extraterrestrial organic molecules. Although dust with all its components plays an important role in the evolution of interstellar (IS) chemistry and in the formation of organic molecules, little is known on the formation processes of carbonaceous dust. We report the progress that was recently achieved in this domain using NASA Ames’ COSmIC facility (Contreras & Salama 2013, ApJS, 208, 6). PAHs are important chemical building blocks of IS dust. They are detected in IDPs and in meteoritic samples. Additionally, observational, laboratory, and theoretical studies have shown that PAHs are an important, ubiquitous component of the ISM. The formation of PAHs from smaller molecules has not been extensively studied. Therefore, we have performed laboratory experiments to study the dynamic processes of carbon grain formation, starting from the smallest hydrocarbon molecules into the formation of larger PAH and further into nanograins. Studies of IS dust analogs formed from a variety of PAH and hydrocarbon precursors as well as species that include the atoms O, N, and S, have recently been performed in our laboratory using the COSmIC facility to provide conditions that simulate IS and circumstellar environments. The species formed in the COSmiC chamber through a pulsed discharge nozzle plasma source are detected and characterized with a cavity ringdown spectrometer coupled to a time-of-flight mass spectrometer, thus providing both spectroscopic and ion mass information in-situ. Analysis of solid soot particles was also conducted using scanning electron microscopy at the UCSC/NASA Ames’ MACS facility. The SEM analysis of the deposition of soot from methane and acetylene precursors seeded in argon plasmas provide examples on the types of nanoparticles and micrograins that are produced in these gas mixtures under our experimental conditions. From these measurements, we derive information on

  3. 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

  4. Conflicting Views on Chemical Carcinogenesis Arising from the Design and Evaluation of Rodent Carcinogenicity Studies

    PubMed Central

    Melnick, Ronald L.; Thayer, Kristina A.; Bucher, John R.

    2008-01-01

    Conflicting views have been expressed frequently on assessments of human cancer risk of environmental agents based on animal carcinogenicity data; this is primarily because of uncertainties associated with extrapolations of toxicologic findings from studies in experimental animals to human circumstances. Underlying these uncertainties are issues related to how experiments are designed, how rigorously hypotheses are tested, and to what extent assertions extend beyond actual findings. National and international health agencies regard carcinogenicity findings in well-conducted experimental animal studies as evidence of potential carcinogenic risk to humans. Controversies arise when both positive and negative carcinogenicity data exist for a specific agent or when incomplete mechanistic data suggest a possible species difference in response. Issues of experimental design and evaluation that might contribute to disparate results are addressed in this article. To serve as reliable sources of data for the evaluation of the carcinogenic potential of environmental agents, experimental studies must include a) animal models that are sensitive to the end points under investigation; b) detailed characterization of the agent and the administered doses; c) challenging doses and durations of exposure (at least 2 years for rats and mice); d) sufficient numbers of animals per dose group to be capable of detecting a true effect; e) multiple dose groups to allow characterization of dose–response relationships, f) complete and peer-reviewed histopathologic evaluations; and g) pairwise comparisons and analyses of trends based on survival-adjusted tumor incidence. Pharmacokinetic models and mechanistic hypotheses may provide insights into the biological behavior of the agent; however, they must be adequately tested before being used to evaluate human cancer risk. PMID:18197312

  5. Atmospheric cloud physics laboratory project study

    NASA Technical Reports Server (NTRS)

    Schultz, W. E.; Stephen, L. A.; Usher, L. H.

    1976-01-01

    Engineering studies were performed for the Zero-G Cloud Physics Experiment liquid cooling and air pressure control systems. A total of four concepts for the liquid cooling system was evaluated, two of which were found to closely approach the systems requirements. Thermal insulation requirements, system hardware, and control sensor locations were established. The reservoir sizes and initial temperatures were defined as well as system power requirements. In the study of the pressure control system, fluid analyses by the Atmospheric Cloud Physics Laboratory were performed to determine flow characteristics of various orifice sizes, vacuum pump adequacy, and control systems performance. System parameters predicted in these analyses as a function of time include the following for various orifice sizes: (1) chamber and vacuum pump mass flow rates, (2) the number of valve openings or closures, (3) the maximum cloud chamber pressure deviation from the allowable, and (4) cloud chamber and accumulator pressure.

  6. Morphometric studies of heavy ion damage in the brains of rodents

    NASA Astrophysics Data System (ADS)

    Kraft, L. M.; Cox, A. B.

    As an approach to determining the relative biological effectiveness (RBE) of each of five different heavy ions for the mammalian brain, histological preparations of brains from mice exposed to various HZE particles at different doses and primary LET∞ values were examined by means of semi-automated image analysis for volume changes in specific regions of the olfactory bulb. The mice were irradiated at 100 days of age and euthanatized about 500 days (16 months) later. Exposures were: 60Co gamma photons (LET∞ = 1-2 keV/μm), 4He (LET∞ = 6 keV/μm, 12C (LET∞ = 80 keV/μm), 20Ne (LET∞ = 150 keV/μm, 56Fe (LET∞ = 180 keV/μm, and 40Ar (LET∞ = 650 keV/μm). Animals receiving particle radiation were exposed in an extended Bragg peak region except for iron where the plateau region was used. The zones measured in the olfactory bulb were 1) the external plexiform layer (zone) and 2) an internal region consisting of the granule cells, internal plexiform layer, and layer of mitral cells. These studies indicated that volume changes did indeed occur, not only in absolute terms but alos when expressed as the ratio of the structures to each other and to the bulb as a whole. Although this study is exploratory in character, the data obtained may nevertheless contribute to a determination of risk factors due to late effects from HZE particles.

  7. Ultrastructural features of masseter muscle exhibiting altered occlusal relationship - a study in a rodent model

    SciTech Connect

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

    2010-05-31

    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.

  8. 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.

  9. Antibiotic-treated versus germ-free rodents for microbiota transplantation studies

    PubMed Central

    Lundberg, Randi; Toft, Martin F.; August, Benjamin; Hansen, Axel K.; Hansen, Camilla H. F.

    2016-01-01

    ABSTRACT We recently investigated the applicability of antibiotic-treated recipient mice for transfer of different gut microbiota profiles. With this addendum we elaborate on perspectives and limitations of using antibiotics as an alternative to germ-free (GF) technology in microbial transplantation studies, and we speculate on the housing effect. It is possible to transfer host phenotypes via fecal transplantation to antibiotic-treated animals, but problems with reproducibility, baseline values, and antibiotic resistance genes should be considered. GF animals maintained in isolators still seem to be the best controlled models for long-term microbial transplantation, but antibiotic-treated recipients are also commonly utilized. We identify a need for systematic experiments investigating the stability of microbial transplantations by addressing 1) the recipient status as either GF, antibiotic-treated or specific pathogen free and 2) different levels of protected housing systems. In addition, the developmental effect of microbes on host physiological functions should be evaluated in the different scenarios. PMID:26744774

  10. Acute, mutagenicity, teratogenicity and subchronic oral toxicity studies of diaveridine in rodents.

    PubMed

    Wang, Jianzhong; Sun, Feifei; Tang, Shusheng; Zhang, Suxia; Cao, Xingyuan

    2015-09-01

    Diaveridine (DVD) is a member of the 2,4-pyrimidinediamine class of dihydrofolate reductase inhibitors. It is used in combination with sulfaquinoxaline as an antiprotozoal agent in animals for the prophylaxis and treatment of coccidiosis and leucocytozoonosis. Herein, we report a complete toxicological safety assessment of DVD for clinical use. The study of toxicity, genetic toxicity (mammalian erythrocyte micronucleus assay, mice sperm abnormality test and in vivo chromosome aberration test of mammalian bone marrow), 90-day sub-chronic toxicity and teratogenicity test were performed. In the acute oral toxicity tests, median lethal dose, LD50, was more than 2378mg/kg body weight in Sprague Dawley rats (1025mg/kg body weight in ICR mice). The testing results for three terms of mutagenicity toxicity (mouse chromosome aberration, erythrocyte micronucleus and sperm abnormality) were all negative at 128-512mg/kg body weight. For 90-day feeding of DVD at the dosage of 10mg/kg body weight in both male and female SD rats, no signs of toxicological effects were detected. Meanwhile, for teratogenicity test in female SD rats at the dosage of 37mg/kg body weight, there were no toxicological signs observed. Thus, our results suggested that the DVD is safe when administered orally in rats at 10mg/kg body weight per day. PMID:26397222

  11. ART and health: clinical outcomes and insights on molecular mechanisms from rodent studies

    PubMed Central

    Feuer, S.K.; Camarano, L.; Rinaudo, P.F.

    2013-01-01

    Since the birth of the first IVF-conceived child in 1978, the use of assisted reproductive technologies (ART) has grown dramatically, contributing to the successful birth of 5 million individuals worldwide. However, there are several reported associations of ART with pregnancy complications, such as low birthweight (LBW), preterm birth, birth defects, epigenetic disorders, cancer and poor metabolic health. Whether this is attributed to ART procedures or to the subset of the population seeking ART remains a controversy, but the most relevant question today concerns the potential long-term implications of assisted conception. Recent evidence has emerged suggesting that ART-conceived children have distinct metabolic profiles that may predispose to cardiovascular pathologies in adulthood. Because the eldest IVF individuals are still too young to exhibit components of chronic middle-aged syndromes, the use of animal models has become particularly useful in describing the effects of unusual or stressful preimplantation experiences on adult fitness. Elucidating the molecular mechanisms by which embryos integrate environmental signals into development and metabolic gene expression programs will be essential for optimizing ART procedures such as in vitro culture conditions, embryo selection and transfer. In the future, additional animal studies to identify mechanisms underlying unfavorable ART outcomes, as well as more epidemiological reviews to monitor the long-term health of ART children are required, given that ART procedures have become routine medical practice. PMID:23264495

  12. 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

  13. 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, α-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 α-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

  14. 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, α-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 α-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

  15. 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

  16. Rodent Working Heart Model for the Study of Myocardial Performance and Oxygen Consumption.

    PubMed

    DeWitt, Elizabeth S; Black, Katherine J; Kheir, John N

    2016-01-01

    Isolated working heart models have been used to understand the effects of loading conditions, heart rate and medications on myocardial performance in ways that cannot be accomplished in vivo. For example, inotropic medications commonly also affect preload and afterload, precluding load-independent assessments of their myocardial effects in vivo. Additionally, this model allows for sampling of coronary sinus effluent without contamination from systemic venous return, permitting assessment of myocardial oxygen consumption. Further, the advent of miniaturized pressure-volume catheters has allowed for the precise quantification of markers of both systolic and diastolic performance. We describe a model in which the left ventricle can be studied while performing both volume and pressure work under controlled conditions. In this technique, the heart and lungs of a Sprague-Dawley rat (weight 300-500 g) are removed en bloc under general anesthesia. The aorta is dissected free and cannulated for retrograde perfusion with oxygenated Krebs buffer. The pulmonary arteries and veins are ligated and the lungs removed from the preparation. The left atrium is then incised and cannulated using a separate venous cannula, attached to a preload block. Once this is determined to be leak-free, the left heart is loaded and retrograde perfusion stopped, creating the working heart model. The pulmonary artery is incised and cannulated for collection of coronary effluent and determination of myocardial oxygen consumption. A pressure-volume catheter is placed into the left ventricle either retrograde or through apical puncture. If desired, atrial pacing wires can be placed for more precise control of heart rate. This model allows for precise control of preload (using a left atrial pressure block), afterload (using an afterload block), heart rate (using pacing wires) and oxygen tension (using oxygen mixtures within the perfusate). PMID:27584550

  17. Zero-gravity cloud physics laboratory: Experiment program definition and preliminary laboratory concept studies

    NASA Technical Reports Server (NTRS)

    Eaton, L. R.; Greco, E. V.

    1973-01-01

    The experiment program definition and preliminary laboratory concept studies on the zero G cloud physics laboratory are reported. This program involves the definition and development of an atmospheric cloud physics laboratory and the selection and delineations of a set of candidate experiments that must utilize the unique environment of zero gravity or near zero gravity.

  18. Laboratory study of mini-magnetosphere

    NASA Astrophysics Data System (ADS)

    Shaikhislamov, Ildar; Zakharov, Yuri; Posukh, Vitaly; Melekhov, Aleksandr; Antonov, Vladimir; Boyarintsev, Eduard; Ponomarenko, Arnold

    Laboratory study of mini-magnetosphere Magnetosphere at ion kinetic scales, or mini-magnetosphere, which is observed above lunar magnetic anomalies or might be discovered around magnetized asteroids in future missions, possesses unusual features as predicted by numerical simulations. However, there are practically no data on the subject from space observations and the data which is available is far too incomplete. In the present work we describe results of laboratory experiment on interaction of plasma flow with magnetic dipole with parameters such that ion inertia length is smaller than a size of observed magnetosphere. A detailed structure of non-coplanar or out-of-plane component of magnetic field has been obtained in meridian plane. Independence of this component on dipole moment reversal, as was reported in previous works (Shaikhislamov et al 2013, 2014), has been verified. In the tail distinct lobes and central current sheet have been observed. It was found that lobe regions adjacent to boundary layer are dominated by non-coplanar component of magnetic field. Tail-ward oriented electric current in plasma associated with that component appears to be equal to ion current in the frontal part of magnetosphere and in the tail current sheet implying that electrons are stationary in those regions while ions flow by. Obtained data strongly support the proposed model of mini-magnetosphere based on two-fluid effects as described by the Hall term and suggest that spacecraft crossing the tail of magnetized asteroid might observe, instead of simple reversion of tail-ward field, a complex 3-D rotation of magnetic field vector. Acknowledgements This work was supported by SB RAS Research Program grant II.8.1.4, Russian Fund for Basic Research grant 12-02-00367, OFN RAS Research Program 15 and Presidium RAS Research Program 22. References Shaikhislamov, I. F., Antonov, V. M., Zakharov, Yu. P., Boyarintsev, E. L., Melekhov, A. V., Posukh, V. G. and Ponomarenko, A. G. Mini

  19. Laboratory Studies of Atmospheric Heterogeneous Chemistry

    NASA Technical Reports Server (NTRS)

    Keyser, L. F.; Leu, M-T.

    1993-01-01

    In the laboratory, ice films formed by freezing from the liquid or more frequently by deposition from the vapor phase have been used to simulate stratospheric cloud surfaces for measurements of reaction and uptake rates. To obtain intrinsic surface reaction probabilities that can be used in atmospheric models, the area of the film surface that actually takes part in the reaction must be known. It is important to know not only the total surface area but also the film morphology in order to determine where and how the surface is situated and, thus, what fraction of it is available for reaction. Information on the structure of these ice films has been obtained by using several experimental methods. In the sections that follow, these methods will be discussed, then the results will be used to construct a working model of the ice films, and finally the model will be applied to an experimental study of HC1 uptake by H_2O ice.

  20. Environmental factors and public health policy associated with human and rodent infection by leptospirosis: a land cover-based study in Nan province, Thailand.

    PubMed

    Della Rossa, P; Tantrakarnapa, K; Sutdan, D; Kasetsinsombat, K; Cosson, J-F; Supputamongkol, Y; Chaisiri, K; Tran, A; Supputamongkol, S; Binot, A; Lajaunie, C; Morand, S

    2016-05-01

    Leptospirosis incidence has increased markedly since 1995 in Thailand, with the eastern and northern parts being the most affected regions, particularly during flooding events. Here, we attempt to overview the evolution of human prevalence during the past decade and identify the environmental factors that correlate with the incidence of leptospirosis and the clinical incidence in humans. We used an extensive survey of Leptospira infection in rodents conducted in 2008 and 2009 and the human incidence of the disease from 2003 to 2012 in 168 villages of two districts of Nan province in Northern Thailand. Using an ad-hoc developed land-use cover implemented in a geographical information system we showed that humans and rodents were not infected in the same environment/habitat in the land-use cover. High village prevalence was observed in open habitat near rivers for the whole decade, or in 2008-2009 mostly in rice fields prone to flooding, whereas infected rodents (2008-2009) were observed in patchy habitat with high forest cover, mostly situated on sloping ground areas. We also investigated the potential effects of public health campaigns conducted after the dramatic flood event of 2006. We showed that, before 2006, human incidence in villages was explained by the population size of the village according to the environmental source of infection of this disease, while as a result of the campaigns, human incidence in villages after 2006 appeared independent of their population size. This study confirms the role of the environment and particularly land use, in the transmission of bacteria, emphasized by the effects of the provincial public health campaigns on the epidemiological pattern of incidence, and questions the role of rodents as reservoirs. PMID:26607833

  1. Urinary Lipocalin Protein in a Female Rodent with Correlation to Phases in the Estrous Cycle: An Experimental Study Accompanied by In Silico Analysis

    PubMed Central

    Saibaba, Ganesan; Alagesan, Alagersamy; Rengarajan, Rengasamy Lakhsminarayanan; Archunan, Govindaraju

    2013-01-01

    Male urinary lipocalin family proteins, practically odorant-binding proteins but also could be pheromones by themselves, in rodents act as a shuttle for chemosignal communication and facilitate delivery of the signals for access to congeners. However, presence of this protein in urine of female rodents has not yet been reported. Therefore, the present investigation was carried out to find if lipocalin family protein is present in the urine of female house rat and, if so, to find whether its expression differs between the phases in the estrous cycle. The rat urinary protein was separated in single dimensional gel electrophoresis. A 14.5 kDa lipocalin protein appeared in the urine prominently during the estrus and metestrus phases compared to proestrus and diestrus phases. The expression of this protein in the urine was very low in ovariectomized rats. MALDI-TOF/MS analysis affirmed the 14.5 kDa protein as a lipocalin family protein. Analysis adopting bio-informatics tools further proved the protein as a lipocalin family member. Thus, this study for the first time demonstrated the presence of a lipocalin family protein in the urine of a female rodent and it was highly expressed during estrus phase. This lipocalin protein in female rat urine may facilitate a chemosignal function independently of a pheromone or in association with a specific pheromone. PMID:23967199

  2. Antitumor efficacy testing in rodents.

    PubMed

    Hollingshead, Melinda G

    2008-11-01

    The preclinical research and human clinical trials necessary for developing anticancer therapeutics are costly. One contributor to these costs is preclinical rodent efficacy studies, which, in addition to the costs associated with conducting them, often guide the selection of agents for clinical development. If inappropriate or inaccurate recommendations are made on the basis of these preclinical studies, then additional costs are incurred. In this commentary, I discuss the issues associated with preclinical rodent efficacy studies. These include the identification of proper preclinical efficacy models, the selection of appropriate experimental endpoints, and the correct statistical evaluation of the resulting data. I also describe important experimental design considerations, such as selecting the drug vehicle, optimizing the therapeutic treatment plan, properly powering the experiment by defining appropriate numbers of replicates in each treatment arm, and proper randomization. Improved preclinical selection criteria can aid in reducing unnecessary human studies, thus reducing the overall costs of anticancer drug development. PMID:18957675

  3. Clinical laboratory studies in Barth Syndrome.

    PubMed

    Vernon, Hilary J; Sandlers, Yana; McClellan, Rebecca; Kelley, Richard I

    2014-06-01

    Barth Syndrome is a rare X-linked disorder characterized principally by dilated cardiomyopathy, skeletal myopathy and neutropenia and caused by defects in tafazzin, an enzyme responsible for modifying the acyl chain moieties of cardiolipin. While several comprehensive clinical studies of Barth Syndrome have been published detailing cardiac and hematologic features, descriptions of its biochemical characteristics are limited. To gain a better understanding of the clinical biochemistry of this rare disease, we measured hematologic and biochemical values in a cohort of Barth Syndrome patients. We characterized multiple biochemical parameters, including plasma amino acids, plasma 3-methylglutaconic acid, cholesterol, cholesterol synthetic intermediates, and red blood cell membrane fatty acid profiles in 28 individuals with Barth Syndrome from ages 10 months to 30 years. We describe a unique biochemical profile for these patients, including decreased plasma arginine levels. We further studied the plasma amino acid profiles, cholesterol, cholesterol synthetic intermediates, and plasma 3-methylglutaconic acid levels in 8 female carriers and showed that they do not share any of the distinct, Barth Syndrome-specific biochemical laboratory abnormalities. Our studies augment and expand the biochemical profiles of individuals with Barth Syndrome, describe a unique biochemical profile for these patients, and provide insight into the possible underlying biochemical pathology in this disorder. PMID:24751896

  4. JaCVAM-organized international validation study of the in vivo rodent alkaline comet assay for the detection of genotoxic carcinogens: I. Summary of pre-validation study results.

    PubMed

    Uno, Yoshifumi; Kojima, Hajime; Omori, Takashi; Corvi, Raffaella; Honma, Masamistu; Schechtman, Leonard M; Tice, Raymond R; Burlinson, Brian; Escobar, Patricia A; Kraynak, Andrew R; Nakagawa, Yuzuki; Nakajima, Madoka; Pant, Kamala; Asano, Norihide; Lovell, David; Morita, Takeshi; Ohno, Yasuo; Hayashi, Makoto

    2015-07-01

    The in vivo rodent alkaline comet assay (comet assay) is used internationally to investigate the in vivo genotoxic potential of test chemicals. This assay, however, has not previously been formally validated. The Japanese Center for the Validation of Alternative Methods (JaCVAM), with the cooperation of the U.S. NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM)/the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), the European Centre for the Validation of Alternative Methods (ECVAM), and the Japanese Environmental Mutagen Society/Mammalian Mutagenesis Study Group (JEMS/MMS), organized an international validation study to evaluate the reliability and relevance of the assay for identifying genotoxic carcinogens, using liver and stomach as target organs. The ultimate goal of this validation effort was to establish an Organisation for Economic Co-operation and Development (OECD) test guideline. The purpose of the pre-validation studies (i.e., Phase 1 through 3), conducted in four or five laboratories with extensive comet assay experience, was to optimize the protocol to be used during the definitive validation study. PMID:26212293

  5. 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

  6. Rocket and Laboratory Studies in Astronomy

    NASA Technical Reports Server (NTRS)

    Feldman, Paul D.

    2001-01-01

    This is the final report for NASA Grant NAG5-5122 and covers the period from March 1, 1997 to February 28, 2001. This grant was a continuation of a program in rocket and laboratory studies in ultraviolet astronomy that was supported by NASA grant NAG5-619. As of March 1, 2001, this program is continuing under grant NAG5-5315. During the period of the grant, annual status reports have been submitted detailing the scientific achievements and current objectives of each report period. These will not be repeated here. Among the highlights of the program are four successful rocket launches including participation in the campaign to study comet Hale-Bopp in April 1997. We have continued our emphasis on long-slit spectroscopy of extended sources in the shorter wavelength far-ultraviolet, necessitating the development of evacuated telescope/spectrograph payloads. Finally, we also note the use of our ultraviolet calibration facilities in support of other sounding rocket investigators and for other space missions such as the Far Ultraviolet Spectroscopic Explorer. We include a list of the sounding rocket launches performed under NASA sponsorship during this period, a list of Ph.D. degrees awarded to students who worked in this program, and a summary bibliography of publications between 1997 and 2001.

  7. Non-Invasive Ultrasound Liver Ablation Using Histotripsy: Chronic Study in an In Vivo Rodent Model.

    PubMed

    Vlaisavljevich, Eli; Greve, Joan; Cheng, Xu; Ives, Kimberly; Shi, Jiaqi; Jin, Lifang; Arvidson, Alexa; Hall, Tim; Welling, Theodore H; Owens, Gabe; Roberts, William; Xu, Zhen

    2016-08-01

    Hepatocellular carcinoma, or liver cancer, has the fastest growing incidence among cancers in the United States. Current liver ablation methods are thermal-based and share limitations due to the heat sink effect from the blood flow through the highly vascular liver. Recently, our group has investigated histotripsy as a non-invasive liver cancer ablation method. Histotripsy is a non-thermal ultrasonic ablation method that fractionates tissue through the control of acoustic cavitation. Previous experiments in an in vivo porcine model show that histotripsy can create well-confined lesions in the liver through ribcage obstruction without damaging the overlying ribs and other tissues. Histotripsy can also completely fractionate liver tissue surrounding major vessels while preserving the vessels. In this study, we investigate the long-term effects of histotripsy liver ablation in a rodent model. We hypothesize that the fractionated histotripsy lesion will be resorbed by the liver, resulting in effective tissue healing. To test this hypothesis, the livers of 20 healthy rats were treated with histotripsy using an 8-element 1-MHz histotripsy transducer. Rats were euthanized after 0, 3, 7, 14 and 28 days (n = 4). In vivo and post mortem results showed histotripsy lesions were successfully generated through the intact abdomen in all 20 rats. Magnetic resonance imaging found primarily negative contrast on day 0, positive contrast on day 3 and rapid normalization of signal intensity thereafter (i.e., signal amplitude returned to baseline levels seen in healthy liver tissue). Histologically, lesions were completely fractionated into an acellular homogenate. The lesions had a maximum cross-sectional area of 17.2 ± 1.9 mm(2) and sharp boundaries between the lesion and the healthy surrounding tissue after treatment. As the animals recovered after treatment, the histotripsy tissue homogenate was almost completely replaced by regenerated liver parenchyma, resulting in a

  8. 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

  9. 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.

  10. A laboratory study of floating lenticular anticyclones

    NASA Astrophysics Data System (ADS)

    Le Gal, Patrice; de La Rosa, Hector; Cros, Anne; Cruz-Gomez, Raúl; Le Bars, Michael

    2014-11-01

    Oceanic vortices play an important role in the redistribution of heat, salt and momentum in the oceans. Among these vortices, floating lenses or rings are often met in the meanders of warm currents. For instance the North Brazil Current rings are among the most intense and large anticyclonic vortices on Earth. In order to better describe these vortices, we propose here a laboratory study of these floating anticyclonic lenses. A blob of fresh water is slowly injected near the surface of a rotating layer of homogeneous salted water. Because of the opposite effects of rotation that tends to generate columnar structures and density stratification that spreads light water on the surface, the vortices take a finite size three dimensionnal typical shape. Visualization and PIV measurements of the shape, aspect ratios and vorticity profiles are compared to analytical predictions that use first a simple solid body rotation model and then a more realistic isolated Gaussian vorticity field inside the anticyclones. This work was carried out within the framework of a bilateral cooperation between CNRS (France) and CONACYT (Mexico).

  11. Infrared laboratory studies of synthetic planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Williams, D.

    1972-01-01

    The initial stages of the research were involved with a test of Burch's law 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. The broadening of individual lines in the CO fundamental by various gases was investigated. Line strength and half-width for individual CO lines were studied as a function of temperature. Measurements of total band absorptance as a function of absorber thickness and total effective pressure were made at various temperatures for bands of CO and N2O. Attempts were made to develop a phenomenological theory of line broadening that would account for the phenomena observed for the CO fundamental and those reported for more highly polar gases. Laboratory measurements of nitric acid vapor absorptance were compared with balloon measurements in arriving at an estimate of the quantity of nitric acid vapor present in the earth's atmosphere in the region of the ozone layer.

  12. Rocket and Laboratory Studies in Astronomy

    NASA Technical Reports Server (NTRS)

    Feldman, Paul D.; McCandliss, Stephan R.

    2004-01-01

    This report covers the period from March 1, 2001 to August 31, 2004. This grant was the continuation of NASA grant NAG5-5122 and supported the Johns Hopkins sounding rocket program that had its roots in the 1960s. The emphasis of this program has been the development of instrumentation for far-ultraviolet astronomy, the training of graduate students in all aspects of a space mission, and the application of these techniques to timely scientific problems. During this period we completed the fabrication of our new long-slit dual-order spectrograph (LIDOS), and successfully flew it on a Black Brant sounding rocket on December 16, 2003 (36.208 UG). The targets were the bright star gamma-Cassiopeiae and its surrounding reflection nebulae, IC 59 and IC 63. We also continued the analysis of the data from our previous flight to study the reflection nebula IC 405 (36.198 UG), which revealed a far-ultraviolet nebular scatter to stellar flux ratio that, contrary to expectations, rises steeply toward the blue. Verifying this result required extensive post-flight analysis and calibration of the Faint Object Telescope FOT) payload, which entailed measuring the telescope mirror reflectivities, the absolute efficiency of the spectrograph, and the telescope point spread function, using a new vacuum collimator developed as part of former graduate student Eric Burgh's Ph.D. dissertation. This work, being done with graduate student Kevin France, has been completed and a paper describing the results has been accepted for publication by the Astrophysical Journal. We have also continued a number of laboratory calibration studies and design efforts.

  13. Temporal changes in aggregation: a laboratory study.

    PubMed

    Scott, M E

    1987-06-01

    Changes in the variance to mean ratio and the parameter k of the negative binomial distribution were used to study temporal changes in the degree of aggregation of the monogenean parasite, Gyrodactylus turnbulli in free-running laboratory populations of the guppy, Poecilia reticulata. The parasite undergoes recurrent epidemic cycles in the host population under conditions of regular immigration of uninfected guppies. During the early phase of the epidemic, heterogeneity among fish together with direct reproduction are thought to contribute to the increasing degree of aggregation. During the increasing phase of the epidemic cycle, parasites become increasingly aggregated in the host population, presumably because of the direct reproduction of the parasite on the surface of a single host. As the peak prevalance and abundance are approached, the parasites become less aggregated with lowest clumping occurring during the declining phase of the cycle. This is thought to be a function of density-dependent death of infected hosts, and density-dependent reduction in parasite survival and reproduction on hosts that recover from infection. This study clearly indicates that the variance to mean ratio and the parameter k of the negative binomial distribution do not quantify the same aspect of the frequency distribution. It is suggested that the variance to mean ratio is a better measure when the prevalence and/or mean burden are changing and when the tail of the distribution is of particular interest, and that k may be a preferred parameter when the zero class or the lightly infected hosts are of primary interest. PMID:3614993

  14. 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,…

  15. 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

  16. 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

  17. 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.

  18. Concise review: Preclinical studies on human cell-based therapy in rodent ischemic stroke models: where are we now after a decade?

    PubMed

    Leong, Wai Khay; Lewis, Martin D; Koblar, Simon A

    2013-06-01

    Stroke, a debilitating brain insult, afflicts millions of individuals globally each year. In the last decade, researchers have investigated cell-based therapy as an alternative strategy to improve neurological outcome following stroke. This concise review critically examines preclinical reports using human adult and fetal stem/progenitor cells in rodent models of ischemic stroke. As we enter the second decade of study, we should aim to optimize our collective likelihood to translational success for stroke victims worldwide. We advocate international consensus recommendations be developed for future preclinical research. PMID:23390084

  19. Gene Polymorphism Studies in a Teaching Laboratory

    ERIC Educational Resources Information Center

    Shultz, Jeffry

    2009-01-01

    I present a laboratory procedure for illustrating transcription, post-transcriptional modification, gene conservation, and comparative genetics for use in undergraduate biology education. Students are individually assigned genes in a targeted biochemical pathway, for which they design and test polymerase chain reaction (PCR) primers. In this…

  20. Progress in the Laboratory Study of Interstellar Analogs

    NASA Technical Reports Server (NTRS)

    Salama, Farid; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Recent progress in the laboratory study of cosmic carbon analogs will be discussed. After a brief review of the history of laboratory studies of interstellar carbon molecules and ions, new gas-phase results will be discussed and contrasted to previous studies that used the techniques of matrix isolation spectroscopy. Finally, the impact of these new laboratory studies on the field of astrophysics will be discussed.

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

    PubMed Central

    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

    2015-01-01

    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

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

    PubMed

    Oliveriusová, Ludmila; Němec, Pavel; Pavelková, Zuzana; Sedláček, 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

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

    NASA Astrophysics Data System (ADS)

    Oliveriusová, Ludmila; Němec, Pavel; Pavelková, Zuzana; Sedláček, 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.

  4. 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

  5. Antibody Response to Cryptococcus neoformans Proteins in Rodents and Humans

    PubMed Central

    Chen, Lin-Chi; Goldman, David L.; Doering, Tamara L.; Pirofski, Liise-anne; Casadevall, Arturo

    1999-01-01

    The prevalence and specificity of serum antibodies to Cryptococcus neoformans proteins was studied in mice and rats with experimental infection, in individuals with or without a history of potential laboratory exposure to C. neoformans, human immunodeficiency virus (HIV)-positive individuals who developed cryptococcosis, in matched samples from HIV-positive individuals who did not develop cryptococcosis, and in HIV-negative individuals. Rodents had little or no serum antibody reactive with C. neoformans proteins prior to infection. The intensity and specificity of the rodent antibody response were dependent on the species, the mouse strain, and the viability of the inoculum. All humans had serum antibodies reactive with C. neoformans proteins regardless of the potential exposure, the HIV infection status, or the subsequent development of cryptococcosis. Our results indicate (i) a high prevalence of antibodies reactive with C. neoformans proteins in the sera of rodents after cryptococcal infection and in humans with or without HIV infection; (ii) qualitative and quantitative differences in the antibody profiles of HIV-positive individuals; and (iii) similarities and differences between humans, mice, and rats with respect to the specificity of the antibodies reactive with C. neoformans proteins. The results are consistent with the view that C. neoformans infections are common in human populations, and the results have implications for the development of vaccination strategies against cryptococcosis. PMID:10225877

  6. Laboratory Needs for Interstellar Ice Studies

    NASA Astrophysics Data System (ADS)

    Boogert, Abraham C. A.

    2012-05-01

    A large fraction of the molecules in dense interstellar and circumstellar environments is stored in icy grain mantles. The mantles are formed by a complex interplay between chemical and physical processes. Key questions on the accretion and desorption processes and the chemistry on the grain surfaces and within the icy mantles can only be answered by laboratory experiments. Recent infrared (2-30 micron) spectroscopic surveys of large samples of Young Stellar Objects (YSOs) and background stars tracing quiescent cloud material have shown that the ice band profiles and depths vary considerably as a function of environment. Using laboratory spectra in the identification process, it is clear that a rather complex mixture of simple species (CH3OH, CO2, H2O, CO) exists even in the quiescent cloud phase. Variations of the local physical conditions (CO freeze out) and time scales (CH3OH formation) appear to be key factors in the observed variations. Sublimation and thermal processing dominate as YSOs heat their environments. The identification of several ice absorption features is still disputed. I will outline laboratory work (e.g., on salts, PAHs, and aliphatic hydrocarbons) needed to further constrain the ice band identification as well as the thermal and chemical history of the carriers. Such experiments will also be essential to interpret future high spectral resolution SOFIA and JWST observations.

