Chaos control and sensitivity analysis of a double pendulum arm excited by an RLC circuit based nonlinear shaker

In this paper the dynamical interactions of a double pendulum arm and an electromechanical shaker is investigated. The double pendulum is a three degree of freedom system coupled to an RLC circuit based nonlinear shaker through a magnetic field, and the capacitor voltage is a nonlinear function of the instantaneous electric charge. Numerical simulations show the existence of chaotic behavior for some regions in the parameter space and this behaviour is characterized by power spectral density and Lyapunov exponents. The bifurcation diagram is constructed to explore the qualitative behaviour of the system. This kind of electromechanical system is frequently found in robotic systems, and in order to suppress the chaotic motion, the State-Dependent Riccati Equation (SDRE) control and the Nonlinear Saturation control (NSC) techniques are analyzed. The robustness of these two controllers is tested by a sensitivity analysis to parametric uncertainties.

Control of bacterial spot of tomato and activation of enzymes related to resistance by chemicals under field conditions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bovine Tuberculosis in Swedish Farmed Deer: Detection and Control of the Disease

Bovine tuberculosis (BTB) was introduced into Swedish farmed deer herds in 1987. Epidemiological investigations showed that 10 deer herds had become infected (July 1994) and a common source of infection, a consignment of 168 imported farmed fallow deer, was identified (I). As trace-back of all imported and in-contact deer was not possible, a control program, based on tuberculin testing, was implemented in July 1994. As Sweden has been free from BTB since 1958, few practicing veterinarians had experience in tuberculin testing. In this test, result relies on the skill, experience and conscientiousness of the testing veterinarian. Deficiencies in performing the test may adversely affect the test results and thereby compromise a control program. Quality indicators may identify possible deficiencies in testing procedures. For that purpose, reference values for measured skin fold thickness (prior to injection of the tuberculin) were established (II) suggested to be used mainly by less experienced veterinarians to identify unexpected measurements. Furthermore, the within-veterinarian variation of the measured skin fold thickness was estimated by fitting general linear models to data (skin fold measurements) (III). The mean square error was used as an estimator of the within-veterinarian variation. Using this method, four (6%) veterinarians were considered to have unexpectedly large variation in measurements. In certain large extensive deer farms, where mustering of all animals was difficult, meat inspection was suggested as an alternative to tuberculin testing. The efficiency of such a control was estimated in paper IV and V. A Reed Frost model was fitted to data from seven BTB-infected deer herds and the spread of infection was estimated (< 0.6 effective contacts per deer and year) (IV). These results were used to model the efficiency of meat inspection in an average extensive Swedish deer herd. Given a 20% annual slaughter and meat inspection, the model predicted that BTB would be either detected or eliminated in most herds (90%) 15 years after introduction of one infected deer. In 2003, an alternative control for BTB in extensive Swedish deer herds, based on the results of paper V, was implemented.

The Role of CEO Statements of Aggressiveness and the Competitive Aggressiveness of Firms: What is the Impact on Performance?

This research examines the impact of a CEO’s statements of aggressiveness on his or her organization’s competitive moves and subsequent performance. Hypotheses were developed based on previous work in Upper Echelon Theory and competitive dynamics. Based on this prior literature, it was hypothesized aggressive statements by CEOs will be associated with more aggressive organizations. It was also hypothesized these more aggressive organizations would display better performance than less aggressive organizations. A content analysis of letters to shareholders and trade publications was performed. This data was analyzed using multiple regression in SPSS 17 to test the hypotheses that aggressive statements by CEOs are associated with aggressive organizations and higher performance. Aggression scores for the content analysis were generated using the software package DICTION. The sample for the study was the organizations with the most revenue in two industries, automobile manufacturing and retailing. Data collection covered a five-year time span from 2003-2007, with performance data lagged one year. Control variables employed included CEO tenure, CEO background, organization size, and organization age. The findings indicate that CEO statements of aggressiveness do not significantly impact the competitive aggressiveness or the performance of their organizations. The implications of these findings are discussed and potential avenues for future research in the area are outlined.

