Non-linear unbalanced Bessel beams: Stationary conical waves supported by nonlinear losses

Nonlinear losses accompanying Kerr self-focusing substantially impacts the dynamic balance of diffraction and nonlinearity, permitting the existence of localized and stationary solutions of the 2D+1 nonlinear Schrodinger equation which are stable against radial collapse. These are featured by linear conical tails that continually refill the nonlinear, central spot. An experiment shows that the discovered solution behaves as strong attractor for the self-focusing dynamics in Kerr media.Comment: 4 pages, 2 figures; experimental verification adde

Glacial cycles drive rapid divergence of cryptic field vole species

Understanding the factors that contribute to the generation of reproductively isolated forms is a fundamental goal of evolutionary biology. Cryptic species are an especially interesting challenge to study in this context since they lack obvious morphological differentiation that provides clues to adaptive divergence that may drive reproductive isolation. Geographical isolation in refugial areas during glacial cycling is known to be important for generating genetically divergent populations, but its role in the origination of new species is still not fully understood and likely to be situation dependent. We combine analysis of 35,434 single‐nucleotide polymorphisms (SNPs) with environmental niche modeling (ENM) to investigate genomic and ecological divergence in three cryptic species formerly classified as the field vole (Microtus agrestis). The SNPs demonstrate high genomic divergence (pairwise FST values of 0.45–0.72) and little evidence of gene flow among the three field vole cryptic species, and we argue that genetic drift may have been a particularly important mechanism for divergence in the group. The ENM reveals three areas as potential glacial refugia for the cryptic species and differing climatic niches, although with spatial overlap between species pairs. This evidence underscores the role that glacial cycling has in promoting genetic differentiation and reproductive isolation by subdivision into disjunct distributions at glacial maxima in areas relatively close to ice sheets. Future investigation of the intrinsic barriers to gene flow between the field vole cryptic species is required to fully assess the mechanisms that contribute to reproductive isolation. In addition, the Portuguese field vole (M. rozianus) shows a high inbreeding coefficient and a restricted climatic niche, and warrants investigation into its conservation status

Polarimetry and the High-Energy Emission Mechanisms in Quasar Jets. The Case of PKS 1136-135

Since the discovery of kiloparsec-scale X-ray emission from quasar jets, the physical processes responsible for their high-energy emission have been poorly defined. A number of mechanisms are under active debate, including synchrotron radiation, inverse-Comptonized CMB (IC/CMB) emission, and other Comptonization processes. In a number of cases, the optical and X-ray emission of jet regions are inked by a single spectral component, and in those, high- resolution multi-band imaging and polarimetry can be combined to yield a powerful diagnostic of jet emission processes. Here we report on deep imaging photometry of the jet of PKS 1136$-$135 obtained with the {\it Hubble Space Telescope.} We find that several knots are highly polarized in the optical, with fractional polarization $\Pi>30$. When combined with the broadband spectral shape observed in these regions, this is very difficult to explain via IC/CMB models, unless the scattering particles are at the lowest-energy tip of the electron energy distribution, with Lorentz factor $\gamma \sim 1$, and the jet is also very highly beamed ($\delta \geq 20$) and viewed within a few degrees of the line of sight. We discuss both the IC/CMB and synchrotron interpretation of the X-ray emission in the light of this new evidence, presenting new models of the spectral energy distribution and also the matter content of this jet. The high polarizations do not completely rule out the possibility of IC/CMB optical-to-X-ray emission in this jet, but they do strongly disfavor the model. We discuss the implications of this finding, and also the prospects for future work.Comment: 14 pages, 8 figures, ApJ in pres

Spatio-temporal distribution of nucleation events during crystal growth

We consider irreversible second-layer nucleation that occurs when two adatoms on a terrace meet. We solve the problem analytically in one dimension for zero and infinite step-edge barriers, and numerically for any value of the barriers in one and two dimensions. For large barriers, the spatial distribution of nucleation events strongly differs from $\rho^2$, where $\rho$ is the stationary adatom density in the presence of a constant flux. The probability $Q(t)$ that nucleation occurs at time $t$ after the deposition of the second adatom, decays for short time as a power law [$Q(t)\sim t^{-1/2}$] in $d=1$ and logarithmically [$Q(t)\sim 1/\ln(t/t_0)$] in $d=2$; for long time it decays exponentially. Theories of the nucleation rate $\omega$ based on the assumption that it is proportional to $\rho^2$ are shown to overestimate $\omega$ by a factor proportional to the number of times an adatom diffusing on the terrace visits an already visited lattice site.Comment: 4 pages, 3 figures; accepted for publication on PR

Nasoseptal flap with extended pedicle dissection based on the maxillary artery: Clinical series of 55 cases

: Nasoseptal flap with extended pedicle dissection is a low morbidity and high success rate flap. It is a flap that can be applied to reconstruct a wide range of ipsilateral skull base defects