  7. Miniature wireless recording and stimulation system for rodent behavioural testing

    NASA Astrophysics Data System (ADS)

    Pinnell, R. C.; Dempster, J.; Pratt, J.

    2015-12-01

    Objective. Elucidation of neural activity underpinning rodent behaviour has traditionally been hampered by the use of tethered systems and human involvement. Furthermore the combination of deep-brain stimulation (DBS) and various neural recording modalities can lead to complex and time-consuming laboratory setups. For studies of this type, novel tools are required to drive forward this research. Approach. A miniature wireless system weighing 8.5 g (including battery) was developed for rodent use that combined multichannel DBS and local-field potential (LFP) recordings. Its performance was verified in a working memory task that involved 4-channel fronto-hippocampal LFP recording and bilateral constant-current fimbria-fornix DBS. The system was synchronised with video-tracking for extraction of LFP at discrete task phases, and DBS was activated intermittently at discrete phases of the task. Main results. In addition to having a fast set-up time, the system could reliably transmit continuous LFP at over 8 hours across 3-5 m distances. During the working memory task, LFP pertaining to discrete task phases was extracted and compared with well-known neural correlates of active exploratory behaviour in rodents. DBS could be wirelessly activated/deactivated at any part of the experiment during EEG recording and transmission, allowing for a seamless integration of this modality. Significance. The wireless system combines a small size with a level of robustness and versatility that can greatly simplify rodent behavioural experiments involving EEG recording and DBS. Designed for versatility and simplicity, the small size and low-cost of the system and its receiver allow for enhanced portability, fast experimental setup times, and pave the way for integration with more complex behaviour.

  8. Gene Polymorphism Studies in a Teaching Laboratory

    NASA Astrophysics Data System (ADS)

    Shultz, Jeffry

    2009-02-01

    I present a laboratory procedure for illustrating transcription, post-transcriptional modification, gene conservation, and comparative genetics for use in undergraduate biology education. Students are individually assigned genes in a targeted biochemical pathway, for which they design and test polymerase chain reaction (PCR) primers. In this example, students used genes annotated for the steroid biosynthesis pathway in soybean. The authoritative Kyoto encyclopedia of genes and genomes (KEGG) interactive database and other online resources were used to design primers based first on soybean expressed sequence tags (ESTs), then on ESTs from an alternate organism if soybean sequence was unavailable. Students designed a total of 50 gene-based primer pairs (37 soybean, 13 alternative) and tested these for polymorphism state and similarity between two soybean and two pea lines. Student assessment was based on acquisition of laboratory skills and successful project completion. This simple procedure illustrates conservation of genes and is not limited to soybean or pea. Cost per student estimates are included, along with a detailed protocol and flow diagram of the procedure.

  9. Alpha-Synuclein Expression in the Oligodendrocyte Lineage: an In Vitro and In Vivo Study Using Rodent and Human Models

    PubMed Central

    Djelloul, Mehdi; Holmqvist, Staffan; Boza-Serrano, Antonio; Azevedo, Carla; Yeung, Maggie S.; Goldwurm, Stefano; Frisén, Jonas; Deierborg, Tomas; Roybon, Laurent

    2015-01-01

    Summary In this study, we sought evidence for alpha-synuclein (ASYN) expression in oligodendrocytes, as a possible endogenous source of ASYN to explain its presence in glial inclusions found in multiple system atrophy (MSA) and Parkinson’s disease (PD). We identified ASYN in oligodendrocyte lineage progenitors isolated from the rodent brain, in oligodendrocytes generated from embryonic stem cells, and in induced pluripotent stem cells produced from fibroblasts of a healthy individual and patients diagnosed with MSA or PD, in cultures in vitro. Notably, we observed a significant decrease in ΑSYN during oligodendrocyte maturation. Additionally, we show the presence of transcripts in PDGFRΑ/CD140a+ cells and SOX10+ oligodendrocyte lineage nuclei isolated by FACS from rodent and human healthy and diseased brains, respectively. Our work identifies ASYN in oligodendrocyte lineage cells, and it offers additional in vitro cellular models that should provide significant insights of the functional implication of ASYN during oligodendrocyte development and disease. PMID:26235891

  10. Positron Emission Tomography studies with [11C]PBR28 in the Healthy Rodent Brain: Validating SUV as an Outcome Measure of Neuroinflammation

    PubMed Central

    Häggkvist, Jenny; Varrone, Andrea; Amini, Nahid; Halldin, Christer; Gulyás, Balázs

    2015-01-01

    Molecular imaging of the 18 kD Translocator protein (TSPO) with positron emission tomography (PET) is of great value for studying neuroinflammation in rodents longitudinally. Quantification of the TSPO in rodents is, however, quite challenging. There is no suitable reference region and the use of plasma-derived input is not an option for longitudinal studies. The aim of this study was therefore to evaluate the use of the standardized uptake value (SUV) as an outcome measure for TSPO imaging in rodent brain PET studies, using [11C]PBR28. In the first part of the study, healthy male Wistar rats (n = 4) were used to determine the correlation between the distribution volume (VT, calculated with Logan graphical analysis) and the SUV. In the second part, healthy male Wistar rats (n = 4) and healthy male C57BL/6J mice (n = 4), were used to determine the test-retest variability of the SUV, with a 7-day interval between measurements. Dynamic PET scans of 63 minutes were acquired with a nanoScan PET/MRI and nanoScan PET/CT. An MRI scan was made for anatomical reference with each measurement. The whole brain VT of [11C]PBR28 in rats was 42.9 ± 1.7. A statistically significant correlation (r2 = 0.96; p < 0.01) was found between the VT and the SUV. The test-retest variability in 8 brain region ranged from 8 to 20% in rats and from 7 to 23% in mice. The interclass correlation coefficient (ICC) was acceptable to excellent for rats, but poor to acceptable for mice. In conclusion: The SUV of [11C]PBR28 showed a high correlation with VT as well as good test-retest variability. For future longitudinal small animal PET studies the SUV can thus be used to describe [11C]PBR28 uptake in healthy brain tissue. Based on the present observations, further studies are needed to explore the applicability of this approach in small animal disease models, with special regard to neuroinflammatory models. PMID:25996996

  11. Rodent Models of Genetic Contributions to Motivation to Abuse Alcohol

    PubMed Central

    Crabbe, John C.

    2016-01-01

    The distinction between alcohol use (normative) and abuse (unfortunately common) implies dysregulation of motivation directed toward the drug. Genetic contributions to abuse risk are mediated through personality differences, other predispositions to drink excessively, and differences in sensitivity to the acute and chronic consequences of the drug. How to assess motivation in laboratory animals is not straightforward but risk factors for and consequences of alcohol abuse can be modeled with reasonable fidelity in laboratory rodents. Remarkably few rodent studies focus on the genetic contributions to alcohol’s reinforcing value: almost all examine preferential drinking of unflavored alcohol over water. Such studies will likely never avoid the confounding role of taste preferences and most often yield intake levels insufficient to yield a pharmacologically significant blood alcohol level. Genotypes that avoid alcohol probably do so based on pre-ingestive sensory cues; however, post-ingestive consequences are also important. Thus, the quest for improved measures of reinforcing value continues. We have genetic differences aplenty, but still lack evidence that any genotype will readily self-administer alcohol to the devastating extent that many alcoholics will. Encouraging results that are emerging include improved behavioral methods for elevating alcohol intake and inferring alcohol reinforcement, as well as new genetic animal models. Several ingenious assays to index alcohol’s motivational effects have been used extensively. Alcoholic drinking that attempts to prevent or to alleviate withdrawal symptoms has been modeled. Another characteristic of alcoholic drinking is its persistence despite abundant evidence to the drinker of the damaging effects of the excessive drinking on work, relationships, and/or health. Modeling such persistence in rodents has been uncommon to date. New genetic animal models include lines of mice selectively bred for chronic high drinking

  12. Hunting, Food Preparation, and Consumption of Rodents in Lao PDR

    PubMed Central

    Suwannarong, Kanokwan; Chapman, Robert S.; Lantican, Cecile; Michaelides, Tula; Zimicki, Susan

    2015-01-01

    A cross-sectional study was conducted in 29 villages of Khamkeuth District in Bolikhamxay Province in the Lao PDR during March to May 2013. The study aimed to determine the characteristics associated with rodent consumption and related behaviors among different ethnic groups, ages, and genders. Five-hundred-eighty-four (584) males and females from 18-50 years of age participated in this study. Half of them were Hmong (292, 50%) while 152 respondents were Lao-Tai (26%) or other ethnic groups (140, 24%). Most of the respondents (79.5%) had farming as their main occupation. Prevalences of the studied outcomes were high: 39.9 for hunting or capturing rodents in the previous year, 77.7% for preparing rodents as food, and 86.3% for rodent consumption. Multivariable logistic regression analysis showed that likelihood of these types of rodent contact was more consistently associated with behavioral factors (gathering things from the forest and elsewhere, cultivation-related activities, and taking measures to prevent rodent-borne disease) than with socio-demographic, environmental, or cultural factors. The strongest associations were observed for gathering things; these associations were consistently positive and statistically significant. Although this study did not directly assess rodent-borne zoonosis risk, we believe that study findings raise concern that such risk may be substantial in the study area and other similar areas. Further epidemiological studies on the association between rodent-borne disease infection and rodent hunting, preparation for food, and consumption are recommended. Moreover, further studies are needed on the association between these potential exposure factors (i.e., rodent hunting, preparation for food, and consumption) and rodent-borne infections, especially among ethnic groups like the Hmong in Lao PDR and those in neighboring countries with similar socio-demographic, environmental, behavioral and cultural contexts. PMID:26196134

  13. Hunting, Food Preparation, and Consumption of Rodents in Lao PDR.

    PubMed

    Suwannarong, Kanokwan; Chapman, Robert S; Lantican, Cecile; Michaelides, Tula; Zimicki, Susan

    2015-01-01

    A cross-sectional study was conducted in 29 villages of Khamkeuth District in Bolikhamxay Province in the Lao PDR during March to May 2013. The study aimed to determine the characteristics associated with rodent consumption and related behaviors among different ethnic groups, ages, and genders. Five-hundred-eighty-four (584) males and females from 18-50 years of age participated in this study. Half of them were Hmong (292, 50%) while 152 respondents were Lao-Tai (26%) or other ethnic groups (140, 24%). Most of the respondents (79.5%) had farming as their main occupation. Prevalences of the studied outcomes were high: 39.9 for hunting or capturing rodents in the previous year, 77.7% for preparing rodents as food, and 86.3% for rodent consumption. Multivariable logistic regression analysis showed that likelihood of these types of rodent contact was more consistently associated with behavioral factors (gathering things from the forest and elsewhere, cultivation-related activities, and taking measures to prevent rodent-borne disease) than with socio-demographic, environmental, or cultural factors. The strongest associations were observed for gathering things; these associations were consistently positive and statistically significant. Although this study did not directly assess rodent-borne zoonosis risk, we believe that study findings raise concern that such risk may be substantial in the study area and other similar areas. Further epidemiological studies on the association between rodent-borne disease infection and rodent hunting, preparation for food, and consumption are recommended. Moreover, further studies are needed on the association between these potential exposure factors (i.e., rodent hunting, preparation for food, and consumption) and rodent-borne infections, especially among ethnic groups like the Hmong in Lao PDR and those in neighboring countries with similar socio-demographic, environmental, behavioral and cultural contexts. PMID:26196134

  14. 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

  15. 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

  16. Glycogen synthesis and immunocytochemical study of fructose-1,6-biphosphatase in methionine sulfoximine epileptogenic rodent brain.

    PubMed

    Hevor, T K; Delorme, P; Beauvillain, J C

    1986-06-01

    The effects of the convulsant methionine sulfoximine (MSO) on the glucose pathway have been investigated in mouse and rat brain. The key gluconeogenic enzyme fructose-1,6-biphosphatase (FBPase) (EC 3.1.3.11) was immunostained by rat anti-FBPase antibody. The rat cortex slices were very lightly stained, almost unstained in controls. After MSO injection, there was a marked staining only in astrocytes (perikarya, processes, and end feet). The activity of this enzyme also increased. MSO induced an increase of 63% in the stability at heating (47 degrees C) and of 36% in the stability at proteolysis (trypsin, 10 micrograms/ml) of FBPase. The convulsant had no effect on the concentrations of the metabolites related to the FBPase-phosphofructokinase step, i.e., fructose-1,6-biphosphate, glyceraldehyde-3-phosphate, and dihydroxyacetone phosphate, before, during, or after the convulsions. These results show that the cellular site of glucose pathway impairment induced by MSO in rodent brain is presumably the astroglial cells and that one mechanism of glycogenesis could be the reinforcement of the molecules of FBPase, which enhances gluconeogenesis. A hypothetical diagram of glucose metabolism under the effect of MSO has been proposed. PMID:3011827

  17. 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

  18. Enucleation for Treating Rodent Ocular Disease

    PubMed Central

    Wilding, Laura A; Uchihashi, Mayu; Bergin, Ingrid L; Nowland, Megan H

    2015-01-01

    Our standard of care for rodent corneal lesions previously included treatment of the primary lesion, application of topical NSAIDs, and systemic NSAIDs in severe cases. When intensive medical management was unsuccessful, animals were euthanized, leading to premature loss of valuable genetically modified animals and those on long-term studies. We investigated enucleation surgery as a treatment for 15 cases of rodent corneal disease that did not respond to medical management. Enucleation was performed under isoflurane anesthesia and involved removal of the globe, extensive hemostasis, and packing the orbital space with absorbable gelatin sponge. The lid margins were closed by tarsorrhaphy and tissue glue. Analgesia was provided by using buprenorphine preoperatively and carprofen chew tabs postoperatively. To date, we have a 100% success rate with this procedure (n = 20; 15 clinically affected rodents [2 rats, 13 mice], 5 healthy controls), which included a 60-d follow-up period. The single complication involved dehiscence of the tarsorrhaphy site and was repaired by trimming the lid margins to provide fresh tissue for closure. Histologic examination at both 1 and 3 mo after surgery revealed no evidence of infection of the enucleation site. Enucleation in rodents is a straightforward procedure that represents a refinement to our current standard of care for rodents, does not cause significant inflammation of remaining periocular structures, and has reduced the number of animals euthanized prior to study endpoint because of severe ocular lesions. PMID:26045460

  19. A Science Librarian in the Laboratory: A Case Study

    ERIC Educational Resources Information Center

    Tomaszewski, Robert

    2011-01-01

    A science librarian in the laboratory can become a "point of access" for database instruction and provide a learning opportunity for students to develop their information literacy skills. A case study describes how a librarian in an organic chemistry laboratory helps the class run smoothly and identifies the science librarian as an ally and a…

  20. Bisphenol-A exposures and behavioural aberrations: median and linear spline and meta-regression analyses of 12 toxicity studies in rodents.

    PubMed

    Peluso, Marco E M; Munnia, Armelle; Ceppi, Marcello

    2014-11-01

    Exposures to bisphenol-A, a weak estrogenic chemical, largely used for the production of plastic containers, can affect the rodent behaviour. Thus, we examined the relationships between bisphenol-A and the anxiety-like behaviour, spatial skills, and aggressiveness, in 12 toxicity studies of rodent offspring from females orally exposed to bisphenol-A, while pregnant and/or lactating, by median and linear splines analyses. Subsequently, the meta-regression analysis was applied to quantify the behavioural changes. U-shaped, inverted U-shaped and J-shaped dose-response curves were found to describe the relationships between bisphenol-A with the behavioural outcomes. The occurrence of anxiogenic-like effects and spatial skill changes displayed U-shaped and inverted U-shaped curves, respectively, providing examples of effects that are observed at low-doses. Conversely, a J-dose-response relationship was observed for aggressiveness. When the proportion of rodents expressing certain traits or the time that they employed to manifest an attitude was analysed, the meta-regression indicated that a borderline significant increment of anxiogenic-like effects was present at low-doses regardless of sexes (β)=-0.8%, 95% C.I. -1.7/0.1, P=0.076, at ≤120 μg bisphenol-A. Whereas, only bisphenol-A-males exhibited a significant inhibition of spatial skills (β)=0.7%, 95% C.I. 0.2/1.2, P=0.004, at ≤100 μg/day. A significant increment of aggressiveness was observed in both the sexes (β)=67.9,C.I. 3.4, 172.5, P=0.038, at >4.0 μg. Then, bisphenol-A treatments significantly abrogated spatial learning and ability in males (P<0.001 vs. females). Overall, our study showed that developmental exposures to low-doses of bisphenol-A, e.g. ≤120 μg/day, were associated to behavioural aberrations in offspring. PMID:25242006

  1. A review of toxicity studies of single-walled carbon nanotubes in laboratory animals.

    PubMed

    Ema, Makoto; Gamo, Masashi; Honda, Kazumasa

    2016-02-01

    We summarized the findings of in vivo toxicity studies of single-walled carbon nanotubes (SWCNTs) in laboratory animals. The large majority addressed the pulmonary toxicity of SWCNTs in rodents. Inhalation, pharyngeal aspiration, and intratracheal instillation studies revealed that SWCNTs caused acute and chronic inflammation, granuloma formation, collagen deposition, fibrosis, and genotoxic effects in the lungs. Pulmonary toxicity of well-dispersed SWCNTs was more potent than less dispersed ones. Airway exposure to SWCNTs also induced cardiovascular diseases in mice. Oxidative stress was caused by the administration of SWCNTs. Injected SWCNTs were distributed throughout most of the organs including the brain, mainly retained in the lungs, liver, and spleen, and eliminated through the kidney and bile duct. Orally administered SWCNTs are suggested to be absorbed from the gastrointestinal tract to the blood circulation in mice and rats. Although no definitive study on the carcinogenicity of SWCNTs is available at present, evidence of carcinogenicity has not been reported in toxicity studies cited in this review. Overall, the available data provides initial information on SWCNT toxicity. To further clarify their toxicity and risk assessment, studies should be conducted using well-characterized SWCNTs, standard protocols, and the relevant route and doses of human exposure. PMID:26619783

  2. 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

  3. LABORATORY STUDIES OF PRIORITY POLLUTANT TREATABILITY

    EPA Science Inventory

    This study investigated several methods currently available to reduce the level of pollutants in an industrial plant wastewater stream. Its purpose was to screen these treatment processes. As a result of this screening, further in-depth evaluations should be considered. The study...

  4. Food habits of rodents inhabiting arid and semi-arid ecosystems of central New Mexico

    USGS Publications Warehouse

    Hope, Andrew G.; Parmenter, Robert R.

    2007-01-01

    In this study, we describe seasonal dietary composition for 15 species of rodents collected in all major habitats on the Sevilleta National Wildlife Refuge (Socorro County) in central New Mexico. A comprehensive literature review of food habits for these species from throughout their distribution also is provided. We collected rodents in the field during winter, spring and late summer in 1998 from six communities: riparian cottonwood forest; piñon-juniper woodland; juniper-oak savanna; mesquite savanna; short-grass steppe; and Chihuahuan Desert scrubland. Rodents included Spermophilus spilosoma (Spotted Ground Squirrel), Perognathus flavescens (Plains Pocket Mouse), Perognathus flavus (Silky Pocket Mouse), Dipodomys merriami (Merriam’s Kangaroo Rat), Dipodomys ordii (Ord’s Kangaroo Rat), Dipodomys spectabilis (Banner-tailed Kangaroo Rat), Reithrodontomys megalotis (Western Harvest Mouse), Peromyscus boylii (Brush Mouse), Peromyscus eremicus (Cactus Mouse), Peromyscus leucopus (White-footed Mouse), Peromyscus truei (Piñon Mouse), Onychomys arenicola (Mearn’s Grasshopper Mouse), Onychomys leucogaster (Northern Grasshopper Mouse), Neotoma albigula/leucodon (White-throated Woodrats), and Neotoma micropus (Southern Plains Woodrat). We collected stomach contents of all species, and cheek-pouch contents of heteromyids, and quantified them in the laboratory. We determined seasonal diets in each habitat by calculating mean percentage volumes of seeds, arthropods and green vegetation (plant leaves and stems) for each species of rodent. Seeds consumed by each rodent were identified to genus, and often species, and quantified by frequency counts. Comparisons of diets between and among species of rodents, seasons, and ecosystems were also examined. We provide an appendix of all plant taxa documented.

  5. Rodents as Sentinels for the Prevalence of Tick-Borne Encephalitis Virus

    PubMed Central

    Růžek, Daniel; Donoso-Mantke, Oliver; Schlegel, Mathias; Ali, Hanan Sheikh; Wenk, Mathias; Schmidt-Chanasit, Jonas; Ohlmeyer, Lutz; Rühe, Ferdinand; Vor, Torsten; Kiffner, Christian; Kallies, René; Ulrich, Rainer G.; Niedrig, Matthias

    2011-01-01

    Abstract Introduction Tick-borne encephalitis virus (TBEV) causes one of the most important flavivirus infections of the central nervous system, affecting humans in Europe and Asia. It is mainly transmitted by the bite of an infected tick and circulates among them and their vertebrate hosts. Until now, TBE risk analysis in Germany has been based on the incidence of human cases. Because of an increasing vaccination rate, this approach might be misleading, especially in regions of low virus circulation. Method To test the suitability of rodents as a surrogate marker for virus spread, laboratory-bred Microtus arvalis voles were experimentally infected with TBEV and analyzed over a period of 100 days by real-time (RT)–quantitative polymerase chain reaction. Further, the prevalence of TBEV in rodents trapped in Brandenburg, a rural federal state in northeastern Germany with autochthonous TBE cases, was determined and compared with that in rodents from German TBE risk areas as well as TBE nonrisk areas. Results In experimentally infected M. arvalis voles, TBEV was detectable in different organs for at least 3 months and in blood for 1 month. Ten percent of all rodents investigated were positive for TBEV. However, in TBE risk areas, the infection rate was higher compared with that of areas with only single human cases or of nonrisk areas. TBEV was detected in six rodent species: Apodemus agrarius, Apodemus flavicollis, Apodemus sylvaticus, Microtus agrestis, Microtus arvalis, and Myodes glareolus. M. glareolus showed a high infection rate in all areas investigated. Discussion and Conclusion The infection experiments proved that TBEV can be reliably detected in infected M. arvalis voles. These voles developed a persistent TBE infection without clinical symptoms. Further, the study showed that rodents, especially M. glareolus, are promising sentinels particularly in areas of low TBEV circulation. PMID:21548766

  6. There is more to the picture than meets the rat: a study on rodent geometric shape and proportion preferences.

    PubMed

    Winne, Jéssica; Teixeira, Leslie; de Andrade Pessoa, Jéssica; Gavioli, Elaine Cristina; Soares-Rachetti, Vanessa; André, Eunice; Lobão-Soares, Bruno

    2015-05-01

    In rodents, the novel object preference test has been used as a behavioral parameter for evaluation of neotic exploratory behavior, and also for memory consolidation tasks. Geometric patterns of this preference are poorly understood, and may vary among species. We evaluated in Wistar rats (Rattus norvergicus) a possible exploration preference considering aluminum tripartite rounded and cylindrical objects of different proportions: 1.2; 1.618; 1.8. At the first day, animals were exposed to 1.2; 1.6 and 1.8 rounded objects. At 24h after, these animals were exposed to the same objects, together with three new steel cylindrical objects (same proportions). ANOVA and T tests were used to quantify object exploration for each animal (p<0.05). Data analysis pointed to a longer exploration time of the object 1.2 at the three different protocols indicating a preference pattern on the first day exposition. On the second day the exploration was similar in both familiar and unfamiliar objects, revealing no novel object preference for cylinders. However, we found an object preference related to the 1.2 proportion (balls plus cylinders), in two of three position protocols. In addition, on a single exposition with both cylinders and rounded objects, rats revealed a rounded object preference. The 1.2 preference disclosed by rats also reflected the proportion of their body. From nine main measures of body ratios, seven were close to 1.2 ratio. The correspondence between body ratios and object preference may be explained by habituation learning and by sexual selection, and highlight innate factors regarding aesthetic preferences among species. PMID:25698599

  7. Liver Dysfunction and Phosphatidylinositol-3-Kinase Signalling in Early Sepsis: Experimental Studies in Rodent Models of Peritonitis

    PubMed Central

    Westermann, Martin; Lambeck, Sandro; Lupp, Amelie; Rudiger, Alain; Dyson, Alex; Carré, Jane E.; Kortgen, Andreas; Krafft, Christoph; Popp, Jürgen; Sponholz, Christoph; Fuhrmann, Valentin; Hilger, Ingrid; Claus, Ralf A.; Riedemann, Niels C.; Wetzker, Reinhard; Singer, Mervyn; Trauner, Michael; Bauer, Michael

    2012-01-01

    Background Hepatic dysfunction and jaundice are traditionally viewed as late features of sepsis and portend poor outcomes. We hypothesized that changes in liver function occur early in the onset of sepsis, yet pass undetected by standard laboratory tests. Methods and Findings In a long-term rat model of faecal peritonitis, biotransformation and hepatobiliary transport were impaired, depending on subsequent disease severity, as early as 6 h after peritoneal contamination. Phosphatidylinositol-3-kinase (PI3K) signalling was simultaneously induced at this time point. At 15 h there was hepatocellular accumulation of bilirubin, bile acids, and xenobiotics, with disturbed bile acid conjugation and drug metabolism. Cholestasis was preceded by disruption of the bile acid and organic anion transport machinery at the canalicular pole. Inhibitors of PI3K partially prevented cytokine-induced loss of villi in cultured HepG2 cells. Notably, mice lacking the PI3Kγ gene were protected against cholestasis and impaired bile acid conjugation. This was partially confirmed by an increase in plasma bile acids (e.g., chenodeoxycholic acid [CDCA] and taurodeoxycholic acid [TDCA]) observed in 48 patients on the day severe sepsis was diagnosed; unlike bilirubin (area under the receiver-operating curve: 0.59), these bile acids predicted 28-d mortality with high sensitivity and specificity (area under the receiver-operating curve: CDCA: 0.77; TDCA: 0.72; CDCA+TDCA: 0.87). Conclusions Liver dysfunction is an early and commonplace event in the rat model of sepsis studied here; PI3K signalling seems to play a crucial role. All aspects of hepatic biotransformation are affected, with severity relating to subsequent prognosis. Detected changes significantly precede conventional markers and are reflected by early alterations in plasma bile acids. These observations carry important implications for the diagnosis of liver dysfunction and pharmacotherapy in the critically ill. Further clinical work is

  8. Laboratory studies with some older anticoccidials.

    PubMed

    Ryley, J F; Wilson, R G

    1976-12-01

    Features of the anticoccidial activity of nicarbazin, amprolium, zoalene, sulphadimidine, diaveridine, Darvisul, spiramycin, chloramphenicol and oxytetracycline have been re-investigated both in vivo and in cell culture using Eimeria tenella. Of the drugs studied, only spiramycin was appreciably coccidiocidal, although nicarbazin and amprolium showed possibly slower coccidiocidal activity. In order to show activity against a particular stage in the life-cycle, higher concentrations of drug than those usually recommended for field usage had in most cases to be used. Under these conditions, parasites were usually inhibited as multinucleate 1st generation schizonts. With delayed medication, effects against 2nd generation parasites were in most cases found, and in many cases, although the parasites never matured to give viable merozoites, the large degenerating forms produced were able to cause extensive tissue destruction and haemorrhage. Methodology in this type of study is discussed in relation to more active and more recent anticoccidials, and some further experiments with robenidine reported. PMID:1012748

  9. Laboratory studies of ocean mixing by microorganisms

    NASA Astrophysics Data System (ADS)

    Martinez-Ortiz, Monica; Dabiri, John O.

    2011-11-01

    Ocean mixing plays a major role in nutrient and energy transport and is an important input to climate models. Recent studies suggest that the contribution of fluid transport by swimming microorganisms to ocean mixing may be of the same order of magnitude as winds and tides. An experimental setup has been designed in order to study the mixing efficiency of vertical migration of plankton. To this end, a stratified water column is created to model the ocean's density gradient. The vertical migration of Artemia Salina (brine shrimp) within the water column is controlled via luminescent signals on the top and bottom of the column. By fluorescently labelling portions of the water column, the stirring of the density gradient by the animals is visualized and quantified. Preliminary results show that the vertical movement of these organisms produces enhanced mixing relative to control cases in which only buoyancy forces and diffusion are present.

  10. 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.

  11. 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

  12. Laboratory Astrophysics: Study of Radiative Shocks

    NASA Astrophysics Data System (ADS)

    Leygnac, S.; Lanz, T.; Stehlé, C.; Michaut, C.

    2002-12-01

    Radiative shocks are high Mach number shocks with a strong coupling between radiation and hydrodynamics which leads to a structure governed by a radiative precursor. They might be encountered in various astrophysical systems: stellar accretion shocks, pulsating stars, interaction of supernovae with the intestellar medium etc. A numerical one dimensional (1D) stationary study of the coupling between hydrodynamics and radiative transfer is being performed. An estimate of the error made by the 1D approach in the radiative transfer treatment is done by an approximate short characteristics approach. It shows, for exemple, how much of the radiation escapes from the medium in the configuration of the experiment. The experimental study of these shocks has been performed with the high energy density laser of the LULI, at the École Polytechnique (France). We have observed several shocks identified as radiative shocks. The shock waves propagate at about 50 km/s in a tiny 10 mm3 shock tube filled with gaz. From the measurements, it is possible to infer several features of the shock such as the speed and the electronic density.

  13. Heparin-induced thrombocytopenia: laboratory studies.

    PubMed

    Kelton, J G; Sheridan, D; Santos, A; Smith, J; Steeves, K; Smith, C; Brown, C; Murphy, W G

    1988-09-01

    This report describes studies into the pathophysiology of heparin-induced thrombocytopenia. The IgG fraction from each of nine patients with heparin-induced thrombocytopenia caused heparin-dependent platelet release of radiolabeled serotonin. Both the Fc and the Fab portions of the IgG molecule were required for the platelet reactivity. The platelet release reaction could be inhibited by the Fc portion of normal human or goat IgG, and patient F(ab')2, but not F(ab')2 from healthy controls. These results suggested that the Fab portion of IgG binds to heparin forming an immune complex and the immune complexes initiate the platelet release reaction by binding to the platelet Fc receptors. To directly challenge this hypothesis, we preincubated the serotonin-labeled platelets with the monoclonal antibody against the platelet Fc receptor (IV.3). This monoclonal antibody completely inhibited the release reaction caused by heparin and patient sera, as well as heat aggregated IgG, but did not block collagen or thrombin-induced platelet release. Heparin-dependent platelet release also could be inhibited in vitro by the addition of monocytes and neutrophils, but not by red cells, presumably because the Fc receptors on the phagocytic cells have a higher binding affinity for IgG complexes than do platelets. Platelets from patients with congenital deficiencies of specific glycoproteins Ib and IX (Bernard-Soulier syndrome) and IIb and IIIa (Glanzmann's thrombasthenia) displayed normal heparin-dependent release indicating that the release reaction did not require the participation of these glycoproteins. These studies indicate that heparin-induced thrombocytopenia is an IgG-heparin immune complex disorder involving both the Fab and Fc portion of the IgG molecule. PMID:3416077

  14. 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...

  15. Dispersal by rodent caching increases seed survival in multiple ways in canopy-fire ecosystems.

    PubMed

    Peterson, N B; Parker, V T

    2016-07-01

    Seed-caching rodents have long been seen as important actors in dispersal ecology. Here, we focus on the interactions with plants in a fire-disturbance community, specifically Arctostaphylos species (Ericaceae) in California chaparral. Although mutualistic relationships between caching rodents and plants are well studied, little is known how this type of relationship functions in a disturbance-driven system, and more specifically to systems shaped by fire disturbance. By burying seeds in the soil, rodents inadvertently improve the probability of seed surviving high temperatures produced by fire. We test two aspects of vertical dispersal, depth of seed and multiple seeds in caches as two important dimensions of rodent-caching behavior. We used a laboratory experimental approach to test seed survival under different heating conditions and seed bank structures. Creating a synthetic soil seed bank and synthetic fire/heating in the laboratory allowed us to have control over surface heating, depth of seed in the soil, and seed cache size. We compared the viability of Arctostaphylos viscida seeds from different treatment groups determined by these factors and found that, as expected, seeds slightly deeper in the soil had substantial increased chances of survival during a heating event. A key result was that some seeds within a cache in shallow soil could survive fire even at a depth with a killing heat pulse compared to isolated seeds; temperature measurements indicated lower temperatures immediately below caches compared to the same depth in adjacent soil. These results suggest seed caching by rodents increases seed survival during fire events in two ways, that caches disrupt heat flow or that caches are buried below the heat pulse kill zone. The context of natural disturbance drives the significance of this mutualism and further expands theory regarding mutualisms into the domain of disturbance-driven systems. PMID:27386076

  16. An FDA overview of rodent carcinogenicity studies of angiotensin II AT-1 receptor blockers: pulmonary adenomas and carcinomas.

