Bose-Einstein condensation of potassium atoms by sympathetic cooling

We report on the Bose-Einstein condensation of potassium atoms, whereby quantum degeneracy is achieved by sympathetic cooling with evaporatively cooled rubidium. Because of the rapid thermalization of the two different atoms, the efficiency of the cooling process is high. The ability to achieve condensation by sympathetic cooling with a different species may provide a route to the production of degenerate systems with a larger choice of components.     

Application of a Photochemical Model in Alpine Forest Sites

Mountain rural sites can be subject to high ozone concentrations (Puxbaum et al., 1991; Gay, 1991; Sandroni,1994) that can lead to plant injuries. Very often, unfortunately,such sites do not have a sufficient number of monitoring stations to accurately capture the spatial patterns and temporal evolution of ozone concentrations. The present studyaims at the reproduction of ozone patterns in a forest site onthe southern slopes of the Alps. The calculation of ozone concentrations has been carried out for a three days episode,by using the CALGRID model. Meteorological fields have been obtained by the application of the CALMET model. Emissions have been calculated for the main sources categories in the area (biogenic and road transport), with a bottom up techniqueand derived from a regional inventory for minor sources. Finally, boundary conditions have been derived from a simulation performed over a larger area (240 × 232 km²). The CALGRID model application has provided realistic ground-level concentrations. However, some differences have been spotted between estimated and observedconcentrations, particularly at nighttime, when concentrationsare more influenced by local effects. The methodology used andresults obtained are presented, the comparison with measurements and the temporal evolution of ozone vertical profile in different locations of the domain is discussed.     

Spatial Response of Mammals to Late Quaternary Environmental Fluctuations

Analyses of fossil mammal faunas from 2945 localities in the United States demonstrate that the geographic ranges of individual species shifted at different times, in different directions, and at different rates in response to late Quaternary environmental fluctuations. The geographic pattern of faunal provinces was similar for the late Pleistocene and late Holocene, but differing environmental gradients resulted in dissimilar species composition for these biogeographic regions. Modern community patterns emerged only in the last few thousand years, and many late Pleistocene communities do not have modern analogs. Faunal heterogeneity was greater in the late Pleistocene.     

Role of Gene Interactions in Hybrid Speciation: Evidence from Ancient and Experimental Hybrids

The origin of a new diploid species by means of hybridization requires the successful merger of differentiated parental species' genomes. To study this process, the genomic composition of three experimentally synthesized hybrid lineages was compared with that of an ancient hybrid species. The genomic composition of the synthesized and ancient hybrids was concordant (rs = 0.68, P < 0.0001), indicating that selection to a large extent governs hybrid species formation. Further, nonrandom rates of introgression and significant associations among unlinked markers in each of the three synthesized hybrid lineages imply that interactions between coadapted parental species' genes constrain the genomic composition of hybrid species.     

Graphosoma lineatum (Hemiptera: Pentatomidae): a suitable host for mass rearing Ooencyrtus telenomicida (Hymenoptera: Encyrtidae)

The species Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae) is currently being considered as a candidate for augmentative biological control agent (BCA) against several pests, including Halyomorpha halys (Stål) (Heteroptera: Pentatomidae). Protocols for mass production of a BCA need fundamental information on its biological attributes. Here we tested a possible laboratory host for the rearing of O. telenomicida: the common bug Graphosoma lineatum L. (Heteroptera: Pentatomidae). At tested conditions, O. telenomicida biological parameters were: r_m 0.154, offspring production 84.07 specimens/female, sex ratio (% females) 71%, juvenile development time about 16 days, population doubling time 4.52 days, emergence rate about 90%.