509 research outputs found
TECNICHE DI CARTOGRAFIA DIGITALE PER LA REDAZIONE DI MAPPE DI DETTAGLIO DEL SUOLO
The goal of this work was to produce high-quality thematic maps for an Apennine area, using digital soil mapping (DSM) techniques; various statistical methods were applied starting from 30 geomorphometric variables, obtained from the digital elevation model (DEM) with 10-m pixel. The aim was to: i) obtain cartographic products, with a low cost both in terms of time and money; and ii) verify their reliability.
The study area, consisting of two adjacent valleys (Oltrepo Pavese, PV), included Val di Nizza (27 km2), Val Ardivestra (47 km2) and the "plaque" of Pizzocorno-Pietragavina (17 km2). With regard to soil data acquisition, two different soil surveys were carried out, one of which was planned to obtain a minimum representative sample of soil variability of the area. A total of 132 georeferenced soil profiles were opened and described, and 468 soil samples were collected and analyzed for the main chemical and physical soil properties.
The thesis work was composed by 7 chapters. The first chapter (Study site) provided the study area description, focusing on main factors which affect pedogenetic processes, such as climate, vegetation, geomorphology and geology. Among these factors, geological characterization was carefully described due to its strong relationship with soil. Previous soil data and land use history were also considered and described.
The second and the third chapters were relative to digital soil mapping and geomorfometric variables respectively.
In the Digital Soil Mapping chapter the theoretical and practical aspects, needed for obtaining soil thematic maps using DSM techniques, were reported. The DSM methodology, its related problems and the different approaches used to represent the pedogenetic processes, were addressed. The two approaches adopted in this work (soil-landscape paradigm and geomorphometric assessment of topography) were described in detail.
The third chapter (Geomorphometric variables) included the preparatory study for soil mapping. In this section the geomorphometric variables were calculated; various inference methods were tested, with different combinations of variables calculated with open source and/or proprietary software. Before statistical elaborations the characteristics of the geomorphometric variables used as predictors were studied: in particular, the trend was analyzed, as well as reciprocal correlations and collinearity. Particular interest has been directed to the outliers, considering the influence they can have on calculations. From the analyzes carried out emerged that the outliers are connected to the calculation of the variables themselves and there is some degree of correlation, which is not said to correspond to collinearity. This redundancy of statistical information, however, corresponds to a different interpretation of the physical morphology of the land, which can be considered an additional information value to be used in statistical elaborations.
The fourth chapter (Soil Sampling Design) provided a guidance for soil sampling strategy. The aim was to reduce time and costs by providing a map of the representative sampling areas. The selected approach was simple from both conceptual and computational point of view. It was based on the soil-landscape paradigm and on landform segmentation. Firstly, a principal component analysis (PCA) was carried out on the overall set of geomorphometric variables; then on the base of PCA results, eight variables were selected and used as input variables of a neural network (Self-Organizing Feature Maps), resulting in the identification of eight different geomorphometric units.
In order to increase the pedological detail, the map was cross-checked with the geological map obtaining a total of 25 land units. To assess the quality of the results, the distribution of the geomorphometric variables of the study area was compared with that of the sampling points: for 77% of cases the target was statistically achieved.
The remaining three chapters are relative to map production of soil characteristics and qualities: soil depth, soil erosion and soil types.
The Solum Thickness Map chapter was relative to production and validation methodologies of solum thickness. Two approaches were used: artificial neural network (ANN) and partial least square regression (PLSR). By adopting two methods based on the PCA results, 28 different sub-sets of geomorphometric variables were created; different ANN types were applied to each of them, obtaining a total of 84 models. With the PLSR approach, 18 models were created by varying the number of retained components. The results showed that: i) the ANN approach was better than PLSR approach; ii) increasing the number of geomorphometric variables increased the prediction perfomance. An external dataset was used for validation. The map with the best performance achieved a R2 values of 0.89 for the validation set and 0.88 for the test set.
The Soil Erosion Map chapter included a description of the different erosion types existing in the study area and explained the approach adopted to produce the soil erosion map. Since soil erosion was present in different forms the following maps were produced: i) a general map of soil erosion; ii) a map of the areas subjected to calanchi dynamics; iii) a map of susceptibility to shallow landslides.