    PubMed

    Link, William T; De Felice, Albert

    2014-11-01

    Sipahi et al. (2010) performed a meta-analysis of 5 clinical trials (n=68,402) of 3 Angiotensin II (AngII) receptor subtype AT-1 blockers (ARBs) in cardiovascular disease. It revealed excess new lung cancer diagnoses in the cohorts treated with an ARB and background therapy (0.9% vs. 0.7% in non-ARB control; RR: 1.25; CI: 1.05-1.49; p=0.01). The FDA responded with a larger meta-analysis of 31 clinical trials (n=155,816) of ARBs that found no evidence of any excess of site-specific cancer (lung, breast, prostate), solid/skin cancer or cancer death (FDA safety communication, 3 June 2011). The FDA then re-visited the 19 rodent carcinogenicity assays of 9 ARBs, starting with those for Losartan in 1994, for any evidence of dosage-related lung tumorigenicity in this class. Assays were performed in 5 strains of rats and 5 strains of wild-type and transgenic mice per protocols and dosages sanctioned by FDA's executive carcinogenicity assessment committee (eCAC). Duration was lifetime except for 26-week assays of azilsartan and olmesartan in transgenic Tg rasH2 mice, and an assay of olmesartan in p53(+/-) transgenic mice. The dosages provided exposures approximating, and in most cases up to 20-300times greater than, that in patients. Depending on strain, up to 35% of untreated mice spontaneously developed lung tumors. Regression analysis of placebo-corrected mouse lung tumor incidence collapsed across strains, gender, and ARBs vs. multiples of human exposure revealed no excess lung neoplasia. The R(2) of <0.001 reflected the virtually identical number of treated cohorts with more tumors than its control cohort vs. those with less. Regardless of strain, both control and medicated rats were essentially devoid of lung tumors in the lifetime trials. Accordingly, there was neither promotion of background lung tumors in the mouse, nor initiation of de novo lung tumors in the rat. The negative lung findings in the mouse Tg rasH2 strain are also noteworthy given that, historically

  17. Recent isolations of Lassa virus from Nigerian rodents

    PubMed Central

    Wulff, Herta; Fabiyi, A.; Monath, T. P.

    1975-01-01

    Rodents were trapped in the Benue-Plateau and North-Eastern States of Nigeria where Lassa fever had been reported in previous years. Eight Lassa virus strains were isolated from tissues and blood of rodents identified in the field as being of 3 different species: Mastomys natalensis, Rattus rattus, and Mus minutoides. All the infected rodents were collected in village habitats. These isolations indicate the presence of Lassa virus in wild rodents in Nigeria during periods when no human infections were evident. Prior studies in Sierra Leone have indicated that a single rodent species, M. natalensis, may be the important reservoir host of Lassa virus. Since the present study indicates that other rodent species may be involved as well, the ecology of Lassa virus may be more complicated than was heretofore supposed. In view of the importance of determining the geographic and species range of rodent hosts of Lassa virus, and because of the problems inherent in rodent identification under austere field conditions, it is urgent that further studies be conducted in the same areas of Nigeria to confirm these findings. PMID:1085216

  18. 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

  19. Laboratory Information Management System (LIMS): A case study

    NASA Technical Reports Server (NTRS)

    Crandall, Karen S.; Auping, Judith V.; Megargle, Robert G.

    1987-01-01

    In the late 70's, a refurbishment of the analytical laboratories serving the Materials Division at NASA Lewis Research Center was undertaken. As part of the modernization efforts, a Laboratory Information Management System (LIMS) was to be included. Preliminary studies indicated a custom-designed system as the best choice in order to satisfy all of the requirements. A scaled down version of the original design has been in operation since 1984. The LIMS, a combination of computer hardware, provides the chemical characterization laboratory with an information data base, a report generator, a user interface, and networking capabilities. This paper is an account of the processes involved in designing and implementing that LIMS.

  20. Hindlimb unloading rodent model: technical aspects

    NASA Technical Reports Server (NTRS)

    Morey-Holton, Emily R.; Globus, Ruth K.

    2002-01-01

    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.

  1. Bartonella Infection in Rodents and Their Flea Ectoparasites: An Overview

    PubMed Central

    Gutiérrez, Ricardo; Krasnov, Boris; Morick, Danny; Gottlieb, Yuval; Khokhlova, Irina S.

    2015-01-01

    Abstract Epidemiological studies worldwide have reported a high prevalence and a great diversity of Bartonella species, both in rodents and their flea parasites. The interaction among Bartonella, wild rodents, and fleas reflects a high degree of adaptation among these organisms. Vertical and horizontal efficient Bartonella transmission pathways within flea communities and from fleas to rodents have been documented in competence studies, suggesting that fleas are key players in the transmission of Bartonella to rodents. Exploration of the ecological traits of rodents and their fleas may shed light on the mechanisms used by bartonellae to become established in these organisms. The present review explores the interrelations within the Bartonella–rodent–flea system. The role of the latter two components is emphasized. PMID:25629778

  2. Analytical evaluation of laboratories wishing to perform environmental characterization studies

    SciTech Connect

    Lauenstein, G.G.; Cantillo, A.Y.

    1997-07-01

    Laboratories competing to analyze bivalve mollusks under contract to the National Oceanic and Atmospheric Administration`s Mussel Watch Project were required to undergo analytical tests of their ability to quantify environmental contaminants as part of the contract evaluation process. During the 1989 selection process laboratories that appeared to qualify on the basis of their written proposals were provided a gravimetrically prepared solution with unknown quantities of an undefined number of organic contaminants that are regularly quantified for the Mussel Watch Project. In 1994, competing laboratories were once again tested but this time using matrix materials for the quantification of both trace elements and organic contaminants. Three laboratory groups participated in the exercises. For the 1989 gravimetrically prepared solutions, all participating laboratories were able to identify the contaminants present and in all but two cases were able to report values to within {+-}25% of the known values. In 1994, all laboratories were within the acceptance criteria for the quantification of trace elements in the homogenate sample. Analytical laboratory testing is an important first step to ensure that environmental characterization studies are successful.

  3. Extremely low frequency fields and cancer: laboratory studies

    SciTech Connect

    Anderson, Larry E.)

    1998-10-01

    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 reported epidemiological studies that suggest an association between EMF exposure and risk of cancer are supported in studies using animal models. Several approaches are outlined in the experimental approach to this question. With specific reference to the radiofrequencies (RF) associated with wireless technology, even less research has been carried out than with ELF. Particularly, in regard to research on carcinogenesis and RF exposure in animals, little is known This section addresses laboratory studies in animals exposed to extremely low-power-frequency EMF, the relevance of which, to RF, is unknown. However, the approaches used with ELF may be useful in guiding laboratory research on the issue of RF exposure and cancer. From the perspective of laboratory animal studies, this paper will discuss studies investigating the potential relationship between ELF magnetic and/or electric field exposure and the risk of cancer.

  4. Environmental enrichment of laboratory animals used in regulatory toxicology studies.

    PubMed

    Dean, S W

    1999-10-01

    There is a wealth of information in the published literature which describes a multitude of approaches to enriching the environment of laboratory animals. This paper attempts to review the various methods of enrichment through social contact, enhancement of the environment and diet, and improvements in husbandry. It attempts to place the various enrichment initiatives within the context of a laboratory which conducts regulatory toxicology, describes some of the experiences in the author's own laboratory and attempts to highlight those ideas which might prove practical to implement in the future. The aim is to demonstrate that a creative approach to environmental enrichment is indeed compatible with regulatory toxicology. It is hoped that this will encourage those responsible for the care and welfare of animals in such a laboratory to challenge historical practices and include environmental enrichment as a fundamental necessity of study design. PMID:10778780

  5. Problems associated with the control of rodents in tropical Africa

    PubMed Central

    Gratz, N. G.; Arata, A. A.

    1975-01-01

    As elsewhere in the world, rodents are responsible for very considerable economic losses in tropical Africa because of their depredations on both growing crops and stored food products. Unfortunately, few accurate data are available on the extent of these losses but there is evidence that they are considerable. The public health importance of rodents, both as reservoirs and vectors of disease in tropical Africa, is also great; plague, leptospirosis, murine typhus, and Lassa fever are among the diseases associated with rodent hosts. Scientifically based rodent control programmes have been carried out in very few areas of Africa and there is urgent need for studies and demonstrations on rodent control in both urban and rural areas. The problems likely to be encountered are reviewed and methods of control proposed. PMID:1085224

  6. Three-dimensional rodent motion analysis and neurodegenerative disorders

    PubMed Central

    Karakostas, Tasos; Hsiang, Simon; Boger, Heather; Middaugh, Lawrence; Granholm, Ann-Charlotte

    2016-01-01

    Background Three-dimensional (3D) motion analysis is established in investigating, human pathological motion. In the field of gait, its use results in the objective identification of primary, and secondary causes of deviations, many current interventions are the result of pre- and post-testing, and it was shown recently that it can result in decreased number of surgeries and overall cost of care. Consequently, recent attempts have implemented 3D motion analysis using rat models to study, parkinsonism. However, to-date, a 3D user friendly analytical approach using rodent models to, identify etiologies of age-related motor impairment and accompanying pathologies has not been, implemented. New method We have developed and presented all aspects of a 3D, three body-segment rodent model, to analyze motions of the lower, upper and head segments between rodents of parkinsonism-type and, normal aging during free walking. Our model does not require transformation matrices to describe the, position of each body-segment. Because body-segment positions are not considered to consist of three, rotations about the laboratory axes, the rotations are not sequence dependent. Results Each body-segment demonstrated distinct 3D movement patterns. The parkinsonism-type, genotype walked slower with less range of motion, similarly to patients with parkinsonism. Comparison with existing methods This is the first model considering the rodent’s body as three, distinct segments. To the best of our knowledge, it is the first model to ever consider and report the 3D, head motion patterns. Conclusions This novel approach will allow unbiased analysis of spontaneous locomotion in mouse, models of parkinsonism or normal aging. PMID:24129039

  7. Rodent Models of Traumatic Brain Injury: Methods and Challenges.

    PubMed

    Marklund, Niklas

    2016-01-01

    Traumatic brain injury (TBI) has been named the most complex disease in the most complex organ of the body. It is the most common cause of death and disability in the Western world in people <40 years old and survivors commonly suffer from persisting cognitive deficits, impaired motor function, depression and personality changes. TBI may vary in severity from uniformly fatal to mild injuries with rapidly resolving symptoms and without doubt, it is a markedly heterogeneous disease. Its different subtypes differs in their pathophysiology, treatment options and long-term consequences and to date, there are no pharmacological treatments with proven clinical benefit available to TBI patients. To enable development of novel treatment options for TBI, clinically relevant animal models are needed. Due to their availability and low costs, numerous rodent models have been developed which have substantially contributed to our current understanding of the pathophysiology of TBI. The most common animal models used in laboratories worldwide are likely the controlled cortical impact (CCI) model, the central and lateral fluid percussion injury (FPI) models, and weight drop/impact acceleration (I/A) models. Each of these models has inherent advantages and disadvantages; these need to be thoroughly considered when selecting the rodent TBI model according to the hypothesis and design of the study. Since TBI is not one disease, refined animal models must take into account the clinical features and complexity of human TBI. To enhance the possibility of establishing preclinical efficacy of a novel treatment, the preclinical use of several different experimental models is encouraged as well as varying the species, gender, and age of the animal. In this chapter, the methods, limitations, and challenges of the CCI and FPI models of TBI used in rodents are described. PMID:27604711

  8. Radionuclide migration laboratory studies for validation of batch sorption data

    SciTech Connect

    Triay, I.R.; Mitchell, A.J.; Ott, M.A.

    1991-12-31

    Advective and diffusive migration experiments (within the Dynamic Transport Column Experiments and Diffusion Studies of the Yucca Mountain Site Characterization Project) involve utilizing crushed material, intact, and fractured tuff in order to test and improve (if necessary) transport models by experimentally observing the migration of sorbing and non-sorbing radionuclides on a laboratory scale. Performing a validation of the sorption data obtained with batch techniques (within the Batch Sorption Study) is an integral part of the mission of the Dynamic Transport Column Experiments and Diffusion Studies. In this paper the work scope of the radionuclide migration laboratory experiments (as they apply to validation of batch sorption data) is reviewed.

  9. 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…

  10. Scatter-hoarding rodents prefer slightly astringent food.

    PubMed

    Wang, Bo; Chen, Jin

    2011-01-01

    The mutualistic interaction between scatter-hoarding rodents and their seed plants is highly complex yet poorly understood. Plants may benefit from the seed dispersal behavior of rodents, as long as seed consumption is minimized. In parallel, rodents may maximize foraging efficiency and cache high-quality resources for future consumption. Defensive compounds, such as tannins, are thought to be a major mechanism for plant control over rodent behavior. However, previous studies, using naturally occurring seeds, have not provided conclusive evidence supporting this hypothesis. Here, we test the importance of tannin concentrations on the scatter-hoarding behavior of rodents by using an artificial seed system. We combined feeding trials and field observations to examine the overall impact of seed tannin concentrations on rodent behavior and health. We found that rodents favored seeds with an intermediate amount of tannin (~5%) in the field. Meanwhile, in rodents that were fed a diet with different tannin content, only diets with high tannin content (25%, 15%, and 10%) caused a significant negative influence on rodent survival and health. Significant differences were not found among treatments with tannin levels of 0-5%. In contrast to many existing studies, our results clearly demonstrate that scatter-hoarding rodents prefer slightly 'astringent' food. In the co-evolutionary arms race between plants and animals, our results suggest that while tannins may play a significant role in reducing general predation levels by the faunal community, they have no precise control over the behavior of their mutualistic partner. Instead, the two partners appear to have reached an evolutionary point where both parties receive adequate benefits, with the year-to-year outcome being dependent on a wide range of factors beyond the control of either partner. PMID:22046284

  11. Tracer Studies In A Laboratory Beach Subjected To Waves

    EPA Science Inventory

    This work investigated the washout of dissolved nutrients from beaches due to waves by conducting tracer studies in a laboratory beach facility. The effects of waves were studied in the case where the beach was subjected to the tide, and that in which no tidal action was present...

  12. Native American Studies in the Laboratory School Curriculum.

    ERIC Educational Resources Information Center

    Kersey, Harry A., Jr.; And Others

    A study was undertaken to determine students' attitudes toward Native Americans before and after they took the Native American studies course developed through an ESEA Title IV-C Curriculum Development Grant by the Alexander D. Henderson University School (ADHUS), a laboratory school on the campus of Florida Atlantic University. To comply with…

  13. Comparative dosimetry for children and rodents exposed to extremely low-frequency magnetic fields.

    PubMed

    Gong, Yijian; Capstick, Myles; Dasenbrock, Clemens; Fedrowitz, Maren; Cobaleda, Cesar; Sánchez-García, Isidro; Kuster, Niels

    2016-07-01

    We describe a method to correlate E-fields induced by exposure to extremely low frequency magnetic fields in laboratory mice and rats during in vivo experiments to those induced in children. Four different approaches of mapping relative dose rates between humans and rodents are herein proposed and analyzed. Based on these mapping methods and volume averaging guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNRP) in 2010, maximum and median induced field values for whole body and for tissues of children and rodents were evaluated and compared. Median induced electric fields in children younger than 10 years old are in the range 5.9-8.5 V/m per T (±0.4 dB). Maximum induced electric fields, generally in the skin, are between 48 V/m and 228 V/m per T (±4 dB). To achieve induced electric fields of comparable magnitude in rodents, external magnetic field must be increased by a factor of 4.0 (±2.6 dB) for rats and 7.4 (±1.8 dB) for mice. Meanwhile, to achieve comparable magnetic field dose in rodents, ratio is close to one. These induced field dose rates for children and rodents can be used to quantifiably compare experimental data from in vivo studies with data on exposure of children from epidemiological studies, such as for leukemia. Bioelectromagnetics. 37:310-322, 2016. © 2016 Wiley Periodicals, Inc. PMID:27176719

  14. Experimental sleep deprivation as a tool to test memory deficits in rodents

    PubMed Central

    Colavito, Valeria; Fabene, Paolo F.; Grassi-Zucconi, Gigliola; Pifferi, Fabien; Lamberty, Yves; Bentivoglio, Marina; Bertini, Giuseppe

    2013-01-01

    Paradigms of sleep deprivation (SD) and memory testing in rodents (laboratory rats and mice) are here reviewed. The vast majority of these studies have been aimed at understanding the contribution of sleep to cognition, and in particular to memory. Relatively little attention, instead, has been devoted to SD as a challenge to induce a transient memory impairment, and therefore as a tool to test cognitive enhancers in drug discovery. Studies that have accurately described methodological aspects of the SD protocol are first reviewed, followed by procedures to investigate SD-induced impairment of learning and memory consolidation in order to propose SD protocols that could be employed as cognitive challenge. Thus, a platform of knowledge is provided for laboratory protocols that could be used to assess the efficacy of drugs designed to improve memory performance in rodents, including rodent models of neurodegenerative diseases that cause cognitive deficits, and Alzheimer's disease in particular. Issues in the interpretation of such preclinical data and their predictive value for clinical translation are also discussed. PMID:24379759

  15. Laboratory studies of sources of HONO in polluted urban atmospheres

    NASA Astrophysics Data System (ADS)

    Saliba, Najat A.; Mochida, Michihiro; Finlayson-Pitts, Barbara. J.

    2000-10-01

    Laboratory studies reported here and in previous work show that the reaction of NO(g) with surface adsorbed HNO3 may be a significant source of HONO in polluted urban atmospheres. If these laboratory studies can be extrapolated to ambient conditions, this heterogeneous reaction may generate HONO to about the same extent as the hydrolysis of NO2 on surfaces, which is greater than the heterogeneous reaction of NO, NO2 and water. It may also be involved in generating HONO in snowpacks, and important in reconciling the discrepancy between measured and modeled HNO3/NOx ratios in the troposphere.

  16. Hemagglutination by Pasteurellaceae isolated from rodents.

    PubMed

    Boot, R; Thuis, H; Teppema, J S

    1993-06-01

    Pasteurellaceae notably P. pneumotropica, have been associated with severe outbreaks of respiratory disease in several species of rodents. Host-specific parasitism of Pasteurellaceae in rodents has hardly been studied. Since host tropism in many bacteria involves adhesive mechanisms, we examined the hemagglutinating (HA) properties of 44 isolates from different rodent species (mouse (15) rat (8), hamster (9), gerbil (10) and Mastomys (2)). Only 13 mouse isolates and the 2 Mastomys isolates hemagglutinated human (type O Rh+) and canine red blood cells (RBCs). No HA was found using RBCs from 10 other animal species. HA was not inhibited by simple sugars and glycoconjugates, but was completely inhibited by heating of bacterial cells for 10 min at 80 or 100 degrees C, partially inhibited by glutaraldehyde and inhibited in a dose-dependent mode by NaIO4, suggesting the involvement of bacterial polysaccharide structures in the HA process. Enrichment procedures did not reveal the presence of HA- subpopulations in HA+ isolates or the presence of HA+ subpopulations in HA- isolates. Electron microscopy revealed the presence of fimbriae both in HA+ and HA- isolates. A regularly structured (RS) layer was detected on cells of part of the HA+ isolates only. Our results suggest that Pasteurellaceae of mice and Mastomys may be related and differ from isolates isolated from other rodent species. PMID:8219497

  17. Epidemiology of Leptospira Transmitted by Rodents in Southeast Asia

    PubMed Central

    Mielcarek, Mathilde; Tatard, Caroline; Chaval, Yannick; Suputtamongkol, Yupin; Buchy, Philippe; Jittapalapong, Sathaporn; Herbreteau, Vincent; Morand, Serge

    2014-01-01

    Background Leptospirosis is the most common bacterial zoonoses and has been identified as an important emerging global public health problem in Southeast Asia. Rodents are important reservoirs for human leptospirosis, but epidemiological data is lacking. Methodology/Principal Findings We sampled rodents living in different habitats from seven localities distributed across Southeast Asia (Thailand, Lao PDR and Cambodia), between 2009 to 2010. Human isolates were also obtained from localities close to where rodents were sampled. The prevalence of Leptospira infection was assessed by real-time PCR using DNA extracted from rodent kidneys, targeting the lipL32 gene. Sequencing rrs and secY genes, and Multi Locus Variable-number Tandem Repeat (VNTR) analyses were performed on DNA extracted from rat kidneys for Leptospira isolates molecular typing. Four species were detected in rodents, L. borgpetersenii (56% of positive samples), L. interrogans (36%), L. kirschneri (3%) and L. weilli (2%), which were identical to human isolates. Mean prevalence in rodents was approximately 7%, and largely varied across localities and habitats, but not between rodent species. The two most abundant Leptospira species displayed different habitat requirements: L. interrogans was linked to humid habitats (rice fields and forests) while L. borgpetersenii was abundant in both humid and dry habitats (non-floodable lands). Conclusion/Significance L. interrogans and L. borgpetersenii species are widely distributed amongst rodent populations, and strain typing confirmed rodents as reservoirs for human leptospirosis. Differences in habitat requirements for L. interrogans and L. borgpetersenii supported differential transmission modes. In Southeast Asia, human infection risk is not only restricted to activities taking place in wetlands and rice fields as is commonly accepted, but should also include tasks such as forestry work, as well as the hunting and preparation of rodents for consumption, which

  18. Influencing behavior of physicians ordering laboratory tests: a literature study.

    PubMed

    Axt-Adam, P; van der Wouden, J C; van der Does, E

    1993-09-01

    There are various reasons why physicians order laboratory tests. Earlier studies have shown that in many cases test-ordering behavior lacks efficiency, resulting in excessive laboratory utilization. Throughout the years various attempts have been made to improve this situation. This review, based on the literature of the past 20 years, gives a survey of interventions and their effectiveness. Various types of education are discussed: general, cost-control oriented and education by means of guidelines, protocols, decision support systems, and feedback (on test ordering or cost). The discussion addresses the quality and apparent restrictions of the studies, and provides possible causes of the widely varying, but mostly low success rates. The long-term effectiveness of interventions aiming at better laboratory ordering is rather unfavorable. PMID:8366680

  19. Hiero-Dermato-Glyphics: Laboratory Study of the Skin

    ERIC Educational Resources Information Center

    Roark, Oakley F.

    1977-01-01

    Explains several laboratory exercises using the skin, including the mapping of receptors, counting of sweat glands, computation of total skin area, comparison of various animal skins, measurement of the palm triradius angle, and study of epidermal ridges (dermatoglyphics) in males and females. (CS)

  20. DESIGN AND EVALUATION OF LABORATORY ECOLOGICAL SYSTEM STUDIES

    EPA Science Inventory

    Design and evaluation of laboratory ecological system studies are considered in relation to problems and objectives in environmental toxicology. Ecological systems are defined to be organismic systems together with their level-specific, co-extensive environmental systems and to o...

  1. 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...

  2. Field Research Studying Whales in an Undergraduate Animal Behavior Laboratory

    ERIC Educational Resources Information Center

    MacLaren, R. David; Schulte, Dianna; Kennedy, Jen

    2012-01-01

    This work describes a new field research laboratory in an undergraduate animal behavior course involving the study of whale behavior, ecology and conservation in partnership with a non-profit research organization--the Blue Ocean Society for Marine Conservation (BOS). The project involves two weeks of training and five weekend trips on whale watch…

  3. LABORATORY STUDIES OF SOIL BEDDING REQUIREMENTS FOR FLEXIBLE MEMBRANE LINERS

    EPA Science Inventory

    The initial objective of this study was to investigate the performance of membrane liners during construction of hazardous waste landfills and develop a means for protecting the liners from damage. This objective included the development of laboratory tests that could be used to ...

  4. 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...

  5. 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

  6. Occupational allergy to laboratory animals: an epidemiologic study.

    PubMed

    Bland, S M; Levine, M S; Wilson, P D; Fox, N L; Rivera, J C

    1986-11-01

    A cross-sectional study has been carried out at The National Institutes of Health to examine the prevalence of laboratory animal allergy (LAA) in a population exposed to animals, and to compare the prevalence of general allergy in the exposed v a control group. A group of 289 workers with light-to-moderate exposure to animals, 260 with heavy exposure, and 242 control subjects were interviewed. A slightly greater prevalence of general allergy was found among those working with laboratory animals (39%), than in the control group (33.9%), but the difference was not statistically significant. The prevalence of LAA in the total exposed group was 23.9%. A history of atopic problems and history of allergy to domestic animals correlated significantly with LAA, as did the number of species of animals handled and the average number of hours per week exposed to laboratory animals, with evidence of dose-response relationships. PMID:3491199

  7. Sero-Prevalence of Rodent Pathogens in India.

    PubMed

    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

  8. 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

  9. The rat: a laboratory model for studies of the diving response.

    PubMed

    Panneton, W Michael; Gan, Qi; Juric, Rajko

    2010-04-01

    Underwater submersion in mammals induces apnea, parasympathetically mediated bradycardia, and sympathetically mediated peripheral vasoconstriction. These effects are collectively termed the diving response, potentially the most powerful autonomic reflex known. Although these physiological responses are directed by neurons in the brain, study of neural control of the diving response has been hampered since 1) it is difficult to study the brains of animals while they are underwater, 2) feral marine mammals are usually large and have brains of variable size, and 3) there are but few references on the brains of naturally diving species. Similar responses are elicited in anesthetized rodents after stimulation of their nasal mucosa, but this nasopharyngeal reflex has not been compared directly with natural diving behavior in the rat. In the present study, we compared hemodynamic responses elicited in awake rats during volitional underwater submersion with those of rats swimming on the water's surface, rats involuntarily submerged, and rats either anesthetized or decerebrate and stimulated nasally with ammonia vapors. We show that the hemodynamic changes to voluntary diving in the rat are similar to those of naturally diving marine mammals. We also show that the responses of voluntary diving rats are 1) significantly different from those seen during swimming, 2) generally similar to those elicited in trained rats involuntarily "dunked" underwater, and 3) generally different from those seen from dunking naive rats underwater. Nasal stimulation of anesthetized rats differed most from the hemodynamic variables of rats trained to dive voluntarily. We propose that the rat trained to dive underwater is an excellent laboratory model to study neural control of the mammalian diving response, and also suggest that some investigations may be done with nasal stimulation of decerebrate preparations to decipher such control. PMID:20093670

  10. Invasive rodent eradication on islands.

    PubMed

    Howald, Gregg; Donlan, C Josh; Galván, Juan Pablo; Russell, James C; Parkes, John; Samaniego, Araceli; Wang, Yiwei; Veitch, Dick; Genovesi, Piero; Pascal, Michel; Saunders, Alan; Tershy, Bernie

    2007-10-01

    Invasive mammals are the greatest threat to island biodiversity and invasive rodents are likely responsible for the greatest number of extinctions and ecosystem changes. Techniques for eradicating rodents from islands were developed over 2 decades ago. Since that time there has been a significant development and application of this conservation tool. We reviewed the literature on invasive rodent eradications to assess its current state and identify actions to make it more effective. Worldwide, 332 successful rodent eradications have been undertaken; we identified 35 failed eradications and 20 campaigns of unknown result. Invasive rodents have been eradicated from 284 islands (47,628 ha). With the exception of two small islands, rodenticides were used in all eradication campaigns. Brodifacoum was used in 71% of campaigns and 91% of the total area treated. The most frequent rodenticide distribution methods (from most to least) are bait stations, hand broadcasting, and aerial broadcasting. Nevertheless, campaigns using aerial broadcast made up 76% of the total area treated. Mortality of native vertebrates due to nontarget poisoning has been documented, but affected species quickly recover to pre-eradication population levels or higher. A variety of methods have been developed to mitigate nontarget impacts, and applied research can further aid in minimizing impacts. Land managers should routinely remove invasive rodents from islands <100 ha that lack vertebrates susceptible to nontarget poisoning. For larger islands and those that require nontarget mitigation, expert consultation and greater planning effort are needed. With the exception of house mice (Mus musculus), island size may no longer be the limiting factor for rodent eradications; rather, social acceptance and funding may be the main challenges. To be successful, large-scale rodent campaigns should be integrated with programs to improve the livelihoods of residents, island biosecurity, and reinvasion response

  11. Diffuse Interstellar Bands: A Combined Laboratory-Astronomical Study

    NASA Astrophysics Data System (ADS)

    Johnson, Fred M.

    2009-05-01

    Diffuse Interstellar Bands: A Combined Laboratory-Astronomical Study Abstract A comprehensive exposition of accumulated experimental laboratory and astronomical spectroscopic DIB data implicates the following molecules: (1) the ultra-thermodynamically stable metal-organic molecule magnesium-tetrabenzoporphyrin (MgTBP) situated within (2) a paraffin matrix (referred to as either grains or dust), and (3) a low concentration of pyridine (also within the grains) whose transmission window at 2175 Å accounts for the ubiquitous UV bump. It is proposed that pyridine coordinates to MgTBP to produce the species responsible for the DIB features. The strongest DIB at 4428.19Å is matched precisely with the most prominent laboratory-measured absorption Soret band of MgTBP at 4428.2Å, including its FWHM value; likewise the next strongest DIB at 6284Å correlates with the MgTBP Q band. Over 27 DIBs are matched with low-temperature laboratory Shploskii data of MgTBP in such matrices, to a precision of 1Å. The most recent DIB catalog using HD204827 is provided by L. M. Hobbs et al. (ApJ 680,1256-1270,2008). This catalog lists weak, narrow DIBs consistent with laboratory Shpolskii spectral data. The DIB-laboratory correlations include minimum linewidths and evidence of crystal electric field effects that act to remove the degeneracy of MgTBP's first and second electronic states resulting in a clear display of vibronic spectral bands whose interpretation is now possible using the published complete vibrational data set of MgTBP (see F. M. Johnson Spectrochimica Acta Part A 65 (2006) 1154-1179.)

  12. Piroplasms from Taiwanese rodents.

    PubMed

    van Peenen, P F; Chang, S J; Banknieder, A R; Santana, F J

    1977-05-01

    Piroplasms from naturally infected bandicoot rats, Bandicota indica (Hodgson), and spiny rats, Rattus coxinga (Swinhoe), from Taiwan caused parasitemias in a wide range of laboratory animals after syringe passage in laboratory rats. Bandicoot and spiny rats could be infected with heterologous piroplasms, but neither species was susceptible to infection with the Gray strain of Babesia microti (França). Nevertheless, the Taiwan piroplasms are probably a geographic strain of B. microti. PMID:881655

  13. Validation of an automated punctate mechanical stimuli delivery system designed for fMRI studies in rodents.

    PubMed

    Governo, Ricardo Jose Moylan; Prior, Malcolm John William; Morris, Peter Gordon; Marsden, Charles Alexander; Chapman, Victoria

    2007-06-15

    Functional magnetic resonance imaging (fMRI) is increasingly being used for animal studies studying the transmission of nociceptive information. Application of noxious mechanical stimuli is widely used for animal and human assessment of pain processing. Any accessory hardware used in animal imaging studies must, however, be sufficiently small to fit in the magnet bore diameter and be non-magnetic. We have developed a system that can apply mechanical stimuli simultaneously with fMRI. This system consists of a standardized instrument to deliver mechanical stimuli (VonFrey monofilament) and a gas-pressured mechanical transducer. These components were integrated with a computer console that controlled the period of stimuli to match acquisition scans. Preliminary experiments demonstrated that the force-stimulus transducer did not influence MRI signal to noise ratio. Mechanical stimulation of the hindpaw significantly increased blood oxygen level dependent (BOLD) signal intensity in several midbrain regions involved in the processing of nociceptive information in the rat (p<0.001, uncorrected for multiple comparisons). This system can be applied to both animal and human imaging studies and has a wide range of applications for studies of nociceptive processing. PMID:17368787

  14. How toxic is coal ash? A laboratory toxicity case study.

    PubMed

    Sherrard, Rick M; Carriker, Neil E; Greeley, Mark S

    2015-01-01

    Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. This brief communication describes a broad range of toxicity studies conducted for the Tennessee Valley Authority (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash. PMID:25348557

  15. How toxic is coal ash? A laboratory toxicity case study

    DOE PAGESBeta

    Sherrard, Rick M.; Carriker, Neil; Greeley, Jr., Mark Stephen

    2014-12-08

    Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. In this paper, we describe a broad range of toxicity studies conducted for the Tennessee Valley Authoritymore » (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash.« less

  16. How toxic is coal ash? A laboratory toxicity case study

    SciTech Connect

    Sherrard, Rick M.; Carriker, Neil; Greeley, Jr., Mark Stephen

    2014-12-08

    Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. In this paper, we describe a broad range of toxicity studies conducted for the Tennessee Valley Authority (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash.

  17. Evaluation of carcinogenic potential of the herbicide glyphosate, drawing on tumor incidence data from fourteen chronic/carcinogenicity rodent studies.

