Experimental test of socially mediated sex change in a protandric simultaneous hermaphrodite,the marine shrimp<Emphasis Type="Italic"> Lysmata wurdemanni</Emphasis> (Caridea: Hippolytidae)

In Lysmata wurdemanni, individuals begin benthic life in a male phase (MP) but later change to a female phase (FP) with female external morphology, but with both male and female reproductive capacity (protandric simultaneous hermaphroditism). Previous studies have demonstrated that the size (timing) of sex change varies considerably in natural populations. We experimentally tested for social mediation of sex change by rearing male-phase individuals (MPs) in both large and small social groups with different sexual and size composition. In the large group experiment, speed of sex change was inversely related to the abundance of female-phase individuals (FPs) in the group (sex-ratio induction). Increased allocation to female function (more rapid change to FP) may occur when male mating opportunities are lower because the simultaneous-hermaphrodite FP can immediately reproduce as a female while maintaining male mating capacity. When FPs are abundant, delayed sex change might be adaptive because the costs of female reproduction are considerable. An MP may gain reproductively by increased growth before changing to FP at a larger size (fewer but much larger broods). Size-ratio induction of sex change by small MPs was suggested but not confirmed. Experimental results from small groups (1–2 individuals) were qualitatively similar but not as conclusive as those from large groups. The number and complexity of social interactions in large groups may be necessary to stimulate labile sex change in this species. In L. wurdemanni, sex change may be influenced not only by abiotic factors related to breeding [Bauer (2002) Biol Bull 203:347–357] but also by social factors in certain demographic situations.Communicated by K. Lindström     

An Evaluation of Emissions and Control Technologies for the Metal Decorating Process

Data are reported on a number of controlled and uncontrolled sources from various metal decorating operations. Emission levels are related to process variables such as ink coverage, coater speed, sheet size, and applied coating film weight. Results are presented depicting variation of organic emission levels from a coating process line with elapsed process time. For controlled sources employing either catalytic or thermal incineration, conversion efficiencies are reported as a function of temperature. Operational curves are presented for each control system studied indicating the dependence of carbon dioxide, NO_x, and organic output on incineration temperatures.     

Recommendations on the use of satellite remote-sensing data for urban air quality

In the last 5 yr, the capabilities of earth-observing satellites and the technological tools to share and use satellite data have advanced sufficiently to consider using satellite imagery in conjunction with ground-based data for urban-scale air quality monitoring. Satellite data can add synoptic and geospatial information to ground-based air quality data and modeling. An assessment of the integrated use of ground-based and satellite data for air quality monitoring, including several short case studies, was conducted. Findings identified current U.S. satellites with potential for air quality applications, with others available internationally and several more to be launched within the next 5 yr; several of these sensors are described in this paper as illustrations. However, use of these data for air quality applications has been hindered by historical lack of collaboration between air quality and satellite scientists, difficulty accessing and understanding new data, limited resources and agency priorities to develop new techniques, ill-defined needs, and poor understanding of the potential and limitations of the data. Specialization in organizations and funding sources has limited the resources for cross-disciplinary projects. To successfully use these new data sets requires increased collaboration between organizations, streamlined access to data, and resources for project implementation.     

The solution phase complexing of atrazine by fulvic acid: Equilibria at 25°c

Abstract

The solution phase complexing equilibria of atrazine by fulvic acid at 25°C±1.° have been investigated over the pH range of 1.3 to 6.0. Experiments with 0.1MKC1 and chelated Cu(II) are compared with those without metal ions. The use of a fulvic acid having calibrated acidic and Cu(II) chelation properties has made it possible to obtain stoicheometricly “exact”; chemical information. This is correlated with previous hydrolysis kinetics work. It is concluded that atrazine is hydrogen bonded in a labile equilibrium, to an identifiable set of protonated carboxyl groups, which act as Brönsted acid catalysts for hydrolysis. 0.1M KC1 changes (1‐α_A), the degree of protonation of the carboxyl groups, without otherwise affecting the atrazine complexing. Cu(II) chelation both reduces and weakens the complexing through a combination of carboxyl group blocking, and fulvic acid aggregation. Simple equations are presented for predictive calculations.     

Surface chemistry of dihydromyrcenol (2,6-dimethyl-7-octen-2-ol) with ozone on silanized glass,glass, and vinyl flooring tiles

The surface-phase reaction products of dihydromyrcenol (2,6-dimethyl-7-octen-2-ol) with ozone (O₃), air, or nitrogen (N₂) on silanized glass, glass and vinyl flooring tile were investigated using the recently published FACS (FLEC (Field and Laboratory Emission Cell) Automation and Control System). The FACS was used to deliver ozone (100 ppb), air, or N₂ to the surface at a specified flow rate (300 mL min^?1) and relative humidity (50%) after application of a 2.0% dihydromyrcenol solution in methanol. Oxidation products were detected using the derivatization agents: O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) and N,O-bis(trimethysilyl)trifluoroacetamide (BSTFA). The positively identified reaction products were glycolaldehyde, 2,6-dimethyl-5-heptenal, and glyoxal. The proposed oxidation products based on previously published VOC/O₃ reaction mechanisms were: 2,6-dimethyl-4-heptenal, 6-methyl-7-octen-2-one and the surface-specific reaction products: 6-methyl-6-hepten-2-one, 6-methyl-5-hepten-2-one, and 6-hydroxy-6-methylheptan-2-one. Though similar products were observed in gas-phase dihydromyrcenol/O₃ reactions, the ratio, based on peak area, of the reaction products was different suggesting stabilization of larger molecular weight species by the surface. Emission profiles of these oxidation products over 72 h are also reported.     

Cloudwater studies at a high elevation site in the Vosges Mountains (France)

Cloud and rainwater samples have been collected at a high elevation site in the Vosges Mountains. An automated collection system has been used to collect bulk cloudwater and small cloudwater droplets. Bulk cloudwater concentrations were up to 10 times more concentrated than rainwater concentrations. Small clouddroplets showed generally higher concentrations than bulk cloudwater. Nevertheless, the enrichment factors depend on the compounds under study and appear to be related to the composition of the cloud condensation nuclei forming small or large clouddroplets. Principal component analysis and factor analysis were applied to the collected datasets and confirmed the influence of the cloud condensation nuclei on the composition difference between small and large cloudwater droplets.     

Impaired benthic macrofauna function 4 years after sediment capping with activated carbon in the Grenland fjords,Norway

Environmental Science and Pollution Research - The sediments in the Grenland fjords in southern Norway are heavily contaminated by large emissions of dioxins and mercury from historic industrial...