Tests of the Dynamic Field Theory and the Spatial Precision Hypothesis: Capturing a Qualitative Developmental Transition in Spatial Working Memory

This study tested a dynamic field theory (DFT) of spatial working memory and an associated spatial precision hypothesis (SPH). Between 3 and 6 years of age, there is a qualitative shift in how children use reference axes to remember locations: 3-year-olds’ spatial recall responses are biased toward reference axes after short memory delays, whereas 6-year-olds’ responses are biased away from reference axes. According to the DFT and the SPH, quantitative improvements over development in the precision of excitatory and inhibitory working memory processes lead to this qualitative shift. Simulations of the DFT in Experiment 1 predict that improvements in precision should cause the spatial range of targets attracted toward a reference axis to narrow gradually over development, with repulsion emerging and gradually increasing until responses to most targets show biases away from the axis. Results from Experiment 2 with 3- to 5-year-olds support these predictions. Simulations of the DFT in Experiment 3 quantitatively fit the empirical results and offer insights into the neural processes underlying this developmental change.

SIGNIFICANCE AND CONTROL OF FUNGAL DISEASES RELATED TO BIRD ROOSTS

Certain fungi have been found frequently as saprophytes in areas containing large amounts of bird excreta. These fungi have the ability to survive, multiply, and cause disease once they have entered a host. Two of these are Crypto-coccus neoformans and Histoplasma capsulatum. Both may easily become airborne and be disseminated throughout an area by the prevailing winds. C. neo-formans is commonly isolated from the excreta of pigeon habitats, and in turn has been associated with clinical cases of cryptococcosis, while blackbird roosts, harboring H. capsulatum, have been responsible for several outbreaks of histoplasmosis. When either of these fungi have become established in nature, the sites may become foci for infection and epidemics may occur if the sites are disturbed. This has led to investigation of these organisms with respect to: 1) the frequency of isolation of H. capsulatum from the soil beneath blackbird roosts in a histoplasmosis endemic area; 2) the infectivity of undisturbed roosts positive for H. capsulatum; and 3) the effectiveness of chemical decontamination of areas containing C. neoformans or H. capsulatum.

A new aspect of sign and its implications for the Theory of Communication

Este artigo propõe que a semiótica peirceana pode oferecer bases tanto lógicas quanto epistemológicas para a busca de uma teoria geral da comunicação. No entanto, o desenvolvimento de uma teoria semiótica da comunicação depende, em primeiro lugar, de uma melhor compreensão dos aspectos formais do signo, tarefa atribuída por Peirce à gramática, o primeiro ramo de sua semiótica. Nós apresentamos uma análise das relações do signo, revelando um aspecto não trabalhado por Peirce, ampliando seu número para onze. Este novo aspecto é a relação triádica entre signo, objeto dinâmico e interpretante dinâmico (S-OD-ID). Nós defendemos que esta relação é essencial para a compreensão da comunicação como semiose, por dar conta da repetição ou redundância do signo comunicativo, quando se cria ou transmite informação. O artigo pretende dar um passo a mais na direção de uma teoria da comunicação verdadeiramente universal, através do vínculo entre a semiótica peirceana e a moderna filosofia da linguagem.

An Alternative Method for the Simultaneous Determination of Copper and Lead for Quality Control of Sugar Cane Spirit using a Nanotube-Based Sensor

The development of an electroanalytical method for simultaneous determination of copper and lead ions in sugar cane spirit (cachaca) using carbon paste electrode modified with ascorbic acid and carbon nanotubes (CPE-AaCNT) is described. Squarewave voltammetry (SWV) with anodic stripping was employed, and this technique was optimized with respect to the following parameters: frequency (50 Hz), amplitude (100 mV) and scan increment (9 mV). The analytical curves were linear in the range from 0.0900 to 7.00 mg L-1 for lead and copper. The limits of detection were 48.5 and 23.9 mu g L-1 for lead and copper, respectively. The developed method was applied to the simultaneous determination of copper and lead in five commercial samples of sugar cane spirit. The results were in good agreement with those obtained by F AAS/GF AAS (flame atomic absorption spectrometry/graphite furnace atomic absorption spectrometry) and showed that CPE-AaCNT can be successfully employed in the simultaneous determination of these metals in real sugar cane spirit samples.

