Blocked Cross-Validation: A Precise and Efficient Method for Hyperparameter Tuning

Hyperparameter tuning plays a crucial role in optimizing the performance of predictive learners. Cross--validation (CV) is a widely adopted technique for estimating the error of different hyperparameter settings. Repeated cross-validation (RCV) has been commonly employed to reduce the variability of CV errors. In this paper, we introduce a novel approach called blocked cross-validation (BCV), where the repetitions are blocked with respect to both CV partition and the random behavior of the learner. Theoretical analysis and empirical experiments demonstrate that BCV provides more precise error estimates compared to RCV, even with a significantly reduced number of runs. We present extensive examples using real--world data sets to showcase the effectiveness and efficiency of BCV in hyperparameter tuning. Our results indicate that BCV outperforms RCV in hyperparameter tuning, achieving greater precision with fewer computations.Comment: 28 pages, 7 figure

Catalytic fuel cell used as an analytical tool for methanol and ethanol determination. Application to ethanol determination in alcoholic beverages

A small direct catalytic methanol 'fuel cell' was used for analytical purposes. Three different formats were investigated for methanol and ethanol determination: two different Open Circuit Voltage (OCV) formats and a potentiostatic (i.e. amperometric) format; the latter was used if the current supplied by the cell was recorded. The measurement times using one or other of these three formats were much different. The time required by the potentiostatic format was more short for a suitable analytical measurement. The cell was used to check ethanol content in several commercial wine and beer samples and the possibility of using the fuel cell for the analytical measures in real samples, discussed. Lastly the results were compared with those obtained using two conventional amperometric enzyme sensors and statistical tests carried out. (C) 2016 Elsevier Ltd. All rights reserved

Comparison between a direct-flow SPR immunosensor for ampicillin and a competitive conventional amperometric device: analytical features and possible applications to real samples

In this research, we developed a direct-flow surface plasmon resonance (SPR) immunosensor for ampicillin to perform direct, simple, and fast measurements of this important antibiotic. In order to better evaluate the performance, it was compared with a conventional amperometric immunosensor, working with a competitive format with the aim of finding out experimental real advantages and disadvantages of two respective methods. Results showed that certain analytical features of the new SPR immunodevice, such as the lower limit of detection (LOD) value and the width of the linear range, are poorer than those of a conventional amperometric immunosensor, which adversely affects the application to samples such as natural waters. On the other hand, the SPR immunosensor was more selective to ampicillin, and measurements were more easily and quickly attained compared to those performed with the conventional competitive immunosensor

Design of an Optically Accessible Intake Manifold for Characterization of Liquid and Gaseous Jets in PFI Operating Conditions

The intake manifold and its components play a key role in the proper formation of air–fuel mixtures suitable for correct engine operation. In this article, starting from the original intake manifold design fitted to an optically accessible spark-ignited engine, a new solution was developed so as to allow the application of high-speed imaging of the fuel jet located between the runner and intake valves (Port Fuel Injection). To compare the two designs in terms of overall engine performance parameters such as volumetric efficiency, 0D/1D simulations were performed in motored conditions. Measurements at different crankshaft speed values were used for calibrating the intake line parameters and providing boundary conditions. Finite Element Analysis (FEM) was performed in SolidWorks to verify the structural strength of the new design when operating in the most critical conditions, i.e., boosted operation. As an overall conclusion, the results show that the new design guarantees a wider range of intake pressure values during the intake stroke, thus expanding the possible operative points. This can be obtained without compromising structural integrity, given that predicted safety factors were well above acceptable limits even for relatively high boost levels

Agrochemical Contamination of Honey and Bee Bread Collected in the Piedmont Region, Italy

