Responses of nocturnal rodents to shrub encroachment in Banni grasslands, Gujarat, India

Science.gov (United States)

Jayadevan, A.

2016-12-01

Shrub encroachment is one of the greatest threats to grasslands globally. These woodlands can strongly influence the behaviour of small mammals adapted to more open habitats, which rely on high visibility for early detection of predators. In semi-arid grasslands, rodents are considered keystone species. Although shrub encroachment is known to negatively affect rodent assemblages, its impact on the foraging behaviour of rodents, which is known to vary in response to risky situations, is unknown. Understanding whether shrub encroachment alters such antipredator behaviour is important as antipredator behaviour can alter the distribution, abundance and ultimately, survival of prey species. In this study, I explored the effects of shrub encroachment on the foraging behaviour of nocturnal rodent communities in the Banni grasslands, India. I examined foraging behaviour, quantified using the giving-up density (GUD) framework and the number of rodent crossings around food patches, in two habitats that differed in the extent of shrub encroachment. Under the GUD framework, the amount of food left behind by a forager in a food patch reflects the costs of feeding at the patch. Higher GUDs imply higher foraging costs. I also investigated how removal of an invasive woody plant, Prosopis juliflora would affect foraging behaviour of nocturnal rodents. High shrub encroachment was associated with higher foraging costs (higher GUDs) and lower activity than the sparsely wooded habitat, likely due to low visibility in the densely wooded habitat. The dense habitat also supported a higher richness and relative abundance of generalist rodents than the sparse habitat, likely due to the increased heterogeneity of the habitat. The tree removal experiment revealed that rodents had lower GUDs (i.e., low foraging costs) after the event of tree cutting. This may be due to the reduction of cover in the habitat, leading to higher visibility and lower predation risk. My results suggest that shrub

Protocol for production of a genetic cross of the rodent malaria parasites.

Science.gov (United States)

Pattaradilokrat, Sittiporn; Li, Jian; Su, Xin-zhuan

2011-01-03

Variation in response to antimalarial drugs and in pathogenicity of malaria parasites is of biologic and medical importance. Linkage mapping has led to successful identification of genes or loci underlying various traits in malaria parasites of rodents and humans. The malaria parasite Plasmodium yoelii is one of many malaria species isolated from wild African rodents and has been adapted to grow in laboratories. This species reproduces many of the biologic characteristics of the human malaria parasites; genetic markers such as microsatellite and amplified fragment length polymorphism (AFLP) markers have also been developed for the parasite. Thus, genetic studies in rodent malaria parasites can be performed to complement research on Plasmodium falciparum. Here, we demonstrate the techniques for producing a genetic cross in P. yoelii that were first pioneered by Drs. David Walliker, Richard Carter, and colleagues at the University of Edinburgh. Genetic crosses in P. yoelii and other rodent malaria parasites are conducted by infecting mice Mus musculus with an inoculum containing gametocytes of two genetically distinct clones that differ in phenotypes of interest and by allowing mosquitoes to feed on the infected mice 4 days after infection. The presence of male and female gametocytes in the mouse blood is microscopically confirmed before feeding. Within 48 hrs after feeding, in the midgut of the mosquito, the haploid gametocytes differentiate into male and female gametes, fertilize, and form a diploid zygote (Fig. 1). During development of a zygote into an ookinete, meiosis appears to occur. If the zygote is derived through cross-fertilization between gametes of the two genetically distinct parasites, genetic exchanges (chromosomal reassortment and cross-overs between the non-sister chromatids of a pair of homologous chromosomes; Fig. 2) may occur, resulting in recombination of genetic material at homologous loci. Each zygote undergoes two successive nuclear

Radicidation and radappertization of animal feeds in Israel, 1968-1977

International Nuclear Information System (INIS)

Lapidot, M.

1979-01-01

Contamination of animal feed and animal products with salmonellae and other enteric microorganisms has considerably increased in recent years. This has resulted in commensurate increases in the incidence of salmonellosis and other enteric diseases in both animals and humans. The development of radappertization for laboratory animal feeds and of radicidation for farm animal feeds over the last ten years in Israel is reviewed. The products considered were radappertized feeds for SPF rodent colonies and for commercial SPF poultry flocks, and radicidized feed for breeder and broiler flocks. In the latter case microbiological, biological, technological and economic aspects are considered. The petition and clearance for radicidized poultry feed are briefly discussed. The potential use of radicidation in the preparation of animal feeds from organic wastes, i.e. putrescibles in household garbage and sewage sludge, is outlined, and the factors involved are evaluated. (author)

Tick parasites of rodents in Romania: host preferences, community structure and geographical distribution.

Science.gov (United States)

Mihalca, Andrei D; Dumitrache, Mirabela O; Sándor, Attila D; Magdaş, Cristian; Oltean, Miruna; Györke, Adriana; Matei, Ioana A; Ionică, Angela; D'Amico, Gianluca; Cozma, Vasile; Gherman, Călin M

2012-11-21

Ticks are among the most important vectors of zoonotic diseases in temperate regions of Europe, with widespread distribution and high densities, posing an important medical risk. Most ticks feed on a variety of progressively larger hosts, with a large number of small mammal species typically harbouring primarily the immature stages. However, there are certain Ixodidae that characteristically attack micromammals also during their adult stage. Rodents are widespread hosts of ticks, important vectors and competent reservoirs of tick-borne pathogens. Micromammal-tick associations have been poorly studied in Romania, and our manuscript shows the results of a large scale study on tick infestation epidemiology in rodents from Romania. Rodents were caught using snap-traps in a variety of habitats in Romania, between May 2010 and November 2011. Ticks were individually collected from these rodents and identified to species and development stage. Frequency, mean intensity, prevalence and its 95% confidence intervals were calculated using the EpiInfo 2000 software. A p value of Romania for the presence of ticks. Each collected tick was identified to species level and the following epidemiological parameters were calculated: prevalence, mean intensity and mean abundance. The total number of ticks collected from rodents was 483, with eight species identified: Ixodes ricinus, I. redikorzevi, I. apronophorus, I. trianguliceps, I. laguri, Dermacentor marginatus, Rhipicephalus sanguineus and Haemaphysalis sulcata. The overall prevalence of tick infestation was 29.55%, with a mean intensity of 3.86 and a mean abundance of 1.14. Only two polyspecific infestations were found: I. ricinus + I. redikorzevi and I. ricinus + D. marginatus. Our study showed a relatively high diversity of ticks parasitizing rodents in Romania. The most common tick in rodents was I. ricinus, followed by I. redikorzevi. Certain rodents seem to host a significantly higher number of tick species than others, the

Rough-legged buzzards, Arctic foxes and red foxes in a tundra ecosystem without rodents.

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Ivan Pokrovsky

Full Text Available Small rodents with multi-annual population cycles strongly influence the dynamics of food webs, and in particular predator-prey interactions, across most of the tundra biome. Rodents are however absent from some arctic islands, and studies on performance of arctic predators under such circumstances may be very instructive since rodent cycles have been predicted to collapse in a warming Arctic. Here we document for the first time how three normally rodent-dependent predator species-rough-legged buzzard, arctic fox and red fox - perform in a low-arctic ecosystem with no rodents. During six years (in 2006-2008 and 2011-2013 we studied diet and breeding performance of these predators in the rodent-free Kolguev Island in Arctic Russia. The rough-legged buzzards, previously known to be a small rodent specialist, have only during the last two decades become established on Kolguev Island. The buzzards successfully breed on the island at stable low density, but with high productivity based on goslings and willow ptarmigan as their main prey - altogether representing a novel ecological situation for this species. Breeding density of arctic fox varied from year to year, but with stable productivity based on mainly geese as prey. The density dynamic of the arctic fox appeared to be correlated with the date of spring arrival of the geese. Red foxes breed regularly on the island but in very low numbers that appear to have been unchanged over a long period - a situation that resemble what has been recently documented from Arctic America. Our study suggests that the three predators found breeding on Kolguev Island possess capacities for shifting to changing circumstances in low-arctic ecosystem as long as other small - medium sized terrestrial herbivores are present in good numbers.

Detection of different states of sleep in the rodents by the means of artificial neural networks

Science.gov (United States)

Musatov, Viacheslav; Dykin, Viacheslav; Pitsik, Elena; Pisarchik, Alexander

2018-04-01

This paper considers the possibility of classification of electroencephalogram (EEG) and electromyogram (EMG) signals corresponding to different phases of sleep and wakefulness of mice by the means of artificial neural networks. A feed-forward artificial neural network based on multilayer perceptron was created and trained on the data of one of the rodents. The trained network was used to read and classify the EEG and EMG data corresponding to different phases of sleep and wakefulness of the same mouse and other mouse. The results show a good recognition quality of all phases for the rodent on which the training was conducted (80-99%) and acceptable recognition quality for the data collected from the same mouse after a stroke.

Melanocortin MC(4) receptor-mediated feeding and grooming in rodents.

Science.gov (United States)

Mul, Joram D; Spruijt, Berry M; Brakkee, Jan H; Adan, Roger A H

2013-11-05

Decades ago it was recognized that the pharmacological profile of melanocortin ligands that stimulated grooming behavior in rats was strikingly similar to that of Xenopus laevis melanophore pigment dispersion. After cloning of the melanocortin MC1 receptor, expressed in melanocytes, and the melanocortin MC4 receptor, expressed mainly in brain, the pharmacological profiles of these receptors appeared to be very similar and it was demonstrated that these receptors mediate melanocortin-induced pigmentation and grooming respectively. Grooming is a low priority behavior that is concerned with care of body surface. Activation of central melanocortin MC4 receptors is also associated with meal termination, and continued postprandial stimulation of melanocortin MC4 receptors may stimulate natural postprandial grooming behavior as part of the behavioral satiety sequence. Indeed, melanocortins fail to suppress food intake or induce grooming behavior in melanocortin MC4 receptor-deficient rats. This review will focus on how melanocortins affect grooming behavior through the melanocortin MC4 receptor, and how melanocortin MC4 receptors mediate feeding behavior. This review also illustrates how melanocortins were the most likely candidates to mediate grooming and feeding based on the natural behaviors they induced. Copyright © 2013 Elsevier B.V. All rights reserved.

Determining the Effect of Early Feeding after Cesarean section Compared with Regular Diet on the Gastrointestinal Function of Women Referred to Tajrish Hospital, Iran

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M Amiri-Siavoshani

2016-10-01

Full Text Available Background & aim: Early feeding after cesarean section can have beneficial effects, however, no sufficient study has been conducted in this area. The aim of this study was to determine the effects of early feeding on the gastrointestinal complications in women after cesarean section and comparing it with a regular diet.   Methods: The present randomized-clinical-trial study was conducted on 160 women who admitted to Shohada hospital and underwent cesarean section in 2011-2012. The inclusion criteria included women with gestational age more than 37 weeks, singleton pregnancy, having at least 8 hours of fasting, and regional anesthesia (spinal cord, respectively. After registration of demographic characteristics and pregnancy, women were randomly divided into two groups: Early feeding (2 hours after completion of the operation, 250 ml filtered juice, tea and biscuits style regime in the next 2 hours and 2 hours after the usual diet and the usual power (8 hours of operation clear liquid diet the day after the usual diet groups. Presence of gastrointestinal symptoms in 2, 4, 8 and 12 hours after surgery, time to the bowel sounds auscultation, passage of flatus and stool were recorded. Data were analyzed by SPSS software version13.The significance level of p-value was considered 0.05.   Conclusion: Early feeding caused the acceleration of gastrointestinal symptoms, earlier bowel sounds auscultation and earlier utilization of gas. It is recommended to investigate the different diets and examined the level of compliance and satisfaction.  

Morphology captures diet and locomotor types in rodents.

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Verde Arregoitia, Luis D; Fisher, Diana O; Schweizer, Manuel

2017-01-01

To understand the functional meaning of morphological features, we need to relate what we know about morphology and ecology in a meaningful, quantitative framework. Closely related species usually share more phenotypic features than distant ones, but close relatives do not necessarily have the same ecologies. Rodents are the most diverse group of living mammals, with impressive ecomorphological diversification. We used museum collections and ecological literature to gather data on morphology, diet and locomotion for 208 species of rodents from different bioregions to investigate how morphological similarity and phylogenetic relatedness are associated with ecology. After considering differences in body size and shared evolutionary history, we find that unrelated species with similar ecologies can be characterized by a well-defined suite of morphological features. Our results validate the hypothesized ecological relevance of the chosen traits. These cranial, dental and external (e.g. ears) characters predicted diet and locomotion and showed consistent differences among species with different feeding and substrate use strategies. We conclude that when ecological characters do not show strong phylogenetic patterns, we cannot simply assume that close relatives are ecologically similar. Museum specimens are valuable records of species' phenotypes and with the characters proposed here, morphology can reflect functional similarity, an important component of community ecology and macroevolution.

Feeding patterns of Culex quinquefasciatus (Diptera: Culicidae) from eastern Santa Catarina state, Brazil.

Science.gov (United States)

Alencar, Jeronimo; Silva, Júlia dos Santos; de Oliveira, Luis Claudio Motta; Marcondes, Carlos Brisola; Morone, Fernanda; Lorosa, Elias Seixas

2012-07-01

Blood-feeding sources of Culex quinquefasciatus Say (Diptera: Culicidae) collected in the eastern region of the Brazilian state of Santa Catarina were analyzed by precipitin technique. One hundred fifty-four female mosquitoes collected by CDC traps in the Navegantes municipality 13-15 February 2005 reacted to one or more of eight antisera, including chicken, dog, goat, sheep, horse, opossum, human and rodent antisera. One hundred thirty-seven specimens (89%) reacted to only one source, and 17 (11%) specimens reacted to two sources. Among the 137 specimens reacting to only one source, reactions to rodent (50.4%), sheep (5.8%), chicken (5.1%), goat (5.1%), dog (2.2%), horse (3.6%), and human (3.6%) antisera were observed. The analyzed species demonstrated a high degree of opportunistic feeding behavior in relation to host preference. Results are compared with results from similar studies, and the low proportion of reactions to human antisera is discussed.

Feeding patterns of mosquitoes (Diptera: Culicidae) in six Brazilian environmental preservation areas.

Science.gov (United States)

dos Santos Silva, Júlia; Alencar, Jeronimo; Costa, Janira Martins; Seixas-Lorosa, Elias; Guimarães, Anthony Érico

2012-12-01

Feeding patterns of mosquitoes in six Brazilian environmental preservation areas were analyzed by the precipitin technique. The mosquito populations were captured using Shannon traps during different time periods. Bird, cow, dog, horse, opossum, human, and rodent antisera diagnostic tests were employed and results were analyzed by calculating the Sørensen similarity index and using the null-model test. Of the 647 analyzed specimens, 443 reacted to the utilized antisera, of which 331 reacted to one blood source, with the most frequent being birds (49.4%); and 112 specimens reacted to two blood sources, with the most frequent combination from birds + rodents (14.3%). The feed profiles demonstrated that Anopheles albitarsis, An. evansae, Aedes fulvus, Psorophora albigenu, Ps. albipes, Ps. ferox, and Mansonia titillans fed predominantly on birds. The similarity index showed that in some localities An. cruzii, Chagasia fajardi, Ae. scapularis, Ae. serratus, Haemagogus leucocelaenus, Ps. albigenu, and Ps. ferox presented similar dietary habits. The null-models test indicated that species from SMSP, INP, CGNP, and THP demonstrated an aggregate pattern, while species from SONP and SBNP showed a random pattern. The mosquitoes fed predominantly on birds, but from an epidemiological standpoint, the eclectic feeding habits were found to be constant among the mosquitoes analyzed. © 2012 The Society for Vector Ecology.

"Got rats?" Global environmental costs of thirst for milk include acute biodiversity impacts linked to dairy feed production.

Science.gov (United States)

Luque-Larena, Juan J; Mougeot, François; Arroyo, Beatriz; Lambin, Xavier

2018-07-01

Rodents damaging alfalfa crops typically destined for export to booming Eastern markets often cause economical losses to farmers, but management interventions attempting to control rodents (i.e., use of rodenticides) are themselves damaging to biodiversity. These damages resonate beyond dairy feed producing regions through animal migration and are an overlooked part of the transferred environmental burden caused by a growing thirst for milk in China and elsewhere. © 2018 John Wiley & Sons Ltd.

21 CFR 1250.96 - Rodent control.

Science.gov (United States)

2010-04-01

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

Feeding livestock food residue and the consequences for the environmental impact of meat

NARCIS (Netherlands)

Elferink, E.V.; Nonhebel, S.; Moll, H.C.

2008-01-01

The environmental impact of meat is high mainly due to the feed required by livestock in combination with the impacts of cultivating, transporting and processing of feed crops such as tapioca and grains. Like regular feed crops, livestock also feed on residue from the food industry, such as pulp,

Feeding Patterns of Mosquitoes (Diptera: Culicidae) in the Atlantic Forest, Rio de Janeiro, Brazil.

Science.gov (United States)

Alencar, Jeronimo; Mello, Cecília Ferreira de; Gil-Santana, Hélcio R; Giupponi, Alessandro Ponce de Leão; Araújo, Andressa Nunes; Lorosa, Elias Seixas; Guimarães, Anthony Érico; Silva, Júlia Dos Santos

2015-09-01

The stomach contents of culicids from the Atlantic Forest in Rio de Janeiro state, Brazil, were analyzed using the precipitin technique to evaluate the feeding patterns of the species. Sampling was performed from February 2012 to December 2013, using CO2-baited Centers for Disease Control and Prevention traps to catch mosquitoes from 15 00 to 07 00 hours. The following antisera were used: bird, rodent, opossum, human, horse, capybara, lizard, and frog. Of the 325 adult bloodfed females caught and analyzed, 273 (84.0%) reacted in the precipitin test. The percentage of specimens with a positive reaction to a single antiserum included bird (39.2%), rodent (22.5%), opossum (13.2%), capybara (6.6%), horse (5.7%), frog (6.2%), human (4.0%), and lizard (2.6%). The specimens that reacted positively against more than one blood source (46) most frequently presented the following combinations: bird + rodent and bird + frog (17.4%), followed by bird + human (13.0%). The predominance of positive results for birds suggested that the avian-rich environment might have influenced the feeding behavior of the culicids. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Virtual reality systems for rodents.

Science.gov (United States)

Thurley, Kay; Ayaz, Aslı

2017-02-01

Over the last decade virtual reality (VR) setups for rodents have been developed and utilized to investigate the neural foundations of behavior. Such VR systems became very popular since they allow the use of state-of-the-art techniques to measure neural activity in behaving rodents that cannot be easily used with classical behavior setups. Here, we provide an overview of rodent VR technologies and review recent results from related research. We discuss commonalities and differences as well as merits and issues of different approaches. A special focus is given to experimental (behavioral) paradigms in use. Finally we comment on possible use cases that may further exploit the potential of VR in rodent research and hence inspire future studies.

Tannin concentration enhances seed caching by scatter-hoarding rodents: An experiment using artificial ‘seeds’

Science.gov (United States)

Wang, Bo; Chen, Jin

2008-11-01

Tannins are very common among plant seeds but their effects on the fate of seeds, for example, via mediation of the feeding preferences of scatter-hoarding rodents, are poorly understood. In this study, we created a series of artificial 'seeds' that only differed in tannin concentration and the type of tannin, and placed them in a pine forest in the Shangri-La Alpine Botanical Garden, Yunnan Province of China. Two rodent species ( Apodemus latronum and A. chevrieri) showed significant preferences for 'seeds' with different tannin concentrations. A significantly higher proportion of seeds with low tannin concentration were consumed in situ compared with seeds with a higher tannin concentration. Meanwhile, the tannin concentration was significantly positively correlated with the proportion of seeds cached. The different types of tannin (hydrolysable tannin vs condensed tannin) did not differ significantly in their effect on the proportion of seeds eaten in situ vs seeds cached. Tannin concentrations had no significant effect on the distance that cached seeds were carried, which suggests that rodents may respond to different seed traits in deciding whether or not to cache seeds and how far they will transport seeds.

Treatment of animal feeds with ionizing radiation. V: Petition and clearance for radicidized poultry feed

International Nuclear Information System (INIS)

Eisenberg, E.; Lapidot, M.

1978-01-01

The experience obtained in Israel regarding procedures for petitioning and granting clearance for irradiated food is briefly reviewed. The Israel Ministry of Health deliberated on the approach to be taken towards irradiated farm animal feed, since feed is normally dealt with under Ministry of Agriculture Plant Protection Division Regulations. A similar situation existed in Canada, where the Feed and Fertilizer Section, Plant Products Division, granted clearance of radicidized poultry feed. However, since the meat of farm animals raised on radicidized feed is to be consumed by humans, and is thus included in the definition of food in the Public Health (Rules as to Food) Ordinance, the Ministry of Health finally decided that it would require a regular petition. The petition to clear irradiated poultry feed is described in detail. It is based on local studies as well as on the detailed material prepared by the Canadian authorities in their petition and the clearance. The petition was submitted in October 1972 and clearance was obtained in July 1973. The implementation of the legislative requirements in the forthcoming pilot scale test, aimed at radicidization of 300 tons of poultry feed, is considered in detail. (author)

A biometric approach to laboratory rodent identification.

Science.gov (United States)

Cameron, Jens; Jacobson, Christina; Nilsson, Kenneth; Rögnvaldsson, Thorsteinn

2007-03-01

Individual identification of laboratory rodents typically involves invasive methods, such as tattoos, ear clips, and implanted transponders. Beyond the ethical dilemmas they may present, these methods may cause pain or distress that confounds research results. The authors describe a prototype device for biometric identification of laboratory rodents that would allow researchers to identify rodents without the complications of other methods. The device, which uses the rodent's ear blood vessel pattern as the identifier, is fast, automatic, noninvasive, and painless.

Rodent Models for Metabolic Syndrome Research

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Sunil K. Panchal

2011-01-01

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

The rodent ultrasound production mechanism.

Science.gov (United States)

Roberts, L H

1975-03-01

Rodents produce two types of sounds, audible and ultrasonic, that differ markedly in physical structure. Studies of sound production in light gases show that whereas the audible cries appear to be produced, as in the case of most other mammals, by vibrating structures in the larynx, the ultrasonic cries are produced by a different mechanism, probably a whistle. 'Bird-call' whistles are shown to have all the properties of rodent ultrasonic cries and to mimic them in almost every detail. Thus it is concluded that rodents have two distinct sound production mechanisms, one for audible cries and one for ultrasonic cries.

UNFOLDED REGULAR AND SEMI-REGULAR POLYHEDRA

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IONIŢĂ Elena

2015-06-01

Full Text Available This paper proposes a presentation unfolding regular and semi-regular polyhedra. Regular polyhedra are convex polyhedra whose faces are regular and equal polygons, with the same number of sides, and whose polyhedral angles are also regular and equal. Semi-regular polyhedra are convex polyhedra with regular polygon faces, several types and equal solid angles of the same type. A net of a polyhedron is a collection of edges in the plane which are the unfolded edges of the solid. Modeling and unfolding Platonic and Arhimediene polyhedra will be using 3dsMAX program. This paper is intended as an example of descriptive geometry applications.

Rodent Habitat on ISS: Advances in Capability for Determining Spaceflight Effects on Mammalian Physiology

Science.gov (United States)

Globus, R. K.; Choi, S.; Gong, C.; Leveson-Gower, D.; Ronca, A.; Taylor, E.; Beegle, J.

2016-01-01

Rodent research is a valuable essential tool for advancing biomedical discoveries in life sciences on Earth and in space. The National Research Counsel's Decadal survey (1) emphasized the importance of expanding NASAs life sciences research to perform long duration, rodent experiments on the International Space Station (ISS). To accomplish this objective, new flight hardware, operations, and science capabilities were developed at NASA ARC to support commercial and government-sponsored research. The flight phases of two separate spaceflight missions (Rodent Research-1 and Rodent Research-2) have been completed and new capabilities are in development. The first flight experiments carrying 20 mice were launched on Sept 21, 2014 in an unmanned Dragon Capsule, SpaceX4; Rodent Research-1 was dedicated to achieving both NASA validation and CASIS science objectives, while Rodent Reesearch-2 extended the period on orbit to 60 days. Groundbased control groups (housed in flight hardware or standard cages) were maintained in environmental chambers at Kennedy Space Center. Crewmembers previously trained in animal handling transferred mice from the Transporter into Habitats under simultaneous veterinary supervision by video streaming and were deemed healthy. Health and behavior of all mice on the ISS was monitored by video feed on a daily basis, and post-flight quantitative analyses of behavior were performed. The 10 mice from RR-1 Validation (16wk old, female C57Bl6/J) ambulated freely and actively throughout the Habitat, relying heavily on their forelimbs for locomotion. The first on-orbit dissections of mice were performed successfully, and high quality RNA (RIN values>9) and liver enzyme activities were obtained, validating the quality of sample recovery. Post-flight sample analysis revealed that body weights of FLT animals did not differ from ground controls (GC) housed in the same hardware, or vivarium controls (VIV) housed in standard cages. Organ weights analyzed post

Wild Rodent Ectoparasites Collected from Northwestern Iran

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Zabihollah Zarei

2017-04-01

Full Text Available Background: Rodents play an important role as reservoir of some pathogens, and the host of some ectoparasites as well. These ectoparasites can transmit rodents’ pathogens to human or animals. The aim of this study was to assess the distribution and infestation load of ectoparasites on rodents in Meshkin-Shahr District, northwestern Iran.Method: Rodents were captured using baited live traps in spring 2014 from Meshkin-Shahr District and were trans­ferred to the laboratory for identification to the species level. Their ectoparasites were collected, mounted and identi­fied.Results: Three rodent species including Meriones persicus (74%, Mus musculus (16.9% and Cricetulus migrato­rius (9% were identified. Among all rodents, 185 specimens (90.69% were infested with a total of 521 ectopara­sites. Overall, 10 arthropods species were collected, including fleas (97.6%, one mite (1.6% and one louse species (0.6% as follows: Xenopsylla nubica, X. astia, X. buxtoni, X. cheopis, Nosopsyllus fasciatus, N. iranus, Cten­ocephalides felis, Ctenophthalmus rettigismiti, Ornithonyssus sp and one species of genus Polyplax. The most prev­alent ectoparasites species was X. nubica (89%.Conclusion: Nearly all rodent species were infested with Xenopsylla species. Monitoring of ectoparasites on infested rodents is very important for awareness and early warning towards control of arthropod-borne diseases.

Health effects of feeding genetically modified (GM) crops to livestock animals: A review.

Science.gov (United States)

de Vos, Clazien J; Swanenburg, Manon

2017-08-31

A large share of genetically modified (GM) crops grown worldwide is processed into livestock feed. Feed safety of GM crops is primarily based on compositional equivalence with near-isogenic cultivars and experimental trials in rodents. However, feeding studies in target animals add to the evaluation of GM crops with respect to animal health. This review aimed to evaluate the possible health effects of feeding GM crops to livestock by reviewing scientific publications on experimental studies in ruminants, pigs, and poultry in which at least one of the following health parameters was investigated: body condition score, organ weight, haematology, serum biochemistry, histopathology, clinical examination, immune response, or gastrointestinal microbiota. In most experiments, either Bt (Bacillus thuringiensis) maize, Roundup Ready (RR) soybean, or both were fed to livestock animals. Significant differences (PGM crops has adverse effects on animal health. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effect of Apple Feeding on Markers of Colon Carcinogenesis

DEFF Research Database (Denmark)

Poulsen, Morten; Mortensen, Alicja; Binderup, Mona-Lise

2011-01-01

Regular consumption of fruits and vegetables is associated with reduced risks of certain cancers and other diseases in observational studies and animal models of human diseases. The aim of the present study was to investigate whether feeding of rats with whole raw apple has potentially chemopreve......Regular consumption of fruits and vegetables is associated with reduced risks of certain cancers and other diseases in observational studies and animal models of human diseases. The aim of the present study was to investigate whether feeding of rats with whole raw apple has potentially...... chemopreventive properties by affecting markers of colon cancer. The end-point was preneoplastic changes in the colon known as aberrant crypt foci (ACF). Rats initiated with the colon carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) were given 0, 5, or 10 g apple/day for 13 wk. The group fed 5 g apple...... but not 10 g had a significantly lower number of ACF (P = 0.009) compared to the initiated control. DNA damage evaluated by the comet assay was significantly increased in leucocytes of DMH-treated animals (P = 0.021). No antigenotoxic effect of apple feeding was apparent in the colon. Apple feeding tended...

Is the expression of autogeny by Culex molestus Forskal (Diptera: Culicidae) influenced by larval nutrition or by adult mating, sugar feeding, or blood feeding?

Science.gov (United States)

Kassim, Nur Faeza A; Webb, Cameron E; Russell, Richard C

2012-06-01

Culex molestus Forskal is suspected to have been introduced into southern Australia during the 1940s. Investigations to determine factors influencing the expression of autogeny, the response of this mosquito to potential blood meals, and the subsequent influence on oviposition were undertaken. Immature mosquitoes raised at five feeding regimes had mortality rates, development rates, wing length, and autogenous egg raft size measured. All surviving female mosquitoes laid autogenous eggs but there was a significant difference between the mean number of eggs per raft. For mosquitoes raised at each of the feeding regimes, there was a significant linear relationship between the number of eggs per autogenous egg raft and wing length. Newly emerged mosquitoes were offered a blood meal (i.e., rodent) daily but no blood feeding occurred until the autogenous egg raft was laid. There was no statistical difference in the rate of autogenous oviposition or post-oviposition blood feeding between control or treatment groups. The results of this study indicate that Cx. molestus is perfectly adapted to subterranean habitats in close association with human habitation, but their preference to delay blood feeding until up to day 8 following emergence may reduce their relative importance as a vector of arboviruses. © 2012 The Society for Vector Ecology.

Effect of high saturated free fatty acids feeding on progression of renal failure in rat model of experimental nephrotoxicity

Directory of Open Access Journals (Sweden)

Zaid O. Ibraheem

2012-02-01

Full Text Available The current study evaluates the impact of high saturated fat feeding in rat model of experimental nephrotoxicity induced by gentamicin. Sprague-Dawley rats weighing 200 g were randomized into four groups; the first one received the standard rodents chow for 8 weeks and was treated as control, the second group (HFDreceived an experimental high fat diet rich in palm kernel oil (40% of Calories as fat for the same period. The third group (HFDG was given 80 mg/kg (body weight/day gentamicin sulphate intraperitoneally during the last 24 days of the feeding period while the fourth group was given gentamicin as above along with the standard rodents chow. Renal function was assessed through measuring serum creatinine, creatinine clearance and absolute and fractional excretion of both sodium and potassium. At the end, rats underwent a surgical procedure for blood pressure measurement. Renal function study showed a stronger nephrotoxicity for HFDG group. Hypertension was observed in HFD group while the pressure declined after gentamicin co-administration. Overall, changing the feeding behavior toward using more SAFFAs for rats injected with gentamicin promotes the progression of renal failure.

Quantitative separation of bone and muscle radioactivity in small rodents using Dermestid beetles

International Nuclear Information System (INIS)

Walburg, H.E.; Eisele, G.R.; Mraz, F.R.

1979-01-01

The use of Dermestid beetles, which feed on dead animals, to separate muscle and bone radioactivity in small rodent carcasses was studied. Eviscerated carcasses of mice injected with 1μCi 95 Nb 48hr before killing were placed in jars with adult beetle larvae. Within 3 weeks the skeletons were completely free of muscle. Losses of radioactivity were acceptably small. The actual muscle activity was measured by counting activity in beetles, larvae and excreta, and compared with estimated values. Dermestid digestion has proved to be effective for small carcasses, where size precludes other methods of separation, and is in current use in studies of tissue localization of radionuclides. (author)

Effluent profile of commercially used low-phosphorus fish feeds

International Nuclear Information System (INIS)

Sugiura, Shozo H.; Marchant, Daniel D.; Kelsey, Kevin; Wiggins, Thomas; Ferraris, Ronaldo P.

2006-01-01

Excess phosphorus (P) in aquaculture feeds contributes to the eutrophication of natural waters. While commercially available low-P (LP) fish feeds have been developed, there is uncertainty about their potential to reduce effluent P while maintaining fish growth relative to regular P (RP) feeds. We therefore simulated commercial aquaculture conditions and fed for 55 days rainbow trout (∼190 kg/raceway, n = 3 raceways/diet) RP (1.4% total P) and LP (1.0%) feeds then determined effluent P levels, fish growth, and feed costs. Excretions of fecal-P and soluble-P, but not particulate-P, in effluents were greater in RP than in LP ponds. Fish growth, bone-P and plasma-P were similar between diets, demonstrating that LP feeds can lower effluent P levels without compromising growth. Costs were $0.97/kg fish production for LP feeds, and $0.74/kg for RP. Because feed is the largest variable cost in commercial aquaculture, the use of LP feeds can significantly increase production costs. - Commercial low-phosphorus fish feeds pollute less but are more costly than standard fish feeds that provide similar fish growth rates

Template based rodent brain extraction and atlas mapping.

Science.gov (United States)

Weimin Huang; Jiaqi Zhang; Zhiping Lin; Su Huang; Yuping Duan; Zhongkang Lu

2016-08-01

Accurate rodent brain extraction is the basic step for many translational studies using MR imaging. This paper presents a template based approach with multi-expert refinement to automatic rodent brain extraction. We first build the brain appearance model based on the learning exemplars. Together with the template matching, we encode the rodent brain position into the search space to reliably locate the rodent brain and estimate the rough segmentation. With the initial mask, a level-set segmentation and a mask-based template learning are implemented further to the brain region. The multi-expert fusion is used to generate a new mask. We finally combine the region growing based on the histogram distribution learning to delineate the final brain mask. A high-resolution rodent atlas is used to illustrate that the segmented low resolution anatomic image can be well mapped to the atlas. Tested on a public data set, all brains are located reliably and we achieve the mean Jaccard similarity score at 94.99% for brain segmentation, which is a statistically significant improvement compared to two other rodent brain extraction methods.

Nocturnal to Diurnal Switches with Spontaneous Suppression of Wheel-Running Behavior in a Subterranean Rodent.

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Patricia Tachinardi

Full Text Available Several rodent species that are diurnal in the field become nocturnal in the lab. It has been suggested that the use of running-wheels in the lab might contribute to this timing switch. This proposition is based on studies that indicate feed-back of vigorous wheel-running on the period and phase of circadian clocks that time daily activity rhythms. Tuco-tucos (Ctenomys aff. knighti are subterranean rodents that are diurnal in the field but are robustly nocturnal in laboratory, with or without access to running wheels. We assessed their energy metabolism by continuously and simultaneously monitoring rates of oxygen consumption, body temperature, general motor and wheel running activity for several days in the presence and absence of wheels. Surprisingly, some individuals spontaneously suppressed running-wheel activity and switched to diurnality in the respirometry chamber, whereas the remaining animals continued to be nocturnal even after wheel removal. This is the first report of timing switches that occur with spontaneous wheel-running suppression and which are not replicated by removal of the wheel.

Nocturnal to Diurnal Switches with Spontaneous Suppression of Wheel-Running Behavior in a Subterranean Rodent

Science.gov (United States)

Tachinardi, Patricia; Tøien, Øivind; Valentinuzzi, Veronica S.; Buck, C. Loren; Oda, Gisele A.

2015-01-01

Several rodent species that are diurnal in the field become nocturnal in the lab. It has been suggested that the use of running-wheels in the lab might contribute to this timing switch. This proposition is based on studies that indicate feed-back of vigorous wheel-running on the period and phase of circadian clocks that time daily activity rhythms. Tuco-tucos (Ctenomys aff. knighti) are subterranean rodents that are diurnal in the field but are robustly nocturnal in laboratory, with or without access to running wheels. We assessed their energy metabolism by continuously and simultaneously monitoring rates of oxygen consumption, body temperature, general motor and wheel running activity for several days in the presence and absence of wheels. Surprisingly, some individuals spontaneously suppressed running-wheel activity and switched to diurnality in the respirometry chamber, whereas the remaining animals continued to be nocturnal even after wheel removal. This is the first report of timing switches that occur with spontaneous wheel-running suppression and which are not replicated by removal of the wheel. PMID:26460828

[Study on feeding behavior patterns of rats on cariogenic diet].

Science.gov (United States)

Sasaki, Y

1989-03-01

The feeding behavior patterns of Jcl:Wistar rats fed on commercial stock diet and cariogenic diet (Diet #2000) were investigated with the newly developed autorecording system. They were caged separately under a regular light-dark cycle (L:D = 12:12). The results and conclusion were as follows. All rats have a circadian feeding rhythm, and 70-85% of feeding frequency were observed during the dark period. The group on the commercial stock diet showed a dual-peak pattern of feeding at 20:30 and 4:00. On the other hand, the cariogenic diet groups showed a more frequent feeding pattern during the dark period. The feeding frequency increased from 1:00 to 3:00 in the high sucrose diet group and more frequent feeding was observed. From these results, it was suggested that dental caries in the rats was caused by not only the local effect of sucrose in the mouth but also by the changing patterns of feeding behavior with cariogenic diet.

Tactile learning in rodents: Neurobiology and neuropharmacology.

Science.gov (United States)

Roohbakhsh, Ali; Shamsizadeh, Ali; Arababadi, Mohammad Kazemi; Ayoobi, Fateme; Fatemi, Iman; Allahtavakoli, Mohammad; Mohammad-Zadeh, Mohammad

2016-02-15

Animal models of learning and memory have been the subject of considerable research. Rodents such as mice and rats are nocturnal animals with poor vision, and their survival depends on their sense of touch. Recent reports have shown that whisker somatosensation is the main channel through which rodents collect and process environmental information. This review describes tactile learning in rodents from a neurobiological and neuropharmacological perspective, and how this is involved in memory-related processes. Copyright © 2016 Elsevier Inc. All rights reserved.

Convergent and Divergent Adaptations of Subterranean Rodents

DEFF Research Database (Denmark)

Fang, Xiaodong

Subterranean rodents comprise approximately 250 species that spend their entire lives in underground, unventilated tunnels, distributed along all continents except Australia and Antarctica. Subterranean rodents escape from predators and extreme climatic fluctuations in their underground habitats,...

[Improving the feed conversion rate in the pig fattening industry by optimising hygienic management].

Science.gov (United States)

Riedl, Antonia M; Völkel, Inger; Schlindwein, Bernhard; Czerny, Claus-Peter

2013-01-01

Considering continuously increasing forage costs, the feed conversion rate has a major impact on the economic efficiency in hog fattening. The influence of hygienic management strategies on animal health and feed efficiency was evaluated by an online-study comprising animal health management data of 202 German pig fatteners. Data analysis included a simple comparison of averages, a linear regression analysis, and a cluster analysis. Due to geographical distribution and size of premises, the random sample was not representative but yielded in significant results. The total impact of hygienic management on feed conversion was calculated to be 23.9 %. Professional performance of rodent control (beta = 0.357; p conversion ranged from Euro 1.15 to and Euro 2.53 per pig. Likewise optimized growth performance as a result of improved hygienic management could partly compensate increasing feed costs. The results of this online-study reveal the need to establish reliable HACCP systems on farm level.

Rodent-borne diseases and their public health importance in Iran.

Directory of Open Access Journals (Sweden)

Mohammad Hasan Rabiee

2018-04-01

Full Text Available Rodents are reservoirs and hosts for several zoonotic diseases such as plague, leptospirosis, and leishmaniasis. Rapid development of industry and agriculture, as well as climate change throughout the globe, has led to change or increase in occurrence of rodent-borne diseases. Considering the distribution of rodents throughout Iran, the aim of this review is to assess the risk of rodent-borne diseases in Iran.We searched Google Scholar, PubMed, Science Direct, Scientific Information Database (SID, and Magiran databases up to September 2016 to obtain articles reporting occurrence of rodent-borne diseases in Iran and extract information from them. Out of 70 known rodent-borne diseases, 34 were reported in Iran: 17 (50% parasitic diseases, 13 (38% bacterial diseases, and 4 (12% viral diseases. Twenty-one out of 34 diseases were reported from both humans and rodents. Among the diseases reported in the rodents of Iran, plague, leishmaniasis, and hymenolepiasis were the most frequent. The most infected rodents were Rattus norvegicus (16 diseases, Mus musculus (14 diseases, Rattus rattus (13 diseases, Meriones persicus (7 diseases, Apodemus spp. (5 diseases, Tatera indica (4 diseases, Meriones libycus (3 diseases, Rhombomys opimus (3 diseases, Cricetulus migratorius (3 diseases, and Nesokia indica (2 diseases.The results of this review indicate the importance of rodent-borne diseases in Iran. Considering notable diversity of rodents and their extensive distribution throughout the country, it is crucial to pay more attention to their role in spreading infectious diseases for better control of the diseases.

Rodent-borne diseases and their public health importance in Iran

Science.gov (United States)

Mahmoudi, Ahmad; Siahsarvie, Roohollah; Kryštufek, Boris; Mostafavi, Ehsan

2018-01-01

Background Rodents are reservoirs and hosts for several zoonotic diseases such as plague, leptospirosis, and leishmaniasis. Rapid development of industry and agriculture, as well as climate change throughout the globe, has led to change or increase in occurrence of rodent-borne diseases. Considering the distribution of rodents throughout Iran, the aim of this review is to assess the risk of rodent-borne diseases in Iran. Methodology/Principal finding We searched Google Scholar, PubMed, Science Direct, Scientific Information Database (SID), and Magiran databases up to September 2016 to obtain articles reporting occurrence of rodent-borne diseases in Iran and extract information from them. Out of 70 known rodent-borne diseases, 34 were reported in Iran: 17 (50%) parasitic diseases, 13 (38%) bacterial diseases, and 4 (12%) viral diseases. Twenty-one out of 34 diseases were reported from both humans and rodents. Among the diseases reported in the rodents of Iran, plague, leishmaniasis, and hymenolepiasis were the most frequent. The most infected rodents were Rattus norvegicus (16 diseases), Mus musculus (14 diseases), Rattus rattus (13 diseases), Meriones persicus (7 diseases), Apodemus spp. (5 diseases), Tatera indica (4 diseases), Meriones libycus (3 diseases), Rhombomys opimus (3 diseases), Cricetulus migratorius (3 diseases), and Nesokia indica (2 diseases). Conclusions/Significance The results of this review indicate the importance of rodent-borne diseases in Iran. Considering notable diversity of rodents and their extensive distribution throughout the country, it is crucial to pay more attention to their role in spreading infectious diseases for better control of the diseases. PMID:29672510

Epidemiology of Leptospira Transmitted by Rodents in Southeast Asia

Science.gov (United States)

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

2014-01-01

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

Ectoparasites of Rodents Captured in Hamedan, Western Iran

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Hamid Zendehfili

2015-10-01

Full Text Available Background: Rodents with a population greater than the entire population of other mammals on earth are the source of economic losses and health conflicts. One of the major health problems with the rodents is their role as reservoir hosts of zoonotic diseases. The aim of this study was to assess the infestation of commensal rodents with ectoparasites in Hamedan City, Western Iran.Methods: The samples were collected by live traps during years 2012–2013. After transferring the samples to the Entomological Laboratory of Hamedan University of Medical Sciences, their ectoparasites were collected andidentified.Results: A total of 171 slides were prepared from 105 captured commensal rodents: Mus musculus, Rattus rattus and R. norvegicus comprising three orders namely Mesostigmata: Hypoaspis (Laelaspis astronomica, Dermanyssius sp, Pachylaelapidae (male. Metastigmata: Rhipicephalus sp and Anoplura: Polyplax spinulosa were recovered in Hamedan City. Seventy (66.6% rodents were found infested with at least one species of ectoparasites.Conclusion: The results of our study indicate that ectoparasites infestation in commensal rodents of Hamedan city is high and more attention by local health authorities is needed to prevent zoonotic diseases.

The Effects of Long-Term Feeding of Rodent Food Bars on Lipid Peroxidation And Antioxidant Enzyme Levels In Fisher Rats

Science.gov (United States)

Ramirez, Joel; Zirkle-Yoshida, M.; Piert, S.; Barrett, J.; Yul, D.; Dalton, B.; Girten, B.

2001-01-01

A specialized rodent food bar diet has been developed and utilized successfully for short-duration shuttle missions. Recent tests conducted in preparation for experiments aboard the International Space Station (ISS) indicated that long-term food bar feeding for three months induced hyperlipidemia in rats. This study examined oxidative stress status in livers of these same animals. Spectrophotometric analysis of 79 Fischer rat livers (40 female and 39 male) for lipid peroxidation (LPO) and superoxide dismutase (SOD) was conducted using Bioxytech LPO-587(TM) assay kit and SOD-525(Tm) assay kit, respectively. The treatment groups consisted of 20 male CHOW and 19 male FOOD BAR rats and 20 female CHOW and 20 female FOOD BAR rats. Statistical analysis to compare differences between groups was performed by standard analysis of variance procedures. The male FOOD BAR group LPO mean (3.6 +/- 0.2 mmol/g) was significantly (p less than or equal to 0.05) greater than that of the male CHOW group (2.1 +/-0.1 mmol/g). Moreover the female FOOD BAR group LPO mean (2.9 +/-0.1 mmol/g) was also significantly greater than the female CHOW group mean (2.2 +/-0.1 mmol/g). The mean values for SOD in both male and female groups showed no significant differences between CHOW and FOOD BAR groups. These results show that LPO levels were significantly higher in both the male and female FOOD BAR groups compared to CHOW groups and that there was no concomitant increase in SOD levels across the group. In addition, males showed a greater difference than females in terms of LPO levels. These findings suggest a need for further investigation into the use of the current food bar formulation for long-term experiments such as those planned for the ISS.

A Community-Based Surveillance on Determinants of Rodent Infestation

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Hsiu-Hua Pai

2003-01-01

Full Text Available Rodent infestation is an important factor in the transmission of infectious diseases of public health importance. From October to November 1998, surveillance stations were established in 110 boroughs of Kaohsiung City in southern Taiwan. Boroughs were chosen by random sampling 10 boroughs from each of 11 districts (464 boroughs in the city. The extent of rodent infestation was determined by cage trapping. The possibility of applying a community-based control program was evaluated by investigating associated demographic and environmental factors as well as related knowledge, attitudes, and behaviors. A total of 90 rodents were trapped in 41% of the 110 boroughs. Using univariate analyses, 17 factors were significantly associated with rodent infestation. A lack of knowledge that rodent control relies on community cooperation was the most important factor among the seven variables associated with the extent of rodent infestation (OR 3.1 by logistic multiple regression. This revealed the importance of community cooperation in controlling rodent infestation. Moreover, improvement of environmental hygiene associated with garbage problems, such as cleanliness of storage rooms and closets, and the hygiene of empty space and resource recycling stations should not be ignored.

Early discharge with tube feeding at home for preterm infants is associated with longer duration of breast feeding.

Science.gov (United States)

Meerlo-Habing, Z E; Kosters-Boes, E A; Klip, H; Brand, P L P

2009-07-01

Mothers of preterm infants are more likely to discontinue breast feeding early than mothers of term infants. We evaluated the effect of early discharge with tube feeding of preterm infants under close supervision by paediatric nurse specialists on the duration of breast feeding. Case-control study. Medium/high-care neonatal unit of a large district general hospital. Preterm infants (paediatric nurse specialists or regular follow-up of preterm infants discharged with oral feeding. Duration of breast feeding assessed by telephone interview 6 months after birth. There were 50 preterm infants in the early discharge group and 78 in the control group. Mothers in the early discharge group continued to breast feed longer than mothers in the control group (log rank test, p = 0.028). Four months after discharge, 63% of preterm infants in the control group were fed formula compared to 36% in the early discharge group (95% CI for difference 9% to 43%, p = 0.04). The relative risk of breast feeding cessation 6 months after birth in the early discharge group compared to the control group was 0.63 (95% CI 0.41 to 0.96). After adjustment for smoking, gestational age and birth weight, this relative risk was 0.67 (95% CI 0.43 to 1.05). Close supervision and follow-up by paediatric nurse specialists of preterm infants discharged early with tube feeding appears to increase duration of breast feeding. A randomised controlled trial to confirm these findings is warranted.

Maternal feeding controls fetal biological clock.

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Hidenobu Ohta

Full Text Available BACKGROUND: It is widely accepted that circadian physiological rhythms of the fetus are affected by oscillators in the maternal brain that are coupled to the environmental light-dark (LD cycle. METHODOLOGY/PRINCIPAL FINDINGS: To study the link between fetal and maternal biological clocks, we investigated the effects of cycles of maternal food availability on the rhythms of Per1 gene expression in the fetal suprachiasmatic nucleus (SCN and liver using a transgenic rat model whose tissues express luciferase in vitro. Although the maternal SCN remained phase-locked to the LD cycle, maternal restricted feeding phase-advanced the fetal SCN and liver by 5 and 7 hours respectively within the 22-day pregnancy. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that maternal feeding entrains the fetal SCN and liver independently of both the maternal SCN and the LD cycle. This indicates that maternal-feeding signals can be more influential for the fetal SCN and particular organ oscillators than hormonal signals controlled by the maternal SCN, suggesting the importance of a regular maternal feeding schedule for appropriate fetal molecular clockwork during pregnancy.

Effects of lactoferrin feeding on growth, feed intake and health of calves.

Science.gov (United States)

Prenner, Maria L; Prgomet, Christian; Sauerwein, Helga; Pfaffl, Michael W; Broz, Jiri; Schwarz, Frieder J

2007-02-01

Lactoferrin (LF) exhibits a broad spectrum of anti-microbial properties and may have regulatory functions in the immune system. In the present study, 40 calves (20 males, 20 females) were used to examine the effects of supplemental bovine LF added to colostrum and milk replacer (at 0.16%) on health, weight development and feed intake during a 70-day experimental period. The calves were allocated to a treatment group (n = 20) and a control group (n = 20); the groups were balanced in terms of sex, live weight and date of birth. Body weight and feed intake were measured at regular intervals. Blood and colostrum samples were collected to determine the content of IgG. In addition, colostrum and milk replacer samples were analysed for their LF concentrations. Significantly higher IgG values were observed in the LF treated than in the control group during the entire feeding experiment from week 2 to week 6. Calves receiving LF had less days of disease with less serious cases of diarrhoea than the control group. Body weight and feed intake were not significantly different between the treatments; in male calves LF-treated animals tended towards higher weight gains. This study indicates that LF is advantageous for health and may therefore be a beneficial supplement in the diets for neonatal calves.

Effects of rodent species, seed species, and predator cues on seed fate

Science.gov (United States)

Sivy, Kelly J.; Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan

2011-07-01

Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord's kangaroo rat ( Dipodomys ordii) and the Great Basin pocket mouse ( Perognathus parvus). The indirect cue was shrub cover, a feature of the environment. Direct cues, presented individually, were (1) control, (2) coyote ( Canis latrans) vocalization, (3) coyote scent, (4) red fox ( Vulpes vulpes) scent, or (5) short-eared owl ( Asio flammeus) vocalization. We offered seeds of three sizes: two native grasses, Indian ricegrass ( Achnatherum hymenoides) and bluebunch wheatgrass ( Pseudoroegneria spicata), and the non-native cereal rye ( Secale cereale), each in separate trays. Kangaroo rats preferentially harvested Indian ricegrass while pocket mice predominately harvested Indian ricegrass and cereal rye. Pocket mice were more likely to scatter hoard preferred seeds, whereas kangaroo rats mostly consumed and/or larder hoarded preferred seeds. No predator cue significantly affected seed preferences. However, both species altered seed handling behavior in response to direct predation cues by leaving more seeds available in the seed pool, though they responded to different predator cues. If these results translate to natural dynamics on the landscape, the two rodents are expected to have different impacts on seed survival and plant recruitment via their different seed selection and seed handling behaviors.

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

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Kanokwan Suwannarong

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

Dietary patterns of two herbivorous rodents: and Parotomys brantsii ...

African Journals Online (AJOL)

Frequency of occurrence of plant species in the diets were compared with availability of the plants in the rodents' habitats. Both rodents are generalist herbivores, eating plants species in proportion to the availability in their habitats. Dietary patterns, diversity of diet and degree of overlap between rodent's diets are a function ...

Thermoregulation of the subterranean rodent genus Bathyergus ...

African Journals Online (AJOL)

The thermoregulation of the largest subterranean rodent, genus Bathyergus, comprising two species, B. suillus and B. janetta,occurring in mesic and semiarid habitats respectively, was investigated and compared with that of other subterranean rodents. Both species display low resting metabolic rates and low body ...

A Field Study of Plague and Tularemia in Rodents, Western Iran.

Science.gov (United States)

Mostafavi, Ehsan; Shahraki, Abdolrazagh Hashemi; Japoni-Nejad, Alireza; Esmaeili, Saber; Darvish, Jamshid; Sedaghat, Mohammad Mehdi; Mohammadi, Ali; Mohammadi, Zeinolabedin; Mahmoudi, Ahmad; Pourhossein, Behzad; Ghasemi, Ahmad; Gyuranecz, Miklós; Carniel, Elisabeth

2017-04-01

Kurdistan Province in Iran is a historical focus for plague and tularemia. This study aimed at assessing the current status of these two foci by studying their rodent reservoirs. Rodents were trapped and their ectoparasites were collected. The genus and species of both rodents and ectoparasites were determined. Serological analyses of rodent blood samples were done by enzyme-linked immunosorbent assay for plague and by standard tube agglutination assay for tularemia. Rodent spleen samples were subjected to bacterial culture, microscopic examination, and real-time PCR to search for active plague or tularemia infection. During this study, 245 rodents were trapped, of which the most abundant genera were Apodemus (40%), Mus (24.49%), and Meriones (12.65%). One hundred fifty-three fleas, 37 mites, and 54 ticks were collected on these rodents. The results of all direct and indirect tests were negative for plague. Serological tests were positive for tularemia in 4.8% of trapped rodents. This study is the first report on the presence of tularemia infection in rodents in Western Iran. Since Meriones persicus is a known reservoir for plague and tularemia, and this rodent carried plague and tularemia vectors in Marivan and Sanandaj districts, there is a real potential for the occurrence of these two diseases in this region.

Coxiella burnetii and Rickettsia conorii: Two zoonotic pathogens in peridomestic rodents and their ectoparasites in Nigeria.

Science.gov (United States)

Kamani, Joshua; Baneth, Gad; Gutiérrez, Ricardo; Nachum-Biala, Yaarit; Mumcuoglu, Kosta Y; Harrus, Shimon

2018-01-01

Rodents are hosts of numerous pathogenic agents of public health importance globally. Their ability to harbor these pathogens without showing overt clinical signs of disease has epidemiologic consequences. In some rural settings in Nigeria, humans and rodents do not only share feeds and abode, but the latter may end up on the table of the former as a source of protein, thereby increasing the risks of disease transmission. Molecular assays were used to detect and characterize two agents of zoonotic importance, Coxiella burnetii and Rickettsia spp. in 194 peridomestic rodents captured in a peri-urban setting in Nigeria, and 32 pools of ectoparasites removed from them, to determine their possible role in the epidemiology of these diseases in this country. Targeting and characterizing the insertion sequence IS1111, C. burnetii DNA was detected in 4 out of 194 (2.1%) rodents comprising 3 out of 121 (2.5%) Rattus norvegicus and 1 out of 48 (2.1%) Rattus rattus screened in this study. Rickettsia spp. DNA was detected in two Rhipicephalus sanginueus sensu lato pools (i.e. RT1 and RT4) using the citrate synthase (gltA) gene and further characterized by amplification and sequence analysis of six genes to determine their identity. The RT1 sample consistently gave 98-100% identity to Rickettsia conorii str. Malish 7 for the various genes and loci studied. However, the identity of RT4 could not be definitively determined due to variable identities to different Rickettsia spp. according to the gene or loci under consideration. Further isolation study to determine if the RT4 characterized is a new variant or a mixture of sequences of different rickettsiae within the pool will be worthwhile. Copyright © 2017 Elsevier GmbH. All rights reserved.

Landscape epidemiology in urban environments: The example of rodent-borne Trypanosoma in Niamey, Niger.

Science.gov (United States)

Rossi, Jean-Pierre; Kadaouré, Ibrahima; Godefroid, Martin; Dobigny, Gauthier

2017-10-05

Trypanosomes are protozoan parasites found worldwide, infecting humans and animals. In the past decade, the number of reports on atypical human cases due to Trypanosoma lewisi or T. lewisi-like has increased urging to investigate the multiple factors driving the disease dynamics, particularly in cities where rodents and humans co-exist at high densities. In the present survey, we used a species distribution model, Maxent, to assess the spatial pattern of Trypanosoma-positive rodents in the city of Niamey. The explanatory variables were landscape metrics describing urban landscape composition and physiognomy computed from 8 land-cover classes. We computed the metrics around each data location using a set of circular buffers of increasing radii (20m, 40m, 60m, 80m and 100m). For each spatial resolution, we determined the optimal combination of feature class and regularization multipliers by fitting Maxent with the full dataset. Since our dataset was small (114 occurrences) we expected an important uncertainty associated to data partitioning into calibration and evaluation datasets. We thus performed 350 independent model runs with a training dataset representing a random subset of 80% of the occurrences and the optimal Maxent parameters. Each model yielded a map of habitat suitability over Niamey, which was transformed into a binary map implementing a threshold maximizing the sensitivity and the specificity. The resulting binary maps were combined to display the proportion of models that indicated a good environmental suitability for Trypanosoma-positive rodents. Maxent performed better with landscape metrics derived from buffers of 80m. Habitat suitability for Trypanosoma-positive rodents exhibited large patches linked to urban features such as patch richness and the proportion of landscape covered by concrete or tarred areas. Such inferences could be helpful in assessing areas at risk, setting of monitoring programs, public and medical staff awareness or even

Diverse Regular Employees and Non-regular Employment (Japanese)

OpenAIRE

MORISHIMA Motohiro

2011-01-01

Currently there are high expectations for the introduction of policies related to diverse regular employees. These policies are a response to the problem of disparities between regular and non-regular employees (part-time, temporary, contract and other non-regular employees) and will make it more likely that workers can balance work and their private lives while companies benefit from the advantages of regular employment. In this paper, I look at two issues that underlie this discussion. The ...

Uus Multiphonic Rodent

Index Scriptorium Estoniae

2009-01-01

Tartus tegutsenud eksperimentaal-rock-duo Opium Flirt Eestisse jäänud liige Erki Hõbe (paarimees Ervin Trofimov tegutseb Ungaris) annab välja oma teise sooloalbumi nime all Multiphonic Rodent, heliplaadi "Astral Dance" esitluskontsert toimub 5. veebruaril Tallinnas baaris Juuksur

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

Science.gov (United States)

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

2003-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

Odor supported place cell model and goal navigation in rodents

DEFF Research Database (Denmark)

Kulvicius, Tomas; Tamosiunaite, Minija; Ainge, James

2008-01-01

Experiments with rodents demonstrate that visual cues play an important role in the control of hippocampal place cells and spatial navigation. Nevertheless, rats may also rely on auditory, olfactory and somatosensory stimuli for orientation. It is also known that rats can track odors or self......-generated scent marks to find a food source. Here we model odor supported place cells by using a simple feed-forward network and analyze the impact of olfactory cues on place cell formation and spatial navigation. The obtained place cells are used to solve a goal navigation task by a novel mechanism based on self......-marking by odor patches combined with a Q-learning algorithm. We also analyze the impact of place cell remapping on goal directed behavior when switching between two environments. We emphasize the importance of olfactory cues in place cell formation and show that the utility of environmental and self...

Rodent management: the man/environment interface

International Nuclear Information System (INIS)

Jackson, W.B.

1978-01-01

Rodents which interact with man generally are regarded as undesirable. Attempts at eliminating such rodents by increasing predation (including traps, microbiological agents, toxicants) have been relatively unsuccessful. Management by environmental manipulation must be basic. This then can be supplemented with predation at critical points where public health, use practices, or imperfections in the system demand. Society mores, practices, and economic considerations also have significant impact on the management system

A vapourized Δ(9)-tetrahydrocannabinol (Δ(9)-THC) delivery system part II: comparison of behavioural effects of pulmonary versus parenteral cannabinoid exposure in rodents.

