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Quantifying the dynamics of Root Distribution and Root Reinforcement of Forest Tree Species and their Applications in Forest Management
Full text linkForest plays a vital role in ecosystem services, including soil stabilization, erosion control, biodiversity conservation, and carbon sequestration. In mountainous regions, tree roots significantly contribute to the prevention of rainfall-induced shallow landslides and soil erosion by reinforcing the soil and increasing its shear strength. However, quantifying root distribution, root reinforcement, and belowground biomass across spatial scales remains a major scientific challenge, given the complexity of root systems, high variability in site conditions, and the lack of spatially explicit field data. This thesis addresses these challenges by combining field measurements, laboratory mechanical tests, and advanced modeling techniques to evaluate the ecological role of tree roots in both stabilizing slopes and sequestering carbon. The study focuses on two important tree species: Populus deltoides × nigra "Tasman" poplar in a study case in New Zealand and Cryptomeria japonica in Switzerland and Japan. These species are widely used in bioengineering and afforestation due to their deep root systems, rapid growth, and adaptability to diverse site conditions. For the Tasman poplar, extensive field excavations were carried out around 4 individual trees of various sizes, with four trenches (360o) at different distances around the stem. Additionally, root distribution in 10 transects locating from sparse to dense planting zones was recorded. Root mechanical properties were assessed through 124 tensile and 66 pullout tests with root diameters up to 0.04 m, conducted within a 26-year-old stand on a pastoral hill slope in New Zealand. The Root Distribution Model (RDM), Root Bundle Model with Weibull survival function, and Root Reinforcement Model (RRM) were calibrated and validated. RDM showed strong performance in predicting root spatial patterns, particularly in sparse stands ( 200 sph. RRM underestimates root force within single tree root systems but performed better in the transects locating in sparse zone. In all cases, RRM predicted well basal root reinforcement. The thesis work revealed that "Tasman" poplars need at least 20 years to reach minimum values of lateral root reinforcement at the stand scale and at least 30 years are needed to reach root reinforcement sufficient for shallow landslide stabilization depending on their disposition. RDM was utilized to estimate root biomass for Tasman poplars. The measurements revealed that root biomass is positively correlated with tree sizes and negatively correlated with soil depth and distance from the stem. RDM underestimated root distribution and root biomass in poplar trees, could be due to missing data of root quantities in the dense zone from 0 to 1.5 m from the stem and at distance further than 4.5 m. A generalized allometric equation was also developed by integrating our field data with existing data from previous studies at same location for estimating root dry weight across a wide DBH range, allowing accurate, non-destructive estimation of root biomass and carbon stocks. A single mature tree can store over 170 kg of carbon in its root system, highlighting its significant potential for climate change mitigation. In the case of Cryptomeria japonica, data from forest stands in China, Japan and Switzerland were used to quantify and compare root distribution and root mechanical properties. Integrating laboratory tensile tests and field pullout tests for roots ≤10 mm proved to be effective in predicting a representative mechanical profile for RBMw calibration. Coarse root distribution was generally consistent between Switzerland and Japan while fine root patterns and basal reinforcement differed with Swiss stands exhibited stronger reinforcement in upper soil layers (0 - 0.15 m) while Japanese stands showed deeper root anchorage (0.15 - 0.45 m). [continue]Forest plays a vital role in ecosystem services, including soil stabilization, erosion control, biodiversity conservation, and carbon sequestration. In mountainous regions, tree roots significantly contribute to the prevention of rainfall-induced shallow landslides and soil erosion by reinforcing the soil and increasing its shear strength. However, quantifying root distribution, root reinforcement, and belowground biomass across spatial scales remains a major scientific challenge, given the complexity of root systems, high variability in site conditions, and the lack of spatially explicit field data. This thesis addresses these challenges by combining field measurements, laboratory mechanical tests, and advanced modeling techniques to evaluate the ecological role of tree roots in both stabilizing slopes and sequestering carbon. The study focuses on