Elastic waves in a soft electrically conducting solid in a strong magnetic field

Shear wave motion of a soft, electrically-conducting solid in the presence of a strong magnetic field excites eddy currents in the solid. These, in turn, give rise to Lorentz forces that resist the wave motion. We derive a mathematical model for linear elastic wave propagation in a soft electrically conducting solid in the presence of a strong magnetic field. The model reduces to an effective anisotropic dissipation term resembling an anisotropic viscous foundation. The application to magnetic resonance elastography, which uses strong magnetic fields to measure shear wave speed in soft tissues for diagnostic purposes, is considered

Shear waves in prestrained poroelastic media

Shear wave elastography measures shear wave speed in soft tissues for diagnostic purposes. In [1], shear wave speed was shown to depend on prestrain, but not necessarily prestress, in a perfused canine liver. We model this phenomenon by examining incremental waves in a pressurized poroelastic medium with incompressible phases. The analysis suggests novel restrictions on the strain energy functions for soft tissues

Towards the mechanical characterization of abdominal wall by inverse analysis

The aim of this study is to characterize the passive mechanical behaviour of abdominal wall in vivo in an animal model using only external cameras and numerical analysis. The main objective lies in defining a methodology that provides in vivo information of a specific patient without altering mechanical properties. It is demonstrated in the mechanical study of abdomen for hernia purposes. Mechanical tests consisted on pneumoperitoneum tests performed on New Zealand rabbits, where inner pressure was varied from 0 mmHg to 12 mmHg. Changes in the external abdominal surface were recorded and several points were tracked. Based on their coordinates we reconstructed a 3D finite element model of the abdominal wall, considering an incompressible hyperelastic material model defined by two parameters. The spatial distributions of these parameters (shear modulus and non linear parameter) were calculated by inverse analysis, using two different types of regularization: Total Variation Diminishing (TVD) and Tikhonov (H1). After solving the inverse problem, the distribution of the material parameters were obtained along the abdominal surface. Accuracy of the results was evaluated for the last level of pressure. Results revealed a higher value of the shear modulus in a wide stripe along the craneo-caudal direction, associated with the presence of linea alba in conjunction with fascias and rectus abdominis. Non linear parameter distribution was smoother and the location of higher values varied with the regularization type. Both regularizations proved to yield in an accurate predicted displacement field, but H1 obtained a smoother material parameter distribution while TVD included some discontinuities. The methodology here presented was able to characterize in vivo the passive non linear mechanical response of the abdominal wall

Somatic disorders and antidepressant use in suicides: A population-based study from the Friuli Venezia Giulia region, Italy, 2003-2013

Background: Many somatic disorders are complicated by depression and increase the risk of suicide. Little is known about whether antidepressants might reduce the suicidal risk in patients with somatic disorders. Methods: Data on diagnoses and antidepressant prescriptions were derived from the Social and Health Information System of the Friuli Venezia Giulia Region. Cases were all suicides that occurred in the region during the years 2003\u20132013 and were sex- and age-matched to controls from the general population. Conditional logistic regression analysis was used to assess the association between suicide and somatic disorders. Results: The suicide rate in Friuli Venezia Giulia decreased from 11.3 to 10.7 per 100,000 inhabitants during the years 2003\u20132013, however patients with somatic disorder had a three times increased risk of suicide. Elderly somatic patients' suicide risk was twice as high as younger patients. The risk increased from 2.6 to 9.8 times as the number of comorbid disorders increased from 1 to 4 and over. Although no significant risk of suicide in patients with somatic disorders was found when patients were adherent to antidepressants, only 11.5% of the suicides was adherent in the year prior to death. Conclusions: Medical illnesses and underlying depressive symptoms may have a synergy effect on the risk of suicide, particularly in older patients and in patients with multiple morbidities. Since medically ill subjects adherent to antidepressants did not showa significant risk of suicide, early identification and adequate treatment of depression in somatic patients should be considered in order to prevent suicide

Rhodolith beds heterogeneity along the apulian continental shelf (Mediterranean sea)

Rhodolith beds represent a key habitat worldwide, from tropical to polar ecosystems. Despite this habitat is considered a hotspot of biodiversity, providing a suite of ecosystem goods and services, still scarce quantitative information is available thus far about rhodolith beds occurrence and ecological role, especially in the Mediterranean Sea. This study reports the composition and patterns of distribution of rhodolith assemblages found in four study areas along ca. 860 km of coast in the Central Mediterranean Sea. These rhodolith beds were studied for the first time and significant differences at all spatial scales have been highlighted, documenting the high variability of this habitat. Rhodolith species composition, morphology and distribution have been discussed considering the potential role of environmental factors in driving these patterns. The need for improving their protection is discussed to complement present conservation and management initiatives, particularly in the frame of the EU Marine Strategy Framework Directive

Charge-carrier complexes in monolayer semiconductors

The photoluminescence (PL) spectra of monolayer (1L) semiconductors feature peaks ascribed to different charge-carrier complexes. We perform diffusion quantum Monte Carlo simulations of the binding energies of these complexes and examine their response to electric and magnetic fields. We focus on quintons (charged biexcitons), since they are the largest free charge-carrier complexes in transition-metal dichalcogenides (TMDs). We examine the accuracy of the Rytova-Keldysh interaction potential between charges by comparing the binding energies of charge-carrier complexes in 1L-TMDs with results obtained using $\textit{ab initio}$ interaction potentials. Magnetic fields$<8$T change the binding energies (BEs) by$\sim0.2$ meV,T$^{-1}$, in agreement with experiments, with the BE variations of different complexes being very similar. Our results will help identify charge complexes in the PL spectra of 1L-semiconductor

Asthma Symptoms, Lung Function, and Markers of Oxidative Stress and Inflammation in Children Exposed to Oil Refinery Pollution

none12mixedF. Rusconi; CATELAN, DOLORES; G. Accetta; M. Peluso; R. Pistelli; F. Barbone; E. Di Felice; A. Munnia; P. Murgia; L. Paladini; A. Serci; BIGGERI, ANNIBALEF., Rusconi; Catelan, Dolores; G., Accetta; M., Peluso; R., Pistelli; F., Barbone; E., Di Felice; A., Munnia; P., Murgia; L., Paladini; A., Serci; Biggeri, Annibal

Exposure to active and passive smoking during pregnancy and severe small for gestational age at term

Objective. The objective of this study was to assess the relationship between active smoking as well as environmental tobacco smoke (ETS) exposure and severe small for gestational age (SGA) at term in a sample of pregnant Italian women. Methods. A case-control study was conducted in nine cities in Italy between October 1999 and September 2000. Cases of severe SGA were singleton, live born, at term children with a birth weight5th percentile for gestational age. Controls (10:1 to cases) were enrolled from among singleton at term births that occurred in the same hospitals one or two days after delivery of the case, with a birth weight10th percentile for gestational age. A total of 84 cases of severe SGA and 858 controls were analyzed. A self-administered questionnaire was used to assess active smoking and ETS exposure, as well as potential confounders. Results. Multivariate logistic regression analysis showed a relationship between active smoking during pregnancy and severe SGA (adjusted odds ratio (OR) 2.10, 95% confidence interval (CI) 1.13-3.68). ETS exposure was associated with severe SGA (adjusted OR 2.51, 95% CI 1.59-3.95) with a dose-response relationship to the number of smokers in the home