Design and implementation of a dc-dc converter based on variable structure control of switched systems

This paper presents a control method for a class of continuous-time switched systems, using state feedback variable structure controllers. The method is applied to the control of a non-trivial dc-dc power converter and a simple and inexpensive control circuit design, that was simulated using the software PSpice, is proposed. The design is based on Lyapunov-Metzler-SPR systems and the performance of the resulting control system is superior to that afforded by a recently proposed alternative sliding-mode control technique. © 2011 IFAC.

Delay time detection and accommodation for a networked DC motor control

This paper presents a control method that is effective to reduce the degenerative effects of delay time caused by a treacherous network. In present application a controlled DC motor is part of an inverted pendulum and provides the equilibrium of this system. The control of DC motor is accomplished at the distance through a treacherous network, which causes delay time in the control signal. A predictive technique is used so that it turns the system free of delay. A robust digital sliding mode controller is proposed to control the free-delay system. Due to the random conditions of the network operation, a delay time detection and accommodation strategy is also proposed. A computer simulation is shown to illustrate the design procedures and the effectiveness of the proposed method. © 2011 IEEE.

Determinants of blood pressure in type 2 diabetic subjects with high occurrence of inadequate glycemic control

Study design: Association study Objective: To analyze the association between different biological/behavioral risk factors and blood pressure in a sample of type 2 diabetes mellitus patients with poor glycemic control. Methods: A sample of 121 type 2 diabetic patients was selected in the Public Healthcare System in a middle size Brazilian city. Blood pressure was measured using an aneroid device, previously calibrated. Six determinants of blood pressure were taken into count: age, hypoglycemic agents, general obesity, abdominal obesity, eating behaviors and physical activity level. Results: The type 2 diabetic patients presented mean age of 60.1±8.9 years-old and, at least, one risk factor. Eating behaviors (OR adj= 0.31 [0.12-0.75]) and sports practice (OR adj= 0.12 [0.02-0.75]) constituted protective factors associated with lower systolic blood pressure. On the other hand, age was positively associated with high systolic blood pressure (OR adj= 3.81 [1.39-10.38]). Patients with 5-6 risk factors, presented higher values of systolic and (F= 3.857; p= 0.011 [post hoc with p= 0.039]), diastolic blood pressure (F= 4.158; p= 0.008 [post hoc with p= 0.036]) and increased occurrence of hypertension (p= 0.010). Conclusion: Our findings indicate that, behavioral variables were important determinants of blood pressure in type 2 diabetic patients with poor glycemic control and clustering of behavioral and biological risk factors increase the hypertension occurrence.

Tm-afm nonlinear motion control with robustness analysis to parametric errors in the control signal determination

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efficiency and soil contamination during underground application of insecticides: control of leaf-cutting ants with thermal foggers

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

Methods for qualitative analysis of cefazolin sodium raw material and pharmaceutical product

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation Method for Strategic Investments

Real Options Analysis (ROA) has become a complimentary tool for engineering economics. It has become popular due to the limitations of conventional engineering valuation methods; specifically, the assumptions of uncertainty. Industry is seeking to quantify the value of engineering investments with uncertainty. One problem with conventional tools are that they may assume that cash flows are certain, therefore minimizing the possibility of the uncertainty of future values. Real options analysis provides a solution to this problem, but has been used sparingly by practitioners. This paper seeks to provide a new model, referred to as the Beta Distribution Real Options Pricing Model (BDROP), which addresses these limitations and can be easily used by practitioners. The positive attributes of this new model include unconstrained market assumptions, robust representation of the underlying asset‟s uncertainty, and an uncomplicated methodology. This research demonstrates the use of the model to evaluate the use of automation for inventory control.

FOREST ANIMAL DAMAGE CONTROL

As a nation we have gained world recognition for our ability to utilize our resources. In forestry our greatest accomplishments have been in the mechanization of harvest methods and in improvements in forest products. The renewal of this resource has been our greatest neglect. Though the end of the 19th Century marked the beginning of the conservation movement, it was not until a half century later that the force of economics through the demands of a growing population made forest re-establishment more than just a desire. Conservation in itself is a Utopian concept which requires other motivating forces to make it a reality. In the post-war years, and as late as the early 195O's, stocked land in the Pacific Northwest could be purchased for less than the cost of planting; the economic incentive was lacking. Only with sustained yield management and increased land values was there a balance in favor of true values. With greater effort placed on forest regeneration there was an increased need for methods of reducing losses to wildlife. The history of forest wildlife damage research, therefore, parallels that of forest land management; after rather austere beginnings, development became predominantly a response to economics. It was not until 1950 that the full time of one scientist was assigned to this important activity. The development of control methods for forest animal damage is a relatively new area of research. All animal life is dependent upon plants for its existence; forest wildlife is no exception. The removal of seed and foliage of undesirable plants often benefits the land managers; only when the losses or injuries are in conflict with man's interest is there damage involved. Unfortunately, the feeding activities of wildlife and the interests of the land managers are often in conflict. Few realize the breadth, scope, and subtilities associated with forest wildlife damage problems. There are not only numerous species of animals involved, but also a myriad of conditions, each combination possessing unique facets. It is a foregone conclusion that an understanding of the conditions is essential to facilitate a solution to any given problem. Though there are numerous methods of reducing animal damage, all of which have application under some situations, in this discussion emphasis will be placed on the role of chemicals and on western problems. Because of the broadness and complexity of the problem, generalizing is necessary and only brief coverage will be possible. However, an attempt will be made to discuss the use and limitations of various control methods.

