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1

In vivo effects of bisphenol A in laboratory rodent studies  

Microsoft Academic Search

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

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

2007-01-01

2

In vivo effects of bisphenol A in laboratory rodent studies  

Microsoft Academic Search

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

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

3

Susceptibility of laboratory rodents to Trichinella papuae.  

PubMed

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

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

2013-12-01

4

Breath-hold Device for Laboratory Rodents Undergoing Imaging Procedures  

Microsoft Academic Search

The increased use in noninvasive imaging of laboratory rodents has prompted innovative techniques in animal han- dling. Lung imaging of rodents can be a diffi cult task because of tissue motion caused by breathing, which affects image quality. The use of a prototype fl at-panel computed tomography unit allows the acquisition of images in as little as 2, 4, or

Belinda Rivera; Mark J Bushman; Richard G Beaver; Dianna D Cody; Roger E Price

5

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

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

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

2012-01-01

6

Laboratory Rodent Welfare: Thinking Outside the Cage  

Microsoft Academic Search

This commentary presents the case against housing rats and mice in laboratory cages; the commentary bases its case on their sentience, natural history, and the varied detriments of laboratory conditions. The commentary gives 5 arguments to support this position: (a) rats and mice have a high degree of sentience and can suffer, (b) laboratory environments cause suffering, (c) rats and

Jonathan Balcombe

2010-01-01

7

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

EPA Science Inventory

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

8

Lung imaging of laboratory rodents in vivo  

NASA Astrophysics Data System (ADS)

We have been acquiring respiratory-gated micro-CT images of live mice and rats for over a year with our General Electric (formerly Enhanced Vision Systems) hybrid scanner. This technique is especially well suited for the lung due to the inherent high tissue contrast. Our current studies focus on the assessment of lung tumors and their response to experimental agents, and the assessment of lung damage due to chemotherapy agents. We have recently installed a custom-built dual flat-panel cone-beam CT scanner with the ability to scan laboratory animals that vary in size from mice to large dogs. A breath-hold technique is used in place of respiratory gating on this scanner. The objective of this pilot study was to converge on scan acquisition parameters and optimize the visualization of lung damage in a mouse model of fibrosis. Example images from both the micro-CT scanner and the flat-panel CT scanner will be presented, as well as preliminary data describing spatial resolution, low contrast resolution, and radiation dose parameters.

Cody, Dianna D.; Cavanaugh, Dawn; Price, Roger E.; Rivera, Belinda; Gladish, Gregory; Travis, Elizabeth

2004-10-01

9

Environmental Enrichment of Laboratory Rodents: The Answer Depends on the Question  

PubMed Central

Efforts to refine the care and use of animals in research have been ongoing for many years and have led to general standardization of rodent models, particularly with regard to animal housing, genetics, and health status. Concurrently, numerous informal practices and recommendations have been promulgated with the laudable intent of promoting general animal wellbeing through so-called enrichment of the cage environment. However, the variety of housing conditions fostered by efforts at environmental enrichment (EE) complicates the goal of establishing standardized or even defined environments for laboratory rodents. Many studies over the years have sought to determine whether or how various enrichment strategies affect the behavior and physiology of laboratory rodents. The findings, conclusions, and interpretations of these studies are mixed, particularly with regard to their application across rodent species, strains, genders, and ages; whether or how they affect the animals and the science; and, in some cases, whether the effects are positive, negative, or neutral in terms of animal wellbeing. Crucial issues related to the application of EE in research settings include its poorly defined effect on the animals, the potential for increased variability in the data, poor definition across labs and in publications, and potential for animal or scientific harm. The complexities, uncertainties, interpretational conundrums, varying conclusions, and lack of consensus in the EE literature warrant careful assessment of the benefits and liabilities associated with implementing such interventions. Reliance on evidence, professional judgment, and performance standards are crucial in the development of EE strategies. PMID:22330246

Toth, Linda A; Kregel, Kevin; Leon, Lisa; Musch, Timothy I

2011-01-01

10

Environmental enrichment of laboratory rodents: the answer depends on the question.  

PubMed

Efforts to refine the care and use of animals in research have been ongoing for many years and have led to general standardization of rodent models, particularly with regard to animal housing, genetics, and health status. Concurrently, numerous informal practices and recommendations have been promulgated with the laudable intent of promoting general animal wellbeing through so-called enrichment of the cage environment. However, the variety of housing conditions fostered by efforts at environmental enrichment (EE) complicates the goal of establishing standardized or even defined environments for laboratory rodents. Many studies over the years have sought to determine whether or how various enrichment strategies affect the behavior and physiology of laboratory rodents. The findings, conclusions, and interpretations of these studies are mixed, particularly with regard to their application across rodent species, strains, genders, and ages; whether or how they affect the animals and the science; and, in some cases, whether the effects are positive, negative, or neutral in terms of animal wellbeing. Crucial issues related to the application of EE in research settings include its poorly defined effect on the animals, the potential for increased variability in the data, poor definition across labs and in publications, and potential for animal or scientific harm. The complexities, uncertainties, interpretational conundrums, varying conclusions, and lack of consensus in the EE literature warrant careful assessment of the benefits and liabilities associated with implementing such interventions. Reliance on evidence, professional judgment, and performance standards are crucial in the development of EE strategies. PMID:22330246

Toth, Linda A; Kregel, Kevin; Leon, Lisa; Musch, Timothy I

2011-08-01

11

Pulmonary Toxicity Studies of Lunar Dusts in Rodents  

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

12

Failure to infect laboratory rodent hosts with human isolates of Rodentolepis (= Hymenolepis) nana.  

PubMed

Confusion exists over the species status and host-specificity of the tapeworm Rodentolepis (= Hymenolepis) nana. It has been described as one species, R. nana, found in both humans and rodents. Others have identified a subspecies; R. nana var. fraterna, describing it as morphologically identical to the human form but only found in rodents. The species present in Australian communities has never been identified with certainty. Fifty one human isolates of Rodentolepis (= Hymenolepis) nana were orally inoculated into Swiss Q, BALB/c, A/J, CBA/ CAH and nude (hypothymic) BALB/c mice, Fischer 344 and Wistar rats and specific pathogen free (SPF) hamsters. Twenty four human isolates of R. nana were cross-tested in flour beetles, Tribolium confusum. No adult worms were obtained from mice, rats or hamsters, even when immunosuppressed with cortisone acetate. Only one of the 24 samples developed to the cysticercoid stage in T. confusum; however, when inoculated into laboratory mice the cysticercoids failed to develop into adult worms. The large sample size used in this study, and the range of techniques employed for extraction and preparation of eggs provide a comprehensive test of the hypothesis that the human strain of R. nana is essentially non-infective to rodents. PMID:12018194

Macnish, M G; Morgan, U M; Behnke, J M; Thompson, R C A

2002-03-01

13

Human and laboratory rodent low response to alcohol: is better consilience possible?  

PubMed

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 the 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 sparse and unsystematic. Therefore, we suggest that more effort is still needed to collect data using refined measures designed to be more directly comparable in humans and animals. Additionally, the genetically mediated mechanisms underlying this endophenotype need to be characterized further across species. PMID:20148776

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

2010-04-01

14

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

PubMed Central

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 sparse and unsystematic. Therefore, we suggest that more effort is still needed to collect data using refined measures designed to be more directly comparable in humans and animals. Additionally, the genetically mediated mechanisms underlying this endophenotype need to be characterized further across species. PMID:20148776

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

2010-01-01

15

Can Rodent Longevity Studies be Both Short and Powerful?  

PubMed Central

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

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

2011-01-01

16

Pulmonary Toxicity Studies of Lunar Dusts in Rodents  

NASA Technical Reports Server (NTRS)

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.

Lam, Chiu-wing; James, John T.

2009-01-01

17

Study of hantavirus infection in captive breed colonies of wild rodents.  

PubMed

Wild sigmondontine rodents are known to be the reservoir of several serotypes of New World hantaviruses. The mechanism of viral transmission is by aerosol inhalation of the excreta from infected rodents. Considering that the captive breed colonies of various wild mammals may present a potential risk for hantaviral transmission, we examined 85 specimens of Thrichomys spp. (Echimyidae) and 17 speciemens of Nectomys squamipes (Sigmodontinae) from our colony for the presence of hantavirus infections. Blood samples were assayed for the presence of antibodies to Andes nucleocapsid antigen using enzyme-linked immunosorbent assay (ELISA). Additionally, serum samples from workers previously exposed to wild rodents, in the laboratories where the study was conducted, were also tested by ELISA to investigate prevalence of anti-hantavirus IgG antibodies. All blood samples were negative for hantavirus antibodies. Although these results suggest that those rodent's colonies are hantavirus free, the work emphasizes the need for hantavirus serological monitoring in wild colonized rodents and secure handling potentially infected rodents as important biosafety measures. PMID:15558166

Oliveira, R C; Rozental, T; Alves-Corrêa, A A; D'Andrea, P S; Schatzmayr, H G; Cerqueira, R; Lemos, E R S

2004-10-01

18

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

E-print Network

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

Weston, Ken

19

A Renewed Look at Laboratory Rodent Housing and Management  

Microsoft Academic Search

Since its publication in 1996, the Guide for the Care and Use of Laboratory Animals (National Research Council, Washington DC, National Academy Press) has become a primary source of information for institutional animal care and use committees (IACUCs) and research facility man- agers. In the ensuing years, recommendations relating to laboratory animal care have evolved in response to new scientific

Janet C. Gonder; Kathy Laber

2007-01-01

20

Rodents for comparative aging studies: from mice to beavers.  

PubMed

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

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

2008-09-01

21

Rodents for comparative aging studies: from mice to beavers  

PubMed Central

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

Bozzella, Michael J.; Seluanov, Andrei

2008-01-01

22

Laboratory and field evaluation of rodent bait treated with fipronil for feed through and systemic control of Phlebotomus papatasi.  

PubMed

The sand fly Phlebotomus papatasi is the main vector of Leishmania major, etiologic agent of zoonotic cutaneous leishmaniasis (ZCL), which is endemic in North Africa, the Middle East, and Asia. In North Africa, Meriones shawi is one of the two main reservoir hosts of L. major. P. papatasi populations are maintained in borrowing rodents such as M. shawi. Three fipronil-treated rodent baits were evaluated for systemic and feed through insecticidal activity against P. papatasi feeding on M. shawi. Through blood feeding bioassays, mortality rates of females P. papatasi increased with the concentration of fipronil in the rodent bait varying from 0.001% to 0.005%. In the laboratory, more than 90.0% of P. papatasi were killed within 48h after blood feeding on the desert's jirds, M. shawi, treated up to 29 days prior with a single application of fipronil at a concentration of 0.001%, 0.0025% and 0.005%. Through larval bioassays, mortality rates of larvae that have fed on faeces of treated bait for M. shawi increase with the concentrations of fipronil. Faeces of orally-treated Meriones were significantly toxic to larvae for 5 weeks with a concentration of 0.005%. In the field, application of treated bait resulted in 80.0% reduction in the populations of P. papatasi up to 6 weeks after a single application of fipronil at a concentration of 0.005%. This is the first study to demonstrate field efficacy of fipronil-treated rodent baits for P. papatasi control and the first study to evaluate this approach in M. shawi, a principal ZCL reservoir host. These results suggest that fipronil-treated rodent baits can be used to effectively reduce the populations of P. papatasi associated with M. shawi in ZCL endemic areas. PMID:24681222

Derbali, M; Polyakova, L; Boujaâma, A; Burruss, D; Cherni, S; Barhoumi, W; Chelbi, I; Poché, R; Zhioua, E

2014-07-01

23

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

PubMed

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

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

2013-03-01

24

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

PubMed Central

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

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

2013-01-01

25

Feeding ecology and laboratory predatory behavior toward live and artificial moving prey in seven rodent species  

Microsoft Academic Search

The present research related the feeding ecology of seven rodent species to the reactions of laboratory-reared and prey-inexperienced\\u000a members of each species both to live prey and to an artificial moving stimulus predicting food pellets. Feeding ecology was\\u000a determined by the degree of carnivory, based on reported stomach contents and observations of feeding. Experiment 1 assessed\\u000a predatory reactions to a

William Timberlake; Donna L. Washburne

1989-01-01

26

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...

27

Problems in the study of rodent aggression  

Microsoft Academic Search

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

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

2003-01-01

28

Sex Differences in Behavioral Circadian Rhythms in Laboratory Rodents  

PubMed Central

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

Krizo, Jessica A.; Mintz, Eric M.

2014-01-01

29

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

PubMed Central

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

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

2014-01-01

30

Transmission Study of Andes Hantavirus Infection in Wild Sigmodontine Rodents†  

PubMed Central

Our study was designed to contribute to an understanding of the timing and conditions under which transmission of Andes hantavirus in Oligoryzomys longicaudatus reservoir populations takes place. Mice were caged in test habitats consisting of steel drums containing holding cages, where seronegative rodents were exposed to wild seropositive individuals by freely sharing the same cage or being separated by a wire mesh. Tests were also performed for potential viral transmission to mice from excrement-tainted bedding in the cages. Andes virus transmitted efficiently; from 130 attempts with direct contact, 12.3% resulted in virus transmission. However, if we consider only those rodents that proved to be infectious, from 93 attempts we obtained 16 infected animals (17.2%). Twelve of them resulted from intraspecies O. longicaudatus encounters where male mice were differentially affected and 4 resulted from O. longicaudatus to Abrothrix olivaceus. Experiments using Abrothrix longipilis as receptors were not successful. Transmission was not observed between wire mesh-separated animals, and mice were not infected from excrement-tainted bedding. Bites seemed not to be a requisite for oral transmission. Genomic viral RNA was amplified in two out of three saliva samples from seropositive rodents, but it was not detected in urine samples obtained by vesicle puncture from two other infected rodents. Immunohistochemistry, using antibodies against Andes (AND) hantavirus proteins, revealed strong reactions in the lung and salivary glands, supporting the possibility of oral transmission. Our study suggests that AND hantavirus may be principally transmitted via saliva or saliva aerosols rather than via feces and urine. PMID:15479837

Padula, P.; Figueroa, R.; Navarrete, M.; Pizarro, E.; Cadiz, R.; Bellomo, C.; Jofre, C.; Zaror, L.; Rodriguez, E.; Murúa, R.

2004-01-01

31

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

SciTech Connect

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.

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

1981-04-01

32

Rodent models to study the relationships between mammals and their bacterial inhabitants  

PubMed Central

Laboratory rodents have been instrumental in helping researchers to unravel the complex interactions that mammals have with their microbial commensals. Progress in defining these interactions has also been possible thanks to the development of culture-independent methods for describing the microbiota associated to body surfaces. Understanding the mechanisms that govern this relationship at the molecular, cellular, and ecological levels is central to both health and disease. The present review of rodent models commonly used to investigate microbial-host “conversations” is focused on those complex bacterial communities residing in the lower gut. Although many types of pathology have been studied using gnotobiotic animals, only the models relevant to commensal bacteria will be described. PMID:22918304

2012-01-01

33

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...

34

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

PubMed

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

Kumar, Mahadeo; Kumar, Sharad

2014-11-01

35

Mammary gland neoplasia in long-term rodent studies.  

PubMed Central

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

Russo, I H; Russo, J

1996-01-01

36

Studying autism in rodent models: reconciling endophenotypes with comorbidities.  

PubMed

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

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

2013-01-01

37

Studying Autism in Rodent Models: Reconciling Endophenotypes with Comorbidities  

PubMed Central

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

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

2013-01-01

38

Teaching laboratory rodent research techniques under the tenets of situated learning improves student confidence and promotes collaboration.  

PubMed

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

Whitcomb, Tiffany L; Taylor, Edward W

2014-07-01

39

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

PubMed Central

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

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

2011-01-01

40

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%) ...

41

STUDY OF THE CHEMICAL AND BEHAVIORAL TOXICOLOGY OF SUBSTITUTE CHEMICALS IN MICROTINE RODENTS  

EPA Science Inventory

Acute oral LD50 and 30-day dietary subacute LC50 studies of 10 selected pesticides were evaluated in microtine rodents. As a means to developing new animal model systems, four species of microtine rodents including Microtus ochrogaster (MO), Microtus canicaudus (MC), Microtus pen...

42

Chemical-induced atrial thrombosis in NTP rodent studies.  

PubMed

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 access them, click on the issue link for 33(5), then select this article. A download option appears at the bottom of this abstract. In order to access the full article online, you must either have an individual subscription or a member subscription accessed through www.toxpath.org. PMID:16048847

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

2005-01-01

43

OCT-aided anastomosis platform study in the rodent model  

NASA Astrophysics Data System (ADS)

Anastomosis is one of the most commonly performed procedure in the clinical environment that involves tubular structures, such as blood vessel, lymphatic vessel, seminal duct and ureter. Suture based anastomosis is still the foundation for most basic surgical training and clinical operation, although alternate techniques have been developed and under development. For those tubular-structure-anastomosis, immediate real-time post-operative evaluation of the surgical outcome is critical to the success of surgery. Previously evaluation is mostly based on surgeons' experience. Fourier-domain optical coherence tomography is high-speed, high-resolution noninvasive 3D imaging modality that has been widely used in the biomedical research and clinical study. In this study we used Fourier-domain optical coherence tomography as an evaluation tool for anastomosis of lymphatic vessels, ureter and seminal duct in rodent model. Immediate post-operative and long term surgical site data were collected and analyzed. Critical clinical parameters such as lumen patency, anastomosed site narrowing and suture error detection are provided to surgeons.

Huang, Yong; Tong, Dedi; Zhu, Shan; Wu, Lehao; Ibrahim, Zuhaib; Lee, WP Andrew; Brandacher, Gerald; Kang, Jin U.

2014-02-01

44

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

SciTech Connect

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.

Huff, J.; Bucher, J.; Yang, R. (National Institute of Environmental Health Sciences, Research Triangle Park, NC (USA))

1991-01-01

45

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

PubMed Central

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

Huff, J; Bucher, J; Yang, R

1991-01-01

46

Tethered gravity laboratories study  

NASA Technical Reports Server (NTRS)

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.

Lucchetti, F.

1989-01-01

47

Pulmonary Toxicity Studies of Lunar Dust in Rodents  

NASA Technical Reports Server (NTRS)

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

Lam, Chiu-Wing; James, John T.

2012-01-01

48

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

PubMed Central

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

Moore, Colleen F.; Adkins, Miriam M.

2014-01-01

49

Seroepidemiologic studies of hantavirus infection among wild rodents in California.  

PubMed Central

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

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

50

Pulmonary Toxicity Studies of Lunar Dusts in Rodents  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

51

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

PubMed Central

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

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

52

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...

53

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

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 3?, ?-histone 2AX, and proliferating cell nuclear antigen. PMID:21640027

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

54

Chimeric rodents with humanized liver: bridging the preclinical/clinical trial gap in ADME/toxicity studies.  

PubMed

1. Immunocompromised mice with humanized livers were developed in the mid-1990s to allow the study of human hepatotropic viruses, which normally replicate only in higher primates. The production of the uPA/SCID mouse was the vanguard of these models and remains the most widely worked upon model for an ever increasing range of applications. 2. Since toxicology is conducted in laboratory animal species with the implicit intent of predicting the outcome of accidental, or intentional, human exposure, the potential for using an in vivo model with a humanised metabolism opens up the possibility of better predicting the human response following exposure to drugs and industrial chemicals. Chimeric humanised mice provide the tool for bridging between the non-clinical laboratory safety and metabolism studies, carried out in rodent and non-rodent species, and the first in man clinical trials. 3. Chimeric mice carrying a human liver have now been validated against a wide range of different drugs and chemical classes, and have been shown to clearly differentiate metabolically from the recipient mouse, and to show metabolic pathways more similar to those expected from human liver. 4. This review critically appraises the available animal models carrying human livers and where future developments would improve the existing systems. PMID:24320885

Foster, John R; Lund, Garry; Sapelnikova, Svetlana; Tyrrell, D Lorne; Kneteman, Norman M

2014-01-01

55

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

USGS Publications Warehouse

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.

Bellack, E.; DeWitt, J.B.

1949-01-01

56

LONG-TERM EXPERIMENTAL STUDY OF A CHIHUAHUAN DESERT RODENT COMMUNITY: 13 YEARS OF COMPETITION  

Microsoft Academic Search

De11arrr)letzt of Blo\\/ogj I nrrersrri of \\\\ert Zleuco -Ilbi(querque \\\\el$ Mekrco 57131 C S,4 d4hstract. An experimental study of competition between kangaroo rats (Dipodornys spp.) and other sympatric desert rodents using exclosures with \\

EDWARD J HESKE; JAMES H BROWN; SHAHROUKH MISTRY

1994-01-01

57

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 ...

58

Anti-ulcer and ulcer healing potentials of Musa sapientum peel extract in the laboratory rodents  

PubMed Central

Background: This study investigated the anti-ulcer and ulcer healing potentials of the methanol extract of Musa sapientum peel in the laboratory rats. Materials and Methods: Methanol extract of the peels on Musa sapientum (MEMS) was evaluated for its anti-ulcer using alcohol-induced, aspirin-induced, and pyloric ligation-induced models, and for its ulcer healing employing acetic acid-induced ulcer models in rats. Results: The findings from this experiment showed that MEMS (50, 100 and 200 mg/kg, b.w.) anti-ulcer and ulcer healing activity (P ? 0.05) is dose-dependent. Also, MEMS exhibited healing of the ulcer base in all the treated groups when compared with the control group. Conclusion: The outcomes of this experiment revealed that the anti-ulcer effect of MEMS may be due to its anti-secretory and cyto-protective activity. The healing of the ulcer base might not be unconnected with basic fibroblast growth factors responsible for epithelial regeneration. PMID:23900937

Onasanwo, Samuel Adetunji; Emikpe, Benjamin Obukowho; Ajah, Austin Azubuike; Elufioye, Taiwo Olayemi

2013-01-01

59

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...

60

Tethered gravity laboratories study  

NASA Technical Reports Server (NTRS)

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.

Lucchetti, F.

1990-01-01

61

Comparative study on the forefoot and hindfoot intrinsic muscles of some cavioidea rodents (Mammalia, Rodentia).  

PubMed

The present study compares the forefoot and hindfoot musculature of five representative species of Cavioidea rodents. In all species, the musculature of both forefeet and hindfeet have the same array regardless of the absence of digit I in the manus of Hydrochaeris hydrochaeris and Cavia porcellus. Our results suggest a tendency in these species towards a three-digit system, with a functional loss of digit V and a predominance of digit III in their forefeet. In the same way, the muscular reduction of digit I in the other rodents analyzed indicates a four-digit system with predominance of digit II in Myoprocta acouchy and Dasyprocta leporina and of digit V in Agouti paca. There seems to be an association between the muscular arrangement and functional axis of the foot, raising the general question why this axis runs between the third and forth digit, or along the third digit. PMID:17008077

Rocha-Barbosa, Oscar; Loguercio, Mariana F C; Renous, Sabine; Gasc, Jean-Pierre

2007-01-01

62

Molecular and functional aspects of the hairless (hr) gene in laboratory rodents and humans  

Microsoft Academic Search

For many years, hairless and rhino mouse mutants have provided a useful and extensively exploited model for studying different aspects of skin physiology, including skin aging, pharmacokinetic evaluation of drug activity and cutaneous absorption, skin carcinogenesis, and skin toxicology. Interestingly, however, hairless and rhino mice have rarely been studied for their primary cellular defect - hairlessness - and thus, the

A A Panteleyev; R Paus; W Ahmad; J P Sundberg; A M Christiano

1998-01-01

63

Establishing Primary Adult Fibroblast Cultures From Rodents  

PubMed Central

The importance of using primary cells, rather than cancer cell lines, for biological studies is becoming widely recognized. Primary cells are preferred in studies of cell cycle control, apoptosis, and DNA repair, as cancer cells carry mutations in genes involved in these processes. Primary cells cannot be cultured indefinitely due to the onset of replicative senescence or aneuploidization. Hence, new cultures need to be established regularly. The procedure for isolation of rodent embryonic fibroblasts is well established, but isolating adult fibroblast cultures often presents a challenge. Adult rodent fibroblasts isolated from mouse models of human disease may be a preferred control when comparing them to fibroblasts from human patients. Furthermore, adult fibroblasts are the only available material when working with wild rodents where pregnant females cannot be easily obtained. Here we provide a protocol for isolation and culture of adult fibroblasts from rodent skin and lungs. We used this procedure successfully to isolate fibroblasts from over twenty rodent species from laboratory mice and rats to wild rodents such as beaver, porcupine, and squirrel. PMID:20972406

Seluanov, Andrei; Vaidya, Amita; Gorbunova, Vera

2010-01-01

64

Laboratory studies of interleaving  

NASA Astrophysics Data System (ADS)

This is a review of laboratory experiments on double-diffusive interleaving. Several configurations are discussed and compared, including thermohaline fronts, heated sidewalls, melting ice-blocks, point heat sources, and double-diffusive plumes, using both the heat-salt and sugar-salt systems to generate property anomalies. Two parallels emerge. The vertical scale of intrusions in most configurations is proportional to the ‘natural’ scale given by the property anomaly divided by the density gradient. The speed of advance of intrusions into undisturbed water is proportional to the product of the buoyancy frequency and intrusion thickness, with a constant of proportionality of order 0.005, but which depends on the vertical gradient density ratio and on the experimental configuration. We end with a long list of questions. Further progress will require new or more complex experimental configurations, more quantitative observations, and close comparisons with intrusion theories, both linear and finite-amplitude.

Ruddick, B.

2003-03-01

65

Neuroimmune Pathways in Alcohol Consumption: Evidence from Behavioral and Genetic Studies in Rodents and Humans  

PubMed Central

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

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

2014-01-01

66

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

PubMed Central

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

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

2012-01-01

67

Activity of and Effect of Subcutaneous Treatment with the Broad-Spectrum Antiviral Lectin Griffithsin in Two Laboratory Rodent Models  

PubMed Central

Griffithsin (GRFT) is a red-alga-derived lectin that binds the terminal mannose residues of N-linked glycans found on the surface of human immunodeficiency virus type 1 (HIV-1), HIV-2, and other enveloped viruses, including hepatitis C virus (HCV), severe acute respiratory syndrome coronavirus (SARS-CoV), and Ebola virus. GRFT displays no human T-cell mitogenic activity and does not induce production of proinflammatory cytokines in treated human cell lines. However, despite the growing evidence showing the broad-spectrum nanomolar or better antiviral activity of GRFT, no study has reported a comprehensive assessment of GRFT safety as a potential systemic antiviral treatment. The results presented in this work show that minimal toxicity was induced by a range of single and repeated daily subcutaneous doses of GRFT in two rodent species, although we noted treatment-associated increases in spleen and liver mass suggestive of an antidrug immune response. The drug is systemically distributed, accumulating to high levels in the serum and plasma after subcutaneous delivery. Further, we showed that serum from GRFT-treated animals retained antiviral activity against HIV-1-enveloped pseudoviruses in a cell-based neutralization assay. Overall, our data presented here show that GRFT accumulates to relevant therapeutic concentrations which are tolerated with minimal toxicity. These studies support further development of GRFT as a systemic antiviral therapeutic agent against enveloped viruses, although deimmunizing the molecule may be necessary if it is to be used in long-term treatment of chronic viral infections. PMID:24145548

Barton, Christopher; Kouokam, J. Calvin; Lasnik, Amanda B.; Foreman, Oded; Cambon, Alexander; Brock, Guy; Montefiori, David C.; Vojdani, Fakhrieh; McCormick, Alison A.; O'Keefe, Barry R.

2014-01-01

68

This information sheet is for the care and use of laboratory rodents (including rats, mice, hamsters, guinea pigs & gerbils).  

E-print Network

, hamsters, guinea pigs & gerbils). Potential Zoonotic Diseases: Colony-born rodents are generally docile) is caused by the arenavirus commonly associated with hamsters, but does infect mice. LCM is rare, rabbits, hamsters, reptiles, dogs, sheep, goats, horses, and standing water. Leptospires are in the urine

Wood, Marcelo A.

69

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

PubMed Central

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

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

2009-01-01

70

Linking human behaviour to environmental effects using a case study of urban rodent control  

Microsoft Academic Search

Pest control is common in many land use activities and can affect non?target species. Our objectives were to evaluate, among chemical rodent control product (rodenticide) users, awareness of non?target effects on wildlife and willingness to change rodent control behaviour given knowledge of possible local non?target effects. Approximately half of respondents to a resident survey in California (USA) practised rodent control;

Anita T. Morzillo; Angela G. Mertig

2011-01-01

71

Tethered gravity laboratories study  

NASA Technical Reports Server (NTRS)

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.