The first two maps were obtained using discriminant analysis (DA), while the last using a standard neural network for pattern recognition; they used a training set consisting of field detection points and five different results were obtained for each map. The results were evaluated using confusion matrices: the best results showed a non-error rate of 81 and 87% respectively. For the map of susceptibility to shallow landslides, no comprehensive analysis was performed, but 12 models with different sub-sets of variables were constructed, based on the PCA results performed on 112 landslide trigger points. The best model correctly classified 80% of the validation set and 64% of the test set points.
The Soil Types chapter was relative to the production of: i) a taxonomical soil map according to WRB classification; and ii) a typological soil map according to a classification based on soil texture and thickness. These maps were produced using DA and evaluated using confusion matrices. The first map included nine soil types at the second level of WRB classification; the best cartographic product had a non-error rate of 58%. The second map included twelve soil categories. The obtained map had a non-error rate of 55%, but some soil classes were characterized by high misclassification risk values
Tetrahedrite-(Hg), a new 'old' member of the tetrahedrite group
Tetrahedrite-(Hg), Cu6(Cu4Hg2)Sb4S13, has been approved as a new mineral species using samples from Buca della Vena mine (hereafter BdV), Italy, Jedová hora (Jh), Czech Republic and RoŽÅ 1/2ava (R), Slovakia. It occurs as anhedral grains or as tetrahedral crystals, black in colour, with metallic lustre. At BdV it is associated with cinnabar and chalcostibite in dolomite veins. At Jh, tetrahedrite-(Hg) is associated with baryte and chalcopyrite in quartz-siderite-dolomite veins; at R it is associated with quartz in siderite-quartz veins. Tetrahedrite-(Hg) is isotropic, greyish-white in colour, with creamy tints. Minimum and maximum reflectance data for Commission on Ore Mineralogy wavelengths in air (BdV sample), R in %) are 32.5 at 420 nm; 32.9 at 546 nm; 33.2 at 589 nm; and 30.9 at 650 nm. Chemical formulae of the samples studied, recalculated on the basis of 4 (As + Sb + Bi) atoms per formula unit, are: (Cu9.44Ag0.07)Σ9.51(Hg1.64Zn0.36Fe0.06)Σ2.06Sb4(S12.69Se0.01)Σ12.70 (BdV), Cu9.69(Hg1.75Fe0.25Zn0.06)Σ2.06(Sb3.94As0.06)S12.87 (Jh) and (Cu9.76Ag0.04) Σ9.80(Hg1.83Fe0.15Zn0.10)Σ2.08(Sb3.17As0.58Bi0.25)S13.01 (R). Tetrahedrite-(Hg) is cubic, I3m, with a = 10.5057(8) Å, V = 1159.5(3) Å3 and Z = 2 (BdV). Unit-cell parameters for the other two samples are a = 10.4939(1) Å and V = 1155.61(5) Å3 (Jh) and a = 10.4725(1) Å and V = 1148.55(6) Å3 (R). The crystal structure of tetrahedrite-(Hg) has been refined by single-crystal X-ray diffraction data to a final R1 = 0.019 on the basis of 335 reflections with Fo > 4σ(Fo) and 20 refined parameters. Tetrahedrite-(Hg) is isotypic with other members of the tetrahedrite group. Mercury is hosted at the tetrahedrally coordinated M(1) site, along with minor Zn and Fe. The occurrence of Hg at this position agrees both with the relatively large M(1)-S(1) bond distance (2.393 Å) and the refined site scattering. Previous occurrences of Hg-rich tetrahedrite and tetrahedrite-(Hg) are reviewed, and its relations with other Hg sulfosalts are discussed
Failures in Reflective Functioning and Reported Symptoms of Anxiety and Depression in Bereaved Individuals: A Study on a Sample of Family Caregivers of Palliative Care Patients
Introduction. This study aims at examining the role of failures in reflective functioning in predicting anxiety and depression among family caregivers of palliative care patients deceased for at least one year. Methods. A sample of 157 bereaved participants (77.1% females, mean age = 43.50 ± 14.04 years) completed the Hospital Anxiety and Depression Scale (HADS) and the Reflective Functioning Questionnaire (RFQ). Results. Results of the correlational analysis showed that anxiety was positively correlated with uncertainty about mental states, indicating one type of impairment in reflective functioning. Anxiety was also negatively correlated with the certainty about mental states. Depression was negatively correlated with certainty but not with uncertainty about mental states. The results of regression analysis indicated that gender and certainty about mental states were statistically significant predictors of anxiety, with the final model explaining 23% of the variance. The results also showed that gender, the condition of being the main caregiver, and the certainty about mental states were significant predictors of depression, with the final model predicting 14% of the variance. Conclusions. Overall, the results of this study point out that the bereaved individuals who scored low on certainty about mental states reported more symptoms of anxiety and depression. Psychological interventions to prevent mental disorders and to promote psychological health in the context of palliative care should carefully consider these findings
