Purification,characterization and toxicity of a mannose-binding lectin from the seeds of Treculia africana plant

In this study, a mannose-specific, homodimeric lectin from the seeds of Treculia africana was purified, characterized and its adverse effects were investigated in mice. The purification protocol involved anionic exchange chromatography on DEAE-Cellulose followed by gel filtration on Sephadex G-100. The hemagglutinating activity of lectin towards human erythrocytes was sensitive to inhibition by D-mannose. Treatment of the protein with EDTA exerted no inhibitory effect; however, analysis of metal content by atomic absorption spectroscopy revealed the presence of Cu²⁺, Fe³⁺, and Mg²⁺. The results obtained showed that the lectin possesses maximum hemagglutinating activity towards human erythrocytes activity over the pH range 3–7.2 and is relatively thermostable up to 50°C. Periodic acid Schiff's (PAS) reagent staining showed that the protein was non-glycosylated while its amino acid composition analysis revealed that the protein contained 155 residues per subunit. The subunit had a minimal molecular weight of 22,139 Daltons, while the native molecular weight was estimated to be 41,000 Daltons. The lectin was found to be moderately toxic to mice with an LD₅₀ of 47.21 µg g^?1 body weight while, histopathological analysis showed no treatment related effects in any of the organs examined.     

Lead availability in soils from Portugal’s Centre Region with special reference to bioaccessibility

Previous environmental biomonitoring studies indicated higher environmental lead (Pb) pollution levels at the districts of Aveiro and Leiria (Portugal). In evaluating the risk for human health, which is associated with contaminated soils after oral uptake, total soil concentrations have generally been held against criteria established from toxicological studies based upon the assumption that the uptake of the contaminant is similar in the toxicological studies and from the soils assessed. This assumption is not always valid, as most toxicological studies are carried out with soluble forms of the contaminants, whereas many soil contaminants are or become embedded in the soil matrix and thus exhibit limited availability. This study intends to estimate the soluble fraction of Pb in the soils from central Portugal, and to assess the bioaccessibility of Pb and, hence, infer exposure and risk for human health. Yet, as the physical–chemical properties of the soil exert some control over the solubility of Pb in the surface environment, the relation between such soil properties and the estimated soluble and/or bioaccessible fractions of Pb is also investigated. Other objective, with a more practical nature, was to give some contribution to find a suitable in vitro mimetic of the gastrointestinal tract environment. The results indicate relatively low total metal concentrations in the soils, even if differences between regions were observed. The Aveiro district has the higher total Pb concentration and the metal is in more soluble forms, that is, geoavailable. Soils with higher concentrations of soluble Pb show higher estimates of bioaccessible Pb. Soil pH seems to influence human bioaccessibility of Pb.     

Preparation of CuO/SiO<Subscript>2</Subscript> and photocatalytic activity by degradation of methylene blue

A photocatalyst based on CuO/SiO₂ was prepared, and evaluated for the degradation of methylene blue in aqueous medium. The photocatalyst was obtained by calcination method of copper salt, in the presence of silica. The characterization by XRD, FTIR, and TPR techniques confirmed the formation of CuO as active phase. SEM studies showed CuO deposited on the surface of SiO₂. By ESI-MS, it was demonstrated that the degradation of methylene blue occurs through successive hydroxylations. Photodegradation assays showed that CuO/SiO₂ was efficient for degradation, and that the material worked better in the presence of UV light.     

On the possibility of sustainable development with less economic growth: a research note

The main purpose of this paper is to discuss whether it is possible to achieve human development without or with less economic growth. For this to happen, it is important that developed countries can maintain high levels of human development while reducing the scale of production and consumption so that developing countries can achieve greater economic growth. Using panel data from 118 countries aggregated in ten blocks of countries, we assess the influence of “growth” on “development”, as proxied by a transformed variable “Social Human Development Index” (SHDI), controlling for the influence of geo-economic factors. In particular, we analyse whether developed countries present a weaker statistical relation between GDP and the social dimension of HDI than their less developed counterparts. Results reveal that the GDP elasticity of SHDI is higher in blocks of countries where the concentration of developing countries occurs than in blocks dominated by the presence of developed countries. Thus, it is possible to envisage that a slowdown in economic activity in developed countries may occur without great sacrifice of human development, at least when it is measured by health and education components. We interpret the findings as meaning that at an aggregate level there are conditions for development to occur without or with less growth.     

Artisanal fisheries of the Itaparica reservoir,São Francisco River,Brazil: socioeconomic profile,environmental dynamics,and management recommendations

Currently, artisanal fisheries in fresh water reservoirs have been losing ground to commercial fish farming and a great deal of fishery resources are being threatened by human interventions, such as reservoir management and increasing net-cage aquaculture. This study aims to understand the impacts of environmental changes on fishery resources and analyse the migratory fish breeding season as a missing link for fishery management in the semi-arid area of the São Francisco River Basin. Among the 870 fishermen operating in the Pernambuco part of the Itaparica Reservoir, 10% were interviewed and affirmed that fish stocks have been compromised due to the closed fishing period’s incoherence, exotic species insertion, and changes to the river flow caused by reservoir construction and operation. A significant correlation was observed between the Reproductive Activity Index (RAI) and precipitation (p?=?0.745) as well as between the RAI and the river’s flow (p?=??0.909). This shows how important it is to consider both the semi-arid climate setting and reservoir operation in determining the closed period which should safeguard fish reproduction. Monitoring the fish reproduction period and research on the reproductive biology of native fish species is needed in the São Francisco River Basin’s different stretches in order to guarantee valuable fish stocks and fisheries maintenance. Integrated action between the fish resource users, civil society, and federal bodies/agencies is essential in order to mitigate impacts and improve fish production systems, not only in Brazil, but in other regions experiencing a similar scenario.     

