Extreme chemical conditions of crystallisation of Umbrian Melilitolites and wealth of rare, late stage/hydrothermal minerals

Abstract Melilitolites of the Umbria Latium Ultra-alkaline District display a complete crystallisation sequence of peculiar, late-stage mineral phases and hydrothermal/cement minerals, analogous to fractionated mineral associations from the Kola Peninsula. This paper summarises 20 years of research which has resulted in the identification of a large number of mineral species, some very rare or completely new and some not yet classified. The progressive increasing alkalinity of the residual liquid allowed the formation of Zr-Ti phases and further delhayelitemacdonaldite mineral crystallisation in the groundmass. The presence of leucite and kalsilite in the igneous assemblage is unusual and gives a kamafugitic nature to the rocks. Passage to non-igneous temperatures (T<600 °C) is marked by the metastable reaction and formation of a rare and complex zeolite association (T<300 °C). Circulation of low-temperature (T<100 °C) K-Ca-Ba-CO2-SO2-fluids led to the precipitation of sulphates and hydrated and/or hydroxylated silicate-sulphate-carbonates. As a whole, this mineral assemblage can be considered typical of ultra-alkaline carbonatitic rocks

Screening of male breast cancer and of breast-ovarian cancer families for BRCA2 mutations using large bifluorescent amplicons

41 breast cancer or breast-ovarian cancer families, including 12 families with at least one affected first-degree male relative, were screened for mutations in the BRCA2 gene. Mutations had not been found in the BRCA1 gene of these families. Chemical cleavage of Mismatch was used to identify nucleotide changes within large PCR products (average size 1.2 kb) that carried strand-specific fluorescent end-labels. 15 amplicons were sufficient to scan 18 exons, including the large exon 11. The remaining 9 small exons were examined by Denaturing Gradient Gel Electrophoresis. The high sensitivity of this approach was documented by the detection, in these 41 patients, of all 9 exonic single nucleotide polymorphisms reported with heterozygosity >0.1. Truncating BRCA2 mutations were found in 7 of the 41 families. 3 of them were in the group of 12 families comprising cases of male breast cancer. Since the methods used here have no bias for particular types of mutations, these data confirm the high proportion of frameshifts among mutations in BRCA2. However, relevant single nucleotide substitutions were also found: one resulting in a stop codon and another one, present in a male patient, was the previously reported change Asp2723His, that affects a highly conserved region of the BRCA2 protein. This study indicates a BRCA2 contribution of 10% (95% CI 2.5–17.5) to our original cohort of 59 breast-ovarian cancer families, whereas the contribution of BRCA1 had been estimated at 46% (95% CI 33–59). © 2001 Cancer Research Campaign http://www.bjcancer.co

Sustainable Production of Stiff and Crystalline Bacterial Cellulose from Orange Peel Extract

In this work, a potentially economic and environmentally friendly method for the synthesis of bacterial cellulose (BC) by Gluconacetobacter xylinus from a biomass containing orange peel extract was evaluated. Orange peel extract was used as a culture medium without any hydrolysis treatment, thus speeding up the synthesis procedure. The efficacy of orange peel as a carbon source was compared with that of sucrose. The orange peel extract formed thicker cellulose gels than those formed using sucrose. X-ray diffraction (XRD) revealed both a high crystallinity index and crystallite size of BC nanofibers in samples obtained from orange peel (BC_Orange). Field emission scanning electron microscopy (FE-SEM) revealed a highly densely packed nanofibrous structure (50 nm in diameter). BC_Orange presented a two-fold increase in water holding capacity (WHC), and dynamic mechanical analysis (DMA) showed a 44% increase in storage modulus compared to sucrose derived BC. These results showed that the naturally available carbon sources derived from orange peel extract can be effectively used for BC production. The orange-based culture medium can be considered a profitable alternative to the generation of high-value products in a virtuous circular economy model

Attempts to detect retrotransposition and de novo deletion of Alus and other dispersed repeats at specific loci in the human genome

