The order of the Roberge-Weiss endpoint (finite size transition) in QCD

We consider the endpoint of the Roberge-Weiss (RW) first order transition line present for imaginary baryon chemical potentials. We remark that it coincides with the finite size transition relevant in the context of large $N_c$ QCD and study its order in the theory with two degenerate flavors. The RW endpoint is first order in the limit of large and small quark masses, while it weakens for intermediate masses where it is likely in the Ising 3d universality class. Phenomenological implications and further speculations about the QCD phase diagram are discussed.Comment: 5 pages, 8 figures. Version accepted for publication in Physical Review D (R

Untenable nonstationarity: An assessment of the fitness for purpose of trend tests in hydrology

The detection and attribution of long-term patterns in hydrological time series have been important research topics for decades. A significant portion of the literature regards such patterns as ‘deterministic components’ or ‘trends’ even though the complexity of hydrological systems does not allow easy deterministic explanations and attributions. Consequently, trend estimation techniques have been developed to make and justify statements about tendencies in the historical data, which are often used to predict future events. Testing trend hypothesis on observed time series is widespread in the hydro-meteorological literature mainly due to the interest in detecting consequences of human activities on the hydrological cycle. This analysis usually relies on the application of some null hypothesis significance tests (NHSTs) for slowly-varying and/or abrupt changes, such as Mann-Kendall, Pettitt, or similar, to summary statistics of hydrological time series (e.g., annual averages, maxima, minima, etc.). However, the reliability of this application has seldom been explored in detail. This paper discusses misuse, misinterpretation, and logical flaws of NHST for trends in the analysis of hydrological data from three different points of view: historic-logical, semantic-epistemological, and practical. Based on a review of NHST rationale, and basic statistical definitions of stationarity, nonstationarity, and ergodicity, we show that even if the empirical estimation of trends in hydrological time series is always feasible from a numerical point of view, it is uninformative and does not allow the inference of nonstationarity without assuming a priori additional information on the underlying stochastic process, according to deductive reasoning. This prevents the use of trend NHST outcomes to support nonstationary frequency analysis and modeling. We also show that the correlation structures characterizing hydrological time series might easily be underestimated, further compromising the attempt to draw conclusions about trends spanning the period of records. Moreover, even though adjusting procedures accounting for correlation have been developed, some of them are insufficient or are applied only to some tests, while some others are theoretically flawed but still widely applied. In particular, using 250 unimpacted stream flow time series across the conterminous United States (CONUS), we show that the test results can dramatically change if the sequences of annual values are reproduced starting from daily stream flow records, whose larger sizes enable a more reliable assessment of the correlation structures

Photon localization versus population trapping in a coupled-cavity array

We consider a coupled-cavity array (CCA), where one cavity interacts with a two-level atom under the rotating-wave approximation. We investigate the excitation transport dynamics across the array, which arises in the atom's emission process into the CCA vacuum. Due to the known formation of atom-photon bound states, partial field localization and atomic population trapping in general take place. We study the functional dependance on the coupling strength of these two phenomena and show that the threshold values beyond which they become significant are different. As the coupling strength grows from zero, field localization is exhibited first.Comment: 9 pages, 5 figures. Replaced one plot in Fig.

Remarks on the genus Severinia Finot 1902 and a description of two new genera of Oxyothespinae (Insecta Mantodea)

A resolution of the confusion surrounding the genus Severinia Finot 1902 is proposed. It is suggested that the males, presently attributed to Severinia lemoroi (Finot 1902), be transferred to the new genus, Paraseverinia, and that the genus Amblythespis Chopard 1943 be considered a synonym of Severinia. In addition, a description is provided of a new genus Somalithespis (Oxyothespini), characterised by the presence of a pre-apical lobe on the mid femurs, a character found for the first time among the tribe of Oxyothespini

A review of the genus Popa Stål 1856 (Insecta Mantodea)

It is suggested that Mantis undata Fabricius 1793 does not belong to the genus Popa Stal 1856 as believed until now, but to the Indian genus Ambivia Stal 1877 (n. comb.). The systematic position of the species of Popa is re-examined and a single species, Popa spurca Stal 1856 (= P. undata auct. nec Fabricius) is recognised. The species is differentiated into two subspecies, one being Popa spurca spurca Stal 1856 (= P. stuhlmanni Rehn 1914, P. batesi Sauss. & Zehnt. 1895) (n. syn.) widespread throughout all Africa south of the Sahara, except in the east which is populated by the other subspecies, P. spurca crassa (Giglio-Tos 1917)