Science.gov (United States)

Manwell, Laurie A; Ford, Brittany; Matthews, Brittany A; Heipel, Heather; Mallet, Paul E

2014-01-01

Studies of the rewarding and addictive properties of cannabinoids using rodents as animal models of human behaviour often fail to replicate findings from human studies. Animal studies typically employ parenteral routes of administration, whereas humans typically smoke cannabis, thus discrepancies may be related to different pharmacokinetics of parenteral and pulmonary routes of administration. Accordingly, a novel delivery system of vapourized Δ(9)-tetrahydrocannabinol (Δ(9)-THC) was developed and assessed for its pharmacokinetic, pharmacodynamic, and behavioural effects in rodents. A commercially available vapourizer was used to assess the effects of pulmonary (vapourized) administration of Δ(9)-THC and directly compared to parenteral (intraperitoneal, IP) administration of Δ(9)-THC. Sprague-Dawley rats were exposed to pure Δ(9)-THC vapour (1, 2, 5, 10, and 20mg/pad), using a Volcano® vapourizing device (Storz and Bickel, Germany) or IP-administered Δ(9)-THC (0.1, 0.3, 0.5, 1.0mg/kg), and drug effects on locomotor activity, food and water consumption, and cross-sensitization to morphine (5mg/kg) were measured. Vapourized Δ(9)-THC significantly increased feeding during the first hour following exposure, whereas IP-administered Δ(9)-THC failed to produce a reliable increase in feeding at all doses tested. Acute administration of 10mg of vapourized Δ(9)-THC induced a short-lasting stimulation in locomotor activity compared to control in the first of four hours of testing over 7days of repeated exposure; this chronic exposure to 10mg of vapourized Δ(9)-THC did not induce behavioural sensitization to morphine. These results suggest vapourized Δ(9)-THC administration produces behavioural effects qualitatively different from those induced by IP administration in rodents. Furthermore, vapourized Δ(9)-THC delivery in rodents may produce behavioural effects more comparable to those observed in humans. We conclude that some of the conflicting findings in animal

Can a native rodent species limit the invasive potential of a non-native rodent species in tropical agroforest habitats?

Science.gov (United States)

Stuart, Alexander M; Prescott, Colin V; Singleton, Grant R

2016-06-01

Little is known about native and non-native rodent species interactions in complex tropical agroecosystems. We hypothesised that the native non-pest rodent Rattus everetti may be competitively dominant over the invasive pest rodent Rattus tanezumi within agroforests. We tested this experimentally by using pulse removal for three consecutive months to reduce populations of R. everetti in agroforest habitat, and assessed over 6 months the response of R. tanezumi and other rodent species. Following removal, R. everetti individuals rapidly immigrated into removal sites. At the end of the study period, R. tanezumi were larger and there was a significant shift in their microhabitat use with respect to the use of ground vegetation cover following the perturbation of R. everetti. Irrespective of treatment, R. tanezumi selected microhabitat with less tree canopy cover, indicative of severely disturbed habitat, whereas R. everetti selected microhabitat with a dense canopy. Our results suggest that sustained habitat disturbance in agroforests favours R. tanezumi, while the regeneration of agroforests towards a more natural state would favour native species and may reduce pest pressure in adjacent crops. In addition, the rapid recolonisation of R. everetti suggests this species would be able to recover from non-target impacts of short-term rodent pest control. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Testing the limits of Rodent Sperm Analysis: azoospermia in an otherwise healthy wild rodent population.

Science.gov (United States)

Tannenbaum, Lawrence V; Thran, Brandolyn H; Willams, Keith J

2009-01-01

By comparing the sperm parameters of small rodents trapped at contaminated terrestrial sites and nearby habitat-matched noncontaminated locations, the patent-pending Rodent Sperm Analysis (RSA) method provides a direct health status appraisal for the maximally chemical-exposed mammalian ecological receptor in the wild. RSA outcomes have consistently allowed for as definitive determinations of receptor health as are possible at the present time, thereby streamlining the ecological risk assessment (ERA) process. Here, we describe the unanticipated discovery, at a contaminated US EPA Superfund National Priorities List site, of a population of Hispid cotton rats (Sigmodon hispidus), with a high percentage of adult males lacking sperm entirely (azoospermia). In light of the RSA method's role in streamlining ERAs and in bringing contaminated Superfund-type site investigations to closure, we consider the consequences of the discovery. The two matters specifically discussed are (1) the computation of a population's average sperm count where azoospermia is present and (2) the merits of the RSA method and its sperm parameter thresholds-for-effect when azoospermia is masked in an otherwise apparently healthy rodent population.

Three months of high-fructose feeding fails to induce excessive weight gain or leptin resistance in mice.

Directory of Open Access Journals (Sweden)

Erik J Tillman

Full Text Available High-fructose diets have been implicated in obesity via impairment of leptin signaling in humans and rodents. We investigated whether fructose-induced leptin resistance in mice could be used to study the metabolic consequences of fructose consumption in humans, particularly in children and adolescents. Male C57Bl/6 mice were weaned to a randomly assigned diet: high fructose, high sucrose, high fat, or control (sugar-free, low-fat. Mice were maintained on their diets for at least 14 weeks. While fructose-fed mice regularly consumed more kcal and expended more energy, there was no difference in body weight compared to control by the end of the study. Additionally, after 14 weeks, both fructose-fed and control mice displayed similar leptin sensitivity. Fructose-feeding also did not change circulating glucose, triglycerides, or free fatty acids. Though fructose has been linked to obesity in several animal models, our data fail to support a role for fructose intake through food lasting 3 months in altering of body weight and leptin signaling in mice. The lack of impact of fructose in the food of growing mice on either body weight or leptin sensitivity over this time frame was surprising, and important information for researchers interested in fructose and body weight regulation.

Forecasting rodent outbreaks in Africa

DEFF Research Database (Denmark)

Leirs, Herwig; Verhagen, Ron; Verheyen, Walter

1996-01-01

1. Rainfall data were collated for years preceding historical outbreaks of Mastomys rats in East Africa in order to test the hypothesis that such outbreaks occur after long dry periods. 2. Rodent outbreaks were generally not preceded by long dry periods. 3. Population dynamics of Mastomys...... natalensis rats in Tanzania are significantly affected by the distribution of rainfall during the rainy season. 4. All previous rodent outbreaks in Tanzania were preceded by abundant rainfall early in the rainy season, i.e, towards the end of the year. 5. A flow chart is constructed to assess the likelihood...

Old World hantaviruses in rodents in New Orleans, Louisiana.

Science.gov (United States)

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

2014-05-01

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

Regularity on absorption and accumulation of 90Sr in yellow-feather broiler (Hypeco)

International Nuclear Information System (INIS)

Xu Shiming; Hou Lanxin; Zhao Wenhu; Li Xia; Yang Zhongyuan

1996-02-01

The feeding experiment was carried for yellow-feather broiler (Hypeco) with 90 Sr[NO 3 ] 2 having of 1.85 x 10 2 ∼1.85 x 10 5 Bq/chicken to observe the regular pattern of absorption and accumulation of 90 Sr in its organs and tissues. The absorption rate of 90 Sr by oral feeding is very low. The most of 90 Sr is drained away by daily excreta from the body. The half-time of its feeding is within 24 hours. The more 90 Sr is fed, the more 90 Sr is absorbed, however, the uptake rate of 90 Sr is decreasing. The affinity of 90 Sr for bone is very strong and the partition ratio is about 90%∼99%. The absorption coefficient of 90 Sr in organs and tissues of broiler is presented. (2 refs., 9 tabs.)

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

Science.gov (United States)

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

2015-04-01

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

Coordinate-invariant regularization

International Nuclear Information System (INIS)

Halpern, M.B.

1987-01-01

A general phase-space framework for coordinate-invariant regularization is given. The development is geometric, with all regularization contained in regularized DeWitt Superstructures on field deformations. Parallel development of invariant coordinate-space regularization is obtained by regularized functional integration of the momenta. As representative examples of the general formulation, the regularized general non-linear sigma model and regularized quantum gravity are discussed. copyright 1987 Academic Press, Inc

Diet of a sigmodontine rodent assemblage in a Peruvian montane forest.

Science.gov (United States)

Sahley, Catherine Teresa; Cervantes, Klauss; Pacheco, Victor; Salas, Edith; Paredes, Diego; Alonso, Alfonso

2015-09-29

Knowledge of feeding habits of small rodents is necessary for understanding food webs, trophic structure, and plant-animal interactions in Neotropical forests. Despite several studies that have investigated community structure and feeding behavior of rodents, large gaps remain in our understanding of their guild occupancy. Our objective was to investigate the diets of 7 species of small (de los hábitos alimenticios de roedores pequeños es necesario para comprender cadenas alimenticias, estructura trófica, e interacciones planta-animal en los bosques neotropicales. A pesar de que numerosos estudios han investigado la estructura de comunidades y el comportamiento de forrajeo en roedores, aún existen grandes vacíos en nuestra comprensión de sus gremios tróficos. Nuestro objetivo fue investigar las dietas de siete especies de pequeños (de roedores capturados entre el 2009 y el 2012. Datos de frecuencia para cuatro categorías de dieta indicaron que las siete especies de roedores consumieron cuatro categorías de dieta: artrópodos (88%), pedazos de hojas y fibras de plantas (61%), semillas intactas (con o sin pulpa de frutos; 50%), y esporas de micorrizas (45%). Omnivoría fue la estrategia utilizada por todas las especies, aunque el análisis con tablas de contingencia reveló diferencias significativas entre y dentro de especies en categorías de dieta. El análisis de agrupación presentó 2 grupos principales: el grupo Thomasomys spp. y Calomys sorellus , que incluye una gran proporción de semillas intactas, y partes de plantas en las muestras fecales y el grupo que incluye los géneros Akodon , Microryzomys y Oligoryzomys , el cual incluyó una proporción mayor de artrópodos en sus muestras fecales, pero con niveles altos de semillas intactas. Semillas intactas de al menos 17 especies de plantas (9 familias) fueron encontradas en las muestras fecales. Concluimos que este ensamble de roedores sigmodontinos es omnívoro y que probablemente las especies

Neurobiology of rodent self-grooming and its value for translational neuroscience.

Science.gov (United States)

Kalueff, Allan V; Stewart, Adam Michael; Song, Cai; Berridge, Kent C; Graybiel, Ann M; Fentress, John C

2016-01-01

Self-grooming is a complex innate behaviour with an evolutionarily conserved sequencing pattern and is one of the most frequently performed behavioural activities in rodents. In this Review, we discuss the neurobiology of rodent self-grooming, and we highlight studies of rodent models of neuropsychiatric disorders--including models of autism spectrum disorder and obsessive compulsive disorder--that have assessed self-grooming phenotypes. We suggest that rodent self-grooming may be a useful measure of repetitive behaviour in such models, and therefore of value to translational psychiatry. Assessment of rodent self-grooming may also be useful for understanding the neural circuits that are involved in complex sequential patterns of action.

Multiple Co-infections of Rodents with Hantaviruses, Leptospira, and Babesia in Croatia

Science.gov (United States)

Turk, Nenad; Korva, Miša; Margaletić, Josip; Beck, Relja; Vucelja, Marko; Habuš, Josipa; Svoboda, Petra; Županc, Tatjana Avšič; Henttonen, Heikki; Markotić, Alemka

2012-01-01

Abstract Hantaviruses, Leptospira spp., and Babesia spp. are rodent-borne pathogens present worldwide. We studied multiple co-infections of small rodents in Croatia with all three pathogens. Twenty-eight Apodemus flavicollis and 16 Myodes glareolus were tested for the presence of hantavirus RNA by real-time RT-PCR, Leptospira strains by renoculture method and Babesia DNA by PCR. Anti-hantavirus antibodies and anti-Leptospira antibodies were detected by serological methods. Very high infection rates with each pathogen were found in A. flavicollis: 20 of 28 rodents (71%) were infected with Dobrava virus, 13 rodents (46%) were infected with Leptospira, and 5 rodents (18%) were infected with Babesia. Multiple co-infections with all three pathogens were found in 3 of 28 (11%) A. flavicollis animals, suggesting that the same rodent host can be infected with several pathogens at the same time. Dual infections with both hantaviruses and Leptospira were found in 7 of 44 rodents (16%), with hantaviruses and Babesia in 2 rodents (5%), and double infection with both Leptospira and Babesia were found in 1 rodent (2%). Since hantaviruses, Leptospira, and Babesia have similar geographical distributions, it is to be expected that in other parts of the world multiple co-infections, representing a serious threat to public health, can be found. PMID:22217170

Feed- and feed additives-related aspects of gut health and development in weanling pigs.

Science.gov (United States)

Pluske, John R

2013-01-07

The development of new/different management and feeding strategies to stimulate gut development and health in newly-weaned pigs, in order to improve growth performance while minimizing the use of antimicrobial compounds such as antibiotic growth promotants (AGP) and heavy mineral compounds, is essential for the long-term sustainability of the pig industry. Factors including the sub-optimal intake of nutrients and energy, inappropriate microbiota biomass and (or) balance, immature and compromised immune function, and psychosomatic factors caused by weaning can compromise both the efficiency of digestion and absorption and intestinal barrier function through mucosal damage and alteration of tight junction integrity. As a consequence, pigs at weaning are highly susceptible to pathogenic enteric conditions such as post-weaning diarrhea that may be caused by serotypes of enterotoxigenic Escherichia coli. Many dietary components, e.g., protein, fiber, feed additives and minerals, are known to influence microbial growth in the gastrointestinal tract that in turn can impact upon pig growth and health, although the relationships between these are sometimes not necessarily apparent or obvious. In a world climate of increased scrutiny over the use of antibiotics per se in pig production, certain feed additives are seen as alternatives/replacements to antibiotics, and have evolved in some cases to have important roles in everyday commercial pig nutrition. Nevertheless and in general, there remains inconsistency and variability in the efficacy of some feed additives and in cases of severe disease outbreaks, for example, therapeutic antibiotics and/or heavy minerals such as zinc oxide (ZnO) are generally relied upon. If feed ingredients and (or) feed additives are to be used with greater regularity and reliability, then it is necessary to better understand the mechanisms whereby antibiotics and minerals such as ZnO influence animal physiology, in conjunction with the use of

Arctic Small Rodents Have Diverse Diets and Flexible Food Selection.

Directory of Open Access Journals (Sweden)

Eeva M Soininen

Full Text Available The ecology of small rodent food selection is poorly understood, as mammalian herbivore food selection theory has mainly been developed by studying ungulates. Especially, the effect of food availability on food selection in natural habitats where a range of food items are available is unknown. We studied diets and selectivity of grey-sided voles (Myodes rufocanus and tundra voles (Microtus oeconomus, key herbivores in European tundra ecosystems, using DNA metabarcoding, a novel method enabling taxonomically detailed diet studies. In order to cover the range of food availabilities present in the wild, we employed a large-scale study design for sampling data on food availability and vole diets. Both vole species had ingested a range of plant species and selected particularly forbs and grasses. Grey-sided voles also selected ericoid shrubs and tundra voles willows. Availability of a food item rarely affected its utilization directly, although seasonal changes of diets and selection suggest that these are positively correlated with availability. Moreover, diets and selectivity were affected by availability of alternative food items. These results show that the focal sub-arctic voles have diverse diets and flexible food preferences and rarely compensate low availability of a food item with increased searching effort. Diet diversity itself is likely to be an important trait and has previously been underrated owing to methodological constraints. We suggest that the roles of alternative food item availability and search time limitations for small rodent feeding ecology should be investigated.Annotated Checklist of the Panarctic Flora (PAF, Vascular plants. Available at: http://nhm2.uio.no/paf/, accessed 15.6.2012.

Selection of regularization parameter for l1-regularized damage detection

Science.gov (United States)

Hou, Rongrong; Xia, Yong; Bao, Yuequan; Zhou, Xiaoqing

2018-06-01

The l1 regularization technique has been developed for structural health monitoring and damage detection through employing the sparsity condition of structural damage. The regularization parameter, which controls the trade-off between data fidelity and solution size of the regularization problem, exerts a crucial effect on the solution. However, the l1 regularization problem has no closed-form solution, and the regularization parameter is usually selected by experience. This study proposes two strategies of selecting the regularization parameter for the l1-regularized damage detection problem. The first method utilizes the residual and solution norms of the optimization problem and ensures that they are both small. The other method is based on the discrepancy principle, which requires that the variance of the discrepancy between the calculated and measured responses is close to the variance of the measurement noise. The two methods are applied to a cantilever beam and a three-story frame. A range of the regularization parameter, rather than one single value, can be determined. When the regularization parameter in this range is selected, the damage can be accurately identified even for multiple damage scenarios. This range also indicates the sensitivity degree of the damage identification problem to the regularization parameter.

Leptospira and rodents in Cambodia : environmental determinants of infection

OpenAIRE

Ivanova, S.; Herbreteau, Vincent; Blasdell, K.; Chaval, Y.; Buchy, P.; Guillard, B.; Morand, S.

2012-01-01

We investigated infection of rodents and shrews by Leptospira spp. in two localities of Cambodia (Veal Renh, Kaev Seima) and in four types of habitat (forests, non-flooded lands, lowland rain-fed paddy fields, houses) during the wet and the dry seasons. Habitat preference was common, and rodent and shrew species were found only in houses or in rain-fed paddy fields or in forests. Among 649 small mammals trapped belonging to 12 rodent species and 1 shrew species, 71 of 642 animals tested were ...

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

Science.gov (United States)

Gyuranecz, Miklós

2015-01-01

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

Household factors influencing participation in bird feeding activity

DEFF Research Database (Denmark)

Davies, Zoe G.; Fuller, Richard A.; Dallimer, Martin

2012-01-01

whether and how the socioeconomic background of a household influences participation in food provision for wild birds, the most popular and widespread form of human-wildlife interaction. A majority of households feed birds (64% across rural and urban areas in England, and 53% within five British study...... cities). House type, household size and the age of the head of the household were all important predictors of bird feeding, whereas gross annual household income, the occupation of the head of the household, and whether the house is owned or rented were not. In both surveys, the prevalence of bird...... a week. The proportion of households regularly feeding birds was positively related to the age of the head of the household, but declined with gross annual income. As concerns grow about the lack of engagement between people and the natural environment, such findings are important if conservation...

Time allocation between feeding and incubation in uniparental arctic-breeding shorebirds: energy reserves provide leeway in a tight schedule

NARCIS (Netherlands)

Tulp, I.Y.M.; Schekkerman, H.

2006-01-01

Birds with uniparental incubation may face a time allocation problem between incubation and feeding. Eggs need regular warming to hatch successfully, but the parent must leave the nest to feed and safeguard its own survival. Time allocation during incubation is likely to depend on factors

Roles of orexin in modulating arousal, feeding and motivation

Directory of Open Access Journals (Sweden)

Natsuko eTsujino

2013-04-01

Full Text Available Orexin deficiency results in narcolepsy in humans, dogs, and rodents, suggesting that the orexin system is particularly important for maintenance of wakefulness. However, orexin neurons are ‘multi-tasking’ neurons that regulate sleep/wake states as well as feeding behavior, emotion, and reward processes. Orexin deficiency causes abnormalities in energy homeostasis, stress-related behavior, and reward systems. Orexin excites waking-active monoaminergic and cholinergic neurons in the hypothalamus and brain stem regions to maintain a long, consolidated waking period. Orexin neurons also have reciprocal links with the hypothalamic nucleus, which regulates feeding. Moreover, the responsiveness of orexin neurons to peripheral metabolic cues suggests that these neurons have an important role as a link between energy homeostasis and vigilance states. The link between orexin and the ventral tegmental nucleus serves to motivate an animal to engage in goal-directed behavior. This review focuses on the interaction of orexin neurons with emotion, reward, and energy homeostasis systems. These connectivities are likely to be highly important to maintain proper vigilance states.

The bioeconomics of controlling an African rodent pest species

DEFF Research Database (Denmark)

Skonhoft, Anders; Leirs, Herwig; Andreassen, Harry P

2006-01-01

The paper treats the economy of controlling an African pest rodent, the multimammate rat, causing major damage in maize production. An ecological population model is presented and used as a basis for the economic analyses carried out at the village level using data from Tanzania. This model...... incorporates both density-dependent and density-independent (stochastic) factors. Rodents are controlled by applying poison, and the costs are made up of the cost of poison plus the damage to maize production. We analyse how the present-value costs of maize production are affected by various rodent control...

Semi-Autonomous Rodent Habitat for Deep Space Exploration

Science.gov (United States)

Alwood, J. S.; Shirazi-Fard, Y.; Pletcher, D.; Globus, R.

2018-01-01

NASA has flown animals to space as part of trailblazing missions and to understand the biological responses to spaceflight. Mice traveled in the Lunar Module with the Apollo 17 astronauts and now mice are frequent research subjects in LEO on the ISS. The ISS rodent missions have focused on unravelling biological mechanisms, better understanding risks to astronaut health, and testing candidate countermeasures. A critical barrier for longer-duration animal missions is the need for humans-in-the-loop to perform animal husbandry and perform routine tasks during a mission. Using autonomous or telerobotic systems to alleviate some of these tasks would enable longer-duration missions to be performed at the Deep Space Gateway. Rodent missions performed using the Gateway as a platform could address a number of critical risks identified by the Human Research Program (HRP), as well as Space Biology Program questions identified by NRC Decadal Survey on Biological and Physical Sciences in Space, (2011). HRP risk areas of potentially greatest relevance that the Gateway rodent missions can address include those related to visual impairment (VIIP) and radiation risks to central nervous system, cardiovascular disease, as well as countermeasure testing. Space Biology focus areas addressed by the Gateway rodent missions include mechanisms and combinatorial effects of microgravity and radiation. The objectives of the work proposed here are to 1) develop capability for semi-autonomous rodent research in cis-lunar orbit, 2) conduct key experiments for testing countermeasures against low gravity and space radiation. The hardware and operations system developed will enable experiments at least one month in duration, which potentially could be extended to one year in duration. To gain novel insights into the health risks to crew of deep space travel (i.e., exposure to space radiation), results obtained from Gateway flight rodents can be compared to ground control groups and separate groups

Study of hantavirus infection in captive breed colonies of wild rodents

Directory of Open Access Journals (Sweden)

RC Oliveira

2004-10-01

Full Text Available 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 potencial risk for hantaviral transmission, we examined 85 speciemens 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.

Thieving rodents as substitute dispersers of megafaunal seeds

Science.gov (United States)

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

2012-01-01

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

A method for reducing environmental pollution by using essential oils in rodent pest management program.

Science.gov (United States)

Jokić, Goran; Blažić, Tanja; Đurović-Pejčev, Rada; Đorđević, Tijana; Đedović, Suzana; Vukša, Marina

2017-08-01

Strong-smelling plant extracts, such as essential oils, have a variety of feeding effects on mammals. Considering current concerns over long-term health issues and environmental effects of chemicals, plant-based products with repellent or antifungal activities may represent good solutions for improvement of rodent pest control programs. The present study was therefore focused on examining the effects of bergamot, lavender, and thyme essential oils as additional bait components on daily intakes of cereal-based baits by wild house mice. Lavender essential oil, containing linalool and linalyl acetate as main components, and thyme essential oil with a prevailing thymol component had no effects on house mice diet. Bergamot essential oil, whose main components were linalool, limonene, and linalyl acetate, showed a repellent effect on house mouse diet.

The rediscovery of infant feeding formula with magnetic resonance imaging

International Nuclear Information System (INIS)

Gerscovich, E.O.; McGahan, J.P.; Buonocore, M.H.; Ablin, D.S.; Lindfors, K.K.

1990-01-01

In six newborns, regular infant feeding formula given approximately one-half hour to four hours prior to MR examination, demonstrated a high intensity signal within the infant's stomach, small bowel, and colon. This effect was observed on both 0.5 Tesla and 1.5 Tesla magnets on T1 (SE TR/TE 433-600/20-25) and on T2 (SE TR/TE 1500/30-80) weighted images. Infant feeding formula has the potential to be used as an oral contrast agent for visualization of the newborn gastrointestinal tract. Chloral hydrate and other agents were also tested. (orig.)

The role of rodents in avian influenza outbreaks in poultry farms: a review.

Science.gov (United States)

Velkers, Francisca C; Blokhuis, Simon J; Veldhuis Kroeze, Edwin J B; Burt, Sara A

2017-12-01

Wild migratory birds are associated with global avian influenza virus (AIV) spread. Although direct contact with wild birds and contaminated fomites is unlikely in modern non-free range poultry farms applying biosecurity measures, AIV outbreaks still occur. This suggests involvement of other intermediate factors for virus transmission between wild birds and poultry. This review describes current evidence of the potential role of rodents in AIV transmission from wild birds to poultry and between poultry houses. Rodents can be abundant around poultry houses, share their habitat with waterfowl and can readily enter poultry houses. Survival of AIV from waterfowl in poultry house surroundings and on the coat of rodents suggests that rodents are likely to act as mechanical vector. AIVs can replicate in rodents without adaptation, resulting in high viral titres in lungs and nasal turbinates, virus presence in nasal washes and saliva, and transmission to naïve contact animals. Therefore, active AIV shedding by infected rodents may play a role in transmission to poultry. Further field and experimental studies are needed to provide evidence for a role of rodents in AIV epidemiology. Making poultry houses rodent-proof and the immediate surroundings unattractive for rodents are recommended as preventive measures against possible AIV introduction.

Towards sustainable management of rodents in organic animal husbandry

NARCIS (Netherlands)

Meerburg, B.G.; Bonde, M.; Brom, F.W.A.; Endepols, S.; Jensen, A.N.; Leirs, H.; Lodal, J.; Singleton, G.R.; Pelz, H.J.; Rodenburg, T.B.; Kijlstra, A.

2004-01-01

From 26 to 28 May 2004 an international seminar was held in Wageningen, the Netherlands, about current knowledge and advice on rodent management on organic pig and poultry farms in Western Europe. This paper summarizes the discussions. Rodent management is necessary to protect the food production

Population dynamics of Rodents and Insectivores in lowland tropical ...

African Journals Online (AJOL)

The community structure of rodents and insectivores in the lowland tropical rainforest of Okomu National Park, Edo State, Nigeria was assessed using a combination of live-trapping and sighting techniques during the dry and wet seasons. Seventeen species (14 species of rodent, 3 species of insectivores) were captured, ...

Multiple infections of rodents with zoonotic pathogens in Austria.

Science.gov (United States)

Schmidt, Sabrina; Essbauer, Sandra S; Mayer-Scholl, Anne; Poppert, Sven; Schmidt-Chanasit, Jonas; Klempa, Boris; Henning, Klaus; Schares, Gereon; Groschup, Martin H; Spitzenberger, Friederike; Richter, Dania; Heckel, Gerald; Ulrich, Rainer G

2014-07-01

Rodents are important reservoirs for a large number of zoonotic pathogens. We examined the occurrence of 11 viral, bacterial, and parasitic agents in rodent populations in Austria, including three different hantaviruses, lymphocytic choriomeningitis virus, orthopox virus, Leptospira spp., Borrelia spp., Rickettsia spp., Bartonella spp., Coxiella burnetii, and Toxoplasma gondii. In 2008, 110 rodents of four species (40 Clethrionomys glareolus, 29 Apodemus flavicollis, 26 Apodemus sylvaticus, and 15 Microtus arvalis) were trapped at two rural sites in Lower Austria. Chest cavity fluid and samples of lung, spleen, kidney, liver, brain, and ear pinna skin were collected. We screened selected tissue samples for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, Leptospira, Borrelia, Rickettsia, Bartonella spp., C. burnetii, and T. gondii by RT-PCR/PCR and detected nucleic acids of Tula hantavirus, Leptospira spp., Borrelia afzelii, Rickettsia spp., and different Bartonella species. Serological investigations were performed for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, and Rickettsia spp. Here, Dobrava-Belgrade hantavirus-, Tula hantavirus-, lymphocytic choriomeningitis virus-, orthopox virus-, and rickettsia-specific antibodies were demonstrated. Puumala hantavirus, C. burnetii, and T. gondii were neither detected by RT-PCR/PCR nor by serological methods. In addition, multiple infections with up to three pathogens were shown in nine animals of three rodent species from different trapping sites. In conclusion, these results show that rodents in Austria may host multiple zoonotic pathogens. Our observation raises important questions regarding the interactions of different pathogens in the host, the countermeasures of the host's immune system, the impact of the host-pathogen interaction on the fitness of the host, and the spread of infectious agents among wild rodents and from those to other animals or humans.

Farmer survey in the hinterland of Kisangani (Democratic Republic of Congo) on rodent crop damage and rodent control techniques used

DEFF Research Database (Denmark)

Drazo, Nicaise Amundala; Kennis, Jan; Leirs, Herwig

2008-01-01

We conducted a survey on rodent crop damage among farmers in the hinterland of Kisangani (Democratic Republic of Congo). We studied the amount of crop damage, the rodent groups causing crop damage, the growth stages affected and the control techniques used. We conducted this survey in three...... municipalities using a standard questionnaire form translated into local languages, between November 2005 and June 2006 and during July 2007. We used the Quotas method and interviewed 70 households per municipality. Farmers indicated rodent groups implicated in crop damage on color photographs. Two types...... of survey techniques were used: individual and focus-group surveys. The sugar cane rat, Thryonomys sp. and Lemniscomys striatus caused most damage to crops, but inside granaries, Rattus rattus was the primary pest species eating stored food supplies and causing damage to stored goods. Cassava and maize were...

Urban Bird Feeding: Connecting People with Nature.

Directory of Open Access Journals (Sweden)

Daniel T C Cox

Full Text Available At a time of unprecedented biodiversity loss, researchers are increasingly recognizing the broad range of benefits provided to humankind by nature. However, as people live more urbanized lifestyles there is a progressive disengagement with the natural world that diminishes these benefits and discourages positive environmental behaviour. The provision of food for garden birds is an increasing global phenomenon, and provides a readily accessible way for people to counter this trend. Yet despite its popularity, quite why people feed birds remains poorly understood. We explore three loosely defined motivations behind bird feeding: that it provides psychological benefits, is due to a concern about bird welfare, and/or is due to a more general orientation towards nature. We quantitatively surveyed households from urban towns in southern England to explore attitudes and actions towards garden bird feeding. Each household scored three Likert statements relating to each of the three motivations. We found that people who fed birds regularly felt more relaxed and connected to nature when they watched garden birds, and perceived that bird feeding is beneficial for bird welfare while investing time in minimising associated risks. Finally, feeding birds may be an expression of a wider orientation towards nature. Overall, we found that the feelings of being relaxed and connected to nature were the strongest drivers. As urban expansion continues both to threaten species conservation and to change peoples' relationship with the natural world, feeding birds may provide an important tool for engaging people with nature to the benefit of both people and conservation.

[Promotion of breast feeding in paediatric outpatient settings].

Science.gov (United States)

Böse-O'Reilly, S; Wermuth, I; Hellmann, J; Siebert, U; Lob-Corzilius, T

2008-03-01

With some data and examples it can be shown that the competence and the knowledge of paediatric doctor's assistants and paediatric nurses can and should be improved. The training courses to become a "prevention assistant" have been very positively accepted by doctor's assistants and paediatric nurses, and it seems an appropriate method to reach these aims. Prevention and especially promotion of breast feeding is possible in paediatric outpatient settings. The immediate contact between infants, parents, paediatric doctor's assistants, paediatric nurses, and doctors offers a unique opportunity to promote the health of children, mainly due to the high acceptance of regular check-ups. So why not introduce the promotion of breast feeding in paediatric outpatient settings with specially trained doctor's assistants and paediatric nurses?

MR microscopy of the lung in small rodents

International Nuclear Information System (INIS)

Takahashi, Masaya; Kubo, Shigeto; Kiryu, Shigeru; Gee, James; Hatabu, Hiroto

2007-01-01

Understanding how the mammalian respiratory system works and how it changes in disease states and under the influence of drugs is frequently pursued in model systems such as small rodents. These have many advantages, including being easily obtained in large numbers as purebred strains. Studies in small rodents are valuable for proof of concept studies and for increasing our knowledge about disease mechanisms. Since the recent developments in the generation of genetically designed animal models of disease, one needs the ability to assess morphology and function in in vivo systems. In this article, we first review previous reports regarding thoracic imaging. We then discuss approaches to take in making use of small rodents to increase MR microscopic sensitivity for these studies and to establish MR methods for clinically relevant lung imaging

Ecology of rodents at an old quarry in Zambia

African Journals Online (AJOL)

Ecology of rodents at an old quarry in Zambia. E.N. Chidumayo. Livingstone Museum, Zambia. An old quarry, 2,5 hain size near Livingstone in southern. Zambia was kill- and live-trapped between September 1974 and December 1976 to determine ecological relations among. rodent species inhabiting it. Seven species ...

Sleep in the Cape Mole Rat: A Short-Sleeping Subterranean Rodent.

Science.gov (United States)

Kruger, Jean-Leigh; Gravett, Nadine; Bhagwandin, Adhil; Bennett, Nigel C; Archer, Elizabeth K; Manger, Paul R

2016-01-01

The Cape mole rat Georychus capensis is a solitary subterranean rodent found in the western and southern Cape of South Africa. This approximately 200-gram bathyergid rodent shows a nocturnal circadian rhythm, but sleep in this species is yet to be investigated. Using telemetric recordings of the electroencephalogram (EEG) and electromyogram (EMG) in conjunction with video recordings, we were able to show that the Cape mole rat, like all other rodents, has sleep periods composed of both rapid eye movement (REM) and slow-wave (non-REM) sleep. These mole rats spent on average 15.4 h awake, 7.1 h in non-REM sleep and 1.5 h in REM sleep each day. Cape mole rats sleep substantially less than other similarly sized terrestrial rodents but have a similar percentage of total sleep time occupied by REM sleep. In addition, the duration of both non-REM and REM sleep episodes was markedly shorter in the Cape mole rat than has been observed in terrestrial rodents. Interestingly, these features (total sleep time and episode duration) are similar to those observed in another subterranean bathyergid mole rat, i.e. Fukomys mechowii. Thus, there appears to be a bathyergid type of sleep amongst the rodents that may be related to their environment and the effect of this on their circadian rhythm. Investigating further species of bathyergid mole rats may fully define the emerging picture of sleep in these subterranean African rodents. © 2016 S. Karger AG, Basel.

Natural Intestinal Protozoa in Rodents (Rodentia: Gerbillinae, Murinae, Cricetinae in Northwestern Iran

Directory of Open Access Journals (Sweden)

Mehdi MOHEBALI

2017-09-01

Full Text Available Background: Majority of parasitic infections in rodents have zoonotic importance. This study aimed to determine the frequency and intensity of intestinal protozoa infections of rodents including Meriones persicus, Mus musculus and, Cricetulus migratorius.Methods: This survey was conducted in Meshkin Shahr district in northwestern Iran from Mar. to Dec. of 2014. Intestinal samples of 204 rodents including M. persicus (n=117, M. musculus (n=63 and C. migratorius (n=24 were parasitologically examined. Formalin-ether concentration method was done for all of rodents stool samples and observed with light microscope. All of suspected cases were stained with trichorome staining Method. Cultivation in dichromate potassium 2.5% was carried out for all of coccidian positive samples. Acid fast and aniline blue staining methods were used for detecting of coccidian oocysts and intestinal microsporidial spores, respectively.Results: About 121(59.3% of the caught rodents were generally infected with intestinal protozoa. Entamoeba muris 14(6.9%, Trichomonas muris 55(27.0%, Chilomastix betencourtti 17 (8.3%, Giardia muris 19(9.3%, Eimeria spp. 46(22.5%, Isospora spp. 4(2% and Cryptosporidium spp. 1(0.5% were found from the collected rodents. Microsporidian spores were identified in 63 (31% out of the 204 collected rodents using aniline blue staining method.Conclusion: Since some of the infections are zoonotic importance thus, control of rodents can be decreased new cases of the parasitic zoonoses in humans.

Natural Intestinal Protozoa in Rodents (Rodentia: Gerbillinae, Murinae, Cricetinae) in Northwestern Iran

Science.gov (United States)

MOHEBALI, Mehdi; ZAREI, Zabiholah; Khanaliha, Khadijeh; KIA, Eshrat Beigom; MOTAVALLI-HAGHI, Afsaneh; DAVOODI, Jaber; REZAEIAN, Tahereh; TARIGHI, Fathemeh; REZAEIAN, Mostafa

2017-01-01

Background: Majority of parasitic infections in rodents have zoonotic importance. This study aimed to determine the frequency and intensity of intestinal protozoa infections of rodents including Meriones persicus, Mus musculus and, Cricetulus migratorius. Methods: This survey was conducted in Meshkin Shahr district in northwestern Iran from Mar. to Dec. of 2014. Intestinal samples of 204 rodents including M. persicus (n=117), M. musculus (n=63) and C. migratorius (n=24) were parasitologically examined. Formalin-ether concentration method was done for all of rodents stool samples and observed with light microscope. All of suspected cases were stained with trichorome staining Method. Cultivation in dichromate potassium 2.5% was carried out for all of coccidian positive samples. Acid fast and aniline blue staining methods were used for detecting of coccidian oocysts and intestinal microsporidial spores, respectively. Results: About 121(59.3%) of the caught rodents were generally infected with intestinal protozoa. Entamoeba muris 14(6.9%), Trichomonas muris 55(27.0%), Chilomastix betencourtti 17 (8.3%), Giardia muris 19(9.3%), Eimeria spp. 46(22.5%), Isospora spp. 4(2%) and Cryptosporidium spp. 1(0.5%) were found from the collected rodents. Microsporidian spores were identified in 63 (31%) out of the 204 collected rodents using aniline blue staining method. Conclusion: Since some of the infections are zoonotic importance thus, control of rodents can be decreased new cases of the parasitic zoonoses in humans. PMID:28979348

Early Eocene rodents (Mammalia) from the Subathu Formation of ...

Indian Academy of Sciences (India)

1997a, b). Most of the rodents from this stratigraphic level have been referred to a rather diverse family Cha- pattimyidae ... Herein we describe a new early Eocene rodent assemblage .... thick zone of brownish red shales that occur as a ..... 1997b;. Plate 3, figure 31). ...... northwestern Pakistan and remarks on the collision.

Research Note. Occurrence of gastrointestinal helminths in commensal rodents from Tabasco, Mexico

Directory of Open Access Journals (Sweden)

Cigarroa-Toledo N.

2017-06-01

Full Text Available The aim of this study was to determine the prevalence and species composition of helminths in commensal rodents captured inside private residences in the city of Villahermosa in Tabasco, Mexico. Trapping was performed at each house for three consecutive nights from October to December 2015. Fifty commensal rodents were captured: 23 Rattus norvegicus, 16 Mus musculus and 11 Rattus rattus. Rodents were transported alive to the laboratory and held in cages until they defecated. Feces were analyzed for helminth eggs using the Sheather’s flotation technique. The overall prevalence of helminths in rodents was 60 %: R. norvegicus was more likely to be parasitized (87.0 % than R. rattus (63.6 % and M. musculus (18.8 %. Eggs from at least 13 species of helminths were identified: Hymenolepis diminuta, Rodentolepis nana, Moniliformis moniliformis, Heligmosomoides polygyrus, Heterakis spumosa, Mastophorus muris, Nippostrongylus brasiliensis, Strongyloides ratti, Syphacia obvelata, Syphacia muris, Toxocara sp., Trichosomoides crassicauda, and Trichuris muris. This is the first study to report the presence of H. polygyrus, S. ratti and T. crassicauda in commensal rodents in Mexico. In conclusion, our results suggest that helminths commonly infect commensal rodents in Villahermosa and therefore rodents present a health risk to inhabitants in this region.

Data Analyses and Modelling for Risk Based Monitoring of Mycotoxins in Animal Feed

Directory of Open Access Journals (Sweden)

H.J. (Ine van der Fels-Klerx

2018-01-01

Full Text Available Following legislation, European Member States should have multi-annual control programs for contaminants, such as for mycotoxins, in feed and food. These programs need to be risk based implying the checks are regular and proportional to the estimated risk for animal and human health. This study aimed to prioritize feed products in the Netherlands for deoxynivalenol and aflatoxin B1 monitoring. Historical mycotoxin monitoring results from the period 2007–2016 were combined with data from other sources. Based on occurrence, groundnuts had high priority for aflatoxin B1 monitoring; some feed materials (maize and maize products and several oil seed products and complete/complementary feed excluding dairy cattle and young animals had medium priority; and all other animal feeds and feed materials had low priority. For deoxynivalenol, maize by-products had a high priority, complete and complementary feed for pigs had a medium priority and all other feed and feed materials a low priority. Also including health consequence estimations showed that feed materials that ranked highest for aflatoxin B1 included sunflower seed and palmkernel expeller/extracts and maize. For deoxynivalenol, maize products were ranked highest, followed by various small grain cereals (products; all other feed materials were of lower concern. Results of this study have proven to be useful in setting up the annual risk based control program for mycotoxins in animal feed and feed materials.

Data Analyses and Modelling for Risk Based Monitoring of Mycotoxins in Animal Feed

Science.gov (United States)

van der Fels-Klerx, H.J. (Ine); Adamse, Paulien; Punt, Ans; van Asselt, Esther D.

2018-01-01

Following legislation, European Member States should have multi-annual control programs for contaminants, such as for mycotoxins, in feed and food. These programs need to be risk based implying the checks are regular and proportional to the estimated risk for animal and human health. This study aimed to prioritize feed products in the Netherlands for deoxynivalenol and aflatoxin B1 monitoring. Historical mycotoxin monitoring results from the period 2007–2016 were combined with data from other sources. Based on occurrence, groundnuts had high priority for aflatoxin B1 monitoring; some feed materials (maize and maize products and several oil seed products) and complete/complementary feed excluding dairy cattle and young animals had medium priority; and all other animal feeds and feed materials had low priority. For deoxynivalenol, maize by-products had a high priority, complete and complementary feed for pigs had a medium priority and all other feed and feed materials a low priority. Also including health consequence estimations showed that feed materials that ranked highest for aflatoxin B1 included sunflower seed and palmkernel expeller/extracts and maize. For deoxynivalenol, maize products were ranked highest, followed by various small grain cereals (products); all other feed materials were of lower concern. Results of this study have proven to be useful in setting up the annual risk based control program for mycotoxins in animal feed and feed materials. PMID:29373559

Hypericum perforatum as a cognitive enhancer in rodents: A meta-analysis

Science.gov (United States)

Ben-Eliezer, Daniel; Yechiam, Eldad

2016-01-01

Considered an antidepressant and anti-anxiety agent, Hypericum perforatum affects multiple neurotransmitters in a non-competitive synergistic manner, and may have nootropic potential. We quantitatively reviewed the pre-clinical literature to examine if there is a cognitive-enhancing effect of H. perforatum in healthy rodents. Additionally, within these studies, we compared the effects observed in intact rodents versus those whose performance has been impaired, mostly through stress manipulations. The meta-analysis incorporated studies that examined the effect of H. perforatum versus placebo on memory indices of task performance. All analyses were based on weighting different studies according to their inverse variance. Thirteen independent studies (published 2000–2014) involving 20 experimental comparisons met our inclusion criteria. The results showed a large positive effect of H. perforatum on cognitive performance for intact, healthy rodents (d = 1.11), though a larger effect emerged for stress-impaired rodents (d = 3.10 for restraint stress). The positive effect on intact rodents was observed in tasks assessing reference memory as well as working memory, and was not moderated by the type of memory or motivation (appetitive versus aversive). Thus, while primarily considered as a medication for depression, H. perforatum shows considerable nootropic potential in rodents. PMID:27762349

Neurogenic inflammation in human and rodent skin

DEFF Research Database (Denmark)

Schmelz, M; Petersen, Lars Jelstrup

2001-01-01

The combination of vasodilation and protein extravasation following activation of nociceptors has been termed "neurogenic inflammation." In contrast to rodents, no neurogenic protein extravasation can be elicited in healthy human skin. Dermal microdialysis has considerably increased our knowledge...... about neurogenic inflammation in human skin, including the involvement of mast cells.......The combination of vasodilation and protein extravasation following activation of nociceptors has been termed "neurogenic inflammation." In contrast to rodents, no neurogenic protein extravasation can be elicited in healthy human skin. Dermal microdialysis has considerably increased our knowledge...

Public Health Implications of Changing Rodent Importation Patterns - United States, 1999-2013.

Science.gov (United States)

Lankau, E W; Sinclair, J R; Schroeder, B A; Galland, G G; Marano, N

2017-04-01

The United States imports a large volume of live wild and domestic animal species; these animals pose a demonstrated risk for introduction of zoonotic diseases. Rodents are imported for multiple purposes, including scientific research, zoo exhibits and the pet trade. Current U.S. public health regulatory restrictions specific to rodent importation pertain only to those of African origin. To understand the impacts of these regulations and the potential public health risks of international rodent trade to the United States, we evaluated live rodent import records during 1999-2013 by shipment volume and geographic origin, source (e.g. wild-caught versus captive- or commercially bred), intended purpose and rodent taxonomy. Live rodent imports increased from 2737 animals during 1999 to 173 761 animals during 2013. Increases in both the number and size of shipments contributed to this trend. The proportion of wild-captured imports declined from 75% during 1999 to guinea pigs and hamsters arriving from other countries in North America were predominant taxa underlying this trend. After 2003, African-origin imports became sporadic events under the federal permit process. These patterns suggest development of large-scale captive rodent breeding markets abroad for commercial sale in the United States. While the shift from wild-captured imports alleviates many conservation concerns and risks for novel disease emergence, such consolidated sourcing might elevate exposure risks for zoonotic diseases associated with high-density rodent breeding (e.g. lymphocytic choriomeningitis or salmonellosis). A responsive border health system must periodically re-evaluate importation regulations in conjunction with key stakeholders to ensure a balance between the economic benefits of rodent trade against the potential public health risks. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Result of 11th regular inspection of No.1 plant in Shimane Nuclear Power Station, Chugoku Electric Power Co., Inc

International Nuclear Information System (INIS)

Anon.

1987-01-01

The 11th regular inspection of No.1 plant in Shimane Nuclear Power Station was carried out from January 9 to July 2, 1986. The parallel operation was resumed on June 19, 1986, 162 days after the parallel off. The facilities as the object of inspection were the reactor proper, reactor cooling system, measurement and control system, fuel facilities, radiation control facilities, waste facilities, reactor containment installation, and emergency power generation system. On these facilities as the object of inspection, the appearance, disassembling, leak, function, performance and other inspections were carried out, as the result, any abnormality was not found. The works related to this regular inspection were accomplished within the range of the allowable radiation dose based on the relevant laws. The main reconstruction works carried out during the period of this regular inspection were as follows. Feed water spargers were replaced with those of welded type, the material of the drain pipe for No.3 feed heater was changed to STPA 23, an exhaust compressor, an exhaust gas-water separator and others, which have not been used, were removed, and the connecting pipe for a liquid nitrogen evaporator was installed. (Kako, I.)

The Revised Neurobehavioral Severity Scale (NSS-R) for Rodents.

Science.gov (United States)

Yarnell, Angela M; Barry, Erin S; Mountney, Andrea; Shear, Deborah; Tortella, Frank; Grunberg, Neil E

2016-04-08

Motor and sensory deficits are common following traumatic brain injury (TBI). Although rodent models provide valuable insight into the biological and functional outcomes of TBI, the success of translational research is critically dependent upon proper selection of sensitive, reliable, and reproducible assessments. Published literature includes various observational scales designed to evaluate post-injury functionality; however, the heterogeneity in TBI location, severity, and symptomology can complicate behavioral assessments. The importance of choosing behavioral outcomes that can be reliably and objectively quantified in an efficient manner is becoming increasingly important. The Revised Neurobehavioral Severity Scale (NSS-R) is a continuous series of specific, sensitive, and standardized observational tests that evaluate balance, motor coordination, and sensorimotor reflexes in rodents. The tasks follow a specific order designed to minimize interference: balance, landing, tail raise, dragging, righting reflex, ear reflex, eye reflex, sound reflex, tail pinch, and hindpaw pinch. The NSS-R has proven to be a reliable method differentiating brain-injured rodents from non-brain-injured rodents across many brain injury models. Copyright © 2016 John Wiley & Sons, Inc.

Competence in confirming correct placement of nasogastric feeding tubes amongst FY1 doctors

OpenAIRE

Lee, Sindy; Mason, Eleanor

2013-01-01

Foundation year one (FY1) doctors are required to confirm correct placement of nasogastric (NG) feeding tubes on chest radiography on a regular basis. Many FY1s do not receive formal training during medical school or during the FY1 year. Multiple incidents of harm to patients, including death, resulting from incorrect placement of an NG feeding tube have been reported to the National Patient Safety Agency (NPSA) since 2005. Our audit assessed the confidence and knowledge of FY1 doctors in cor...

Public Health and Rodents: A Game of Cat and Mouse

NARCIS (Netherlands)

Meerburg, B.G.

2015-01-01

Rodents are the most abundant order of living mammals, distributed on every continent except Antarctic and represent 43 % of all mammalian species. Beside causing food losses and infrastructural damage, rodents can harbour pathogens that may cause serious problems to human and animal health.

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

Science.gov (United States)

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

2016-01-01

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

Mathematical Model and Simulation of Particle Flow around Choanoflagellates Using the Method of Regularized Stokeslets

Science.gov (United States)

Nararidh, Niti

2013-11-01

Choanoflagellates are unicellular organisms whose intriguing morphology includes a set of collars/microvilli emanating from the cell body, surrounding the beating flagellum. We investigated the role of the microvilli in the feeding and swimming behavior of the organism using a three-dimensional model based on the method of regularized Stokeslets. This model allows us to examine the velocity generated around the feeding organism tethered in place, as well as to predict the paths of surrounding free flowing particles. In particular, we can depict the effective capture of nutritional particles and bacteria in the fluid, showing the hydrodynamic cooperation between the cell, flagellum, and microvilli of the organism. Funding Source: Murchison Undergraduate Research Fellowship.

Capacity for absorption of water-soluble secondary metabolites greater in birds than in rodents.

Science.gov (United States)

Karasov, William H; Caviedes-Vidal, Enrique; Bakken, Bradley Hartman; Izhaki, Ido; Samuni-Blank, Michal; Arad, Zeev

2012-01-01

Plant secondary metabolites (SMs) are pervasive in animal foods and potentially influence feeding behavior, interspecies interactions, and the distribution and abundance of animals. Some of the major classes of naturally occurring SMs in plants include many water-soluble compounds in the molecular size range that could cross the intestinal epithelium via the paracellular space by diffusion or solvent drag. There are differences among species in paracellular permeability. Using Middle Eastern rodent and avian consumers of fruits containing SMs, we tested the hypothesis that avian species would have significantly higher paracellular permeability than rodent species. Permeability in intact animals was assessed using standard pharmacological methodology to measure absorption of two radiolabeled, inert, neutral water-soluble probes that do not interact with intestinal nutrient transporters, L-arabinose (M(r) = 150.1 Da) and lactulose (M(r) = 342.3 Da). We also measured absorption of labeled 3-O-methyl-D-glucose (3OMD-glucose; M(r) = 194.2 Da), which is a nonmetabolized analogue of D-glucose that is passively absorbed through the paracellular space but also transported across the enterocyte membranes. Most glucose was absorbed by all species, but arabinose fractional absorption (f) was nearly three times higher in birds (1.03±0.17, n = 15 in two species) compared to rodents (0.37±0.06, n = 10 in two species) (Pbirds of arabinose exceeded those of 3OMD-glucose. Our findings are in agreement with previous work showing that the paracellular pathway is more prominent in birds relative to nonflying mammals, and suggests that birds may be challenged by greater absorption of water-soluble, dietary SMs. The increased expression of the paracellular pathway in birds hints at a tradeoff: the free energy birds gain by absorbing water-soluble nutrients passively may be offset by the metabolic demands placed on them to eliminate concomitantly absorbed SMs.

Molecular Survey of Zoonotic Agents in Rodents and Other Small Mammals in Croatia.

Science.gov (United States)

Tadin, Ante; Tokarz, Rafal; Markotić, Alemka; Margaletić, Josip; Turk, Nenad; Habuš, Josipa; Svoboda, Petra; Vucelja, Marko; Desai, Aaloki; Jain, Komal; Lipkin, W Ian

2016-02-01

Croatia is a focus for many rodent-borne zoonosis. Here, we report a survey of 242 rodents and small mammals, including 43 Myodes glareolus, 131 Apodemus flavicollis, 53 Apodemus agrarius, three Apodemus sylvaticus, six Sorex araneus, four Microtus arvalis, one Microtus agrestis, and one Muscardinus avellanarius, collected at eight sites in Croatia over an 8-year period. Multiplex MassTag polymerase chain reaction (PCR) was used for detection of Borrelia, Rickettsia, Bartonella, Babesia, Ehrlichia, Anaplasma, Francisella tularensis, and Coxiella burnetii. Individual PCR assays were used for detection of Leptospira, lymphocytic choriomeningitis virus, orthopoxviruses, flaviviruses, hantaviruses, and Toxoplasma gondii. Of the rodents, 52 (21.5%) were infected with Leptospira, 9 (3.7%) with Borrelia miyamotoi, 5 (2%) with Borrelia afzelii, 29 (12.0%) with Bartonella, 8 (3.3%) with Babesia microti, 2 (0.8%) with Ehrlichia, 4 (1.7%) with Anaplasma, 2 (0.8%) with F. tularensis, 43 (17.8%) with hantaviruses, and 1 (0.4%) with an orthopoxvirus. Other agents were not detected. Multiple infections were found in 32 rodents (13.2%): dual infections in 26 rodents (10.7%), triple infections in four rodents (2.9%), and quadruple infections in two rodents (0.8%). Our findings indicate that rodents in Croatia harbor a wide range of bacteria and viruses that are pathogenic to humans. © The American Society of Tropical Medicine and Hygiene.

A Profile Analysis on the Effectiveness of Two kinds of Feeds on ...

African Journals Online (AJOL)

A Profile Analysis on the Effectiveness of Two kinds of Feeds on Poultry. Birds. Onuoha, Desmond O+. and Opara Pius N*. +Department of Mathematics and Statistics, Federal ... birds using chicken from Michika Farm in Igwuruta in Port Harcourt, Rivers State as a case study. .... easy to manage, regularly lay eggs, disease.

Wild Rodents as Experimental Intermediate Hosts of Lagochilascaris minor Leiper, 1909

Directory of Open Access Journals (Sweden)

Julieta Machado Paçô

1999-07-01

Full Text Available A total of 25 specimens of Cavia porcellus (guinea pig, 5 Dasyprocta agouti (agouti, and 22 Calomys callosus (vesper mice were inoculated with infective eggs of Lagochilascaris minor. The inoculum was prepared with embryonated eggs and orally administered to each individual animal through an esophagus probe. In parallel, 100 specimens of Felis catus domesticus were individually fed with 55-70 nodules containing 3rd-stage larvae encysted in tissues of infected rodents. Animals were examined and necropsied at different time intervals. The migration and encystment of L3 larva was observed in viscera, skeletal muscle, adipose and subcutaneous tissues from all rodents. Adult worms localized at abscesses in the cervical region, rhino, and oropharynx were recovered from domestic cats inoculated with infected rodent tissues. Through this study we can conclude that: (1 wild rodents act as intermediate hosts, characterizing this ascarid heteroxenic cycle; (2 in natural conditions rodents could possibly act as either intermediate hosts or paratenic hosts of Lagochilascaris minor; (3 despite the occurrence of an auto-infecting cycle, in prime-infection of felines (definite hosts the cycle is only completed when intermediate hosts are provided; and (4 in the wild, rodents could serve as a source of infection for humans as they are frequently used as food in regions with the highest incidence of human lagochilascariasis.

Data analyses and modelling for risk based monitoring of mycotoxins in animal feed

NARCIS (Netherlands)

Ine van der Fels-Klerx, H.J.; Adamse, Paulien; Punt, Ans; Asselt, van Esther D.

2018-01-01

Following legislation, European Member States should have multi-annual control programs for contaminants, such as for mycotoxins, in feed and food. These programs need to be risk based implying the checks are regular and proportional to the estimated risk for animal and human health. This study

Hypothalamic gliosis associated with high-fat diet feeding is reversible in mice: a combined immunohistochemical and magnetic resonance imaging study.

Science.gov (United States)

Berkseth, Kathryn E; Guyenet, Stephan J; Melhorn, Susan J; Lee, Donghoon; Thaler, Joshua P; Schur, Ellen A; Schwartz, Michael W

2014-08-01

Gliosis, the activation of astrocyte and microglial cell populations, is a hallmark of central nervous system injury and is detectable using either immunohistochemistry or in vivo magnetic resonance imaging (MRI). Obesity in rodents and humans is associated with gliosis of the arcuate nucleus, a key hypothalamic region for the regulation of energy homeostasis and adiposity, but whether this response is permanent or reversible is unknown. Here we combine terminal immunohistochemistry analysis with serial, noninvasive MRI to characterize the progression and reversibility of hypothalamic gliosis in high-fat diet (HFD)-fed mice. The effects of HFD feeding for 16 weeks to increase body weight and adiposity relative to chow were nearly normalized after the return to chow feeding for an additional 4 weeks in the diet-reversal group. Mice maintained on the HFD for the full 20-week study period experienced continued weight gain associated with the expected increases of astrocyte and microglial activation in the arcuate nucleus, but these changes were not observed in the diet-reversal group. The proopiomelanocortin neuron number did not differ between groups. Although MRI demonstrated a positive correlation between body weight, adiposity, and the gliosis-associated T2 signal in the mediobasal hypothalamus, it did not detect the reversal of gliosis among the HFD-fed mice after the return to chow diet. We conclude that hypothalamic gliosis associated with 16-week HFD feeding is largely reversible in rodents, consistent with the reversal of the HFD-induced obesity phenotype, and extend published evidence regarding the utility of MRI as a tool for studying obesity-associated hypothalamic gliosis in vivo.

Effect of woodland patch size on rodent seed predation in a fragmented landscape

Directory of Open Access Journals (Sweden)

J. Loman

2007-05-01

Full Text Available Predation on large woody plant seeds; chestnuts, acorns and sloe kernels, was studied in deciduous forests of two size classes: small woodlots (<1 ha and large woods (at least 25 ha in southern Sweden. Seeds used for the study were artificially distributed on the forest ground and seed predation measured as seed removal. Predation rate was similar in both types of woods. However, rodent density was higher in small woodlots and a correction for differences in rodent density showed that predation rate per individual rodent was higher in the large woods. This suggests that the small woodlots (including the border zone and their adjacent fields have more rodent food per area unit. A small woodlot cannot be considered a representative sample of a large continuous forest, even if the habitats appear similar. There was a strong effect of rodent density on seed predation rate. This suggests that rodents are major seed predators in this habitat.

Rodent Species Distribution and Hantavirus Seroprevalence in Residential and Forested areas of Sarawak, Malaysia.

Science.gov (United States)

Hamdan, Nur Elfieyra Syazana; Ng, Yee Ling; Lee, Wei Bin; Tan, Cheng Siang; Khan, Faisal Ali Anwarali; Chong, Yee Ling

2017-01-01

Rodents belong to the order Rodentia, which consists of three families in Borneo (i.e., Muridae, Sciuridae and Hystricidae). These include rats, mice, squirrels, and porcupines. They are widespread throughout the world and considered pests that harm humans and livestock. Some rodent species are natural reservoirs of hantaviruses (Family: Bunyaviridae) that can cause zoonotic diseases in humans. Although hantavirus seropositive human sera were reported in Peninsular Malaysia in the early 1980s, information on their infection in rodent species in Malaysia is still lacking. The rodent populations in residential and forested areas in Sarawak were sampled. A total of 108 individuals from 15 species of rodents were collected in residential ( n = 44) and forested ( n = 64) areas. The species diversity of rodents in forested areas was significantly higher (H = 2.2342) compared to rodents in residential areas (H = 0.64715) ( p Sarawak, East Malaysia. The results suggested that hantavirus was not circulating in the studied rodent populations in Sarawak, or it was otherwise at a low prevalence that is below the detection threshold. It is important to remain vigilant because of the zoonotic potential of this virus and its severe disease outcome. Further studies, such as molecular detection of viral genetic materials, are needed to fully assess the risk of hantavirus infection in rodents and humans in this region of Malaysia.

