Strategies for RANS/VMS-LES coupling

A new hybrid RANS/LES approach is proposed. The key feature of this approach is a blending between two eddy-viscosities, one given by the $k-\varepsilon$ RANS model and the other by the Smagorinsky VMS-LES (variational multiscale LES) closure. The blending is set by a parameter $\theta$: VMS-LES mode is active when $\theta=0$, RANS mode if $\theta=1$, a hybrid mode for $0<\theta<1$. The proposed hybrid model has been applied to the numerical simulation of the flow around a square cylinder at $Re_L=22000$. Three different parameters (based on viscosity ratio, time ratio and length ratio) are tested. The results obtained with this new hybrid approach are compared with those obtained using the LNS approach for two different grid resolutions; comparisons with experimental data in the litterature are also provided. The sensitivity of the model to some setting parameters (the inflow value of the turbulent kinetic energy, $k_0$ and the parameter $\delta$ in the approximate wall treatment) is also analysed

Is the choice of statistical model relevant in the cost estimation of patients with chronic diseases? An empirical approach from the Piedmont Diabetes Registry.

BACKGROUND: Chronic diseases impose large economic burdens. Cost analysis is not straightforward, particularly when the goal is to relate costs to specific patterns of covariates, and to compare costs between diseased and healthy populations. Using different statistical methods this study describes the impact on results and conclusions of analyzing health care costs in a population with diabetes. METHODS: Direct health care costs of people living in Turin were estimated from administrative databases of the Regional Health System. Patients with diabetes were identified through the Piedmont Diabetes Registry. The effect of diabetes on mean annual expenditure was analyzed using the following multivariable models: 1) an ordinary least squares regression (OLS); 2) a lognormal linear regression model; 3) a generalized linear model (GLM) with gamma distribution. Presence of zero cost observation was handled by means of a two part model. RESULTS: The OLS provides the effect of covariates in terms of absolute additive costs due to the presence of diabetes (€ 1,832). Lognormal and GLM provide relative estimates of the effect: the cost for diabetes would be six fold that for non diabetes patients calculated with the lognormal. The same data give a 2.6-fold increase if calculated with the GLM. Different methods provide quite different estimated costs for patients with and without diabetes, and different costs ratios between them, ranging from 3.2 to 5.6. CONCLUSIONS: Costs estimates of a chronic disease vary considerably depending on the statistical method employed; therefore a careful choice of methods to analyze data is required before inferring results

Native Ion Mobility Mass Spectrometry: When Gas-Phase Ion Structures Depend on the Electrospray Charging Process

International audienceIon mobility spectrometry (IMS) has become popular to characterize biomolecule folding. Numerous studies have shown that proteins that are folded in solution remain folded in the gas phase, whereas proteins that are unfolded in solution adopt more extended conformations in the gas phase. Here, we discuss how general this tenet is. We studied single-stranded DNAs (human telomeric cytosine-rich sequences with CCCTAA repeats), which fold into an intercalated motif (i-motif) structure in a pH-dependent manner, thanks to the formation of C-H +-C base pairs. As i-motif formation is favored at low ionic strength, we could investigate the ESI-IMS-MS behavior of i-motif structures at pH ~5.5 over a wide range of ammonium acetate concentrations (15 mM to 100 mM). The control experiments consisted of either the same sequence at pH ~7.5, wherein the sequence is unfolded, or sequence variants that cannot form i-motifs (CTCTAA repeats). The surprising results came from the control experiments. We found that the ionic strength of the solution had a greater effect on the compactness of the gas-phase structures than the solution folding state. This means that electrosprayed ions keep a memory of the charging process, which is influenced by the electrolyte concentration. We discuss these results in light of the analyte partitioning between the droplet interior and droplet surface, which in turn influences the probability of being ionized via a charged residue-type pathway or a chain extrusion-type pathway.La spectrométrie de mobilité ionique (IMS) est devenue populaire pour caractériser le pliage des biomolécules. De nombreuses études ont montré que les protéines repliées en solution restent repliées en phase gazeuse, alors que les protéines dépliées en solution adoptent des conformations plus étendues en phase gazeuse. Ici, nous discutons du caractère général de ce principe. Nous avons étudié les ADN simple brins (séquences télomériques humaines riches en cytosine avec répétitions CCCTAA), qui se replient en une structure de motif intercalé (i-motif) d'une manière dépendant du pH, grâce à la formation de paires de bases C-H +-C. Comme la formation de motifs i-motifs est favorisée à faible force ionique, nous avons pu étudier le comportement des structures i-motifs ESI-IMS-MS à pH ~5,5 sur une large gamme de concentrations en acétate d'ammonium (15 mM à 100 mM). Les expériences de contrôle consistent soit en la même séquence à pH ~7,5 (à ce pH la séquence est dépliée), soit en des variantes de séquence qui ne peuvent pas former d'i-motifs (répétitions CTCTAA). Les résultats surprenants proviennent des expériences de contrôle. Nous avons constaté que la force ionique de la solution avait un effet plus important sur la compacité des structures en phase gazeuse que l'état de repliement de la solution. Cela signifie que les ions produits par électrospray gardent une mémoire du processus d'acquisition de la charge, et que celui-ci est influencé par la concentration de l'électrolyte. Nous discutons de ces résultats à la lumière de la répartition de l'analyte entre l'intérieur des gouttelettes et la surface des gouttelettes, réaprtition qui à son tour influence la probabilité pour la molécule d'être ionisée par une voie de type résidu chargé ou par une voie d'extrusion de la chaîne

