Characterization of the field saturated hydraulic conductivity on a hillslope: measurement techniques, data sensitivity analysis and spatial correlation modelling

International audienceIn the context of studies aiming at the estimation of effective parameters for unsaturated zone modelling, this work tackles the problem of experimental data quality, considering the large collection of data gathered at an experimental site equipped for unsaturated zone hydraulic monitoring in the alluvial basin of a Calabrian river, in the South of Italy. Focusing attention on field saturated hydraulic conductivity, the in-site measurement techniques by tension disc and pressure ring infiltrometers are considered, pointing out the main indications for the correct use of each measuring approach; laboratory techniques are also considered. Statistical data analysis showed that the measurements performed by tension disc infiltrometer supplied values of hydraulic conductivity which are on average lower and more homogeneous than the values provided by the other measurement techniques considered. Sensitivity analysis was then carried out by Monte Carlo simulation on the parameter sampling achieved by field measurement techniques in order to evaluate the influence of any possible small measurement errors on the data. Sensitivity analysis showed that both ring and disc infiltrometer are tools reliable enough for the in situ measurements of field saturated hydraulic conductivity. Finally, after a data merging procedure giving origin to different sets of data, the spatial correlation structure of field saturated hydraulic conductivity is investigated, using well-known geostatistical techniques

Comparison of three measurement methods of saturated hydraulic condutivity

International audienceAfter pointing out the importance of the saturated hydraulic conductivity (ks) measurements and the difficulties and uncertainties that are present, and after recalling salient aspects of three well-known measurement methods of this parameter (i.e. constant-head tension infiltrometer (TI) method, constant-head pressure infiltrometer (PI) method and soil core (SC) estimates method), the results of an investigation on data which were obtained during a measurement campaign on an area of 800 m2, on a sandy loam hillslope, located in Southern Italy, were carried out again here. Three sets of values of ks, obtained with these measurement methods, were analyzed statistically, verifying that the log-normal distribution describes these better than the normal one; moreover, the more significant statistical parameters of each set were compared (average value , amplitude A, coefficient of variation CV and standard deviation SD), individualizing the more significant differences. The greatest value of hydraulic conductivity was found with method (PI), while the smallest with (SC) and the intermediate with (TI); these differences were translated into macroporosity and into the influence of the single measurement method. Moreover, referring to the possible factors affecting the results, the importance can be noted of the structure, the texture and the soil events, in terms of utilization, which can affect the measure of ks leading often to very different values even for similar soils, but with a different history, independently of the coincidence of the measurement points and they can be determining to explain the differences affecting the results obtained in analogous investigations by other researchers. Having confirmed that generalization is not possible, the need was emphasized to adopt the necessary devices relating to the specific measurement method, case by case, and to carefully explain the obtained results, in the light of the peculiarities and the limits of each situation. Finally, the results of similar statistical analysis carried out on a greater number of ks values, measured through the (TI) and (PI) methods are shown in this paper, with some statistical considerations on the increasing of the measurements number

Coverage of exposed hardware after lower leg fractures with free flaps or pedicled flaps

Abstract. – OBJECTIVE: The placement of osteosynthetic materials in the leg may be complicated by hardware exposure. Successful soft tissue reconstruction often provides a critical means for limb salvage in patients with hardware exposure in the leg. Free flaps are currently considered the standard surgical procedure for soft tissue coverage of the wounds with internal hardware exposure. However, to date, no conclusive literature shows the superiority of a specific type of flap. MATERIALS AND METHODS: The current review compares data from the literature concerning outcomes and complications of free and pedicled flaps for exposed osteosynthetic material preservation in the leg. RESULTS: A total of 81 cases from twelve different articles presenting internal hardware exposure of the leg were analyzed in our study. Thirty-two patients underwent immediate reconstructive surgery with pedicled flaps, while forty-nine patients underwent free flap reconstruction. The overall survival rate for pedicled flaps was 96.77%, while for free flaps it was 97.77%. The overall implant preservation rate was 78.12% for pedicled flaps and 53.33% for free flaps. With reference to postoperative complications, the overall complication rate was 46.87% for pedicled flaps and 10.20% for free flaps. CONCLUSIONS: No significant difference was found in terms of overall flap survival. However, a significant difference was found regarding successful implant preservation (78.12% in the pedicled flap group vs. 53.33% in the free flap group). In particular, the first observation appears to be in contrast with the current trend of considering the free flaps the first choice procedure for soft tissue coverage of the wounds with internal hardware exposure. Nevertheless, a higher occurrence of postoperative complications was observed in the pedicled flap group (46.87% vs. 10.20%). The choice of the most appropriate reconstructive procedure should take into account several issues including the size of the wounds with internal hardware exposure, the possibility of soft tissue coverage with pedicled flaps, the availability of recipient vessels, general conditions of the patients (such as age, diabetes, smoking history), patients’ preference and presence of a microsurgical team. However, according to the results of this review, we believe that pedicled flap reconstruction should be reconsidered as a valid alternative procedure for skin tissue loss with hardware exposure whenever it is possible

Porous Medium Typology Influence on the Scaling Laws of Confined Aquifer Characteristic Parameters

