Soil mineral genesis and distribution in a saline lake landscape of the Pantanal Wetland, Brazil

The origin of the saline lakes in the Pantanal wetland has been classically attributed to processes occurring in past periods. However, recent studies have suggested that saline water is currently forming from evaporative concentration of fresh water, which is provided annually by seasonal floods. Major elements (Ca, Mg, K) and alkalinity appear to be geochemically controlled during the concentration of waters and may be involved in the formation of carbonates and clay minerals around the saline lakes. The mineralogy of soils associated with a representative saline lake was investigated using XRD, TEM-EDS, and ICP-MS in order to identify the composition and genesis of the secondary minerals suspected to be involved in the control of major elements. The results showed that Ca, Mg, and K effectively undergo oversaturation and precipitation as the waters become more saline. These elements are incorporated in the authigenically formed carbonates, smectites, and micas surrounding the saline lake. The control of Ca occurs by precipitation of calcite and dolomite in nodules while Mg and K are mainly involved in the neoformation of Mg-smectites (stevensitic and saponitic minerals) and, probably, iron-enriched micas (ferric-illite) in surface and subsurface horizons. Therefore, our study confirms that the salinity of Pantanal, historically attributed to inheritance from former regimes, has a contribution of current processes. (C) 2009 Elsevier B.V. All rights reserved.

Incidence and distribution of viruses of Taro (Colocasia esculenta) in Pacific Island countries

Four viruses have been reported from taro; Dasheen mosaic virus (DsMV), Taro bacilliform virus (TaBV) and two putative rhabdoviruses, Colocasia bobone disease virus (CBDV) and Taro vein chlorosis virus (TaVCV). A fifth virus, tentatively named Taro reovirus (TaRV), has also been recently identified. The distribution of these viruses throughout the Pacific Islands, and the symptoms associated with their infection, are unknown in many cases due to a lack of sensitive diagnostic tests. We have used recently developed PCR-based diagnostic tests to survey taro growing in 11 Pacific Island countries for the presence of known viruses. DsMV and TaBV were widespread, whereas TaVCV and TaRV were more restricted in their distribution. CBDV was restricted to PNG and Solomon Islands and was always associated with the two most serious viral diseases of taro; alomae disease and bobone disease, but the causal agent of these two diseases remains unclear.

Distribution of an asymmetrical copepod, Hatschekia plectropomi, on the gills of Plectropomus leopardus

Hatschekia plectropomi, an ectoparasitic copepod found on the gills, infected Plectropomus leopardus from Heron Island Reef with 100% prevalence (n = 32) and a mean +/- S.E. infection intensity of 131.9 +/- 22.1. The distribution of 4222 adult female parasites across 32 individual host fish was investigated at several organizational levels ranging from the level of holobranch pairs to that of individual filaments. Parasites demonstrated a site preference for the two central holobranchs (2 and 3). Along the lengths of hemibranchs, filaments near the dorsal and ventral ends and those in the proximity of the bend region were rarely occupied. The probability of coming into contact with a suitable attachment site and the ability to withstand ventilation forces at that site were proposed as the major factors affecting distribution. Two H. plectropomi morphotypes were identified based on the direction of body curvature. Regardless of morphotype, 99.9% of individuals were attached such that the convex side of the body was oriented towards the oncoming ventilating water currents. Further, 93.3% of individuals attached to the posterior faces of filaments, leading to a predictable pattern of attachment for this species. It is suggested that the direction of body curvature develops in response to the direction of the ventilating water currents. (c) 2006 The Fisheries Society of the British Isles.

Privacy and security enhanced offline oblivious transfer for massive data distribution

Unauthorized accesses to digital contents are serious threats to international security and informatics. We propose an offline oblivious data distribution framework that preserves the sender's security and the receiver's privacy using tamper-proof smart cards. This framework provides persistent content protections from digital piracy and promises private content consumption.

