929 resultados para Animals Behavior--Juvenile literature.
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The code STATFLUX, implementing a new and simple statistical procedure for the calculation of transfer coefficients in radionuclide transport to animals and plants, is proposed. The method is based on the general multiple-compartment model, which uses a system of linear equations involving geometrical volume considerations. Flow parameters were estimated by employing two different least-squares procedures: Derivative and Gauss-Marquardt methods, with the available experimental data of radionuclide concentrations as the input functions of time. The solution of the inverse problem, which relates a given set of flow parameter with the time evolution of concentration functions, is achieved via a Monte Carlo Simulation procedure.Program summaryTitle of program: STATFLUXCatalogue identifier: ADYS_v1_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADYS_v1_0Program obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions: noneComputer for which the program is designed and others on which it has been tested: Micro-computer with Intel Pentium III, 3.0 GHzInstallation: Laboratory of Linear Accelerator, Department of Experimental Physics, University of São Paulo, BrazilOperating system: Windows 2000 and Windows XPProgramming language used: Fortran-77 as implemented in Microsoft Fortran 4.0. NOTE: Microsoft Fortran includes non-standard features which are used in this program. Standard Fortran compilers such as, g77, f77, ifort and NAG95, are not able to compile the code and therefore it has not been possible for the CPC Program Library to test the program.Memory, required to execute with typical data: 8 Mbytes of RAM memory and 100 MB of Hard disk memoryNo. of bits in a word: 16No. of lines in distributed program, including test data, etc.: 6912No. of bytes in distributed Program, including test data, etc.: 229 541Distribution format: tar.gzNature of the physical problem: the investigation of transport mechanisms for radioactive substances, through environmental pathways, is very important for radiological protection of populations. One such pathway, associated with the food chain, is the grass-animal-man sequence. The distribution of trace elements in humans and laboratory animals has been intensively studied over the past 60 years [R.C. Pendlenton, C.W. Mays, R.D. Lloyd, A.L. Brooks, Differential accumulation of iodine-131 from local fallout in people and milk, Health Phys. 9 (1963) 1253-1262]. In addition, investigations on the incidence of cancer in humans, and a possible causal relationship to radioactive fallout, have been undertaken [E.S. Weiss, M.L. Rallison, W.T. London, W.T. Carlyle Thompson, Thyroid nodularity in southwestern Utah school children exposed to fallout radiation, Amer. J. Public Health 61 (1971) 241-249; M.L. Rallison, B.M. Dobyns, F.R. Keating, J.E. Rall, F.H. Tyler, Thyroid diseases in children, Amer. J. Med. 56 (1974) 457-463; J.L. Lyon, M.R. Klauber, J.W. Gardner, K.S. Udall, Childhood leukemia associated with fallout from nuclear testing, N. Engl. J. Med. 300 (1979) 397-402]. From the pathways of entry of radionuclides in the human (or animal) body, ingestion is the most important because it is closely related to life-long alimentary (or dietary) habits. Those radionuclides which are able to enter the living cells by either metabolic or other processes give rise to localized doses which can be very high. The evaluation of these internally localized doses is of paramount importance for the assessment of radiobiological risks and radiological protection. The time behavior of trace concentration in organs is the principal input for prediction of internal doses after acute or chronic exposure. The General Multiple-Compartment Model (GMCM) is the powerful and more accepted method for biokinetical studies, which allows the calculation of concentration of trace elements in organs as a function of time, when the flow parameters of the model are known. However, few biokinetics data exist in the literature, and the determination of flow and transfer parameters by statistical fitting for each system is an open problem.Restriction on the complexity of the problem: This version of the code works with the constant volume approximation, which is valid for many situations where the biological half-live of a trace is lower than the volume rise time. Another restriction is related to the central flux model. The model considered in the code assumes that exist one central compartment (e.g., blood), that connect the flow with all compartments, and the flow between other compartments is not included.Typical running time: Depends on the choice for calculations. Using the Derivative Method the time is very short (a few minutes) for any number of compartments considered. When the Gauss-Marquardt iterative method is used the calculation time can be approximately 5-6 hours when similar to 15 compartments are considered. (C) 2006 Elsevier B.V. All rights reserved.
