25 research outputs found

    An integrated approach to investigate climate-driven rockfall occurrence in high alpine slopes: the Bessanese glacial basin, Western Italian Alps

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    Rockfalls are one of the most common instability processes in high mountains. They represent a relevant issue, both for the risks they represent for (infra) structures and frequentation, and for their potential role as terrestrial indicators of climate change. This study aims to contribute to the growing topic of the relationship between climate change and slope instability at the basin scale. The selected study area is the Bessanese glacial basin (Western Italian Alps) which, since 2016, has been specifically equipped, monitored and investigated for this purpose. In order to provide a broader context for the interpretation of the recent rockfall events and associated climate conditions, a cross-temporal and integrated approach has been adopted. For this purpose, geomorphological investigations (last 100 years), local climate (last 30 years) and near-surface rock/air temperatures analyses, have been carried out. First research outcomes show that rockfalls occurred in two different geomorphological positions: on rock slopes in permafrost condition, facing from NW to NE and/or along the glacier margins, on rock slopes uncovered by the ice in the last decades. Seasonal thaw of the active layer and/or glacier debutressing can be deemed responsible for slope failure preparation. With regard to timing, almost all dated rock falls occurred in summer. For the July events, initiation may have been caused by a combination of rapid snow melt and enhanced seasonal thaw of the active layer due to anomalous high temperatures, and rainfall. August events are, instead, associated with a significant positive temperature anomaly on the quarterly scale, and they can be ascribed to the rapid and/or in depth thaw of the permafrost active layer. According to our findings, we can expect that in the Bessanese glacierized basin, as in similar high mountain areas, climate change will cause an increase of slope instability in the future. To fasten knowledge deepening, we highlight the need for a growth of a network of high elevation experimental sites at the basin scale, and the definition of shared methodological and measurement standards, that would allow a more rapid and effective comparison of data

    DETERMINATION OF THERMAL RESPONSE OF CARRARA AND SNEZNIKOVSKY MARBLE USED AS A BUILDING MATERIALS

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    Physical weathering of marble, widely used as a cladding material on buildings, is one of the most common damaging mechanism caused by anisotropic thermal expansion of calcite grains. The extent of marble deterioration depends mainly on stone fabric and texture. Dry cuboids of Carrara marble and marble from Dolni Morava quarry were subjected to microscopic analysis and thermal cycling, to determine the thermal expansion related to stone fabric and predominant lattice orientation of grains (i.e. texture)

    Radiotherapy combined or not with chemotherapy in adult or pediatric patients with brainstem glioma: a population-based study

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    Background: The purpose of this study was to assess the treatment outcomes and prognostic factors of brainstem glioma (BCG) patients treated by radiotherapy (RT) or chemoradiation (CHRT) in the last 20 years in a population cohort. Materials and methods: Patients diagnosed with BSG from 2000–2020 treated by RT or CHRT were identified from The Fundação Oncocentro de São Paulo database. Data on age, gender, practice setting, period of treatment, and treatment modality were extracted. The overall survival (OS) was estimated, and the subgroups were compared with the log-rank test. Cox proportional test was used in multivariate analysis. Results: A total of 253 patients with a median follow-up of 12 months were included. There were 197 pediatric and 56 adult patients. For the entire cohort, the 1 and 3-year OS was 46%, and 23%, with a median OS of 11 months. In the subgroup analysis, adults had a median survival of 33 months versus 10 months in pediatric patients (p = 0.002). No significant difference in OS between RT and CHRT was observed in pediatric or adult subgroups (p > 0.05). The use of CHRT has significantly increased over the years. In the multivariate analysis, adult patients were the only independent prognostic factor associated with a better OS (p < 0.001). Conclusions: BSG had poor survival with no significant improvement in the treatment outcomes over the last 20 years, despite the addition of chemotherapy. Adult patients were independently associated with better survival.

