Epidemiological survey of the taeniasis/cysticercosis complex in cattle farms in Viçosa County, Minas Gerais, Brazil

Despite the importance of human taeniasis/bovine cysticercosis for public and animal health and the economy, its actual epidemiological status in Brazil is not well-studied. We sought to assess the epidemiological profile of this zoonosis in the rural area of Viçosa County, Minas Gerais, Brazil. The prevalence of bovine cysticercosis was 0.42%, whereas no case of human taeniasis was diagnosed. Factors favoring the persistence of zoonosis were identified. These included the supply of untreated water to animals, animals raised for slaughter without sanitary supervision, poor mechanization of raising techniques, and the use of untreated water for human consumption. Bovine meat for human consumption acquired in the city or from the farm itself was characterized as a risk factor for bovine cysticercosis (Odds Ratio (OR) =16.77; p<0.05). Nevertheless, the families on the investigated farms did apply several appropriate measures to control this disease, such as the virtual lack of open sewers and the consumption of well-cooked meat. The presence of bovine cysticercosis cases, and the factors favoring its persistence, point to the need for constant epidemiological and sanitary surveillance in this county.

Oxidative metabolism and muscle biochemical profile of polo horses supplemented with an ADE vitamin complex

Horses used for the game of polo experience abrupt and frequent changes in exercise intensity. To meet this variable energy demand, the horses use both aerobic and anaerobic pathways in varying proportions and intensities. In this context, there must be a balance between the formation of reactive oxygen species (ROS) and the action of antioxidants to prevent oxidative stress and its consequences. The effect of supplementation with an ADE vitamin complex on oxidative metabolism was evaluated in 18 crossbred horses randomly divided between a treated group (TG) and a control group (CG). The TG animals received the ADE vitamin complex (1mL/50 kg of body weight) by deep intramuscular injection at 30 and 15 days before the game. The CG horses received 10ml of saline by the same administration route and schedule. During the polo match, the animals played for a total of 7.5 min. Blood samples were collected on the same days as the treatments were administered, and immediately before and at 15, 90 and 180 minutes after the game. The concentrations of creatine phosphokinase (CK), lactate dehydrogenase (LDH), lactate, glucose, aspartate aminotransferase (AST), glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured in the blood samples. After the game, the TG demonstrated higher levels of AST, lactate and glucose than the CG, suggesting more efficient energy use by the treated animals. The higher GSH and lower lactate levels in the TG before the game suggest the presence of a greater antioxidant supply in the treated animals. The maintenance of the MDA levels indicates that neither of the groups exhibited oxidative stress.

Roles of leadership in complex environments : Enhancing Knowledge Flows in Organisational Constellations through Practice-Based Innovation Processes

Global challenges, complexity and continuous uncertainty demand development of leadership approaches, employees and multi-organisation constellations. Current leadership theories do not sufficiently address the needs of complex business environments. First of all, before successful leadership models can be applied in practice, leadership needs to shift from the industrial age to the knowledge era. Many leadership models still view leadership solely through the perspective of linear process thinking. In addition, there is not enough knowledge or experience in applying these newer models in practice. Leadership theories continue to be based on the assumption that leaders possess or have access to all the relevant knowledge and capabilities to decide future directions without external advice. In many companies, however, the workforce consists of skilled professionals whose work and related interfaces are so challenging that the leaders cannot grasp all the linked viewpoints and cross-impacts alone. One of the main objectives of this study is to understand how to support participants in organisations and their stakeholders to, through practice-based innovation processes, confront various environments. Another aim is to find effective ways of recognising and reacting to diverse contexts, so companies and other stakeholders are better able to link to knowledge flows and shared value creation processes in advancing joint value to their customers. The main research question of this dissertation is, then, to seek understanding of how to enhance leadership in complex environments. The dissertation can, on the whole, be characterised as a qualitative multiple-case study. The research questions and objectives were investigated through six studies published in international scientific journals. The main methods applied were interviews, action research and a survey. The empirical focus was on Finnish companies, and the research questions were examined in various organisations at the top levels (leaders and managers) and bottom levels (employees) in the context of collaboration between organisations and cooperation between case companies and their client organisations. However, the emphasis of the analysis is the internal and external aspects of organisations, which are conducted in practice-based innovation processes. The results of this study suggest that the Cynefin framework, complexity leadership theory and transformational leadership represent theoretical models applicable to developing leadership through practice-based innovation. In and of themselves, they all support confronting contemporary challenges, but an implementable method for organisations may be constructed by assimilating them into practice-based innovation processes. Recognition of diverse environments, their various contexts and roles in the activities and collaboration of organisations and their interest groups is ever-more important to achieving better interaction in which a strategic or formal status may be bypassed. In innovation processes, it is not necessarily the leader who is in possession of the essential knowledge; thus, it is the role of leadership to offer methods and arenas where different actors may generate advances. Enabling and supporting continuous interaction and integrated knowledge flows is of crucial importance, to achieve emergence of innovations in the activities of organisations and various forms of collaboration. The main contribution of this dissertation relates to applying these new conceptual models in practice. Empirical evidence on the relevance of different leadership roles in practice-based innovation processes in Finnish companies is another valuable contribution. Finally, the dissertation sheds light on the significance of combining complexity science with leadership and innovation theories in research.