Spatial distribution of pink wax scale, Ceroplastes rubens Maskell (Hemiptera: Coccidae), on umbrella trees in south-eastern Queensland: The pattern of outbreaks

The spatial pattern of outbreaks of pink wax scale, Ceroplastes rubens Maskell, within and among umbrella trees, Schefflera actinophylla (Endl.), in southeastern Queensland was investigated. Pink wax scale was common on S. actinophylla, with approximately 84% of trees positive for scale and 14% of bees recording outbreak densities exceeding 0.4 adults per leaflet. Highly aggregated distributions of C. rubens occur within and among umbrella trees. Clumped distributions within trees appear to result from variable birth and death rates and limited movement of first instar crawlers. The patchy distribution of pink wax scale among trees is probably a consequence of variation in dispersal success of scale, host and environmental suitability for establishment and rates of biological control. Pink wax scale was more prevalent on trees in roadside positions and in exposed situations, indicating that such trees are more suitable and/or susceptible to scale colonisation.

Texture Image Analysis in Differentiating Malignant from Benign Adrenal Cortical Tumors in Children and Adults

Objective: To investigate the possible role of chromatin texture parameters, nuclear morphology, DNA ploidy and clinical functional status in discriminating benign from malignant adrenocortical tumors (ACT). Patients and Methods: Forty-eight cases of clinically benign (n=40) and clinically malignant (n=8) ACT with a minimum of 5-years` follow-up were evaluated for chromatin texture parameters (run length, standard deviation, configurable run length, valley, slope, peak and other 21 Markovian features that describe the distribution of the chromatin in the nucleus), nuclear morphology (nuclear area, nuclear perimeter, nuclear maximum and minumum diameter, nuclear shape), and DNA ploidy. Nuclear parameters were evaluated in Feulgen-stained 5 mu m paraffin-sections analyzed using a CAS 200 image analyzer. Results: Since ACTs present different biological features in children and adults, patients were divided into two groups: children (<= 15 years) and adults (>15 years). In the group of children DNA ploidy presented a marginal significance (p=0.05) in discriminating ACTs. None of the parameters discriminated between malignant and benign ACT in the adult group. Conclusion: ACTs are uncommon and definitive predictive criteria for malignancy remain uncertain, particularly in children. Our data point to DNA content evaluated by image analysis as a new candidate tool for this challenging task. Texture image analysis did not help to differentiate malignant from benign adrenal cortical tumors in children and adults.

Pore structure characterisation of pillared clays using a modified MP method

The data of nitrogen adsorption on pillared clays (PILC) are converted to comparison plots (t-plots) to derive their pore size distribution (PSD). As in the MP method, the surface area of a group of pores having similar pore sizes is calculated from the slopes of tangent lines at two succeeding points on a comparison plot. By the modified MP method in this work, the tangent line is extrapolated to the adsorption axis on the t-plot, and the difference between intercepts is used to obtain the volume of the group of pores. From the information of surface area and pore volume, the average width of the pore group can be calculated and hence the PSDs of PILCs are obtained by carrying out such calculation procedures from high to low t. With this method, PSDs of several pillared clays are calculated over a wide pore size range, from micropores to mesopores. It is found that the modified MP method could result in the underestimation of the width of ultramicropores due to the enhancement in adsorption energy in these pores. Nevertheless, the method can be very useful in calculating the surface area and pore volume, as well as a mean width of these pores. For super-micropores and mesopores, pore size can also be underestimated, due to deviation of the pore shape from a slit. The principles of the improved MP method, as well as problems associated with it are thoroughly discussed in this paper. In general, this modified method provides practically meaningful results which are consistent with the pore dimension obtained from powder X-ray diffraction measurements, but involves no complicated theoretical treatment or assumptions.

Modelling the distribution of stamp paper thickness via finite normal mixtures: The 1872 Hidalgo stamp issue of Mexico revisited

Izenman and Sommer (1988) used a non-parametric Kernel density estimation technique to fit a seven-component model to the paper thickness of the 1872 Hidalgo stamp issue of Mexico. They observed an apparent conflict when fitting a normal mixture model with three components with unequal variances. This conflict is examined further by investigating the most appropriate number of components when fitting a normal mixture of components with equal variances.

