Monogamy in large bee societies: a stingless paradox

High genetic diversity is important for the functioning of large insect societies. Across the social Hymenoptera (ants, bees, and wasps), species with the largest colonies tend to have a high colony-level genetic diversity resulting from multiple queens (polygyny) or queens that mate with multiple males (polyandry). Here we studied the genetic structure of Trigona spinipes, a stingless bee species with colonies an order of magnitude larger than those of polyandrous honeybees. Genotypes of adult workers and pupae from 43 nests distributed across three Brazilian biomes showed that T. spinipes colonies are usually headed by one singly mated queen. Apart from revealing a notable exception from the general incidence of high genetic diversity in large insect societies, our results reinforce previous findings suggesting the absence of polyandry in stingless bees and provide evidence against the sperm limitation hypothesis for the evolution of polyandry. Stingless bee species with large colonies, such as T. spinipes, thus seem promising study models to unravel alternative mechanisms to increase genetic diversity within colonies or understand the adaptive value of low genetic diversity in large insect societies.     

Kinetics of uranium uptake in soft water and the effect of body size,bioaccumulation and toxicity to Hyalella azteca

The kinetics of uptake and the effect of body size on uranium (U) bioaccumulation and toxicity to Hyalella azteca exposed to water-only U concentrations in soft water were evaluated. The effect of body size on U bioaccumulation was significant with a slope of ?0.35 between log body concentration and log body mass. A saturation kinetic model was satisfactory to describe the uptake rate, elimination rate and the effect of gut-clearance on size-corrected U bioaccumulation in H. azteca. The one-week lethal water concentrations causing 50% mortality for juvenile and adult H. azteca were 1100 and 4000 nmol U/L, respectively. The one-week lethal body concentration causing 50% mortality was 140 nmol U/g for juvenile H. azteca and 220 nmol U/g for adult H. azteca. One-week bioaccumulation studies that properly account for body-size and gut-clearance times can provide valuable data on U bioavailability and toxicity in the environment.     

Joining sheet panels to thin-walled tubular profiles by tube end forming

This paper is focused on novel utilizations of the fundamental modes of deformation of tube end forming for assembling sheet panels to thin-walled tubular profiles.The objective is to present an innovative and environmental friendly joining technology built upon the combination of compression beading with tube inversion that can successfully eliminate currently available technologies based on mechanical fixing with fasteners, welding and structural adhesive bonding. The technology works at room temperature, is capable of ensuring significant economic and time savings and offers potential for opening new markets for the assembly of lightweight frame structures.The presentation is supported by experimentation and numerical modelling based on independently determined mechanical properties of the materials with the purpose of characterizing and evaluating the process feasibility limits as a function of the major operative parameters.The feasibility of joining sheet panels to tubular profiles by means of the proposed technology is demonstrated by presenting industrial applications and by evaluating the performance of a safety auto part in an operation failure test.     

Potential application of 2-(6-ethylamino-3-ethylimino-2,7-dimethyl-3H-xanthen-9-yl) benzoic acid phenyl thiourea for mercury determination

Heavy metal contamination of the environment is a public health problem and research to develop new tools for monitoring the environmental impact of these elements is necessary. This study describes the preparation of a rhodamine-based probe 1 and its potential applications for detecting mercuric ion [Hg(II)] in samples from a nutrition media containing Salvinia auriculata. It was observed that an excess of probe 1 led to quenching in the fluorescence/absorption response, which was evidenced by a decrease in the signal when the stoichiometry differed from 1:1. Consequently, this probe is not suitable for quantitative analysis of Hg(II). Also, probe 1 reacts with methylmercury (MeHg) with different stoichiometry than that observed for Hg(II). These results indicate the potential application of probe 1 for qualitative detection of Hg(II) and MeHg in environmental samples.     

International retirement migration in the Alicante region,Spain: process,spatial pattern and environmental impacts

International retirement migration has become an increasing phenomenon in the Mediterranean region of Alicante, Spain. Through an interdisciplinary approach, relationships between the migration process, landscape change and environmental impacts are examined. Lifestyle-related perceptions and demands of UK retirees are studied as a major driving force of urbanisation. The extent and quality of the process is assessed by statistical and land use data analysis. Results reveal a distinctive spatial pattern of in-migration and the emergence of an archetypical landscape, consisting of a mosaic of remaining natural and urbanised landscape along the Mediterranean coast. The paper discusses the necessity of retirees' integration into sustainable planning and decision making.     

Hydrological benefits in the context of Brazilian environmental services program

The Brazilian program of payment for environmental services (PES) is based on ranges of potential erosion decrease (ED) from soil and water conservation proposals estimated from the Universal Soil Loss Equation. Changes in land use and land cover (LULC) result in many alterations of the basin water balance. Therefore, to contribute to the methodological development of Brazilian PES, this paper proposes a quantification of hydrological benefits based on conservation measures. We propose basing the PES program on adding the potential water storage increase (WSI) parameter estimated from the runoff curve number model. Two LULC change scenarios were run considering conservation measures on degraded areas. We found that indicators of ED and WSI were compatible tools for driving the eligibility of soil and water conservation measures. However, the water storage parameter seems to be better at managing the PES mechanism because it is based on water prices and can contribute to appreciation of the efforts performed by the rural producers. The use of the SCS-CN method presents greater feasibility as a tool for the implementation of PES programs in ungauged basins. Thus, an analysis of the success of the innovation proposal of the Brazilian PES program allows inferences to be made about the quantification and financial valuation of hydrological benefits of the potential storage increase and current water price.     

Forecasting of municipal solid waste generation in China based on an optimized grey multiple regression model

Journal of Material Cycles and Waste Management - The massive generation of municipal solid waste (MSW) has become an essential social problem that not only damages the ecological environment but...     

Micronucleus and different nuclear abnormalities in wild birds in the Cerrado,Brazil

Environmental Science and Pollution Research - Free-living birds play an important role as bioindicators in natural environments. In this study, we used the micronucleus test and nuclear...