Competitive adsorption of heavy metals by two different types of soils

Soil is a key element in human survival and can be described by various definitions according to its main utility. Nowadays, it is accepted that soil is a very complex heterogeneous medium which consists of solid phases containing minerals and organic matter and soil solution, defined as the fluid phase where soil reactions, transport and adsorption occurs (Alloway, 1995). Unfortunately, in the last decades, soils have been used as a deposit of residues. Therefore, the contamination and pollution of soils, sediments, surface and groundwater are of main concern. There are several ions and compounds of organic or inorganic nature that can contaminate soil and water. The inorganic contaminants include heavy metals like cadmium, chromium, cooper, lead and zinc, which are focused in this study. These metals are commonly present in industrial wastes (electroplating, textile and dyes, etc.), in fertilizers or in sewage sludge, but they can also contaminate soils through atmospheric deposition or runoff water (Serrano et al., 2005). Since adsorption is well recognized as the main process affecting the mobility of heavy metals through soils (Bradl, 2004), the aim of this work is the study the non competitive adsorption of these five metals, as well as the competitive adsorption in two different typical soils of the North of Portugal The soil samples were collected in Póvoa de Varzim, from O-horizon and A-horizon (0 cm -30 cm), one from a culture land and another from a beach land. To evaluate the adsorption equilibrium, batch tests were performed by adding to 2 g of air dried soil, 20 mL of 0.01 M CaCl2 solution, containing different initial concentrations of Pb [Pb(NO3)2], Cd [CdN2O6·4H2O], Cu [Cu(NO3)2·3H2O], Zn [Zn(NO3)2·6H2O] and Cr [K2Cr2O7], isolated (non-competitive system) and coupled (competitive system).To eliminate the mass effect, the multi-metal solutions were prepared in terms of molar concentrations (Echeverría et al., 1998). To avoid precipitation the pH of initial solution was adjusted to 2. Isotherm models like Freundlich and Langmuir equations were adjusted to experimental data. Batch tests are useful for the understanding of the adsorption process. However, advection and dispersion may occur in dynamic systems justifying the need of flow experiments (Miretzky et al., 2006). For continuous experiments, soil samples were packed in a column (25 cm × 3.2 cm) and a single – or multi – element solution of 50 mg/L was pass upwards during seven days. Then, using the CXTFIT code, the convection-dispersion equation was adjusted to the breakthrough curves in order to determine the retardation factor (R) and to compare the behavior of the different ions and soils

Herpetofauna of an urban environmental protection area in an Amazon forest remnant of Amapá state, northern Brazil

The herpetofauna of Amazonia biome is one of the richest in the world. However, there is a lack of information on its richness and distribution. Here we provide a list of the herpetofauna from the Environmental Protection Area of Lagoa dos Índios, state of Amapá, Brazil, in the northern Amazon Forest. Sampling effort was conducted by active search in three distinct transects from January to May 2018 (rainy season) and August to December 2019 (drought season). We recorded 46 species composing the local herpetofauna, being 18 amphibians and 28 reptiles. Scinax ruber, Gonatodes humeralis and Helicops angulatus were the most abundant species. Regarding the conservation status, two species are categorized as Date Data deficient, (Lysapsus bolivianus and Eunectes deschauenseei), and one as Vulnerable (Podocnemis unifilis) in the Red List of the International Union for Conservation of Nature. Podocnemis unifilis is also considered Near Threatened in the Brazilian Red List of Endangered Species. Our results suggest that local biodiversity is still underestimated and, if expanded, could increase the species richness in the area. This study represents preliminary trends and raise further questions concerning the herpetofauna assemblage of Eastern Brazilian Amazonia.El bioma de la herpetofauna de la Amazonia es uno de los más ricos del mundo. Sin embargo, falta información sobre su riqueza y distribución. Aquí proporcionamos una lista de la herpetofauna del Área de Protección Ambiental de Lagoa dos Índios, estado de Amapá, Brasil, en el norte de la Selva Amazónica. El esfuerzo de muestreo se realizó mediante búsqueda activa en tres transectos distintos de enero a mayo de 2018 (temporada de lluvias) y de agosto a diciembre de 2019 (temporada de sequía). Registramos 46 especies que componen la herpetofauna local, siendo 18 anfibios y 28 reptiles. Scinax ruber, Gonatodes humeralis y Helicops angulatus fueron las especies más abundantes. En cuanto al estado de conservación, dos especies están categorizadas como Datos deficientes en fecha, (Lysapsus bolivianus y Eunectes deschauenseei), y una como Vulnerable (Podocnemis unifilis) en la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza. Podocnemis unifilis también se considera Casi Amenazada en la Lista Roja Brasileña de Especies Amenazadas. Nuestros resultados sugieren que la biodiversidad local todavía se subestima y, si se amplía, podría aumentar la riqueza de especies en el área. Este estudio representa tendencias preliminares y plantea más preguntas sobre el conjunto de herpetofauna de la Amazonia brasileña oriental.Asociación Herpetológica Argentin

Palatability and digestibility of horse diets containing increasing levels of citrus pulp