Loss of Y-chromosome does not correlate with age at onset of head and neck carcinoma: a case-control study

Loss of Y-chromosome has been correlated with older age in males. Furthermore, current evidence indicates that Y-chromosome loss also occurs in several human tumors, including head and neck carcinomas. However, the association between Y nullisomy and the occurrence of neoplasias in elderly men has not been well established. In the present study, the association between Y-chromosome loss and head and neck carcinomas was evaluated by comparison to cells from peripheral blood lymphocytes and normal mucosa of cancer-free individuals matched for age using dual-color fluorescence in situ hybridization. Twenty-one patients ranging in age from 28 to 68 years were divided into five-year groups for comparison with 16 cancer-free individuals matched for age. The medical records of all patients were examined to obtain clinical and histopathological data. None of the patients had undergone radiotherapy or chemotherapy before surgery. In all groups, the frequency of Y-chromosome loss was higher among patients than among normal reference subjects (P < 0.0001) and was not age-dependent. These data suggest that Y-chromosome loss is a tumor-specific alteration not associated with advanced age in head and neck carcinomas.

An in vitro study showing the three-dimensional microenvironment influence over the behavior of head and neck squamous cell carcinoma

Objectives: The Head and Neck Squamous Cell Carcinoma (HNSCC) ranks sixth worldwide. The mechanisms of growth, invasion and metastasis of this pathology are extensively studied and generally related to specific variations in signaling pathways like the PI3K-Akt; however most of these competent studies have been performed bidimensionally, which may hide important questions. This study sought to analyze the influence of the microenvironment upon the behavior of HNSCC. Study Design: The status of pAkt, NF-kappa B and Cyclin D1 proteins was accessed through immunofluorescence and western blot methods in HNSCC cell lines originating from tongue, pharynx and metastatic lymph node when submitted to a three-dimensional culture model utilizing a matrix system. A bidimensional culture model (monolayer) was used as control. Results: The HNSCC cell lines cultured three-dimensionally exhibited a growth pattern characterized by small isolated islands, different from the control group. When the three-dimensional model was applied, two of the studied cell lines showed the same expression pattern as the bidimensional model regarding nuclear or cytoplasmatic localization, as well as reduction of all protein levels; however, the cell line originated from tongue, which specially has the epidermal growth factor receptor constitutively activated, demonstrated nuclear translocation of pAkt and also an increase in the levels of Cyclin D1. Conclusions: The results suggest the influence of the microenvironment upon the behavior of HNSCC cells due to the changed expression of proteins related to tumor growth and cellular invasion. Furthermore, intrinsically genetic conditions also played important roles over the cells, despite the culture model employed.

Home blood pressure monitoring and control in a group of hypertensive patients

This qualitative study was performed with 71 hypertensive patients, with the objectives to compare outpatient and home blood pressure monitoring (HBPM), to assess blood pressure control, and characterize white-coat hypertension. A nurse performed the outpatient blood pressure measurement. The home blood pressure monitoring was carried out over seven days. White-coat hypertension was quantified as a difference between the outpatient measurement and home blood pressure monitoring in the ranges from 1 to 5, 6 to 10 and > 10 mmHg. The outpatient blood pressure measurement was significantly higher (p<0.05) than the home blood pressure measurement. Pressure control corresponded to 9.9% in the outpatient measurement and 23.9% in the home blood pressure measurement. The white-coat effect > 10 mmHg was 57.7% for systolic and 32.4% for diastolic pressure, in the range from 6 to 10 mmHg. Home blood pressure measurement provided a better assessment of hypertensive patients' control.

Chronic intermittent hypoxia alters glutamatergic control of sympathetic and respiratory activities in the commissural NTS of rats

