85 research outputs found
Geochemical characterization of bauxite deposits from the Abruzzi Mining district (Italy)
The Abruzzi bauxite district includes the deposits located on the Campo Felice plateau and those of the Monti d'Ocre, which had been mined in the first part of the 20th century. Bauxite is of the karst type, with textures ranging between oolitic and oolitic-conglomeratic, the latter suggesting a partial reworking of evolved lateritic soils. The high contents of Al2O3 and Fe2O3 (average values 53.76 and 21.76 wt %, respectively) are associated with the presence of boehmite, hematite, and minor goethite. SiO2 and TiO2 have average values of 7.79 and 2.75 wt %, corresponding to the presence of kaolinite, anatase and rutile. Among the minor so-called "bauxitophile" elements V, Co, Ni, Cr and Zr, the most enriched is Cr, with an average value of 0.07 wt %. Nickel has an average value of 210.83 ppm. Vanadium shows an average value of 266.57 ppm, whereas the average Co concentration is 35.89 ppm. The total rare earth elements (REE) concentration in the sampled bauxite sites is variable between ca. 700 and 550 ppm. Among REEs, the most abundant element is Ce, with Ce anomalies commonly associated with authigenic REE-fluoro-carbonates, probably produced after the REEs remobilization from primary detrital minerals and their precipitation in neo-formed phases during the bauxitization process. Scandium and Ga occur in small amounts (57 and 60 ppm, respectively), but geochemical proxies of their remobilization and uptake in neo-formed minerals (Feand Al-(hydr) oxides, respectively) have been observed. The mean Eu/Eu* and Al2O3/TiO2 ratios and the Ni-Cr contents of the Abruzzi bauxites suggest that the parent rock of these deposits was a material of acid affinity, likely corresponding to volcanic tephra or eolic loess-type sands
Genetic diversity and introgression by AFLP analisys in Phaseolus vulgaris L.
Phaseolus vulgaris L. is an economically important species whose origin is in the America continent where domestication took place and diverged in Mesoamerican and Andean gene pools.
After Columbus’s voyage common bean was introduced into the Iberian Peninsula from which this species spread into the European countries and around the world. In this study investigate the extent of diversity of European germplasm compared to the American germplasm and to define the level
of introgression between the European Mesoamerican and Andean gene pools are investigated. 68 accessions representative of Mesoamerican and Andean American gene pools and 241 accessions from 24 different countries belonging to an European bean core collection were analysed for three
morphologic quantitative (length, height and width ) and 4 qualitative (shape, lighter colour, darker colour and coat pattern of seed) seed characters and for 4 AFLP primer combinations: E-AGT/MGAC, E-AGT/M-GTA, E-ACC/M-AGA and E-ACC/M-ATG. A total of 138 polymorphic bands were scored among the 309 accessions analysed.
The European and the Mesoamerican gene pools had a number of common and very common AFLP polymorphic bands higher than the American and the Andean gene pools. The European
accessions moreover were used for Structure and cpSSR analysis to identify pure and introgressed lines. These groups were compared for morphological traits and AFLP profiles. Results showed significative differences among diverse groups for morphological traits and for AFLP band frequencies, even though the diversity index were the same (He = 0.23).
Hypothesis of introgression among American and European, Mesoamerican and Andean gene pools are discussed
Nuclear and chloroplast microsatellite diversity in Phaseolus vulgaris L. from Sardinia (Italy).
Studies of the level and the structure of
the genetic diversity of local varieties of Phaseolus
vulgaris are of fundamental importance, both for the
management of genetic resources and to improve our understanding of the pathways of dissemination and
the evolution of this species in Europe. We have here
characterized 73 local bean populations from Sardinia
(Italy) using seed traits and molecular markers
(phaseolins, nuSSRs and cpSSRs). American landraces
and commercial varieties were also included for
comparison. We see that: (a) the Sardinian material is
distinct from the commercial varieties considered; (b)
the variation in the seed traits is high and it mostly
occurs among populations (95%); (c) compared to the
American sample and the commercial varieties, the
Sardinian collection has a low level of diversity; (d)
the majority ([95%) of the Sardinian individuals
belong to the Andean gene pool; (e) the Sardinian
material shows a strong genetic structure, both for
cpSSRs and nuSSRs; (f) the nuSSRs and cpSSRs
concur in differentiating between gene pools, but a
lack of congruence between nuclear and chloroplast
has been observed within gene pools; and (g) there
are three putative hybrids between the Andean and
Mesoamerican gene pools. Despite the relatively low
level of diversity, which is probably due to a strong
founder effect, the Sardinian landraces are worth
being conserved and studied further because of their
distinctiveness and because hybridization within and
between the gene pools could generate variation that
will be useful for breeding
Introduction bottleneck and the contribute of Mesoamerican and Andean gene pools to common bean (Phaseolus vulgaris L.) diversity in Europe.
