294 research outputs found
Environmental niche and global potential distribution of the giant resin bee Megachile sculpturalis, a rapidly spreading invasive pollinator
Abstract Since alien species may threaten native ecosystems when becoming invasive, one of the main challenges is try to predict their potential spread. Despite bees are essential pollinators and provide important ecosystem services in their native areas, outside these areas they could represent a risk for the local bee fauna, e.g. by competing for resources or by transmitting pathogens, as it was observed for species of Megachile, the bee genus with the highest number of recorded alien species. Here, using two complementary methods (Multidimensional Envelope procedure (MDE) and the Maximum Entropy algorithm (MaxEnt)), we aim to explore environmental niche as well as to identify potential worldwide distribution of the giant resin bee Megachile sculpturalis, native to Asia and recently introduced in North America and Europe. The two methodological approaches predict an important expansion for the species and reveal a preference for areas of Palearctic and Nearctic regions with reduced temperature fluctuations and moderate precipitation regimes. The Southern hemisphere seems not having good conditions for this species. Estimations for the future (2070) predict a further, though limited expansion to northern areas in the North hemisphere. However, during roughly 25 years of spreading outside its native range, M. sculpturalis clearly expanded the range of inhabitable environmental conditions, which may increase its potential invasiveness in a pattern difficult to predict using only correlative methods. Physiological and ecological data are necessary to better assess the potential niche of this bee species and in consequence to better predict its future spreading dynamics
New research opportunities for roadside safety barriers improvement
Among the major topics regarding the protection of roads, restraint systems still represent a big opportunity in order to increase safety performances. When accidents happen, in fact, the infrastructure can substantially contribute to the reduction of consequences if its marginal spaces are well designed and/or effective restraint systems are installed there. Nevertheless, basic concepts and technology of road safety barriers have not significantly changed for the last two decades. The paper proposes a new approach to the study aimed to define possible enhancements of restraint safety systems performances, by using new materials and defining innovative design principles. In particular, roadside systems can be developed with regard to vehicle-barrier interaction, vehicle-oriented design (included low-mass and extremely low-mass vehicles), traffic suitability, user protection, working width reduction. In addition, thanks to sensors embedded into the barriers, it is also expected to deal with new challenges related to the guidance of automatic vehicles and I2V communication
Prevalence of Side Effects Treatment with Carbamazepine and Other Antiepileptics in Patients with Epilepsy
This paper reveals the studies of carbamazepine monitoring in the manifestation of side effects during clinical use. It is important to realize that these ranges are derived statistically, with most patients who have high levels suffering side effects and some with poor control having low levels. Broadly, the newer agents have advantages of lower risk of side effects and less drug interaction. At the presence they are more expensive than the, than "older" agents. Current recommendations and practice are to use newer agents as second line drugs, although in some countries there are gaining favour as potential first line agents
Eumelanin and pheomelanin are predominant pigments in bumblebee (Apidae: Bombus) pubescence
Background: Bumblebees (Hymenoptera: Apidae: Bombus) are well known for their important inter- and intra-specific variation in hair (or pubescence) color patterns, but the chemical nature of the pigments associated with these patterns is not fully understood. For example, though melanization is believed to provide darker colors, it still unknown which types of melanin are responsible for each color, and no conclusive data are available for the lighter colors, including white. Methods: By using dispersive Raman spectroscopy analysis on 12 species/subspecies of bumblebees from seven subgenera, we tested the hypothesis that eumelanin and pheomelanin, the two main melanin types occurring in animals, are largely responsible for bumblebee pubescence coloration. Results: Eumelanin and pheomelanin occur in bumblebee pubescence. Black pigmentation is due to prevalent eumelanin, with visible signals of additional pheomelanin, while the yellow, orange, red and brown hairs clearly include pheomelanin. On the other hand, white hairs reward very weak Raman signals, suggesting that they are depigmented. Additional non-melanic pigments in yellow hair cannot be excluded but need other techniques to be detected. Raman spectra were more similar across similarly colored hairs, with no apparent effect of phylogeny and both melanin types appeared to be already used at the beginning of bumblebee radiation. Discussion: We suggest that the two main melanin forms, at variable amounts and/or vibrational states, are sufficient in giving almost the whole color range of bumblebee pubescence, allowing these insects to use a single precursor instead of synthesizing a variety of chemically different pigments. This would agree with commonly seen color interchanges between body segments across Bombus species
Involvement of cocaine-amphetamine regulated transcript in the differential feeding responses to nociceptin/orphanin FQ in dark agouti and Wistar Ottawa Karlsburg W rats
Wistar Ottawa Karlsburg W (WOKW) rats and their controls, dark agouti (DA), present different features: in particular, DA rats are lean, while the WOKW are obese and present symptoms of hypertension, dyslipidemia, hyperinsulinemia, and impaired glucose tolerance. The present study tested the hypothesis that these two strains would demonstrate different sensitivity to nociceptin/orphanin FQ (N/OFQ). N/OFQ was injected into the lateral brain ventricle (LBV) of sated DA and WOKW rats, and corticosterone levels in both strains were measured after LBV injection of N/OFQ. LBV N/OFQ injections dose-dependently produced a significant increase in food intake (4 h) in DA rats, but not in WOKW. However, corticosterone levels were increased by N/OFQ to a greater degree in WOKW than in DA rats. Gene sequencing and gene expression of ORL1 receptor and cocaine-amphetamine regulated transcript (Cart) peptide were evaluated to study the difference in N/OFQ-induced feeding behavior in the two strains. WOKW rats had a different amino acid sequence of Cart peptide and a significantly higher expression of Cart in the hypothalamus. The present data show that DA and WOKW rats demonstrate different sensitivity to N/OFQ, and suggest that Cart peptide might be the underlying mechanism of this difference
Association of the scuttle fly Megaselia leucozona Schmitz (Diptera: Phoridae) with sweat bees (Hymenoptera: Halictidae), with a description of the male fly
Megaselia leucozona Schmitz (Diptera, Phoridae) is reported from nests of Lasioglossum malachurum Kirby and Halictus scabiosae (Rossi) in Central Italy. The flies patrolled two nesting sites of the hosts and sometimes mated close to their nest entrances before entering. Observations agree with the general behaviour reported for other Megaselia species associated with fossorial bees and wasps. The hitherto unknownmale of M. leucozona is described, and the original description of a female is augmented and modified. This is the first report of a scuttle fly associated with nests of Halictidae in the Palaearctic Region
Floral Resources and Nesting Requirements of the Ground-Nesting Social Bee, Lasioglossum malachurum (Hymenoptera: Halictidae), in a Mediterranean Semiagricultural Landscape
In order to adopt correct conservation strike plans to maintain bee pollination activity it is necessary to know the species' resource utilisation and requirements. We investigated the floral resources and the nesting requirements of the eusocial beeLasioglossum malachurumKirby at various sites in a Mediterranean landscape. Analysis of bees' pollen loads showed that Compositae was the more exploited family, although interpopulations differences appeared in the pollen types used. From 5 to 7 pollen types were used by bees, but only as few as 1–1.9 per load. Variations of the pollen spectrum through the annual nesting cycle were conspicuous. At all sites, bees nested in horizontal ground areas with high soil hardness, low acidity, and rare superficial stones. On the other side, the exploited soil was variable in soil granulometry (although always high in % of silt or sand) and it was moderately variable in content of organic matter and highly variable in vegetation cover. Creation of ground patches with these characteristics in proximity of both cultivated and natural flowering fields may successfully promote colonization of new areas by this bee
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