Lucchetti, F.

1989-01-01

72

Laboratory and simulation studies  

Microsoft Academic Search

The study of Solar System bodies by remote and in situ measurements provides information about geological, chemical and physical properties of materials present in different space environments. Processes (e.g., thermal annealing, UV irradiation, ion bombardment, gas-solid interaction) contribute with different efficiencies to determine the characteristics of materials, depending on both the local environment properties and on the sensitivity of species

L. Colangeli; R. Battaglia; J. R. Brucato; V. della Corte; A. Esposito; F. Esposito; G. Ferrini; E. Mazzotta Epifani; V. Mennella; E. Palomba; P. Palumbo; A. Rotundi

2002-01-01

73

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

USGS Publications Warehouse

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.

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

1953-01-01

74

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

Microsoft Academic Search

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

Martin E. Hahn; Maria J. Lavooy

2005-01-01

75

A longitudinal study of Sin Nombre virus prevalence in rodents, southeastern Arizona.  

PubMed Central

We determined the prevalence of Sin Nombre virus antibodies in small mammals in southeastern Arizona. Of 1,234 rodents (from 13 species) captured each month from May through December 1995, only mice in the genus Peromyscus were seropositive. Antibody prevalence was 14.3% in 21 white-footed mice (P. leucopus), 13.3% in 98 brush mice (P. boylii), 0.8% in 118 cactus mice (P. eremicus), and 0% in 2 deer mice (P. maniculatus). Most antibody-positive mice were adult male Peromyscus captured close to one another early in the study. Population dynamics of brush mice suggest a correlation between population size and hantavirus-antibody prevalence. PMID:10081678

Kuenzi, A. J.; Morrison, M. L.; Swann, D. E.; Hardy, P. C.; Downard, G. T.

1999-01-01

76

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

PubMed Central

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

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

2007-01-01

77

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

SciTech Connect

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.

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

2010-09-15

78

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

Microsoft Academic Search

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

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

1997-01-01

79

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...

80

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

PubMed

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

Campi, Katharine L; Krubitzer, Leah

2010-11-15

81

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

PubMed Central

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

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

2013-01-01

82

Diversity of mnemonic function within the entorhinal cortex: a meta-analysis of rodent behavioral studies.  

PubMed

The entorhinal cortex (EC) has been shown to be an integral piece of the hippocampal memory system. It sits in a unique position within the brain with strong, intricate, reciprocal connectivity with the hippocampus as well as a vast array of neocortical regions. Topographical patterns of afferent and efferent projections suggest that the EC can be divided into the medial and lateral regions, each of which can be further divided into dorsal, intermediate, and lateral bands. These EC sub-regions, with variable anatomical features, indicate a multifaceted role of the EC in memory processing. The present article reviews rodent behavioral studies which tested the effect of manipulation to EC sub-regions in several different memory paradigms. An analysis of the specific targets of EC manipulations reveals an important role of the caudomedial EC for spatial memory. In recognition memory paradigms, damage to the lateral EC impairs recognition of the combined information of objects, locations, and environmental contexts relevant to the content of an experience; whereas damage to medial EC preferentially impairs the recognition of the spatial arrangement of objects relevant to the spatial location of an experience. Fewer studies have examined the impact of EC manipulations on contextual memory and temporal associative memory, the results of which are fairly conflicting and possible confounds are explored. Our summary provides further support for the functional dissociation within the EC for learning and memory and generates several ideas for future investigations. PMID:25151400

Morrissey, Mark D; Takehara-Nishiuchi, Kaori

2014-11-01

83

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

PubMed

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

Vorhees, Charles V; Williams, Michael T

2014-01-01

84

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

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

85

Novel Rodent Models for Macular Research  

PubMed Central

Background Many disabling human retinal disorders involve the central retina, particularly the macula. However, the commonly used rodent models in research, mouse and rat, do not possess a macula. The purpose of this study was to identify small laboratory rodents with a significant central region as potential new models for macular research. Methodology/Principal Findings Gerbillus perpallidus, Meriones unguiculatus and Phodopus campbelli, laboratory rodents less commonly used in retinal research, were subjected to confocal scanning laser ophthalmoscopy (cSLO), fluorescein and indocyanine green angiography, and spectral-domain optical coherence tomography (SD-OCT) using standard equipment (Heidelberg Engineering HRA1 and Spectralis™) adapted to small rodent eyes. The existence of a visual streak-like pattern was assessed on the basis of vascular topography, retinal thickness, and the topography of retinal ganglion cells and cone photoreceptors. All three species examined showed evidence of a significant horizontal streak-like specialization. cSLO angiography and retinal wholemounts revealed that superficial retinal blood vessels typically ramify and narrow into a sparse capillary net at the border of the respective area located dorsal to the optic nerve. Similar to the macular region, there was an absence of larger blood vessels in the streak region. Furthermore, the thickness of the photoreceptor layer and the population density of neurons in the ganglion cell layer were markedly increased in the visual streak region. Conclusions/Significance The retinal specializations of Gerbillus perpallidus, Meriones unguiculatus and Phodopus campbelli resemble features of the primate macula. Hence, the rodents reported here may serve to study aspects of macular development and diseases like age-related macular degeneration and diabetic macular edema, and the preclinical assessment of therapeutic strategies. PMID:20976212

Huber, Gesine; Heynen, Severin; Imsand, Coni; vom Hagen, Franziska; Muehlfriedel, Regine; Tanimoto, Naoyuki; Feng, Yuxi; Hammes, Hans-Peter; Grimm, Christian; Peichl, Leo; Seeliger, Mathias W.; Beck, Susanne C.

2010-01-01

86

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...

87

Imaging neuronal populations in behaving rodents: paradigms for studying neural circuits underlying behavior in the mammalian cortex.  

PubMed

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

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

2013-11-01

88

75 FR 80011 - Good Laboratory Practice for Nonclinical Laboratory Studies  

Federal Register 2010, 2011, 2012, 2013, 2014

...applications for research or marketing permits for products...article has any potential utility or to determine physical...standards governing the ethical and humane use of laboratory...laboratory studies. This issue is not specifically...interested persons on these issues and any other...

2010-12-21

89

Wentworth Institute Mechanical Engineering Laboratory Manual. Laboratory Study Guide.  

ERIC Educational Resources Information Center

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…

Avakian, Harry; And Others

90

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...

91

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

USGS Publications Warehouse

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.

Bellack, E.; DeWitt, J.B.

1949-01-01

92

Characterization of spontaneous and chemically induced cardiac lesions in rodent model systems  

Microsoft Academic Search

Induction of heart disease can be related to exposure to a number of agents, including environmental chemicals. Studies with\\u000a laboratory rodents are commonly use to identify cardiotoxic agents and to investigate mechanisms of toxicity. This study was\\u000a conducted to characterize spontaneous and chemically-induced rodent heart lesions. A retrospective light-microscopic evaluation\\u000a was performed on the hearts of F344 rats and B6C3F1

Micheal P. Jokinen; Warren G. Lieuallen; Crystal L. Johnson; June Dunnick; Abraham Nyska

2005-01-01

93

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

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

94

Meal-feeding rodents and toxicology research.  

PubMed

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 important variable that should be controlled in toxicology experiments, and research continues to underscore this position. PMID:22642213

Carey, Gale B; Merrill, Lisa C

2012-08-20

95

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

PubMed Central

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

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

96

Behavioral aspects of competition in a three-species rodent guild of coastal southern California  

Microsoft Academic Search

The influence of vole cycles on the demography, spatial organization, and abundance of potential rodent competitors was studied in three California rodents in the laboratory and in the field. Population densities ofMicrotus californicus were inversely correlated with reproductive success in two potential competitors (Reithrodontomys megalotis andMus musculus). Additionally, high-density vole populations forced these species into suboptimal habitats. During low-density vole

Andrew R. Blaustein

1980-01-01

97

Ectoparasites of Rodents Captured in Bandar Abbas, Southern Iran  

PubMed Central

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

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

2009-01-01

98

Laboratory Study of Till Rheology  

NASA Astrophysics Data System (ADS)

Recent studies show that small-amplitude stress changes can trigger ice sheet motion and subglacial seismicity. Deformation in the subglacial region plays a key role in determining slip behavior, including creep, transient slip, stick-slip motion, and seismicity. However, progress in understanding these phenomena is limited by uncertainty in the rheology and frictional properties of glacial till. We report on detailed laboratory experiments to measure the creep and frictional constitutive properties of till sampled from the Matanuska Glacier, Alaska and Caesar Till from the Scioto Lobe of the Laurentide Ice Sheet, sampled in central Ohio. Experiments were conducted in a servo-controlled, double direct shear apparatus with air dried samples at a normal stresses ranging from 50 kPa to 5 MPa. Till was sheared in a three-block arrangement in which two layers are sandwiched between a central forcing block and two stationary blocks. We studied the effect of saturation, initial deformation fabric, stress history, and the boundary conditions of loading. The nominal frictional contact area is 100 cm2 and remains constant during shear. The layer thickness is 1 cm prior to shear. All blocks are grooved perpendicular to the shear direction to ensure that deformation occurs within the layer. The Matanuska till has grains ranging from 6.3 mm to finer than .063 mm with a mean of 2.67 mm whereas the Caesar till has a smaller mean grain size of 0.60 mm, but lacks silt and clay sized particles. We conducted both constant strain rate and constant stress tests. Constant shear stress experiments were employed to study frictional creep. In these tests, stress steps were conducted at 2 % and 5 % steps of the shear strength with strain rate calculated at 20 and 40 minute intervals after the stress steps. Strain rate was calculated by taking a linear fit of strain versus time over two minutes. The stress exponent, n was then calculated from the equation d?/dt = b?n. Where ? is strain, ? shear stress, and b is a constant. Under these conditions till was found to deform plasticly with a stress exponent that ranged from n=10 to n=18. Experiments taken directly to constant load conditions without an initial displacement exhibited a lower strain rate and smaller stress exponent than experiments, which first deformed the sample to failure with an initial 10 mm displacement. Constant strain rate tests were used to study rate/state frictional rheology using perturbations in slip rate of 1 to 300 ?m/s, imposed during steady sliding. Results of velocity stepping experiments showed velocity strengthening frictional behavior for both Matanuska and Caesar Till. The degree of velocity strengthening is less for the Caesar till compared to the Matanuska, and both tills exhibit lesser velocity strengthening for saturated compared to dry tests. Coulomb-Mohr failure envelopes for saturated conditions indicate that the Matanuska and Caesar tills have angles of internal friction and cohesion of 31.5° and 9.5 kPa, and 28.0° and near zero, respectively.

Rathbun, A. P.; Marone, C. J.; Anandakrishnan, S.; Alley, R. B.

2005-12-01

99

[Efficacy of Ro 15-0216 against human strains of Trypanosoma gambiense maintained in rodents. A preliminary study].  

PubMed

The 2-nitro-imidazole derivative Ro 15-0216, closely related to benznidazole used for the treatment of South American trypanosomiasis (T. cruzi) proved effective against T. brucei brucei and T. brucei rhodesiense in rodents and sheep models. Diffusion in CSF is large in dogs and sheep. We studied splenectomised or immunodepressed mice and rats, infested with T. brucei gambiense human strain T-M1 isolated from a Gabonese patient with sleeping sickness. 2 groups of 5 mice were treated with oral doses of 50 mg/kg and 100 mg/kg for 3 days. 3 mice were injected with 10 mg/kg intraperitoneally. 3 rats were given 50 mg/kg orally for 2 days. 3 rats were injected with 25 mg/kg, 4 rats with 10 mg/kg, 2 rats with 100 mg/kg intraperitoneally. 13 animals were "controls". A dose of 10 mg/kg was rapidly active against the parasites circulating in blood. The diffusion in CSF was not studied. No side effects have been observed. 24/25 treated rodents were in good health without parasites in the blood at Day 12. PMID:3197254

Richard-Lenoble, D; Kombila, M Y; Felix, H

1988-01-01

100

The allometry of rodent intestines  

Microsoft Academic Search

This study examined the allometry of the small intestine, caecum, colon and large intestine of rodents (n = 51) using a phylogenetically informed approach. Strong phylogenetic signal was detected in the data for the caecum, colon\\u000a and large intestine, but not for the small intestine. Most of the phylogenetic signal could be attributed to clade effects\\u000a associated with herbivorous versus omnivorous rodents.

Barry G. Lovegrove

2010-01-01

101

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

PubMed

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

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

2012-09-01

102

New Building, Old Parasite: Mesostigmatid Mites—An Ever-Present Threat to Barrier Rodent Facilities  

Microsoft Academic Search

Mesostigmatid mites are blood-sucking parasitic mites found in wild rodent populations. Periodically they can also become a problem for laboratory rodent colonies, particu- larly when building construction or renovations disturb colonies of commensal (building) rodents that had been act- ing as hosts. Mesostigmatid mites infest both rats and mice and, unlike the more common rodent fur mites (Myobia, Myocoptes, and

Julie Watson

103

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

PubMed Central

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

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

2012-01-01

104

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...

105

Erythrocyte permeability to urea and water: comparative study in rodents, ruminants, carnivores, humans, and birds.  

PubMed

Mammalian erythrocytes exhibit high urea permeability (P (urea)) due to UT-B expression in their cytoplasmic membrane. This high P (urea) allows fast equilibration of urea in erythrocytes during their transit in the hyperosmotic renal medulla. It also allows more urea (in addition to that in plasma) to participate in counter-current exchange between ascending and descending vasa recta, thus improving the trapping of urea in the medulla and improving urine concentrating ability. To determine if P (urea) in erythrocytes is related to diet and urine concentrating ability, we measured P (urea) in erythrocytes from 11 different mammals and 5 birds using stopped-flow light scattering. Carnivores (dog, fox, cat) exhibited high P (urea) (in x10(-5) cm/s, 5.3 ± 0.6, 3.8 ± 0.5 and 2.8 ± 0.7, respectively). In contrast, herbivores (cow, donkey, sheep) showed much lower P (urea) (0.8 ± 0.2, 0.7 ± 0.2, 1.0 ± 0.1, respectively). Erythrocyte P (urea) in human (1.1 ± 0.2), and pig (1.5 ± 0.1), the two omnivores, was intermediate. Rodents and lagomorphs (mouse, rat, rabbit) had P (urea) intermediate between carnivores and omnivores (3.3 ± 0.4, 2.5 ± 0.3 and 2.4 ± 0.3, respectively). Birds that do not excrete urea and do not express UT-B in their erythrocytes had very low values (<0.1 × 10(-5) cm/s). In contrast to P (urea), water permeability, measured simultaneously, was relatively similar in all mammals. The species differences in erythrocytes P (urea) most probably reflect adaptation to the different types of diet and resulting different needs for concentrating urea in the urine. PMID:20878327

Liu, Lifeng; Lei, Tianluo; Bankir, Lise; Zhao, Dan; Gai, Xiaodong; Zhao, Xuejian; Yang, Baoxue

2011-01-01

106

An experimental study of the impacts of understorey forest vegetation and herbivory by red deer and rodents on seedling establishment and species composition in Waitutu Forest, New Zealand  

Microsoft Academic Search

Introduced mammalian herbivores are changing the structure and composition of New Zealand's forest ecosystems and may modify forest succession after natural disturbances. We studied how introduced ungulates (red deer and feral pigs) and rodents (rats and house mice) affected the rate of recovery (i.e. the engineering resilience) of the forest understorey following artificial disturbance. We imposed disturbances by clearing understorey

Deborah J. Wilson; Wendy A. Ruscoe; Larry E. Burrows; Lisa M. McElrea; David Choquenot

107

Radiogenic Isotope Laboratory: Provenance Studies  

NSDL National Science Digital Library

This site showcases two research projects at the University of Wisconsin that are using radiogenic isotopes to study sediment provenance. One research group is studying large-scale terrane translation along western North America, and the other is looking at tectonics, provenance, and paleoclimate in Wyoming's Green River Basin. The site provides a project description and selected publications for each research focus. Some publications are available as PDF's.

Department of Geology and Geophysics Radiogenic Isotope Laboratory

108

Laboratory Studies of DIB Carriers  

NASA Technical Reports Server (NTRS)

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.

Allamandola, L. J.

1995-01-01

109

Laboratory studies of lean combustion  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

110

Photographic laboratory studies of explosions.  

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

111

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

PubMed Central

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

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

112

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

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

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

113

Vasovagal Syncope Case Study/Laboratory Supplement  

NSDL National Science Digital Library

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

PhD Jan Foster (North Greenville University Biology)

2012-05-01

114

Rodent Research-1 Validation of Rodent Hardware  

NASA Technical Reports Server (NTRS)

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)

Globus, Ruth; Beegle, Janet

2013-01-01

115

Probing perceptual decisions in rodents  

PubMed Central

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

Carandini, Matteo; Churchland, Anne K

2014-01-01

116

[(18)F]FPEB and [(18)F]FDEGPECO comparative study of mGlu5 quantification in rodent brain.  

PubMed

The aim of this study is to compare [(18)F]FPEB and [(18)F]FDEGPECO for the quantification of mGlu5 receptors in rodent brains. After preparation of radioligands, dynamic PET data was acquired for 90min. Estimated non-displaceable binding potential (BPND) values were calculated from the non-invasive Logan's graphical analysis method. Although both radioligands showed similar radiochemical amenability, [(18)F]FPEB PET showed higher brain uptake and superior binding potential values than those of [(18)F]FDEGPECO PET (peak brain uptakes in the hippocampus and the striatum: 7.2-8.7 vs. 5.0-6.2, BPND: 7.3-9.6 vs. 0.3-0.4 for [(18)F]FPEB and [(18)F]FDEGPECO, respectively). In addition, the target-to-reference ratios for [(18)F]FPEB is >4 fold than those of [(18)F]FDEGPECO. From this evidence, we conclude that [(18)F]FPEB is a superior radioligand for mGlu5 imaging in preclinical studies. PMID:25658029

Hae Kang, Jee; Lee, Minkyung; Hoon Ryu, Young; Hyoung Lyoo, Chul; Hoon Kim, Chul; Chul Lee, Kyo; Hyun Choi, Tae; Yong Choi, Jae

2015-04-01

117

Oral treatment of rodents with fipronil for feed-through and systemic control of sand flies (Diptera: Psychodidae).  

PubMed

The sand fly Phlebotomus papatasi Scopoli is the vector of Leishmania major (Yakimoff & Schokhor), which is maintained in populations of burrowing rodents. The purpose of this study was to conduct a laboratory study to determine the efficacy of oral treatment of rodents with fipronil for control of sand flies that feed on rodent feces as larvae or on rodent blood as adults. We determined through larval bioassays that fipronil was eliminated in feces of orally-treated hamsters at a level that was significantly toxic to sand fly larvae for 21 d after the hamsters had been withdrawn from a fipronil-treated diet. Through bloodfeeding bioassays, we also found that fipronil was present in the peripheral blood of hamsters at a concentration that was significantly toxic to bloodfeeding adult female sand flies for 49 d after the hamsters had been withdrawn from their treated diet. The results of this study suggest that fipronil acts as well as or better than feed-through or systemic insecticides that previously have been measured against sand flies, and is particularly promising because this single compound acts against both larvae and bloodfeeding adults. An area-wide approach using rodent baits containing a fipronil could suppress vector populations that originate in the vicinity of rodent reservoirs, and could be used to eliminate the most epidemiologically important part of the vector population: female sand flies that take bloodmeals on rodent reservoirs. PMID:23427660

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

2013-01-01

118

Laboratory Animal Science Issues in the Design and Conduct of Studies with Endocrine-active Compounds  

Microsoft Academic Search

The use of rodent models for research and testing on endo- crine-active compounds necessitates an awareness of a number of laboratory animal science issues to standardize bioassay methods and facilitate reproducibility of results between laboratories. These issues are not unique to endo- crine research but are particularly important in this field due to the complexities and interdependencies of the endocrine

Jeffrey I. Everitt; Paul M. D. Foster

2004-01-01

119

Social Learning of Food Preferences in Rodents: Rapid Appetitive Learning  

E-print Network

, and there is an extensive literature describing both causes and consequences of social effects on food preference in rodentsSocial Learning of Food Preferences in Rodents: Rapid Appetitive Learning For the neuroscientist studying the consequences of manipulation of specific regions of the brain on learning in rodents

Galef Jr., Bennett G.

120

Validation Study of OECD Rodent Uterotrophic Assay for The Assessment of Estrogenic Activity in Sprague-Dawley Immature Female Rats  

Microsoft Academic Search

The Organization for Economic Cooperation and Development (OECD) is developing a screening and testing method to identify estrogenic\\/antiestrogenic compounds. Based on these demands, phase 1 study for OECD uterotrophic assay was undertaken. The OECD is in the process of validating the assay results from international participating laboratories, which carried out this study with established environmental estrogenic compounds using designed protocols.

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

2005-01-01

121

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

Code of Federal Regulations, 2010 CFR

...When possible, numerical results should be evaluated by an appropriate and generally acceptable statistical method. The statistical methods should be selected during the design of the study. (2) Test report. The test report must...

2010-07-01

122

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

Code of Federal Regulations, 2013 CFR

...When possible, numerical results should be evaluated by an appropriate and generally acceptable statistical method. The statistical methods should be selected during the design of the study. (2) Test report. The test report must...

2013-07-01

123

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

Code of Federal Regulations, 2011 CFR

...When possible, numerical results should be evaluated by an appropriate and generally acceptable statistical method. The statistical methods should be selected during the design of the study. (2) Test report. The test report must...

2011-07-01

124

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

Code of Federal Regulations, 2014 CFR

...When possible, numerical results should be evaluated by an appropriate and generally acceptable statistical method. The statistical methods should be selected during the design of the study. (2) Test report. The test report must...

2014-07-01

125

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

Code of Federal Regulations, 2012 CFR

...When possible, numerical results should be evaluated by an appropriate and generally acceptable statistical method. The statistical methods should be selected during the design of the study. (2) Test report. The test report must...

2012-07-01

126

Resistin in Rodents and Humans  

PubMed Central

Obesity is characterized by excess accumulation of lipids in adipose tissue and other organs, and chronic inflammation associated with insulin resistance and an increased risk of type 2 diabetes. Obesity, type 2 diabetes, and cardiovascular diseases are major health concerns. Resistin was first discovered as an adipose-secreted hormone (adipokine) linked to obesity and insulin resistance in rodents. Adipocyte-derived resistin is increased in obese rodents and strongly related to insulin resistance. However, in contrast to rodents, resistin is expressed and secreted from macrophages in humans and is increased in inflammatory conditions. Some studies have also suggested an association between increased resistin levels and insulin resistance, diabetes and cardiovascular disease. Genetic studies have provided additional evidence for a role of resistin in insulin resistance and inflammation. Resistin appears to mediate the pathogenesis of atherosclerosis by promoting endothelial dysfunction, vascular smooth muscle cell proliferation, arterial inflammation, and formation of foam cells. Indeed, resistin is predictive of atherosclerosis and poor clinical outcomes in patients with coronary artery disease and ischemic stroke. There is also growing evidence that elevated resistin is associated with the development of heart failure. This review will focus on the biology of resistin in rodents and humans, and evidence linking resistin with type 2 diabetes, atherosclerosis, and cardiovascular disease. PMID:24404511

Park, Hyeong Kyu

2013-01-01

127

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

PubMed

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

Ford, Matthew M

2014-05-01

128

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

Microsoft Academic Search

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

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

1981-01-01

129

Rodent models to study the metabolic effects of shiftwork in humans  

PubMed Central

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. PMID:25852554

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

2015-01-01

130

Chemical characterization of coal fly ash and quantification of lung deposition in rodent inhalation studies  

SciTech Connect

Studies of the elemental content of reaerosolized coal fly ash revealed increased concentrations of biologically active trace elements, Cd, Co, Cr, Cu, V, and Zn, compared to the initial stock material. Concentrations of the matrix elements, Al, Si, and Ti, were not altered during reaerosolization. Because of the absence of concentration dependence on particle size and on analytical recovery experiments, aluminum was chosen as an indicator element for quantification of lung-deposited fly ash in rat inhalation studies. Calculated lung depositions for inhaled fly ash were in agreement with expected values.

Fisher, G.L.; Silberman, D.; Raabe, O.G.

1980-08-01

131

Small wild rodents rabies in Czechoslovakia.  

PubMed

During a period of 1969-1979 a total of 3174 small wild rodents of the genus Muridae and Microtinae (predominantly Microtus arvalis) were examined. The animals were trapped in five localities differing both in type of ecological conditions and epizootologic situation. Fox-rabies occurred here either enzootically, or epizootologically, or had been completely absent for many years in one of the localities investigated. Of the 71 isolated strains of RV 18 strains were isolated from brain, 25 from brown fat and 28 from salivary glands. Simultaneous isolation positivity in more than one tissue was sporadic. Virus isolations from deep-frozen material were mostly unsuccessful. Basic biological characteristics were determined in each isolate. The isolated strains differed in the rate of adaptation on albino mice and in intracerebral virulence. All isolates exhibited extraneural pathogenicity for common laboratory animals, dogs and foxes, showed distinct viscerotropism, stimulated formation of interferon and produced various forms of non-lethal infection. Incidence of "murine" rabies did not show any locality-specific differences and in longitudinally studied areas was enzootic. In a number of Czech districts there was observed a distinct relationship between fox-rabies incidence and the density of small game animal populations. Role of small wild rodents in the epizootology and epidemiology of rabies is discussed. PMID:6749977

Sodja, I; Lím, D; Matouch, O; Seidlová, A; Farník, J; Svec, J; Cerný, J; Klimes, A

1982-01-01

132

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

PubMed

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

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

133

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

E-print Network

-caught Norway rats (Rattus norvegicus), wild-caught California ground squirrels (Spermophilus beecheyi for Neuroscience, University of California, Davis, Davis, California 2 Department of Psychology, University of California, Davis, Davis, California ABSTRACT In this study we examine and describe the neuroana- tomical

Krubitzer, Leah A.

134

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 ...

135

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

Microsoft Academic Search

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

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

2004-01-01

136

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

PubMed Central

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

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

2015-01-01

137

Heteroxenous coccidia increase the predation risk of parasitized rodents.  

PubMed

We have investigated the influence of heteroxenous coccidia (Apicomplexa: Eimeriorina) on the predation risk of intermediate hosts. Voles infected with Frenkelia spp. were found more frequently in buzzards' (Buteo buteo) prey than among snap-trapped rodents. To eliminate the possibility of traps selecting for uninfected rodents, a laboratory experiment was performed. Mice experimentally infected with Sarcocystis dispersa seemed to be more likely caught by the final host, the long-eared owl (Asio otus); this result was confirmed by a mathematical model. Field data confirmed the adaptive value of parasite-induced changes. The increase of predation is directed towards the specific final host only or is non-specific. In the populations studied the probability of predation of parasitized individuals by the specific predator was increased. PMID:9881375

Vorísek, P; Votýpka, J; Zvára, K; Svobodová, M

1998-12-01

138

Comparative study of chloroquine and quinine on malaria rodents and their effects on the mouse testis  

PubMed Central

Objective To evaluate the effects of quinine and chloroquine against male mice infected with Plasmodium berghei and their adverse effects on the mice testes. Methods In this study, 48 adult male mice, (20–25 g), aged 8 to 12 weeks were divided into four groups. This study was carried out from December 2009 until May 2010 in the School of Public Health, Tehran University of Medical Sciences. Results The results showed that 58.33% of mice treated with chloroquine were completely recovered. Parasitemia was 4% on day 8 when compared to that on day 0, whereas it was 9% on day 9. There was no orchitis found in this group. The mortality of mice after exposing to quinine on day 5 was 8.3%, whereas from day 10 to day 14 it was 91.7%. We found 75% orchitis occurred in quinine treated group. There was a significant difference between quinine and chloroquine effects on the parasite and also mice testes (P<0.05). Conclusions In this study, It can be concluded that male mice have full resistance to the quinine. Quinine does not only make male mice recover completely, but also cause inflammation on mice testicles tissue. PMID:23569921

Abolghasemi, Esmail; Moosa-Kazemi, Seyed Hassan; Davoudi, Maryam; Reisi, Ahmad; Satvat, Mohammad Taghi

2012-01-01

139

Allometric disparity in rodent evolution  

PubMed Central

In this study, allometric trajectories for 51 rodent species, comprising equal representatives from each of the major clades (Ctenohystrica, Muroidea, Sciuridae), are compared in a multivariate morphospace (=allometric space) to quantify magnitudes of disparity in cranial growth. Variability in allometric trajectory patterns was compared to measures of adult disparity in each clade, and dietary habit among the examined species, which together encapsulated an ecomorphological breadth. Results indicate that the evolution of allometric trajectories in rodents is characterized by different features in sciurids compared with muroids and Ctenohystrica. Sciuridae was found to have a reduced magnitude of inter-trajectory change and growth patterns with less variation in allometric coefficient values among members. In contrast, a greater magnitude of difference between trajectories and an increased variation in allometric coefficient values was evident for both Ctenohystrica and muroids. Ctenohystrica and muroids achieved considerably higher adult disparities than sciurids, suggesting that conservatism in allometric trajectory modification may constrain morphological diversity in rodents. The results provide support for a role of ecology (dietary habit) in the evolution of allometric trajectories in rodents. PMID:23610638

Wilson, Laura A B

2013-01-01

140

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

PubMed Central

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

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

141

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

PubMed

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

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

142

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

NASA Astrophysics Data System (ADS)

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.

