Efficient Optimal Minimum Error Discrimination of Symmetric Quantum States

This paper deals with the quantum optimal discrimination among mixed quantum states enjoying geometrical uniform symmetry with respect to a reference density operator $\rho_0$. It is well-known that the minimal error probability is given by the positive operator-valued measure (POVM) obtained as a solution of a convex optimization problem, namely a set of operators satisfying geometrical symmetry, with respect to a reference operator $\Pi_0$, and maximizing $\textrm{Tr}(\rho_0 \Pi_0)$. In this paper, by resolving the dual problem, we show that the same result is obtained by minimizing the trace of a semidefinite positive operator $X$ commuting with the symmetry operator and such that $X >= \rho_0$. The new formulation gives a deeper insight into the optimization problem and allows to obtain closed-form analytical solutions, as shown by a simple but not trivial explanatory example. Besides the theoretical interest, the result leads to semidefinite programming solutions of reduced complexity, allowing to extend the numerical performance evaluation to quantum communication systems modeled in Hilbert spaces of large dimension.Comment: 5 pages, 1 Table, no figure

The use of complementary and alternative medicine is frequent in patients with pancreatic disorder

BACKGROUND: Herbal remedies and other complementary and alternative medicine (CAM) are used by 30% of the patients with liver and inflammatory bowel diseases. However, there are no data regarding CAM use in patients with pancreatic disorders, including potential pancreatotoxicity. AIM OF THE STUDY: The aim of the study was to assess the prevalence of CAM use in patients with pancreatic disorders and screen for pancreatotoxicity. MATERIALS AND METHODS: This was a cross-sectional survey of consecutive outpatients seen at a Pancreas Center. Data were collected in a specific questionnaire. Descriptive statistics were used to analyze the prevalence and the patterns of CAM use. Characteristics associated with CAM use were analyzed by appropriate statistics. RESULTS: Of 108 patients (52% male; mean age, 65±13 years), 47 (43.5%) used CAM. The use of CAM was more frequent among patients with previous acute pancreatitis (47%). Reported reasons for the use of CAM were to help standard therapies and for an overall better feeling. About 61% of the patients reported advantages with treatment. As compared with nonusers, CAM users were more often female (55% vs. 42%), with a higher school degree (43% vs. 36%), more frequently performing physical activity (51% vs. 41%), and reporting anxiety (45% vs. 31%). However, none of these differences were statistically significant. Three patients with previous acute pancreatitis reported the use of Serenoa repens that is potentially pancreatotoxic. DISCUSSION: The rate of CAM use in patients with pancreatic disorders is similar to those reported for other digestive diseases. CAM use seems to be more frequent in women with a higher education level and a "healthier lifestyle." Patients might not be aware of the potential pancreatotoxicity of CAM, which should be carefully considered by physician

Titanium versus absorbable tacks comparative study (TACS): a multicenter, non-inferiority prospective evaluation during laparoscopic repair of ventral and incisional hernia: study protocol for randomized controlled trial

BACKGROUND: Laparoscopic repair of ventral and incisional hernias has gained popularity since many studies have reported encouraging results in terms of outcomee and recurrence. Choice of mesh and fixation methods are considered crucial issues in preventing recurrences and complications. Lightweight meshes are considered the first choice due to their biomechanical properties and the ability to integrate into the abdominal wall. Titanium helicoidal tacks still represent the "gold standard" for mesh fixation, even if they have been suggested to be involved in the genesis of post-operative pain and complications. Recently, absorbable tacks have been introduced, under the hypothesis that there will be no need to maintain a permanent fixation device after mesh integration. Nevertheless, there is no evidence that absorbable tacks may guarantee the same results as titanium tacks in terms of strength of fixation and recurrence rates. The primary end point of the present trial is to test the hypothesis that absorbable tacks are non-inferior to titanium tacks in laparoscopic incisional and ventral hernia repair (LIVHR) by lightweight polypropylene mesh, in terms of recurrence rates at 3-year follow-up. Surgical complications, post-operative stay, comfort and pain are secondary end points to be assessed. METHODS/DESIGN: Two hundred and twenty patients with ventral hernia will be randomized into 2 groups: Group A (110) patients will be submitted to LIVHR by lightweight polypropylene mesh fixed by titanium tacks; Group B (110) patients will be submitted to LIVHR by lightweight polypropylene mesh fixed by absorbable tacks. DISCUSSION: A few retrospective studies have reported similar results when comparing absorbable versus non-absorbable tacks in terms of intraoperative and early post-operative outcomes. These studies have the pitfalls to be retrospective evaluation of small series of patients, and the reported results still need to be validated by larger series and prospective studies. The aim of the present trial is to investigate and test the non-inferiority of absorbable versus non-absorbable tacks in terms of hernia recurrence rates, in order to assess whether the use of absorbable tacks may achieve the same results as non-absorbable tacks in mid-term and long-term settings

