170,161 research outputs found
Current status, uncertainty and future needs in soil carbon monitoring
No full textThe need for cataloguing global soil carbon was recently highlighted by Gianelle et
al., (2010) in a letter to Science, where the importance of considering soils and
SOM sensitivity to temperature were underscored. Moreover the need to understand
the global distribution of soil carbon is a real concern for climate change
international policy issues. In order to establish the status of our knowledge regarding global soil carbon stocks in relation to climate change problems, an International workshop named G-SCAN (Global Soil Carbon Network) was organized in Florence (20-21, April) by the Edmund Mach Foundation (San Michele All'Adige, Italy). Some of the top scientists working on soil carbon dynamics from Europe and the US discussed the topic according to three working groups: a) Methodological standardization of soil C stocks; b) Detecting changes in Soil C; and c) Long-term experiments. Starting from real situations of soil carbon inventories and databases, the main problems and needs related to monitoring were highlighted and discussed. The results of the workshop will be published soon as an opinion paper in a peer reviewed journal. The unresolved problems still concerning soil carbon monitoring were discussed and could serve as a basis to homogenize current databases,
compare soil inventories and improve global soil mappin
Association of plasma fibrinogen, C-reactive protein and G-455>A polymorphism with early atherosclerosis in the VITA Project cohort.
No full textThrombopoietin receptor agonists in hereditary thrombocytopenias
No full textHereditary thrombocytopenias (HTPs) constitute a heterogeneous group of diseases characterized by a reduction in platelet count and a potential bleeding risk. As a result of advances in diagnostic methods, HTPs are increasingly being identified, and appear to be less rare than previously thought. Most HTPs do not have effective treatments, except for platelet transfusion when bleeding occurs and in preparation for procedures associated with a risk of bleeding. Preliminary clinical evidence suggests that thrombopoietin receptor agonists (TPO-RAs) with an established use in the treatment of certain acquired thrombocytopenias are well tolerated and provide clinical benefits in patients with some forms of HTP. These drugs may therefore be considered for the treatment of HTPs in clinical practice. However, caution and close monitoring are recommended, owing to the absence of long-term safety data and the potential risks posed by prolonged bone marrow stimulation in certain HTPs. In this review, we summarize the available clinical data on TPO-RAs in the treatment of HTPs, and discuss their use in patients with these disorders. We believe that TPO-RAs will play a major role in the treatment of HTPs, particularly myosin heavy chain 9-related disease, Wiskott-Aldrich syndrome, X-linked thrombocytopenia, and thrombocytopenia caused by THPO mutations
IoT technology as a support tool for the calculation of Crop Water Stress Index in a Vitis vinifera L. cv. Chardonnay vineyard in Northern Italy
No full textNowadays agriculure is one of the main sectors affected by climate change. The continuous increase of temperature and drought periods are posing serious problems in terms of shift of plants’ phenological phases and a reduction of crop yield quantity and quality. Among the indexes used to assess plant water status, the Crop Water Stress Index (CWSI) is one of the most studied due to its ease of calculation. We performed a study in a vineyard in Trentino (San Michele all’Adige, Northern Italy) where we took advantage of IoT Technology to build a device to measure leaf temperature and automatically calculate the CWSI. Parameters necessary to determine the CWSI were the temperature of a non-transpiring leaf, (artificial 3D printed black leaf), and the temperature of a fully-transpiring leaf (wet bulb temperature of the air). We compared various types of thermometers to measure temperatures of the real leaves, and with repeated measuring campaigns performed during the summer of 2022 we could obtain spatial maps of CWSI that could highlight the stress levels of the vineyard and therefore address the irrigation management in a context of precision agricultur
Effects of tree species biodiversity on soil C and N pools: a regional case study in northern Italy
No full textSite conditions are known to affect local resource availability, therefore being an
important driver of plant species diversity. In this context, soil fertility is thought to
influence the relationship between plant species diversity and climate in forests
ecosystems. The data collected with the Regional Forest Carbon Inventory of the
Trento Province (InFoCarb), on 150 plots of 600 m2
size, were used to investigate
possible impacts of tree biodiversity on local soil conditions. Biodiversity was
