Anatomical localization and stereoisomeric composition of <Emphasis Type="Italic">Tribolium castaneum</Emphasis> aggregation pheromones

We report that the abdominal epidermis and associated tissues are the predominant sources of male-produced pheromones in the red flour beetle, Tribolium castaneum and, for the first time, describe the stereoisomeric composition of the natural blend of isomers of the aggregation pheromone 4,8-dimethyldecanal (DMD) in this important pest species. Quantitative analyses via gas chromatography–mass spectrometry showed that the average amount of DMD released daily by single feeding males of T. castaneum was 878 ± 72 ng (SE). Analysis of different body parts identified the abdominal epidermis as the major source of aggregation pheromone; the thorax was a minor source, while no DMD was detectable in the head. No internal organs or obvious male-specific glands were associated with pheromone deposition. Complete separation of all four stereoisomers of DMD was achieved following oxidation to the corresponding acid, derivatization with (1R, 2R)- and (1S, 2S)-2-(anthracene-2,3-dicarboximido)cyclohexanol to diastereomeric esters, and their separation on reversed-phase high-performance liquid chromatography at −54°C. Analysis of the hexane eluate from Porapak-Q-collected volatiles from feeding males revealed the presence of all four isomers (4R,8R)/(4R,8S)/(4S,8R)/(4S,8S) at a ratio of approximately 4:4:1:1. A walking orientation bioassay in a wind tunnel with various blends of the four synthetic isomers further indicated that the attractive potency of the reconstituted natural blend of 4:4:1:1 was equivalent to that of the natural pheromone and greater than that of the 1:1 blend of (4R,8R)/(4R,8S) used in commercial lures.     

Heterospecific pairing and hybridization between <Emphasis Type="Italic">Nasutitermes corniger</Emphasis> and <Emphasis Type="Italic">N. ephratae</Emphasis>

The sympatric neotropical termites Nasutitermes corniger and Nasutitermes ephratae are clearly distinguishable based on morphology, nest architecture, defensive secretion composition, and molecular markers. However, given the extensive ecological, geographical, and behavioral overlap of these closely related species, the potential for interbreeding may exist. To explore this possibility, heterospecific pairs were formed experimentally to examine courtship and colony-establishment behaviors, and reproductive potential. Courtship and nest construction behavior occurred in heterospecific pairs in a similar manner to that of conspecific pairs. Survival of pairs depended upon the species of the female partner. N. ephratae females paired with N. corniger males produced as many offspring as conspecific pairs. N. corniger females mated to N. ephratae males, however, produced significantly fewer offspring at 60 days post-establishment than the reciprocal cross or conspecific N. ephratae or N. corniger pairs. This was also the only pairing in which any aggression was observed. Heterospecific pairs and groups formed in mate choice mesocosms, suggesting that species recognition between these two termites is not an important aspect of mate choice. Overall, species mismatch tolerance and hybrid offspring viability are high. The present data, together with previous evidence from defensive secretions and isozyme analysis, suggest that hybridization may periodically occur in nature, and that reproductive barriers between these two species may be incomplete. Hybridization could provide a rare but important source of genetic diversity and may ensure mating opportunities for the more abundant sex of alates in each species.     

Forming a tough shell via an intracellular matrix and cellular junctions in the tail epidermis of <Emphasis Type="Italic">Oikopleura dioica</Emphasis> (Chordata: Tunicata: Appendicularia)

A postanal tail is a major synapomorphy of the phylum Chordata, which is composed of three subphyla: Vertebrata, Cephalochordata, and Tunicata (Urochordata). Among tunicates, appendicularians are the only group that retains the tail in the adult, and the adult tail functions in locomotion and feeding in combination with a cellulose-based house structure. Given the phylogenetic position of tunicates, the appendicularian adult tail may possess ancestral features of the chordate tail. We assess the ultrastructural development of the tail epidermis of the appendicularian Oikopleura dioica. The epidermis of the larval tail is enclosed by the larval envelope, which is a thin sheet similar to the outer tunic layer of ascidian larvae. The epidermis of the adult tail seems to bear no tunic-like cellulosic integuments, and the tail fin is a simple folding of the epidermis. Every epidermal cell, except for the triangular cells at the edge of the tail fin, has a conspicuous matrix layer of fibrous content in the apical cytoplasm without enclosing membranes. The epidermis of the larval tail does not have a fibrous matrix layer, suggesting the production of the layer during larval development and metamorphosis. Zonulae adhaerentes firmly bind the epidermal cells of the adult tail to one another, and the dense microfilaments lining the cell borders constitute a mechanical support for the cell membranes. The intracellular matrix, cell junctions, and cytoskeletons probably make the tail epidermis a tough, flexible shell supporting the active beating of the oikopleuran adult tail.     