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

143

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

SciTech Connect

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.

Lisboa, Marcio V.; Aciole, Gilberth T. S.; Oliveira, Susana C. P. S.; Marques, Aparecida M. C.; Pinheiro, Antonio L. B.; Santos, Jean N. [School of Dentistry, Federal University of Bahia, Salvador, BA, 40110-150 (Brazil); Baptista, Abrahao F.; Aguiar, Marcio C. [Biomorphology Department, Federal University of Bahia, Bahia, 40110-150 (Brazil)

2010-05-31

144

Laboratory studies in ultraviolet solar physics  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

145

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

PubMed

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

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

1998-11-01

146

Genotoxicity studies of rodents exposed to coal dust and diesel emission particulates.  

PubMed

Genotoxicity studies with mice and/or rats have been conducted to evaluate the potential mutagenic hazard associated with exposures of coal miners to diesel emission particulates (DEP) and/or coal dusts (CD). Rats and mice were exposed to filtered air, DEP, and/or CD for periods ranging from 3 months to 2 years. Levels of respirable particulates were maintained at 2 mg/m3 in all exposed groups. DEP and/or CD were collected in the inhalation chambers in which animals were exposed. Urine samples were collected for 5 consecutive days from rats exposed to DEP and/or CD for 3, 6, and 24 months. The particulate samples extracted with dichloromethane and the urine samples concentrated with XAD-2 columns were analyzed for mutagenic activity by the Ames Salmonella/microsome assay system. Peripheral blood lymphocytes from rats exposed for 3 months were analyzed for sister chromatid exchanges (SCE). The femur bone marrow cells from rats exposed for 24 months and mice exposed for 6 months were analyzed for micronuclei in both polychromatic and normochromatic erythrocytes. The results indicate that the solvent extract of DEP was mutagenic, while no mutagenic activity was found for the CD extract. Combination of CD and DEP did not show any synergistic effect. No mutagenic activity was found for urine samples from rats exposed to DEP and/or CD for up to 2 years. A slight increase in the micronucleated polychromatic erythrocytes over the control level was found in mice exposed to DEP and DEP plus CD for 6 months but the increase was not statistically significant. No increase in micronuclei was detected in rats exposed for 24 months. The frequencies of SCE in the peripheral lymphocytes of the 3-month-exposed rats were similar for control and DEP plus CD-exposed groups. PMID:2410249

Ong, T; Whong, W Z; Xu, J; Burchell, B; Green, F H; Lewis, T

1985-08-01

147

Galanin impairs cognitive abilities in rodents: relevance to Alzheimers Disease  

E-print Network

Galanin impairs cognitive abilities in rodents: relevance to Alzheimers Disease J. N. Crawley Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Porter Neuroscience Research processes, taken together with the overexpression of galanin in Alzheimers disease, suggests that galanin

148

Can experimental models of rodent implantation glioma be improved? A study of pure and mixed glioma cell line tumours  

Microsoft Academic Search

To evaluate the hypothesis that co-implantation of different rodent glioma cell lines might result in experimental brain tumours that more closely resemble human gliomas the neuropathology and immunocytochemical features of implantation gliomas derived from single cell lines (C6, A15A5, F98), two cell lines admixed 50:50 prior to implantation (C6 + F98 and C6 + A15A5) and three cell lines equally

Ian R. Whittle; Donald C. Macarthur; George P. Malcolm; Mingwei Li; Kate Washington; James W. Ironside

1998-01-01

149

Can experimental models of rodent implantation glioma be improved? A study of pure and mixed glioma cell line tumours.  

PubMed

To evaluate the hypothesis that co-implantation of different rodent glioma cell lines might result in experimental brain tumours that more closely resemble human gliomas the neuropathology and immunocytochemical features of implantation gliomas derived from single cell lines (C6, A15A5, F98), two cell lines admixed 50:50 prior to implantation (C6 + F98 and C6 + A15A5) and three cell lines equally admixed (C6 + A15A5 + F98) was studied in the adult Wistar rat. Tumours grew consistently following implantation of the single and the two admixed cell lines, however tumour growth following triple mix implantation was considerably and consistently impaired. The tumours derived from admixed cell lines showed regional heterogeneity with areas characteristic of both the primary cell lines. Foci of lymphocytic infiltrates, tumoural necrosis, often with pseudopallisading, and peritumoural edema were consistent features of all tumours. Limited parenchymal and more extensive perivascular tumoural invasion was seen predominantly in tumours containing the C6 cell line. There were no significant differences in GFAP, vimentin and HSP70 staining between the mixed tumours, although the pure F98 and A15A5 tumours were, unlike the pure C6 gliomas, S-100 negative. Using PCNA expression as a measure of the tumour proliferation all except the tumours derived from the three cell lines mix, which had a staining index of 7-10%, had focal staining indices in viable tumour of between 40-80%. There was focal positive staining in both perilesional brain and in regions of all tumours for the macrophage markers ED-1 and ED-2. None of the three cell lines stained in vitro for either ED1 and ED2 but all were constitutively positive in vitro for OX-6, a proposed marker for antigen presenting cells. The macrophage and lymphocytic response suggest a vigorous but largely ineffective immunological response had been mounted against all tumours. The consistent failure of the triple mix tumours to grow is unexplained. This work has shown the feasibility of producing 'mixed' cell line experimental gliomas by combining two cell lines at the time of innoculation. However, the relative failure to produce (i) mixed tumours that have properties not inherent to either parent cell line and (ii) implantation glioma with three cell lines suggest there are limits to this approach. Admixture of cell lines at the time of implantation therefore does not make experimental glioma models that more closely resemble natural gliomas, and also has some particular disadvantages. This experimental approach is therefore not recommended for use in the study of tumour biology and in evaluating the effectiveness of novel therapies. PMID:9524101

Whittle, I R; Macarthur, D C; Malcolm, G P; Li, M; Washington, K; Ironside, J W

1998-02-01

150

Laboratory studies of polar stratospheric cloud formation  

SciTech Connect

It is now well established that heterogeneous reactions on polar stratospheric clouds (PSCs) play an important role in Arctic and Antarctic ozone loss. The most common PSCs, denoted type I, form several degrees above the ice frost point and are thought to be composed primarily of nitric acid and water. Although these clouds have often been assumed to be nitric acid trihydrate (NAT) their exact composition is not known. We are using FTIR spectroscopy to study the nucleation and growth of model type I PSCs in the laboratory. We are studying both thin film samples mimicking stratospheric particulate and freely-floating sub-micrometer sized particles. The results of these studies will be discussed in the context of current theories for type I PSC formation.

Tolbert, M.A. [Univ. of Colorado, Boulder, CO (United States)

1996-10-01

151

Laboratory studies of polar stratospheric cloud formation  

SciTech Connect

Polar stratospheric clouds (PSCs) are generally classified as type I or type II, depending on their formation temperature. Type II PSCs form at stratospheric temperatures near 189 K and are composed of water ice. Type I PSCs are stable at warmer temperatures and contain both nitric acid and water. Because nitric acid trihydrate (NAT) is the thermodynamically stable form of HNO{sub 3}/H{sub 2}O under stratospheric conditions, it has often been assumed that type I PSCs are composed of NAT. Recent measurements, however, suggest that NAT may not form readily in the stratosphere due to a kinetic barrier. Type I PSCs are believed to nucleate on preexisting stratospheric sulfate aerosols composed of sulfuric acid and water. We are performing laboratory experiments to measure the nucleation and growth of type I PSCs on sulfuric acid. We study both thin film samples modeling stratospheric particles and actual aerosol samples generated in the laboratory. The results of these studies will be discussed in the context of current theories for type I PSC formation.

Tolbert, M.A.; Anthony, S.E.; Disselkamp, R.; Iraci, L.T. [Univ. of Colorado, Boulder, CO (United States)

1995-12-31

152

Experimental Study of Ventilation Performance in Laboratories with Chemical Spills  

E-print Network

1 Experimental Study of Ventilation Performance in Laboratories with Chemical Spills Mingang Chemical spills occur frequently in laboratories. The current ventilation code for laboratories recommends a ventilation rate of 12 ACH for maintaining a safe laboratory environment. On the other hand, the energy saving

Chen, Qingyan "Yan"

153

Atmospheric cloud physics laboratory project study  

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

154

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

PubMed Central

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

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

155

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

156

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

PubMed

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

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

2014-07-01

157

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

PubMed Central

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

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

2011-01-01

158

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

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

159

Rodent Models of Depression: Neurotrophic and Neuroinflammatory Biomarkers  

PubMed Central

Rodent models are an indispensable tool for studying etiology and progress of depression. Since interrelated systems of neurotrophic factors and cytokines comprise major regulatory mechanisms controlling normal brain plasticity, impairments of these systems form the basis for development of cerebral pathologies, including mental diseases. The present review focuses on the numerous experimental rodent models of depression induced by different stress factors (exteroceptive and interoceptive) during early life (including prenatal period) or adulthood, giving emphasis to the data on the changes of neurotrophic factors and neuroinflammatory indices in the brain. These parameters are closely related to behavioral depression-like symptoms and impairments of neuronal plasticity and are both gender- and genotype-dependent. Stress-related changes in expression of neurotrophins and cytokines in rodent brain are region-specific. Some contradictory data reported by different groups may be a consequence of differences of stress paradigms or their realization in different laboratories. Like all experimental models, stress-induced depression-like conditions are experimental simplification of clinical depression states; however, they are suitable for understanding the involvement of neurotrophic factors and cytokines in the pathogenesis of the disease—a goal unachievable in the clinical reality. These major regulatory systems may be important targets for therapeutic measures as well as for development of drugs for treatment of depression states. PMID:24999483

Stepanichev, Mikhail; Dygalo, Nikolay N.; Grigoryan, Grigory; Shishkina, Galina T.; Gulyaeva, Natalia

2014-01-01

160

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

PubMed

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

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

2015-05-01

161

SMTP-7, a novel small-molecule thrombolytic for ischemic stroke: a study in rodents and primates  

PubMed Central

SMTP-7 (Stachybotrys microspora triprenyl phenol-7), a small molecule that promotes plasminogen activation through the modulation of plasminogen conformation, has excellent therapeutic activity against cerebral infarction in several rodent models. Detailed evaluations of SMTP-7 in a primate stroke model are needed for effective, safe drug development. Here we evaluated SMTP-7 in a monkey photochemical-induced thrombotic middle cerebral artery (MCA) occlusion model (n=6), in which MCA occlusion was followed by recanalization/reocclusion. SMTP-7 (10?mg/kg, intravenous infusion) significantly increased the postinfusion MCA recanalization rate (32.5-fold, P=0.043) and ameliorated the post-24-h neurologic deficit (by 29%, P=0.02), cerebral infarct (by 46%, P=0.033), and cerebral hemorrhage (by 51%, P=0.013) compared with the vehicle control animals. In normal monkeys, SMTP-7 did not affect general physiologic or hemostatic variables, including coagulation and platelet parameters. Investigations in rodent models of transient and permanent focal cerebral ischemia, as well as arterial thrombosis and bleeding tests, suggest a role for SMTP-7's regulated profibrinolytic action and neuroprotective properties in the monkey MCA occlusion model. In conclusion, SMTP-7 is effective in treating thrombotic stroke in monkeys. SMTP-7 is thus a promising candidate for the development of alternative therapy for ischemic stroke. PMID:24192639

Sawada, Hironobu; Nishimura, Naoko; Suzuki, Eriko; Zhuang, Jie; Hasegawa, Keiko; Takamatsu, Hiroyuki; Honda, Kazuo; Hasumi, Keiji

2014-01-01

162

SMTP-7, a novel small-molecule thrombolytic for ischemic stroke: a study in rodents and primates.  

PubMed

SMTP-7 (Stachybotrys microspora triprenyl phenol-7), a small molecule that promotes plasminogen activation through the modulation of plasminogen conformation, has excellent therapeutic activity against cerebral infarction in several rodent models. Detailed evaluations of SMTP-7 in a primate stroke model are needed for effective, safe drug development. Here we evaluated SMTP-7 in a monkey photochemical-induced thrombotic middle cerebral artery (MCA) occlusion model (n=6), in which MCA occlusion was followed by recanalization/reocclusion. SMTP-7 (10?mg/kg, intravenous infusion) significantly increased the postinfusion MCA recanalization rate (32.5-fold, P=0.043) and ameliorated the post-24-h neurologic deficit (by 29%, P=0.02), cerebral infarct (by 46%, P=0.033), and cerebral hemorrhage (by 51%, P=0.013) compared with the vehicle control animals. In normal monkeys, SMTP-7 did not affect general physiologic or hemostatic variables, including coagulation and platelet parameters. Investigations in rodent models of transient and permanent focal cerebral ischemia, as well as arterial thrombosis and bleeding tests, suggest a role for SMTP-7's regulated profibrinolytic action and neuroprotective properties in the monkey MCA occlusion model. In conclusion, SMTP-7 is effective in treating thrombotic stroke in monkeys. SMTP-7 is thus a promising candidate for the development of alternative therapy for ischemic stroke. PMID:24192639

Sawada, Hironobu; Nishimura, Naoko; Suzuki, Eriko; Zhuang, Jie; Hasegawa, Keiko; Takamatsu, Hiroyuki; Honda, Kazuo; Hasumi, Keiji

2014-02-01

163

The largest fossil rodent  

PubMed Central

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

Rinderknecht, Andrés; Blanco, R. Ernesto

2008-01-01

164

Neutron Studies at the Canfranc Underground Laboratory  

NASA Astrophysics Data System (ADS)

Four sets of the IGEX-DM low energy data, obtained with different neutron-shielding conditions, have been compared to simulations to quantify the neutron populations from different sources: the flux of neutrons coming from the radioactivity of the surrounding rock, (3.82 ± 0.44) × 10-6 cm-2s-1, the flux of muon-induced neutrons in the rock, (1.73 ± 0.22(stat)±0.69(syst))×10-9 cm-2s-1 and the rate of neutron production by muons in the lead shielding, (4.8 ± 0.6(stat)±1.9(syst))×10-9 cm-3s-1. It can be concluded that a suitable neutron shielding practically eliminates the main contribution (rock radioactivity neutrons) to the IGEX background at the present level of sensitivity, while the remaining neutron populations (muon-induced neutrons in the rock or in the shielding) are below the present background level thanks to the veto system. These neutron studies are extremely useful to understand the effect of neutrons in other current and future experiments at the Canfranc Underground Laboratory.

Luzón, G.; Amaré, J.; Beltrán, B.; Carmona, J. M.; Cebrián, S.; García, E.; Irastorza, I. G.; Gómez, H.; Martínez, M.; Morales, A.; Morales, J.; de Solórzano, A. Ortiz; Pobes, C.; Puimedón, J.; Rodríguez, A.; Ruz, J.; Sarsa, M. L.; Torres, L.; Villar, J. A.

2005-04-01

165

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

ERIC Educational Resources Information Center

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,…

Roberts, Keith J.

166

Laboratory Studies in Support of Planetary Science  

NASA Astrophysics Data System (ADS)

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

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

2009-09-01

167

Rocket and Laboratory Studies in Astronomy  

NASA Technical Reports Server (NTRS)

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.

Feldman, Paul D.; McCandliss, Stephan R.

2004-01-01

168

Rodent Control in India  

Microsoft Academic Search

Eighteen species of rodents are pests in agriculture, horticulture, forestry, animal and human dwellings and rural and urban storage facilities in India. Their habitat, distribution, abundance and economic significance varies in different crops, seasons and geographical regions of the country. Of these, Bandicota bengalensis is the most predominant and widespread pest of agriculture in wet and irrigated soils and has

V. R. Parshad

1999-01-01

169

The Fecal Viral Flora of Wild Rodents  

PubMed Central

The frequent interactions of rodents with humans make them a common source of zoonotic infections. To obtain an initial unbiased measure of the viral diversity in the enteric tract of wild rodents we sequenced partially purified, randomly amplified viral RNA and DNA in the feces of 105 wild rodents (mouse, vole, and rat) collected in California and Virginia. We identified in decreasing frequency sequences related to the mammalian viruses families Circoviridae, Picobirnaviridae, Picornaviridae, Astroviridae, Parvoviridae, Papillomaviridae, Adenoviridae, and Coronaviridae. Seventeen small circular DNA genomes containing one or two replicase genes distantly related to the Circoviridae representing several potentially new viral families were characterized. In the Picornaviridae family two new candidate genera as well as a close genetic relative of the human pathogen Aichi virus were characterized. Fragments of the first mouse sapelovirus and picobirnaviruses were identified and the first murine astrovirus genome was characterized. A mouse papillomavirus genome and fragments of a novel adenovirus and adenovirus-associated virus were also sequenced. The next largest fraction of the rodent fecal virome was related to insect viruses of the Densoviridae, Iridoviridae, Polydnaviridae, Dicistroviriade, Bromoviridae, and Virgaviridae families followed by plant virus-related sequences in the Nanoviridae, Geminiviridae, Phycodnaviridae, Secoviridae, Partitiviridae, Tymoviridae, Alphaflexiviridae, and Tombusviridae families reflecting the largely insect and plant rodent diet. Phylogenetic analyses of full and partial viral genomes therefore revealed many previously unreported viral species, genera, and families. The close genetic similarities noted between some rodent and human viruses might reflect past zoonoses. This study increases our understanding of the viral diversity in wild rodents and highlights the large number of still uncharacterized viruses in mammals. PMID:21909269

Phan, Tung G.; Kapusinszky, Beatrix; Wang, Chunlin; Rose, Robert K.; Lipton, Howard L.; Delwart, Eric L.

2011-01-01

170

222-S LABORATORY FUME HOOD TESTING STUDY  

SciTech Connect

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.

RUELAS, B.H.

2007-03-26

171

Laboratory studies of crystal growth in magma  

NASA Astrophysics Data System (ADS)

The proportions, compositions, and interrelationships among crystalline phases and glasses in volcanic rocks cryptically record pre-eruptive intensive conditions, the timing of changes in crystallization environment, and the devolatilization history of eruptive ascent. These parameters are recognized as important monitoring tools at active volcanoes and interpreting geologic events at prehistoric and remote eruptions, thus motivating our attempts to understand the information preserved in crystals through an experimental appoach. We are performing laboratory experiments in mafic, felsic, and intermediate composition magmas to study the mechanisms of crystal growth in thermochemical environments relevant to volcanic environments. We target features common to natural crystals in igneous rocks for our experimental studies of rapid crystal growth phenomena: (1) Surface curvature. Do curved interfaces and spongy cores represent evidence of dissolution (i.e., are they corrosion features), or do they record the transition from dendritic to polyhedral morphology? (2) Trapped melt inclusions. Do trapped liquids represent bulk (i.e., far-field) liquids, boundary layer liquids, or something intermediate, depending on individual species diffusivity? What sequence of crystal growth rates leads to preservation of sealed melt inclusions? (3) Subgrain boundaries. Natural phenocrysts commonly exhibit tabular subgrain regions distinguished by small angle lattice misorientations or "dislocation lamellae" and undulatory extinction. Might these crystal defects be produced as dendrites undergo ripening? (4) Clusters. Contacting clusters of polymineralic crystals are the building blocks of cumulates, and are ubiquitous features of mafic volcanic rocks. Are plagioclase and clinopyroxene aligned crystallographically, suggesting an epitaxial (surface energy) relationship? (5) Log-normal size distribution. What synthetic cooling histories produce "natural" distributions of crystal sizes, and are phenocrystic textures uniquely attributed to staged cooling? In addition, we seek to explore the limitations of the experimental approach. Which aspects of natural crystallization sequences are adequately reproduced in experimental charges, and which are compromised by the obligatory reduced temporal and spatial scales of crystal growth experiments? What are the implications of synthetic starting materials and thermal pre-treatments for nucleation, growth, heterophase equilibria, and textural maturation?

Hammer, J. E.; Welsch, B. T.; First, E.; Shea, T.

2012-12-01

172

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

PubMed

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 (?)=-0.8%, 95% C.I. -1.7/0.1, P=0.076, at ?120 ?g bisphenol-A. Whereas, only bisphenol-A-males exhibited a significant inhibition of spatial skills (?)=0.7%, 95% C.I. 0.2/1.2, P=0.004, at ?100 ?g/day. A significant increment of aggressiveness was observed in both the sexes (?)=67.9,C.I. 3.4, 172.5, P=0.038, at >4.0 ?g. 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 ?g/day, were associated to behavioural aberrations in offspring. PMID:25242006

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

2014-11-01

173

Gene Polymorphism Studies in a Teaching Laboratory  

ERIC Educational Resources Information Center

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…

Shultz, Jeffry

2009-01-01

174

Laboratory studies of hard rock for CAES  

NASA Astrophysics Data System (ADS)

The properties of hard rock specimens, from formations suitable for compressed air energy storage (CAES) that are subject to the conditions envisioned for a CAES cavern, were investigated by means of laboratory testing. It was concluded that although the compressive and tensile strengths are adversely influenced by a CAES cavern environment, the reduced failure strength of hard rocks is sufficiently high to indicate that a CAES plant could be operated satisfactorily.

Fossum, A. F.

1980-10-01

175

Field, Laboratory, and Modeling Study of Reactive Transport of  

E-print Network

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

176

Competition between harvester ants and rodents in the cold desert  

Microsoft Academic Search

Local distribution patterns of three rodent species (Perognathus parvus, Peromyscus maniculatus, Reithrodontomys megalotis) were studied in areas of high and low densities of harvester ants (Pogonomyrmex owyheei) in Raft River Valley, Idaho. Numbers of rodents were greatest in areas of high ant-density during May, but partially reduced in August; whereas, the trend was reversed in areas of low ant-density. Seed

D. S. Landeen; C. D. Jorgensen; H. D. Smith

1979-01-01

177

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...

178

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

PubMed

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

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

2015-05-01

179

Atmospheric Science Field Laboratory - A feasibility study  

NASA Technical Reports Server (NTRS)

Plans are underway to transfer the technology represented by the lightning and atmospheric science research facilities and capabilities at the Kennedy Space Center to outside users in other government agencies, private industry, and the academic community. Rocket triggered lightning is being used to demonstrate the feasibility of establishing an Atmospheric Science Field Laboratory as a permanent facility and long-term cost sharing. Results from previous programs and data from a lightning event which occurred during the STS-7 flight are presented to demonstrate the adequacy of the present lightning protection and measuring system to protect personnel, vehicle, and ground equipment, as well as to rapidly assess damage due to a lightning event.

Jafferis, William

1987-01-01

180

Airborne and laboratory studies of interstellar PAHs  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

181

Gene Polymorphism Studies in a Teaching Laboratory  

NASA Astrophysics Data System (ADS)

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.

Shultz, Jeffry

2009-02-01

182

Geomagnetic field detection in rodents  

SciTech Connect

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

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

1988-01-01

183

Hindlimb unloading rodent model: technical aspects  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

184

Original Article Using amphibians in laboratory studies: precautions against  

E-print Network

Original Article Using amphibians in laboratory studies: precautions against the emerging is by far the most widely used amphibian species in laboratories. In the wild, X. laevis is an asymptomatic Batrachochytrium dendrobatidis (Bd), which has devastating effects on wild amphibian populations around the world

Schmeller, Dirk S.

185

A Science Librarian in the Laboratory: A Case Study  

ERIC Educational Resources Information Center

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…

Tomaszewski, Robert

2011-01-01

186

Postsecondary Reading and Study Skills Laboratories: Variations and Similarities.  

ERIC Educational Resources Information Center

In this report about reading and study skills laboratories in colleges and universities, the importance of considering the differing needs of each institution and knowing what has been successful in different situations is stressed. The report presents descriptions of five developmental skills laboratories, representing an urban community college,…

Bartlett, Joan C.; Moore, Janet R.

187

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

ERIC Educational Resources Information Center

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…

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

2008-01-01

188

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

PubMed Central

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

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

2013-01-01

189

Scatter-Hoarding Rodents Prefer Slightly Astringent Food  

PubMed Central

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

Wang, Bo; Chen, Jin

2011-01-01

190

Scatter-hoarding rodents prefer slightly astringent food.  

PubMed

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

Wang, Bo; Chen, Jin

2011-01-01

191

Lymphocytic Choriomeningitis Virus from Pet Rodents  

MedlinePLUS

... rodent? Rodents, such as mice, hamsters and guinea pigs, are popular as pets in many households. However, ... and pet mice, hamsters, and, on occasion, guinea pigs. What is LCMV? LCMV is carried by rodents ...

192

Heterogeneous processes: Laboratory, field, and modeling studies  

NASA Technical Reports Server (NTRS)

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

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

193

ENVIRONMENTAL RADIOACTIVITY LABORATORY INTERCOMPARISON STUDIES PROGRAM, 1978-1979  

EPA Science Inventory

The U.S. Environmental Protection Agency's intercomparison studies program for laboratories involved in environmental radiation measurements is described. The types of environmental samples distributed, the analyses required for each sample, the distribution schedule, and the sta...

194

ENVIRONMENTAL RADIOACTIVITY LABORATORY INTERCOMPARISON STUDIES PROGRAM, FY 1977  

EPA Science Inventory

The U.S. Environmental Protection Agency's intercomparison studies program for laboratories involved in environmental radiation measurements is described. The types of environmental samples distributed, the analysis required for each sample, the distribution schedule, and the sta...

195

Structural insights into the rodent CNS via diffusion tensor imaging  

PubMed Central

Diffusion tensor imaging (DTI) is a useful tool for studying anatomy and pathology in the rodent central nervous system (CNS).The unique tissue contrasts provided by DTI are well suited for monitoring disease progression, studying brain development, and characterizing anatomical phenotypes. Recent technical developments have vastly improved the speed and resolution of rodent DTI. Ongoing research efforts exploring the microstructural basis of DTI signals have provided useful insights into its capabilities to delineate brain structures and detect neuropathology. Significant progress has also been made in combining DTI results with data acquired using other imaging modalities to enhance our understanding of the rodent CNS. PMID:22651954

Zhang, Jiangyang; Aggarwal, Manisha; Mori, Susumu

2012-01-01

196

Laboratory Information Management System (LIMS): A case study  

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

197

Laboratory studies of ocean mixing by microorganisms  

NASA Astrophysics Data System (ADS)

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.

Martinez-Ortiz, Monica; Dabiri, John O.

2011-11-01

198

Liver tumors in rodents: extrapolation to man.  

PubMed

Man is a poor model for the prediction of agents that are hepatocarcinogenic for laboratory rodents. Relatively few agents are known to cause any form of primary liver cancer in man. The most important is hepatitis B virus, for which there is possibly a model in the woodchuck but not one in rats or mice. The only other agents known to cause primary liver cancer in man are certain steroid hormones, vinyl chloride, and thorium dioxide. There are animal models for the first two of these and a reasonable expectation that thorium dioxide would produce liver tumors in animals if the appropriate experiments were done. Aflatoxin, a potent hepatocarcinogen in rats and other species but not mice, is strongly suspected of being an important human hepatocarcinogen in certain geographical areas of the world, but the evidence is circumstantial. There is no more than a weak association between the nutritional type of cirrhosis secondary to excessive intake of alcohol and increased primary liver cancer in man, and no evidence at all that ethanol per se causes liver tumors in mice, rats, hamsters, or mastomys. By contrast, a very large number of chemicals to which people in the West have been exposed for many decades have been found to be hepatocarcinogens in laboratory rodents. In most cases the levels of exposure required to produce liver tumors in rodents far exceed those to which man is normally exposed. The problem is to guess whether low-level exposure to such rodent hepatocarcinogens poses any real liver cancer threat to man?The mortality from primary liver cancer is very low in countries such as England and Wales where there is widespread exposure to low doses of both natural and synthetic agents which, in high dosage, cause liver tumors in rodents. This suggests that, if there is any risk, it can only be very small. Death rate data collected in England and Wales by the Registrar General are consistent with there having been a small increase in the incidence of primary liver cancer in England and Wales during the past 20 years, but the apparent increase might well be a consequence of revisions in the International Classification of Diseases system and not real. During the first half of the present century the age-standardized incidence of primary liver cancer in England and Wales was falling.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3300204

Roe, F J

1987-01-01

199

Laboratory study of avalanches in magnetized plasmas  

NASA Astrophysics Data System (ADS)

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.