Computational studies for the design of process equipment with complex geometries

This study combines several projects related to the flows in vessels with complex shapes representing different chemical apparata. Three major cases were studied. The first one is a two-phase plate reactor with a complex structure of intersecting micro channels engraved on one plate which is covered by another plain plate. The second case is a tubular microreactor, consisting of two subcases. The first subcase is a multi-channel two-component commercial micromixer (slit interdigital) used to mix two liquid reagents before they enter the reactor. The second subcase is a micro-tube, where the distribution of the heat generated by the reaction was studied. The third case is a conventionally packed column. However, flow, reactions or mass transfer were not modeled. Instead, the research focused on how to describe mathematically the realistic geometry of the column packing, which is rather random and can not be created using conventional computeraided design or engineering (CAD/CAE) methods. Several modeling approaches were used to describe the performance of the processes in the considered vessels. Computational fluid dynamics (CFD) was used to describe the details of the flow in the plate microreactor and micromixer. A space-averaged mass transfer model based on Fick’s law was used to describe the exchange of the species through the gas-liquid interface in the microreactor. This model utilized data, namely the values of the interfacial area, obtained by the corresponding CFD model. A common heat transfer model was used to find the heat distribution in the micro-tube. To generate the column packing, an additional multibody dynamic model was implemented. Auxiliary simulation was carried out to determine the position and orientation of every packing element in the column. This data was then exported into a CAD system to generate desirable geometry, which could further be used for CFD simulations. The results demonstrated that the CFD model of the microreactor could predict the flow pattern well enough and agreed with experiments. The mass transfer model allowed to estimate the mass transfer coefficient. Modeling for the second case showed that the flow in the micromixer and the heat transfer in the tube could be excluded from the larger model which describes the chemical kinetics in the reactor. Results of the third case demonstrated that the auxiliary simulation could successfully generate complex random packing not only for the column but also for other similar cases.

Nutrient cycling disturbance in Atlantic Forest sites affected by air pollution coming from the industrial complex of Cubatão, Southeast Brazil

