Short-term variability of gamma radiation at the ARM Eastern North Atlantic facility (Azores).

This work addresses the short-term variability of gamma radiation measured continuously at the Eastern North Atlantic (ENA) facility located in the Graciosa island (Azores, 39N; 28W), a fixed site of the Atmospheric Radiation Measurement programme (ARM). The temporal variability of gamma radiation is characterized by occasional anomalies over a slowly-varying signal. Sharp peaks lasting typically 2-4 h are coincident with heavy precipitation and result from the scavenging effect of precipitation bringing radon progeny from the upper levels to the ground surface. However the connection between gamma variability and precipitation is not straightforward as a result of the complex interplay of factors such as the precipitation intensity, the PBL height, the cloud's base height and thickness, or the air mass origin and atmospheric concentration of sub-micron aerosols, which influence the scavenging processes and therefore the concentration of radon progeny. Convective precipitation associated with cumuliform clouds forming under conditions of warming of the ground relative to the air does not produce enhancements in gamma radiation, since the drop growing process is dominated by the fast accretion of liquid water, resulting in the reduction of the concentration of radionuclides by dilution. Events of convective precipitation further contribute to a reduction in gamma counts by inhibiting radon release from the soil surface and by attenuating gamma rays from all gamma-emitting elements on the ground. Anomalies occurring in the absence of precipitation are found to be associated with a diurnal cycle of maximum gamma counts before sunrise decreasing to a minimum in the evening, which are observed in conditions of thermal stability and very weak winds enabling the build-up of near surface radon progeny during the night.

Urinary creatinine as a nutritional and urinary volume marker in sheep fed with tropical or temperate forages / Uso da creatinina urinária como marcador nutricional e de volume urinário em ovinos alimentados com forragem tropical ou temperada

To test the accuracy of creatinine as a marker for estimating urinary volume and its use as a nutritional index, the possible interference of forage intake and forage quality over creatinine excretion was evaluated. For this, sheep were fed different levels of pearl millet (Pennisetum americanum(L) Leeke) or Italian ryegrass (Lolium multiflorum Lam). The experiment consisted of a compilation of digestibility trials (n=6) with pearl millet or Italian ryegrass in completely randomized designs with four replications and four forage levels: 1.5, 2.0, 2.5% (kg dry matter (DM)/ 100 kg of live weight (LW)). The trials were repeated at different periods to evaluate how stable the average metabolic excretion of creatinine is. In each trial, total urine collection was performed individually during a period of 24 hours for five consecutive days and subsequently analyzed by colorimetry for creatinine and purine derivatives. The creatinine excretion was not affected (P>0.05) by forage offer or forage type, but there were period effects (P=0.0001). The average creatinine excretion for both forages was 0.21mmol/kg PV0,75. Linear regressions between the purine derivatives:creatinine index with total excretion of purine derivatives were detected for pearl millet (P<0.0001, R2= 0.64) and Italian ryegrass (P=0.02, R2=0.20). These results demonstrate that creatinine excretion is independent of the type and availability of forage and can be a marker for urinary volume prediction and nutritional measures under grazing systems.

Para testar a precisão da creatinina como marcador para estimativas de volume urinário e índice nutricional, foram avaliadas a possível influência do consumo e a qualidade da forragem sobre esse marcador. Para isso, ovinos foram alimentados com diferentes níveis de milheto (Pennisetum americanum (L) Leeke) ou azevém (Lolium multiflorum Lam). O experimento consistiu de uma compilação de ensaios de digestibilidade (n=6) com milheto ou azevém, em um desenho experimental de blocos completamente ao acaso, com quatro repetições e quatro níveis de forragem: 1,5; 2,0; 2,5% (kg de matéria seca (MS)/ 100kg de peso vivo (PV)). Os ensaios foram repetidos em diferentes períodos, com ambas as forragens, se para avaliar a estabilidade da excreção média de creatinina metabólica. Em cada ensaio, foi coletado o volume total de urina individualmente, durante períodos de 24 horas, por cinco dias consecutivos. Posteriormente, esses ensaios foram analisados por colorimetria para creatinina e derivados de purina. A excreção de creatinina não foi afetada (P>0,05) pelo consumo de forragem ou pelo tipo de forragem, mas foi influenciada pelo período (P=0,0001). A excreção média de creatinina para ambas as forragens foi 0,21mmol/kg PV0,75. Regressões lineares entre os índices derivados de purina:creatinina com a excreção total de derivados de purina foram detectadas para milheto (P<0,0001; R2=0,64) e azevém (P=0,02; R2=0,20). Os resultados demonstraram que a excreção de creatinina é independente do tipo e do consumo de forragem e pode ser usada como marcador preditivo do volume urinário e do status nutricional em sistemas de pastejo.