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

2015-03-01

200

Laboratory studies of water column separation  

NASA Astrophysics Data System (ADS)

Results of experimental studies of water column separation following an upstream valve closure are presented. Different geometrical arrangements with transparent PVC pipes are installed immediately downstream of the closing valve, namely, horizontal pipes, vertical pipes flowing down, and humpback profile pipes, the last two being used in order to obtain full pipe section vapor cavities. Maximum over pressures at water column rejoining, and maximum cavity lengths and duration, are compared with theoretical values and with previous experiments with horizontal pipes. Good agreement is found between theory and experiments, and interesting visual material is obtained.

Autrique, R.; Rodal, E.

2013-12-01

201

A mechanism for resource allocation among sympatric heteromyid rodent species  

Microsoft Academic Search

Laboratory feeding experiments were conducted with Dipodomys ordii and Perognathus flavus in an attempt to discover a mechanism which might result in seed size selection. There was no marked difference in the proportions of four seed types collected whether the rodents foraged in the presence or absence of one another. However, analysis of the variability in weight of each of

Richard L. Hutto

1978-01-01

202

Evaluation of the Adequacy of Published Studies of Low-Dose Effects of Bisphenol A on the Rodent Prostate for Use in Human Risk Assessment  

Microsoft Academic Search

Studies conducted in our laboratories and by others found no consistent correlation between prostate size, prostate pathology, or the development of prostate cancer under a variety of experimental conditions. Furthermore, an evaluation of eight published studies that were conducted in mice and rats following in utero exposure by oral treatment of dams with low levels of bisphenol A (BPA) and

Harry A. Milman; Maarten C. Bosland; Paul D. Walden; John E. Heinze

2002-01-01

203

Laboratory acoustic emission study for earthquake generation process  

NASA Astrophysics Data System (ADS)

Since the similarity in size distribution of earthquakes and acoustic emissions (AE) was found in the 1960s, many laboratory studies have been motivated by the need to provide tools for the prediction of mining failures and natural earthquakes. This paper aims, on the one hand, to draw an outline of laboratory AE studies in the last 50 years, which have addressed seismological problems. Topics include the power laws in which the similarity between AEs and earthquakes is involved and progress that has been made in AE technology and laboratory AE study. On the other hand, this study will highlight some key issues intensively discussed, especially in the last three decades, such as aspects related to the pre-failure damage evolution, fault nucleation and growth in brittle rocks and discuss factors governing these processes.

Lei, Xinglin; Ma, Shengli

2014-12-01

204

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

PubMed Central

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

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

2000-01-01

205

NIMROD: a computational laboratory for studying nonlinear fusion MHD  

Microsoft Academic Search

In analogy to a facility for studying a range of scientific issues, the publicly available NIMROD simulation code [1] is a computational laboratory for macroscopic plasma dynamics. Early results include the first numerical studies of poloidal flux amplification from helicity injection in spheromaks [2] and toroidal geometry effects in RFPs. These strongly nonlinear computations exercise NIMROD's flexibility, but temporal and

C. R. Sovinec

2002-01-01

206

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...

207

A Laboratory Analogue for the Study of Peer Sexual Harassment  

ERIC Educational Resources Information Center

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

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

2004-01-01

208

Sources of Variance in Baseline Gene Expression in the Rodent Liver  

PubMed Central

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

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

2012-01-01

209

Sources of variance in baseline gene expression in the rodent liver.  

PubMed

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

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

2012-08-15

210

A novel variable delay Go/No-Go task to study attention, motivation and working memory in the head-fixed rodent  

PubMed Central

In order to parse the causal elements underlying complex behaviors and decision-making processes, appropriate behavioral methods must be developed and used in concurrence with molecular, pharmacological, and electrophysiological approaches. Presented is a protocol for a novel Go/No-Go behavioral paradigm to study the brain attention and motivation/reward circuitry in awake, head-restrained rodents. This experimental setup allows: (1) Pharmacological and viral manipulation of various brain regions via targeted guide cannula; (2) Optogenetic cell-type specific activation and silencing with simultaneous electrophysiological recording and; (3) Repeated electrophysiological single and multiple unit recordings during ongoing behavior. The task consists of three components. The subject first makes an observing response by initiating a trial by lever pressing in response to distinctive Go or No-Go tones.  Then, after a variable delay period, the subject is presented with a challenge period cued by white noise during which they must respond with a lever press for the Go condition or withhold from lever pressing for the duration of the cue in the No-Go condition. After correctly responding during the challenge period (Challenge) and a brief delay, a final reward tone of the same frequency as the initiation tone is presented and sucrose reward delivery is available and contingent upon lever pressing. Here, we provide a novel procedure and validating data set that allows researchers to study and manipulate components of behavior such as attention, motivation, impulsivity, and reward-related working memory during an ongoing operant behavioral task while limiting interference from non task-related behaviors. PMID:24715953

Cooper, Donald C

2014-01-01

211

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

PubMed

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

Weyrich, Alexandra; Axtner, Jan; Sommer, Simone

2010-02-01

212

What can we get from “BARRELs” -the rodent barrel cortex as a model to study the establishment of neural circuits  

PubMed Central

Sensory inputs triggered by external stimuli are projected into discrete arrays of neuronal modules in the primary sensory cortex. This whisker-to-barrel pathway has gained in popularity as a model system to study the development of cortical circuits and sensory processing because its clear patterns facilitate the identification of genetically modified mice with whisker map deficits and make possible coordinated in vitro and in vivo electrophysiological studies. Numerous whisker map determinants have been identified in the past two decades. In this review, we summarize what have we learned from the detailed studies conducted in various mutant mice with cortical whisker map deficits. We will specifically focus on the anatomical and functional establishment of the somatosensory thalamocortical circuits. PMID:22103423

Wu, Chia-Shan; Rosado, Carlos J. Ballester; Lu, Hui-Chen

2011-01-01

213

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

PubMed Central

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

Gan, Qi; Juric, Rajko

2010-01-01

214

A fully automated rodent conditioning protocol for sensorimotor integration and cognitive control experiments.  

PubMed

Rodents have been traditionally used as a standard animal model in laboratory experiments involving a myriad of sensory, cognitive, and motor tasks. Higher cognitive functions that require precise control over sensorimotor responses such as decision-making and attentional modulation, however, are typically assessed in nonhuman primates. Despite the richness of primate behavior that allows multiple variants of these functions to be studied, the rodent model remains an attractive, cost-effective alternative to primate models. Furthermore, the ability to fully automate operant conditioning in rodents adds unique advantages over the labor intensive training of nonhuman primates while studying a broad range of these complex functions. Here, we introduce a protocol for operantly conditioning rats on performing working memory tasks. During critical epochs of the task, the protocol ensures that the animal's overt movement is minimized by requiring the animal to 'fixate' until a Go cue is delivered, akin to nonhuman primate experimental design. A simple two alternative forced choice task is implemented to demonstrate the performance. We discuss the application of this paradigm to other tasks. PMID:24798582

Mohebi, Ali; Oweiss, Karim G

2014-01-01

215

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

PubMed Central

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 ? 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 ? 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 ? cell glucotoxicity. Evidence presented includes: 1) continued ? 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 ? 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 ? cell dysfunction are also discussed. PMID:25897251

Wu, Jinzi; Yan, Liang-Jun

2015-01-01

216

Methodological considerations in the development of HPLC-MS methods for the analysis of rodent plasma for metabonomic studies.  

PubMed

A study of the factors involved in obtaining valid global metabolite profiles from the HPLC-MS of rat or mouse plasma for the purposes of metabonomic analysis has been undertaken. Plasma proteins were precipitated with three volumes of either methanol or acetonitrile. Chromatographic separations were performed on a C18-bonded stationary phase using 3.5 and 5 mum particles packed into 2.1 and 4.6 mm i.d. formats, respectively, and on a C8 phase using 3.5 mum particles and a 2.1 mm i.d. column. Three reversed-phase gradient solvent systems, based on acidified water-acetonitrile, acidified water-methanol and acidified water-methanol-acetonitrile mixtures, were investigated. The column eluent was analysed with both positive and negative electrospray ionisation using a quadrupole-linear ion trap mass spectrometer. These studies revealed that while accurate classification of sample type can be made, there are a number of methodological problems associated with the analysis of plasma with respect to factors such as repeatability and column longevity. In particular, special care has to be taken to ensure that the analytical system is properly "conditioned" by the repeated injection of matrix samples. The use of biological quality control (QC) samples provided an important means of monitoring method performance. Finally, the source of the plasma (Zucker wild-type or (fa/fa) rat or mouse tumour model) also appeared to have an effect on the repeatability of the methodology. PMID:20024072

Lai, Lindsay; Michopoulos, Filippos; Gika, Helen; Theodoridis, Georgios; Wilkinson, Robert W; Odedra, Rajesh; Wingate, Julie; Bonner, Ron; Tate, Stephen; Wilson, Ian D

2010-01-01

217

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...

218

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

Microsoft Academic Search

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

Françoise Roux; Pierre-Olivier Couraud

2005-01-01

219

Laboratory Study of Heavy Metal Phytoremediation by Three Wetland Macrophytes  

Microsoft Academic Search

Detention ponds and constructed wetlands have proven to be effective in reducing peak stormwater runoff volume and flow, and recent interest has extended to utilizing them to improve stormwater runoff quality. A review of stormwater runoff studies indicated that lead, zinc, copper, cadmium, phosphorus, and chloride are contaminants of primary concern. In laboratory settings, the uptake of contaminants by three

Jeff Weiss; Miki Hondzo; David Biesboer; Michael Semmens

2006-01-01

220

Ethnic Dislikes and Stereotypes: A Laboratory Study: Correction  

Microsoft Academic Search

Reports four errors in the article by Gregory Raran, Ethnic Dislikes and Stereotypes: A Laboratory Study (1950). Each error is described in detail. Face photographs of 30 college girls with ethnically nonspecific features were judged for General Liking, Beauty, Intelligence, Ambition, and Entertainingness by 150 male judges stratified to represent American adults. Two months later the judging was repeated, each

Gregory Razran

1950-01-01

221

The Coso Geothermal Area: A Laboratory for Advanced MEQ Studies  

E-print Network

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

Foulger, G. R.

222

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...

223

Field Research Studying Whales in an Undergraduate Animal Behavior Laboratory  

ERIC Educational Resources Information Center

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…

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

2012-01-01

224

DNA-based and geometric morphometric analysis to validate species designation: a case study of the subterranean rodent Ctenomys bicolor.  

PubMed

The genus Ctenomys (Rodentia: Ctenomyidae) shows several taxonomic inconsistencies. In this study, we used an integrative approach including DNA sequences, karyotypes, and geometric morphometrics to evaluate the taxonomic validity of a nominal species, Ctenomys bicolor, which was described based on only one specimen in 1912 by Miranda Ribeiro, and since then neglected. We sampled near the type locality assigned to this species and collected 10 specimens. A total of 820 base pairs of the cytochrome b gene were sequenced and analyzed together with nine other species and four morphotypes obtained from GenBank. Bayesian analyses showed that C. bicolor is monophyletic and related to the Bolivian-Matogrossense group, a clade that originated about 3 mya. We compared the cranial shape through morphometric geometrics of C. bicolor, including the specimen originally sampled in 1912, with other species representative of the same phylogenetic group (C. boliviensis and C. steinbachi). C. bicolor shows unique skull traits that distinguish it from all other currently known taxa. Our findings confirm that the specimen collected by Miranda Ribeiro is a valid species, and improve the knowledge about Ctenomys in the Amazon region. PMID:24301764

Stolz, J F B; Gonçalves, G L; Leipnitz, L; Freitas, T R O

2013-01-01

225

Developing Medicare Competitive Bidding: A Study of Clinical Laboratories  

PubMed Central

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

Hoerger, Thomas J.; Meadow, Ann

1997-01-01

226

Immunity to type IX collagen in rodents: a study of type IX collagen for autoimmune and arthritogenic activities  

PubMed Central

Type IX collagen (CIX), a cartilage-specific glycoprotein, constitutes ? 10% of cartilage collagen. To ascertain whether CIX can induce arthritis as shown for type II and XI collagen (CII and CXI), outbred rats were sensitized with bovine, chick and human CIX; inbred rats, mice, and guinea pigs were sensitized with bovine CIX. Mice and guinea pigs proved resistant to arthritis, as did rats sensitized with CIX/Freund's incomplete adjuvant (FIA). Arthritis was seen in rats when 100 ?g of Mycobacterium tuberculosis (Mtb) were added to FIA, but seldom with smaller doses of Mtb, suggesting the arthritis was adjuvant-induced. High levels of antibodies to rat CIX, containing complement-fixing subclasses, were detected in rat sera in addition to DTH and lymphocyte proliferation responses to rat CIX. Given the potential for CIX-induced disease, CIX-sensitized rats were injected intraperitoneally with lipopolysaccharide (LPS) to stimulate proinflammatory cytokine release, and intra-articularly with rat CIX to stimulate arthritis. LPS stimulation was ineffective; however, intra-articularly injected CIX produced transient synovitis. When rats with stable adjuvant arthritis were sensitized with CIX/FIA, significant increases in paw volume were measured compared with controls given CI/FIA. Immunohistochemical studies of actively and passively sensitized rats revealed deposits of CIX antibody, but not C3, at the joint margins where proteoglycan staining was weak. Together, these findings suggest that autoimmunity to CIX, in contrast to CII and CXI, is not directly pathogenic but may contribute to joint injury provided arthritis is initiated by an independent disease process. PMID:9649204

Cremer, M A; Ye, X J; Terato, K; Griffiths, M M; Watson, W C; Kang, A H

1998-01-01

227

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

PubMed Central

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

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

2013-01-01

228

Rodent models of TDP-43: Recent advances  

PubMed Central

Recently, missense mutations in the gene TARDBP encoding TDP-43 have been linked to familial ALS. The discovery of genes encoding these RNA binding proteins, such as TDP-43 and FUS/TLS, raised the notion that altered RNA metabolism is a major factor underlying the pathogenesis of ALS. To begin to unravel how mutations in TDP-43 cause dysfunction and death of motor neurons, investigators have employed both gain- and loss-of-function studies in rodent model systems. Here, we will summarize major findings from the initial sets of TDP-43 transgenic and knockout rodent models, identify their limitations, and point to future directions toward clarification of disease mechanism(s) and testing of therapeutic strategies that ultimately may lead to novel therapy for this devastating disease. PMID:22608070

Tsao, William; Jeong, Yun Ha; Lin, Sophie; Ling, Jonathan; Price, Donald L.; Chiang, Po-Min; Wong, Philip C.

2013-01-01

229

The role of rodents and shrews in the transmission of Toxoplasma gondii to pigs.  

PubMed

Inadequate rodent control is considered to play a role in Toxoplasma gondii infection of pigs. This issue was addressed in the current study by combining a 4-month rodent control campaign and a 7-month longitudinal analysis of T. gondii seroprevalence in slaughter pigs. Three organic pig farms with known rodent infestation were included in the study. On these farms, presence of T. gondii in trapped rodents was evaluated by real-time PCR. All rodent species and shrews investigated had T. gondii DNA in brain or heart tissue. Prevalence was 10.3% in Rattus norvegicus, 6.5% in Mus musculus, 14.3% in Apodemus sylvaticus and 13.6% in Crocidura russula. Initial T. gondii seroprevalence in the slaughter pigs ranged between 8% and 17% and dropped on the three farms during the rodent control campaign to 0-10%, respectively. After 4 months of rodent control, T. gondii infection was absent from pigs from two of the three farms investigated and appeared again in one of those two farms after the rodent control campaign had stopped. This study emphasizes the role of rodents and shrews in the transmission of T. gondii to pigs and the importance of rodent control towards production of T. gondii-free pig meat. PMID:18606498

Kijlstra, Aize; Meerburg, Bastiaan; Cornelissen, Jan; De Craeye, Stéphane; Vereijken, Pieter; Jongert, Erik

2008-10-01

230

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

PubMed

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

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

2011-04-01

231

Geometric Morphometrics of Rodent Sperm Head Shape  

PubMed Central

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

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

2013-01-01

232

Studying X-ray Burst Nucleosynthesis in the Laboratory  

NASA Astrophysics Data System (ADS)

Type I X-ray bursts are the most common explosions in the Galaxy; however, the nucleosynthesis that occurs during the thermonuclear runaway and explosion is poorly understood. In this proceedings we discuss current experimental efforts and techniques that are being used to study X-ray burst nucleosynthesis in the laboratory. Specifically, radioactive ion beam techniques that have recently been developed have allowed the study of some of the most important (?, p) reactions in X-ray bursts for the first time.

Deibel, C. M.; Afanasieva, L.; Albers, M.; Alcorta, M.; Almarez-Calderon, S.; Bedoor, S.; Bertone, P. F.; Carnelli, P.; Chen, A. A.; Chen, J.; Clark, J. A.; Figueira, J. M.; Greene, J. P.; Hoffman, C. R.; Irvine, D.; Jiang, C. L.; Kay, B. P.; Lai, J.; Lee, H. Y.; Lighthall, J. C.; Manwell, S.; Marley, S. T.; Nair, C.; Palachan-Hazan, T.; Pardo, R. C.; Patel, N.; Paul, M.; Rasco, B. C.; Rehm, K. E.; Rogers, A. M.; Shetty, D.; Ugalde, C.; Wuosmaa, A.; Zinkann, G.

2012-12-01

233

Sensitization to rodents (mouse/rat) in urban atopic populations without occupational exposure living in Campania district (Southern Italy): a multicenter study  

PubMed Central

Background Up to now very few data on allergic sensitization to rodent allergens in Western Europe and Italy are available, and there are no information at district level. The aim of this report was to investigate clinical significance and characteristics of allergic sensitization to mouse/rat (M/Rt) allergens in atopic subjects living in Campania district (Southern Italy). Methods Allergists from the whole Campania district were required to report the results of skin prick tests of at least 100 consecutive subjects. In 1,477 consecutive outpatients, we selected all subjects with an immediate skin reaction to M/Rt dander. Clinical history including a careful evaluation of the modality of exposure and the results of skin-prick tests (SPTs) were recorded. Results Fifty seven patients were sensitized to M/Rt dander (5.78%). Two patients were mono-sensitized. Fourteen patients reported indoor conditions suggesting presence of rodents allergens at home. All patients exhibited low-moderate degree of SPT positivity to M/Rt. High frequency of concomitant allergic sensitization to dust mites was found. Conclusions Our results suggest that the role of allergic sensitization to rodents is not negligible in atopic subjects without occupational exposure living in Campania district area; these values are higher in comparison to those previously found in Naples area. Highly atopic individuals should be tested by SPTs/evaluation of serum specific IgE to rodents in the case they should begin an occupational exposure to M/Rt or keep these animals as pets. PMID:23591013

2013-01-01

234

Evidence for Novel Hepaciviruses in Rodents  

PubMed Central

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 develop rodent surrogate models for HCV. PMID:23818848

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

235

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

PubMed

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

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

2015-01-01

236

Bioaccumulation data from laboratory and field studies: are they comparable?  

PubMed

Once they are released into the environment, a number of chemicals are known to bioaccumulate in organisms, sometimes to concentrations that may threaten the individual or their predators. However, use of physical or chemical properties or results from laboratory bioaccumulation tests to predict concentrations sometimes found in wild organisms remains a challenge. How well laboratory studies and field measurements agree or disagree, and the cause of any discrepancies, is a subject of great interest and discussion from both a scientific and a regulatory perspective. A workshop sponsored by the ILSI Health and Environmental Sciences Institute, US Environmental Protection Agency, and the Society of Environmental Toxicology and Chemistry assembled scientists from academia, industry, and government to compare and contrast laboratory and field bioaccumulation data. The results of this workshop are summarized in a series of 5 articles published in this issue of Integrated Environmental Assessment and Management. The articles describe: 1) a weight-of-evidence approach that uses fugacity ratios to bring field measurements into the assessment of biomagnification potential for legacy chemicals; 2) a detailed comparison between laboratory and field data for the most commonly measured bioaccumulation endpoint, the biota-sediment accumulation factor; 3) a study that identifies and quantifies the differences between laboratory and field metrics of bioaccumulation for aquatic and terrestrial organisms; and 4) 2 reports on trophic magnification factors: the 1st addresses how trophic magnification factors are determined and interpreted and the 2nd describes how they could be used in regulatory assessments. Collectively, these articles present the workshop participants' current understanding and assessment of bioaccumulation science and make a number of recommendations on how to improve the collection and interpretation of bioaccumulation data. PMID:21538830

Burkhard, Lawrence P; Cowan-Ellsberry, Christina; Embry, Michelle R; Hoke, Robert A; Kidd, Karen A

2012-01-01

237

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

PubMed

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

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

2005-01-01

238

Laboratory studies of O\\/++\\/ reactions of ionospheric importance  

Microsoft Academic Search

The rate constants for the reactions of O(++) ions with several molecules and atoms have been measured. For reaction with N2 the rate constant was found to be (1.6 + or - 0.6) x 10 to the -9th cu cm\\/sec, which agrees very well with an earlier laboratory study but which is considerably larger than the upper limit deduced from

F. Howorka; A. A. Viggiano; E. E. Ferguson; D. L. Albritton; F. C. Fehsenfeld

1979-01-01

239

Study of the neutron background at the Canfranc Underground Laboratory  

Microsoft Academic Search

A quantitative study of the neutron environment in the Canfranc Underground Laboratory is being carried out, specially focused on the IGEX Dark Matter Experiment. A set of simulations based on GEANT4 and FLUKA codes together with data obtained in different experimental conditions in the IGEX set-up allow us to quantify the effect of neutrons in the low-energy spectrum of the

S. Cebrián; B. Beltrán; J. M. Carmona; E. García; I. G. Irastorza; G. Luzón; M. Martínez; A. Morales; J. Morales; A. Ortiz de Solórzano; C. Pobes; J. Puimedón; J. Ruz; M. L. Sarsa; L. Torres; J. A. Villar

2005-01-01

240

Laboratory studies on adhesion of microalgae to hard substrates  

Microsoft Academic Search

\\u000a Adhesion of Chlorella vulgaris (chlorophyceae), Nitzschia amphibia (bacillariophceae) and Chroococcus minutus (cyanobacteria) to hydrophobic (perspex, titanium and stainless steel 316-L), hydrophilic (glass) and toxic (copper, aluminium\\u000a brass and admiralty brass) substrata were studied in the laboratory. The influence of surface wettability, surface roughness,\\u000a pH of the medium, culture age, culture density, cell viability and presence of organic and bacterial films

R. Sekar; V. P. Venugopalan; K. K. Satpathy; K. V. K. Nair; V. N. R. Rao

241

New insights into the karyotypic evolution in muroid rodents revealed by multicolor banding applying murine probes.  

PubMed

Muroid rodents are composed of a wide range of species characterized by extensive karyotypic evolution. Even if this group includes such important laboratory animal models as domestic mouse (Mus musculus), Norway rat (Rattus norvegicus), Chinese hamster (Cricetulus griseus), and golden hamster (Mesocricetus auratus), comparative cytogenetic studies between rodents are difficult due to the characteristic rapid karyotypic evolution. Molecular cytogenetic methods can help resolve problems of comparing muroid chromosomes. Here, we used cross-species comparative multicolour banding with probes obtained from mouse chromosomes 3, 6, 18, and 19 to study the karyotypes of nine muroid species from the three subfamilies Murinae, Cricetinae, and Arvicolinae. Results from multicolour banding with these murine probes (mcb) allowed us to improve the comparative homology maps between these species and to obtain new insights into their karyotypic evolution. We identified evolutionary conserved chromosomal breakpoints and revealed four previously unrecognized homologous segments, four inversions, and 14 evolutionary new centromeres in the nine muroid species studied. We found Mus apomorphic rearrangements, not seen in other muroids, and defined several subfamily specific chromosome breaks, characteristic for Arvicolinae and Cricetinae. We show that mcb libraries are an effective tool both for the cytogenetic characterisation of important laboratory models such as the rat and hamster as well as elucidating the complex phylogenomics relationships of muroids. PMID:20127166

Trifonov, Vladimir A; Kosyakova, Nadezda; Romanenko, Svetlana A; Stanyon, Roscoe; Graphodatsky, Alexander S; Liehr, Thomas

2010-02-01

242

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

PubMed

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

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

2014-03-01

243

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

PubMed Central

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

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

2014-01-01

244

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

PubMed Central

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

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

245

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

PubMed Central

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

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

2013-01-01

246

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

SciTech Connect

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.

McBee, K.; Bickham, J.W.

1988-03-01

247

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

PubMed

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

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

2009-11-01

248

Development and Implementation of Multimedia Content for an Electronic Learning Course on Rodent Surgery  

PubMed Central

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

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

2010-01-01

249

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

USGS Publications Warehouse

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.

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

250

Laboratory studies of oil spill bioremediation; toward understanding field behavior  

SciTech Connect

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.

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. [Exxon Research and Engineering Co., Annandale, NJ (United States); Bragg, J.R. [Exxon Production Research Co., Houston, TX (United States); Douglas, G.S. [Battelle Ocean Sciences, Duxbury, MA (United States)

1993-12-31

251

Geographical distribution of rodent-associated hantaviruses in Texas.  

PubMed

The purpose of this study was to increase our knowledge of the geographic distribution and natural host range of hantaviruses in Texas, southeastern New Mexico, and Mexico. Blood samples from 3,225 wild rodents, representing 34 species, were tested for hantavirus antibody (IgG), using an enzyme-linked immunosorbent assay. Hantavirus antibody was found in one or more rodents from each of 13 counties in Texas, Otero County in southeastern New Mexico, and Mexico State (central Mexico). The 133 antibody-positive rodents included seven Peromyscus species (P. attwateri, P. boylii, P. hylocetes, P. leucopus, P. maniculatis, P. melanotis, and P. pectoralis), Sigmodon hispidus, Oryzomys palustris, two Reithrodontomys species (R. fulvescens and R. megalotis), Neotoma albigula, and Perognathus merriami. This study provides further evidence that rodent-associated hantaviruses are geographically widely distributed in Texas. The discovery of antibody in P. hylocetes and P. melanotis is evidence that peromyscine rodents in Mexico are naturally associated with viruses belonging to the genus Hantavirus. PMID:11469186

Mantooth, S J; Milazzo, M L; Bradley, R D; Hice, C L; Ceballos, G; Tesh, R B; Fulhorst, C F

2001-06-01

252

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

PubMed Central

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

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

2013-01-01

253

Evolution of the Genomic Recombination Rate in Murid Rodents  

PubMed Central

Although very closely related species can differ in their fine-scale patterns of recombination hotspots, variation in the average genomic recombination rate among recently diverged taxa has rarely been surveyed. We measured recombination rates in eight species that collectively represent several temporal scales of divergence within a single rodent family, Muridae. We used a cytological approach that enables in situ visualization of crossovers at meiosis to quantify recombination rates in multiple males from each rodent group. We uncovered large differences in genomic recombination rate between rodent species, which were independent of karyotypic variation. The divergence in genomic recombination rate that we document is not proportional to DNA sequence divergence, suggesting that recombination has evolved at variable rates along the murid phylogeny. Additionally, we document significant variation in genomic recombination rate both within and between subspecies of house mice. Recombination rates estimated in F1 hybrids reveal evidence for sex-linked loci contributing to the evolution of recombination in house mice. Our results provide one of the first detailed portraits of genomic-scale recombination rate variation within a single mammalian family and demonstrate that the low recombination rates in laboratory mice and rats reflect a more general reduction in recombination rate across murid rodents. PMID:21149647

Dumont, Beth L.; Payseur, Bret A.

