Numerical Stochastic Perturbation Theory in the Schr\"odinger Functional

The Schr\"odinger functional (SF) is a powerful and widely used tool for the treatment of a variety of problems in renormalization and related areas. Albeit offering many conceptual advantages, one major downside of the SF scheme is the fact that perturbative calculations quickly become cumbersome with the inclusion of higher orders in the gauge coupling and hence the use of an automated perturbation theory framework is desirable. We present the implementation of the SF in numerical stochastic perturbation theory (NSPT) and compare first results for the running coupling at two loops in pure SU(3) Yang-Mills theory with the literature.Comment: 7 pages, 2 figures, 2 tables, presented at the 31st International Symposium on Lattice Field Theory - LATTICE 2013 July 29 - August 3, 2013 Mainz, German

Optical spectra of molecular aggregates and crystals: testing approximation schemes

The interplay between exciton delocalization and molecular vibrations profoundly affects optical spectra of molecular aggregates and crystals. The exciton motion occurs on a similar timescale as molecular vibrations, leading to a complex and intrinsically non-adiabatic problem that has been handled over the years introducing several approximation schemes. Here we discuss systems where intermolecular distances are large enough so that only electrostatic intermolecular interactions enter into play and can be treated in the dipolar approximation. Moreover, we only account for interactions between transition dipole moments, as relevant to symmetric molecules, with negligible permanent (multi)polar moments in the ground and low-lying excited states. Translational symmetry is fully exploited to obtain numerically exact solutions of the relevant Hamiltonian for systems of comparatively large size. This offers a unique opportunity to assess the reliability of different approximation schemes. The so-called Heitler–London approximation, only accounting for the effects of intermolecular interactions among degenerate electronic states, leads to the celebrated exciton model, widely adopted to describe optical spectra of molecular aggregates and crystals. We demonstrate that, mainly due to a cancellation of errors, the exciton model approximates well the position of exciton bands and reasonably well the bandshapes, but it fails to predict spectral intensities, leading to underestimated intensities in J-aggregates and overestimated intensities in H-aggregates. This general result is validated against an exact sum-rule. Finally, we address the validity of several approximation schemes adopted to reduce the dimension of the vibrational basis

Characterization of the Morning Transition over the Gentle Slope of a Semi-Isolated Massif

This paper investigates the surface-layer processes associated with the morning transition from nighttime downslope winds to daytime upslope winds over a semi-isolated massif. It provides an insight into the characteristics of the transition and its connection with the processes controlling the erosion of the temperature inversion at the foot of the slope. First, a criterion for the identification of days prone to the development of purely thermally driven slope winds is proposed and adopted to select five representative case studies. Then, the mechanisms leading to different patterns of erosion of the nocturnal temperature inversion at the foot of the slope are analyzed. Three main patterns of erosion are identified: the first is connected to the growth of the convective boundary layer at the surface, the second is connected to the descent of the inversion top, and the third is a combination of the previous two. The first pattern is linked to the initiation of the morning transition through surface heating, and the second pattern is connected to the top-down dilution mechanism and so to mixing with the above air. The discriminating factor in the determination of the erosion pattern is identified in the partitioning of turbulent sensible heat flux at the surface

Black Hole - Neutron Star mergers: using kilonovae to constrain the equation of state

The merging of a binary system involving two neutron stars (NSs), or a black hole (BH) and a NS, often results in the emission of an electromagnetic (EM) transient. One component of this EM transient is the epic explosion known as a kilonova (KN). The characteristics of the KN emission can be used to probe the equation of state (EoS) of NS matter responsible for its formation. We predict KN light curves from computationally simulated BH-NS mergers, by using the 3D radiative transfer code \texttt{POSSIS}. We investigate two EoSs spanning most of the allowed range of the mass-radius diagram. We also consider a soft EoS compatible with the observational data within the so-called 2-families scenario in which hadronic stars coexist with strange stars. Computed results show that the 2-families scenario, characterized by a soft EoS, should not produce a KN unless the mass of the binary components are small ($M_{\rm BH} \leq 6M_{\odot}$, $M_{\rm NS} \leq 1.4M_{\odot}$) and the BH is rapidly spinning ($\chi_{\rm BH} \geq 0.3$). In contrast, a strong KN signal potentially observable from future surveys (e.g. VRO/LSST) is produced in the 1-family scenario for a wider region of the parameter space, and even for non-rotating BHs ($\chi_{\rm BH} = 0$) when $M_{\rm BH} = 4M_{\odot}$ and $M_{\rm NS} = 1.2M_{\odot}$. We also provide a fit that allows for the calculation of the unbound mass from the observed KN magnitude, without running timely and costly radiative transfer simulations. Findings presented in this paper will be used to interpret light curves anticipated during the fourth observing run (O4), of the advanced LIGO, advanced Virgo and KAGRA interferometers and thus to constrain the EoS of NS matter.Comment: 14 pages, 16 figures, 2 table