Dispersed repeat elements contribute to genome instability by de novo insertion and unequal recombination between repeats. To study the dynamics of these processes, we have developed single DNA molecule approaches to detect de novo insertions at a single locus and Alu-mediated deletions at two different loci in human genomic DNA. Validation experiments showed these approaches could detect insertions and deletions at frequencies below 10(-6) per cell. However, bulk analysis of germline (sperm) and somatic DNA showed no evidence for genuine mutant molecules, placing an upper limit of insertion and deletion rates of 2 x 10(-7) and 3 x 10(-7), respectively, in the individuals tested. Such re-arrangements at these loci therefore occur at a rate lower than that detectable by the most sensitive methods currently available

Valutazione della funzionalità dei boschi planiziali relitti della pianura veneta orientale per la conservazione delle specie nemorali erbacee.

The effects of fragmentation as a driver affecting environmental condition, habitat integrity and, consequently, the possibility of a long-term persistence of ancient forest species populations were evaluated. A check list of the flora was compiled for each forest. Repeated samplings have been surveyed in spring and in late summer-autumn following a stratified random design. 80 permanent plot (25m x 25m) were fixed, randomly and proportionately to the correspondent surface, on the two woodland habitat types: 1) the “edge habitat”, that is the concentric zone up to 50 meters from woods boundary and 2) the “core area”, the interior and protected zone. Species were clustered in 7 ecological groups, on the basis of similar ecology and similar role inside the community. The group assignment was based on phytosociological affinity. Binary data on occurrence of species in the 80 plots were used to perform Principal Coordinates Analysis (Sörensen Index). For each woods we defined richness, structure (on the basis of ecological groups) and an index of floristic quality (FQAI). Species richness and FQAI have been related to environmental variables (area and age, that is time from last fragmentation event) using a linear regression approach. Data analysis pointed out that three main indipendent variables affect habitat quality: surface, surrounding matrix and age. Our data confirm woodlands patches are experiencing the “relaxation time”, namely the time taken for a community to reach a new equilibrium after an environmental disturbance. After fragmentation, woodlands have lost their typical structure and, at present, they seem unable to assure a long-term conservation of herbaceous nemoral species

La componente floristica dei relitti boscati della pianura veneta orientale: qualità e grado di conservazione

The floristic composition of venetian relic woods: quality and conservation status. The aim of the study was to collect up-to-date data on the floristic composition of fragments of relic woods in venetian Po plain. For each forest a check list of the flora has been compiled. The floristic originality of woods has been confirmed: thanks to their geographic position they show the co-occurrence of Temperate-Continental species, Mediterranean and Balkanian elements. In order to evaluate the floristic quality, species were clustered in 7 ecological groups, on the basis of similar ecology and similar role inside the community. The group assignment was based on phytosociological affinity. Quality of the plant communities didn’t show a gradual change from larger to smaller patches, with larger patches being characterised by a higher proportion of quality species, and both larger and smaller patches hosted rare and threatened forest species depending on their inner quality

Stability data, irregular connections and tropical curves

We study a class of meromorphic connections nabla(Z) on P^1, parametrised by the central charge Z of a stability condition, with values in a Lie algebra of formal vector fields on a torus. Their definition is motivated by the work of Gaiotto, Moore and Neitzke on wall-crossing and three-dimensional field theories. Our main results concern two limits of the families nabla(Z) as we rescale the central charge Z to RZ. In the R to 0 ``conformal limit'' we recover a version of the connections introduced by Bridgeland and Toledano Laredo (and so the Joyce holomorphic generating functions for enumerative invariants), although with a different construction yielding new explicit formulae. In the R to infty ``large complex structure" limit the connections nabla(Z) make contact with the Gross-Pandharipande-Siebert approach to wall-crossing based on tropical geometry. Their flat sections display tropical behaviour, and also encode certain tropical/relative Gromov-Witten invariants