Copernicus and Earth observation in support of EU policies

The Copernicus programme for Earth observation represents a big investment by the EU, justified by expected returns in public governance and private business. Copernicus is user and policy driven, and provides cross-domain products and services with a full free and open data policy and where possible taking up new technologies and research. This study has made a survey of the extent that Copernicus is used to support policy making in the European Commission, also assessing the perspectives for increased uptake. Also other Earth observation data and information has been looked at. An extensive use of the services is observed for policies monitoring landuse, climatic and environmental conditions, and this is expected to increase further with e.g. the new Common Agricultural Policy and the Land Use, Land-Use Change and Forestry Regulation. Information of the Climate Change Service on optimal land-use targeting specific human activities, harnessing the beneficial opportunities of climate change, provides policy makers with a new set of adaptation measures. While air quality measures can be monitored by the atmosphere service, the marine service provides input to the information system for marine knowledge. The emergency service supports disaster risk reduction measures and a resilient build-up of society. Security is of increasing importance where land and water resources are at the origin of conflict and migration. Several lines of action have been identified to improve uptake: Increasing engagement within the policy Directorates-General, fostering feedback loops between the end-users and Copernicus services, Increasing communication, information and training, setting standards and guaranteeing quality controls, enabling full integration of different datasets. The Copernicus programme brings a unique opportunity to the EU for being a global player, addressing SDGs and International Conventions because of its a long-term sustained commitment and strong international dimension. No such space programme is currently available elsewhere.JRC.D.6-Knowledge for Sustainable Development and Food Securit

Clinical Judgment Versus Biomarker Prostate Cancer Gene 3: Which Is Best When Determining the Need for Repeat Prostate Biopsy?

ObjectiveTo assess the value of best clinical judgment (BCJ) and the prostate cancer gene 3 (PCA3) assay in guiding the decision to perform a repeat prostate biopsy (PBx) after a previous negative PBx.Materials and MethodsUsing the RAND/UCLA Appropriateness Method, 12 European urologists established recommendations (BCJ) for the appropriateness of PBx according to the prostate-specific antigen level, digital rectal examination findings, number of previous negative PBxs, prostate volume, and life expectancy, with and without consideration of the PCA3 scores. These recommendations were applied to 1024 subjects receiving placebo in the Reduction by Dutasteride of Prostate Cancer Events trial, including men with a previous negative PBx, a baseline prostate-specific antigen level of 2.5-10 ng/mL, and a PCA3 test performed before the protocol-mandated 2- and 4-year repeat PBxs. Three scenarios (ie, BCJ alone, BCJ with PCA3, and the PCA3 score alone) were tested for their ability to reduce the repeat PBx rate versus missing Gleason sum ≥7 prostate cancer (PCa).ResultsBCJ with PCA3 would have avoided 64% of repeat PBxs compared with 26% for BCJ alone and 55% for PCA3 alone (cutoff score 20). Of 55 PCa cases (Gleason sum ≥7), 13 would have been missed using BCJ alone compared with 7 using PCA3 (cutoff score 20) alone and 8 using BCJ plus PCA3. The diagnostic accuracy for Gleason sum ≥7 PCa of the BCJ with PCA3 scenario was superior to that of the other scenarios, with a negative predictive value of 99%.ConclusionApplication of the BCJ together with PCA3 testing can reduce the number of repeat PBxs while maintaining the sensitivity to detect Gleason sum ≥7 PCa

Strategic analysis for the MER Cape Verde approach

The Mars Exploration Rover Opportunity has recently completed a two year campaign studying Victoria Crater. The campaign culminated in a close approach of Cape Verde in order to acquire high resolution imagery of the exposed stratigraphy in the cliff face. The close approach to Cape Verde provided significant challenges for every subsystem of the rover as the rover needed to traverse difficult, un-characterised terrain and approach a cliff face with the potential of blocking out solar energy and communications with Earth. In this paper we describe the strategic analyses performed by the science and engineering teams so that we could successfully achieve the science objectives while keeping the rover safe

Patterns of recurrences in sinonasal cancers undergoing an endoscopic surgery-based treatment: Results of the MUSES* on 940 patients: *MUlti-institutional collaborative Study on Endoscopically treated Sinonasal cancers

The improvements in survival with expansion of the survivors' population, along with evolution of endoscopically-based treatment modalities, have contributed to emphasize the clinical relevance of recurrences in sinonasal cancers. However, at present, literature is scant regarding the pattern of recurrences and the therapeutic strategies available to manage long survivors who experienced single or multiple failures. The aim of the present study was to analyze sinonasal cancers recurrences to provide data regarding rates and patterns of relapse, predictors of failure and prognostic impact of the recurrence

The Imaging X-ray Polarimetry Explorer (IXPE)

The Imaging X-ray Polarimetry Explorer (IXPE) expands observation space by simultaneously adding polarization measurements to the array of source properties currently measured (energy, time, and location). IXPE will thus open new dimensions for understanding how X-ray emission is produced in astrophysical objects, especially systems under extreme physical conditions - such as neutron stars and black holes. Polarization singularly probes physical anisotropies - ordered magnetic fields, aspheric matter distributions, or general relativistic coupling to black-hole spin - that are not otherwise measurable. Hence, IXPE complements all other investigations in high-energy astrophysics by adding important and relatively unexplored information to the parameter space for studying cosmic X-ray sources and processes, as well as for using extreme astrophysical environments as laboratories for fundamental physics. Keywords: X-ray astronomy, X-ray polarimetry, X-ray imagin