2011-01-01

254

Characteristics associated with contact with rodents in, around, and outside homes in khon kaen province, Thailand.  

PubMed

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

Suwannarong, Kanokwan; Chapman, Robert S

2015-04-01

255

A review of bioeffects of static magnetic field on rodent models.  

PubMed

This review is aimed to summarize the experimental researches in the influences of static magnetic field on laboratory rodent models, reported by laboratory scientists, experimental technicians, clinical surgeons, animal veterinarians, and other researchers. Past studies suggested that static magnetic field-singly applied or used combined with other physical or chemical substances-significantly relieved some pains and ameliorated certain diseases in different organ systems, e.g. hypertension, osteoporosis, neuralgia, diabetes and leukemia etc. But on the other hand, some harmful events have also been observed in a number of investigations, from cellular level to fetal development. So exposure to static magnetic field might have dual effects on experimental rodent in various environments, viz. there are potentially therapeutic benefits, as well as adverse effects from it. The positive effect may relate to moderate intensities, while negative influence seems to be in connection with acute strong static magnetic fields. In addition, different orientations of static magnetic field exert different degrees of impact. Thus, the bioeffects of static magnetic field exposure on mice/rats depend on magnetic field intensities, durations and directions, though the exactly relationship between them is still vague. Further researches need to perform with appropriate methodologies, ingenious designs repeatedly and systemically, not only in animal models, but also in human volunteers and patients. PMID:24239500

Yu, Shuguang; Shang, Peng

2014-01-01

256

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

SciTech Connect

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.

Not Available

2007-03-01

257

Laboratory studies of radionuclide transport in fractured Climax granite  

SciTech Connect

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.

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

1982-06-01

258

A new dust generator for laboratory dust emission studies  

NASA Astrophysics Data System (ADS)

The aim of this study was to develop a cheap and replicable dust generator for production and investigation of fugitive dusts. We call the device the Easy Dust Generator (EDG). The EDG was constructed with common materials widely available in any laboratory so that it can be replicating anywhere in the world. In order to evaluate the performance of EDG, six repetitions of dust emissions on clay loam, sandy loam, loamy sand, and silt loam soils were measured. According to Gill et al. (2006), the EDG is a "Class C" dust generator. The emission curves obtained with EDG were similar to those obtained with other "Class C" dust generators such as the Lubbock dust generation sampling and analysis systems (LDGASS) and the Southard Laboratory dust generator, but with some differences in the absolute values. Maximum PM10 concentration was higher in fine texture than in coarse-textured soils. The average PM10 concentration and PM10 emissions per grams of soil ordered in the sequence loamy-sand < sandy loam < silt loam < clay loam. These results are in agreement with previous studies where PM10 emissions were higher in fine soils than in coarse soils. The standard deviation (SD) of the averaged PM10 concentration of all analyzed soils varied between 10% and 13%, being these values similar to those reported using other dust generator (from 6% to 24%). We concluded that the EDG can be reproduced anywhere in the world by using common materials and reliable PM10 emission measurements with good repeatability.

Mendez, Mariano J.; Panebianco, Juan E.; Buschiazzo, Daniel E.

2013-03-01

259

Rodent Herpesvirus Peru Encodes a Secreted Chemokine Decoy Receptor  

PubMed Central

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

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

2014-01-01

260

Identification of Rodent Homologs of Hepatitis C Virus and Pegiviruses  

PubMed Central

ABSTRACT Hepatitis C virus (HCV) and human pegivirus (HPgV or GB virus C) are globally distributed and infect 2 to 5% of the human population. The lack of tractable-animal models for these viruses, in particular for HCV, has hampered the study of infection, transmission, virulence, immunity, and pathogenesis. To address this challenge, we searched for homologous viruses in small mammals, including wild rodents. Here we report the discovery of several new hepaciviruses (HCV-like viruses) and pegiviruses (GB virus-like viruses) that infect wild rodents. Complete genome sequences were acquired for a rodent hepacivirus (RHV) found in Peromyscus maniculatus and a rodent pegivirus (RPgV) found in Neotoma albigula. Unique genomic features and phylogenetic analyses confirmed that these RHV and RPgV variants represent several novel virus species in the Hepacivirus and Pegivirus genera within the family Flaviviridae. The genetic diversity of the rodent hepaciviruses exceeded that observed for hepaciviruses infecting either humans or non-primates, leading to new insights into the origin, evolution, and host range of hepaciviruses. The presence of genes, encoded proteins, and translation elements homologous to those found in human hepaciviruses and pegiviruses suggests the potential for the development of new animal systems with which to model HCV pathogenesis, vaccine design, and treatment. PMID:23572554

Kapoor, Amit; Simmonds, Peter; Scheel, Troels K. H.; Hjelle, Brian; Cullen, John M.; Burbelo, Peter D.; Chauhan, Lokendra V.; Duraisamy, Raja; Sanchez Leon, Maria; Jain, Komal; Vandegrift, Kurt Jason; Calisher, Charles H.; Rice, Charles M.; Lipkin, W. Ian

2013-01-01

261

Thieving rodents as substitute dispersers of megafaunal seeds  

PubMed Central

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

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

2012-01-01

262

Laboratory Based Case Studies: Closer to the Real World  

NSDL National Science Digital Library

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, their own experimental procedures, and to think about and interpret the significance of the results they obtain.

Frank J. Dinan

2005-10-01

263

Review: Population Fluctuations in Rodents  

E-print Network

Bats: Work- ing the Night Shift. By Greg Richards and Les Hall; principal photographer: Steve Parish. Collingwood (Australia): CSIRO Publish- ing. AU $79.95. viii #2; 184 p.; ill.; index. ISBN: 978-0-643-10374-0. 2012. The authors... interested in bats. Brock Fenton, Biology, University of Western On- tario, London, Ontario, Canada Population Fluctuations in Rodents. By Charles J. Krebs. Chicago (Illinois): University of Chicago Press. $55.00. x #2; 306 p.; ill.; index. ISBN: 978...

Armitage, Kenneth

2014-03-01

264

NATURAL RODENT HOST ASSOCIATIONS OF GUANARITO AND PIRITAL VIRUSES (FAMILY ARENAVIRIDAE) IN CENTRAL VENEZUELA  

Microsoft Academic Search

The objective of this study was to elucidate the natural rodent host relationships of Guanarito and Pirital viruses (family Arenaviridae) in the plains of central Venezuela. Ninety-two arenavirus isolates from 607 animals, representing 10 different rodent species, were characterized to the level of serotype. The 92 isolates comprised 19 Guanarito virus strains and 73 Pirital virus strains. The 19 Guanarito

CHARLES F. FULHORST; MICHAEL D. BOWEN; ROSA ALBA SALAS; GLORIA DUNO; ANTONIO UTRERA; THOMAS G. KSIAZEK; NURIS M. C. DE MANZIONE; EDITH DE MILLER; CLOVIS VASQUEZ; CLARENCE J. PETERS; ROBERT B. TESH

1999-01-01

265

shuttle-based system. Advanced capabilities of the new Rodent Habitat include providing  

E-print Network

to the space station. The second is the Animal Access Unit that will be used to transfer the rodents upon ar and Space Administration Rodent Habitat Studying Animals in Space Aboard the International Space Station shuttle. The International Space Station is the first essen- tially "permanent" orbiting science laborato

Waliser, Duane E.

266

Anterior chamber lenses. Part II: A laboratory study.  

PubMed

An analysis of 606 surgically removed anterior chamber intraocular lens (IOL) specimens revealed that 351 or 58% of these were small-diameter, round loop, closed-loop styles. Because of the extremely high percentage of IOLs with this design received in our laboratory and the correlation of clinical histories with our histopathologic findings, we have concluded that such IOLs do not provide the safety and efficacy achieved by other anterior chamber lens designs. The finely polished, one-piece, all-PMMA styles fared well in our study. Although these one-piece styles comprise well over 50% of the American market share of anterior chamber IOLs, they comprise only 14% of all anterior chamber IOLs accessioned in our laboratory, compared to 58% for closed-loop designs. We believe that implantation of anterior chamber lenses with small-diameter, round, closed loops is no longer warranted. Patients in whom these IOLs have already been implanted should be carefully followed. It is our opinion that the FDA should recall or closely monitor all IOLs of this design and that implantation of closed-loop lenses should be discontinued in the United States. Furthermore, we believe that an IOL deemed to be not medically sound or worthy of implantation in the United States should not be marketed or donated outside of this country. PMID:3572773

Apple, D J; Hansen, S O; Richards, S C; Ellis, G W; Kavka-Van Norman, D; Tetz, M R; Pfeffer, B R; Park, R B; Crandall, A S; Olson, R J

1987-03-01

267

Feasibility study of medical isotope production at Sandia National Laboratories  

SciTech Connect

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.

Massey, C.D.; Miller, D.L.; Carson, S.D. [Sandia National Labs., Albuquerque, NM (United States). Environmental Regulatory Assessment Dept.] [and others

1995-12-01

268

Laboratory Studies Of Astrophysically-interesting Phosphorus-bearing Molecules  

NASA Astrophysics Data System (ADS)

Over the past year, there has been a renewed interest in the presence of phosphorus-containing molecules in the interstellar medium. Recent observations have increased the number of known interstellar phosphorus-bearing species from two (PN, CP) to six with the identification of HCP, CCP, and PH3 in the carbon-rich circumstellar shell of IRC+10216 and PO in the oxygen-rich envelope of VY Canis Majoris. More species of this type may be present in the ISM, but laboratory rest frequencies, necessary for such detections, are not generally known for many potential molecules. To fill in this gap, we have been conducting measurements of the pure rotational spectra of phosphorus-containing molecules of astrophysical interest, using both millimeter/submm direct absorption and Fourier transform microwave (FTMW) spectroscopy. We have developed a new phosphorus source for this purpose. These methods cover the frequency ranges 65-850 GHz and 4-40 GHz, respectively. Our recent study of the CCP radical (X2?r) using both of these techniques has resulted in its identification in IRC+10216. Rotational spectra of other molecules such as PCN, HPS, and CH3PH2 have been recorded. We will report on these species and additional new laboratory developments

Ziurys, Lucy M.; Halfen, D. T.; Sun, M.; Clouthier, D. J.

2009-05-01

269

Nitrogen miscible displacement of light crude oil; A laboratory study--  

SciTech Connect

A comprehensive laboratory study of N{sub 2} miscible flooding for enhanced recovery of light crude oil was performed. The minimum miscibility pressure (MMP) of N{sub 2} is a major constraint to its EOR application, so an empirical correlation for MMP estimation was developed and found to be reliable. Supporting work included many in-house slim-tube displacement determinations of MMP and the compilation and analysis of previously published data. The reservoir fluid composition, especially the amounts of the methane and ethane-through-pentane fractions, was found to be the major determining factor for miscibility. High-pressure coreflooding tests with sandstone cores were performed to evaluate the effects of gravity stability and injection mode on the N{sub 2} miscible process. N{sub 2}-gas miscible flooding successfully recovered most of the oil from laboratory cores. Gravity-stable and gravity-unstable displacements gave different oil recoveries, as did secondary and tertiary N{sub 2} displacements.

Hudgins, D.A.; Llave, F.M.; Chung, F.T.H. (National Institute for Petroleum and Energy Research, Bartlesville, OK (US))

1990-02-01

270

Unexpected primitive rodents in the Quaternary of Argentina  

NASA Astrophysics Data System (ADS)

This article describes the first fossils recorded in the Hernandarias Formation (Pleistocene) in Entre Ríos province (eastern Argentina). They are represented by three teeth assigned to the caviomorph rodents (Rodentia, Mammalia) Aenigmys diamantensis gen. et sp. nov. and Eumysops. To establish the phylogenetic affinities of the two most enigmatic teeth, their enamel microstructure was studied. Aenigmys diamantensis is considered the most primitive taxon of a clade formed by Dinomyidae-Neoepiblemidae-Heptaxodontidae. Evidence of the close relationships among these families also is presented herein. The new fossils reinforce previous hypotheses about the survival of primitive Brazilian taxa after their extinction in the Pampas and Patagonia of southern South America. They also show that the diversity of caviomorph rodents during the Quaternary was greater than supposed and that an important Quaternary extinction, not previously detected, affected several lineages. With the available evidence, it is not possible to determine if these rodents indicate a warm pulse or a particular biogeographic situation in Entre Ríos.

Vucetich, María G.; Vieytes, Emma C.; Verzi, Diego H.; Noriega, Jorge I.; Tonni, Eduardo P.

2005-10-01

271

Can shrub cover increase predation risk for a desert rodent?  

USGS Publications Warehouse

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.

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

1996-01-01

272

Anatomy and Histology of Rodent and Human Major Salivary Glands  

PubMed Central

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

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

2012-01-01

273

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

PubMed

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

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

2014-02-01

274

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

PubMed Central

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

Wang, Bo; Yang, Xiaolan

2014-01-01

275

Study of CSR Effects in the Jefferson Laboratory FEL Driver  

SciTech Connect

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.

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

2013-08-01

276

Laboratory Scale Antifoam Studies for the STTPB Process  

SciTech Connect

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.

Baich, M.A.

2001-02-13

277

No effect of running and laboratory housing on adult hippocampal neurogenesis in wild caught long-tailed wood mouse  

Microsoft Academic Search

BACKGROUND: Studies of adult hippocampal neurogenesis (AHN) in laboratory rodents have raised hopes for therapeutic interventions in neurodegenerative diseases and mood disorders, as AHN can be modulated by physical exercise, stress and environmental changes in these animals. Since it is not known whether cell proliferation and neurogenesis in wild living mice can be experimentally changed, this study investigates the responsiveness

Thomas Hauser; Fabienne Klaus; Hans-Peter Lipp; Irmgard Amrein

2009-01-01

278

Rodent leptospirosis in Colorado.  

PubMed

A study was conducted to evaluate leptospirosis in brown rats (Rattus norvegicus), muskrats (Ondatra zibethicus) and mice (Mus musculus) in southeastern Larimer County, Colorado. Leptospira serotype icterohaemorrhagiae was isolated from fourteen of 143 feral brown rats, an infection rate of 9.8%. Serological evidence of infection with this stereotype was found in 66.4% of the rats. Serological evidence of L. serotype ballum infection was present in three of 17 muskrats. Leptospires were seen in histological sections of kidney tissue from two of 61 feral mice. No isolations were made from cultures and serology was not done on mice. PMID:16498868

Al Saadi, M; Podt, G

1976-07-01

279

Pet Rodents and Fatal Lymphocytic Choriomeningitis in Transplant Patients  

PubMed Central

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

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

2007-01-01

280

Susceptibility of selected rodent species from Colorado to Borrelia burgdorferi.  

PubMed

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

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

1996-04-01

281

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

PubMed

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

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

2012-03-01

282

Synthetic cathinones and their rewarding and reinforcing effects in rodents  

PubMed Central

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 ?-pyrrolidinovalerophenone (?-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

Watterson, Lucas R.; Olive, M. Foster

2014-01-01

283

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

PubMed

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

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

2008-06-01

284

ELF electric and magnetic fields: Pacific Northwest Laboratory studies  

SciTech Connect

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.

Anderson, L.E.

1992-06-01

285

ELF electric and magnetic fields: Pacific Northwest Laboratory studies  

NASA Astrophysics Data System (ADS)

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

Anderson, L. E.

1992-06-01

286

Molecular Carbon in the Galaxy: Laboratory and Observational Studies  

NASA Technical Reports Server (NTRS)

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.

Saykally, Richard James

2003-01-01

287

Mycobacteriosis in the rabbit and rodent.  

PubMed

Spontaneous mycobacteriosis is rare in rabbits and rodents with the exception of the pygmy rabbit, and there are only a handful of reported cases involving other rodents. Mycobacterium avium complex was the most commonly identified organism in reports of spontaneous mycobacteriosis involving rabbits and rodents. The resistance of rabbits and rodents to mycobacterial disease has been useful in understanding the disease in humans and other animals. Preventing or controlling Mycobacterium sp transmission from wildlife to domestic animals will require collaboration between agriculture, wildlife, environmental, and political entities. Understanding the ecology and epidemiology of mycobacteria is needed for better worldwide management of tuberculosis. PMID:22244115

McClure, Diane E

2012-01-01

288

21 CFR 58.130 - Conduct of a nonclinical laboratory study.  

Code of Federal Regulations, 2010 CFR

...FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

2010-04-01

289

21 CFR 58.130 - Conduct of a nonclinical laboratory study.  

Code of Federal Regulations, 2011 CFR

...FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

2011-04-01

290

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...

291

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

292

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

PubMed

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

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

2012-01-01

293

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...

294

A numerical, laboratory, and field study of riverbed filtration  

NASA Astrophysics Data System (ADS)

Riverbed filtration is an appealing alternative to conventional riverbank and surface water intake systems, offering advantages of high flow rates, natural filtering, and undiminished performance under ice conditions. Its proper functioning requires careful study and monitoring of river flow dynamics, subsurface characteristics, and the interactions between these surface water and groundwater components. A research effort has been underway at INRS to develop principles and guidelines for the design, operation, and maintenance of riverbed filtration systems. A pilot system has just been completed in the Montmorency River near Quebec City (Canada). The installation consists of 4 horizontal wells (or drains), each of 20 m length and 30 cm diameter, placed 4 m apart, at a depth of 1.5 m within the riverbed sediments, and in a direction orthogonal to river flow. The housing trench for each drain is 2 m wide and 2.10 m deep and is composed of 90 cm of gravel topped with 70 cm of sifted alluvial sediments and a 50 cm protective layer of pebbles extracted from the sifted sediments. The average annual water level in the river is 1.2 m, while its mean head during low flow periods is 90 cm. The pilot installation is instrumented with multilevel pressure and temperature sensors and several flowmeters for continuous monitoring in both drainage and backwash modes. In gravity drainage (water intake) mode, the yield is expected to exceed the municipal demand criterion of 35 000 m3/d. Backwash operations, needed to unclog the trenches of fine sediments that can accumulate during water intake, are considered critical to maintaining the design performance targets for the system. Prior to construction of the pilot system, flow patterns, pressure responses, and turbidity behavior in both drainage and backwash modes were extensively studied in laboratory (sand column and sand box) and numerical (SEEP2D) experiments. These tests were fundamental to defining the design parameters and instrumentation features of the pilot system. More detailed lab and numerical simulation studies will be undertaken in tandem with the pilot system operation. The presentation will give an overview of the findings from the prior laboratory and numerical experiments and present initial results from the operation of the pilot system.

Racine, C.; Lefebvre, R.; Martel, R.; Paniconi, C.

2012-04-01

295

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

Microsoft Academic Search

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

Robert R. Parmenter; James A. MacMahon

1983-01-01

296

A human laboratory pilot study with baclofen in alcoholic individuals  

PubMed Central

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

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

2015-01-01

297

Software Engineering Laboratory Ada performance study: Results and implications  

NASA Technical Reports Server (NTRS)

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.

Booth, Eric W.; Stark, Michael E.

1992-01-01

298

Development and characterization of rodent cardiac phantoms: comparison with in vivo cardiac imaging  

PubMed Central

The increasing availability of rodent models of human cardiovascular disease has led to a need to translate noninvasive imaging techniques such as magnetic resonance imaging (MRI) from the clinic to the animal laboratory. The aim of this study was to develop phantoms simulating the short-axis view of left ventricular motion of rats and mice, thus reducing the need for live animals in the development of MRI. Cylindrical phantoms were moulded from polyvinyl alcohol (PVA) Cryogel and attached via stiff water-filled tubing to a gear pump. Pulsatile distension of the phantoms was effected by suitable programming of the pump. Cine MRI scanning was carried out at 7 T and compared with in vivo rodent cardiac imaging. Suitable pulsatile performance was achieved with phantoms for which the PVA material had been subjected to two freeze–thaw cycles, resulting in T1 and T2 relaxation time constants of 1656±124 ms and 55±10 ms, respectively. For the rat phantom operating at 240 beats per min (bpm), the dynamic range of the outer diameter was from 10.3 to 12.4 mm with the wall thickness varying between 1.9 and 1.2 mm. Corresponding figures for the mouse phantom at 480 bpm were outer diameter range from 5.4 to 6.4 mm and wall thickness from 1.5 to 1.2 mm. Dynamic cardiac phantoms simulating rodent left ventricular motion in the short-axis view were successfully developed and compared with in vivo imaging. The phantoms can be used for future development work with reduced need of live animals. PMID:22770689

Fortune, Steven; Jansen, Maurits A.; Anderson, Tom; Gray, Gillian A.; Schneider, Jürgen E.; Hoskins, Peter R.; Marshall, Ian

2012-01-01

299

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

NASA Astrophysics Data System (ADS)

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.

Croom, John R., III

300

Effects of Fat and Protein Levels on Foraging Preferences of Tannin in Scatter-Hoarding Rodents  

PubMed Central

Both as consumers and dispersers of seeds, scatter-hoarding rodents often play an important role in the reproductive ecology of many plant species. However, the seeds of many plant species contain tannins, which are a diverse group of water-soluble phenolic compounds that have a high affinity for proteins. The amount of tannins in seeds is expected to affect rodent foraging preferences because of their major impact on rodent physiology and survival. However, variable results have been obtained in studies that evaluated the effects of tannin on rodent foraging behavior. Hence, in this study, we aimed to explain these inconsistent results and proposed that a combination of seed traits might be important in rodent foraging behavior, because it is difficult to distinguish between the effects of individual traits on rodent foraging behavior and the interactions among them. By using a novel artificial seed system, we manipulated seed tannin and fat/protein levels to examine directly the univariate effects of each component on the seed preferences of free-ranging forest rats (Apodemus latronum and Apodemus chevrieri) during the behavioral process of scatter hoarding. Our results showed that both tannin and fat/protein had significant effects on rodent foraging behavior. Although only a few interactive effects of tannin and fat/protein were recorded, higher concentrations of both fat and protein could attenuate the exclusion of seeds with higher tannin concentrations by rodents, thus influencing seed fate. Furthermore, aside from the concentrations of tannin, fat, and protein, numerous other traits of plant seeds may also influence rodent foraging behavior. We suggest that by clarifying rodent foraging preferences, a better understanding of the evolution of plant seed traits may be obtained because of their strong potential for selective pressure. PMID:22808217

Wang, Bo; Chen, Jin

2012-01-01

301

Next-Generation Sequencing for Rodent Barcoding: Species Identification from Fresh, Degraded and Environmental Samples  

PubMed Central

Rodentia is the most diverse order among mammals, with more than 2,000 species currently described. Most of the time, species assignation is so difficult based on morphological data solely that identifying rodents at the specific level corresponds to a real challenge. In this study, we compared the applicability of 100 bp mini-barcodes from cytochrome b and cytochrome c oxidase 1 genes to enable rodent species identification. Based on GenBank sequence datasets of 115 rodent species, a 136 bp fragment of cytochrome b was selected as the most discriminatory mini-barcode, and rodent universal primers surrounding this fragment were designed. The efficacy of this new molecular tool was assessed on 946 samples including rodent tissues, feces, museum samples and feces/pellets from predators known to ingest rodents. Utilizing next-generation sequencing technologies able to sequence mixes of DNA, 1,140 amplicons were tagged, multiplexed and sequenced together in one single 454 GS-FLX run. Our method was initially validated on a reference sample set including 265 clearly identified rodent tissues, corresponding to 103 different species. Following validation, 85.6% of 555 rodent samples from Europe, Asia and Africa whose species identity was unknown were able to be identified using the BLASTN program and GenBank reference sequences. In addition, our method proved effective even on degraded rodent DNA samples: 91.8% and 75.9% of samples from feces and museum specimens respectively were correctly identified. Finally, we succeeded in determining the diet of 66.7% of the investigated carnivores from their feces and 81.8% of owls from their pellets. Non-rodent species were also identified, suggesting that our method is sensitive enough to investigate complete predator diets. This study demonstrates how this molecular identification method combined with high-throughput sequencing can open new realms of possibilities in achieving fast, accurate and inexpensive species identification. PMID:23144869

Galan, Maxime; Pagès, Marie; Cosson, Jean-François

2012-01-01

302

Rodent Abundance Dynamics and Leptospirosis Carriage in an Area of Hyper-Endemicity in New Caledonia  

PubMed Central

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

Perez, Julie; Brescia, Fabrice; Becam, Jérôme; Mauron, Carine; Goarant, Cyrille

2011-01-01

303

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 ...

304

ER-2: Flying Laboratory for Earth Science Studies  

NASA Technical Reports Server (NTRS)

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.

Navarro, Robert

2007-01-01

305

Study of the neutron background at the Canfranc Underground Laboratory  

NASA Astrophysics Data System (ADS)

A quantitative study of the neutron environment in the Canfranc Underground Laboratory is being carried out, specially focused on the IGEX Dark Matter Experiment. A set of simulations based on GEANT4 and FLUKA codes together with data obtained in different experimental conditions in the IGEX set-up allow us to quantify the effect of neutrons in the low-energy spectrum of the IGEX-DM detector. As an intermediate result, we have estimated the flux of neutrons from radioactivity of the rock (4 × 10 -6 n cm -2 s -1), the flux of muon-induced neutrons in the rock (2 × 10 -9 n cm -2 s -1), and the rate of neutron production by muons in the lead shielding (4×10 -9 n cm -3 s -1). As a first conclusion, 40 cm of neutron moderator should be enough to push far below the present level of sensitivity of the IGEX-DM detector, the contribution to the low energy region (from 4 to 10 keV) of neutrons coming from fission and ( ?,n) reactions in the rock. The contribution of muon-induced neutrons in the rock is also estimated to be far below the present level of sensitivity, so the residual background of IGEX-DM in the low energy region cannot be attributed to neutrons.

Cebrián, S.; Beltrán, B.; Carmona, J. M.; García, E.; Irastorza, I. G.; Luzón, G.; Martínez, M.; Morales, A.; Morales, J.; de Solórzano, A. Ortiz; Pobes, C.; Puimedón, J.; Ruz, J.; Sarsa, M. L.; Torres, L.; Villar, J. A.

2005-01-01

306

Study of driven magnetic reconnection in a laboratory plasma  

SciTech Connect

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.

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

1998-12-31

307

Laboratory study of heavy metal phytoremediation by three wetland macrophytes.  

PubMed

Detention ponds and constructed wetlands have proven to be effective in reducing peak stormwater runoff volume and flow, and recent interest has extended to utilizing them to improve stormwater runoff quality. A review of stormwater runoff studies indicated that lead, zinc, copper, cadmium, phosphorus, and chloride are contaminants of primary concern. In laboratory settings, the uptake of contaminants by three wetland plant species, Glyceria grandis, Scirpus validus, and Spartina pectinata, was examined and removal rates from nutrient solutions inflow and nonflow reactors were measured. The removal rates varied by plant species and target contaminant, and no one species was the best accumulator of all six contaminants. Belowground tissues of all three species accumulated higher concentrations of the four heavy metals and aboveground tissues accumulated higher concentrations of phosphorus and chloride. Plants grown in flow reactors showed significantly higher accumulation rates than those grown in nonflow reactors. Also, plants grown hydroponically accumulated higher concentrations of the six target contaminants than those grown in sand reactors. However, those grown in sand had a much greater increase of biomass and removed a greater mass of the six target contaminants. Removal rates measured in these experiments can be used to design detention ponds to maximize stormwater remediation. PMID:17120528

Weiss, Jeff; Hondzo, Miki; Biesboer, David; Semmens, Michael

2006-01-01

308

Asymmetry of wind waves studied in a laboratory tank  

NASA Astrophysics Data System (ADS)

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.

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

1995-03-01

309

Asymmetry of wind waves studied in a laboratory tank  

NASA Astrophysics Data System (ADS)

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.

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

310

Arenavirus antibody in rodents indigenous to coastal southern California.  