    “Wake-up time activation” in older adults: first randomized experimental clinical trial

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    Balance main rely on vestibular, proprioceptive and visual apparatus integrity. In elderly, postural control fails also due to deficit of sensory functions, atrophy of the musculoskeletal system and neuronal reduction. Deterioration of these functions finally lead to abnormality in performing voluntary muscle movements, subjective feeling of vulnerability, insecurity and depression. Besides, physical inactivity (hypokinesia) is a major risk factor for developing coronary artery disease and stroke, contributing to obesity, high blood pressure, hypercholesterolemia and diabetes. For these reasons, especially in elderly, it is important to include physical activity as part of a regular routine. Aim of this randomized controlled trial was to demonstrate that daily subministration of “Wake-up Time Activation” protocol allow individual recovery of balance and tensile properties of periarticular and intra-articular structures, so preventing morning stiffness and reduction of the Range Of Motion (R.O.M.), mainly in the Vertebral Columna. Therefore, we propose to 50 Healthy individuals (age 45-86) of both sexes a peculiar sequence of movements that allow individual recovery of balance and tensile properties of periarticular and intra-articular structures, so preventing morning stiffness and reduction of the Range Of Motion (R.O.M.), mainly in the Vertebral Columna. To verify the effectiveness of this exercises, we scientifically detected, by mean of validated test and instruments, different parameters at tifferent time, for each individual, for two months. Tests were detected at T0 (before starting daily exercises), T1 (after one month of daily exercises), T2 (at the end of the second month of exercises). At each time, on every person, we performed: Cervical Test, Spinal motility, Pelvic motility (mobility); Standing one leg Test (balance); Get up and Go (reactivity); SF-36 (mood/depression); Paint Rating Scales (joint pain). Statistical analysis of obtained results, discussed in detail in the Postrer, scientifically demonstrate that performing of “Wake-up Time Activation” protocol of adapted fisical activity lead to immediate and persistent back pain reduction, articular R.O.M. increase, recovery of balance and coordination, improved autonomy and mood, also in elderly

    Assessing the efficacy of palliative radiation treatment schemes for locally advanced squamous cell carcinoma of the head and neck: a meta-analysis

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    Background: The objective to assess the outcomes from different palliative radiotherapy (RT) schedules in incurable head and neck cancer (HNC), to evaluate if there is a relationship between RT dose, technique, and fractionation with tumor response in contrast to the occurrence of adverse effects. Materials and methods: Eligible studies were identified on Medline, Embase, the Cochrane Library, and annual meetings proceedings through June 2020. Following PRISMA and MOOSE guidelines, a cumulative meta-analysis of studies for overall response rate (ORR), overall survival (OS), progression-free survival (PFS), pain/dysphagia relief, and toxicity was performed. A meta-regression analysis was done to assess if there is a connection between RT dose, schedule, and technique with ORR. Results: Twenty-eight studies with 1,986 patients treated with palliative RT due to incurable HNC were included. The median OS was 6.5 months [95% confidence interval (CI): 5.6–7.4], and PFS was 3.6 months (95% CI: 2.7–4.3). The ORR, pain and dysphagia relief rates were 72% (95% CI: 0.6–0.8), 83% (95% CI: 52–100%), and 75% (95% CI: 52–100%), respectively. Conventional radiotherapy (2D-RT) or conformational radiotherapy (3D-RT) use were significantly associated with a higher acute toxicity rate (grade ≥ 3) than intensity-modulated radiation therapy (IMRT) or stereotactic body radiation therapy (SBRT). On meta-regression analyses, the total biological effective doses (BED) of RT (p = 0.001), BED > 60 Gy10 (p = 0.001), short course (p = 0.01) and SBRT (p = 0.02) were associated with a superior ORR. Conclusions: Palliative RT achieves tumor response and symptom relief in incurable HNC patients. Short course RT of BED > 60 Gy using IMRT could improve its therapeutic ratio. SBRT should be considered when available

    Moderately hypofractionated post-operative radiation therapy for breast cancer: Preferences amongst radiation oncologists from countries in Latin America and the Caribbean