Language-Related Skills in Bilingual Children With Specific Learning Disorders
Purpose: The purpose of this study is to better understand the characteristics of the language-related skills of bilingual children with specific learning disorders (SLD). The aim is achieved by analyzing language-related skills in a sample of bilingual (Italian plus another language) and Italian monolingual children, with and without SLD. Patients and methods: A total of 72 minors aged between 9 and 11 were recruited and divided into four groups: 18 Italian monolingual children with SLD, 18 bilingual children with SLD, 18 Italian monolingual children without SLD, and 18 bilingual children without SLD. Each child underwent tests to evaluate different aspects of language skills: lexical and grammar, metalanguage and executive functions. Results: With regard to lexical and grammatical skills, the conditions of SLD and bilingualism both impact naming in terms of total number of errors for words with low frequency of use, while the condition of SLD has an effect on semantic errors for words with low frequency of use. The condition of bilingualism impacts on the total errors for words with high frequency of use and on circumlocution-type errors for words with low frequency of use. There were significant effects of bilingualism and SLD on the metalinguistic test for understanding implicit meaning, and an impact of SLD on phonological awareness was also found. Conclusion: The results suggest that both SLD and bilingualism have an effect on some lexical skills, in particular for words with low frequency of use. Both conditions, bilingualism and SLD, seem to impact on metalinguistic abilities that depend on lexical knowledge. These findings reinforce the importance of improving understanding of the neuropsychological profile of bilingual children with SLD
Gender and Psychosocial Differences in Psychological Resilience among a Community of Older Adults during the COVID-19 Pandemic
The study aimed at exploring gender and additional sociodemographic differences in psychological resilience, as well as the association between resilience and psychological distress in older adults, during the first lockdown in Italy, due to the COVID-19 pandemic. Participants attended an online survey during the first lockdown in May 2020. Psychological distress was assessed through the Depression Anxiety Stress Scale-21, the Resilience Scale (RS) was administered to evaluate psychological resilience, and sociodemographic variables were also collected. The study involved 108 community older adults (mean age 70.02 ± 3.5 years). Comparisons revealed that women reported significantly lower total scores of RS (p = 0.027), as well as lower levels of resilience-related domains, namely Meaningfulness (p = 0.049), Self-Reliance (p = 0.011), Perseverance (p = 0.035), and Existential Aloneness (p = 0.014), compared to men. Significantly higher RS scores were found in older adults being involved in a relationship, compared to those not involved in relationships (p = 0.026), and in older adults with children (p = 0.015), compared to those without offspring, suggesting the importance for older adults of not dealing alone with such a dramatic and stressful event, such as the pandemic. Negative correlations were found between psychological resilience and stress, depression, and anxiety. Linear regressions revealed that lower RS total scores, as well as lower scores in the majority of the RS scales, were associated with greater levels of stress, greater levels of anxiety, and greater levels of depressive symptoms. This study suggested that older women might appear more vulnerable in facing the pandemic, compared to men; having not lived alone through the lockdown period might also be considered as a factor of resilience for older adults
'Candidatus Phytoplasma solani' interferes with the distribution and uptake of iron in tomato
Background: \u2018Candidatus Phytoplasma solani\u2019 is endemic in Europe and infects a wide range of weeds and cultivated plants. Phytoplasmas are prokaryotic plant pathogens that colonize the sieve elements of their host plant, causing severe alterations in phloem function and impairment of assimilate translocation. Typical symptoms of infected plants include yellowing of leaves or shoots, leaf curling, and general stunting, but the molecular mechanisms underlying most of the reported changes remain largely enigmatic. To infer a possible involvement of Fe in the host-phytoplasma interaction, we investigated the effects of \u2018Candidatus Phytoplasma solani\u2019 infection on tomato plants (Solanum lycopersicum cv. Micro-Tom) grown under different Fe regimes.
