Mate quality,not aggressive spillover,explains sexual cannibalism in a size-dimorphic spider

Sexual cannibalism particularly before mating is costly for the male victim but also for the female aggressor if she risks remaining unmated. The aggressive spillover hypothesis explains the persistence of this behavior as a maladaptive side effect of positive selection on aggressiveness in a foraging context. The hypothesis predicts that the occurrence of sexual cannibalism is explained by female aggressiveness but is not related to male phenotype or behavioral type. An alternative hypothesis invokes sexual selection and makes the opposite prediction namely that sexual cannibalism is an expression of female choice and should hence mainly target males of low quality. We tested the above hypotheses on a sexually dimorphic nephilid spider Nephilengys livida, known for male monopolization of females via genital damage, female genital plugging, and mate guarding, by staging mating trials during which we recorded mating behaviors and occurrences of pre- and postcopulatory cannibalism. We did not restrict assessment of aggressiveness to the mating and foraging context but also included aggression against same sex conspecifics. To assess female personalities, i.e., consistent individual differences in behavior including aggressiveness, we repeatedly tested them for intra-sex aggression, voracity towards prey, locomotory activity, and boldness. Females exhibited consistent differences in intra-sex aggressiveness, latency to attack prey, and boldness. Aggressive females had shorter latencies to attack prey and were more active than non-aggressive ones. In contrast to the predictions of the aggressive spillover hypothesis, females that were aggressive towards prey and towards other females were not more likely to attack a male than non-aggressive females. In support of the mate choice hypothesis, less aggressive males were more likely attacked and cannibalized than more aggressive ones. This hints at sexual selection for aggressiveness in males and raises the question of mechanisms that maintain variation in male aggressiveness.     

Radionuclide concentrations in raw and purified phosphoric acids from Brazil and their processing wastes: implications for radiation exposures

Radionuclides from the U and Th natural series are present in alkaline rocks, which are used as feedstock in Brazil for the production of raw phosphoric acid, which can be considered as a NORM (naturally occurring radioactive material). As a result of the purification of raw phosphoric acid to food-grade phosphoric acid, two by-products are generated, i.e., solid and liquid wastes. Taking this into account, the main aim of this study was to evaluate the fluxes of natural radionuclide in the production of food-grade phosphoric acids in Brazil, to determine the radiological impact caused by ingestion of food-grade phosphoric acid, and to evaluate the solid waste environmental hazards caused by its application in crop soils. Radiological characterization of raw phosphoric acid, food-grade phosphoric acid, solid waste, and liquid waste was performed by alpha and gamma spectrometry. The ²³⁸U, ²³⁴U, ²²⁶Ra, and ²³²Th activity concentrations varied depending on the source of raw phosphoric acid. Decreasing radionuclides activity concentrations in raw phosphoric acids used by the producer of the purified phosphoric acid were observed as follows: Tapira (raw phosphoric acid D) > Catal?o (raw phosphoric acids B and C) > Cajati (raw phosphoric acid A). The industrial purification process produces a reduction in radionuclide activity concentrations in food-grade phosphoric acid in relation to raw phosphoric acid produced in plant D and single raw phosphoric acid used in recent years. The most common use of food-grade phosphoric acid is in cola soft drinks, with an average consumption in Brazil of 72 l per person per year. Each liter of cola soft drink contains 0.5 ml of food-grade phosphoric acid, which gives an annual average intake of 36 ml of food-grade phosphoric acid per person. Under these conditions, radionuclide intake through consumption of food-grade phosphoric acid per year per person via cola soft drinks is not hazardous to human health in Brazil. Considering these annual additions of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K, and since these radionuclide should be homogeneously distributed in the upper 10 cm of soils with an assumed apparent density of 1.5 g/cm³, a maximum increase of 0.19 ± 0.03 Bq kg⁻¹ of soil is expected for ²³⁸U and ²³⁴U. Thus, the addition of solid waste as phosphate fertilizers to Brazilian agricultural soils does not represent a hazard to the ecosystem or to human health.     

