On elimination of chaotic behavior in a non-ideal portal frame structural system, using both passive and active controls

In this paper, an application is considered of both active and passive controls, to suppression of chaotic behavior of a simple portal frame, under the excitation of an unbalanced DC motor, with limited power supply (non-ideal problem). The adopted active control strategy consists of two controls: the nonlinear (feedforward) in order to keep the controlled system in a desirable orbit, and the feedback control, which may be obtained by considering state-dependent Riccati equation control to bringing the system into the desired orbit using a magneto rheological (MR) damper. To control the electric current applied in control of the MR damper the Bouc-Wen mathematical model was used to the MR damper. The passive control was obtained by means of a nonlinear sub-structure with properties of nonlinear energy sink. Simulations showed the efficiency of both the passive control (energy pumping) and active control strategies in the suppression of the chaotic behavior. © The Author(s) 2012.

Influence of visual feedback sampling on obstacle crossing behavior in people with Parkinson's disease

The purpose of the current study was to investigate the role of visual information on gait control in people with Parkinson's disease as they crossed over obstacles. Twelve healthy individuals, and 12 patients with mild to moderate Parkinson's disease, walked at their preferred speeds along a walkway and stepped over obstacles of varying heights (ankle height or half-knee height), under three visual sampling conditions: dynamic (normal lighting), static (static visual samples, similar to stroboscopic lighting), and voluntary visual sampling. Subjects wore liquid crystal glasses for visual manipulation. In the static visual sampling condition only, the patients with Parkinson's disease made contact with the obstacle more often than did the control subjects. In the successful trials, the patients increased their crossing step width in the static visual sampling condition as compared to the dynamic and voluntary visual sampling conditions; the control group maintained the same step width for all visual sampling conditions. The patients showed lower horizontal mean velocity values during obstacle crossing than did the controls. The patients with Parkinson's disease were more dependent on optic flow information for successful task and postural stability than were the control subjects. Bradykinesia influenced obstacle crossing in the patients with Parkinson's disease. © 2013 Elsevier B.V.

Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius)

Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius). During nest excavation, leaf-cutting ant workers undergo reduction in their body reserve, particularly carbohydrates. In order to estimate the energetic cost of digging, groups of 30 workers of the leaf-cutting ant Atta sexdens were sealed in a hermetic chamber for 24, 48 and 72 hours, with and without soil for digging, and had the CO2 concentration measured using respirometric chambers as well as volume of soil excavated (g). As expected, the worker groups that carried out soil excavation expelled more carbon dioxide than the groups that did not excavate. Therefore, a worker with body mass of 9.65 ± 1.50 mg dug in average 0.85 ± 0.27 g of soil for 24 hours, consuming ca. 0.58 ± 0.23 J. In this study, we calculate that the energetic cost of excavation per worker per day in the experimental set-up was ca. 0.58 J.

Perinatal Periodontal Disease Reduces Social Behavior in Male Offspring

Objective: Our objective was to verify whether prenatal maternal periodontitis is a risk factor for the development of central nervous system disorders in rats. Methods: Periodontitis was induced by placing a ligature around the upper and lower first molars in 9 female Wistar rats (experimental group); 9 rats were left unligated (control group). The maternal general activity in an open field was observed on gestational day (GD) 0, GD 4, and GD 14, and the maternal performance was assessed on the second day after birth. The pups' play behavior was assessed on postnatal day 30. The relative level of reelin was measured in the frontal cortex by real-time PCR analysis. Results: The results showed that, compared with the control group, (1) the general activity in female rats with periodontitis was decreased, (2) the maternal performance of these rats was not modified by periodontitis, (3) the play behavior of pups from dams with periodontitis was decreased, and (4) there were no differences in the frontal cortex reelin levels of pups from dams with periodontitis. Conclusions: We conclude that pre- and postnatal periodontitis induces maternal sickness behavior and reduces the pups' play behavior without interference with frontal cortex reelin expression. Copyright (C) 2012 S. Karger AG, Basel

Temporal Analysis of Lipopolysaccharide-Induced Sickness Behavior in Virgin and Lactating Female Rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Coordination of construction behavior in the termite Procornitermes araujoi: structure is a stronger stimulus than volatile marking

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

How does tourist monitoring alter fish behavior in underwater trails?

Nature based tourism is becoming more popular because it is perceived as a solution to the conflict between conservation and economic exploitation. Nevertheless, it is known to cause several effects. This paper reports findings whereby monitored tourism avoids triggering adverse effects for social cichlid fish species, Crenicichla lepidota. Measures used included aggression toward territorial intruders and the number of nests built in pristine reference areas for monitored and in non-monitored tourist areas. We observed suppressed aggressive behavior and suppressed nesting only in the non-monitored area. We conclude that by monitoring visits, and using techniques including avoiding stepping on the river bed, reducing the number of visitors, prohibiting fish feeding and protecting riparian vegetation, it is possible to avoid the enduring damage caused by nature tourism. (C) 2014 Elsevier Ltd. All rights reserved.

