Sexual behavior,cannibalism, and mating plugs as sticky traps in the orb weaver spider <Emphasis Type="BoldItalic">Leucauge argyra</Emphasis> (Tetragnathidae)

Unpublished field observations in Leucauge argyra, a tropical orb weaver spider, suggest the occurrence of conspicuous mating plugs that could reduce or prevent remating attempts. Otherwise, the sexual behavior of this species remains unknown. The aims of this study were to describe the courtship behavior and copulation in L. argyra and investigate mating plug formation in this species. Fourteen virgin females and 12 plugged females were exposed to up to three males and checked for mating plug formation. Of the 12 virgins that copulated, nine produced plugs (five immediately after copulation), and the five plugged females that copulated produced another mating plug immediately after copulation. We did not detect the transfer of any male substance during copulation but observed a whitish liquid emerging from female genital ducts. Plug formation was positively associated with male twanging during courtship. One virgin and four plugged females cannibalized males. In seven trials with virgins and in three trials with plugged females, the male’s palp adhered to a substance that emerged from female genital ducts and spread on her genital plate. The male had to struggle energetically to free his glued palp; two of these males were cannibalized while trying to release their palps. Females seem to determine copulation duration by altering the timing of mating plug formation and through sexual cannibalism. This is the first case reported of a mating plug as a sticky trap for males.     

PM2.5 and PM10 air pollution peaks are associated with emergency department visits for psychotic and mood disorders

Environmental Science and Pollution Research - Particulate matters with a diameter of less than 10&nbsp;µm (PM10) or less than 2.5&nbsp;µm (PM2.5) are major air pollutants. Their...     

Understanding why consumers in China switch between wild,farmed, and synthetic bear bile products

An important rationale for legally farmed and synthetic wildlife products is that they reduce illegal, wild-sourced trade by supplying markets with sustainable alternatives. For this to work, more established illegal-product consumers must switch to legal alternatives than new legal-product consumers switch to illegal wild products. Despite the widespread debate on the magnitude and direction of switching, studies among actual consumers are lacking. We used an anonymous online survey of 1421 traditional Chinese medicine consumers in China to investigate switching among legal farmed, synthetic, and illegal wild bear bile. We examined the past consumption behavior, applied a discrete choice experiment framed within worsening hypothetical disease scenarios, and used latent class models to investigate groups with shared preferences. Bear bile consumers (86% respondents) were wealthier, more likely to have family who consumed bile, and less knowledgeable about bile treatments than nonconsumers. Consumer preferences were heterogenous, but most consumer preferences switched between bile types as disease worsened. We identified five distinct latent classes within our sample: law-abiding consumers (34% respondents), who prefer legal products and were unlikely to switch; two all-natural consumer groups (53%), who dislike synthetics but may switch between farmed and wild; and two nonconsumer groups (12%), who prefer not to buy bile. People with past experience of bile consumption had different preferences than those without. Willingness to switch to wild products was related to believing they were legal, although the likelihood of switching was mediated by preferences for cheaper products sold in legal, familiar places. We found that consumers of wild bile may switch to legal alternatives, given the availability of a range of products, whereas legal-product consumers may switch to illegal products if the barriers to doing so are small. Understanding preferences that promote or impede switching should be a key consideration when attempting to predict consumer behavior in complex wildlife markets.     

Efficient oxidation of bisphenol A with oxysulfur radicals generated by iron-catalyzed autoxidation of sulfite at circumneutral pH under UV irradiation

There is actually a need for efficient methods to clean waters and wastewaters from pollutants such as the bisphenol A endocrine disrupter. Advanced oxidation processes currently use persulfate or peroxymonosulfate to generate sulfate radicals. There are, however, few reports on the use of sulfite to generate sulfate radicals, instead of persulfate or peroxymonosulfate, except for dyes. Here we studied the degradation of the bisphenol A using iron(III) as catalyst and sulfite as precursor of oxysulfur radicals, at initial pH of 6, under UV irradiation at 395 nm. The occurrence of radicals was checked by quenching with tert-butyl alcohol and ethanol. Bisphenol A degradation products were analyzed by liquid chromatography coupled with mass spectrometry (LC–MS). Results reveal that iron(III) or iron(II) have a similar oxidation efficiency. Quenching experiments show that the oxidation rate of bisphenol A is 47.7 % for SO ₄ ^·? , 37.3 % for SO ₅ ^·? and 15 % for HO^·. Bisphenol A degradation products include catechol and quinone derivatives. Overall, our findings show that the photo-iron(III)–sulfite system is efficient for the oxidation of bisphenol A at circumneutral pH.     