two important tree species: Populus deltoides × nigra "Tasman" poplar in a study case in New Zealand and Cryptomeria japonica in Switzerland and Japan. These species are widely used in bioengineering and afforestation due to their deep root systems, rapid growth, and adaptability to diverse site conditions. For the Tasman poplar, extensive field excavations were carried out around 4 individual trees of various sizes, with four trenches (360o) at different distances around the stem. Additionally, root distribution in 10 transects locating from sparse to dense planting zones was recorded. Root mechanical properties were assessed through 124 tensile and 66 pullout tests with root diameters up to 0.04 m, conducted within a 26-year-old stand on a pastoral hill slope in New Zealand. The Root Distribution Model (RDM), Root Bundle Model with Weibull survival function, and Root Reinforcement Model (RRM) were calibrated and validated. RDM showed strong performance in predicting root spatial patterns, particularly in sparse stands ( 200 sph. RRM underestimates root force within single tree root systems but performed better in the transects locating in sparse zone. In all cases, RRM predicted well basal root reinforcement. The thesis work revealed that "Tasman" poplars need at least 20 years to reach minimum values of lateral root reinforcement at the stand scale and at least 30 years are needed to reach root reinforcement sufficient for shallow landslide stabilization depending on their disposition. RDM was utilized to estimate root biomass for Tasman poplars. The measurements revealed that root biomass is positively correlated with tree sizes and negatively correlated with soil depth and distance from the stem. RDM underestimated root distribution and root biomass in poplar trees, could be due to missing data of root quantities in the dense zone from 0 to 1.5 m from the stem and at distance further than 4.5 m. A generalized allometric equation was also developed by integrating our field data with existing data from previous studies at same location for estimating root dry weight across a wide DBH range, allowing accurate, non-destructive estimation of root biomass and carbon stocks. A single mature tree can store over 170 kg of carbon in its root system, highlighting its significant potential for climate change mitigation. In the case of Cryptomeria japonica, data from forest stands in China, Japan and Switzerland were used to quantify and compare root distribution and root mechanical properties. Integrating laboratory tensile tests and field pullout tests for roots ≤10 mm proved to be effective in predicting a representative mechanical profile for RBMw calibration. Coarse root distribution was generally consistent between Switzerland and Japan while fine root patterns and basal reinforcement differed with Swiss stands exhibited stronger reinforcement in upper soil layers (0 - 0.15 m) while Japanese stands showed deeper root anchorage (0.15 - 0.45 m). [continue
Preserving Esthetics: Interventional Radiotherapy (Brachytherapy) as a Potential Alternative to Surgery for Basal Cell Carcinoma of the Midface
No full textBackground/Objectives: High-dose-rate (HDR) interventional radiotherapy (IRT) represents a valuable treatment alternative for basal cell carcinoma (BCC) of the midface, especially in the presence of esthetic or functional issues related to surgery. This retrospective study examines the clinical outcomes of patients who underwent HDR-IRT at our institution. Methods: Patients (pts) with histologically confirmed midface BCC were treated with HDR-IRT using superficial, interstitial, or endocavitary implants depending on tumor characteristics. Fractionation regimens were tailored to tumor location: 45 Gy in 9 fractions twice a day (the cheeks/lips) and 44 Gy in 14 fractions (the nose, with the first and last fractions delivering 4 Gy each, administered once daily, and the remaining 12 fractions delivering 3 Gy each, administered twice daily (BID) with an inter-fraction interval of at least 6 h). Treatment efficacy was assessed based on local control rates, toxicity (CTCAE criteria), and cosmetic outcomes. Results: Eight patients were considered. The most common tumor site was the nose (seven patients, 87.5%), followed by the upper lip. Tumors were either primary (three patients, 37.5%) or residual/recurrent after previous surgery with involved margins (five patients, 62.5%). The median follow-up was 6 months (range: 1–19 months). Clinical local control was achieved in all cases, with persistent alteration at dermoscopy in one patient six months after the completion of treatment. Acute toxicities were minimal, with two patients developing grade 3 skin toxicity, which resolved within 1–3 months with topical management. Cosmetic outcomes were favorable across all patients. Conclusions: HDR-IRT is a well-tolerated, effective, and cosmetically favorable treatment for midface BCC. Our institutional experience supports its use as an alternative to surgery in cosmetically sensitive areas and in selected patients/lesions unfit for surgery. Endocavitary implants appear to be an effective option to cover the full thickness nasal wall without resorting to interstitial implants
