Specification of Supervisory Control Systems for Ventricular Assist Devices

One of the most important recent improvements in cardiology is the use of ventricular assist devices (VADs) to help patients with severe heart diseases, especially when they are indicated to heart transplantation. The Institute Dante Pazzanese of Cardiology has been developing an implantable centrifugal blood pump that will be able to help a sick human heart to keep blood flow and pressure at physiological levels. This device will be used as a totally or partially implantable VAD. Therefore, an improvement on device performance is important for the betterment of the level of interaction with patient`s behavior or conditions. But some failures may occur if the device`s pumping control does not follow the changes in patient`s behavior or conditions. The VAD control system must consider tolerance to faults and have a dynamic adaptation according to patient`s cardiovascular system changes, and also must attend to changes in patient conditions, behavior, or comportments. This work proposes an application of the mechatronic approach to this class of devices based on advanced techniques for control, instrumentation, and automation to define a method for developing a hierarchical supervisory control system that is able to perform VAD control dynamically, automatically, and securely. For this methodology, we used concepts based on Bayesian network for patients` diagnoses, Petri nets to generate a VAD control algorithm, and Safety Instrumented Systems to ensure VAD system security. Applying these concepts, a VAD control system is being built for method effectiveness confirmation.

Towards modular and coordinated manufacturing systems oriented to services

Nowadays, there is a trend for industry reorganization in geographically dispersed systems, carried out of their activities with autonomy. These systems must maintain coordinated relationship among themselves in order to assure an expected performance of the overall system. Thus, a manufacturing system is proposed, based on ""web services"" to assure an effective orchestration of services in order to produce final products. In addition, it considers special functions, such as teleoperation and remote monitoring, users` online request, among others. Considering the proposed system as discrete event system (DES), techniques derived from Petri nets (PN), including the Production Flow Schema (PFS), can be used in a PFS/PN approach for modeling. The system is approached in different levels of abstraction: a conceptual model which is obtained by applying the PFS technique and a functional model which is obtained by applying PN. Finally, a particular example of the proposed system is presented.

Development of Control Systems for Safety Instrumented Systems

Safety Instrumented Systems (SIS) are designed to prevent and / or mitigate accidents, avoiding undesirable high potential risk scenarios, assuring protection of people`s health, protecting the environment and saving costs of industrial equipment. The design of these systems require formal methods for ensuring the safety requirements, but according material published in this area, has not identified a consolidated procedure to match the task. This sense, this article introduces a formal method for diagnosis and treatment of critical faults based on Bayesian network (BN) and Petri net (PN). This approach considers diagnosis and treatment for each safety instrumented function (SIF) including hazard and operability (HAZOP) study in the equipment or system under control. It also uses BN and Behavioral Petri net (BPN) for diagnoses and decision-making and the PN for the synthesis, modeling and control to be implemented by Safety Programmable Logic Controller (PLC). An application example considering the diagnosis and treatment of critical faults is presented and illustrates the methodology proposed.

Determination of heavy metals by inductively coupled plasma-optical emission spectrometry in fish from the Piracicaba River in Southern Brazil

A total of 202 fish, representing 16 species, were collected during 2008 (March-October) in the Tanquan region of the Piracicaba River using nets. Flesh samples were collected and analyzed, using inductively coupled plasma-optical emission spectroscopy for Al, As, Cd, Co Cr, Cu, Mn, Mo, Ni, Ph, Se, Sn, Sr, and Zn. The results showed that the flesh of these fish all contained extremely high levels of Al and Sr, and moderately high levels of Cr, As, Zn, Ni. Mn and Pb. The metals were higher in these fish during rainy season, with fish collected during the months of March and October being the highest. In addition, the accumulation of metals was species-dependent. Cascudos (Hypostomus punctatus) and piranhas (Serrasalmus spilopleura) exhibited high levels of almost all of the metals, while curimbata (Prochilodus lineatus) had moderate levels. A few species, including pacu (Piaractus mesopotamicus) and dourado (Salminus maxillosus), had very low levels of most metals. The results show that the Piracicaba River Basin is widely contaminated with high levels of many toxic heavy metals, and that human consumption of some fish species is a human health concern. (C) 2009 Elsevier B.V. All rights reserved.