    PubMed

    Greim, Helmut; Saltmiras, David; Mostert, Volker; Strupp, Christian

    2015-03-01

    Abstract Glyphosate, an herbicidal derivative of the amino acid glycine, was introduced to agriculture in the 1970s. Glyphosate targets and blocks a plant metabolic pathway not found in animals, the shikimate pathway, required for the synthesis of aromatic amino acids in plants. After almost forty years of commercial use, and multiple regulatory approvals including toxicology evaluations, literature reviews, and numerous human health risk assessments, the clear and consistent conclusions are that glyphosate is of low toxicological concern, and no concerns exist with respect to glyphosate use and cancer in humans. This manuscript discusses the basis for these conclusions. Most toxicological studies informing regulatory evaluations are of commercial interest and are proprietary in nature. Given the widespread attention to this molecule, the authors gained access to carcinogenicity data submitted to regulatory agencies and present overviews of each study, followed by a weight of evidence evaluation of tumor incidence data. Fourteen carcinogenicity studies (nine rat and five mouse) are evaluated for their individual reliability, and select neoplasms are identified for further evaluation across the data base. The original tumor incidence data from study reports are presented in the online data supplement. There was no evidence of a carcinogenic effect related to glyphosate treatment. The lack of a plausible mechanism, along with published epidemiology studies, which fail to demonstrate clear, statistically significant, unbiased and non-confounded associations between glyphosate and cancer of any single etiology, and a compelling weight of evidence, support the conclusion that glyphosate does not present concern with respect to carcinogenic potential in humans. PMID:25716480

  18. Evaluation of carcinogenic potential of the herbicide glyphosate, drawing on tumor incidence data from fourteen chronic/carcinogenicity rodent studies

    PubMed Central

    Greim, Helmut; Saltmiras, David; Mostert, Volker; Strupp, Christian

    2015-01-01

    Abstract Glyphosate, an herbicidal derivative of the amino acid glycine, was introduced to agriculture in the 1970s. Glyphosate targets and blocks a plant metabolic pathway not found in animals, the shikimate pathway, required for the synthesis of aromatic amino acids in plants. After almost forty years of commercial use, and multiple regulatory approvals including toxicology evaluations, literature reviews, and numerous human health risk assessments, the clear and consistent conclusions are that glyphosate is of low toxicological concern, and no concerns exist with respect to glyphosate use and cancer in humans. This manuscript discusses the basis for these conclusions. Most toxicological studies informing regulatory evaluations are of commercial interest and are proprietary in nature. Given the widespread attention to this molecule, the authors gained access to carcinogenicity data submitted to regulatory agencies and present overviews of each study, followed by a weight of evidence evaluation of tumor incidence data. Fourteen carcinogenicity studies (nine rat and five mouse) are evaluated for their individual reliability, and select neoplasms are identified for further evaluation across the data base. The original tumor incidence data from study reports are presented in the online data supplement. There was no evidence of a carcinogenic effect related to glyphosate treatment. The lack of a plausible mechanism, along with published epidemiology studies, which fail to demonstrate clear, statistically significant, unbiased and non-confounded associations between glyphosate and cancer of any single etiology, and a compelling weight of evidence, support the conclusion that glyphosate does not present concern with respect to carcinogenic potential in humans. PMID:25716480

  19. Comparison of cell counting methods in rodent pulmonary toxicity studies: automated and manual protocols and considerations for experimental design

    PubMed Central

    Zeidler-Erdely, Patti C.; Antonini, James M.; Meighan, Terence G.; Young, Shih-Houng; Eye, Tracy J.; Hammer, Mary Ann; Erdely, Aaron

    2016-01-01

    Pulmonary toxicity studies often use bronchoalveolar lavage (BAL) to investigate potential adverse lung responses to a particulate exposure. The BAL cellular fraction is counted, using automated (i.e. Coulter Counter®), flow cytometry or manual (i.e. hemocytometer) methods, to determine inflammatory cell influx. The goal of the study was to compare the different counting methods to determine which is optimal for examining BAL cell influx after exposure by inhalation or intratracheal instillation (ITI) to different particles with varying inherent pulmonary toxicities in both rat and mouse models. General findings indicate that total BAL cell counts using the automated and manual methods tended to agree after inhalation or ITI exposure to particle samples that are relatively nontoxic or at later time points after exposure to a pneumotoxic particle when the response resolves. However, when the initial lung inflammation and cytotoxicity was high after exposure to a pneumotoxic particle, significant differences were observed when comparing cell counts from the automated, flow cytometry and manual methods. When using total BAL cell count for differential calculations from the automated method, depending on the cell diameter size range cutoff, the data suggest that the number of lung polymorphonuclear leukocytes (PMN) varies. Importantly, the automated counts, regardless of the size cutoff, still indicated a greater number of total lung PMN when compared with the manual method, which agreed more closely with flow cytometry. The results suggest that either the manual method or flow cytometry would be better suited for BAL studies where cytotoxicity is an unknown variable. PMID:27251196

  20. Comparison of cell counting methods in rodent pulmonary toxicity studies: automated and manual protocols and considerations for experimental design.

    PubMed

    Zeidler-Erdely, Patti C; Antonini, James M; Meighan, Terence G; Young, Shih-Houng; Eye, Tracy J; Hammer, Mary Ann; Erdely, Aaron

    2016-08-01

    Pulmonary toxicity studies often use bronchoalveolar lavage (BAL) to investigate potential adverse lung responses to a particulate exposure. The BAL cellular fraction is counted, using automated (i.e. Coulter Counter®), flow cytometry or manual (i.e. hemocytometer) methods, to determine inflammatory cell influx. The goal of the study was to compare the different counting methods to determine which is optimal for examining BAL cell influx after exposure by inhalation or intratracheal instillation (ITI) to different particles with varying inherent pulmonary toxicities in both rat and mouse models. General findings indicate that total BAL cell counts using the automated and manual methods tended to agree after inhalation or ITI exposure to particle samples that are relatively nontoxic or at later time points after exposure to a pneumotoxic particle when the response resolves. However, when the initial lung inflammation and cytotoxicity was high after exposure to a pneumotoxic particle, significant differences were observed when comparing cell counts from the automated, flow cytometry and manual methods. When using total BAL cell count for differential calculations from the automated method, depending on the cell diameter size range cutoff, the data suggest that the number of lung polymorphonuclear leukocytes (PMN) varies. Importantly, the automated counts, regardless of the size cutoff, still indicated a greater number of total lung PMN when compared with the manual method, which agreed more closely with flow cytometry. The results suggest that either the manual method or flow cytometry would be better suited for BAL studies where cytotoxicity is an unknown variable. PMID:27251196

  1. Streptozotocin-induced type 1 diabetes in rodents as a model for studying mitochondrial mechanisms of diabetic β cell glucotoxicity

    PubMed Central

    Wu, Jinzi; Yan, Liang-Jun

    2015-01-01

    Chronic hyperglycemia and the corresponding glucotoxicity are the main pathogenic mechanisms of diabetes and its complications. Streptozotocin (STZ)-induced diabetic animal models are useful platforms for the understanding of β cell glucotoxicity in diabetes. As diabetes induced by a single STZ injection is often referred to as type 1 diabetes that is caused by STZ’s partial destruction of pancreas, one question often being asked is whether the STZ type 1 diabetes animal model is a good model for studying the mitochondrial mechanisms of β cell glucotoxicity. In this mini review, we provide evidence garnered from the literature that the STZ type 1 diabetes is indeed a suitable model for studying mitochondrial mechanisms of diabetic β cell glucotoxicity. Evidence presented includes: 1) continued β cell derangement is due to chronic hyperglycemia after STZ is completely eliminated out of the body; 2) STZ diabetes can be reversed by insulin treatment, which indicates that β cell responds to treatment and shows ability to regenerate; and 3) STZ diabetes can be ameliorated or alleviated by administration of phytochemicals. In addition, mechanisms of STZ action and fundamental gaps in understanding mitochondrial mechanisms of β cell dysfunction are also discussed. PMID:25897251

  2. Short-term exposure of rodents to diesel exhausts: usefulness for studies of genotoxic and immunotoxic effects.

    PubMed

    Nilsen, A; Trønnes, T; Westerholm, R; Rannug, U; Nilsen, O G; Helleberg, H; Kautiainen, A; Hedenskog, M; Törnqvist, M

    1999-03-01

    An exposure facility was tested with regard to the information obtainable from short-term animal experiments for the assessment of health hazards from automotive engine exhausts. Indicators of immunotoxicity and genotoxicity were studied in guinea pigs and mice, respectively, exposed for 2 weeks, 8 h/day, to ten times diluted exhausts from a one-cylinder research diesel engine running at constant load. Regulated and non-regulated pollutants were determined. Besides increased number of lavageable cells in the airways, exposed guinea pigs exhibited, after immunization and challenge to ovalbumin, reduced leukotrienes B4 and C4 in lavage fluid and reduced anti-ovalbumin IgG in serum. Absence of increased CYP1A activity indicated that the exposure was below the threshold for induction of these enzymes. Instead a certain reduction of this activity indicated interaction with active enzyme sites. In vivo doses of some reactive metabolites of low molecular mass were measured by adducts to hemoglobin. Doses from aliphatic epoxides were low, in accordance with low hydrocarbon levels in the exhaust. The levels of hemoglobin adducts from aldehydes showed no clearcut influences of exposure. Genetic effects determined by DNA fingerprint analysis were indicated. It is concluded that repeated dose inhalation exposure of small numbers of animals is a useful mode of exposure for studying parameters that may elucidate toxic effects of air pollutants emitted from automotive engines, with a possibility to evaluate engine and fuel with regard to health hazards. PMID:10227576

  3. Bats and Rodents Shape Mammalian Retroviral Phylogeny

    PubMed Central

    Cui, Jie; Tachedjian, Gilda; Wang, Lin-Fa

    2015-01-01

    Endogenous retroviruses (ERVs) represent past retroviral infections and accordingly can provide an ideal framework to infer virus-host interaction over their evolutionary history. In this study, we target high quality Pol sequences from 7,994 Class I and 8,119 Class II ERVs from 69 mammalian genomes and surprisingly find that retroviruses harbored by bats and rodents combined occupy the major phylogenetic diversity of both classes. By analyzing transmission patterns of 30 well-defined ERV clades, we corroborate the previously published observation that rodents are more competent as originators of mammalian retroviruses and reveal that bats are more capable of receiving retroviruses from non-bat mammalian origins. The powerful retroviral hosting ability of bats is further supported by a detailed analysis revealing that the novel bat gammaretrovirus, Rhinolophus ferrumequinum retrovirus, likely originated from tree shrews. Taken together, this study advances our understanding of host-shaped mammalian retroviral evolution in general. PMID:26548564

  4. Bats and Rodents Shape Mammalian Retroviral Phylogeny.

    PubMed

    Cui, Jie; Tachedjian, Gilda; Wang, Lin-Fa

    2015-01-01

    Endogenous retroviruses (ERVs) represent past retroviral infections and accordingly can provide an ideal framework to infer virus-host interaction over their evolutionary history. In this study, we target high quality Pol sequences from 7,994 Class I and 8,119 Class II ERVs from 69 mammalian genomes and surprisingly find that retroviruses harbored by bats and rodents combined occupy the major phylogenetic diversity of both classes. By analyzing transmission patterns of 30 well-defined ERV clades, we corroborate the previously published observation that rodents are more competent as originators of mammalian retroviruses and reveal that bats are more capable of receiving retroviruses from non-bat mammalian origins. The powerful retroviral hosting ability of bats is further supported by a detailed analysis revealing that the novel bat gammaretrovirus, Rhinolophus ferrumequinum retrovirus, likely originated from tree shrews. Taken together, this study advances our understanding of host-shaped mammalian retroviral evolution in general. PMID:26548564

  5. The power of using functional fMRI on small rodents to study brain pharmacology and disease

    PubMed Central

    Jonckers, Elisabeth; Shah, Disha; Hamaide, Julie; Verhoye, Marleen; Van der Linden, Annemie

    2015-01-01

    Functional magnetic resonance imaging (fMRI) is an excellent tool to study the effect of pharmacological modulations on brain function in a non-invasive and longitudinal manner. We introduce several blood oxygenation level dependent (BOLD) fMRI techniques, including resting state (rsfMRI), stimulus-evoked (st-fMRI), and pharmacological MRI (phMRI). Respectively, these techniques permit the assessment of functional connectivity during rest as well as brain activation triggered by sensory stimulation and/or a pharmacological challenge. The first part of this review describes the physiological basis of BOLD fMRI and the hemodynamic response on which the MRI contrast is based. Specific emphasis goes to possible effects of anesthesia and the animal’s physiological conditions on neural activity and the hemodynamic response. The second part of this review describes applications of the aforementioned techniques in pharmacologically induced, as well as in traumatic and transgenic disease models and illustrates how multiple fMRI methods can be applied successfully to evaluate different aspects of a specific disorder. For example, fMRI techniques can be used to pinpoint the neural substrate of a disease beyond previously defined hypothesis-driven regions-of-interest. In addition, fMRI techniques allow one to dissect how specific modifications (e.g., treatment, lesion etc.) modulate the functioning of specific brain areas (st-fMRI, phMRI) and how functional connectivity (rsfMRI) between several brain regions is affected, both in acute and extended time frames. Furthermore, fMRI techniques can be used to assess/explore the efficacy of novel treatments in depth, both in fundamental research as well as in preclinical settings. In conclusion, by describing several exemplary studies, we aim to highlight the advantages of functional MRI in exploring the acute and long-term effects of pharmacological substances and/or pathology on brain functioning along with several methodological

  6. Sleep-Wake Sensitive Mechanisms of Adenosine Release in the Basal Forebrain of Rodents: An In Vitro Study

    PubMed Central

    Sims, Robert Edward; Wu, Houdini Ho Tin; Dale, Nicholas

    2013-01-01

    Adenosine acting in the basal forebrain is a key mediator of sleep homeostasis. Extracellular adenosine concentrations increase during wakefulness, especially during prolonged wakefulness and lead to increased sleep pressure and subsequent rebound sleep. The release of endogenous adenosine during the sleep-wake cycle has mainly been studied in vivo with microdialysis techniques. The biochemical changes that accompany sleep-wake status may be preserved in vitro. We have therefore used adenosine-sensitive biosensors in slices of the basal forebrain (BFB) to study both depolarization-evoked adenosine release and the steady state adenosine tone in rats, mice and hamsters. Adenosine release was evoked by high K+, AMPA, NMDA and mGlu receptor agonists, but not by other transmitters associated with wakefulness such as orexin, histamine or neurotensin. Evoked and basal adenosine release in the BFB in vitro exhibited three key features: the magnitude of each varied systematically with the diurnal time at which the animal was sacrificed; sleep deprivation prior to sacrifice greatly increased both evoked adenosine release and the basal tone; and the enhancement of evoked adenosine release and basal tone resulting from sleep deprivation was reversed by the inducible nitric oxide synthase (iNOS) inhibitor, 1400 W. These data indicate that characteristics of adenosine release recorded in the BFB in vitro reflect those that have been linked in vivo to the homeostatic control of sleep. Our results provide methodologically independent support for a key role for induction of iNOS as a trigger for enhanced adenosine release following sleep deprivation and suggest that this induction may constitute a biochemical memory of this state. PMID:23326515

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

    PubMed

    Yu, Shukun; Mei, Jie; Ahrén, Bo

    2004-10-01

    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 alpha-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 strains of the bacterium Salmonella typhimurium TA 98, 100, 102, 1535 and 1537. AF caused no mammalian gene mutation as tested with mouse lymphoma L5178Y cells. AF did not cause toxic symptoms in rats when it was administered as a single oral dose of 5 g/kg and observed over a 14-day period. Furthermore, at necropsy, no signs of abnormality were detected. Daily intraperitoneal (ip) administration of 2 g/kg AF to mice did not induce adverse effects throughout a 28-day period. Radioactive tracing experiments using 14C-labeled AF indicated that AF was efficiently absorbed since the major portion of radioactive material was recovered in urine. Further work using unlabeled AF indicated that the cyclic polyol 1,5-anhydro-D-sorbitol (AS) increased dramatically in both blood and urine upon AF administration at 1 g/kg ip, suggesting the existence of an efficient reduction mechanism from AF to AS, which was then excreted in urine. In conclusion, these studies indicate that AF had low or no toxicity and showed no mutagenicity. PMID:15354319

  8. Interstellar dust: interfacing laboratory, theoretical and observational studies

    NASA Astrophysics Data System (ADS)

    Jones, Anthony Peter

    2015-08-01

    In this talk I will consider how our understanding of interstellar dust can only be advanced through a combination of laboratory, theoretical and observational studies, which provide the critical framework for advancing our understanding. I will summarise what we currently know, or think we know, about the physical and compositional properties of dust and their evolution in interstellar media. Along the way I will question the utility of astronomical dust analogues and show, based on data from the laboratory, theoretical studies and from astronomical observations, that some of our prior interpretations need to be subjected to a critical re-evaluation. I will present interstellar dust modelling from a new vantage point and review ideas on the interpretation of observations within the framework of this model and its predictions for dust evolution within and between interstellar media. Finally, I will summarise some of the current outstanding issues and what we would like to learn in the future.

  9. Sediment retention in constructed wetland ponds--a laboratory study.

    PubMed

    Stephan, Ursula; Hengl, Michael; Schmid, Bernhard H

    2005-01-01

    Laboratory experiments on sediment removal and particle settlement were conducted in a hydraulic laboratory model scaled 1:1 to study processes and mechanisms governing sediment transport under well defined and reproducible conditions. Parameters governing particle settling were varied and their effect studied ceteris paribus. These governing parameters were flow velocity, TSS input concentration, presence of plants, vegetation density, and the presence of wind. Changes in sediment removal due to different parameters were analyzed by means of deposition curves in main flow direction. We found that particle settling is enhanced by increased inflow concentrations of suspended solids in the absence of plant stems (substance used: kaolin), whereas deposition is reduced by wind shear. The presence of plant stems strengthens vertical mixing and, consequently, does not generally result in enhanced deposition of suspended solids. Higher plant densities tend to be associated with lower settling rates. The effect of flow velocity on particle settling is small for the present experimental set-up. PMID:15921291

  10. Bone tissue reaction to Ti-48Al-2Cr-2Nb (at.%) in a rodent model: a preliminary SEM study.

    PubMed

    Castañeda-Muñoz, Diego F; Sundaram, Paul Antony; Ramírez, Norman

    2007-07-01

    A variety of metals have been used to replace the skeletal framework of human beings. Gamma titanium aluminide (gammaTiAl) has been recently developed as a prospective material for turbine applications. In this preliminary study, the potential of gammaTiAl as a biomaterial was evaluated using an in vivo rat model. Sprague-Dawley rats were implanted with gammaTiAl cylinders in the femur and observed for an experimental period lasting up to 180 days. The rats were sacrificed after periods of 45, 90 and 180 days. The femurs with the gammaTiAl implants were extracted and examined using scanning electron microscopy (SEM). Normal bone growth processes were observed as early as 45 days after gammaTiAl cylinder implantation. No signs of rejection of the implant metal were observed. In fact, a layered bone growth was observed on the implant metal surface. The bone-metal interface showed signs of tissue growth from original bone to the metal surface. gammaTiAl appears to elicit a normal bone tissue reaction and hence, has potential as a metallic implant material. PMID:17387593

  11. Choline acetyltransferase immunoreactive cortical interneurons do not occur in all rodents: a study of the phylogenetic occurrence of this neural characteristic.

    PubMed

    Bhagwandin, Adhil; Fuxe, Kjell; Manger, Paul R

    2006-12-01

    The present study was designed to provide results aimed at testing whether the interneurons with choline acetyltransferase immunoreactivity (ChAT), probably representing GABA interneurons, found in the cerebral cortex of the rat represent a common feature of the order Rodentia. Initially we verified the presence of ChAT immunoreactive bipolar cell bodies, axons and terminal-like fibres in pigmented (Long-Evans) and non-pigmented (Sprague-Dawley) strains of Rattus norvegicus, confirming that the ChAT polyclonal antibodies (AB144P and AB143, Chemicon; VChAT, Sigma) with the immunohistochemical techniques used provided the same staining as previously described for this species. We then examined pigmented (AKR3) and non-pigmented (C3H) strains of Mus musculus, wild caught striped mice (Rhabdomys pumilio), bushveld gerbil (Tatera brantsii), greater canerat (Thryonomys swinderianus) and common molerat (Cryptomys hottentotus). The AB144P antibody revealed cortical interneurons in both strains of M. musculus and in R. pumilio, but not in the other species. In all species/strains cortical ChAT immunoreactive axons and terminal-like fibres were localized with the AB144P antibody. In the non-Rattus species/strains there was no evidence for localization of ChAT immunoreactivity in any cortical cell bodies using the AB143 and vesicular acetylcholine transporter (VChAT) antibodies despite extensive localization in axons and terminal-like fibres. It is concluded that bipolar cortical GABA interneurons in certain rodent species may develop ChAT immunoreactivity but not VChAT immunoreactivity making the cholinergic relevance of ChAT in the GABA interneurons uncertain and may exclude these neurons from being part of the traditionally defined cholinergic system. PMID:17049807

  12. 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

  13. 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

  14. Laboratory Experiments and Instrument Intercomparison Studies of Carbonaceous Aerosol Particles

    SciTech Connect

    Davidovits, Paul

    2015-10-20

    Aerosols containing black carbon (and some specific types of organic particulate matter) directly absorb incoming light, heating the atmosphere. In addition, all aerosol particles backscatter solar light, leading to a net-cooling effect. Indirect effects involve hydrophilic aerosols, which serve as cloud condensation nuclei (CCN) that affect cloud cover and cloud stability, impacting both atmospheric radiation balance and precipitation patterns. At night, all clouds produce local warming, but overall clouds exert a net-cooling effect on the Earth. The effect of aerosol radiative forcing on climate may be as large as that of the greenhouse gases, but predominantly opposite in sign and much more uncertain. The uncertainties in the representation of aerosol interactions in climate models makes it problematic to use model projections to guide energy policy. The objective of our program is to reduce the uncertainties in the aerosol radiative forcing in the two areas highlighted in the ASR Science and Program Plan. That is, (1) addressing the direct effect by correlating particle chemistry and morphology with particle optical properties (i.e. absorption, scattering, extinction), and (2) addressing the indirect effect by correlating particle hygroscopicity and CCN activity with particle size, chemistry, and morphology. In this connection we are systematically studying particle formation, oxidation, and the effects of particle coating. The work is specifically focused on carbonaceous particles where the uncertainties in the climate relevant properties are the highest. The ongoing work consists of laboratory experiments and related instrument inter-comparison studies both coordinated with field and modeling studies, with the aim of providing reliable data to represent aerosol processes in climate models. The work is performed in the aerosol laboratory at Boston College. At the center of our laboratory setup are two main sources for the production of aerosol particles: (a

  15. A laboratory model for studying blast overpressure injury.

    PubMed

    Jaffin, J H; McKinney, L; Kinney, R C; Cunningham, J A; Moritz, D M; Kraimer, J M; Graeber, G M; Moe, J B; Salander, J M; Harmon, J W

    1987-04-01

    Blast injury remains an important source of trauma in both civilian and military settings. We have studied a recently developed blast wave generator to evaluate its effectiveness for laboratory study of blast injury. In order to determine the reliability of the device and the pathology of the lesions caused by the short duration (0.5-1.0 msec), and high intensity (60-375 psi) pressure wave, laboratory rats were exposed to the pressure waves generated by the machine. The animals were divided into three groups: the first exposed to midthoracic blasts, the second to abdominal blasts, and a group of controls exposed to a gentle stream of gas. Group I showed gross and microscopic evidence of lung blast injury of "rib imprint" hemorrhages, intra-alveolar hemorrhage, marked increase in lung weight, prolonged apnea, and bradycardia. Group II showed typical blunt abdominal trauma at the closest ranges, but characteristic submucosal hemorrhages up to 4.0 cm from the blast nozzle. In both groups, a protective effect was seen in heavier animals. The blast wave generator permits reproducible blast injury in the laboratory that is safer and faster than current methods. The lung and bowel lesions induced are grossly and microscopically similar to injuries of blast exposure seen in clinical patients. PMID:3494851

  16. Laboratory studies of in vivo fluorescence of phytoplankton

    NASA Technical Reports Server (NTRS)

    Brown, C. A., Jr.; Farmer, F. H.; Jarrett, O., Jr.; Staton, W. L.

    1978-01-01

    A lidar system is developed that uses four selected excitation wavelengths to induce chlorophyll 'a' fluorescence which is indicative of both the concentration and diversity of phytoplankton. The operating principles of the system and the results of measurements of phytoplankton fluorescence in a controlled laboratory environment are presented. A comparative study of results from lidar fluorosensor laboratory tank tests using representative species of phytoplankton in single and multispecies cultures from each of four color groups reveals that (1) there is good correlation between the fluorescence of chlorophyll 'a' remotely simulated and detected by the lidar system and in-situ measurements using four similar excitation wavelengths in a flow-through fluorometer; (2) good correlation exists between the total chlorophyll 'a' calculated from lidar-fluorosensor data and measurements obtained by the Strickland-Parsons method; and (3) the lidar fluorosensor can provide an index of population diversity.

  17. Volumes of cochlear nucleus regions in rodents.

    PubMed

    Godfrey, Donald A; Lee, Augustine C; Hamilton, Walter D; Benjamin, Louis C; Vishwanath, Shilpa; Simo, Hermann; Godfrey, Lynn M; Mustapha, Abdurrahman I A A; Heffner, Rickye S

    2016-09-01

    The cochlear nucleus receives all the coded information about sound from the cochlea and is the source of auditory information for the rest of the central auditory system. As such, it is a critical auditory nucleus. The sizes of the cochlear nucleus as a whole and its three major subdivisions - anteroventral cochlear nucleus (AVCN), posteroventral cochlear nucleus (PVCN), and dorsal cochlear nucleus (DCN) - have been measured in a large number of mammals, but measurements of its subregions at a more detailed level for a variety of species have not previously been made. Size measurements are reported here for the summed granular regions, DCN layers, AVCN, PVCN, and interstitial nucleus in 15 different rodent species, as well as a lagomorph, carnivore, and small primate. This further refinement of measurements is important because the granular regions and superficial layers of the DCN appear to have some different functions than the other cochlear nucleus regions. Except for DCN layers in the mountain beaver, all regions were clearly identifiable in all the animals studied. Relative regional size differences among most of the rodents, and even the 3 non-rodents, were not large and did not show a consistent relation to their wide range of lifestyles and hearing parameters. However, the mountain beaver, and to a lesser extent the pocket gopher, two rodents that live in tunnel systems, had relative sizes of summed granular regions and DCN molecular layer distinctly larger than those of the other mammals. Among all the mammals studied, there was a high correlation between the size per body weight of summed granular regions and that of the DCN molecular layer, consistent with other evidence for a close relationship between granule cells and superficial DCN neurons. PMID:27435005

  18. 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

  19. 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

  20. First Isolates of Leptospira spp., from Rodents Captured in Angola.

    PubMed

    Fortes-Gabriel, Elsa; Carreira, Teresa; Vieira, Maria Luísa

    2016-05-01

    Rodents play an important role in the transmission of pathogenic Leptospira spp. However, in Angola, neither the natural reservoirs of these spirochetes nor leptospirosis diagnosis has been considered. Regarding this gap, we captured rodents in Luanda and Huambo provinces to identify circulating Leptospira spp. Rodent kidney tissue was cultured and DNA amplified and sequenced. Culture isolates were evaluated for pathogenic status and typing with rabbit antisera; polymerase chain reaction (PCR) and sequencing were also performed. A total of 37 rodents were captured: Rattus rattus (15, 40.5%), Rattus norvegicus (9, 24.3%), and Mus musculus (13, 35.2%). Leptospiral DNA was amplified in eight (21.6%) kidney samples. From the cultures, we obtained four (10.8%) Leptospira isolates belonging to the Icterohaemorrhagiae and Ballum serogroups of Leptospira interrogans and Leptospira borgpetersenii genospecies, respectively. This study provides information about circulating leptospires spread by rats and mice in Angola. PMID:26928840

  1. First Isolates of Leptospira spp., from Rodents Captured in Angola

    PubMed Central

    Fortes-Gabriel, Elsa; Carreira, Teresa; Vieira, Maria Luísa

    2016-01-01

    Rodents play an important role in the transmission of pathogenic Leptospira spp. However, in Angola, neither the natural reservoirs of these spirochetes nor leptospirosis diagnosis has been considered. Regarding this gap, we captured rodents in Luanda and Huambo provinces to identify circulating Leptospira spp. Rodent kidney tissue was cultured and DNA amplified and sequenced. Culture isolates were evaluated for pathogenic status and typing with rabbit antisera; polymerase chain reaction (PCR) and sequencing were also performed. A total of 37 rodents were captured: Rattus rattus (15, 40.5%), Rattus norvegicus (9, 24.3%), and Mus musculus (13, 35.2%). Leptospiral DNA was amplified in eight (21.6%) kidney samples. From the cultures, we obtained four (10.8%) Leptospira isolates belonging to the Icterohaemorrhagiae and Ballum serogroups of Leptospira interrogans and Leptospira borgpetersenii genospecies, respectively. This study provides information about circulating leptospires spread by rats and mice in Angola. PMID:26928840

  2. Change in argonne national laboratory: a case study.

    PubMed

    Mozley, A

    1971-10-01

    Despite traditional opposition to change within an institution and the known reluctance of an "old guard" to accept new managerial policies and techniques, the reactions suggested in this study go well beyond the level of a basic resistance to change. The response, indeed, drawn from a random sampling of Laboratory scientific and engineering personnel, comes close to what Philip Handler has recently described as a run on the scientific bank in a period of depression (1, p. 146). It appears that Argonne's apprehension stems less from the financial cuts that have reduced staff and diminished programs by an annual 10 percent across the last 3 fiscal years than from the administrative and conceptual changes that have stamped the institution since 1966. Administratively, the advent of the AUA has not forged a sense of collaborative effort implicit in the founding negotiations or contributed noticeably to increasing standards of excellence at Argonne. The AUA has, in fact, yet to exercise the constructive powers vested in them by the contract of reviewing and formulating long-term policy on the research and reactor side. Additionally, the University of Chicago, once the single operator, appears to have forfeited some of the trust and understanding that characterized the Laboratory's attitude to it in former years. In a period of complex and sensitive management the present directorate at Argonne is seriously dissociated from a responsible spectrum of opinion within the Laboratory. The crux of discontent among the creative scientific and engineering community appears to lie in a developed sense of being overadministered. In contrast to earlier periods, Argonne's professional staff feels a critical need for a voice in the formulation of Laboratory programs and policy. The Argonne senate could supply this mechanism. Slow to rally, their present concern springs from a firm conviction that the Laboratory is "withering on the vine." By contrast, the Laboratory director Powers

  3. A Laboratory Study of Heterogeneity and Scaling in Geologic Media

    NASA Astrophysics Data System (ADS)

    Brown, S.; Boitnott, G.; Bussod, G.; Hagan, P.

    2004-05-01

    In rocks and soils, the bulk geophysical and transport properties of the matrix and of fracture systems are determined by the juxtaposition of geometric features at many length scales. For sedimentary materials the length scales are: the pore scale (irregularities in grain surface roughness and cementation), the scale of grain packing faults (and the resulting correlated porosity structures), the scale dominated by sorting or winnowing due to depositional processes, and the scale of geomorphology at the time of deposition. We are studying the heterogeneity and anisotropy in geometry, permeability, and geophysical response from the pore (microscopic), laboratory (mesoscopic), and backyard field (macroscopic) scales. In turn these data are being described and synthesized for development of mathematical models. Eventually, we will perform parameter studies to explore these models in the context of transport in the vadose and saturated zones. We have developed a multi-probe physical properties scanner which allows for the mapping of geophysical properties on a slabbed sample or core. This device allows for detailed study of heterogeneity at those length scales most difficult to quantify using standard field and laboratory practices. The measurement head consists of a variety of probes designed to make local measurements of various properties, including: gas permeability, acoustic velocities (compressional and shear), complex electrical impedance (4 electrode, wide frequency coverage), and ultrasonic reflection (ultrasonic impedance and permeability). We can thus routinely generate detailed geophysical maps of a particular sample. We are testing and modifying these probes as necessary for use on soil samples. As a baseline study we have been characterizing the heterogeneity of a bench-size Berea sandstone block. Berea Sandstone has long been regarded as a laboratory standard in rock properties studies, owing to its uniformity and ``typical'' physical properties. We find

  4. Evidence for Novel Hepaciviruses in Rodents

    PubMed Central

    Drexler, Jan Felix; Corman, Victor Max; Müller, Marcel Alexander; Lukashev, Alexander N.; Gmyl, Anatoly; Coutard, Bruno; Adam, Alexander; Ritz, Daniel; Leijten, Lonneke M.; van Riel, Debby; Kallies, Rene; Klose, Stefan M.; Gloza-Rausch, Florian; Binger, Tabea; Annan, Augustina; Adu-Sarkodie, Yaw; Oppong, Samuel; Bourgarel, Mathieu; Rupp, Daniel; Hoffmann, Bernd; Schlegel, Mathias; Kümmerer, Beate M.; Krüger, Detlev H.; Schmidt-Chanasit, Jonas; Setién, Alvaro Aguilar; Cottontail, Veronika M.; Hemachudha, Thiravat; Wacharapluesadee, Supaporn; Osterrieder, Klaus; Bartenschlager, Ralf; Matthee, Sonja; Beer, Martin; Kuiken, Thijs; Reusken, Chantal; Leroy, Eric M.; Ulrich, Rainer G.; Drosten, Christian

    2013-01-01

    Hepatitis C virus (HCV) is among the most relevant causes of liver cirrhosis and hepatocellular carcinoma. Research is complicated by a lack of accessible small animal models. The systematic investigation of viruses of small mammals could guide efforts to establish such models, while providing insight into viral evolutionary biology. We have assembled the so-far largest collection of small-mammal samples from around the world, qualified to be screened for bloodborne viruses, including sera and organs from 4,770 rodents (41 species); and sera from 2,939 bats (51 species). Three highly divergent rodent hepacivirus clades were detected in 27 (1.8%) of 1,465 European bank voles (Myodes glareolus) and 10 (1.9%) of 518 South African four-striped mice (Rhabdomys pumilio). Bats showed anti-HCV immunoblot reactivities but no virus detection, although the genetic relatedness suggested by the serologic results should have enabled RNA detection using the broadly reactive PCR assays developed for this study. 210 horses and 858 cats and dogs were tested, yielding further horse-associated hepaciviruses but none in dogs or cats. The rodent viruses were equidistant to HCV, exceeding by far the diversity of HCV and the canine/equine hepaciviruses taken together. Five full genomes were sequenced, representing all viral lineages. Salient genome features and distance criteria supported classification of all viruses as hepaciviruses. Quantitative RT-PCR, RNA in-situ hybridisation, and histopathology suggested hepatic tropism with liver inflammation resembling hepatitis C. Recombinant serology for two distinct hepacivirus lineages in 97 bank voles identified seroprevalence rates of 8.3 and 12.4%, respectively. Antibodies in bank vole sera neither cross-reacted with HCV, nor the heterologous bank vole hepacivirus. Co-occurrence of RNA and antibodies was found in 3 of 57 PCR-positive bank vole sera (5.3%). Our data enable new hypotheses regarding HCV evolution and encourage efforts to

  5. Transmission ecology of rodent-borne diseases: New frontiers.

    PubMed

    Bordes, Frédéric; Blasdell, Kim; Morand, Serge

    2015-09-01

    Rodents are recognized reservoir hosts for many human zoonotic pathogens. The current trends resulting from anthropocene defaunation suggest that in the future they, along with other small mammals, are likely to become the dominant mammals in almost all human-modified environments. Recent intricate studies on bat-borne emerging diseases have highlighted that many gaps exist in our understanding of the zoonotic transmission of rodent-borne pathogens. This has emphasized the need for scientists interested in rodent-borne diseases to integrate rodent ecology into their analysis of rodent-borne pathogen transmission in order to identify in more detail the mechanisms of spillover and chains of transmission. Further studies are required to better understand the true impact of rodent abundance and the importance of pathogen sharing and circulation in multi-host- multi-pathogen communities. We also need to explore in more depth the roles of generalist and abundant species as the potential links between pathogen-sharing, co-infections and disease transmission. PMID:26176684

  6. Rodent models for compulsive alcohol intake

    PubMed Central

    Hopf, F. Woodward; Lesscher, Heidi M.B.

