Primeval very low-mass stars and brown dwarfs - IV. New L subdwarfs, Gaia astrometry, population properties, and a blue brown dwarf binary

30 pages, 23 figuresWe present 27 new L subdwarfs and classify five of them as esdL and 22 as sdL. Our L subdwarf candidates were selected with the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey. Spectroscopic follow-up was carried out primarily with the OSIRIS spectrograph on the Gran Telescopio Canarias. Some of these new objects were followed up with the X-shooter instrument on the Very Large Telescope. We studied the photometric properties of the population of known L subdwarfs using colour-spectral type diagrams and colour-colour diagrams, by comparison with L dwarfs and main-sequence stars, and identified new colour spaces for L subdwarf selection/study in current and future surveys. We further discussed the brown dwarf transition-zone and the observational stellar/substellar boundary. We found that about one-third of 66 known L subdwarfs are substellar objects, with two-thirds being very low-mass stars. We also present the Hertzsprung-Russell diagrams, spectral type-absolute magnitude corrections, and tangential velocities of 20 known L subdwarfs observed by the Gaia astrometry satellite. One of our L subdwarf candidates, ULAS J233227.03+123452.0, is a mildly metal-poor spectroscopic binary brown dwarf: a ~L6p dwarf and a ~T4p dwarf. This binary is likely a thick disc member according to its kinematics.Peer reviewedFinal Accepted Versio

Exploring pig trade patterns to inform the design of risk-based disease surveillance and control strategies

An understanding of the patterns of animal contact networks provides essential information for the design of risk-based animal disease surveillance and control strategies. This study characterises pig movements throughout England and Wales between 2009 and 2013 with a view to characterising spatial and temporal patterns, network topology and trade communities. Data were extracted from the Animal and Plant Health Agency (APHA)’s RADAR (Rapid Analysis and Detection of Animal-related Risks) database, and analysed using descriptive and network approaches. A total of 61,937,855 pigs were moved through 872,493 movements of batches in England and Wales during the 5-year study period. Results show that the network exhibited scale-free and small-world topologies, indicating the potential for diseases to quickly spread within the pig industry. The findings also provide suggestions for how risk-based surveillance strategies could be optimised in the country by taking account of highly connected holdings, geographical regions and time periods with the greatest number of movements and pigs moved, as these are likely to be at higher risk for disease introduction. This study is also the first attempt to identify trade communities in the country, information which could be used to facilitate the pig trade and maintain disease-free status across the country in the event of an outbreak

Application of the laboratory risk indicator for necrotizing fasciitis score for patients with hand infection in Mexican population

Background: Necrotizing fasciitis (NF) is a severe form of soft tissue infection, early diagnosis, and surgical intervention are direct factors in mortality, it may arise from many infectious aetiologies, at our hospital in Mexico city, it is not uncommon that hand infection patients progress to NF, that in many cases its recognition and treatment may also be delayed, resulting in fatal outcomes. Wong et al in 2004 introduced a laboratory risk indicator for necrotizing fasciitis (LRINEC score) that utilizes common laboratory values of patients with clinical infection and stratifies them by their risk of developing NF, so the aim of our study was to validate this tool in Mexican population. Methods: We reviewed all patients with an initial diagnosis of hand infection admitted at the emergency department of our hospital in Mexico City, from April 2020 to March 2022 and examined the LRINEC score at admission, post-debridement, and at the end of the hospitalization to evaluate its usefulness in our population. Results: The LRINEC score at cut-off ≥6 reported sensitivity for the diagnosis of NF of 35.71% (95% CI 12.76-64.86%), specificity of 100% (95% CI 78.2-100%), positive predictive value of 100% (95% CI 71-100%), and negative predictive value of 62.5% (95% CI 53.01-71.12%). Conclusions: The LRINEC score is a useful tool to distinguish NF from other soft tissue infections, but it is not helpful for early recognition of NF alone, LRINEC score could predict worse hospital outcomes in patients with NF and identify the high-risk patients.