Elevated blood lead levels in a riverside population in the Brazilian Amazon

Lead (Pb) is recognized as one of the most toxic metals. Sources of Pb exposure have been widely documented in North America, and the removal of Pb additives from gasoline was reflected in a dramatic lowering of blood Pb concentration. In Latin America, the removal of Pb from gasoline resulted in decreased exposure, but Pb levels in many areas remain high due to occupational and environmental sources of exposure. While many of the Pb sources have been identified (mining, industries, battery recycling, lead-based paint, ceramics), new ones occasionally crop up. Here we report on blood Pb (B-Pb) levels in remote riverside communities of the Brazilian Amazon. Blood Pb (B-Pb) levels were determined in 448 persons from 12 villages of the Lower Tapajos River Basin, Par, Brazil. Socio-demographic and dietary information, as well as occupational, residential and medical history was collected using an interview-administered questionnaire. B-Pb, measured by ICP-MS, showed elevated concentrations. Mean B-Pb was 13.1 mu g/dL +/- 8.5, median B-Pb was 11.2 mu g/dL and ranged from 0.59 to 48.3 mu g/dL. Men had higher B-Pb compared to women (median: 15.3 mu g/dL vs 7.9 mu g/dL respectively). B-Pb increased with age for women, while it decreased for men. For both genders, B-Pb decreased with education. There were significant differences between villages. Exploratory analyses, using linear partition models, showed that for men B-Pb was lower among those who were involved in cattle-raising, and higher among those who hunted, farmed and fished. The distribution profile of B-Pb directed us towards artisanal transformation of manioc to flour (farinha), which requires heating in a large metal pan, with stirring primarily done by young men. In the village with the highest B-Pb, analysis of Pb concentrations (dry weight) of manioc (prior to transformation) and farinha (following transformation) from 6 houses showed a tenfold increase in Pb concentration (mean: 0.017 +/- 0.016 to 0.19 +/- 0.10 mu g/g). This was confirmed in one of these villages where we sampled manioc paste Oust before roasting) and the roasted farinha (0.05 mu g/g vs 0.20 mu g/g). While there may be other sources (ammunition, sinkers for fishing nets), the high concentrations in farinha, a dietary staple, assuredly makes an important contribution. Further action needs to reduce Pb sources in this region. (C) 2009 Elsevier Inc. All rights reserved.

Biological features of a puzzling symbiotic association between the hermit crab Dardanus insignis and the porcellanid crab Porcellana Sayana (Crustacea)

The symbiotic lifestyle is widespread among porcellanid crabs, which maintain ecological and co-evolutionary associations with annelid polychaetes, poriferans, cnidarians, echinoderms, gastropod. mollusks, and other crustaceans such as shrimps and hermit crabs, among others. We investigated the ecological association between the hermit crab Dardanus insignis and the porcellanid Porcellana sayana, in southeastern Brazil. Porcellanid crabs, hermit crabs, and available shells were collected monthly from July 2001 to June 2003, with a shrimp boat equipped with two double-rig trawl nets. The majority of P. sayana specimens were collected in shells occupied by D. insignis (96.6%); a few were found in empty shells (3.4%). The catch of both symbionts and hosts increased with increasing depth, with the highest occurrence at 35 m. The F. sayana crabs of various sizes could be found solitary or forming aggregations of up to 14 individuals per host, showing no sex or size segregation. In spite of the high diversity of shell species occupied by the hermit crabs and also available in the field, only a few of them were also utilized by P. sayana. The majority (93%) of shells utilized by P. sayana also hosted other symbiont species, constituting the basis of extensive symbiotic complexes. Thus, the ecological relationship between D. insignis and P. sayana may be classified as a non-obligate and non-specific symbiosis that may also involve other facultative organisms such as sea anemones. (C) 2008 Elsevier B.V. All rights reserved.