PubMed

The purpose of this study was to extend our knowledge on the geographic and natural rodent host ranges of New World arenaviruses in California. Sera from 1,094 sigmodontine and 112 murine rodents were tested for antibody against Whitewater Arroyo and Amapari viruses. Antibody was found in 55 (4.6%) of the 1,206 rodents: 4 from northwestern San Diego County, 3 from Los Angeles County, and 48 from Orange County. The antibody-positive rodents included 8 (7.8%) of 103 Neotoma fuscipes, 1 (0.6%) of 180 Neotoma lepida, 1 (3.1%) of 32 Peromyscus boylii, 8 (11.0%) of 73 Peromyscus californicus, 1 (1.2%) of 85 Peromyscus eremicus, 30 (8.5%) of 353 Peromyscus maniculatus, and 6 (2.2%) of 268 Reithrodontomys megalotis. This study provides the first evidence that New World arenaviruses occur in Los Angeles and Orange counties and northwestern San Diego County, and the first evidence that Peromyscus and Reithrodontomys species are naturally infected with New World arenaviruses. PMID:11289675

Bennett, S G; Milazzo, M L; Webb, J P; Fulhorst, C F

2000-05-01

311

A laboratory plasma experiment for studying magnetic dynamics of accretion discs and jets  

E-print Network

A laboratory plasma experiment for studying magnetic dynamics of accretion discs and jets S. C. Hsu T This work describes a laboratory plasma experiment and initial results which should give insight gun. Key words: accretion, accretion discs ­ MHD ­ plasmas ­ methods: laboratory. 1 I NT RODU CTION

Hsu, Scott

312

COMPARISON OF FIELD- AND LABORATORY-DEVELOPED ESTUARINE BENTHIC COMMUNITIES FOR TOXICANT-EXPOSURE STUDIES  

EPA Science Inventory

The structures of macrobenthic communities that colonized sand-filled boxes in laboratory and field were compared to learn if laboratory-developed assemblages of animals used in toxicity studies realistically simulate those in nature. Laboratory boxes were colonized for eight wee...

313

A Laboratory Study of X-to-Frequency Converters.  

ERIC Educational Resources Information Center

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)

Kartalopoulos, Stamatios V.

1979-01-01

314

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

NASA Technical Reports Server (NTRS)

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.

Davis, M. H.

1977-01-01

315

The Opposition Effect: Laboratory Studies Compared to Theoretical Models  

NASA Technical Reports Server (NTRS)

Laboratory measurements of the reflectance phase curve, a measurement of great importance in understanding the texture of planetary regoliths, are not consistent with widely accepted theoretical models. Additional information is contained in the original extended abstract.

Nelson, R. M.; Hapke, B. W.; Smythe, W. D.; Hale, A. S.; Piatek, J. L.

2002-01-01

316

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

ERIC Educational Resources Information Center

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)

Loehlin, James H.; And Others

1982-01-01

317

A laboratory study of the friction behavior of granular materials  

E-print Network

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

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

2002-01-01

318

Understanding arid environments using fossil rodent middens  

Microsoft Academic Search

American rodent middens have made a more dramatic contribution to understanding past environments and the development of ecological theory than Australian rodent middens. This relates to differences in the natural environment, the landscape histories, the scale and scientific approaches of the researchers. The comparison demonstrates: the power of synoptic perspectives; the value of thorough macrofossil identification in midden analysis and

Stuart Pearson; Julio L. Betancourtz

2002-01-01

319

Rock fragment movement in shallow rill flow - A laboratory study  

NASA Astrophysics Data System (ADS)

Studies concerning rill erosion mainly deal with the erosion and transport of fine material. The transport of rock fragments is examined mostly for mountain rivers. But there are important differences between the conditions and processes in rivers and in rills: (1) In most cases, the river cuts into a coarse substrate, where fine material is sparse, whereas rill erosion occurs on arable land. So the main part of the substrate is fine material and only single rock fragments influence the processes. (2) In rivers, the water depth is relatively high. There are a lot of studies about hydraulic parameters in such flows, but there is almost nothing known about hydraulic conditions in surface runoff events of a few centimeters. Additionally, little information exists about the rock fragment movement as a part of rill erosion processes on arable land. This knowledge should be increased because rock fragments cause non-stationary water turbulences in rills, which enhance the erosive force of flowing water. Field experiments can only show the fact that a certain rock fragment has moved: The starting point and the final position can be estimated. But the moving path and especially the initiation of the movement is not detectable under field conditions. Hence, we developed a laboratory setup to analyze the movement of rock fragments depending on rock fragment properties (size, form), slope gradient, flow velocity and surface roughness. By observing the rock fragments with cameras from two different angles we are able (1) to measure the rotation angles of a rock fragment during the experiment and (2) to deduce different rock fragment movement patterns. On this poster we want to present the experimental setup, developed within the scope of a master thesis, and the results of these experiments.

Becker, Kerstin; Wirtz, Stefan; Seeger, Manuel; Gronz, Oliver; Remke, Alexander; Iserloh, Thomas; Brings, Christine; Casper, Markus; Ries, Johannes B.

2014-05-01

320

NIMROD: a computational laboratory for studying nonlinear fusion MHD  

NASA Astrophysics Data System (ADS)

In analogy to a facility for studying a range of scientific issues, the publicly available NIMROD simulation code [1] is a computational laboratory for macroscopic plasma dynamics. Early results include the first numerical studies of poloidal flux amplification from helicity injection in spheromaks [2] and toroidal geometry effects in RFPs. These strongly nonlinear computations exercise NIMROD's flexibility, but temporal and spatial scale variations are moderate. Recent improvements make the code equally effective for realistic conditions in tokamaks. General Lagrange-type finite elements produce high-order convergence at realistic levels of anisotropy, such as thermal conductivity ratios of 10^10, with respect to 3D magnetic structures. Implicit and semi-implicit techniques are also important for avoiding time-step restriction; calculations with time steps 10^5 times larger than limits for explicit MHD methods are common for NIMROD. These changes make the code suitable for simulating NTMs including the thermal conductivity-dependent threshold effect [3]. Nonlinear free-boundary physics, such as separatrix evolution, arise in a physical manner with temperature-dependent resistivity and parallel transport on open magnetic field lines. The code is presently being applied to fusion MHD in DIII-D, the SSPX spheromak at LLNL, the HIT-SIHI project at the University of Washington, and the Pegasus spherical torus and MST RFP at the University of Wisconsin. The NIMROD Team is currently pursuing developments to make resistive wall, kinetic, and two-fluid effects practical in large-scale simulations. [1] http://nimrodteam.org. [2] C. R. Sovinec, J. M. Finn, and D. del-Castillo-Negrete, PoP 8, 475 (2001). [3] T. A. Gianakon, S. E. Kruger, and C. C. Hegna, PoP 9, 536 (2002).

Sovinec, C. R.

2002-11-01

321

Los Alamos National Laboratory W76 Pit Tube Lifetime Study  

SciTech Connect

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.

Abeln, Terri G. [Los Alamos National Laboratory

2012-04-25

322

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

SciTech Connect

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.

Batzli, G.O.

1987-05-01

323

Assessing Spatial Learning and Memory in Rodents  

PubMed Central

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

Vorhees, Charles V.; Williams, Michael T.

2014-01-01

324

[Neurosteroidogenesis and exploratory responses in rodents].  

PubMed

We have studied the influence of intraperitoneal introduction of a selective blocker of mitochondrial translocation protein 18kD PK11195 (5 mg/kg), indomethacin (5 and 10 mg/kg), finasteride (5 and 15 mg/kg), and neurosteroid pregnenolone (20 mg/kg) on the exploratory behavior of male BALB/c mice, C57BL/6 mice, and Wistar rats in open-field test. It is found that treatment with PK11195 weakens the exploratory behavior in open-field test in mice of both strains. Finasteride and indomethacin decrease the exploratory responses in rodents regardless of the species or type of stress emotional response phenotype. Pregnenolone possesses activating effect in open-field in open-field test, but enhances the inhibitory effect of finasteride in BALB/c mice. PMID:24791332

Kalinina, T S; Shimshirt, A A; Kudriashov, N V; Voronina, T A; Seredenin, S B

2014-01-01

325

Lassa serology in natural populations of rodents and horizontal transmission.  

PubMed

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

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

2014-09-01

326

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

PubMed

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

Young, E O; Ross, D S

2001-01-01

327

[Laboratory and clinical studies of cefpodoxime proxetil in pediatric field].  

PubMed

We have carried out laboratory and clinical studies on cefpodoxime proxetil (CS-807, CPDX-PR). The results are summarized as follows. CPDX-PR was given via oral administration to each 2 children at a single dose of 3 mg/kg and to each of 3 children in a 100 mg tablet. After the oral administration, mean peak serum levels of CPDX obtained for the 2 dose levels were 1.86 +/- 0.35 micrograms/ml and 2.16 +/- 0.63 micrograms/ml at 2 hours, respectively, and mean half-lives were 1.31 +/- 0.02 hours and 1.47 +/- 0.18 hours, respectively. The mean urinary excretion rate of CPDX was 32.8 +/- 1.0% in the first 12 hours after the oral administration of 3 mg/kg. When a dose of 100 mg tablet was given to each of the 3 children, urinary excretion rates in the first 12 hours were 43.5%, 48.6% and 24.8%, respectively. Treatment with CPDX-PR was done in 38 cases of pediatric bacterial infections; 19 cases of tonsillitis, 3 cases of pharyngitis, 1 case of bronchitis, 3 cases of pneumonia, 3 cases of scarlet fever, 2 cases of impetigo, 4 cases of UTI and 1 case each of phlegmone, subcutaneous abscess and balanitis. Results obtained were excellent in 23 cases, good in 15 cases. No significant side effect due to the drug was observed in any cases. PMID:2810732

Nishimura, T; Tabuki, K; Aoki, S; Takagi, M

1989-07-01

328

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

SciTech Connect

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.

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

2000-01-01

329

Nutritional Evaluation of NASA's Rodent Food Bar Diet  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

330

Behavioral testing in rodent models of orofacial neuropathic and inflammatory pain  

PubMed Central

Orofacial pain conditions are often very debilitating to the patient and difficult to treat. While clinical interest is high, the proportion of studies performed in the orofacial region in laboratory animals is relatively low, compared with other body regions. This is partly due to difficulties in testing freely moving animals and therefore lack of reliable testing methods. Here we present a comprehensive review of the currently used rodent models of inflammatory and neuropathic pain adapted to the orofacial areas, taking into account the difficulties and drawbacks of the existing approaches. We examine the available testing methods and procedures used for assessing the behavioral responses in the face in both mice and rats and provide a summary of some pharmacological agents used in these paradigms to date. The use of these agents in animal models is also compared with outcomes observed in the clinic. PMID:23139912

Krzyzanowska, Agnieszka; Avendaño, Carlos

2012-01-01

331

Effects of Helicobacter Infection on Research: The Case for Eradication of Helicobacter from Rodent Research Colonies  

PubMed Central

Infection of mouse colonies with Helicobacter spp. has become an increasing concern for the research community. Although Helicobacter infection may cause clinical disease, investigators may be unaware that their laboratory mice are infected because the pathology of Helicobacter species is host-dependent and may not be recognized clinically. The effects of Helicobacter infections are not limited to the gastrointestinal system and can affect reproduction, the development of cancers in gastrointestinal organs and remote organs such as the breast, responses to vaccines, and other areas of research. The data we present in this review show clearly that unintentional Helicobacter infection has the potential to significantly interfere with the reliability of research studies based on murine models. Therefore, frequent screening of rodent research colonies for Helicobacter spp. and the eradication of these pathogens should be key goals of the research community. PMID:19295050

Chichlowski, Maciej; Hale, Laura P

2009-01-01

332

Microbial Evolution at High Pressure: Deep Sea and Laboratory Studies  

NASA Astrophysics Data System (ADS)

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 Escherichia coli during laboratory cultivation. More than 60 subcultures were obtained at progressively increasing hydrostatic pressures ranging from 28 - 62 megapascals. A strain isolated from the 63rd subculture displayed dramatically improved growth over the parental strain at 59 megapascals but reduced growth rate relative to the parental strain at atmospheric pressure. The mutant also produced far more unsaturated fatty acids than its parent and also acquired the ability to upregulate these fatty acids species at elevated pressure. Solexa sequencing revealed mutations within an operon (acpP operon) governing unsaturated fatty acid production, and these have been examined as a function of generation at high pressure. These and other results indicate that a large number and variety of microbes are adapted to life at high pressure, that the selective constraints of pressure increases up to ~60 megapascals are not so severe as to preclude the rapid evolution to a piezotolerant phenotype, and that the production of increased levels of unsaturated fatty acids correlates with adaptation to this stressor. This work was supported by grants from the National Science Foundation (EF-0801793 and EF-0827051) and the National Aeronautics and Space Administration (NASA SSC NNX10AR13G).

Bartlett, D. H.

2011-12-01

333

Household Characteristics Associated with Rodent Presence and Leptospira Infection in Rural and Urban Communities from Southern Chile  

PubMed Central

Rodents are well-recognized reservoirs of Leptospira, contributing to its maintenance in endemic areas and playing a role in the public health risk associated with the infection. This study sought to provide some insights into rodent populations from Chile and their Leptospira carriage. In total, 393 rodents were trapped in 177 households. Higher rodent counts were associated with year 2 of the study, rainfall, and number of rodent signs. There was an inverse correlation with the number of cats. The number of rodents was higher in villages compared with slums (rate ratio = 3.23) but modified by average household age. Eighty rodents (20.4%) tested positive for Leptospira: 19.7% on the farms, 25.9% in villages, and 12.3% in the slums. Prevalence was 22.5% in Mus musculus, 20.7% in Rattus rattus, 21.1% in wild rodents, and 10.3% in R. norvegicus. Seasonal and temporal effects were the major determinants of Leptospira infection in rodent populations. PMID:24445209

Muñoz-Zanzi, Claudia; Mason, Meghan; Encina, Carolina; Gonzalez, Marcelo; Berg, Sergey

2014-01-01

334

Household characteristics associated with rodent presence and Leptospira infection in rural and urban communities from Southern Chile.  

PubMed

Rodents are well-recognized reservoirs of Leptospira, contributing to its maintenance in endemic areas and playing a role in the public health risk associated with the infection. This study sought to provide some insights into rodent populations from Chile and their Leptospira carriage. In total, 393 rodents were trapped in 177 households. Higher rodent counts were associated with year 2 of the study, rainfall, and number of rodent signs. There was an inverse correlation with the number of cats. The number of rodents was higher in villages compared with slums (rate ratio = 3.23) but modified by average household age. Eighty rodents (20.4%) tested positive for Leptospira: 19.7% on the farms, 25.9% in villages, and 12.3% in the slums. Prevalence was 22.5% in Mus musculus, 20.7% in Rattus rattus, 21.1% in wild rodents, and 10.3% in R. norvegicus. Seasonal and temporal effects were the major determinants of Leptospira infection in rodent populations. PMID:24445209

Muñoz-Zanzi, Claudia; Mason, Meghan; Encina, Carolina; Gonzalez, Marcelo; Berg, Sergey

2014-03-01

335

Laboratory study of wind- and mechanically-generated water waves  

NASA Astrophysics Data System (ADS)

Evolution of the wind-wave spectrum and their down- shifting mechanism were studied experimentally, in both the small and the large wind-wave facilities at the Ocean Engineering Laboratory. We made observations in order to investigate: (1) the generation and evolution of the short wind waves (small facility); (2) the infuence of changes in the wind speed on the evolution of wind waves (small facility); (3) the long-time evolution of a non- linear wave train, breaking in groups, including the influence of wind pumping (large facility). We statistically analyzed the first observational results under the assumption of a stationary and Gaussian random process. We revealed that within the short fetch (0-7 m), there exist three stages: (1) initial generation of waves due to a coupled viscous shear instability (initial wavelet); (2) sudden down-shifting of energy to form a rhombic wave pattern, created possibly by the large scale turbulence; (3) growth and down-shifting of the wind-wave spectrum as a result of exchange of energy among energetic wave components in a deterministic fashion. We revealed from the second observational results that wind waves responded to the sudden changes in the wind speed with two distinct time scales, /Delta t1 and /Delta t2. The former is associated with the adjustment of wind waves to achieve a quasi-balance with the new wind speed and the latter is associated with the energy convection in a limited fetch. Some additional findings are: (1) there exists a proportionality between wind pumping and energy dissipation, which leads to a global law between wave height and wave period such as Toba's 3/2 law, satisfied by waves in a quasi-balance with wind; (2) wind wave energy convects along a ray. In the third observational study we successfully conducted an experiment of the sideband wave system with a variety of parameter combinations (ak, /delta f/f and ac/a0). We found that: (1) the breaking event causes a permanent down-shifting, while without the breaking event the wave train demodulates; (2) the existence of wind did not change the characteristics of the side band growth; (3) the inclusion of higher frequency waves is necessary for describing the long time evolution of the wave system as demonstrated by the comparison of the experimental results with the numerical solution of the weakly non-linear theory. The wind wave evolution may be governed by deterministic non-linear processes with a strong coupling of the action of wind and the energy dissipation due to wave breaking.

Waseda, Takuji

1997-09-01

336

Tethered variable gravity laboratory study: Low gravity process identification report  

NASA Technical Reports Server (NTRS)

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.

Briccarello, M.

1989-01-01

337

SHELTER COMPETITION BETWEEN TWO INVASIVE CRAYFISH SPECIES: A LABORATORY STUDY  

Microsoft Academic Search

Alien crayfishes represent a common threat to aquatic ecosystems. Their spread in Europe is leading to more frequent contacts between different invasive species populations. Shelter can be an important factor in the resulting interactions. A laboratory experiment was designed to analyse the competition for shelter in similarly sized males of two species that show an invasive behaviour in Spain, Pacifastacus

F. ALONSO; R. MARTÍNEZ

2006-01-01

338

Waste management study: Process development at Lawrence Livermore National Laboratory  

SciTech Connect

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.

Not Available

1984-12-01

339

The Study of Biobehavioral Rhythms in a Psychology Laboratory Course.  

ERIC Educational Resources Information Center

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)

Rowland, David L.; Wesselhoft, Theresa

1998-01-01

340

REGIONAL AIR POLLUTION STUDY: GAS CHROMATOGRAPHY LABORATORY OPERATION  

EPA Science Inventory

A gas chromatography laboratory was set up to analyze air samples collected in Teflon bags and stainless steel tanks. Samples were analyzed for total hydrocarbons, methane, CO, and C2-C10 hydrocarbons. A total of 455 samples, including replicates, were analyzed during the summer ...

341

The Relevance of Rodent-Specific Tumors in Cancer Risk Assessment  

EPA Science Inventory

Laboratory animal species have organs that do not specifically occur in humans and somtimes tumors arise in these organs. The lack of direct site concordance frequently results in significant debate on the human relevance of tumors that arise from rodent specific organs. The re...

342

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

E-print Network

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

Rogers, William Elliott

2002-01-01

343

PREDICTING RODENT CARCINOGENICITY OF HALOGENATED HYDROCARBON BY IN VIVO BIOCHEMICAL PARAMETERS  

EPA Science Inventory

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

344

COMPARATIVE MICROARRAY EXPRESSION ANALYSIS OF SELECTED CANCER RELEVANT GENES IN HYPERTENSIVE RESISTANT VERSUS SUSCEPTIBLE RODENT STRAINS  

EPA Science Inventory

Hypertension and cancer are prevalent diseases. Epidemiological studies suggest that hypertension may increase the long term risk of cancer. Identification of resistance and/or susceptibility genes using rodent models could provide important insights into the management and treat...

345

Inverse association between rural environment in infancy and sensitization to rodents in adulthood  

E-print Network

the prevalence of sensitization to allergens in adulthood. Methods: Sensitization to rodents was determined. 2007;98:440­446. INTRODUCTION Epidemiologic studies of the hygiene hypothesis have pri- marily focused

Illinois at Chicago, University of

346

Adaptation in Rodent Moles and Insectivorous Moles, and the Theory of Convergence  

Microsoft Academic Search

STUDIES in connexion with the life-history of the Orange Free State rodent mole, Cryptomys, brought to light a remarkable degree of adaptation, anatomically and psychologically, to its mode of life in total darkness.

G. Eloff

1951-01-01

347

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

PubMed

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

Wang, Bo; Yang, Xiaolan

2015-04-01

348

Differentiation in seed hoarding among three sympatric rodent species in a warm temperate forest.  

PubMed

Although seed hoarding by rodents has been extensively studied, differentiation in seed-hoarding behaviors among sympatric rodent species has not been well investigated. Using semi-natural enclosures, we demonstrated that three sympatric rodent species showed clear differentiation in food selection, scatter versus larder hoarding behaviors and eating behaviors when offered seeds of four plant species from a warm temperate forest in northern China. The large field mouse Apodemus peninsulae preferred seeds of wild apricot (Prunus armeniaca) and Liaodong oak (Quercus liaotungensis), whereas the Chinese white-bellied rat Niviventor confucianus preferred seeds of cultivated walnut and Liaodong oak, and the David's rock squirrel Sciurotamias davidianus preferred seeds of cultivated walnut, wild apricot and Liaodong oak. All three rodents showed larder hoarding of seeds from all four plant species, but the large field mouse showed scatter hoarding of wild apricot, and the David's rock squirrel showed scatter hoarding of Liaodong oak and wild walnut. Acorns of Liaodong oak, which have a soft seed hull, were more often eaten in situ, whereas wild walnuts, which have a hard seed hull and more tannin, were less hoarded by all rodent species. Differentiation in the scatter versus larder hoarding behaviors of sympatric rodent species suggests that sympatric rodents play different roles in the regeneration of different sympatric plant species. PMID:21396061

Lu, Jiqi; Zhang, Zhibin

2008-06-01

349

Laboratory Study of Nonlinearity and Fabric-Dependence of Till  

NASA Astrophysics Data System (ADS)

The nonlinearity of till deformation can be strong or slight, depending on initial fabric and on deformation conditions, as shown by our new experiments. Recent studies show that small-amplitude stress changes can trigger ice sheet motion and subglacial seismicity. Deformation in the subglacial region plays a key role in determining slip behavior, including creep, transient slip, stick-slip motion, and seismicity. However, progress in understanding these phenomena is limited by uncertainty in the rheology and frictional properties of glacial till. We report on detailed laboratory experiments to measure the creep and frictional constitutive properties of Caesar till sampled from the Scioto Lobe of the Laurentide Ice Sheet, collected in central Ohio. Experiments were conducted in a servo-controlled, double-direct shear apparatus with dried samples at normal stresses ranging from 50 kPa to 5 MPa. Till was sheared in a three-block arrangement in which two till layers are sandwiched between a central forcing block and two stationary blocks. We studied the effect of saturation, initial deformation fabric, stress history, and the boundary conditions of loading. The nominal frictional contact area is 100 cm2 and remains constant during shear. The layer thickness is 1 cm prior to shear. All blocks are grooved perpendicular to the shear direction to ensure that deformation occurs within the layer. Caesar till has a mean grain size of 0.60 mm, but lacks large amounts of silt and clay sized particles. Constant shear stress experiments were employed to study frictional creep. Creep was induced after an initial strain ranging from 0 to 1 to investigate the role of shear fabric on deformation. Experiments were started at 68% of the shear strength with stress increased in steps until tertiary creep occurred. Stress steps were either 2% or 5% of the shear strength. At 20 minutes and 40 minutes after a stress step, we calculated strain rate (slope of strain versus time over a two minute period). The stress exponent, n, was determined from the equation d?/dt = b?^{n}. Where ? is strain, ? shear stress, and b is a constant. We find that fabric has a significant effect on the rheology of till. With no initial strain, strain rates were 10^{- 6} to 10^{-5} s-1 with a corresponding stress exponent of n=6.8. At strains of 1, strain rates were slightly less (5x10-7 s-1) and increased rapidly as the stress approached the shear strength. Intermediate initial strains of 0.15, 0.25, 0.55, and 0.68 showed progressively decreasing strain rate with initial strain. In experiments with no fabric development corresponding to initial strain of less than 0.2, the stress exponent ranged from n~3 to n~7 until the onset of tertiary creep, which occurred immediately when stress reached 90% of the shear strength. For experiments with initial strain of greater than 0.2 the stress exponent is greater than 10 indicating plastic deformation. In cases of strong fabric development, strains larger than 0.6, the stress exponent was larger than 40 near the shear strength.

Rathbun, A. P.; Marone, C. J.; Alley, R. B.; Anandakrishnan, S.

2006-12-01

350

Rodent neurotoxicity bioassays for screening contaminated Great Lakes fish  

SciTech Connect

Standard laboratory rat neurotoxicity protocols were used to study the consequences resulting from the consumption of walleye (Stizostedion vitreum), whitefish (Coregonus clupeaformis), and lake trout (Salvelinus namaycush) from Lake Superior (LS) and the consumption of carp (Cyprinus carpio) from Little Lake Butte des Morte (LLBM) near Oshkosh, Wisconsin, USA. Two 90-d subchronic studies are described, including a 45-d exposure to fish diets using male Sprague-Dawley hooded rats, and a 90-d exposure to fish diets using female rats of the same species. Behavioral alterations were tested using a battery of behavioral tests. In addition, pharmacologic challenges using apomorphine and D-amphetamine were administered to the rats to reveal latent neurotoxic effects. Cumulative fish consumption data were recorded daily, weight gain recorded weekly, and behavior data collected prior to exposure, and on days 7, 14, 55 {+-} 2, 85 {+-} 2. Motor activity data were collected on days 30 {+-} 2, 60 {+-} 2, and 90 {+-} 2 of the feeding protocols. Brain tissue from rodents fed these fish were subsequently analyzed for either mercury (Hg) or polychlorinated biphenyls (PCB). Mercury concentrations were increased in the brains of the walleye-fed rats, and PCB concentrations ranged from 0.5 nl/L to 10 nl/L in the brains of rats fed carp from LLBM, a Lake Michigan tributary. Adult male rats fed LLBM carp for 45 d exhibited the greatest behavior responses to the dopaminergic agonist apomorphine on the accelerating rotarod, although these differences were not significant. The 90-d exposure of LS walleye or Hg-spiked LS walleye resulted in behavior alterations on tactile startle response and second footsplay. D-Amphetamine challenge caused changes in tactile startle response, second footsplay, and accelerating rotarod performance after consuming walleye diets. Rats fed LLBM carp had altered behavioral responses to apomorphine on the accelerating rotarod.

Beattie, M.K.; Hoffman, R. [Univ. of Minnesota, Duluth, MN (United States); Gerstenberger, S. [Univ. of Illinois, Urbana, IL (United States). Dept. of Veterinary Biosciences; Dellinger, J.A. [Medical Coll. of Wisconsin, Milwaukee, MI (United States). Dept. of Preventive Medicine

1996-03-01

351

Natural Host Relationships and Genetic Diversity of Rodent-Associated Hantaviruses in Southeastern Brazil  

Microsoft Academic Search

Objective: Hantaviruses are rodent-borne RNA viruses that have caused hantavirus cardiopulmonary syndrome in several Brazilian regions. In the present study, geographical distribution, seroprevalence, natural host range, and phylogenetic relations of rodent-associated hantaviruses collected from seven counties of Southeastern Brazil were evaluated. Methods: ELISA, RT-PCR and phylogenetic analysis were used in this study. Results: Antibodies to hantavirus were detected in Bolomys

Ricardo Luiz Moro de Sousa; Marcos Lázaro Moreli; Alessandra Abel Borges; Gelse Mazzoni Campos; Márcia Cristina Livonesi; Luiz Tadeu Moraes Figueiredo; Aramis Augusto Pinto

2008-01-01

352

Detection of Toxoplasma gondii by PCR and Mouse Bioassay in Rodents of Ahvaz District, Southwestern Iran  

PubMed Central

Toxoplasma gondii is obligate coccidian zoonotic parasite. Felidae family is definitive and wide ranges of warm-blooded vertebrates are intermediate hosts for the parasite. Rodents are measured as an important source of T. gondii infection for the definitive host. Thus, this study aimed to investigate Toxoplasm infection in rodents of Ahvaz district, southwest of Iran. A total of 100 rodents (73 Rattus norvegicus, 21 Rattus rattus, and 6 Mus musculus) were collected and studied by GRA6PCR and mouse bioassay. The finding indicated that 6 out of 100 (6%) and 2 out of 100 (2%) samples were positive by PCR and mouse bioassay, respectively. The results show notable chronic infection in the rodent and potential transmission of the infection among animal and men in the region. Accordingly, this study recommended investigating of the T. gondii infection in definitive and other intermediate hosts in other points of Khuzestan province, Southwest, Iran. PMID:24605327

Saki, J.; Khademvatan, S.