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Four. male Wistar rats were housed in pairs of siblings, on LD 12:12h and 22 degrees C + 2 degrees C. Food and water were provided ad libitum. Behavior was videotaped from the 1st to the 3rd month of life. In each age-bracket the spectral composition of rhythmic expressions of the following behavioral categories was analyzed: rest, eat, drink, cage exploration, self-grooming, and social interaction. Rats maintained a stable rank order of time engaged in different behaviors through development, despite modification of time spent in grooming, drinking and social interaction as they got older. Spectral composition of behaviors followed a general ontogenetic pattern: ultradian frequencies of 12-h and 8-h were the strongest in the 1st month and circadian periodicity was predominant in the 3rd month. The increase of circadian power compared with ultradian power components agrees with literature findings. To our knowledge, self-grooming and social interaction have not been investigated before in this context. The similarities between siblings suggest the mutual influence of partners and/ or the existence of genetic factors. Ongoing studies are examining the importance of the social surroundings in which animals develop to the acquisition of adult rhythmic pattern.
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The preparation and thermal decomposition ammonium selenate and calcium and beryllium selenates have been reported previously. However, there are not any information in the literature concerning the thermal decomposition of double selenates of calcium, of beryllium and ammonium. Thermogravimetry (TG), Differential Thermal Analysis (DTA) were used in the studies and characterisation of these compounds.
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Introduction the selective serotonin reuptake inhibitors have become the most frequently prescribed drugs for the treatment of depression. Sexual side effects have been noted to occur with this treatment on heterosexual behavior in rats. Heterosexual experience facilitates sexual orientation of male rats and decreases the latencies to first mount and first intromission. on the other hand, homosexual behavior in male rats induced by female hormones has not been evaluated.Aim the objective of this work is to evaluate the effects of heterosexual and homosexual experience in male rats long-term treated with fluoxetine (FLX) on homosexual hormone-induced behavior.Materials and Methods Male rats were treated with FLX or saline solution (10 mg/kg for 65 days). At days 36, 50, and 65 of the treatment, the rats were evaluated for homosexual behavior. Other rats treated with FLX or saline solution for 60 consecutive days were submitted to heterosexual behavior at 14, 21, and 28 days of the treatment. After this, they were orquiectomized and homosexual hormone-induced behavior was observed at 45 and 60 days of the treatment.Results (1) Only treatment with FLX did not affect the homosexual behavior. (2) the homosexual experience facilitated the homosexual behavior mainly on the animals from the control group. (3) the heterosexual experience facilitated the homosexual behavior on both groups.Conclusions Only long-term administration of FLX does not interfere with the homosexual behavior in male rats. The homosexual and the heterosexual experience facilitated the homosexual behavior on the control and experimental groups. We suggested that learning aspects related to sexual behavior are responsible by these results.
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During the winding process of HTS coils the tapes of Bi-2223 are subjected to the influence of bending strain, axial strain, compressive force and torsional deformation resulting in I-c degradation. In the literature the effects of the individual strain components are separately analyzed in spite of during coil winding and energizing the strain-stress effects are combined. In this work using commercial tapes of Bi-2223 Ag/AgMg with and without stainless steel reinforcement several samples were wound on cylindrical FRP G-10 holder in which different combined strains are applied. Measurements of I - V characteristic curves are done to determine the degree of critical current degradation and the operational limits. The results are compared with the I, values of short samples and other specimens subjected to deformation generated by loading types such as tensile and bending strain.
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Fatigue-free Bi3.25La0.75Ti3O12 (BLT) thin films were grown on LaNiO3,RuO2, and La0.5Sr0.5CoO3 bottom electrodes in a microwave furnace at 700 degreesC for 10 min. The remanent polarization (P-r) and the drive voltage (V-c) were in the range of 11-23 muC/cm(2) and 0.86-1.56 V, respectively, and are better than the values found in the literature. The BLT capacitors did not show any significant fatigue up to 10(10) read/write switching cycles. (C) 2004 American Institute of Physics.