Faecal nitrogen excretion as an approach to estimate forage intake of wethers.

Data from twenty-two digestibility trials were compiled to examine the relationship between faecal N concentration and organic matter (OM) digestibility (OMD), and between faecal N excretion and OM intake (OMI) by wethers fed tropical or temperate forages alone or with supplements. Data set was grouped by diet type as follows: only tropical grass (n = 204), only temperate grass (n = 160), tropical grass plus supplement (n = 216), temperate grass plus supplement (n = 48), tropical grass plus tropical legume (n = 60) and temperate grass with ruminal infusion of tannins (n = 16). Positive correlation between OMD and either total faecal N concentration (Nfc, % of OM) or metabolic faecal N concentration (Nmetfc, % of OM) was significant for most diet types. Exceptions were the diet that included a tropical legume, where both relationships were negative, and the diet that included tannin extract, where the correlation between OMD and Nfc was not significant. Pearson correlation and linear regressions between OM intake (OMI, g/day) and faecal N excretion (Nf, g/day) were significant for all diet types. When OMI was estimated from the OM faecal excretion and Nfc-based OMD values, the linear comparison between observed and estimated OMI values showed intercept different from 0 and slope different from 1. When OMI was estimated using the Nf-based linear regressions, the linear comparison between observed and estimated OMI values showed neither intercept different from 0 nor slope different from 1. Both linear comparisons showed similar R(2) values (i.e. 0.78 vs. 0.79). In conclusion, linear equations are suitable for directly estimating OM intake by wethers, fed only forage or forage plus supplements, from the amount of N excreted in faeces. The use of this approach in experiments with grazing wethers has the advantage of accounting for individual variations in diet selection and digestion processes and precludes the use of techniques to estimate forage digestibility.

Photo-assisted electrochemical degradation of the commercial herbicide atrazine.

This paper presents a degradation study of the pesticide atrazine using photo-assisted electrochemical methods at a dimensionally stable anode (DSA(®)) of nominal composition Ti/Ru(0.3)Ti(0.7)O(2) in a prototype reactor. The effects of current density, electrolyte flow-rate, as well as the use of different atrazine concentrations are reported. The results indicate that the energy consumption is substantially reduced for the combined photochemical and electrochemical processes when compared to the isolated systems. It is observed that complete atrazine removal is achieved at low current densities when using the combined method, thus reducing the energy required to operate the electrochemical system. The results also include the investigation of the phytotoxicity of the treated solutions.

Photo-assisted electrochemical degradation of real textile wastewater.

In the present study, photo-assisted electrochemical degradation of real textile wastewater was performed. Degradation assays were performed at constant current (40 mA cm(-2)) in a combined electro/photochemical flow-cell using a Ti/Ru(0.3)Ti(0.7)O(2) DSA type electrode. The results show that the method is capable of removing color and chemical oxygen demand (COD) from the effluent. Additionally, the effect of initial pH and type of supporting electrolyte (Na(2)SO(4) or NaCl) was investigated. The principal figures of merit used in this study were COD removal and color removal (605 nm). The results show that up to 72% color and up to 59% COD removal in 120 min is possible under the operating conditions employed. Studies of the phytotoxicity of the wastewater before and after the photo-assisted degradation assays are also presented and the results demonstrate that the toxicity of the effluent is dependent on the length of electrolysis time and the treatment procedure employed.