2014-01-01

353

Microbiological study of selected risk areas in dental technology laboratories  

Microsoft Academic Search

Objectives: To investigate the microbiological status of certain risk areas in the dental technology laboratory, namely pumice slurry, impression agar and curing water baths.Methods: Samples were inoculated onto selective and non-selective media. Resultant fungal and bacterial colonies were counted and identified to genus or species level.Results: Pumice slurry freshly made up using disinfectant was free from contamination, but colony counts

J. Verran; S. Kossar; J. F. McCord

1996-01-01

354

Camera Trapping: A Contemporary Approach to Monitoring Invasive Rodents in High Conservation Priority Ecosystems  

PubMed Central

Invasive rodent species have established on 80% of the world's islands causing significant damage to island environments. Insular ecosystems support proportionally more biodiversity than comparative mainland areas, highlighting them as critical for global biodiversity conservation. Few techniques currently exist to adequately detect, with high confidence, species that are trap-adverse such as the black rat, Rattus rattus, in high conservation priority areas where multiple non-target species persist. This study investigates the effectiveness of camera trapping for monitoring invasive rodents in high conservation areas, and the influence of habitat features and density of colonial-nesting seabirds on rodent relative activity levels to provide insights into their potential impacts. A total of 276 camera sites were established and left in situ for 8 days. Identified species were recorded in discrete 15 min intervals, referred to as ‘events’. In total, 19 804 events were recorded. From these, 31 species were identified comprising 25 native species and six introduced. Two introduced rodent species were detected: the black rat (90% of sites), and house mouse Mus musculus (56% of sites). Rodent activity of both black rats and house mice were positively associated with the structural density of habitats. Density of seabird burrows was not strongly associated with relative activity levels of rodents, yet rodents were still present in these areas. Camera trapping enabled a large number of rodents to be detected with confidence in site-specific absences and high resolution to quantify relative activity levels. This method enables detection of multiple species simultaneously with low impact (for both target and non-target individuals); an ideal strategy for monitoring trap-adverse invasive rodents in high conservation areas. PMID:24599307

Rendall, Anthony R.; Sutherland, Duncan R.; Cooke, Raylene; White, John

2014-01-01

355

Embargoed African Rodents and Monkeypox Virus  

MedlinePLUS

... order also banned within the United States any sale, offering for distribution, transport, or release into the ... bans on importation of African rodents and the sale, distribution, transport, and release into the environment as ...

356

Guinea-zilla? World's largest rodent  

NSDL National Science Digital Library

Roughly the size of a buffalo, a giant rodent that roamed the banks of an ancient Venezuelan river some 8 million years ago, dining on sea grass and dodging crocodiles, was an evolutionary sibling to modern-day guinea pigs.

American Association for the Advancement of Science (AAAS; )

2008-07-03

357

Helminth parasite spectrum in rodent hosts from bamboo growing areas of Mizoram, North-east India.  

PubMed

In the northeastern state of Mizoram, India the rodent outbreak is periodic and coincides with bamboo (Melocanna baccifera) bloom causing a tremendous destruction to food crops that often results in famine. The present study was undertaken during the bamboo flowering period (2006-2008) to assess the parasite spectrum and load in the bourgeoning rodent population of the affected region. The survey results of the populations of 9 prevalent rodent species revealed that nematodes were the most dominant parasitic group followed by cestodes of the order Cyclophyllidea; however, the trematodes were found to be conspicuously missing. The nematodes harbored by the rodents belonged to the genera: Syphacia, Aspicularis, Trichuris, Rictularia, Capillaria, Trichosomoides, Nippostrongylus, Hepatojarakus and Heterakis, whereas the cestode genera included Hymenolepis, Raillietina and Taenia. Hymenolepis diminuta was the commonly encountered species. Only one acanthocephalan (Moniliformis sp.) could be collected during the entire study. PMID:23129885

Malsawmtluangi, C; Tandon, V

2009-12-01

358

Experimental infections by Brucella suis type 4 in Alaskan rodents.  

PubMed

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

Miller, L G; Neiland, K A

1980-10-01

359

Hantavirus Infection in Humans and Rodents, Northwestern Argentina  

PubMed Central

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

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

2003-01-01

360

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

Microsoft Academic Search

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

Therese M. Pham; Stefan Brené; Vera Baumans

361

Trypomastigotes and potential flea vectors of the endemic rodents and the introduced Rattus rattus in the rainforests of Madagascar  

Microsoft Academic Search

Transmission of parasites and diseases may be one of the mechanisms for the displacement of native and endemic rodents of Madagascar (subfamily Nesomyinae) by the introduced Rattus rattus (subfamily Murinae). We studied the occurrence of trypomastigotes in rodents at several rainforest sites on the island. Examination of blood smears showed Trypanosoma lewisi-like trypomastigotes in 11.5% of the R. rattus (n

Juha Laakkonen; Steven M. Goodman; Jean-Bernard Duchemin; Jean-Marc Duplantier

2003-01-01

362

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

Microsoft Academic Search

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

Virginie Millien-Parra; Michel Loreau

2000-01-01

363

Can rodents conceive hyperbolic spaces?  

E-print Network

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

Urdapilleta, Eugenio; Stella, Federico; Treves, Alessandro

2015-01-01

364

Rodents as potential couriers for bioterrorism agents.  

PubMed

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

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

2013-09-01

365

Oxidation of atmospheric reduced sulphur compounds: perspective from laboratory studies  

PubMed Central

Results of laboratory experiments which address the course of the OH + DMS (dimethyl sulphide) reaction in the atmosphere are presented. It is shown that OH reacts via a complex sequence of reactions to produce CH3S and other products, and argued that NO3 is unlikely to be an important oxidizer of DMS in the marine boundary layer (MBL) because it is very efficiently taken up by water droplets. A simplified mechanism for the oxidation of DMS in the troposphere is presented. This mechanism explains some of the field observations on the end products of DMS oxidation and their variations with temperature.

Ravishankara, A. R.; Rudich, Y.; Talukdar, R.; Barone, S. B.

1997-01-01

366

Laboratory study supporting the interpretation of Solar Dynamics Observatory data  

NASA Astrophysics Data System (ADS)

High-resolution extreme ultraviolet spectra of ions in an electron beam ion trap are investigated as a laboratory complement of the moderate-resolution observation bands of the AIA experiment on board the Solar Dynamics Observatory (SDO) spacecraft. The latter observations depend on dominant iron lines of various charge states which in combination yield temperature information on the solar plasma. Our measurements suggest additions to the spectral models that are used in the SDO data interpretation. In the process, we also note a fair number of inconsistencies among the wavelength reference data bases.

Träbert, E.; Beiersdorfer, P.

2015-01-01

367

Evaluation of bioaccumulation using in vivo laboratory and field studies.  

PubMed

A primary consideration in the evaluation of chemicals is the potential for substances to be absorbed and retained in an organism's tissues (i.e., bioaccumulated) at concentrations sufficient to pose health concerns. Substances that exhibit properties that enable biomagnification in the food chain (i.e., amplification of tissue concentrations at successive trophic levels) are of particular concern due to the elevated long-term exposures these substances pose to higher trophic organisms, including humans. Historically, biomarkers of in vivo chemical exposure (e.g., eggshell thinning, bill deformities) retrospectively led to the identification of such compounds, which were later categorized as persistent organic pollutants. Today, multiple bioaccumulation metrics are available to quantitatively assess the bioaccumulation potential of new and existing chemicals and identify substances that, upon or before environmental release, may be characterized as persistent organic pollutants. This paper reviews the various in vivo measurement approaches that can be used to assess the bioaccumulation of chemicals in aquatic or terrestrial species using laboratory-exposed, field-deployed, or collected organisms. Important issues associated with laboratory measurements of bioaccumulation include appropriate test species selection, test chemical dosing methods, exposure duration, and chemical and statistical analyses. Measuring bioaccumulation at a particular field site requires consideration of which test species to use and whether to examine natural populations or to use field-deployed populations. Both laboratory and field methods also require reliable determination of chemical concentrations in exposure media of interest (i.e., water, sediment, food or prey, etc.), accumulated body residues, or both. The advantages and disadvantages of various laboratory and field bioaccumulation metrics for assessing biomagnification potential in aquatic or terrestrial food chains are discussed. Guidance is provided on how to consider the uncertainty in these metrics and develop a weight-of-evidence evaluation that supports technically sound and consistent persistent organic pollutant and persistent, bioaccumulative, and toxic chemical identification. Based on the bioaccumulation information shared in 8 draft risk profiles submitted for review under the United Nations Stockholm Convention, recommendations are given for the information that is most critical to aid transparency and consistency in decision making. PMID:19552500

Weisbrod, Annie V; Woodburn, Kent B; Koelmans, Albert A; Parkerton, Thomas F; McElroy, Anne E; Borgå, Katrine

2009-10-01

368

A SURVEY OF LABORATORY AND STATISTICAL ISSUES RELATED TO FARMWORKER EXPOSURE STUDIES  

EPA Science Inventory

Developing internally valid, and perhaps generalizable, farmworker exposure studies is a complex process that involves many statistical and laboratory considerations. Statistics are an integral component of each study beginning with the design stage and continuing to the final da...

369

Wide Distribution and Genetic Diversity of “Candidatus Neoehrlichia mikurensis” in Rodents from China  

PubMed Central

“Candidatus Neoehrlichia mikurensis” was detected by PCR in 4.0% (34/841) of the rodents tested in this study. The 34 rodents represented nine species from seven regions of China. Phylogenetic analyses based on the partial groEL and nearly entire 16S rRNA gene sequences of the agent revealed genetic diversity, which was correlated with its geographic origins. PMID:23183973

Li, Hao; Jiang, Jiafu; Tang, Fang; Sun, Yi; Li, Zengde; Zhang, Weilong; Gong, Zhengda; Liu, Kun; Yang, Hong

2013-01-01

370

PHYLOGENETICS OF THE NEW WORLD RODENT FAMILY HETEROMYIDAE  

Microsoft Academic Search

The family Heteromyidae includes 6 genera of rodents traditionally placed in 3 subfamilies endemic to the Nearctic and northern Neotropical biogeographic regions. Although several of these taxa represent intensively studied members of North and Central American ecosystems (e.g., kangaroo rats and pocket mice), phylogenetic relationships within and among subfamilies, genera, and species-groups are not well understood. Here, we used maximum-likelihood,

Lois F. Alexander; Brett R. Riddle

2005-01-01

371

Seasonal activity patterns of rodents in a sagebrush community  

Microsoft Academic Search

Twelve species of nocturnal rodents were studied on a 2.7-hectare plot of sagebrush desert in west-central Nevada. Six species, Dipodomys merriami, D. ordii, D. panamintinus, D. microps, Onychomys torridus, and Peromyscus maniculatus, were active throughout the year. Four species, Perognathus longimembris, P. formosus, Microdipodops megacephalus, and Reithrodontomys megalotis, hibernated and were active only in spring, summer, and autumn. Onychomys leucogaster

OFarrell

1974-01-01

372

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

PubMed

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

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

2014-02-01

373

Isolation of members of the Haemophilus-Pasteurella-Actinobacillus group from feral rodents.  

PubMed

46 feral rodents, including a common vole (Microtus arvalis), house mice (Mus musculus), muskrats (ondatra zibetica), house rats (Rattus rattus) and brown rats (R. norvegicus) were examined for bacteria of the Haemophilus-Pasteurella-Actinobacillus group. Haemophilus spp. (only M. musculus examined) were not obtained. All animal species were found contaminated by P. pneumotropica and/or Actinobacillus spp. Almost all M. musculus (96%) and most Rattus spp. (76%) were contaminated by P. pneumotropica and/or Actinobacillus spp. These bacteria were obtained most frequently from the upper respiratory tract, to a lesser extent from the lung and rarely from caecal contents. It is concluded that feral rodents might constitute an important source of contamination of laboratory rodents by members of the HPA-group. PMID:3512906

Boot, R; Lammers, R M; Busschbach, A E

1986-01-01

374

Meeting report: Urinary Pathology; sixth Research Triangle Park Rodent Pathology Course.  

PubMed

Urinary system toxicity is a significant concern to pathologists in the hazard identification, drug and chemical safety evaluation, and diagnostic service industries worldwide. There are myriad known human and animal urinary system toxicants, and investigatory renal toxicology and pathology is continually evolving. The system-specific Research Triangle Park (RTP) Rodent Pathology Course biennially serves to update scientists on the latest research, laboratory techniques, and debates. The Sixth RTP Rodent Pathology Course, Urinary Pathology, featured experts from the government, pharmaceutical, academic, and diagnostic arenas sharing the state of the science in urinary pathology. Speakers presented on a wide range of topics including background lesions, treatment-related non-neoplastic and neoplastic lesions, transgenic rodent models of human disease, diagnostic imaging, biomarkers, and molecular analyses. These seminars were accompanied by case presentation sessions focused on usual and unusual lesions, grading schemes, and tumors. PMID:23645617

Boyle, M C; Boyle, M H

2013-05-01

375

Rhythmic 24 h Variation of Core Body Temperature and Locomotor Activity in a Subterranean Rodent (Ctenomys aff. knighti), the Tuco-Tuco  

PubMed Central

The tuco-tuco Ctenomys aff. knighti is a subterranean rodent which inhabits a semi-arid area in Northwestern Argentina. Although they live in underground burrows where environmental cycles are attenuated, they display robust, 24 h locomotor activity rhythms that are synchronized by light/dark cycles, both in laboratory and field conditions. The underground environment also poses energetic challenges (e.g. high-energy demands of digging, hypoxia, high humidity, low food availability) that have motivated thermoregulation studies in several subterranean rodent species. By using chronobiological protocols, the present work aims to contribute towards these studies by exploring day-night variations of thermoregulatory functions in tuco-tucos, starting with body temperature and its temporal relationship to locomotor activity. Animals showed daily, 24 h body temperature rhythms that persisted even in constant darkness and temperature, synchronizing to a daily light/dark cycle, with highest values occurring during darkness hours. The range of oscillation of body temperature was slightly lower than those reported for similar-sized and dark-active rodents. Most rhythmic parameters, such as period and phase, did not change upon removal of the running wheel. Body temperature and locomotor activity rhythms were robustly associated in time. The former persisted even after removal of the acute effects of intense activity on body temperature by a statistical method. Finally, regression gradients between body temperature and activity were higher in the beginning of the night, suggesting day-night variation in thermal conductance and heat production. Consideration of these day-night variations in thermoregulatory processes is beneficial for further studies on thermoregulation and energetics of subterranean rodents. PMID:24454916

Tachinardi, Patricia; Bicudo, José Eduardo Wilken; Oda, Gisele Akemi; Valentinuzzi, Verónica Sandra

2014-01-01

376

Rodent Facial Nerve Recovery After Selected Lesions and Repair Techniques  

PubMed Central

Background Measuring rodent facial movements is a reliable method for studying recovery from facial nerve manipulation, and for examining the behavioral correlates of aberrant regeneration. We quantitatively compared recovery of vibrissal and ocular function following three types of clinically relevant nerve injury. Methods 178 adult rats underwent facial nerve manipulation and testing. In the experimental groups, the left facial nerve was either crushed, transected and repaired epineurially, or transected and the stumps suture-secured into a tube with a 2 mm gap between them. Facial recovery was measured for the ensuing 1–4 months. Data were analyzed for whisking recovery. Previously developed markers of co-contraction of the upper and midfacial zones (possible synkinesis markers) were also examined. Results Animals in the crush groups recovered nearly normal whisking parameters within 25 days. The distal branch crush group showed improved recovery over the main trunk crush group for several days during early recovery. By week 9, the transection/repair groups showed evidence of recovery that trended further upward throughout the study period. The entubulation groups followed a similar recovery pattern, though they did not maintain significant recovery levels by the study conclusion. Markers of potential synkinesis increased in selected groups following facial nerve injury. Conclusions Rodent vibrissial function recovers in a predictable fashion following manipulation. Generalized co-contraction of the upper and midfacial zones emerges following facial nerve manipulation, possibly related to aberrant regeneration, polyterminal axons, or hypersensitivity of the rodent to sensory stimuli following nerve manipulation. PMID:20048604

Hadlock, Tessa A.; Kowaleski, Jeffrey; Lo, David; Mackinnon, Susan E.; Heaton, James T.

2015-01-01

377

Mycobacterium microti Infection (Vole Tuberculosis) in Wild Rodent Populations  

PubMed Central

Mycobacterium microti (vole tuberculosis) infections in small wild mammals were first described more than 60 years ago in several populations in Great Britain. Few studies of vole tuberculosis have been undertaken since then, and little is known about the relationship between M. microti isolates originating from different populations or at different times or of the prevalence of this infection in wild rodent populations, despite human cases of M. microti infections being increasingly reported. In this study, field voles (Microtus agrestis), bank voles (Clethrionomys glareolus), and wood mice (Apodemus sylvaticus) were found to be infected, with up to 8% having external tuberculous signs, in wild populations in Northumberland and Cheshire, England. Spoligotyping applied directly to the clinical material simultaneously detected and typed M. microti bacteria in skin lesions, lymph glands, and internal abcesses. IS6110 restriction fragment length polymorphism typing of cultured bacteria was used to compare these isolates with previously isolated strains from both animals and humans. This demonstrated that although the current rodent isolates were distinct from those isolated from voles in the 1930s in Great Britain, they had a high degree of similarity to these strains and were distinct from the M. microti isolates from humans, a pig, and a ferret from The Netherlands. Thus, M. microti infection seems to be widespread in wild rodent populations, but more studies are needed to understand how M. microti might be transmitted from animals to humans and to determine better the zoonotic risk posed. PMID:12202566

Cavanagh, Rachel; Begon, Michael; Bennett, Malcolm; Ergon, Torbjørn; Graham, Isla M.; de Haas, Petra E. W.; Hart, C. A.; Koedam, Marianne; Kremer, Kristin; Lambin, Xavier; Roholl, Paul; Soolingen, Dick van

2002-01-01

378

Ventral tegmental area/substantia nigra and prefrontal cortex rodent organotypic brain slices as an integrated model to study the cellular changes induced by oxygen/glucose deprivation and reperfusion: effect of neuroprotective agents.  

PubMed

Unveiling the roles of distinct cell types in brain response to insults is a partially unsolved challenge and a key issue for new neuroreparative approaches. In vivo models are not able to dissect the contribution of residential microglia and infiltrating blood-borne monocytes/macrophages, which are fundamentally undistinguishable; conversely, cultured cells lack original tissue anatomical and functional complexity, which profoundly alters reactivity. Here, we tested whether rodent organotypic co-cultures from mesencephalic ventral tegmental area/substantia nigra and prefrontal cortex (VTA/SN-PFC) represent a suitable model to study changes induced by oxygen/glucose deprivation and reperfusion (OGD/R). OGD/R induced cytotoxicity to both VTA/SN and PFC slices, with higher VTA/SN susceptibility. Neurons were highly affected, with astrocytes and oligodendrocytes undergoing very mild damage. Marked reactive astrogliosis was also evident. Notably, OGD/R triggered the activation of CD68-expressing microglia and increased expression of Ym1 and Arg1, two markers of "alternatively" activated beneficial microglia. Treatment with two well-known neuroprotective drugs, the anticonvulsant agent valproic acid and the purinergic P2-antagonist PPADS, prevented neuronal damage. Thus, VTA/SN-PFC cultures are an integrated model to investigate OGD/R-induced effects on distinct cells and easily screen neuroprotective agents. The model is particularly adequate to dissect the microglia phenotypic shift in the lack of a functional vascular compartment. PMID:24463100

Colombo, Laura; Parravicini, Chiara; Lecca, Davide; Dossi, Elena; Heine, Claudia; Cimino, Mauro; Wanke, Enzo; Illes, Peter; Franke, Heike; Abbracchio, Maria P

2014-01-01

379

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

SciTech Connect

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

Kostova, T; Carlsen, T

2003-11-21

380

Use of Laboratory Studies for the Design, Explanation, and Validation of Human Micronutrient Intervention Studies123  

PubMed Central

Many micronutrient supplementation trials have led to important new findings relevant to public health, but some outcomes have been unclear or concerning. Can and should laboratory studies and animal models be used more extensively to pretest the proposed designs of human studies? This paper illustrates, as examples, the contributions that animal models have made to several major advances in understanding the biology of the micronutrients vitamin A and carotenoids, and it proposes that animal studies can play a more integrated role in public health nutrition by serving as a first line of interrogation for study designs and thereby as a means of refining the designs of human studies so that large, expensive, and logistically difficult human trials will yield the best possible information. PMID:22090470

Ross, A. Catharine

2012-01-01

381

Laboratory Studies of Organic Compounds With Reflectance Spectroscopy  

NASA Astrophysics Data System (ADS)

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 absorptions at approximately 2.3 microns, as well as the first C-H stretching overtones at 1.6 to 1.7 microns, and even the second stretching overtones at 1.2+ microns. Additionally, the spectral properties of these organic materials have applications to remote sensing of terrestrial environments, including hazardous waste and disaster site characterization.

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

2007-12-01

382

Leishmania species: Detection and identification by nested PCR assay from skin samples of rodent reservoirs  

PubMed Central

Many rodent species act as reservoir hosts of zoonotic cutaneous leishmaniasis in endemic areas. In the present study a simple and reliable assay based on nested PCR was developed for the detection and identification of Leishmania parasites from rodent skin samples. We designed Leishmania-specific primers that successfully amplified ITS regions of Leishmania major, Leishmania gerbilli and Leishmania turanica using nested PCR. Out of 95 field collected Rhombomys opimus, 21 were positive by microscopic examination and 48 by nested PCR. The percentage of gerbils infected with L. major, L. gerbilli and L. turanica was 3.2%, 1.1% and 27.4%, respectively. In 15.8% of the rodents, we found mixed natural infections by L. major and L. turanica, 1.1% by L. major and L. gerbilli, and 2.1% by the three species. We concluded that this method is simple and reliable for detecting and identifying Leishmania species circulating in rodent populations. PMID:20566364

Akhavan, Amir Ahmad; Mirhendi, Hossein; Khamesipour, Ali; Alimohammadian, Mohammad Hossein; Rassi, Yavar; Bates, Paul; Kamhawi, Shaden; Valenzuela, Jesus G.; Arandian, Mohammad Hossein; Abdoli, Hamid; Jalali-zand, Niloufar; Jafari, Reza; Shareghi, Niloufar; Ghanei, Maryam; Yaghoobi-Ershadi, Mohammad Reza

2010-01-01

383

Renewable Energy Laboratory Development for Biofuels Advanced Combustion Studies  

SciTech Connect

The research advanced fundamental science and applied engineering for increasing the efficiency of internal combustion engines and meeting emissions regulations with biofuels. The project developed a laboratory with new experiments and allowed investigation of new fuels and their combustion and emissions. This project supports a sustainable domestic biofuels and automotive industry creating economic opportunities across the nation, reducing the dependence on foreign oil, and enhancing U.S. energy security. The one year period of research developed fundamental knowledge and applied technology in advanced combustion, emissions and biofuels formulation to increase vehicle's efficiency. Biofuelsâ?? combustion was investigated in a Compression Ignition Direct Injection (DI) to develop idling strategies with biofuels and an Indirect Diesel Injection (IDI) intended for auxiliary power unit.

Valentin Soloiu

2012-03-31

384

Microbial transformations of substituted benzenes during infiltration of river water to groundwater: Laboratory column studies  

Microsoft Academic Search

The microbial transformations of dimethyl- and dichlorobenzenes have been studied in laboratory aquifer columns simulating saturated-flow conditions typical for a river water\\/groundwater infiltration system. The behavior of all compounds in the laboratory was qualitatively the same as that observed at a field site. Both dimethyl- and dichlorobenzenes were biotransformed under aerobic conditions, the dimethylbenzenes faster than the chlorinated analogues. Evidence

Elmar P. Kuhn; Patricia J. Colberg; Jerald L. Schnoor; Oskar Wanner; Alexander J. P. Zehnder; Rene P. Schwarzenbach

1985-01-01

385

A Matched-Pairs Study of Interactive Computer Laboratory Activities in a Liberal Arts Math Course  

ERIC Educational Resources Information Center

This paper details the culmination of a large, multi-year study on the effects of an interactive computer laboratory component in a large liberal arts math course at a state university. After several semesters of piloting these laboratory activities in the course, one of two sections, taught by the same senior instructor, was randomly selected to…

Butler, Frederick; Butler, Melanie

2011-01-01

386

Feasibility study of an orbiting laboratory for testing CSI technology  

NASA Astrophysics Data System (ADS)

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.

Bicos, Andrew S.; Loboda, Gregory G.

1993-08-01

387

Feasibility study of an orbiting laboratory for testing CSI technology  

NASA Technical Reports Server (NTRS)

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.

Bicos, Andrew S.; Loboda, Gregory G.

1993-01-01

388

Rodent outbreaks in Australia: mouse plagues in cereal crops 225 Rodent outbreaks in Australia: mouse  

E-print Network

Rodent outbreaks in Australia: mouse plagues in cereal crops 225 Rodent outbreaks in Australia: mouse plagues in cereal crops Peter R. Brown, Grant R. Singleton, Roger P. Pech, Lyn A. Hinds, and Charles J. Krebs Mouse plagues have been a feature in cereal cropping areas in southeastern Australia

Krebs, Charles J.

389

Towards an integrative model of sociality in caviomorph rodents  

PubMed Central

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

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

2012-01-01

390

Distinct Leishmania Species Infecting Wild Caviomorph Rodents (Rodentia: Hystricognathi) from Brazil  

PubMed Central

Background Caviomorph rodents, some of the oldest Leishmania spp. hosts, are widely dispersed in Brazil. Despite both experimental and field studies having suggested that these rodents are potential reservoirs of Leishmania parasites, not more than 88 specimens were analyzed in the few studies of natural infection. Our hypothesis was that caviomorph rodents are inserted in the transmission cycles of Leishmania in different regions, more so than is currently recognized. Methodology We investigated the Leishmania infection in spleen fragments of 373 caviomorph rodents from 20 different species collected in five Brazilian biomes in a period of 13 years. PCR reactions targeting kDNA of Leishmania sp. were used to diagnose infection, while Leishmania species identification was performed by DNA sequencing of the amplified products obtained in the HSP70 (234) targeting. Serology by IFAT was performed on the available serum of these rodents. Principal findings In 13 caviomorph rodents, DNA sequencing analyses allowed the identification of 4 species of the subgenus L. (Viannia): L. shawi, L. guyanensis, L. naiffi, and L. braziliensis; and 1 species of the subgenus L. (Leishmania): L. infantum. These include the description of parasite species in areas not previously included in their known distribution: L. shawi in Thrichomys inermis from Northeastern Brazil and L. naiffi in T. fosteri from Western Brazil. From the four other positive rodents, two were positive for HSP70 (234) targeting but did not generate sequences that enabled the species identification, and another two were positive only in kDNA targeting. Conclusions/Significance The infection rate demonstrated by the serology (51.3%) points out that the natural Leishmania infection in caviomorph rodents is much higher than that observed in the molecular diagnosis (4.6%), highlighting that, in terms of the host species responsible for maintaining Leishmania species in the wild, our current knowledge represents only the “tip of the iceberg.” PMID:25503973

Cássia-Pires, Renata; Boité, Mariana C.; D'Andrea, Paulo S.; Herrera, Heitor M.; Cupolillo, Elisa; Jansen, Ana Maria; Roque, André Luiz R.

2014-01-01

391

Field efficacy of deltamethrin for rodent flea control in San Bernardino County, California, USA.  

PubMed

A study was conducted to determine the initial and residual activity of deltamethrin (0.05% dust) applied to rodent burrows (at approximately 14 g/burrow) against fleas in the Silverwood Lake area of San Bernardino County. In initial toxicity (2-d post-treatment), deltamethrin provided 97% flea control and in residual toxicity it resulted in 68% control of the rodent fleas at 15-d post-treatment. The flea fauna consisted of Oropsylla montana (89.9%) and Hoplopsylls anomalus (10.1%). All rodents captured in this study were California ground squirrels, Spermophilus beecheyi. In mark-release-recapture trials, using the microchip identification implant method at the treatment site, the recapture rate of rodents was 29% from 2- to 58-d post-treatment, declining to 21% after 98 d. In the tail-clip method at the treatment site, the recapture rate of 40% at 15-d post-treatment rose to 87% and 73% at 56- and 58-d post-treatment, respectively. At the control site, the recapture rate of 100% at 15-d post-post-treatment dropped to 20% after 98 d. In another trial at Camp Cedar Crest in the Running Springs area, deltamethrin applied to rodent burrows resulted in 70% control of fleas infesting S. beecheyi. Based on the two trials, deltamethrin showed a good initial control of rodent fleas in enzootic or epizootic plague control. PMID:15707280

Mian, Lal S; Hitchcock, James C; Madon, Minoo B; Myers, Charles M

2004-12-01

392

Pilot-Scale Fermentation and Laboratory Nutrient Studies on Mixed-Acid Fermentation  

E-print Network

PILOT-SCALE FERMENTATION AND LABORATORY NUTRIENT STUDIES ON MIXED-ACID FERMENTATION A Dissertation by AARON DOUGLAS SMITH Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2011 Major Subject: Chemical Engineering PILOT-SCALE FERMENTATION AND LABORATORY NUTRIENT STUDIES ON MIXED-ACID FERMENTATION A Dissertation by AARON DOUGLAS SMITH...

