A nonparametric approach for model individualization in an artificial pancreas

The identification of patient-tailored linear time invariant glucose-insulin models is investigated for type 1 diabetic patients, that are characterized by a substantial inter-subject variability. The individualized linear models are identified by considering a novel kernel-based nonparametric approach and are compared with a linear time invariant average model in terms of prediction performance by means of the coefficient of determination, fit, positive and negative max errors, and root mean squared error. Model identification and validation are based on in-silico data collected from the adult virtual population of the UVA/Padova simulator. The data generation involves a protocol designed to produce a sufficient input excitation without compromising patient safety, compatible also with real life scenarios. The identified models are exploited to synthesize an individualized Model Predictive Controller (MPC) for each patient, which is used in an Artificial Pancreas to maintain the blood glucose concentration within an euglycemic range. The MPC used in several clinical studies, synthesized on the basis of a non-individualized average linear time invariant model, is also considered as reference. The closed-loop control performance is evaluated in an in-silico study on the adult virtual population of the UVA/Padova simulator in a perturbed scenario, in which the MPC is blind to random variations of insulin sensitivity in each virtual patient. © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved

Statistical analysis of correlations and intermittency of a turbulent rotating column in a magnetoplasma device

12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France)A detailed statistical analysis of density fluctuations in the cylindrical non-fusion device "Mistral" is performed. The experimental set-up is implemented in order to reach turbulent behavior in the rotating plasma column. Two different turbulent regimes are obtained corresponding to two selected sets of values for the anode potential and the biasing of the collecting plate. The first regime displays a slowly-rotating column characterized by the presence of a shear layer separating the plasma bulk from the scrape-off layer (SOL), the latter showing a strong intermittent behavior. The second regime corresponds to a weakly-rotating column in which coherence is lost in the plasma bulk and a standard diffusive process takes place in the SOL. These findings are supported by the calculation of the Hurst exponent of the turbulent signals using Wavelet-analysis techniques

Creation of Controlled Defects Inside Colloidal Crystal Arrays with a Focused Ion Beam

In this work the reliability of the focused-ion-beam (FIB) patterning on polystyrene (PS) colloidal crystals at different scales is determined. Ordered arrays of PS spheres (465 nm) are successfully modified by selectively removing a single sphere. The water-vapor assisted FIB milling is crucial to obtain this result. Furthermore, isolated PS spheres are FIB drilled with or without chemically enhanced milling aiming at the exploration of the limits of such a technique. These controlled defects created using the FIB-assisted techniques may be helpful in preparing mockups of photonic crystals, sensors or as colloidal masks for diverse lithographic processes

A single polyploidization event at the origin of the tetraploid genome of Coffea arabica is responsible for the extremely low genetic variation in wild and cultivated germplasm

The genome of the allotetraploid species Coffea arabica L. was sequenced to assemble independently the two component subgenomes (putatively deriving from C. canephora and C. eugenioides) and to perform a genome-wide analysis of the genetic diversity in cultivated coffee germplasm and in wild populations growing in the center of origin of the species. We assembled a total length of 1.536 Gbp, 444 Mb and 527 Mb of which were assigned to the canephora and eugenioides subgenomes, respectively, and predicted 46,562 gene models, 21,254 and 22,888 of which were assigned to the canephora and to the eugeniodes subgenome, respectively. Through a genome-wide SNP genotyping of 736 C. arabica accessions, we analyzed the genetic diversity in the species and its relationship with geographic distribution and historical records. We observed a weak population structure due to low-frequency derived alleles and highly negative values of Taijma's D, suggesting a recent and severe bottleneck, most likely resulting from a single event of polyploidization, not only for the cultivated germplasm but also for the entire species. This conclusion is strongly supported by forward simulations of mutation accumulation. However, PCA revealed a cline of genetic diversity reflecting a west-to-east geographical distribution from the center of origin in East Africa to the Arabian Peninsula. The extremely low levels of variation observed in the species, as a consequence of the polyploidization event, make the exploitation of diversity within the species for breeding purposes less interesting than in most crop species and stress the need for introgression of new variability from the diploid progenitors