Distribution of HDL-cholesterol and non-HDL-cholesterol in Brazilian children and adolescents - The Floripa study

Background and aims: HDL-cholesterol (HDL-C) and non-HDL-cholesterol (nHDL-C) are involved in atherosclerosis. The aim of this study was to determine the distribution of HDL-C and nHDL-C and its association with cardiovascular and socio-cultural variables in a pediatric Brazilian sample. Methods and results: Children and adolescents from Florianopolis were randomly selected and a structured questionnaire was administered, a physical examination was performed and a blood sample was collected. Enzymatic and Direct methods in vitro were used to determine the total cholesterol and HDL-cholesterol levels. The associations among HDL-C and nHDL-C and the described variables were tested by odds ratio and logistic regression. A total of 1009 individuals were examined. Based on the Brazilian criteria, 23% were classified with low levels of HDL-C and 25% with high levels of non-HDL-C. After multivariate analysis there were significant associations among low HDL-C and high C-reactive protein (OR, 3.3; 95% CI, 2.1-5.2), paternal tobacco use (OR, 1.5; 95% CI, 1.1-2.1), and high triceps-to-subscapular index (OR, 1.5; 95% CI, 1.1-2.2). There were also significant associations among high nHDL-C and high waist circumference (OR, 1.95; 95% CI, 1.16-3.29), black skin color (OR, 1.78; 95% CI, 1.06-3.06), and high income (OR, 1.48; 95% CI, 1.09-2.02). Conclusions: In this sample, low levels of HDL-C were associated with other clinical variables such as a centripetal fat pattern and C-reactive protein, and n-HDL-C was associated with abdominal obesity, skin color and economic class. (C) 2009 Elsevier B. V. All rights reserved.

Regional Blood Flow Distribution and Oxygen Metabolism During Mesenteric Ischemia and Congestion

Background. Acute mesenteric ischemia is a potentially fatal vascular emergency with mortality rates ranging between 60% and 80%. Several studies have extensively examined the hemodynamic and metabolic effects of superior mesenteric artery occlusion. On the other hand, the cardiocirculatory derangement and the tissue damage induced by intestinal outflow obstruction have not been investigated systematically. For these reasons we decided to assess the initial impact of venous mesenteric occlusion on intestinal blood flow distribution, and correlate these findings with other systemic and regional perfusion markers. Methods. Fourteen mongrel dogs were subjected to 45 min of superior mesenteric artery (SMAO) or vein occlusion (SMVO), and observed for 120 min after reperfusion. Systemic hemodynamics were evaluated using Swan-Ganz and arterial catheters. Regional blood flow (ultrasonic flow probes), intestinal O(2)-derived variables, and mesenteric-arterial and tonometric-arterial pCO(2) gradients (D(mv-a)pCO(2) and D(t-a)pCO(2)) were also calculated. Results. SMVO was associated with hypotension and low cardiac output. A significant increase in the regional pCO(2) gradients was also observed in both groups during the ischemic period. After reperfusion, a progressive reduction in D(mv-a)pCO(2) occurred in the SMVO group; however, no improvement in D(t-p)CO(2) was observed. The histopathologic injury scores were 2.7 +/- 0.5 and 4.8 +/- 0.2 for SMAO and SMVO, respectively. Conclusions. SMV occlusion promoted early and significant hemodynamic and metabolic derangement at systemic and regional levels. Additionally, systemic pCO(2) gradient is not a reliable parameter to evaluate the local intestinal oxygenation. Finally, the D(t-a)pCO(2) correlates with histologic changes during intestinal congestion or ischemia. However, minor histologic changes cannot be detected using this methodology. (C) 2010 Elsevier Inc. All rights reserved.

Melphalan dosing regimens for management of recurrent melanoma by isolated limb perfusion: Application of a physiological pharmacokinetic model based on melphalan distribution in the isolated perfused rat hindlimb