Adsorptive removal of mercury from acid mine drainage: a comparison of silica and maghemite nanoparticles

Mercury adsorption by silica and maghemite nanoparticles (NPs) was studied with the aim of comparing their performance in the remediation of acid mine drainage (AMD) contaminated water. Calculated distribution coefficients (K_d) showed that both NPs are exceptional adsorbents. However, adsorbate coverage per unit area was 30 times higher for maghemite than for silica NPs, despite the latter having a surface area ～15 times greater. Maghemite adsorbed 75% of available Hg compared to 56% by silica, making it a more efficient sorbent than silica under AMD conditions. Kinetics and isotherm data for both adsorbents were fitted by the pseudo-second-order (R² = 1) and the Freundlich (R² ≥ 0.98) models, implying that adsorption to both NP types was by chemisorption. Adsorption increased with NP concentrations and pH and was enhanced in the presence of manganese and sulfate ions although adsorption to silica was inhibited in 1:2 Hg-to-Mn systems. Importantly, trends in simulated wastewater were replicated in actual AMD-contaminated water samples. This study highlights the fact that properties besides surface area and charge of adsorbents determine adsorbent performance, and superior attributes may not always lead to higher adsorption efficiencies.     

Effect of iron speciation on the photodegradation of Monuron in combined photocatalytic systems with immobilized or suspended TiO2

Photodegradation kinetics of Monuron (3-(4-chlorophenyl)-1,1-dimethylurea) in photoreactor with immobilized and suspended TiO₂ photocatalyst were studied. The effect of addition of ferric or ferrous perchlorate was investigated. Whatever the concentration of Fe(III/II) added there is no significant negative effect on the photodegradation rate of pollutants. On the contrary, depending on speciation and concentration of iron salts, slight or marked acceleration of the photodegradation kinetics was observed. This positive influence was more pronounced in the case of TiO₂ suspensions than for TiO₂ layers. Fe(III) was generally more effective than Fe(II).     

Don’t get the blues: conspicuous nuptial colouration of male moor frogs (Rana arvalis) supports visual mate recognition during scramble competition in large breeding aggregations

Conspicuous male colouration is expected to have evolved primarily through selection by female choice. In what way conspicuous colours could be advantageous to males scrambling for mates remains largely unknown. The moor frog (Rana arvalis) belongs to the so-called explosive breeders in which spawning period is short; intrasexual competition is strong, and males actively search and scramble for females. During breeding, male body colouration changes from a dull brown (similar to females) to a conspicuous blue, and we wanted to test if male blueness influences mating success or facilitates male mate recognition. To do so, we first measured the colour of mated and non-mated males using a spectrophotometer. In an experiment, we then analysed interactions of actual male moor frogs in natural spawning aggregations with a brown (resembling a female or a non-breeding male) and a blue model frog. Mated and non-mated males did not differ in colouration, suggesting that female choice based on colour traits was unlikely. In our behavioural experiment, male moor frogs spent significantly more time in contact and in amplexus with the brown model than with the blue model. Our results suggest that the nuptial colouration in moor frogs can act as a new type of visual signal in anurans evolved to promote instantaneous mate recognition allowing males to quickly move between rivals while scrambling for females.     

Effects of low concentrations of the phenylurea herbicide diuron on biofilm algae and bacteria

A system of recirculating channels was used in this study to examine the long-term effects (29 d) of environmentally realistic concentrations of the herbicide diuron (from 0.07 to 7 μg L⁻¹) on biofilm communities. The autotrophic activity of biofilms was affected by this herbicide, as reflected by a marked decrease in the photosynthetic efficiency. Diuron exposure also increased chlorophyll-a content and reduced the biovolume of diatom taxa at low concentrations. The effects on bacteria were also remarkable. Bacterial abundance was reduced after a week of exposure to the herbicide at a range of concentrations. Effects were on the number of live bacteria and on the increase in the leucine-aminopeptidase activity. It is suggested that inputs of herbicides to the river ecosystem at low concentrations may cause a chain of effects in the biofilm, which include inhibitory effects on algae but also indirect effects on the relationships between biofilm components.     

Participatory diagnosis in urban planning: proposal for a learning process based on geographical information

Urban planning involves compromise between the diverse and often contradictory issues supported by the different stakeholders. The literature generally agrees on the need to broaden the participation base to overcome this difficulty. However, participation should not be limited to problem solving, but should also take place in the problem setting phase. This paper proposes a participatory diagnosis process for structuring the problem setting phase. We describe an experiment in a participatory diagnosis conducted with the residents of a Geneva neighborhood. The experiment began by identifying the residents' concerns, which were then reformulated under broader issues. Some 20 spatial indicators were built using GIS tools, and were then applied in a second phase of resident consultations to assess the relative importance of each issue. The ensuing priority issues formed the core of the diagnosis. The approach emphasized comparison between the daily experiences of residents and so-called official information (i.e. census tract, traffic measurement, and so on). The residents were therefore involved in a learning process that allowed them to consolidate or modify their opinions. The process led to the emergence of a clearly defined collective awareness that supplanted individual aspirations.