quantified both as Species Richness and with Biodiversity Indexes (Simpson's Index
and Shannon-Wiener index) moreover, canopy species evenness was expressed by
the Simpson's dominance index by using the proportions of basal area for each
constituent species. Forest floor and mineral soil were collected on three mini-pits
inside each sampling plot. Relationships between the soil C and N pools and tree
biodiversity were investigated with linear regressions whereas Boosted Regression
Trees models were used to highlight the main determinants of canopy species
diversit
Changes in soil organic carbon and nitrogen following forest expansion on grassland in the Southern Alps
No full textThe dominant land-use change in the Southern Alps is grassland abandonment, followed by forest expansion. Forest expansion is commonly thought to increase ecosystem C sequestration, but contradictory results have been reported. Our objective was to investigate soil organic carbon (SOC) and nitrogen (N) changes after forest expansion on abandoned grasslands. A land use and management gradient was identified in a subalpine area of Trentino (Italy) comprising four successional stages: (i) managed grassland (manG), mown and manured annually for more than 100 years; (ii) grassland abandoned 10 years ago (abanG), with shrubs and Picea abies saplings; (iii) early-stage forest (earlyF), dominated by P. abies established on grassland abandoned around 1970; and (iv) old forest (oldF), dominated by Fagus sylvatica and P. abies, representing a reference for long-term forest land use. Organic and mineral soil layers were collected down to 30 cm at eight points within three plots for each successional stage.
Significantly more SOC was stored in organic layers of oldF compared with other successional stages and the organic layer N stocks were higher in oldF compared with manG and abanG. The SOC and N concentrations were higher in the top 10 cm mineral soil of grassland plots compared with forest. The earlyF and oldF stored, on average, 28–35% less SOC in top 10 cm mineral soil compared with manG and abanG when stocks were calculated using equivalent soil mass (ESM) and equivalent soil depth (ESD) approaches respectively. SOC stocks in mineral soil (0–30 cm) calculated with ESD decreased from manG to oldF; when accounting for total stone content, SOC stocks in earlyF and oldF were 40% and 50% lower than in manG, respectively. The inclusion of organic layers offset mineral SOC stock differences when only stones <5 cm were accounted for, but when considering the total stone content, SOC stocks in earlyF remained significantly lower (−31%) than in manG. Tree biomass contributed to higher ecosystem C stocks in oldF, which stored 82–93 Mg ha−1 of C more than grasslands.
Our study revealed a decrease in total SOC stocks after forest expansion on abandoned subalpine grasslands. Tree biomass development contributed to increasing C storage, especially in a long-term forest land use. Forest management should consider that tree biomass and organic layer development require a minimum time period following grassland abandonment to compensate for the decrease in mineral SOC stocks and contribute positively to climate change mitigatio
Changes in SOC stocks and fractions after natural afforestation of alpine grasslands
No full textLand use changes are considered one of the major driving forces of global carbon fluxes and can induce significant alterations of soil organic carbon stocks. In the European Alps, the dominant form of land use change is represented by the abandonment of marginal mountain grasslands and their invasion by tree species, i.e. a transition from grassland to forest. While an increase in live and dead aboveground biomass is commonly reported, the impact on soil organic carbon (SOC) is still unclear. The main objective of the current study was to quantify the effect of abandonment and forest regrowth of mountain grassland on SOC, considering both SOC stocks and its physically separated fractions.
The study area is located in a pre-alpine area of the Trentino region (Italy), with an elevation of about 1150 m. We compared four land uses representing a transition from grassland to forest: I) managed grassland; II) grassland abandoned 10 years ago; III) natural afforested grassland abandoned after 1973; IV) reference forest, already present in 1861. The afforested area and the reference forest are both dominated by Norway spruce (Picea abies) and beech (Fagus sylvatica). For each land use intensity three sampling areas were selected. In each area we collected eight soil cores to a depth of 30 cm, dividing the soil core in 4 depth increments. To assess changes in SOC stocks, we measured bulk density, stoniness, root biomass and organic carbon content. Mineral SOC stocks were calculated using both an equivalent depth and an equivalent mass approach. Changes in SOC fractions were assessed using aggregate size fractionation (Cambardella and Elliott, 1993) and size-density fractionation procedures.