Tracking pigeons in a magnetic anomaly and in magnetically “quiet” terrain

Pigeons were released at two sites of equal distance from the loft, one within a magnetic anomaly, the other in magnetically quiet terrain, and their tracks were recorded with the help of GPS receivers. A comparison of the beginning of the tracks revealed striking differences: within the anomaly, the initial phase lasted longer, and the distance flown was longer, with the pigeons' headings considerably farther from the home direction. During the following departure phase, the birds were well homeward oriented at the magnetically quiet site, whereas they continued to be disoriented within the anomaly. Comparing the tracks in the anomaly with the underlying magnetic contours shows considerable differences between individuals, without a common pattern emerging. The differences in magnetic intensity along the pigeons' path do not differ from a random distribution of intensity differences around the release site, indicating that the magnetic contours do not directly affect the pigeons' routes. Within the anomaly, pigeons take longer until their flights are oriented, but 5 km from the release point, the birds, still within the anomaly, are also significantly oriented in the home direction. These findings support the assumption that magnetically anomalous conditions initially interfere with the pigeons' navigational processes, with birds showing rather individual responses in their attempts to overcome these problems.     

An abbreviated alternatives assessment process for product designers: a children’s furniture manufacturing case study

Alternatives assessment is becoming increasingly popular to evaluate the potential environmental and human health hazards of materials. A three step process was used to identify and evaluate alternative products for a children's furniture manufacturer. An alternatives assessment framework was developed to analyze alternative mattresses. The framework specifically addresses those environmental and safety attributes applicable to the product and the product components in accordance with the product’s intended use. The result of the assessment allowed the manufacturer to select the most environmentally friendly alternative and eliminate polyvinyl chloride from their product.     

Minimizing leakage from a smelter off-gas system by enhanced control

The off-gas handling system is a vital component of a smelter and it is essential that it operates in accordance with environmental regulations. A key feature of the off-gas management system is maintaining a slightly negative system pressure to prevent gas leakage, such as SO₂, out into the work and external environments. To enhance sustainable development, there is also growing interest in capturing and reusing the significant amount of heat and CO₂ contained within off-gas. The potential incorporation of heat and CO₂ recovery systems places importance on enhancing control to minimize the risk of both gas leakage and disturbance of the smelting process. With these requirements in mind, an easily implementable feedforward control enhancement to existing control schemes is proposed to help provide improved performance.     

Activity ratios of 137Cs, 90Sr and 239+240Pu in environmental samples

Both global and Chernobyl fallout have resulted in environmental contamination with radionuclides such as 137Cs, 90Sr and 239+240Pu. In environmental samples, 137Cs and 239+240Pu can be divided into the contributions of either source, if also the isotopes 134Cs and 238Pu are measurable, based on the known isotopic ratios in global and Chernobyl fallout. No analogous method is available for 90Sr. The activity ratios of Sr to Cs and Pu, respectively, are known for the actual fallout mainly from air filter measurements; but due to the high mobility of Sr in the environment, compared to Cs and Pu, these ratios generally do not hold for the inventory many years after deposition. In this paper we suggest a method to identify the mean contributions of global and Chernobyl fallout to total Sr in soil, sediment and cryoconite samples from Alpine and pre-Alpine regions of Austria, based on a statistical evaluation of Sr/Cs/Pu radionuclide activity ratios. Results are given for Sr:Cs, Sr:Pu and Cs:Pu ratios. Comparison with fallout data shows a strong depletion of Sr against Cs and Pu.     

Probabilistic risk assessment for long-range atmospheric transport of radionuclides

A simplified means of probabilistic risk assessment (PRA) for long-range atmospheric transport based on a K-diffusion model is presented. In a case study, model parameters are estimated by comparing with the results of long-range atmospheric dispersion model calculations using one-year numerical weather prediction model data. It is found that the estimated ensemble mean provides a reasonable first approximation to the total dry and wet deposition from the one-year continuous release.     

Cladocerans under conditions of small river damming by man and beavers

In beaver ponds, the species diversity, abundance, biomass, and production of cladocerans and the amount of food consumed by them have increased and the composition of dominant species has changed as compared to those in the stretches of small rivers with running water or dammed by man. The stimulating effect of water from a beaver pond has been confirmed in laboratory experiments. The average number of juvenile Ceriodaphnia affinis produced by one female was considerably greater in this water than in the water from flowing and dammed (by man) river stretches.     

Relict communities and populations of petrophilous plant species in northern regions of Sverdlovsk oblast and problems in their conservation

An inventory of rock vegetation has been taken in river valleys on the eastern slope of the southern part of the Northern Urals and the northern part of the Middle Urals. New habitats of some rare plant species, relict communities of forest-steppe species at the northern limit of their distribution, and ultrasmall populations of petrophilous species growing in isolation for a long time have been revealed. In studies on a group of similar specially protected areas (e.g., within river valleys), it is proposed to identify key sites distinguished by the highest species richness of vegetation