Comparative analysis of population structure of endemic Western Atlantic hermit crab Loxopagurus loxochelis (Decapoda, Anomura) in two regions of state of Sao Paulo, Brazil

This work characterized the population structure of the hermit crab Loxopagurus loxochelis (Moreira, 1901) in terms of size frequency distribution and sex ratio. Specimens were collected monthly, over a period of one year (from July 2002 to June 2003), in seven transects (from 5 to 35 m of depth) using fishing boat equipped with two double-rig trawl nets, in Caraguatatuba and Ubatuba regions (state of Sao Paulo, Brazil). A total of 366 hermit crabs were collected in Caraguatatuba [222 males (60.65%), 114 non-ovigerous females (31.15%) and 30 ovigerous females (8.20%)] and 126 hermit crabs in Ubatuba [81 males (64.28%), 38 non-ovigerous females (30.16%) and seven ovigerous females (5.56%)]. In Caraguatatuba the highest incidence of ovigerous females occurred during winter (July 2002), whereas in Ubatuba, the number was incipient. The cephalothoracic shield length ranged from 2.0 to 7.9mm (5.29 +/- 0.96mm) in Caraguatatuba, and from 2.7 to 7.5mm (5.32 +/- 0.95mm) in Ubatuba. The mean size of males was significantly larger than the mean size of females in both regions. Overall sex ratio was in favor of males (1.54:1 in Caraguatatuba and 1.9:1 in Ubatuba). Sexual dimorphism was recorded to L. loxochelis by the presence of males in the largest size classes, following the standard pattern observed in Decapoda. There was an unimodal size distribution for both sexes, with normal distributions in both regions. The higher number of males in relation to females may indicate the existence of different growth and mortality rates between the sexes. Despite of the different geomorphologic characteristics between Caraguatatuba and Ubatuba regions, the dynamics of development was similar for both populations.

The nymph of Tortopus harrisi Traver (Ephemeroptera: Polymitarcyidae)

Polymitarcyidae is a family of burrowing mayflies (Ephemeroptera: Ephemeroidea) distributed throughout the world but with highest diversity in the Neotropics. Tortopus Needham & Murphy, with a Panamerican distribution, is known from twelve species described in the adult stage. Nymphs are only known for three species: T. puella (Pictet), T. obscuripennis Dominguez and T. sarae Dominguez, and present a rather homogeneous morphology (Molineri 2008). They were firstly described for T. puella by Scott et al. (1959) and later Molineri (2008) described the other two. Both studies reported that these species burrow U-shaped tunnels in clay banks of rivers and streams, thus preventing them from being sampled in most limnological studies (that use surbers, drags, or drift nets). The aim of the present contribution is to describe and illustrate the previously unknown nymph of Tortopus harrisi Traver that shows important anatomical differences with the other nymphs known in the genus. This morphological differentiation suggests a different habitat use by these nymphs, sampled with drag and surber samplers in sandy substrate. New locality records are given for T. harrisi in Brazil. The nymphs are preserved in alcohol, mouthparts, legs and genital rudiments were mounted in microscope slides with Canada Balsam. Drawings were made with a camera lucida attached to a stereo microscope. The material is deposited in CUIC (Cornell University Insect Collection, Ithaca, NY), IML (Instituto Miguel Lillo, Tucuman) and in MZSP (Museu de Zoologia da Universidade de Sao Paulo, Sao Paulo). Catalogs and bibliography were consulted at Ephemeroptera Galactica (Hubbard 2009).