An accurate measurement campaign, carried out on a confined porous aquifer, expressly reproduced in laboratory, allowed the determining of hydraulic conductivity values by performing a series of slug tests. This was done for four porous medium configurations with dierent granulometric compositions. At the scale considered, intermediate between those of the laboratory and the field, the scalar behaviors of the hydraulic conductivity and the eective porosity was verified, determining the respective scaling laws. Moreover, assuming the eective porosity as scale parameter, the scaling laws of the hydraulic conductivity were determined for the dierent injection volumes of the slug test, determining a new relationship, valid for coarse-grained porous media. The results obtained allow the influence that the dierences among the characteristics of the porous media considered exerted on the scaling laws obtained to be highlighted. Finally, a comparison was made with the results obtained in a previous investigation carried out at the field scale

INCUMBENT’S DIGITAL TRANSFORMATION: A MULTI-DISCIPLINARY AND PARADOXICAL PERSPECTIVE

Digital transformation (DT) is a major challenge for incumbent organisations with an astonishing failure rate. We review digital transformation in established, old, large, and incumbent organisations adopting a Structured and Computational Literature Review (SLR and CLR). We employ a machine learning algorithm (LDA) to inspect the topics discussed in 103 peer-reviewed studies published between 2010 and 2022 in the fields of Information Management, Innovation Management, Operation Management, Strategic Management and General Management. We extract and discuss the top-five key topics emerging from the studies to understand the state-of-the-art literature on DT in established firms. Then, we advance paradox thinking as a lens to study DT in incumbent settings. We contribute to the DT discourse by providing a multidisciplinary review of the current trends on the topic of DT of in-cumbent firms; moreover, we contribute by advancing paradox thinking as a novel lens to study DT in incumbent organisations, further proposing research questions and avenues; finally, we propose managerial insights in line with paradox thinking to create momentum and thrive as DT champions

Clinical significance of the buccal fat pad: how to determine the correct surgical indications based on preoperative analysis

Background: Despite the multitude of clinical and aesthetic uses, the correct surgical indications for buccal fat pad (BFP) removal have yet to be fully elucidated. Although the procedure is widely performed and promoted for aesthetic purpose, literature lacks of studies accounting for a proper evaluation of patients undergoing BFP removal. Methods: Between 2012 and 2016 patients seeking an improvement of the malar contour by reduction of the submalar prominence have been visited at the Department of Plastic Surgery of the Institution. A preoperative MRI was requested in order to correctly identify the volume of the BFP and the presence of a masseter muscle (MM) hypertrophy. Results: According to clinical examination and the results of the preoperative imaging, patients were offered different treatment options: patients with BFP hypertrophy underwent BFP removal through an itraoral approach; patients with MM hypertrophy received injection of 50 UI of botulinum toxin (BTX). No complications were observed in the postoperative period and all patients were satisfied with the results. Conclusions: According to the experience, midface contouring procedures should take account of both surgeons’ experience, patients’ expectations and anatomical evaluation. As such, there is no given approach suitable for all cases. Suggested visual criteria, clinical examination and imaging analysis are useful in establishing patient’s condition and determining the appropriate methods of treatment to enhance the facial profile

High-throughput DNA sequencing to survey bacterial histidine and tyrosine decarboxylases in raw milk cheeses

peer-reviewedBackground The aim of this study was to employ high-throughput DNA sequencing to assess the incidence of bacteria with biogenic amine (BA; histamine and tyramine) producing potential from among 10 different cheeses varieties. To facilitate this, a diagnostic approach using degenerate PCR primer pairs that were previously designed to amplify segments of the histidine (hdc) and tyrosine (tdc) decarboxylase gene clusters were employed. In contrast to previous studies in which the decarboxylase genes of specific isolates were studied, in this instance amplifications were performed using total metagenomic DNA extracts. Results Amplicons were initially cloned to facilitate Sanger sequencing of individual gene fragments to ensure that a variety of hdc and tdc genes were present. Once this was established, high throughput DNA sequencing of these amplicons was performed to provide a more in-depth analysis of the histamine- and tyramine-producing bacteria present in the cheeses. High-throughput sequencing resulted in generation of a total of 1,563,764 sequencing reads and revealed that Lactobacillus curvatus, Enterococcus faecium and E. faecalis were the dominant species with tyramine producing potential, while Lb. buchneri was found to be the dominant species harbouring histaminogenic potential. Commonly used cheese starter bacteria, including Streptococcus thermophilus and Lb. delbreueckii, were also identified as having biogenic amine producing potential in the cheese studied. Molecular analysis of bacterial communities was then further complemented with HPLC quantification of histamine and tyramine in the sampled cheeses. Conclusions In this study, high-throughput DNA sequencing successfully identified populations capable of amine production in a variety of cheeses. This approach also gave an insight into the broader hdc and tdc complement within the various cheeses. This approach can be used to detect amine producing communities not only in food matrices but also in the production environment itself.This work was funded by the Department of Agriculture, Food and the Marine under the Food Institutional Research Measure through the ‘Cheeseboard 2015’ project. Daniel J. O’Sullivan is in receipt of a Teagasc Walsh Fellowship, Grant Number: 2012205