12 research outputs found

    Influence of Root Reinforcement on Shallow Landslide Distribution: A Case Study in Garfagnana (Northern Tuscany, Italy)

    Get PDF
    In this work, we evaluated the influence of root structure on shallow landslide distribution. Root density measurements were acquired in the field and the corresponding root cohesion was estimated. Data were acquired from 150 hillslope deposit trenches dug in areas either devoid or affected by shallow landslides within the Garfagnana Valley (northern Tuscany, Italy). Results highlighted a correlation between the root reinforcement and the location of measurement sites. Namely, lower root density was detected within shallow landslides, with respect to neighboring areas. Root area ratio (RAR) data allowed us to estimate root cohesion by the application of the revised version of the Wu and Waldron Model. Then, we propose a new method for the assimilation of the lateral root reinforcement into the infinite slope model and the limit equilibrium approach by introducing the equivalent root cohesion parameter. The results fall within the range of root cohesion values adopted in most of the physically based shallow landslide susceptibility models known in the literature (mean values ranging between ca. 2 and 3 kPa). Moreover, the results are in line with the scientific literature that has demonstrated the link between root mechanical properties, spatial variability of root reinforcement, and shallow landslide locations

    Exploring the Potential of Portable Spectroscopic Techniques for the Biochemical Characterization of Roots in Shallow Landslides

    Get PDF
    In the present work, Raman, Fourier Transform Infrared (FTIR) and elemental Laser-Induced Breakdown Spectroscopy (LIBS) spectroscopic techniques were used for the assessment of the influence of plant root composition towards shallow landslide occurrence. For this purpose, analyses were directly carried out on root samples collected from chestnut forests of the Garfagnana basin (northern Apennines, Italy) in different areas devoid and affected by shallow landslides due to frequent heavy rain events. Results have highlighted a correlation between the biochemical constituents of wooden roots and the sampling areas. In particular, different content of lignin/cellulose, as well as minerals nutrients, have been detected in roots collected where shallow landslides occurred, with respect to more stable areas. The results achieved are in line with the scientific literature which has demonstrated the link between the chemical composition of roots with their mechanical properties and, in particular, tensile strength and cohesion. Finally, portable spectroscopic instrumentations were employed without the need for either any sample preparation for Raman and LIBS spectroscopy or minimal preparation for FTIR spectroscopy. This novel and fast approach has allowed achieving information on the content of the major constituents of the root cell, such as cellulose and lignin, as well as their mineral nutrients. This approach could be reasonably included among the vegetation protection actions towards instability, as well as for the evaluation of shallow landslide susceptibility, combining geological, vegetational and biochemical parameters with sustainability

    Mapping forest windthrows using high spatial resolution multispectral satellite images

    Get PDF
    Wind disturbances represent the main source of damage in European forests, affecting them directly (windthrows) or indirectly due to secondary damages (insect outbreaks and forest fires). The assessment of windthrows damages is very important to establish adequate management plans and remote sensing can be very useful for this purpose. Many types of optical remote sensing data are available with different spectral, spatial and temporal resolutions, and many options are possible for data acquisition, i.e. immediately after the event or after a certain time. The objective of this study is to compare the windthrows mapping capabilities of two multispectral satellite constellations (i.e. Sentinel-2 and PlanetScope) characterized by very different spectral, spatial and temporal resolutions, and to evaluate the impact of the acquisition conditions on the mapping results. The analysed area, with an extent of 732 km2, is located in the Trentino-South Tyrol region (Italy) which was affected by the Vaia storm on the 27th-30th of October 2018, causing serious forest damages. The change vector analysis technique was used to detect the windthrows. For each data source, two pairs of images were considered: 1) pre- and post- event images acquired as close as possible to the event; 2) pre- and post- event images acquired at optimal conditions, i.e. at similar phenological state and similar illumination conditions. The results obtained with the two satellite constellations are very similar despite their different resolutions. Data acquired in optimal conditions allowed having the best detection rate (accuracy above 80 %), while data acquired just after the event showed many limitations. Improved spatial resolution (PlanetScope data) allows for a better delineation of the borders of the windthrow areas and of the detection of smaller windthrow patche