This study shows the results of a local biomonitoring plan developed by a regional beekeeping association, Aspromiele, in several areas of Piedmont (Italy), in order to understand the status of contamination from pesticides present in the environment and eventually to evaluate their impact on apiculture. Glyphosate was the most abundant chemical found in the bee bread and honey samples. The other pesticides detected at lower concentrations and minor frequency were mandipropamid, tau-fluvalinate, metalaxil and spiroxamine. Even if in the present study the pesticides found in the bee bread and honey were limited to a few molecules, it is important to highlight that the presence of glyphosate could represent a hazard to bees. Honeybees are the main pollinators in agricultural ecosystems, and thus appropriate environmental management could lead to a reduction in the impact of these chemicals on bees and other beneficial insects

Emergency endovascular management of the common femoral artery rupture due to radiotherapy for scrotal carcinoma

We describe the case of a 72-year-old man with massive hemorrhage and shock resulting from rupture of the left common femoral artery as a complication of radiotherapy in the groin for cancer of the scrotum. This complication is extremely rare, presents dramatically, and is usually fatal. The patient was successfully treated with a stent graft deployment in order to achieve immediate hemostasis maintaining blood flow to the leg. Open surgery is not ideal in those cases especially when there is extensive tumor involvement of the groin causing altered anatomy and increasing the risk of re-bleeding

Archeologia preventiva a Pontelatone (CE): nuovi dati sulle dinamiche insediative in prossimità del fiume Volturno

The research project, carried out as part of the preliminary planning for the environmental requalification of the Barignano area (Pontelatone, CE), consists in a multidisciplinary application model for the best practice of preventive archaeology. The project started thanks to a recent agreement between the Municipality of Pontelatone (CE) and the Institute for Technologies Applied to Cultural Heritage (ITABC) of the Italian CNR, encharged of drawing up an archaeological map of the territory of Barignano and the surrounding territory. Recent surveys increased the knowledge about the exploitation of the Pontelatone district since prehistoric times and defined a more articulated settlement model of the perifluvial part of the territory, providing it with a different economic position in the ancient world. Research data, confronted with geographically and historically comparable areas, propose a new territorial and economic development model for the areas located on the Volturno river, both in Roman and in earlier periods. Starting from archive research and published scientific literature, the survey was supported by remote sensing data and new software to map land markers - both historical and archaeological - and for their 3D representation. The dataset have been organized in different topics and informative layers on a GIS platform. The survey and the interpretation of remote sensing data provided new elements for the topography of the area. Traces that suggest a different environmental model for some regions of the Volturno plain have been identified. Furthermore, today’s research supported by targeted geophysical surveys represents an actual prospect for future research

Is Shouldice the best NON-MESH inguinal hernia repair technique? A systematic review and network metanalysis of randomized controlled trials comparing Shouldice and Desarda

Background Current guidelines state that the Shouldice technique has lower recurrence rates than other suture repairs and therefore is strongly recommended in non-mesh inguinal hernia repair. Recently a new tissue repair technique has been proposed by Desarda and studied in trials against Lichtenstein technique. Methods The present study was performed according to the PRISMA Statement for Network Meta-analysis and the AMSTAR 2 checklist. The method of network meta-analysis was chosen to evaluate randomized controlled trial published on tissue repair and comparing Lichtenstein respectively with Desarda and Shouldice techniques. The following parameters: operative time, recurrence, complications (general, intraoperative, Surgical Surgical Site Occurrences), VAS score on postoperative day 1, numbness, chronic pain and return to daily activities. Results Fourteen RCTs, involving 2791 patients, fulfilled the inclusion criteria and were selected for final analysis. The anchored indirect treatment comparison showed that Desarda's technique requires a significantly shorter operative time (MD: −12.9 min; 95% CI: −20.6 to −5.2) and has a quicker recovery (MD: −6.6 days; 95% CI: −11.7 to −1.4). Outcomes concerning intraoperative complications, early postoperative pain, seroma/hematoma, hydrocele and infection rates, recurrence, numbness and chronic pain were similar among the two techniques. Conclusions Desarda's hernia repair can be a valuable alternative to Shouldice technique for the treatment of primary inguinal hernia repair if a non-mesh technique is chosen, because of its reproducibility and quicker postoperative recovery. We recommend performing well designed prospective studies comparing both techniques directly