Modulation of PKM alternative splicing by PTBP1 promotes gemcitabine resistance in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and incurable disease. Poor prognosis is due to multiple reasons, including acquisition of resistance to gemcitabine, the first-line chemotherapeutic approach. Thus, there is a strong need for novel therapies, targeting more directly the molecular aberrations of this disease. We found that chronic exposure of PDAC cells to gemcitabine selected a subpopulation of cells that are drug-resistant (DR-PDAC cells). Importantly, alternative splicing (AS) of the pyruvate kinase gene (PKM) was differentially modulated in DR-PDAC cells, resulting in promotion of the cancer-related PKM2 isoform, whose high expression also correlated with shorter recurrence-free survival in PDAC patients. Switching PKM splicing by antisense oligonucleotides to favor the alternative PKM1 variant rescued sensitivity of DR-PDAC cells to gemcitabine and cisplatin, suggesting that PKM2 expression is required to withstand drug-induced genotoxic stress. Mechanistically, upregulation of the polypyrimidine-tract binding protein (PTBP1), a key modulator of PKM splicing, correlated with PKM2 expression in DR-PDAC cell lines. PTBP1 was recruited more efficiently to PKM pre-mRNA in DR- than in parental PDAC cells. Accordingly, knockdown of PTBP1 in DR-PDAC cells reduced its recruitment to the PKM pre-mRNA, promoted splicing of the PKM1 variant and abolished drug resistance. Thus, chronic exposure to gemcitabine leads to upregulation of PTBP1 and modulation of PKM AS in PDAC cells, conferring resistance to the drug. These findings point to PKM2 and PTBP1 as new potential therapeutic targets to improve response of PDAC to chemotherapy.Oncogene advance online publication, 3 August 2015; doi:10.1038/onc.2015.270

Deviancy as social problem: the answers of psychology [La devianza come problema sociale: le risposte della psicologia]

Scopo: Il comportamento deviante è tale in quanto infrange una serie di norme sociali più o meno consapevolmente riconosciute dai più. Scopo dello studio è descrivere e analizzare le caratteristiche di tale comportamento. Materiali e metodi: Si è tentato di individuare le cause della devianza in un rapporto complesso con le figure genitoriali, con l’Autorità generalmente intesa, con i Gruppi sociali che detengono il Potere ecc. valutando teorie a partire dalla psicoanalisi fino alla più recente sociologia. Risultati e conclusioni: Pur ammettendo la possibile presenza di un certo tipo di disturbi di personalità nella struttura psichica del deviante, non si può non puntare l’attenzione sulle metodiche che le varie società utilizzano per l’integrazione dei cittadini, soprattutto nelle agenzie fondamentali preposte all’educazione del minore: famiglia e scuola. Metodi didattici all’avanguardia, che senz’altro forniscano al discente griglie comportamentali e regole di condotta, che però al tempo stesso non dimentichino la dimensione fondamentale del gioco, dello svago e della ricerca personale, sono da incentivare fortemente. Con la consapevolezza che, nel bambino e nell’adolescente, “trasgredire” determinate regole con coscienza critica e capacità di discernimento, aiuta a formare un cittadino consapevole, responsabile e rivolto all’innovazione di paradigmi comportamentali spesso datati e inadeguati, anche se comunemente accettati con passività dai più.Scope: Deviant behaviour is the one that breaks those rules most people regard as social. The study describes and analyzes the characteristics of this behavior. Materials and Methods: Psychology and also the latest Sociological Theories have tried to find the causes of deviance in the complex and difficult relationship with parental figures, with Authority in general, with the Part of society that holds Power etc. Results and Conclusions: While admitting the possible presence of some kinds of personality disorders in the deviant’s psychic structure we cannot avoid focusing on the methodologies used for the integration of citizen above all in those fundamental units in charge of minors’ education: Family and School. Advanced teaching methods which can provide behavioural models and rules are to be strongly encouraged, without forgetting the essential dimension of playing, of research and also of individual personal growth. Nevertheless we must be aware that ‘breaking’ the rules with a sense of responsibility and discernment helps a young man to grow informed and responsible, able to renew his behavioural patterns often dated and deficient albeit mainly passively accepted