The hip adductor muscle group in caviomorph rodents: anatomy and homology.

Science.gov (United States)

García-Esponda, César M; Candela, Adriana M

2015-06-01

Anatomical comparative studies including myological data of caviomorph rodents are relatively scarce, leading to a lack of use of muscular features in cladistic and morphofunctional analyses. In rodents, the hip adductor muscles constitute an important group of the hindlimb musculature, having an important function during the beginning of the stance phase. These muscles are subdivided in several distinct ways in the different clades of rodents, making the identification of their homologies hard to establish. In this contribution we provide a detailed description of the anatomical variation of the hip adductor muscle group of different genera of caviomorph rodents and identify the homologies of these muscles in the context of Rodentia. On this basis, we identify the characteristic pattern of the hip adductor muscles in Caviomorpha. Our results indicate that caviomorphs present a singular pattern of the hip adductor musculature that distinguishes them from other groups of rodents. They are characterized by having a single m. adductor brevis that includes solely its genicular part. This muscle, together with the m. gracilis, composes a muscular sheet that is medial to all other muscles of the hip adductor group. Both muscles probably have a synergistic action during locomotion, where the m. adductor brevis reinforces the multiple functions of the m. gracilis in caviomorphs. Mapping of analyzed myological characters in the context of Rodentia indicates that several features are recovered as potential synapomorphies of caviomorphs. Thus, analysis of the myological data described here adds to the current knowledge of caviomorph rodents from anatomical and functional points of view, indicating that this group has features that clearly differentiate them from other rodents. Copyright © 2015 Elsevier GmbH. All rights reserved.

Helminth Infections of Rodents and Their Zoonotic Importance in Boyer-Ahmad District, Southwestern Iran.

Science.gov (United States)

Ranjbar, Mohammad Javad; Sarkari, Bahador; Mowlavi, Gholam Reza; Seifollahi, Zeinab; Moshfe, Abdolali; Abdolahi Khabisi, Samaneh; Mobedi, Iraj

2017-01-01

Rodents are considered as reservoirs of various zoonotic diseases including helminthic infections. The current study aimed to evaluate the prevalence of helminth infections in rodents, in Boyer-Ahmad district, Southwestern Iran. Overall, 52 rodents were captured from various areas of the district by Sherman live traps. The animals were then euthanized and dissected. During necropsy, each organ was examined macroscopically for presence of any cyst or visible parasite. The gastrointestinal tract was removed and their contents were evaluated for larva or adult worms. Trichinella larvae in the rodents' muscles were investigated by both digestion and pathological methods. Twenty-eight (53.8%) of the trapped rodents were male. The rodents were including 25 (48.1%) Meriones persicus , 1(1.9%) Calomyscus bailwardi , 1 (1.9%) Arvicola terresterris , 7 (13.5%) Rattus rattus , 8 (15.4%) R. norvegicus , and 10 (19.2%) Apodemus sylvaticus . Of them, 38 (73.0%) were infected with at least one helminth. Collected rodents were infected with Hymenolepis diminuta (50%), Hymenolepis nana fraterna (28.8%), Skrjabinotaenia sp. (15.4%), Anoplocephalidae sp. (15.4%), Cysticercus fasciolaris (5.8%), Trichuris muris (36.5%), Aspiculuris tetraptera (15.4%), Syphacia sp. (5.7%), Rictularia sp. (15.4%), Trichostrongylus sp. (3.8%), and Gongylonema sp. (3.8%). M. persicus was the most (84%) infected rodent, yet the differences between rodent genus and helminth infectivity were not statistically significant ( P >0.05). The rodents in Boyer-Ahmad district are infected with different helminths infections that some of them are recognized as threat to human health.

Bone morphology of the hind limbs in two caviomorph rodents.

Science.gov (United States)

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

2013-04-01

In order to evaluate the hind limbs of caviomorph rodents a descriptive analysis of the Cuniculus paca (Linnaeus, 1766) and Hydrochoerus hydrochaeris (Linnaeus, 1766) was performed using anatomical specimens, radiography, computed tomography (CT) and full-coloured prototype models to generate bone anatomy data. The appendicular skeleton of the two largest rodents of Neotropical America was compared with the previously reported anatomical features of Rattus norvegicus (Berkenhout, 1769) and domestic Cavia porcellus (Linnaeus, 1758). The structures were analyzed macroscopically and particular findings of each species reported. Features including the presence of articular fibular projection and lunulae were observed in the stifle joint of all rodents. Imaging aided in anatomical description and, specifically in the identification of bone structures in Cuniculus paca and Hydrochoerus hydrochaeris. The imaging findings were correlated with the anatomical structures observed. The data may be used in future studies comparing these animals to other rodents and mammalian species. © 2012 Blackwell Verlag GmbH.

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

Science.gov (United States)

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

2016-05-04

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

Central effects of insulin detemir on feeding, body weight, and metabolism in rats.

Science.gov (United States)

Vasselli, Joseph R; Pi-Sunyer, F Xavier; Wall, Daniel G; John, Catherine S; Chapman, Colin D; Currie, Paul J

2017-11-01

Insulin detemir (DET) is a basal insulin analog that, in contrast to other long-acting forms of insulin, has significant weight-gain-sparing effects in diabetic patients. We hypothesized that this effect of DET may be due to its enhanced catabolic action in the central nervous system. We investigated the long-term effects of single third ventricular (3V) microinjections of equimolar doses of DET and regular insulin in normal male rats on feeding, body weight, energy expenditure (EE), and respiratory quotient (RQ). Also, in acute testing, we assessed the ability of lower doses of DET to alter feeding, EE, and RQ when microinjected directly into the paraventricular nucleus (PVN). The anabolic peptide ghrelin served as a positive control in acute testing. 3V administration of both DET (0.5-2.0 mU) and regular insulin (2.0-8.0 mU) significantly reduced feeding and body weight over 48 and 120 h, respectively, with DET yielding greater inhibitory effects. DET also stimulated greater elevations of EE and reductions of RQ over 72 and 48 h postinjection, respectively. In acute (4 h) testing, microinjections of DET (0.5 mU) into the PVN reduced feeding, increased EE, and reduced RQ, while ghrelin (100 pmol) had the opposite effects. When administered sequentially into the PVN, DET (0.25 and 0.5 mU) reversed ghrelin-induced feeding, EE, and RQ effects. These data support the notion that the weight-sparing effect of DET is at least in part based on its central catabolic action and that enhanced EE and reduced RQ may participate in this effect. Copyright © 2017 the American Physiological Society.

Rodent Research on the International Space Station - A Look Forward

Science.gov (United States)

Kapusta, A. B.; Smithwick, M.; Wigley, C. L.

2014-01-01

Rodent Research on the International Space Station (ISS) is one of the highest priority science activities being supported by NASA and is planned for up to two flights per year. The first Rodent Research flight, Rodent Research-1 (RR-1) validates the hardware and basic science operations (dissections and tissue preservation). Subsequent flights will add new capabilities to support rodent research on the ISS. RR-1 will validate the following capabilities: animal husbandry for up to 30 days, video downlink to support animal health checks and scientific analysis, on-orbit dissections, sample preservation in RNA. Later and formalin, sample transfer from formalin to ethanol (hindlimbs), rapid cool-down and subsequent freezing at -80 of tissues and carcasses, sample return and recovery. RR-2, scheduled for SpX-6 (Winter 20142015) will add the following capabilities: animal husbandry for up to 60 days, RFID chip reader for individual animal identification, water refill and food replenishment, anesthesia and recovery, bone densitometry, blood collection (via cardiac puncture), blood separation via centrifugation, soft tissue fixation in formalin with transfer to ethanol, and delivery of injectable drugs that require frozen storage prior to use. Additional capabilities are also planned for future flights and these include but are not limited to male mice, live animal return, and the development of experiment unique equipment to support science requirements for principal investigators that are selected for flight. In addition to the hardware capabilities to support rodent research the Crew Office has implemented a training program in generic rodent skills for all USOS crew members during their pre-assignment training rotation. This class includes training in general animal handling, euthanasia, injections, and dissections. The dissection portion of this training focuses on the dissection of the spleen, liver, kidney with adrenals, brain, eyes, and hindlimbs. By achieving and

Public health implications of changing rodent importation patterns— United States, 1999–2013

Science.gov (United States)

Lankau, Emily W.; Sinclair, Julie R.; Schroeder, Betsy A.; Galland, G. Gale; Marano, Nina

2015-01-01

Summary The United States imports a large volume of live wild and domestic animal species; these animals pose a demonstrated risk for introduction of zoonotic diseases. Rodents are imported for multiple purposes, including scientific research, zoo exhibits, and the pet trade. Current U.S. public health regulatory restrictions specific to rodent importation pertain only to those of African origin. To understand the impacts of these regulations and the potential public health risks of international rodent trade to the United States, we evaluated live rodent import records during 1999 –2013 by shipment volume and geographic origin, source (e.g., wild -caught versus captive-or commercially bred), intended purpose, and rodent taxonomy. Live rodent imports increased from 2,737 animals during 1999 to 173,761 animals during 2013. Increases in both the number and size of shipments contributed to this trend. The proportion of wild-captured imports declined from 75% during 1999 to guinea pigs, and hamsters arriving from other countries in North America were predominant taxa underlying this trend . After 2003, African-origin imports became sporadic events under the federal permit process. These patterns suggest development of large -scale captive rodent breeding markets abroad for commercial sale in the United States. While the shift from wild-captured imports alleviates many conservation concerns and risks for novel disease emergence, such consolidated sourcing might elevate exposure risks for zoonotic diseases associated with high-density rodent breeding(e.g. , lymphocytic choriomeningitis or salmonellosis). A responsive border health system must periodically re-evaluate importation regulations in conjunction with key stakeholders to ensure a balance between the economic benefits of rodent trade against the potential public health risks. PMID:26245515

Inefficient co-feeding transmission of Borrelia afzelii in two common European songbirds

Science.gov (United States)

Heylen, Dieter J. A.; Sprong, Hein; Krawczyk, Aleksandra; Van Houtte, Natalie; Genné, Dolores; Gomez-Chamorro, Andrea; van Oers, Kees; Voordouw, Maarten J.

2017-01-01

The spirochete bacterium Borrelia afzelii is the most common cause of Lyme borreliosis in Europe. This tick-borne pathogen can establish systemic infections in rodents but not in birds. However, several field studies have recovered larval Ixodes ricinus ticks infected with B. afzelii from songbirds suggesting successful transmission of B. afzelii. We reviewed the literature to determine which songbird species were the most frequent carriers of B. afzelii-infected I. ricinus larvae and nymphs. We tested experimentally whether B. afzelii is capable of co-feeding transmission on two common European bird species, the blackbird (Turdus merula) and the great tit (Parus major). For each bird species, four naïve individuals were infested with B. afzelii-infected I. ricinus nymphal ticks and pathogen-free larval ticks. None of the co-feeding larvae tested positive for B. afzelii in blackbirds, but a low percentage of infected larvae (3.33%) was observed in great tits. Transstadial transmission of B. afzelii DNA from the engorged nymphs to the adult ticks was observed in both bird species. However, BSK culture found that these spirochetes were not viable. Our study suggests that co-feeding transmission of B. afzelii is not efficient in these two songbird species. PMID:28054584

Distance-regular graphs

NARCIS (Netherlands)

van Dam, Edwin R.; Koolen, Jack H.; Tanaka, Hajime

2016-01-01

This is a survey of distance-regular graphs. We present an introduction to distance-regular graphs for the reader who is unfamiliar with the subject, and then give an overview of some developments in the area of distance-regular graphs since the monograph 'BCN'[Brouwer, A.E., Cohen, A.M., Neumaier,

The response of human and rodent cells to hyperthermia

International Nuclear Information System (INIS)

Roizin-Towle, L.; Pirro, J.P.

1991-01-01

Inherent cellular radiosensitivity in vitro has been shown to be a good predictor of human tumor response in vivo. In contrast, the importance of the intrinsic thermosensitivity of normal and neoplastic human cells as a factor in the responsiveness of human tumors to adjuvant hyperthermia has never been analyzed systematically. A comparison of thermal sensitivity and thermo-radiosensitization in four rodent and eight human-derived cell lines was made in vitro. Arrhenius plots indicated that the rodent cells were more sensitive to heat killing than the human, and the break-point was 0.5 degrees C higher for the human than rodent cells. The relationship between thermal sensitivity and the interaction of heat with X rays at low doses was documented by thermal enhancement ratios (TER's). Cells received either a 1 hr exposure to 43 degrees C or a 20 minute treatment at 45 degrees C before exposure to 300 kVp X rays. Thermal enhancement ratios ranged from 1.0 to 2.7 for human cells heated at 43 degrees C and from 2.1 to 5.3 for heat exposures at 45 degrees C. Thermal enhancement ratios for rodent cells were generally 2 to 3 times higher than for human cells, because of the fact that the greater thermosensitivity of rodent cells results in a greater enhancement of radiation damage. Intrinsic thermosensitivity of human cells has relevance to the concept of thermal dose; intrinsic thermo-radiosensitization of a range of different tumor cells is useful in documenting the interactive effects of radiation combined with heat

Failure analyses and weld repair of boiler feed water pumps

Energy Technology Data Exchange (ETDEWEB)

Vulpen, R van [KemaPower Generation, Arnhem (Netherlands)

1999-12-31

During a regular inspection of the Boiler Auxiliaries at one of the Dutch Electricity Production Companies serious cracks were found in the cover and casings of the feed water circulation pumps in two units after 108.000 and 122.000 hours of boiler operation. Kema Laboratories carried out Failure analyses on boat samples at the cracked areas. Corrosion fatigue cracking was found on the inner side of the GS-24CrNiMo325 casing. Shop Weld repairs were carried out using a newly developed mechanized Plasma Welding Technique. The repaired feed water circulation pumps showed no problems alter several years of operation. The costs of repair were substantially lower than the costs of replacement. (orig.) 3 refs.

Failure analyses and weld repair of boiler feed water pumps

Energy Technology Data Exchange (ETDEWEB)

Vulpen, R. van [KemaPower Generation, Arnhem (Netherlands)

1998-12-31

During a regular inspection of the Boiler Auxiliaries at one of the Dutch Electricity Production Companies serious cracks were found in the cover and casings of the feed water circulation pumps in two units after 108.000 and 122.000 hours of boiler operation. Kema Laboratories carried out Failure analyses on boat samples at the cracked areas. Corrosion fatigue cracking was found on the inner side of the GS-24CrNiMo325 casing. Shop Weld repairs were carried out using a newly developed mechanized Plasma Welding Technique. The repaired feed water circulation pumps showed no problems alter several years of operation. The costs of repair were substantially lower than the costs of replacement. (orig.) 3 refs.

Regular expressions cookbook

CERN Document Server

Goyvaerts, Jan

2009-01-01

This cookbook provides more than 100 recipes to help you crunch data and manipulate text with regular expressions. Every programmer can find uses for regular expressions, but their power doesn't come worry-free. Even seasoned users often suffer from poor performance, false positives, false negatives, or perplexing bugs. Regular Expressions Cookbook offers step-by-step instructions for some of the most common tasks involving this tool, with recipes for C#, Java, JavaScript, Perl, PHP, Python, Ruby, and VB.NET. With this book, you will: Understand the basics of regular expressions through a

Visual Landmarks Facilitate Rodent Spatial Navigation in Virtual Reality Environments

Science.gov (United States)

Youngstrom, Isaac A.; Strowbridge, Ben W.

2012-01-01

Because many different sensory modalities contribute to spatial learning in rodents, it has been difficult to determine whether spatial navigation can be guided solely by visual cues. Rodents moving within physical environments with visual cues engage a variety of nonvisual sensory systems that cannot be easily inhibited without lesioning brain…

LL-regular grammars

NARCIS (Netherlands)

Nijholt, Antinus

1980-01-01

Culik II and Cogen introduced the class of LR-regular grammars, an extension of the LR(k) grammars. In this paper we consider an analogous extension of the LL(k) grammars called the LL-regular grammars. The relation of this class of grammars to other classes of grammars will be shown. Any LL-regular

The feed-back regulation of erythropoietin production in healthy humans

International Nuclear Information System (INIS)

Klausen, T.

1998-01-01

The proposed oxygen-dependent feed-back loop regulation of EPO (erythropoietin) production is mainly supported by data from studies in animals and cell cultures. The feed-back loop and its dependence on oxygen was therefore challenged by studies in healthy humans: Exposure of humans to different levels of acute and continued altitude hypobaria provided evidence for an oxygen dependence of the EPO response. This response is consistent with the proposed feed-back loop regulation of EPO production; Exposure to continued altitude hypobaria demonstrated that the decline in human EPO production is initiated before an EPO-induced erythopoiesis is detectable, and that this decline is related to a concomitant decrease in the haemoglobin-oxygen affinity. Contrary to the feed-back loop, this time-relation indicate that the feed-back regulation of EPO production during continued hypobaric hypoxia is exerted primarily through a decrease in the haemoglobin-oxygen affinity, rather than by the effects of an EPO-stimulated erythropoiesis; Increased circulating levels of the proinflammatory cytokine IL-6 was found in healthy humans during four days of altitude exposure as compared with sea level. The other proinflammatory cytokines IL-1 beta, and TNF alpha remained unchanged, and the increased serum IL-6 did not induce production of c-reactive protein; Comparable circadian variations in human EPO production were shown in sedentary subjects, athletes, and healthy but hypoxaemic subjects. Human EPO production could not be triggered by one hour of high-intensity exercise, whereas longitudinal changes in exercise showed a trend of relation between human EPO production, serum concentration of free testosterone, and indices of body composition. These results have demonstrated and endogenous, probably hormonal, and oxygen-independent regulation of human EPO production, which is at variance with the oxygen dependent feed-back loop regulation of EPO production. Conclusively, the present

Relationships between rodent white adipose fat pads and human white adipose fat depots

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Daniella E. Chusyd

2016-04-01

Full Text Available The objective of this review was to compare and contrast the physiological and metabolic profiles of rodent white adipose fat pads with white adipose fat depots in humans. Human fat distribution and its metabolic consequences have received extensive attention, but much of what has been tested in translational research has relied heavily on rodents. Unfortunately, the validity of using rodent fat pads as a model of human adiposity has received less attention. There is a surprisingly lack of studies demonstrating an analogous relationship between rodent and human adiposity on obesity-related comorbidities. Therefore, we aimed to compare known similarities and disparities in terms of white adipose tissue development and distribution, sexual dimorphism, weight loss, adipokine secretion, and aging. While the literature supports the notion that many similarities exist between rodents and humans, notable differences emerge related to fat deposition and function of white adipose tissue. Thus, further research is warranted to more carefully define the strengths and limitations of rodent white adipose tissue as a model for humans, with a particular emphasis on comparable fat depots, such as mesenteric fat.

The Ethics of Rodent Control

NARCIS (Netherlands)

Meerburg, B.G.; Brom, F.W.A.; Kijlstra, A.

2008-01-01

Because western societies generally see animals as objects of moral concern, demands have been made on the way they are treated, e.g. during animal experimentation. In the case of rodent pests, however, inhumane control methods are often applied. This inconsistency in the human-animal relationship

The water economy of South American desert rodents: from integrative to molecular physiological ecology.

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Bozinovic, Francisco; Gallardo, Pedro

2006-01-01

Rodents from arid and semi-arid habitats live under conditions where the spatial and temporal availability of free water is limited, or scarce, thus forcing these rodents to deal with the problem of water conservation. The response of rodents to unproductive desert environments and water deficits has been intensively investigated in many deserts of the world. However, current understanding of the cellular, systemic and organismal physiology of water economy relies heavily on short-term, laboratory-oriented experiments, which usually focus on responses at isolated levels of biological organization. In addition, studies in small South American mammals are scarce. Indeed xeric habitats have existed in South America for a long time and it is intriguing why present day South American desert rodents do not show the wide array of adaptive traits to desert life observed for rodents on other continents. Several authors have pointed out that South American desert rodents lack physiological and energetic specialization for energy and water conservation, hypothesizing that their success is based more on behavioral and ecological strategies. We review phenotypic flexibility and physiological diversity in water flux rate, urine osmolality, and expression of water channels in South American desert-dwelling rodents. As far as we know, this is the first review of integrative studies at cellular, systemic and organismal levels. Our main conclusion is that South American desert rodents possess structural as well as physiological systems for water conservation, which are as remarkable as those found in "classical" rodents inhabiting other desert areas of the world.

Helminth Infections of Rodents and Their Zoonotic Importance in Boyer-Ahmad District, Southwestern Iran

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Mohammad Javad RANJBAR

2017-12-01

Full Text Available AbstractBackground: Rodents are considered as reservoirs of various zoonotic diseases including helminthic infections. The current study aimed to evaluate the prevalence of helminth infections in rodents, in Boyer-Ahmad district, Southwestern Iran.Methods: Overall, 52 rodents were captured from various areas of the district by Sherman live traps. The animals were then euthanized and dissected. During necropsy, each organ was examined macroscopically for presence of any cyst or visible parasite. The gastrointestinal tract was removed and their contents were evaluated for larva or adult worms. Trichinella larvae in the rodents’ muscles were investigated by both digestion and pathological methods.Results: Twenty-eight (53.8% of the trapped rodents were male. The rodents were including 25 (48.1% Meriones persicus, 1(1.9% Calomyscus bailwardi, 1 (1.9% Arvicola terresterris, 7 (13.5% Rattus rattus, 8 (15.4% R. norvegicus, and 10 (19.2% Apodemus sylvaticus. Of them, 38 (73.0% were infected with at least one helminth. Collected rodents were infected with Hymenolepis diminuta (50%, Hymenolepis nana fraterna (28.8%, Skrjabinotaenia sp. (15.4%, Anoplocephalidae sp. (15.4%, Cysticercus fasciolaris (5.8%, Trichuris muris (36.5%, Aspiculuris tetraptera (15.4%, Syphacia sp. (5.7%, Rictularia sp. (15.4%, Trichostrongylus sp. (3.8%, and Gongylonema sp. (3.8%. M. persicus was the most (84% infected rodent, yet the differences between rodent genus and helminth infectivity were not statistically significant (P>0.05.Conclusion: The rodents in Boyer-Ahmad district are infected with different helminths infections that some of them are recognized as threat to human health.

Stress, social behavior, and resilience: Insights from rodents

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Beery, Annaliese K.; Kaufer, Daniela

2014-01-01

The neurobiology of stress and the neurobiology of social behavior are deeply intertwined. The social environment interacts with stress on almost every front: social interactions can be potent stressors; they can buffer the response to an external stressor; and social behavior often changes in response to stressful life experience. This review explores mechanistic and behavioral links between stress, anxiety, resilience, and social behavior in rodents, with particular attention to different social contexts. We consider variation between several different rodent species and make connections to research on humans and non-human primates. PMID:25562050

Timing of host feeding drives rhythms in parasite replication

KAUST Repository

Prior, Kimberley F.

2018-02-26

Circadian rhythms enable organisms to synchronise the processes underpinning survival and reproduction to anticipate daily changes in the external environment. Recent work shows that daily (circadian) rhythms also enable parasites to maximise fitness in the context of ecological interactions with their hosts. Because parasite rhythms matter for their fitness, understanding how they are regulated could lead to innovative ways to reduce the severity and spread of diseases. Here, we examine how host circadian rhythms influence rhythms in the asexual replication of malaria parasites. Asexual replication is responsible for the severity of malaria and fuels transmission of the disease, yet, how parasite rhythms are driven remains a mystery. We perturbed feeding rhythms of hosts by 12 hours (i.e. diurnal feeding in nocturnal mice) to desynchronise the host’s peripheral oscillators from the central, light-entrained oscillator in the brain and their rhythmic outputs. We demonstrate that the rhythms of rodent malaria parasites in day-fed hosts become inverted relative to the rhythms of parasites in night-fed hosts. Our results reveal that the host’s peripheral rhythms (associated with the timing of feeding and metabolism), but not rhythms driven by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms resynchronise to the altered host feeding rhythms when food availability is shifted, which is not mediated through rhythms in the host immune system. Our observations suggest that parasites actively control their developmental rhythms. Finally, counter to expectation, the severity of disease symptoms expressed by hosts was not affected by desynchronisation of their central and peripheral rhythms. Our study at the intersection of disease ecology and chronobiology opens up a new

Timing of host feeding drives rhythms in parasite replication

KAUST Repository

Prior, Kimberley F

2017-12-07

Circadian rhythms enable organisms to synchronise the processes underpinning survival and reproduction to anticipate daily changes in the external environment. Recent work shows that daily (circadian) rhythms also enable parasites to maximise fitness in the context of ecological interactions with their hosts. Because parasite rhythms matter for their fitness, understanding how they are regulated could lead to innovative ways to reduce the severity and spread of diseases. Here, we examine how host circadian rhythms influence rhythms in the asexual replication of malaria parasites. Asexual replication is responsible for the severity of malaria and fuels transmission of the disease, yet, how parasite rhythms are driven remains a mystery. We perturbed feeding rhythms of hosts by 12 hours (i.e. diurnal feeding in nocturnal mice) to desynchronise the host\\'s peripheral oscillators from the central, light-entrained oscillator in the brain and their rhythmic outputs. We demonstrate that the rhythms of rodent malaria parasites in day-fed hosts become inverted relative to the rhythms of parasites in night-fed hosts. Our results reveal that the host\\'s peripheral rhythms (associated with the timing of feeding and metabolism), but not rhythms driven by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms resynchronise to the altered host feeding rhythms when food availability is shifted, which is not mediated through rhythms in the host immune system. Our observations suggest that parasites actively control their developmental rhythms. Finally, counter to expectation, the severity of disease symptoms expressed by hosts was not affected by desynchronisation of their central and peripheral rhythms. Our study at the intersection of disease ecology and chronobiology opens up a new

Knowledge, opinions and practices of healthcare workers related to infant feeding in the context of HIV

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Liska Janse van Rensburg

2016-12-01

Conclusion: Healthcare workers' knowledge did not conform favourably with the current WHO guidelines. These healthcare workers were actively involved in the care of patients in the maternity wards where HIV-infected mothers regularly seek counselling on infant feeding matters.

Research Note. Occurrence of gastrointestinal helminths in commensal rodents from Tabasco, Mexico

OpenAIRE

Cigarroa-Toledo N.; Santos-Martinez Y. De Los; Zaragoza-Vera C. V.; Garcia-Rodriguez M. M.; Baak-Baak C. M.; Machain-Williams C.; Garcia-Rejon J. E.; Panti-May J. A.; Torres-Chable O. M.

2017-01-01

The aim of this study was to determine the prevalence and species composition of helminths in commensal rodents captured inside private residences in the city of Villahermosa in Tabasco, Mexico. Trapping was performed at each house for three consecutive nights from October to December 2015. Fifty commensal rodents were captured: 23 Rattus norvegicus, 16 Mus musculus and 11 Rattus rattus. Rodents were transported alive to the laboratory and held in cages until they defecated. Feces were analyz...

Comparison of food hoarding of two sympatric rodent species under interspecific competition.

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Zhang, Yi-Feng; Tong, Lei; Ji, Wei-Hong; Lu, Ji-Qi

2013-01-01

Competition can greatly affect the food hoarding strategies of rodents and the fate of seeds hoarded. In order to understand the influence of interspecific competition on food caching behavior of sympatric rodents, we investigated food hoarding patterns of two sympatric rodent species, buff-breasted rat (Rattus flavipectus) and Chinese white-bellied rat (Niviventor confucianus), and compared their responses and adjustment in hoarding behavior under interspecific competition. The results showed that: (1) the buff-breasted rat larder hoarded seeds only, while Chinese white-bellied rat hoarded seeds in both larder and scatter forms; (2) two species of rodents both larder hoarded more seeds when competitors were present; and (3) the Chinese white-bellied rats adjusted their seed hoarding from scatter to larder when competitors were introduced, which reduced the seed availability. Therefore, we concluded that rodents would adjust their food hoarding strategy when interspecific competitors were present, and this may produce a different effect on the fate of seeds and the recruitment of plants. This article is part of a Special Issue entitled: insert SI title. Copyright © 2012. Published by Elsevier B.V.

Sex differences in feeding behavior in rats: the relationship with neuronal activation in the hypothalamus

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Atsushi eFukushima

2015-03-01

Full Text Available There is general agreement that the central nervous system in rodents differs between sexes due to the presence of gonadal steroid hormone during differentiation. Sex differences in feeding seem to occur among species, and responses to fasting (i.e., starvation, gonadal steroids (i.e., testosterone and estradiol, and diet (i.e., western-style diet vary significantly between sexes. The hypothalamus is the center for controlling feeding behavior. We examined the activation of feeding-related peptides in neurons in the hypothalamus. Phosphorylation of cyclic AMP response element-binding protein (CREB is a good marker for neural activation, as is the Fos antigen. Therefore, we predicted that sex differences in the activity of melanin-concentrating hormone (MCH neurons would be associated with feeding behavior. We determined the response of MCH neurons to glucose in the lateral hypothalamic area (LHA and our results suggested MCH neurons play an important role in sex differences in feeding behavior. In addition, fasting increased the number of orexin neurons harboring phosphorylated CREB in female rats (regardless of the estrous day, but not male rats. Glucose injection decreased the number of these neurons with phosphorylated CREB in fasted female rats. Finally, under normal spontaneous food intake, MCH neurons, but not orexin neurons, expressed phosphorylated CREB. These sex differences in response to fasting and glucose, as well as under normal conditions, suggest a vulnerability to metabolic challenges in females.

The need to implement the landscape of fear within rodent pest management strategies.

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Krijger, Inge M; Belmain, Steven R; Singleton, Grant R; Groot Koerkamp, Peter Wg; Meerburg, Bastiaan G

2017-12-01

Current reactive pest management methods have serious drawbacks such as the heavy reliance on chemicals, emerging genetic rodenticide resistance and high secondary exposure risks. Rodent control needs to be based on pest species ecology and ethology to facilitate the development of ecologically based rodent management (EBRM). An important aspect of EBRM is a strong understanding of rodent pest species ecology, behaviour and spatiotemporal factors. Gaining insight into the behaviour of pest species is a key aspect of EBRM. The landscape of fear (LOF) is a mapping of the spatial variation in the foraging cost arising from the risk of predation, and reflects the levels of fear a prey species perceives at different locations within its home range. In practice, the LOF maps habitat use as a result of perceived fear, which shows where bait or traps are most likely to be encountered and used by rodents. Several studies have linked perceived predation risk of foraging animals with quitting-harvest rates or giving-up densities (GUDs). GUDs have been used to reflect foraging behaviour strategies of predator avoidance, but to our knowledge very few papers have directly used GUDs in relation to pest management strategies. An opportunity for rodent control strategies lies in the integration of the LOF of rodents in EBRM methodologies. Rodent management could be more efficient and effective by concentrating on those areas where rodents perceive the least levels of predation risk. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Zoonotic pathogens in Atlantic Forest wild rodents in Brazil: Bartonella and Coxiella infections.

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Rozental, Tatiana; Ferreira, Michelle Santos; Guterres, Alexandro; Mares-Guia, Maria Angélica; Teixeira, Bernardo R; Gonçalves, Jonathan; Bonvicino, Cibele Rodrigues; D'Andrea, Paulo Sergio; de Lemos, Elba Regina Sampaio

2017-04-01

Zoonotic pathogens comprise a significant and increasing fraction of all emerging and re-emerging infectious diseases that plague humans. Identifying host species is one of the keys to controlling emerging infectious diseases. From March 2007 until April 2012, we collected a total of 131 wild rodents in eight municipalities of Rio de Janeiro, Brazil. We investigated these rodents for infection with Coxiella burnetii, Bartonella spp. and Rickettsia spp. In total, 22.1% (29/131) of the rodents were infected by at least one pathogen; co-infection was detected in 1.5% (2/131) of rodents. Coxiella burnetii was detected in 4.6% (6/131) of the wild animals, 17.6% of the rodents harbored Bartonella spp. No cases of Rickettsia were identified. Bartonella doshiae and Bartonella vinsonii were the species found on the wild mammals. This report is the first to note C. burnetii, B. doshiae and B. vinsonii natural infections in Atlantic Forest wild rodents in Brazil. Our work highlights the potential risk of transmission to humans, since most of the infected specimens belong to generalist species that live near human dwellings. Copyright © 2017 Elsevier B.V. All rights reserved.

Neurogenetics of aggressive behavior: studies in rodents.

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Takahashi, Aki; Miczek, Klaus A

2014-01-01

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

Comparison of Subcutaneous Regular Insulin and Lispro Insulin in Diabetics Receiving Continuous Nutrition

Science.gov (United States)

Stull, Mamie C.; Strilka, Richard J.; Clemens, Michael S.; Armen, Scott B.

2015-01-01

Background: Optimal management of non–critically ill patients with diabetes maintained on continuous enteral feeding (CEN) is poorly defined. Subcutaneous (SQ) lispro and SQ regular insulin were compared in a simulated type 1 and type 2 diabetic patient receiving CEN. Method: A glucose-insulin feedback mathematical model was employed to simulate type 1 and type 2 diabetic patients on CEN. Each patient received 25 SQ injections of regular insulin or insulin lispro, ranging from 0-6 U. Primary endpoints were the change in mean glucose concentration (MGC) and change in glucose variability (GV); hypoglycemic episodes were also reported. The model was first validated against patient data. Results: Both SQ insulin preparations linearly decreased MGC, however, SQ regular insulin decreased GV whereas SQ lispro tended to increase GV. Hourly glucose concentration measurements were needed to capture the increase in GV. In the type 2 diabetic patient, “rebound hyperglycemia” occurred after SQ lispro was rapidly metabolized. Although neither SQ insulin preparation caused hypoglycemia, SQ lispro significantly lowered MGC compared to SQ regular insulin. Thus, it may be more likely to cause hypoglycemia. Analyses of the detailed glucose concentration versus time data suggest that the inferior performance of lispro resulted from its shorter duration of action. Finally, the effects of both insulin preparations persisted beyond their duration of actions in the type 2 diabetic patient. Conclusions: Subcutaneous regular insulin may be the short-acting insulin preparation of choice for this subset of diabetic patients. Clinical trial is required before a definitive recommendation can be made. PMID:26134836

An iterative method for Tikhonov regularization with a general linear regularization operator

NARCIS (Netherlands)

Hochstenbach, M.E.; Reichel, L.

2010-01-01

Tikhonov regularization is one of the most popular approaches to solve discrete ill-posed problems with error-contaminated data. A regularization operator and a suitable value of a regularization parameter have to be chosen. This paper describes an iterative method, based on Golub-Kahan

The valproic acid-induced rodent model of autism.

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Nicolini, Chiara; Fahnestock, Margaret

2018-01-01

Autism is a lifelong neurodevelopmental disorder characterized by impairments in social communication and interaction and by repetitive patterns of behavior, interests and activities. While autism has a strong genetic component, environmental factors including toxins, pesticides, infection and drugs are known to confer autism susceptibility, likely by inducing epigenetic changes. In particular, exposure to valproic acid (VPA) during pregnancy has been demonstrated to increase the risk of autism in children. Furthermore, rodents prenatally exposed to this drug display behavioral phenotypes characteristics of the human condition. Indeed, in utero exposure of rodents to VPA represents a robust model of autism exhibiting face, construct and predictive validity. This model might better represent the many cases of idiopathic autism which are of environmental/epigenetic origins than do transgenic models carrying mutations in single autism-associated genes. The VPA model provides a valuable tool to investigate the neurobiology underlying autistic behavior and to screen for novel therapeutics. Here we review the VPA-induced rodent model of autism, highlighting its importance and reliability as an environmentally-induced animal model of autism. Copyright © 2017 Elsevier Inc. All rights reserved.

Guide to Commensal Rodent Control

Science.gov (United States)

1991-12-01

in many detergents also fluoresce. For positive identification, place the suspect material on Urease Siom lhymol Blue test paper, moisten with water...are applied in a thin layer in protected rat and mouse r’unways, baitboxes, or tubes along walls. The powder is picked up by the rodents on their feet

Occurrence and distribution of Giardia species in wild rodents in Germany.

Science.gov (United States)

Helmy, Yosra A; Spierling, Nastasja G; Schmidt, Sabrina; Rosenfeld, Ulrike M; Reil, Daniela; Imholt, Christian; Jacob, Jens; Ulrich, Rainer G; Aebischer, Toni; Klotz, Christian

2018-03-27

Giardiasis is an important gastrointestinal parasitic disease in humans and other mammals caused by the protozoan Giardia duodenalis. This species complex is represented by genetically distinct groups (assemblages A-H) with varying zoonotic potential and host preferences. Wild rodents can harbor potentially zoonotic assemblages A and B, and the rodent-specific assemblage G. Other Giardia spp. found in these animals are Giardia muris and Giardia microti. For the latter, only limited information on genetic typing is available. It has been speculated that wild rodents might represent an important reservoir for parasites causing human giardiasis. The aim of this study was to investigate the occurrence and distribution of Giardia spp. and assemblage types in wild rodents from different study sites in Germany. Screening of 577 wild rodents of the genera Apodemus, Microtus and Myodes, sampled at eleven study sites in Germany, revealed a high overall Giardia prevalence. Giardia species determination at the SSU rDNA gene locus revealed that Apodemus mice, depending on species, were predominantly infected with one of two distinct G. muris sequence types. Giardia microti was the predominant parasite species found in voles of the genera Microtus and Myodes. Only a few animals were positive for potentially zoonotic G. duodenalis. Subtyping at the beta-giardin (bg) and glutamine dehydrogenase (gdh) genes strongly supported the existence of different phylogenetic subgroups of G. microti that are preferentially harbored by distinct host species. The present study highlights the preference of G. muris for Apodemus, and G. microti for Microtus and Myodes hosts and argues for a very low prevalence of zoonotic G. duodenalis assemblages in wild rodents in Germany. It also provides evidence that G. muris and G. microti subdivide into several phylogenetically distinguishable subgroups, each of which appears to be preferentially harbored by species of a particular rodent host genus

The bioeconomics of controlling an African rodent pest species

OpenAIRE

Skonhoft, Anders; Herwig, Leirs; Andreassen, Harry Peter; Mulungu, Loth S. A.; Stenseth, Nils Christian

2006-01-01

The paper treats the economy of controlling an African pest rodent, the multimammate rat, causing major damage in maize production. An ecological population model is presented and used as a basis for the economic analyses carried out at the village level using data from Tanzania. This model incorporates both density-dependent and density-independent (stochastic) factors. Rodents are controlled by applying poison, and the economic benefits depend on the income from maize production minus the c...

Regular Expression Pocket Reference

CERN Document Server

Stubblebine, Tony

2007-01-01

This handy little book offers programmers a complete overview of the syntax and semantics of regular expressions that are at the heart of every text-processing application. Ideal as a quick reference, Regular Expression Pocket Reference covers the regular expression APIs for Perl 5.8, Ruby (including some upcoming 1.9 features), Java, PHP, .NET and C#, Python, vi, JavaScript, and the PCRE regular expression libraries. This concise and easy-to-use reference puts a very powerful tool for manipulating text and data right at your fingertips. Composed of a mixture of symbols and text, regular exp

Experience with early postoperative feeding after abdominal aortic surgery.

Science.gov (United States)

Ko, Po-Jen; Hsieh, Hung-Chang; Liu, Yun-Hen; Liu, Hui-Ping

2004-03-01

Abdominal aortic surgery is a form of major vascular surgery, which traditionally involves long hospital stays and significant postoperative morbidity. Experiences with transit ileus are often encountered after the aortic surgery. Thus traditional postoperative care involves delayed oral feeding until the patients regain their normal bowel activities. This report examines the feasibility of early postoperative feeding after abdominal aortic aneurysm (AAA) open-repair. From May 2002 through May 2003, 10 consecutive patients with infrarenal AAA who underwent elective surgical open-repair by the same surgeon in our department were reviewed. All of them had been operated upon and cared for according to the early feeding postoperative care protocol, which comprised of adjuvant epidural anesthesia, postoperative patient controlled analgesia, early postoperative feeding and early rehabilitation. The postoperative recovery and length of hospital stay were reviewed and analyzed. All patients were able to sip water within 1 day postoperatively without trouble (Average; 12.4 hours postoperatively). All but one patient was put on regular diet within 3 days postoperatively (Average; 2.2 days postoperatively). The average postoperative length of stay in hospital was 5.8 days. No patient died or had major morbidity. Early postoperative feeding after open repair of abdominal aorta is safe and feasible. The postoperative recovery could be improved and the length of stay reduced by simply using adjuvant epidural anesthesia during surgery, postoperative epidural patient-controlled analgesia, early feeding, early ambulation, and early rehabilitation. The initial success of our postoperative recovery program of aortic repair was demonstrated.

Protozoan Parasites of Rodents and Their Zoonotic Significance in Boyer-Ahmad District, Southwestern Iran

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Zeinab Seifollahi

2016-01-01

Full Text Available Backgrounds. Wild rodents are reservoirs of various zoonotic diseases, such as toxoplasmosis, babesiosis, and leishmaniasis. The current study aimed to assess the protozoan infection of rodents in Boyer-Ahmad district, southwestern Iran. Materials and Methods. A total of 52 rodents were collected from different parts of Boyer-Ahmad district, in Kohgiluyeh and Boyer-Ahmad province, using Sherman live traps. Each rodent was anesthetized with ether, according to the ethics of working with animals, and was dissected. Samples were taken from various tissues and stool samples were collected from the contents of the colon and small intestines. Moreover, 2 to 5 mL of blood was taken from each of the rodents and the sera were examined for anti-Leishmania antibodies, by ELISA, or anti-T. gondii antibodies, by modified agglutination test (MAT. DNA was extracted from brain tissue samples of each rodent and PCR was used to identify the DNA of T. gondii. Results. Of the 52 stool samples of rodents studied by parasitological methods, intestinal protozoa infection was seen in 28 cases (53.8%. From 52 rodents, 19 (36.5% were infected with Trichomonas, 10 (19.2% with Giardia muris, and 11 (21.2% with Entamoeba spp. Also, 10 cases (19.2% were infected with Blastocystis, 3 (5.8% were infected with Chilomastix, 7 (13.5% were infected with Endolimax, 1 (1.9% was infected with Retortamonas, 3 (5.77% were infected with T. gondii, and 6 (11.54% were infected with Trypanosoma lewisi. Antibodies to T. gondii were detected in the sera of 5 (9.61% cases. Results of the molecular study showed T. gondii infection in 3 (5.77% of the rodents. Findings of this study showed that rodents in Kohgiluyeh and Boyer-Ahmad province, southwestern Iran, are infected with several blood and intestinal parasites; some of them might be potential risks to residents and domestic animals in the region.

Population response of rodents to control with rodenticides

Directory of Open Access Journals (Sweden)

A.V. TCHABOVSKY

2009-04-01

Full Text Available We summarize theoretical approaches and practice of rodent pest control in Russia and former USSR during last 50 years. We review literature as well as original data to understand mechanisms of rodent populations recovery after chemical control campaigns in urban areas, agricultural lands and natural foci of plague. Laboratory and field experiments indicate that inherent individual variation in behavioural, physiological and life-history traits provides survival of heterogeneous mix of individuals in residual population with increased resistance to poisonous baits and high reproductive potential that leads to fast recovery of a population. In a series of field experiments with various rodent and lagomorph species (Mus musculus, Rattus norvegicus, Meriones unguiculatus, M.meridianus, M.tamariscinus, Ochotona pallasii we have shown that patterns of recolonization of depopulated area and mechanisms of population recovery vary among species and depend on species-specific social organization. After control territorial and group-living species demonstrated an increase in mobility and affiliative and marking behaviour and a decrease in intraspecific aggression. The rate of recolonization of treated areas was high due to redistribution of survived individuals and immigration by neighbors. Population recovered to original level due to increased breeding performance and fecundity of both survived residents and immigrants. In contrast, socially-independent species exhibited minor changes in behaviour. Recolonization was mainly due to better survival and recruitment of youngs, so the rate of recolonization was low. Species-specificity of behavioural compensation mechanisms to control should be considered when developing ecologically based rodent management strategies.

an ecological study on rodents of natural vegetation and farm lands ...

African Journals Online (AJOL)

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habitat association of rodents was conducted in Siltie natural vegetation and nearby farmlands ... In each habitat type, one representative grid was selected for live trapping. In addition, rodents were also snap- trapped from these habitats. A total of 562 captures was made .... into seeds, leaves, roots, earthworms and arthro-.

Measuring feeding difficulties in toddlers with Down syndrome.

Science.gov (United States)

van Dijk, Marijn; Lipke-Steenbeek, Wilma

2018-07-01

Early feeding problems occur frequently across the population, but have a higher incidence in children with Down syndrome (DS). Early identification can possibly be improved with the help of a valid screening instrument based on caregiver reports. In a previous study, we investigated the concurrent validity of the Dutch version of the Montreal Children's Hospital Feeding Scale (MCH-FS, SEP in Dutch) in a sample of typically developing toddlers, and we found a correlation between the score on the instrument and observed behavior during a regular meal. The current pilot study was a replication in a sample of children with DS (aged 1; 0-3; 0) and their primary caregivers (n = 32). The results showed that children in the sample did not score higher on the SEP than children in their respective norm groups. In addition, when caregivers reported more symptoms of feeding problems on the SEP, children showed more food refusal and negative affect during the observed meal. This suggests that the screening instrument is particularly associated with negative mealtime interactions. This is in contrast with earlier results, which mainly indicated a relation with eating skills. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dietary Protein Source and Cyclooxygenase-Inhibition Influence Development of Diet-Induced Obesity, Glucose Homeostasis and Brown Adipose Tissue

DEFF Research Database (Denmark)

Aune, Ulrike Liisberg

striking differences between various protein sources in relation to the development of obesity, insulin resistance and hepatic lipid accumulation. Casein protein, despite being the regular protein source used in experimental diets for rodents, seems to provide strong protection against obesity. This was......, the lean protein source, pork, seemed to promote obesity. However, this was attenuated when pork was exchanged for cod. Reduced feed-intake in the cod-fed mice could provide some explanation for this, but, other mechanisms, potentially involving endocannabinoids, may play a role. The small amount...

Small rodents as paratenic or intermediate hosts of carnivore parasites in Berlin, Germany.

Science.gov (United States)

Krücken, Jürgen; Blümke, Julia; Maaz, Denny; Demeler, Janina; Ramünke, Sabrina; Antolová, Daniela; Schaper, Roland; von Samson-Himmelstjerna, Georg

2017-01-01

Rodents are important intermediate and paratenic hosts for carnivore parasites, including the important zoonotic agents Toxoplasma, Echinococcus and Toxocara. Monitoring of such parasites in rodents can be used to detect increasing risks for human and veterinary public health. Rodents were trapped at four sites in Berlin, two near the city center, two at the periphery. PCRs were conducted to detect Coccidia (target ITS-1) and specifically Toxoplasma gondii (repetitive element) in brain and ascarids (ITS-2) in muscle or brain tissue. During necropsies, metacestodes were collected and identified using ITS-2 and 12S rRNA PCRs. An ELISA to detect antibodies against Toxocara canis ES antigens was performed. Within the 257 examined rodents, the most frequently observed parasite was Frenkelia glareoli predominantly found in Myodes glareolus. T. gondii was only detected in 12 rodents and Microtus spp. (although strongly underrepresented) had a significantly increased chance of being positive. Neither Echinococcus nor typical Taenia parasites of dogs and cats were found but Mesocestoides litteratus and Taenia martis metacestodes were identified which can cause severe peritoneal or ocular cysticercosis in dogs, primates and humans. Using PCR, the ascarids T. canis (n = 8), Toxocara cati (4) and Parascaris sp. (1) were detected predominantly in muscles. Seroprevalence of T. canis was 14.2% and ELISA was thus more sensitive than PCR to detect infection with this parasite. Non-parametric multidimensional scaling and cluster analysis revealed that parasite communities could be grouped into an urban and a peri-urban cluster with high frequency of ascarid-positive rodents in urban and high frequency of F. glareoli in peri-urban sites. Prevalence rates of parasites in rodents with potential impact for human or veterinary public health are considerable and the monitoring of transmission cycles of carnivore parasites in intermediate rodent hosts is recommended to estimate the health

Small rodents as paratenic or intermediate hosts of carnivore parasites in Berlin, Germany.

Directory of Open Access Journals (Sweden)

Jürgen Krücken

Full Text Available Rodents are important intermediate and paratenic hosts for carnivore parasites, including the important zoonotic agents Toxoplasma, Echinococcus and Toxocara. Monitoring of such parasites in rodents can be used to detect increasing risks for human and veterinary public health. Rodents were trapped at four sites in Berlin, two near the city center, two at the periphery. PCRs were conducted to detect Coccidia (target ITS-1 and specifically Toxoplasma gondii (repetitive element in brain and ascarids (ITS-2 in muscle or brain tissue. During necropsies, metacestodes were collected and identified using ITS-2 and 12S rRNA PCRs. An ELISA to detect antibodies against Toxocara canis ES antigens was performed. Within the 257 examined rodents, the most frequently observed parasite was Frenkelia glareoli predominantly found in Myodes glareolus. T. gondii was only detected in 12 rodents and Microtus spp. (although strongly underrepresented had a significantly increased chance of being positive. Neither Echinococcus nor typical Taenia parasites of dogs and cats were found but Mesocestoides litteratus and Taenia martis metacestodes were identified which can cause severe peritoneal or ocular cysticercosis in dogs, primates and humans. Using PCR, the ascarids T. canis (n = 8, Toxocara cati (4 and Parascaris sp. (1 were detected predominantly in muscles. Seroprevalence of T. canis was 14.2% and ELISA was thus more sensitive than PCR to detect infection with this parasite. Non-parametric multidimensional scaling and cluster analysis revealed that parasite communities could be grouped into an urban and a peri-urban cluster with high frequency of ascarid-positive rodents in urban and high frequency of F. glareoli in peri-urban sites. Prevalence rates of parasites in rodents with potential impact for human or veterinary public health are considerable and the monitoring of transmission cycles of carnivore parasites in intermediate rodent hosts is recommended to

Comparative Ultrastructural Studies on the Impact of Moderate and Hyperthermic Environment on the Corneal Structure of two Species of Wild Rodents

International Nuclear Information System (INIS)

Naguib, N.I.; El-Dawi, E.F.

2011-01-01

This study was carried out to investigate the impact of environmental climate (temperature) on the corneal structure of two wild rodents; the nocturnal Norway rats (Rattus norvegicus) and the diurnal golden spiny mouse (Acomys russatus). Both rodents were collected from two extreme climatic environment and their dissected corneas were prepared for light, scanning and transmission electron microscopy. The corneas of both rodents are composed of three main layers; an outer epithelium, stroma, Descemet's membrane, and an inner endothelium. The mean thickness of the epithelium, stroma, Descemet's membrane and inner endothelium of both rodents were measured. The scanning electron microscopy revealed that in R. norvegicus and A. russatus; the outermost cells of the corneal epithelium, are mostly polygonal in shape with nearly regular borders and show dense pattern of microplicae with different scatter electron that exhibits three polymorphic appearances (A, B, C) and two (A, B), respectively. Numerous A-light cells with dense microplicae, many B-dark cells with a moderate density of microplicae and few C-dark cells with a less density of microplicae were observed. Using transmission electron microscope, the epithelial cells of both species possess glycocalyx and the cytokeratin filaments are more extensive in the apical epithelial cells in A. russatus. The stroma in R. norvegicus is formed of outer and inner lamellar zones with spaces in between its wavy bundles. In A. russatus, the stroma is formed of one lamellar zone of flattened bundles of highly wavy and branched collagen fibrils. On the other hand, the surface of the endothelial cells in R. norvegicus is slightly bulging with many blebs whereas it showed flattened and nearly smooth surface in A. russatus. In conclusion, the differences in the number of the superficial epithelial cells and the thickness of the stroma and structure of the endothelium of R. norvegicus (nocturnal) and A. russatus (diurnal) are most

Prevalence and genetic diversity of Bartonella strains in rodents from northwestern Mexico.

Science.gov (United States)

Rubio, André V; Ávila-Flores, Rafael; Osikowicz, Lynn M; Bai, Ying; Suzán, Gerardo; Kosoy, Michael Y

2014-12-01

Bartonella infections were investigated in wild rodents from northwestern Chihuahua, Mexico. A total of 489 rodents belonging to 14 species were surveyed in four areas. Bartonella bacteria were cultured from 50.1% of rodent samples (245/489). Infection rates ranged from 0% to 83.3% per rodent species, with no significant difference between sites except for Cynomys ludovicianus. Phylogenetic analyses of the citrate synthase gene (gltA) of the Bartonella isolates revealed 23 genetic variants (15 novel and 8 previously described), clustering into five phylogroups. Three phylogroups were associated with Bartonella vinsonii subsp. vinsonii, B. vinsonii subsp. arupensis, and B. washoensis, respectively. The other two phylogroups were not genetically related to any known Bartonella species. The genetic variants and phylogenetic groups exhibited a high degree of host specificity, mainly at the genus and family levels. This is the first study that describes the genetic diversity of Bartonella strains in wild rodents from Mexico. Considering that some variants found in this study are associated with Bartonella species that have been reported as zoonotic, more investigations are needed to further understand the ecology of Bartonella species in Mexican wildlife and their implications for human health.

Synanthropic rodents as possible reservoirs of shigatoxigenic Escherichia coli strains

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Ximena eBlanco Crivelli

2012-11-01

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

Contamination of broiler chickens with radiocaesium contaminated feed and its reduction

International Nuclear Information System (INIS)

Poeschl, M.

2004-01-01

The present study summarises information gleaned during investigations of the transfer of radiocaesium ( 137 Cs) and tests of countermeasures of a chemical character, i.e. feed additives limiting the transfer from the feed of broiler chicken. The regularities of the transport and distribution of radiocaesium in the organism (liver, kidneys, muscles, intestines) from feed were studied, including tests of the effect of the source of radiocaesium, date of administration and age of the chickens. The results confirmed that the retention of radiocaesium from feed into the body organs was very rapid (several hours) as was the release from the body (T 1/2b = 0.5-2 days) during the decontamination. Differences were discovered in the distribution and dynamics of the content of 137 Cs between breast and leg meat. The tests showed a very effective and relatively simple method of measuring the contaminated chickens in vivo. Special clay mineral or cellulose-based feed additives, and also modified hexacyanoferrates, especially when applied prior to contamination proper, considerably reduced the retention of radiocaesium into the breast and leg meat, and if the meat has already been contaminated, or if contamination was inevitable, the concentrations of 137 Cs in broiler chicken meat admissible for foodstuffs could be obtained much more quickly. (authors)

BEHAVIOURAL STUDIES ON SOME RHODESIAN RODENTS

African Journals Online (AJOL)

behaviour, . courtship, parental and juvenile behaviour and activity patterns. ... behavioural observations were facilitated by the development of a glass-fronted ~'double-storey" cage which ..... Adolescent siblings in both single sex and mixed groups ..... Wild rodents as Laboratory Animals and their contribution to medical.

Vision in laboratory rodents-Tools to measure it and implications for behavioral research.

Science.gov (United States)

Leinonen, Henri; Tanila, Heikki

2017-07-29

Mice and rats are nocturnal mammals and their vision is specialized for detection of motion and contrast in dim light conditions. These species possess a large proportion of UV-sensitive cones in their retinas and the majority of their optic nerve axons target superior colliculus rather than visual cortex. Therefore, it was a widely held belief that laboratory rodents hardly utilize vision during day-time behavior. This dogma is being questioned as accumulating evidence suggests that laboratory rodents are able to perform complex visual functions, such as perceiving subjective contours, and that declined vision may affect their performance in many behavioral tasks. For instance, genetic engineering may have unexpected consequences on vision as mouse models of Alzheimer's and Huntington's diseases have declined visual function. Rodent vision can be tested in numerous ways using operant training or reflex-based behavioral tasks, or alternatively using electrophysiological recordings. In this article, we will first provide a summary of visual system and explain its characteristics unique to rodents. Then, we present well-established techniques to test rodent vision, with an emphasis on pattern vision: visual water test, optomotor reflex test, pattern electroretinography and pattern visual evoked potentials. Finally, we highlight the importance of visual phenotyping in rodents. As the number of genetically engineered rodent models and volume of behavioral testing increase simultaneously, the possibility of visual dysfunctions needs to be addressed. Neglect in this matter potentially leads to crude biases in the field of neuroscience and beyond. Copyright © 2017 Elsevier B.V. All rights reserved.

A test of five mechanisms of species coexistence between rodents in ...

African Journals Online (AJOL)

A test of five mechanisms of species coexistence between rodents in a southern African savanna. M.R. Perrin, B.P. Kotler. Abstract. The operation of five different mechanisms of species coexistence in a community of rodents was examined in a semi-arid Kalahari savanna in southern Africa. The two most common species ...

Mycotoxin contamination in laboratory rat feeds and their implications in animal research.

Science.gov (United States)

Escrivá, Laura; Font, Guillermina; Berrada, Houda; Manyes, Lara

2016-09-01

Compound feed is particularly vulnerable to multi-mycotoxin contamination. A method for the determination of 12 mycotoxins; enniatins A, A1, B, B1; aflatoxins B1, B2, G1, G2; OTA; ZEA; T-2 and HT-2 by liquid chromatography-tandem mass spectrometry has been developed and applied for the analysis of laboratory rat commercial feeds. The method trueness was checked by recovery assays at three different spiked levels (n = 9). Recoveries ranged from 73% to 112%, and the intra-day and inter-day precision were lower than 9% and 13%, respectively. Limits of quantitation were lower than 15 μg/kg. Twenty-seven laboratory rats feed samples showed multi-contamination by at least three up to six different mycotoxins. ENNs B and B1, followed by ZEA were the most prevalent mycotoxins. T-2, HT-2, and OTA were not detected. ZEA showed the highest concentration levels reaching 492 μg/kg. The results underline the importance of implementing mycotoxin regular surveillance programs for laboratory animal feeds.

Cardiometabolic and reproductive benefits of early dietary energy restriction and voluntary exercise in an obese PCOS-prone rodent model.

Science.gov (United States)

Diane, Abdoulaye; Kupreeva, Maria; Borthwick, Faye; Proctor, Spencer D; Pierce, W David; Vine, Donna F

2015-09-01

Polycystic ovary syndrome (PCOS) is one of the most common endocrine-metabolic disorders in women of reproductive age characterized by ovulatory dysfunction, hyperandrogenism and cardiometabolic risk. The overweight-obese PCOS phenotype appears to have exacerbated reproductive dysfunction and cardiometabolic risk. In overweight-obese adult women with PCOS, exercise and energy restricted diets have shown limited and inconsistent effects on both cardiometabolic indices and reproductive outcomes. We hypothesized that an early lifestyle intervention involving exercise and dietary energy restriction to prevent or reduce the propensity for adiposity would modulate reproductive indices and cardiometabolic risk in an obese PCOS-prone rodent model. Weanling obese PCOS-prone and Lean-Control JCR:LA-cp rodents were given a chow diet ad libitum or an energy-restricted diet combined with or without voluntary exercise (4  h/day) for 8 weeks. Dietary energy restriction and exercise lowered total body weight gain and body fat mass by 30% compared to free-fed sedentary or exercising obese PCOS-prone animals (Pexercise intensity compared to free-feeding plus exercise conditions. Energy restriction and exercise decreased fasting plasma triglycerides and apoB48 concentrations in obese PCOS-prone animals compared to free-fed and exercise or sedentary groups. The energy restriction and exercise combination in obese PCOS-prone animals significantly increased plasma sex-hormone binding globulin, hypothalamic cocaine-and amphetamine-regulated transcript (CART) and Kisspeptin mRNA expression to levels of the Lean-Control group, and this was further associated with improvements in estrous cyclicity. The combination of exercise and dietary energy restriction when initiated in early life exerts beneficial effects on cardiometabolic and reproductive indices in an obese PCOS-prone rodent model, and this may be associated with normalization of the hypothalamic neuropeptides, Kisspeptin and CART

Studies into abnormal aggression in humans and rodents: Methodological and translational aspects.