    2014-01-01

    Continued seeking and drinking of alcohol despite adverse legal, health, economic, and societal consequences is a central hallmark of human alcohol use disorders. This compulsive drive for alcohol, defined by resistance to adverse and deleterious consequences, represents a major challenge when attempting to treat alcoholism clinically. Thus, there has long been interest in developing pre-clinical rodent models for the compulsive drug use that characterizes drug addiction. Here, we review recent studies that have attempted to model compulsive aspects of alcohol and cocaine intake in rodents, and consider technical and conceptual issues that need to be addressed when trying to recapitulate compulsive aspects of human addiction. Aversion-resistant alcohol intake has been examined by pairing intake or seeking with the bitter tastant quinine or with footshock, and exciting recent work has used these models to identify neuroadaptations in the amygdala, cortex, and striatal regions that promote compulsive intake. Thus, rodent models do seem to reflect important aspects of compulsive drives that sustain human addiction, and will likely provide critical insights into the molecular and circuit underpinnings of aversion-resistant intake as well as novel therapeutic interventions for compulsive aspects of addiction. PMID:24731992

  7. Rodent models for compulsive alcohol intake.

    PubMed

    Hopf, F Woodward; Lesscher, Heidi M B

    2014-05-01

    Continued seeking and drinking of alcohol despite adverse legal, health, economic, and societal consequences is a central hallmark of human alcohol use disorders. This compulsive drive for alcohol, defined by resistance to adverse and deleterious consequences, represents a major challenge when attempting to treat alcoholism clinically. Thus, there has long been interest in developing pre-clinical rodent models for the compulsive drug use that characterizes drug addiction. Here, we review recent studies that have attempted to model compulsive aspects of alcohol and cocaine intake in rodents, and consider technical and conceptual issues that need to be addressed when trying to recapitulate compulsive aspects of human addiction. Aversion-resistant alcohol intake has been examined by pairing intake or seeking with the bitter tastant quinine or with footshock, and exciting recent work has used these models to identify neuroadaptations in the amygdala, cortex, and striatal regions that promote compulsive intake. Thus, rodent models do seem to reflect important aspects of compulsive drives that sustain human addiction, and will likely provide critical insights into the molecular and circuit underpinnings of aversion-resistant intake as well as novel therapeutic interventions for compulsive aspects of addiction. PMID:24731992

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory Study § 58.130 Conduct of...

  9. Leaching of coal combustion products: Field and laboratory studies

    NASA Astrophysics Data System (ADS)

    Cheng, Chin-Min

    This study combines field monitoring and laboratory experiments to investigate the environmental impacts associated with the re-use of coal combustion by-products (CCPs). The monitoring data obtained from two full-scale CCP applications (i.e., re-use of fixated flue gas desulfurization (FGD) material as a low permeability liner for a swine manure pond and portland cement concrete pavements containing CCPs) allowed environmental impacts to be evaluated under real or simulated in-service conditions. A complimentary laboratory leaching study elucidated fundamental physical and chemical mechanisms that determine the leaching kinetics of inorganic contaminants from CCPs. In the first field study, water quality impacts associated with the re-use of FGD material as a low permeability liner for a swine manure pond were examined by monitoring the water quality of water samples collected from the pond surface water and a sump collection system beneath the liner over a period of 5 years. Water samples collected from the sump and pond surface water met all Ohio non-toxic criteria, and in fact, generally met all national primary and secondary drinking water standards. Furthermore it was found that hazardous (i.e., As, B, Cr, Cu, and Zn) and agricultural pollutants (i.e., phosphate and ammonia) were effectively retained by the FGD liner system. The retention might be due to both sorption and precipitation. In the second field study, the release of metals and metalloids from full-scale portland cement concrete pavements containing CCPs was evaluated by laboratory leaching tests and accelerated loading of full-scale pavement sections under controlled loading and environmental conditions. Three types of portland-cement-concrete driving surfaces were tested, including a control section (i.e., ordinary portland cement (OPC) concrete) containing no fly ash and two sections in which fly ash was substituted for a fraction of the cement; i.e., 30% fly ash (FA30) and 50% fly ash (FA50

  10. Laboratory study of the cosmic-ray muon lifetime

    NASA Astrophysics Data System (ADS)

    Ward, T.; Barker, M.; Breeden, J.; Komisarcik, K.; Pickar, M.; Wark, D.; Wiggins, J.

    1985-06-01

    The cosmic-ray muon lifetime was measured with a variety of counters designed to study both the free and μ- capture lifetimes. The data were obtained using scintillation detectors and a lead glass detector. These data show the dependence of μ- capture on the atomic number of the chemical element in the detector. The Z dependence of the weak interaction capture process is discussed in terms of the familiar Fermi (ΔJ=0) and Gamow-Teller (ΔJ=1) decays. This experiment was designed for use in advanced undergraduate physics laboratories.

  11. Laboratory and community studies of aircraft noise effects

    NASA Technical Reports Server (NTRS)

    Stephens, D. G.; Powell, C. A.

    1978-01-01

    The noise effects programs objective is to develop aircraft noise criteria and noise reduction methods for achieving greater community and passenger acceptance of air transportation systems. The approach consists of laboratory tests to subjectively evaluate the properties of aircraft-generated noise that are responsible for causing annoyance and field surveys to study the broader problems of community and passenger acceptability. The program is organized into two major thrusts: community acceptance and passenger acceptance. The community acceptance includes subjective response studies of single and multiple aircraft overflights as well as longer term community noise exposure. Emphasis is on the development of units and indices which accurately quantify annoyance. The passenger acceptance program includes studies to determine acceptably levels of interior noise and vibration for speech intelligibility and comfort of crew and passengers. Selected results from several recent studies are presented to indicate the nature, scope, and methods of the research program.

  12. Laboratory studies of oil spill bioremediation; toward understanding field behavior

    SciTech Connect

    Prince, R.C.; Hinton, S.M.; Elmendorf, D.L.; Lute, J.R.; Grossman, M.J.; Robbins, W.K.; Hsu, Chang S.; Richard, B.E.; Haith, C.E.; Senius, J.D.; Minak-Bernero, V.; Chianelli, R.R.; Bragg, J.R.; Douglas, G.S.

    1993-12-31

    Oil spill remediation aims to enhance the natural process of microbial hydrocarbon biodegradation. The microbial foundations have been studied throughout this century, but the focus of most of this work has been on the degradation of well defined compounds by well defined microbial species. This paper addresses laboratory studies on crude oil biodegradation by microbial consortia obtained from oiled beaches in Prince William Sound, Alaska following the spill from the Exxon Valdez. It demonstrates that oil degradation is indeed likely to be nitrogen-limited in Prince William Sound, the different molecular classes in crude oil that are subjected to biodegradation, the identification of conserved species in the oil that can be used for assessing biodegradation and bioremediation in the field, the effectiveness of fertilizers in stimulating sub-surface biodegradation, the role of the olephilic fertilizer Inipol EAP22, and the identification of the oil-degrading microorganisms in Prince William Sound. Together, these laboratory studies provided guidance and important insights into the microbial phenomena underlying the successful bioremediation of the oiled shorelines.

  13. Serologic Survey of Orthopoxvirus Infection Among Rodents in Hungary

    PubMed Central

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

    2015-01-01

    Abstract 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

  14. Simulation studies of plasma lens experiments at Daresbury laboratory

    NASA Astrophysics Data System (ADS)

    Hanahoe, K.; Mete, O.; Xia, G.; Angal-Kalinin, D.; Jones, J.; Smith, J.

    2016-03-01

    Experiments are planned to study plasma lensing using the VELA and CLARA Front End accelerators at Daresbury Laboratory. This paper presents results of 2-dimensional particle-in-cell simulations of the proposed experiments. The variation in focusing strength and emittance growth with beam and plasma parameters are studied in the overdense (plasma density much greater than bunch density) regime for the VELA beam. The effect of spherical and longitudinal aberrations on the beam emittance was estimated through numerical and theoretical studies. Simulation results show that a focusing strength equivalent to a magnetic field gradient of 10 T m-1 can be achieved using VELA, and a gradient of 247 T m-1 can be achieved using CLARA Front End.

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Records and Reports § 58.185 Reporting of nonclinical laboratory...

  16. Laboratories for the 21st Century: Case Studies; National Renewable Energy Laboratory, Science and Technology Facility, Golden, Colorado

    SciTech Connect

    Not Available

    2007-03-01

    This publication is one in series of case studies for "Laboratories for the 21st Century," a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy Federal Energy Management Program. It is intended for those who plan to design and construct public and private-sector laboratory buildings. This case study describes the Science and Technology Facility, a new laboratory at NREL that incorporated energy-efficient and sustainable design features including underfloor air distribution in offices, daylighting, and process cooling.

  17. Laboratory-Based Studies of Eating among Children and Adolescents

    PubMed Central

    Tanofsky-Kraff, Marian; Haynos, Ann F.; Kotler, Lisa A.; Yanovski, Susan Z.; Yanovski, Jack A.

    2008-01-01

    The prevalence of pediatric overweight has increased dramatically over the past three decades, likely due to changes in food intake as well as physical activity. Therefore, information examining eating patterns among children and adolescents is needed to illuminate which aspects of eating behavior require modification to prevent and treat pediatric overweight. Because child self-report and parent-report of children's eating habits are often inconsistent and limited by recall and other biases, laboratory-based studies in which food intake is observed and monitored have increased in number. Such studies offer objective and controlled methods of measuring and describing eating behaviors. However, to our knowledge, no publication exists that consolidates, reviews, and provides critical commentary on the literature to date in pediatric samples. In this paper, we review the literature of studies utilizing laboratory methods to examine eating behavior in samples ranging from birth through adolescence. Our review includes all relevant articles retrieved from the PubMed, Medline and PsychInfo search engines. Specifically, we examine meal-feeding studies conducted during the various developmental stages (infancy, preschool, middle childhood, and adolescence), with a focus on methodology. Included in our review are feeding studies related to dietary regulation, exposure and preference, as well as paradigms examining disordered eating patterns and their relationship to body composition. We have structured this review so that both consistent and inconsistent findings are presented by age group, and innovative methods of assessment are discussed in more detail. Following each section, we summarize findings and draw potential conclusions from the available data. We then discuss clinical implications of the research data and suggest directions for the next generation of studies of feeding behavior in children. PMID:19030122

  18. Laboratory-Based Studies of Eating among Children and Adolescents.

    PubMed

    Tanofsky-Kraff, Marian; Haynos, Ann F; Kotler, Lisa A; Yanovski, Susan Z; Yanovski, Jack A

    2007-01-01

    The prevalence of pediatric overweight has increased dramatically over the past three decades, likely due to changes in food intake as well as physical activity. Therefore, information examining eating patterns among children and adolescents is needed to illuminate which aspects of eating behavior require modification to prevent and treat pediatric overweight. Because child self-report and parent-report of children's eating habits are often inconsistent and limited by recall and other biases, laboratory-based studies in which food intake is observed and monitored have increased in number. Such studies offer objective and controlled methods of measuring and describing eating behaviors. However, to our knowledge, no publication exists that consolidates, reviews, and provides critical commentary on the literature to date in pediatric samples. In this paper, we review the literature of studies utilizing laboratory methods to examine eating behavior in samples ranging from birth through adolescence. Our review includes all relevant articles retrieved from the PubMed, Medline and PsychInfo search engines. Specifically, we examine meal-feeding studies conducted during the various developmental stages (infancy, preschool, middle childhood, and adolescence), with a focus on methodology. Included in our review are feeding studies related to dietary regulation, exposure and preference, as well as paradigms examining disordered eating patterns and their relationship to body composition. We have structured this review so that both consistent and inconsistent findings are presented by age group, and innovative methods of assessment are discussed in more detail. Following each section, we summarize findings and draw potential conclusions from the available data. We then discuss clinical implications of the research data and suggest directions for the next generation of studies of feeding behavior in children. PMID:19030122

  19. Laboratory studies of radionuclide transport in fractured Climax granite

    SciTech Connect

    Failor, R.; Isherwood, D.; Raber, E.; Vandergraaf, T.

    1982-06-01

    This report documents our laboratory studies of radionuclide transport in fractured granite cores. To simulate natural conditions, our laboratory studies used naturally fractured cores and natural ground water from the Climax Granite Stock at the Nevada Test Site. For comparison, additional tests used artificially fractured granite cores or distilled water. Relative to the flow of tritiated water, {sup 85}Sr and /sup 95m/Tc showed little or no retardation, whereas {sup 137}Cs was retarded. After the transport runs the cores retained varying amounts of the injected radionuclides along the fracture. Autoradiography revealed some correlation between sorption and the fracture fill material. Strontium and cesium retention increased when the change was made from natural ground water to distilled water. Artificial fractures retained less {sup 137}Cs than most natural fractures. Estimated fracture apertures from 18 to 60 {mu}m and hydraulic conductivities from 1.7 to 26 x 10{sup -3} m/s were calculated from the core measurements.

  20. Laboratory plant study on the melting process of asbestos waste

    SciTech Connect

    Sakai, Shinichi; Terazono, Atsushi; Takatsuki, Hiroshi; Tsunemi, Takeshi

    1996-12-31

    The melting process was studied as a method of changing asbestos into non-hazardous waste and recovering it as a reusable resource. In an initial effort, the thermal behaviors of asbestos waste in terms of physical and chemical structure have been studied. Then, 10 kg/h-scale laboratory plant experiments were carried out. By X-ray diffraction analysis, the thermal behaviors of sprayed-on asbestos waste revealed that chrysotile asbestos waste change in crystal structure at around 800 C, and becomes melted slag, mainly composed of magnesium silicate, at around 1,500 C. Laboratory plant experiments on the melting process of sprayed-on asbestos have shown that melted slag can be obtained. X-ray diffraction analysis of the melted slag revealed crystal structure change, and SEM analysis showed the slag to have a non-fibrous form. And more, TEM analysis proved the very high treatment efficiency of the process, that is, reduction of the asbestos content to 1/10{sup 6} as a weight basis. These analytical results indicate the effectiveness of the melting process for asbestos waste treatment.

  1. 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.

  2. Circadian pattern of wheel-running activity of a South American subterranean rodent (Ctenomys cf knightii).

    PubMed

    Valentinuzzi, Veronica Sandra; Oda, Gisele Akemi; Araujo, John Fontenele; Ralph, Martin Roland

    2009-01-01

    Circadian rhythms are regarded as essentially ubiquitous features of animal behavior and are thought to confer important adaptive advantages. However, although circadian systems of rodents have been among the most extensively studied, most comparative biology is restricted to a few related species. In this study, the circadian organization of locomotor activity was studied in the subterranean, solitary north Argentinean rodent, Ctenomys knightii. The genus, Ctenomys, commonly known as Tuco-tucos, comprises more than 50 known species over a range that extends from 12 degrees S latitude into Patagonia, and includes at least one social species. The genus, therefore, is ideal for comparative and ecological studies of circadian rhythms. Ctenomys knightii is the first of these to be studied for its circadian behavior. All animals were wild caught but adapted quickly to laboratory conditions, with clear and precise activity-rest rhythms in a light-dark (LD) cycle and strongly nocturnal wheel running behavior. In constant dark (DD), the rhythm expression persisted with free-running periods always longer than 24 h. Upon reinstatement of the LD cycle, rhythms resynchronized rapidly with large phase advances in 7/8 animals. In constant light (LL), six animals had free-running periods shorter than in DD, and 4/8 showed evidence of "splitting." We conclude that under laboratory conditions, in wheel-running cages, this species shows a clear nocturnal rhythmic organization controlled by an endogenous circadian oscillator that is entrained to 24 h LD cycles, predominantly by light-induced advances, and shows the same interindividual variable responses to constant light as reported in other non-subterranean species. These data are the first step toward understanding the chronobiology of the largest genus of subterranean rodents. PMID:19142755

  3. Laboratory Based Case Studies: Closer to the Real World

    ERIC Educational Resources Information Center

    Dinan, Frank J.

    2005-01-01

    Case-based laboratories offer students the chance to approximate real science. Based on interesting stories that pose problems requiring experimental solutions, they avoid the cookbook approach characteristic of traditional undergraduate laboratory instruction. Instead, case-based laboratories challenge students to develop, as much as possible,…

  4. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be maintained free of rodent infestation through the use of traps, poisons, and other generally accepted...

  5. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be maintained free of rodent infestation through the use of traps, poisons, and other generally accepted...

  6. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be maintained free of rodent infestation through the use of traps, poisons, and other generally accepted...

  7. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be... of rodent control....

  8. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be... of rodent control....

  9. 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.

  10. Oxytocin-dependent consolation behavior in rodents

    PubMed Central

    Burkett, J. P.; Andari, E.; Johnson, Z. V.; Curry, D. C.; de Waal, F. B. M.; Young, L. J.

    2016-01-01

    Consolation behavior toward distressed others is common in humans and great apes, yet our ability to explore the biological mechanisms underlying this behavior is limited by its apparent absence in laboratory animals. Here, we provide empirical evidence that a rodent species, the highly social and monogamous prairie vole (Microtus ochrogaster), greatly increases partner-directed grooming toward familiar conspecifics (but not strangers) that have experienced an unobserved stressor, providing social buffering. Prairie voles also match the fear response, anxiety-related behaviors, and corticosterone increase of the stressed cagemate, suggesting an empathy mechanism. Exposure to the stressed cagemate increases activity in the anterior cingulate cortex, and oxytocin receptor antagonist infused into this region abolishes the partner-directed response, showing conserved neural mechanisms between prairie vole and human. PMID:26798013

  11. Oxytocin-dependent consolation behavior in rodents.

    PubMed

    Burkett, J P; Andari, E; Johnson, Z V; Curry, D C; de Waal, F B M; Young, L J

    2016-01-22

    Consolation behavior toward distressed others is common in humans and great apes, yet our ability to explore the biological mechanisms underlying this behavior is limited by its apparent absence in laboratory animals. Here, we provide empirical evidence that a rodent species, the highly social and monogamous prairie vole (Microtus ochrogaster), greatly increases partner-directed grooming toward familiar conspecifics (but not strangers) that have experienced an unobserved stressor, providing social buffering. Prairie voles also match the fear response, anxiety-related behaviors, and corticosterone increase of the stressed cagemate, suggesting an empathy mechanism. Exposure to the stressed cagemate increases activity in the anterior cingulate cortex, and oxytocin receptor antagonist infused into this region abolishes the partner-directed response, showing conserved neural mechanisms between prairie vole and human. PMID:26798013

  12. 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

  13. Feasibility study of medical isotope production at Sandia National Laboratories

    SciTech Connect

    Massey, C.D.; Miller, D.L.; Carson, S.D.

    1995-12-01

    In late 1994, Sandia National Laboratories in Albuquerque, New Mexico, (SNL/NM), was instructed by the Department of Energy (DOE) Isotope Production and Distribution Program (IPDP) to examine the feasibility of producing medically useful radioisotopes using the Annular Core Research Reactor (ACRR) and the Hot Cell Facility (HCF). Los Alamos National Laboratory (LANL) would be expected to supply the targets to be irradiated in the ACRR. The intent of DOE would be to provide a capability to satisfy the North American health care system demand for {sup 99}Mo, the parent of {sup 99m}Tc, in the event of an interruption in the current Canadian supply. {sup 99m}Tc is used in 70 to 80% of all nuclear medicine procedures in the US. The goal of the SNL/NM study effort is to determine the physical plant capability, infrastructure, and staffing necessary to meet the North American need for {sup 99}Mo and to identify and examine all issues with potential for environmental impact.

  14. Laboratory study of carbonaceous dust and molecules of astrochemical interest

    NASA Astrophysics Data System (ADS)

    Cataldo, F.; Garcia-Hernandez, D. A.; Manchado, A.; Kwok, S.

    2016-07-01

    In this paper are reviewed some research works dedicated to the study of carbonaceous dust and molecules of astrochemical interest. First of all it is discussed the carbon arc through which it is possible to produce carbon soot and fullerenes under helium but also many other different products just changing the arcing conditions. For example, when the carbon arc is struck in an hydrocarbon solvent it is possible to produce and trap polyynes in the solvent. Monocyanopolyynes and dicyanopolyynes can be produced as well by selecting the appropriate conditions. Amorphous carbon soot or partially graphitized carbon black can be produced with the carbon arc. Fullerenes were found in space thanks to the reference infrared spectra and the absorption cross sections which were determined in laboratory. Fullerenes are readily reactive with hydrogen yielding fulleranes the hydrogenated fullerenes. Furthermore fullerenes react with PAHs and with iron carbonyl yielding adducts. All these fullerene derivatives were synthesized and their reference spectra recorded in laboratory. It was proposed that petroleum fractions can be used as model substrates in the explanation of the carriers of the AIB (Aromatic Infrared Bands) observed in protoplanetary and planetary nebulae and the UIE (Unidentified Infrared Bands) found in the interstellar medium.

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

    SciTech Connect

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

    1995-07-01

    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 improve the low combustion efficiency, a fuel zoning combustion concept was investigated by using a subscale combustor model first. Combustion efficiency more than 90 percent was achieved and the concept was found very effective. Then a laboratory scale ram combustor was fabricated and combustion tests were carried out mainly at the simulated condition of Mach 5. A vitiation technique wa used to simulate a high temperature of 1,263 K. The test results indicate that ignition, flame stability, and combustion efficiency were not significant, but the NO{sub x} emissions are a critical problem for the ram combustor at Mach 5 condition.

  16. METABOLIC AND THERMOREGULATORY RESPONSES OF THE RAT MAINTAINED IN ACRYLIC OR WIRE-SCREEN CAGES: IMPLICATIONS FOR PHARMACOLOGICAL STUDIES

    EPA Science Inventory

    Laboratory rodents are usually housed and studied in cages with walls and floor made of ventilated metal or solid plastic materials. It should be recognized that a rodent's thermoregulatory requirements will vary in metal and plastic cages; and it is likely that its metabolic res...

  17. Study of CSR Effects in the Jefferson Laboratory FEL Driver

    SciTech Connect

    Hall, C. C.; Biedron, S.; Burleson, Theodore A.; Milton, Stephen V.; Morin, Auralee L.; Benson, Stephen V.; Douglas, David R.; Evtushenko, Pavel E.; Hannon, Fay E.; Li, Rui; Tennant, Christopher D.; Zhang, Shukui; Carlsten, Bruce E.; Lewellen, John W.

    2013-08-01

    In a recent experiment conducted on the Jefferson Laboratory IR FEL driver the effects of Coherent Synchrotron Radiation (CSR) on beam quality were studied. The primary goal of this work was to explore CSR output and effect on the beam with variation of the bunch compression in the IR chicane. This experiment also provides a valuable opportunity to benchmark existing CSR models in a system that may not be fully represented by a 1-D CSR model. Here we present results from this experiment and compare to initial simulations of CSR in the magnetic compression chicane of the machine. Finally, we touch upon the possibility for CSR induced microbunching gain in the magnetic compression chicane, and show that parameters in the machine are such that it should be thoroughly damped.

  18. An Undergraduate Laboratory Exercise to Study Weber’s Law

    PubMed Central

    Holden, Jameson K.; Francisco, Eric M.; Zhang, Zheng; Baric, Cristina; Tommerdahl, Mark

    2011-01-01

    Weber’s Law describes the relationship between actual and perceived differences in stimulus intensity. To observe the relationship described in this law, we developed an exercise for undergraduate students, as experiential learning is an integral part of scientific education. We describe the experimental methods used for determining the subject’s discriminative capacity at multiple vibrotactile amplitudes. A novel four-point stimulator (designed and fabricated at the University of North Carolina) was used for the study. Features of the device, such as automated skin detection, make it feasible to perform this laboratory exercise in a reasonable lab period. At the conclusion of the lab exercise, students will thoroughly understand the principle of Weber’s Law as well as fundamental quantitative sensory testing concepts. This introduction to sensory testing will provide a suitable foundation for the undergraduate neuroscience student to investigate other aspects of sensory information processing in subsequent lab exercises. PMID:23493843

  19. NASA ER-2: Flying Laboratory for Earth Science Studies

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    2007-01-01

    This viewgraph presentation gives an overview of the NASA ER-2 aircraft. The contents include: 1) ER-2 Specifications; 2) ER-2 Basic Configuration; 3) ER-2 Payload Areas: Nose Area; 4) ER-2 Payload Areas: SuperPod Fore and Aftbody; 5) ER-2 Payload Areas: SuperPod Midbody; 6) ER-2 Payload Areas: Q-Bay; 7) ER-2 Payload Areas: Q-Bay Hatch Designs; 8) ER-2 Payload Areas: External Pods; 9) ER-2 Electrical/Control Interface; 10) ER-2 Typical Flight Profile; 11) Tropical Composition, Cloud and Climate Coupling TC-4; 12) TC-4 Timeline; 13) TC4 Area of Interest; 14) ER-2 TC4 Payload; 15) A/C ready for fuel; 16) ER-2 Pilot being suited; 17) ER-2 Taxing; 18) ER-2 Pilot post flight debrief; and 19) NASA ER-2: Flying Laboratory for Earth Science Studies and Remote Sensing.

  20. 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..

  1. Laboratory study of vortex dipoles interacting with step topography

    NASA Astrophysics Data System (ADS)

    Hinds, A. K.; Eames, I.; Johnson, E. R.; McDonald, N. R.

    2009-06-01

    Laboratory experiments are performed which study the behavior of two-dimensional vortex dipoles propagating toward a rectilinear step change in depth. The dipoles are formed in a homogeneous shallow water layer by an impulsive jet and approach the step from either relatively deep or shallow water at normal or oblique incidence. Qualitative observations agree well with previous theoretical predictions: At normal incidence the separation of the two vortices forming the dipole increases for a dipole crossing from deep water and decreases for a dipole crossing from shallow water. Dipoles with oblique angles of incidence refract toward the normal when passing into shallower water, and dipoles that cross the step into deep water refract away from the normal. Dipoles approaching from shallow water at sufficiently large angles of incidence reflect off the step.

  2. Laboratory studies of baroclinic instability at small Richardson number

    NASA Technical Reports Server (NTRS)

    Miller, T. L.; Fowlis, W. W.

    1984-01-01

    As part of the support program for the Atmospheric General Circulation Experiment, laboratory studies of baroclinic and other convective instabilities were performed for a thin layer of fluid between thermally conducting horizontal discs. There were three types of modes identified. The first has a spiral-arm appearance, and exists for large enough horizontal thermal forcing, weak enough static stability, and large enough rotation. The source of this wave is shown to be the Eady mode of instability. The second mode is due to convective instability in the thermal boundary layers which exist due to the thermally conducting horizontal boundaries. Finally, for strong enough negative static stability, thermal convection of the Benard type appears. The most significant result is that the symmetric (Solberg) mode was not found, even though the infinite-plane theory predicts this mode under certain experimental conditions.

  3. Laboratory Scale Antifoam Studies for the STTPB Process

    SciTech Connect

    Baich, M.A.

    2001-02-13

    Three candidate antifoam/defoam agents were tested on a laboratory scale with simulated KTPB slurry using the proposed STTPB process precipitation, concentration, and washing steps. Conclusions are if air entrainment in the slurry is carefully avoided, little or no foam will be generated during normal operations during precipitation, concentration, and washing of the precipitate. Three candidate antifoam/defoam agents were tested on a laboratory scale with simulated KTPB slurry using the proposed STTPB process precipitation, concentration and washing steps. In all cases little or no foam formed during normal operations of precipitation, concentration and washing. Foam was produced by purposely-introducing gas sub-surface into the slurry. Once produced, the IIT B52 antifoam was effective in defoaming the slurry. In separate foam column tests, all antifoam/defoam agents were effective in mitigating foam formation and in defoaming a foamed 10 wt % insoluble solids slurry. Based on the results in this report as well as foam column studies at IIT, it is recommended that IIT B52 antifoam at the 1000 ppmV level be used in subsequent STTPB work where foaming is a concern. This study indicates that the addition of antifoam agent hinders the recovery of NaTPB during washing. Washing precipitate with no antifoam agent added had the highest level of NaTPB recovery, but had the shortest overall washing time ({approximately}19 hours) compared to 26-28 hours for antifoam runs. The solubilities of the three candidate antifoam/defoam agents were measured in a 4.7 M sodium salt solution. The Surfynol DF-110D defoamer was essentially insoluble while the two IIT antifoamers; Particle Modifier (PM) and B52 were soluble to at least the 2000 ppmV level.

  4. 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

  5. Prospective power calculations for the Four Lab study of a multigenerational reproductive/developmental toxicity rodent bioassay using a complex mixture of disinfection by-products in the low-response region.

    PubMed

    Dingus, Cheryl A; Teuschler, Linda K; Rice, Glenn E; Simmons, Jane Ellen; Narotsky, Michael G

    2011-10-01

    In complex mixture toxicology, there is growing emphasis on testing environmentally representative doses that improve the relevance of results for health risk assessment, but are typically much lower than those used in traditional toxicology studies. Traditional experimental designs with typical sample sizes may have insufficient statistical power to detect effects caused by environmentally relevant doses. Proper study design, with adequate statistical power, is critical to ensuring that experimental results are useful for environmental health risk assessment. Studies with environmentally realistic complex mixtures have practical constraints on sample concentration factor and sample volume as well as the number of animals that can be accommodated. This article describes methodology for calculation of statistical power for non-independent observations for a multigenerational rodent reproductive/developmental bioassay. The use of the methodology is illustrated using the U.S. EPA's Four Lab study in which rodents were exposed to chlorinated water concentrates containing complex mixtures of drinking water disinfection by-products. Possible experimental designs included two single-block designs and a two-block design. Considering the possible study designs and constraints, a design of two blocks of 100 females with a 40:60 ratio of control:treated animals and a significance level of 0.05 yielded maximum prospective power (~90%) to detect pup weight decreases, while providing the most power to detect increased prenatal loss. PMID:22073030

  6. Field and Laboratory Studies of Atmospheric Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Coggon, Matthew Mitchell

    This thesis is the culmination of field and laboratory studies aimed at assessing processes that affect the composition and distribution of atmospheric organic aerosol. An emphasis is placed on measurements conducted using compact and high-resolution Aerodyne Aerosol Mass Spectrometers (AMS). The first three chapters summarize results from aircraft campaigns designed to evaluate anthropogenic and biogenic impacts on marine aerosol and clouds off the coast of California. Subsequent chapters describe laboratory studies intended to evaluate gas and particle-phase mechanisms of organic aerosol oxidation. The 2013 Nucleation in California Experiment (NiCE) was a campaign designed to study environments impacted by nucleated and/or freshly formed aerosol particles. Terrestrial biogenic aerosol with > 85% organic mass was observed to reside in the free troposphere above marine stratocumulus. This biogenic organic aerosol (BOA) originated from the Northwestern United States and was transported to the marine atmosphere during periodic cloud-clearing events. Spectra recorded by a cloud condensation nuclei counter demonstrated that BOA is CCN active. BOA enhancements at latitudes north of San Francisco, CA coincided with enhanced cloud water concentrations of organic species such as acetate and formate. Airborne measurements conducted during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) were aimed at evaluating the contribution of ship emissions to the properties of marine aerosol and clouds off the coast of central California. In one study, analysis of organic aerosol mass spectra during periods of enhanced shipping activity yielded unique tracers indicative of cloud-processed ship emissions (m/z 42 and 99). The variation of their organic fraction (f42 and f 99) was found to coincide with periods of heavy (f 42 > 0.15; f99 > 0.04), moderate (0.05 < f42 < 0.15; 0.01 < f99 < 0.04), and negligible (f42 < 0.05; f99 < 0.01) ship influence. Application of

  7. 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.

  8. Assays of homeopathic remedies in rodent behavioural and psychopathological models.

    PubMed

    Bellavite, Paolo; Magnani, Paolo; Marzotto, Marta; Conforti, Anita

    2009-10-01

    The first part of this paper reviews the effects of homeopathic remedies on several models of anxiety-like behaviours developed and described in rodents. The existing literature in this field comprises some fifteen exploratory studies, often published in non-indexed and non-peer-reviewed journals. Only a few results have been confirmed by multiple laboratories, and concern Ignatia, Gelsemium, Chamomilla (in homeopathic dilutions/potencies). Nevertheless, there are some interesting results pointing to the possible efficacy of other remedies, and confirming a statistically significant effect of high dilutions of neurotrophic molecules and antibodies. In the second part of this paper we report some recent results obtained in our laboratory, testing Aconitum, Nux vomica, Belladonna, Argentum nitricum, Tabacum (all 5CH potency) and Gelsemium (5, 7, 9 and 30CH potencies) on mice using ethological models of behaviour. The test was performed using coded drugs and controls in double blind (operations and calculations). After an initial screening that showed all the tested remedies (except for Belladonna) to have some effects on the behavioural parameters (light-dark test and open-field test), but with high experimental variability, we focused our study on Gelsemium, and carried out two complete series of experiments. The results showed that Gelsemium had several effects on the exploratory behaviour of mice, which in some models were highly statistically significant (p < 0.001), in all the dilutions/dynamizations used, but with complex differences according to the experimental conditions and test performed. Finally, some methodological issues of animal research in this field of homeopathy are discussed. The "Gelsemium model" - encompassing experimental studies in vitro and in vivo from different laboratories and with different methods, including significant effects of its major active principle gelsemine - may play a pivotal rule for investigations on other homeopathic

  9. Microbial colonization of retorted shale in field and laboratory studies

    SciTech Connect

    Rogers, J.E.; McNair, V.M.; Li, S.W.; Garland, T.R.; Wildung, R.E.

