Litotipi bauxitici dell\u2019isola di Krk (Ba\u161ka e Stara Ba\u161ka \u2013 Croazia)

Vengono descritti i litotipi bauxitici rinvenuti nel corso di una ricerca condotta nella parte meridionale dell\u2019isola di Krk (Dalmazia settentrionale \u2013 Croazia) nelle localit\ue0 di Ba\u161ka e Stara Ba\u161ka. Si tratta di rocce residuali, spesso compatte e di elevato peso specifi co, ricche di ossidi ed idrossidi di alluminio e ferro. La ricerca \ue8 stata condotta sul campo ed in laboratorio, al fi ne di comprendere meglio i rapporti che intercorrono con le rocce calcaree incassanti e con il fenomeno carsico presente nell\u2019area

Detrital pyroxenes in the Eocene flysch of the Istrian Basin (Slovenia, Croatia)

For the first time, few detrital augite and pigeonite crystals have been found in the Eocene flysch basins of Istria (Trieste-Koper basin; Italy, Slovenia, Croatia) and Krk Island (Croatia). Their chemistry suggests that they are related to subalkaline rocks (within-plate tholeiites) crystallized at a pressure between 0 and 5 kbar. As a possible source, the nearby basaltic andesites of Ljubac have been taken into consideration. The argument for a ?Late Tertiary age of the Ljubac volcanics is that no detrital pyroxenes have been found in the Eocene flysch and Oligo- Miocene molasse deposits of the area (Lugovic et al., 1998). Radiometric data are not available until now. The detection of detrital pyroxene could be an indication of an older age of the Ljubac volcanics. The presence of similar pyroxenes in the Trieste-Koper and the Krk Island flysch and their absence in Brkini flysch suggest that the basin of Krk was linked with the Istrian basin rather than the Brkini basin

First crystal-structure determination of chromites from an acapulcoite and ordinary chondrites

We report the first crystal structure determinations of chromites from an acapulcoite and from ordinary chondrites. Cell edges range from 8.3212 (3) to 8.3501 (1) \uc5, while the oxygen positional parameters are in the range 0.2624 (3) to 0.26298 (9). Their compositions show they are very close to the chromite end-member FeCr2O4 with limited Al and Mg content. Titanium oxide content exceeds 1%, whereas the amount of Fe3+ is negligible. Extraterrestrial chromite is readily distinguished from terrestrial analogues on the basis of cell edge and oxygen positional parameter. These distinctions will facilitate ongoing attempts to reconstruct the paleoflux of meteorites to Earth from resistant extraterrestrial spinel grains recovered from ancient sediments

Estudio sedimentológico preliminar y análisis de minerales pesados en la cueva Pocala

[Abstract] In 1999 two borings were performedin the area of Pocala Cave, one outside the cave and the other inside in the cave. In particular four samples of the first boring were studied.It seems that mineralogy is strictly connected with sedimentology where quartz and plagioclase are present. It could be a consequence of a periodical floods of flysch sediments during interglacial perio

The Stillwater Complex chromitites : the response of chromite crystal chemistry to magma injection

Nineteen chromite crystals from the A, B, E, G, H, J and K chromitite layers of the Peridotite Zone of the Stillwater Complex (Montana, USA) have been studied by means of X-ray single crystal diffraction and microprobe analyses. The results show that samples from the basal A layer are quite different from the others showing very high oxygen positional parameter u (0.2633-0.2635) and Ti- contents (0.059-0.067apfu). Mg# values are within the range 0.21-0.23 while for the other chromites it is in the range 0.45-0.47. Moreover, for the other samples, according to the structural parameters, two groups have been identified. The first one comprises samples of layers B, E and G, the second includes H, J and K layer samples. It is supposed that high Fe2+ and Ti contents of A layer samples are due to the post-crystallization reaction with interstitial liquid. This fact allowed a very slow cooling rate as evidenced by the high u values. The fractionation of evolved magma from within the intrusion and pulse of a new magma bringing more chromium into the chamber lead to Cr- and Fe3+ -rich compositions and consequently to the increase of the cell edges. The decrease of u values seems to be related to the Cr+Fe3+ and/or Al contents

First evidence of testate amoebae in Lago fagnano (54\ub0S), Tierra del Fuego (Argentina): Proxies to reconstruct environmental changes