Costa-Silva JH, Zoccal DB, Machado BH. Chronic intermittent hypoxia alters glutamatergic control of sympathetic and respiratory activities in the commissural NTS of rats. Am J Physiol Regul Integr Comp Physiol 302: R785-R793, 2012. First published December 28, 2011; doi:10.1152/ajpregu.00363.2011.-Sympathetic overactivity and altered respiratory control are commonly observed after chronic intermittent hypoxia (CIH) exposure. However, the central mechanisms underlying such neurovegetative dysfunctions remain unclear. Herein, we hypothesized that CIH (6% O-2 every 9 min, 8 h/day, 10 days) in juvenile rats alters glutamatergic transmission in the commissural nucleus tractus solitarius (cNTS), a pivotal site for integration of peripheral chemoreceptor inputs. Using an in situ working heart-brain stem preparation, we found that L-glutamate microinjections (1, 3, and 10 mM) into the cNTS of control rats (n = 8) evoked increases in thoracic sympathetic nerve (tSN) and central vagus nerve (cVN) activities combined with inhibition of phrenic nerve (PN) activity. Besides, the ionotropic glutamatergic receptor antagonism with kynurenic acid (KYN; 250 mM) in the cNTS of control group (n = 7) increased PN burst duration and frequency. In the CIH group (n = 10), the magnitude of L-glutamate-induced cVN excitation was smaller, and the PN inhibitory response was blunted (P < 0.05). In addition, KYN microinjections into the cNTS of CIH rats (n = 9) did not alter PN burst duration and produced smaller increases in its frequency compared with controls. Moreover, KYN microinjections into the cNTS attenuated the sympathoexcitatory response to peripheral chemoreflex activation in control but not in CIH rats (P < 0.05). These functional CIH-induced alterations were accompanied by a significant 10% increase of N-methyl-D-aspartate receptor 1 (NMDAR1) and glutamate receptor 2/3 (GluR2/3) receptor subunit density in the cNTS (n = 3-8, P < 0.05), evaluated by Western blot analysis. These data indicate that glutamatergic transmission is altered in the cNTS of CIH rats and may contribute to the sympathetic and respiratory changes observed in this experimental model.

DengueTools: innovative tools and strategies for the surveillance and control of dengue

Dengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of 'Comprehensive control of Dengue fever under changing climatic conditions'. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named 'DengueTools' to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe) in the context of globalization and climate change. The consortium comprises 12 work packages to address a set of research questions in three areas: Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability for epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring. Research area 2: Develop novel strategies to prevent dengue in children. Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change. In this paper, we report on the rationale and specific study objectives of 'DengueTools'. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant Agreement Number: 282589 Dengue Tools.

OPTIMIZATION AND CONTROL OF A CONTINUOUS POLYMERIZATION REACTOR

This work studies the optimization and control of a styrene polymerization reactor. The proposed strategy deals with the case where, because of market conditions and equipment deterioration, the optimal operating point of the continuous reactor is modified significantly along the operation time and the control system has to search for this optimum point, besides keeping the reactor system stable at any possible point. The approach considered here consists of three layers: the Real Time Optimization (RTO), the Model Predictive Control (MPC) and a Target Calculation (TC) that coordinates the communication between the two other layers and guarantees the stability of the whole structure. The proposed algorithm is simulated with the phenomenological model of a styrene polymerization reactor, which has been widely used as a benchmark for process control. The complete optimization structure for the styrene process including disturbances rejection is developed. The simulation results show the robustness of the proposed strategy and the capability to deal with disturbances while the economic objective is optimized.

Effect of fungicides and alternative products in control of anthracnose and black spot of guava

This work aimed to evaluate the efficiency of fungicides in controlling in vitro and in vivo the causal agents of anthracnose (Colletotrichum gloeosporioides and C. acutatum) and black spot (Guignardia psidii) and evaluate the effect of alternative products to control these diseases. Inhibition of mycelial growth of the pathogens was evaluated for ten fungicides at concentrations of 1, 10 and 100 mg L-1 of active ingredient in potato-dextrose-agar medium. The effectiveness of the fungicides azoxystrobin + difenoconazole, cyproconazole, pyraclostrobin, tebuconazole and tebuconazole + trifloxystrobin in controlling disease incidence and severity of anthracnose, through applications in the field, was measured in fruits collected at three stages of maturation, according to the skin color ( dark green, light green and yellowish green). In postharvest dipping of fruits, the products evaluated were citric acid, peracetic acid, salicylic acid, sodium bicarbonate, chlorine dioxide, Ecolife (R) and chitosan. The fungicides azoxystrobin + difenoconazole, pyraclostrobin, tebuconazole and trifloxystrobin + tebuconazole were highly effective in inhibiting the in vitro mycelial growth of G. psidii and moderately to highly effective in inhibiting C. acutatum and C. gloeosporioides. In field conditions, the fungicide azoxystrobin + difenoconazole was effective in controlling anthracnose and black spot in fruit at three maturity stage ( skin color yellowish green). The alternative products tested were ineffective in the curative control of anthracnose and early blight at postharvest of guava.