466 research outputs found
UAV-based multitemporal remote sensing surveys of volcano unstable flanks: a case study from Stromboli
UAV-based photogrammetry is becoming increasingly popular even in application fields that, until recently, were deemed unsuitable for this technique. Depending on the characteristics of the investigated scenario, the generation of three-dimensional (3D) topographic models may in fact be affected by significant inaccuracies unless site-specific adaptations are implemented into the data collection and processing routines. In this paper, an ad hoc procedure to exploit high-resolution aerial photogrammetry for the multitemporal analysis of the unstable Sciara del Fuoco (SdF) slope at Stromboli Island (Italy) is presented. Use of the technique is inherently problematic because of the homogeneous aspect of the gray ash slope, which prevents a straightforward identification of match points in continuous frames. Moreover, due to site accessibility restrictions enforced by local authorities after the volcanic paroxysm in July 2019, Ground Control Points (GCPs) cannot be positioned to constrain georeferencing. Therefore, all 3D point clouds were georeferenced using GCPs acquired in a 2019 (pre-paroxysm) survey, together with stable Virtual Ground Control Points (VGCPs) belonging to a LiDAR survey carried out in 2012. Alignment refinement was then performed by means of an iterative algorithm based on the closest points. The procedure succeeded in correctly georeferencing six high-resolution point clouds acquired from April 2017 to July 2021, whose time-focused analysis made it possible to track several geomorphological structures associated with the continued volcanic activity. The procedure can be further extended to smaller-scale analyses such as the estimation of locally eroded/accumulated volumes and pave the way for rapid UAV-based georeferenced surveys in emergency conditions at the SdF
Tracking the evolution of riverbed morphology on the basis of uav photogrammetry
Unmanned aerial vehicle (UAV) photogrammetry has recently become a widespread technique to investigate and monitor the evolution of different types of natural processes. Fluvial geomorphology is one of such fields of application where UAV potentially assumes a key role, since it allows for overcoming the intrinsic limits of satellite and airborne-based optical imagery on one side, and in situ traditional investigations on the other. The main purpose of this paper was to obtain extensive products (digital terrain models (DTMs), orthophotos, and 3D models) in a short time, with low costs and at a high resolution, in order to verify the capability of this technique to analyze the active geomorphic processes on a 12 km long stretch of the French–Italian Roia River at both large and small scales. Two surveys, one year apart from each other, were carried out over the study area and a change detection analysis was performed on the basis of the comparison of the obtained DTMs to point out and characterize both the possible morphologic variations related to fluvial dynamics and modifications in vegetation coverage. The results highlight how the understanding of different fluvial processes may be improved by appropriately exploiting UAV-based products, which can thus represent a low-cost and non-invasive tool to crucially support decisionmakers involved in land management practices
Anthropometric comparison between young Estonian and Chinese swimmers
Due to the progressive lowering of the age of peak performance among swimmers, it became important to better understand the factors influencing performance in prepuberal boys and girls. Aim of this study is to compare two different racial/ethnic groups of young swimmers, one from Nord-Europe, Estonia (Tartuma Region), and the other from China (Shanghai District) in order to assess existing differences in respect to body dimension, body fat, technical parameters of swimming performance and maximum lactate production. 26 Estonian and 7 Chinese female and 25 Estonian and 10 Chinese male, from two swimming schools, took part in the study. Anthropometric parameters were measured in accord with ISAK guidelines. BMI, Stroke Index, Stroke Length, mean velocity on a 200 m freestyle all out, and blood lactate after three minutes were measured. Significant differences exist in anthropometry between Nord-European and Asian young swimmers. These differences are more pronounced in female, with higher fat tissue in Nordic girls. Leg lengths are different between Chinese and Estonian girls having the Estonian longer legs. Hands lengths are different both in male and in female subjects. Being the Chinese groups of higher level of performance (higher mean velocity in the 200 m freestyle, such differences seems not to be as major determinants of the performance, also if they are often indicated as determinants of buoyancy and stroke efficiency
Productive and physiological implications of top-dress addition of branched-chain amino acids and arginine on lactating sows and offspring
BackgroundBranched-chain amino acids (BCAAs), including L-leucine (L-Leu), L-isoleucine (L-Ile), L-valine (L-Val), and L-arginine (L-Arg), play a crucial role in mammary gland development, secretion of milk and regulation of the catabolic state and immune response of lactating sows. Furthermore, it has recently been suggested that free amino acids (AAs) can also act as microbial modulators. This study aimed at evaluating whether the supplementation of lactating sows with BCAAs (9, 4.5 and 9 g/d/sow of L-Val, L-Ile and L-Leu, respectively) and/or L-Arg (22.5 g/d/sow), above the estimated nutritional requirement, could influence the physiological and immunological parameters, microbial profile, colostrum and milk composition and performance of sows and their offspring.ResultsAt d 41, piglets born from the sows supplemented with the AAs were heavier (P = 0.03). The BCAAs increased glucose and prolactin (P < 0.05) in the sows' serum at d 27, tended to increase immunoglobulin A (IgA) and IgM in the colostrum (P = 0.06), increased the IgA (P = 0.004) in the milk at d 20 and tended to increase lymphocyte% in the sows' blood at d 27 (P = 0.07). Furthermore, the BCAAs tended to reduce the Chao1 and Shannon microbial indices (P < 0.10) in the sows' faeces. The BCAA group was discriminated by Prevotellaceae_UCG-004, Erysipelatoclostridiaceae UCG-004, the Rikenellaceae_RC9_gut_group and Treponemaberlinense. Arginine reduced piglet mortality pre- (d 7, d 14) and post-weaning (d 41) (P < 0.05). Furthermore, Arg increased the IgM in the sow serum at d 10 (P = 0.05), glucose and