Tools in the orbit space approach to the study of invariant functions: rational parametrization of strata

Functions which are equivariant or invariant under the transformations of a compact linear group $G$ acting in an euclidean space $\real^n$, can profitably be studied as functions defined in the orbit space of the group. The orbit space is the union of a finite set of strata, which are semialgebraic manifolds formed by the $G$-orbits with the same orbit-type. In this paper we provide a simple recipe to obtain rational parametrizations of the strata. Our results can be easily exploited, in many physical contexts where the study of equivariant or invariant functions is important, for instance in the determination of patterns of spontaneous symmetry breaking, in the analysis of phase spaces and structural phase transitions (Landau theory), in equivariant bifurcation theory, in crystal field theory and in most areas where use is made of symmetry adapted functions. A physically significant example of utilization of the recipe is given, related to spontaneous polarization in chiral biaxial liquid crystals, where the advantages with respect to previous heuristic approaches are shown.Comment: Figures generated through texdraw package; revised version appearing in J. Phys. A: Math. Ge

Another new species of the genus Habrophlebia Eaton, 1881 (Ephemeroptera, Leptophlebiidae) from the Maghreb.

A new species belonging to the genus Habrophlebia Eaton, 1881 is described at the nymphal stage from the Rif Mountains of Morocco. This species presents unique features, such as the chorionic arrangement of the egg and the ornamentation of the posterior margin of abdominal tergites. It is compared to all west European Habrophlebia species and a table with discriminating characters is given. A phylogenetic reconstruction based on COI sequences fully supports the hypothesis of a new species in the Rif Mountains, with possible further distribution in southern Spain

Lightweight rotor design by optimal spar cap offset

Bend-twist coupling behavior is induced in a blade by displacing the suction side spar cap towards the leading edge, and the pressure side one in the opposite direction. Additional couplings are introduced by rotating the spar cap fibers. The structural configuration of the blade is optimized using an automated design environment. The resulting blade shows significant benefits in terms of mass and loads when compared to the baseline uncoupled one. Finally, the lightweight design concept is used to increase the rotor size, resulting in a larger energy yield for the same hub loads

Level-3 Calorimetric Resolution available for the Level-1 and Level-2 CDF Triggers

As the Tevatron luminosity increases sophisticated selections are required to be efficient in selecting rare events among a very huge background. To cope with this problem, CDF has pushed the offline calorimeter algorithm reconstruction resolution up to Level 2 and, when possible, even up to Level 1, increasing efficiency and, at the same time, keeping under control the rates. The CDF Run II Level 2 calorimeter trigger is implemented in hardware and is based on a simple algorithm that was used in Run I. This system has worked well for Run II at low luminosity. As the Tevatron instantaneous luminosity increases, the limitation due to this simple algorithm starts to become clear: some of the most important jet and MET (Missing ET) related triggers have large growth terms in cross section at higher luminosity. In this paper, we present an upgrade of the Level 2 Calorimeter system which makes the calorimeter trigger tower information available directly to a CPU allowing more sophisticated algorithms to be implemented in software. Both Level 2 jets and MET can be made nearly equivalent to offline quality, thus significantly improving the performance and flexibility of the jet and MET related triggers. However in order to fully take advantage of the new L2 triggering capabilities having at Level 1 the same L2 MET resolution is necessary. The new Level-1 MET resolution is calculated by dedicated hardware. This paper describes the design, the hardware and software implementation and the performance of the upgraded calorimeter trigger system both at Level 2 and Level 1.Comment: 5 pages, 5 figures,34th International Conference on High Energy Physics, Philadelphia, 200

Cost-effectiveness of buffered soluble alendronate 70 mg effervescent tablet for the treatment of postmenopausal women with osteoporosis in Italy

Summary: The use of buffered soluble alendronate 70 mg effervescent tablet, a convenient dosing regimen for bisphosphonate therapy, seems a cost-effective strategy compared with relevant alternative treatments for postmenopausal women with osteoporosis aged 60 years and over in Italy. Introduction: To assess the cost-effectiveness of buffered soluble alendronate (ALN) 70 mg effervescent tablet compared with relevant alternative treatments for postmenopausal osteoporotic women in Italy. Methods: A previously validated Markov microsimulation model was adjusted to the Italian healthcare setting to estimate the lifetime costs (expressed in €2019) per quality-adjusted life-years (QALY) of buffered soluble ALN compared with generic ALN, denosumab, zoledronic acid and no treatment. Pooled efficacy data derived from the NICE network meta-analysis were used for bisphosphonate treatments. Two treatment duration scenarios were assessed: 1 year using persistence data derived from an Italian prospective observational study including 144 and 216 postmenopausal osteoporotic women on buffered soluble ALN and oral ALN, respectively, and 3 years. Analyses were conducted for women 60–80 years of age with a bone mineral density T-score ≤ − 3.0 or with existing vertebral fractures. Results: In all simulated populations, buffered soluble ALN was dominant (more QALYs, lower costs) compared to denosumab. The cost per QALY gained of buffered soluble ALN compared to generic ALN and no treatment always falls below €20,000 per QALY gained. In the 1-year treatment scenario, zoledronic acid was associated with more QALY than buffered soluble ALN but the cost per QALY gained of zoledronic acid compared with buffered soluble ALN was always higher than €70,000, while buffered soluble ALN was dominant in the 3-year treatment scenario. Conclusion: This study suggests that buffered soluble ALN represents a cost-effective strategy compared with relevant alternative treatments for postmenopausal osteoporosis women in Italy aged 60 years and over. © 2021, The Author(s)

Global diversity of mayflies (Ephemeroptera, Insecta) in freshwater

The extant global Ephemeroptera fauna is represented by over 3,000 described species in 42 families and more than 400 genera. The highest generic diversity occurs in the Neotropics, with a correspondingly high species diversity, while the Palaearctic has the lowest generic diversity, but a high species diversity. Such distribution patterns may relate to how long evolutionary processes have been carrying on in isolation in a bioregion. Over an extended period, there may be extinction of species, but evolution of more genera. Dramatic extinction events such as the K-T mass extinction have affected current mayfly diversity and distribution. Climatic history plays an important role in the rate of speciation in an area, with regions which have been climatically stable over long periods having fewer species per genus, when compared to regions subjected to climatic stresses, such as glaciation. A total of 13 families are endemic to specific bioregions, with eight among them being monospecific. Most of these have restricted distributions which may be the result of them being the relict of a previously more diverse, but presently almost completely extinct family, or may be the consequence of vicariance events, resulting from evolution due to long-term isolation

Preoperative staging of colorectal cancer using virtual colonoscopy: correlation with surgical results

The aim of this study was to evaluate the clinical usefulness of computed tomography colonography (CTC) in the preoperative staging in patients with abdominal pain for occlusive colorectal cancer (CRC) and to compare the results of CTC with the surgical ones