Nature, formation, and distribution of carbonates on Ceres

Different carbonates have been detected on Ceres, and their abundance and spatial distribution have been mapped using a visible and infrared mapping spectrometer (VIR), the Dawn imaging spectrometer. Carbonates are abundant and ubiquitous across the surface, but variations in the strength and position of infrared spectral absorptions indicate variations in the composition and amount of these minerals. Mg-Ca carbonates are detected all over the surface, but localized areas show Na carbonates, such as natrite (Na_2CO_3) and hydrated Na carbonates (for example, Na_2CO_3·H_2O). Their geological settings and accessory NH_4-bearing phases suggest the upwelling, excavation, and exposure of salts formed from Na-CO_3-NH_4-Cl brine solutions at multiple locations across the planet. The presence of the hydrated carbonates indicates that their formation/exposure on Ceres’ surface is geologically recent and dehydration to the anhydrous form (Na_2CO_3) is ongoing, implying a still-evolving body

Characterization of color, phenolic profile, and antioxidant activity of Italian pigmented rice varieties after different technological treatments

Pigmented rice varieties are rich in antioxidant and anti-inflammatory compounds (e.g. anthocyanins and proanthocyanidins). Therefore, their consumption could exert beneficial effects, particularly in people suffering from chronic diseases (e.g., celiac disease). Pigmented rice is commonly consumed as brown rice, but technological treatments could be applied to reduce its cooking time and improve its nutritional value (vitamins and minerals). In this study, two relatively new pigmented varieties (Violet and Orange) were characterized in terms of phenolic content and antioxidant capacity and the impact of two technological treatments (e.g., milling and parboiling) on their phytochemical composition was evaluated. Two pigmented and one non-pigmented Italian varieties were included for comparison. Both technological processes affected the concentration of phenolic compounds and their relative antioxidant property. Although milling mainly reduced the phenolic content and the antioxidant activity, anthocyanins seem to be more affected by parboiling (reduction of 91.5%). Despite the effects of technological treatments on active compounds, pigmented varieties still represent an interesting antioxidant source when compared to the non-pigmented ones

Does the Uterine Injection Site Matter for the Pelvic Sentinel Lymph Node Mapping? A Systematic Review and Meta-Analysis

: Background and Objectives: To summarize the evidence on in vivo uterine pelvic lymphatic drainage. Materials and Methods: A literature search was performed in multiple electronic databases from inception to December 2024. We included all the studies that compared two different uterine injection sites in the mapping of pelvic sentinel lymph nodes by injecting two different tracers into two distinct injection sites. The primary outcomes included the concordance and discordance rates in the mapped pelvic sentinel lymph nodes between the pairs of injection sites. The secondary outcomes were the detection rates per injection site and tracer. Four reviewers independently reviewed the records for inclusion, assessed the risk of bias, and extracted the data. Pooled concordance, discordance, and detection rates with 95% confidence intervals (CIs) were estimated using the random effects model. Heterogeneity was quantified using the I2 tests. Results: Out of 2512 records, we included 4 studies (172 patients and 344 hemipelves). Three studies injected the cervix with the technetium-99m and the uterine corpus with methylene blue; one study injected the cervix with indocyanine green and the utero-ovarian ligament with methylene blue. Both tracers/injection sites successfully identified a sentinel lymph node in 132 hemipelves (132/344; 38.4%), identifying the same sentinel lymph node in 116 cases (116/132; 87.9%). The pooled concordance rate per hemipelvis was 91.8% (95% CI 0.665-1.000; I2 = 92%; chi2p-value < 0.01). Two different sentinel lymph nodes were identified in the remaining 16 hemipelves, with a pooled hemipelvis discordance rate of 8.2% (95% CI 0.000-0.335; I2 = 92%; chi2p-value < 0.01). The cervix and technetium-99m were the injection site and tracer with the highest pooled detection rate. Conclusions: Different uterine injection sites appear to share a common pelvic lymphatic pathway and sentinel lymph node in most cases, consistent with the current practice in endometrial cancer. Future research will confirm whether cervical injections might be proposed for pelvic sentinel lymph node mapping in all gynecological cancers