Science.gov (United States)

Haller, Jozsef

2017-05-01

Here we review the principles based on which aggression is rendered abnormal in humans and laboratory rodents, and comparatively overview the main methodological approaches based on which this behavior is studied in the two categories of subjects. It appears that the discriminating property of abnormal aggression is rule breaking, which renders aggression dysfunctional from the point of view of the perpetrator. We show that rodent models of abnormal aggression were created by the translation of human conditions into rodent equivalents, and discuss how findings obtained with such models may be "translated back" to human conditions when the mechanisms underlying aggression and its possibilities of treatment are investigated. We suggest that the complementary nature of human and rodent research approaches invite a more intense cross-talk between the two sides of aggression research than the one presently observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

The geometry of continuum regularization

International Nuclear Information System (INIS)

Halpern, M.B.

1987-03-01

This lecture is primarily an introduction to coordinate-invariant regularization, a recent advance in the continuum regularization program. In this context, the program is seen as fundamentally geometric, with all regularization contained in regularized DeWitt superstructures on field deformations

Correlates of Recent Declines of Rodents in Northern and Southern Australia: Habitat Structure Is Critical.

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Michael J Lawes

Full Text Available Australia has experienced dramatic declines and extinctions of its native rodent species over the last 200 years, particularly in southern Australia. In the tropical savanna of northern Australia significant declines have occurred only in recent decades. The later onset of these declines suggests that the causes may differ from earlier declines in the south. We examine potential regional effects (northern versus southern Australia on biological and ecological correlates of range decline in Australian rodents. We demonstrate that rodent declines have been greater in the south than in the tropical north, are strongly influenced by phylogeny, and are consistently greater for species inhabiting relatively open or sparsely vegetated habitat. Unlike in marsupials, where some species have much larger body size than rodents, body mass was not an important predictor of decline in rodents. All Australian rodent species are within the prey-size range of cats (throughout the continent and red foxes (in the south. Contrary to the hypothesis that mammal declines are related directly to ecosystem productivity (annual rainfall, our results are consistent with the hypothesis that disturbances such as fire and grazing, which occur in non-rainforest habitats and remove cover used by rodents for shelter, nesting and foraging, increase predation risk. We agree with calls to introduce conservation management that limits the size and intensity of fires, increases fire patchiness and reduces grazing impacts at ecological scales appropriate for rodents. Controlling feral predators, even creating predator-free reserves in relatively sparsely-vegetated habitats, is urgently required to ensure the survival of rodent species, particularly in northern Australia where declines are not yet as severe as those in the south.

Intestinal Helminths in Different Species of Rodents in North Khorasan Province, Northeast of Iran

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Kourosh ARZAMANI

2017-06-01

Full Text Available Background: Rodents are an important source of zoonotic diseases for human. The aim of this study was to determine the infectivity of rodents with intestinal helminths in North Khorasan Province, Iran.Methods: One hundred and thirteen rodents were collected using different collection methods such as kill and live traps, digging of their burrow, filling of their hiding places with water and hand net during 2011-2013. Their alimentary canals were removed in the laboratory and helminths were determined in the department of parasitology, Tehran University of Medical Sciences.Results: Thirteen species of helminths parasites were found in 13 species of rodents, including Aspiculuris tetraptera, Hymenolepis diminuta, Nippostrongylus brasiliensis, Protospirura Seurat, Rictolaria ratti, Skrjabinitaenia lobata, Streptopharagus kuntzi, Syphacia obvelata, Taenia taeniaeformis, Trichuris muris, Cysticercus fasciolaris, Acanthocephal. spp and Trichuris spp. Some of them were reported for the first time in new host in Iran. S. obvelata and A. tetraptera were the most frequent parasites and P. Seurat, R. ratti and C. fasciolaris were found only in one rodent.Conclusion: This is the first study to investigate the intestinal parasites in rodents in this area. Among different species identified, some of helminths were reported in new host.

Intestinal Helminths in Different Species of Rodents in North Khorasan Province, Northeast of Iran.

Science.gov (United States)

Arzamani, Kourosh; Salehi, Mitra; Mobedi, Iraj; Adinezade, Amir; Hasanpour, Hamid; Alavinia, Mohammad; Darvish, Jamshid; Shirzadi, Mohammad Reza; Mohammadi, Zeinolabedin

2017-01-01

Rodents are an important source of zoonotic diseases for human. The aim of this study was to determine the infectivity of rodents with intestinal helminths in North Khorasan Province, Iran. One hundred and thirteen rodents were collected using different collection methods such as kill and live traps, digging of their burrow, filling of their hiding places with water and hand net during 2011-2013. Their alimentary canals were removed in the laboratory and helminths were determined in the department of parasitology, Tehran University of Medical Sciences. Thirteen species of helminths parasites were found in 13 species of rodents, including Aspiculuris tetraptera, Hymenolepis diminuta, Nippostrongylus brasiliensis, Protospirura Seurat, Rictolaria ratti, Skrjabinitaenia lobata, Streptopharagus kuntzi, Syphacia obvelata, Taenia taeniaeformis, Trichuris muris, Cysticercus fasciolaris, Acanthocephal. spp and Trichuris spp . Some of them were reported for the first time in new host in Iran. S. obvelata and A. tetraptera were the most frequent parasites and P. Seurat, R. ratti and C. fasciolaris were found only in one rodent. This is the first study to investigate the intestinal parasites in rodents in this area. Among different species identified, some of helminths were reported in new host.

Regular expression containment

DEFF Research Database (Denmark)

Henglein, Fritz; Nielsen, Lasse

2011-01-01

We present a new sound and complete axiomatization of regular expression containment. It consists of the conventional axiomatiza- tion of concatenation, alternation, empty set and (the singleton set containing) the empty string as an idempotent semiring, the fixed- point rule E* = 1 + E × E......* for Kleene-star, and a general coin- duction rule as the only additional rule. Our axiomatization gives rise to a natural computational inter- pretation of regular expressions as simple types that represent parse trees, and of containment proofs as coercions. This gives the axiom- atization a Curry......-Howard-style constructive interpretation: Con- tainment proofs do not only certify a language-theoretic contain- ment, but, under our computational interpretation, constructively transform a membership proof of a string in one regular expres- sion into a membership proof of the same string in another regular expression. We...

Supersymmetric dimensional regularization

International Nuclear Information System (INIS)

Siegel, W.; Townsend, P.K.; van Nieuwenhuizen, P.

1980-01-01

There is a simple modification of dimension regularization which preserves supersymmetry: dimensional reduction to real D < 4, followed by analytic continuation to complex D. In terms of component fields, this means fixing the ranges of all indices on the fields (and therefore the numbers of Fermi and Bose components). For superfields, it means continuing in the dimensionality of x-space while fixing the dimensionality of theta-space. This regularization procedure allows the simple manipulation of spinor derivatives in supergraph calculations. The resulting rules are: (1) First do all algebra exactly as in D = 4; (2) Then do the momentum integrals as in ordinary dimensional regularization. This regularization procedure needs extra rules before one can say that it is consistent. Such extra rules needed for superconformal anomalies are discussed. Problems associated with renormalizability and higher order loops are also discussed

Randomized controlled trial: impact of glycerin suppositories on time to full feeds in preterm infants.

Science.gov (United States)

Khadr, Sophie N; Ibhanesebhor, Samuel E; Rennix, Connie; Fisher, Hazel E; Manjunatha, Chikkanayakanahalli M; Young, David; Abara, Rosemary C

2011-01-01

Feed intolerance delays achievement of enteral feeding in preterm infants. Parenteral nutrition is associated with cholestasis and increased risk of sepsis. Glycerin suppositories have been used to promote gastrointestinal motility and feed tolerance. To investigate whether daily glycerin suppositories (a) reduce the time to full enteral feeding in infants born at suppositories; 28-31(+6) weeks subgroup); controls - no intervention. The same feeding protocol and departmental guidelines for other aspects of neonatal intensive care were used in all subjects. Analysis was by intention to treat. 54 babies were recruited (31 males), 29 randomized to receive suppositories; 48 achieved full enteral feeds. The median (range) time to full feeds was 1.6 days shorter in intervention group babies than controls, but not statistically significant: 7.4 (4.6-30.9) days versus 9.0 (4.4-13.3) days (p = 0.780; 95% confidence interval: -1.917, 2.166). No significant differences were observed in secondary outcomes. Intervention group babies passed their first stool earlier than controls (median: day 2 vs. day 4; p = 0.016). Regular glycerin suppositories did not reduce the time to full enteral feeds in infants born at <32 weeks' gestation in our setting. Copyright © 2011 S. Karger AG, Basel.

Anatomy and Histology of Rodent and Human Major Salivary Glands

Science.gov (United States)

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

2012-01-01

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

Occurrence of ectoparasitic arthropods associated with rodents in Hail region northern Saudi Arabia.

Science.gov (United States)

Asiry, Khalid A; Fetoh, Badr El-Sabah A

2014-09-01

Ectoparasitic arthropods are a diverse element of the Saudi fauna. Due to this, a survey of ectoparasites associated with rodents was conducted as a preliminary study in five districts of Hail region of northern Saudi Arabia for the first time. Ectoparasites extracted from 750 rodents were sampled and identified by recording their frequency of appearance. Results revealed that 1,287 ectoparasites infested 316 of the captured rodent hosts. These ectoparasites parasitized on four species of rodents including three species of rats Rattus rattus rattus, Rattus rattus frugivorus, and Rattus rattus alexandrinus and one species of mouse Acomys dimidiatus (Rodentia: Muridae). The ectoparasites belong to four different groups: ticks, fleas, lice, and mites. Ticks were the highest in the number, while fleas were the lowest among all the extracted ectoparasite groups. The collected ectoparasitic arthropods consisted of seven species. Ticks were of two species: Rhipicephalus turanicus and Rhipicephalus sanguineus (Acari: Ixodidae), fleas were of two species: Xenopsylla cheopis and Xenopsyllus conformis mycerini (Siphonaptera: Pulicidae), lice was a single species: Polyplax serrata (Anoplura: Hoplopleuridae), and mites were of two species: Laelaps nuttali and Laelaps echidninus (Mesostigmata: Laelapidae). The findings of the study showed that the intensity of infestation was varied between rodent host sexes, wherein females had the highest rate of parasitic infestation, and the parasitic index of appearance was very high for one group of parasites (i.e., ticks). The parasitic prevalence was 42.13 % on rodents, and mites were the most prevalent parasite species. Overall, this study was carried out to establish baseline data for ectoparasite-infested rodents in Hail region, Saudi Arabia, and may help for appropriate planning to control zoonotic diseases in this area.

Regularization by External Variables

DEFF Research Database (Denmark)

Bossolini, Elena; Edwards, R.; Glendinning, P. A.

2016-01-01

Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind of regula......Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind...

Mycotoxin Contamination in the EU Feed Supply Chain: A Focus on Cereal Byproducts

Science.gov (United States)

Pinotti, Luciano; Ottoboni, Matteo; Giromini, Carlotta; Dell’Orto, Vittorio; Cheli, Federica

2016-01-01

Mycotoxins represent a risk to the feed supply chain with an impact on economies and international trade. A high percentage of feed samples have been reported to be contaminated with more than one mycotoxin. In most cases, the concentrations were low enough to ensure compliance with the European Union (EU) guidance values or maximum admitted levels. However, mycotoxin co-contamination might still exert adverse effects on animals due to additive/synergistic interactions. Studies on the fate of mycotoxins during cereal processing, such as milling, production of ethanol fuels, and beer brewing, have shown that mycotoxins are concentrated into fractions that are commonly used as animal feed. Published data show a high variability in mycotoxin repartitioning, mainly due to the type of mycotoxins, the level and extent of fungal contamination, and a failure to understand the complexity of food processing technologies. Precise knowledge of mycotoxin repartitioning during technological processes is critical and may provide a sound technical basis for feed managers to conform to legislation requirements and reduce the risk of severe adverse market and trade repercussions. Regular, economical and straightforward feed testing is critical to reach a quick and accurate diagnosis of feed quality. The use of rapid methods represents a future challenge. PMID:26891326

Mycotoxin Contamination in the EU Feed Supply Chain: A Focus on Cereal Byproducts

Directory of Open Access Journals (Sweden)

Luciano Pinotti

2016-02-01

Full Text Available Mycotoxins represent a risk to the feed supply chain with an impact on economies and international trade. A high percentage of feed samples have been reported to be contaminated with more than one mycotoxin. In most cases, the concentrations were low enough to ensure compliance with the European Union (EU guidance values or maximum admitted levels. However, mycotoxin co-contamination might still exert adverse effects on animals due to additive/synergistic interactions. Studies on the fate of mycotoxins during cereal processing, such as milling, production of ethanol fuels, and beer brewing, have shown that mycotoxins are concentrated into fractions that are commonly used as animal feed. Published data show a high variability in mycotoxin repartitioning, mainly due to the type of mycotoxins, the level and extent of fungal contamination, and a failure to understand the complexity of food processing technologies. Precise knowledge of mycotoxin repartitioning during technological processes is critical and may provide a sound technical basis for feed managers to conform to legislation requirements and reduce the risk of severe adverse market and trade repercussions. Regular, economical and straightforward feed testing is critical to reach a quick and accurate diagnosis of feed quality. The use of rapid methods represents a future challenge.

Regular Single Valued Neutrosophic Hypergraphs

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Muhammad Aslam Malik

2016-12-01

Full Text Available In this paper, we define the regular and totally regular single valued neutrosophic hypergraphs, and discuss the order and size along with properties of regular and totally regular single valued neutrosophic hypergraphs. We also extend work on completeness of single valued neutrosophic hypergraphs.

Homeobox Genes in the Rodent Pineal Gland

DEFF Research Database (Denmark)

Rath, Martin Fredensborg; Rohde, Kristian; Klein, David C

2013-01-01

The pineal gland is a neuroendocrine gland responsible for nocturnal synthesis of melatonin. During early development of the rodent pineal gland from the roof of the diencephalon, homeobox genes of the orthodenticle homeobox (Otx)- and paired box (Pax)-families are expressed and are essential...... for normal pineal development consistent with the well-established role that homeobox genes play in developmental processes. However, the pineal gland appears to be unusual because strong homeobox gene expression persists in the pineal gland of the adult brain. Accordingly, in addition to developmental...... functions, homeobox genes appear to be key regulators in postnatal phenotype maintenance in this tissue. In this paper, we review ontogenetic and phylogenetic aspects of pineal development and recent progress in understanding the involvement of homebox genes in rodent pineal development and adult function...

Parasitocenoses in productional rodent breeds in Czech Republic

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Marie Borkovcová

2009-01-01

Full Text Available Aim of this work was to monitor the occurrence of most common parasites of rodents in 13 commercial and hobby breeds. Most often detected protozoans belonged to genera Giardia, Eimeria and Cryptosporidium, tapeworms Hymenolepis nana and H. diminuta, nematods Syphacia obvelata and Aspiculuris tetraptera and mites Ornithonyssus bacoti, Laelaps hilaris and Notoedres muris. Diseases broke out mainly during summer months. In animals with clinical signs of illnesses there was an expectation of pa­ra­si­te presence, and most of them were nematods – 80%, tapeworms – 45.2%, protozoans – 41.1% and ectoparasites – 22%. Samples of animals without clinical signs of illnesses contained nematods – 16%, tapeworms – 11%, coccidians – 6% and ectoparasites – 0%. Besides evaluation of all samples, breeding conditions were evaluated as well. Consequently plan was made to remove the causes of parasitoses for each monitored breed. Most dangerous parasites were coccidians of the genus Cryp­tos­po­ri­dium, which caused high mortality of the young animals. In Czech Republic high percent of breeds are contaminated with parasites, however, there is little experience in how to deal with these illnesses. Results are weak and low-quality breeds, especially of mice and common rats. Important protection is buying animals from well-known and verified breed with no signs of illness and also regular control of excrement samples.

Modelling the Flow Stress of Alloy 316L using a Multi-Layered Feed Forward Neural Network with Bayesian Regularization

Science.gov (United States)

Abiriand Bhekisipho Twala, Olufunminiyi

2017-08-01

In this paper, a multilayer feedforward neural network with Bayesian regularization constitutive model is developed for alloy 316L during high strain rate and high temperature plastic deformation. The input variables are strain rate, temperature and strain while the output value is the flow stress of the material. The results show that the use of Bayesian regularized technique reduces the potential of overfitting and overtraining. The prediction quality of the model is thereby improved. The model predictions are in good agreement with experimental measurements. The measurement data used for the network training and model comparison were taken from relevant literature. The developed model is robust as it can be generalized to deformation conditions slightly below or above the training dataset.

A randomized controlled trial evaluating early versus traditional oral feeding after colorectal surgery

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Ahmet Dag

2011-01-01

Full Text Available OBJECTIVE: This prospective randomized clinical study was conducted to evaluate the safety and tolerability of early oral feeding after colorectal operations. METHODS: A total of 199 patients underwent colorectal surgery and were randomly assigned to early feeding (n = 99 or a regular diet (n = 100. Patients’ characteristics, diagnoses, surgical procedures, comorbidity, bowel movements, defecation, nasogastric tube reinsertion, time of tolerance of solid diet, complications, and length of hospitalization were assessed. RESULTS: The two groups were similar in terms of gender, age, diagnosis, surgical procedures, and comorbidity. In the early feeding group, 85.9% of patients tolerated the early feeding schedule. Bowel movements (1.7±0.89 vs. 3.27±1.3, defecation (3.4±0.77 vs. 4.38±1.18 and time of tolerance of solid diet (2.48±0.85 vs. 4.77±1.81 were significantly earlier in the early feeding group. There was no change between the groups in terms of nasogastric tube reinsertion, overall complication or anastomotic leakage. Hospitalization (5.55±2.35 vs. 9.0±6.5 was shorter in the early feeding group. CONCLUSIONS: The present study indicated that early oral feeding after elective colorectal surgery was not only well tolerated by patients but also affected the postoperative outcomes positively. Early postoperative feeding is safe and leads to the early recovery of gastrointestinal functions.

Helminth Infections of Rodents and Their Zoonotic Importance in Boyer-Ahmad District, Southwestern Iran

OpenAIRE

RANJBAR, Mohammad Javad; SARKARI, Bahador; MOWLAVI, Gholam Reza; SEIFOLLAHI, Zeinab; MOSHFE, Abdolali; ABDOLAHI KHABISI, Samaneh; MOBEDI, Iraj

2017-01-01

AbstractBackground: Rodents are considered as reservoirs of various zoonotic diseases including helminthic infections. The current study aimed to evaluate the prevalence of helminth infections in rodents, in Boyer-Ahmad district, Southwestern Iran.Methods: Overall, 52 rodents were captured from various areas of the district by Sherman live traps. The animals were then euthanized and dissected. During necropsy, each organ was examined macroscopically for presence of any cyst or visible parasit...

Adaptation for rodent pollination in Leucospermum arenarium (Proteaceae) despite rapid pollen loss during grooming.

Science.gov (United States)

Johnson, Christopher Michael; Pauw, Anton

2014-05-01

Plants are adapted for rodent pollination in diverse and intricate ways. This study explores an extraordinary example of these adaptations in the pincushion Leucospermum arenarium (Proteaceae) from South Africa. Live trapping and differential exclusion experiments were used to test the role of rodents versus birds and insects as pollinators. To explore the adaptive significance of geoflory, inflorescences were raised above ground level and seed production was compared. Captive rodents and flowers with artificial stigmas were used to test the effect of grooming on the rate of pollen loss. Microscopy, nectar composition analysis and manipulative experiments were used to investigate the bizarre nectar production and transport system. Differential exclusion of rodents, birds and insects demonstrated the importance of rodents in promoting seed production. Live trapping revealed that hairy-footed gerbils, Gerbillurus paeba, and striped field mice, Rhabdomys pumilio, both carried L. arenarium pollen on their forehead and rostrum, but much larger quantities ended up in faeces as a result of grooming. Terrarium experiments showed that grooming exponentially diminished the pollen loads that they carried. The nectar of L. arenarium was found to be unusually viscous and to be presented in a novel location on the petal tips, where rodents could access it without destroying the flowers. Nectar was produced inside the perianth, but was translocated to the petal tips via capillary ducts. In common with many other rodent-pollinated plants, the flowers are presented at ground level, but when raised to higher positions seed production was not reduced, indicating that selection through female function does not drive the evolution of geoflory. Despite the apparent cost of pollen lost to grooming, L. arenarium has evolved remarkable adaptations for rodent pollination and provides the first case of this pollination system in the genus.

Serological Survey of Zoonotic Viruses in Invasive and Native Commensal Rodents in Senegal, West Africa.

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Diagne, Christophe A; Charbonnel, Nathalie; Henttonen, Heikki; Sironen, Tarja; Brouat, Carine

2017-10-01

Increasing studies on rodent-borne diseases still highlight the major role of rodents as reservoirs of numerous zoonoses of which the frequency is likely to increase worldwide as a result of accelerated anthropogenic changes, including biological invasions. Such a situation makes pathogen detection in rodent populations important, especially in the context of developing countries characterized by high infectious disease burden. Here, we used indirect fluorescent antibody tests to describe the circulation of potentially zoonotic viruses in both invasive (Mus musculus domesticus and Rattus rattus) and native (Mastomys erythroleucus and Mastomys natalensis) murine rodent populations in Senegal (West Africa). Of the 672 rodents tested, we reported 22 seropositive tests for Hantavirus, Orthopoxvirus, and Mammarenavirus genera, and no evidence of viral coinfection. This study is the first to report serological detection of Orthopoxvirus in rodents from Senegal, Mammarenavirus in R. rattus from Africa, and Hantavirus in M. m. domesticus and in M. erythroleucus. Further specific identification of the viral agents highlighted here is urgently needed for crucial public health concerns.

Isolating human DNA repair genes using rodent-cell mutants

International Nuclear Information System (INIS)

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

1987-01-01

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

Activity and heart rate in semi-domesticated reindeer during adaptation to emergency feeding.

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Nilsson, A; Ahman, B; Norberg, H; Redbo, I; Eloranta, E; Olsson, K

2006-06-15

Although reindeer are well adapted to limited food resources during winter, semi-domesticated reindeer are regularly fed when snow conditions are bad in order to prevent starvation. Feeding sometimes results in health problems and loss of animals. This study was made to assess if activity pattern in reindeer could be used as a tool for the reindeer herder in early detection of animals that are not adapting to feeding. The frequency of 10 behavioural categories was recorded in five groups of penned, eight-month-old, female semi-domesticated reindeer. Three reindeer per group were fitted with heart rate monitors. Lying was the most frequent behaviour, whilst there were few cases of agonistic behaviour. Heart rate varied during the day, with peaks during feeding and low heart rates in the early morning. Restricted feed intake resulted in more locomotion and seeking but less ruminating compared to feeding ad libitum. This was followed by a generally lower heart rate in reindeer in the restricted groups compared to controls. Subsequent feeding with different combinations of lichens, silage and pellets ad libitum resulted initially in significantly more of the animals lying curled up, compared to controls, combined with increased heart rates. As the experiment continued the general activity pattern, as well as the heart rate, gradually became more similar in all groups. Lying curled was the behavioural indicator most consistently affected by feed deprivation and adaptation to feeding and may thus be a useful indicator to distinguish individual reindeer that are not adjusting to feeding.

A higher-taxon approach to rodent conservation priorities for the 21st century

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Amori, G.

2003-12-01

Full Text Available Although rodents are not considered among the most threatened mammals, there is ample historical evidence concerning the vulnerability to extinction of several rodent phylogenetic lineages. Owing to the high number of species, poor taxonomy and the lack of detailed information on population status, the assessment of threat status according to IUCN criteria has still to be considered arbitrary in some cases. Public appreciation is scarce and tends to overlook the ecological role and conservation problems of an order representing about 41 percent of mammalian species. We provide an overview of the most relevant information concerning the conservation status of rodents at the genus, subfamily, and family level. For species¿poor taxa, the importance of distinct populations is highlighted and a splitter approach in taxonomy is adopted. Considering present constraints, strategies for the conservation of rodent diversity must rely mainly on higher taxon and hot-spot approaches. A clear understanding of phyletic relationships among difficult groups -such as Rattus, for instance- is an urgent goal. Even if rodent taxonomy is still unstable, high taxon approach is amply justified from a conservation standpoint as it offers a more subtle overview of the world terrestrial biodiversity than that offered by large mammals. Of the circa 451 living rodent genera, 126 (27,9 %, representing 168 living species, deserve conservation attention according to the present study. About 76 % of genera at risk are monotypic, confirming the danger of losing a considerable amount of phylogenetic distinctiveness.

Allometric disparity in rodent evolution

OpenAIRE

Wilson LAB

2013-01-01

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 ...

Genotyping and subtyping of Giardia and Cryptosporidium isolates from commensal rodents in China.

Science.gov (United States)

Zhao, Z; Wang, R; Zhao, W; Qi, M; Zhao, J; Zhang, L; Li, J; Liu, A

2015-05-01

Cryptosporidium and Giardia are two important zoonotic intestinal parasites responsible for diarrhoea in humans and other animals worldwide. Rodents, as reservoirs or carriers of Cryptosporidium and Giardia, are abundant and globally widespread. In the present study, we collected 232 fecal specimens from commensal rodents captured in animal farms and farm neighbourhoods in China. We collected 33 Asian house rats, 168 brown rats and 31 house mice. 6.0% (14/232) and 8.2% (19/232) of these rodents were microscopy-positive for Giardia cysts and Cryptosporidium oocysts, respectively. All 14 Giardia isolates were identified as Giardia duodenalis assemblage G at a minimum of one or maximum of three gene loci (tpi, gdh and bg). By small subunit rRNA (SSU rRNA) gene sequencing, Cryptosporidium parvum (n = 12) and Cryptosporidium muris (n = 7) were identified. The gp60 gene encoding the 60-kDa glycoprotein was successfully amplified and sequenced in nine C. parvum isolates, all of which belonged to the IIdA15G1 subtype. Observation of the same IIdA15G1 subtype in humans (previously) and in rodents (here) suggests that rodents infected with Cryptosporidium have the potential to transmit cryptosporidiosis to humans.

Two new rodent models for actinide toxicity studies

International Nuclear Information System (INIS)

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

1981-01-01

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

On a correspondence between regular and non-regular operator monotone functions

DEFF Research Database (Denmark)

Gibilisco, P.; Hansen, Frank; Isola, T.

2009-01-01

We prove the existence of a bijection between the regular and the non-regular operator monotone functions satisfying a certain functional equation. As an application we give a new proof of the operator monotonicity of certain functions related to the Wigner-Yanase-Dyson skew information....

Effects of anatomy and diet on gastrointestinal pH in rodents.

Science.gov (United States)

Kohl, Kevin D; Stengel, Ashley; Samuni-Blank, Michal; Dearing, M Denise

2013-04-01

The pH of the gastrointestinal tract can have profound influences on digestive processes. Rodents exhibit wide variation in both stomach morphology and dietary strategies, both of which may influence gut pH. Various rodent species have evolved bilocular (or semi-segmented) stomachs that may allow for more microbial growth compared to unilocular (single-chambered) stomachs. Additionally, herbivory has evolved multiple times in rodents. The high dietary fiber typical of an herbivorous diet is known to induce secretion of bicarbonate in the gut. We predicted that stomach segmentation might facilitate the separation of contents in the proximal chamber from that of the gastric stomach, facilitating a chemical environment suitable to microbial growth. To investigate the effect of stomach anatomy and diet on gut pH, several species of rodent with varying stomach morphology were fed either a high or low-fiber diet for 7 days, and pH of the proximal stomach, gastric stomach, small intestine, and cecum were measured. We discovered that rodents with bilocular stomach anatomy maintained a larger pH gradient between the proximal and gastric stomach compartments, and were able to achieve a lower absolute gastric pH compared to those with unilocular stomachs. Dietary fiber increased the pH of the small intestine, but not in any other gut regions. The stomach pH data supports the century old hypothesis that bilocular stomach anatomy creates an environment in the proximal stomach that is suitable for microbial growth. Additionally, the alkaline small intestinal pH on a high fiber diet may enhance digestion. Copyright © 2013 Wiley Periodicals, Inc.

Fire ignition during laser surgery in pet rodents

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Collarile Tommaso

2012-09-01

Full Text Available Abstract Background Laser surgery is an attractive alternative to other means of section device in terms of tissue inflammation and interaction, which has been extensively used in human and veterinary medicine. Although accidental ignition during laser surgeries is sporadically reported in human medical literature, to the authors’ knowledge this is the first report regarding laser-dependent fire ignition during surgery in veterinary medicine. Case presentation Two rodents, a 13-month old, 27-gram, male pet mouse (Mus musculus and a 1-year old, female Russian hamster (Phodopus sungorus, underwent surgical removal of masses with diode laser. During the surgical procedures fires ignited from the face masks. The mouse presented severe burns on the head and both forelimbs, it was hospitalized and approximately 2 months after surgery burns were resolved. The hamster presented severe burns on the face and the proximal regions of the body. At 72 hours from the accident the hamster was euthanized. Conclusion The present report suggests that fire ignition is a potential life-threatening complication of laser surgery in non-intubated rodents maintained under volatile anesthesia. High oxygen concentrations, the presence of combustible, and the narrowness of the surgical field with the face mask during laser surgery on rodents are risk factors for fire ignition.

Modeling hydrodynamic effects on choanoflagellate feeding

Science.gov (United States)

Oakes, Christian; Hguyen, Hoa; Koehl, Mimi; Fauci, Lisa

2017-11-01

Choanoflagellates are unicellular organisms whose intriguing morphology includes a set of collars/microvilli emanating from the cell body, surrounding the beating flagellum. As the closest living relative to animals, they are important for both ecological and evolutionary studies. Choanoflagellates have three unicellular types: slow swimmers, fast swimmers, and thecate (attached to a surface by a stalk). Each has different morphology and feeding rate. We use the method of regularized Stokeslets to simulate cell-fluid interactions of each type and show the hydrodynamic effects on the amount and directions of fluid flow toward the collar. After validating the swimming speeds of our models with experimental data, we calculate the rate of flow across a capture zone around the collar (flux). This sheds light on how each morphological aspect of the cell aids in bacteria capture during feeding. Among the three types, the thecate cells have the largest average flux values, implying that they take advantage of the nearby surface by creating eddies that draw bacteria into their collar for ingestion. Funding Source: FASTER Grant SURF `` National Science Foundation DUE S-STEM Award 1153796, Mach Fellowship.

Identification of collected ectoparasites of rodents in the west of Khuzestan Province (Ahvaz and Hovizeh, southwest of Iran

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Mahmood Rahdar

2015-08-01

Full Text Available Objective: To determine possible parasitic arthropods fauna in certain rodent species in the west of Khuzestan Province including Ahvaz and its suburb and suburb of Hovizeh, southwest of Iran. Methods: In the current study Sherman live traps were used to catch the rodents. The rodents were identified using Iranian keys of rodents. The ectoparasites were picked up in different ways from bodies of the anesthetized rodents and stored in 70% ethanol to preserve and identified using international keys. Results: In the present study 3 species and 4 genera of ectoparasites and 4 species of rodents were identified. Conclusions: It is important to explain that the great ectoparasite biodiversity in the west of Khuzestan, with small sampling of rodents, described a high risk factor to transmit the different infectious diseases among domestic animals and humans.

Stochastic analytic regularization

International Nuclear Information System (INIS)

Alfaro, J.

1984-07-01

Stochastic regularization is reexamined, pointing out a restriction on its use due to a new type of divergence which is not present in the unregulated theory. Furthermore, we introduce a new form of stochastic regularization which permits the use of a minimal subtraction scheme to define the renormalized Green functions. (author)

Preservation of rodent bones from El Harhoura 2 cave (Morocco, Neolithic - Middle Palaeolithic): Microstructure, mineralogy, crystallinity and composition

Science.gov (United States)

Farre, Bastien; Massard, Pierre; Nouet, Julius; Dauphin, Yannicke

2014-04-01

Thin sections, scanning electron microscopy (SEM), diffraction X (DRX) and infrared spectrometry (FTIR) have been used to study the structure, mineralogy, crystallinity and bulk composition of fossil rodent long bones extracted from a succession of sedimentary layers in a cave from Morocco (Neolithic - Middle Palaeolithic, El Harhoura 2). The microstructure of fossil bones is well-preserved at this scale of observation, and encrusted deposits are rare. All bones are preserved in apatite, but the crystallinity is modified, as well as the crystallite shape, the organic content and the organic-mineral ratio. No fluor enrichment has been observed. Alone or together, the studied parameters do not show a regular trend from the upper to the lower layers of the cave. The preservation of the fossil bones does not confirm the sequence of arid and humid periods inferred from taphonomic analyses.

Gender Differences in Response to Prolonged Every-Other-Day Feeding on the Proliferation and Apoptosis of Hepatocytes in Mice.

Science.gov (United States)

Piotrowska, Katarzyna; Tarnowski, Maciej; Zgutka, Katarzyna; Pawlik, Andrzej

2016-03-19

Intermittent fasting decreases glucose and insulin levels and increases insulin sensitivity and lifespan. Decreased food intake influences the liver. Previous studies have shown gender differences in response to various types of caloric restriction, including every-other-day (EOD) feeding, in humans and rodents. Our goal was to show the influence of prolonged EOD feeding on the morphology, proliferation and apoptosis of livers from male and female mice. After nine months of an EOD diet, the livers from male and female mice were collected. We examined their morphology on histological slides using the Hematoxilin and Eosine (H_E) method and Hoechst staining of cell nuclei to evaluate the nuclear area of hepatocytes. We also evaluated the expression of mRNA for proto-oncogens, pro-survival proteins and apoptotic markers using Real Time Polimerase Chain Reaction (PCR). We noted increased lipid content in the livers of EOD fed female mice. EOD feeding lead to a decrease of proliferation and apoptosis in the livers of female and male mice, which suggest that tissue maintenance occurred during EOD feeding. Our experiment revealed sex-specific expression of mRNA for proto-oncogenes and pro-survival and pro-apoptotic genes in mice as well as sex-specific responses to the EOD treatment.

Gender Differences in Response to Prolonged Every-Other-Day Feeding on the Proliferation and Apoptosis of Hepatocytes in Mice

Directory of Open Access Journals (Sweden)

Katarzyna Piotrowska

2016-03-01

Full Text Available Intermittent fasting decreases glucose and insulin levels and increases insulin sensitivity and lifespan. Decreased food intake influences the liver. Previous studies have shown gender differences in response to various types of caloric restriction, including every-other-day (EOD feeding, in humans and rodents. Our goal was to show the influence of prolonged EOD feeding on the morphology, proliferation and apoptosis of livers from male and female mice. After nine months of an EOD diet, the livers from male and female mice were collected. We examined their morphology on histological slides using the Hematoxilin and Eosine (H_E method and Hoechst staining of cell nuclei to evaluate the nuclear area of hepatocytes. We also evaluated the expression of mRNA for proto-oncogens, pro-survival proteins and apoptotic markers using Real Time Polimerase Chain Reaction (PCR. We noted increased lipid content in the livers of EOD fed female mice. EOD feeding lead to a decrease of proliferation and apoptosis in the livers of female and male mice, which suggest that tissue maintenance occurred during EOD feeding. Our experiment revealed sex-specific expression of mRNA for proto-oncogenes and pro-survival and pro-apoptotic genes in mice as well as sex-specific responses to the EOD treatment.

Results of the 5th regular inspection of Unit 1 in the Hamaoka Nuclear Power Station

International Nuclear Information System (INIS)

1983-01-01

The 5th regular inspection of Unit 1 in the Hamaoka Nuclear Power Station was carried out from March 27 to July 27, 1982. Inspection was made on the reactor proper, reactor cooling system, instrumentation/control system, radiation control facility, etc. By the examinations of external appearance, leakage, performance, etc., no abnormality was observed. In the regular inspection, personnel exposure dose was all below the permissible level. The works done during the inspection were the following: the replacement of control rod drives, the replacement of core support-plate plugs, the repair of steam piping, steam extraction pipes and feed water heaters, the repair of a waste-liquid concentrator, the installation of barriers and leak detectors, the installation of drain sump monitors in a containment vessel, the replacement of concentrated liquid waste pumps, the employment of type B fuel. (Mori, K.)

Survey for hantaviruses, tick-borne encephalitis virus, and Rickettsia spp. in small rodents in Croatia.

Science.gov (United States)

Svoboda, Petra; Dobler, Gerhard; Markotić, Alemka; Kurolt, Ivan-Christian; Speck, Stephanie; Habuš, Josipa; Vucelja, Marko; Krajinović, Lidija Cvetko; Tadin, Ante; Margaletić, Josip; Essbauer, Sandra

2014-07-01

In Croatia, several rodent- and vector-borne agents are endemic and of medical importance. In this study, we investigated hantaviruses and, for the first time, tick-borne encephalitis virus (TBEV) and Rickettsia spp. in small wild rodents from two different sites (mountainous and lowland region) in Croatia. In total, 194 transudate and tissue samples from 170 rodents (A. flavicollis, n=115; A. agrarius, n=2; Myodes glareolus, n=53) were tested for antibodies by indirect immunofluorescence assays (IIFT) and for nucleic acids by conventional (hantaviruses) and real-time RT-/PCRs (TBEV and Rickettsia spp.). A total of 25.5% (24/94) of the rodents from the mountainous area revealed specific antibodies against hantaviruses. In all, 21.3% (20/94) of the samples from the mountainous area and 29.0% (9/31) from the lowland area yielded positive results for either Puumala virus (PUUV) or Dobrava-Belgrade virus (DOBV) using a conventional RT-PCR. All processed samples (n=194) were negative for TBEV by IIFT or real-time RT-PCR. Serological evidence of rickettsial infection was detected in 4.3% (4/94) rodents from the mountainous region. Another 3.2% (3/94) rodents were positive for Rickettsia spp. by real-time PCR. None of the rodents (n=76) from the lowland area were positive for Rickettsia spp. by real-time PCR. Dual infection of PUUV and Rickettsia spp. was found in one M. glareolus from the mountainous area by RT-PCR and real-time PCR, respectively. To our knowledge, this is the first detection of Rickettsia spp. in small rodents from Croatia. Phylogenetic analyses of S- and M-segment sequences obtained from the two study sites revealed well-supported subgroups in Croatian PUUV and DOBV. Although somewhat limited, our data showed occurrence and prevalence of PUUV, DOBV, and rickettsiae in Croatia. Further studies are warranted to confirm these data and to determine the Rickettsia species present in rodents in these areas.

Eating nanomaterials: cruelty-free and safe? the EFSA guidance on risk assessment of nanomaterials in food and feed.

Science.gov (United States)

Sauer, Ursula G

2011-12-01

Nanomaterials are increasingly being added to food handling and packaging materials, or directly, to human food and animal feed. To ensure the safety of such engineered nanomaterials (ENMs), in May 2011, the European Food Safety Authority (EFSA) published a guidance document on Risk assessment of the application of nanoscience and nanotechnologies in the food and feed chain. It states that risk assessment should be performed by following a step-wise procedure. Whenever human or animal exposure to nanomaterials is expected, the general hazard characterisation scheme requests information from in vitro genotoxicity, toxicokinetic and repeated dose 90-day oral toxicity studies in rodents. Numerous prevailing uncertainties with regard to nanomaterial characterisation and their hazard and risk assessment are addressed in the guidance document. This article discusses the impact of these knowledge gaps on meeting the goal of ensuring human safety. The EFSA's guidance on the risk assessment of ENMs in food and animal feed is taken as an example for discussion, from the point of view of animal welfare, on what level of uncertainty should be considered acceptable for human safety assessment of products with non-medical applications, and whether animal testing should be considered ethically acceptable for such products.

Forest rodents provide directed dispersal of Jeffrey pine seeds

Science.gov (United States)

Briggs, J.S.; Wall, S.B.V.; Jenkins, S.H.

2009-01-01

Some species of animals provide directed dispersal of plant seeds by transporting them nonrandomly to microsites where their chances of producing healthy seedlings are enhanced. We investigated whether this mutualistic interaction occurs between granivorous rodents and Jeffrey pine (Pinus jeffreyi) in the eastern Sierra Nevada by comparing the effectiveness of random abiotic seed dispersal with the dispersal performed by four species of rodents: deer mice (Peromyscus maniculatus), yellow-pine and long-eared chipmunks (Tamias amoenus and T. quadrimaculatus), and golden-mantled ground squirrels (Spermophilus lateralis). We conducted two caching studies using radio-labeled seeds, the first with individual animals in field enclosures and the second with a community of rodents in open forest. We used artificial caches to compare the fates of seeds placed at the range of microsites and depths used by animals with the fates of seeds dispersed abiotically. Finally, we examined the distribution and survival of naturally establishing seedlings over an eight-year period.Several lines of evidence suggested that this community of rodents provided directed dispersal. Animals preferred to cache seeds in microsites that were favorable for emergence or survival of seedlings and avoided caching in microsites in which seedlings fared worst. Seeds buried at depths typical of animal caches (5–25 mm) produced at least five times more seedlings than did seeds on the forest floor. The four species of rodents differed in the quality of dispersal they provided. Small, shallow caches made by deer mice most resembled seeds dispersed by abiotic processes, whereas many of the large caches made by ground squirrels were buried too deeply for successful emergence of seedlings. Chipmunks made the greatest number of caches within the range of depths and microsites favorable for establishment of pine seedlings. Directed dispersal is an important element of the population dynamics of Jeffrey pine, a

Leptospira interrogans in Rodents from Cape Verde.

Science.gov (United States)

Plata-Luis, Josué; Foronda, Pilar; Martín-Alonso, Aaron; Feliu, Carlos; Alves, Joana; Gil, Horacio; Valladares, Basilio

2016-11-01

Leptospirosis is an important worldwide zoonotic disease that can infect both animals and humans. In most cases, leptospirosis is a nonspecific self-limiting illness, but some patients can develop a severe form with a high mortality. This study was carried out in Santiago Island, Cape Verde, in 2012-2013. A total of 62 wild rodents (Rattus rattus and Mus domesticus) were analyzed. The lipL32 gene, present only in pathogenic Leptospira spp., was amplified by PCR, and 16 samples were positive (25.8%). In both rodent species, Leptospira interrogans was identified. The results show the presence of pathogenic Leptospira in the three localities analyzed in Santiago. The presence of L. interrogans demonstrates a serious health risk for the population, since this species has been associated with the most severe form of leptospirosis, the Weil's disease in humans, a severe infection with jaundice, renal failure, and hemorrhage.

The in vivo rodent test systems for assessment of carcinogenic potential

DEFF Research Database (Denmark)

van der Laan, Jan-Willem; Spindler, Per

2002-01-01

A Drug Information Association (DIA) workshop was held in May 2001 to discuss the outcome of the International Life Sciences Institute-Health and Environmental Sciences Institute (ILSI-HESI) project on alternative models for carcinogenicity assessment such as the P53(+/-) and XPA(+/-) knockout...... mouse models, the RasH2 and Tg.AC transgenic mouse models, and the neonatal mouse model. The "ICH Guideline S1B on Testing for Carcinogenicity of Pharmaceuticals" advocates that carcinogenicity testing of pharmaceuticals, when needed, might be carried out choosing one 2-year rodent carcinogenicity study...... (rat) plus one other study that supplements the 2-year study and providing additional information that is not readily available from the 2-year study: either (1) a short- or medium-term in vivo rodent test system or (2) a 2-year carcinogenicity study in a second rodent species (mouse). Another topic...

Rodent movements, densities and radionuclide concentrations at a liquid radioactive waste disposal area

International Nuclear Information System (INIS)

Halford, D.K.

1983-01-01

Movements and densities of rodents at a liquid radioactive waste disposal area were studied from June to September 1981 using trap line and assessment line techniques. The average distance between points of successive capture was 42 +- 25 (SD) m for deer mice (Peromyscus maniculatus) and 37 +- 21 m for kangaroo rats (Dipodomys ordii). Densities of deer mice averaged 10.2/ha with a population estimate of 57 within the area of rodent captures. The population estimate of 4 species of small mammals at the waste pond complex was 93. Radionuclide concentrations averaged 133 +- 97 pCi/g for rodents captured inside the disposal area boundary, 18 +- 22 pCi/g for those captured outside of the dispoal area fence and 0.50 +- 0.6 pCi/g for control animals. Species captured outside of the waste area boundary had significantly lower (P 137 Cs, 134 Cs, 60 Co and 65 Zn) in rodents at the liquid waste disposal area was estimated to be about 162 nCi

Endotoxin, Coliform, and Dust Levels in Various Types of Rodent Bedding

OpenAIRE

Whiteside, Tanya E; Thigpen, Julius E; Kissling, Grace E; Grant, Mary G; Forsythe, Diane B

2010-01-01

Endotoxins in grain dust, household dust, and animal bedding may induce respiratory symptoms in rodents and humans. We assayed the endotoxin, coliform, and dust levels in 20 types of rodent bedding. Endotoxin concentrations were measured by using a commercial test kit, coliform counts were determined by using conventional microbiologic procedures, and dust content was evaluated by using a rotating–tapping shaker. Paper bedding types contained significantly less endotoxin than did other beddin...

Prenatal stressors in rodents: Effects on behavior

Directory of Open Access Journals (Sweden)

Marta Weinstock

2017-02-01

Full Text Available The current review focuses on studies in rodents published since 2008 and explores possible reasons for any differences they report in the effects of gestational stress on various types of behavior in the offspring. An abundance of experimental data shows that different maternal stressors in rodents can replicate some of the abnormalities in offspring behavior observed in humans. These include, anxiety, in juvenile and adult rats and mice, assessed in the elevated plus maze and open field tests and depression, detected in the forced swim and sucrose-preference tests. Deficits were reported in social interaction that is suggestive of pathology associated with schizophrenia, and in spatial learning and memory in adult rats in the Morris water maze test, but in most studies only males were tested. There were too few studies on the novel object recognition test at different inter-trial intervals to enable a conclusion about the effect of prenatal stress and whether any deficits are more prevalent in males. Among hippocampal glutamate receptors, NR2B was the only subtype consistently reduced in association with learning deficits. However, like in humans with schizophrenia and depression, prenatal stress lowered hippocampal levels of BDNF, which were closely correlated with decreases in hippocampal long-term potentiation. In mice, down-regulation of BDNF appeared to occur through the action of gene-methylating enzymes that are already increased above controls in prenatally-stressed neonates. In conclusion, the data obtained so far from experiments in rodents lend support to a physiological basis for the neurodevelopmental hypothesis of schizophrenia and depression.

Euthanasia using gaseous agents in laboratory rodents.

Science.gov (United States)

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

2016-08-01

Several questions have been raised in recent years about the euthanasia of laboratory rodents. Euthanasia using inhaled agents is considered to be a suitable aesthetic method for use with a large number of animals simultaneously. Nevertheless, its aversive potential has been criticized in terms of animal welfare. The data available regarding the use of carbon dioxide (CO2), inhaled anaesthetics (such as isoflurane, sevoflurane, halothane and enflurane), as well as carbon monoxide and inert gases are discussed throughout this review. Euthanasia of fetuses and neonates is also addressed. A table listing currently available information to ease access to data regarding euthanasia techniques using gaseous agents in laboratory rodents was compiled. Regarding better animal welfare, there is currently insufficient evidence to advocate banning or replacing CO2 in the euthanasia of rodents; however, there are hints that alternative gases are more humane. The exposure to a volatile anaesthetic gas before loss of consciousness has been proposed by some scientific studies to minimize distress; however, the impact of such a measure is not clear. Areas of inconsistency within the euthanasia literature have been highlighted recently and stem from insufficient knowledge, especially regarding the advantages of the administration of isoflurane or sevoflurane over CO2, or other methods, before loss of consciousness. Alternative methods to minimize distress may include the development of techniques aimed at inducing death in the home cage of animals. Scientific outcomes have to be considered before choosing the most suitable euthanasia method to obtain the best results and accomplish the 3Rs (replacement, reduction and refinement). © The Author(s) 2015.

Discovery of Novel Alphacoronaviruses in European Rodents and Shrews

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Theocharis Tsoleridis

2016-03-01

Full Text Available Eight hundred and thirteen European rodents and shrews encompassing seven different species were screened for alphacoronaviruses using PCR detection. Novel alphacoronaviruses were detected in the species Rattus norvegicus, Microtus agrestis, Sorex araneus and Myodes glareolus. These, together with the recently described Lucheng virus found in China, form a distinct rodent/shrew-specific clade within the coronavirus phylogeny. Across a highly conserved region of the viral polymerase gene, the new members of this clade were up to 22% dissimilar at the nucleotide level to the previously described Lucheng virus. As such they might represent distinct species of alphacoronaviruses. These data greatly extend our knowledge of wildlife reservoirs of alphacoronaviruses.

Short interspersed elements (SINEs) of the Geomyoidea superfamily rodents.

Science.gov (United States)

Gogolevsky, Konstantin P; Kramerov, Dmitri A

2006-05-24

A new short interspersed element (SINE) was isolated from the genome of desert kangaroo rat (Dipodomys deserti) using single-primer PCR. This SINE consists of two monomers: the left monomer (IDL) resembles rodent ID element and other tRNAAla(CGC)-derived SINEs, whereas the right one (Geo) shows no similarity with known SINE sequences. PCR and hybridization analyses demonstrated that IDL-Geo SINE is restricted to the rodent superfamily Geomyoidea (families Geomyidea and Heteromyidea). Isolation and analysis of IDL-Geo from California pocket mouse (Chaetodipus californicus) and Botta's pocket gopher (Thomomys bottae) revealed some species-specific features of this SINE family. The structure and evolution of known dimeric SINEs are discussed.

Effective field theory dimensional regularization

International Nuclear Information System (INIS)

Lehmann, Dirk; Prezeau, Gary

2002-01-01

A Lorentz-covariant regularization scheme for effective field theories with an arbitrary number of propagating heavy and light particles is given. This regularization scheme leaves the low-energy analytic structure of Greens functions intact and preserves all the symmetries of the underlying Lagrangian. The power divergences of regularized loop integrals are controlled by the low-energy kinematic variables. Simple diagrammatic rules are derived for the regularization of arbitrary one-loop graphs and the generalization to higher loops is discussed

Effective field theory dimensional regularization

Science.gov (United States)

Lehmann, Dirk; Prézeau, Gary

2002-01-01

A Lorentz-covariant regularization scheme for effective field theories with an arbitrary number of propagating heavy and light particles is given. This regularization scheme leaves the low-energy analytic structure of Greens functions intact and preserves all the symmetries of the underlying Lagrangian. The power divergences of regularized loop integrals are controlled by the low-energy kinematic variables. Simple diagrammatic rules are derived for the regularization of arbitrary one-loop graphs and the generalization to higher loops is discussed.

Hantavirus pulmonary syndrome and rodent reservoirs in the savanna-like biome of Brazil's southeastern region.

Science.gov (United States)

Limongi, J E; Oliveira, R C; Guterres, A; Costa Neto, S F; Fernandes, J; Vicente, L H B; Coelho, M G; Ramos, V N; Ferreira, M S; Bonvicino, C R; D'Andrea, P S; Lemos, E R S

2016-04-01

This paper describes the diversity of rodent fauna in an area endemic for hantavirus cardiopulmonary syndrome (HCPS) in Brazil, the population dynamics and the relationship of rodents with hantavirus in the Cerrado (savanna-like) biome. Additionally, an analysis is made of the partial S segment sequences of the hantaviruses obtained from serologically confirmed human HCPS cases and from rodent specimens. Rodents were collected during four campaigns. Human serum samples were collected from suspected cases of HCPS at hospitals in the state of Minas Gerais. The samples antibody-reactive by ELISA were processed by RT-PCR. The PCR product was amplified and sequenced. Hantavirus was detected only in Necromys lasiurus, the wild rodent species most prevalent in the Cerrado biome (min-max: 50-83·7%). All the six human serum samples were hantavirus seropositive and five showed amplified PCR products. The analysis of the nucleotide sequences showed the circulation of a single genotype, the Araraquara hantavirus. The environmental changes that have occurred in the Cerrado biome in recent decades have favoured N. lasiurus in interspecific competition of habitats, thus increasing the risk of contact between humans and rodent species infected with hantavirus. Our data corroborate the definition of N. lasiurus as the main hantavirus reservoir in the Cerrado biome.

Detection and Characterization of Homologues of Human Hepatitis Viruses and Pegiviruses in Rodents and Bats in Vietnam.

Science.gov (United States)

Van Nguyen, Dung; Van Nguyen, Cuong; Bonsall, David; Ngo, Tue Tri; Carrique-Mas, Juan; Pham, Anh Hong; Bryant, Juliet E; Thwaites, Guy; Baker, Stephen; Woolhouse, Mark; Simmonds, Peter

2018-02-28

Rodents and bats are now widely recognised as important sources of zoonotic virus infections in other mammals, including humans. Numerous surveys have expanded our knowledge of diverse viruses in a range of rodent and bat species, including their origins, evolution, and range of hosts. In this study of pegivirus and human hepatitis-related viruses, liver and serum samples from Vietnamese rodents and bats were examined by PCR and sequencing. Nucleic acids homologous to human hepatitis B, C, E viruses were detected in liver samples of 2 (1.3%) of 157 bats, 38 (8.1%), and 14 (3%) of 470 rodents, respectively. Hepacivirus-like viruses were frequently detected (42.7%) in the bamboo rat, Rhizomys pruinosus , while pegivirus RNA was only evident in 2 (0.3%) of 638 rodent serum samples. Complete or near-complete genome sequences of HBV, HEV and pegivirus homologues closely resembled those previously reported from rodents and bats. However, complete coding region sequences of the rodent hepacivirus-like viruses substantially diverged from all of the currently classified variants and potentially represent a new species in the Hepacivirus genus. Of the viruses identified, their routes of transmission and potential to establish zoonoses remain to be determined.

Translational Rodent Models for Research on Parasitic Protozoa-A Review of Confounders and Possibilities.

Science.gov (United States)

Ehret, Totta; Torelli, Francesca; Klotz, Christian; Pedersen, Amy B; Seeber, Frank

2017-01-01

Rodents, in particular Mus musculus , have a long and invaluable history as models for human diseases in biomedical research, although their translational value has been challenged in a number of cases. We provide some examples in which rodents have been suboptimal as models for human biology and discuss confounders which influence experiments and may explain some of the misleading results. Infections of rodents with protozoan parasites are no exception in requiring close consideration upon model choice. We focus on the significant differences between inbred, outbred and wild animals, and the importance of factors such as microbiota, which are gaining attention as crucial variables in infection experiments. Frequently, mouse or rat models are chosen for convenience, e.g., availability in the institution rather than on an unbiased evaluation of whether they provide the answer to a given question. Apart from a general discussion on translational success or failure, we provide examples where infections with single-celled parasites in a chosen lab rodent gave contradictory or misleading results, and when possible discuss the reason for this. We present emerging alternatives to traditional rodent models, such as humanized mice and organoid primary cell cultures. So-called recombinant inbred strains such as the Collaborative Cross collection are also a potential solution for certain challenges. In addition, we emphasize the advantages of using wild rodents for certain immunological, ecological, and/or behavioral questions. The experimental challenges (e.g., availability of species-specific reagents) that come with the use of such non-model systems are also discussed. Our intention is to foster critical judgment of both traditional and newly available translational rodent models for research on parasitic protozoa that can complement the existing mouse and rat models.

Translational Rodent Models for Research on Parasitic Protozoa—A Review of Confounders and Possibilities

Directory of Open Access Journals (Sweden)

Totta Ehret

2017-06-01

Full Text Available Rodents, in particular Mus musculus, have a long and invaluable history as models for human diseases in biomedical research, although their translational value has been challenged in a number of cases. We provide some examples in which rodents have been suboptimal as models for human biology and discuss confounders which influence experiments and may explain some of the misleading results. Infections of rodents with protozoan parasites are no exception in requiring close consideration upon model choice. We focus on the significant differences between inbred, outbred and wild animals, and the importance of factors such as microbiota, which are gaining attention as crucial variables in infection experiments. Frequently, mouse or rat models are chosen for convenience, e.g., availability in the institution rather than on an unbiased evaluation of whether they provide the answer to a given question. Apart from a general discussion on translational success or failure, we provide examples where infections with single-celled parasites in a chosen lab rodent gave contradictory or misleading results, and when possible discuss the reason for this. We present emerging alternatives to traditional rodent models, such as humanized mice and organoid primary cell cultures. So-called recombinant inbred strains such as the Collaborative Cross collection are also a potential solution for certain challenges. In addition, we emphasize the advantages of using wild rodents for certain immunological, ecological, and/or behavioral questions. The experimental challenges (e.g., availability of species-specific reagents that come with the use of such non-model systems are also discussed. Our intention is to foster critical judgment of both traditional and newly available translational rodent models for research on parasitic protozoa that can complement the existing mouse and rat models.

A comparison of bats and rodents as reservoirs of zoonotic viruses: are bats special?

Science.gov (United States)

Luis, Angela D.; Hayman, David T. S.; O'Shea, Thomas J.; Cryan, Paul M.; Gilbert, Amy T.; Pulliam, Juliet R. C.; Mills, James N.; Timonin, Mary E.; Willis, Craig K. R.; Cunningham, Andrew A.; Fooks, Anthony R.; Rupprecht, Charles E.; Wood, James L. N.; Webb, Colleen T.

2013-01-01

Bats are the natural reservoirs of a number of high-impact viral zoonoses. We present a quantitative analysis to address the hypothesis that bats are unique in their propensity to host zoonotic viruses based on a comparison with rodents, another important host order. We found that bats indeed host more zoonotic viruses per species than rodents, and we identified life-history and ecological factors that promote zoonotic viral richness. More zoonotic viruses are hosted by species whose distributions overlap with a greater number of other species in the same taxonomic order (sympatry). Specifically in bats, there was evidence for increased zoonotic viral richness in species with smaller litters (one young), greater longevity and more litters per year. Furthermore, our results point to a new hypothesis to explain in part why bats host more zoonotic viruses per species: the stronger effect of sympatry in bats and more viruses shared between bat species suggests that interspecific transmission is more prevalent among bats than among rodents. Although bats host more zoonotic viruses per species, the total number of zoonotic viruses identified in bats (61) was lower than in rodents (68), a result of there being approximately twice the number of rodent species as bat species. Therefore, rodents should still be a serious concern as reservoirs of emerging viruses. These findings shed light on disease emergence and perpetuation mechanisms and may help lead to a predictive framework for identifying future emerging infectious virus reservoirs. PMID:23378666

A comparison of bats and rodents as reservoirs of zoonotic viruses: are bats special?

Science.gov (United States)

Luis, Angela D.; Hayman, David T.S.; O'Shea, Thomas J.; Cryan, Paul M.; Gilbert, Amy T.; Pulliam, Juliet R.C.; Mills, James N.; Timonin, Mary E.; Willis, Craig K.R.; Cunningham, Andrew A.; Fooks, Anthony R.; Rupprecht, Charles E.; Wood, James L.N.; Webb, Colleen T.

2013-01-01

Bats are the natural reservoirs of a number of high-impact viral zoonoses. We present a quantitative analysis to address the hypothesis that bats are unique in their propensity to host zoonotic viruses based on a comparison with rodents, another important host order. We found that bats indeed host more zoonotic viruses per species than rodents, and we identified life-history and ecological factors that promote zoonotic viral richness. More zoonotic viruses are hosted by species whose distributions overlap with a greater number of other species in the same taxonomic order (sympatry). Specifically in bats, there was evidence for increased zoonotic viral richness in species with smaller litters (one young), greater longevity and more litters per year. Furthermore, our results point to a new hypothesis to explain in part why bats host more zoonotic viruses per species: the stronger effect of sympatry in bats and more viruses shared between bat species suggests that interspecific transmission is more prevalent among bats than among rodents. Although bats host more zoonotic viruses per species, the total number of zoonotic viruses identified in bats (61) was lower than in rodents (68), a result of there being approximately twice the number of rodent species as bat species. Therefore, rodents should still be a serious concern as reservoirs of emerging viruses. These findings shed light on disease emergence and perpetuation mechanisms and may help lead to a predictive framework for identifying future emerging infectious virus reservoirs.