Several aspects of nutrient cycling were studied at two sites of Atlantic Forest, in São Paulo State, Southeast Brazil (23o46’ S; 46o18’ W), which exhibited different degrees of forest structure decline caused by the air pollution emitted by the industrial complex of Cubatão, being referred here as the most and least affected sites (MAS and LAS, respectively). These investigations were developed during 1984 - 1986, a period in which the most severe negative effects of air pollution could be observed. Concentrations and amounts of N, P, K, Ca, Mg and S in four ecosystem compartments (leaves, litter layer, soil and roots) and in rainfall, throughfall and litterfall are briefly presented. At each site, the content of mineral elements generally decreased from leaves to litterfall and litter layer on the forest floor. Soil surface layer (0 - 5 cm) in both sites was the richest in mineral elements. Soil fertility was greater at LAS. In general, nutrient amounts remaining in the compartments and cycling through the ecosystem were greater at LAS as well, which could be due to the higher complexity of the forest structure at this site. Rainfall contributed more to soil inputs of K, Ca, Mg and S than litterfall at both sites. The nutrient residence times in the litter layer were higher and the index of nutrient use efficiency was lower at the most affected site. It was concluded that nutrient cycling was disturbed by air pollution at both sites, but to a greater extent at MAS. The main consequences of the air pollution stress were detected in the flux of nutrients through litterfall and in the litter layer on the forest floor.

Morphometric analysis of the Brasiliorchis picta complex (Orchidaceae)

One of the largest genera of Orchidaceae in the Neotropics with about 450 species, Maxillaria presents several taxonomic uncertainties about its generic circumscription and the delimitation of species groups, mainly due to the large variability of some species. The present study aims at verifying the morphological variation and species delimitation in the Brasiliorchis picta complex, a recent new genus derived from Maxillaria, using morphometric multivariate analysis. A total of 340 specimens belonging to six species (B. chrysantha (Barb. Rodr.) R.B. Singer, S. Koehler & Carnevali, B. gracilis (Lodd.) R.B. Singer, S. Koehler & Carnevali, B. marginata (Lindl.) R.B. Singer, S. Koehler & Carnevali, B. picta (Hook.) R. Singer, S. Koehler & Carnevali, B. porphyrostele (Rchb. f.) R.B. Singer, S. Koehler & Carnevali and B. ubatubana (Hoehne) R.B. Singer, S. Koehler & Carnevali) were analyzed using multivariate methods (PCA, CVA, DA, and Cluster Analysis with UPGMA). B. gracilis shows the largest morphological discontinuity, mainly due to its smaller size. The other species tend to form distinct groups, but intermediate characteristics between pairs of species induce overlaps among the individuals of different species and thus confuse the distinction of each one. Hybridization and geographic distribution can be involved in the differentiation of the species and lineages in this complex. Because the species classified a priori in this work cannot be recognized by the quantitative characters measured here, such other tools as geometric morphometry and molecular data should be employed in future works to clarify species relationships in this complex.

Are there evidences of a complex mimicry system among Asclepias curassavica (Apocynaceae), Epidendrum fulgens (Orchidaceae), and Lantana camara (Verbenaceae) in Southern Brazil?

The goal of this paper was to test the presence of mimicry in Asclepias curassavica L., Epidendrum fulgens Brong., and Lantana camara L. The study was carried out at the Parque Estadual de Itapeva, RS, southern Brazil, from 2004 to 2006. Flowering period of each of the three species was followed up; focal observations of butterflies visiting flowers, from fixed point and during random walks were carried out. We also estimated the frequency of pollinaria removal in the orchid, as well as its mode of reproduction. All these variables were important for testing the mimicry hypothesis. Despite some temporal coincidences in the flowering period of two plants in the system, there was no statistical association among the three plants as to flowering period. Twenty-nine species of butterflies, as potential pollinators, were recorded, particularly Agraulis vanillae maculosa, Dryas iulia alcionea, Urbanus simplicius, Tegosa claudina, and Heliconius erato phyllis, which were the more frequent visitors of the three plants. There was association between the number of visits to L. camara and E. fulgens, based on Pearson correlation (r = 0.4603; n = 19; P = 0.0473). Pollinaria removal of E. fulgens was low, as measured by the percentage of removal (range: 0 - 10%). The analysis of the mode of reproduction of this orchid showed its pollinator-dependence, since no fruits were formed by spontaneous self-pollination. In contrast, the percentage of fruit set that resulted from geitonogamy and xenogamy was, in average, 86%. The results here shown are not conclusive as to the occurrence of a mimicry system among the three plants.

