The Jurassic pleurotomarioidean gastropod Laevitomaria and its palaeobiogeographical history

The genus Laevitomaria is reviewed and its palaeobiogeographical history is reconstructed based on the re-examination of its type species L. problematica, the study of material stored at the National Natural History Museum of Luxembourg, and an extensive review of the literature. The systematic study allows ascribing to Laevitomaria a number of Jurassic species from the western European region formerly included in other pleurotomariid genera. The following new combinations are proposed: Laevitomaria allionta, Laevitomaria amyntas, Laevitomaria angulba, Laevitomaria asurai, Laevitomaria daityai, Laevitomaria fasciata, Laevitomaria gyroplata, Laevitomaria isarensis, Laevitomaria joannis, Laevitomaria repeliniana, Laevitomaria stoddarti, Laevitomaria subplatyspira, and Laevitomaria zonata. The genus, which was once considered as endemic of the central part of the western Tethys, shows an evolutionary and palaeogeographical history considerably more complex than previously assumed. It first appeared in the Late Sinemurian in the northern belt of the central western Tethys involved in the Neotethyan rifting, where it experienced a first radiation followed by an abrupt decline of diversity in the Toarcian. Species diversity increased again during Toarcian\u2013Aalenian times in the southernmost part of western European shelf and a major radiation occurred during the Middle Aalenian to Early Bajocian in the northern Paris Basin and southern England. After a latest Bajocian collapse of diversity, Laevitomaria disappeared from both the central part of western Tethys and the European shelf. In the Bathonian, the genus appeared in the south-eastern margin of the Tethys where it lasted until the Oxfordian

Aircraft control via variable cant-angle winglets

Copyright @ 2008 American Institute of Aeronautics and AstronauticsThis paper investigates a novel method for the control of "morphing" aircraft. The concept consists of a pair of winglets; with adjustable cant angle, independently actuated and mounted at the tips of a baseline flying wing. The general philosophy behind the concept was that for specific flight conditions such as a coordinated turn, the use of two control devices would be sufficient for adequate control. Computations with a vortex lattice model and subsequent wind-tunnel tests demonstrate the viability of the concept, with individual and/or dual winglet deflection producing multi-axis coupled control moments. Comparisons between the experimental and computational results showed reasonable to good agreement, with the major discrepancies thought to be due to wind-tunnel model aeroelastic effects.This work has been supported by a Marie Curie excellence research grant funded by the European Commission

A Strong Electroweak Sector at Future mu^+ mu^- Colliders

We discuss the prospects for detecting at a muon collider the massive new vector resonances V and light pseudo-Nambu-Goldstone bosons P of a typical strongly interacting electroweak sector (as represented by the BESS model). Expected sensitivities to V's at a high energy collider are evaluated and the excellent prospects for discovering P's via scanning at a low energy collider are delineated.Comment: LaTeX, uses aipproc.cls, aipproc.sty, 10 pages, 6 figures, presented at the Workshop on Physics at the First Muon Collider, Fermilab, November 1997, to appear in the Proceedings, some references added and minor changes in the tex

Analysis of Narrow s-channel Resonances at Lepton Colliders

The procedures for studying a single narrow s-channel resonance or nearly degenerate resonances at a lepton collider, especially a muon collider, are discussed. In particular, we examine four methods for determining the parameters of a narrow s-channel resonance: scanning the resonance, measuring the convoluted cross section, measuring the Breit-Wigner area, and sitting on the resonance while varying the beam energy resolution. This latter procedure is new and appears to be potentially very powerful. Our focus is on computing the errors in resonance parameters resulting from uncertainty in the beam energy spread. Means for minimizing these errors are discussed. The discussion is applied to the examples of a light SM-Higgs, of the lightest pseudogoldstone boson of strong electroweak breaking, and of the two spin-1 resonances of the Degenerate BESS model (assuming that the beam energy spread is less than their mass splitting). We also examine the most effective procedures for nearly degenerate resonances, and apply these to the case of Degenerate BESS resonances with mass splitting of order the beam energy spread.Comment: 63 pages, 16 figure

The Lightest Pseudo-Goldstone Boson at Future e+e- Colliders

In a class of models of dynamical symmetry breaking not ruled out by the available data, the lightest neutral pseudo-Nambu-Goldstone boson P0 contains only down-type techniquarks and charged technileptons. Its mass scale is naturally determined by the b-quark and therefore it is likely to be light. As the presence of pseudo-Nambu-Goldstone bosons in models of dynamical symmetry breaking is a quite general feature, the search of the P0 at colliders is an interesting opportunity of putting limits on or discovering a dynamical electroweak symmetry breaking scenario. In this note we discuss the prospects for discovering and studying the P0 at future e+e- and gamma-gamma colliders.Comment: 15 pages, 8 figures, LaTeX (epsfig), Proceedings of the Second ECFA/DESY Study on Physics Studies for a Future Linear Collide

A New Technique for Determining the Properties of a Narrow ss-channel Resonance at a Muon Collider

We explore an alternative to the usual procedure of scanning for determining the properties of a narrow $s$-channel resonance. By varying the beam energy resolution while sitting on the resonance peak, the width and branching ratios of the resonance can be determined. The statistical accuracy achieved is superior to that of the usual scan procedure in the case of a light SM-like Higgs boson with \mh>130\gev or for the lightest pseudogoldstone boson of a strong electroweak breaking model if \mpzero>150\gev.Comment: 4 pages, 1 figur

Range of reproduction number estimates for COVID-19 spread

To monitor local and global COVID-19 outbreaks, and to plan containment measures, accessible and comprehensible decision-making tools need to be based on the growth rates of new confirmed infections, hospitalization or case fatality rates. Growth rates of new cases form the empirical basis for estimates of a variety of reproduction numbers, dimensionless numbers whose value, when larger than unity, describes surging infections and generally worsening epidemiological conditions. Typically, these determinations rely on noisy or incomplete data gained over limited periods of time, and on many parameters to estimate. This paper examines how estimates from data and models of time-evolving reproduction numbers of national COVID-19 infection spread change by using different techniques and assumptions. Given the importance acquired by reproduction numbers as diagnostic tools, assessing their range of possible variations obtainable from the same epidemiological data is relevant. We compute control reproduction numbers from Swiss and Italian COVID-19 time series adopting both data convolution (renewal equation) and a SEIR-type model. Within these two paradigms we run a comparative analysis of the possible inferences obtained through approximations of the distributions typically used to describe serial intervals, generation, latency and incubation times, and the delays between onset of symptoms and notification. Our results suggest that estimates of reproduction numbers under these different assumptions may show significant temporal differences, while the actual variability range of computed values is rather small

Nanoparticles in Cancer Diagnosis and Treatment

The use of tailored medication delivery in cancer treatment has the potential to increase efficacy while decreasing unfavourable side effects. For researchers looking to improve clinical outcomes, chemotherapy for cancer continues to be the most challenging topic. Cancer is one of the worst illnesses despite the limits of current cancer therapies. New anticancer medications are therefore required to treat cancer. Nanotechnology has revolutionized medical research with new and improved materials for biomedical applications, with a particular focus on therapy and diagnostics. In cancer research, the application of metal nanoparticles as substitute chemotherapy drugs is growing. Metals exhibit inherent or surface-induced anticancer properties, making metallic nanoparticles extremely useful. The development of metal nanoparticles is proceeding rapidly and in many directions, offering alternative therapeutic strategies and improving outcomes for many cancer treatments. This review aimed to present the most commonly used nanoparticles for cancer applications