Foraging opportunism and feeding frequency in the red-footed falcon (Falco vespertinus in Slovakia: case study from 2017

Directory of Open Access Journals (Sweden)

Chavko Jozef

2017-12-01

Full Text Available Foraging opportunism and feeding frequency are less studied parameters of behaviour in insectivorous falcons, many of which are endangered bird species. In this short study, prey composition and feeding frequency of red-footed falcon (Falco vespertinus nestlings were studied using the method of camera recordings during seven days in July 2017 in southwestern Slovakia. Camera recording analyses of 2–3 chicks (14–26 days old in three nests revealed a significant preference for insects (97%, n = 305 prey items, of which the Italian locust (Calliptamus italicus was highly predominant (54%. We also found very high average chick feeding frequency (9.9 feedings per hour, n = 29 hours 22 min of regular observations, whereby the females fed their young ones more frequently (64.9%, n = 305 feedings than the males (35.1%. Analyses of food composition in adverse weather conditions showed that unfavourable weather had a negative effect on chick feeding frequency, and in rainy weather the males fed significantly less than the females.

Hepatozoon spp. infections in wild rodents in an area of endemic canine hepatozoonosis in southeastern Brazil.

Science.gov (United States)

Demoner, Larissa de Castro; Magro, Natalia Mizuhira; da Silva, Maria Regina Lucas; de Paula Antunes, João Marcelo Azevedo; Calabuig, Cecilia Irene Pérez; O'Dwyer, Lucia Helena

2016-07-01

Hepatozoon canis is a tick-borne parasite that occurs worldwide. In rural areas of Brazil, H. canis vectors remain unknown, which has led to speculation about alternative routes of transmission. Small rodents can play a role in the transmission (via predation) of Hepatozoon americanum, which led us to question whether predation might be an alternative mode of transmission for H. canis. Thus, this study investigated whether Hepatozoon spp. are present in wild small rodents in forest fragments that surround rural areas in Botucatu County, São Paulo, Brazil, where canine hepatozoonosis is endemic. The study included blood samples from 158 dogs, which were screened by microscopy and molecular analysis. Blood samples and tissues from 67 rodents were obtained for histopathology and molecular detection. The prevalence of H. canis was high (66.45%) in dogs from rural areas of Botucatu, São Paulo, Brazil. The molecular analysis showed that wild rodent species in Brazil were infected with Hepatozoon spp. other than H. canis. Therefore, although the hypothesis that sylvatic rodents act as reservoirs for H. canis was not supported, the presence of monozoic cysts in the rodents suggests that, in addition to intermediate hosts, wild small rodents in Brazil might act as paratenic hosts of Hepatozoon spp. because they harbor infective stages for intermediate host predators. Copyright © 2016 Elsevier GmbH. All rights reserved.

Hierarchical regular small-world networks

International Nuclear Information System (INIS)

Boettcher, Stefan; Goncalves, Bruno; Guclu, Hasan

2008-01-01

Two new networks are introduced that resemble small-world properties. These networks are recursively constructed but retain a fixed, regular degree. They possess a unique one-dimensional lattice backbone overlaid by a hierarchical sequence of long-distance links, mixing real-space and small-world features. Both networks, one 3-regular and the other 4-regular, lead to distinct behaviors, as revealed by renormalization group studies. The 3-regular network is planar, has a diameter growing as √N with system size N, and leads to super-diffusion with an exact, anomalous exponent d w = 1.306..., but possesses only a trivial fixed point T c = 0 for the Ising ferromagnet. In turn, the 4-regular network is non-planar, has a diameter growing as ∼2 √(log 2 N 2 ) , exhibits 'ballistic' diffusion (d w = 1), and a non-trivial ferromagnetic transition, T c > 0. It suggests that the 3-regular network is still quite 'geometric', while the 4-regular network qualifies as a true small world with mean-field properties. As an engineering application we discuss synchronization of processors on these networks. (fast track communication)

Verification of natural infection of peridomestic rodents by PCV2 on commercial swine farms.

Science.gov (United States)

Pinheiro, Albanno Leonard Braz Campos; Bulos, Luiz Henrique Silva; Onofre, Thiago Souza; de Paula Gabardo, Michelle; de Carvalho, Otávio Valério; Fausto, Mariana Costa; Guedes, Roberto Maurício Carvalho; de Almeida, Márcia Rogéria; Silva Júnior, Abelardo

2013-06-01

The porcine circovirus-2 (PCV2) is the main agent responsible for porcine circovirus associated diseases (PCVAD). Few studies have been done regarding PCV2 infection in other species. The purpose of this study was to investigate the occurrence of PCV2 infection in the peridomestic rodent species Mus musculus and Rattus rattus on commercial pig farms in Brazil. Immunohistochemistry assay demonstrated PCV2 in the spleen, lung and kidney. Viral DNA was detected in tissues by nested PCR assay. Partial sequences of PCV2 genomes detected in the rodents had strong identity with gene sequences of PCV2 isolates from pigs. These results show that the studied peridomestic rodent species can be naturally infected by PCV2. However, further studies are needed to confirm PCV2 transmission from rodents to pigs. Copyright © 2012 Elsevier Ltd. All rights reserved.

Taxonomical studies of ticks infesting wild rodents from Asir Province in Saudi Arabia.

Science.gov (United States)

Al-Mohammed, Hamdan I

2008-04-01

Ticks infesting rodents in Asir Province, which is about 3000 meter above sea level, were surveyed in Wadi Dalaghan and Wadi Bin Hachbal. They were examined from September to December 2006, where ten local life baited traps were distributed for 3 days each month. The rodents were Acomys c. dimitatus (20), Meriones rex (19) & one Gerbillus cheesmani. Fifty three nymphs were dropped off from the rodents in the laboratory 3 to 12 days post-trapping. Forty eight nymphs were reared to adults for identification and 5 ones died. The reared ticks were Rhipicephalus turanicus and R. sanguineus. The medical and veterinary importance was discussed.

75 FR 76006 - Regular Meeting

Science.gov (United States)

2010-12-07

... FARM CREDIT SYSTEM INSURANCE CORPORATION Regular Meeting AGENCY: Farm Credit System Insurance Corporation Board. ACTION: Regular meeting. SUMMARY: Notice is hereby given of the regular meeting of the Farm Credit System Insurance Corporation Board (Board). Date and Time: The meeting of the Board will be held...

General inverse problems for regular variation

DEFF Research Database (Denmark)

Damek, Ewa; Mikosch, Thomas Valentin; Rosinski, Jan

2014-01-01

Regular variation of distributional tails is known to be preserved by various linear transformations of some random structures. An inverse problem for regular variation aims at understanding whether the regular variation of a transformed random object is caused by regular variation of components ...

Long-lived cancer-resistant rodents as new model species for cancer research

Directory of Open Access Journals (Sweden)

Jorge eAzpurua

2013-01-01

Full Text Available Most rodents are small and short-lived, but several lineages have independently evolved long lifespans without a concomitant increase in body mass. Most notably, the two subterranean species naked mole rat (NMR and blind mole rat (BMR which have maximum lifespans of 32 and 21 years respectively. The longevity of these species has sparked interest in the tumor suppression strategies that may have also evolved, because for many rodent species (including mice, rats, guinea pigs, gerbils and hamsters tumors are major source of late-life mortality. Here, we review the recent literature on anticancer mechanisms in long-lived rodents. Both NMR and BMR seem to have developed tumor defenses that rely on extra-cellular signals. However, while the NMR relies on a form of contact inhibition to suppress growth, the BMR evolved a mechanism mediated by the release of interferon and rapid necrotic cell death. Although both organisms ultimately rely on canonical downstream tumor suppressors (pRB and p53 the studies reveal species can evolve different strategies to achieve tumor-resistance. Importantly, studies of these cancer-resistant rodents may benefit human health if such mechanisms can be activated in human cells.

A glimpse on the pattern of rodent diversification

DEFF Research Database (Denmark)

Fabre, Pierre-Henri Fréderic; Hautier, Lionel; Dimitrov, Dimitar Stefanov

2012-01-01

BACKGROUND:Development of phylogenetic methods that do not rely on fossils for the study of evolutionary processes through time have revolutionized the field of evolutionary biology and resulted in an unprecedented expansion of our knowledge about the tree of life. These methods have helped to shed...... molecular works. A relaxed molecular clock dating approach provided a time framework for speciation events. We found that the Myomorpha clade shows a greater degree of variation in diversification rates than Sciuroidea, Caviomorpha, Castorimorpha and Anomaluromorpha. We identified a number of shifts...... imbalances and the time line we discuss the potential role of different diversification factors that might have shaped the rodents radiation. CONCLUSIONS:The present glimpse on the diversification pattern of rodents can be used for further comparative meta-analyses. Muroid lineages have a greater degree...

Comparison of Subcutaneous Regular Insulin and Lispro Insulin in Diabetics Receiving Continuous Nutrition: A Numerical Study.

Science.gov (United States)

Stull, Mamie C; Strilka, Richard J; Clemens, Michael S; Armen, Scott B

2015-06-30

Optimal management of non-critically ill patients with diabetes maintained on continuous enteral feeding (CEN) is poorly defined. Subcutaneous (SQ) lispro and SQ regular insulin were compared in a simulated type 1 and type 2 diabetic patient receiving CEN. A glucose-insulin feedback mathematical model was employed to simulate type 1 and type 2 diabetic patients on CEN. Each patient received 25 SQ injections of regular insulin or insulin lispro, ranging from 0-6 U. Primary endpoints were the change in mean glucose concentration (MGC) and change in glucose variability (GV); hypoglycemic episodes were also reported. The model was first validated against patient data. Both SQ insulin preparations linearly decreased MGC, however, SQ regular insulin decreased GV whereas SQ lispro tended to increase GV. Hourly glucose concentration measurements were needed to capture the increase in GV. In the type 2 diabetic patient, "rebound hyperglycemia" occurred after SQ lispro was rapidly metabolized. Although neither SQ insulin preparation caused hypoglycemia, SQ lispro significantly lowered MGC compared to SQ regular insulin. Thus, it may be more likely to cause hypoglycemia. Analyses of the detailed glucose concentration versus time data suggest that the inferior performance of lispro resulted from its shorter duration of action. Finally, the effects of both insulin preparations persisted beyond their duration of actions in the type 2 diabetic patient. Subcutaneous regular insulin may be the short-acting insulin preparation of choice for this subset of diabetic patients. Clinical trial is required before a definitive recommendation can be made. © 2015 Diabetes Technology Society.

The Upper Miocene rodents from the Pezinok in the Danube Basin, Slovakia

OpenAIRE

Peter Joniak

2016-01-01

Rodent assemblages are described from two sampled sites at the Pezinok clay pit in the Danube Basin. Although these assemblages contain material poor in specimens, the following eleven rodent taxa are distinguished and described: Progonomys hispanicus, Kowalskia sp., Microtocricetus molassicus, Anomalomys gaillardi, Graphiurops austriacus, Paraglirulus sp., Eomyops catalaunicus, Keramidomys sp., Spermophilinus sp., Albanensia sp. and Euroxenomys minutum. The co-occurrence of very primitive Pr...

Multigenerational Independent Colony for Extraterrestrial Habitation, Autonomy, and Behavior Health (MICEHAB): An Investigation of a Long Duration, Partial Gravity, Autonomous Rodent Colony

Science.gov (United States)

Rodgers, Erica M.; Simon, Matthew A.; Antol, Jeffrey; Chai, Patrick R.; Jones, Christopher A.; Klovstad, Jordan J.; Neilan, James H.; Stillwagen, Frederic H.; Williams, Phillip A.; Bednara, Michael;

Endotoxin, coliform, and dust levels in various types of rodent bedding.

Science.gov (United States)

Whiteside, Tanya E; Thigpen, Julius E; Kissling, Grace E; Grant, Mary G; Forsythe, Diane

2010-03-01

Endotoxins in grain dust, household dust, and animal bedding may induce respiratory symptoms in rodents and humans. We assayed the endotoxin, coliform, and dust levels in 20 types of rodent bedding. Endotoxin concentrations were measured by using a commercial test kit, coliform counts were determined by using conventional microbiologic procedures, and dust content was evaluated by using a rotating-tapping shaker. Paper bedding types contained significantly less endotoxin than did other bedding types; the highest levels of endotoxin were detected in hardwood and corncob beddings. The range of endotoxin content for each bedding type was: corncob bedding, 1913 to 4504 endotoxin units per gram (EU/g); hardwood bedding, 3121 to 5401 EU/g; corncob-paper mixed bedding, 1586 to 2416 EU/g; and paper bedding, less than 5 to 105 EU/g. Coliform counts varied from less than 10 to 7591 cfu/g in corncob beddings, 90 to 4010 cfu/g in corncob-paper mixed beddings, less than 10 to 137 cfu/g in hardwood beddings, and less than 10 cfu/g in paper beddings. Average dust content was less than 0.15% in all commercial bedding types. We conclude that paper bedding is the optimal bedding type for conducting LPS inhalation studies and that rodent bedding containing high levels of endotoxin may alter the results of respiratory and immunologic studies in rodents.

Neural correlates of food anticipatory activity in mice subjected to once- or twice-daily feeding periods.

Science.gov (United States)

Rastogi, Ashutosh; Mintz, Eric M

2017-10-01

In rodents, restricted food access to a limited period each day at a predictable time results in the appearance of food anticipatory activity (FAA). Two shorter periods of food access each day can result in two FAA bouts. In this study, we examine FAA under 12:12 and 18:6 photoperiods in mice (Mus musculus) with one or two food access periods per day and measure the activation of the suprachiasmatic, dorsomedial and arcuate nuclei by assaying Fos protein expression, while making use of tissue-type plasminogen activator knockout mice to assess the role of neural plasticity in adaptation to restricted feeding cycles. Long days were utilised to allow for temporal separation of two restricted feeding periods during the light phase. Mice fed twice per day generally divided FAA into two distinct bouts, with mice lacking tissue-type plasminogen activator showing reduced FAA. Increases in Fos expression in response to one restricted feeding period per day were seen in the dorsomedial and arcuate nuclei in both 12:12 and 18:6 conditions, with an increase seen in the SCN in only the 12:12 condition. These increases were eliminated or reduced in the two feeding time conditions (done in 18:6 only). Both activity patterns and Fos expression differed for single restricted feeding times between 18:6 and 12:12 photoperiods. Fos activation was lower during RF in 18:6 than 12:12 across all three brain regions, a pattern not reflective of changes in FAA. These data suggest that involvement of these regions in FAA may be influenced by photoperiodic context. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Continuum-regularized quantum gravity

International Nuclear Information System (INIS)

Chan Huesum; Halpern, M.B.

1987-01-01

The recent continuum regularization of d-dimensional Euclidean gravity is generalized to arbitrary power-law measure and studied in some detail as a representative example of coordinate-invariant regularization. The weak-coupling expansion of the theory illustrates a generic geometrization of regularized Schwinger-Dyson rules, generalizing previous rules in flat space and flat superspace. The rules are applied in a non-trivial explicit check of Einstein invariance at one loop: the cosmological counterterm is computed and its contribution is included in a verification that the graviton mass is zero. (orig.)

Rodent malaria parasites : genome organization & comparative genomics

NARCIS (Netherlands)

Kooij, Taco W.A.

2006-01-01

The aim of the studies described in this thesis was to investigate the genome organization of rodent malaria parasites (RMPs) and compare the organization and gene content of the genomes of RMPs and the human malaria parasite P. falciparum. The release of the complete genome sequence of P.

Online co-regularized algorithms

NARCIS (Netherlands)

Ruijter, T. de; Tsivtsivadze, E.; Heskes, T.

2012-01-01

We propose an online co-regularized learning algorithm for classification and regression tasks. We demonstrate that by sequentially co-regularizing prediction functions on unlabeled data points, our algorithm provides improved performance in comparison to supervised methods on several UCI benchmarks

Geometric continuum regularization of quantum field theory

International Nuclear Information System (INIS)

Halpern, M.B.

1989-01-01

An overview of the continuum regularization program is given. The program is traced from its roots in stochastic quantization, with emphasis on the examples of regularized gauge theory, the regularized general nonlinear sigma model and regularized quantum gravity. In its coordinate-invariant form, the regularization is seen as entirely geometric: only the supermetric on field deformations is regularized, and the prescription provides universal nonperturbative invariant continuum regularization across all quantum field theory. 54 refs

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

Science.gov (United States)

Hope, Andrew G.; Parmenter, Robert R.

2007-01-01

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

[Population change of farmland rodent and the influences of climate and cultivation factors in Fengxian District of Shanghai, China].

Science.gov (United States)

Fei, Lei; Wang, Zu-guo; Yao, Yao; Xu, Xiang-ming; Gu, Pin-qiang

2015-02-01

We analyzed the changes of rodent population from 1988 to 2013 in Fengxian District, Shanghai, and discussed the relevance of rodent population dynamics and climate, and ecological factors. Results showed that the average rat density was 1.3% from 1988 to 2013, and the dominant species was Apodemus agrarius. There was little change of density between years. The average composition ratio was 97.5%. The peak of rodent density appeared from February to May, highest in March. Average density and peak decreased obviously year after year. Numbers of adult rodents of 1st group were positively correlated, while that of adult rodents of 2nd group and elderly group negatively correlated with years. Rat age presented a shortened trend annually. Rodent density and temperature factors were negatively correlated except in January. Extreme warmth in February had a lagged, positive effect on the rat density. Precipitation factors had no significant correlation with the density of rodents. Relative humidity was positively correlated with the density, mostly. Planting structure adjustment and reduction of planting acreage were significantly correlated with the reduction of rodent density. Increased deratization rate was also correlated with the reduction.

Bypassing the Limits of Ll Regularization: Convex Sparse Signal Processing Using Non-Convex Regularization

Science.gov (United States)

Parekh, Ankit

Sparsity has become the basis of some important signal processing methods over the last ten years. Many signal processing problems (e.g., denoising, deconvolution, non-linear component analysis) can be expressed as inverse problems. Sparsity is invoked through the formulation of an inverse problem with suitably designed regularization terms. The regularization terms alone encode sparsity into the problem formulation. Often, the ℓ1 norm is used to induce sparsity, so much so that ℓ1 regularization is considered to be `modern least-squares'. The use of ℓ1 norm, as a sparsity-inducing regularizer, leads to a convex optimization problem, which has several benefits: the absence of extraneous local minima, well developed theory of globally convergent algorithms, even for large-scale problems. Convex regularization via the ℓ1 norm, however, tends to under-estimate the non-zero values of sparse signals. In order to estimate the non-zero values more accurately, non-convex regularization is often favored over convex regularization. However, non-convex regularization generally leads to non-convex optimization, which suffers from numerous issues: convergence may be guaranteed to only a stationary point, problem specific parameters may be difficult to set, and the solution is sensitive to the initialization of the algorithm. The first part of this thesis is aimed toward combining the benefits of non-convex regularization and convex optimization to estimate sparse signals more effectively. To this end, we propose to use parameterized non-convex regularizers with designated non-convexity and provide a range for the non-convex parameter so as to ensure that the objective function is strictly convex. By ensuring convexity of the objective function (sum of data-fidelity and non-convex regularizer), we can make use of a wide variety of convex optimization algorithms to obtain the unique global minimum reliably. The second part of this thesis proposes a non-linear signal

Using Tikhonov Regularization for Spatial Projections from CSR Regularized Spherical Harmonic GRACE Solutions

Science.gov (United States)

Save, H.; Bettadpur, S. V.

2013-12-01

It has been demonstrated before that using Tikhonov regularization produces spherical harmonic solutions from GRACE that have very little residual stripes while capturing all the signal observed by GRACE within the noise level. This paper demonstrates a two-step process and uses Tikhonov regularization to remove the residual stripes in the CSR regularized spherical harmonic coefficients when computing the spatial projections. We discuss methods to produce mass anomaly grids that have no stripe features while satisfying the necessary condition of capturing all observed signal within the GRACE noise level.

Regularized maximum correntropy machine

KAUST Repository

Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

2015-01-01

In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

Regularized maximum correntropy machine

KAUST Repository

Wang, Jim Jing-Yan

2015-02-12

In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

Overview of FEED, the feeding experiments end-user database.

Science.gov (United States)

Wall, Christine E; Vinyard, Christopher J; Williams, Susan H; Gapeyev, Vladimir; Liu, Xianhua; Lapp, Hilmar; German, Rebecca Z

2011-08-01

The Feeding Experiments End-user Database (FEED) is a research tool developed by the Mammalian Feeding Working Group at the National Evolutionary Synthesis Center that permits synthetic, evolutionary analyses of the physiology of mammalian feeding. The tasks of the Working Group are to compile physiologic data sets into a uniform digital format stored at a central source, develop a standardized terminology for describing and organizing the data, and carry out a set of novel analyses using FEED. FEED contains raw physiologic data linked to extensive metadata. It serves as an archive for a large number of existing data sets and a repository for future data sets. The metadata are stored as text and images that describe experimental protocols, research subjects, and anatomical information. The metadata incorporate controlled vocabularies to allow consistent use of the terms used to describe and organize the physiologic data. The planned analyses address long-standing questions concerning the phylogenetic distribution of phenotypes involving muscle anatomy and feeding physiology among mammals, the presence and nature of motor pattern conservation in the mammalian feeding muscles, and the extent to which suckling constrains the evolution of feeding behavior in adult mammals. We expect FEED to be a growing digital archive that will facilitate new research into understanding the evolution of feeding anatomy.

Effect of feed presentation on feeding patterns of dairy calves.

Science.gov (United States)

Miller-Cushon, E K; Bergeron, R; Leslie, K E; Mason, G J; DeVries, T J

2013-01-01

The objectives of this study were to determine the effect of feed presentation on meal frequency and duration, as well as diurnal feeding patterns of dairy calves, and to assess any longer-term differences in feeding patterns resulting from previous experience. Twenty Holstein bull calves were exposed from wk 1 to 8 of life to 1 of 2 feed presentation treatments: concentrate and chopped grass hay (Feed was provided ad libitum. Calves received 8L/d of milk replacer (1.2 kg of dry matter), with the amount progressively reduced after 5 wk to facilitate weaning by the end of wk 7. At the beginning of wk 9, all calves received the MIX diet and remained on trial for an additional 3 wk. Feeding behavior was recorded from video for 4d during wk 6, 8, 9, and 11. In wk 6, calves fed MIX spent more time feeding than calves fed COM (56.7 vs. 46.8 min/d). In wk 8, calves fed MIX spent more time feeding (174.0 vs. 139.1 min/d) and had a lower rate of intake (11.5 vs. 14.7 g/min) compared with calves fed COM. Meal frequency was similar between treatments (12.2 meals/d). Diurnal feeding patterns in wk 8 were also affected by feed presentation, with calves fed MIX spending less time feeding at time of feed delivery and more time feeding throughout the rest of the daylight hours than calves fed COM. Diurnal feeding patterns of hay and concentrate in wk 8 differed for calves fed COM, with more time spent consuming hay at time of feed delivery and less time spent consuming hay throughout the rest of the day. Once calves previously fed COM were transitioned to the MIX diet in wk 9, meal frequency, meal duration, and diurnal feeding patterns were similar between treatments: both treatments spent similar amounts of time feeding (173.9 min/d) and had similar peaks in feeding activity at time of feed delivery, sunrise, and sunset. Provision of hay and concentrate to young calves as a mixed ration, compared with separate components, increases time spent feeding and results in more evenly

Segmentation of rodent whole-body dynamic PET images: an unsupervised method based on voxel dynamics

DEFF Research Database (Denmark)

Maroy, Renaud; Boisgard, Raphaël; Comtat, Claude

2008-01-01

Positron emission tomography (PET) is a useful tool for pharmacokinetics studies in rodents during the preclinical phase of drug and tracer development. However, rodent organs are small as compared to the scanner's intrinsic resolution and are affected by physiological movements. We present a new...... method for the segmentation of rodent whole-body PET images that takes these two difficulties into account by estimating the pharmacokinetics far from organ borders. The segmentation method proved efficient on whole-body numerical rat phantom simulations, including 3-14 organs, together...

Toxoplasma gondii antibodies in wild rodents and marsupials from the Atlantic Forest, state of São Paulo, Brazil

Directory of Open Access Journals (Sweden)

Solange Maria Gennari

Full Text Available Toxoplasma gondii is a protozoan parasite that infects a large spectrum of warm-blooded animals, including humans. Small rodents and marsupials play an important role in the epidemiology of T. gondii because they are sources of infection for domestic and feral cats. Serum samples from 151 rodents and 48 marsupials, captured in the Atlantic Forest, São Paulo State, southeastern Brazil, were analyzed for the presence of T. gondii antibodies. Antibodies detected by the modified agglutination test (MAT ≥ 25 were found in 8.6% (13/151 of the rodents and 10.4% (5/48 of the marsupials, with titers ranging from 25 to 6400 and from 25 to 3200, respectively for the rodents and marsupials. Three of the eight species of rodents (Akodon spp., Oligoryzomys nigripesand Rattus norvegicus, and one from the four marsupial species (Didelphis aurita presented positive animals. T. gondii was described for the first time in the rodent Oligoryzomys nigripes.

Object Recognition Memory and the Rodent Hippocampus

Science.gov (United States)

Broadbent, Nicola J.; Gaskin, Stephane; Squire, Larry R.; Clark, Robert E.

2010-01-01

In rodents, the novel object recognition task (NOR) has become a benchmark task for assessing recognition memory. Yet, despite its widespread use, a consensus has not developed about which brain structures are important for task performance. We assessed both the anterograde and retrograde effects of hippocampal lesions on performance in the NOR…

Miniature wireless recording and stimulation system for rodent behavioural testing

Science.gov (United States)

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

2015-12-01

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

Sexual selection halts the relaxation of protamine 2 among rodents.

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Lena Lüke

Full Text Available Sexual selection has been proposed as the driving force promoting the rapid evolutionary changes observed in some reproductive genes including protamines. We test this hypothesis in a group of rodents which show marked differences in the intensity of sexual selection. Levels of sperm competition were not associated with the evolutionary rates of protamine 1 but, contrary to expectations, were negatively related to the evolutionary rate of cleaved- and mature-protamine 2. Since both domains were found to be under relaxation, our findings reveal an unforeseen role of sexual selection: to halt the degree of degeneration that proteins within families may experience due to functional redundancy. The degree of relaxation of protamine 2 in this group of rodents is such that in some species it has become dysfunctional and it is not expressed in mature spermatozoa. In contrast, protamine 1 is functionally conserved but shows directed positive selection on specific sites which are functionally relevant such as DNA-anchoring domains and phosphorylation sites. We conclude that in rodents protamine 2 is under relaxation and that sexual selection removes deleterious mutations among species with high levels of sperm competition to maintain the protein functional and the spermatozoa competitive.

Knowledge, opinions and practices of healthcare workers related to infant feeding in the context of HIV

Directory of Open Access Journals (Sweden)

Liska Janse van Rensburg

2016-10-01

Objective: To determine the knowledge, opinions and practices of healthcare workers in maternity wards in a regional hospital in Bloemfontein, Free State Province, South Africa, regarding infant feeding in the context of HIV. Methods: For this descriptive cross-sectional study, all the healthcare workers in the maternity wards of Pelonomi Regional Hospital who voluntarily gave their consent during the scheduled meetings (n = 64, were enrolled and handed over the self-administered questionnaires. Results: Only 14% of the respondents considered themselves to be experts in HIV and infant feeding. Approximately 97% felt that breastfeeding was an excellent feeding choice provided proper guidelines were followed. However, 10% indicated that formula feeding is the safest feeding option. 45% stated that heat-treated breast milk is a good infant feeding option; however, 29% considered it a good infant feeding option but it requires too much work. Only 6% could comprehensively explain the term “exclusive breastfeeding” as per World Health Organisation (WHO definition. Confusion existed regarding the period for which an infant could be breastfed according to the newest WHO guidelines, with only 26% providing the correct answer. Twenty per cent reported that no risk exists for HIV transmission via breastfeeding if all the necessary guidelines are followed. Conclusion: Healthcare workers' knowledge did not conform favourably with the current WHO guidelines. These healthcare workers were actively involved in the care of patients in the maternity wards where HIV-infected mothers regularly seek counselling on infant feeding matters.

A study of ectoparasites in wild rodents of the Jaz Murian area in the southeast of Iran

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Asghar Khajeh

2017-07-01

Full Text Available Objective: To detect wild rodents ectoparasites in the southeast of Iran. Methods: In this survey, the wild rodents were trapped from 2014 to 2015. The captured rodents were checked for any ectoparasites. Results: In this study, 681 ectoparasites belonged to 6 species of flea, 2 species of lice, 1 species of mite and 2 species of hard tick were collected. The flea species were including, Xenopsylla gerbilli, Xenopsylla cheopis, Xenopsylla buxtoni, Xenopsylla conformis, Nosopsyllus medus and Amphipysylla spp., the lice species were including Hoplopleura spp. and Polyplax spp., the mite species was Ornithonyssus bacoti and tick species were Rhipicephalus spp. and Hyalomma spp. Conclusions: Among all ectoparasites, Hoplopleura spp. and Amphipysylla spp. had the high and low frequency infestation in rodents, respectively. Also among captured rodents, the highest ectoparasites infestation was found in Tatera indica and no ectoparasites in Apodemus witherbyi, Cricetelus migratorius, and Microtus mystacinus kermanesis.

Regularities of Multifractal Measures

Indian Academy of Sciences (India)

First, we prove the decomposition theorem for the regularities of multifractal Hausdorff measure and packing measure in R R d . This decomposition theorem enables us to split a set into regular and irregular parts, so that we can analyze each separately, and recombine them without affecting density properties. Next, we ...

Assessment of possible carcinogenicity of oxyfluorfen to humans using mode of action analysis of rodent liver effects.

Science.gov (United States)

Stagg, Nicola J; LeBaron, Matthew J; Eisenbrandt, David L; Gollapudi, B Bhaskar; Klaunig, James E

2012-08-01

Oxyfluorfen is a herbicide that is not genotoxic and produces liver toxicity in rodents, following repeated administration at high dose levels. Lifetime rodent feeding studies reported in 1977 with low-purity oxyfluorfen (85%) showed no increase in any tumor type in rats (800 ppm, high dose) and only a marginally increased incidence of hepatocellular tumors in male CD-1 mice at the highest dose (200 ppm). To evaluate the potential carcinogenicity of the currently registered oxyfluorfen (> 98% purity), we conducted a series of short-term liver mode of action (MOA) toxicology studies in male CD-1 mice administered dietary doses of 0, 40, 200, 800, and 1600 ppm for durations of 3, 7, 10, or 28 days. MOA endpoints examined included liver weight, histopathology, cell proliferation, nuclear receptor-mediated gene expression, and other peroxisome proliferator-specific endpoints and their reversibility. Minimal liver effects were observed in mice administered doses at or below 200 ppm for up to 28 days. Increased liver weight, single-cell necrosis, cell proliferation, and peroxisomal acyl-CoA oxidase (ACO) were observed at 800 ppm after 28 days, but there was no increase in peroxisomes. Expression of Cyp2b10 and Cyp4a10 transcripts, markers of constitutive androstane receptor and peroxisome proliferator activated receptor α nuclear receptor activation, respectively, were increased at 800 and 1600 ppm after 3 or 10 days. Collectively, these data along with the negative genotoxicity demonstrate that oxyfluorfen (> 98% purity) has the potential to induce mouse liver tumors through a nongenotoxic, mitogenic MOA with a clear threshold and is not predicted to be carcinogenic in humans at relevant exposure levels.

31 CFR 540.317 - Uranium feed; natural uranium feed.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed. The...

Adaptive Regularization of Neural Classifiers

DEFF Research Database (Denmark)

Andersen, Lars Nonboe; Larsen, Jan; Hansen, Lars Kai

1997-01-01

We present a regularization scheme which iteratively adapts the regularization parameters by minimizing the validation error. It is suggested to use the adaptive regularization scheme in conjunction with optimal brain damage pruning to optimize the architecture and to avoid overfitting. Furthermo......, we propose an improved neural classification architecture eliminating an inherent redundancy in the widely used SoftMax classification network. Numerical results demonstrate the viability of the method...

Feeding styles and evening family meals among recent immigrants

Science.gov (United States)

2013-01-01

The protective effect of family meals on unhealthy weight gain and diet has been shown across multiple age groups; however, it is unknown whether a similar effect is present among diverse immigrant populations. In addition, little research has focused on factors associated with the frequency of evening family meals, such as feeding styles (how parents interact with their child around feeding). Therefore the goals of this paper are to explore the 1) association between the frequency of evening family meals and child weight status among new immigrant families, and 2) influence of immigrant mothers’ feeding styles on the frequency of evening family meals. Baseline self-reported socio-demographic information and measured heights and weights were collected for both mother and child (age range: 3–12 years) among 387 mother-child dyads enrolled in Live Well, a community-based, participatory-research, randomized controlled lifestyle intervention to prevent excessive weight gain in recent (eating dinner in front of the TV, acculturation and responses to the Caregiver’s Feeding Styles Questionnaire (CFSQ) were also obtained from the mother. Children were categorized as “eating evening family meals regularly” if they had an evening family meal ≥5 times per week. Overall, 20% of children were overweight and 25% were obese. Less than half (40.9%) of families had regular evening family meals. In multivariate analyses, adjusting for covariates, children who were overweight/obese were significantly less likely to have ≥5 evening family meals/week compared with normal weight children (OR = 0.51, 95% CI 0.32-0.82) . Mothers who had a low demanding/high responsive or a low demanding/low responsive feeding style, were less likely to have ≥5 evening family meals/week compared to mothers with a high demanding/high responsive feeding style (OR = 0.41, 95% CI 0.18-0.0.96, OR = 0.33, 95% CI 0.13-0.87, respectively). Future interventions and programs that seek

Default-mode-like network activation in awake rodents.

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Jaymin Upadhyay

Full Text Available During wakefulness and in absence of performing tasks or sensory processing, the default-mode network (DMN, an intrinsic central nervous system (CNS network, is in an active state. Non-human primate and human CNS imaging studies have identified the DMN in these two species. Clinical imaging studies have shown that the pattern of activity within the DMN is often modulated in various disease states (e.g., Alzheimer's, schizophrenia or chronic pain. However, whether the DMN exists in awake rodents has not been characterized. The current data provides evidence that awake rodents also possess 'DMN-like' functional connectivity, but only subsequent to habituation to what is initially a novel magnetic resonance imaging (MRI environment as well as physical restraint. Specifically, the habituation process spanned across four separate scanning sessions (Day 2, 4, 6 and 8. At Day 8, significant (p<0.05 functional connectivity was observed amongst structures such as the anterior cingulate (seed region, retrosplenial, parietal, and hippocampal cortices. Prior to habituation (Day 2, functional connectivity was only detected (p<0.05 amongst CNS structures known to mediate anxiety (i.e., anterior cingulate (seed region, posterior hypothalamic area, amygdala and parabracial nucleus. In relating functional connectivity between cingulate-default-mode and cingulate-anxiety structures across Days 2-8, a significant inverse relationship (r = -0.65, p = 0.0004 was observed between these two functional interactions such that increased cingulate-DMN connectivity corresponded to decreased cingulate anxiety network connectivity. This investigation demonstrates that the cingulate is an important component of both the rodent DMN-like and anxiety networks.

Integrative rodent models for assessing male reproductive toxicity of environmental endocrine active substances

Directory of Open Access Journals (Sweden)

Jacques Auger

2014-02-01

Full Text Available In the present review, we first summarize the main benefits, limitations and pitfalls of conventional in vivo approaches to assessing male reproductive structures and functions in rodents in cases of endocrine active substance (EAS exposure from the postulate that they may provide data that can be extrapolated to humans. Then, we briefly present some integrated approaches in rodents we have recently developed at the organism level. We particularly focus on the possible effects and modes of action (MOA of these substances at low doses and in mixtures, real-life conditions and at the organ level, deciphering the precise effects and MOA on the fetal testis. It can be considered that the in vivo experimental EAS exposure of rodents remains the first choice for studies and is a necessary tool (together with the epidemiological approach for understanding the reproductive effects and MOA of EASs, provided the pitfalls and limitations of the rodent models are known and considered. We also provide some evidence that classical rodent models may be refined for studying the multiple consequences of EAS exposure, not only on the reproductive axis but also on various hormonally regulated organs and tissues, among which several are implicated in the complex process of mammalian reproduction. Such models constitute an interesting way of approaching human exposure conditions. Finally, we show that organotypic culture models are powerful complementary tools, especially when focusing on the MOA. All these approaches have contributed in a combinatorial manner to a better understanding of the impact of EAS exposure on human reproduction.

Control of (pre-analytical aspects in immunoassay measurements of metabolic hormones in rodents

Directory of Open Access Journals (Sweden)

Maximilian Bielohuby

2018-04-01

Full Text Available The measurement of circulating hormones by immunoassay remains a cornerstone in preclinical endocrine research. For scientists conducting and interpreting immunoassay measurements of rodent samples, the paramount aim usually is to obtain reliable and meaningful measurement data in order to draw conclusions on biological processes. However, the biological variability between samples is not the only variable affecting the readout of an immunoassay measurement and a considerable amount of unwanted or unintended variability can be quickly introduced during the pre-analytical and analytical phase. This review aims to increase the awareness for the factors ‘pre-analytical’ and ‘analytical’ variability particularly in the context of immunoassay measurement of circulating metabolic hormones in rodent samples. In addition, guidance is provided how to gain control over these variables and how to avoid common pitfalls associated with sample collection, processing, storage and measurement. Furthermore, recommendations are given on how to perform a basic validation of novel single and multiplex immunoassays for the measurement of metabolic hormones in rodents. Finally, practical examples from immunoassay measurements of plasma insulin in mice address the factors ‘sampling site and inhalation anesthesia’ as frequent sources of introducing an unwanted variability during the pre-analytical phase. The knowledge about the influence of both types of variability on the immunoassay measurement of circulating hormones as well as strategies to control these variables are crucial, on the one hand, for planning and realization of metabolic rodent studies and, on the other hand, for the generation and interpretation of meaningful immunoassay data from rodent samples.

Condition Number Regularized Covariance Estimation.

Science.gov (United States)

Won, Joong-Ho; Lim, Johan; Kim, Seung-Jean; Rajaratnam, Bala

2013-06-01

Estimation of high-dimensional covariance matrices is known to be a difficult problem, has many applications, and is of current interest to the larger statistics community. In many applications including so-called the "large p small n " setting, the estimate of the covariance matrix is required to be not only invertible, but also well-conditioned. Although many regularization schemes attempt to do this, none of them address the ill-conditioning problem directly. In this paper, we propose a maximum likelihood approach, with the direct goal of obtaining a well-conditioned estimator. No sparsity assumption on either the covariance matrix or its inverse are are imposed, thus making our procedure more widely applicable. We demonstrate that the proposed regularization scheme is computationally efficient, yields a type of Steinian shrinkage estimator, and has a natural Bayesian interpretation. We investigate the theoretical properties of the regularized covariance estimator comprehensively, including its regularization path, and proceed to develop an approach that adaptively determines the level of regularization that is required. Finally, we demonstrate the performance of the regularized estimator in decision-theoretic comparisons and in the financial portfolio optimization setting. The proposed approach has desirable properties, and can serve as a competitive procedure, especially when the sample size is small and when a well-conditioned estimator is required.

Comparative Analysis of Human and Rodent Brain Primary Neuronal Culture Spontaneous Activity Using Micro-Electrode Array Technology.

Science.gov (United States)

Napoli, Alessandro; Obeid, Iyad

2016-03-01

Electrical activity in embryonic brain tissue has typically been studied using Micro Electrode Array (MEA) technology to make dozens of simultaneous recordings from dissociated neuronal cultures, brain stem cell progenitors, or brain slices from fetal rodents. Although these rodent neuronal primary culture electrical properties are mostly investigated, it has not been yet established to what extent the electrical characteristics of rodent brain neuronal cultures can be generalized to those of humans. A direct comparison of spontaneous spiking activity between rodent and human primary neurons grown under the same in vitro conditions using MEA technology has never been carried out before and will be described in the present study. Human and rodent dissociated fetal brain neuronal cultures were established in-vitro by culturing on a glass grid of 60 planar microelectrodes neurons under identical conditions. Three different cultures of human neurons were produced from tissue sourced from a single aborted fetus (at 16-18 gestational weeks) and these were compared with seven different cultures of embryonic rat neurons (at 18 gestational days) originally isolated from a single rat. The results show that the human and rodent cultures behaved significantly differently. Whereas the rodent cultures demonstrated robust spontaneous activation and network activity after only 10 days, the human cultures required nearly 40 days to achieve a substantially weaker level of electrical function. These results suggest that rat neuron preparations may yield inferences that do not necessarily transfer to humans. © 2015 Wiley Periodicals, Inc.

Epidemiological distribution of rodents as potent reservoirs for infectious diseases in the provinces of Mazandaran, Gilan and Golestan, northern Iran

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Behzad Esfandiari

2017-05-01

Full Text Available Rodents are mammals that comprise more than 2000 species and approximately 30 families. There are many morphological and ecological differences among them as variations in their shape, size, weight and habitat. In addition to significant economic losses, rodents have a major role in the dissemination of infectious diseases caused by viruses, bacteria, parasites or other micro-organisms. Rodents are important reservoirs of diseases which have been observed in many cities of Iran provinces especially along Caspian Sea border to Alborz Mountain. The aim of this study is to assess the geographical distribution of rodents in three provinces of northern part of Iran as reservoir of potential endemic infectious diseases. Rodents in 10 major parts of each of the three provinces of Mazandaran, Gilan and Golestan, northern Iran were collected and a total of 404 rodents were trapped alive. They were determined by the key characteristics such as gender, genus, species, different locations and topological situation. Statistical analysis was performed to characterize the study sample and to correlate all variables and parameters. The distribution frequencies of three, five and six genera of rodents were identified in Mazandaran, Gilan and Golestan provinces respectively. The overall distribution frequency of eight genera of rodents in the three provinces were identified as Rattus (R. norvegicus (67.3%, R. rattus (13.6%, Apodemus sylvaticus (13.9%, Arvicola (1%, Mus musculus (0.3%, Nesokia indica (2.5%, Cricetulus migrates (0.7% and Rhombomys opimus (0.7%. The results of this study determined the geographic distribution of the rodents in the three northern provinces of Iran. It is indicated the association of various distribution and diversity of rodents with provincial location. The overall distribution frequency of eight genera of rodents was recognized in the above three provinces geographical locations. This study confirms epidemiological distribution of

Feeding a diet devoid of choline to lactating rodents restricts growth and lymphocyte development in offspring.

Science.gov (United States)

Lewis, E D; Goruk, S; Richard, C; Dellschaft, N S; Curtis, J M; Jacobs, R L; Field, C J

2016-09-01

The nutrient choline is necessary for membrane synthesis and methyl donation, with increased requirements during lactation. The majority of immune development occurs postnatally, but the importance of choline supply for immune development during this critical period is unknown. The objective of this study was to determine the importance of maternal supply of choline during suckling on immune function in their offspring among rodents. At parturition, Sprague-Dawley dams were randomised to either a choline-devoid (ChD; n 7) or choline-sufficient (ChS, 1 g/kg choline; n 10) diet with their offspring euthanised at 3 weeks of age. In a second experiment, offspring were weaned to a ChS diet until 10 weeks of age (ChD-ChS, n 5 and ChS-ChS, n 9). Splenocytes were isolated, and parameters of immune function were measured. The ChD offspring received less choline in breast milk and had lower final body and organ weight compared with ChS offspring (P<0·05), but this effect disappeared by week 10 with choline supplementation from weaning. ChD offspring had a higher proportion of T cells expressing activation markers (CD71 or CD28) and a lower proportion of total B cells (CD45RA+) and responded less to T cell stimulation (lower stimulation index and less IFN-γ production) ex vivo (P<0·05). ChD-ChS offspring had a lower proportion of total and activated CD4+ T cells, and produced less IL-6 after mitogen stimulation compared with cells from ChS-ChS (P<0·05). Our study suggests that choline is required in the suckling diet to facilitate immune development, and choline deprivation during this critical period has lasting effects on T cell function later in life.

Mathematical modeling of sleep state dynamics in a rodent model of shift work

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Michael J. Rempe

2018-06-01

Full Text Available Millions of people worldwide are required to work when their physiology is tuned for sleep. By forcing wakefulness out of the body’s normal schedule, shift workers face numerous adverse health consequences, including gastrointestinal problems, sleep problems, and higher rates of some diseases, including cancers. Recent studies have developed protocols to simulate shift work in rodents with the intention of assessing the effects of night-shift work on subsequent sleep (Grønli et al., 2017. These studies have already provided important contributions to the understanding of the metabolic consequences of shift work (Arble et al., 2015; Marti et al., 2016; Opperhuizen et al., 2015 and sleep-wake-specific impacts of night-shift work (Grønli et al., 2017. However, our understanding of the causal mechanisms underlying night-shift-related sleep disturbances is limited. In order to advance toward a mechanistic understanding of sleep disruption in shift work, we model these data with two different approaches. First we apply a simple homeostatic model to quantify differences in the rates at which sleep need, as measured by slow wave activity during slow wave sleep (SWS rises and falls. Second, we develop a simple and novel mathematical model of rodent sleep and use it to investigate the timing of sleep in a simulated shift work protocol (Grønli et al., 2017. This mathematical framework includes the circadian and homeostatic processes of the two-process model, but additionally incorporates a stochastic process to model the polyphasic nature of rodent sleep. By changing only the time at which the rodents are forced to be awake, the model reproduces some key experimental results from the previous study, including correct proportions of time spent in each stage of sleep as a function of circadian time and the differences in total wake time and SWS bout durations in the rodents representing night-shift workers and those representing day-shift workers

Gender-specific feeding rates in planktonic copepods with different feeding behavior

DEFF Research Database (Denmark)

van Someren Gréve, Hans; Almeda, Rodrigo; Lindegren, Martin

2017-01-01

Planktonic copepods have sexually dimorphic behaviors, which can cause differences in feeding efficiency between genders. Copepod feeding rates have been studied extensively but most studies have focused only on females. In this study, we experimentally quantified feeding rates of males and females...... copepods, particularly in ambush feeders, where the males must sacrifice feeding for mate searching. We conducted gender-specific functional feeding response experiments using prey of different size and motility. In most cases, gender-specific maximum ingestion and clearance rates were largely explained...... in copepods with different feeding behavior: ambush feeding (Oithona nana), feeding-current feeding (Temora longicornis) and cruising feeding (Centropages hamatus). We hypothesize that carbon-specific maximum ingestion rates are similar between genders, but that maximum clearance rates are lower for male...

Prevalence of Leishmania species in rodents: A systematic review and meta-analysis in Iran.

Science.gov (United States)

Foroutan, Masoud; Khademvatan, Shahram; Majidiani, Hamidreza; Khalkhali, Hamidreza; Hedayati-Rad, Faezeh; Khashaveh, Shahla; Mohammadzadeh, Habib

2017-08-01

Leishmaniasis are diverse group of diseases caused by numerous species of genus Leishmania. Herein we have contrived a systematic review and meta-analysis on the prevalence of Leishmania species in rodents of Iran. For this purpose, following the general methodology recommended for systematic reviews and meta-analysis, six English databases (PubMed, Science Direct, Scopus, Ovid, Web of Science and Google Scholar) and four Persian databases (Magiran, SID, Iran Doc and Iran Medex) were explored during January 1995 till June 2015. Papers were selected based on 8 pre-defined inclusion criteria. During the years, a total number of 4485 different rodents were captured; among which 1291 cases were Leishmania positive. The calculated weighted prevalence of Leishmania species in rodents was 23% (95% CI=18-28). Given geographical zones of Iran, the highest and lowest prevalence rate was belonged to North 50% (95% CI=40-61) and West 11% (95% CI=5-17), respectively. Rhombomys opimus (1766), Meriones lybicus (1258) and Tatera indica (488) were the three most abundant captured rodents, while the highest prevalence of Leishmania species was observed in Nesokia indica 48% (95% CI=42-54) and followed by R. opimus 39% (95% CI=30-47). Egger's regression test was performed to detect publication bias, which revealed it may not have a significant influence on overall weighted prevalence estimate (P=0.317). Meta-regression analysis demonstrated that there is no significant relationship between overall prevalence with sample size (P=0.1) and year of publication (P=0.7). The results showed remarkable prevalence of Leishmania species in rodent reservoirs. In future, adopting a suitable strategy for control and combat with rodents is necessary. Copyright © 2017 Elsevier B.V. All rights reserved.

Phylogeographic Characterization of Tick-Borne Encephalitis Virus from Patients, Rodents and Ticks in Slovenia

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Fajs, Luka; Durmiši, Emina; Knap, Nataša; Strle, Franc; Avšič-Županc, Tatjana

2012-01-01

Tick-borne encephalitis virus (TBEV) is the most important arboviral agent causing infections of the central nervous system in central Europe. Previous studies have shown that TBEV exhibits pronounced genetic variability, which is often correlated to the geographical origin of TBEV. Genetic variability of TBEV has previously been studied predominantly in rodents and ticks, while information about the variability in patients is scarce. In order to understand the molecular relationships of TBEV between natural hosts, vectors and humans, as well as correlation between phylogenetic and geographical clustering, sequences of TBEV E and NS5 protein genes, were obtained by direct sequencing of RT-PCR products from TBE-confirmed patients as well as from rodents and ticks collected from TBE-endemic regions in Slovenia. A total of 27 partial E protein gene sequences representing 15 human, 4 rodent and 8 tick samples and 30 partial NS5 protein gene sequences representing 17 human, 5 rodent and 8 tick samples were obtained. The complete genome sequence of TBEV strain Ljubljana I was simultaneously obtained. Phylogenetic analysis of the E and NS5 protein gene sequences revealed a high degree of TBEV variability in patients, ticks and rodents. Furthermore, an evident correlation between geographical and phylogenetic clustering was shown that was independent of the TBEV host. Moreover, we show the presence of a possible recombination event in the TBEV genome obtained from a patient sample, which was supported with multiple recombination event detection methods. This is the first study that simultaneously analyzed the genetic relationships of directly sequenced TBEV samples from patients, ticks and rodents and provides the largest set of patient-derived TBEV sequences up to date. In addition, we have confirmed the geographical clustering of TBEV sequences in Slovenia and have provided evidence of a possible recombination event in the TBEV genome, obtained from a patient. PMID

The rodent research animal holding facility as a barrier to environmental contamination

Science.gov (United States)

Savage, P. D., Jr.; Jahns, G. C.; Dalton, B. P.; Hogan, R. P.; Wray, A. E.

1989-01-01

The rodent Research Animal Holding Facility (RAHF), developed by NASA Ames Research Center (ARC) to separately house rodents in a Spacelab, was verified as a barrier to environmental contaminants during a 12-day biocompatibility test. Environmental contaminants considered were solid particulates, microorganisms, ammonia, and typical animal odors. The 12-day test conducted in August 1988 was designed to verify that the rodent RAHF system would adequately support and maintain animal specimens during normal system operations. Additional objectives of this test were to demonstrate that: (1) the system would capture typical particulate debris produced by the animal; (2) microorganisms would be contained; and (3) the passage of animal odors was adequately controlled. In addition, the amount of carbon dioxide exhausted by the RAHF system was to be quantified. Of primary importance during the test was the demonstration that the RAHF would contain particles greater than 150 micrometers. This was verified after analyzing collection plates placed under exhaust air ducts and rodent cages during cage maintenance operations, e.g., waste tray and feeder changeouts. Microbiological testing identified no additional organisms in the test environment that could be traced to the RAHF. Odor containment was demonstrated to be less than barely detectable. Ammonia could not be detected in the exhaust air from the RAHF system. Carbon dioxide levels were verified to be less than 0.35 percent.

Prospects of complete feed system in ruminant feeding: A review

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Yasir Afzal Beigh

2017-04-01

Full Text Available Effective utilization of available feed resources is the key for economical livestock rearing. Complete feed system is one of the latest developments to exploit the potential of animal feed resources in the best possible way. The complete feed is a quantitative mixture of all dietary ingredients, blended thoroughly to prevent separation and selection, fed as a sole source of nutrients except water and is formulated in a desired proportion to meet the specific nutrient requirements. The concentrate and roughage levels may vary according to the nutrient requirement of ruminants for different production purposes. The complete feed with the use of fibrous crop residue is a noble way to increase the voluntary feed intake and thus animal's production performance. In this system of feeding, the ruminant animals have continuous free choice availability of uniform feed mixture, resulting in more uniform load on the rumen and less fluctuation in release of ammonia which supports more efficient utilization of ruminal non-protein nitrogen. Feeding complete diet stabilizes ruminal fermentation, thereby improves nutrient utilization. This feeding system allows expanded use of agro-industrial byproducts, crop residues and nonconventional feeds in ruminant ration for maximizing production and minimizing feeding cost, thus being increasingly appreciated. However, to extend the concept extensively to the field and make this technology successful and viable for farmers, more efforts are needed to be taken.

Gastrointestinal parasites in feral cats and rodents from the Fernando de Noronha Archipelago, Brazil.

Science.gov (United States)

Lima, Victor Fernando Santana; Ramos, Rafael Antonio Nascimento; Lepold, Raphael; Borges, João Carlos Gomes; Ferreira, Carlos Diógenes; Rinaldi, Laura; Cringoli, Giuseppe; Alves, Leucio Câmara

2017-01-01

Gastrointestinal parasites are important pathogens affecting animals, some of them are of medical and veterinary concern. Although the dynamic of parasitic infections is a complex phenomenon that has been studied under experimental conditions, it shows several gaps in knowledge, especially in insular regions where a confined population of animals and parasites co-exists. In this study was assessed the parasitism by endoparasite gastrointestinal in feral cats (n = 37) and rodents (n = 30) from the Fernando de Noronha Archipelago; in addition, the risk of human infection and ecological implications of these findings were discussed. Out of all samples analysed, 100% scored positive for the presence of gastrointestinal parasites in both feral cats and rodents. A total 17 genera and/or species of endoparasite gastrointestinal were identified, Ancylostoma sp., Strongyloides sp., Trichuris campanula and Toxocara cati were the parasites more frequently in feral cats. In rodents Eimeria sp., Strongyloides sp. and Trichuris muris were parasites more frequently herein detected. Human population living in this area are at risk of parasite infections due to the population of rodents and feral cats in the archipelago.

Single-Iteration Learning Algorithm for Feed-Forward Neural Networks

Energy Technology Data Exchange (ETDEWEB)

Barhen, J.; Cogswell, R.; Protopopescu, V.

1999-07-31

A new methodology for neural learning is presented, whereby only a single iteration is required to train a feed-forward network with near-optimal results. To this aim, a virtual input layer is added to the multi-layer architecture. The virtual input layer is connected to the nominal input layer by a specird nonlinear transfer function, and to the fwst hidden layer by regular (linear) synapses. A sequence of alternating direction singular vrdue decompositions is then used to determine precisely the inter-layer synaptic weights. This algorithm exploits the known separability of the linear (inter-layer propagation) and nonlinear (neuron activation) aspects of information &ansfer within a neural network.

Of mice and women: rodent models of placental malaria

DEFF Research Database (Denmark)

Hviid, Lars; Marinho, Claudio R F; Staalsoe, Trine

2010-01-01

Pregnant women are at increased malaria risk. The infections are characterized by placental accumulation of infected erythrocytes (IEs) with adverse consequences for mother and baby. Placental IE sequestration in the intervillous space is mediated by variant surface antigens (VSAs) selectively...... expressed in placental malaria (PM) and specific for chondroitin sulfate A (CSA). In Plasmodium falciparum, these VSA(PM) appear largely synonymous with the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family variant VAR2CSA. As rodent malaria parasites do not possess PfEMP1 homologs......, the usefulness of experimental mouse PM models remains controversial. However, many features of murine and human PM are similar, including involvement of VSAs analogous to PfEMP1. It thus appears that rodent model studies can further the understanding of VSA-dependent malaria pathogenesis and immunity....

A model of Leptospirosis infection in an African rodent to determine risk to humans: Seasonal fluctuations and the impact of rodent control

DEFF Research Database (Denmark)

Holt, J; Davis, S; Leirs, Herwig

2006-01-01

Human leptospirosis (Leptospira spp. infection) is aworldwide public health problem that is of greatest concern for humid tropical and subtropical regions. The magnitude of the problem in these areas is larger because of the climatic and environmental conditions the bacterium face outside...... their hosts but also because of the frequency of contacts between people and sources of infection. Rodents are thought to play the most important role in the transmission of human leptospirosis. We here model the dynamics of infection in an African rodent (Mastomys natalensis) that is thought...... to be the principal source of infection in parts of Tanzania. Our model, representing the climatic conditions in central Tanzania, suggests a strong seasonality in the force of infection on humans with a peak in the abundance of infectious mice between January and April in agricultural environments. In urban areas...

Studies on the Feeding Habits of Lutzomyia (Lutzomyia longipalpis (Lutz & Neiva, 1912 (Diptera: Psychodidae: Phlebotominae Populations from Endemic Areas of American Visceral Leishmaniasis in Northeastern Brazil

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Margarete Martins dos Santos Afonso

2012-01-01

Full Text Available The aim of this study was to identify potential blood feeding sources of L. (L. longipalpis specimens from populations in Northeastern Brazil, endemic areas of American Visceral Leishmaniasis (AVL and its correlation with the transmission of L. (L. i. chagasi. The ELISA technique was applied using bird, dog, goat, opossum, equine, feline, human, sheep, and rodent antisera to analyze 609 females, resulting in an overall positivity of 60%. In all municipalities, females showed higher positivity for bird followed by dog antiserum and sand fly specimens were also positive for equine, feline, human, sheep, goat, opossum, and rodent antisera. The finding for 17 combinations of two or three types of blood in some females corroborates the opportunistic habit of this sand fly species. The results demonstrating the association between L. (L. longipalpis and opossum suggest the need for further evaluation of the real role of this synanthropic mammal in the eco-epidemiology of AVL.

An early warning system for IPM-based rodent control in smallholder farming systems in Tanzania

DEFF Research Database (Denmark)

Mwanjabe, Patrick S.; Leirs, Herwig

1997-01-01

numbers increased faster. Where abundant short rains were a normal condition returning every year, such effect was not clear. A method to assess rodent damage to germinating seedlings was found to be robust and can be used for monitoring rodent problems. Using this assessment technique, we showed...

Evaluating rodent motor functions: Which tests to choose?

Science.gov (United States)

Schönfeld, Lisa-Maria; Dooley, Dearbhaile; Jahanshahi, Ali; Temel, Yasin; Hendrix, Sven

2017-12-01

Damage to the motor cortex induced by stroke or traumatic brain injury (TBI) can result in chronic motor deficits. For the development and improvement of therapies, animal models which possess symptoms comparable to the clinical population are used. However, the use of experimental animals raises valid ethical and methodological concerns. To decrease discomfort by experimental procedures and to increase the quality of results, non-invasive and sensitive rodent motor tests are needed. A broad variety of rodent motor tests are available to determine deficits after stroke or TBI. The current review describes and evaluates motor tests that fall into three categories: Tests to evaluate fine motor skills and grip strength, tests for gait and inter-limb coordination and neurological deficit scores. In this review, we share our thoughts on standardized data presentation to increase data comparability between studies. We also critically evaluate current methods and provide recommendations for choosing the best behavioral test for a new research line. Copyright © 2017 Elsevier Ltd. All rights reserved.