Digital Marketing strategies for the internationalization of agri-food industries: Theoretical insights and Italian case examples with a focus on China as a key export market
No full textThis research paper explores how digital technologies can effectively support and improve the internationalization processes of agri-food enterprises, with a specific focus on innovation, competitiveness, and strategies for market expansion. Structured into key analytical phases, this paper facilitates a deeper understanding of its subject matter
Role of ACE1, ACE2, and CCR5-Δ32 Polymorphisms in the Transmission of SARS-CoV-2 to Intimate Contacts
No full textBackground. Despite the high transmissibility of SARS-CoV-2, some individuals remain uninfected despite prolonged exposure to a high viral load, suggesting the involvement of an innate resistance mechanism, possibly underpinned by the host’s genetic factors. The angiotensin-converting enzyme-1 (ACE1), ACE2, and C-C Chemokine Receptor 5 (CCR5) polymorphisms have been shown to influence susceptibility to the infection. In this study, the role of ACE1, ACE2, and CCR5 gene polymorphisms in modulating susceptibility to SARS-CoV-2 infection within the context of intimate contact was evaluated. Methods. A cohort of heterosexual couples from Northern Sardinia, characterized by a homogenous genetic background, was recruited during the initial pandemic wave (March–June 2020). In each couple, one partner (index case) tested positive for SARS-CoV-2 by at least two consecutive independent molecular tests (real-time polymerase chain reaction: RT-PCR) on nasopharyngeal swabs. Bed-sharing partners of SARS-CoV-2 positive index cases, resistant and susceptible to the infection, were genotyped for ACE1 287 bp Alu repeat insertion/deletion (I/D) polymorphism, ACE2 G8790A (rs2285666) variant, and a 32-base pair deletion (Δ32) of CCR5. Resistant and susceptible partners to the infection were compared for polymorphisms. Results. Out of 63 couples, 30 partners acquired SARS-CoV-2 infection, while 33 remained uninfected despite intimate exposure. Clinical history was minimal for current or past illnesses. SARS-CoV-2-infected index spouses and partners who acquired the infection developed a mild disease, not requiring hospitalization. The observed distribution of ACE1 I/D and ACE2 G8790A genotypes was consistent with previously reported frequencies in Sardinia and across European populations. None of the study participants carried the CCR5-Δ32 variant. No statistically significant differences (p > 0.05) in the allelic or genotypic frequencies of these polymorphisms were observed between the infected and resistant partners. Conclusions. No differences in the distribution of ACE1, ACE2, and CCR5 polymorphisms between the two groups were detected. These findings suggest that resistance is likely multifactorial, involving a complex interplay of genetic, immunological, and environmental factors
15-year trends in efficacy and effectiveness of treatment outcomes in drug-resistant pulmonary TB
No full textBACKGROUND: This study describes the evolution of treatment outcomes in drug-resistant (DR) pulmonary TB, focusing on efficacy and effectiveness. METHODS: We searched PubMed/MEDLINE, Embase, Cochrane CENTRAL, Scopus, and Web of Science reporting DR-TB regimens from 1 January 2009 to 8 May 2024 and performed a systematic literature review and meta-analysis. RESULTS: A gradual increase in success rates in the treatment of DR pulmonary TB was observed from 2009 to 2024 across all studies. In observational studies, the average treatment success rate for mono-resistant TB (non-rifampicin-resistant TB, RR-TB) was 82.9%, while the average treatment success rate for RR/multidrug-resistant TB (MDR-TB) was 68.4%, and that of pre extensively drug-resistant TB (pre-XDR-TB) and XDR-TB was 54.4% with an increasing trend over time. The outcomes of experimental studies, which included fewer patients, demonstrated 69.6% treatment success for RR/ MDR-TB, with higher rates for pre-XDR/XDR-TB (79.2%) and a mix of the two groups (85.8%). Significant geographic variations in outcome rates were observed across studies. CONCLUSION: The current study demonstrates a steady improvement in treatment outcomes for DR-TB after a long period of stagnation. However, new drugs and novel regimens are needed to maintain or further improve treatment outcomes in DR-TB
Risk of False Acetylcholine Receptor Autoantibody Positivity by Radioimmunoprecipitation Assay in Clinical Practice