Treatment of the butadiene washing stream from a synthetic rubber industry and recovery of p-TBC.

Butadiene is marketed containing p-tertbutylcatechol (p-TBC), a polymerization inhibitor that should be removed before butadiene utilization in synthetic rubber production. p-TBC can be removed from butadiene by washing with sodium hydroxide (NaOH) solution, producing a wastewater with pH 14, which contains high amounts of p-TBC, a toxic chemical compound. The aim of this work was to develop a treatment process that could reduce the content of p-TBC from the wastewater. Since p-TBC is very soluble in basic, but not in neutral and acid solutions, acidification tests were performed with phosphoric acid (H3PO4) to precipitate p-TBC. Reaction between NaOH and H3PO4 can result in crystallization of large amounts of salt without p-TBC precipitation. Under selected acidifying conditions p-TBC precipitates and the wastewater COD is highly reduced (> 90/o). Chromatographic determinations showed that the precipitated p-TBC could be recovered with 99% purity.

[Histopathological aspects of tertiary pinta]. / Aspectos histopatológicos da pinta terciária.

A study was made of twenty-two biopsies of achromic lesions of Tikuna Indians, carriers of tertiary pinta, inhabitants of the Umariuassu island, on the Peruvian border, ten of the subjects had been treated two years previously with a single dose of penicillin. The histopathological picture was similar for both groups. In most cases (86.36%) slight hyperkeratosis was found on the epidermis, as well as acanthosis (18.18%), with atrophy in only two cases (9.09%). In all cases there was a reduction of the melanin of the basal layer. The inflammatory lymphocyte infiltrate was predominantly perivascular (88.18%). There wasn't any endothelial swelling.

A crianca hospitalizada: refexoes de equipe. / Hospitalized child: reflexions of the health team

Este trabalho foi escrito a partir das reflexoes de um grupo que se reunia semanalmente para discutir aspectos relativos a internacao de seus pacientes, sendo um primeiro esforco de sistematizacao e supondo dois momentos: o questionamento de aspectos que consideramos muito pregnantes em nossas relacoes com a crianca hospitalizada e seus familiares e o aprofundamento destas questoes a partir de uma compreensao teorica. Procuramos, assim, identificar em aspectos particulares os denominadores comuns do trabalho de uma equipe de saude, detectando vivencias e sentimentos que nao se prenderiam as especificidades desta equipe, mas que seriam quase determinados pelo lidar com a crianca hospitalizada

O impacto emocional da hospitalizacao da crianca. / Emotional impact in child hospitalization

Neste trabalho, refletimos sobre a situacao de hospitalizacao da crianca. Admitimos que esta e uma experiencia estressante, mas que pode ser amenizada pelo favorecimento de certas condicoes, como presenca de familiares, contato com outras criancas, disponibilidade afetiva da equipe, informacao etc. Analisamos problemas como recusa a medicacao ou dificuldade em permitir a realizacao de exames dolorosos e assinalamos a maior sensibilizacao da crianca com doenca cronica ou terminal.Observamos que as criancas costumam expressar suas duvidas e angustias por vias indiretas, ou mesmo por perguntas a alguem da equipe, sendo fundamental estar atento a comunicacao da crianca hospitalizada

A hospitalizacao da crianca: a visao do familiar. / Children hospitalization: the familiar view

Neste trabalho, procuramos pensar a questao da hospitalizacao da crianca pelo lado do familiar, dando especial atencao a maneira como a familia vive este problema.Utilizamos material diretamente expresso pelos familiares ou observacoes realizadas em nosso contato quotidiano, podendo concluir que, em geral, os familiares desejam acompanhar suas criancas, excetuando-se situacoes onde existam graves impedimentos objetivos e (ou) emocionais. Observamos, tambem, que o esclarecimento a familia desempenha importante papel na relacao equipe-familiar, embora, muitas vezes, a familia possa negar uma informacao grave, necessitando de um tempo emocional para elaborar o que foi comunicado. Finalmente, e importante observar que processos emocionais foram desencadeados pela situacao de hospitalizacao, atualizando os antigos conflitos