Condition Number Regularized Covariance Estimation*

Science.gov (United States)

Won, Joong-Ho; Lim, Johan; Kim, Seung-Jean; Rajaratnam, Bala

2012-01-01

Estimation of high-dimensional covariance matrices is known to be a difficult problem, has many applications, and is of current interest to the larger statistics community. In many applications including so-called the “large p small n” setting, the estimate of the covariance matrix is required to be not only invertible, but also well-conditioned. Although many regularization schemes attempt to do this, none of them address the ill-conditioning problem directly. In this paper, we propose a maximum likelihood approach, with the direct goal of obtaining a well-conditioned estimator. No sparsity assumption on either the covariance matrix or its inverse are are imposed, thus making our procedure more widely applicable. We demonstrate that the proposed regularization scheme is computationally efficient, yields a type of Steinian shrinkage estimator, and has a natural Bayesian interpretation. We investigate the theoretical properties of the regularized covariance estimator comprehensively, including its regularization path, and proceed to develop an approach that adaptively determines the level of regularization that is required. Finally, we demonstrate the performance of the regularized estimator in decision-theoretic comparisons and in the financial portfolio optimization setting. The proposed approach has desirable properties, and can serve as a competitive procedure, especially when the sample size is small and when a well-conditioned estimator is required. PMID:23730197

Culex nigripalpus Theobald (Diptera, Culicidae feeding habit at the Parque Ecológico do Tietê, São Paulo, Brazil Hábito alimentar de Culex nigripalpus Theobald (Diptera, Culicidae no Parque Ecológico do Tietê, São Paulo, Brasil

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Gabriel Z. Laporta

2008-01-01

Full Text Available The blood feeding of a population of Cx. nigripalpus from Parque Ecológico do Tietê (PET was investigated using an indirect ELISA protocol. Mosquitoes were captured outside houses. Five hundred sixteen engorged females collected in a reforested area and 25 in an open area were tested. Rodents and dogs were the most common blood sources, accounting for approximately 65.3% of blood meals. Human blood was detected in 10.9%, dog blood in 26.1%, chicken blood in 2.4%, and rodent blood in 39.2% of the 541 insects tested. ELISA failed in identifying the blood sources of 233 engorged females, indicating that the mosquitoes may have fed on a host which was not tested. One hundred six individuals were positive for more than one host. The unweighted human blood index was 0.14 and the rodent/human, human/chicken, and dog/rodent feeding index values were 2.70, 1.51, and 1.33, respectively. Furthermore, rodents are defensive hosts for this haematophagous insect which looks for another host to complete blood-feeding. Considering that rodents are potential reservoirs for Mucambo virus and Saint Louis encephalitis virus and that Cx. nigripalpus feed on the blood of those mammals, we hypothesize that mosquito population in PET could participate in the transmission cycle of those arboviruses. Additionally, this species might be involved in the transmission of Dirofilaria immitis to dogs at this area.O hábito alimentar da população de Cx. nigripalpus do Parque Ecológico do Tietê (PET foi investigado usando um protocolo de ELISA indireto. Foram testadas 516 e 25 fêmeas ingurgitadas e capturadas, respectivamente, em áreas reflorestadas e abertas. Roedores e canídeos foram fontes alimentares mais freqüentes, em aproximadamente 65.3% dos repastos sangüíneos. De um total de 541 fêmeas ingurgitadas, foram detectadas freqüências de repastos sangüíneos em humanos (10.9%, canídeos (26.1%, galinídeos (2.4% e roedores (39.2%. As fontes alimentares de 233 f

Serologic evidence for Borrelia hermsii infection in rodents on federally owned recreational areas in California.

Science.gov (United States)

Fritz, Curtis L; Payne, Jessica R; Schwan, Tom G

2013-06-01

Tick-borne relapsing fever (TBRF) is endemic in mountainous regions of the western United States. In California, the principal agent is the spirochete Borrelia hermsii, which is transmitted by the argasid tick Ornithodoros hermsi. Humans are at risk of TBRF when infected ticks leave an abandoned rodent nest in quest of a blood meal. Rodents are the primary vertebrate hosts for B. hermsii. Sciurid rodents were collected from 23 sites in California between August, 2006, and September, 2008, and tested for serum antibodies to B. hermsii by immunoblot using a whole-cell sonicate and a specific antigen, glycerophosphodiester phosphodiesterase (GlpQ). Antibodies were detected in 20% of rodents; seroprevalence was highest (36%) in chipmunks (Tamias spp). Seroprevalence in chipmunks was highest in the Sierra Nevada (41%) and Mono (43%) ecoregions and between 1900 and 2300 meters elevation (43%). The serological studies described here are effective in implicating the primary vertebrate hosts involved in the maintenance of the ticks and spirochetes in regions endemic for TBRF.

Morphological and functional maturation of Leydig cells: from rodent models to primates.

Science.gov (United States)

Teerds, Katja J; Huhtaniemi, Ilpo T

2015-01-01

Leydig cells (LC) are the sites of testicular androgen production. Development of LC occurs in the testes of most mammalian species as two distinct growth phases, i.e. as fetal and pubertal/adult populations. In primates there are indications of a third neonatal growth phase. LC androgen production begins in embryonic life and is crucial for the intrauterine masculinization of the male fetal genital tract and brain, and continues until birth after which it rapidly declines. A short post-natal phase of LC activity in primates (including human) termed 'mini-puberty' precedes the period of juvenile quiescence. The adult population of LC evolves, depending on species, in mid- to late-prepuberty upon reawakening of the hypothalamic-pituitary-testicular axis, and these cells are responsible for testicular androgen production in adult life, which continues with a slight gradual decline until senescence. This review is an updated comparative analysis of the functional and morphological maturation of LC in model species with special reference to rodents and primates. Pubmed, Scopus, Web of Science and Google Scholar databases were searched between December 2012 and October 2014. Studies published in languages other than English or German were excluded, as were data in abstract form only. Studies available on primates were primarily examined and compared with available data from specific animal models with emphasis on rodents. Expression of different marker genes in rodents provides evidence that at least two distinct progenitor lineages give rise to the fetal LC (FLC) population, one arising from the coelomic epithelium and the other from specialized vascular-associated cells along the gonad-mesonephros border. There is general agreement that the formation and functioning of the FLC population in rodents is gonadotrophin-responsive but not gonadotrophin-dependent. In contrast, although there is in primates some controversy on the role of gonadotrophins in the formation of

Two New Mylagaulid Rodents from the Early Miocene of China.

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Xiaoyu Lu

Full Text Available Mylagaulid fossorial rodents are a common component of North American Miocene fossil faunas. However outside of North America, only three species are known from Asia. Here we report two new mylagaulids, Irtyshogaulus minor gen. et sp. nov. and Irtyshogaulus major gen. et sp. nov., recovered from early Miocene sediments in the Junggar Basin in northwestern China. The two new taxa are small-sized, high-crowned promylagauline rodents. Their lower molars possess high metastylid crests, small mesostylids, broad and posterolingually expanded labial inflections, and transversely extending metalophid IIs. The mesoconid is absent in both species. The anterior and posterior fossettids are large and equally developed. Their upper M1-2s possess a square occlusal surface with five deep fossettes. The two new taxa are distinguished from each other mainly by their size, the morphology of fossettes and fossettids, development of mesial and distal lophs, posterior reduction of M3, and the orientation of m2 hypolophid. Our phylogenetic analysis indicates that Irtyshogaulus and Lamugaulus (another early Miocene Asian mylagaulid are sister taxa. The two genera are nested among the North American promylagaulines, and share a common ancestor from North America, indicating early Miocene intercontinental dispersal within this clade of rodents.

Temporal and Spatial Characterization of Gait Pattern in Rodents as an Animal model of Cerebrovascular Lesion

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Jaison D Cucarián

2017-09-01

Full Text Available Animal experimentation is crucial for the advance in the understanding of pathophysiological mechanisms and their application on both clinical diagnosis and neuro-rehabilitation. Particularly, rodent brain lesion is commonly used in the modeling of locomotor, somatosensory and cognitive symptoms. The automated rodent gait analysis has been proposed as a tool for studying locomotor and sensory abilities and its use includes the identification of functional alterations, structural adaptations as well as neuro-rehabilitation mechanisms. From that standpoint, the effectiveness of many therapeutic intervention (i.e. physical exercises has been documented in rodents and humans. The translation from experimental data to clinical conditions requires the continuous collaboration and feedback between researchers and health clinicians looking for the selection of the best rehabilitation protocols obtained from animal research. Here we will show some locomotor alterations, the traditional methods used to assess motor dysfunction and gait abnormalities in rodent models with stroke. The aim of this review is to show some motor deficiencies and some methods used to establish gait disturbances in rodents with cerebrovascular lesion. The review included the search of defined terms (MeSH in PychINFO, Medline and Web of Science, between January 2000 and January 2017. Qualitative and narrative reports, dissertations, end course works and conference resumes were discarded. The review focuses on some clinical signs, their effects on rodent locomotor activity, some methodologies used to create lesion and to study motor function, some assessment methods and some translational aspects.

An integrated approach for prospectively investigating a mode-of-action for rodent liver effects

International Nuclear Information System (INIS)

LeBaron, Matthew J.; Geter, David R.; Rasoulpour, Reza J.; Gollapudi, B. Bhaskar; Thomas, Johnson; Murray, Jennifer; Kan, H. Lynn; Wood, Amanda J.; Elcombe, Cliff; Vardy, Audrey; McEwan, Jillian; Terry, Claire; Billington, Richard

2013-01-01

Registration of new plant protection products (e.g., herbicide, insecticide, or fungicide) requires comprehensive mammalian toxicity evaluation including carcinogenicity studies in two species. The outcome of the carcinogenicity testing has a significant bearing on the overall human health risk assessment of the substance and, consequently, approved uses for different crops across geographies. In order to understand the relevance of a specific tumor finding to human health, a systematic, transparent, and hypothesis-driven mode of action (MoA) investigation is, appropriately, an expectation by the regulatory agencies. Here, we describe a novel approach of prospectively generating the MoA data by implementing additional end points to the standard guideline toxicity studies with sulfoxaflor, a molecule in development. This proactive MoA approach results in a more robust integration of molecular with apical end points while minimizing animal use. Sulfoxaflor, a molecule targeting sap-feeding insects, induced liver effects (increased liver weight due to hepatocellular hypertrophy) in an initial palatability probe study for selecting doses for subsequent repeat-dose dietary studies. This finding triggered the inclusion of dose-response investigations of the potential key events for rodent liver carcinogenesis, concurrent with the hazard assessment studies. As predicted, sulfoxaflor induced liver tumors in rats and mice in the bioassays. The MoA data available by the time of the carcinogenicity finding supported the conclusion that the carcinogenic potential of sulfoxaflor was due to CAR/PXR nuclear receptor activation with subsequent hepatocellular proliferation. This MoA was not considered to be relevant to humans as sulfoxaflor is unlikely to induce hepatocellular proliferation in humans and therefore would not be a human liver carcinogen. - Highlights: • We prospectively generated MoA data into standard guideline toxicity studies. • A proactive MoA approach

An integrated approach for prospectively investigating a mode-of-action for rodent liver effects

Energy Technology Data Exchange (ETDEWEB)

LeBaron, Matthew J., E-mail: MJLeBaron@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Geter, David R., E-mail: dave.geter@gmail.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Rasoulpour, Reza J. [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Gollapudi, B. Bhaskar, E-mail: BBGollapudi@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Thomas, Johnson, E-mail: JThomas4@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Murray, Jennifer, E-mail: AMurray@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Kan, H. Lynn, E-mail: HLKan@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Wood, Amanda J., E-mail: AJWood@dow.com [Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48674 (United States); Elcombe, Cliff, E-mail: CliffElcombe@cxrbiosciences.com [CXR Biosciences, 2 James Lindsay Place, Dundee Technopole, Dundee, DD1 5JJ, Scotland (United Kingdom); Vardy, Audrey, E-mail: audrey_vardy@europe.bd.com [CXR Biosciences, 2 James Lindsay Place, Dundee Technopole, Dundee, DD1 5JJ, Scotland (United Kingdom); McEwan, Jillian, E-mail: jillian.mcewan@rtmcewan.co.uk [CXR Biosciences, 2 James Lindsay Place, Dundee Technopole, Dundee, DD1 5JJ, Scotland (United Kingdom); Terry, Claire, E-mail: CTerry@dow.com [Dow AgroSciences, Abingdon, Oxfordshire (United Kingdom); Billington, Richard, E-mail: RBillington@dow.com [Dow AgroSciences, Abingdon, Oxfordshire (United Kingdom)

2013-07-15

Registration of new plant protection products (e.g., herbicide, insecticide, or fungicide) requires comprehensive mammalian toxicity evaluation including carcinogenicity studies in two species. The outcome of the carcinogenicity testing has a significant bearing on the overall human health risk assessment of the substance and, consequently, approved uses for different crops across geographies. In order to understand the relevance of a specific tumor finding to human health, a systematic, transparent, and hypothesis-driven mode of action (MoA) investigation is, appropriately, an expectation by the regulatory agencies. Here, we describe a novel approach of prospectively generating the MoA data by implementing additional end points to the standard guideline toxicity studies with sulfoxaflor, a molecule in development. This proactive MoA approach results in a more robust integration of molecular with apical end points while minimizing animal use. Sulfoxaflor, a molecule targeting sap-feeding insects, induced liver effects (increased liver weight due to hepatocellular hypertrophy) in an initial palatability probe study for selecting doses for subsequent repeat-dose dietary studies. This finding triggered the inclusion of dose-response investigations of the potential key events for rodent liver carcinogenesis, concurrent with the hazard assessment studies. As predicted, sulfoxaflor induced liver tumors in rats and mice in the bioassays. The MoA data available by the time of the carcinogenicity finding supported the conclusion that the carcinogenic potential of sulfoxaflor was due to CAR/PXR nuclear receptor activation with subsequent hepatocellular proliferation. This MoA was not considered to be relevant to humans as sulfoxaflor is unlikely to induce hepatocellular proliferation in humans and therefore would not be a human liver carcinogen. - Highlights: • We prospectively generated MoA data into standard guideline toxicity studies. • A proactive MoA approach

Using GeoRSS feeds to distribute house renting and selling information based on Google map

Science.gov (United States)

Nong, Yu; Wang, Kun; Miao, Lei; Chen, Fei

2007-06-01

Geographically Encoded Objects RSS (GeoRSS) is a way to encode location in RSS feeds. RSS is a widely supported format for syndication of news and weblogs, and is extendable to publish any sort of itemized data. When Weblogs explode since RSS became new portals, Geo-tagged feed is necessary to show the location that story tells. Geographically Encoded Objects adopts the core of RSS framework, making itself the map annotations specified in the RSS XML format. The case studied illuminates that GeoRSS could be maximally concise in representation and conception, so it's simple to manipulate generation and then mashup GeoRSS feeds with Google Map through API to show the real estate information with other attribute in the information window. After subscribe to feeds of concerned subjects, users could easily check for new bulletin showing on map through syndication. The primary design goal of GeoRSS is to make spatial data creation as easy as regular Web content development. However, it does more for successfully bridging the gap between traditional GIS professionals and amateurs, Web map hackers, and numerous services that enable location-based content for its simplicity and effectiveness.

Prevalence of leptospirosis and toxoplasmosis: A study of rodents ...

African Journals Online (AJOL)

prevalence of toxoplasmosis in child-bearing women in rural Sudan is even higher ranging ... crops. Animal trapping. Live rodents and shrews were captured in cultivated ..... P., Hodný, Z. & Vondrová, M. (2011) Fatal attraction phenomenon in.

Interacting Neural Processes of Feeding, Hyperactivity, Stress, Reward, and the Utility of the Activity-Based Anorexia Model of Anorexia Nervosa.

Science.gov (United States)

Ross, Rachel A; Mandelblat-Cerf, Yael; Verstegen, Anne M J

Anorexia nervosa (AN) is a psychiatric illness with minimal effective treatments and a very high rate of mortality. Understanding the neurobiological underpinnings of the disease is imperative for improving outcomes and can be aided by the study of animal models. The activity-based anorexia rodent model (ABA) is the current best parallel for the study of AN. This review describes the basic neurobiology of feeding and hyperactivity seen in both ABA and AN, and compiles the research on the role that stress-response and reward pathways play in modulating the homeostatic drive to eat and to expend energy, which become dysfunctional in ABA and AN.

Comparing strategies for controlling an African pest rodent: an empirically based theoretical study

DEFF Research Database (Denmark)

Stenseth, Nils Chr.; Leirs, Herwig; Mercelis, Saskia

2001-01-01

of rats. Control measures affecting survival as well as reproduction were considered.4. The model showed that control measures reducing survival will only have long-term effects on population size if they are also applied when rodent densities are low. Control measures applied only when rodent densities...... are high will not have persistent effects, even at high mortality rates.5. The model demonstrated that control measures reducing reproduction are likely to prevent Mastomys outbreaks, but will keep densities low over a long period only when the contraceptive effect is strong (> 75% reduction).6. Provided...... in particular cause major economic losses in Africa through damage to crops. Attempts to develop dynamic population models for this and other pest rodents are ongoing. 2. Demographic estimates from a capture-mark-recapture (CMR) study in Tanzania were used to parameterize a population model for this species...

The Prevalence of Trypanosoma cruzi, the Causal Agent of Chagas Disease, in Texas Rodent Populations.

Science.gov (United States)

Aleman, Adriana; Guerra, Trina; Maikis, Troy J; Milholland, Matthew T; Castro-Arellano, Ivan; Forstner, Michael R J; Hahn, Dittmar

2017-03-01

Rodent species were assessed as potential hosts of Trypanosoma cruzi, the etiologic agent of Chagas disease, from five sites throughout Texas in sylvan and disturbed habitats. A total of 592 rodents were captured, resulting in a wide taxonomic representation of 11 genera and 15 species. Heart samples of 543 individuals were successfully analyzed by SybrGreen-based quantitative PCR (qPCR) targeting a 166 bp fragment of satellite DNA of T. cruzi. Eight rodents representing six species from six genera and two families were infected with T. cruzi. This is the first report of T. cruzi in the pygmy mouse (Baiomys taylori) and the white-footed mouse (Peromyscus leucopus) for the USA. All infected rodents were from the southernmost site (Las Palomas Wildlife Management Area). No differences in pathogen prevalence existed between disturbed habitats (5 of 131 tested; 3.8%) and sylvan habitats (3 of 40 tested; 7.5%). Most positives (n = 6, 16% prevalence) were detected in late winter with single positives in both spring (3% prevalence) and fall (1% prevalence). Additionally, 30 Triatoma insects were collected opportunistically from sites in central Texas. Fifty percent of these insects, i.e., 13 T. gerstaeckeri (68%), and two T. lecticularia (100%) were positive for T. cruzi. Comparative sequence analyses of 18S rRNA of samples provided identical results with respect to detection of the presence or absence of T. cruzi and assigned T. cruzi from rodents collected in late winter to lineage TcI. T. cruzi from Triatoma sp. and rodents from subsequent collections in spring and fall were different, however, and could not be assigned to other lineages with certainty.

Inbred or Outbred? Genetic Diversity in Laboratory Rodent Colonies

Science.gov (United States)

Brekke, Thomas D.; Steele, Katherine A.; Mulley, John F.

2017-01-01

Nonmodel rodents are widely used as subjects for both basic and applied biological research, but the genetic diversity of the study individuals is rarely quantified. University-housed colonies tend to be small and subject to founder effects and genetic drift; so they may be highly inbred or show substantial genetic divergence from other colonies, even those derived from the same source. Disregard for the levels of genetic diversity in an animal colony may result in a failure to replicate results if a different colony is used to repeat an experiment, as different colonies may have fixed alternative variants. Here we use high throughput sequencing to demonstrate genetic divergence in three isolated colonies of Mongolian gerbil (Meriones unguiculatus) even though they were all established recently from the same source. We also show that genetic diversity in allegedly “outbred” colonies of nonmodel rodents (gerbils, hamsters, house mice, deer mice, and rats) varies considerably from nearly no segregating diversity to very high levels of polymorphism. We conclude that genetic divergence in isolated colonies may play an important role in the “replication crisis.” In a more positive light, divergent rodent colonies represent an opportunity to leverage genetically distinct individuals in genetic crossing experiments. In sum, awareness of the genetic diversity of an animal colony is paramount as it allows researchers to properly replicate experiments and also to capitalize on other genetically distinct individuals to explore the genetic basis of a trait. PMID:29242387

Mathematical modeling of filling of gas centrifuge cascade for nickel isotope separation by various feed flow rate

Science.gov (United States)

Ushakov, Anton; Orlov, Alexey; Sovach, Victor P.

2018-03-01

This article presents the results of research filling of gas centrifuge cascade for separation of the multicomponent isotope mixture with process gas by various feed flow rate. It has been used mathematical model of the nonstationary hydraulic and separation processes occurring in the gas centrifuge cascade. The research object is definition of the regularity transient of nickel isotopes into cascade during filling of the cascade. It is shown that isotope concentrations into cascade stages after its filling depend on variable parameters and are not equal to its concentration on initial isotope mixture (or feed flow of cascade). This assumption is used earlier any researchers for modeling such nonstationary process as set of steady-state concentration of isotopes into cascade. Article shows physical laws of isotope distribution into cascade stage after its filling. It's shown that varying each parameters of cascade (feed flow rate, feed stage number or cascade stage number) it is possible to change isotope concentration on output cascade flows (light or heavy fraction) for reduction of duration of further process to set of steady-state concentration of isotopes into cascade.

Regular-, irregular-, and pseudo-character processing in Chinese: The regularity effect in normal adult readers

Directory of Open Access Journals (Sweden)

Dustin Kai Yan Lau

2014-03-01

Full Text Available Background Unlike alphabetic languages, Chinese uses a logographic script. However, the pronunciation of many character’s phonetic radical has the same pronunciation as the character as a whole. These are considered regular characters and can be read through a lexical non-semantic route (Weekes & Chen, 1999. Pseudocharacters are another way to study this non-semantic route. A pseudocharacter is the combination of existing semantic and phonetic radicals in their legal positions resulting in a non-existing character (Ho, Chan, Chung, Lee, & Tsang, 2007. Pseudocharacters can be pronounced by direct derivation from the sound of its phonetic radical. Conversely, if the pronunciation of a character does not follow that of the phonetic radical, it is considered as irregular and can only be correctly read through the lexical-semantic route. The aim of the current investigation was to examine reading aloud in normal adults. We hypothesized that the regularity effect, previously described for alphabetical scripts and acquired dyslexic patients of Chinese (Weekes & Chen, 1999; Wu, Liu, Sun, Chromik, & Zhang, 2014, would also be present in normal adult Chinese readers. Method Participants. Thirty (50% female native Hong Kong Cantonese speakers with a mean age of 19.6 years and a mean education of 12.9 years. Stimuli. Sixty regular-, 60 irregular-, and 60 pseudo-characters (with at least 75% of name agreement in Chinese were matched by initial phoneme, number of strokes and family size. Additionally, regular- and irregular-characters were matched by frequency (low and consistency. Procedure. Each participant was asked to read aloud the stimuli presented on a laptop using the DMDX software. The order of stimuli presentation was randomized. Data analysis. ANOVAs were carried out by participants and items with RTs and errors as dependent variables and type of stimuli (regular-, irregular- and pseudo-character as repeated measures (F1 or between subject�

New Development in NASA's Rodent Research Hardware for Conducting Long Duration Biomedical and Basic Research in Space

Science.gov (United States)

Shirazi-Fard, Y.; Choi, S.; Harris, C.; Gong, C.; Beegle, J. E.; Stube, K. C.; Martin, K. J.; Nevitt, R. G.; Globus, R. G.

2017-01-01

Animal models, particularly rodents, are the foundation of pre-clinical research to understand human diseases and evaluate new therapeutics, and play a key role in advancing biomedical discoveries both on Earth and in space. The National Research Councils Decadal survey emphasized the importance of expanding NASAs life sciences research to perform long duration, rodent experiments on the International Space Station (ISS). To accomplish this objective, flight hardware, operations, and science capabilities were developed at NASA Ames Research Center (ARC) to enhance science return for both commercial (CASIS) and government-sponsored rodent research. The Rodent Research program at NASA ARC has pioneered a new research capability on the International Space Station and has progressed toward translating research to the ISS utilizing commercial rockets, collaborating with academia and science industry, while training crewmembers to assist in performing research on orbit. Throughout phases of these missions, our practices, hardware and operations have evolved from tested to developed standards, and we are able to modify and customize our procedure and operations for mission specific requirements. The Rodent Research Habitat is capable of providing a living environment for animals on ISS according to standard animal welfare requirements. Using the cameras in the Habitat, the Rodent Research team has the ability to perform daily health checks on animals, and further analyze the collected videos for behavioral studies. A recent development of the Rodent Research hardware is inclusion of enrichment, to provide the animals the ability to rest and huddle. The Enrichment Hut is designed carefully for adult mice (up to 35 week old) within animal welfare, engineering, and operations constraints. The Hut is made out of the same stainless steel mesh as the cage interior, it has an ingress and an egress to allow animals move freely, and a hinge door to allow crewmembers remove the

Regularity effect in prospective memory during aging

Directory of Open Access Journals (Sweden)

Geoffrey Blondelle

2016-10-01

Full Text Available Background: Regularity effect can affect performance in prospective memory (PM, but little is known on the cognitive processes linked to this effect. Moreover, its impacts with regard to aging remain unknown. To our knowledge, this study is the first to examine regularity effect in PM in a lifespan perspective, with a sample of young, intermediate, and older adults. Objective and design: Our study examined the regularity effect in PM in three groups of participants: 28 young adults (18–30, 16 intermediate adults (40–55, and 25 older adults (65–80. The task, adapted from the Virtual Week, was designed to manipulate the regularity of the various activities of daily life that were to be recalled (regular repeated activities vs. irregular non-repeated activities. We examine the role of several cognitive functions including certain dimensions of executive functions (planning, inhibition, shifting, and binding, short-term memory, and retrospective episodic memory to identify those involved in PM, according to regularity and age. Results: A mixed-design ANOVA showed a main effect of task regularity and an interaction between age and regularity: an age-related difference in PM performances was found for irregular activities (older < young, but not for regular activities. All participants recalled more regular activities than irregular ones with no age effect. It appeared that recalling of regular activities only involved planning for both intermediate and older adults, while recalling of irregular ones were linked to planning, inhibition, short-term memory, binding, and retrospective episodic memory. Conclusion: Taken together, our data suggest that planning capacities seem to play a major role in remembering to perform intended actions with advancing age. Furthermore, the age-PM-paradox may be attenuated when the experimental design is adapted by implementing a familiar context through the use of activities of daily living. The clinical

Fossil Rodents from Curaçao and Bonaire

NARCIS (Netherlands)

Hooijer, D.A.

1959-01-01

The fossil remains of rodents described in the present paper are from various localities. The large extinct musk rat Megalomys occurs in reddish-brown phosphatic “oolite” fillings of irregular cavities in a marine limestone found by Mr. P. H. DE BUISONJÉ in the north-western part of the Duivelsklip,

J-regular rings with injectivities

OpenAIRE

Shen, Liang

2010-01-01

A ring $R$ is called a J-regular ring if R/J(R) is von Neumann regular, where J(R) is the Jacobson radical of R. It is proved that if R is J-regular, then (i) R is right n-injective if and only if every homomorphism from an $n$-generated small right ideal of $R$ to $R_{R}$ can be extended to one from $R_{R}$ to $R_{R}$; (ii) R is right FP-injective if and only if R is right (J, R)-FP-injective. Some known results are improved.

Bartonella in Rodents and Ectoparasites in the Canary Islands, Spain: New Insights into Host-Vector-Pathogen Relationships.

Science.gov (United States)

Abreu-Yanes, Estefania; Martin-Alonso, Aaron; Martin-Carrillo, Natalia; Livia, Katherine Garcia; Marrero-Gagliardi, Alessandro; Valladares, Basilio; Feliu, Carlos; Foronda, Pilar

2018-01-01

Bartonella genus is comprised of several species of zoonotic relevance and rodents are reservoirs for some of these Bartonella species. As there were no data about the range of Bartonella species circulating among rodents in the Canary Islands, our main aim was to overcome this lack of knowledge by targeting both the citrate synthase (gltA) and the RNA polymerase beta subunit (rpoB) genes. A total of 181 small mammals and 154 ectoparasites were obtained in three of the Canary Islands, namely Tenerife, La Palma, and Lanzarote. The overall prevalence of Bartonella DNA in rodents was 18.8%, whereas the prevalence in ectoparasites was 13.6%. Bartonella sequences closely related to the zoonotic species Bartonella elizabethae, Bartonella tribocorum, and Bartonella rochalimae were identified in rodents, whereas two different gltA haplotypes similar to B. elizabethae were also detected in fleas. Furthermore, Bartonella queenslandensis DNA was also identified in rodents. A strong host specificity was observed, since B. elizabethae DNA was only found in Mus musculus domesticus, whereas gltA and rpoB sequences closely related to the rest of Bartonella species were only identified in Rattus rattus, which is probably due to the host specificity of the arthropod species that act as vectors in these islands. Our results indicate that humans may contract Bartonella infection by contact with rodents in the Canary Islands.

Gastrointestinal parasites in feral cats and rodents from the Fernando de Noronha Archipelago, Brazil

Directory of Open Access Journals (Sweden)

Victor Fernando Santana Lima

2017-11-01

Full Text Available Abstract Gastrointestinal parasites are important pathogens affecting animals, some of them are of medical and veterinary concern. Although the dynamic of parasitic infections is a complex phenomenon that has been studied under experimental conditions, it shows several gaps in knowledge, especially in insular regions where a confined population of animals and parasites co-exists. In this study was assessed the parasitism by endoparasite gastrointestinal in feral cats (n = 37 and rodents (n = 30 from the Fernando de Noronha Archipelago; in addition, the risk of human infection and ecological implications of these findings were discussed. Out of all samples analysed, 100% scored positive for the presence of gastrointestinal parasites in both feral cats and rodents. A total 17 genera and/or species of endoparasite gastrointestinal were identified, Ancylostoma sp., Strongyloides sp., Trichuris campanula and Toxocara cati were the parasites more frequently in feral cats. In rodents Eimeria sp., Strongyloides sp. and Trichuris muris were parasites more frequently herein detected. Human population living in this area are at risk of parasite infections due to the population of rodents and feral cats in the archipelago.

Iterative Regularization with Minimum-Residual Methods

DEFF Research Database (Denmark)

Jensen, Toke Koldborg; Hansen, Per Christian

2007-01-01

subspaces. We provide a combination of theory and numerical examples, and our analysis confirms the experience that MINRES and MR-II can work as general regularization methods. We also demonstrate theoretically and experimentally that the same is not true, in general, for GMRES and RRGMRES their success......We study the regularization properties of iterative minimum-residual methods applied to discrete ill-posed problems. In these methods, the projection onto the underlying Krylov subspace acts as a regularizer, and the emphasis of this work is on the role played by the basis vectors of these Krylov...... as regularization methods is highly problem dependent....

Iterative regularization with minimum-residual methods

DEFF Research Database (Denmark)

Jensen, Toke Koldborg; Hansen, Per Christian

2006-01-01

subspaces. We provide a combination of theory and numerical examples, and our analysis confirms the experience that MINRES and MR-II can work as general regularization methods. We also demonstrate theoretically and experimentally that the same is not true, in general, for GMRES and RRGMRES - their success......We study the regularization properties of iterative minimum-residual methods applied to discrete ill-posed problems. In these methods, the projection onto the underlying Krylov subspace acts as a regularizer, and the emphasis of this work is on the role played by the basis vectors of these Krylov...... as regularization methods is highly problem dependent....

Resting Is Rusting: A Critical View on Rodent Wheel-Running Behavior.

Science.gov (United States)

Richter, Sophie Helene; Gass, Peter; Fuss, Johannes

2014-08-01

Physical exercise is known to exert various beneficial effects on brain function and bodily health throughout life. In biomedical research, these effects are widely studied by introducing running wheels into the cages of laboratory rodents. Yet, although rodents start to run in the wheels immediately, and perform wheel-running excessively on a voluntary basis, the biological significance of wheel-running is still not clear. Here, we review the current literature on wheel-running and discuss potentially negative side-effects that may give cause for concern. We particularly emphasize on analogies of wheel-running with stereotypic and addictive behavior to stimulate further research on this topic. © The Author(s) 2014.

Gut microbiome may contribute to insulin resistance and systemic inflammation in obese rodents: a meta-analysis.

Science.gov (United States)

Jiao, Na; Baker, Susan S; Nugent, Colleen A; Tsompana, Maria; Cai, Liting; Wang, Yong; Buck, Michael J; Genco, Robert J; Baker, Robert D; Zhu, Ruixin; Zhu, Lixin

2018-04-01

A number of studies have associated obesity with altered gut microbiota, although results are discordant regarding compositional changes in the gut microbiota of obese animals. Herein we used a meta-analysis to obtain an unbiased evaluation of structural and functional changes of the gut microbiota in diet-induced obese rodents. The raw sequencing data of nine studies generated from high-fat diet (HFD)-induced obese rodent models were processed with QIIME to obtain gut microbiota compositions. Biological functions were predicted and annotated with KEGG pathways with PICRUSt. No significant difference was observed for alpha diversity and Bacteroidetes-to-Firmicutes ratio between obese and lean rodents. Bacteroidia, Clostridia, Bacilli, and Erysipelotrichi were dominant classes, but gut microbiota compositions varied among studies. Meta-analysis of the nine microbiome data sets identified 15 differential taxa and 57 differential pathways between obese and lean rodents. In obese rodents, increased abundance was observed for Dorea, Oscillospira, and Ruminococcus, known for fermenting polysaccharide into short chain fatty acids (SCFAs). Decreased Turicibacter and increased Lactococcus are consistent with elevated inflammation in the obese status. Differential functional pathways of the gut microbiome in obese rodents included enriched pyruvate metabolism, butanoate metabolism, propanoate metabolism, pentose phosphate pathway, fatty acid biosynthesis, and glycerolipid metabolism pathways. These pathways converge in the function of carbohydrate metabolism, SCFA metabolism, and biosynthesis of lipid. HFD-induced obesity results in structural and functional dysbiosis of gut microbiota. The altered gut microbiome may contribute to obesity development by promoting insulin resistance and systemic inflammation.

Multiple graph regularized protein domain ranking.

Science.gov (United States)

Wang, Jim Jing-Yan; Bensmail, Halima; Gao, Xin

2012-11-19

Protein domain ranking is a fundamental task in structural biology. Most protein domain ranking methods rely on the pairwise comparison of protein domains while neglecting the global manifold structure of the protein domain database. Recently, graph regularized ranking that exploits the global structure of the graph defined by the pairwise similarities has been proposed. However, the existing graph regularized ranking methods are very sensitive to the choice of the graph model and parameters, and this remains a difficult problem for most of the protein domain ranking methods. To tackle this problem, we have developed the Multiple Graph regularized Ranking algorithm, MultiG-Rank. Instead of using a single graph to regularize the ranking scores, MultiG-Rank approximates the intrinsic manifold of protein domain distribution by combining multiple initial graphs for the regularization. Graph weights are learned with ranking scores jointly and automatically, by alternately minimizing an objective function in an iterative algorithm. Experimental results on a subset of the ASTRAL SCOP protein domain database demonstrate that MultiG-Rank achieves a better ranking performance than single graph regularized ranking methods and pairwise similarity based ranking methods. The problem of graph model and parameter selection in graph regularized protein domain ranking can be solved effectively by combining multiple graphs. This aspect of generalization introduces a new frontier in applying multiple graphs to solving protein domain ranking applications.

Ecology, Genetic Diversity, and Phylogeographic Structure of Andes Virus in Humans and Rodents in Chile▿

Science.gov (United States)

Medina, Rafael A.; Torres-Perez, Fernando; Galeno, Hector; Navarrete, Maritza; Vial, Pablo A.; Palma, R. Eduardo; Ferres, Marcela; Cook, Joseph A.; Hjelle, Brian

2009-01-01

Andes virus (ANDV) is the predominant etiologic agent of hantavirus cardiopulmonary syndrome (HCPS) in southern South America. In Chile, serologically confirmed human hantavirus infections have occurred throughout a wide latitudinal distribution extending from the regions of Valparaíso (32 to 33°S) to Aysén (46°S) in southern Patagonia. In this study, we found seropositive rodents further north in the Coquimbo region (30°S) in Chile. Rodent seroprevalence was 1.4%, with Oligoryzomys longicaudatus displaying the highest seroprevalence (5.9%), followed by Abrothrix longipilis (1.9%) and other species exhibiting ≤0.6% seropositivity. We sequenced partial ANDV small (S) segment RNA from 6 HCPS patients and 32 rodents of four different species collected throughout the known range of hantavirus infection in Chile. Phylogenetic analyses showed two major ANDV South (ANDV Sout) clades, congruent with two major Chilean ecoregions, Mediterranean (Chilean matorral [shrubland]) and Valdivian temperate forest. Human and rodent samples grouped according to geographic location. Phylogenetic comparative analyses of portions of S and medium segments (encoding glycoproteins Gn and Gc) from a subset of rodent specimens exhibited similar topologies, corroborating two major ANDV Sout clades in Chile and suggesting that yet unknown factors influence viral gene flow and persistence throughout the two Chilean ecoregions. Genetic algorithms for recombination detection identified recombination events within the S segment. Molecular demographic analyses showed that the virus is undergoing purifying selection and demonstrated a recent exponential growth in the effective number of ANDV Sout infections in Chile that correlates with the increased number of human cases reported. Although we determined virus sequences from four rodent species, our results confirmed O. longicaudatus as the primary ANDV Sout reservoir in Chile. While evidence of geographic differentiation exists, a single

Foraging response and acclimation of ambush feeding and feeding-current feeding copepods to toxic dinoflagellates

DEFF Research Database (Denmark)

Xu, Jiayi; Nielsen, Lasse Tor; Kiørboe, Thomas

2018-01-01

reticulatum. We hypothesize (1) that ambush feeders are less affected by toxic algae than feeding-current feeders, (2) that copepods acclimate to the toxic algae, and (3) that phytoplankton cells previously exposed to copepod cues elicit stronger responses. Both copepod species consumed the toxic algae...... to examine the response and temporal acclimation (5 d) of two copepods with different foraging behaviors to toxic dinoflagellates. Feeding-current feeding Temora longicornis and ambush feeding Acartia tonsa were offered three strains of toxic Alexandrium tamarense and a nontoxic control Protoceratium...... at a reduced rate and there was no difference in their net-response, but the mechanisms differed. T. longicornis responded in strain-specific ways by reducing its feeding activity, by rejecting captured algae, or by regurgitating consumed cells. A. tonsa reduced its consumption rate, jump frequency, and jump...

SHP-1 activation inhibits vascular smooth muscle cell proliferation and intimal hyperplasia in a rodent model of insulin resistance and diabetes

DEFF Research Database (Denmark)

Qi, Weier; Li, Qian; Liew, Chong Wee

2017-01-01

. However, the role of SHP-1 in intimal hyperplasia and restenosis has not been clarified in insulin resistance and diabetes. METHODS: We used a femoral artery wire injury mouse model, rodent models with insulin resistance and diabetes, and patients with type 2 diabetes. Further, we modulated SHP-1...... expression using a transgenic mouse that overexpresses SHP-1 in VSMCs (Shp-1-Tg). SHP-1 agonists were also employed to study the molecular mechanisms underlying the regulation of SHP-1 by oxidised lipids. RESULTS: Mice fed a high-fat diet (HFD) exhibited increased femoral artery intimal hyperplasia...... and decreased arterial SHP-1 expression compared with mice fed a regular diet. Arterial SHP-1 expression was also decreased in Zucker fatty rats, Zucker diabetic fatty rats and in patients with type 2 diabetes. In primary cultured VSMCs, oxidised LDL suppressed SHP-1 expression by activating Mek-1 (also known...

Energetics and water relations ofN amib desert rodents

African Journals Online (AJOL)

and the possible effects of advective fog on the water balance of the .... Table 2 Energy balance of Namib desert rodents in the laboratory on a diet of air-dried bird seed and with, and with, ad lib water. .... responding mercury thermometer.

Muleshoe Virus and Other Hantaviruses Associated with Neotomine or Sigmodontine Rodents in Texas.

Science.gov (United States)

Milazzo, Mary Louise; Cajimat, Maria N B; Richter, Martin H; Bradley, Robert D; Fulhorst, Charles F

2017-10-01

The broad objective of this study was to increase our knowledge of Muleshoe virus and other hantaviruses associated with cricetid rodents in Texas. Anti-hantavirus antibody was found in 38 (3.2%) of 1171 neotomine rodents and 6 (1.8%) of 332 sigmodontine rodents from 10 Texas counties; hantaviral RNA was detected in 23 (71.9%) of 32 antibody-positive rodents. Analyses of nucleocapsid protein gene sequences indicated Muleshoe virus infection in four hispid cotton rats (Sigmodon hispidus) from northern Texas; Bayou virus, three Texas marsh oryzomys (Oryzomys texensis) from the Gulf Coast; Limestone Canyon virus, five brush mice (Peromyscus boylii) from western Texas; and Sin Nombre virus-five Texas mice (P. attwateri), one Lacey's white-ankled deer mouse (P. laceianus), four white-footed mice (P. leucopus), and one fulvous harvest mouse (Reithrodontomys fulvescens) from northern, central, or southern Texas. The results of this study together with the results of a previous study revealed that Muleshoe virus, perhaps in association with S. hispidus, is distributed across northern Texas. Finally, the results of Bayesian analyses of glycoprotein precursor (GPC) gene sequences and pairwise comparisons of complete GPC (amino acid) sequences strengthened support for the notion that Muleshoe virus is distinct from Black Creek Canal virus, Bayou virus, and all other species included in the Bunyaviridae, genus Hantavirus.

Architecture of interstitial nodal spaces in the rodent renal inner medulla.

Science.gov (United States)

Gilbert, Rebecca L; Pannabecker, Thomas L

2013-09-01

Every collecting duct (CD) of the rat inner medulla is uniformly surrounded by about four abutting ascending vasa recta (AVR) running parallel to it. One or two ascending thin limbs (ATLs) lie between and parallel to each abutting AVR pair, opposite the CD. These structures form boundaries of axially running interstitial compartments. Viewed in transverse sections, these compartments appear as four interstitial nodal spaces (INSs) positioned symmetrically around each CD. The axially running compartments are segmented by interstitial cells spaced at regular intervals. The pairing of ATLs and CDs bounded by an abundant supply of AVR carrying reabsorbed water, NaCl, and urea make a strong argument that the mixing of NaCl and urea within the INSs and countercurrent flows play a critical role in generating the inner medullary osmotic gradient. The results of this study fully support that hypothesis. We quantified interactions of all structures comprising INSs along the corticopapillary axis for two rodent species, the Munich-Wistar rat and the kangaroo rat. The results showed remarkable similarities in the configurations of INSs, suggesting that the structural arrangement of INSs is a highly conserved architecture that plays a fundamental role in renal function. The number density of INSs along the corticopapillary axis directly correlated with a loop population that declines exponentially with distance below the outer medullary-inner medullary boundary. The axial configurations were consistent with discrete association between near-bend loop segments and INSs and with upper loop segments lying distant from INSs.

Genetic variance components for residual feed intake and feed ...

African Journals Online (AJOL)

Feeding costs of animals is a major determinant of profitability in livestock production enterprises. Genetic selection to improve feed efficiency aims to reduce feeding cost in beef cattle and thereby improve profitability. This study estimated genetic (co)variances between weaning weight and other production, reproduction ...

Higher derivative regularization and chiral anomaly

International Nuclear Information System (INIS)

Nagahama, Yoshinori.

1985-02-01

A higher derivative regularization which automatically leads to the consistent chiral anomaly is analyzed in detail. It explicitly breaks all the local gauge symmetry but preserves global chiral symmetry and leads to the chirally symmetric consistent anomaly. This regularization thus clarifies the physics content contained in the consistent anomaly. We also briefly comment on the application of this higher derivative regularization to massless QED. (author)

Rodent models of congenital and hereditary cataract in man.

Science.gov (United States)

Tripathi, B J; Tripathi, R C; Borisuth, N S; Dhaliwal, R; Dhaliwal, D

1991-01-01

Because the organogenesis and physiology of the lens are essentially similar in various mammals, an understanding of the etiology and pathogenesis of the formation of cataract in an animal model will enhance our knowledge of cataractogenesis in man. In this review, we summarize the background, etiology, and pathogenesis of cataracts that occur in rodents. The main advantages of using rodent mutants include the well-researched genetics of the animals and the comparative ease of breeding of large litters. Numerous rodent models of congenital and hereditary cataracts have been studied extensively. In mice, the models include the Cts strain, Fraser mouse, lens opacity gene (Lop) strain, Lop-2 and Lop-3 strains, Philly mouse, Nakano mouse, Nop strain, Deer mouse, Emory mouse, Swiss Webster strain, Balb/c-nct/nct mouse, and SAM-R/3 strain. The rat models include BUdR, ICR, Sprague-Dawley, and Wistar rats, the spontaneously hypertensive rat (SHR), the John Rapp inbred strain of Dahl salt-sensitive rat, as well as WBN/Kob, Royal College of Surgeons (RCS), and Brown-Norway rats. Other proposed models for the study of hereditary cataract include the degu and the guinea pig. Because of the ease of making clinical observations in vivo and the subsequent availability of the intact lens for laboratory analyses at different stages of cataract formation, these animals provide excellent models for clinicopathologic correlations, for monitoring of the natural history of the aging process and of metabolic defects, as well as for investigations on the effect of cataract-modulating agents and drugs, including the prospect of gene therapy.

Rodent Models of Alcoholic Liver Disease: Role of Binge Ethanol Administration

Directory of Open Access Journals (Sweden)

Shubha Ghosh Dastidar

2018-01-01

Full Text Available Both chronic and acute (binge alcohol drinking are important health and economic concerns worldwide and prominent risk factors for the development of alcoholic liver disease (ALD. There are no FDA-approved medications to prevent or to treat any stage of ALD. Therefore, discovery of novel therapeutic strategies remains a critical need for patients with ALD. Relevant experimental animal models that simulate human drinking patterns and mimic the spectrum and severity of alcohol-induced liver pathology in humans are critical to our ability to identify new mechanisms and therapeutic targets. There are several animal models currently in use, including the most widely utilized chronic ad libitum ethanol (EtOH feeding (Lieber–DeCarli liquid diet model, chronic intragastric EtOH administration (Tsukamoto–French model, and chronic-plus-binge EtOH challenge (Bin Gao—National Institute on Alcohol Abuse and Alcoholism (NIAAA model. This review provides an overview of recent advances in rodent models of binge EtOH administration which help to recapitulate different features and etiologies of progressive ALD. These models include EtOH binge alone, and EtOH binge coupled with chronic EtOH intake, a high fat diet, or endotoxin challenge. We analyze the strengths, limitations, and translational relevance of these models, as well as summarize the liver injury outcomes and mechanistic insights. We further discuss the application(s of binge EtOH models in examining alcohol-induced multi-organ pathology, sex- and age-related differences, as well as circadian rhythm disruption.

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

Science.gov (United States)

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

2014-07-01

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

Comparative anatomy of the prosubiculum, subiculum, presubiculum, postsubiculum, and parasubiculum in human, monkey, and rodent.

Science.gov (United States)

Ding, Song-Lin

2013-12-15

The subicular complex, including the prosubiculum (ProS), subiculum (Sub), presubiculum, postsubiculum (PoS), and parasubiculum (PaS), plays important roles in the medial temporal memory system and is heavily involved in many neurological diseases such as Alzheimer's disease and epilepsy. In the literature, the ProS (in primate) and PoS (in rodent) are inconstantly identified, making data comparison difficult across species. This review is an attempt to discuss equivalencies and extent of the five subicular components in human, monkey, and rodent based on available information on their cytoarchitecture, chemoarchitecture, molecular signature, and neural connectivity. All five subicular cortices exist in human, monkey, and rodent. In human and monkey, the ProS and Sub extend into the uncal region anteriorly, and the PoS and PaS reach the cingulate isthmus posteriorly. In rodent, most of the typical subicular cortices are located in the dorsal and caudal portions of the hippocampal formation, and the modified version of the ventral ProS and Sub corresponds to the modified description of the uncal ProS and Sub in monkey and human. An interesting triangular region in rodent located at the juncture of the PoS, PaS, retrosplenial cortex, and visual cortex appears to be the equivalent of the monkey area prostriata. Major connections of the five subicular cortices are also summarized based on unified criteria discussed in this review, with distinct connections revealed between the ProS and the Sub. Copyright © 2013 Wiley Periodicals, Inc.

Multiple graph regularized protein domain ranking

KAUST Repository

Wang, Jim Jing-Yan

2012-11-19

Background: Protein domain ranking is a fundamental task in structural biology. Most protein domain ranking methods rely on the pairwise comparison of protein domains while neglecting the global manifold structure of the protein domain database. Recently, graph regularized ranking that exploits the global structure of the graph defined by the pairwise similarities has been proposed. However, the existing graph regularized ranking methods are very sensitive to the choice of the graph model and parameters, and this remains a difficult problem for most of the protein domain ranking methods.Results: To tackle this problem, we have developed the Multiple Graph regularized Ranking algorithm, MultiG-Rank. Instead of using a single graph to regularize the ranking scores, MultiG-Rank approximates the intrinsic manifold of protein domain distribution by combining multiple initial graphs for the regularization. Graph weights are learned with ranking scores jointly and automatically, by alternately minimizing an objective function in an iterative algorithm. Experimental results on a subset of the ASTRAL SCOP protein domain database demonstrate that MultiG-Rank achieves a better ranking performance than single graph regularized ranking methods and pairwise similarity based ranking methods.Conclusion: The problem of graph model and parameter selection in graph regularized protein domain ranking can be solved effectively by combining multiple graphs. This aspect of generalization introduces a new frontier in applying multiple graphs to solving protein domain ranking applications. 2012 Wang et al; licensee BioMed Central Ltd.

Multiple graph regularized protein domain ranking

KAUST Repository

Wang, Jim Jing-Yan; Bensmail, Halima; Gao, Xin

2012-01-01

Background: Protein domain ranking is a fundamental task in structural biology. Most protein domain ranking methods rely on the pairwise comparison of protein domains while neglecting the global manifold structure of the protein domain database. Recently, graph regularized ranking that exploits the global structure of the graph defined by the pairwise similarities has been proposed. However, the existing graph regularized ranking methods are very sensitive to the choice of the graph model and parameters, and this remains a difficult problem for most of the protein domain ranking methods.Results: To tackle this problem, we have developed the Multiple Graph regularized Ranking algorithm, MultiG-Rank. Instead of using a single graph to regularize the ranking scores, MultiG-Rank approximates the intrinsic manifold of protein domain distribution by combining multiple initial graphs for the regularization. Graph weights are learned with ranking scores jointly and automatically, by alternately minimizing an objective function in an iterative algorithm. Experimental results on a subset of the ASTRAL SCOP protein domain database demonstrate that MultiG-Rank achieves a better ranking performance than single graph regularized ranking methods and pairwise similarity based ranking methods.Conclusion: The problem of graph model and parameter selection in graph regularized protein domain ranking can be solved effectively by combining multiple graphs. This aspect of generalization introduces a new frontier in applying multiple graphs to solving protein domain ranking applications. 2012 Wang et al; licensee BioMed Central Ltd.

Multiple graph regularized protein domain ranking

Directory of Open Access Journals (Sweden)

Wang Jim

2012-11-01

Full Text Available Abstract Background Protein domain ranking is a fundamental task in structural biology. Most protein domain ranking methods rely on the pairwise comparison of protein domains while neglecting the global manifold structure of the protein domain database. Recently, graph regularized ranking that exploits the global structure of the graph defined by the pairwise similarities has been proposed. However, the existing graph regularized ranking methods are very sensitive to the choice of the graph model and parameters, and this remains a difficult problem for most of the protein domain ranking methods. Results To tackle this problem, we have developed the Multiple Graph regularized Ranking algorithm, MultiG-Rank. Instead of using a single graph to regularize the ranking scores, MultiG-Rank approximates the intrinsic manifold of protein domain distribution by combining multiple initial graphs for the regularization. Graph weights are learned with ranking scores jointly and automatically, by alternately minimizing an objective function in an iterative algorithm. Experimental results on a subset of the ASTRAL SCOP protein domain database demonstrate that MultiG-Rank achieves a better ranking performance than single graph regularized ranking methods and pairwise similarity based ranking methods. Conclusion The problem of graph model and parameter selection in graph regularized protein domain ranking can be solved effectively by combining multiple graphs. This aspect of generalization introduces a new frontier in applying multiple graphs to solving protein domain ranking applications.

Sex steroid hormones matter for learning and memory: estrogenic regulation of hippocampal function in male and female rodents

Science.gov (United States)

Kim, Jaekyoon; Tuscher, Jennifer J.; Fortress, Ashley M.

2015-01-01

Ample evidence has demonstrated that sex steroid hormones, such as the potent estrogen 17β-estradiol (E2), affect hippocampal morphology, plasticity, and memory in male and female rodents. Yet relatively few investigators who work with male subjects consider the effects of these hormones on learning and memory. This review describes the effects of E2 on hippocampal spinogenesis, neurogenesis, physiology, and memory, with particular attention paid to the effects of E2 in male rodents. The estrogen receptors, cell-signaling pathways, and epigenetic processes necessary for E2 to enhance memory in female rodents are also discussed in detail. Finally, practical considerations for working with female rodents are described for those investigators thinking of adding females to their experimental designs. PMID:26286657

Reproducibility and replicability of rodent phenotyping in preclinical studies

NARCIS (Netherlands)

Kafkafi, Neri; Agassi, Joseph; Chesler, Elissa J.; Crabbe, John C.; Crusio, Wim E.; Eilam, David; Gerlai, Robert; Golani, Ilan; Gomez-Marin, Alex; Heller, Ruth; Iraqi, Fuad; Jaljuli, Iman; Karp, Natasha A.; Morgan, Hugh; Nicholson, George; Pfaff, Donald W.; Richter, S. Helene; Stark, Philip B.; Stiedl, Oliver; Stodden, Victoria; Tarantino, Lisa M.; Tucci, Valter; Valdar, William; Williams, Robert W.; Würbel, Hanno; Benjamini, Yoav

The scientific community is increasingly concerned with the proportion of published “discoveries” that are not replicated in subsequent studies. The field of rodent behavioral phenotyping was one of the first to raise this concern, and to relate it to other methodological issues: the complex

First identification of Echinococcus multilocularis in rodent intermediate hosts in Sweden

Directory of Open Access Journals (Sweden)

Andrea L. Miller

2016-04-01

Full Text Available Echinococcus multilocularis is a zoonotic tapeworm with a sylvatic lifecycle and an expanding range in Europe. Monitoring efforts following its first identification in 2011 in Sweden have focused on the parasite's definitive host, the red fox (Vulpes vulpes. However, identifying rodent intermediate hosts is important to recognize opportunities for parasite transmission. During 2013–2015, livers from a total of 1566 rodents from four regions in Sweden were examined for E. multilocularis metacestode lesions. Species identity of suspect parasite lesions was confirmed by PCR and sequencing. E. multilocularis positive lesions >6 mm in diameter were also examined histologically. One Microtus agrestis out of 187 (0.5%, 95%CI: 0–2.9%, 8/439 (1.8%, 95%CI: 0.8–3.6% Arvicola amphibius, 0/655 (0%, 95%CI: 0–0.6% Myodes glareolus, and 0/285 (0%, 95%CI: 0–1.3% Apodemus spp. contained E. multilocularis metacestode lesions. Presence of protoscoleces was confirmed in the infected M. agrestis and in three of eight infected A. amphibius. Six of the nine positive rodents were captured from the same field. This is the first report of E. multilocularis in intermediate hosts in Sweden. The cluster of positive rodents in one field shows that local parasite prevalence can be high in Sweden despite overall low national prevalence in foxes (<0.1%. The presence of protoscoleces in infected M. agrestis and A. amphibius indicate these species can serve as competent intermediate hosts in Sweden. However, their relative importance for E. multilocularis transmission in the Swedish environment is not yet possible to assess. In contrast, the negative findings in all M. glareolus and Apodemus spp. suggest that these species are of no importance.

75 FR 53966 - Regular Meeting

Science.gov (United States)

2010-09-02

... FARM CREDIT SYSTEM INSURANCE CORPORATION Regular Meeting AGENCY: Farm Credit System Insurance Corporation Board. SUMMARY: Notice is hereby given of the regular meeting of the Farm Credit System Insurance Corporation Board (Board). DATE AND TIME: The meeting of the Board will be held at the offices of the Farm...

Xenopsylla spp. (Siphonaptera: Pulicidae) in murid rodents from the Canary Islands: an update.

Science.gov (United States)

Sánchez, S; Gómez, M S

2012-11-01

The geographical and host distributions of Xenopsylla fleas parasitizing murid rodents on the Canary Islands have been reported. Three Xenopsylla species, X. cheopis, X. brasiliensis and X. guancha, have been detected on two rodents species, Mus musculus and Rattus rattus. X. guancha has been the most prevalent species detected, specifically on M. musculus, the most abundant rodent, but it has been detected only on three eastern islands, where the species is endemic. X. cheopis has been shown to be the most widely distributed species throughout the archipelago and the species most frequently found on R. rattus. X. brasiliensis has been shown to be the least prevalent Xenopsylla species, with the lowest geographical distribution on the Canary Islands and focused only on R. rattus. The detection of both X. cheopis and X. brasiliensis on the island of Lanzarote, and of X. guancha on the island of Fuerteventura and the islet of La Graciosa represents the first report of these species on those particular Canary Islands.

Xenopsylla spp. (Siphonaptera: Pulicidae in murid rodents from the Canary Islands: An update

Directory of Open Access Journals (Sweden)

Sánchez S.

2012-11-01

Full Text Available The geographical and host distributions of Xenopsylla fleas parasitizing murid rodents on the Canary Islands have been reported. Three Xenopsylla species, X. cheopis, X. brasiliensis and X. guancha, have been detected on two rodents species, Mus musculus and Rattus rattus. X. guancha has been the most prevalent species detected, specifically on M. musculus, the most abundant rodent, but it has been detected only on three eastern islands, where the species is endemic. X. cheopis has been shown to be the most widely distributed species throughout the archipelago and the species most frequently found on R. rattus. X. brasiliensis has been shown to be the least prevalent Xenopsylla species, with the lowest geographical distribution on the Canary Islands and focused only on R. rattus. The detection of both X. cheopis and X. brasiliensis on the island of Lanzarote, and of X. guancha on the island of Fuerteventura and the islet of La Graciosa represents the first report of these species on those particular Canary Islands.

Work and family life of childrearing women workers in Japan: comparison of non-regular employees with short working hours, non-regular employees with long working hours, and regular employees.

Science.gov (United States)

Seto, Masako; Morimoto, Kanehisa; Maruyama, Soichiro

2006-05-01

This study assessed the working and family life characteristics, and the degree of domestic and work strain of female workers with different employment statuses and weekly working hours who are rearing children. Participants were the mothers of preschoolers in a large Japanese city. We classified the women into three groups according to the hours they worked and their employment conditions. The three groups were: non-regular employees working less than 30 h a week (n=136); non-regular employees working 30 h or more per week (n=141); and regular employees working 30 h or more a week (n=184). We compared among the groups the subjective values of work, financial difficulties, childcare and housework burdens, psychological effects, and strains such as work and family strain, work-family conflict, and work dissatisfaction. Regular employees were more likely to report job pressures and inflexible work schedules and to experience more strain related to work and family than non-regular employees. Non-regular employees were more likely to be facing financial difficulties. In particular, non-regular employees working longer hours tended to encounter socioeconomic difficulties and often lacked support from family and friends. Female workers with children may have different social backgrounds and different stressors according to their working hours and work status.

Long-term follow-up of vocal fold movement impairment and feeding after neonatal cardiac surgery.