Systematic uncertainties in the determination of the local dark matter density

A precise determination of the local dark matter density and an accurate control over the corresponding uncertainties are of paramount importance for Dark Matter (DM) searches. Using very recent high-resolution numerical simulations of a Milky Way like object, we study the systematic uncertainties that affect the determination of the local dark matter density based on dynamical measurements in the Galaxy. In particular, extracting from the simulation with baryons the orientation of the Galactic stellar disk with respect to the DM distribution, we study the DM density for an observer located at $\sim$8 kpc from the Galactic center {\it on the stellar disk}, $\rho_0$. This quantity is found to be always larger than the average density in a spherical shell of same radius $\bar{\rho}_0$, which is the quantity inferred from dynamical measurements in the Galaxy, and to vary in the range $\rho_0/\bar{\rho}_0=1.01-1.41$. This suggests that the actual dark matter density in the solar neighbourhood is on average 21\% larger than the value inferred from most dynamical measurements, and that the associated systematic errors are larger than the statistical errors recently discussed in the literature.Comment: 6 pages, 3 figures, matches published versio

Time-Dependent Models for Dark Matter at the Galactic Center

The prospects of indirect detection of dark matter at the galactic center depend sensitively on the mass profile within the inner parsec. We calculate the distribution of dark matter on sub-parsec scales by integrating the time-dependent Fokker-Planck equation, including the effects of self-annihilations, scattering of dark matter particles by stars, and capture in the supermassive black hole. We consider a variety of initial dark matter distributions, including models with very high densities ("spikes") near the black hole, and models with "adiabatic compression" of the baryons. The annihilation signal after 10 Gyr is found to be substantially reduced from its initial value, but in dark matter models with an initial spike, order-of-magnitude enhancements can persist compared with the rate in spike-free models, with important implications for indirect dark matter searches with GLAST and Air Cherenkov Telescopes like HESS and CANGAROO.Comment: Four page

Astrophysical limitations to the identification of dark matter: indirect neutrino signals vis-a-vis direct detection recoil rates

A convincing identification of dark matter (DM) particles can probably be achieved only through a combined analysis of different detections strategies, which provides an effective way of removing degeneracies in the parameter space of DM models. In practice, however, this program is made complicated by the fact that different strategies depend on different physical quantities, or on the same quantities but in a different way, making the treatment of systematic errors rather tricky. We discuss here the uncertainties on the recoil rate in direct detection experiments and on the muon rate induced by neutrinos from dark matter annihilations in the Sun, and we show that, contrarily to the local DM density or overall cross section scale, irreducible astrophysical uncertainties affect the two rates in a different fashion, therefore limiting our ability to reconstruct the parameters of the dark matter particle. By varying within their respective errors astrophysical parameters such as the escape velocity and the velocity dispersion of dark matter particles, we show that the uncertainty on the relative strength of the neutrino and direct-detection signal is as large as a factor of two for typical values of the parameters, but can be even larger in some circumstances.Comment: 12 pages, 3 figures. Improved presentation and Fig.3; clarifications, references and an appendix added; conclusions unchanged. Matches version published in PR

The WIMP Forest: Indirect Detection of a Chiral Square

The spectrum of photons arising from WIMP annihilation carries a detailed imprint of the structure of the dark sector. In particular, loop-level annihilations into a photon and another boson can in principle lead to a series of lines (a WIMP forest) at energies up to the WIMP mass. A specific model which illustrates this feature nicely is a theory of two universal extra dimensions compactified on a chiral square. Aside from the continuum emission, which is a generic prediction of most dark matter candidates, we find a "forest" of prominent annihilation lines that, after convolution with the angular resolution of current experiments, leads to a distinctive (2-bump plus continuum) spectrum, which may be visible in the near future with the Fermi Gamma-Ray Space Telescope (formerly known as GLAST).Comment: 11 pages, 4 figure