Behavioral effects of "vehicle" microinjected into the dorsal periaqueductal grey of rats tested in the elevated plus maze

To investigate the behavioral effects of different vehicles microinjected into the dorsal periaqueductal grey (DPAG) of male Wistar rats, weighing 200-250 g, tested in the elevated plus maze, animals were implanted with cannulas aimed at this structure. One week after surgery the animals received microinjections into the DPAG of 0.9% (w/v) saline, 10% (v/v) dimethyl sulfoxide (DMSO), 2% (v/v) Tween-80, 10% (v/v) propylene glycol, or synthetic cerebrospinal fluid (CSF). Ten min after the injection (0.5 &micro;l) the animals (N = 8-13/group) were submitted to the elevated plus maze test. DMSO significantly increased the number of entries into both the open and enclosed arms when compared to 0.9% saline (2.7 &plusmn; 0.8 and 8.7 &plusmn; 1.3 vs 0.8 &plusmn; 0.3 and 5.1 &plusmn; 0.9, respectively, Duncan test, P<0.05), and tended to increase enclosed arm entries as compared to 2% Tween-80 (8.7 &plusmn; 1.3 vs 5.7 &plusmn; 0.9, Duncan test, P<0.10). In a second experiment no difference in plus maze exploration was found between 0.9% saline- or sham-injected animals (N = 11-13/group). These results indicate that intra-DPAG injection of some commonly used vehicles such as DMSO, saline or Tween-80 affects the exploratory activity of rats exposed to the elevated plus maze in statistically different manners

The effect of methotrexate and azathioprine on the serum levels of IgA-a1-antitrypsin complex in juvenile chronic arthritis

In the present study we investigated the influence of methotrexate (MTX) and azathioprine (AZA) on the serum levels of the IgA-a1-antitrypsin (IgA-AT) complex in patients with the systemic form of juvenile chronic arthritis (JCA). Fifty-six JCA patients (22 treated with MTX, 18 treated with AZA, and 16 not treated with any immunosuppressive agent) were enrolled in the study. MTX dosage ranged from 0.3 to 0.5 mg kg-1 week-1, while AZA was given daily at an average dose of 1 mg/kg. MTX was given for 13 months (SD = 7 months) whereas AZA for 11 months (SD = 6 months). The average value of the complex was higher in JCA patients than in both control groups (0.74 ± 0.73 U vs 0.37 ± 0.13 U (control children), P<0.001 and vs 0.23 ± 0.12 U (control adults), P<0.001). Values exceeding the normal range were found in twenty-two JCA patients (39.4%). Serum IgA-AT level was lowest in the MTX group compared to AZA and non-treated patients (0.56 ± 0.24 U, 0.76 ± 0.43 U, 0.95 ± 0.52 U, respectively, P<0.05). IgA values exceeding normal levels for age were found in 14% of the patients. A correlation between the levels of the IgA-AT complex and C-reactive protein (r = 0.43, P<0.01), a1-acid-glycoprotein (r = 0.45, P<0.01), a1-antichymotrypsin (r = 0.52, P<0.01), a1-antitrypsin (r = 0.40, P<0.01) and IgA (r = 0.56, P<0.01) was established

Axotomy increases NADPH-diaphorase activity in the dorsal root ganglia and lumbar spinal cord of the turtle Trachemys dorbigni

Seven days after transection of the sciatic nerve NADPH-diaphorase activity increased in the small and medium neurons of the dorsal root ganglia of the turtle. However, this increase was observed only in medium neurons for up to 90 days. At this time a bilateral increase of NADPH-diaphorase staining was observed in all areas and neuronal types of the dorsal horn, and in positive motoneurons in the lumbar spinal cord, ipsilateral to the lesion. A similar increase was also demonstrable in spinal glial and endothelial cells. These findings are discussed in relation to the role of nitric oxide in hyperalgesia and neuronal regeneration or degeneration.

