1,721,017 research outputs found
Underground Geodiversity of Italian Show Caves: an Overview
Full text linkAbout a ffth of the Italian territory is characterised by the presence of soluble rocks, consisting mainly of limestone and dolostone but also of marble and evaporite rocks (gypsum). More than 50,000 natural caves are currently known in this country, a number that is constantly increasing thanks to speleological exploration. Less than 1% of these caves are equipped for visits, and only 64 can be defned as real show (tourist) caves. In the latter, it is necessary to buy an entrance ticket, visits take place only accompanied by a guide, and the underground trail is equipped with paths, walkways and, generally, lighting systems. The Italian show caves expose a great geodiversity and biodiversity, often accompanied by a considerable historical and/or archaeological interest. The underground geodiversity of Italian show caves is related to the variety of lithologies characterising this territory and to the geomorphological and geodynamic processes that have been active during diferent
geological periods. Important scientifc research has taken place in many of these caves, and several of these fragile environments are monitored continuously to verify their environmental conditions
Corona G., Mannucci E., Petrone L., Balercia G., Paggi F., Fisher A.D., Lotti F., Chiarini V., Forti G., Maggi M.
No full textIn Vivo Dissection of the Helicobacter pylori Fur Regulatory Circuit by Genome-Wide Location Analysis.
No full textIron homeostasis is particularly important in pathogenic bacteria, which need to compete with the host for this essential cofactor. In Helicobacter pylori, a causative agent of several gastric pathologies, iron uptake and storage genes are regulated at the transcriptional level by the ferric uptake regulator Fur. The regulatory circuit of Fur has recently come under focus because of an intimate interlink with a broader regulatory network governing metal homeostasis, acidic response, and virulence. To dissect the Fur regulatory circuit and identify in vivo targets of regulation, we developed a genome-wide location analysis protocol which allowed the identification of 200 genomic loci bound by Fur as well as the investigation of the binding efficiency of the protein to these loci in response to iron. Comparative analysis with transcriptomes of wild-type and fur deletion mutant strains allowed the distinction between targets associated with Fur regulation and genes indirectly influenced by the fur mutation. The Fur regulon includes 59 genes, 25 of which appear to be positively regulated. A case study conducted by primer extension analysis of two oppositely regulated genes, hpn2 and flaB, suggests that negative regulation as well as positive regulation occurs at the transcriptional level. Furthermore, the results revealed the existence of 13 Fur targeted loci within polycistronic operons, which were associated with transcript deregulation in the fur mutant strain. This study provides a systematic insight of Fur regulation at the genome-wide level in H. pylori and points to regulatory functions extending beyond the classical Fur repression paradigm
Treated Wilm's tumor in childhood as potential risk factor for second thyroid cancer
No full textThe potential risk of a treatment-induced second neoplasia affecting the thyroid is well known after radiation therapy for several types of cancer, but few cases have been related to incidental irradiation for Wilms' tumor. We report a case of a papillary thyroid carcinoma discovered in a young patient 15 years after treatment of a Wilms' tumor. An 18-year-old man was referred to our Endocrinological Department for a single 3 cm nodule in the right lobe of the thyroid. His past medical history included at the age of 2 years surgical resection, chemotherapy (actinomycin-D and vincristine) and cesium radiation therapy to the right side for a Wilms' tumor in stage III: a total dose of 7700 rads was delivered to an area of 17 x 10 cm in the right flank. After fine-needle demonstration of a follicular thyroid lesion, the patient underwent right lobectomy, followed by total thyroidectomy for histologic diagnosis of a follicular variant papillary cancer. Residual thyroid tissue was ablated by iodine-131 administration (3700 MBq), but scanning after therapeutic iodine showed radioactive uptake in the left regional lymph nodes, with elevated serum thyroglobulin off therapy (830 ng/ml). Magnetic resonance imaging confirmed the presence of lymph node enlargements and bilateral neck dissection was performed, followed by radioiodine treatment (3700 MBq) and thyroxine suppressive therapy. After 3-year follow-up the patient is disease-free. Although few cases of thyroid cancer have been reported in the literature after irradiation for a Wilms' tumor during childhood, this association should be considered in the long-term follow-up
Treated Wilms' tumor in childhood as potential risk factor for second thyroid cancer
No full textThe potential risk of a treatment-induced second neoplasia affecting the thyroid is well known after radiation therapy for several types of cancer, but few cases have been related to incidental irradiation for Wilms' tumor. We report a case of a papillary thyroid carcinoma discovered in a young patient 15 years after treatment of a Wilms' tumor. An 18-year-old man was referred to our Endocrinological Department for a single 3 cm nodule in the right lobe of the thyroid. His past medical history included at the age of 2 years surgical resection, chemotherapy (actinomycin-D and vincristine) and cesium radiation therapy to the right side for a Wilms' tumor in stage III: a total dose of 7700 rads was delivered to an area of 17x10 cm in the right flank. After fine-needle demonstration of a follicular thyroid lesion, the patient underwent right lobectomy, followed by total thyroidectomy for histologic diagnosis of a follicular variant papillary cancer. Residual thyroid tissue was ablated by iodine-131 administration (3700 MBq), but scanning after therapeutic iodine showed radioactive uptake in the left regional lymphnodes, with elevated serum thyroglobulin off therapy (830 ng/ml). Magnetic resonance imaging confirmed the presence of lymph node enlargements and bilateral neck dissection was performed, followed by radioiodine treatment (3700 MBq) and thyroxine suppressive therapy. After 3-year follow-up the patient is disease-free. Although few cases of thyroid cancer have been reported in the literature after irradiation for a Wilms' tumor during childhood, this association should be considered in the long-term follow-up
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
UNDERSTANDING THE INFLUENCE OF CLIMATE OSCILLATIONS AND DRAINAGE BASIN REORGANIZATION ON CAVE AND LANDSCAPE EVOLUTION IN THE “VENA DEL GESSO ROMAGNOLA” AREA (ITALY)
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