Hyaluronic Acid Behavior in the Lamina Propria of the Larynx with Advancing Age

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

How can an invasive grass affect fire behavior in a tropical savanna? A community and individual plant level approach

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Moulting behavior in leaf-frogs of the genus phyllomedusa (Anura : hylidae)

The species belonging to the subfamily Phyllomedusinae presents physiological and behavioral adaptations to economise water such as secretion of lipids coupled with its spreading onto the skin surface through a complex behavior, adoption of diurnal torpor and secretion of uric acid. Here we describe other adaptation probably involved with water economy, registered in Phyllomedusa distincta, P. tarsius, P. tetraploidea and natural hybrids of P. distincta and P. tetraploidea - at dusk, these amphibians perform an elaborate moulting behavior that encompasses the cleaning of the body with the limbs plus gaping and body contractions. Our data show the daily moulting in P. distincta and suggest that the same mechanism occurs for the other species studied. We suppose that daily moulting improves the skin permeability to water being a characteristic of the phyllomedusines which spread lipids onto the skin surface.

Acute-phase protein behavior in dairy cattle herd naturally infected with Trypanosoma vivax

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

High blood pressure and sedentary behavior in adolescents are associated even after controlling for confounding factors

The aim of this study was to determine whether high blood pressure (HBP) is associated with sedentary behavior in young people even after controlling for potential confounders (gender, age, socioeconomic level, tobacco, alcohol, obesity and physical activity). In this epidemiological study, 1231 adolescents were evaluated. Blood pressure was measured with an oscillometric device and waist circumference with an inextensible tape. Sedentary behavior (watching television, computer use and playing video games) and physical activity were assessed by a questionnaire. We used mean and standard deviation to describe the statistical analysis, and the association between HBP and sedentary behavior was assessed by the chi-squared test. Binary logistic regression was used to observe the magnitude of association and cluster analyses (sedentary behavior and abdominal obesity; sedentary behavior and physical inactivity). HBP was associated with sedentary behaviors [odds ratio (OR) = 2.21, 95% confidence interval (CI) = 1.41-3.96], even after controlling for various confounders (OR = 1.68, CI = 1.03-2.75). In cluster analysis the combination of sedentary behavior and elevated abdominal obesity contributed significantly to an increased likelihood of having HBP (OR = 13.51, CI 7.21-23.97). Sedentary behavior was associated with HBP, and excess fat in the abdominal region contributed to the modulation of this association.

Pemphigus vulgaris in adolescence: a case report

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tobacco in adolescence: importance to knowledge the health hazards and preventive measures

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estrous behavior and the estrus-to-ovulation interval in Nelore cattle (Bos indicus) with natural estrus or estrus induced with prostaglandin F2 alpha or norgestomet and estradiol valerate

Estrous behavior and the estrus-to-ovulation interval are essential for estimating the best time to artificially inseminate cattle. Because these parameters are not well characterized in the Nelore breed (Bos indicus), the main purpose of the this study was to determine the estrus-to-ovulation interval in Nelore heifers and cows with natural estrus or with estrus induced by treatments with PGF2 alpha or norgestomet and estradiol valerate (NEV). The cows and heifers were observed continuously (24 h a day) to determine the onset of estrus and to study estrous behavior in the cows. Ten hours after the start of estrus the ovaries were scanned every 2 h by ultrasonography to monitor the dominant follicle until ovulation. Blood samples were collected periodically to determine progesterone levels by RIA. Administration of PGF2 alpha (2 injections, 11 days apart) did not induce estrus in most Nelore females in spite of the presence of functional CL, indicated by progesterone concentrations above 6.0 ng/ml in 25 of 28 animals. Treatment with NEV induced high sexual receptivity in cows (10/11), but only 66% ovulated. Cows with natural or induced estrus exhibited behavioral estrus of 10.9 +/- 1.4 h, and ovulation occurred 26.6 +/- 0.44 h (n = 26) after the onset of estrus. In most of the cows (53.8%) estrus began at night (between 1801 and 600 h), and 34.6% it started and finished during the night. It is concluded that in Nelore females ovulation occurs approximately 26 h after the onset of estrus. Additionally, estrous behavior is shorter than in European breeds, and there is a high incidence of estrus at night, which makes it difficult to detect and, consequently, impairs Al in Nelore cattle. The observation that a high percentage of Nelore females with an active CL did not respond to usual dosages of PGF2 alpha warrants further investigation. (C) 1998 by Elsevier B.V.