Identification of Plasmodium relictum causing mortality in penguins (Spheniscus magellanicus) from Sao Paulo Zoo, Brazil

This study reports avian malaria caused by Plasmodium relictum in Magellanic Penguins (Spheniscus magellanicus) from Sao Paulo Zoo. The disease was highly infective among the birds and was clinically characterized by its acute course and high mortality. The penguins of Sao Paulo Zoo were housed for at least 2 years without malaria; however, they had always been maintained in an enclosure protected from mosquito exposure during the night period. When they presented pododermatitis, they were freed at night for a short period. sao Paulo Zoo is located in one of the last forest remnants of the city, an area of original Atlantic forest. In the winter, the space destined for Zoo birds is shared with migratory species. Hence the possibility exists that the disease was transmitted to the penguins by mosquitoes that had previously bitten infected wild birds. Avian malaria parasites are transmitted mainly by mosquitoes of the genera Aedes and Culex, common vectors in the Atlantic forest. In this study, one Culex (Cux.) sp. was found, infected with P. relictum. There are diverse problems in housing distinct species of animals in captivity, principally when occupying the same enclosure, since it facilitates the transmission of diseases with indirect cycles, as is the case of Plasmodium spp., because certain species that cause discrete infections in some bird species can become a serious danger for others, especially penguins, which do not possess natural resistance. Thus, serious implications exist for periodically testing and administrating malaria therapy in captive penguins potentially exposed to mosquitoes during the night period, as well as other captive birds from Sao Paulo Zoo. (C) 2010 Elsevier B.V. All rights reserved.

Management of Neuroendocrine Tumors: A Meeting of Experts from Latin America

A panel of experts from Latin America convened in Brazil, in May of 2007, for consensus recommendations regarding the management of neuroendocrine tumors ( NETs) of the gastrointestinal tract and pancreas. The recently introduced World Health Organization classification of NETs represents a step forward, but the former classification of carcinoids into foregut, midgut and hindgut is still likely to be useful in the near future. Macroscopic description of the tumor should be followed by light microscopic examination and immunohistochemical staining, whereas other techniques might not be widely available in Latin America. Surgery remains the mainstay of treatment for patients with potentially curable tumors, and adequate selection is paramount in order to optimize treatment results. Regarding systemic therapy, patients with well-differentiated tumors or islet-cell carcinomas may be categorized as having indolent disease, while patients with poorly differentiated, anaplastic, and small-cell carcinomas, or with atypical carcinoids, may be approached initially as having aggressive disease. Somatostatin analogues play a cytostatic role in indolent tumors, and chemotherapy may play a role against other, more aggressive NETs. Obviously, there is an urgent need for novel therapies that are effective against NETs. Copyright (C) 2008 S. Karger AG, Basel

An Insight into the Sialotranscriptome of Simulium nigrimanum, a Black Fly Associated with Fogo Selvagem in South America

Pemphigus foliaceus is a life threatening skin disease that is associated with autoimmunity to desmoglein, a skin protein involved in the adhesion of keratinocytes. This disease is endemic in certain areas of South America, suggesting the mediation of environmental factors triggering autoimmunity. Among the possible environmental factors, exposure to bites of black flies, in particular Simulittm nigrimanum has been suggested. In this work, we describe the sialotranscriptome of adult female S. nigrimanum flies. It reveals the complexity of the salivary potion of this insect, comprised by over 70 distinct genes within over 30 protein families, including several novel families, even when compared with the previously described sialotranscriptome of the autogenous black fly, S. vitiation. The uncovering of this sialotranscriptome provides a platform for testing pemphigus patient sera against recombinant salivary proteins from S. nigrimanum and for the discovery of novel pharmacologically active compounds.

FOR DEBATE A hypothesis for the 2007 dengue outbreak in Singapore

A previous mathematical model explaining dengue in Singapore predicted a reasonable outbreak of about 6500 cases for 2006 and a very mild outbreak with about 2000 cases for 2007. However, only 3051 cases were reported in 2006 while more than 7800 were reported in the first 44 weeks of 2007. We hypothesized that the combination of haze with other local sources of particulate matter had a significant impact on mosquito life expectancy, significantly increasing their mortality rate. To test the hypothesis a mathematical model based on the reproduction number of dengue fever and aimed at comparing the impact of several possible alternative control strategies was proposed. This model also aimed at contributing to the understanding of the causes of dengue resurgence in Singapore in the last decade. The model`s simulation demonstrated that an increase in mosquito mortality in 2006 and either a reduction in mortality or an increase in the carrying capacity of mosquitoes in 2007 explained the patterned observed in Singapore. Based on the model`s simulation we concluded that the fewer than expected number of dengue cases in Singapore in 2006 was caused by an increase in mosquito mortality due to the disproportionate haze affecting the country that year and that particularly favourable environmental conditions in 2007 propitiated mosquitoes with a lower mortality rate, which explains the greater than expected number of dengue cases in 2007. Whether our hypothesis is plausible or not should be debated further.