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It is reported in the literature that nearly 20% of rats are susceptible to displays of wild running (WR) behavior when submitted to high intensity acoustic stimulation. Some characteristics of WR suggest that it can be viewed as a panic-like reaction. This work aimed to test whether WR-sensitive rats show higher levels of anxiety in elevated-plus-maze (EPM) and predator-odor exposure paradigms in comparison with WR-resistant ones. Male adult Wistar rats were submitted to two trials of acoustic stimulation (104 dB, 60 s) in order to assess WR susceptibility. Seven WR-sensitive and 15 WR-resistant rats were evaluated by the EPM test. Other 13 WR-sensitive and 18 WR-resistant animals were submitted to the predator-odor exposure test which consisted of a 10 min-session of free exploration in a specific apparatus containing two odoriferous stimuli: cotton swab imbedded with snake cloacal gland secretion or with iguana feces (control). WR-sensitive rats presented a significantly higher closed-to open-ann-entry ratio in the EPM test. All rats responded with anxiety-like behaviors to the predator odor exposure, although the WR-sensitive ones showed a marked behavioral inhibition regardless of the odor condition. We conclude that WR-sensitive rats present elevated levels of anxiety manifested by means of passive behavioral strategies. (C) 2004 Elsevier B.V. All rights reserved.
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The effects of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on the central nervous system (CNS) were studied in rats. Behavioural and neurochemical studies were performed. Results show that acute and oral administration of dimethylamine 2,4-D was able to decrease locomotion and rearing frequencies and to increase immobility duration of rats observed in an open-field test. Treatment of rats with p-chlorophenylalanine (PCPA) was unable to change rat's open-field behaviour; 5-hydroxytryptophan (5-HTP) administration not only increased locomotion and rearing frequences but also decreased immobility duration. Pretreatment of the rats with PCPA and 5-HTP decreased and increased dimethylamine 2,4-D effects, respectively. The herbicide was not able to change the striatal levels of dopamine and homovanilic acid but decreased the striatal levels of serotonin (5-HT), as observed for the doses of 100 and 200 mg/kg and increased those of 5-hydroxyindoleacetic acid (5-HIAA) as measured after the 200 mg/kg dose treatment. When the levels of serotonin and 5-HIAA were measured at the brain stem level, only those of 5-HIAA were modified, being increased by diethylamine 2,4-D (60; 100 and 200 mg/kg); this increment on 5-HIAA levels was observed even 1 hr after pesticide administration. Further analysis showed that 2,4-D concentrations chromatographycally detected both in serum and brain of the intoxicated animals were dose-dependent, being found as early as 1 hr after the smaller dose of the herbicide used (10 mg/kg). The results suggest that diethylamine 2,4-D modify 5-HT functional activity within the CNS. Thus, the effects of the herbicide on open-field behaviour of rats could be attributed to a direct or indirect pesticide action on serotoninergic systems.
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The involvement of neurotoxicants in the etiology of emotional pathologies is becoming an issue in neurotoxicology. Lead (Pb) exposure during childhood has been associated with increased impulsivity, aggressivity, and delinquency. Considering the paucity of experimental studies investigating the involvement of developmental Pb exposure in emotional disorders, our objective was to investigate whether Pb exposure during pregnancy and/or lactation could be related to depressive symptoms in adult male and female rats. Wistar dams received 10 mg of Pb, as Pb acetate, or 13.4 mg of Na acetate, by gavage, daily, during pregnancy and lactation. By cross-fostering at the time of birth, pups were either exposed to Ph or Na acetate during pregnancy only, lactation only, or during both pregnancy and lactation. At 70 days of age, animals were submitted to the open-field test followed by the forced swimming test. Ph levels were measured in the blood of dams (weaning) and pups (after behavioral evaluation). The results demonstrated that exposure to Ph during both pregnancy and lactation induced, in males, an increased emotionality state detected in the open-field test, and in females, depressive-like behavior detected in the forced swimming test. These alterations were observed at residual blood Pb levels (i.e., around 5 mug/dL).
