Pfaffian representations of cubic threefolds

Given a cubic hypersurface $X\subset \mathbb{P}^4$, we study the existence of Pfaffian representations of $X$, namely of $6\times 6$ skew-symmetric matrices of linear forms $M$ such that $X$ is defined by the equation $Pf(M)=0$. It was known that such a matrix always exists whenever $X$ is smooth. Here we prove that the same holds whenever $X$ is singular, hence that every cubic threefold is Pfaffian

Probing high-redshift galaxies with Lyα\alpha intensity mapping

We present a study of the cosmological Ly$\alpha$ emission signal at $z > 4$. Our goal is to predict the power spectrum of the spatial fluctuations that could be observed by an intensity mapping survey. The model uses the latest data from the HST legacy fields and the abundance matching technique to associate UV emission and dust properties with the halos, computing the emission from the interstellar medium (ISM) of galaxies and the intergalactic medium (IGM), including the effects of reionization, self-consistently. The Ly$\alpha$ intensity from the diffuse IGM emission is 1.3 (2.0) times more intense than the ISM emission at $z = 4(7)$; both components are fair tracers of the star-forming galaxy distribution. However the power spectrum is dominated by ISM emission on small scales ($k > 0.01 h{\rm Mpc}^{-1}$) with shot noise being significant only above $k = 1 h{\rm Mpc}^{-1}$. At very lange scales ($k < 0.01h{\rm Mpc}^{-1}$) diffuse IGM emission becomes important. The comoving Ly$\alpha$ luminosity density from IGM and galaxies, $\dot \rho_{{\rm Ly}\alpha}^{\rm IGM} = 8.73(6.51) \times 10^{40} {\rm erg}{\rm s}^{-1}{\rm Mpc}^{-3}$ and $\dot \rho_{{\rm Ly}\alpha}^{\rm ISM} = 6.62(3.21) \times 10^{40} {\rm erg}{\rm s}^{-1}{\rm Mpc}^{-3}$ at $z = 4(7)$, is consistent with recent SDSS determinations. We predict a power $k^3 P^{{\rm Ly}\alpha}(k, z)/2\pi^2 = 9.76\times 10^{-4}(2.09\times 10^{-5}){\rm nW}^2{\rm m}^{-4}{\rm sr}^{-2}$ at $z = 4(7)$ for $k = 0.1 h {\rm Mpc}^{-1}$.Comment: 14 Pages, 13 figure

Computational prediction of L_{3} EXAFS spectra of gold nanoparticles from classical molecular dynamics simulations

We present a computational approach for the simulation of extended x-ray absorption fine structure (EXAFS) spectra of nanoparticles directly from molecular dynamics simulations without fitting any of the structural parameters of the nanoparticle to experimental data. The calculation consists of two stages. First, a molecular dynamics simulation of the nanoparticle is performed and then the EXAFS spectrum is computed from “snapshots” of structures extracted from the simulation. A probability distribution function approach calculated directly from the molecular dynamics simulations is used to ensure a balanced sampling of photoabsorbing atoms and their surrounding scattering atoms while keeping the number of EXAFS calculations that need to be performed to a manageable level. The average spectrum from all configurations and photoabsorbing atoms is computed as an Au L3-edge EXAFS spectrum with the FEFF 8.4 package, which includes the self-consistent calculation of atomic potentials. We validate and apply this approach in simulations of EXAFS spectra of gold nanoparticles with sizes between 20 and 60 Å. We investigate the effect of size, structural anisotropy, and thermal motion on the gold nanoparticle EXAFS spectra and we find that our simulations closely reproduce the experimentally determined spectra

A tool for fast ground truth generation for object detection and tracking from video

Object detection and tracking is one of the most important components in computer vision applications. To carefully evaluate the performance of detection and tracking algorithms, it is important to develop benchmark data sets. One of the most tedious and error-prone aspects when developing benchmarks, is the generation of the ground truth. This paper presents FAST-GT (FAst Semi-automatic Tool for Ground Truth generation), a new generic framework for the semiautomatic generation of ground truths. FAST-GT reduces the need for manual intervention thus speeding-up the ground-truthing process

Knowledge and Health Care resource allocation: CME/CPD course guidelines-based efficacy