A transposon toolkit for gene transfer and mutagenesis in protozoan parasites

Protozoan parasites affect millions of people around the world. Treatment and control of these diseases are complicated partly due to the intricate biology of these organisms. The interactions of species of Plasmodium, Leishmania and trypanosomes with their hosts are mediated by an unusual control of gene expression that is not fully understood. The availability of the genome sequence of these protozoa sets the stage for using more comprehensive, genome-wide strategies to study gene function. Transposons are effective tools for the systematic introduction of genetic alterations and different transposition systems have been adapted to study gene function in these human pathogens. A mariner transposon toolkit for use in vivo or in vitro in Leishmania parasites has been developed and can be used in a variety of applications. These modified mariner elements not only permit the inactivation of genes, but also mediate the rescue of translational gene fusions, bringing a major contribution to the investigation of Leishmania gene function. The piggyBac and Tn5 transposons have also been shown to mobilize across Plasmodium spp. genomes circumventing the current limitations in the genetic manipulation of these organisms.

Helminths of Sotalia guianensis (Cetacea: Delphinidae) from the South and Southeastern Coasts of Brazil

From May 1997 to October 2000, 49 Sotalia guianensis (tucuxi dolphin) incidentally caught in fishing nets or stranded in Sao Paulo (SP) and Parana (PH) states in Brazil were necropsied. In total, 17 lungs, 35 stomachs, and 30 intestines were analyzed. Contents were washed through a sieve (mesh, 150 mm) and examined under a stereoscopic microscope for parasites. Histopathologic analyses were performed in the lungs of five infected dolphins. The nematode Halocereus brasiliensis was found in 88% of all lungs examined, inducing moderate-to-severe pneumonia. Braunina cordiformis, Anisakis sp., and acanthocephalans were found in the stomachs. The trematode Synthesium tursionis was the only parasite found in the intestines, and it was identified in 73% of the animals necropsied. No macroscopic lesions were seen due to parasites in the stomachs and intestines analyzed.

Spatial expansion and population structure of the neotropical malaria vector, Anopheles darlingi (Diptera: Culicidae)

Extensive population structuring is known to occur in Anopheles darlingi, the primary malaria vector of the Neotropics. We analysed the phylogeographic structure of the species using the mitochondrial cytochrome oxidase I marker. Diversity is divided into six main population groups in South America: Colombia, central Amazonia, southern Brazil, south-eastern Brazil, and two groups in north-east Brazil. The ancestral distribution of the taxon is hypothesized to be central Amazonia, and there is evidence of expansion from this region during the late Pleistocene. The expansion was not a homogeneous front, however, with at least four subgroups being formed due to geographic barriers. As the species spread, populations became isolated from each other by the Amazon River and the coastal mountain ranges of south-eastern Brazil and the Andes. Analyses incorporating distances around these barriers suggest that the entire South American range of An. darlingi is at mutation-dispersal-drift equilibrium. Because the species is distributed throughout such a broad area, the limited dispersal across some landscape types promotes differentiation between otherwise proximate populations. Moreover, samples from the An. darlingi holotype location in Rio de Janeiro State are substantially derived from all other populations, implying that there may be additional genetic differences of epidemiological relevance. The results obtained contribute to our understanding of gene flow in this species and allow the formulation of human mosquito health protocols in light of the potential population differences in vector capacity or tolerance to control strategies. (C) 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 854-866.