    1982-08-01

    The microbial colonization of retorted shale was measured in field lysimeters and laboratory with retorted shale obtained from an above-ground retort operating in the direct heating mode. In field lysimeter studies, total aerobic heterotrophic bacterial colony forming units (cfu), as measured by a selective plating medium in surface horizons of retorted shale and adjacent soils, were similar (3.3 x 10/sup 6/ and 2.7 x 10/sup 6/ bacterial cfu/g dry weight) two months after disposal. However, unlike the soil that exhibited a diverse community, the retorted shale was dominated by a single Micrococcus species that composed 30% of the total bacterial community. After one and two years, the total aerobic heterotrophic bacterial cfu in the retorted shale and soil were again similar; however, no bacterium dominated either community. A core sample from the field lysimeter indicated microbial colonization to a depth of 150 cm after one year. An increased ratio of anaerobic to aerobic heterotrophic bacterial cfu in the deepest sample (120 to 150 cm) implied the development of anaerobic conditions. In the laboratory, aerobic heterotrophic bacteria were shown capable of using, as the sole source of carbon, retorted shale in liquid cultures. Of the added nutritional amendments, PO/sub 4//sup -3/, NO/sub 3//sup -/ and SO/sub 4//sup -2/, only phosphate markedly altered the colonization of retorted shale in liquid culture; shortening the lag phase of colonization from less than three to seven weeks to less than one week and leading to a greater aerobic heterotrophic population over the incubation interval. The addition of phosphate also led to a aerobic heterotrophic bacterial community composed entirely of Micrococcus species.

  10. Laboratory Studies of Supersonic Magnetized Plasma Jets and Radiative Shocks

    NASA Astrophysics Data System (ADS)

    Lebedev, Sergey

    2013-06-01

    In this talk I will focus on laboratory plasma experiments producing magnetically driven supersonic plasma jets and on the interaction of these jets with ambient media. The experiments are scalable to astrophysical flows in that the critical dimensionless numbers such as the plasma collisionality, the plasma beta, the Reynolds number and the magnetic Reynolds number are all in the astrophysically appropriate ranges. The experimental results will be compared with computer simulations performed with laboratory plasma codes and with astrophysical codes. In the experiments the jets are driven and collimated by the toroidal magnetic fields and it is found that the level of MHD instabilities in the jets strongly depends on the strength of the field represented by the ratio of the thermal to magnetic field pressures (plasma beta). The experiments show the possibility of formation of episodic outflows, with periodic ejections of magnetic bubbles naturally evolving into a heterogeneous jet propagating inside a channel made of self-collimated magnetic cavities [1,2]. We also found that it is possible to form quasi-laminar jets which are “indirectly” collimated by the toroidal magnetic fields, but this requires the presence of the lower density halo plasma surrounding the central jet [3]. Studies of the radiative shocks formed in the interaction of the supersonic magnetized plasma flows with ambient plasma will be also presented, and the development of cooling instabilities in the post-shock plasma will be discussed. This research was sponsored by EPSRC Grant No. EP/G001324/1 and by the OFES DOE under DOE Cooperative Agreement No. DE-SC-0001063. References 1. A. Ciardi, S.V. Lebedev, A. Frank et al., The Astrophysical Journal, 691: L147-L150 (2009) 2. F.A. Suzuki-Vidal, S.V. Lebedev, S.N. Bland et al., Physics of Plasmas, 17, 112708 (2010). 3. F.A. Suzuki-Vidal, M. Bocchi, S.V. Lebedev et al., Physics of Plasmas, 19, 022708 (2012).

  11. Tularemia and plague survey in rodents in an earthquake zone in southeastern Iran

    PubMed Central

    Gyuranecz, Miklós

    2015-01-01

    OBJECTIVES: Earthquakes are one the most common natural disasters that lead to increased mortality and morbidity from transmissible diseases, partially because the rodents displaced by an earthquake can lead to an increased rate of disease transmission. The aim of this study was to evaluate the prevalence of plague and tularemia in rodents in the earthquake zones in southeastern Iran. METHODS: In April 2013, a research team was dispatched to explore the possible presence of diseases in rodents displaced by a recent earthquake magnitude 7.7 around the cities of Khash and Saravan in Sistan and Baluchestan Province. Rodents were trapped near and in the earthquake zone, in a location where an outbreak of tularemia was reported in 2007. Rodent serums were tested for a serological survey using an enzyme-linked immunosorbent assay. RESULTS: In the 13 areas that were studied, nine rodents were caught over a total of 200 trap-days. Forty-eight fleas and 10 ticks were obtained from the rodents. The ticks were from the Hyalomma genus and the fleas were from the Xenopsylla genus. All the trapped rodents were Tatera indica. Serological results were negative for plague, but the serum agglutination test was positive for tularemia in one of the rodents. Tatera indica has never been previously documented to be involved in the transmission of tularemia. CONCLUSIONS: No evidence of the plague cycle was found in the rodents of the area, but evidence was found of tularemia infection in rodents, as demonstrated by a positive serological test for tularemia in one rodent. PMID:26602769

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

    SciTech Connect

    Anderson, L.E.

    1992-06-01

    Studies have been 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 have been 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 have been conducted to demonstrate an apparent stress-related response in rats exposed to 60-Hz electric fields. Nighttime pineal melatonin levels have been 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 have been performed which form the basis for animals and human exposure comparisons.

  13. Recent laboratory studies of loudness and annoyance to sonic booms

    NASA Technical Reports Server (NTRS)

    Leatherwood, Jack D.; Sullivan, Brenda M.

    1993-01-01

    NASA Langley Research Center is supporting NASA High-Speed Research Program efforts to develop an updated technology base for future high-speed civil transport aircraft. Part of this effort involves (a) quantification of loudness and annoyance benefits due to sonic boom shaping and (b) determination of boom exposures acceptable to the public. Langley is conducting a series of laboratory studies to investigate in detail the subjective reactions to a wide range of shaped sonic boom signatures and to examine several metrics as estimators of sonic boom subjective effects. Results from several of these studies, as well as results obtained by other investigators, demonstrated that substantial reductions in the loudness of sonic booms can be achieved by careful shaping of the boom signatures. Recent Langley studies extended this work to include: (a) quantification of subjective effects due to booms heard indoors, (b) determination of subjective reactions due to ground-reflected booms, and (c) determination of subjective reactions to simulator reproductions of booms recently at White Sands Missile Range.

  14. 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.

  15. Native Rodent Species Are Unlikely Sources of Infection for Leishmania (Viannia) braziliensis along the Transoceanic Highway in Madre de Dios, Peru

    PubMed Central

    Shender, Lisa A.; De Los Santos, Maxy; Montgomery, Joel M.; Conrad, Patricia A.; Ghersi, Bruno M.; Razuri, Hugo; Lescano, Andres G.; Mazet, Jonna A. K.

    2014-01-01

    An estimated 2.3 million disability-adjusted life years are lost globally from leishmaniasis. In Peru's Amazon region, the department of Madre de Dios (MDD) rises above the rest of the country in terms of the annual incidence rates of human leishmaniasis. Leishmania (Viannia) braziliensis is the species most frequently responsible for the form of disease that results in tissue destruction of the nose and mouth. However, essentially nothing is known regarding the reservoirs of this vector-borne, zoonotic parasite in MDD. Wild rodents have been suspected, or proven, to be reservoirs of several Leishmania spp. in various ecosystems and countries. Additionally, people who live or work in forested terrain, especially those who are not regionally local and whose immune systems are thus naïve to the parasite, are at most risk for contracting L. (V.) braziliensis. Hence, the objective of this study was to collect tissues from wild rodents captured at several study sites along the Amazonian segment of the newly constructed Transoceanic Highway and to use molecular laboratory techniques to analyze samples for the presence of Leishmania parasites. Liver tissues were tested via polymerase chain reaction from a total of 217 rodents; bone marrow and skin biopsies (ear and tail) were also tested from a subset of these same animals. The most numerous rodent species captured and tested were Oligoryzomys microtis (40.7%), Hylaeamys perenensis (15.7%), and Proechimys spp. (12%). All samples were negative for Leishmania, implying that although incidental infections may occur, these abundant rodent species are unlikely to serve as primary reservoirs of L. (V.) braziliensis along the Transoceanic Highway in MDD. Therefore, although these rodent species may persist and even thrive in moderately altered landscapes, we did not find any evidence to suggest they pose a risk for L. (V.) braziliensis transmission to human inhabitants in this highly prevalent region. PMID:25062033

  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. 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

  18. 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

  19. Development and implementation of multimedia content for an electronic learning course on rodent surgery.

    PubMed

    Baran, Szczepan W; Johnson, Elizabeth J; Kehler, James; Hankenson, F Claire

    2010-05-01

    The development of new rodent models of human disease and advances in surgical equipment and technologies have increased the demand for expertise in rodent surgery. Because of the limited availability of rodent surgical training courses, electronic (e-) learning is presented as an alternative to in-person education and as a means to hone the expertise of current surgeons in biomedical research, similar to e-learning applications for human surgery training. Translating this model to the biomedical research field provides participants with an opportunity to train themselves on rodent surgical techniques prior to operating on live models. An e-learning rodent surgery course was incorporated into a training class of undergraduate (n = 39) and graduate (n = 12) laboratory animal students, and a portion of the course was presented to laboratory animal professionals (n = 15). The effectiveness of the method was evaluated using written examination and postcourse surveys. The exam data demonstrated that the e-learning course transferred knowledge comparable to a lecture course on surgery that was presented in-person. Students responded favorably to videos, step-by-step photographs of surgical procedures, and the ready accessibility of the course. Critiques included the need to improve video resolution and quality of the voice-overs. These results support the continued development and implementation of electronic rodent surgical technique courses for use in laboratory animal and biomedical research communities. PMID:20587161

  20. Software Engineering Laboratory Ada performance study: Results and implications

    NASA Technical Reports Server (NTRS)

    Booth, Eric W.; Stark, Michael E.

    1992-01-01

    The SEL is an organization sponsored by NASA/GSFC to investigate the effectiveness of software engineering technologies applied to the development of applications software. The SEL was created in 1977 and has three organizational members: NASA/GSFC, Systems Development Branch; The University of Maryland, Computer Sciences Department; and Computer Sciences Corporation, Systems Development Operation. The goals of the SEL are as follows: (1) to understand the software development process in the GSFC environments; (2) to measure the effect of various methodologies, tools, and models on this process; and (3) to identify and then to apply successful development practices. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that include the Ada Performance Study Report. This paper describes the background of Ada in the Flight Dynamics Division (FDD), the objectives and scope of the Ada Performance Study, the measurement approach used, the performance tests performed, the major test results, and the implications for future FDD Ada development efforts.

  1. Development of a corrosion inhibition model. 1: Laboratory studies

    SciTech Connect

    Hausler, R.H.; Martin, T.G.; Stegmann, D.W.; Ward, M.B.

    1999-11-01

    The production of a CO{sub 2} flood in the Oklahoma panhandle led to severe corrosion of the carbon steel production tubing and casing. Traditional approaches to chemical corrosion inhibition were unsuccessful. A laboratory study was initiated to determine first the best corrosion inhibitor, and second the optimum effective inhibitor concentration in the produced fluids as a function of the production rate, CO{sub 2} partial pressure, and water to oil ratio. The tool used was the high speed autoclave test (HSACT) discussed in earlier publications. Statistical experimental designs were used to study the three major parameters. The results were expressed in terms of the inhibitor concentration necessary to achieve a desired corrosion rate (for example 1 mpy), and presented either in the form of response surfaces or linear multiple regression equations. While it was generally known that higher fluid velocities require a higher inhibitor concentration for equal target corrosion rates, it was less well appreciated that the CO{sub 2} partial pressure also has a significant effect on the effective inhibitor concentration. The model as represented either by the response surface or the predictive equations is both inhibitor and field specific.

  2. A chamber for laboratory studies of atmospheric aerosols and clouds

    NASA Astrophysics Data System (ADS)

    Narus, M. L.; Schoenfelder, N. C.; Na, Y.; Chavasse, L. A.; Disselkamp, R. S.

    1996-12-01

    A stainless-steel chamber has been constructed and interfaced to a Fourier transform infrared spectrometer for the purpose of studying laboratory simulated atmospheric aerosols and clouds. The chamber is cylindrical in design and is comprised of a double-walled inner assembly that resides within an outer vacuum jacket. The volume of the aerosol sample region is 28 L. By circulating refrigerated methanol between the double walls of the inner assembly, constant temperature control of the sample region can be maintained between 187 and 300 K. A study of temperature uniformity within the chamber at 291, 240, and 187 K revealed a standard deviation in temperature of 1.6 K as determined from measurements made using five copper-constantan thermocouples. Good agreement is obtained between thermocouple measured temperatures and rotational temperatures computed from infrared absorption spectra of methane gas. The chamber described here has been used to examine heterogeneous chemistry of solid powder samples. A technique of generating an aerosol sample by rapidly dispersing a solid powder in a gas is presented. The half-life of a γ-alumina aerosol sample was measured to be 25 min.

  3. Laboratory study of forced rotating shallow water turbulence

    NASA Astrophysics Data System (ADS)

    Espa, Stefania; Di Nitto, Gabriella; Cenedese, Antonio

    2011-12-01

    During the last three decades several authors have studied the appearance of multiple zonal jets in planetary atmospheres and in the Earths oceans. The appearance of zonal jets has been recovered in numerical simulations (Yoden & Yamada, 1993), laboratory experiments (Afanasyev & Wells, 2005; Espa et al., 2008, 2010) and in field measurements of the atmosphere of giant planets (Galperin et al., 2001). Recent studies have revealed the presence of zonation also in the Earths oceans, in fact zonal jets have been found in the outputs of Oceanic General Circulation Models-GCMs (Nakano & Hasumi, 2005) and from the analysis of satellite altimetry observations (Maximenko et al., 2005). In previous works (Espa et al., 2008, 2010) we have investigated the impact of the variation of the rotation rate and of the fluid depth on jets organization in decaying and forced regimes. In this work we show results from experiments performed in a bigger domain in which the fluid is forced continuously. The experimental set-up consists of a rotating tank (1m in diameter) where the initial distribution of vorticity has been generated via the Lorentz force in an electromagnetic cell. The latitudinal variation of the Coriolis parameter has been simulated by the parabolic profile assumed by the free surface of the rotating fluid. Flow measurements have been performed using an image analysis technique. Experiments have been performed changing the tank rotation rate and the fluid thickness. We have investigated the flow in terms of zonal and radial flow pattern, flow variability and jet scales.

  4. Chemical reaction and dust formation studies in laboratory hydrocarbon plasmas.

    NASA Astrophysics Data System (ADS)

    Hippler, Rainer; Majumdar, Abhijit; Thejaswini, H. C.

    Plasma chemical reaction studies with relevance to, e.g., Titan's atmosphere have been per-formed in various laboratory plasmas [1,2]. Chemical reactions in a dielectric barrier discharge at medium pressure of 250-300 mbar have been studied in CH4 /N2 and CH4 /Ar gas mixtures by means of mass spectrometry. The main reaction scheme is production of H2 by fragmenta-tion of CH4 , but also production of larger hydrocarbons like Cn Hm with n up to 10 including formation of different functional CN groups is observed. [1] A. Majumdar and R. Hippler, Development of dielectric barrier discharge plasma processing apparatus for mass spectrometry and thin film deposition, Rev. Sci. Instrum. 78, 075103 (2007) [2] H.T. Do, G. Thieme, M. Frühlich, H. Kersten, and R. Hippler, Ion Molecule and Dust Particle Formation in Ar/CH4 , Ar/C2 H2 and Ar/C3 H6 Radio-frequency Plasmas, Contrib. Plasma Phys. 45, No. 5-6, 378-384 (2005)

  5. Modeling menopause: The utility of rodents in translational behavioral endocrinology research.

    PubMed

    Koebele, Stephanie V; Bimonte-Nelson, Heather A

    2016-05-01

    The human menopause transition and aging are each associated with an increase in a variety of health risk factors including, but not limited to, cardiovascular disease, osteoporosis, cancer, diabetes, stroke, sexual dysfunction, affective disorders, sleep disturbances, and cognitive decline. It is challenging to systematically evaluate the biological underpinnings associated with the menopause transition in the human population. For this reason, rodent models have been invaluable tools for studying the impact of gonadal hormone fluctuations and eventual decline on a variety of body systems. While it is essential to keep in mind that some of the mechanisms associated with aging and the transition into a reproductively senescent state can differ when translating from one species to another, animal models provide researchers with opportunities to gain a fundamental understanding of the key elements underlying reproduction and aging processes, paving the way to explore novel pathways for intervention associated with known health risks. Here, we discuss the utility of several rodent models used in the laboratory for translational menopause research, examining the benefits and drawbacks in helping us to better understand aging and the menopause transition in women. The rodent models discussed are ovary-intact, ovariectomy, and 4-vinylcylohexene diepoxide for the menopause transition. We then describe how these models may be implemented in the laboratory, particularly in the context of cognition. Ultimately, we aim to use these animal models to elucidate novel perspectives and interventions for maintaining a high quality of life in women, and to potentially prevent or postpone the onset of negative health consequences associated with these significant life changes during aging. PMID:27013283

  6. Nuclear accident dosimetry studies at Los Alamos National Laboratory

    SciTech Connect

    Casson, W.H.; Buhl, T.E.; Upp, D.L.

    1995-12-01

    Two critical assemblies have been characterized at the Los Alamos Critical Experiments Facility (LACEF) for use in testing nuclear accident dosimeters and related devices. These device, Godiva IV and SHEBA II, have very different characteristics in both operation and emitted neutron energy spectra. The Godiva assembly is a bare metal fast burst device with a hard spectrum. This spectrum can be modified by use of several shields including steel, concrete, and plexiglas. The modified spectra vary in both average neutron energy and in the specific distribution of the neutron energies in the intermediate energy range. This makes for a very favorable test arrangement as the response ratios between different activation foils used in accident dosimeters are significantly altered such as the ratio between gold, copper, and sulfur elements. The SHEBA device is a solution assembly which has both a slow ramp and decay period and a much softer spectrum. The uncertainly introduced in the response of fast decay foils such as indium can therefore be evaluated into the test results. The neutron energy spectrum for each configuration was measured during low power operations with a multisphere system. These measurements were extended to high dose pulsed operation by use of TLDs moderated TLDs, and special activation techniques. The assemblies were used in the testing of several accident dosimetry devices in studies modeled after the Nuclear Accident Dosimetry Studies that were conducted at Oak Ridge National Laboratory for about 25 years using the Health Physics Research Reactor. It is our intention to conduct these studies approximately annually for the evaluation of the nuclear accident dosimeter systems currently in use within the DOE, alternative systems used internationally, and new dosimeter designs being developed or considered for field application. Participation in selected studies will be open to all participants.

  7. Helminth parasite species richness in rodents from Southeast Asia: role of host species and habitat.

    PubMed

    Palmeirim, Marta; Bordes, Frédéric; Chaisiri, Kittipong; Siribat, Praphaiphat; Ribas, Alexis; Morand, Serge

    2014-10-01

    Southeast Asia is a biodiversity hotspot that harbours many species of rodents, including some that live in close contact with humans. They host helminth parasites, some of which are of zoonotic importance. It is therefore important to understand the factors that influence the richness of the helminths parasitizing rodents. The specific objectives of this study were to evaluate rodent species as a factor determining helminth richness in rodent assemblages, to identify the major rodent helminth reservoir species and to explore the influence of habitat on helminth richness. We estimated helminth species richness using a large dataset of 18 rodent species (1,651 individuals) originating from Southeast Asia and screened for helminth parasites. The use of an unbiased estimator shows that the helminth species richness varies substantially among rodent species and across habitats. We confirmed this pattern by investigating the number of helminth species per individual rodent in all rodent species, and specifically in the two mitochondrial lineages Rattus tanezumi and R. tanezumi R3, which were captured in all habitats. PMID:25082015

  8. Observations on the food habits of some African rodents.

    PubMed

    Iwuala, M O; Braide, E I; Maduka, N

    1980-12-01

    Food habits of four common species of African rodents: the giant rat (Cricetomys gambianus), the black house rat (Rattus rattus), the multimammate rat (Mastomys natalensis) and the pygmy mouse (Mus minutoides) were studied on the basis of stomach content analysis, habitat sampling and experimental trials with caged animals. Vegetable items (especially grass, grains and tubers) formed the bulk of the food of all the species. Oil-palm nuts and kernels were also common in the guts of C. gambianus and M. natalensis. Animal food components of all the rodent species comprised mainly insects (especially ants, crickets etc.). Vertebrate flesh and scales were also well represented in the guts of C. gambianus. Domestic and miscellaneous food items were recorded from R. rattus, most of which were trapped in human and animal shelters. Inorganic gut contents, primarily sand grains, were found in sizeable quantities in more than 70% of the rodents examined. Results of experimental feeding trials with caged rodents showed close correlation with those recorded from field samples, especially in terms of food choices and the relative quantities consumed. The ecological and practical implications of these observations are discussed in the light of the importance of the rodents as agricultural and domestic pests. PMID:7323341

  9. 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

  10. Increased levels of IgE and autoreactive, polyreactive IgG in wild rodents: implications for the hygiene hypothesis

    USGS Publications Warehouse

    Devalapalli, A.P.; Lesher, A.; Shieh, K.; Solow, J.S.; Everett, M.L.; Edala, A.S.; Whitt, P.; Long, Renee R.; Newton, N.; Parker, W.

    2006-01-01

    To probe the potential role of Th1 versus Th2 reactivity underlying the hygiene hypothesis, intrinsic levels of Th1-associated and Th2-associated antibodies in the serum of wild rodents were compared with that in various strains of laboratory rodents. Studies using rat lung antigens as a target indicated that wild rats have substantially greater levels of autoreactive, polyreactive immunoglobulin G (IgG), but not autoreactive, polyreactive IgM than do laboratory rats, both on a quantitative and qualitative basis. Increased levels of serum IgG and IgE were observed in both wild rats and wild mice relative to their laboratory-raised counterparts, with the effect being most pronounced for IgE levels. Further, wild rats had greater intrinsic levels of both Th1- and Th2-associated IgG subclasses than did lab rats. The habitat (wild versus laboratory raised) had a more substantial impact on immunoglobulin concentration than did age, strain or gender in the animals studied. The presence in wild rodents of increased intrinsic, presumably protective, non-pathogenic responses similar to both autoimmune (autoreactive IgG, Th1-associated) and allergic (IgE, Th2-associated) reactions as well as increased levels of Th1-associated and Th2-associated IgG subclasses points toward a generally increased stimulation of the immune system in these animals rather than a shift in the nature of the immunoreactivity. It is concluded that, at least to the extent that feedback inhibition is a controlling element of immunoreactivity, an overly hygienic environment may affect the threshold of both types of immune responses more so than the balance between the different responses.

  11. Modeling natural photic entrainment in a subterranean rodent (Ctenomys aff. knighti), the Tuco-Tuco.

    PubMed

    Flôres, Danilo E F L; Tomotani, Barbara M; Tachinardi, Patricia; Oda, Gisele A; Valentinuzzi, Veronica S

    2013-01-01

    Subterranean rodents spend most of the day inside underground tunnels, where there is little daily change in environmental variables. Our observations of tuco-tucos (Ctenomys aff. knighti) in a field enclosure indicated that these animals perceive the aboveground light-dark cycle by several bouts of light-exposure at irregular times during the light hours of the day. To assess whether such light-dark pattern acts as an entraining agent of the circadian clock, we first constructed in laboratory the Phase Response Curve for 1 h light-pulses (1000lux). Its shape is qualitatively similar to other curves reported in the literature and to our knowledge it is the first Phase Response Curve of a subterranean rodent. Computer simulations were performed with a non-linear limit-cycle oscillator subjected to a simple model of the light regimen experienced by tuco-tucos. Results showed that synchronization is achieved even by a simple regimen of a single daily light pulse scattered uniformly along the light hours of the day. Natural entrainment studies benefit from integrated laboratory, field and computational approaches. PMID:23874562

  12. Modeling Natural Photic Entrainment in a Subterranean Rodent (Ctenomys aff. knighti), the Tuco-Tuco

    PubMed Central

    Flôres, Danilo E. F. L.; Tomotani, Barbara M.; Tachinardi, Patricia; Oda, Gisele A.; Valentinuzzi, Veronica S.

    2013-01-01

    Subterranean rodents spend most of the day inside underground tunnels, where there is little daily change in environmental variables. Our observations of tuco-tucos (Ctenomys aff. knighti) in a field enclosure indicated that these animals perceive the aboveground light-dark cycle by several bouts of light-exposure at irregular times during the light hours of the day. To assess whether such light-dark pattern acts as an entraining agent of the circadian clock, we first constructed in laboratory the Phase Response Curve for 1 h light-pulses (1000lux). Its shape is qualitatively similar to other curves reported in the literature and to our knowledge it is the first Phase Response Curve of a subterranean rodent. Computer simulations were performed with a non-linear limit-cycle oscillator subjected to a simple model of the light regimen experienced by tuco-tucos. Results showed that synchronization is achieved even by a simple regimen of a single daily light pulse scattered uniformly along the light hours of the day. Natural entrainment studies benefit from integrated laboratory, field and computational approaches. PMID:23874562

  13. Rodent herpesvirus Peru encodes a secreted chemokine decoy receptor.

    PubMed

    Lubman, Olga Y; Cella, Marina; Wang, Xinxin; Monte, Kristen; Lenschow, Deborah J; Huang, Yina H; Fremont, Daved H

    2014-01-01

    Viruses have long been studied not only for their pathology and associated disease but also as model systems for understanding cellular and immunological processes. Rodent herpesvirus Peru (RHVP) is a recently characterized rhadinovirus related to murine gammaherpesvirus 68 (MHV68) and Kaposi's sarcoma-associated herpesvirus (KSHV) that establishes acute and latent infection in laboratory mice. RHVP encodes numerous unique proteins that we hypothesize might facilitate host immune evasion during infection. We report here that open reading frame (ORF) R17 encodes a high-affinity chemokine binding protein that broadly recognizes human and murine CC and C chemokines. The interaction of R17 with chemokines is generally characterized by rapid association kinetics, and in the case of CCL3, CCL4, CCL5, CCL24, and XCL1, extremely stable complexes are formed. Functionally, R17 potently inhibited CCL2-driven chemotaxis of the human monocytic cell line THP-1, CCL3-driven chemotaxis of peripheral blood mononuclear cells, and CCL2-mediated calcium flux. Our studies also reveal that R17 binds to glycosaminoglycans (GAGs) in a process dependent upon two BBXB motifs and that chemokine and GAG binding can occur simultaneously at distinct sites. Collectively, these studies suggest that R17 may play a role in RHVP immune evasion through the targeted sabotage of chemokine-mediated immune surveillance. PMID:24173234

  14. Laboratory studies of aeolian sediment transport processes on planetary surfaces

    NASA Astrophysics Data System (ADS)

    Rasmussen, Keld R.; Valance, Alexandre; Merrison, Jonathan

    2015-09-01

    We review selected experimental saltation studies performed in laboratory wind tunnels and collision experiments performed in (splash-) laboratory facilities that allow detailed observations between impinging particles on a stationary bed. We also discuss progress in understanding aeolian transport in nonterrestrial environments. Saltation studies in terrestrial wind tunnels can be divided into two groups. The first group comprises studies using a short test bed, typically 1-4 m long, and focuses on the transitional behavior near the upwind roughness discontinuity where saltation starts. The other group focuses on studies using long test beds - typically 6 m or more - where the saturated saltation takes place under equilibrium conditions between wind flow and the underlying rough bed. Splash studies using upscaled model experiments allow collision simulations with large spherical particles to be recorded with a high speed video camera. The findings indicate that the number of ejected particles per impact scales linearly with the impact velocity of the saltating particles. Studies of saturated saltation in several facilities using predominantly Particle Tracking Velocimetry or Laser Doppler Velocimetry indicate that the velocity of the (few) particles having high trajectories increases with increasing friction velocity. However, the speed of the majority of particles that do not reach much higher than Bagnold's focal point is virtually independent of Shields parameter - at least for low or intermediate u*-values. In this case mass flux depends on friction velocity squared and not cubed as originally suggested by Bagnold. Over short beds particle velocity shows stronger dependence on friction velocity and profiles of particle velocity deviate from those obtained over long beds. Measurements using horizontally segmented traps give average saltation jump-lengths near 60-70 mm and appear to be only weakly dependent on friction velocity, which is in agreement with some

  15. 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)

  16. 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)

  17. RAINFALL SIMULATOR FOR LABORATORY USE IN ACIDIC PRECIPITATION STUDIES

    EPA Science Inventory

    A rainfall simulator, developed on the principle of droplet formation from needle tips, is described. The simulator is designed for laboratory experimentation to examine the effects of acidic precipitation on terrestrial plants. The system offers sufficient flexibility to simulat...

  18. Analytical study of the Atmospheric Cloud Physics Laboratory (ACPL) experiments

    NASA Technical Reports Server (NTRS)

    Davis, M. H.

    1977-01-01

    The design specifications of the research laboratory as a Spacelab facility are discussed along with the types of planned experiments. These include cloud formation, freezing and scavenging, and electrical phenomena. A summary of the program conferences is included.

  19. New Laboratory and Field Studies on Shatter Cones

    NASA Astrophysics Data System (ADS)

    Zaag, P. T.; Hasch, M.; Reimold, W. U.; Raschke, U.; Hipsley, C. A.; Hess, K.-U.; Dobson, K. J.

    2015-09-01

    Investigations of orientation, distribution, and shock micro-deformation of shatter cones were undertaken with micro-Computed Tomography and polarizing microscopy in the laboratory, and in the field at the Keurusselkä impact structure (Finland).

  20. A Laboratory Study of X-to-Frequency Converters.

    ERIC Educational Resources Information Center

    Kartalopoulos, Stamatios V.

    1979-01-01

    Describes a laboratory demonstration that can be used to convert an analog quantity into frequency, which can then be converted into a binary measure using either an oscilloscope or a frequency counter. (MA)

  1. Study of driven magnetic reconnection in a laboratory plasma

    SciTech Connect

    Yamada, Masaaki; Ji, H.; Hsu, S.; Carter, T.; Kulsrud, R.; Bretz, N.; Jobes, F.; Ono, Yasushi; Perkins, F.

    1998-12-31

    The Magnetic Reconnection Experiment (MRX) has been constructed to investigate the fundamental physics of magnetic reconnection in a well controlled laboratory setting. This device creates an environment satisfying the criteria for a magnetohydrodynamic (MHD) plasma (S {much_gt} 1, {rho}{sub i} {much_lt} L). The boundary conditions can be controlled externally, and experiments with fully three-dimensional reconnection are now possible. In the initial experiments, the effects of the third vector component of reconnecting fields have been studied. Two distinctively different shapes of neutral sheet current layers, depending on the third component, are identified during driven magnetic reconnection. Without the third component (anti-parallel or null-helicity reconnection), a thin double-Y shaped diffusion region is identified. A neutral sheet current profile is measured accurately to be as narrow as order ion gyro-radius. In the presence of an appreciable third component (co-helicity reconnection), an O-shaped diffusion region appears and grows into a spheromak configuration.

  2. Methanogenic Hydrocarbon Degradation: Evidence from Field and Laboratory Studies.

    PubMed

    Jiménez, Núria; Richnow, Hans H; Vogt, Carsten; Treude, Tina; Krüger, Martin

    2016-01-01

    Microbial transformation of hydrocarbons to methane is an environmentally relevant process taking place in a wide variety of electron acceptor-depleted habitats, from oil reservoirs and coal deposits to contaminated groundwater and deep sediments. Methanogenic hydrocarbon degradation is considered to be a major process in reservoir degradation and one of the main processes responsible for the formation of heavy oil deposits and oil sands. In the absence of external electron acceptors such as oxygen, nitrate, sulfate or Fe(III), fermentation and methanogenesis become the dominant microbial metabolisms. The major end product under these conditions is methane, and the only electron acceptor necessary to sustain the intermediate steps in this process is CO2, which is itself a net product of the overall reaction. We are summarizing the state of the art and recent advances in methanogenic hydrocarbon degradation research. Both the key microbial groups involved as well as metabolic pathways are described, and we discuss the novel insights into methanogenic hydrocarbon-degrading populations studied in laboratory as well as environmental systems enabled by novel cultivation-based and molecular approaches. Their possible implications on energy resources, bioremediation of contaminated sites, deep-biosphere research, and consequences for atmospheric composition and ultimately climate change are also addressed. PMID:26959375

  3. A Laboratory Study of Vortical Structures in Rotating Convection Plumes

    NASA Astrophysics Data System (ADS)

    Fu, Hao; Sun, Shiwei; Wang, Yuan; Zhou, Bowen; Thermal Turbulence Research Team

    2015-11-01

    A laboratory study of the columnar vortex structure in rotating Rayleigh-Bénard convection is conducted. A rectangular water tank is uniformly heated from below and cooled from above, with Ra = (6 . 35 +/- 0 . 77) ×107 , Ta = 9 . 84 ×107 , Pr = 7 . 34 . The columnar vortices are vertically aligned and quasi steady. Two 2D PIV systems were used to measure velocity field. One system performs horizontal scans at 9 different heights every 13.6s, covering 62% of the total depth. The other system scans vertically to obtain the vertical velocity profile. The measured vertical vorticity profiles of most vortices are quasi-linear with height while the vertical velocities are nearly uniform with only a small curvature. A simple model to deduce vertical velocity profile from vertical vorticity profile is proposed. Under quasi-steady and axisymmetric conditions, a ``vortex core'' assumption is introduced to simplify vertical vorticity equation. A linear ODE about vertical velocity is obtained whenever a vertical vorticity profile is given and solved with experimental data as input. The result is approximately in agreement with the measurement. This work was supported by Undergraduates Training Project (J1103410).

