Improving habitat heterogenity on coastal defence structures

Sea level rise and higher storm frequency is increasing the need for hard coastal defences worldwide. The majority of these structures lack optimal habitats for intertidal species, resulting in low diversity. Here, we evaluate low-cost enhancement techniques which increase habitat heterogeneity and surface texture on different rock types. Arrays of holes and grooves inspired by ‘blast features’ produced during the quarrying process were created on both granite rock armour and limestone rock groynes in two locations in England. After 12 months the treatments were successful at attracting new species to the defence structures and increasing the overall diversity and abundance of organisms. Mobile fauna including crabs and fish were recorded utilising the holes and grooves. Non -native species were recorded in grooves at one site but in no greater abundance than control areas. At the southern site, species known to be spreading in response to climate changes were found in both treatments but not in controls. The cost of these treatments was low in relation to that of the defence scheme and could be easily replicated either during or after construction. Through evaluatio n of the use of these ecological enhancement techniques on coastal structures, we suggest that they have considerable potential to enhance local patterns of biodiversity when used within large -scale defence projects

Intersection rules, dynamics and symmetries

We consider theories containing gravity, at most one dilaton and form field strengths. We show that the existence of particular BPS solutions of intersecting extremal closed branes select the theories, which upon dimensional reduction to three dimensions possess a simple simply laced Lie group symmetry G. Furthermore these theories can be fully reconstructed from the dynamics of such branes and of their openings. Amongst such theories are the effective actions of the bosonic sector of M-theory and of the bosonic string. The BPS intersecting brane solutions form representations of a subgroup of the group of Weyl reflections and outer automorphisms of the triple Kac-Moody extension G+++ of the G algebra, which cannot be embedded in the overextended Kac-Moody subalgebra G++ characterising the cosmological Kasner solutions.Comment: Latex 30 pages, 3 figure

COVID-19 vaccination in athletes: ready, set, go…

In the fight against the COVID-19 global pandemic, the focus in 2021 has fortunately turned to vaccination strategies. The successful development of several vaccines, and their proven efficacy and short-term safety in large scale multinational trials against severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), offers promise in controlling the pandemic. Many countries are now operationalising their vaccination programmes, and prioritising health-care workers and the most vulnerable individuals within the population—eg, the elderly and those with chronic health conditions.https://www.thelancet.com/journals/lanreshj2022Sports Medicin

COVID-19 vaccination in athletes: ready, set, go…

In the fight against the COVID-19 global pandemic, the focus in 2021 has fortunately turned to vaccination strategies. The successful development of several vaccines, and their proven efficacy and short-term safety in large scale multinational trials against severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), offers promise in controlling the pandemic. Many countries are now operationalising their vaccination programmes, and prioritising health-care workers and the most vulnerable individuals within the population—eg, the elderly and those with chronic health conditions.https://www.thelancet.com/journals/lanreshj2022Sports Medicin

Introduction to M Theory and AdS/CFT Duality

An introductory survey of some of the developments that have taken place in superstring theory in the past few years is presented. The main focus is on three particular dualities. The first one is the appearance of an 11th dimension in the strong coupling limit of the type IIA theory, which give rise to M theory. The second one is the duality between the type IIB theory compactified on a circle and M theory on a two-torus. The final topic is an introduction to the recently proposed duality between superstring theory or M theory on certain anti de Sitter space backgrounds and conformally invariant quantum field theories.Comment: 26 pages; To be published in the Proceedings of a conference held in Corfu, Greece in September 1998. v2: reference adde

Lipid-laden bronchoalveolar macrophages in asthma and chronic cough

SummaryBackgroundThe presence of lipids in alveolar macrophages (AMs) may impair their phagocytic response, and determine airway inflammation and obstruction.ObjectiveTo determine the factors such as severity of asthma, chronic cough, airway inflammation and obesity that may influence the presence of lipids in lung macrophages.MethodsBronchoalveolar lavage fluid (BALF) was obtained from 38 asthmatics (21 severe and 17 mild/moderate), 16 subjects with chronic cough and 11 healthy control subjects. The presence of lipids in macrophages was detected using an Oil-red-O stain and an index of lipid-laden macrophages (LLMI) was obtained.ResultsLLMI scores were higher in healthy subjects (median 48 [IQR 10–61]) and the severe asthma group (37 [11.5–61]) compared to mild/moderate asthmatics (7 [0.5–37]; p < 0.05 each). Subjects reporting a history of gastro-oesophageal reflux disease (GORD) had higher LLMI values (41.5 [11.3–138] versus 13 [0–39.3], p = 0.02). There was no significant correlation between LLMI and chronic cough, BAL cell differential counts, FEV1, FEV1/FVC or body mass index (BMI).ConclusionsThe reduced LLMI in mild/moderate asthma may be related to lower incidence of GORD. However, this was not related to the degree of airflow obstruction, obesity or airway inflammation