Characterization of a Toxoneuron nigriceps (Viereck) (Hymenoptera: Braconidae) - derived chitinase and its potential for pest control

The larval endoparasitoid Toxoneuron nigriceps (Viereck) (Hymenoptera: Braconidae) has a toolbox of biological weapons to secure for host colonization and the successful parasitization of its host Heliothis virescens (F.) (Lepidoptera: Noctuidae). The cDNA of a putative chitinase has been previously isolated and initially characterized from teratocytes of this parasitoid among the plethora of molecules available in the venom and calyx fluids injected by females, oral and/or anal secretions released by the parasitoid larvae and/or produced by the expression of genes of the symbiotic associated polydnavirus. This putative chitinase has been initially associated with the host cuticle digestion to allow for parasitoid egression and with the asepsis of the host environment, acting as an antimicrobial. As chitinases are commonly expressed in plants against plant pathogens, the chitinase derived from the teratocytes of T. nigriceps is a potential tool for the development of insect pest control methods based on the disruption of the perithrophic membrane of herbivores. Therefore, we aimed to characterize the activity of the putative chitinase from teratocytes of T. nigriceps (Tnchi) produced using the Escherichia coli expression system and its potential to control H. virescens larvae when expressed into transgenic tobacco plants. The purified E. coli-produced Tnchi protein showed no chitinolitic activity, but was active in binding with colloidal and crystalline chitins in water and with colloidal chitin in buffered solution (pH = 6.74). Transgenic tobacco plants showed no enhanced chitinolitic activity relative to control plants, but survival of three-day old larvae of H. virescens was severely affected when directly fed on transgenic tobacco leaves expressing the recombinant Tnchi protein. Some properties of the Tnchi protein and the potential use of Tnchi-transgenic plants to control plant pests are discussed. (c) 2012 Elsevier Inc. All rights reserved.

Chronic pain associated with the Chikungunya Fever: long lasting burden of an acute illness

Abstract Background Chikungunya virus (CHIKV) is responsible for major epidemics worldwide. Autochthonous cases were recently reported in several European countries. Acute infection is thought to be monophasic. However reports on chronic pain related to CHIKV infection have been made. In particular, the fact that many of these patients do not respond well to usual analgesics suggests that the nature of chronic pain may be not only nociceptive but also neuropathic. Neuropathic pain syndromes require specific treatment and the identification of neuropathic characteristics (NC) in a pain syndrome is a major step towards pain control. Methods We carried out a cross-sectional study at the end of the major two-wave outbreak lasting 17 months in Réunion Island. We assessed pain in 106 patients seeking general practitioners with confirmed infection with the CHIK virus, and evaluated its impact on quality of life (QoL). Results The mean intensity of pain on the visual-analogical scale (VAS) was 5.8 ± 2.1, and its mean duration was 89 ± 2 days. Fifty-six patients fulfilled the definition of chronic pain. Pain had NC in 18.9% according to the DN4 questionnaire. Conversely, about two thirds (65%) of patients with NC had chronic pain. The average pain intensity was similar between patients with or without NC (6.0 ± 1.7 vs 6.1 ± 2.0). However, the total score of the Short Form-McGill Pain Questionnaire (SF-MPQ)(15.5 ± 5.2 vs 11.6 ± 5.2; p < 0.01) and both the affective (18.8 ± 6.2 vs 13.4 ± 6.7; p < 0.01) and sensory subscores (34.3 ± 10.7 vs 25.0 ± 9.9; p < 0.01) were significantly higher in patients with NC. The mean pain interference in life activities calculated from the Brief Pain Inventory (BPI) was significantly higher in patients with chronic pain than in patients without it (6.8 ± 1.9 vs 5.9 ± 1.9, p < 0.05). This score was also significantly higher in patients with NC than in those without such a feature (7.2 ± 1.5 vs 6.1 ± 1.9, p < 0.05). Conclusions There exists a specific chronic pain condition associated to CHIKV. Pain with NC seems to be associated with more aggressive clinical picture, more intense impact in QoL and more challenging pharmacological treatment.

Genetic Control of Mosquitoes: population suppression strategies

Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT) is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL) offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural and ethical aspects of the use and deployment of these vector control methods.