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The effects of prenatal exposure of rat pups to 0.08 mg/kg deltamethrin (DTM) on physical, reflex and behavioral developmental parameters, on forced swimming and open-field behaviors, and on striatal monoamine levels at 60 days of age were observed. Maternal and offspring body weight, physical and reflex development were unaffected by the exposure to the pesticide. At 21 days of age, open-field locomotion frequency and immobility duration of male and female offspring were not different between control and exposed animals. However, male rearing frequency was increased in experimental animals. A decreased immobility latency to float and in general activity after the swimming test in male offspring was observed at adult age; no interference was detected in the float duration during the swimming test. In addition, these animals presented higher striatal 3,4-dihydroxyphenylacetic acid (DOPAC) levels without modification in dopamine (DA) levels and an increased DOPAC/DA ratio. These data indicate a higher activity of the dopaminergic system in these animals. Noradrenaline (NA) levels were increased, while MHPG levels were not detectable in the system studied. Serotonin (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) levels, as well as the homovanillic acid (HVA)/DA ratio, were not modified by the exposure to the pesticide. No changes were observed in swimming and open-field behaviors nor were there any changes in striatal monoamines or their metabolites in the female experimental group. In relation to the pesticide formula, the present data showing that prenatal exposure to DTM alters latency to float and the activity of striatal dopaminergic system might reflect a persistent effect of the pesticide on animal motor activity, mainly in males. on the other hand, the decrease in general activity observed in experimental male rats suggests higher levels of emotionality induced by previous exposure to the swimming behavior test in relation to control animals. Data gathered in the present study may be important for the assessment of the safety of pyrethroid insecticides. (C) 2001 Elsevier B.V. All rights reserved.
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Foraging associations between birds and other groups of animals have been widely reported in the literature. I report the first observation of a foraging tactic involving a flock of Greater Ani (Crotophaga major), which deliberately followed fish along an artificial ditch in the Pantanal wetlands, feeding on animals flushed by the movement of the vegetation on the ditch banks. Further observations of the feeding behavior and foraging tactics of Greater Anis are necessary to ascertain if this type of behavior is a frequent event or merely sporadic. Received 22 June 2010. Accepted 11 October 2010.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Objective. To investigate the long-term outcome and prognostic factors of juvenile dermatomyositis (DM) through a multinational, multicenter study.Methods. Patients consisted of inception cohorts seen between 1980 and 2004 in 27 centers in Europe and Latin America. Predictor variables were sex, continent, ethnicity, onset year, onset age, onset type, onset manifestations, course type, disease duration, and active disease duration. Outcomes were muscle strength/endurance, continued disease activity, cumulative damage, muscle damage, cutaneous damage, calcinosis, lipodystrophy, physical function, and health-related quality of life (HRQOL).Results. A total of 490 patients with a mean disease duration of 7.7 years were included. At the cross-sectional visit, 41.2-52.8% of patients, depending on the instrument used, had reduced muscle strength/endurance, but less than 10% had severe impairment. Persistently active disease was recorded in 41.2-60.5% of the patients, depending on the activity measure used. Sixty-nine percent of the patients had cumulative damage. The frequency of calcinosis and lipodystrophy was 23.6% and 9.7%, respectively. A total of 40.7% of the patients had decreased functional ability, but only 6.5% had major impairment. Only a small fraction had decreased HRQOL. A chronic course, either polycyclic or continuous, consistently predicted a poorer outcome. Mortality rate was 3.1%.Conclusion. This study confirms the marked improvement in functional outcome of juvenile DM when compared with earlier literature. However, many patients had continued disease activity and cumulative damage at followup. A chronic course was the strongest predictor of poor prognosis. These findings highlight the need for treatment strategies that enable a better control of disease activity over time and the reduction of nonreversible damage.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Environmental toxicants and stress influence the health and behavior of people from different parts of the world. In the present study, aggressive behavior was evaluated in rats exposed to cadmium (Cd) for four weeks and subjected to immobilization stress (IS) based on the resident/intruder paradigm. Latency to the first bite (LB), total number of attacks (NA), total duration of attack manifestations (DAM), and a composite aggression score (CAS) were used to assess aggressiveness. Cadmium concentrations in the blood and the brain were determined. We observed that the parameters of aggressiveness were not altered by either Cd or IS when administered separately. However, animals exposed to Cd + IS had increased NA, DAM, and CAS. Cadmium was detected in the blood and the brain after treatment and Cd + IS exposure modified Cd distribution in these tissues. These results suggest that exposure to low levels of Cd associated with stress may lead to increased aggressiveness in rats. (C) 2011 Elsevier B.V. All rights reserved.