Olfactory cues and nest recognition in the solitary bee Osmia lignaria

Abstract.  The use of olfactory cues for nest recognition by the solitary bee Osmia lignaria is studied in a greenhouse environment. Glass tubes are provided as nesting cavities to allow the in-nest behaviour of bees to be observed. In addition, each glass tube is cut into three sections for experimental manipulation and for subsequent chemical analysis. Nesting females drag their abdomen along the tube before exiting, spiral inside the tube, and sometimes deposit fluid droplets from the tip of the abdomen. For the manipulation, the outer section, the middle section, or both sections are removed and replaced with similar clean glass tube sections, and the behaviour exhibited by test females is recorded upon arrival in front of the nesting site and inside the nesting tubes. The resulting hesitation behaviour displayed by females after treatments appears to indicate the loss of some olfactory cues used for nest recognition inside the entire nest. Chemical analysis of the depositions inside the nesting tube, as well as analysis of the cuticular lipids of the nesting bees, reveals the presence of free fatty acids, hydrocarbons and wax esters.     

Serial monodomy in ants: an antipredator strategy?

Abstract.  1. The term serial monodomy is used to describe a life-history phenomenon in social insects. Serially monodomous colonies maintain multiple nests for their exclusive use, but only occupy one nest at a time.
2. The hypothesis that colony odours mediate nest relocation decisions was tested in the serially monodomous species Aphaenogaster araneoides from Central America. Odour extracts of colony members were created using a non-polar solvent.
3. Colonies strongly avoided reoccupying nests treated with colony odour extracts, while control colonies often returned to nests subjected to solvent-only control. Behavioural observations indicated that A. araneoides colonies are capable of detecting army ant ( Eciton burchellii ) raids up to 1.4 m from the raiding front, with several seconds to evacuate nests.
4. It is proposed that the function of serial monodomy in A. araneoides is the reduction of nest odour to enhance detection of predaceous army ants. Serial monodomy may be a widespread but undocumented mode of nesting where army ants occur in tropical and subtropical climates.     

Waste Treatment and Assessment of Long-Term Emissions (8pp)

Goal, Scope and Background The disposal phase of a product’s life cycle in LCA is often neglected or based on coarse indicators like ‘kilogram waste’. The goal of report No. 13 of the ecoinvent project (Doka 2003) is to create detailed Life Cycle Inventories of waste disposal processes. The purpose of this paper is to give an overview of the models behind the waste disposal inventories in ecoinvent, to present exemplary results and to discuss the assessment of long-term emissions. This paper does not present a particular LCA study. Inventories are compiled for many different materials and various disposal technologies. Considered disposal technologies are municipal incineration and different landfill types, including sanitary landfills, hazardous waste incineration, waste deposits in deep salt mines, surface spreading of sludges, municipal wastewater treatment, and building dismantling. The inventoried technologies are largely based on Swiss plants. Inventories can be used for assessment of the disposal of common, generic waste materials like paper, plastics, packaging etc. Inventories are also used within the ecoinvent database itself to inventory the disposal of specific wastes generated during the production phase. Inventories relate as far as possible to the specific chemical composition of the waste material (waste-specific burdens). Certain expenditures are not related to the waste composition and are inventoried with average values (process-specific burdens). Methods The disposal models are based on previous work, partly used in earlier versions of ecoinvent/ETH LCI data. Important improvements were the extension of the number of considered chemical elements to 41 throughout all disposal models and new landfill models based on field data. New inventories are compiled for waste deposits in deep salt mines and building material disposal. Along with the ecoinvent data and the reports, also Excel-based software tools were created, which allow ecoinvent members to calculate waste disposal inventories from arbitrary waste compositions. The modelling of long-term emissions from landfills is a crucial part in any waste disposal process. In ecoinvent long-term emissions are defined as emissions occurring 100 years after present. They are reported in separate emission categories. The landfill inventories include long-term emissions with a time horizon of 60’000 years after present. Results and Discussion As in earlier studies, the landfills prove to be generally relevant disposal processes, as also incineration and wastewater treatment processes produce landfilled wastes. Heavy metals tend to concentrate in landfills and are washed out to a varying degree over time. Long-term emissions usually represent an important burden from landfills. Comparisons between burdens from production of materials and the burdens from their disposal show that disposal has a certain relevance. Conclusion The disposal phase should by default be included in LCA studies. The use of a material not only necessitates its production, but also requires its disposal. The created inventories and user tools facilitate heeding the disposal phase with a similar level of detail as production processes. The risk of LCA-based decisions shifting burdens from the production or use phase to the disposal phase because of data gaps can therefore be diminished. Recommendation and Perspective Future improvements should include the modelling of metal ore refining waste (tailings) which is currently neglected in ecoinvent, but is likely to be relevant for metals production. The disposal technologies considered here are those of developed Western countries. Disposal in other parts of the World can differ distinctly, for logistic, climatic and economic reasons. The cross-examination of landfill models to LCIA soil fate models could be advantageous. Currently only chemical elements, like copper, zinc, nitrogen etc. are heeded by the disposal models. A possible extension could be the modelling of the behaviour of chemical compounds, like dioxins or other hydrocarbons.     