The optimal dosing schedule for melphalan therapy of recurrent malignant melanoma in isolated limb perfusions has been examined using a physiological pharmacokinetic model with data from isolated rat hindlimb perfusions (IRHP), The study included a comparison of melphalan distribution in IRHP under hyperthermia and normothermia conditions. Rat hindlimbs were perfused with Krebs-Henseleit buffer containing 4.7% bovine serum albumin at 37 or 41.5 degrees C at a flow rate of 4 ml/min. Concentrations of melphalan in perfusate and tissues were determined by high performance liquid chromatography with fluorescence detection, The concentration of melphalan in perfusate and tissues was linearly related to the input concentration. The rate and amount of melphalan uptake into the different tissues was higher at 41.5 degrees C than at 37 degrees C. A physiological pharmacokinetic model was validated from the tissue and perfusate time course of melphalan after melphalan perfusion. Application of the model involved the amount of melphalan exposure in the muscle, skin and fat in a recirculation system was related to the method of melphalan administration: single bolus > divided bolus > infusion, The peak concentration of melphalan in the perfusate was also related to the method of administration in the same order, Infusing the total dose of melphalan over 20 min during a 60 min perfusion optimized the exposure of tissues to melphalan whilst minimizing the peak perfusate concentration of melphalan. It is suggested that this method of melphalan administration may be preferable to other methods in terms of optimizing the efficacy of melphalan whilst minimizing the limb toxicity associated with its use in isolated limb perfusion.

The effects of perfusion conditions on melphalan distribution in the isolated perfused rat hindlimb bearing a human melanoma xenograft

An isolated rat hindlimb perfusion model carrying xenografts of the human melanoma cell line MM96 was used to study the effects of perfusion conditions on melphalan distribution. Krebs-Henseleit buffer and Hartmann's solution containing 4.7% bovine serum albumin (BSA) or 2.8% dextran 40 were used as perfusates. Melphalan concentrations in perfusate, tumour nodules and normal tissues were measured using high-performance liquid chromatography (HPLC). Increasing the perfusion flow rates (from 4 to 8 mi min(-1)) resulted in higher tissue blood flow (determined with Cr-51-labelled microspheres) and melphalan uptake by tumour and normal tissues. me distribution of melphalan within tumour nodules and normal tissues was similar for both Krebs-Henseleit buffer and Hartmann's solution; however, tissue concentrations of melphalan were significantly higher for a perfusate containing 2.8% dextran 40 than for one containing 4.7% BSA. The melphalan concentration in the tumour was one-third of that found in the skin if the perfusate contained 4.7% BSA. In conclusion, this study has shown that a high perfusion flow enhances the delivery of melphalan into implanted tumour nodules and normal tissues, and a perfusate with low melphalan binding (no albumin) is preferred for maximum uptake of drug by the tumour.

Transmission electron microscopy of a transformation toughened white cast iron

Transmission electron microscopy has been used to study the microstructure of an experimental white cast iran, in which a combination of modified alloy composition and unconventional heat treatment has resulted in a fracture toughness of 40 MPa m(-1/2). Microstructural features of the alloy that contribute to the toughness improvement and hence distinguish it from conventional white irons have been investigated. In the as-cast condition the dendrites are fully austenitic and the eutectic consists of M7C3 carbides and martensite. During heat treatment at 1130 degrees C the austenite is partially destabilized by precipitation of chromium-rich M7C3 carbides. This results in a dendritic microconstituent consisting of bulk retained austenite and secondary carbides which are sheathed with martensite. The martensite sheaths, which contain interlath films of retained austenite, are irregular in shape with some laths extending into the bulk retained austenite. Emphasis has been placed on the morphology, distribution, and stability of the retained austenite and its transformation products in the dendrites. The implications of these findings on the transformation toughening mechanism in this alloy are discussed.

Kinetics of elimination and distribution in blood and liver of biocompatible ferrofluids based on Fe(3)O(4) nanoparticles: An EPR and XRF study

In this study, we evaluated the biodistribution and the elimination kinetics of a biocompatible magnetic fluid, Endorem (TM), based on dextrancoated Fe(3)O(4) nanoparticles endovenously injected into Winstar rats. The iron content in blood and liver samples was recorded using electron paramagnetic resonance (EPR) and X-ray fluorescence (XRF) techniques. The EPR line intensity at g=2.1 was found to be proportional to the concentration of magnetic nanoparticles and the best temperature for spectra acquisition was 298 K. Both EPR and XRF analysis indicated that the maximum concentration of iron in the liver occurred 95 min after the ferrofluid administration. The half-life of the magnetic nanoparticles (MNP) in the blood was (11.6 +/- 0.6) min measured by EPR and (12.6 +/- 0.6) min determined by XRF. These results indicate that both EPR and XRF are very useful and appropriate techniques for the study of kinetics of ferrofluid elimination and biodistribution after its administration into the organism. (c) 2007 Elsevier B.V. All rights reserved.