Preliminary results show higher soil C concentrations in forest sites compared to grassland. This can be attributed to higher C inputs and lower mineralization rates due to a higher degree of soil aggregation and protection of soil organic matter, but also to the higher stoniness registered in forest sites which can lead to a concentration of C inputs in a smaller volume of soil. If C stocks are computed using an equivalent soil depth approach, mineral SOC stocks are lower in forest land uses compared to grassland while no significant difference emerges if an equivalent soil mass approach is used. The aggregate size fractionation highlighted an increase in C stored in large macroaggregates following afforestation and a decrease in silt and clay size fraction (<53 μm). The strongest change shown through the size-density fractionation procedure is a three-fold increase in C stored in free organic matter (POM) from grassland to forest. Intriguingly, we found a decreasing trend in the microaggregate (53-250 μm) fraction as well as for the mineral-associated heavy fraction following afforestation, suggesting a decrease in the more stable SOC fraction, while the labile fractions increase
Age-adjusted reference limits for carotid intima-media thickness as better indicator of vascular risk: population-based estimates from the VITA project.
No full textThe role of ground reference data collection in the prediction of stem volume with LiDAR data in mountain areas
No full textGround reference data collection represents an important element in the prediction of stem volume with LiDAR-derived variables, and at present it is the most expensive part of such analyses. In this paper two aspects of ground reference data collection were analyzed: (1) the positioning error of the ground plots; and (2) the optimal number of training plots. A system for the prediction of stem volume at area-based level was adopted. LiDAR data were preprocessed and 13 variables describing both height and coverage were extracted. Models were defined using a stepwise ordinary least square (OLS) regression. Three experiments were conducted: (i) the role of the plots positioning error on prediction accuracy; (ii) the influence of random downsampling of plot numbers on prediction accuracy; and (iii) the influence of a stratified downsampling of plot numbers on prediction accuracy based on LiDAR-derived variables. A dataset comprising 799 ground plots was used. They were distributed throughout a mountainous area in the Southern Alps, where the presence of a complex landscape increases the uncertainty of the Global Positioning System (GPS) accuracy, and where a large variety of tree forest species and climatic environments make it necessary to have a large number of sample plots for accurate characterization of the study area. All the experiments provided important indications for LiDAR based forest inventories: the GPS error did not significantly influence the prediction accuracy and it was possible to reduce the number of training samples without compromising the generalization ability of the prediction model. Leading on from these findings, a new ground sampling protocol based on genetic algorithms was proposed. The new protocol allowed us to obtain promising results for the considered dataset: using only 53 training plots, instead of 534 in the original dataset, we obtained the same results for the validation set. These results, obtained in a complex mountainous area, are representative of Alpine environments and allow us to infer that similar (or better) results could also be obtained within non mountainous areas
Catalytic Stereoselective SN1-Type Reactions Promoted by Chiral Phosphoric Acids as Brønsted Acid Catalysts
No full textIn recent years, the field of organocatalysis has extensively explored the use of carbenium ions for practical C−C bond forming reactions. In order to control the formation of new stereocenters, the generation of carbenium ions was investigated by exploring asymmetric Brønsted acid catalysis. Oxocarbenium ions, iminium ions, and other carbenium ions stabilized by heteroatoms could also be generated by Brønsted acid catalysis, through the departure of suitable leaving groups. The aforementioned reactivity has recently been exploited leading to remarkable achievements. The application of chiral Brønsted acids in the generation of heteroatom stabilized carbenium ions has recently been investigated, with the demonstration of important results. Although diverse architectural arrays of Brønsted acid catalysts were conceived, BINOL-derived phosphoric acids have played a dominant role in this area of research. Their low pKa values combined with the possibility to alter their architecture, and their ability to assemble ordered transition states was exploited in different SN1-type reactions allowing the formation of a variety of products with high enantiomeric excesses. In addition, the generation of highly stabilized chiral counter anions allowed the exploitation of counterion asymmetric catalysis with various nucleophiles
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