  4. Laboratory study of the underground sound generated by debris flows

    NASA Astrophysics Data System (ADS)

    Huang, Ching-Jer; Shieh, Chieng-Lun; Yin, Hsiao-Yuan

    2004-03-01

    This experimental study investigates the underground sound generated by different kinds of rock motions that occur in debris flows. The experiments were divided into two parts. The first part consisted of measuring the main characteristics of the underground sound caused by friction of a rock rubbed against a bed of gravel and of that caused by a free-falling rock hitting a similar bed of gravel. In the second part a hydrophone was installed at the bottom of a laboratory channel to measure the underground sound of debris flows in that channel. The sound signals were analyzed using both the fast Fourier transform and the Gabor transform to represent the signals in both the frequency and time-frequency domains. The measurement results reveal that the frequency of the sound generated by the rock-gravel bed friction is relatively low, being mostly between 20 and 80 Hz. In contrast, the frequency range of the collision sound is relatively higher, between 10 and 500 Hz. Finally, the frequency of the underground sound caused by the debris flows in the flume is in the range of 20-300 Hz.

  5. Useful laboratory tests for studying thrombogenesis in acute cardiac syndromes.

    PubMed

    Fareed, J; Hoppensteadt, D A; Leya, F; Iqbal, O; Wolf, H; Bick, R

    1998-08-01

    We review laboratory tests that evaluate thrombogenesis during acute coronary syndromes. These tests have been found to be valuable research tools in more clearly understanding the pathophysiology of acute coronary syndromes. In particular, we describe tissue factor, tissue factor pathway inhibitor, prothrombin fragment 1.2, thrombin-antithrombin complex, fibrinopeptide A, tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), t-PA-PAI complex, Bbeta 15-42-related peptides, fibrinogen degradation products, fibrin degradation products, D-dimer, platelet factor 4, beta-thromboglobulin, 5-hydroxytryptamine, thromboxane B2, prostacyclin, endothelin, angiotensin-converting enzyme, soluble thrombomodulin, C1-esterase inhibitor, anaphylotoxins C3a, C4a, and C5a, bradykinin, tumor necrosis factor, leukotriene C4, platelet activating factor, anti-phospholipid antibody, and von Willebrand factor. Some of these tests may prove to be useful in clinical diagnosis and management of acute coronary syndromes. Clinical outcome studies are needed to determine which tests may be cost effective and medically useful. PMID:9702994

  6. 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.

  7. Asymmetry of wind waves studied in a laboratory tank

    NASA Astrophysics Data System (ADS)

    Ileykin, L. A.; Donelan, M. A.; Mellen, R. H.; McLaughlin, D. J.

    1995-03-01

    Asymmetry of wind waves was studied in laboratory tank tinder varied wind and fetch conditions using both bispectral analysis of wave records and third-order statistics of the surface elevation. It is found skewness S (the normalized third-order moment of surface elevation describing the horizontal asymmetry waves) varies only slightly with the inverse wave u*/Cm (where u* is the air friction velocity and Cm is phase speed of the dominant waves). At the same time asymmetry A, which is determined from the Hilbert transform of the wave record and characterizes the skewness of the rate of change of surface elevation, increase consistently in magnitude with the ratio u*/Cm. This suggests that nonlinear distortion of the wave profile determined by the degree of wind forcing and is a sensitive indicator of wind-wave interaction processes. It is shown that the asymmetric profile of waves can described within the frameworks of the nonlinear nonspectral concept (Plate, 1972; Lake and Yuen, 197 according to which the wind-wave field can be represented as a coherent bound-wave system consisting mainly of dominant component w. and its harmonics propagating with the same speed C. , as observed by Ramamonjiaris and Coantic (1976). The phase shift between o). harmonics is found and shown to increase with the asymmetry of the waves.

  8. Asymmetry of wind waves studied in a laboratory tank

    NASA Astrophysics Data System (ADS)

    Leykin, I. A.; Donelan, M. A.; Mellen, R. H.; McLaughlin, D. J.

    Asymmetry of wind waves was studied in laboratory tank tinder varied wind and fetch conditions using both bispectral analysis of wave records and third-order statistics of the surface elevation. It is found skewness S (the normalized third-order moment of surface elevation describing the horizontal asymmetry waves) varies only slightly with the inverse wave u*/Cm (where u* is the air friction velocity and Cm is phase speed of the dominant waves). At the same time asymmetry A, which is determined from the Hilbert transform of the wave record and characterizes the skewness of the rate of change of surface elevation, increase consistently in magnitude with the ratio u*/Cm. This suggests that nonlinear distortion of the wave profile determined by the degree of wind forcing and is a sensitive indicator of wind-wave interaction processes. It is shown that the asymmetric profile of waves can described within the frameworks of the nonlinear nonspectral concept (Plate, 1972; Lake and Yuen, 197 according to which the wind-wave field can be represented as a coherent bound-wave system consisting mainly of dominant component w. and its harmonics propagating with the same speed C. , as observed by Ramamonjiaris and Coantic (1976). The phase shift between o). harmonics is found and shown to increase with the asymmetry of the waves.

  9. Meteoric water - basalt interactions: a field and laboratory study

    SciTech Connect

    Gislason, S.R.

    1985-01-01

    The goal of this study is to define and interpret the composition of the meteoric waters in N.E. Iceland in their cycle through the hydrosphere and the upper part of the crust, and to calibrate the natural process by dissolution experiments done in the laboratory. The composition of rain, snow, spring and geothermal waters from the rift zone of N.E. Iceland can be explained by sea-spray addition (1/10000), dissolution of basalts and buffering by alteration minerals. Rates, stoichiometry and activation energy of dissolution, pH vs. time and activity-activity paths were determined by dissolving basaltic rocks under simulated natural conditions at 25 to 60/sup 0/C. Dissolution follows a linear rate law, with basaltic glass dissolving 10 times faster than the crystalline basalt. Rates are independent of pH from 7 to 10. The average activation energy for dissolution of basaltic glass is 31.8 kJ/mol (+/-3). For individual elements leached from crystalline basalt it ranges from 35 to 15 kJ/mol. This indicates that under the experimental conditions reactions on the surfaces of the solids are the rate determining step in the dissolution mechanism. Considerable differences (2 to 4 log units) exist in the calculated oxygen fugacities obtained from different redox species in the geothermal fluids. This is primarily caused by the nonequilibrium state of the sulfur redox pair.

  10. Recent laboratory photochemical studies and their relationship to the photochemical formation of cometary radicals

    NASA Technical Reports Server (NTRS)

    Jackson, William M.

    1991-01-01

    Experimental laboratory techniques used in studying the photochemistry of stable and unstable molecules are discussed. The laboratory evidence for the photochemical formation of C2 from C2H, C3 from C3H2, and NH from NH2 is presented. Other recent results obtained in laboratory studies of H2O, H2S, NH3, and HCN are reported.

  11. Single media thermocline TES studies at Sandia National Laboratories

    SciTech Connect

    Gross, R.J.

    1981-01-01

    The status of thermocline thermal energy storage (TES) development at Sandia National Laboratories is summarized. The work centers around testing in the 1200 gal engineering prototype thermocline test facility. The results of heat loss, charge, discharge and static tests in the prototype tank are described. Also described are analytical work and a supportive laboratory-scale program which is investigating diffusers to inhibit mixing in the tank.

  12. Photochemical Aging of Organic Aerosols: A Laboratory Study

    NASA Astrophysics Data System (ADS)

    Papanastasiou, Dimitrios K.; Kostenidou, Evangelia; Gkatzelis, Georgios I.; Psichoudaki, Magdalini; Louvaris, Evangelos; Pandis, Spyros N.

    2014-05-01

    Organic aerosols (OA) are either emitted directly (primary OA) or formed (secondary OA) in the atmosphere and consist of an extremely complex mixture of thousands of organic compounds. Although the scientific community has put significant effort, in the past few decades, to understand organic aerosol (OA) formation, evolution and fate in the atmosphere, traditional models often fail to reproduce the ambient OA levels. Secondary organic aerosol (SOA) formed, in traditional laboratory chamber experiments, from the gas phase oxidation of known precursors, such as α-pinene, is semi-volatile and with an O:C ratio of around 0.4. In contrast, OA found in the atmosphere is significantly less volatile, while the O:C ratio often ranges from 0.5 to 1. In conclusion, there is a significant gap of knowledge in our understanding of OA formation and photochemical transformation in the atmosphere. There is increased evidence that homogeneous gas phase aging by OH radicals might be able to explain, at least in part, the significantly higher OA mass loadings observed and also the oxidation state and volatility of OA in the atmosphere. In this study, laboratory chamber experiments were performed to study the role of the continued oxidation of first generation volatile and semi-volatile species by OH radicals in the evolution of the SOA characteristics (mass concentration, volatility, and oxidation state). Ambient air mixtures or freshly formed SOA from α-pinene ozonolysis were used as the source of organic aerosols and semi-volatile species. The initial mixture of organic aerosols and gas phase species (volatile and semi-volatile) was then exposed to atmospheric concentrations of OH radicals to study the aging of aerosols. Experiments were performed with various OH radical sources (H2O2 or HONO) and under various NOx conditions. A suite of instruments was employed to characterize both the gas and the aerosol phase. A Scanning Mobility Particle Sizer (SMPS) and a High

  13. Field and Laboratory Studies of Atmospheric Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Coggon, Matthew Mitchell

    This thesis is the culmination of field and laboratory studies aimed at assessing processes that affect the composition and distribution of atmospheric organic aerosol. An emphasis is placed on measurements conducted using compact and high-resolution Aerodyne Aerosol Mass Spectrometers (AMS). The first three chapters summarize results from aircraft campaigns designed to evaluate anthropogenic and biogenic impacts on marine aerosol and clouds off the coast of California. Subsequent chapters describe laboratory studies intended to evaluate gas and particle-phase mechanisms of organic aerosol oxidation. The 2013 Nucleation in California Experiment (NiCE) was a campaign designed to study environments impacted by nucleated and/or freshly formed aerosol particles. Terrestrial biogenic aerosol with > 85% organic mass was observed to reside in the free troposphere above marine stratocumulus. This biogenic organic aerosol (BOA) originated from the Northwestern United States and was transported to the marine atmosphere during periodic cloud-clearing events. Spectra recorded by a cloud condensation nuclei counter demonstrated that BOA is CCN active. BOA enhancements at latitudes north of San Francisco, CA coincided with enhanced cloud water concentrations of organic species such as acetate and formate. Airborne measurements conducted during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) were aimed at evaluating the contribution of ship emissions to the properties of marine aerosol and clouds off the coast of central California. In one study, analysis of organic aerosol mass spectra during periods of enhanced shipping activity yielded unique tracers indicative of cloud-processed ship emissions (m/z 42 and 99). The variation of their organic fraction (f42 and f 99) was found to coincide with periods of heavy (f 42 > 0.15; f99 > 0.04), moderate (0.05 < f42 < 0.15; 0.01 < f99 < 0.04), and negligible (f42 < 0.05; f99 < 0.01) ship influence. Application of

  14. Los Alamos National Laboratory W76 Pit Tube Lifetime Study

    SciTech Connect

    Abeln, Terri G.

    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.

  15. 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

  16. 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.

  17. Large-scale functional connectivity networks in the rodent brain.

    PubMed

    Gozzi, Alessandro; Schwarz, Adam J

    2016-02-15

    Resting-state functional Magnetic Resonance Imaging (rsfMRI) of the human brain has revealed multiple large-scale neural networks within a hierarchical and complex structure of coordinated functional activity. These distributed neuroanatomical systems provide a sensitive window on brain function and its disruption in a variety of neuropathological conditions. The study of macroscale intrinsic connectivity networks in preclinical species, where genetic and environmental conditions can be controlled and manipulated with high specificity, offers the opportunity to elucidate the biological determinants of these alterations. While rsfMRI methods are now widely used in human connectivity research, these approaches have only relatively recently been back-translated into laboratory animals. Here we review recent progress in the study of functional connectivity in rodent species, emphasising the ability of this approach to resolve large-scale brain networks that recapitulate neuroanatomical features of known functional systems in the human brain. These include, but are not limited to, a distributed set of regions identified in rats and mice that may represent a putative evolutionary precursor of the human default mode network (DMN). The impact and control of potential experimental and methodological confounds are also critically discussed. Finally, we highlight the enormous potential and some initial application of connectivity mapping in transgenic models as a tool to investigate the neuropathological underpinnings of the large-scale connectional alterations associated with human neuropsychiatric and neurological conditions. We conclude by discussing the translational potential of these methods in basic and applied neuroscience. PMID:26706448

  18. Prediction of rodent carcinogenicity for 30 chemicals

    SciTech Connect

    Ashby, J.

    1996-10-01

    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. 3 refs., 1 fig.

  19. 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.

  20. Experimental infection of Rio Mamore hantavirus in Sigmodontinae rodents.

    PubMed

    Souza, William Marciel de; Machado, Alex Martins; Figueiredo, Luiz Tadeu Moraes

    2016-05-24

    This study shows an experimental spillover infection of Sigmodontinae rodents with Rio Mamore hantavirus (RIOMV). Necromys lasiurus and Akodon sp were infected with 103 RNA copies of RIOMV by intraperitoneal administration. The viral genome was detected in heart, lung, and kidney tissues 18 days after infection (ai), and viral excretion in urine and faeces began at four and six ai, respectively. These results reveal that urine and faeces of infected rodents contain the virus for at least 18 days. It is possible that inhaled aerosols of these excreta could transmit hantavirus to humans and other animals. PMID:27223653

  1. Experimental infection of Rio Mamore hantavirus in Sigmodontinae rodents

    PubMed Central

    de Souza, William Marciel; Machado, Alex Martins; Figueiredo, Luiz Tadeu Moraes

    2016-01-01

    This study shows an experimental spillover infection ofSigmodontinae rodents with Rio Mamore hantavirus (RIOMV).Necromys lasiurus and Akodon sp were infected with 103 RNA copies of RIOMV by intraperitoneal administration. The viral genome was detected in heart, lung, and kidney tissues 18 days after infection (ai), and viral excretion in urine and faeces began at four and six ai, respectively. These results reveal that urine and faeces of infected rodents contain the virus for at least 18 days. It is possible that inhaled aerosols of these excreta could transmit hantavirus to humans and other animals. PMID:27223653

  2. Olfactory detection of caches containing wildland versus cultivated seeds by granivorous rodents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted a study to examine the ability of rodents to detect caches made with wildland (native and non-native) and cultivated seeds at three locations in western Nevada with different vegetation types and rodent community structures. We established artificial caches containing either one of two...

  3. Clinical hematology of rodent species.

    PubMed

    Pilny, Anthony A

    2008-09-01

    Pet rodents, such as rats, guinea pigs, and chinchillas, differ from more traditional companion animal species in many aspects of their hematologic parameters. Animals within this order have much diversity in size, anatomy, methods of restraint, and blood collection technique. Appropriate sample collection is often the most challenging aspect of the diagnostic protocol, and inappropriate restraint may cause a stress response that interferes with blood test results. For many of these patients, sedation is required and can also affect results as well. In most cases, however, obtaining a standard database is necessary and very possible when providing medical care for this popular group of pets. PMID:18675732

  4. Sniffing and whisking in rodents

    PubMed Central

    Deschênes, Martin; Moore, Jeffrey; Kleinfeld, David

    2016-01-01

    Summary Sniffing and whisking are two rhythmic orofacial motor activities that enable rodents to localize and track objects in their environment. They have related temporal dynamics, possibly as a result of both shared musculature and shared sensory tasks. Sniffing and whisking also constitute the overt expression of an animal's anticipation of a reward. Yet, the neuronal mechanisms that underlie the control of these behaviors have not been established. Here, we review the similarities between sniffing and whisking and suggest that such similarities indicate a mechanistic link between these two rhythmic exploratory behaviors. PMID:22177596

  5. Phosphate release from seasonally flooded soils: a laboratory microcosm study.

    PubMed

    Young, E O; Ross, D S

    2001-01-01

    Phosphorus derived from agricultural practices has been targeted as a leading cause of water quality degradation in Lake Champlain. Mobilization of P from seasonally flooded agricultural soils is a concern. Using 14 soils from a research farm in New York's Champlain Valley, we characterized the available P status, extractable Fe and Al, P sorption capacities, and soluble phosphate release in flooded laboratory microcosms. Quantities of NH4-acetate available P ranged from 3 to 100 mg kg(-1) and fluoride-extractable P from 10 to 211 mg kg(-1). Flooding soils induced significant release of phosphate to the porewater over a 60- to 90-d period in 13 of the 14 soils studied. Porewater phosphate increases ranged from 2.2 to 27.0 times the initial phosphate concentrations. However, floodwater phosphate increases were much lower, with a maximum of 3.6 times the initial concentration. Average porewater phosphate concentrations over the flooding period ranged from 0.046 to 7.0 mg L(-1) and average floodwater P from 0.032 to 3.70 mg L(-1). Ammonium-acetate P and the degree of phosphorus saturation (DPS) were highly correlated with the average porewater and floodwater phosphate concentration. Average ratio of porewater to floodwater phosphate concentrations ranged from 1.0 to 3.3. Five soils that were lower in fluoride-extractable P had increasing porewater phosphate accompanied by increasing porewater Fe2+ and decreasing floodwater phosphate. Results suggest that P solubility and mobility were a function of both the available P status and redox cycling. PMID:11215671

  6. Pinon Pine Tree Study, Los Alamos National Laboratory: Source document

    SciTech Connect

    P. R. Fresquez; J. D. Huchton; M. A. Mullen; L. Naranjo, Jr.

    2000-01-01

    One of the dominant tree species growing within and around Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis) tree. Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food--the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup tot}U, {sup 238}Pu, {sup 239,240}Pu, and {sup 241}Am in soils (0- to 12-in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) concentrations of radionuclides in PPN collected in 1977 to present data, (3) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (4) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of {sup 3}H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 {micro}Sv). Soil-to-nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.

  7. A laboratory study of explosives malfunction in blasting

    SciTech Connect

    Katsabanis, P.D.; Ghorbani, A.

    1995-12-31

    Explosives malfunction due to shock waves is a serious concern for successful blasting results. Malfunction includes sympathetic detonation and desensitization of explosive charges as well as the modification of firing times of conventional pyrotechnic detonators. Small diameter emulsions and detonators were tested in a laboratory environment to identify the parameters affecting malfunction. The experiments had a donor-acceptor configuration and the charges were detonated in the same sequence. Continuous velocity of detonation monitoring was used as an indicator of explosives performance and for studying the timing of the initiation of the acceptor charge and/or detonator, while distance and delay interval between the donor and acceptor were modified. Fumes from the detonating charges were analyzed in a number of experiments while a few experiments were conducted in rock confinement. It was found that both distance and delay interval are important as far as desensitization is concerned. At certain separation distances temporary desensitization, followed by temporary recovery was observed. Toxicity of the product gases was affected by desensitization although this effect ranged from negligible to pronounced and was not consistent. In many cases desensitized explosives reacted completely as evidenced by the concentration of the fumes in the blasting chamber. Conventional pyrotechnic delay detonators malfunctioned due to a shock produced by a 40mm diameter emulsion explosive at similar distances as the explosives (below 203 mm). Furthermore the experiments in granite showed that 40 mm diameter charges can malfunction at separation distances below 330 mm. This malfunction ranged from sympathetic detonation to shock desensitization; in most cases it was associated with severe loss of performance.

  8. Soil erosion-runoff relationships: insights from laboratory studies

    NASA Astrophysics Data System (ADS)

    Mamedov, Amrakh; Warrington, David; Levy, Guy

    2016-04-01

    Understanding the processes and mechanisms affecting runoff generation and subsequent soil erosion in semi-arid regions is essential for the development of improved soil and water conservation management practices. Using a drip type laboratory rain simulator, we studied runoff and soil erosion, and the relationships between them, in 60 semi-arid region soils varying in their intrinsic properties (e.g., texture, organic matter) under differing extrinsic conditions (e.g., rain properties, and conditions prevailing in the field soil). Both runoff and soil erosion were significantly affected by the intrinsic soil and rain properties, and soil conditions within agricultural fields or watersheds. The relationship between soil erosion and runoff was stronger when the rain kinetic energy was higher rather than lower, and could be expressed either as a linear or exponential function. Linear functions applied to certain limited cases associated with conditions that enhanced soil structure stability, (e.g., slow wetting, amending with soil stabilizers, minimum tillage in clay soils, and short duration exposure to rain). Exponential functions applied to most of the cases under conditions that tended to harm soil stability (e.g., fast wetting of soils, a wide range of antecedent soil water contents and rain kinetic energies, conventional tillage, following biosolid applications, irrigation with water of poor quality, consecutive rain simulations). The established relationships between runoff and soil erosion contributed to a better understanding of the mechanisms governing overland flow and soil loss, and could assist in (i) further development of soil erosion models and research techniques, and (ii) the design of more suitable management practices for soil and water conservation.

  9. 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

  10. Social modulation of and by pain in humans and rodents.

    PubMed

    Mogil, Jeffrey S

    2015-04-01

    The social domain of the biopsychosocial model of pain has been greatly understudied compared with the biological and psychological domains but holds great promise for furthering our understanding, and better treatment, of pain. Recent years have seen an explosion of interest in social neuroscience and have revealed the ability of pain stimuli to alter social interactions. These experiments suggest that rodents are capable of producing simplified versions of any number of social phenomena involving empathy, previously thought to be the sole province of human beings. This review describes the state of science in both humans and nonhuman animals, and notes intriguing parallels in observations from both species. Indeed, my laboratory is starting to demonstrate perfectly translatable findings regarding social modulation of pain in rodents and humans. PMID:25789435

  11. Sex differences in the parental behavior of rodents.

    PubMed

    Lonstein, J S; De Vries, G J

    2000-08-01

    The reproductive strategy of many mammalian species that give birth to altricial young involves intense and prolonged care of their offspring. In most cases, the mother provides all nurturance, but in some cases fathers, older siblings, or unrelated conspecifics participate in parental care. The display of these behaviors by animals other than mothers is affected by numerous factors, including their sex. We herein review the literature on similarities and/or differences between male and female laboratory rodents (rats, mice, voles, gerbils, and hamsters) in their parental responsiveness and discuss how the parental behavior of males and females is influenced by hormones, developmental processes, and prior social experiences. Understanding the mechanisms that generate sex differences in the parental responsiveness of rodents may indicate how similar sex differences in parental care are generated in other mammals. PMID:10940441

  12. Prevalence and diversity of Bartonella in rodents of northern Thailand: a comparison with Bartonella in rodents from southern China.

    PubMed

    Castle, Kevin T; Kosoy, Michael; Lerdthusnee, Kriangkrai; Phelan, Lori; Bai, Ying; Gage, Kenneth L; Leepitakrat, Warisa; Monkanna, Taweesak; Khlaimanee, Nittaya; Chandranoi, Kirkvich; Jones, James W; Coleman, Russell E

    2004-04-01

    We report results of the first study to investigate the distribution and diversity of Bartonella in rodents from Thailand. Whole blood from 195 rodents, representing six species, was tested for the presence of Bartonella species using standard culture techniques. Isolates were obtained from 17 (8.7%) of the samples, and 14 of those isolates represented distinct strains, based upon partial sequencing of the citrate synthase (gltA) gene. Phylogenetic analysis of the isolates and other Bartonella species indicated that five unique isolates from Bandicota indica form a cluster that may represent a new Bartonella species. Two additional isolates from B. indica clustered together, and were nearly identical to an isolate from Apodemus draco collected in southern China. Importantly, a number of the isolates from Thailand rodents are closely related to B. grahamii and B. elizabethae, species which have been associated with human illness. PMID:15100459

  13. Teasing apart the effects of seed size and energy content on rodent scatter-hoarding behavior.

    PubMed

    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

  14. Microbial Evolution at High Pressure: Deep Sea and Laboratory Studies

    NASA Astrophysics Data System (ADS)

    Bartlett, D. H.

    2011-12-01

    Elevated hydrostatic pressures are present in deep-sea and deep-Earth environments where this physical parameter has influenced the evolution and characteristics of life. Piezophilic (high-pressure-adapted) microbes have been isolated from diverse deep-sea settings, and would appear likely to occur in deep-subsurface habitats as well. In order to discern the factors enabling life at high pressure my research group has explored these adaptations at various levels, most recently including molecular analyses of deep-sea trench communities, and through the selective evolution of the model microbe Escherichia coli in the laboratory to progressively higher pressures. Much of the field work has focused on the microbes present in the deeper portions of the Puerto Rico Trench (PRT)and in the Peru-Chile Trench (PCT), from 6-8.5 km below the sea surface (~60-85 megapascals pressure). Culture-independent phylogenetic data on the Bacteria and Archaea present on particles or free-living, along with data on the microeukarya present was complemented with genomic analyses and the isolation and characterization of microbes in culture. Metagenomic analyses of the PRT revealed increased genome sizes and an overrepresentation at depth of sulfatases for the breakdown of sulfated polysaccharides and specific categories of transporters, including those associated with the transport of diverse cations or carboxylate ions, or associated with heavy metal resistance. Single-cell genomic studies revealed several linneages which recruited to the PRT metagenome far better than existing marine microbial genome sequences. analyses. Novel high pressure culture approaches have yielded new piezophiles including species preferring very low nutrient levels, those living off of hydrocarbons, and those adapted to various electron donor/electron acceptor combinations. In order to more specifically focus on functions enabling life at increased pressure selective evolution experiments were performed with

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

    EPA Science Inventory

    Rodent control in urban areas can result in the inadvertent mortality of non-target species (e.g., bobcats). However, there is little detailed information about rodent control practices of urban residents. Our objective was to evaluate urban rodent control behaviors in two area...

  16. A Curated Database of Rodent Uterotrophic Bioactivity

    PubMed Central

    Kleinstreuer, Nicole C.; Ceger, Patricia C.; Allen, David G.; Strickland, Judy; Chang, Xiaoqing; Hamm, Jonathan T.; Casey, Warren M.

    2015-01-01

    Background: Novel in vitro methods are being developed to identify chemicals that may interfere with estrogen receptor (ER) signaling, but the results are difficult to put into biological context because of reliance on reference chemicals established using results from other in vitro assays and because of the lack of high-quality in vivo reference data. The Organisation for Economic Co-operation and Development (OECD)-validated rodent uterotrophic bioassay is considered the “gold standard” for identifying potential ER agonists. Objectives: We performed a comprehensive literature review to identify and evaluate data from uterotrophic studies and to analyze study variability. Methods: We reviewed 670 articles with results from 2,615 uterotrophic bioassays using 235 unique chemicals. Study descriptors, such as species/strain, route of administration, dosing regimen, lowest effect level, and test outcome, were captured in a database of uterotrophic results. Studies were assessed for adherence to six criteria that were based on uterotrophic regulatory test guidelines. Studies meeting all six criteria (458 bioassays on 118 unique chemicals) were considered guideline-like (GL) and were subsequently analyzed. Results: The immature rat model was used for 76% of the GL studies. Active outcomes were more prevalent across rat models (74% active) than across mouse models (36% active). Of the 70 chemicals with at least two GL studies, 18 (26%) had discordant outcomes and were classified as both active and inactive. Many discordant results were attributable to differences in study design (e.g., injection vs. oral dosing). Conclusions: This uterotrophic database provides a valuable resource for understanding in vivo outcome variability and for evaluating the performance of in vitro assays that measure estrogenic activity. Citation: Kleinstreuer NC, Ceger PC, Allen DG, Strickland J, Chang X, Hamm JT, Casey WM. 2016. A curated database of rodent uterotrophic bioactivity. Environ

  17. 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.

  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. Medical Laboratory Technician Student & Graduate. Articulation Interest Study.

    ERIC Educational Resources Information Center

    Morris, Frances J.

    Interests in articulation by students and graduates of the nine medical laboratory technology programs in Kentucky were surveyed. Articulation refers to transfer between programs or institutions and increased opportunities for career mobility and advancement. The 131 respondents to a questionnaire indicated: their interest in articulation, marital…

  20. The Study of Biobehavioral Rhythms in a Psychology Laboratory Course.

    ERIC Educational Resources Information Center

    Rowland, David L.; Wesselhoft, Theresa

    1998-01-01

    Reports on a laboratory experiment where students measured their heart rate, blood pressure, mood, alertness, and cognitive performance. Measures showed significant circadian heart rhythm variations. They were strongly correlated and peaked at different times. Discusses the implications of this and students' reactions to the experiment. (MJP)

  1. An Undergraduate Laboratory Exercise for Studying Kinetics of Batch Crystallization

    ERIC Educational Resources Information Center

    Louhi­-Kultanen, Marjatta; Han, Bing; Nurkka, Annikka; Hatakka, Henry

    2015-01-01

    The present work describes an undergraduate laboratory exercise for improving understanding of fundamental phenomena in cooling crystallization. The exercise of nucleation and crystal growth kinetics supports learning of theories and models presented in lectures and calculation exercises. The teaching methodology incorporates precepts the…

  2. Lunar and Planetary Laboratory studies of Jupiter. II.

    NASA Technical Reports Server (NTRS)

    Kuiper, G. P.

    1972-01-01

    Discussion of Jovian belts, zones and atmospheric features as identified by an analysis of photographs of the planet at the Laboratory. The topics include the circulation of the Jovian atmosphere, the rotation periods of zones and belts, the Great Red Spot shown by methane photographs, and some high altitude photographs of terrestrial atmospheric conditions. Hypothetical mechanisms controlling the atmospheric conditions on Jupiter are considered.

  3. Synthetic cathinones and their rewarding and reinforcing effects in rodents.

    PubMed

    Watterson, Lucas R; Olive, M Foster

    2014-06-01

    Synthetic cathinones, colloquially referred to as "bath salts", are derivatives of the psychoactive alkaloid cathinone found in Catha edulis (Khat). Since the mid-to-late 2000's, these amphetamine-like psychostimulants have gained popularity amongst drug users due to their potency, low cost, ease of procurement, and constantly evolving chemical structures. Concomitant with their increased use is the emergence of a growing collection of case reports of bizarre and dangerous behaviors, toxicity to numerous organ systems, and death. However, scientific information regarding the abuse liability of these drugs has been relatively slower to materialize. Recently we have published several studies demonstrating that laboratory rodents will readily self-administer the "first generation" synthetic cathinones methylenedioxypyrovalerone (MDPV) and methylone via the intravenous route, in patterns similar to those of methamphetamine. Under progressive ratio schedules of reinforcement, the rank order of reinforcing efficacy of these compounds are MDPV ≥ methamphetamine > methylone. MDPV and methylone, as well as the "second generation" synthetic cathinones α-pyrrolidinovalerophenone (α-PVP) and 4-methylethcathinone (4-MEC), also dose-dependently increase brain reward function. Collectively, these findings indicate that synthetic cathinones have a high abuse and addiction potential and underscore the need for future assessment of the extent and duration of neurotoxicity induced by these emerging drugs of abuse. PMID:25328910

  4. Synthetic cathinones and their rewarding and reinforcing effects in rodents

    PubMed Central

    Watterson, Lucas R.; Olive, M. Foster

    2014-01-01

    Synthetic cathinones, colloquially referred to as “bath salts”, are derivatives of the psychoactive alkaloid cathinone found in Catha edulis (Khat). Since the mid-to-late 2000’s, these amphetamine-like psychostimulants have gained popularity amongst drug users due to their potency, low cost, ease of procurement, and constantly evolving chemical structures. Concomitant with their increased use is the emergence of a growing collection of case reports of bizarre and dangerous behaviors, toxicity to numerous organ systems, and death. However, scientific information regarding the abuse liability of these drugs has been relatively slower to materialize. Recently we have published several studies demonstrating that laboratory rodents will readily self-administer the “first generation” synthetic cathinones methylenedioxypyrovalerone (MDPV) and methylone via the intravenous route, in patterns similar to those of methamphetamine. Under progressive ratio schedules of reinforcement, the rank order of reinforcing efficacy of these compounds are MDPV ≥ methamphetamine > methylone. MDPV and methylone, as well as the “second generation” synthetic cathinones α-pyrrolidinovalerophenone (α-PVP) and 4-methylethcathinone (4-MEC), also dose-dependently increase brain reward function. Collectively, these findings indicate that synthetic cathinones have a high abuse and addiction potential and underscore the need for future assessment of the extent and duration of neurotoxicity induced by these emerging drugs of abuse. PMID:25328910

  5. The Miocene rodents of Serbia

    NASA Astrophysics Data System (ADS)

    Markovic, Z.

    2009-04-01

    During the Miocene period a group of shallow lakes was created in depressions at the territory of present-day Serbia. This caused the present wide distribution of lacustrine sediments, which occasionally alternate with the alluvial and marsh sediments. The remains of large mammals are relatively common, while the remains of small mammals used to be known only from two localities - Mala Miliva and Sibnica. The method of sediment sieving, used during the last decade, led to discovery of 6 new localities with remains of fossil vertebrates - Sibnica 1, Vračevići, village Lazarevac, Bele Vode, Brajkovac and Tavnik. Most of the fossil material is represented by osteological and odontological remains of small mammals. The best represented group of small mammals at each of the localities was the rodents. According to the odontological material presence was proven for 35 rodent species from 6 families. MN zonation was determined according to structure of associations. The geological age of fossil-bearing sediments was determined by using the method of correlation with the sites in Europe and Turkey.

