Evaluation of the nutrient inputs to a coastal lagoon: the case of the Ria de Aveiro, Portugal

The Ria de Aveiro estuary-coastal lagoon system of northern Portugal is estimated to currently receive mean annual influxes of total nitrogen (N) and total phosphorus (P) of c. 6118 t y−1 and 779 t y−1, respectively, from its influent rivers. In low summer flows the mean N and P fluxes decrease to c. 10% of the annual average. The sewage contribution to the inland-derived N load on an annual basis is c. 5% but, during the summer low flow conditions, the sewage component increases to c. 65% of the total river loading. The sewage contribution to the inland-derived P load on an annual basis is c. 11% but, during the dry season, it is 1.2 times larger than the river-derived flux. The construction of a regional sewer system linked to a submarine outfall, due for completion in 2005, is expected to lead to a reduction in nutrient fluxes from inland to the lagoon of c. 15% for N and c. 26% for P relative to the present values. While this system will reduce the nutrient loading in the upper reaches of the lagoon, an increase in nutrients derived from the ocean is anticipated, due to the proximity of the outfall to the inlet.

Inputs from a mercury-contaminated lagoon: impact on the nearshore waters of the Atlantic Ocean

Ria de Aveiro, a Portuguese coastal lagoon that exchanges water with the Atlantic Ocean, received the effluent from a chlor-alkali industry for over 50 years; consequently several tons of mercury had been buried in the sediments of an inner basin. To assess the importance (and seasonal variation) of the lagoon waters as carriers of mercury to the nearby coastal area, we measured total mercury levels in several compartments: in surface sediments, in surface and deep waters (including dissolved and particulate matter!, and in biota. Dissolved (reactive and total) mercury concentrations both in surface and deep waters were low (<1 to 15 ng L '). Mean mercury values in suspended particulate matter varied hetween 0.2 and 0.6 jxg g ' and in sediments between 1 and 9 ng g '. Aquatic organisms displayed levels below regulatory limits but exhibited some bioaccumulation of mercury, with concentrations ranging from 0.05 to 0.8 ^ig g ' Idry weight (dw)|. No seasonal pattern was found in this study for mercury-related determinations. Levels found in the estuary mouth during ebb tide provide evidence for the transport of mercury to the coastal zone. No significant changes in the partition of mercury between dissolved and particulate phases were found in the coastal waters in comparison with the values found in the estuary mouth. In spite of the high levels of mercury found inside some areas of the lagoon, the wide web of islands and channels allows some spreading of contaminants before they reach the coastal waters. Moreover, the low efficiency of local marine sediments in trapping mercury contributes to a dilution of mercury transported in suspended particulate matter over a broader area, reducing the impact in the nearby manne coastal zone.

Impacts of high-nitrate freshwater inputs on macrotidal ecosystems. I. Seasonal evolution of nutrient limitation for the diatom-dominated phytoplankton of the Bay of Brest (France)

The chemical factors (inorganic nitrogen, phosphate, silicic acid) that potentially or actually control primary production were determined for the Bay of Brest, France, a macrotidal ecosystem submitted to high-nitrate-loaded freshwater inputs (winter nitrate freshwater concentrations >700 mu M, Si:N molar ratio as low as 0.2, i.e. among the lowest ever published). Intensive data collection and observations were carried out from February 1993 to March 1994 to determine the variations of physical [salinity, temperature, photosynthetically active radiation (PAR), freshwater discharges] and chemical (oxygen and nutrients) parameters and their impacts on the phytoplankton cycle (fluorescence, pigments, primary production). With insufficient PAR the winter stocks of nutrients were almost nonutilized and the nitrate excess was exported to the adjacent ocean, due to rapid tidal exchange. By early April, a diatom-dominated spring bloom developed (chlorophyll a maximum = 7.7 mu g l(-1); primary production maximum = 2.34 g C m(-2) d(-1)) under high initial nutrient concentrations. Silicic acid was rapidly exhausted over the whole water column; it is inferred to be the primary limiting factor responsible for the collapse of the spring bloom by mid-May. Successive phytoplankton developments characterized the period of secondary blooms during summer and fall (successive surface chlorophyll a maxima = 3.5, 1.6, 1.8 and 1.0 mu g l(-1); primary production = 1.24, 1.18 and 0.35 g C m(-2) d(-1)). Those secondary blooms developed under lower nutrient concentrations, mostly originating from nutrient recycling. Until August, Si and P most likely limited primary production, whereas the last stage of the productive period in September seemed to be N limited instead, this being a period of total nitrate depletion in almost the whole water column. Si limitation of spring blooms has become a common feature in coastal ecosystems that receive freshwater inputs with Si:N molar ratios <1. The peculiarity of Si Limitation in the Bay of Brest is its extension through the summer period.

