Digital Elevation Models of Rockfalls and Landslides: A Review and Meta-Analysis

The scope of this paper is to summarize previous research pertaining to the use of digital elevation models (DEMs) and digital terrain models (DTMs) in the study of rockfalls and landslides. Research from 1983 to 2020 was surveyed in order to understand how the spatial resolution of DEMs and DTMs affects landslide detection, validation, and mapping. Another major question examined was the relationship between the DEM resolution and the extent of the rockfall or landslide event. It emerged from the study that, for landslides, the majority of researchers used DEMs with a spatial resolution of between 10 m and 30 m, while for rockfalls, they used DEMs with a spatial resolution of between 5 m and 20 m. We concluded that DEMs with a very high resolution (less than 5 m) are suitable for local-scale occurrences, while medium-resolution (from 20 m to 30 m) DEMs are suitable for regional-scale events. High resolution is associated with high accuracy and detailed structural characteristics, while medium accuracy better illustrates the topographic features. A low pixel size (more than 90 m) is not recommended for this type of research. Susceptibility maps, inventory maps, hazard risk zones, and vulnerability assessments are some of the main tools used in landslide/rockfall investigations, and topographic indexes, methods, models, and software optimize the reliability of the results. All of these parameters are closely related to DEMs and DTMs as the cell size affects the credibility of the final outcome

Erythropoetin as a novel agent with pleiotropic effects against acute lung injury

Current pharmacotherapy for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is not optimal, and the biological and physiological complexity of these severe lung injury syndromes requires consideration of combined-agent treatments or agents with pleiotropic action. In this regard, exogenous erythropoietin (EPO) represents a possible candidate since a number of preclinical studies have revealed beneficial effects of EPO administration in various experimental models of ALI. Taken together, this treatment strategy is not a single mediator approach, but it rather provides protection by modulating multiple levels of early signaling pathways involved in apoptosis, inflammation, and peroxidation, potentially restoring overall homeostasis. Furthermore, EPO appears to confer vascular protection by promoting angiogenesis. However, only preliminary studies exist and more experimental and clinical studies are necessary to clarify the efficacy and potentially cytoprotective mechanisms of EPO action. In addition to the attempts to optimize the dose and timing of EPO administration, it would be of great value to minimize any potential toxicity, which is essential for EPO to fulfill its role as a potential candidate for the treatment of ALI in routine clinical practice. The present article reviews recent advances that have elucidated biological and biochemical activities of EPO that may be potentially applicable for ALI/ARDS management. © 2010 Springer-Verlag

The Influence of the DSM Spatial Resolution in Rockfall Simulation and Validation with In Situ Data

Remote sensing constitutes an advantageous tool towards the landslide/rockfall susceptibility mapping by incorporating optical satellite or radar data and photogrammetric data in Geographical Information System environment. A plethora of rockfall data can be derived by gigital surface models (DSMs). This article focuses on the effect of the spatial resolution of DSMs in rockfall investigations solely. DSMs with pixel size ranging from 5 cm to 90 m were taken into account for the study of three different rockfall events occurring in Western Greece, namely, at Moira, Myloi and Platiana settlements. Elevation profiles along the rockfall bodies were created from the diverse DSMs in GIS environment. Then, these profiles were implemented into the RocFall software for 2D rockfall simulations. The produced simulations were evaluated against their spatial resolution of DSMs and were confirmed with field observations and measurements. The ultimate scope of this paper is to conclude to the most appropriate DSM for rockfall simulations via RocFall software. It is observed that DSMs with high spatial resolution depicted a detailed and realistic topography, while DSMs with coarse/low resolution flattened the surface roughness. As rockfall simulations are linked to slope profile, this observation has an impact on RocFall outcomes. According to this study the most appropriate DSM, pertaining to this type of research, is the UAV, which produces the more accurate and realistic results. These results were assessed through the use of in situ measurements taken by the real rockfall events

Estimating the dynamic ratio of the lateral/medial hamstrings. A case control study

Purpose. Hamstring injuries are among the most common injuries in sports. The current study estimates the hamstrings dynamic ratio (HDR) between the mean muscle activation of lateral (biceps femoris longus) and medial part (semitendinosus) of the hamstring muscles during a maximal voluntary isometric contraction in elite uninjured track and field athletes. Methods. Following isokinetic assessment to estimate the hamstrings to quadriceps dynamic ratio (H:Q), the participants were divided in two groups (Group 1 (N = 10): Athletes with a H:Q ratio range 55-70% and no side to side difference of the ratios more than 6 units; and Group 2 (N = 8) athletes with a H:Q ratio outside of the 55-70% range and/or a side to side difference of the ratios greater than 6 units). All athletes were assessed by electromyography during a maximum voluntary isometric contraction of their hamstrings. Results. There was difference on the range and means between the two groups regarding hamstrings dynamic ratio (78% and 69% respectively), although this difference did not reach statistical significance. Conclusions. A proposed HDR of 78% between lateral to medial hamstrings could be used as a risk factor for hamstring injuries in athletes with hamstring muscle imbalances. Better characterisation of the normal patterns of hamstring muscle activation will allow targeted rehabilitation to address specific neuromuscular coordination patterns. © 2021, CIC Edizioni Internazionali s.r.l.. All rights reserved