Anxiolytic effect of methylene blue microinjected into the dorsal periaqueductal gray matter

The dorsal periaqueductal gray (DPAG) has been implicated in the behavioral and autonomic expression of defensive reactions. Several results suggest that, along with GABA, glutamate and serotonin, nitric oxide (NO) may play a role in defense reactions mediated by this region. To further investigate this possibility we microinjected methylene blue (MB; 10, 30 or 100 nmol/0.5 µl) into the DPAG of rats submitted to the elevated plus-maze test, an animal model of anxiety. MB has been used as an inhibitor of soluble guanylate cyclase (sGC) to demonstrate cGMP-mediated processes, and there is evidence that NO may exert its biological effects by binding to the heme part of guanylate cyclase, causing an increase in cGMP levels. The results showed that MB (30 nmol) significantly increased the percent of time spent in the open arms (saline = 11.57 ± 1.54, MB = 18.5 ± 2.45, P<0.05) and tended to do the same with the percentage of open arm entries (saline = 25.8 ± 1.97, MB = 33.77 ± 3.07, P<0.10), but did not change the number of enclosed arm entries. The dose-response curve, however, had an inverted U shape. These results indicate that MB, within a limited dose range, has anxiolytic properties when microinjected into the DPAG.

Defense reaction induced by a metabotropic glutamate receptor agonist microinjected into the dorsal periaqueductal gray of rats

The behavioral effects of trans-(±)-1-amino-1,3-cyclopentanedicarboxylic acid (t-ACPD), a metabotropic glutamate receptor (mGluR) agonist, or 0.9% (w/v) saline, injected into the dorsal periaqueductal gray (DPAG), was investigated. Male Wistar rats showed defense reactions characterized by jumps toward the top edges of the cages (saline = 0 vs t-ACPD = 6.0, medians P<0.05) and gallops (saline = 0 vs t-ACPD = 10.0, medians P<0.05) during the 60-s period after the beginning of the injection. In another experiment animals were placed inside an open arena for 5 min immediately after injection. Their behavior was recorded by a video camera and a computer program analyzed the videotapes. Eleven of fifteen rats injected with t-ACPD showed a short-lasting (about 1 min) flight reaction. No saline-treated animal showed this reaction (P<0.0005, chi-square test). The drug induced an increase in turning behavior (P = 0.002, MANOVA) and a decrease in the number of rearings (P<0.001, MANOVA) and grooming episodes (P<0.001, MANOVA). These results suggest that mGluRs play a role in the control of defense reactions in the DPAG.

The molecular basis of selective permeability of connexins is complex and includes both size and charge

Although gap junction channels are still widely viewed as large, non-specific pores connecting cells, the diversity in the connexin family has led more attention to be focused on their permeability characteristics. We summarize here the current status of these investigations, both published and on-going, that reveal both charge and size selectivity between gap junction channels composed of different connexins. In particular, this review will focus on quantitative approaches that monitor the expression level of the connexins, so that it is clear that differences that are seen can be attributed to channel properties. The degree of selectivity that is observed is modest compared to other channels, but is likely to be significant for biological molecules that are labile within the cell. Of particular relevance to the in vivo function of gap junctions, recent studies are summarized that demonstrate that the connexin phenotype can control the nature of the endogenous traffic between cells, with consequent effects on biological effects of gap junctions such as tumor suppression.

In vitro cytotoxicity of the LDE: daunorubicin complex in acute myelogenous leukemia blast cells

Acute myelogenous leukemia (AML) blast cells show high-affinity degradation of low-density lipoprotein (LDL), suggesting an increased expression of cellular LDL receptors. LDE is a lipid microemulsion easily synthesized in vitro which is known to mimic the metabolic pathway of LDL. We used LDE as a carrier for daunorubicin and assayed the cytotoxicity of the complex using AML blast cells since RT-PCR analysis showed that AML cells express LDL receptor mRNA. The LDE:daunorubicin complex killed 46.7% of blast cells and 20.2% of normal bone marrow cells (P<0.001; Student t-test). Moreover, this complex destroyed AML blast cells as efficiently as free daunorubicin. Thus, LDE might be a suitable carrier of chemotherapeutic agents targeting these drugs to neoplastic cells and protecting normal tissues.