Quasi-static and dynamic photon bubbles in cold atom clouds

Turbulent radiation flow is ubiquitous in many physical systems where light–matter interaction becomes relevant. Photon bubble instabilities, in particular, have been identified as a possible source of turbulent radiation transport in astrophysical objects such as massive stars and black hole accretion disks. Here, we report on the experimental observation of a photon bubble instability in cold atomic gases, in the presence of multiple scattering of light. Two different regimes are identified, namely, the growth and formation of quasi-static structures of depleted atom density and increased photon number, akin to photon bubbles in astrophysical objects, and the destabilisation of these structures in a second regime of photon bubble turbulence. A two-fluid theory is developed to model the coupled atom–photon gas and to describe both the saturation of the instability in the regime of quasi-static bubbles and the low-frequency turbulent phase associated with the growth and collapse of photon bubbles inside the atomic sample. We also employ statistical dimensionality reduction techniques to describe the low-dimensional nature of the turbulent regime. The experimental results reported here, along with the theoretical model we have developed, may shed light on analogue photon bubble instabilities in astrophysical scenarios. Our findings are consistent with recent analyses based on spatially resolved pump–probe measurements.info:eu-repo/semantics/publishedVersio

Comparison between "In-bore" MRI guided prostate biopsy and standard ultrasound guided biopsy in the patient with suspicious prostate cancer: Preliminary results.

OBJECTIVES: To evaluate the detection rate of prostate cancer (PCa) in patients who underwent to "in bore" Magnetic Resonance Imaging -guided prostate (MRI-GB) biopsy compared to the standard transrectal ultrasound guided prostate biopsy (TRUS-GB). MATERIALS AND METHODS: Between January 2017 and March 2015 a cohort of 39 consecutive patients was prospectively enrolled. All the patients underwent an "in-bore" guided MRI prostatic biopsy and subsequently ultrasound-guided standard prostate biopsy. RESULTS: Median age of patients was 65.5 years (SD \ub1 6.6), median total PSA serum level was 6.6 ng/ml (SD \ub1 4.1), median prostate total volume was 51.1 cc (SD \ub1 26.7). Thirty of 39 (76.9%) were biopsy-na\uefve patients while 7/39 (17.9%) had at least one previous negative random TRUS-GB; 2/39 (5.1%) patients were already diagnosed as PCa and were on active surveillance. In 18/39 (53.8%) men Pca was diagnosed; as regards the MRI-GB results related to the PI-RADS score, biopsies of PIRADS 3 lesions were positive in 5/18 cases (27.8%), while the number of positive cases of PI-RADS 4 and 5 lesions was 7/11 (63.6%) and 6/10 (60%)respectively. At the histological examination, 4/39 (10.3%) had a PCa ISUP grade group 1, 11/39 (28.2%) had a ISUP 2, 6/39(15.4%) had a ISUP grade group 3 and 2/39 (5.1%) had a ISUP 4-5. CONCLUSIONS: MRI-GB represents a promising technique that may offer some of advantages compared to standard systematic TRUSGB. Our preliminary experience in MRI-GB resulted safe and feasible and represents a viable procedure for the diagnosis and characterization of PCa

Information compression at the turbulent-phase transition in cold atom gases

The statistical properties of physical systems in thermal equilibrium are blatantly different from their far-from-equilibrium counterparts. In the latter, fluctuations often dominate the dynamics and might cluster in ordered patterns in the form of dissipative coherent structures. Here, we study the transition of a cold atomic cloud, driven close to a sharp electronic resonance, from a stable to a turbulent phase. From the atomic density distribution -- measured using a spatially-resolved pump-probe technique -- we have computed the Shannon entropy on two different basis sets. Information compression, corresponding to a minimum in the Shannon entropy, has been observed at criticality, where the system fluctuations organize into high-order (low-entropy) patterns. Being independent of the representation used, this feature is a property shared by a vast class of physical systems undergoing phase transitions.Comment: information compression, turbulent-phase transition, cold atoms, critical opalescence, second-order phase transitio

Italian cardiovascular mortality charts of the CUORE Project: are they comparable with the SCORE charts?

Background The aim of this study was to build risk charts for the assessment of cardiovascular mortality of the CUORE project, an Italian longitudinal study, and to compare them with the systematic coronary risk evaluation (SCORE) project charts for low risk European countries. Design Random population samples enrolled in the 1980s and 1990s in Italy were included in the analysis: 7520 men and 13 127 women aged 35-69 years without previous cardiovascular events and with a mean follow-up period of 10 years for cardiovascular disease. ICD-9 codes of death certificates similar to those of the SCORE project were considered when they appear as first cause of death. Methods Sex-stratified Cox proportional hazard model including age, systolic blood pressure, ratio between total and HDL cholesterol, and smoking habit as risk factors was used to assess cardiovascular mortality. Results Analysis showed that all risk factors included in the model were statistically significant. The corresponding area under the receiver operating characteristic curve was 0.825 (95% confidence interval: 0.803-0.846) for men and 0.850 (0.823-0.877) for women. The CUORE project charts yielded similar results to the corresponding charts of the SCORE project: Lin's coefficient was 0.929 for men and 0.935 for women. Conclusion The comparison between CUORE and SCORE mortality risk charts shows that SCORE charts reflect quite well the Italian cardiovascular mortality and, correspondingly, Italian cohorts of the CUORE project are quite representative of European countries at low risk for cardiovascular mortality

Mini-invasive robotic assisted pyelolithotomy: Comparison between the transperitoneal and retroperitoneal approach.