Treatment with implants in patients with diabetes. A 7-year comparative study

Introducción. La implantología oral puede constituir una modalidad terapéutica en el tratamiento prostodóncico de los pacientes con compromiso médico. El estudio muestra la evaluación del tratamiento con implantes en pacientes con diabetes comparados con pacientes sin diabetes. Métodos. 48 pacientes edéntulos totales (24 pacientes diabéticos y 24 no diabéticos) fueron tratados con 96 implan- tes con superficie arenada y grabada Galimplant ® en la mandíbula para su rehabilitación prostodóncica con sobre- dentaduras mandibulares. 2 implantes fueron insertados en cada paciente. Los implantes fueron cargados funcional- mente tras un periodo de tiempo de 6 semanas con retenedores de fricción. Los hallazgos clínicos (implantológicos y prostodóncicos) se han seguido durante 7 años. Resultados. Los resultados indican una supervivencia de los implantes del 95,8%. Durante el periodo de seguimeinto clínico se perdieron 4 implantes (dos implantes en cada grupo). La pérdida de hueso marginal media fué de 0,7 mm en ambos grupos. El 100% de los pacientes fueron tratados mediante una sobredentadura implantorretenida con anclajes de fricción. En 14 pacientes se realizaron cambios en los componentes plásticos de los ataches. El seguimiento clínico medio fue de 82,5 meses (60-102 meses). Conclusiones. Los resultados del presente estudio indican que el tratamiento con implantes dentales en pacientes diabéticos es una terapéutica exitosa sin diferencias entre los pacientes diabéticos y no diabéticos. PALABRAS CLAVE: Implantes dentales, pacientes geriátricos, diabetes mellitus, sobredentaduras, oseo- integración, implantología oral.Introduction. Implant dentistry can to constitute a therapeutic modality in the prosthodontic treatment of medically compromised patients. This study reports the evaluation of treatment with implants in patients with diabetes compared with patients without diabetes. Methods. 48 edentulous patients (24 diabetic patients and 24 non-diabetic patients) were treated with 96 Galimplant ® sand-blasted and acid-etched surface implants for prosthodontic rehabilitation with mandibular overdentures. Two implants were inserted in each patient. Implants were loaded after a healing free-loading period between 6 weeks with locator attaches. Clinical findings (implant and prosthodontics) were followed during at 7 years. Results. Clinical results indicate a survival rate of implants of 95.8% in both groups. Four implant was lost during the follow-up period (two implants in each group). Media marginal bone loss was 0.7 mm in both groups. 100% of patients were treated with overdentures retained with 2 implants with locator attaches. Changes in plastic components of attaches were reported in 14 patients. The media follow-up was of 82.5 months (60-102 months). Conclusions. Clinical results of this study indicate that treatment with dental implants in diabetic patients is a successful implant treatment without differences with nondiabetic patients

Materials design for ambipolar devices: tuning orbital energetics in oligothiophene-naphthalimides semiconductors

Ambipolar organic field-effect transistors (OFETs), which can efficiently transport both holes and electrons, using a single type of electrode, are currently of great interest due to their possible applications in complementary metal oxide semiconductor (CMOS)-like circuits, sensors, and in light-emitting transistors. Several theoretical and experimental studies have argued that most organic semiconductors should be able to transport both types of carrier, although typically unipolar behavior is observed. One factor that can compromise ambipolar transport in organic semiconductors is poor solid state overlap between the HOMO (p-type) or LUMO (n-type) orbitals of neighboring molecules in the semiconductor thin film. In the search of low-bandgap ambipolar materials, where the absence of skeletal distortions allows closer intermolecular π-π stacking and enhanced intramolecular π-conjugation, a new family of oligothiophene-naphthalimide assemblies have been synthesized and characterized, in which both donor and acceptor moieties are directly conjugated through rigid linkers. In previous works we found that oligothiophene-napthalimide assemblies connected through amidine linkers (NDI derivates) exhibit skeletal distortions (50-60º) arising from steric hindrance between the carbonyl group of the arylene core and the sulphur atom of the neighbored thiophene ring (see Figure 1). In the present work we report novel oligo- and polythiophene–naphthalimide analogues NAI-3T, NAI-5T and poly-NAI-8C-3T, in which the connections of the amidine linkage have been inverted in order to prevent steric interactions. Thus, the nitrogen atoms are directly connected to the naphthalene moiety in NAI derivatives while they were attached directly to the thiophene moiety in the previously investigated NDI-3T and NDI-5T. In Figure 1 is depicted the calculated molecular structure of NAI-3T together with that of NDI-3T showing how the steric interactions are not present in the novel NAI derivative. The planar skeletons in these new family induce higher degree of crystallinity and the carrier charge transport can be switched from n-type to ambipolar behaviour. The highest FET performance is achieved for vapor-deposited films of NAI-3T with mobilities of 1.95x10-4cm2V-1s-1 and 2.00x10-4cm2V-1s-1 for electrons and holes, respectively. Finally, these planar semiconductors are compared with their NDI derivates analogues, which exhibit only n-type mobility, in order to understand the origin of the ambipolarity in this new series of molecular semiconductors.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Logarithmic asymptotics of the densities of SPDEs driven by spatially correlated noise