Comparative studies of fungal degradation of single or mixed bioaccessible reactive azo dyes

A screening using several fungi (Phanerochaete chrysosporium, Pleurotus ostreatus, Trametes versicolor and Aureobasidium pullulans) was performed on the degradation of syringol derivatives of azo dyes possessing either carboxylic or sulphonic groups, under optimized conditions previously established by us. T. versicolor showed the best biodegradation performance and its potential was confirmed by the degradation of differently substituted fungal bioaccessible dyes. Enzymatic assays (lignin peroxidase, manganese peroxidase, laccase, proteases and glyoxal oxidase) and GC-MS analysis were performed upon the assay obtained using the most degraded dye. The identification of hydroxylated metabolites allowed us to propose a possible metabolic pathway. Biodegradation assays using mixtures of these bioaccessible dyes were performed to evaluate the possibility of a fungal wastewater treatment for textile industries.     

A fair comparison between the spatial scan and the Besag–Newell Disease clustering tests

Routine surveillance of a large geographic region for clusters of adverse health events, particularly cancers, often involves small area health data, possibly controlling for exposure information. Many different methods have been proposed to test for the presence of geographical clusters. Two of the most popular methods are the spatial scan method proposed by Kulldorff and that using a fixed number of cases within scanning circles proposed by Besag and Newell. Although the second test is very popular, it has some difficulties. While the scan test controls for the multiple testing problem, the Besag and Newell test does not. Additionally, the latter method requires the setting of several tuning parameters whose values affect the test performance and are subjectively chosen by the user. This creates a difficulty to make a fair comparison between the two methods and it explains why there have been few formal studies evaluating their relative performances. In this paper, we modify the Besag and Newell test allowing for the control of the error type I probability and compare its power with respect to that of the spatial scan test. We used data sets from a publicly available simulated benchmark. We found that the two methods have similar results, except for clusters located in sparsely populated regions, where the spatial scan method presented a better performance.     

Variations in circulating hemocytes are affected by age and caste in the stingless bee <Emphasis Type="Italic">Melipona quadrifasciata</Emphasis>

The insect immune system faces various challenges; particularly in social bees, caste system and age polyethism expose individuals to numerous environmental and working conditions. However, little is known about how cellular defenses in social bees may be organized to respond to a variety of immune challenges. Here, we describe the morphological features and the total and differential counts of hemocytes in different female classes (newly emerged workers, nurses, foragers, and virgin queens) of the eusocial stingless bee Melipona quadrifasciata. Granulocytes and prohemocytes were, respectively, the most and the least abundant cells among all classes of females. Furthermore, there were more prohemocytes in virgin queens than in foragers. The total number of hemocytes was smaller in foragers, whereas the largest number was observed in nurse workers. This reduced amount of hemocytes in foragers might allow energy savings to perform colony activities such as foraging and defense. Foragers also had the biggest hemocytes (either prohemocytes, granulocytes, or plasmatocytes) in comparison to the other classes of females, which might have arisen as a compensation for the reduction in number of these cells during aging. These results suggest that profiles of hemocytes of M. quadrifasciata vary according to the caste and age of this eusocial bee.     

Determination of plate waste in primary school lunches by weighing and visual estimation methods: A validation study

The aim of this study was to validate the visual estimation method for aggregated plate waste of main dish at Portuguese primary school canteens. For this purpose plate waste at school lunch was measured for 505 individual servings, using weighing individual servings and plate waste and visual estimation method by a 6-point scale, as developed by Comstock et al. (1981). A high variability of initial serving weights was found with serving sizes ranging from 88.9 to 283.3 g and with a coefficient of variation ranging from 5.5% to 24.7%. Mean plate waste was 27.5% according to the weighing method. There was a significant bias in the conversion of the visual waste estimations to actual waste, being overestimated by an average of 8.0 g (ranging from ?12.9 g to 41.4 g). According to Bland and Altman plot, the mean difference between methods was of 8.0 g and the amplitude interval was 102.6 g. The study showed that the visual estimation method is not as accurate as the weighing method in assessing nonselective aggregated plate waste at primary school canteens. Our findings are thus very important on considering plate waste assessment, since the wide variation on initial servings introduces a relevant bias when considering standard portions or a random sample of initial servings. Although, greater convenience, time-saving and the possibility to monitor plate waste of large groups, make the visual estimation method an important method to assess plate waste at school canteens, these results highlighted the need of portions standardization and control of initial servings to allow for its use.