A comparative analysis of the relative efficacy of vector-control strategies against dengue fever

Dengue is considered one of the most important vector-borne infection, affecting almost half of the world population with 50 to 100 million cases every year. In this paper, we present one of the simplest models that can encapsulate all the important variables related to vector control of dengue fever. The model considers the human population, the adult mosquito population and the population of immature stages, which includes eggs, larvae and pupae. The model also considers the vertical transmission of dengue in the mosquitoes and the seasonal variation in the mosquito population. From this basic model describing the dynamics of dengue infection, we deduce thresholds for avoiding the introduction of the disease and for the elimination of the disease. In particular, we deduce a Basic Reproduction Number for dengue that includes parameters related to the immature stages of the mosquito. By neglecting seasonal variation, we calculate the equilibrium values of the model’s variables. We also present a sensitivity analysis of the impact of four vector-control strategies on the Basic Reproduction Number, on the Force of Infection and on the human prevalence of dengue. Each of the strategies was studied separately from the others. The analysis presented allows us to conclude that of the available vector control strategies, adulticide application is the most effective, followed by the reduction of the exposure to mosquito bites, locating and destroying breeding places and, finally, larvicides. Current vector-control methods are concentrated on mechanical destruction of mosquitoes’ breeding places. Our results suggest that reducing the contact between vector and hosts (biting rates) is as efficient as the logistically difficult but very efficient adult mosquito’s control.

Reliability of intraoperative high-resolution 2D ultrasound as an alternative to high-field strength MR imaging for tumor resection control: a prospective comparative study

OBJECT: Ultrasound may be a reliable but simpler alternative to intraoperative MR imaging (iMR imaging) for tumor resection control. However, its reliability in the detection of tumor remnants has not been definitely proven. The aim of the study was to compare high-field iMR imaging (1.5 T) and high-resolution 2D ultrasound in terms of tumor resection control. METHODS: A prospective comparative study of 26 consecutive patients was performed. The following parameters were compared: the existence of tumor remnants after presumed radical removal and the quality of the images. Tumor remnants were categorized as: detectable with both imaging modalities or visible only with 1 modality. RESULTS: Tumor remnants were detected in 21 cases (80.8%) with iMR imaging. All large remnants were demonstrated with both modalities, and their image quality was good. Two-dimensional ultrasound was not as effective in detecting remnants<1 cm. Two remnants detected with iMR imaging were missed by ultrasound. In 2 cases suspicious signals visible only on ultrasound images were misinterpreted as remnants but turned out to be a blood clot and peritumoral parenchyma. The average time for acquisition of an ultrasound image was 2 minutes, whereas that for an iMR image was approximately 10 minutes. Neither modality resulted in any procedure-related complications or morbidity. CONCLUSIONS: Intraoperative MR imaging is more precise in detecting small tumor remnants than 2D ultrasound. Nevertheless, the latter may be used as a less expensive and less time-consuming alternative that provides almost real-time feedback information. Its accuracy is highest in case of more confined, deeply located remnants. In cases of more superficially located remnants, its role is more limited.

Standard methods for Nosema research

Methods are described for working with Nosema apis and Nosema ceranae in the field and in the laboratory. For fieldwork, different sampling methods are described to determine colony level infections at a given point in time, but also for following the temporal infection dynamics. Suggestions are made for how to standardise field trials for evaluating treatments and disease impact. The laboratory methods described include different means for determining colony level and individual bee infection levels and methods for species determination, including light microscopy, electron microscopy, and molecular methods (PCR). Suggestions are made for how to standardise cage trials, and different inoculation methods for infecting bees are described, including control methods for spore viability. A cell culture system for in vitro rearing of Nosema spp. is described. Finally, how to conduct different types of experiments are described, including infectious dose, dose effects, course of infection and longevity tests

Effects of subthalamic nucleus stimulation on cognition and mood in Parkinson’s disease (PD)

Objective: To assess the neuropsychological outcome as a safety measure and quality control in patients with subthalamic nucleus (STN) stimulation for PD. Background: Deep brain stimulation (DBS) is considered a relatively safe treatment used in patients with movement disorders. However, neuropsychological alterations have been reported in patients with STN DBS for PD. Cognition and mood are important determinants of quality of life in PD patients and must be assessed for safety control. Methods: Seventeen consecutive patients (8 women) who underwent STN DBS for PD have been assessed before and 4 months after surgery. Besides motor symptoms (UPDRS-III), mood (Beck Depression Inventory, Hamilton Depression Rating Scale) and neuropsychological aspects, mainly executive functions, have been assessed (mini mental state examination, semantic and phonematic verbal fluency, go-no go test, stroop test, trail making test, tests of alertness and attention, digit span, wordlist learning, praxia, Boston naming test, figure drawing, visual perception). Paired t-tests were used for comparisons before and after surgery. Results: Patients were 61.6±7.8 years old at baseline assessment. All surgeries were performed without major adverse events. Motor symptoms ‘‘on’’ medication remained stable whereas they improved in the ‘‘off’’ condition (p<0.001). Mood was not depressed before surgery and remained unchanged at follow-up. All neuropsychological assessment outcome measures remained stable at follow-up with the exception of semantic verbal fluency and wordlist learning. Semantic verbal fluency decreased by 21±16% (p<0.001) and there was a trend to worse phonematic verbal fluency after surgery (p=0.06). Recall of a list of 10 words was worse after surgery only for the third attempt of recall (13%, p<0.005). Conclusions: Verbal fluency decreased in our patients after STN DBS, as previously reported. The procedure was otherwise safe and did not lead to deterioration of mood.