    Ossigenazione extracorporea a membrana (ECMO) nel neonato e nel bambino con insufficienza respiratoria intrattabile

    No full text
    Extracorporeal membrane oxygenation (ECMO) has become a nearly standard treatment for neonates with refractory hypoxemic respiratory failure due to various disease. Even though in the non-neonatal age the experience is less extensive, an increased widespread interest on the possible applications in children with severe life-threatening respiratory or cardiovascular insufficiency is well documented in the literature. General contraindications include presence of active bleeding, underlying lethal disease, congenital malformations, or severe brain damage. Whilst in the neonatal population common entry criteria have been widely accepted, the identification of precise parameters capable to predict mortality and thus indicating an ECMO support in older patients are still lacking. At present, nonetheless, more than 10.000 newborns and 1.000 children with severe respiratory insufficiency at high mortality risk have received an ECMO treatment, with a survival rate of more than 80% and 50%, respectively. The initial results of our ECMO program for both neonatal and pediatric patients with refractory respiratory failure are encouraging, both in terms of mortality and morbidity, and they will be briefly discussed

    Extracorporeal membrane oxygenation (ECMO) in the newborn infant and the child with intractable respiratory failure,Ossigenazione extracorporea a membrana (ECMO) nel neonato e nel bambino con insufficienza respiratoria intrattabile

    No full text
    Extracorporeal membrane oxygenation (ECMO) has become a nearly standard treatment for neonates with refractory hypoxemic respiratory failure due to various disease. Even though in the non-neonatal age the experience is less extensive, an increased widespread interest on the possible applications in children with severe life-threatening respiratory or cardiovascular insufficiency is well documented in the literature. General contraindications include presence of active bleeding, underlying lethal disease, congenital malformations, or severe brain damage. Whilst in the neonatal population common entry criteria have been widely accepted, the identification of precise parameters capable to predict mortality and thus indicating an ECMO support in older patients are still lacking. At present, nonetheless, more than 10.000 newborns and 1.000 children with severe respiratory insufficiency at high mortality risk have received an ECMO treatment, with a survival rate of more than 80% and 50%, respectively. The initial results of our ECMO program for both neonatal and pediatric patients with refractory respiratory failure are encouraging, both in terms of mortality and morbidity, and they will be briefly discussed

    Diagnosis and management of urinary tract infections in children aged 2 months to 3 years in the Italian emergency units: the ItaUTI study

    Get PDF
    Urinary tract infections (UTIs) are among the most frequent bacterial diseases in infants and children. Physician adherence to recommendations is notoriously often poor, but no data are available on UTIs management in the emergency setting. In this multicenter national study, we investigated the policies regarding UTIs management in children aged 2 months to 3 years in Italian emergency units. Between April and June 2021, directors of the emergency units were invited to answer an online survey on the following items: diagnostic approach to children with fever without an apparent source, therapeutic approach to UTIs, the use of kidney and urinary tract ultrasound, and the criteria for hospitalization. A total of 121 (89%) out of 139 of invited units participated in the study. Overall, units manage children with a suspected or confirmed UTI according to available recommendations for most of the items. However, in almost 80% (n = 94) of units, a sterile perineal bag is used to collect urine for culture. When urine is collected by cathether, heterogeneity exists on the threshold of bacterial load considered for UTI diagnosis. Conclusions: Available recommendations on UTIs in children are followed by Italian emergency units for most of the items. However, the methods to collect urine specimens for culture, one of the crucial steps of the diagnostic work-up, often do not align with current recommendations and CFU thresholds considered for diagnosis largely vary among centers. Efforts should be addressed to validate and implement new child and family friendly urine collection techniques.What is Known:• Several guidelines are published on the management of children with suspected or confirmed urinary tract infection.• No data are available on the management of pediatric urinary tract infections in the emergency setting.What is New:• Almost 80% of the Italian emergency units employ a sterile perineal bag to collect urine for culture.• Diagnostic CFU thresholds largely vary among centers
    corecore