Application to the Port of Sines of a new tool for risk assessment in port navigation

This paper describes a first approach on the risk assessment in port navigation using GUIOMAR, an integrated system for port and coastal engineering modelling developed at the National Civil Engineering Laboratory (LNEC), Portugal, using a GIS software environment. A set of automatic procedures was designed to include a new methodology based on the amplitude of the wave-induced vertical movement of a ship along its trajectory. In this methodology, the risk in port navigation is assessed on the basis of a combination of the probability of exceedance of a pre-set threshold for the ship??s vertical movements and its consequences. To test the new procedures, a set of sea wave records obtained at the Sines wave-buoy from 1988 to 2002 was transferred into Sines Port using two numerical models of sea wave propagation and deformation (SWAN and DREAMS), included in the GUIOMAR system. The numerical model WAMIT was used for estimating the wave-induced ship??s vertical movements inside the port. By applying the new procedures, automatic generation of risk maps was carried out for navigation in the vicinity of the West breakwater of the Port of Sines. The recent developments contribute towards a more versatile and efficient GUIOMAR system, which results in a more adequate tool to support decision-making processes in port and coastal management.     

White-collar workers' self-reported physical symptoms associated with using computers

The aim of our work was to study the physical symptoms of upper- and lower-level white-collar workers using a questionnaire. The study was cross-sectional with a questionnaire posted to 15 000 working-age persons. The responses (6121) included 970 upper- and 1150 lower-level white-collar workers. In the upper- and lower-level white-collar worker groups, 45.7 and 56.0%, respectively, had experienced pain, numbness and aches in the neck either pretty often or more frequently. When comparing daily computer users and nonusers, there were significant differences in pain, numbness and aches in the neck or in the shoulders. In addition, age and gender influenced some physical symptoms. In the future, it is essential to take into account that working with computers can be especially associated with physical symptoms in the neck and in the shoulders when workers use computers daily.     

A general process-based mass-balance model for phosphorus/eutrophication as a tool to estimate historical reference values for key bioindicators,as exemplified using data for the Gulf of Riga

This work describes how a general, process-based mass-balance model (CoastMab) for phosphorus for coastal areas may be used as a tool to estimate realistic values of “natural” or preindustrial reference levels of key bioindicators in coastal science, including the Secchi depth, a standard measure of water clarity, the chlorophyll-a concentration, an operational measure of phytoplankton biomass and the concentration of cyanobacteria, a measure of the concentration of harmful algae. The CoastMab-model is an ecosystem model giving monthly predictions to achieve seasonal variations of basin-wide properties. The selected case-study area, the Gulf of Riga, is sensitive to nutrient loading because of its shallowness and low openness towards the Baltic Proper. The morphometry of any coastal area, as given by the size and form parameters, influences all internal processes, such as sedimentation, resuspension, diffusion in water and from sediments to water, biouptake and retention in biota, stratification, mixing and outflow. There has been no mass-balance modeling for nitrogen (N) in this work because empirical data (from the HELCOM database) clearly indicate that the monthly primary production in the Gulf of Riga is regulated by phosphorus (P) – the mean monthly total-N to total-P ratios are well over 7.2 (the Redfield-ratio) and generally higher than 15 for the data used in this study (from 1992 to 2005). At present anthropogenic loads, the average modeled monthly values for Secchi depth, chlorophyll (Chl), cyanobacteria (CB) and total-P (TP) are 3.2 m, 3.8 μg/l, 78 μg/l and 31.3 μg/l, respectively. If 50% of all anthropogenic sources to the Gulf of Riga via rivers, point sources and diffuse sources were to be removed, these values would be 3.6 m, 3.4 μg Chl/l, 63 μg CB/l and 29.1 μg TP/l. If 60% of the anthropogenic phosphorus fluxes to the Baltic Proper were to be omitted and as well as 75% of all direct anthropogenic sources to the Gulf of Riga, the values would be 4.6 m, 2.7 μg Chl/l, 45 μg CB/l and 25.4 μg TP/l. These values represent the “natural” reference levels and it is not realistic to expect that remedial measures would improve the conditions more than that. Using the CoastWeb-model, similar calculations can be made for any given coastal area and the data necessary for such calculations are discussed in this work.     