We consider the family of stochastic partial differential equations indexed by a parameter \eps\in(0,1], \begin{equation*} Lu^{\eps}(t,x) = \eps\sigma(u^\eps(t,x))\dot{F}(t,x)+b(u^\eps(t,x)), \end{equation*} (t,x)\in(0,T]\times\Rd with suitable initial conditions. In this equation, $L$ is a second-order partial differential operator with constant coefficients, $\sigma$ and $b$ are smooth functions and $\dot{F}$ is a Gaussian noise, white in time and with a stationary correlation in space. Let p^\eps_{t,x} denote the density of the law of u^\eps(t,x) at a fixed point (t,x)\in(0,T]\times\Rd. We study the existence of \lim_{\eps\downarrow 0} \eps^2\log p^\eps_{t,x}(y) for a fixed $y\in\R$. The results apply to a class of stochastic wave equations with $d\in\{1,2,3\}$ and to a class of stochastic heat equations with $d\ge1$.Comment: 39 pages. Will be published in the book " Stochastic Analysis and Applications 2014. A volume in honour of Terry Lyons". Springer Verla

Calculation of Band Edge Eigenfunctions and Eigenvalues of Periodic Potentials through the Quantum Hamilton - Jacobi Formalism

We obtain the band edge eigenfunctions and the eigenvalues of solvable periodic potentials using the quantum Hamilton - Jacobi formalism. The potentials studied here are the Lam{\'e} and the associated Lam{\'e} which belong to the class of elliptic potentials. The formalism requires an assumption about the singularity structure of the quantum momentum function $p$, which satisfies the Riccati type quantum Hamilton - Jacobi equation, $p^{2} -i \hbar \frac{d}{dx}p = 2m(E- V(x))$ in the complex $x$ plane. Essential use is made of suitable conformal transformations, which leads to the eigenvalues and the eigenfunctions corresponding to the band edges in a simple and straightforward manner. Our study reveals interesting features about the singularity structure of $p$, responsible in yielding the band edge eigenfunctions and eigenvalues.Comment: 21 pages, 5 table

Pressure-induced phase-transition sequence in CoF2: An experimental and first-principles study on the crystal, vibrational, and electronic properties

We report a complete structural study of CoF2 under pressure. Its crystal structure and vibrational and electronic properties have been studied both theoretically and experimentally using first-principles density functional theory (DFT) methods, x-ray diffraction, x-ray absorption at Co K-edge experiments, Raman spectroscopy, and optical absorption in the 0–80 GPa range. We have determined the structural phase-transition sequence in CoF2 and corresponding transition pressures. The results are similar to other transition-metal difluorides such as FeF2 but different to ZnF2 and MgF2, despite that the Co2+ size (ionic radius) is similar to Zn2+ and Mg2+. We found that the complete phase-transition sequence is tetragonal rutile (P42/mnm) → CaCl2 type (orthorhombic Pnnm) → distorted PdF2 (orthorhombic Pbca)+PdF2 (cubic Pa3¯) in coexistence → fluorite (cubic Fm3¯m) → cotunnite (orthorhombic Pnma). It was observed that the structural phase transition to the fluorite at 15 GPa involves a drastic change of coordination from sixfold octahedral to eightfold cubic with important modifications in the vibrational and electronic properties. We show that the stabilization of this high-pressure cubic phase is possible under nonhydrostatic conditions since ideal hydrostaticity would stabilize the distorted-fluorite structure (tetragonal I4/mmm) instead. Although the first rutile → CaCl2-type second-order phase transition is subtle by Raman spectroscopy, it was possible to define it through the broadening of the Eg Raman mode which is split in the CaCl2-type phase. First-principles DFT calculations are in fair agreement with the experimental Raman mode frequencies, thus providing an accurate description for all vibrational modes and elastic properties of CoF2 as a function of pressure