Properties of Intersecting p-branes in Various Dimensions

General properties of intersecting extremal p-brane solutions of gravity coupled with dilatons and several different d-form fields in arbitrary space-time dimensions are considered. It is show that heuristically expected properties of the intersecting p-branes follow from the explicit formulae for solutions. In particular, harmonic superposition and S-duality hold for all p-brane solutions. Generalized T-duality takes place under additional restrictions on the initial theory parameters .Comment: 14 pages, RevTeX, misprints are corrected and more Comments are added, information about one of the authors (M.G.I.) available at http://www.geocities.com/CapeCanaveral/Lab/419

On the verge of Umdeutung in Minnesota: Van Vleck and the correspondence principle (Part One)

In October 1924, the Physical Review, a relatively minor journal at the time, published a remarkable two-part paper by John H. Van Vleck, working in virtual isolation at the University of Minnesota. Van Vleck combined advanced techniques of classical mechanics with Bohr's correspondence principle and Einstein's quantum theory of radiation to find quantum analogues of classical expressions for the emission, absorption, and dispersion of radiation. For modern readers Van Vleck's paper is much easier to follow than the famous paper by Kramers and Heisenberg on dispersion theory, which covers similar terrain and is widely credited to have led directly to Heisenberg's "Umdeutung" paper. This makes Van Vleck's paper extremely valuable for the reconstruction of the genesis of matrix mechanics. It also makes it tempting to ask why Van Vleck did not take the next step and develop matrix mechanics himself.Comment: 82 page

Topology, Entropy and Witten Index of Dilaton Black Holes

We have found that for extreme dilaton black holes an inner boundary must be introduced in addition to the outer boundary to give an integer value to the Euler number. The resulting manifolds have (if one identifies imaginary time) topology $S^1 \times R \times S^2$ and Euler number $\chi = 0$ in contrast to the non-extreme case with $\chi=2$. The entropy of extreme $U(1)$ dilaton black holes is already known to be zero. We include a review of some recent ideas due to Hawking on the Reissner-Nordstr\"om case. By regarding all extreme black holes as having an inner boundary, we conclude that the entropy of {\sl all} extreme black holes, including $[U(1)]^2$ black holes, vanishes. We discuss the relevance of this to the vanishing of quantum corrections and the idea that the functional integral for extreme holes gives a Witten Index. We have studied also the topology of ``moduli space'' of multi black holes. The quantum mechanics on black hole moduli spaces is expected to be supersymmetric despite the fact that they are not HyperK\"ahler since the corresponding geometry has torsion unlike the BPS monopole case. Finally, we describe the possibility of extreme black hole fission for states with an energy gap. The energy released, as a proportion of the initial rest mass, during the decay of an electro-magnetic black hole is 300 times greater than that released by the fission of an ${}^{235} U$ nucleus.Comment: 51 pages, 4 figures, LaTeX. Considerably extended version. New sections include discussion of the Witten index, topology of the moduli space, black hole sigma model, and black hole fission with huge energy releas

Electronic structure of fluorides: general trends for ground and excited state properties

The electronic structure of fluorite crystals are studied by means of density functional theory within the local density approximation for the exchange correlation energy. The ground-state electronic properties, which have been calculated for the cubic structures $CaF_{2}$,$SrF_{2}$, $BaF_{2}$, $CdF_{2}$, $HgF_{2}$, $\beta$-$PbF_{2}$, using a plane waves expansion of the wave functions, show good comparison with existing experimental data and previous theoretical results. The electronic density of states at the gap region for all the compounds and their energy-band structure have been calculated and compared with the existing data in the literature. General trends for the ground-state parameters, the electronic energy-bands and transition energies for all the fluorides considered are given and discussed in details. Moreover, for the first time results for $HgF_{2}$ have been presented