Changes in the annual harmful algal blooms of Alexandrium minutum : effects of environmental conditions and drainage basin inputs in the Rance estuary (Brittany, France)

Time series of physico-chemical data and concentrations (cell L-1) of the toxic dinoflagellate Alexandrium minutum collected in the Rance macrotidal estuary (Brittany, France) were analyzed to understand the physico-chemical processes of the estuary and their relation to changes in bloom development from 1996 to 2009. The construction of the tidal power plant in the north and the presence of a lock in the south have greatly altered hydrodynamics, blocking the zone of maximum turbidity upstream, in the narrowest part of the estuary. Alexandrium minutum occurs in the middle part of the estuary. Most physical and chemical parameters of the Rance estuary are similar to those observed elsewhere in Brittany with water temperatures between 15–18 °C, slightly lowered salinities (31.8–33.1 PSU), low river flow rates upstream and significant solar radiation (8 h day-1). A notable exception is phosphate input from the drainage basin which seems to limit bloom development: in recent years, bloom decline can be significantly correlated with the decrease in phosphate input. On the other hand, the chemical processes occurring in the freshwater-saltwater interface do not seem to have an influence on these occurrences. The other hypotheses for bloom declines are discussed, including the prevalence of parasitism, but remain to be verified in further studies.

UNDERSTANDING CHASSIS INPUTS FROM THE REAR SUSPENSION OF A SNOWMOBILE

Today’s snowmobile industry faces great challenges in the field of noise & vibration. The area of main concern is the pass-by noise restriction defined by the Society of Automotive Engineers (SAE) test standard J192, with a maximum sound pressure level of 78 dB(A) being required by many states and national parks. To continue meet or beat this requirement without effecting machine performance, a deeper understanding of the sound transfer paths is required. This thesis examines the transfer paths created by the tunnel, rear suspension, drive shaft, and rubber composite track, with the primary source being suspension input through the ground. Using a combination of field experiments and analytical modeling, perspective was gained on which suspension and drive elements create the primary transfer paths. With further understanding of these paths, industry can tailor and fine-tune the approaches taken in to control overall noise output.

Long-term Spinal Ventral Root Reimplantation, But Not Bone Marrow Mononuclear Cell Treatment, Positively Influences Ultrastructural Synapse Recovery And Motor Axonal Regrowth.

We recently proposed a new surgical approach to treat ventral root avulsion, resulting in motoneuron protection. The present work combined such a surgical approach with bone marrow mononuclear cells (MC) therapy. Therefore, MC were added to the site of reimplantation. Female Lewis rats (seven weeks old) were subjected to unilateral ventral root avulsion (VRA) at L4, L5 and L6 levels and divided into the following groups (n = 5 for each group): Avulsion, sealant reimplanted roots and sealant reimplanted roots plus MC. After four weeks and 12 weeks post-surgery, the lumbar intumescences were processed by transmission electron microscopy, to analyze synaptic inputs to the repaired α motoneurons. Also, the ipsi and contralateral sciatic nerves were processed for axon counting and morphometry. The ultrastructural results indicated a significant preservation of inhibitory pre-synaptic boutons in the groups repaired with sealant alone and associated with MC therapy. Moreover, the average number of axons was higher in treated groups when compared to avulsion only. Complementary to the fiber counting, the morphometric analysis of axonal diameter and g ratio demonstrated that root reimplantation improved the motor component recovery. In conclusion, the data herein demonstrate that root reimplantation at the lesion site may be considered a therapeutic approach, following proximal lesions in the interface of central nervous system (CNS) and peripheral nervous system (PNS), and that MC therapy does not further improve the regenerative recovery, up to 12 weeks post lesion.

Synaptic Rearrangement Following Axonal Injury: Old And New Players.

Following axotomy, the contact between motoneurons and muscle fibers is disrupted, triggering a retrograde reaction at the neuron cell body within the spinal cord. Together with chromatolysis, a hallmark of such response to injury is the elimination of presynaptic terminals apposing to the soma and proximal dendrites of the injured neuron. Excitatory inputs are preferentially eliminated, leaving the cells under an inhibitory influence during the repair process. This is particularly important to avoid glutamate excitotoxicity. Such shift from transmission to a regeneration state is also reflected by deep metabolic changes, seen by the regulation of several genes related to cell survival and axonal growth. It is unclear, however, how exactly synaptic stripping occurs, but there is substantial evidence that glial cells play an active role in this process. In one hand, immune molecules, such as the major histocompatibility complex (MHC) class I, members of the complement family and Toll-like receptors are actively involved in the elimination/reapposition of presynaptic boutons. On the other hand, plastic changes that involve sprouting might be negatively regulated by extracellular matrix proteins such as Nogo-A, MAG and scar-related chondroitin sulfate proteoglycans. Also, neurotrophins, stem cells, physical exercise and several drugs seem to improve synaptic stability, leading to functional recovery after lesion.