QCD at High Temperature : Results from Lattice Simulations with an Imaginary mu

We summarize our results on the phase diagram of QCD with emphasis on the high temperature regime. For $T \ge 1.5 T_c$ the results are compatible with a free field behavior, while for $T \simeq 1.1 T_c$ this is not the case, clearly exposing the strongly interacting nature of QCD in this regionComment: 7 pages, 2 figures; To appear in the proceedings of QCD@Work 2005,International Workshop on Quantum Chromodynamics, Conversano, Bari, Italy, 16-20 Jun 200

Terapia della eiaculazione precoce

L’eiaculazione precoce (EP) è il più frequente disturbo sessuale riferito nel maschio, ed è a tutti gli effetti un sintomo auto-identificato, auto-riportato e auto-valutato da chi ne soffre. Attualmente la International Society for Sexual Medicine ha definito l’EP come un’eiaculazione che avviene sempre o quasi sempre entro 1 minuto (EP life-long) o 3 minuti (EP acquisita) dalla penetrazione, con incapacità di ritardare l’eiaculazione e conseguenze negative sul piano personale come frustrazione, sofferenza e/o condotte di rifiuto dell’atto sessuale [1]. Dal punto di vista tassonomico, possiamo riconoscere forme assolute e relazionali, organiche e psicogene (o meglio non-organiche), acquisite o life-long. Il corretto approccio all’EP consiste nel non considerarla esclusivamente una patologia a sé stante, ma un possibile sintomo di una condizione latent

Direction of arrival estimation using a cluster of beams in a cone-shaped digital array radar'

In this paper some potential system and processing advantages of conformal cone shaped digital array radar have been investigated, in particular in relation to potential alternative approaches for angle estimation with respect to the traditional monopulse. First of all potential benefit in terms of reduction of the number of radiating elements is shown when a conical array is considered with respect to a traditional system formed by four planar arrays, if a coverage of 360° must be assured. Secondly, having in mind an innovative digital array system where the received signals are analog to digital converted at element level and the corresponding data are possibly transferred to a central elaboration unit, an alternative approach is investigated for angular estimation. In this paper we derive the theoretical expression of the Cramer Rao Lower Bound for elevation angle estimation using a cluster of beams; we compare the limit performance of the traditional approach for angle estimation based on Sum and Difference beams with the approach based on a crowded cluster of RX beams properly spaced. The approaches show approximately equivalent performance, making the second particularly interesting for those situations where monopulse is known to experience performance degradation, as low elevation angle estimation; in this particular case an example of cluster design is shown, where the direct signal from a low altitude target must compete with a specular multipath

Sperm glyceraldehyde 3-phosphate dehydrogenase gene expression in asthenozoospermic spermatozoa

It has been suggested that the energy required for sperm motility is produced by oxidative phosphorylation while glycolysis seems to be an important source for ATP transmission along the flagellum. Some studies have investigated the chemical and kinetic properties of the enzyme glyceraldehyde 3‐phosphate dehydrogenase to identify any changes in the regulation of glycolysis and sperm motility. In contrast, there are few studies analyzing the genetic basis of hypokinesis. For this reason, we investigated the glyceraldehyde 3‐phosphate dehydrogenase gene in human sperm to evaluate whether asthenozoospermia was correlated with any changes in its expression. Semen examination and glyceraldehyde 3‐phosphate dehydrogenase gene expression studies were carried out on 116 semen samples divided into two groups – Group A consisted of 58 normokinetic samples and Group B of 58 hypokinetic samples. Total RNA was extracted from spermatozoa, and real‐time PCR quantification of mRNA was carried out using specific primers and probes. The expression profiles for the Groups A and B were very similar. The mean delta Ct was as follows – Group A, 5.79 ± 1.04; Group B, 5.47 ± 1.27. Our study shows that in human sperm, there is no difference in glyceraldehyde 3‐phosphate dehydrogenase gene expression between samples with impaired motility and samples with normal kinetics. We believe that this study could help in the understanding of the molecular mechanisms of sperm kinetics, suggesting that hypomotility may be due to a possible posttranscriptional impairment of the control mechanism, such as mRNA splicing, or to posttranslational changes