Results: Both phytoplasma infection and Fe starvation led to the development of chlorotic leaves and altered thylakoid organization. In infected plants, Fe accumulated in phloem tissue, altering the local distribution of Fe. In infected plants, Fe starvation had additive effects on chlorophyll content and leaf chlorosis, suggesting that the two conditions affected the phenotypic readout via separate routes. To gain insights into the transcriptional response to phytoplasma infection, or Fe deficiency, transcriptome profiling was performed on midrib-enriched leaves. RNA-seq analysis revealed that both stress conditions altered the expression of a large (> 800) subset of common genes involved in photosynthetic light reactions, porphyrin / chlorophyll metabolism, and in flowering control. In Fe-deficient plants, phytoplasma infection perturbed the Fe deficiency response in roots, possibly by interference with the synthesis or transport of a promotive signal transmitted from the leaves to the roots.
Conclusions: \u2018Candidatus Phytoplasma solani\u2019 infection changes the Fe distribution in tomato leaves, affects the photosynthetic machinery and perturbs the orchestration of root-mediated transport processes by compromising shoot-to-root communication
From Parental Bonding to Problematic Gaming: The Mediating Role of Adult Attachment Styles
Background: Research has found that parental failures of care during childhood and insecure attachment styles are positively associated with problematic gaming. From a developmental framework, it is possible to hypothesize that attachment styles mediate the relationship between parental bonding and problematic gaming. Methods: This hypothesis was tested in a sample of 598 videogame players (410 males, 68.56%) aged between 18 and 61 years old (M = 26.68, SD = 7.23). Participants were recruited through an online survey. Self-report instruments were administered to assess problematic gaming, parental bonding, and adult attachment styles. Results: Positive paternal care was a direct and negative predictor of problematic gaming, whereas maternal overprotection indirectly predicted problematic gaming through preoccupied attachment. Conclusions: These findings suggest that positive paternal care represents a protective factor for problematic gaming; in contrast, maternal overprotection might foster a negative view of the self in the child, which increases the risk to excessively use videogames, perhaps as a maladaptive coping strategy to regulate negative feelings. Prevention programs might be aimed to improve the responsiveness of parents towards the child’s emotional needs, to prevent the development of problematic gaming. Also, clinical intervention with problematic gamers might foster their feelings of security toward relationships, to promote both a healthier use of videogames and a better quality of life
Cannabis sativa extracts protect LDL from Cu2+-mediated oxidation
Background: Multiple therapeutic properties have been attributed to Cannabis sativa. However, further research is
required to unveil the medicinal potential of Cannabis and the relationship between biological activity and
chemical profile.
Objectives: The primary objective of this study was to characterize the chemical profile and antioxidant properties
of three varieties of Cannabis sativa available in Uruguay during progressive stages of maturation.
Methods: Fresh samples of female inflorescences from three stable Cannabis sativa phenotypes, collected at
different time points during the end of the flowering period were analyzed. Chemical characterization of
chloroform extracts was performed by 1 H-NMR. The antioxidant properties of the Cannabis sativa extracts, and pure cannabinoids, were measured in a Cu2+-induced LDL oxidation assay.
Results: The main cannabinoids in the youngest inflorescences were tetrahydrocannabinolic acid (THC-A, 242 ± 62 mg/g) and tetrahydrocannabinol (THC, 7.3 ± 6.5 mg/g). Cannabinoid levels increased more than twice in two of the mature samples. A third sample showed a lower and constant concentration of THC-A and THC (177 ± 25 and 1 ± 1, respectively). The THC-A/THC rich cannabis extracts increased the latency phase of LDL oxidation by a factor of 1.2–3.5 per μg, and slowed down the propagation phase of lipoperoxidation (IC50 1.7–4.6 μg/mL). Hemp, a cannabidiol (CBD, 198 mg/g) and cannabidiolic acid (CBD-A, 92 mg/g) rich variety, also prevented the formation of conjugated dienes during LDL oxidation. In fact, 1 μg of extract was able to stretch the latency phase 3.7 times and also to significantly reduce the steepness of the propagation phase (IC50 of 8 μg/mL). Synthetic THC lengthened the duration of the lag phase by a factor of 21 per μg, while for the propagation phase showed an IC50 ≤ 1 μg/mL. Conversely, THC-A was unable to improve any parameter. Meanwhile, the presence of 1 μg of pure CBD and CBD-A increased the initial latency phase 4.8 and 9.4 times, respectively, but did not have an effect on the propagation phase.
Conclusion: Cannabis whole extracts acted on both phases of lipid oxidation in copper challenged LDL. Those
effects were just partially related with the content of cannabinoids and partially recapitulated by isolated pure
cannabinoids. Our results support the potentially beneficial effects of Cannabis sativa whole extracts on the initial
phase of atherosclerosis
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