prolactin (P < 0.05) in the sow serum at d 27 and the monocyte percentage in the piglet blood at d 27 (P = 0.025) and their jejunal expression of NFKB2 (P = 0.035) while it reduced the expression of GPX-2 (P = 0.024). The faecal microbiota of the sows in Arg group was discriminated by Bacteroidales. The combination of BCAAs and Arg tended to increase spermine at d 27 (P = 0.099), tended to increase the Igs (IgA and IgG, P < 0.10) at d 20 in the milk, favoured the faecal colonisation of Oscillospiraceae UCG-005 and improved piglet growth.ConclusionFeeding Arg and BCAAs above the estimated requirements for milk production may be a strategy to improve sow productive performance in terms of piglet average daily gain (ADG), immune competence and survivability via modulation of the metabolism, colostrum and milk compositions and intestinal microbiota of the sows. The synergistic effect between these AAs, noticeable by the increase of Igs and spermine in the milk and in the improvement of the performance of the piglets, deserves additional investigation
Plasma visfatin and adiponectin concentrations in physically active adolescent girls: relationships with insulin sensitivity and body composition variables
The purpose of this study was to evaluate the associations of visfatin and adiponectin concentrations with insulin resistance and body composition in regularly physically active pubertal girls . In 129 girls, aged 13-15 years (pubertal stages 3-5), visfatin, adiponectin, insulin resistance measured with homeostasis model assessment (HOMA) and body composition measured with dual-x ray absorptiometry were evaluated. Visfatin concentration was related to HOMA and overall adiposity (body mass index, fat mass) markers, whereas adiponectin concentration was related to overall adiposity (fat mass), central adiposity (trunk fat) and fat free mass values. These relationships remained significant (p >0.05) after adjusting for pubertal stage. Visfatin was independently related to body mass index (beta=0.936, p=0.0001) and HOMA (beta=0.444, p=0.039) indices, whereas adiponectin was indipendently related to fat free mass (beta=0.468;P=0.042) values. In conclusion visfatin could be related to insulin resistance and overall adiposity indices, whereas adiponectin was related to different body composition values in regularly physically active puberal girls
Imported and Indigenous cases of Invasive Meningocococcal Disease W:P1.5,2:F1-1: ST-11 in migrants' reception centers. Italy, June-November 2014.
We report about three unliked cases of meningococcal meningitis caused by the ST-11/ET-37 strain of Neisseria meningitidis serogroup W. Two of the three cases, detected in Sicily on June and July 2014, were migrants from Mali and Eritrea. The third case was a fatal meningitis occurred on November 2014 in a 37 years old man, working in an immigrant center in Calabria. This report suggests that tetravalent conjugate vaccines (ACYW) should be actively offered to the staff of migrants\u2019 reception centers
An engineering approach to quantify geomechanical safety factors in UGS programs
Abstract. Underground Gas Storage (UGS) has become one of the most
widely used practices to cope with seasonal peaks in energy consumption. The
planning of any new UGS facility, or its upgrading to increase the working
gas volume and reservoir performance, must be supported by an evaluation of
possible induced effects on the environment. From a geomechanical point of
view, storage activity results in a cyclic change in stress and deformation
in the reservoir rock and the surrounding formations. The main environmental
issues to be accounted for when natural fluid pore pressure is planned to be
exceeded are the following: (a) the differential displacements at the land
surface possibly mining the integrity of ground structure; (b) the integrity
of the reservoir and caprock; (c) the possible reactivation of faults, if
the target reservoir is located in a faulted basin; and (d) the vertical
upheaval and land subsidence that can impact on the surface drainage network
in low lying coastal areas. We present an original methodology for
evaluating the geomechanical safety of UGS activities using an approach
derived from what is traditionally applied in the structural design of
buildings. A safety factor, a margin of security against risks, is defined
for each of the geomechanical issues listed above. First, a 3D FE-IE
numerical model is developed to reproduce the stress and displacement due to
the UGS program under evaluation. Then the reservoir pressure is increased
until the "failure" condition is reached allowing to evaluate how far the
project designed condition is from the above limit. The proposed approach is
applied to Romagna, a depleted gas reservoir in Northern Italy converted to
UGS, with the aim of investigating the safety of the project to increase the
reservoir pressure up to 120 % pi, where pi is the original reservoir pressure
before the start of primary production. The 3D geomechanical model has been
developed using recent 3D seismic data, land displacements by InSAR, lab
tests on reservoir and caprock samples, in-situ Modular Formation Dynamic
Tester (MDT) stress tests, and large background information acquired from
other UGS reservoirs located in the same sedimentary basin. The analysis
outcome has revealed that the investigated scenario is safe, with safety
factor larger than 1, in the range from 1.2 to 4. The most critical
condition (the smallest safety factor) has been obtained in relation to the
mechanical integrity of the reservoir formation, under very conservative
conditions (cohesion = 0, friction angle = 30∘)
The dual/global value of SARS-COV- 2 genome surveillance on migrants arriving to Europe via the mediterranean routes
Despite the pandemic, 34,154 migrants, refugees or asylum-seekers landed in Sicily (Italy) in 2020, representing the main point of entry by sea into Europe. The SARS-CoV-2 surveillance program among migrants arriving to Sicily via the Mediterranean Sea, made by the combination of clinical examination and molecular testing, has been integrated by full-genome sequencing strains using the NGS technology from the last week of February. To date, more than one hundred full-genome strains have been sequenced and 8 different lineages have been identified mostly belonging to the lineages B.1.1.7 and B.1.525. As global access to COVID-19 vaccines should be ensured, the need to provide more detailed information to inform policies and to drive the possible re-engineering of vaccines needed to deal with the challenge of new and future variants should be highlighted
- …