No full textBackground and Objectives Radioimmunoprecipitation assay (RIPA) is the gold standard for acetylcholine receptor (AChR)–immunoglobulin G (IgG) detection in patients with myasthenia gravis (MG), with a reported specificity of ≈99%. The risk of “false” AChR-IgG positivity in clinical practice is often considered negligible, although data on large, real-life populations are scarce. The objective of this study was to determine the positive predictive value (PPV) and risk of false AChR-IgG positivity with RIPA in a large cohort of patients with suspected MG. Methods We retrospectively identified patients consecutively tested for AChR-IgG by RIPA at the University-Hospital of Sassari over 20 years (2003–2022) (n = 4,795). Medical records of AChR-IgG–positive patients (titer ≥0.5 nmol/L) were reviewed by 2 investigators to identify nonmyasthenic cases with false antibody positivity, defined as follows: (1) clinical phenotypes not consistent with MG and/or (2) symptoms better explained by alternative diagnoses. The characteristics of myasthenic and nonmyasthenic patients with AChR-IgG positivity were compared. A sample of nonmyasthenic patients was retested by fixed cell-based assay (CBA). Results Among 445 of 4,795 patients testing positive for AChR-IgG during the study period, 83 were excluded (insufficient information). Of 362 AChR-IgG–positive patients included, 50 (13.8%) were designated as nonmyasthenic. The PPV and specificity were 86.2% (95% CI 82.2–89.6) and 98.9% (95% CI 98.5–99.2), respectively. Alternative diagnoses in nonmyasthenic patients included ophthalmologic diseases (n = 8), rheumatic diseases (n = 7), pseudoptosis (n = 5), myopathy (n = 4), functional disorders (n = 3), cranial nerve palsy (n = 2), parkinsonism (n = 2), demyelinating diseases (n = 2), and others (n = 17). Compared with patients with MG, nonmyasthenic patients were younger (median age 65 [range 7–91] vs 38 [range 5–80] years), more frequently female (155/312 [49.8%] vs 37/50 [74%]), had lower AChR-IgG titers (median 6 [range 0.5–28] vs 0.7 [range 0.5–5.5] nmol/L), and were more likely to become seronegative on subsequent tests (9/120 [8%] vs 6/11 [55%]). After stratification by titer ≥1 nmol/L, the PPV increased to 96.6% (95% CI 94–98.3). Serum of 7 nonmyasthenic patients was retested by CBA, giving negative results (n = 6) or selective positivity against the fetal AChR isoform (n = 1). Discussion False AChR-IgG positivity may occur in clinical practice with RIPA and associates with low antibody titer. Caution is needed when titers between 0.5 and 0.9 nmol/L are detected in low-probability situations because failure to recognize false antibody positivity may lead to misdiagnosis and inappropriate treatments
Effect of essential oils from Cymbopogon citratus, Citrus grandis, and Mentha arvensis on Trichomonas vaginalis and role of its symbionts Mycoplasma hominis and Ca. Mycoplasma girerdii
No full textIntroduction: Trichomoniasis, the most common non-viral sexually transmitted disease, is caused by the protozoon Trichomonas vaginalis. T. vaginalis can establish a symbiosis with two bacteria, Mycoplasma hominis and Candidatus Mycoplasma girerdii, whose intracellular presence may modulate several characteristics of the protozoan, including its sensitivity to 5-nitroimidazoles, the only class of drugs currently effective in treating trichomoniasis. The rising prevalence of T.vaginalis strains resistant to metronidazole, the most commonly used antitrichomonal drug, underscores the need for therapeutic alternatives active against the protozoon. Methods: In this study, we evaluate the antimicrobial activity of essential oils extracted from three plants cultivated in Vietnam — Cymbopogon citratus, Citrus grandis, and Mentha arvensis — against thirty T. vaginalis strains isolated from symptomatic women in Italy and Vietnam. We also assess the influence of M. hominis and Ca. M. girerdii on T. vaginalis susceptibility to essential oils and metronidazole, through dedicated susceptibility assays. Additionally, given the importance of lactobacilli in maintaining vaginal health, we investigate the effects of the essential oils on Lactobacillus gasseri and Lactobacillus crispatus. The cytotoxic activity of the oils against HeLa cells was also tested in vitro. Results: All three essential oils showed effective antitrichomonal activity without inhibiting lactobacilli growth. Among them, C. citratus oil exhibited the strongest inhibitory effect on T. vaginalis, including strains harboring bacterial symbionts. Moreover, the oils demonstrated no cytotoxic activity against HeLa cells at the concentrations effective against the protozoan. Discussion: The results support the potential of C. citratus essential oil as a natural antitrichomonal agent. Its effectiveness against both free and symbiont-infected T. vaginalis strains positions it as a promising candidate for developing alternative therapies against drug-resistant trichomoniasis