Desenvolvimento e avaliação de uma servoválvula de baixo custo para a aplicação de insumos líquidos

The present work aimed the development of a low cost servo-valve that answers to an electronic control signal, for variable rates liquid inputs application. A literature research to define which valve type should be used was made. A mechanically activated proportional valve with an electronically controlled servo-engine was designed and evaluated. Since developed the servo-valve, the system was submited to a number of tests .The evaluation of its behavior was obtained in terms of repeatability, hystheresis and linearity. The test was accomplished in a bench, specially developed for this aim. As a result, were obtained three curves of opening percentage as function of flow rate, describing three opening and closing increments in two different work pressures. The servo-valve presented a good repeatability, reasonable hysteresis and a typically quadratic curve. This one maintained the low cost target. These results were very satisfied because the non-linearity and the hysteresis could be easily corrected by software.

Identificação das causas subjetivas da ansiedade competitiva e das estrategias de superação de atletas de equipes adultas masculinas de basquetebol

Universidade Estadual de Campinas . Faculdade de Educação Física

Participation of neuronal nitric oxide synthase in experimental neuropathic pain induced by sciatic nerve transection

Nerve injury leads to a neuropathic pain state that results from central sensitization. This phenomenom is mediated by NMDA receptors and may involve the production of nitric oxide (NO). In this study, we investigated the expression of the neuronal isoform of NO synthase (nNOS) in the spinal cord of 3-month-old male, Wistar rats after sciatic nerve transection (SNT). Our attention was focused on the dorsal part of L3-L5 segments receiving sensory inputs from the sciatic nerve. SNT resulted in the development of neuropathic pain symptoms confirmed by evaluating mechanical hyperalgesia (Randall and Selitto test) and allodynia (von Frey hair test). Control animals did not present any alteration (sham-animals). The selective inhibitor of nNOS, 7-nitroindazole (0.2 and 2 µg in 50 µL), blocked hyperalgesia and allodynia induced by SNT. Immunohistochemical analysis showed that nNOS was increased (48% by day 30) in the lumbar spinal cord after SNT. This increase was observed near the central canal (Rexed’s lamina X) and also in lamina I-IV of the dorsal horn. Real-time PCR results indicated an increase of nNOS mRNA detected from 1 to 30 days after SNT, with the highest increase observed 1 day after injury (1469%). Immunoblotting confirmed the increase of nNOS in the spinal cord between 1 and 15 days post-lesion (20%), reaching the greatest increase (60%) 30 days after surgery. The present findings demonstrate an increase of nNOS after peripheral nerve injury that may contribute to the increase of NO production observed after peripheral neuropathy.

Central chemoreceptors and neural mechanisms of cardiorespiratory control

The arterial partial pressure (P CO2) of carbon dioxide is virtually constant because of the close match between the metabolic production of this gas and its excretion via breathing. Blood gas homeostasis does not rely solely on changes in lung ventilation, but also to a considerable extent on circulatory adjustments that regulate the transport of CO2 from its sites of production to the lungs. The neural mechanisms that coordinate circulatory and ventilatory changes to achieve blood gas homeostasis are the subject of this review. Emphasis will be placed on the control of sympathetic outflow by central chemoreceptors. High levels of CO2 exert an excitatory effect on sympathetic outflow that is mediated by specialized chemoreceptors such as the neurons located in the retrotrapezoid region. In addition, high CO2 causes an aversive awareness in conscious animals, activating wake-promoting pathways such as the noradrenergic neurons. These neuronal groups, which may also be directly activated by brain acidification, have projections that contribute to the CO2-induced rise in breathing and sympathetic outflow. However, since the level of activity of the retrotrapezoid nucleus is regulated by converging inputs from wake-promoting systems, behavior-specific inputs from higher centers and by chemical drive, the main focus of the present manuscript is to review the contribution of central chemoreceptors to the control of autonomic and respiratory mechanisms.

Neural networks and statistical analysis for classification of corneal videokeratography maps based on Zernike coefficients: a quantitative comparison

PURPOSE: The main goal of this study was to develop and compare two different techniques for classification of specific types of corneal shapes when Zernike coefficients are used as inputs. A feed-forward artificial Neural Network (NN) and discriminant analysis (DA) techniques were used. METHODS: The inputs both for the NN and DA were the first 15 standard Zernike coefficients for 80 previously classified corneal elevation data files from an Eyesys System 2000 Videokeratograph (VK), installed at the Departamento de Oftalmologia of the Escola Paulista de Medicina, São Paulo. The NN had 5 output neurons which were associated with 5 typical corneal shapes: keratoconus, with-the-rule astigmatism, against-the-rule astigmatism, "regular" or "normal" shape and post-PRK. RESULTS: The NN and DA responses were statistically analyzed in terms of precision ([true positive+true negative]/total number of cases). Mean overall results for all cases for the NN and DA techniques were, respectively, 94% and 84.8%. CONCLUSION: Although we used a relatively small database, results obtained in the present study indicate that Zernike polynomials as descriptors of corneal shape may be a reliable parameter as input data for diagnostic automation of VK maps, using either NN or DA.