Smith, Aaron Douglas

2011-08-08

393

Learning Style and Laboratory Preference: A Study of Middle School Technology Education Teachers in Virginia  

NSDL National Science Digital Library

Laboratory instruction has long been a cornerstone of technology education pedagogy. The French realized the potential for technical laboratory instruction within general education in 1865 (Bennett, 1926). By the 1880s, the United States also realized the benefits of the technical laboratory for general education (Anderson, 1926). Despite these early roots and the continued practice of utilizing laboratory instruction within technology education, there is little research to support this teaching method. McCrory (1987) noted that there were no studies on laboratories (excluding machine safety) or new technology education equipment during the period 1980-1986. Laboratory studies during the period 1987-1993 concentrated on curriculum and did not focus on new instructional methods and strategies (Zuga, 1994). The adoption of modular technology education has only heightened the need for research on laboratory instructional methods. Since the middle of the 1980s, modular technology education has grown considerably. Brusic and LaPorte (2000) found that almost half of the technology education teachers they surveyed in Virginia taught in some type of modular lab. Despite such emerging research, opinions concerning the merit of modular technology education, especially commercially created packages, dominate the field of technology education. To address these opinions, this study investigated whether the preference for a conventional or modular laboratory is influenced by the learning style of the teacher. Target Audience: Middle School Faculty/Administrators

Reed, Philip A.

394

Feeding laboratory studies in patients with eating disorders: A review  

Microsoft Academic Search

Objective: The authors review the available literature on feeding lab studies in individuals with anorexia nervosa, bulimia nervosa, and binge eating disorder. Method: Studies were grouped by the research groups which have conducted such studies since these studies have tended to cluster in certain research settings, using specific methodologies at each sites. Results: The results of this review indicate that

James E. Mitchell; Scott Crow; Carol B. Peterson; Steve Wonderlich; Ross D. Crosby

1998-01-01

395

Laboratory Studies of Ammonia Ices Relevant to the Jovian Atmosphere  

NASA Astrophysics Data System (ADS)

Ammonia ice condensation and cloud formation microphysics are topics of relevance for understanding the atmospheres of the giant planets. Ammonia ices are also considered important components of the icy satellites found in the outer solar system, and are thought to play an important role in their geological activity. Although observational evidence and thermochemical models suggest ammonia clouds in the Jovian atmosphere should be ubiquitous, less than only 1% of Jupiter's atmosphere appears covered by spectrally identifiable ammonia clouds, with a clear preference in turbulent regions.1,2 The paradox of the rather scarce spectroscopic signatures of ammonia clouds and their appearance in turbulent regions suggests that the nascent ammonia clouds may undergo processing that modifies their spectroscopic properties. No relevant laboratory experimental results are available to resolve this problem. Two possible sources of processing that have been suggested in the literature include photochemical solid-state modification (''tanning'') and coating of ammonia particles by other substances present in the stratospheric haze.2,3 We are performing laboratory investigations with the objective to provide information on the photophysical and chemical processes that control the optical properties of the Jovian ammonia clouds. In the experiments, thin ice films of ammonia are coated with organic molecules, such as saturated and aromatic hydrocarbons, and characterized by infrared spectroscopy. Preliminary results indicate suppression of the ammonia absorption feature at 2.7 ? m by a thin layer of hydrocarbons. The implications for the spectral signatures of ammonia clouds in the atmospheres of Jupiter and Saturn will be discussed. Funding from the NSF Planetary Astronomy Program under grant AST-0206270 is gratefully acknowledged. The participation of Rhiannon Meharchand and Christina Baer was made possible by the NSF Research Experiences for Undergraduates Program under grant PHY-0353745. 1. S. K. Atreya and A.-S. Wong, Eos. Trans. 84(46), Fall. Meet. Suppl., Abstract A12A-0072 (2003), and references therein. 2. K. H. Baines, R. W. Carlson, and L. W. Kamp, Icarus 159, 74 (2002). 3. A.-S. Wong, Y. L. Yung, and A. J. Friedson, Geophys. Res. Lett. 30, 1447 (2003).

Meharchand, R. T.; Boulter, J. E.; Baer, C. E.; Kalogerakis, K. S.

2004-12-01

396

Virucidal effects of rodent cage-cleaning practices on the viability of adenovirus vectors.  

PubMed

Human adenoviruses and adenoviral vectors are classified as Risk Group 2 agents and require BSL2 containment and practices. An additional consideration in using adenoviruses and viral vectors in laboratory animal studies is the possible transmission of these agents to other animals and/or personnel as a result of viral shedding in animal urine and feces. When handling BSL2 agents, cage-wash staff are required to wear appropriate personnel protective equipment, including scrubs, Tyvek suit, hair covering, dust mask, shoes covers, and gloves. Current decontamination procedures are to bag and autoclave soiled rodent cages containing bedding prior to washing in the cage washer to prevent possible adenoviral transmission. However, the practice of autoclaving softens the polycarbonate-based rodent cages, allowing damaging agents or conditions to affect the integrity of the plastic and degrade the cages. The objective of this study was to determine whether current rodent cage-cleaning practices produced virucidal effects for use in lieu of or prior to autoclaving the cages. We found that heating an Av3GFP vector in a test tube to a temperature of 74 degrees C (165 degrees F) for 6 min conditions equivalent to those of the cage washer resulted in greater than an 11-log reduction in infectivity of the vector as evaluated by its cytopathic effect on cells. The combination of heating and a liquid, phosphate-free alkaline detergent produced the same reduction in vector infectivity. However, common cage-cleaning solutions alone possessed no virucidal activity. The high temperatures used in cage-washing procedures alone or in combination with a cleaning solution reduced or eliminated the risk of transmission from viral shedding through urine and feces even at vector concentrations far greater than would ever be expected to be present. Autoclaving cages diminishes the stability and integrity of the polycarbonate cages without providing a further reduction in the risk of virus or vector transmission. On the basis of results from this study, new cage-wash recommendations include dumping the contaminated bedding into a HEPA-filtered waste disposal system and autoclaving the bags of bedding before disposal, then cleaning the cages in the rack washer at wash temperatures of 74 degrees C (165 F) and rinse temperatures of 82 degrees C (180 F). PMID:12213048

Porter, Jacqueline D; Lyons, Russette M

2002-09-01

397

Zero-gravity cloud physics laboratory: Candidate experiments definition and preliminary concept studies  

NASA Technical Reports Server (NTRS)

The candidate definition studies on the zero-g cloud physics laboratory are covered. This laboratory will be an independent self-contained shuttle sortie payload. Several critical technology areas have been identified and studied to assure proper consideration in terms of engineering requirements for the final design. Areas include chambers, gas and particle generators, environmental controls, motion controls, change controls, observational techniques, and composition controls. This unique laboratory will allow studies to be performed without mechanical, aerodynamics, electrical, or other type techniques to support the object under study. This report also covers the candidate experiment definitions, chambers and experiment classes, laboratory concepts and plans, special supporting studies, early flight opportunities and payload planning data for overall shuttle payload requirements assessments.

Eaton, L. R.; Greco, R. V.; Hollinden, A. B.

1973-01-01

398

Laboratory studies of Kapton degradation in an oxygen ion beam  

NASA Technical Reports Server (NTRS)

Results are presented from a preliminary laboratory investigation of the degradation of the widely used polyimide Kapton under oxygen ion bombardment. Recent space shuttle flights have shown that Kapton and some other materials exposed to the apparent ram flow of residual atmosphere (at orbital velocity in low Earth orbit) lose mass and change their optical properties. It was hypothesized that these changes are caused by chemical interaction with atomic oxygen, aided by the 5-eV impact energy of atmospheric oxygen atoms in the ram. The reaction rate under O(+) bombardment seemed to be independent of incident energy over a wide range of energies. Although the flux of thermal ions in this experiment was much greater than the accelerated flux, the observed Kapton degradation was limited to the beam area and ram flow direction. This is consistent with an activation energy above the thermal energies but well below the beam energies. The results reproduce well the material loss, optical changes, SEM surface structure, and ram directionality of the samples returned by the shuttle. These factors, along with the lack of degradation under argon ion bombardment, are convincing evidence for ram flow oxidation as the mechanism of degradation.

Ferguson, D. C.

1985-01-01

399

Rainfall simulator for laboratory use in acidic precipitation studies  

SciTech Connect

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. Droplet diameter can be varied from 2.5 to 3.4 mm with different gauge needles, and rainfall intensities from 0.50 to 1.25 cm h/sup -1/ can be attained by a variable speed peristaltic pump. Uniform distribution of rainfall was achieved by rotating the target area and by spacing needles, using an empirical cumulative probability distribution function, along eight radial tubular arms. Variation in rainfall distribution across a 1.2 m diameter circular target area was < 5%. Integrity of solution chemistry was maintained upon passage through the simulator with variations in cation concentrations < 10%, anion concentrations < 5% and pH < 0.2. The system offers sufficient flexibility to simulate a range of rainfall characteristics by varying needle diameter, changing pump speed and/or altering the number of radial arms on each unit.

Chevone, B.I.; Yang, Y.S.; Winner, W.E.; Storks-Cotter, I.; Long, S.J.

1984-04-01

400

Laboratory experimental studies of seismic scattering from fractures  

NASA Astrophysics Data System (ADS)

Laboratory acoustic measurements are performed with Lucite fracture models to understand the scattering characteristics of a seismic wave in a fracture zone. The fracture models include single, dual, and multiple fracture zones with varying fracture apertures, height, and spacing. Fractures are created by both very fine saw cuts and laser-etching. A vertical P-wave source is used with vertical (P) and horizontal (S) receivers to measure the reflected and scattered wavefield as a function of offset and azimuth relative to the fracture orientation. The amplitude of the arrival generated from the fracture tips is proportional to the fracture aperture. Comparison of traces from a single fracture and a dual fracture model indicates that multiple scattering is an important component of the scattered wave signal in fracture systems. In the fracture zone models, the PP and PS scattered wave energy varies azimuthally providing multiple methods for fracture orientation estimation. In particular, PS scattering on the transverse component is a maximum at 45°, while the PS inline component shows a systematic increase in amplitude as the azimuth approaches 90°. Total scattered wave energy is also observed to vary with changes in fracture aperture and height providing a possible means to estimate fracture zone flow capacity from seismic data.

Zhu, Zhenya; Burns, Daniel R.; Brown, Steve; Fehler, Michael

2015-04-01

401

Pretreatment for membrane water treatment systems: a laboratory study  

SciTech Connect

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.

Wend, Christopher F.; Stewart, Philip S.; Jones, Warren L.; Camper, Anne K.

2003-09-30

402

Synchrotron and laboratory studies utilizing a new powder diffraction technique  

SciTech Connect

We have developed a new type of powder diffractometer that is much more efficient than existing methods. The diffractometer has the potential of both high count rates and very high resolution when used at a synchrotron source. The laboratory based instrument has an order of magnitude improvement in count rate over existing methods. The method uses a focusing diffracted beam monochromator in combination with a multichannel detector. The incident x-rays fall on a flat plate or capillary sample and are intercepted by a bent focusing monochromator which has the focus of the bend at the sample surface. The powder diffraction lines emerging from the bent crystal monochromator are detected by a linear or 2-dimensional detector. This allows us to eliminate the background from fluorescence or other scattering and to take data over a range of 3{degrees} to 4{degrees} instead of one angle at a time thereby providing a large improvement over conventional diffractometers. Results are presented for fluorapatite Fe{sub 2}O{sub 3}, and a high-TC superconductor.

Knapp, G.S.; Beno, M.A.; Jennings, G.; Engbretson, M.; Ramanathan, M.

1992-10-01

403

Synchrotron and laboratory studies utilizing a new powder diffraction technique  

SciTech Connect

We have developed a new type of powder diffractometer that is much more efficient than existing methods. The diffractometer has the potential of both high count rates and very high resolution when used at a synchrotron source. The laboratory based instrument has an order of magnitude improvement in count rate over existing methods. The method uses a focusing diffracted beam monochromator in combination with a multichannel detector. The incident x-rays fall on a flat plate or capillary sample and are intercepted by a bent focusing monochromator which has the focus of the bend at the sample surface. The powder diffraction lines emerging from the bent crystal monochromator are detected by a linear or 2-dimensional detector. This allows us to eliminate the background from fluorescence or other scattering and to take data over a range of 3[degrees] to 4[degrees] instead of one angle at a time thereby providing a large improvement over conventional diffractometers. Results are presented for fluorapatite Fe[sub 2]O[sub 3], and a high-TC superconductor.

Knapp, G.S.; Beno, M.A.; Jennings, G.; Engbretson, M.; Ramanathan, M.

1992-10-01

404

Laboratory Studies of Cometary Materials - Continuity Between Asteroid and Comet  

NASA Technical Reports Server (NTRS)

Laboratory analysis of cometary samples have been enabled by collection of cometary dust in the stratosphere by high altitude aircraft and by the direct sampling of the comet Wild-2 coma by the NASA Stardust spacecraft. Cometary materials are composed of a complex assemblage of highly primitive, unprocessed interstellar and primordial solar system materials as well as a variety of high temperature phases that must have condensed in the inner regions of the protoplanetary disk. These findings support and contradict conclusions of comet properties based solely on astronomical observations. These sample return missions have instead shown that there is a continuity of properties between comets and asteroids, where both types of materials show evidence for primitive and processed materials. Furthermore, these findings underscore the importance and value of direct sample return. There will be great value in comparing the findings of the Stardust cometary coma sample return mission with those of future asteroid surface sample returns OSIRIS-REx and Hayabusa II as well as future comet nucleus sample returns.

Messenger, Scott; Walker, Robert M.

2015-01-01

405

The Genetic Basis of Resistance to Anticoagulants in Rodents  

PubMed Central

Anticoagulant compounds, i.e., derivatives of either 4-hydroxycoumarin (e.g., warfarin, bromadiolone) or indane-1,3-dione (e.g., diphacinone, chlorophacinone), have been in worldwide use as rodenticides for >50 years. These compounds inhibit blood coagulation by repression of the vitamin K reductase reaction (VKOR). Anticoagulant-resistant rodent populations have been reported from many countries and pose a considerable problem for pest control. Resistance is transmitted as an autosomal dominant trait although, until recently, the basic genetic mutation was unknown. Here, we report on the identification of eight different mutations in the VKORC1 gene in resistant laboratory strains of brown rats and house mice and in wild-caught brown rats from various locations in Europe with five of these mutations affecting only two amino acids (Tyr139Cys, Tyr139Ser, Tyr139Phe and Leu128Gln, Leu128Ser). By recombinant expression of VKORC1 constructs in HEK293 cells we demonstrate that mutations at Tyr139 confer resistance to warfarin at variable degrees while the other mutations, in addition, dramatically reduce VKOR activity. Our data strongly argue for at least seven independent mutation events in brown rats and two in mice. They suggest that mutations in VKORC1 are the genetic basis of anticoagulant resistance in wild populations of rodents, although the mutations alone do not explain all aspects of resistance that have been reported. We hypothesize that these mutations, apart from generating structural changes in the VKORC1 protein, may induce compensatory mechanisms to maintain blood clotting. Our findings provide the basis for a DNA-based field monitoring of anticoagulant resistance in rodents. PMID:15879509

Pelz, Hans-Joachim; Rost, Simone; Hünerberg, Mirja; Fregin, Andreas; Heiberg, Ann-Charlotte; Baert, Kristof; MacNicoll, Alan D.; Prescott, Colin V.; Walker, Anne-Sophie; Oldenburg, Johannes; Müller, Clemens R.

2005-01-01

406

Microdialysis as a tool to determine free kidney levels of voriconazole in rodents: A model to study the technique feasibility for a moderately lipophilic drug  

Microsoft Academic Search

Microdialysis has been employed for the in vivo measurement of endogenous compounds and a variety of drugs in different tissues. The applicability of this technique can be limited by drug lipophilicity which can impair the diffusion through dialysis membrane. The objective of this study was to evaluate the feasibility of using microdialysis to study kidney penetration of voriconazole, a moderately

B. V. Araujo; C. F. Silva; S. E. Haas; T. Dalla Costa

2008-01-01

407

Phylogenetic characterization of hantaviruses from wild rodents and hantavirus pulmonary syndrome cases in the state of Parana (southern Brazil).  

PubMed

Over 1,100 cases of hantavirus pulmonary syndrome (HPS) have occurred in Brazil since 1993, but little is known about Brazilian hantaviruses, and many of their rodent hosts remain unknown. The Araucaria hantavirus (ARAUV) was described recently from HPS patients from Paraná, in southern Brazil, but its host could not be identified. In this study, rodents were captured from regions with high HPS prevalence to address this issue. ARAUV RNA was detected in three distantly related rodent species: Oligoryzomys nigripes, Oxymycterus judex and Akodon montensis. Furthermore, a specimen of A. montensis was infected with a Jaborá-like virus, implying that A. montensis can be infected by at least two different hantaviruses. The presence of the same hantavirus strain in three different rodent species and the co-circulation of two different strains in the same rodent species highlight the potential for genomic reassortment, which could have an impact on hantavirus transmission dynamics in nature and on human epidemiology. PMID:19439554

Raboni, Sonia Mara; Hoffmann, Federico G; Oliveira, Renata C; Teixeira, Bernardo R; Bonvicino, Cibele R; Stella, Vanessa; Carstensen, Suzana; Bordignon, Juliano; D'Andrea, Paulo S; Lemos, Elba R S; Duarte Dos Santos, Claudia Nunes

2009-09-01

408

Effects of deer density on tick infestation of rodents and the hazard of tick-borne encephalitis. I: empirical assessment.  

PubMed

Tick borne encephalitis (TBE) is endemic to eastern and central Europe with broad temporal and spatial variation in infection risk. Although many studies have focused on understanding the environmental and socio-economic factors affecting exposure of humans to TBE, comparatively little research has been devoted to assessing the underlying ecological mechanisms of TBE occurrence in enzootic cycles, and therefore TBE hazard. The aim of this study was to evaluate the effect of the main ungulate tick hosts on the pattern of tick infestation in rodents and TBE occurrence in rodents and questing adult ticks. In this empirical study, we considered three areas where endemic human TBE occurs and three control sites having no reported human TBE cases. In these six sites located in Italy and Slovakia, we assessed deer density using the pellet group count-plot sampling technique, collected questing ticks, live-trapped rodents (primarily Apodemus flavicollis and Myodes glareolus) and counted ticks feeding on rodents. Both rodents and questing ticks were screened for TBE infection. TBE infection in ticks and rodents was positively associated with the number of co-feeding ticks on rodents and negatively correlated with deer density. We hypothesise that the negative relationship between deer density and TBE occurrence on a local scale (defined by the minimum overlapping area of host species) could be attributed to deer (incompetent hosts) diverting questing ticks from rodents (competent hosts), know as the 'dilution effect hypothesis'. We observed that, after an initial increase, the number of ticks feeding on rodents reached a peak for an intermediate value of estimated deer density and then decreased. Therefore, while at a regional scale, tick host availability has already been shown to be directly correlated with TBE distribution, our results suggest that the interactions between deer, rodents and ticks are much more complex on a local scale, supporting the possibility of a dilution effect for TBE. PMID:22464896

Cagnacci, F; Bolzoni, L; Rosà, R; Carpi, G; Hauffe, H C; Valent, M; Tagliapietra, V; Kazimirova, M; Koci, J; Stanko, M; Lukan, M; Henttonen, H; Rizzoli, A

2012-04-01

409

Detection of newly recognized rodent parvoviruses by PCR.  

PubMed Central

Several autonomous parvovirus isolates distinct from the prototypic rodent parvoviruses have recently been identified. These include variants of a mouse orphan parvovirus (MOPV) and a hamster isolate designated hamster orphan parvovirus (HOPV). In this study, a PCR primer set specific for these newly identified rodent parvoviruses was designed on the basis of DNA sequence comparisons of these isolates with other autonomous parvoviruses. The specificity of the primer set was determined by testing viral preparations of seven different parvoviruses and eight other viruses known to infect rodents. The PCR assay amplified the expected 260-bp product only in the presence of DNA from MOPV, HOPV, or LuIII a parvovirus of unknown species origin. The assay was able to detect as little as 10 pg of MOPV viral DNA or 1 pg of HOPV viral DNA, and it was able to detect MOPV in tissues from naturally infected mice and HOPV in tissues from experimentally infected hamsters. In contrast, the 260-bp product was not amplified from tissues of MOPV-negative mice or mock-infected hamsters. Our findings indicate that this PCR assay provides a rapid, specific, and sensitive method for the detection of MOPV in mice, HOPV in hamsters, and MOPV and HOPV in cell culture systems and that it may also be useful for the detection of LuIII contamination of cell culture systems. PMID:8576334

Besselsen, D G; Besch-Williford, C L; Pintel, D J; Franklin, C L; Hook, R R; Riley, L K

1995-01-01

410

Mammalogy Laboratory 6 -Rodents II: Castoridae, Geomyidae, Heteromyidae, Dipodidae, Muridae  

E-print Network

; Bandicota Material in Lab: Rattus norvegicus (Norway rat)+ Mus musculus (House mouse)+ + Introduced species, arboreal, burrowing, or semi-aquatic. Mus and Rattus are commensal with humans; habits, food, etc, Eurasia, Africa, and Indonesia Representative Genera: Rattus; Mus; Apodemus; Acomys; Notomys; Hydromys

Sullivan, Jack

411

Mammalogy Laboratory 5 -Rodents I: Hystricognathi, Sciuridae, Aplodontidae  

E-print Network

, most families are South and Central American, with one ranging into North America Family Erethizontidae; nocturnal. Range: North, Central and South America Representative Genera: Erethizon, Coendu Material in Lab submerge for up to 1/2 hour. Range: Native to southern South America, have been widely introduced

Sullivan, Jack

412

Calcimimetics inhibit renal pathology in rodent nephronophthisis.  

PubMed

The development and progression of renal cysts appears to be driven by reduced cellular calcium and increased cyclic adenosine monophosphate (cAMP) from G-protein-coupled receptors. To test whether treatment with a calcimimetic that stimulates the G-protein-coupled calcium-sensing receptor might normalize cystic epithelial cell intracellular calcium and cAMP, thereby inhibiting cyst progression, we used pcy mice. These animals develop cysts principally in the collecting duct, as do humans with nephronophthisis (NPHP). We administered the calcimimetic R-568 mixed in their food at early or late stages in the pathogenesis of cyst formation. The treatment reduced cyst enlargement, and the early treatment inhibited development of renal fibrosis. Although the effect of later treatment was more modest, both stages of the disease responded positively to treatment. Additionally, R-568 decreased total kidney cAMP in the pcy mice and, in vitro, decreased cAMP levels and cell proliferation, while increasing intracellular calcium in immortalized human autosomal recessive polycystic kidney disease renal epithelial cells. The latter two effects were unique to R-568 and not replicated by raising extracellular calcium. Thus, treating pcy mice with R-568 was effective in reducing cyst progression in this rodent model of NPHP. Direct studies will be needed to determine whether these results can be applied to the human disease. PMID:21633408

Chen, Neal X; Moe, Sharon M; Eggleston-Gulyas, Tracy; Chen, Xianming; Hoffmeyer, William D; Bacallao, Robert L; Herbert, Brittney S; Gattone, Vincent H

2011-09-01

413

Rodent models of neuroinflammation for Alzheimer's disease.  

PubMed

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

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

2015-01-01

414

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

USGS Publications Warehouse

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

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

2006-01-01

415

Laboratory Studies of Magnetically Driven, Radiatively Cooled Supersonic Plasma Jets  

NASA Astrophysics Data System (ADS)

Results of the recent experiments with radiatively cooled jets performed on the pulsed power MAGPIE facility (1.5MA, 250ns) at Imperial College will be presented. The experiments are scalable to astrophysical flows in that critical dimensionless numbers such as the plasma collisionality, the plasma beta, 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. The main part of the presentation will concentrate on the dynamics of magnetically driven jets, in particular on formation of episodic outflows [1]. The experimental results show the periodic ejections of magnetic bubbles naturally evolving into a heterogeneous jet propagating inside a channel made of self-collimated magnetic cavities. Experimental data on the energy balance in the magnetically driven jets, the conversion of the Poynting flux energy into kinetic energy of the outflow, will be also presented. *) In collaboration with A. CIARDI, F.A. SUZUKI-VIDAL, S.N. BLAND, M. BOCCHI, G. BURDIAK, J.P. CHITTENDEN, P. de GROUCHY, G. HALL, A. HARVEY-THOMSON, A. MAROCCHINO, G. SWADLING, A. FRANK, E. G. BLACKMAN, C. STEHLE, M. CAMENZIND. This research was sponsored by EPSRC, by the OFES DOE, by the NNSA under DOE Cooperative Agreement No. DE-FC03-02NA00057 and by the European Community's Marie Curie Actions within the JETSET network under Contract No. MRTNCT- 2004 005592. References [1] A. Ciardi, S.V. Lebedev, A. Frank et al., The Astrophysical Journal, 691: L147-L150 (2009).

Lebedev, Sergey V.

2010-05-01

416

A Case-Study of Assessment in Materials Laboratory  

NSDL National Science Digital Library

Materials engineering students are often ill prepared to enter the workforce upon graduation. While students master the content knowledge they often lack critical skills for success. Our industry feedback of internship students indicates weakness in the areas of: technical writing, critical thinking, professional attitude & teamwork, analysis, reasoning and decision making. We have examined the effectiveness of new teaching and assessment methods in the Materials Laboratory classes. Through our use of new materials and assessment instruments support our thesis that will lead to student improvement in the defined areas of weakness. The integration of peer review strengthens teamwork and professional attitude both in the classroom and later in the students' professional lives. We have used interdisciplinary collaboration as another component to help develop analysis and reasoning skills by utilizing field trips to manufacturers who have quality control and project management programs. Our feedback system in scoring student reports will likely strengthen their technical writing skills. This works as follows: The group consists of one author and two to three reviewers every week. The roles alternate. The author sends a draft to the reviewers, who in turn review electronically and send the response to both the author and the instructor. This is to make sure the review process can also be graded and the author receives the material in time. The author now makes changes to the report and also responds to the reviewers suggestions in writing. The entire report is submitted to the instructor for assessment. The grades for the reviewers and the author alike, including the comments on the documents teach the students where strengths and weaknesses lie. We have exposed the students to professional engineering centers such as MAIC (Major Analytical Instrumentation Center) and PERC (Particle Engineering Research Center) where they develop better insight and can mirror an appropriate attitude in a professional environment.

Carter, Rufus L.

417

ENHANCED BIOREMEDIATION UTILIZING HYDROGEN PEROXIDE AS A SUPPLEMENTAL SOURCE OF OXYGEN: A LABORATORY AND FIELD STUDY  

EPA Science Inventory

Laboratory and field scale studies were conducted to investigate the feasibility of using hydrogen peroxide as a supplemental source of oxygen for bioremediation of an aviation gasoline fuel spill. Field samples of aviation gasoline contaminated aquifer material were artificially...

418

Laboratory studies of the aqueous-phase oxidation of polyols: submicron particles vs. bulk aqueous solution  

E-print Network

Oxidation in the atmospheric aqueous phase (cloud droplets and deliquesced particles) has received recent attention as a potential pathway for the formation of highly oxidized organic aerosol. Most laboratory studies of ...

Daumit, Kelly Elizabeth

419

Laboratories for the 21st Century: Case Studies, Molecular Foundry, Berkeley, California  

SciTech Connect

This case study provides information on the Molecular Foundry, which incorporates Labs21 principles in its design and construction. The design includes many of the strategies researched at Lawrence Berkeley Laboratory for energy efficient cleanroom and data centers.

Not Available

2010-11-01

420

CHARACTERIZATION AND LABORATORY SOIL TREATABILITY STUDIES FOR CREOSOTE AND PENTACHLOROPHENOL SLUDGES AND CONTAMINATED SOIL  

EPA Science Inventory

Information is presented from characterization and laboratory treatability phases of a 3-phase study pertaining to on-site treatability potential of soils containing hazardous constituents from wood-treatment waste. Specific information includes: (1) literature assessment of soil...