  6. Rodent sociality and parasite diversity.

    PubMed

    Bordes, Frédéric; Blumstein, Daniel T; Morand, Serge

    2007-12-22

    The risk of parasitism is considered to be a general cost of sociality and individuals living in larger groups are typically considered to be more likely to be infected with parasites. However, contradictory results have been reported for the relationship between group size and infection by directly transmitted parasites. We used independent contrasts to examine the relationship between an index of sociality in rodents and the diversity of their macroparasites (helminths and arthropods such as fleas, ticks, suckling lice and mesostigmatid mites). We found that the species richness of directly transmitted ectoparasites, but not endoparasites, decreased significantly with the level of rodent sociality. A greater homogeneity in the biotic environment (i.e. a reduced number of cohabiting host species) of the more social species may have reduced ectoparasites' diversity by impairing ectoparasites transmission and exchange. Our finding may also result from beneficial outcomes of social living that include behavioural defences, like allogrooming, and the increased avoidance of parasites through dilution effects. PMID:17925270

  7. 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

  8. Laboratory Studies of Coherent Structures in Quasi - Flows

    NASA Astrophysics Data System (ADS)

    Meyers, Steven David

    1990-01-01

    Laboratory experiments were conducted in a large, rapidly rotating annulus of fluid. Low Rossby and Ekman numbers, 0.1 and 10^{-5} respectively, were achieved while maintaining large Reynolds number (greater than 10^4). The apparatus had a flat lid and conical bottom (slope s = -0.1) to mimic the planetary beta-effect. Motion was forced with six source-sink pairs, distributed symmetrically in a ring in the bottom of the tank. Two primary flow states were studied: marginally stable westward and eastward jets. Westward jets tended to be wide, and developed a central region of strong shear with quasi-uniform potential vorticity. Elliptical vortices of the same sign as the shear always formed. Due to design limitations, only cyclonic vortices were produced. Multiple vortex states were found for relatively narrow jets when the inertial time scale was comparable to the Ekman time scale. At increasingly shorter inertial time scale, produced with stronger forcing, the number of vortices decreased from a maximum of 5 to 1. The multiple vortex states were essentially laminar, inspite of their high Reynolds number; the single vortex state was turbulent, producing many small vortices that merged with the main vortex. The broad region of quasi -uniform potential vorticity was considered necessary for the formation of a single robust vortex. These vortices had many properties in common with vortices found on the large gaseous planets. Eastward jets tended to be narrow and exhibited Rossby wave instability. The number of waves was fairly well predicted by linear theory, except for the low forcing situation, when the pumping geometry strongly influenced the instability. Potential vorticity was quasi-uniform on either side of the jet, with a strong gradient in the jet center. This gradient was a strong barrier to particle transport. A Hamiltonian model of the flow demonstrated the presence of a robust invariant surface at the jet center, with large chaotic seas on either side. The

  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. Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System

    PubMed Central

    Zayachkivsky, Andrew; Lehmkuhle, Mark J.; Dudek, F. Edward

    2015-01-01

    Many progressive neurologic diseases in humans, such as epilepsy, require pre-clinical animal models that slowly develop the disease in order to test interventions at various stages of the disease process. These animal models are particularly difficult to implement in immature rodents, a classic model organism for laboratory study of these disorders. Recording continuous EEG in young animal models of seizures and other neurological disorders presents a technical challenge due to the small physical size of young rodents and their dependence on the dam prior to weaning. Therefore, there is not only a clear need for improving pre-clinical research that will better identify those therapies suitable for translation to the clinic but also a need for new devices capable of recording continuous EEG in immature rodents. Here, we describe the technology behind and demonstrate the use of a novel miniature telemetry system, specifically engineered for use in immature rats or mice, which is also effective for use in adult animals. PMID:26274779

  11. Neuregulin 1: a prime candidate for research into gene-environment interactions in schizophrenia? Insights from genetic rodent models

    PubMed Central

    Karl, Tim

    2013-01-01

    Schizophrenia is a multi-factorial disease characterized by a high heritability and environmental risk factors. In recent years, an increasing number of researchers worldwide have started investigating the “two-hit hypothesis” of schizophrenia predicting that genetic and environmental risk factors (GxE) interactively cause the development of the disorder. This work is starting to produce valuable new animal models and reveal novel insights into the pathophysiology of schizophrenia. This mini review will focus on recent advancements in the field made by challenging mutant and transgenic rodent models for the schizophrenia candidate gene neuregulin 1 (NRG1) with particular environmental factors. It will outline results obtained from mouse and rat models for various Nrg1 isoforms/isoform types (e.g., transmembrane domain Nrg1, Type II Nrg1), which have been exposed to different forms of stress (acute versus chronic, restraint versus social) and housing conditions (standard laboratory versus minimally enriched housing). These studies suggest Nrg1 as a prime candidate for GxE interactions in schizophrenia rodent models and that the use of rodent models will enable a better understanding of GxE interactions and the underlying mechanisms. PMID:23966917

  12. Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System.

    PubMed

    Zayachkivsky, Andrew; Lehmkuhle, Mark J; Dudek, F Edward

    2015-01-01

    Many progressive neurologic diseases in humans, such as epilepsy, require pre-clinical animal models that slowly develop the disease in order to test interventions at various stages of the disease process. These animal models are particularly difficult to implement in immature rodents, a classic model organism for laboratory study of these disorders. Recording continuous EEG in young animal models of seizures and other neurological disorders presents a technical challenge due to the small physical size of young rodents and their dependence on the dam prior to weaning. Therefore, there is not only a clear need for improving pre-clinical research that will better identify those therapies suitable for translation to the clinic but also a need for new devices capable of recording continuous EEG in immature rodents. Here, we describe the technology behind and demonstrate the use of a novel miniature telemetry system, specifically engineered for use in immature rats or mice, which is also effective for use in adult animals. PMID:26274779

  13. Hindlimb unloading: rodent analog for microgravity.

    PubMed

    Globus, Ruth K; Morey-Holton, Emily

    2016-05-15

    The rodent hindlimb unloading (HU) model was developed in the 1980s to make it possible to study mechanisms, responses, and treatments for the adverse consequences of spaceflight. Decades before development of the HU model, weightlessness was predicted to yield deficits in the principal tissues responsible for structure and movement on Earth, primarily muscle and bone. Indeed, results from early spaceflight and HU experiments confirmed the expected sensitivity of the musculoskeletal system to gravity loading. Results from human and animal spaceflight and HU experiments show that nearly all organ systems and tissues studied display some measurable changes, albeit sometimes minor and of uncertain relevance to astronaut health. The focus of this review is to examine key HU results for various organ systems including those related to stress; the immune, cardiovascular, and nervous systems; vision changes; and wound healing. Analysis of the validity of the HU model is important given its potential value for both hypothesis testing and countermeasure development. PMID:26869711

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

    PubMed

    Novak, Colleen M; Burghardt, Paul R; Levine, James A

    2012-03-01

    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

  15. 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...

  16. Anti-erosion stone bunds influence rodent dynamics and crop damage in Ethiopian highlands

    NASA Astrophysics Data System (ADS)

    Meheretu, Yonas; Welegerima, Kiros; Teferi, Mekonen; Yirga, Gidey; Haile, Mitiku; Sluydts, Vincent; Bauer, Hans; Nyssen, Jan; Deckers, Jozef; Leirs, Herwig

    2014-05-01

    In areas of subsistence agriculture, a variety of soil conservation methods have been implemented in the last few decades to improve crop yields, however these can have unintended consequences such as providing habitat for rodent pests. We studied rodent population dynamics and estimated crop damage in high and low stone bund density fields for four cropping seasons in Tigray highlands, northern Ethiopia. Stone bunds are physical structures for soil and water conservation, and potentially habitat for rodents. We used a general model to relate the proportion of crop damage to rodent abundance, stone bund density and crop stages. We found a positive correlation between rodent abundance and crop damage, and significant variation in rodent abundance and crop damage between high and low stone bund density fields. Furthermore, crop damage also varied significantly between crop stages. We concluded that Mastomys awashensis and Arvicanthis dembeensis were the two most important crop pests in the highlands causing significant damage. Fields with high stone bund density (~10 m average distance apart) harbor more rodents and endure a significantly higher proportion of crop damage compared to fields with lower stone bund density (~15 m average distance apart). The fact that rodent abundances peaked during the reproductive stage of the crop and around harvest implies the need for management intervention before these crop stages are attained.

  17. 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

  18. 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 ...

  19. Robust Reproducible Resting State Networks in the Awake Rodent Brain

    PubMed Central

    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

  20. The role of phylogeny in desert rodent community assembly.

    PubMed

    Brown, James H

    2012-03-01

    Recent advances in molecular genetics and phylogenetic reconstruction have the potential to transform ecology by providing new insights into the historical evolution of ecological communities. This study by Stevens and collaborators complements decades of previous research on desert rodents, by combining data from a field study and a phylogenetic tree for Mojave Desert rodents to address patterns and processes of community assembly. The number of coexisting rodent species is positively correlated, and the average phylogenetic distance among these species is negatively correlated with perennial plant species richness. As rodent species diversity increases along a gradient of increasing environmental heterogeneity, communities are composed of increasingly related species: there is a consistent pattern of phylogenetic structure from over-dispersed through random to clumped. I discuss this pattern in the light of complementary results of previous studies. This paper is noteworthy for calling attention to still unanswered questions about how the historical events of speciation, colonization, extinction, and trait evolution and their relationship to past climates and vegetation have given rise to current patterns of community organization. PMID:22324970

  1. 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

  2. Neurobiology of rodent self-grooming and its value for translational neuroscience.

    PubMed

    Kalueff, Allan V; Stewart, Adam Michael; Song, Cai; Berridge, Kent C; Graybiel, Ann M; Fentress, John C

    2016-01-01

    Self-grooming is a complex innate behaviour with an evolutionarily conserved sequencing pattern and is one of the most frequently performed behavioural activities in rodents. In this Review, we discuss the neurobiology of rodent self-grooming, and we highlight studies of rodent models of neuropsychiatric disorders--including models of autism spectrum disorder and obsessive compulsive disorder--that have assessed self-grooming phenotypes. We suggest that rodent self-grooming may be a useful measure of repetitive behaviour in such models, and therefore of value to translational psychiatry. Assessment of rodent self-grooming may also be useful for understanding the neural circuits that are involved in complex sequential patterns of action. PMID:26675822

  3. Assessing Spatial Learning and Memory in Rodents

    PubMed Central

    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

  4. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... laboratory study shall be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall be identified by test system, study, nature, and... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Conduct of a nonclinical laboratory study....

  5. Rodent Abundance Dynamics and Leptospirosis Carriage in an Area of Hyper-Endemicity in New Caledonia

    PubMed Central

    Perez, Julie; Brescia, Fabrice; Becam, Jérôme; Mauron, Carine; Goarant, Cyrille

    2011-01-01

    Background Widespread but particularly incident in the tropics, leptospirosis is transmitted to humans directly or indirectly by virtually any Mammal species. However, rodents are recognized as the most important reservoir. In endemic regions, seasonal outbreaks are observed during hot rainy periods. In such regions, hot spots can be evidenced, where leptospirosis is “hyper-endemic”, its incidence reaching 500 annual cases per 100,000. A better knowledge of how rodent populations and their Leptospira prevalence respond to seasonal and meteorological fluctuations might help implement relevant control measures. Methodology/Principal Findings In two tribes in New Caledonia with hyper-endemic leptospirosis, rodent abundance and Leptospira prevalence was studied twice a year, in hot and cool seasons for two consecutive years. Highly contrasted meteorological situations, particularly rainfall intensities, were noted between the two hot seasons studied. Our results show that during a hot and rainy period, both the rodent populations and their Leptospira carriage were higher. This pattern was more salient in commensal rodents than in the sylvatic rats. Conclusions/Significance The dynamics of rodents and their Leptospira carriage changed during the survey, probably under the influence of meteorology. Rodents were both more numerous and more frequently carrying (therefore disseminating) leptospires during a hot rainy period, also corresponding to a flooding period with higher risks of human exposure to waters and watered soils. The outbreaks of leptospirosis in hyper-endemic areas could arise from meteorological conditions leading to both an increased risk of exposure of humans and an increased volume of the rodent reservoir. Rodent control measures would therefore be most effective during cool and dry seasons, when rodent populations and leptospirosis incidence are low. PMID:22039557

  6. Holographic study of a vibrating bell: An undergraduate laboratory experiment

    NASA Astrophysics Data System (ADS)

    Menou, Kristen; Audit, Benjamin; Boutillon, Xavier; Vach, Holger

    1998-05-01

    An experiment combining holography and musical acoustics is described. Structures of vibration modes of a bell are visualized by time-average holography under either acoustical or mechanical excitation. The vibration amplitude as measured by an accelerometer shows very good quantitative agreement with that determined from our holograms by fringe counting. An effect of degenerate level separation is shown in the mechanical case. It is argued that this experiment is not only very inexpensive for a physics laboratory already equipped for holography, but that it also strongly stimulates students to deepen their insight into a variety of different topics in applied physics.

  7. Case Study: Formal Inspections at the Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Kelly, J. C.; Welz, L. W.

    1993-01-01

    The Jet Propulsion Laboratory (JPL) of the California Institute of Technology is a federally funded research and development center operating under contract to the National Aeronautics and Space Administration (NASA). JPL's charter emphasizes the exploration of the solar system including observations of Earth as well as other stellar systems and extra-solar-system bodies. Within JPL, the Software Product Assurance (SPA) Section helps to ensure the operational integrity of the software within the system. SPA evaluates the operational requirements, the acceptability and readiness of all software, hardware/software interfaces, and the integrity of the completed software before its final release into the operational environment.

  8. Radiative shocks: An opportunity to study laboratory astrophysics

    SciTech Connect

    Koenig, M.; Vinci, T.; Benuzzi-Mounaix, A.; Ozaki, N.; Ravasio, A.; Rabec le Glohaec, M.; Boireau, L.; Michaut, C.; Bouquet, S.; Atzeni, S.; Schiavi, A.; Peyrusse, O.; Batani, D.

    2006-05-15

    In this paper, experimental results on radiative shocks generated by a high power laser in a xenon gas cell are presented. Two sets of experiments have been performed at the Laser pour l'Utilisation des Lasers Intenses (LULI) laboratory. Several shock parameters were simultaneously measured: shock temperature and velocities, the precursor two-dimensional (2D) time evolution, its electron density, density gradient, and temperature. Data were obtained varying initial conditions for different laser intensities and gas pressures. Comparisons with 1D and 2D radiative hydrodynamic simulations are shown for all measured parameters (shock velocity, shape, radial expansion, and temperature as well as precursor velocity and electron density)

  9. Radiative shocks: An opportunity to study laboratory astrophysics

    NASA Astrophysics Data System (ADS)

    Koenig, M.; Vinci, T.; Benuzzi-Mounaix, A.; Ozaki, N.; Ravasio, A.; Rabec Le Glohaec, M.; Boireau, L.; Michaut, C.; Bouquet, S.; Atzeni, S.; Schiavi, A.; Peyrusse, O.; Batani, D.

    2006-05-01

    In this paper, experimental results on radiative shocks generated by a high power laser in a xenon gas cell are presented. Two sets of experiments have been performed at the Laser pour l'Utilisation des Lasers Intenses (LULI) laboratory. Several shock parameters were simultaneously measured: shock temperature and velocities, the precursor two-dimensional (2D) time evolution, its electron density, density gradient, and temperature. Data were obtained varying initial conditions for different laser intensities and gas pressures. Comparisons with 1D and 2D radiative hydrodynamic simulations are shown for all measured parameters (shock velocity, shape, radial expansion, and temperature as well as precursor velocity and electron density).

  10. Defective enamel ultrastructure in diabetic rodents.

    PubMed

    Atar, M; Atar-Zwillenberg, D R; Verry, P; Spornitz, U M

    2004-07-01

    We investigated six different types of diabetic rodents. Four expressed a genetic obesity resulting in diabetes. One developed diabetes induced by a diet-dependent obesity, and one with genetic diabetes received anti-diabetic medication. The tooth samples were examined under a scanning electron microscope and with an energy dispersive microanalysis (EDX). The electron micrographs showed severe, varying degrees of damage within the six different diabetic animal types, such as irregular crystallite deposition and prism perforations in genetically obese animals compared to less-disordered prism structures in diet-dependent obesity. Anti-diabetic medication resulted in normal enamel ultrastructure. The EDX analysis revealed a reduction in the amount of calcium and phosphorus in all regions affected by diabetes. Based on these animal studies, we suggest that both juvenile diabetes type I (in infants) and adult diabetes type II (in pregnant mothers, affecting the developing foetus) may affect the normal development of teeth in humans. PMID:15242388

  11. [Tuberculosis Laboratory Surveillance Network (TuLSA) study group. The first step for national tuberculosis laboratory surveillance: Ankara, 2011].

    PubMed

    Sezen, Figen; Albayrak, Nurhan; Özkara, Şeref; Karagöz, Alper; Alp, Alpaslan; Duyar Ağca, Filiz; İnan Süer, Asiye; Müderris, Tuba; Ceyhan, İsmail; Durmaz, Rıza; Ertek, Mustafa

    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

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

    USGS Publications Warehouse

    Gragg, J.E.; Rodda, G.H.; Savidge, J.A.; White, Gary 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.

  13. [The anti-tumor mechanisms in long-lived rodents].

    PubMed

    Dong, Yanjiao; Pang, Yue; Li, Qingwei

    2016-05-01

    Rodents, including the nude mice with congenital aplasia of the thymus, cancer-resistant naked mole rat (Heterocephalus glaber) and blind mole rat (Spalax galili), are important model organisms that are widely used in biomedical research. The aging process is closely related to cancer incidence in mammals and the aging degree is positively correlated with the risk of cancer. Since rodents account for 40% of mammals, study of the unique antitumor mechanism in long-lived rodents is very important. Replicative senescence is anti-tumor mechanism that prevalently exist in rodents, however, unique anti-tumor mechanisms have been found in naked mole-rats and blind mole-rats. The cancer resistance of Spalax galili is mediated by cell-released IFN-β which activates p53 and Rb signaling pathway and the cells undergoes concerted cell death while that of Heterocephalus glaber is mediated by high molecular weight hyaluronan (HMW-HA) which causes contact inhibition. In addition, highly expressed pro-cell-death and anti-inflammation related genes are found in the genome of both naked mole-rats and blind mole-rats. In this review, we summarize the anti-tumor mechanisms in both Heterocephalus glaber and Spalax galili, which may provide information for related research. PMID:27232489

  14. Laboratory Studies of Organic Compounds With Reflectance Spectroscopy

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

    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 temperatures at visible to near infrared wavelengths. Reflectance spectra not only enhance weak or unseen transmission features, they are also more analogous to spectra obtained by spacecraft that are imaging such bodies as giant planet moons, kuiper belt objects, centaurs, comets and asteroids, as well as remote sensing of the earth. The USGS Spectroscopy Laboratory is measuring reflectance spectra of organic compounds from room to cryogenic temperatures over the spectral range of 0.35 to 15.5 microns. This region encompasses the fundamental absorptions and many overtones and combinations of C, H, O, and N molecular bonds. Because most organic compounds belong to families whose members have similar structure and composition, individual species identification within a narrow wavelength range may be ambiguous. By measuring spectral reflectance of the pure laboratory samples from the visible through the near and mid-infrared, absorption bands unique to each can be observed, cataloged, and compared to planetary reflectance data. We present here spectra of organic compounds belonging to five families: the alkanes, alkenes, alkynes, aromatics, and cyanides. Common to all of these are the deep C-H stretch fundamental absorptions, which shift shortward from 3.35+ microns in alkanes to 3.25+ microns in aromatics, to 3.2+ microns in alkenes, and down to 3.0+ microns in alkynes. Mid-IR absorptions due to C-H bending deformations at 6.8+ and 7.2+ microns are also identified. In the near infrared these stretching and bending fundamentals yield a diagnostic set of combination

  15. Laboratory measurements in support of radar studies of Titan seas

    NASA Astrophysics Data System (ADS)

    Spilker, T. R.; Hodyss, R. P.; Beauchamp, P. M.; Reh, K. R.

    2009-04-01

    Data from Cassini RADAR instrument observations of Titan's lakes and seas show tantalizing hints that in some locations the radar signals might penetrate the liquids, returning measurable reflections from the solid surfaces beneath. At the microwave frequencies used by the RADAR instrument, non-polar liquid alkanes such as methane, ethane, and propane are fairly transparent, supporting the possibility that propagation through the liquids at Titan occurs. But relatively small amounts of other species dissolved in a liquid can strongly influence its microwave absorption coefficient. The dissolution of small amounts of sodium chloride in water, which increases the absorption coefficient by orders of magnitude, illustrates the potential of this effect. At Titan it is almost certain that some of the organic materials observed on the surface, and possibly other species, would dissolve in the methane-ethane mixture thought to constitute the bulk of the seas and lakes. If the microwave propagation constants of the liquids were known, Cassini RADAR data could provide estimates of depth profiles for areas yielding lake-bottom returns, and lower limits to depth for those areas where returns are absent. But the effects of anticipated dissolved species on the microwave properties of liquid alkane mixtures are largely unknown. Laboratory measurements could provide the key to inferring the lake-depth implications of Cassini RADAR results. There are multiple laboratory techniques available for measuring refractive indices and absorption coefficients of liquid samples at microwave frequencies. In the case of liquids relevant to Titan, the primary challenge is to maintain the samples and experimental apparatus at temperatures and pressures that keep the samples in the liquid phase, but this is not an impossible task. Other considerations include ensuring that the composition of a sample within the apparatus is well known. Notably, it is important that all surfaces in contact with

  16. Nocturnal to Diurnal Switches with Spontaneous Suppression of Wheel-Running Behavior in a Subterranean Rodent

    PubMed Central

    Tachinardi, Patricia; Tøien, Øivind; Valentinuzzi, Veronica S.; Buck, C. Loren; Oda, Gisele A.

    2015-01-01

    Several rodent species that are diurnal in the field become nocturnal in the lab. It has been suggested that the use of running-wheels in the lab might contribute to this timing switch. This proposition is based on studies that indicate feed-back of vigorous wheel-running on the period and phase of circadian clocks that time daily activity rhythms. Tuco-tucos (Ctenomys aff. knighti) are subterranean rodents that are diurnal in the field but are robustly nocturnal in laboratory, with or without access to running wheels. We assessed their energy metabolism by continuously and simultaneously monitoring rates of oxygen consumption, body temperature, general motor and wheel running activity for several days in the presence and absence of wheels. Surprisingly, some individuals spontaneously suppressed running-wheel activity and switched to diurnality in the respirometry chamber, whereas the remaining animals continued to be nocturnal even after wheel removal. This is the first report of timing switches that occur with spontaneous wheel-running suppression and which are not replicated by removal of the wheel. PMID:26460828

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

    PubMed Central

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

    2015-01-01

    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

  18. 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

  19. Nocturnal to Diurnal Switches with Spontaneous Suppression of Wheel-Running Behavior in a Subterranean Rodent.

    PubMed

    Tachinardi, Patricia; Tøien, Øivind; Valentinuzzi, Veronica S; Buck, C Loren; Oda, Gisele A

    2015-01-01

    Several rodent species that are diurnal in the field become nocturnal in the lab. It has been suggested that the use of running-wheels in the lab might contribute to this timing switch. This proposition is based on studies that indicate feed-back of vigorous wheel-running on the period and phase of circadian clocks that time daily activity rhythms. Tuco-tucos (Ctenomys aff. knighti) are subterranean rodents that are diurnal in the field but are robustly nocturnal in laboratory, with or without access to running wheels. We assessed their energy metabolism by continuously and simultaneously monitoring rates of oxygen consumption, body temperature, general motor and wheel running activity for several days in the presence and absence of wheels. Surprisingly, some individuals spontaneously suppressed running-wheel activity and switched to diurnality in the respirometry chamber, whereas the remaining animals continued to be nocturnal even after wheel removal. This is the first report of timing switches that occur with spontaneous wheel-running suppression and which are not replicated by removal of the wheel. PMID:26460828

  20. PCB biodegradation: Laboratory studies transitioned into the field

    SciTech Connect

    Abramowicz, D.A.

    1993-12-31

    Two distinct bacterial systems are known to be involved in PCB biotransformations. Both aerobic PCB biodegradation (Oxidative attack) and anaerobic PCB dechlorination (reductive attack) have been demonstrated in the laboratory. These results have been successfully reproducted in recent experiments performed in aquatic sediments. In 1991, GE performed a large scale test of in situ aerobic PCB biodegradation in the Upper Hudson River. The experiments involved six sealed caissons (six feet in diameter) lowered into Aroclor 1242 contaminated sediments that had already undergone extensive anaerobic PCB dechlorination. Stimulation of indigenous PCB-degrading microorganisms resulted in >50% biodegradation over 10 weeks. A large scale stimulation of in situ anaerobic PCB dechlorination in Housatonic River sediments contaminated with untransformed Aroclor 1260 was initiated in 1992. The experiments similarly involve six sealed caissons (six feet in diameter) lowered into contaminated sediments to investigate new methods developed to accelerate PCB dechlorination in the field. Preliminary results from this ongoing field test will be discussed.

  1. Diamonds in space: a brief history and recent laboratory studies

    NASA Astrophysics Data System (ADS)

    Chang, Huan-Cheng

    2016-07-01

    Stardust grains exist in outer space. However, due to their low abundance, structural heterogeneities, and lack of distinct spectroscopic features, unambiguous identification of their chemical composition has been a challenge. Diamond is a notable exception because it is composed of carbon and has several unique physicochemical properties that make the identification possible. Here, we provide a brief review on how diamonds were discovered in space based on the remarkable spectral matching between laboratory spectra and astronomical observations of the infrared emission at 3.43 and 3.53 µm, followed by a discussion of fluorescent nanodiamond as a possible carrier for extended red emission at 600 — 800 nm. Recent evidence to support the latter suggestion is provided.

  2. Study of polyelectrolytes for Los Alamos National Laboratory. Final report

    SciTech Connect

    Labonne, N.

    1994-11-01

    To assess the safety of a potential radioactive waste repository, analysis of the fluid solution containing low levels of activity need to be performed. In some cases, the radioactivity would be so weak (3--30 pCi/L) that the solution must be concentrated for measurement. For this purpose, Los Alamos National Laboratory scientists are synthesizing some water soluble polyelectrolytes, which, because they are strong complexing agents for inorganic cations, can concentrate the radioelements in solution. To assist in characterization of these polyelectrolytes, the author has performed experiments to determine physico-chemical constants, such as pKa values and stability constants. The complexation constants between both polyelectrolytes and europium were determined by two methods: solvent extraction and ion exchange. Results are presented.

  3. A laboratory study of spray generation in high winds

    NASA Astrophysics Data System (ADS)

    Ortiz-Suslow, D. G.; Haus, B. K.; Mehta, S.; Laxague, N. J. M.

    2016-05-01

    Characterizing the vertical distribution of large spray particles (i.e., spume) in high wind conditions is necessary for better understanding of the development of the atmospheric boundary layer in extreme conditions. To this end a laboratory experiment was designed to observe the droplet concentration in the air above actively breaking waves. The experiments were carried out in hurricane force conditions (U 10 equivalent wind speed of 36 to 54 m/s) and using both fresh water and salt water. While small differences between fresh and salt water were observed in profiles of radius-integrated spray volume fraction, the profiles tend to converge as the wind forcing increases. This supports the assumption that the physical mechanism for spume production is not sensitive to salinity and its corresponding link to the bubble size distribution.

  4. Renewable Energy Laboratory Development for Biofuels Advanced Combustion Studies

    SciTech Connect

    Soloiu, Valentin A.

    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. Biofuels 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.

  5. Rodent Models of Amyotrophic Lateral Sclerosis

    PubMed Central

    Philips, Thomas; Rothstein, Jeffrey D.

    2015-01-01

    Amyotrophic Lateral Sclerosis (ALS) is a motor neuron disease affecting upper and lower motor neurons in the CNS. Patients with ALS develop extensive muscle wasting and atrophy leading to paralysis and death 3-5 years after disease onset. ALS may be familial (fALS 10%) or sporadic ALS (sALS, 90%). The large majority of fALS) cases are due to genetic mutations in the Superoxide dismutase 1 gene (SOD1, 15% of fALS) and repeat nucleotide expansions in the gene encoding C9ORF72 (around 40-50% of fALS and ~10% of sALS). From a wide range of pathological studies the general conclusion is that ALS disease is mediated through aberrant protein homeostasis (ie ER stress and autophagy) and/or changes in RNA processing (as seen in all non-SOD1-mediated ALS). In all of these cases, animal models suggest that the disease is mediated non-cell-autonomously, i.e. not only motor neurons are involved, but glial cells including microglia, astrocytes and oligodendrocytes and other neuronal subpopulations are also implicated in disease pathogenesis. This overview will give a chronological overview of a wide range of different ALS rodent models generated so far with a thorough description of their intrinsic advantages and disadvantages. We will focus on their respective correlation with disease as seen in humans and their potential for understanding basic disease biology. As RNA processing has more recently come to the foreground of ALS research, we will mainly focus on a thorough description of the most recently generated ALS rodent models. PMID:26344214

  6. 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.

  7. 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.

  8. 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.

  9. A Manpower Study of Technical Personnel in Hospital Clinical Laboratories. Final Report.

    ERIC Educational Resources Information Center

    Harkness, James P., And Others

    As one of the efforts related to closing the gap between the growing demands for clinical laboratory workers and the supply of well-trained workers, the volume and quality of laboratory procedures and the general characteristics of workers in North Carolina hospitals were studied. Approaches to the study included tests on "unknowns" by laboratory…

  10. 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…

  11. Care of Mastomys in the laboratory.

    PubMed

    Scholz, Jodi; Wilson, Steven

    2016-05-20

    Mastomys rodents occupy a valuable niche in biomedical research, but there is very little published information regarding how to care for them in the laboratory. Here we provide information about the physical and behavioral characteristics of this unusual laboratory rodent, its taxonomic history, common diseases that affect it, and its use in research. We also provide housing recommendations based upon almost 15 years of experience successfully maintaining a colony of Mastomys coucha at our institution. PMID:27203263

  12. 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.

  13. Ultrasonic attenuation and backscatter coefficient estimates of rodent-tumor-mimicking structures: comparison of results among clinical scanners.

    PubMed

    Nam, Kibo; Rosado-Mendez, Ivan M; Wirtzfeld, Lauren A; Pawlicki, Alexander D; Kumar, Viksit; Madsen, Ernest L; Ghoshal, Goutam; Lavarello, Roberto J; Oelze, Michael L; Bigelow, Timothy A; Zagzebski, James A; O'Brien, William D; Hall, Timothy J

    2011-10-01

    In vivo estimations of the frequency-dependent acoustic attenuation (alpha) and backscatter (eta) coefficients using radiofrequency (rf) echoes acquired with clinical ultrasound systems must be independent of the data acquisition setup and the estimation procedures. In a recent in vivo assessment of these parameters in rodent mammary tumors, overall agreement was observed among alpha and eta estimates using data from four clinical imaging systems. In some cases, particularly in highly-attenuating heterogeneous tumors, multisystem variability was observed. This paper compares alpha and eta estimates of a well-characterized rodent-tumor-mimicking homogeneous phantom scanned using seven transducers with the same four clinical imaging systems: a Siemens Acuson S2000, an Ultrasonix RP, a Zonare Z.one and a VisualSonics Vevo2100. alpha and eta estimates of lesion-mimicking spheres in the phantom were independently assessed by three research groups, who analyzed their system's rf echo signals. Imaging-system-based estimates of alpha and eta of both lesion-mimicking spheres were comparable to through-transmission laboratory estimates and to predictions using Faran's theory, respectively. A few notable variations in results among the clinical systems were observed but the average and maximum percent difference between alpha estimates and laboratory-assessed values was 11% and 29%, respectively. Excluding a single outlier dataset, the average and maximum average difference between eta estimates for the clinical systems and values predicted from scattering theory was 16% and 33%, respectively. These results were an improvement over previous interlaboratory comparisons of attenuation and backscatter estimates. Although the standardization of our estimation methodologies can be further improved, this study validates our results from previous rodent breast-tumor model studies. PMID:22518954

  14. Involuntary autobiographical memories in dysphoric mood: a laboratory study.

    PubMed

    Kvavilashvili, Lia; Schlagman, Simone

    2011-05-01

    The frequency and characteristics of involuntary autobiographical memories were compared in 25 stable dysphoric and 28 non-dysphoric participants, using a new laboratory-based task (Schlagman & Kvavilashvili, 2008). Participants detected infrequent target stimuli (vertical lines) in a simple vigilance task and recorded any involuntary autobiographical memories that came to mind, mostly in response to irrelevant words presented on the screen. Dysphoric participants reported involuntary memories as frequently and as quickly as non-dysphoric participants and their memories were not repetitive intrusive memories of negative or traumatic events. Additional content analysis showed that dysphoric participants did not recall more memories of objectively negative events (e.g., accidents, illnesses, deaths) than non-dysphoric participants. However, significant group differences emerged in terms of a mood congruency effect whereby dysphoric participants rated their memories as more negative than non-dysphoric participants. Moreover, the proportion of negatively rated involuntary memories was related to lower mood ratings at the end of the session in the dysphoric but not in the non-dysphoric group. Finally, groups did not differ on several memory characteristics such as vividness, specificity (high in both groups) and rates of rehearsal (low in both groups). Theoretical and practical implications of these findings for research on depression and autobiographical memory are discussed. PMID:21678152

  15. Pretreatment for membrane water treatment systems: a laboratory study

    SciTech Connect

    Wend, Christopher F.; Stewart, Philip S.; Jones, Warren L.; Camper, Anne K.

    2003-09-30

    The goal of the work was to determine if biological treatment of water containing soil-derived humic substances has the potential for reducing the fouling of membranes used in water treatment. Laboratory scale biological filters containing biologically active carbon or iron oxide coated sand were fed humic-laden water with or without prechlorination. This stream was split, with half being further treated by microfiltration. Treated water was assessed for total organic carbon removal and biofouling potential using a glass bead assay and membrane assay for total cell counts, fouling layer thickness, and flux reduction. A combination of these assays provided more insight than any single measurement. Compared to untreated control water, biological treatment was capable of reducing downstream fouling of membrane systems. For example, fouling layer thickness was reduced by half after biological treatment, and cell counts were reduced four- to five-fold. Biological treatment coupled with microfiltration provided the best reduction of fouling, while prechlorination did not appear to impact the process. These results suggest that biological treatment may be valuable in reducing membrane fouling while reducing the amount of disinfectants used in pretreatment.

  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 uppe