Differences in regulation of the first two M-phases in Xenopus laevis embryo cell-free extracts

The first embryonic M-phase is special, being the time when paternal and maternal chromosomes mix together for the first time. Reports from a variety of species suggest that the regulation of first M-phase has many particularities; however, no systematic comparative study of the biochemical aspects of first and the following M-phases has been previously undertaken. Here, we ask whether the regulation of the first embryonic M-phase is modified, using Xenopus cell-free extracts. We developed new types of extract specific for the first and the second M-phase obtained either from parthenogenetic or from in vitro fertilized embryos. Analyses of these extracts confirmed that the amplitude of histone H1 kinase activity reflecting CDK1/cyclin B (or MPF for M-phase Promoting Factor) activity is higher and persists longer than during the second M-phase, and that levels of cyclins B1 and B2 are correspondingly higher during the first than the second embryonic M-phase. Inhibition of protein synthesis shortly before M-phase entry reduced mitotic histone H1 kinase amplitude, shortened the period of mitotic phosphorylation of chosen marker proteins, and reduced cyclin B1 and B2 levels, suggesting a role of B-type cyclins in regulating the duration of mitotic events. Moreover, addition of exogenous cyclin B to the extract prior the second mitosis brought forward the activation of mitotic histone H1 kinase but prolonged the duration of this activity. We also confirmed that the inhibitory phosphorylation of CDK1 on tyrosine 15 oscillates between the first two embryonic M-phases, but is clearly more pronounced before the first than the second mitosis, while the MAP kinase ERK2 tended to show greater activation during the first embryonic M-phase but with a similar duration of activation. We conclude that discrete differences exist between the first two M-phases in Xenopus embryo and that higher CDK1/cyclin B activity and B-type cyclin levels could account for the different characteristics of these M-phases.     

Organic-inorganic hybrid materials constructed from copper-organoimine subunits and molybdoarsonate clusters

The hydrothermal reactions of MoO₃, As₂O₅, Cu(CH₃CO₂)₂ · H₂O and an appropriate organonitrogen ligand in the presence of HF as mineralizer yield a series of bimetallic oxides of the Cu/Mo/O/As system. The compounds [{Cu₂(4,7-phen)(4,7-phenH)₂}Mo₁₂AsO₄₀] · 2.66H₂O (1 · 2.66H₂O) and [{Cu₃(qtpyr)₂}Mo₁₂AsO₄₀] · 0.4H₂O (2 · 0.4H₂O) (qtpyr = 2,4′:5′, 3″:4″,2?-quaterpyridine) are two-dimensional phases constructed from Keggin clusters linked through binuclear {Cu₂(4,7-phen)(4,7-Hphen)₂}²⁺ units in metal organic networks in 2. In contrast, the structure of [{Cu₂(2,4′-Hbpy)₄}Mo₁₈As₂O₆₂] · 2H₂O (3 · 2H₂O) is one-dimensional, consisting of Dawson clusters linked through binuclear {Cu₂(Hbpy)₄}⁶⁺ subunits. In the case of the compounds [{Cu(5,5′-dimethyl-2,2′-bpy)}₂Mo₂O₄F₂(AsO₄)₂] (4) and [{Cu(phen)}₂Mo₂O₄F₂(AsO₄)₂] (5), the fluoride mineralizer has been incorporated into the structure to give one-dimensional phases constructed from oxyfluoride {Mo₂O₄F₂(AsO₄)₂}²⁻clusters bridged through {Cu(organonitrogen)}²⁺ units.     

Development of specific inhibitors for heparin-binding proteins based on the cobra cardiotoxin structure: an effective synthetic strategy for rationally modified heparin-like disaccharides and a trisaccharide

Recently, a new heparin disaccharide-binding site on the convex side of cobra cardiotoxin (CTX) was identified by NMR spectroscopy and molecular modeling. To further characterize this site two heparin-like disaccharides were synthesized for binding studies with CTX, and a trisaccharide was synthesized for testing the sequence of the disaccharide binding to CTX. Thus six differentially protected monosaccharide building blocks (three l-iduronic acids and three d-glucosamines) were prepared. These include a l-iduronic acid elongation building block namely methyl 2-O-acetyl-4-O-levulinoyl-3-O-pivaloyl-alpha-l-idopyranosyluronate trichloroacetimidate for which a single-crystal X-ray structure was determined to have M(r)=576.79, a=9.3098(11)A alpha=90 degrees , b=10.3967(12)A beta=90 degrees , c=28.026(3)A gamma=90 degrees , V=2712.7(6)A(3), P2(1)2(1)2(1), Z=4, mu=0.71073A, and R=0.0378 for 7586 observed reflections. It shows that the molecular structure of the donor is in the (1)C(4) conformation with significant 1,3-diaxial interactions between O-1 and O-3 as well as O-2 and O-4. The disaccharides and trisaccharide vary in the degree and position of O- and N-sulfation. The pivaloyl group was used as permanent protecting group of hydroxyl. The levulinoyl group was used as the temporary protecting group to protect the hydroxyl for elongation.     