OBJECTIVE: To compare the retroperitoneal with the transperitoneal approach in a series of patients underwent to robotic-assisted pyelolithotomy (RP). MATERIALS AND METHODS: From January 2015 to December 2018 we evaluated 20 patients subjected to robotic pyelolithotomy; 11 patients were treated with retroperitoneal approach (RRP) and 9 with transperitoneal approach (TRP). For each patient intra and perioperative data were recorded: operative time (OT), blood loss (BL), length of hospital stay (LOS), stone clearance, post-operative complications and time to remove the drain. The presence of stone fragments < 4 mm was considered as stone free rate. RESULTS: The principal stone burden was greater in the TRP group than in the RRP group (48 ± 10 mm vs 32 ± 14 mm, p = 0.12). Preoperative hydronephrosis was present in 7 (64%) patients in RRP group and a mild hydronephrosis in 3 of TRP group (p = 0.04). The average operative time was higher in the RRP group than in the TRP group (203 ± 45 min vs 137 ± 31 min, p = 0.002). The average blood loss was 305 ± 175 ml in the RRP group versus 94 ± 104 ml in the TRP group (p = 0.005). The stone free rate was similar between the two groups, 36% (4 patients) in the RRP group and 44% (4 patients) in the TRP (p = 0.966). CONCLUSIONS: RP appears to be a safe and effective minimally invasive treatment for some patients with renal staghorn calculi or urinary tract malformations. The TRP may give lower operative time and better results in terms of blood loss and length of hospital stay

An international comparative study of blood pressure in populations of European vs. African descent

Background: The consistent finding of higher prevalence of hypertension in US blacks compared to whites has led to speculation that African-origin populations are particularly susceptible to this condition. Large surveys now provide new information on this issue. Methods: Using a standardized analysis strategy we examined prevalence estimates for 8 white and 3 black populations (N = 85,000 participants). Results: The range in hypertension prevalence was from 27 to 55% for whites and 14 to 44% for blacks. Conclusions: These data demonstrate that not only is there a wide variation in hypertension prevalence among both racial groups, the rates among blacks are not unusually high when viewed internationally. These data suggest that the impact of environmental factors among both populations may have been under-appreciated

Noise control in enclosures: Modeling and experiments with T-shaped acoustic resonators

This paper presents a theoretical and experimental study of noise control in enclosures using a T-shaped acoustic resonator array. A general model with multiple resonators is developed to predict the acoustic performance of small resonators placed in an acoustic enclosure. Analytical solutions for the sound pressure inside the enclosure and the volume velocity source strength out of the resonator aperture are derived when a single resonator is installed, which provides insight into the physics of acoustic interaction between the enclosure and the resonator. Based on the understanding of the coupling between the individual resonators and enclosure modes, both targeted and nontargeted, a sequential design methodology is proposed for noise control in the enclosure using an array of acoustic resonators. Design examples are given to illustrate the control performance at a specific or at several resonance peaks within a frequency band of interest. Experiments are conducted to systematically validate the theory and the design method. The agreement between the theoretical and experimental results shows that, with the help of the presented theory and design methodology, either single or multiple resonance peaks of the enclosure can be successfully controlled using an optimally located acoustic resonator array. © 2007 Acoustical Society of America

How artificial intelligence tools can be used to assess individual patient risk in cardiovascular disease: problems with the current methods

BACKGROUND: In recent years a number of algorithms for cardiovascular risk assessment has been proposed to the medical community. These algorithms consider a number of variables and express their results as the percentage risk of developing a major fatal or non-fatal cardiovascular event in the following 10 to 20 years DISCUSSION: The author has identified three major pitfalls of these algorithms, linked to the limitation of the classical statistical approach in dealing with this kind of non linear and complex information. The pitfalls are the inability to capture the disease complexity, the inability to capture process dynamics, and the wide confidence interval of individual risk assessment. Artificial Intelligence tools can provide potential advantage in trying to overcome these limitations. The theoretical background and some application examples related to artificial neural networks and fuzzy logic have been reviewed and discussed. SUMMARY: The use of predictive algorithms to assess individual absolute risk of cardiovascular future events is currently hampered by methodological and mathematical flaws. The use of newer approaches, such as fuzzy logic and artificial neural networks, linked to artificial intelligence, seems to better address both the challenge of increasing complexity resulting from a correlation between predisposing factors, data on the occurrence of cardiovascular events, and the prediction of future events on an individual level