UX Designer and Software Developer at the Mirror: Assessing Sensory Immersion and Emotional Involvement in Virtual Museums

Virtual Museums (VMs) and their audiences have always been studied as separated worlds. Recently the importance of cross-methodological studies has been accepted by the academic sector for their usefulness in the process of assessing the impact of such VMs. Hedonic aspects, such as emotions, senses, perception, and environmental atmosphere rather than technicalities, like usability and affordance, have indeed played a precise and crucial role in the meaning-making of the world around us. This contribution will highlight the need for a collaborative sharing of ideas among designers and developers, creators and technicians, in order to reach sensory immersion and emotional involvement in VMs that will translate into enhanced participation and the predisposition to assimilate and memorize cultural contents. It has been stated that “a virtual museum is a digital entity.” As such, it is inevitably based on technology, on its user interface (UI), on the visualization solutions it employs, and on its usability and ability to interact with the end user in order to transfer a certain message. VMs are designed to complement, enhance, or augment the ordinary museum experience through contextualization, narration, personalization, interactivity and richness of content. This contribution originates not only from the lessons learned in twenty years of research by CNR ITABC, but it also moves one step further in the direction of exchanged experiences and good practices between the humanistic and the technological sectors, therefore contributing to the promotion of lifelong learning in Virtual Museums

Platelet lysate-derived neuropeptide y influences migration and angiogenesis of human adipose tissue-derived stromal cells

Neuropeptide Y (NPY), a powerful neurotransmitter of the central nervous system, is a key regulator of angiogenesis and biology of adipose depots. Intriguingly, its peripheral vascular and angiogenic powerful activity is strictly associated to platelets, which are source of clinical hemoderivates, such as platelet lysate (PL), routinely employed in several clinical applications as wound healing, and to preserve ex vivo the progenitor properties of the adipose stromal cells pool. So far, the presence of NPY in PL and its biological effects on the adipose stromal cell fraction (ASCs) have never been investigated. Here, we aimed to identify endogenous sources of NPY such as PL-based preparations and to investigate which biological properties PL-derived NPY is able to exert on ASCs. The results show that PL contains a high amount of NPY, which is in part also excreted by ASCs when stimulated with PL. The protein levels of the three main NPY subtype receptors (Y1, Y2, Y5) are unaltered by stimulation of ASCs with PL, but their inhibition through selective pharmacological antagonists, considerably enhances migration, and a parallel reduction of angiogenic features of ASCs including decrease in VEGF mRNA and intracellular calcium levels, both downstream targets of NPY. The expression of VEGF and NPY is enhanced within the sites of neovascularisation of difficult wounds in patients after treatment with leuco-platelet concentrates. Our data highlight the presence of NPY in PL preparations and its peripheral effects on adipose progenitors

Undertreatment of breast cancer in the elderly

AIMS: The effect of undertreatment with adjuvant hormonal therapy, chemotherapy or radiation was studied in elderly women with breast cancer. METHODS: A prospectively maintained database was used to identify women undergoing potentially curative surgery between 1997 and 2011. The presentation, pathologic findings, treatment and outcomes of 449 women over 65 were compared to the findings in 1049 younger patients. Moreover, conventionally treated and undertreated elderly patients were identified and their characteristics and outcomes were compared. RESULTS: Both young and old patients presented most frequently with mammographic findings, but older patients presented more frequently with mammographic masses while younger patients presented more frequently with mammographic calcifications. Cancers of older patients were signicantly more favorable than cancers in younger patients with more infiltrating lobular, fewer ductal carcinoma in situ and more frequently estrogen receptor positive and fewer were poorly differentiated. Elderly patients had less axillary surgery, less adjuvant radiation therapy and more hormonal therapy. Fourty-six percent of the 449 elderly patients were undertreated by conventional criteria. Undertreated patients were more frequently in situ, better differentiated, smaller, and more often estrogen receptor positive. Forty-four percent of the undertreated patients died during follow-up without disease recurrence. CONCLUSIONS: Despite undertreatment, local and distant disease-free survival was comparable to patients who were not undertreated

Breast cancer surgery in elderly patients: postoperative complications and survival

AIMS AND BACKGROUND: Old age is associated with comorbidity and decreased functioning which influences treatment decisions in elderly breast cancer patients. The purpose of this study was to identify risk factors for complications after breast cancer surgery in elderly patients, and to assess mortality in patients with postoperative complications. METHODS: We retrospectively considered all female patients aged 65 years and older with invasive and in situ breast cancer who were diagnosed and treated between 1997 and 2012 in the Department of General and Geriatric Surgery of the University of Naples "Federico II". RESULTS AND CONCLUSION: 449 patients received surgery, of whom 18,2% (n = 82) developed one or more postoperative complications. The odds ratio of having postoperative complications show an increase with age, reaching statistical significance only for patients older than 85 [OR 5,75 (95% confidence interval 2,38-14,04); p < 0,001]. Number of concomitant diseases [OR 2,51 (95% CI 1,17 - 5,45); p = 0,01 for 3 or more concomitant diseases] and polypharmacy [OR 16,7 (95% CI 9,12 - 30,58); p < 0,0001) are associated to an increased risk of postoperative complications. Overall survival was worse in patients with postoperative complications [HR 2,06 (95% CI 1,52-2,70), p < 0,001]. This increased risk of mortality is probably due to geriatric parameters such as comorbidity or poor physical function, more than to higher complication rates