Science.gov (United States)

Richter, Amy Li; Ongkasuwan, Julina; Ocampo, Elena C

2016-04-01

To determine the long-term prognosis of children with vocal fold mobility impairment (VFMI) after cardiac surgery, with respect to time to normal feeding and incidence of admissions for pneumonia and feeding difficulties. A retrospective chart review was conducted of all neonates who had otolaryngology exam after cardiac surgery at a tertiary children's hospital from May 2007 to May 2008. Charts were reviewed for demographics, type of cardiac surgery, vocal fold mobility, diet at time of discharge and at last follow-up, time to full oral feeding, and hospital admissions. There were a total of 94 patients included in the study, 17 of whom had VFMI. While significantly more patients with VFMI required modified diet at discharge, 48% compared to 19% of patients with normal vocal fold mobility; there was no statistically significant difference in time to regular diet on long-term follow-up, 0.8 years (VFMI) compared to 0.4 years (normal vocal fold mobility). Of the 25 patients with modified diet or gastrostomy tube at discharge, 52% returned to full feeds within a year. There was no difference in hospitalizations for pneumonia in patients with or without VFMI. However in patients with VFMI, 35% required readmission for feeding difficulty or poor weight gain compared to only 5% in the infants with normal vocal fold mobility. After neonatal cardiac surgery, there do not appear to be long-term effects of VFMI with regards to readmission for pneumonia. However, there is an increased risk for hospitalization with respect to feeding difficulties in those neonates with VFMI. The overall prognosis for time to oral feeding is good. Copyright © 2016. Published by Elsevier Ireland Ltd.

Gut morpbology of tbe Otomyine rodents: an arid-mesic comparison

African Journals Online (AJOL)

1998-06-15

Jun 15, 1998 ... Despite the broad similarity in the gross gastro-intestinal anatomy between the speCies ... Present address: Department of Physiology, University of the Western ..... on growth and renal performance of juvenile Namib rodents.

Incremental projection approach of regularization for inverse problems

Energy Technology Data Exchange (ETDEWEB)

Souopgui, Innocent, E-mail: innocent.souopgui@usm.edu [The University of Southern Mississippi, Department of Marine Science (United States); Ngodock, Hans E., E-mail: hans.ngodock@nrlssc.navy.mil [Naval Research Laboratory (United States); Vidard, Arthur, E-mail: arthur.vidard@imag.fr; Le Dimet, François-Xavier, E-mail: ledimet@imag.fr [Laboratoire Jean Kuntzmann (France)

2016-10-15

This paper presents an alternative approach to the regularized least squares solution of ill-posed inverse problems. Instead of solving a minimization problem with an objective function composed of a data term and a regularization term, the regularization information is used to define a projection onto a convex subspace of regularized candidate solutions. The objective function is modified to include the projection of each iterate in the place of the regularization. Numerical experiments based on the problem of motion estimation for geophysical fluid images, show the improvement of the proposed method compared with regularization methods. For the presented test case, the incremental projection method uses 7 times less computation time than the regularization method, to reach the same error target. Moreover, at convergence, the incremental projection is two order of magnitude more accurate than the regularization method.

Geometric regularizations and dual conifold transitions

International Nuclear Information System (INIS)

Landsteiner, Karl; Lazaroiu, Calin I.

2003-01-01

We consider a geometric regularization for the class of conifold transitions relating D-brane systems on noncompact Calabi-Yau spaces to certain flux backgrounds. This regularization respects the SL(2,Z) invariance of the flux superpotential, and allows for computation of the relevant periods through the method of Picard-Fuchs equations. The regularized geometry is a noncompact Calabi-Yau which can be viewed as a monodromic fibration, with the nontrivial monodromy being induced by the regulator. It reduces to the original, non-monodromic background when the regulator is removed. Using this regularization, we discuss the simple case of the local conifold, and show how the relevant field-theoretic information can be extracted in this approach. (author)

Adaptive regularization

DEFF Research Database (Denmark)

Hansen, Lars Kai; Rasmussen, Carl Edward; Svarer, C.

1994-01-01

Regularization, e.g., in the form of weight decay, is important for training and optimization of neural network architectures. In this work the authors provide a tool based on asymptotic sampling theory, for iterative estimation of weight decay parameters. The basic idea is to do a gradient desce...

Regularizing portfolio optimization

International Nuclear Information System (INIS)

Still, Susanne; Kondor, Imre

2010-01-01

The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.

Regularizing portfolio optimization

Science.gov (United States)

Still, Susanne; Kondor, Imre

2010-07-01

The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.

Endoparasites of rodents from the Chittagong Hill Tracts in Southeastern Bangladesh.

Science.gov (United States)

Fuehrer, Hans-Peter; Baumann, Timo A; Riedl, Julia; Treiber, Moritz; Igel, Petra; Swoboda, Paul; Joachim, Anja; Noedl, Harald

2012-11-01

Rodents are a key mammalian group highly successful in adapting to a variety of environments throughout the world and play an important role in many zoonotic cycles. Within this project, the gastrointestinal and extraintestinal parasite fauna of 76 rodents (Muroidea and Sciuridae) was determined in the District of Bandarban (Chittagong Hill Tracts) in Southeastern Bangladesh. Gastrointestinal and extraintestinal parasites were examined with macro- and microscopical tools (e.g. Ziehl-Neelsen Staining) at a field site in Bandarban. A wide variety of parasites were found in rodent hosts, including protozoa-Giardia sp. (n = 8), Cryptosporidium sp. (n = 1), Entamoeba sp. (n = 8), Trichomonadida (n = 4), Isospora sp. (n = 1), trematodes (Echinostoma sp.; n = 3), cestodes-Hymenolepis nana (n = 1), Hymenolepis diminuta (n = 3), Hymenolepis sp. (n = 2), Taenia taeniaeformis-Larven (n = 4), Catenotaenia sp. (n = 1), Taenia sp. (n = 1), nematodes-Heterakis spumosa (n = 4), Heterakis sp. (n = 1), Aspiculuris tetraptera (n = 2), Capillaria hepatica (n = 2), Capillaria sp. (n = 3), Syphacia sp. (n = 2), Strongyloides sp. (n = 10), Trichostrongylus sp. (n = 2) and Trichuris sp. (n = 1)-and acanthocephalans (Moniliformis moniliformis; n = 2). Several of the examined parasites are of zoonotic importance via direct or indirect transmission (e.g. C. hepatica) and may affect humans.

Assessing the Diversity of Rodent-Borne Viruses: Exploring of High-Throughput Sequencing and Classical Amplification/Sequencing Approaches.

Science.gov (United States)

Drewes, Stephan; Straková, Petra; Drexler, Jan F; Jacob, Jens; Ulrich, Rainer G

2017-01-01

Rodents are distributed throughout the world and interact with humans in many ways. They provide vital ecosystem services, some species are useful models in biomedical research and some are held as pet animals. However, many rodent species can have adverse effects such as damage to crops and stored produce, and they are of health concern because of the transmission of pathogens to humans and livestock. The first rodent viruses were discovered by isolation approaches and resulted in break-through knowledge in immunology, molecular and cell biology, and cancer research. In addition to rodent-specific viruses, rodent-borne viruses are causing a large number of zoonotic diseases. Most prominent examples are reemerging outbreaks of human hemorrhagic fever disease cases caused by arena- and hantaviruses. In addition, rodents are reservoirs for vector-borne pathogens, such as tick-borne encephalitis virus and Borrelia spp., and may carry human pathogenic agents, but likely are not involved in their transmission to human. In our days, next-generation sequencing or high-throughput sequencing (HTS) is revolutionizing the speed of the discovery of novel viruses, but other molecular approaches, such as generic RT-PCR/PCR and rolling circle amplification techniques, contribute significantly to the rapidly ongoing process. However, the current knowledge still represents only the tip of the iceberg, when comparing the known human viruses to those known for rodents, the mammalian taxon with the largest species number. The diagnostic potential of HTS-based metagenomic approaches is illustrated by their use in the discovery and complete genome determination of novel borna- and adenoviruses as causative disease agents in squirrels. In conclusion, HTS, in combination with conventional RT-PCR/PCR-based approaches, resulted in a drastically increased knowledge of the diversity of rodent viruses. Future improvements of the used workflows, including bioinformatics analysis, will further

Brain development in rodents and humans: Identifying benchmarks of maturation and vulnerability to injury across species

Science.gov (United States)

Semple, Bridgette D.; Blomgren, Klas; Gimlin, Kayleen; Ferriero, Donna M.; Noble-Haeusslein, Linda J.

2013-01-01

Hypoxic-ischemic and traumatic brain injuries are leading causes of long-term mortality and disability in infants and children. Although several preclinical models using rodents of different ages have been developed, species differences in the timing of key brain maturation events can render comparisons of vulnerability and regenerative capacities difficult to interpret. Traditional models of developmental brain injury have utilized rodents at postnatal day 7–10 as being roughly equivalent to a term human infant, based historically on the measurement of post-mortem brain weights during the 1970s. Here we will examine fundamental brain development processes that occur in both rodents and humans, to delineate a comparable time course of postnatal brain development across species. We consider the timing of neurogenesis, synaptogenesis, gliogenesis, oligodendrocyte maturation and age-dependent behaviors that coincide with developmentally regulated molecular and biochemical changes. In general, while the time scale is considerably different, the sequence of key events in brain maturation is largely consistent between humans and rodents. Further, there are distinct parallels in regional vulnerability as well as functional consequences in response to brain injuries. With a focus on developmental hypoxicischemic encephalopathy and traumatic brain injury, this review offers guidelines for researchers when considering the most appropriate rodent age for the developmental stage or process of interest to approximate human brain development. PMID:23583307

Population Ecology of Hantavirus Rodent Hosts in Southern Brazil

Science.gov (United States)

Teixeira, Bernardo R.; Loureiro, Nathalie; Strecht, Liana; Gentile, Rosana; Oliveira, Renata C.; Guterres, Alexandro; Fernandes, Jorlan; Mattos, Luciana H. B. V.; Raboni, Sonia M.; Rubio, Giselia; Bonvicino, Cibele R.; Duarte dos Santos, Claudia N.; Lemos, Elba R. S.; D'Andrea, Paulo S.

2014-01-01

In this study we analyze population dynamics of hantavirus rodent hosts and prevalence of infection over a 2-year period in Southern Brazil, a region with a high incidence of hantavirus pulmonary syndrome. The 14 small mammal species captured were composed of 10 rodents and four marsupials, the six most abundant species being Akodon serrensis, Oxymycterus judex, Akodon montensis, Akodon paranaensis, Oligoryzomys nigripes, and Thaptomys nigrita. These species displayed a similar pattern with increasing population sizes in fall/winter caused by recruitment and both, increase in reproductive activity and higher hantavirus prevalence in spring/summer. Specific associations between A. montensis/Jaborá Virus (JABV) and O. nigripes/Juquitiba-like Virus (JUQV-like) and spillover infections between A. paranaensis/JABV, A. serrensis/JABV, and A. paranaensis/JUQV-like were observed. Spillover infection in secondary hosts seems to play an important role in maintaining JABV and JUQV-like in the hantavirus sylvatic cycle mainly during periods of low prevalence in primary hosts. PMID:24935954

Tessellating the Sphere with Regular Polygons

Science.gov (United States)

Soto-Johnson, Hortensia; Bechthold, Dawn

2004-01-01

Tessellations in the Euclidean plane and regular polygons that tessellate the sphere are reviewed. The regular polygons that can possibly tesellate the sphere are spherical triangles, squares and pentagons.

Age, lighting treatment, feed allocation and feed form influence ...

African Journals Online (AJOL)

During a broiler breeder trial with 3200 Cobb 500 hens, the effects of lighting treatment after 20 weeks' feed allocation and of feed form on the length of time taken to consume the daily allocation of feed were measured. Pullets were reared on 8-hour photoperiods to 20 weeks, then transferred to one of four lighting ...

Accretion onto some well-known regular black holes

International Nuclear Information System (INIS)

Jawad, Abdul; Shahzad, M.U.

2016-01-01

In this work, we discuss the accretion onto static spherically symmetric regular black holes for specific choices of the equation of state parameter. The underlying regular black holes are charged regular black holes using the Fermi-Dirac distribution, logistic distribution, nonlinear electrodynamics, respectively, and Kehagias-Sftesos asymptotically flat regular black holes. We obtain the critical radius, critical speed, and squared sound speed during the accretion process near the regular black holes. We also study the behavior of radial velocity, energy density, and the rate of change of the mass for each of the regular black holes. (orig.)

Accretion onto some well-known regular black holes

Energy Technology Data Exchange (ETDEWEB)

Jawad, Abdul; Shahzad, M.U. [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan)

2016-03-15

In this work, we discuss the accretion onto static spherically symmetric regular black holes for specific choices of the equation of state parameter. The underlying regular black holes are charged regular black holes using the Fermi-Dirac distribution, logistic distribution, nonlinear electrodynamics, respectively, and Kehagias-Sftesos asymptotically flat regular black holes. We obtain the critical radius, critical speed, and squared sound speed during the accretion process near the regular black holes. We also study the behavior of radial velocity, energy density, and the rate of change of the mass for each of the regular black holes. (orig.)

Accretion onto some well-known regular black holes

Science.gov (United States)

Jawad, Abdul; Shahzad, M. Umair

2016-03-01

In this work, we discuss the accretion onto static spherically symmetric regular black holes for specific choices of the equation of state parameter. The underlying regular black holes are charged regular black holes using the Fermi-Dirac distribution, logistic distribution, nonlinear electrodynamics, respectively, and Kehagias-Sftesos asymptotically flat regular black holes. We obtain the critical radius, critical speed, and squared sound speed during the accretion process near the regular black holes. We also study the behavior of radial velocity, energy density, and the rate of change of the mass for each of the regular black holes.

Effects of rodent community diversity and composition on prevalence of an endemic bacterial pathogen - Bartonella

Science.gov (United States)

Bai, Y.; Kosoy, M.Y.; Calisher, C.H.; Cully, J.F.; Collinge, S.K.

2009-01-01

By studying Bartonella prevalence in rodent communities from 23 geographic sites in the western United States and one site in northern Mexico, the present study focused on the effects of rodent community diversity (measured by richness and Shannon index) and composition on prevalence of Bartonella infections. The analysis showed negative correlations of Bartonella prevalence with rodent richness and Shannon index. Further, Bartonella prevalence varied among rodent genera/species. Three models were applied to explain the observations. (1) Within-species/genus transmission: Bartonella strains usually are host-specific and adding non-host species would decrease Bartonella prevalence in its principal host through reduction of host contact (encounter reduction); (2) Frequency-dependence: Adding hosts would decrease the proportion of all infected individuals in the community, resulting in a reduction in the number of contacts between susceptible and infected individuals that usually leads to transmission (transmission reduction); and (3) Dominant species effect: Dominant species, if not susceptible to Bartonellae, can constrain the abundance of susceptible hosts (susceptible host regulation). These mechanisms work in concert; and the level of Bartonella prevalence is an outcome of regulation of all of these mechanisms on the entire system.

Effect of Room Ventilation Rates in Rodent Rooms with Direct-Exhaust IVC Systems.

Science.gov (United States)

Geertsema, Roger S; Lindsell, Claire E

2015-09-01

When IVC are directly exhausted from a rodent housing room, the air quality of the room can become independent of the intracage air quality and may reduce the need for high room ventilation rates. This study assessed the effect of decreasing the ventilation rate in rodent rooms using direct-exhaust IVC systems. The study was conducted over 16 wk and compared conditions in 8 rodent rooms that had ventilation rates of 5 to 6 air changes per hour (ACH) with those in rooms at 10 to 12 ACH. At the low ventilation rate, rooms had higher CO₂ concentrations, higher dew point temperature, and lower particulate levels and spent a greater percentage of time above the temperature set point than did rooms at the high rate. The levels of allergens and endotoxins in room air were the same regardless of the ventilation rate. Differences seen in parameters within cages at the 2 ventilation rates were operationally irrelevant. We detected no total volatile organic compounds in the room that were attributable to ammonia, regardless of the ventilation rate. Clearing the air of ethanol after a spill took longer at the low compared with high rate. However, ethanol clearance was faster at the low rate when the demand-control system was activated than at the high ventilation rate alone. Air quality in the room and in the cages were acceptable with room ventilation rates of 5 to 6 ACH in rodent rooms that use direct-exhaust IVC systems.

Synthesis, Characterization and Application of the novel, regular mesoporous materials MCM-41 and MCM-48

Energy Technology Data Exchange (ETDEWEB)

Schmidt, R

1995-07-01

In the application of zeolites to catalytic cracking of heavy oil fractions the need of regular solids with large pore sizes has become very obvious. The scope of this thesis was to synthesize and characterize the novel mesoporous materials MCM-41 and MCM-48 with the major emphasis laid on MCM-41. MCM-41 materials with bulk Si/Al ratios of 4, 9, 18 and {infinity} were synthesized and characterized by XRD and HREM. The catalytic cracking behaviour of Al-containing MCM-41 materials was investigated by pulse reactor studies using decalin as model feed and by Micro Activity Tests using atmospheric residue or n-hexadecane as feed. Aluminium containing MCM-41 was found to be active for the cracking of heavy oil fractions. Purely siliceous MCM-41 materials with pore sizes ranging from 18 Aa to 40 Aa were synthesized and their properties studied by means of NMR spectroscopy. The MCM-48, which is a cubic member of the M41S family with a three dimensional pore system, was studied by means of a combination of X-ray powder diffraction and HREM technique. 210 refs., 76 figs., 9 tabs.

Diagrammatic methods in phase-space regularization

International Nuclear Information System (INIS)

Bern, Z.; Halpern, M.B.; California Univ., Berkeley

1987-11-01

Using the scalar prototype and gauge theory as the simplest possible examples, diagrammatic methods are developed for the recently proposed phase-space form of continuum regularization. A number of one-loop and all-order applications are given, including general diagrammatic discussions of the nogrowth theorem and the uniqueness of the phase-space stochastic calculus. The approach also generates an alternate derivation of the equivalence of the large-β phase-space regularization to the more conventional coordinate-space regularization. (orig.)

Metric regularity and subdifferential calculus

International Nuclear Information System (INIS)

Ioffe, A D

2000-01-01

The theory of metric regularity is an extension of two classical results: the Lyusternik tangent space theorem and the Graves surjection theorem. Developments in non-smooth analysis in the 1980s and 1990s paved the way for a number of far-reaching extensions of these results. It was also well understood that the phenomena behind the results are of metric origin, not connected with any linear structure. At the same time it became clear that some basic hypotheses of the subdifferential calculus are closely connected with the metric regularity of certain set-valued maps. The survey is devoted to the metric theory of metric regularity and its connection with subdifferential calculus in Banach spaces

Feed safety in the feed supply chain

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Pinotti, L.

2011-01-01

Full Text Available A number of issues have weakened the public's confidence in the quality and wholesomeness of foods of animal origin. As a result farmers, nutritionists, industry and governments have been forced to pay serious attention to animal feedstuff production processes, thereby acknowledging that animal feed safety is an essential prerequisite for human food safety. Concerns about these issues have produced a number of important effects including the ban on the use of processed animal proteins, the ban on the addition of most antimicrobials to farm animals diets for growth‐promotion purposes, and the implementation of feed contaminant regulations in the EU. In this context it is essential to integrate knowledge on feed safety and feed supply. Consequently, purchase of new and more economic sources of energy and protein in animal diets, which is expected to conform to adequate quality, traceability, environmental sustainability and safety standards, is an emerging issue in livestock production system.

Performance Analysis of Exam Gloves Used for Aseptic Rodent Surgery

Science.gov (United States)

LeMoine, Dana M; Bergdall, Valerie K; Freed, Carrie

2015-01-01

Aseptic technique includes the use of sterile surgical gloves for survival surgeries in rodents to minimize the incidence of infections. Exam gloves are much less expensive than are surgical gloves and may represent a cost-effective, readily available option for use in rodent surgery. This study examined the effectiveness of surface disinfection of exam gloves with 70% isopropyl alcohol or a solution of hydrogen peroxide and peracetic acid (HP–PA) in reducing bacterial contamination. Performance levels for asepsis were met when gloves were negative for bacterial contamination after surface disinfection and sham ‘exertion’ activity. According to these criteria, 94% of HP–PA-disinfected gloves passed, compared with 47% of alcohol-disinfected gloves. In addition, the effect of autoclaving on the integrity of exam gloves was examined, given that autoclaving is another readily available option for aseptic preparation. Performance criteria for glove integrity after autoclaving consisted of: the ability to don the gloves followed by successful simulation of wound closure and completion of stretch tests without tearing or observable defects. Using this criteria, 98% of autoclaved nitrile exam gloves and 76% of autoclaved latex exam gloves met performance expectations compared with the performance of standard surgical gloves (88% nitrile, 100% latex). The results of this study support the use of HP–PA-disinfected latex and nitrile exam gloves or autoclaved nitrile exam gloves as viable cost-effective alternatives to sterile surgical gloves for rodent surgeries. PMID:26045458

Performance analysis of exam gloves used for aseptic rodent surgery.

Science.gov (United States)

LeMoine, Dana M; Bergdall, Valerie K; Freed, Carrie

2015-05-01

Aseptic technique includes the use of sterile surgical gloves for survival surgeries in rodents to minimize the incidence of infections. Exam gloves are much less expensive than are surgical gloves and may represent a cost-effective, readily available option for use in rodent surgery. This study examined the effectiveness of surface disinfection of exam gloves with 70% isopropyl alcohol or a solution of hydrogen peroxide and peracetic acid (HP-PA) in reducing bacterial contamination. Performance levels for asepsis were met when gloves were negative for bacterial contamination after surface disinfection and sham 'exertion' activity. According to these criteria, 94% of HP-PA-disinfected gloves passed, compared with 47% of alcohol-disinfected gloves. In addition, the effect of autoclaving on the integrity of exam gloves was examined, given that autoclaving is another readily available option for aseptic preparation. Performance criteria for glove integrity after autoclaving consisted of: the ability to don the gloves followed by successful simulation of wound closure and completion of stretch tests without tearing or observable defects. Using this criteria, 98% of autoclaved nitrile exam gloves and 76% of autoclaved latex exam gloves met performance expectations compared with the performance of standard surgical gloves (88% nitrile, 100% latex). The results of this study support the use of HP-PA-disinfected latex and nitrile exam gloves or autoclaved nitrile exam gloves as viable cost-effective alternatives to sterile surgical gloves for rodent surgeries.

seasonal population dynamics of rodents of mount chilalo, arsi ...

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ABSTRACT: A study on seasonal population dynamics of rodents was carried out on Mount. Chilalo from .... vegetation growth, availability of food and water, and ... vegetation (3,300–4,200 masl) (Alemayehu. Mengistu, 1975; APEDO and ABRDP, 2004). The mountain is one of the Afrotropical biodiversity hotspots areas.

Importance of rodents for hydrology: lessons learnt from various field experiments

Science.gov (United States)

van Schaik, Loes; Zangerlé, Anne; Schneider, Anne-Kathrin; Schröder, Boris; Eccard, Jana

2017-04-01

organisms are known to create soil macropores of different sizes and with varying extent and orientation: most commonly earthworms, rodents, moles and roots. Preferential flow through macropore networks is dynamic and typically occurs when short individual macropores become connected at the hillslope scale as the nodes between the macropores become wet. Large lateral macropores may contribute to rapid subsurface stormflow of water and solutes at hillslope scale and supply a significant part of the catchment scale discharge during high intensity rainfall events even under relatively dry catchment state. Outflow from soil pipes, especially in the valley bottom or along the banking near to streams, is frequently observed, however, it remains a challenge to measure the spatial distribution, extent and connectivity of macropores at hill slope scales. We hypothesize that local information on organism abundances may be used as an indicator for spatial variability in infiltration, water storage and fluxes at the small scale and that knowledge on the landscape scale spatial distribution of organisms can provide information on connectivity of macropores at hillslope scale. Here we summarize the lessons learnt during three years of measurements aimed at determining the influence of rodent burrows on soil hydrology in a meso-scale catchment. Within the Attert Catchment (297 km2) in Luxembourg we performed sprinkling experiments with a brilliant blue tracer on twelve plots, of which six directly above rodent burrow openings and six on a surface without a rodent burrow opening, in order to examine the influence of the burrow openings on the infiltration pattern. Then we tested the extent of flow through mice burrows in different forest types, with varying geology and slope, by supplying 5 Liters of water with brilliant blue tracer directly to 24 burrow openings at soil surface. We excavated the burrows to measure how far the water was transported laterally in the burrow. Though

Lawsonia intracellularis in the feces of wild rodents and stray cats captured around equine farms.

Science.gov (United States)

Hwang, Jeong-Min; Seo, Myung-Ji; Yeh, Jung-Yong

2017-08-11

Proliferative enteropathy is a global enteric disease of particular importance in pigs. The causative bacterium, Lawsonia intracellularis, has a wide range of susceptible host species. Recently, L. intracellularis has been recognized as an etiologic agent of an emerging enteric disease in foals called equine proliferative enteropathy (EPE). The presence of L. intracellularis in nonruminant wildlife has raised questions regarding the role of these species in EPE transmission. This study investigated exposure to L. intracellularis in wild rodents and feral cats from eight farms with confirmed EPE. Serum (42) and fecal (40) samples from resident foals and fecal samples (131), intestinal mucosa tissues (14), and mesenteric lymph nodes (14) from wild and feral animals were collected for the evaluation of the farm status and the molecular detection of L. intracellularis following the diagnosis of EPE in index cases. Fresh feces from wild rodents and feral cats were collected from the ground while walking the premises or after trapping the animals using live traps. A total of 3 brown rats, 7 house mice, 1 striped field mouse, 2 grey red-backed voles, and 3 feral cats showed evidence of prior exposure to L. intracellularis. Our data add to increasing evidence demonstrating the potential for L. intracellularis transmission and infection in wild rodents and feral cats and provide possible evidence of interspecies transmission. The exposure of wild rodents and feral cats provides potential evidence for the spillover of L. intracellularis to wildlife species and raises the question of spillback to horses. Additionally, these animals may represent an indicator of environmental exposure or may be actively involved in the transmission of L. intracellularis to foals by acting as potential reservoir/amplifier hosts. This study is the first to demonstrate the magnitude of L. intracellularis shedding in the feces of wild rodents and feral cats and to indicate the significant

Temporal regularity of the environment drives time perception

OpenAIRE

van Rijn, H; Rhodes, D; Di Luca, M

2016-01-01

It’s reasonable to assume that a regularly paced sequence should be perceived as regular, but here we show that perceived regularity depends on the context in which the sequence is embedded. We presented one group of participants with perceptually regularly paced sequences, and another group of participants with mostly irregularly paced sequences (75% irregular, 25% regular). The timing of the final stimulus in each sequence could be var- ied. In one experiment, we asked whether the last stim...

Feeding tube-related complications and problems in patients receiving long-term home enteral nutrition

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Vasileios Alivizatos

2015-04-01

Full Text Available Aim: The aim of this study was to evaluate the long-term complications and problems related to gastrostomy and jejunostomy feeding tubes used for home enteral nutrition support and the effect these have on health care use. Materials and Methods: The medical records of 31 patients having gastrostomy (27 patients and jejunostomy (4 feeding tubes inserted in our Department were retrospectively studied. All were discharged on long-term (>3 months enteral nutrition and followed up at regular intervals by a dedicated nurse. Any problem or complication associated with tube feeding as well as the intervention, if any, that occurred, was recorded. Data were collected and analyzed. Results: All the patients were followed up for a mean of 17.5 months (4-78. The most frequent tube-related complications included inadvertent removal of the tube (broken tube, plugged tube; 45.1%, tube leakage (6.4%, dermatitis of the stoma (6.4%, and diarrhea (6.4%. There were 92 unscheduled health care contacts, with an average rate of such 2.9 contacts over the mean follow-up time of 17.5 months. Conclusion: In patients receiving long-term home enteral nutrition, feeding tube-related complications and problems are frequent and result in significant health care use. Further studies are needed to address their optimal prevention modalities and management.

Dairy cattle; Farming system; Animal feeding; Milk; Productivity; Work organization; Role of women; India

Directory of Open Access Journals (Sweden)

V. Alary

2008-01-01

Full Text Available To satisfy Indian consumers’ rising demand for milk products, Indian breeders will have to boost their production rapidly, especially through improved feeding practices. Many experts point out that currently used crop by-products will not be sufficient to meet increasing feed requirements from cow and buffalo herds and that it will be necessary to turn to grains such as wheat and maize. But other experts think that grain will not be enough and that the increasing animal consumption of grain will affect human consumption, unless India decides on massive grain imports, putting pressure on the world grain market. The present survey carried out in two districts of Haryana showed that grain was not an essential feed for cattle and buffaloes, and that improving cotton and mustard by-products, and green fodder had great potential. A second finding was that wealthier farmers tended to underuse the genetic potential of milk cows and buffaloes. Moreover, biotechnical management of the herd, in particular the feeding system, was closely related to the socioeconomic management of the family farming system; family strategies aimed at ensuring sufficient milk production for the family in larger farms and to provide a regular income in smaller ones. This paper also stressed out the need to design, implement, and monitor development programs that integrate sociocultural and, especially, gender issues, to facilitate technological innovation with respect to forage storage.

Jaundice, terminating breast-feeding, and the vulnerable child.

Science.gov (United States)

Kemper, K; Forsyth, B; McCarthy, P

1989-11-01

Jaundice is the most commonly treated condition of otherwise well newborns. Although recommended treatments are thought to be safe and effective, the impact of jaundice and therapy on maternal attitudes and behavior is unknown. It was hypothesized that, in contrast to comparison mothers, mothers of jaundiced infants would be more likely to stop breast-feeding in the first month of life, have more separation difficulties with their infant, and be greater users of health care. Both groups of mothers were surveyed in the hospital and 1 month after discharge. Mothers were eligible if their infants were born at Yale-New Haven Hospital after February 1987 and were in the regular nursery. Jaundiced infants had a total serum bilirubin concentration greater than or equal to 205 mmol/L (12 mg/dL); control infants were not jaundiced. Of those who agreed to participate, 84% (85/101) of mothers of jaundiced infants and 80% (124/155) of control mothers completed the 1-month questionnaire. There were no substantial differences between the control and jaundiced groups, respectively, with regard to maternal age (29.1 years vs 29 years) education (66% vs 60% some college), or race (86% vs 82% white). Breast-feeding was more common in the jaundiced group (61% vs 79%, P less than .05). By 1 month, more mothers of jaundiced infants had completely stopped breast-feeding (19% vs 42%, P less than .01). They were more likely to have never left the baby with anyone else (including the father) or left the baby at most one time for less than 1 hour (15% vs 31%, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Contrasting Patterns in Mammal–Bacteria Coevolution: Bartonella and Leptospira in Bats and Rodents

Science.gov (United States)

Lei, Bonnie R.; Olival, Kevin J.

2014-01-01

Background Emerging bacterial zoonoses in bats and rodents remain relatively understudied. We conduct the first comparative host–pathogen coevolutionary analyses of bacterial pathogens in these hosts, using Bartonella spp. and Leptospira spp. as a model. Methodology/Principal Findings We used published genetic data for 51 Bartonella genotypes from 24 bat species, 129 Bartonella from 38 rodents, and 26 Leptospira from 20 bats. We generated maximum likelihood and Bayesian phylogenies for hosts and bacteria, and tested for coevoutionary congruence using programs ParaFit, PACO, and Jane. Bartonella spp. and their bat hosts had a significant coevolutionary fit (ParaFitGlobal = 1.9703, P≤0.001; m2 global value = 7.3320, P≤0.0001). Bartonella spp. and rodent hosts also indicated strong overall patterns of cospeciation (ParaFitGlobal = 102.4409, P≤0.001; m2 global value = 86.532, P≤0.0001). In contrast, we were unable to reject independence of speciation events in Leptospira and bats (ParaFitGlobal = 0.0042, P = 0.84; m2 global value = 4.6310, P = 0.5629). Separate analyses of New World and Old World data subsets yielded results congruent with analysis from entire datasets. We also conducted event-based cophylogeny analyses to reconstruct likely evolutionary histories for each group of pathogens and hosts. Leptospira and bats had the greatest number of host switches per parasite (0.731), while Bartonella and rodents had the fewest (0.264). Conclusions/Significance In both bat and rodent hosts, Bartonella exhibits significant coevolution with minimal host switching, while Leptospira in bats lacks evolutionary congruence with its host and has high number of host switches. Reasons underlying these variable coevolutionary patterns in host range are likely due to differences in disease-specific transmission and host ecology. Understanding the coevolutionary patterns and frequency of host-switching events between bacterial pathogens and

Fruit Size Determines the Role of Three Scatter-Hoarding Rodents as Dispersers or Seed Predators of a Fleshy-Fruited Atacama Desert Shrub

Science.gov (United States)

Loayza, Andrea P.; Squeo, Francisco A.

2016-01-01

Scatter-hoarding rodents can act as both predators and dispersers for many large-seeded plants because they cache seeds for future use, but occasionally forget them in sites with high survival and establishment probabilities. The most important fruit or seed trait influencing rodent foraging behavior is seed size; rodents prefer large seeds because they have higher nutritional content, but this preference can be counterbalanced by the higher costs of handling larger seeds. We designed a cafeteria experiment to assess whether fruit and seed size of Myrcianthes coquimbensis, an endangered desert shrub, influence the decision-making process during foraging by three species of scatter-hoarding rodents differing in body size: Abrothrix olivaceus, Phyllotis darwini and Octodon degus. We found that the size of fruits and seeds influenced foraging behavior in the three rodent species; the probability of a fruit being harvested and hoarded was higher for larger fruits than for smaller ones. Patterns of fruit size preference were not affected by rodent size; all species were able to hoard fruits within the entire range of sizes offered. Finally, fruit and seed size had no effect on the probability of seed predation, rodents typically ate only the fleshy pulp of the fruits offered and discarded whole, intact seeds. In conclusion, our results reveal that larger M. coquimbensis fruits have higher probabilities of being harvested, and ultimately of its seeds being hoarded and dispersed by scatter-hoarding rodents. As this plant has no other dispersers, rodents play an important role in its recruitment dynamics. PMID:27861550

An evaluation of factors influencing feeding in babies with a cleft palate with and without a cleft lip.

Science.gov (United States)

Martin, Vanessa; Greatrex-White, Sheila

2014-03-01

The objective of this article was to determine the impact of different bottles and teats for feeding babies with a cleft palate (with and without a cleft lip) on weight velocity, feeding behaviour, and maternal self-esteem. A mixed methods study incorporating the use of diaries to record feeding patterns of babies and levels of professional support received was used. Growth was assessed by converting weights into standard deviation scores and using the differences to express weight velocity over a six-week period. Visual analogue scales were used to assess mothers' perceptions of their children and themselves. The Edinburgh Postnatal Depression Score (EPDS) was used to identify maternal depression. The study demonstrated that the most significant effect on weight was determined by cleft type. Babies with isolated clefts of the hard and soft palate experienced greater feeding problems and suffered the biggest weight losses. This remained significant independently of the type of bottle/teat used. Poor weight gain was also associated with a mother's low perception of herself and her child, and her tendency towards depression. The study highlights the importance of the early assessment of babies' feeding skills and regular follow-up and support from trained and experienced nurse specialists.

[Identification of wild rodents as hosts of Angiostrongylus costaricencis in southern Brazil].

Science.gov (United States)

Graeff-Teixeira, C; de Avila-Pires, F D; Machado, R de C; Camillo-Coura, L; Lenzi, H L

1990-01-01

Increasing number of human cases of abdominal angiostrongyliasis has been diagnosed in the south of Brazil. The main definitive host of Angiostrongylus costaricensis in Central America is the cotton rat (Sigmodon hispidus) that does not occur in South America, except in the north of Colombia, Peru and Venezuela. Rodents were captured in the endemic area in Rio Grande do Sul (RS) and definitive hosts were identified for the first time in Brazil: Oryzomys nigripes and Oryzomys ratticeps. O. nigripes is a small wild rodent and it appears to be the main definitive host of A. costaricensis in the highlands of RS, Brazil's southernmost State.

Sensing through friction: the biomechanics of texture perception in rodents and primates

Science.gov (United States)

Debrégeas, Georges; Boubenec, Yves

2015-10-01

Rodents and primates possess an exquisite tactile sensitivity, which allows them to extract a wealth of information about their immediate environment. They can distinguish subtle differences in surface roughness through tactile exploration in a much more precise way than they can do visually. In both sensory systems, tactile information is contained in the sequence of deformation of the tactile organ--the facial hair for rodents (the whiskers), the digital skin for primates -- elicited by active rubbing on the probed surface (Figure 8.1). These deformations, registered by mechanosensitive neurons located in inner tissues, are processed by the central nervous system to produce a sensory representation of the surface...

Systematic analysis of feeding behaviors and their effects on feed efficiency in Pekin ducks

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Feng Zhu

2017-11-01

Full Text Available Abstract Background Feeding behavior study is important for animal husbandry and production. However, few studies were conducted on the feeding behavior and their relationship with feeding efficiency in Pekin ducks. In order to investigate the feeding behavior and their relationship with feed efficiency and other economic traits in Pekin ducks, we selected 358 male Pekin ducks and recorded feeding information between 3 to 6 wk of age using automatic electronic feeders, and compared the feeding behavior under different residual feed intake (RFI levels. Results We observed that total feed time, daily feed intake and feed intake per meal had strong positive correlations with feed efficiency traits; moreover, strong correlation between feed intake per meal and body weight was found (R=0.32, 0.36. Daily feeding rate meal and meal duration had weak correlations with feed efficiency (R=0.14~0.15. The phenotypic correlation of between-meal pauses, with feed efficiency was not observed. When daily changes were analyzed, high RFI ducks had the highest feed consumption over all times, and obvious differences in daily visits were found among different RFI level animals during the middle period; these differences were magnified with age, but there was no difference in daily meal number. Moreover, our data indicate that high RFI birds mainly take their meals at the edge of the population enclosure, where they are more susceptible to environmental interference. Conclusions Overall, this study suggests that the general feeding behaviors can be accurately measured using automatic electronic feeders and certain feeding behaviors in Pekin ducks are associated with improved feed efficiency.

INFLUENCE OF FEEDING TIME ON FEED UTILIZATION BY SIAMESE CATFISH, Pangasius hypophthalmus JUVENILE

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Nina Meilisza

2010-06-01

Full Text Available Siamese catfish (Pangasius hypophthalmus at juvenile stage is used as ornamental fish by fish hobbies because of their beautiful shape and movement. Feeding time is a part of feeding management to get the best and effective strategy on feed input. This study aimed to determine the growth of Siamese catfish juvenile by looking at the influence of feeding time on feed utilization. The average individual weight of juveniles used was ± 3.2 g stocked 15 fish per aquarium equipped with recirculation system. Two level factors in the factorial design consisted of 4 feeding times (at 8:00, at 12:00, at 16:00, and as control (8:00, 12:00, 16:00 and feeding level (45 g feed kg-1 fish, 90 g feed kg-1 fish. Interaction between feeding time and feeding level resulting eight types of treatments research, namely A (8/45, B (12/45, C (16/45, D (8:12:16/45, E (8:12:16/90, F (8/90, G (12/90, and H (16/90. The results showed that feeding time had significant effect on the specific growth rate, feed conversion, and protein efficiency ratio and were significantly different among the treatments (P<0.05. Besides feeding time control (treatments D and E, treatment C also showed the highest of specific growth rate (2.03%, protein efficiency ratio (1.46, and the lowest feed conversion ratio (1.85.

Feeding Ecology of Northeast Atlantic Mackerel, Norwegian Spring-Spawning Herring and Blue Whiting in the Norwegian Sea.

Directory of Open Access Journals (Sweden)

Eneko Bachiller

Full Text Available The Norwegian spring-spawning (NSS herring (Clupea harengus, blue whiting (Micromesistius poutassou and Northeast Atlantic (NEA mackerel (Scomber scombrus are extremely abundant pelagic planktivores that feed in the Norwegian Sea (NS during spring and summer. This study investigated the feeding ecology and diet composition of these commercially important fish stocks on the basis of biological data, including an extensive set of stomach samples in combination with hydrographical data, zooplankton samples and acoustic abundance data from 12 stock monitoring surveys carried out in 2005-2010. Mackerel were absent during the spring, but had generally high feeding overlap with herring in the summer, with a diet mainly based on calanoid copepods, especially Calanus finmarchicus, as well as a similar diet width. Stomach fullness in herring diminished from spring to summer and feeding incidence was lower than that of mackerel in summer. However, stomach fullness did not differ between the two species, indicating that herring maintain an equally efficient pattern of feeding as mackerel in summer, but on a diet that is less dominated by copepods and is more reliant on larger prey. Blue whiting tended to have a low dietary overlap with mackerel and herring, with larger prey such as euphausiids and amphipods dominating, and stomach fullness and feeding incidence increasing with length. For all the species, feeding incidence increased with decreasing temperature, and for mackerel so did stomach fullness, indicating that feeding activity is highest in areas associated with colder water masses. Significant annual effects on diet composition and feeding-related variables suggested that the three species are able to adapt to different food and environmental conditions. These annual effects are likely to have an important impact on the predation pressure on different plankton groups and the carrying capacity of individual systems, and emphasise the importance of

Feeding Ecology of Northeast Atlantic Mackerel, Norwegian Spring-Spawning Herring and Blue Whiting in the Norwegian Sea.

Science.gov (United States)

Bachiller, Eneko; Skaret, Georg; Nøttestad, Leif; Slotte, Aril

2016-01-01

The Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and Northeast Atlantic (NEA) mackerel (Scomber scombrus) are extremely abundant pelagic planktivores that feed in the Norwegian Sea (NS) during spring and summer. This study investigated the feeding ecology and diet composition of these commercially important fish stocks on the basis of biological data, including an extensive set of stomach samples in combination with hydrographical data, zooplankton samples and acoustic abundance data from 12 stock monitoring surveys carried out in 2005-2010. Mackerel were absent during the spring, but had generally high feeding overlap with herring in the summer, with a diet mainly based on calanoid copepods, especially Calanus finmarchicus, as well as a similar diet width. Stomach fullness in herring diminished from spring to summer and feeding incidence was lower than that of mackerel in summer. However, stomach fullness did not differ between the two species, indicating that herring maintain an equally efficient pattern of feeding as mackerel in summer, but on a diet that is less dominated by copepods and is more reliant on larger prey. Blue whiting tended to have a low dietary overlap with mackerel and herring, with larger prey such as euphausiids and amphipods dominating, and stomach fullness and feeding incidence increasing with length. For all the species, feeding incidence increased with decreasing temperature, and for mackerel so did stomach fullness, indicating that feeding activity is highest in areas associated with colder water masses. Significant annual effects on diet composition and feeding-related variables suggested that the three species are able to adapt to different food and environmental conditions. These annual effects are likely to have an important impact on the predation pressure on different plankton groups and the carrying capacity of individual systems, and emphasise the importance of regular

The uniqueness of the regularization procedure

International Nuclear Information System (INIS)

Brzezowski, S.

1981-01-01

On the grounds of the BPHZ procedure, the criteria of correct regularization in perturbation calculations of QFT are given, together with the prescription for dividing the regularized formulas into the finite and infinite parts. (author)

STATUS OF COMMENSAL RODENT -BORNE DISEASES RESEARCH IN INDONESIA

Directory of Open Access Journals (Sweden)

Lim Boo Liat

2012-09-01

Full Text Available Rodents yang terdapat di rumah-rumah maupun di lapangan mempunyai peranan penting dalam penyebaran penyakit terhadap manusia dan binatang. Dalam tulisan ini disajikan peninjauan kembali literatur tentang penyakit-penyakit yang ditularkan oleh binatang, seperti : plague, scrub and murine typhus, leptospirosis, schistosomiasis, angiostrongyliasis, yang biaya terdapat di Indonesia.

Animal Feeding Operations

Science.gov (United States)

... type=”submit” value=”Submit” /> Healthy Water Home Animal Feeding Operations Recommend on Facebook Tweet Share Compartir ... of Concentrated Animal Feeding Operations (CAFOs) What are Animal Feeding Operations (AFOs)? According to the United States ...

Unpredictability of escape trajectory explains predator evasion ability and microhabitat preference of desert rodents.

Science.gov (United States)

Moore, Talia Y; Cooper, Kimberly L; Biewener, Andrew A; Vasudevan, Ramanarayan

2017-09-05

Mechanistically linking movement behaviors and ecology is key to understanding the adaptive evolution of locomotion. Predator evasion, a behavior that enhances fitness, may depend upon short bursts or complex patterns of locomotion. However, such movements are poorly characterized by existing biomechanical metrics. We present methods based on the entropy measure of randomness from Information Theory to quantitatively characterize the unpredictability of non-steady-state locomotion. We then apply the method by examining sympatric rodent species whose escape trajectories differ in dimensionality. Unlike the speed-regulated gait use of cursorial animals to enhance locomotor economy, bipedal jerboa (family Dipodidae) gait transitions likely enhance maneuverability. In field-based observations, jerboa trajectories are significantly less predictable than those of quadrupedal rodents, likely increasing predator evasion ability. Consistent with this hypothesis, jerboas exhibit lower anxiety in open fields than quadrupedal rodents, a behavior that varies inversely with predator evasion ability. Our unpredictability metric expands the scope of quantitative biomechanical studies to include non-steady-state locomotion in a variety of evolutionary and ecologically significant contexts.Biomechanical understanding of animal gait and maneuverability has primarily been limited to species with more predictable, steady-state movement patterns. Here, the authors develop a method to quantify movement predictability, and apply the method to study escape-related movement in several species of desert rodents.

Coupling regularizes individual units in noisy populations

International Nuclear Information System (INIS)

Ly Cheng; Ermentrout, G. Bard

2010-01-01

The regularity of a noisy system can modulate in various ways. It is well known that coupling in a population can lower the variability of the entire network; the collective activity is more regular. Here, we show that diffusive (reciprocal) coupling of two simple Ornstein-Uhlenbeck (O-U) processes can regularize the individual, even when it is coupled to a noisier process. In cellular networks, the regularity of individual cells is important when a select few play a significant role. The regularizing effect of coupling surprisingly applies also to general nonlinear noisy oscillators. However, unlike with the O-U process, coupling-induced regularity is robust to different kinds of coupling. With two coupled noisy oscillators, we derive an asymptotic formula assuming weak noise and coupling for the variance of the period (i.e., spike times) that accurately captures this effect. Moreover, we find that reciprocal coupling can regularize the individual period of higher dimensional oscillators such as the Morris-Lecar and Brusselator models, even when coupled to noisier oscillators. Coupling can have a counterintuitive and beneficial effect on noisy systems. These results have implications for the role of connectivity with noisy oscillators and the modulation of variability of individual oscillators.

Learning regularization parameters for general-form Tikhonov

International Nuclear Information System (INIS)

Chung, Julianne; Español, Malena I

2017-01-01

Computing regularization parameters for general-form Tikhonov regularization can be an expensive and difficult task, especially if multiple parameters or many solutions need to be computed in real time. In this work, we assume training data is available and describe an efficient learning approach for computing regularization parameters that can be used for a large set of problems. We consider an empirical Bayes risk minimization framework for finding regularization parameters that minimize average errors for the training data. We first extend methods from Chung et al (2011 SIAM J. Sci. Comput. 33 3132–52) to the general-form Tikhonov problem. Then we develop a learning approach for multi-parameter Tikhonov problems, for the case where all involved matrices are simultaneously diagonalizable. For problems where this is not the case, we describe an approach to compute near-optimal regularization parameters by using operator approximations for the original problem. Finally, we propose a new class of regularizing filters, where solutions correspond to multi-parameter Tikhonov solutions, that requires less data than previously proposed optimal error filters, avoids the generalized SVD, and allows flexibility and novelty in the choice of regularization matrices. Numerical results for 1D and 2D examples using different norms on the errors show the effectiveness of our methods. (paper)

Emmonsiosis of subterranean rodents (Bathyergidae, Spalacidae) in Africa and Israel

Czech Academy of Sciences Publication Activity Database

Hubálek, Zdeněk; Burda, H.; Scharff, A.; Heth, G.; Nevo, E.; Šumbera, R.; Peško, Juraj; Zima, Jan

2005-01-01

Roč. 43, č. 8 (2005), s. 691-697 ISSN 1369-3786 Grant - others:DAAD(DE) 323-PPP-sp Institutional research plan: CEZ:AV0Z60930519 Keywords : adiasporomycosis * rodents Subject RIV: EG - Zoology Impact factor: 1.422, year: 2005

5 CFR 551.421 - Regular working hours.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Regular working hours. 551.421 Section... Activities § 551.421 Regular working hours. (a) Under the Act there is no requirement that a Federal employee... distinction based on whether the activity is performed by an employee during regular working hours or outside...

Regular extensions of some classes of grammars

NARCIS (Netherlands)

Nijholt, Antinus

Culik and Cohen introduced the class of LR-regular grammars, an extension of the LR(k) grammars. In this report we consider the analogous extension of the LL(k) grammers, called the LL-regular grammars. The relations of this class of grammars to other classes of grammars are shown. Every LL-regular

Regular non-twisting S-branes

International Nuclear Information System (INIS)

Obregon, Octavio; Quevedo, Hernando; Ryan, Michael P.

2004-01-01

We construct a family of time and angular dependent, regular S-brane solutions which corresponds to a simple analytical continuation of the Zipoy-Voorhees 4-dimensional vacuum spacetime. The solutions are asymptotically flat and turn out to be free of singularities without requiring a twist in space. They can be considered as the simplest non-singular generalization of the singular S0-brane solution. We analyze the properties of a representative of this family of solutions and show that it resembles to some extent the asymptotic properties of the regular Kerr S-brane. The R-symmetry corresponds, however, to the general lorentzian symmetry. Several generalizations of this regular solution are derived which include a charged S-brane and an additional dilatonic field. (author)

LATE PLEISTOCENE RODENTS (MAMMALIA: RODENTIA FROM THE BARANICA CAVE NEAR KNJAZEVAC (EASTERN SERBIA: SYSTEMATICS AND PALAEOECOLOGY

Directory of Open Access Journals (Sweden)

KATARINA BOGICEVIC

2011-07-01

Full Text Available Baranica is a cave in the Balkan mountain range in the eastern part of Serbia. It contains four layers of sediments of Quaternary age. The Upper Pleistocene deposits (layers 2-4 have yielded a rich and diverse assemblage of vertebrate fauna, including fish, amphibians, reptiles, birds, and small and large mammals. In this work, preliminary results of a study of the rodent fauna from the Upper Pleistocene deposits of the Baranica Cave (Knjazevac, eastern Serbia are presented. The fossil material comes from the 1995 archaeological excavation. The remains of 10 rodent species are described herein: Spermophilus cf. citelloides, Castor fiber, Sicista subtilis, Cricetulus migratorius, Cricetus cricetus, Mesocricetus newtoni, Apodemus ex gr. sylvaticus-flavicollis, Spalax leucodon, Dryomys nitedula, and Muscardinus avellanarius. Along with eight vole species, this makes altogether 18 species of rodents found in this locality. Both layers 2 and 4 (layer 3 is very poor in fossils have yielded a rodent fauna typical for the cold periods of the Late Pleistocene on the Balkan Peninsula, with a prevalence of open and steppe inhabitants, but some forest dwellers were also present. The assemblages from these layers are similar, but there are some differences in the composition of the fauna, which may indicate a slight shift towards drier conditions. They have also been compared to rodent associations from some Serbian and Bulgarian localities of the same age and their similarities and differences are discussed. SHORT NOTE-NOTA BREVE

Qualitative analysis of subcutaneous Lispro and regular insulin injections for stress hyperglycemia: a pilot numerical study.

Science.gov (United States)

Strilka, Richard J; Armen, Scott B; Indeck, Matthew C

2014-09-07

Increased glucose variability (GV) is an independent risk factor for mortality in the critically ill; unfortunately, the optimal insulin therapy that minimizes GV is not known. We simulate the glucose-insulin feedback system to study how stress hyperglycemia (SH) states, taken to be a non-uniform group of physiologic disorders with varying insulin resistance (IR) and similar levels of hyperglycemia, respond to the type and dose of subcutaneous (SQ) insulin. Two groups of 100 virtual patients are studied: those receiving and those not receiving continuous enteral feeds. Stress hyperglycemia was facilitated by doubling the gluconeogenesis rate and IR was stepwise varied from a borderline to a high value. Lispro and regular insulin were simulated with dosages that ranged from 0 to 6 units; the resulting GV was analyzed after each insulin injection. The numerical model used consists of a set of non-linear differential equations with two time delays and five adjustable parameters. The results show that regular insulin decreased GV in both patient groups and rarely caused hypoglycemia. With continuous enteral feeds and borderline to mild IR, Lispro showed minimal effect on GV; however, rebound hyperglycemia that increased GV occurred when the IR was moderate to high. Without a nutritional source, Lispro worsened GV through frequent hypoglycemia episodes as the injection dose increased. The inferior performance of Lispro is a result of its rapid absorption profile; half of its duration of action is similar to the glucose ultradian period. Clinical trials are needed to examine whether these numerical results represent the glucose-insulin dynamics that occur in intensive care units, and if such dynamics are present, their clinical effects should be evaluated. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Molecular identification of Taenia mustelae cysts in subterranean rodent plateau zokors (Eospalax baileyi).

Science.gov (United States)

Zhao, Fang; Ma, Jun-Ying; Cai, Hui-Xia; Su, Jian-Ping; Hou, Zhi-Bin; Zhang, Tong-Zuo; Lin, Gong-Hua

2014-07-01

Cestode larvae spend one phase of their two-phase life cycle in the viscera of rodents, but cases of cestodes infecting subterranean rodents have only been rarely observed. To experimentally gain some insight into this phenomenon, we captured approximately 300 plateau zokors (Eospalax baileyi), a typical subterranean rodent inhabiting the Qinghai-Tibet Plateau, and examined their livers for the presence of cysts. Totally, we collected five cysts, and using a mitochondrial gene (cox1) and two nuclear genes (pepck and pold) as genetic markers, we were able to analyze the taxonomy of the cysts. Both the maximum likelihood and Bayesian methods showed that the cysts share a monophyly with Taenia mustelae, while Kimura 2-parameter distances and number of different sites between our sequences and T. mustelae were far less than those found between the examined sequences and other Taeniidae species. These results, alongside supporting paraffin section histology, imply that the cysts found in plateau zokors can be regarded as larvae of T. mustelae, illustrating that zokors are a newly discovered intermediate host record of this parasite.

Feeding Your Baby

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Full Text Available ... care Is it safe? Labor & birth Postpartum care Baby Caring for your baby Feeding your baby Family ... community Home > Baby > Feeding your baby Feeding your baby E-mail to a friend Please fill in ...

Feeding Your Baby

Medline Plus

Full Text Available ... our online community Home > Baby > Feeding your baby Feeding your baby E-mail to a friend Please ... been added to your dashboard . Time to eat! Feeding your baby helps her grow healthy and strong. ...

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

Science.gov (United States)

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

2015-01-01

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

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

Directory of Open Access Journals (Sweden)

Gauthier Dobigny

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

Short Communications

African Journals Online (AJOL)

densities, diet composition, seed predation by captive rodents and published .... Although small, this was a suituble sample size, since the percenwge of prey ... in the wild after 4 days, and rodent feeding preference for Acacia seeds. (Kelnck ef at. ..... rodents. birds and ants: the relationship of seed auributes and seed usc.

Near-Regular Structure Discovery Using Linear Programming

KAUST Repository

Huang, Qixing

2014-06-02

Near-regular structures are common in manmade and natural objects. Algorithmic detection of such regularity greatly facilitates our understanding of shape structures, leads to compact encoding of input geometries, and enables efficient generation and manipulation of complex patterns on both acquired and synthesized objects. Such regularity manifests itself both in the repetition of certain geometric elements, as well as in the structured arrangement of the elements. We cast the regularity detection problem as an optimization and efficiently solve it using linear programming techniques. Our optimization has a discrete aspect, that is, the connectivity relationships among the elements, as well as a continuous aspect, namely the locations of the elements of interest. Both these aspects are captured by our near-regular structure extraction framework, which alternates between discrete and continuous optimizations. We demonstrate the effectiveness of our framework on a variety of problems including near-regular structure extraction, structure-preserving pattern manipulation, and markerless correspondence detection. Robustness results with respect to geometric and topological noise are presented on synthesized, real-world, and also benchmark datasets. © 2014 ACM.

Regular Expression Matching and Operational Semantics

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Asiri Rathnayake

2011-08-01

Full Text Available Many programming languages and tools, ranging from grep to the Java String library, contain regular expression matchers. Rather than first translating a regular expression into a deterministic finite automaton, such implementations typically match the regular expression on the fly. Thus they can be seen as virtual machines interpreting the regular expression much as if it were a program with some non-deterministic constructs such as the Kleene star. We formalize this implementation technique for regular expression matching using operational semantics. Specifically, we derive a series of abstract machines, moving from the abstract definition of matching to increasingly realistic machines. First a continuation is added to the operational semantics to describe what remains to be matched after the current expression. Next, we represent the expression as a data structure using pointers, which enables redundant searches to be eliminated via testing for pointer equality. From there, we arrive both at Thompson's lockstep construction and a machine that performs some operations in parallel, suitable for implementation on a large number of cores, such as a GPU. We formalize the parallel machine using process algebra and report some preliminary experiments with an implementation on a graphics processor using CUDA.

Factors associated with flea infestation among the different rodent ...

African Journals Online (AJOL)

Flea infection with the bacterium, Yersinia pestis is acquired from reservoirs which include several rodents and other small mammals. In areas that are endemic of plague, reservoirs of Y. pestis and various flea vectors are responsible for perpetuating existence of the disease. The objective of this cross sectional study was to ...

Tetravalent one-regular graphs of order 4p2

DEFF Research Database (Denmark)

Feng, Yan-Quan; Kutnar, Klavdija; Marusic, Dragan

2014-01-01

A graph is one-regular if its automorphism group acts regularly on the set of its arcs. In this paper tetravalent one-regular graphs of order 4p2, where p is a prime, are classified.......A graph is one-regular if its automorphism group acts regularly on the set of its arcs. In this paper tetravalent one-regular graphs of order 4p2, where p is a prime, are classified....

Influence of parasitism on the use of small terrestrial rodents in environmental pollution monitoring

Energy Technology Data Exchange (ETDEWEB)

Jankovska, Ivana, E-mail: jankovska@af.czu.c [Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamycka 129, 165 21 Prague 6 - Suchdol (Czech Republic); Miholova, Daniela [Department of Chemistry, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamycka 129, 165 21 Prague 6 - Suchdol (Czech Republic); Langrova, Iva [Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamycka 129, 165 21 Prague 6 - Suchdol (Czech Republic); Bejcek, Vladimir [Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences, Kamycka 129, 165 21 Prague 6 - Suchdol (Czech Republic); Vadlejch, Jaroslav [Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamycka 129, 165 21 Prague 6 - Suchdol (Czech Republic); Kolihova, Dana; Sulc, Miloslav [Department of Chemistry, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamycka 129, 165 21 Prague 6 - Suchdol (Czech Republic)

2009-08-15

Bioaccumulation of cadmium, chromium, copper, manganese, nickel, lead and zinc in small terrestrial rodents - voles and their cestode parasite Paranoplocephala dentata was studied. Contents of Pb, Mn, Ni and Zn in the parasite were found to be higher than in the kidney and liver of the parasitized animals. Lead level in the cestode was 37 fold higher than in the liver of the infected rodents. Bioaccumulation factors of zinc, nickel and manganese in the cestode are mostly in the range from 2 to 4.5. Considering the different contents of manganese and zinc in livers of non-parasitized and parasitized rodents, kidney tissue was found to be more reliable than liver as an indicator of environmental pollution by manganese and zinc; the kidneys of parasitized animals showed no significant change in the concentrations of those elements that are accumulated in the cestode. - Liver tissue from voles infected by Paranoplocephala dentata was less suitable as a biomonitor for metal contamination than kidney tissue.

A macroecological glance at the structure of late Miocene rodent assemblages from Southwest Europe

Science.gov (United States)

Cano, Ana Rosa Gómez; Cantalapiedra, Juan L.; Álvarez-Sierra, M. Ángeles; Fernández, Manuel Hernández

2014-10-01

Deep-time perspectives in macroecology are essential with regard to understanding the impact of climate forcing on faunal communities. Using late Miocene rodent faunas (12 to 5 Ma) from two different biogeographical provinces from southwestern Europe, we asked whether the waxing and waning of faunas with dissimilar ecological affinities tracked climate in different ways. The latest middle Miocene featured a fauna dominated by dormice with forest and mixed-habitat affinities. This group declined towards the Upper Miocene. Rodent taxa with the highest values of richness at the beginning of the Upper Miocene are generalists in the southern province and specialists of forested habitats in the northern province. Finally, we identified a third, increasingly significant group of rodents linked to open landscapes towards the end of the Miocene. These three broad ecological groups showed differential responses to a complex set of interconnected circumstances, including the biogeographic structure of the study area and climatic changes throughout time.

