Adsorption/desorption of arsenic by tropical peat: influence of organic matter, iron and aluminium

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aspects of Manual Wheelchair Configuration Affecting Mobility: A Review

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A simple method based on ICP-MS for estimation of background levels of arsenic, cadmium, copper, manganese, nickel, lead, and selenium in blood of the Brazillian population

Throughout the world, biomonitoring has become the standard for assessing exposure of individuals to toxic elements as well as for responding to serious environmental public health problems. However, extensive biomonitoring surveys require rapid and simple analytical methods. Thus, a simple and high-throughput method is proposed for the determination of arsenic (As), cadmium (Cd), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and selenium (Se) in blood samples by using inductively coupled plasma–mass spectrometry (ICPMS). Prior to analysis, 200 ml of blood samples was mixed with 500 ml of 10% v/v tetramethylammonium hydroxide (TMAH) solution, incubated for 10 min, and subsequently diluted to 10 ml with a solution containing 0.05% w/v ethylenediamine tetraacetic acid (EDTA) + 0.005% v/v Triton X-100. After that, samples were directly analyzed by ICP-MS (ELAN DRC II). Rhodium was selected as an internal standard with matrix-matching calibration. Method detection limits were 0.08, 0.04, 0.5, 0.09, 0.12, 0.04, and 0.1 mg//L for As, Cd, Cu, Mn, Ni, Pb, and Se, respectively. Validation data are provided based on the analysis of blood samples from the trace elements inter-\comparison program operated by the Institut National de Santé Publique du Quebec, Canada. Additional validation was provided by the analysis of human blood samples by the proposed method and by using electrothermal atomic absorption spectrometry (ETAAS). The method was subsequently applied for the estimation of background metal blood values in the Brazilian population. In general, the mean concentrations of As, Cd, Cu, Mn, Ni, Pb, and Se in blood were 1.1, 0.4, 890, 9.6, 2.1, 65.4, and 89.3 mg/L, respectively, and are in agreement with other global populations. Influences of age, gender, smoking habits, alcohol consumption, and geographical variation on the values were also considered. Smoking habits influenced the levels of Cd in blood. The levels of Cu, Mn, and Pb were significantly correlated with gender, whereas Cu and Pb were significantly correlated with age. There were also interesting differences in Mn and Se levels in the population living in the north of Brazil compared to the south.

Road wanderers in Brazil: a study on modern psychosocial human mobility

Human mobility patterns are quite diverse nowadays and a very singular, extreme pattern is seen in the Brazilian scene: road wandering. Road wanderers are individuals who leave their home, family, work and other territories of a settled life and throw themselves into a life of solitary wandering along Brazilian highways. This study aimed to describe the lifestyle of road wanderers, investigate the reasons that led them choose this way of living and understand it against a background of modern human mobility patterns. A total of 63 interviews were conducted with individuals wandering on road shoulders. We found road wandering is associated with the following determinants: poverty; unemployment; marital conflicts; emotional suffering following the loss of loved ones; desires for adventure and freedom; and cultural symbols related to journey, migration, exodus and other modes of displacement. Despite its particularities, road wandering can be understood as a way of human mobility in the modern world.

Influence of mobility models in precision spray aided by wireless sensor networks

Precision Spray is a technique to increase performance of Precision Agriculture. This spray technique may be aided by a Wireless Sensor Network, however, for such approach, the communication between the agricultural input applicator vehicle and network is critical due to its proper functioning. Thus, this work analyzes how the number of nodes in a wireless sensor network, its type of distribution and different areas of scenario affects the performance of communication. We performed simulations to observe system's behavior changing to find the most fitted non-controlled mobility model to the system.

Levels of metals, arsenic and phosphorus in sediments from two sectors of a Brazilian Marine Protected Area (Tupinambas Ecological Station)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oxygen mobility in Bi:Sr:Ca:Cu:O ceramic measured using anelastic relaxation methods

Since the discovery of YBaCuO, experiments have shown that its superconducting properties are strongly affected by the oxygen content. More recently, anelastic relaxation measurements in La2CuO4+δ, showed that the decrease in the oxygen content can be related to two events. One is the decrease in mobility between two adjacent CuO planes, and the other is the increase in the number of tilting patterns of the CuO6 octahedra. In the case of the bismuth-based ceramic, it is known that the oxygen content, within some limits, does not affect its superconducting properties. In order to evaluate the mobility and the effect of the oxygen content on this material we have prepared BSCCO ceramic and tested regarding its internal friction and electrical resistivity as a function of the temperature while the oxygen content was being reduced by a sequence of vacuum annelaing at 620 K. The samples were prepared in the Bi:Sr:Ca:Cu = 2212 and 2223 proportion, using powder obtained by the sol-gel route and conventional solid state reaction. The anelastic relaxation measurements were performed using a torsion pendulum operating with frequency about 15-35 Hz between 77 to 700 K. The diffraction pattern of the as sintered and the vacuum annealed material were also presented. The results have shown complex anelastic relaxation structures that were associated to the jump of interstitial oxygen atoms between two adjacent CuO planes. The vacuum annealing showed to be deleterious to the critical temperature of the superconducting ceramic.

Long-term multimodal exercise program enhances mobility of patients with Parkinson's disease

Objective. This study aimed to evaluate the effect of a long-period multimodal exercise program on balance, mobility and clinical status of patients with Parkinson’s disease (PD). Methods. Thirty-three PD patients were assigned into two groups: a training group (TG—n = 22; aged 67.23 ± 8.39 years) and a control group (CG—n = 9; aged 71.56 ± 8.50 years). The TG patients were enrolled in a 6-month multimodal exercise program. This program was designed to improve physical capacity components and to reduce PD impairments. Balance and mobility were assessed immediately before and after the training protocol using the Berg Balance Scale (BBS), the “Timed up and go” (TUG), and the Posture Locomotion Test (PLM). Also, clinical variables were assessed (disease stage and impairments). Results. The TG showed an improvement in the TUG (P = 0.006) while CG were not influenced by the 6-months period. Both groups showed no differences for BBS and PLM and for their disease impairments—assessed through the Unified Parkinson’s disease Scale. Conclusions. Long-term multimodal exercise programs are able to improve mobility of patients with Parkinson’s disease and therefore should be used on clinical day life.