We report here the first findings of testate amoebae at high southern latitudes (54 S) from four gravity cores recovered in the Lago Fagnano (Tierra del Fuego, Argentina), where twelve taxa have been recognized. Among them, Centropyxis constricta \u201cconstricta\u201d, Centropyxis elongata, Difflugia globulus, Difflugia oblonga \u201coblonga\u201d, and Difflugia protaeiformis \u201camphoralis\u201d are always present, while other taxa are randomly distributed. According to the sand/silt ratio in the different cores, the Total Organic Carbon content and the Carbon/Nitrogen ratio, as well as the presence/disappearance and abundance of testate amoebae from cluster analysis, we infer a correlation between major textural/granulometrical changes found in the cores and environmental changes. A seismic event occurred on 1949, which substantially modified the morphology of the eastern Lago Fagnano shoreline and the supply pattern from two main eastern tributaries of the lake, is recorded in the studied cores. This event has in part modified the distribution of testate amoebae taxa within the studied cores. Present results show that testate amoebae represent important indicators to detect changes occurring in the environment in which they live

Quaternary evolution of the fluviokarst Rosandra Valley (Trieste, NE Italy)

The stratigraphy of terraced sediments as well as morphological features of the middle reach of the Rosandra Valley (Trieste, NE Italy) were studied in order to reconstruct its Quaternary evolution. This sector forms a fluviokarst valley, which is characterized by a deep incised gorge with abrasional features. Downstream, the gradient is reduced, the valley widens and terraced deposits occur. Alluvial/colluvial terraces crop out for about 1 to 1.5 km along the creek. They show the coalescence of the alluvial deposits with debrisfalls from the steep limestone slopes and colluvial fans related to some minor tributaries. The highest terrace is roughly 15 m high. 14C datings on a frustule plant collected in the lower part of the deposit (> 45.000 yrs. BP), together with geological and geomorphological considerations, suggested that the terrace scarp could be Middle Pleistocene in age. The geomorphic regime of the creek changed from aggradation to erosion, as recorded by fanhead trenching and incision of fluvial terrace scarps, and it still persists. The tectonic uplift, which is partly responsible for the downcutting of the terrace and is still active, could be related to the SE-NW tilting of the Karst plateau

Mutant MYO1F alters the mitochondrial network and induces tumor proliferation in thyroid cancer

Familial aggregation is a significant risk factor for the development of thyroid cancer and Familial Non-Medullary Thyroid Cancer (FNMTC) accounts for 5-7% of all NMTC. Whole Exome Sequencing analysis in the family affected by FNMTC with oncocytic features where our group previously identified a predisposing locus on chromosome 19p13.2, revealed a novel heterozygous mutation (c.400G>A, NM_012335; p.Gly134Ser) in exon 5 of MYO1F, mapping to the linkage locus. In the thyroid FRTL-5 cell model stably expressing the mutant MYO1F p.Gly134Ser protein we observed an altered mitochondrial network, with increased mitochondrial mass and a significant increase of both intracellular and extracellular Reactive Oxygen Species, compared to cells expressing the wild-type protein or carrying the empty vector. The mutation conferred a significant advantage in colony formation, invasion and anchorage independent growth. These data were corroborated by in vivo studies in zebrafish, since we demonstrated that the mutant MYO1F p.Gly134Ser, when overexpressed, can induce proliferation in whole vertebrate embryos, compared to the wild-type one. MYO1F screening in additional 192 FNMTC families identified another variant in exon 7, which leads to exon skipping, and is predicted to alter the ATP-binding domain in MYO1F. Our study identified for the first time a role for MYO1F in NMTC. This article is protected by copyright. All rights reserved

Cell proliferation within small intestinal crypts is the principal driving force for cell migration on villi

The functional integrity of the intestinal epithelial barrier relies on tight coordination of cell proliferation and migration, with failure to regulate these processes resulting in disease. It is not known whether cell proliferation is sufficient to drive epithelial cell migration during homoeostatic turnover of the epithelium. Nor is it known precisely how villus cell migration is affected when proliferation is perturbed. Some reports suggest that proliferation and migration may not be related while other studies support a direct relationship. We used established cell-tracking methods based on thymine analog cell labeling and developed tailored mathematical models to quantify cell proliferation and migration under normal conditions and when proliferation is reduced and when it is temporarily halted. We found that epithelial cell migration velocities along the villi are coupled to cell proliferation rates within the crypts in all conditions. Furthermore, halting and resuming proliferation results in the synchronized response of cell migration on the villi. We conclude that cell proliferation within the crypt is the primary force that drives cell migration along the villus. This methodology can be applied to interrogate intestinal epithelial dynamics and characterize situations in which processes involved in cell turnover become uncoupled, including pharmacological treatments and disease models