Successful endovascular embolization of a giant splenic artery pseudoaneurysm secondary to a huge pancreatic pseudocyst with concomitant spleen invasion

Pseudoaneurysms of the pancreatic and peripancreatic arteries is a well-known complication of chronic or necrotizing pancreatitis due to proteolytic enzymatic digestion of the arterial wall. A major part of peripancreatic pseudoaneurysms involve the splenic artery, but any peripancreatic artery may be involved and bleed. They are potentially life threatening for patients, due to spontaneous intraperitoneal rupture, rupture and fistulization into the surrounding organs, or fistulization into the pancreatic duct. Small ones are usually asymptomatic and are often diagnosed incidentally, while giant (> 5 cm) aneurysms and pseudoaneurysms are symptomatic and may be detected as a pulsatile mass in the upper-left quadrant or epigastrium. Imaging plays a key role in the identification of splenic artery aneurysms and pseudoaneurysms, while angiography still represents the gold standard for the diagnosis, although nowadays it plays a prominent role in treatment. Treatment of splenic artery pseudoaneurysms is mandatory because of the high probability of rupture, with a mortality rate of up to 90%. The gold standard treatment is represented by surgery, with a mortality rate between 16% and 50%. In recent years the endovascular approach has proven to be an effective alternative treatment for splenic artery pseudoaneurysms, and it is currently the method of choice. In this article, we present the case of a ant pseudoaneurysm of the splenic artery due to huge pseudocysts in a young alcoholic patient with recurrent and chronic pancreatitis, complicated by fistulization and invasion of spleen parenchyma and arteriovenous fistula

Influence of Myeloperoxidase Levels on Periodontal Disease: An Applied Clinical Study

In this trial, we evaluated the influence on plasma and salivary myeloperoxidase (MPO) levels of periodontal health, coronary heart disease (CHD), periodontitis, or both periodontitis and CHD. Clinical and periodontal parameters were collected from periodontitis patients (n = 31), CHD patients (n = 31), patients with both periodontitis and CHD (n = 31), and from healthy patients (n = 31) together with saliva and plasma samples. The median concentrations of salivary and plasma MPO were statistically higher in the CHD patients [plasma: 26.2 (18.2–34.4) ng/mg; saliva 83.2 (77.4–101.5) ng/mL, p < 0.01] and in the periodontitis plus CHD patients [plasma: 27.8 (22.5–35.7) ng/mg; saliva 85.6 (76.5–106.7) ng/mL, p < 0.001] with respect to periodontitis and control patients. Through a univariate regression analysis, c-reactive protein (CRP) and CHD (both p < 0.001) and periodontitis (p = 0.024) were statistically correlated with MPO in plasma. The multivariate regression analysis demonstrated that only CRP was statistically the predictor of MPO in plasma (p < 0.001). The multivariate regression analysis in saliva demonstrated that, regarding MPO levels the only predictors were CRP (p < 0.001) and total cholesterol (p = 0.035). The present study evidenced that subjects with CHD and periodontitis plus CHD had higher plasma and salivary levels of MPO compared to subjects with periodontitis and healthy controls

Some like it hot: Thermal preference of the groundwater amphipod Niphargus longicaudatus (Costa, 1851) and climate change implications

Groundwater is a crucial resource for humans and the environment, but its global human demand currently exceeds available volumes by 3.5 times. Climate change is expected to exacerbate this situation by increasing the frequency of droughts along with human impacts on groundwater ecosystems. Despite prior research on the quantitative effects of climate change on groundwater, the direct impacts on groundwater biodiversity, especially obligate groundwater species, remain largely unexplored. Therefore, investigating the potential impacts of climate change, including groundwater temperature changes, is crucial for the survival of obligate groundwater species. This study aimed to determine the thermal niche breadth of the crustacean amphipod species Niphargus longicaudatus by using the chronic method. We found that N. longicaudatus has a wide thermal niche with a natural performance range of 7–9 °C, which corresponds to the thermal regime this species experiences within its distribution range in Italy. The observed range of preferred temperature (PT) was different from the mean annual temperature of the sites from which the species has been collected, challenging the idea that groundwater species are only adapted to narrow temperature ranges. Considering the significant threats of climate change to groundwater ecosystems, these findings provide crucial information for the conservation of obligate groundwater species, suggesting that some of them may be more resilient to temperature changes than previously thought. Understanding the fundamental thermal niche of these species can inform conservation efforts and management strategies to protect groundwater ecosystems and their communities.info:eu-repo/semantics/publishedVersio