典型土壤持久性有机污染物空间分布特征及环境行为研究进展

持久性有机污染物(POPs)由于具有致癌性、致畸性和致突变效应的"三致性",近年来已经越来越受到人们的关注.本文综合分析了有机氯农药(OCPs)、多氯联苯(PCBs)、二英类(PCDD/Fs)、多环芳烃(PAHs)及多溴联苯醚(PBDEs)等几种典型土壤持久性有机污染物的空间分布特征.同时,对土壤POPs的挥发作用、吸附/解吸、迁移、生物降解、化学降解等环境行为进行了深入分析,并指出了这些环境行为的影响因素,包括POPs的物质属性、土壤理化性质及周围环境等共性影响因素及其它因素.此外,针对国内外研究现状中存在的问题,提出了相关建议,指出控制土壤POPs污染的根本手段在于管理措施的完善.     

Northern magnetic displacements trigger endogenous fuelling responses in a naive bird migrant

In a previous study, we found that juvenile northern wheatears (Oenanthe oenanthe) exposed to a magnetic displacement to the west of their natural migration route increased their body mass. The total intensity and inclination used for the western displacement may also have been interpreted as northern compared to the experimental site (stronger total field intensity and steeper inclination angle). In order to investigate whether the fuelling response was a response to an unexpected magnetic field or specific to the northern magnetic field, we conducted a new experiment. Juvenile wheatears from the same study population were magnetically displaced to southwestern magnetic fields, exposing the birds to unexpected magnetic combinations, but eliminating the possible effect of a northern magnetic field. A control group was kept in the local geomagnetic field in Sweden for comparison. There was no difference in body mass increase between treatments, suggesting that the fuelling response previously found was not a simple response to an unexpected magnetic field, but rather a specific response to the northern magnetic field. Juvenile wheatears may have developed a fuelling response to northern magnetic fields in order to enable a successful flight towards the migration goal.     

Objectively best or most acceptable? Expert and lay knowledge in Swedish wind power permit processes

This article analyses legal aspects of the Swedish wind power development, theoretically based on how different types of knowledge are represented in legal contexts, mainly in the courts. A sample of appealed wind power permits is analysed, a handful of relevant informants are interviewed – including two judges in the Land and Environment Court and the appeal court – and the legal setting is analysed. Of key interest here is the interplay between expert and lay statements in the court cases, which here is related to the concepts of calculating and communicative rationalities that are developed in the planning literature. The results indicate that the juridification – which takes place as a permit issue is appealed in the judiciary system – supports the calculating rationality more than the communicative, and that the plaintiffs often attempt to adapt in how they shape their argumentation.     

Future agriculture with minimized phosphorus losses to waters: Research needs and direction

The series of papers in this issue of AMBIO represent technical presentations made at the 7th International Phosphorus Workshop (IPW7), held in September, 2013 in Uppsala, Sweden. At that meeting, the 150 delegates were involved in round table discussions on major, predetermined themes facing the management of agricultural phosphorus (P) for optimum production goals with minimal water quality impairment. The six themes were (1) P management in a changing world; (2) transport pathways of P from soil to water; (3) monitoring, modeling, and communication; (4) importance of manure and agricultural production systems for P management; (5) identification of appropriate mitigation measures for reduction of P loss; and (6) implementation of mitigation strategies to reduce P loss. This paper details the major challenges and research needs that were identified for each theme and identifies a future roadmap for catchment management that cost-effectively minimizes P loss from agricultural activities.