The variability and predictors of quality of AIDS care services in Brazil

Background: Since establishing universal free access to antiretroviral therapy in 1996, the Brazilian Health System has increased the number of centers providing HIV/AIDS outpatient care from 33 to 540. There had been no formal monitoring of the quality of these services until a survey of 336 AIDS health centers across 7 Brazilian states was undertaken in 2002. Managers of the services were asked to assess their clinics according to parameters of service inputs and service delivery processes. This report analyzes the survey results and identifies predictors of the overall quality of service delivery. Methods: The survey involved completion of a multiple-choice questionnaire comprising 107 parameters of service inputs and processes of delivering care, with responses assessed according to their likely impact on service quality using a 3-point scale. K-means clustering was used to group these services according to their scored responses. Logistic regression analysis was performed to identify predictors of high service quality. Results: The questionnaire was completed by 95.8% (322) of the managers of the sites surveyed. Most sites scored about 50% of the benchmark expectation. K-means clustering analysis identified four quality levels within which services could be grouped: 76 services (24%) were classed as level 1 (best), 53 (16%) as level 2 (medium), 113 (35%) as level 3 (poor), and 80 (25%) as level 4 (very poor). Parameters of service delivery processes were more important than those relating to service inputs for determining the quality classification. Predictors of quality services included larger care sites, specialization for HIV/AIDS, and location within large municipalities. Conclusion: The survey demonstrated highly variable levels of HIV/AIDS service quality across the sites. Many sites were found to have deficiencies in the processes of service delivery processes that could benefit from quality improvement initiatives. These findings could have implications for how HIV/AIDS services are planned in Brazil to achieve quality standards, such as for where service sites should be located, their size and staffing requirements. A set of service delivery indicators has been identified that could be used for routine monitoring of HIV/AIDS service delivery for HIV/AIDS in Brazil (and potentially in other similar settings).

Proteomic analysis of total cellular proteins of human neutrophils

Background: Neutrophils are the most abundant leukocytes in peripheral blood and represent one of the most important elements of innate immunity. Recent subcellular proteomic studies have focused on the identification of human neutrophil proteins in various subcellular membrane and granular fractions. Although there are relatively few studies dealing with the analysis of the total extract of human neutrophils, many biological problems such as the role of chemokines, adhesion molecules, and other activating inputs involved in neutrophil responses and signaling can be approached on the basis of the identification of the total cellular proteins. Results: Using gel-LC-MS/MS, 251 total cellular proteins were identified from resting human neutrophils. This is more than ten times the number of proteins identified by an initial proteome analysis of human neutrophils and almost five times the number of proteins identified by the first 2-DE map of extracts of rat polymorphonuclear leukocytes. Most of the proteins identified in the present study are well-known, but some of them, such as neutrophil-secreted proteins and centaurin beta-1, a cytoplasmic protein involved in the regulation of NF-kappa B activity, are described here for the first-time. Conclusion: The present report provides new information about the protein content of human neutrophils. Importantly, our study resulted in the discovery of a series of proteins not previously reported to be associated with human neutrophils. These data are relevant to the investigation of comparative pathological states and models for novel classes of pharmaceutical drugs that could be useful in the treatment of inflammatory disorders in which neutrophils participate.

Afferent Connections to the Rostrolateral Part of the Periaqueductal Gray: A Critical Region Influencing the Motivation Drive to Hunt and Forage

Previous studies have shown that a particular site in the periaqueductal gray (PAG), the rostrolateral PAG, influences the motivation drive to forage or hunt. To have a deeper understanding on the putative paths involved in the decision-making process between foraging, hunting, and other behavioral responses, in the present investigation, we carried out a systematic analysis of the neural inputs to the rostrolateral PAG (rlPAG), using Fluorogold as a retrograde tracer. According to the present findings, the rlPAG appears to be importantly driven by medial prefrontal cortical areas involved in controlling attention-related and decision-making processes. Moreover, the rlPAG also receives a wealth of information from different amygdalar, hypothalamic, and brainstem sites related to feeding, drinking, or hunting behavioral responses. Therefore, this unique combination of afferent connections puts the rlPAG in a privileged position to influence the motivation drive to choose whether hunting and foraging would be the most appropriate adaptive responses. Copyright (C) 2009 Sandra Regina Mota-Ortiz et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.