Spatio-temporal patterns of colony distribution in monodomous and polydomous species of North African desert ants,genus <Emphasis Type="Italic">Cataglyphis</Emphasis>

Summary Two monogynous species of North African desert ants belonging to the formicine genus Cataglyphis exhibit extremely different habitat preferences, population densities, and population structures. C. fortis is the only Cataglyphis species within the salt-pan flats of the Algerian and Tunisian chotts and sebkhas, whereas C. bicolor, alongside C. albicans and C. ruber, inhabits the nutritionally richer low-shrub semi-deserts surrounding the salt pans. We present a comparative study of the spatio-temporal patterns of colony distribution of the two monogynous species over periods of at least 5 (maximally 15) years. In C. fortis low population densities (0.5 kg body mass per km²) and, correspondingly, large inter-nest distances (40.6 m mean nearest neighbour nest distance) are correlated with absolute intra-annual and high inter-annual nest-site stability (more than 75% inter-annual survival rate) and a monodomous colony structure. In C. bicolor the population density is one hundred times higher (42 kg body mass per km², 9.1 m mean nearest neighbour nest distance), nest-site stability is extremely low in both intra-annual and inter-annual terms (67% intra-annual survival rate for 13-day periods; less than 5% inter-annual survival rate), and polydomy prevails. These marked differences in population structure are discussed with respect to adapted traits such as foraging range, running speed, and relative lengths of the legs.Received 8 August 2003; revised 27 November 2003; accepted 2 December 2003.     

A test of adaptive hypotheses: Mandibular traits,nest construction materials,and feeding habits in neotropical social wasps (Vespidae,Polistinae)

Summary. The success of many behaviors in hymenoptera depends on the shape and structure of their mandibles. Neotropical social wasps exhibit variation in the shape of their mandibles; both the type of material used in the nest construction and the food sources have been proposed as selective forces that explain that variation. These hypotheses were studied using Independent Contrast analyses and combined tests of significance between: nine mandibles traits, the type of nest material and food source types. Necrophagy and short fiber use are derived conditions in the subfamily that have evolved five times each, while the use of long fibers and live prey are primitive conditions. The mandible structures appear related to the nest fiber type but not to necrophagy. Particularly, species that use long fibers have bigger internal dorsal tooth, longer internal ventral tooth, and shorter and more curved mandibles. Similar results were obtained by including plant hairs as a third nest material type. These findings open related questions for groups of social insects where studies on evolution of mandibles have emphasized food sources.Received 23 November 2003; revised 9 March 2004; accepted 21 April 2004.     

A multi-scale perspective of water pulses in dryland ecosystems: climatology and ecohydrology of the western USA

In dryland ecosystems, the timing and magnitude of precipitation pulses drive many key ecological processes, notably soil water availability for plants and soil microbiota. Plant available water has frequently been viewed simply as incoming precipitation, yet processes at larger scales drive precipitation pulses, and the subsequent transformation of precipitation pulses to plant available water are complex. We provide an overview of the factors that influence the spatial and temporal availability of water to plants and soil biota using examples from western USA drylands. Large spatial- and temporal-scale drivers of regional precipitation patterns include the position of the jet streams and frontal boundaries, the North American Monsoon, El Niño Southern Oscillation events, and the Pacific Decadal Oscillation. Topography and orography modify the patterns set up by the larger-scale drivers, resulting in regional patterns (10²–10⁶ km²) of precipitation magnitude, timing, and variation. Together, the large-scale and regional drivers impose important pulsed patterns on long-term precipitation trends at landscape scales, in which most site precipitation is received as small events (<5 mm) and with most of the intervals between events being short (<10 days). The drivers also influence the translation of precipitation events into available water via linkages between soil water content and components of the water budget, including interception, infiltration and runoff, soil evaporation, plant water use and hydraulic redistribution, and seepage below the rooting zone. Soil water content varies not only vertically with depth but also horizontally beneath versus between plants and/or soil crusts in ways that are ecologically important to different plant and crust types. We highlight the importance of considering larger-scale drivers, and their effects on regional patterns; small, frequent precipitation events; and spatio-temporal heterogeneity in soil water content in translating from climatology to precipitation pulses to the dryland ecohydrology of water availability for plants and soil biota.     

Genetic mating patterns studied in pools with manipulated nest site availability in two populations of Pomatoschistus minutus

Pomatoschistus minutus show paternal care in a resource defence mating system. We investigated the effect of nest-site availability on parasitic spawning. Each experimental pool contained four potentially nest-building males, four females and nests-sites in shortage (2) or excess (6). Both treatments were conducted in two populations; one with natural nest-sites in excess, one with a nest-site shortage. Microsatellite-DNA revealed that all nest-holders had fertilized most of the eggs they tended. Yet, 35% of the nests contained eggs fertilized by another male and 14.4% of the males had performed parasitic spawning. There was no site or treatment effect. Several females spawned in two nests, which coincided with parasitic spawnings, suggesting a cost to the nest-holder in terms of lost mating success. Nest-holders with and without eggs and non-nesting males all spawned parasitically, generating a significantly lower opportunity for sexual selection compared to if there had been no parasitic spawning.