Debris flow hazard assessment: Laboratory experiences and numerical modelling

In the last years, the study of debris flow has become very important in the research activity and in the engineering practice. The use of numerical models is able for the study of debris flow’s propagation. The study area is located in the north-east Sicilian coast and in particular in the municipality of Gioiosa Marea, severely affected by landslides occurred from 2000 to 2013. In this case study, the FLO-2D code has been used. The soil parameters has been determined by means of in situ investigations and laboratory tests. The knowledge of the physical and mechanical properties is very important to define the input parameters of the model, including the volumetric concentration associated with the soil friction angle

The Beaker phenomenon and the genomic transformation of northwest Europe

From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries

Evaluation of Unsaturated Soil Properties for a Debris-Flow Simulation

Fast-moving landslides (i.e., debris/earth flows) are often caused by heavy rainfall occurring in small areas, and are not predictable. On the other hand, innovative methods for geomechanical characterization, numerical analysis, and modeling are required to attempt to reproduce a given debris/earth flow event. As our capability to reproduce very complex phenomena increases, we can improve our prevention approaches. In this paper, a debris flow event that occurred in the Enna area (Sicily) is described. Starting from the study of the geological framework and the historical background, this research focused on the causes that triggered the landslide. In situ and laboratory tests, including geophysical investigations and triaxial tests in unsaturated conditions, were carried out to investigate the factors affecting the dynamics of the event. This study gives us better knowledge of the mechanical and hydraulic properties that can be used to model these events, to assess the most appropriate strategies for the prevention and mitigation of related risks

Debris flow hazard assessment: Laboratory experiences and numerical modelling

In the last years, the study of debris flow has become very important in the research activity and in the engineering practice. The use of numerical models is able for the study of debris flow’s propagation. The study area is located in the north-east Sicilian coast and in particular in the municipality of Gioiosa Marea, severely affected by landslides occurred from 2000 to 2013. In this case study, the FLO-2D code has been used. The soil parameters has been determined by means of in situ investigations and laboratory tests. The knowledge of the physical and mechanical properties is very important to define the input parameters of the model, including the volumetric concentration associated with the soil friction angle

Evaluation of Unsaturated Soil Properties for a Debris-Flow Simulation

Fast-moving landslides (i.e., debris/earth flows) are often caused by heavy rainfall occurring in small areas, and are not predictable. On the other hand, innovative methods for geomechanical characterization, numerical analysis, and modeling are required to attempt to reproduce a given debris/earth flow event. As our capability to reproduce very complex phenomena increases, we can improve our prevention approaches. In this paper, a debris flow event that occurred in the Enna area (Sicily) is described. Starting from the study of the geological framework and the historical background, this research focused on the causes that triggered the landslide. In situ and laboratory tests, including geophysical investigations and triaxial tests in unsaturated conditions, were carried out to investigate the factors affecting the dynamics of the event. This study gives us better knowledge of the mechanical and hydraulic properties that can be used to model these events, to assess the most appropriate strategies for the prevention and mitigation of related risks

Comparative development and reproduction of <i>Planococcus ficus</i> and <i>Planococcus citri</i> (Hemiptera: Pseudococcidae) on grapevine under field conditions

1. Mealybugs are major pests in grape-growing areas worldwide, causing direct and indirect crop damage. The vine mealybug Planococcus ficus (Signoret) is a key pest in most of grape-producing countries, whereas the citrus mealybug Planococcus citri (Risso) is reported as being destructive in Brazilian and Spanish vineyards. 2. We examined the adaptation of the citrus mealybug to grapevine by investigating its development, reproduction and life-history parameters under Mediterranean field conditions in comparison with those of P. ficus. 3. Both mealybug species developed and reproduced successfully on grapevine. However, P. ficus showed a shorter development time, larger female body size, and higher fecundity, fertility and survival than P. citri. 4. The life-history parameters further highlighted the different growth potential of vine and citrus mealybug populations because P. ficus exhibited a net reproductive rate and an intrinsic rate of increase two- to four-fold higher than that of P. citri. Furthermore, the vine mealybug population doubled its number in approximately half time with respect to the citrus mealybug. 5. Overall, the results of the present study show a better development and reproductive performance and a higher population growth potential of P. ficus compared with P. citri, indicating a higher capacity of the vine mealybug to develop on grapevine in Mediterranean vineyards

Results of closed subtalar dislocations

Background The subtalar dislocation (SD) of the foot is an uncommon injury characterized by a simultaneous dislocation of talocalcaneal and talonavicular joints without involvement of the tibiotalar and calcaneocuboid joints. Purposes The purpose of this study was to evaluate the clinical and radiological outcome in a consecutive series of close SD. Methods We retrospectively evaluated a case series of patients who presented a close SD. Thirteen patients were selected for this study. There were 9 patients with a medial SD, 3 patients with a lateral dislocation and 1 patient with a posterior subtalar dislocation. Results The most frequent symptoms observed in our study included transient mild pain, swelling and decreased ankle ROM, which did not restrict patients’ daily activities. However, lower AOFAS scores were observed on patients with associate peritalar osseous injuries. Conclusion The results of the present study suggest that detecting and treating any associate peritalar fractures are the keys to a successful long-term outcome