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    Background: The safety and effectiveness of moderately hypofractionated post-operative radiation therapy for breast cancer were demonstrated by several trials. This study aimed to evaluate the current patterns of practice and prescription preference about moderately hypofractionated post-operative radiation therapy to assess possible aspects that affect the decision-making process regarding the use of fractionation in breast cancer patients in Latin America and the Caribbean (LAC). We also aimed to identify factors that can restrain the utilization of moderately hypofractionated post-operative radiation therapy for breast cancer. Materials an methods: Radiation oncologists from LAC were invited to contribute to this study. A 38-question survey was used to evaluate their opinions. Results: A total of 173 radiation oncologists from 13 countries answered the questionnaire. The majority of respondents (84.9%) preferred moderately hypofractionated post-operative radiation therapy as their first choice in cases of whole breast irradiation. Whole breast plus regional nodal irradiation, post-mastectomy (chest wall and regional nodal irradiation) without reconstruction, and post-mastectomy (chest wall and regional node irradiation) with reconstruction hypofractionated post-operative radiation therapy was preferred by 72.2% 71.1%, and 53.7% of respondents, respectively. Breast cancer stage, and flap-based breast reconstruction were the factors associated with absolute contraindications for the use of hypofractionated schedules. Conclusion: Even though moderately hypofractionated post-operative radiation therapy for breast cancer is considered a new standard to the vast majority of the patients, its unrestricted application in clinical practice across LAC still faces reluctance

    Characterisation and development of fine porosity in magnesium potassium phosphate ceramics

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    Characterisation of porosity and microstructure in chemically- bonded ceramics was accomplished by small-angle neutron scattering. Microstructural parameters were also followed during the setting reaction and obtained kinetic curves were compared with results of XRD quantitative phase analysis up to 1 month. Results indicate that less reactive MgO yields a more compact microstructure, the same happens during the progress of the reaction. The reaction product forms from an amorphous precursor and its development was found to scale with the microstructural parameters. A change in reaction mechanism after 40 min is suggested.Depto. de Pintura y Conservación-RestauraciónFac. de Bellas ArtesTRUEpu

    Tolerancia a la desecación de semillas de dos especies arbóreas del Chaco Salteño (Argentina): Erithryna falcata Benth. y Tecoma garrocha Hieron

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    Long-term conservation of plant resources in seed banks depends on the longevity of seeds, their quality, the treatments they are exposed between collection and storage, and storage conditions. Lot of information and research is needed specially for native species about germination requirements, methods for interrupting dormancy, tolerance to desiccation and seed longevity. The aim of this work was to study desiccation tolerance and germinability in two native tree species. The humidity content (HC) was assessed keeping the seeds in oven at 103± 2°C and weghting the samples at regular intervals till constant weight. Germination essays with different HC of the seeds were carried out (fresh, 10-12%, 3-5% and with seed keept for three months at -18°C and at 3-5% HC). The HC of T. garrocha and E. falcata seeds were 11.37% and 16.07%. We conclude that both species seeds are probably ortodox becuase germinability was higher than 50% in all the essays.La conservación de los recursos fitogenéticos a largo plazo en bancos de germoplasma depende de la longevidad de las semillas, de su calidad, del tratamiento que se les da entre la recolección y el almacenamiento y de las condiciones de almacenamiento. Es necesaria mucha información e investigación básica que es escasa para las especies nativas, especialmente sobre los requerimientos de germinación, los métodos para interrumpir la dormición, la tolerancia a la desecación y la longevidad de las semillas. El objetivo del trabajo fue estudiar la tolerancia a la desecación de dos especies de árboles nativos. El contenido de humedad (CH) se determinó colocando las semillas de cada especie en estufa a 103 ± 2°C y pesando las muestras a intervalos regulares hasta peso constante. Se realizaron ensayos de germinabilidad en distintos CH (semillas frescas, 10-12%, 3-5%, y en semillas mantenidas 3 meses a -18°C y a 3-5%, de CH). El CH de las semillas frescas de Tecoma garrocha fue de 11,37% y el de Erithryna falcata de 16,07%. Se concluye que las semillas de ambas especies son probablemente ortodoxas ya que la germinabilidad superó el 50% en todos los casos
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