Rhipicephalus sanguineus sensu lato(Ixodidae in synantropic rodents in Rio Grande do Sul, Brazil

Directory of Open Access Journals (Sweden)

Kathleen Tavares Winkel

Full Text Available Rhipicephalus sanguineus, the brown dog tick, is responsible for maintaining and transmitting various pathogens, both in animals and human beings, and it is of great sanitary importance. This communication reports the first occurrence of Rhipicephalus sanguineus sensu lato parasitizing Rattus norvegicus in the state of Rio Grande do Sul, Brazil, and it is also the first record of this tick species parasitizing Rattus rattus in Brazil. The rodents were captured from the port area, located in the city of Pelotas, Rio Grande do Sul, Brazil. We collected 6 larvae of this tick species from 2 male R. rattus individuals, and 3 larvae from 2 female R. norvegicus individuals; parasitized specimens of both rodent species were captured from different sites within the experimental area. This record broadens the number of Rhipicephalus sanguineus sensu lato hosts in urban areas, indicating the need for continued monitoring on population density for both R. sanguineus and synanthropic rodents.

Ecology, genetic diversity, and phylogeographic structure of andes virus in humans and rodents in Chile.

Science.gov (United States)

Medina, Rafael A; Torres-Perez, Fernando; Galeno, Hector; Navarrete, Maritza; Vial, Pablo A; Palma, R Eduardo; Ferres, Marcela; Cook, Joseph A; Hjelle, Brian

2009-03-01

Andes virus (ANDV) is the predominant etiologic agent of hantavirus cardiopulmonary syndrome (HCPS) in southern South America. In Chile, serologically confirmed human hantavirus infections have occurred throughout a wide latitudinal distribution extending from the regions of Valparaíso (32 to 33 degrees S) to Aysén (46 degrees S) in southern Patagonia. In this study, we found seropositive rodents further north in the Coquimbo region (30 degrees S) in Chile. Rodent seroprevalence was 1.4%, with Oligoryzomys longicaudatus displaying the highest seroprevalence (5.9%), followed by Abrothrix longipilis (1.9%) and other species exhibiting Chile. Phylogenetic analyses showed two major ANDV South (ANDV Sout) clades, congruent with two major Chilean ecoregions, Mediterranean (Chilean matorral [shrubland]) and Valdivian temperate forest. Human and rodent samples grouped according to geographic location. Phylogenetic comparative analyses of portions of S and medium segments (encoding glycoproteins Gn and Gc) from a subset of rodent specimens exhibited similar topologies, corroborating two major ANDV Sout clades in Chile and suggesting that yet unknown factors influence viral gene flow and persistence throughout the two Chilean ecoregions. Genetic algorithms for recombination detection identified recombination events within the S segment. Molecular demographic analyses showed that the virus is undergoing purifying selection and demonstrated a recent exponential growth in the effective number of ANDV Sout infections in Chile that correlates with the increased number of human cases reported. Although we determined virus sequences from four rodent species, our results confirmed O. longicaudatus as the primary ANDV Sout reservoir in Chile. While evidence of geographic differentiation exists, a single cosmopolitan lineage of ANDV Sout remains the sole etiologic agent for HCPS in Chile.

Occurrence of ochratoxin A in poultry feeds and feed ingredients from Pakistan.

Science.gov (United States)

Sherazi, S T H; Shar, Z H; Sumbal, G A; Tan, Eddie T; Bhanger, M I; Kara, Huseyin; Nizamani, S M

2015-02-01

A study was conducted to evaluate the occurrence of ochratoxin A (OTA) in complete poultry feeds (n=80) and poultry feed ingredients (n=286) from Pakistan. All samples were first analyzed by indirect enzyme linked immunosorbent assay (ELISA), samples with OTA concentrations above the European Union maximum regulatory limit (MRL, 100 μg/kg) were further confirmed by HPLC-FLD. Contamination frequency and mean OTA levels were 31% and 51 μg/kg in feed ingredients, and the corresponding values for complete feeds were 38% and 75 μg/kg. Ten samples of complete poultry feed and 19 samples of feed ingredients contained OTA at levels higher than the MRL. The results of the present study indicate that there is a strong need for a more intense monitoring programs for OTA in poultry feed.

Regularization and error assignment to unfolded distributions

CERN Document Server

Zech, Gunter

2011-01-01

The commonly used approach to present unfolded data only in graphical formwith the diagonal error depending on the regularization strength is unsatisfac-tory. It does not permit the adjustment of parameters of theories, the exclusionof theories that are admitted by the observed data and does not allow the com-bination of data from different experiments. We propose fixing the regulariza-tion strength by a p-value criterion, indicating the experimental uncertaintiesindependent of the regularization and publishing the unfolded data in additionwithout regularization. These considerations are illustrated with three differentunfolding and smoothing approaches applied to a toy example.

Hantavirus Immunology of Rodent Reservoirs: Current Status and Future Directions

Directory of Open Access Journals (Sweden)

Tony Schountz

2014-03-01

Full Text Available Hantaviruses are hosted by rodents, insectivores and bats. Several rodent-borne hantaviruses cause two diseases that share many features in humans, hemorrhagic fever with renal syndrome in Eurasia or hantavirus cardiopulmonary syndrome in the Americas. It is thought that the immune response plays a significant contributory role in these diseases. However, in reservoir hosts that have been closely examined, little or no pathology occurs and infection is persistent despite evidence of adaptive immune responses. Because most hantavirus reservoirs are not model organisms, it is difficult to conduct meaningful experiments that might shed light on how the viruses evade sterilizing immune responses and why immunopathology does not occur. Despite these limitations, recent advances in instrumentation and bioinformatics will have a dramatic impact on understanding reservoir host responses to hantaviruses by employing a systems biology approach to identify important pathways that mediate virus/reservoir relationships.

Ventilation of multi-entranced rodent burrows by boundary layer eddies.

Science.gov (United States)

Brickner-Braun, Inbal; Zucker-Milwerger, Daniel; Braun, Avi; Turner, J Scott; Pinshow, Berry; Berliner, Pedro

2014-12-01

Rodent burrows are often assumed to be environments wherein the air has a high concentration of CO₂. Although high burrow [CO₂] has been recorded, many studies report burrow [CO₂] that differs only slightly from atmospheric concentrations. Here, we advocate that one of the reasons for these differences is the penetration into burrows of air gusts (eddies), which originate in the turbulent boundary layer and prevent build-up of CO₂. We have characterized the means by which burrows of Sundevall's jird, which are representative of the burrows of many rodent species with more than one entrance, are ventilated. Our results demonstrate that, even at low wind speeds, the random penetration of eddies into a burrow through its openings is sufficient to keep the burrow [CO₂] low enough to be physiologically inconsequential, even in its deep and remote parts. © 2014. Published by The Company of Biologists Ltd.

Parent-reported feeding and feeding problems in a sample of Dutch toddlers

NARCIS (Netherlands)

Moor, J.M.H. de; Didden, H.C.M.; Korzilius, H.P.L.M.

2007-01-01

Little is known about the feeding behaviors and problems with feeding in toddlers. In the present questionnaire study, data were collected on the feeding behaviors and feeding problems in a relatively large (n = 422) sample of Dutch healthy toddlers (i.e. 18-36 months old) who lived at home with

Evaluation of PCDD/Fs characterization in animal feed and feed additives.

Science.gov (United States)

Kim, MeeKyung; Kim, Sooyeon; Yun, Seon Jong; Kwon, Jin-Wook; Son, Seong-Wan

2007-09-01

Safety control of feed and feed additives is necessary to have safe food of animal origin. Based on media reports, nine incidents regarding dioxins and/or PCBs contaminations occurred worldwide during the last decade. Korea is a country which imports feed and feed additives. In this study, various kinds of feed and feed additives were analyzed to monitor the contamination level of dioxins. The level of PCDD/Fs in fish oil was the highest with a concentration of 23.33ngkg(-1), which is equivalent to a toxicological concentration of 4.68ngWHO-TEQ/kg. Feed from animals origin such as chicken meal, animal fat, fish meal, fish oil, and shell powder showed relatively higher concentrations of PCDD/Fs. Feed from plants origin, minerals, and additives ranged from non-detects for bit pulp and ethoxyquin to 8.28ngkg(-1) for dl-methionine. From a toxicological point of view, the highest concentration in vitamins was 0.08ngWHO-TEQ/kg among the feed additives. 2,3,4,7,8-PeCDF was the dominant congener in samples of fish oil, fish meal, and shell powder. Animal fat showed that the pattern of PCDD/Fs depends on the sources of contamination. A sample of animal fat showed 1,2,3,4,7,8-HxCDF and the other sample showed 1,2,3,4,7,8-HxCDD as a primary congener. Generally, low levels of PCDDs were detected in feed additives. Patterns of PCDD/Fs in choline chloride were different with that in choline chloride from an incident in Europe in 2000.

Prevalence of leptospiral DNA among wild rodents from a selected area in Beguk Dam Labis, Segamat, Johor, Malaysia.

Science.gov (United States)

Latifah, I; Rahmat, M S; Hayarti, K B; Paramasvaran, S; Azizah, M R; Imran, F; Normaznah, Y

2012-12-01

Leptospirosis is an emerging infectious disease. The differential diagnosis of leptospirosis is difficult due to the varied and often "flu like" symptoms which may result in a missed or delayed diagnosis. Leptospira is the aetiological agent of leptospirosis, a bacterial zoonosis with worldwide distribution. There are over 230 known serovars in the genus Leptospira. The true prevalence of leptospirosis in Malaysia is unknown or underestimated. Our goal was to determine the prevalence for Leptospira infection in rodents in a selected area in Beguk Dam Labis, Segamat, Johor. A study was carried out on 69 serum samples of trapped wild rodents. DNA was extracted from the sera using Leptospira PCR kit (Shanghai ZJ Bio-Tech Co., Ltd). Of 69 rodent serum samples tested by PCR, 9 (13%) showed positive results. In this study we found that (13%) of wild rodents caught in Beguk Dam Labis were infected by Leptospira.

Prevalence of infection with hantavirus in rodent populations of central Argentina

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Olga V Suárez

2003-09-01

Full Text Available We studied hantavirus seroprevalence and virus variability in rodent populations in Diego Gaynor, northwest of Buenos Aires province, Argentina. Rodent samplings were conducted in railroads and cropfield borders in March and July 1999, September and December 2000, and March 2001. Antibody detection was performed by an enzyme link immunosorbent assay (ELISA, using the recombinant nucleoprotein of Andes (AND virus as antigen. Tissue samples were taken from positive antibody individuals in order to confirm the presence of hantavirus genomic material and to identify virus genotypes. Akodon azarae was the most abundant species, followed by Oligoryzomys flavescens, while Calomys laucha and C. musculinus were rarely caught. We found a rate of seroprevalence of 9.3% for a total sample of 291 A. azarae and 13.5% for 37 O. flavescens. After molecular analyses of hantavirus, we confirmed the presence of hantavirus genomic material in 16 individuals with ELISA (+ results and two individuals with ELISA (-. Four amplimers for each species were sequenced and compared to the corresponding sequences of representative hantaviruses. We identified the AND Cent Lec from three O. flavescens, and the Pergamino virus from four A. azarae and from one O. flavescens. A. azarae males had higher seroprevalence than females, and heavier individuals showed higher seroprevalence than lighter ones. We did not find seroprevalence differences according to sex in O. flavescens, although this result may have been produced by the low sample size. The lowest seroprevalence was found in a period of high rodent density, when juveniles prevailed in the population. We found higher seroprevalences than those detected in previous studies for other localities of central Argentina where cases of hantavirus pulmonary syndrome (HPS have been reported. The presence of AND Cent Lec virus in rodent populations of the study area, which is responsible of HPS cases in central Argentina, suggests

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

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Charles C Horn

Full Text Available 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.

Higher order total variation regularization for EIT reconstruction.

Science.gov (United States)

Gong, Bo; Schullcke, Benjamin; Krueger-Ziolek, Sabine; Zhang, Fan; Mueller-Lisse, Ullrich; Moeller, Knut

2018-01-08

Electrical impedance tomography (EIT) attempts to reveal the conductivity distribution of a domain based on the electrical boundary condition. This is an ill-posed inverse problem; its solution is very unstable. Total variation (TV) regularization is one of the techniques commonly employed to stabilize reconstructions. However, it is well known that TV regularization induces staircase effects, which are not realistic in clinical applications. To reduce such artifacts, modified TV regularization terms considering a higher order differential operator were developed in several previous studies. One of them is called total generalized variation (TGV) regularization. TGV regularization has been successively applied in image processing in a regular grid context. In this study, we adapted TGV regularization to the finite element model (FEM) framework for EIT reconstruction. Reconstructions using simulation and clinical data were performed. First results indicate that, in comparison to TV regularization, TGV regularization promotes more realistic images. Graphical abstract Reconstructed conductivity changes located on selected vertical lines. For each of the reconstructed images as well as the ground truth image, conductivity changes located along the selected left and right vertical lines are plotted. In these plots, the notation GT in the legend stands for ground truth, TV stands for total variation method, and TGV stands for total generalized variation method. Reconstructed conductivity distributions from the GREIT algorithm are also demonstrated.

Application of Turchin's method of statistical regularization

Science.gov (United States)

Zelenyi, Mikhail; Poliakova, Mariia; Nozik, Alexander; Khudyakov, Alexey

2018-04-01

During analysis of experimental data, one usually needs to restore a signal after it has been convoluted with some kind of apparatus function. According to Hadamard's definition this problem is ill-posed and requires regularization to provide sensible results. In this article we describe an implementation of the Turchin's method of statistical regularization based on the Bayesian approach to the regularization strategy.

Sex differences in chronic stress effects on cognition in rodents.

Science.gov (United States)

Luine, Victoria; Gomez, Juan; Beck, Kevin; Bowman, Rachel

2017-01-01

Chronic stress causes deleterious changes in physiological function in systems ranging from neural cells in culture to laboratory rodents, sub-human primates and humans. It is notable, however, that the vast majority of research in this area has been conducted in males. In this review, we provide information about chronic stress effects on cognition in female rodents and contrast it with responses in male rodents. In general, females show cognitive resilience to chronic stressors which impair male cognitive function using spatial tasks including the radial arm maze, radial arm water maze, Morris water maze, Y-maze and object placement. Moreover, stress often enhances female performance in some of these cognitive tasks. Memory in females is not affected by stress in non-spatial memory tasks like recognition memory and temporal order recognition memory while males show impaired memory following stress. We discuss possible bases for these sex-dependent differences including the use of different strategies by the sexes to solve cognitive tasks. Whether the sex differences result from changes in non-mnemonic factors is also considered. Sex-dependent differences in alcohol and drug influences on stress responses are also described. Finally, the role of neurally derived estradiol in driving sex differences and providing resilience to stress in females is shown. The importance of determining the nature and extent of sex differences in stress responses is that such differences may provide vital information for understanding why some stress related diseases have different incidence rates between the sexes and for developing novel therapeutic treatments. Copyright © 2016 Elsevier Inc. All rights reserved.

Organic Poultry Feeding

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Arda Yıldırım

2014-02-01

Full Text Available Many people have led to the consumption of organic animal products in the event that the increase in sensitivity to a healthy diet in developed countries, and maintaining the safety of food of animal origin. Feeding and breeding in conventional production are emerged some of the negative effects and also it is more in organic production with new restrictions. Organic production is based on animal welfare. On the basis of behaviors such as feather-pecking and cannibalism known to be low in protein level of rations and unbalanced in terms of amino acids or minerals. As of 2015, organic poultry feed provided the appropriate conditions that will be 95% organic certified in Turkey and therefore, to create a balanced ration and feed hygiene in protecting brings serious challenges. Fodder supply of organic poultry feed raw materials that make up the quality, quantity and issue forms a significant effect on the health of the poultry additives permitted. The quality of the feed raw materials that constituent diets, quantity, feed supplying form and permitted feed additives significantly affects the health of poultry. Different physiological stages of the animal's nutritional requirements in order to ensure production of quality poultry products must be met from organically produced and very well-known with the contents of feedstuff digestibility. In this study, the problems encountered in feeding can be eliminated while performing economic production with considering animal welfare, following that balanced and adequate organic ration formulations and issues such as improving the production of feed raw materials are discussed.

Effects of Mycotoxin Sequestering Agents Added Into Feed on Health, Reproduction and Milk Yield of Dairy Cattle

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Michal Hulík

2014-01-01

Full Text Available Effects of mycotoxin sequestering agents in feed on health, reproduction and milk yield of dairy cattle were studied in a 5-month long experiment on 300 dairy cows divided into two groups and six subgroups. The experiment was conducted in adding a mycotoxin sequestering agent based on 1,3 and 1,6 β-glucans to standard cattle nutrition (TMR, which was regularly tested for content of important mycotoxins, in order to gain knowledge about possible positive effect of this agent on the health of dairy cattle and about possible avoidance of negative effects of mycotoxins on dairy cattle due to their structural elimination caused by the agent. The experiment’s setting and conditions during it were in all aspects common and comparable within the European Union, the experiment’s results should be therefore seen as relevant. Health, pregnancy rate and milk yield were carefully monitored during the experiment. Indicators of state of health (occurrence of mastitis and somatic cell count in milk did not show any significant differences between test and control groups of dairy cows. The average milk yield of dairy cows which were fed the agent enriched feed (30.2 kg a day was slightly lower in comparison to control groups (31 kg a day, both results with P < 0.001, however, fat content of milk of test groups’ cows (4.02% was considerably higher than that of control groups’ cows (3.79%. The average pregnancy rate of cows which were fed the agent enriched feed also manifested considerable increase in percentage and stability (from 42.95% of control groups’ cows to 62.25% of test groups’ cows, the standard deviation decreased from 21.1% to 14.4% which means smaller differences among pregnancy rate of test groups’ cows, hence higher stability, this increase manifested even long after the cows had been fed regular feed again.

Ghrelin influences novelty seeking behavior in rodents and men.

Science.gov (United States)

Hansson, Caroline; Shirazi, Rozita H; Näslund, Jakob; Vogel, Heike; Neuber, Corinna; Holm, Göran; Anckarsäter, Henrik; Dickson, Suzanne L; Eriksson, Elias; Skibicka, Karolina P

2012-01-01

Recent discoveries indicate an important role for ghrelin in drug and alcohol reward and an ability of ghrelin to regulate mesolimbic dopamine activity. The role of dopamine in novelty seeking, and the association between this trait and drug and alcohol abuse, led us to hypothesize that ghrelin may influence novelty seeking behavior. To test this possibility we applied several complementary rodent models of novelty seeking behavior, i.e. inescapable novelty-induced locomotor activity (NILA), novelty-induced place preference and novel object exploration, in rats subjected to acute ghrelin receptor (growth hormone secretagogue receptor; GHSR) stimulation or blockade. Furthermore we assessed the possible association between polymorphisms in the genes encoding ghrelin and GHSR and novelty seeking behavior in humans. The rodent studies indicate an important role for ghrelin in a wide range of novelty seeking behaviors. Ghrelin-injected rats exhibited a higher preference for a novel environment and increased novel object exploration. Conversely, those with GHSR blockade drastically reduced their preference for a novel environment and displayed decreased NILA. Importantly, the mesolimbic ventral tegmental area selective GHSR blockade was sufficient to reduce the NILA response indicating that the mesolimbic GHSRs might play an important role in the observed novelty responses. Moreover, in untreated animals, a striking positive correlation between NILA and sucrose reward behavior was detected. Two GHSR single nucleotide polymorphisms (SNPs), rs2948694 and rs495225, were significantly associated with the personality trait novelty seeking, as assessed using the Temperament and Character Inventory (TCI), in human subjects. This study provides the first evidence for a role of ghrelin in novelty seeking behavior in animals and humans, and also points to an association between food reward and novelty seeking in rodents.

[11 C]Rhodamine-123: Synthesis and biodistribution in rodents

International Nuclear Information System (INIS)

Bao Xiaofeng; Lu Shuiyu; Liow, Jeih-San; Morse, Cheryl L.; Anderson, Kacey B.; Zoghbi, Sami S.; Innis, Robert B.; Pike, Victor W.

2012-01-01

Introduction: Rhodamine-123 is a known substrate for the efflux transporter, P-glycoprotein (P-gp). We wished to assess whether rhodamine-123 might serve as a useful substrate for developing probes for imaging efflux transporters in vivo with positron emission tomography (PET). For this purpose, we aimed to label rhodamine-123 with carbon-11 (t 1/2 = 20.4 min) and to study its biodistribution in rodents. Methods: [ 11 C]Rhodamine-123 was prepared by treating rhodamine-110 (desmethyl-rhodamine-123) with [ 11 C]methyl iodide. The biodistribution of this radiotracer was studied with PET in wild-type mice and rats, in efflux transporter knockout mice, in wild-type rats pretreated with DCPQ (an inhibitor of P-gp) or with cimetidine (an inhibitor of organic cation transporters; OCT), and in P-gp knockout mice pretreated with cimetidine. Unchanged radiotracer in forebrain, plasma and peripheral tissues was also measured ex vivo at 30 min after radiotracer administration to wild-type and efflux transporter knockout rodents. Results: [ 11 C]Rhodamine-123 was obtained in 4.4% decay-corrected radiochemical yield from cyclotron-produced [ 11 C]carbon dioxide. After intravenous administration of [ 11 C]rhodamine-123 to wild-type rodents, PET and ex vivo measurements showed radioactivity uptake was very low in brain, but relatively high in some other organs such as heart, and especially liver and kidney. Inhibition of P-gp increased uptake in brain, heart, kidney and liver, but only by up to twofold. Secretion of radioactivity from kidney was markedly reduced by OCT knockout or pretreatment with cimetidine. Conclusions: [ 11 C]Rhodamine-123 was unpromising as a PET probe for P-gp function and appears to be a strong substrate of OCT in kidney. Cimetidine appears effective for blocking OCT in kidney in vivo.

Andes hantavirus variant in rodents, southern Amazon Basin, Peru.

Science.gov (United States)

Razuri, Hugo; Tokarz, Rafal; Ghersi, Bruno M; Salmon-Mulanovich, Gabriela; Guezala, M Claudia; Albujar, Christian; Mendoza, A Patricia; Tinoco, Yeny O; Cruz, Christopher; Silva, Maria; Vasquez, Alicia; Pacheco, Víctor; Ströher, Ute; Guerrero, Lisa Wiggleton; Cannon, Deborah; Nichol, Stuart T; Hirschberg, David L; Lipkin, W Ian; Bausch, Daniel G; Montgomery, Joel M

2014-02-01

We investigated hantaviruses in rodents in the southern Amazon Basin of Peru and identified an Andes virus variant from Neacomys spinosus mice. This finding extends the known range of this virus in South America and the range of recognized hantaviruses in Peru. Further studies of the epizoology of hantaviruses in this region are warranted.

Andes Hantavirus Variant in Rodents, Southern Amazon Basin, Peru

OpenAIRE

Razuri, Hugo; Tokarz, Rafal; Ghersi, Bruno M.; Salmon-Mulanovich, Gabriela; Guezala, M. Claudia; Albujar, Christian; Mendoza, A. Patricia; Tinoco, Yeny O.; Cruz, Christopher; Silva, Maria; Vasquez, Alicia; Pacheco, Víctor; Ströher, Ute; Guerrero, Lisa Wiggleton; Cannon, Deborah

2014-01-01

We investigated hantaviruses in rodents in the southern Amazon Basin of Peru and identified an Andes virus variant from Neacomys spinosus mice. This finding extends the known range of this virus in South America and the range of recognized hantaviruses in Peru. Further studies of the epizoology of hantaviruses in this region are warranted.

On the regularized fermionic projector of the vacuum

Science.gov (United States)

Finster, Felix

2008-03-01

We construct families of fermionic projectors with spherically symmetric regularization, which satisfy the condition of a distributional MP-product. The method is to analyze regularization tails with a power law or logarithmic scaling in composite expressions in the fermionic projector. The resulting regularizations break the Lorentz symmetry and give rise to a multilayer structure of the fermionic projector near the light cone. Furthermore, we construct regularizations which go beyond the distributional MP-product in that they yield additional distributional contributions supported at the origin. The remaining freedom for the regularization parameters and the consequences for the normalization of the fermionic states are discussed.

On the regularized fermionic projector of the vacuum

International Nuclear Information System (INIS)

Finster, Felix

2008-01-01

We construct families of fermionic projectors with spherically symmetric regularization, which satisfy the condition of a distributional MP-product. The method is to analyze regularization tails with a power law or logarithmic scaling in composite expressions in the fermionic projector. The resulting regularizations break the Lorentz symmetry and give rise to a multilayer structure of the fermionic projector near the light cone. Furthermore, we construct regularizations which go beyond the distributional MP-product in that they yield additional distributional contributions supported at the origin. The remaining freedom for the regularization parameters and the consequences for the normalization of the fermionic states are discussed

Conspecific Interactions in Adult Laboratory Rodents: Friends or Foes?

Science.gov (United States)

Lukas, Michael; de Jong, Trynke R

2017-01-01

Interactions between adult conspecifics, including sexual behaviors, affiliation, and aggression are crucial for the well-being, survival, and reproduction of mammals. This holds true for any mammalian species, but certainly for humans: An inability to optimally navigate the social system can have a strong negative impact on physical and mental health. Translational rodent models have been used for decades to unravel the neural pathways and substrates involved in normal and abnormal conspecific interactions. Researchers in the field of translational social neuroscience face a double challenge: Not only do they need to pay considerable attention to the behavioral ecology of their model species or their ancestors, they also have to expect a relatively large variability in behavior and adjust their experimental design accordingly. In this chapter, we will lay out traditional and novel rodent models and paradigms to study sexual, affiliative, and aggressive interactions among adult conspecifics. We will discuss the merits and main findings and briefly consider the most promising novel directions. Finally, we review the modulatory involvement of two major players in mammal social interaction: the central oxytocin and vasopressin system.

A Practical Guide to Rodent Islet Isolation and Assessment

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Carter Jeffrey D

2009-12-01

Full Text Available Abstract Pancreatic islets of Langerhans secrete hormones that are vital to the regulation of blood glucose and are, therefore, a key focus of diabetes research. Purifying viable and functional islets from the pancreas for study is an intricate process. This review highlights the key elements involved with mouse and rat islet isolation, including choices of collagenase, the collagenase digestion process, purification of islets using a density gradient, and islet culture conditions. In addition, this paper reviews commonly used techniques for assessing islet viability and function, including visual assessment, fluorescent markers of cell death, glucose-stimulated insulin secretion, and intracellular calcium measurements. A detailed protocol is also included that describes a common method for rodent islet isolation that our laboratory uses to obtain viable and functional mouse islets for in vitro study of islet function, beta-cell physiology, and in vivo rodent islet transplantation. The purpose of this review is to serve as a resource and foundation for successfully procuring and purifying high-quality islets for research purposes.

A rodent malarial model of Plasmodium berghei for the development ...

African Journals Online (AJOL)

A rodent malarial model of Plasmodium berghei for the development of pyrimethamine and sulphadoxine-pyrimethamine resistant malaria in mice. ... course approach with 125/6.25mg/kg S/P. The stability of resistance phenotypes, parasite pathogenic disposition and host leukocyte response were also investigated.

Factors associated with exclusive breast-feeding and breast-feeding in Norway

OpenAIRE

Kristiansen, Anne Lene; Lande, Britt; Øverby, Nina Cecilie; Andersen, Lene Frost

2010-01-01

Objective To identify factors associated with exclusive breast-feeding and breast-feeding during the first year of life among Norwegian infants. Design Data on breast-feeding practices were collected by a semi-quantitative FFQ. Setting In 2006?2007 about 3000 infants were invited to participate in a population-based prospective cohort study in Norway. Subjects A total of 1490 mothers/infants participated at both 6 and 12 months of age. Results Exclusive breast-feeding at 4 months was associat...

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

Directory of Open Access Journals (Sweden)

VALERIA eCOLAVITO

2013-12-01

Full Text Available 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. The purpose of this article is to provide an overview of the studies that have accurately described methodological aspects of the SD protocol and behavioral paradigm in order to critically assess them and propose SD protocols that could be employed as cognitive challenge. Total SD, partial or state-selective SD (rapid eye movement SD procedures are first reviewed, followed by procedures to investigate SD-induced impairment of learning and memory consolidation. Thus, a platform of knowledge is here 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.

Regularization modeling for large-eddy simulation

NARCIS (Netherlands)

Geurts, Bernardus J.; Holm, D.D.

2003-01-01

A new modeling approach for large-eddy simulation (LES) is obtained by combining a "regularization principle" with an explicit filter and its inversion. This regularization approach allows a systematic derivation of the implied subgrid model, which resolves the closure problem. The central role of

Spatially-Variant Tikhonov Regularization for Double-Difference Waveform Inversion

Energy Technology Data Exchange (ETDEWEB)

Lin, Youzuo [Los Alamos National Laboratory; Huang, Lianjie [Los Alamos National Laboratory; Zhang, Zhigang [Los Alamos National Laboratory

2011-01-01

Double-difference waveform inversion is a potential tool for quantitative monitoring for geologic carbon storage. It jointly inverts time-lapse seismic data for changes in reservoir geophysical properties. Due to the ill-posedness of waveform inversion, it is a great challenge to obtain reservoir changes accurately and efficiently, particularly when using time-lapse seismic reflection data. Regularization techniques can be utilized to address the issue of ill-posedness. The regularization parameter controls the smoothness of inversion results. A constant regularization parameter is normally used in waveform inversion, and an optimal regularization parameter has to be selected. The resulting inversion results are a trade off among regions with different smoothness or noise levels; therefore the images are either over regularized in some regions while under regularized in the others. In this paper, we employ a spatially-variant parameter in the Tikhonov regularization scheme used in double-difference waveform tomography to improve the inversion accuracy and robustness. We compare the results obtained using a spatially-variant parameter with those obtained using a constant regularization parameter and those produced without any regularization. We observe that, utilizing a spatially-variant regularization scheme, the target regions are well reconstructed while the noise is reduced in the other regions. We show that the spatially-variant regularization scheme provides the flexibility to regularize local regions based on the a priori information without increasing computational costs and the computer memory requirement.

Feeding Tubes

Science.gov (United States)

... feeding therapies have been exhausted. Please review product brand and method of placement carefully with your physician ... Total Parenteral Nutrition. Resources: Oley Foundation Feeding Tube Awareness Foundation Children’s Medical Nutrition Alliance APFED’s Educational Webinar ...

Citral reduces nociceptive and inflammatory response in rodents

OpenAIRE

Quintans-Júnior, Lucindo J.; Guimarães, Adriana G.; Santana, Marilia T. de; Araújo, Bruno E.S.; Moreira, Flávia V.; Bonjardim, Leonardo R.; Araújo, Adriano A. S.; Siqueira, Jullyana S.; Antoniolli, Ângelo R.; Botelho, Marco A.; Almeida, Jackson R. G. S.; Santos, Márcio R. V.

2011-01-01

Citral (CIT), which contains the chiral enantiomers, neral (cis) and geranial (trans), is the majority monoterpene from Lippia alba and Cymbopogon citratus. The present study aimed to evaluate CIT for antinociceptive and anti-inflammatory activities in rodents. Antinociceptive and anti-inflammatory effects were studied by measuring nociception through acetic acid and formalin tests, while inflammation was verified by inducing peritonitis and paw edema with carrageenan. All tested doses of CIT...

Evaluation on the effectiveness of actions for controlling infestation by rodents in Campo Limpo region, Sao Paulo Municipality, Brazil.

Science.gov (United States)

de Masi, Eduardo; Vilaça, Pedro José; Razzolini, Maria Tereza Pepe

2009-08-01

Rodents are responsible for the transmission of more than 60 diseases both to human beings and to domestic animals. The increase in rodent infestation in a given area brings several health problems to the nearby population. Thus, when infestation increases, it is time to take intervention measures. Although many countries have implemented programs aimed at controlling rodent infestation, literature on studies evaluating the effectiveness of intervention measures in urban areas is scarce. Aimed at contributing to the understanding of rodents' population dynamics in urban areas, the objective of this study was to evaluate the effectiveness of the control methods proposed by "Programa de Vigilancia e Controle de Roedores do Municipio de Sao Paulo" (Program for Rodents Surveillance and Control in Sao Paulo Municipality), conducted on Jardim Comercial District. As a first step, a survey to assess infestation rates was conducted in 1529 dwellings located in the area studied. After that, a chemical control upon rodents was accomplished in every dwelling infested. One week and six months after completion of control measures, a new evaluation on infestation rates was carried out, in order to verify the effectiveness of the procedures taken and to estimate the re-infestation capacity. Initial infestation rate was 40.0%, and the final infestation rate, 14.4%. Therefore, the effectiveness of the control methods utilized was 63.8%. It can thus be concluded that the control methods applied were quite effective.

Manifold Regularized Correlation Object Tracking.

Science.gov (United States)

Hu, Hongwei; Ma, Bo; Shen, Jianbing; Shao, Ling

2018-05-01

In this paper, we propose a manifold regularized correlation tracking method with augmented samples. To make better use of the unlabeled data and the manifold structure of the sample space, a manifold regularization-based correlation filter is introduced, which aims to assign similar labels to neighbor samples. Meanwhile, the regression model is learned by exploiting the block-circulant structure of matrices resulting from the augmented translated samples over multiple base samples cropped from both target and nontarget regions. Thus, the final classifier in our method is trained with positive, negative, and unlabeled base samples, which is a semisupervised learning framework. A block optimization strategy is further introduced to learn a manifold regularization-based correlation filter for efficient online tracking. Experiments on two public tracking data sets demonstrate the superior performance of our tracker compared with the state-of-the-art tracking approaches.

Potential role of masting by introduced bamboos in deer mice (Peromyscus maniculatus population irruptions holds public health consequences.

Directory of Open Access Journals (Sweden)

Melissa C Smith

Full Text Available We hypothesized that the ongoing naturalization of frost/shade tolerant Asian bamboos in North America could cause environmental consequences involving introduced bamboos, native rodents and ultimately humans. More specifically, we asked whether the eventual masting by an abundant leptomorphic ("running" bamboo within Pacific Northwest coniferous forests could produce a temporary surfeit of food capable of driving a population irruption of a common native seed predator, the deer mouse (Peromyscus maniculatus, a hantavirus carrier. Single-choice and cafeteria-style feeding trials were conducted for deer mice with seeds of two bamboo species (Bambusa distegia and Yushania brevipaniculata, wheat, Pinus ponderosa, and native mixed diets compared to rodent laboratory feed. Adult deer mice consumed bamboo seeds as readily as they consumed native seeds. In the cafeteria-style feeding trials, Y. brevipaniculata seeds were consumed at the same rate as native seeds but more frequently than wheat seeds or rodent laboratory feed. Females produced a median litter of 4 pups on a bamboo diet. Given the ability of deer mice to reproduce frequently whenever food is abundant, we employed our feeding trial results in a modified Rosenzweig-MacArthur consumer-resource model to project the population-level response of deer mice to a suddenly available/rapidly depleted supply of bamboo seeds. The simulations predict rodent population irruptions and declines similar to reported cycles involving Asian and South American rodents but unprecedented in deer mice. Following depletion of a mast seed supply, the incidence of Sin Nombre Virus (SNV transmission to humans could subsequently rise with dispersal of the peridomestic deer mice into nearby human settlements seeking food.

From recreational to regular drug use

DEFF Research Database (Denmark)

Järvinen, Margaretha; Ravn, Signe

2011-01-01

This article analyses the process of going from recreational use to regular and problematic use of illegal drugs. We present a model containing six career contingencies relevant for young people’s progress from recreational to regular drug use: the closing of social networks, changes in forms...

Prey perception in feeding-current feeding copepods

DEFF Research Database (Denmark)

Kiørboe, Thomas; Goncalves, Rodrigo J.; Florian Couespel, Damien

2016-01-01

We reply to the comments of Paffenhöfer and Jiang () who argues that remote chemical prey perception is necessary for feeding-current feeding copepods to fulfill their nutritional requirements in a dilute ocean, that remote chemical prey detection may only be observed at very low prey concentrati......We reply to the comments of Paffenhöfer and Jiang () who argues that remote chemical prey perception is necessary for feeding-current feeding copepods to fulfill their nutritional requirements in a dilute ocean, that remote chemical prey detection may only be observed at very low prey...... cells have short intense leakage burst, only a very small fraction of prey cells would be available to the copepod at any instance in time and, thus would be inefficient at low prey concentration. Finally, we report a few new observations of prey capture in two species of copepods, Temora longicornis...... and Centropages hamatus, offered a 45-μm sized dinoflagellate at very low concentration. The observed short prey detection distances, up to a few prey cell radii, are consistent with mechanoreception and we argue briefly that near-field mechanoreception is the most likely and common prey perception mechanism...

Prediction of Chemical Carcinogenicity in Rodents from in vitro Genetic Toxicity Assays

Science.gov (United States)

Tennant, Raymond W.; Margolin, Barry H.; Shelby, Michael D.; Zeiger, Errol; Haseman, Joseph K.; Spalding, Judson; Caspary, William; Resnick, Michael; Stasiewicz, Stanley; Anderson, Beth; Minor, Robert

1987-05-01

Four widely used in vitro assays for genetic toxicity were evaluated for their ability to predict the carcinogenicity of selected chemicals in rodents. These assays were mutagenesis in Salmonella and mouse lymphoma cells and chromosome aberrations and sister chromatid exchanges in Chinese hamster ovary cells. Seventy-three chemicals recently tested in 2-year carcinogenicity studies conducted by the National Cancer Institute and the National Toxicology Program were used in this evaluation. Test results from the four in vitro assays did not show significant differences in individual concordance with the rodent carcinogenicity results; the concordance of each assay was approximately 60 percent. Within the limits of this study there was no evidence of complementarity among the four assays, and no battery of tests constructed from these assays improved substantially on the overall performance of the Salmonella assay. The in vitro assays which represented a range of three cell types and four end points did show substantial agreement among themselves, indicating that chemicals positive in one in vitro assay tended to be positive in the other in vitro assays. To help put this project into its proper context, we emphasize certain features of the study: 1) Standard protocols were used to mimic the major use of STTs worldwide--screening for mutagens and carcinogens; no attempt was made to optimize protocols for specific chemicals. 2) The 73 NTP chemicals and their 60% incidence of carcinogenicity are probably not representative of the universe of chemicals but rather reflect the recent chemical selection process for the NTP carcinogenicity assay. 3) The small, diverse group of chemicals precludes a meaningful evaluation of the predictive utility of chemical structure information. 4) The NTP is currently testing these same 73 chemicals in two in vivo STTs for chromosomal effects. 5) Complete data for an additional group of 30 to 40 NTP chemicals will be gathered on

A new form of rodent placentation in the relict species, Laonastes aenigmamus (Rodentia Diatomyidae)

DEFF Research Database (Denmark)

Carter, Anthony Michael; Enders, A C; Jones, C J P

2013-01-01

INTRODUCTION: The Laotian rock rat is a relict species in a sister group relationship to hystricognath rodents (Hystricognathi). We asked whether there were similarities in placentation that might reflect this relationship or differences that might cast light on the evolution of Hystricognathi....... METHODS: We examined the reproductive tract of nonpregnant (n = 5), early (n = 3) and mid to late gestation (n = 2) females. Selected characters were mapped to a phylogenetic tree to examine their evolution in rodents. RESULTS: The chorionic placenta was discoid and labyrinthine with a spongy zone...

Phenotypic and genetic relationships of feeding behavior with feed intake, growth performance, feed efficiency, and carcass merit traits in Angus and Charolais steers.

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Chen, L; Mao, F; Crews, D H; Vinsky, M; Li, C

2014-03-01

Feeding behavior traits including daily feeding duration (FD), daily feeding head down time (HD), average feeding duration per feeding event (FD_AVE), average feeding head down time per feeding event (HD_AVE), feeding frequency (FF), and meal eating rate (ER) were analyzed to estimate their phenotypic and genetic correlations with feed intake, growth performance, residual feed intake (RFI), ultrasound, and carcass merit traits in Angus and Charolais finishing steers. Heritability estimates for FD, HD, FD_AVE, HD_AVE, FF, and ER were 0.27 ± 0.09 (SE), 0.25 ± 0.09, 0.19 ± 0.06, 0.11 ± 0.05, 0.24 ± 0.08, and 0.38 ± 0.10, respectively, in the Angus population and 0.49 ± 0.12, 0.38 ± 0.11, 0.31 ± 0.09, 0.29 ± 0.10, 0.43 ± 0.11, and 0.56 ± 0.13, respectively, in the Charolais population. In both the Angus and Charolais steer populations, FD and HD had relatively stronger phenotypic (0.17 ± 0.06 to 0.32 ± 0.04) and genetic (0.29 ± 0.17 to 0.54 ± 0.18) correlations with RFI in comparison to other feeding behavior traits investigated, suggesting the potential of FD and HD as indicators in assessing variation of RFI. In general, feeding behavior traits had weak phenotypic correlations with most of the ultrasound and carcass merit traits; however, estimated genetic correlations of the feeding behavior traits with some fat deposition related traits were moderate to moderately strong but differed in magnitude or sign between the Angus and Charolais steer populations, likely reflecting their different biological types. Genetic parameter estimation studies involving feeding behavior traits in beef cattle are lacking and more research is needed to better characterize the relationships between feeding behavior and feed intake, growth, feed utilization, and carcass merit traits, in particular with respect to different biological types of cattle.

Lack of a response of the sub-tropical rodent (Saccostomus ...

African Journals Online (AJOL)

1998-03-09

Mar 9, 1998 ... A potential strategy for southern African small mammals to maximise reproductive success is to cue breeding activity to rainfall and subsequent vegetative growth via a secondary plant compound such as 6-methoxyben- zoxazolinone (6MBOA). This study investigated whether the sub-tropical rodent ...

Detection, identification and genotyping of Borrellia spp. in rodents in Slovenia by PCR and culture.

Science.gov (United States)

Cerar, Tjaša; Korva, Miša; Avšič-Županc, Tatjana; Ružić-Sabljić, Eva

2015-08-08

Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis, is mainly maintained in natural foci through the transmission cycles of competent tick vectors (Ixodes sp.) and a vertebrate reservoir. Specific rodents have been identified as the principal reservoir of Borrelia burgdorferi sensu lato in Europe. Borrelia miyamotoi is the only relapsing fever spirochete transmitted by the same tick. The aim of the present study was to perform an epidemiological survey to determine the presence of B. burgdorferi sensu lato in rodents occurring in Slovenia and to explore the presence of Borrelia miyamotoi. The study was performed in two parts, retrospective and prospective; a total of 297 rodents was analyzed. Detection and identification of borrelia was performed by molecular methods and additionally in the prospective study by isolation and genotyping (MluI-LRFP and MLST). During the prospective part of the study, borrelia was isolated from 2/46 (4.3 %) lung specimens and from 10/46 (21.7 %) heart specimens of rodents. All isolated strains were identified as B. afzelii subtype Mla1, and MLST analysis revealed 5 distinct sequence types. Borrelia DNA was successfully detected by one or other of the PCR methods in 18/46 (39.1 %) and 75/251 (29.9 %) samples in the prospective and retrospective studies, respectively. LightMix® was found to be more sensitive than the ''in-house" nested PCR (91/297 (30.6 %) vs 48/297 (16.1 %)). Borrelia miyamotoi DNA was detected in 1/251 (0.4 %) and in 1/46 (2.2 %) heart specimens, in the retrospective and prospective parts of the study, respectively. We determined the prevalence of B. afzelii in rodents and report for the first time the presence of B. miyamotoi in Slovenia.

Regular variation on measure chains

Czech Academy of Sciences Publication Activity Database

Řehák, Pavel; Vitovec, J.

2010-01-01

Roč. 72, č. 1 (2010), s. 439-448 ISSN 0362-546X R&D Projects: GA AV ČR KJB100190701 Institutional research plan: CEZ:AV0Z10190503 Keywords : regularly varying function * regularly varying sequence * measure chain * time scale * embedding theorem * representation theorem * second order dynamic equation * asymptotic properties Subject RIV: BA - General Mathematics Impact factor: 1.279, year: 2010 http://www.sciencedirect.com/science/article/pii/S0362546X09008475

New regular black hole solutions

International Nuclear Information System (INIS)

Lemos, Jose P. S.; Zanchin, Vilson T.

2011-01-01

In the present work we consider general relativity coupled to Maxwell's electromagnetism and charged matter. Under the assumption of spherical symmetry, there is a particular class of solutions that correspond to regular charged black holes whose interior region is de Sitter, the exterior region is Reissner-Nordstroem and there is a charged thin-layer in-between the two. The main physical and geometrical properties of such charged regular black holes are analyzed.

Manifold Regularized Correlation Object Tracking

OpenAIRE

Hu, Hongwei; Ma, Bo; Shen, Jianbing; Shao, Ling

2017-01-01

In this paper, we propose a manifold regularized correlation tracking method with augmented samples. To make better use of the unlabeled data and the manifold structure of the sample space, a manifold regularization-based correlation filter is introduced, which aims to assign similar labels to neighbor samples. Meanwhile, the regression model is learned by exploiting the block-circulant structure of matrices resulting from the augmented translated samples over multiple base samples cropped fr...

On geodesics in low regularity

Science.gov (United States)

Sämann, Clemens; Steinbauer, Roland

2018-02-01

We consider geodesics in both Riemannian and Lorentzian manifolds with metrics of low regularity. We discuss existence of extremal curves for continuous metrics and present several old and new examples that highlight their subtle interrelation with solutions of the geodesic equations. Then we turn to the initial value problem for geodesics for locally Lipschitz continuous metrics and generalize recent results on existence, regularity and uniqueness of solutions in the sense of Filippov.

Multiplex PCR identification of Taenia spp. in rodents and carnivores.

Science.gov (United States)

Al-Sabi, Mohammad N S; Kapel, Christian M O

2011-11-01

The genus Taenia includes several species of veterinary and public health importance, but diagnosis of the etiological agent in definitive and intermediate hosts often relies on labor intensive and few specific morphometric criteria, especially in immature worms and underdeveloped metacestodes. In the present study, a multiplex PCR, based on five primers targeting the 18S rDNA and ITS2 sequences, produced a species-specific banding patterns for a range of Taenia spp. Species typing by the multiplex PCR was compared to morphological identification and sequencing of cox1 and/or 12S rDNA genes. As compared to sequencing, the multiplex PCR identified 31 of 32 Taenia metacestodes from rodents, whereas only 14 cysts were specifically identified by morphology. Likewise, the multiplex PCR identified 108 of 130 adult worms, while only 57 were identified to species by morphology. The tested multiplex PCR system may potentially be used for studies of Taenia spp. transmitted between rodents and carnivores.

Methods for Dissecting Motivation and Related Psychological Processes in Rodents.

Science.gov (United States)

Ward, Ryan D

2016-01-01

Motivational impairments are increasingly recognized as being critical to functional deficits and decreased quality of life in patients diagnosed with psychiatric disease. Accordingly, much preclinical research has focused on identifying psychological and neurobiological processes which underlie motivation . Inferring motivation from changes in overt behavioural responding in animal models, however, is complicated, and care must be taken to ensure that the observed change is accurately characterized as a change in motivation , and not due to some other, task-related process. This chapter discusses current methods for assessing motivation and related psychological processes in rodents. Using an example from work characterizing the motivational impairments in an animal model of the negative symptoms of schizophrenia, we highlight the importance of careful and rigorous experimental dissection of motivation and the related psychological processes when characterizing motivational deficits in rodent models . We suggest that such work is critical to the successful translation of preclinical findings to therapeutic benefits for patients.

Morphology of bronchial epithelium in rodent streptozotocin-induced diabetes mellitus

Directory of Open Access Journals (Sweden)

Oksana Anatolyevna Pivovarova

2013-12-01

Full Text Available Aim. To study the morphology of bronchial epithelium in a rodent streptozotocin-induced (STZ diabetes mellitus.Materials and Methods. Diabetes mellitus was introduced in 47 white Wistar rats aged 5–6 months (body weight 234.0±2.64 g. 43 white Wistar rats of the same age were used as control subjects (body weight 242.0±2.13. Diabetes was induced by single intraperitoneal injection of STZ (SIGMA, USA 60 mg/kg in 0.1 M citrate buffer, pH 4.5.Results. A statistically significant decrease in the total epithelial area by 25.9% was observed in the study group, accompanied by a reduction of the supranuclear zone by 22.1% vs. the control group.Conclusion. We found that bronchial mucous membrane in rodents with STZ-induced diabetes mellitus exhibits signs of atrophy and partial loss of mucous production by bronchial secretory cells.

Efficiency of organic acid preparations for the elimination of naturally occurring Salmonella in feed material.

Science.gov (United States)

Axmann, Sonja; Kolar, Veronika; Adler, Andreas; Strnad, Irmengard

2017-11-01

Salmonella can enter animal stocks via feedstuffs, thus posing not only an infection risk for animals, but also threatening to contaminate food of animal origin and finally humans. Salmonella contamination in feedstuffs is still a recurring and serious issue in animal production (especially for the poultry sector), and is regularly detected upon self-monitoring by feed companies (self-checks) and official inspections authorities. Operators within the feed chain in certain cases need to use hygienic condition enhancers, such as organic acids, to improve the quality of feed for animal nutrition, providing additional guarantees for the protection of animal and public health. The present study investigated the efficiencies of five organic acid preparations. The acid products were added to three different feed materials contaminated with Salmonella (contamination occurred by recontamination in the course of the production process) at seven different inclusion rates (1-7%) and analysed after 1, 2, and 7 days' exposure time using culture method (tenfold analysis). A reliable standard was established for defining a successful decontamination under the prevailing test conditions: 10 Salmonella-negative results out of 10 tested samples (0/10: i.e. 0 positive samples and 10 negative samples). The results demonstrated that the tested preparations showed significant differences with regard to the reduction in Salmonella contamination. At an inclusion rate of 7% of the feed materials, two out of five acid preparations showed an insufficient, very small, decontamination effect, whereas two others had a relatively large partial effect. Reliable decontamination was demonstrated only for one acid preparation, however, subject to the use of the highest acid concentration.

Manifold Regularized Reinforcement Learning.

Science.gov (United States)

Li, Hongliang; Liu, Derong; Wang, Ding

2018-04-01

This paper introduces a novel manifold regularized reinforcement learning scheme for continuous Markov decision processes. Smooth feature representations for value function approximation can be automatically learned using the unsupervised manifold regularization method. The learned features are data-driven, and can be adapted to the geometry of the state space. Furthermore, the scheme provides a direct basis representation extension for novel samples during policy learning and control. The performance of the proposed scheme is evaluated on two benchmark control tasks, i.e., the inverted pendulum and the energy storage problem. Simulation results illustrate the concepts of the proposed scheme and show that it can obtain excellent performance.

Rodent Habitat On ISS: Spaceflight Effects On Mouse Behavior

Science.gov (United States)

Ronca, A. E.; Moyer, E. L.; Talyansky, Y.; Padmanabhan, S.; Choi, S.; Gong, C.; Globus, R. K.

2016-01-01

The NASA Decadal Survey (2011), Recapturing a Future for Space Exploration: Life and Physical Sciences Research for a New Era, emphasized the importance of expanding NASA life sciences research to long duration, rodent experiments on the International Space Station (ISS). To accomplish this objective, flight hardware, operations, and science capabilities supporting mouse studies in space were developed at NASA Ames Research Center. The first flight experiment carrying mice, Rodent Research Hardware and Operations Validation (Rodent Research-1), was launched on Sept 21, 2014 in an unmanned Dragon Capsule, SpaceX4, exposing the mice to a total of 37 days in space. Ground control groups were maintained in environmental chambers at Kennedy Space Center. Mouse health and behavior were monitored for the duration of the experiment via video streaming. Here we present behavioral analysis of two groups of five C57BL/6 female adult mice viewed via fixed camera views compared with identically housed Ground Controls. Flight (Flt) and Ground Control (GC) mice exhibited the same range of behaviors, including eating, drinking, exploratory behavior, self- and allo-grooming, and social interactions at similar or greater levels of occurrence. Mice propelled themselves freely and actively throughout the Habitat using their forelimbs to push off or by floating from one cage area to another, and they quickly learned to anchor themselves using tails and/or paws. Overall activity was greater in Flt as compared to GC mice, with spontaneous ambulatory behavior including the development of organized ‘circling’ or ‘race-tracking’ behavior that emerged within the first few days of flight and encompassed the primary dark cycle activity for the remainder of the experiment. We quantified the bout frequency, duration and rate of circling with respect to characteristic behaviors observed in the varying stages of the progressive development of circling: flipping utilizing two sides of the

A Limited Survey of Aflatoxins in Poultry Feed and Feed Ingredients in Guyana

Directory of Open Access Journals (Sweden)

Donna M. Morrison

2017-11-01

Full Text Available A study was conducted to determine the presence of aflatoxins in finished poultry feed from manufacturing companies, feed ingredients, and poultry feed at the point of sale. Two collections were made. In the first collection, samples of the finished feed and feed ingredients were analyzed by high-performance liquid chromatography (HPLC. For the second collection, all samples were analyzed by ELISA while a subset was analyzed by HPLC. Of the 27 samples of finished feed, five samples had aflatoxin concentrations greater than the United States Food and Drug Administration (USFDA and European Union Commission (EUC maximum tolerable limit of 20 µg/kg, while for the feed ingredients, three of the 30 samples of feed ingredients exceeded the limit. Of the 93 samples of finished feed purchased from retailers, five samples had aflatoxin concentrations greater than the maximum tolerable limit. This survey indicates that most of the samples were below the maximum regulatory limit and maintained quality up to the point of sale for 2015 and 2016. However, given that some samples were above the limit, there is a need to monitor the production and marketing chain to ensure that the quality of the finished feed is not compromised.

Animal models of polycystic ovary syndrome: a focused review of rodent models in relationship to clinical phenotypes and cardiometabolic risk.

Science.gov (United States)

Shi, Danni; Vine, Donna F

2012-07-01

To review rodent animal models of polycystic ovary syndrome (PCOS), with a focus on those associated with the metabolic syndrome and cardiovascular disease risk factors. Review. Rodent models of PCOS. Description and comparison of animal models. Comparison of animal models to clinical phenotypes of PCOS. Animals used to study PCOS include rodents, mice, rhesus monkeys, and ewes. Major methods to induce PCOS in these models include subcutaneous injection or implantation of androgens, estrogens, antiprogesterone, letrozole, prenatal exposure to excess androgens, and exposure to constant light. In addition, transgenic mice models and spontaneous PCOS-like rodent models have also been developed. Rodents are the most economical and widely used animals to study PCOS and ovarian dysfunction. The model chosen to study the development of PCOS and other metabolic parameters remains dependent on the specific etiologic hypotheses being investigated. Rodent models have been shown to demonstrate changes in insulin metabolism, with or without induction of hyperandrogenemia, and limited studies have investigated cardiometabolic risk factors for type 2 diabetes and cardiovascular disease. Given the clinical heterogeneity of PCOS, the utilization of different animal models may be the best approach to further our understanding of the pathophysiologic mechanisms associated with the early etiology of PCOS and cardiometabolic risk. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

FEEDING DIFFICULTIES IN PRESCHOOL CHILDREN, PREVIOUS FEEDING PRACTICES, AND NUTRITIONAL STATUS.

Science.gov (United States)

Maranhão, Hélcio de Sousa; Aguiar, Renata Cunha de; Lira, Débora Teixeira Jales de; Sales, Mônica Úrsula Figuerêdo; Nóbrega, Nathalia Ávila do Nascimento

2018-01-01

To identify the prevalence of feeding difficulties in preschoolers, its association with epidemiological factors and previous eating habits, and repercussion on nutritional status. Cross-sectional study with a questionnaire given to the mothers of 301 children aged 2-6 years enrolled in public and private kindergartens in Natal, Northeast Brazil, conducted in 2014-2015. Feeding difficulty was assessed according to Kerzner's criteria, resulting in the profiles "highly selective intake", "active child with small appetite", "fear of feeding", and "child with psychological disorder or neglected". Association with the following independent variables was analyzed by logistic regression: breastfeeding time, age of cows' milk and complementary feeding introduction, age range, family income, type of school, mothers' profile (responsive or nonresponsive), and body mass index (BMI). Feeding difficulty was found in 37.2% of cases, with predominance of "highly selective intake" (25.4%). It was not associated with infancy feeding practices, family income or type of school. There were no differences between the BMI Z score means for the groups with and without feeding difficulty (1.0±1.5 SD and 1.1±1.4 SD, respectively). The five-to-six age range had more occurrences (OR 1.8; 95%CI 1.1-2.9). Children of responsive mothers were less likely to have feeding difficulties (OR 0.4; 95%CI 0.2-0.8). Feeding difficulties were very frequent. Nutritional status was not impacted by it, and infancy eating habits were not associated with it. Responsive mothers' profile is a protective factor against eating difficulties and reinforces the importance of behavioral factors and mother-child interaction.

Infant sleep and night feeding patterns during later infancy: association with breastfeeding frequency, daytime complementary food intake, and infant weight.

Science.gov (United States)

Brown, Amy; Harries, Victoria

2015-06-01

Infant sleep is a common concern for new parents. Although many expect a newborn infant to wake frequently, encouraging a baby to sleep through the night by a few months of age is seen as both a developmental aim and a parenting success. Many new mothers believe that their infants' diet is related to their sleep; formula milk or increased levels of solid food are often given in an attempt to promote sleep. However, the impact of these in later infancy is not understood. In the current study 715 mothers with an infant 6-12 months of age reported their infants' typical night wakings and night feeds alongside any breastfeeding and frequency of solid meals. Of infants in this age range, 78.6% still regularly woke at least once a night, with 61.4% receiving one or more milk feeds. Both night wakings and night feeds decreased with age. No difference in night wakings or night feeds was found between mothers who were currently breastfeeding or formula feeding. However, infants who received more milk or solid feeds during the day were less likely to feed at night but not less likely to wake. The findings have important implications for health professionals who support new mothers with infant sleep and diet in the first year. Increasing infant calories during the day may therefore reduce the likelihood of night feeding but will not reduce the need for parents to attend to the infant in the night. Breastfeeding has no impact on infant sleep in the second 6 months postpartum.

Plague cycles in two rodent species from China: Dry years might provide context for epizootics in wet years

Science.gov (United States)

Eads, David A.; Biggins, Dean E.; Xu, Lei; Liu, Qiyong

2016-01-01

Plague, a rodent-associated, flea-borne zoonosis, is one of the most notorious diseases in history. Rates of plague transmission can increase when fleas are abundant. Fleas commonly desiccate and die when reared under dry conditions in laboratories, suggesting fleas will be suppressed during droughts in the wild, thus reducing the rate at which plague spreads among hosts. In contrast, fleas might increase in abundance when precipitation is plentiful, producing epizootic outbreaks during wet years. We tested these hypotheses using a 27-yr data set from two rodents in Inner Mongolia, China: Mongolian gerbils (Meriones unguiculatus) and Daurian ground squirrels (Spermophilus dauricus). For both species of rodents, fleas were most abundant during years preceded by dry growing seasons. For gerbils, the prevalence of plague increased during wet years preceded by dry growing seasons. If precipitation is scarce during the primary growing season, succulent plants decline in abundance and, consequently, herbivorous rodents can suffer declines in body condition. Fleas produce more offspring and better survive when parasitizing food-limited hosts, because starving animals tend to exhibit inefficient behavioral and immunological defenses against fleas. Further, rodent burrows might buffer fleas from xeric conditions aboveground during dry years. After a dry year, fleas might be abundant due to the preceding drought, and if precipitation and succulent plants become more plentiful, rodents could increase in density, thereby creating connectivity that facilitates the spread of plague. Moreover, in wet years, mild temperatures might increase the efficiency at which fleas transmit the plague bacterium, while also helping fleas to survive as they quest among hosts. In this way, dry years could provide context for epizootics of plague in wet years.