Common bean (Phaseolus vulgaris L., 2n = 2x = 22) is the most important edible food legume for direct human consumption in Europe and in the world as it represents a valuable source of proteins, vitamins, fibres, and minerals. Genetic and archaeological studies have shown that domestication of P. vulgaris was originated and domesticated in the New World and has two major gene pools, the Andean and the Mesoamerican, based on their centers of origin in South and Central America, respectively. After the first voyages of Columbus (1492) common bean was brought to Europe but historical and linguistic sources provide little evidence of the introduction and expansion of common bean in Europe. In common bean a large number of nuclear microsatellite markers (nuSSRs) have been already developed and mapped that show relatively high levels of polymorphism, thus providing an attractive choice for describing population structure. However, to the best of our knowledge, population studies of the European common bean, using nuSSRs, so far have been performed with only a small number of landraces or a small number of samples from a few geographic regions. In the present study, we used thirteen highly polymorphic nuSSRs to assess
the genetic structure and level of diversity of a large collection of European landraces (256
individuals), in comparison with a representative American sample (89 individuals). Moreover, to
obtain a detailed picture and to elucidate the effects of bottleneck of introduction and selection for
adaptation during the expansion of common bean over the whole Europe, we also complemented
the nuSSRs analysis by information provided by a Bayesian analysis implemented in
STRUCTURE. Here, we present and discuss the role that inter-gene pool hybridization have had in
shaping the genetic structure of the European bean landraces. The implication for evolution and the
advantages for common bean breeding are also discussed
Systemic amyloidosis due to unknown multiple myeloma in small bowel pseudo-obstruction: case report
Amyloidosis is a pathologic diagnosis characterized by extracellular deposition of insoluble protein fibrils in various organs and tissues. There are two main forms of amyloidosis, primary amyloidosis, and secondary amyloidosis. Gastrointestinal involvement is common in both amyloidosis forms. We describe the case of a 78-year-old woman taken to the operating room for small bowel obstruction, found to have pseudo-obstruction and enteritis. Exploratory laparotomy revealed gastric mass and histological examen showed extensive amyloid deposition consistent with amyloidosis. Hematological evaluation revealed unknown multiple myeloma. This case report and literature data suggest to perform a hematological examination in patients with amyloidosis diagnosis to exclude a multiple myeloma or other plasma cell disorder
Selection and adaptive introgression guided the complex evolutionary history of the European common bean
: Domesticated crops have been disseminated by humans over vast geographic areas. Common bean (Phaseolus vulgaris L.) was introduced in Europe after 1492. Here, by combining whole-genome profiling, metabolic fingerprinting and phenotypic characterisation, we show that the first common bean cultigens successfully introduced into Europe were of Andean origin, after Francisco Pizarro's expedition to northern Peru in 1529. We reveal that hybridisation, selection and recombination have shaped the genomic diversity of the European common bean in parallel with political constraints. There is clear evidence of adaptive introgression into the Mesoamerican-derived European genotypes, with 44 Andean introgressed genomic segments shared by more than 90% of European accessions and distributed across all chromosomes except PvChr11. Genomic scans for signatures of selection highlight the role of genes relevant to flowering and environmental adaptation, suggesting that introgression has been crucial for the dissemination of this tropical crop to the temperate regions of Europe
The DICA Endoscopic Classification for Diverticular Disease of the Colon Shows a Significant Interobserver Agreement among Community Endoscopists: an International Study
Background & Aims: The Diverticular Inflammation and Complication Assessment (DICA) endoscopic classification of diverticulosis and diverticular disease (DD) is currently available. It scores severity of the disease as DICA 1, DICA 2 and DICA 3. Our aim was to assess the agreement on this classification in an international endoscopists community setting. Methods: A total of 96 doctors (82.9% endoscopists) independently scored a set of DD endoscopic videos. The percentages of overall agreement on DICA score and a free-marginal multirater kappa (kappa) coefficient were reported as statistical measures of interrater agreement. Results: Overall agreement in using DICA was 91.8% with a free-marginal kappa of 88% (95% CI 80-95). The overall agreement levels were: DICA 1, 85.2%; DICA 2, 96.5%; DICA 3, 99.5%. The free marginal. was: DICA 1 = 0.753, DICA 2 = 0.958, DICA 3 = 0.919. The agreement about the main endoscopic items was 83.4% (k 67%) for diverticular extension, 62.6% (k 65%) for number of diverticula for each district, 86.8% (k 82%) for presence of inflammation, and 98.5 (k 98%) for presence of complications. Conclusions: The overall interrater agreement in this study ranges from good to very good. DICA score is a simple and reproducible endoscopic scoring system for diverticulosis and DD
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