ABSTRACT Objective. To evaluate the impact of citrus pulp on the palatability and digestibility of horse diets and the physicochemical characteristics of the feces. Materials and methods. The diets were composed of 60% of the energy from the forage and 40% from the concentrate, with increasing levels of citrus pulp. Two different tests were performed. The first test assessed the palatability of concentrates. Using a randomized experimental design, 15 horses were observed for 10 days. The variables recorded were first action, first choice and intake ratio (IR). Five horses were arranged in 5x5 Latin Square design for the test assessing digestibility and fecal physicochemical characteristics. The apparent digestibility of the nutrients and the color, consistency, pH and buffering capacity (BC) of the feces were evaluated. Results. The addition of increasing levels of citrus pulp had an effect (p≤0.001) on first action. A difference was also observed in first choice, and the addition of 0, 7 or 14% of citrus pulp was preferred. A difference between treatments (p≤0.001) was also observed for IR, and the control concentrate was consumed the most. The amount of citrus pulp included had no effect (p>0.05) on the digestibility of nutrients, fecal consistency and color, and there was no effect (p>0.05) on fecal pH and BC. Conclusions. Horses can identify the presence of citrus pulp in concentrates but prefer concentrates without added citrus pulp. Citrus pulp does not negatively affect the digestibility of concentrates or the physicochemical characteristics of the feces; thus, citrus pulp is a viable alternative ingredient in the formulation of horse diets. RESUMEN Objetivo. Evaluar la inclusión de pulpa de cítricos en la dieta de los caballos a través de la evaluación de la de palatabilidad, digestibilidad y características fisicoquímicas de las heces. Materiales y métodos. El valor energético de las dietas fue aportado en el 60% por la energía del forraje y en el 40% a partir del concentrado con niveles crecientes de pulpa de cítricos. En la primera prueba se evaluó la palatabilidad de los concentrados. Se utilizó un diseño experimental aleatório. Se observaron 15 caballos durante 10 días. Las variables registradas fueron la primera acción, la primera opción y la relación de la ingesta (IR). Cinco caballos fueron dispuestos en un diseño cuadrado latino 5x5 para la evaluación de la digestibilidad y las características fisicoquímicas fecales. La digestibilidad de los nutrientes y el color, la consistencia, el pH, y se evaluó la capacidad de tamponamiento (CT) de las heces. Resultados. El nível de inclusión de pulpa de cítricos tuvo un efecto (p0.05) la digestibilidad, consistencia fecal y el color de las heces, pH fecal y CT de las heces. Conclusiones. Los caballos pueden identificar la presencia de pulpa de cítricos en los concentrados, pero prefieren concentrados sin pulpa de cítricos. La pulpa de cítricos no afecta la digestibilidad de los nutrimentos en el concentrado, ni las características fisicoquímicas de las heces; la pulpa de cítricos es un ingrediente alternativo viable en la formulación de dietas para caballos

Ensino de Ciências interdisciplinar em um espaço não-formal de aprendizagem na UFV

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Global online trade in primates for pets

The trade in primates as pets is a global enterprise and as access to the Internet has increased, so too has the trade of live primates online. While quantifying primate trade in physical markets is relatively straightforward, limited insights have been made into trade via the Internet. Here we followed a three-pronged approach to estimate the prevalence and ease of purchasing primates online in countries with different socioeconomic characteristics. We first conducted a literature review, in which we found that Malaysia, Thailand, the USA, Ukraine, South Africa, and Russia stood out in terms of the number of primate individuals being offered for sale as pets in the online trade. Then, we assessed the perceived ease of purchasing pet primates online in 77 countries, for which we found a positive relationship with the Internet Penetration Rate, total human population and Human Development Index, but not to Gross Domestic Product per capita or corruption levels of the countries. Using these results, we then predicted the levels of online primate trade in countries for which we did not have first-hand data. From this we created a global map of potential prevalence of primate trade online. Finally, we analysed price data of the two primate taxa most consistently offered for sale, marmosets and capuchins. We found that prices increased with the ease of purchasing primates online and the Gross Domestic Product per capita. This overview provides insight into the nature and intricacies of the online primate pet trade and advocates for increased trade regulation and monitoring in both primate range and non-range countries where trade has been substantially reported. © 2023 The Author

Aortic Response to Strength Training and Spirulina platensis Dependent on Nitric Oxide and Antioxidants

Studies have shown that supplementation with Spirulina platensis improves vascular reactivity. However, it is unclear whether in association with strength training this effect can be enhanced. Thus, this study aimed to determine the effects of strength training and S. platensis on the reactivity of the aorta from Wistar rat and the possible mechanisms involved. The animals were supplemented with S. platensis and divided into sedentary (SG, SG50, SG150, and SG500) and trained groups (TG, TG50, TG150, and TG500). Nitrite, malondialdehyde (MDA) and antioxidant activity were determined by biochemical assays. To evaluate vascular response, cumulative concentration—response curves to phenylephrine (PHE) and acetylcholine (ACh) were constructed. L-NAME was used to assess the participation of nitric oxide (NO). It was observed that the PHE contractile potency was reduced in TG50, TG150, and TG500 groups compared to SG50, SG150, and SG500 groups, respectively. However, the presence of L-NAME increased the contractile response in all groups. Strength training potentiated the increase in relaxing activity induced by S. platensis, where the pCE50 values of ACh increased in TG150 and TG500. These responses were accompanied by increased nitrite production, MDA reduction and increased antioxidant activity in the aorta of both TG150 and TG500 groups. Thus, the present study demonstrated that combined with strength training, S. platensis potentiates vascular improvement through the participation of NO and reduction of oxidative stress