Background: Most Health Care Systems consider Continuing Medical Education a potential tool to improve quality of care and reduce disease management costs. Its efficacy in general practitioners needs to be further explored. Objective: This study assesses the effectiveness of a one-year continuing medical education/continuing professional development course for general practitioners, regarding the improvement in knowledge of ARIA and GINA guidelines and compliance with them in asthma management. Methods: Sixty general practitioners, covering 68,146 inhabitants, were randomly allocated to continuing medical education/continuing professional development (five residential events + four short distance-learning refresher courses over one year) or no training. Participants completed a questionnaire after each continuing medical education event; key questions were repeated at least twice. The Local Health Unit prescription database was used to verify prescription habits (diagnostic investigations and pharmacological therapy) and hospitalizations over one year before and after training. Results: Fourteen general practitioners (46.7%) reached the cut-off of 50% attendance of the training courses. Knowledge improved significantly after training (p&lt;0.001, correct answers to key questions +13%). Training resulted in pharmaceutical cost containment (trained general practitioners +0.5% vs controls +18.8%) and greater attention to diagnosis and monitoring (increase in spirometry +63.4%, p&lt;0.01). Conclusion: This study revealed an encouraging impact of educational events on improvement in general practitioner knowledge of guidelines and daily practice behavioral changes. Long-term studies of large populations are required to assess the effectiveness of education on the behavior of physicians in asthma management, and to establish the best format for educational events

RASW: A run-time adaptive sliding window to improve Viola-Jones object detection

Abstract—In recent years accurate algorithms for detecting objects in images have been developed. Among these algorithms, the object detection scheme proposed by Viola and Jones gained great popularity, especially after the release of high-quality face classifiers by the OpenCV group. However, as any other slidingwindow based object detector, it is affected by a strong increase in the computational cost as the size of the scene grows. Especially in real-time applications, a search strategy based on a sliding window can be computationally too expensive. In this paper, we propose an efficient approach to adapt at run time the sliding window step size in order to speed-up the detection task without compromising the accuracy. We demonstrate the effectiveness of the proposed Run-time Adaptive Sliding Window (RASW) in improving the performance of Viola-Jones object detection by providing better throughput-accuracy tradeoffs. When comparing our approach with the OpenCV face detection implementation, we obtain up to 2.03x speedup in frames per second without any loss in accuracy

sensor augmented pump and down syndrome a new tool in tricky patients

W e read with great interest the paper by Piccini and cols. (1) published in the July issue of this Journal. Some years ago, we published the first report ever (to the best of our knowledge) of successful treatment of a girl with Down syndrome, Hashimoto's thyroiditis and celiac disease with continuous subcutaneous insulin infusion (2). Since then, her glycemic control was kept constant and, most of the time, in the target range (HbA1c in 2009: 7.75 ± 0.21%; HbA1c in 2010: 7.35 ± 0.19%; HbA1c in 2011: 7.42 ± 0.30%). At the end of 2011, sensor-augmented pump was initiated (Animas® VibeTM, West Chester, PA, USA) because of both a quite high glycemic variability and the parents' request, and her HbA1c kept improving (HbA1c in 2012: 7.30 ± 0.20%; HbA1c in 2013: 7.10 ± 0.28%). CSII has been recognized as effective and safe in pediatric (3) and in adult patients (4), not only in the short run, but even after many years (5). In patients with Down syndrome and type 1 diabetes, glycemic control may sometimes be particularly tricky (6,7). In our patient, as well as in the one of Piccini and cols. (1), CSII was a safe and effective way to manage diabetes. For a successful CSII therapy in a patient with Down syndrome, whose mental function may be impaired, the collaboration of a highly motivated and compliant family is essential, as well as a skilled multidisciplinary diabetes team (8). Given all of this, pump increased the patient's and family's flexibility, as we had previously reported (2). The significant improvement in the glycemic control observed, and the high level of acceptance of CSII therapy observed in both our case and in that of Piccini and cols. is worth the effort of the patient's family and of the diabetes team in ensuring that the patient has a flexible life. Perhaps CSII therapy might be taken into account when considering insulin therapy in patients with Down's syndrome

Necrobiosis Lipoidica Diabeticorum

Necrobiosis lipoidica is a rare disorder that usually appears in the lower extremities and it is often related to diabetes mellitus. There are few reported cases of necrobiosis lipoidica in children. We present an interesting case in that the patient developed lesions on the abdomen, which is an unusual location

Epidemiological and molecular approaches for management of a measles outbreak in Liguria, Italy

Since March 2010 a measles outbreak has been occurred in Genoa, Liguria, an administrative Region in Northern Italy. Epi- demiological and molecular data on the outbreak, obtained from the passive mandatory notification system, the laboratory surveillance and an innovative syndrome surveillance system, were investigated. Overall 39 cases were reported in the urban area. Information about demography, vaccination status, hospitalization and geographic distribution of measles cases are available. 19 cases (48.7%) were laboratory-confirmed and were characterized by sequence analysis: 18 strains belonged to genotype D8, so identifying a new measles variant within the Liguria population. Adopted control measures seem to have limited viral circulation. The outbreak allowed to test the efficacy of the 3 surveillance systems active in Liguria, highlighting their advantages and some important limitations. More efforts are needed to collect and integrate any epidemiological and virological available data in order to better describe the local measles transmission dynamics