Spreading and accumulation of river-borne sediments in the coastal ocean after the environmental disaster at the Doce River in Brazil

This study is focused on the fate of a large volume of mine slurry discharged from the Doce River (DR) to the coastal ocean after the worst environmental disaster in Brazilian which occurred in November 2015. We used Eulerian (ROMS) and Lagrangian (STRiPE) numerical models, as well as satellite remote sensing data, to study the spreading and seafloor accumulation of fine river-borne sediments during the initial six months following the disaster. We show that the regions of intense sediment accumulation were determined by spreading patterns of the surface-advected DR plume. The river discharge rate governed the plume surface area, while its position depended on local wind forcing conditions. The spreading of sediments carried by the DR plume was dominated by southward transport caused by prevailing upwelling-favorable northeasterly winds during the study period. Under high discharge conditions, river-borne sediments were transported over 100 km southward from the DR mouth and reached the outer shelf. In contrast, sediments were arrested near the mouth during drought periods and remained on the inner shelf. As a result, fine river-borne sediments accumulated on the seafloor, mainly in the large shallow shelf area southward from the DR mouth. Conversely, only a small fraction of residue was deposited northward. Thus, the Environmental Protection Area (EPA) of Costa das Algas, located 40 km southward from the DR, potentially exhibited more susceptibility to sediment arrival. On the other hand, their influence on Abrolhos Marine National Park, located 200 km northeastward from the DR mouth, was presumably minimal

Neurodevelopmental risk factors in schizophrenia

The authors review environmental and neurodevelopmental risk factors for schizophrenic disorders, with emphasis on minor physical anomalies, particularly craniofacial anomalies and dermatoglyphic variations. The high prevalence of these anomalies among schizophrenic subjects supports the neurodevelopmental theory of the etiology of schizophrenia, since they suggest either genetically or epigenetically controlled faulty embryonic development of structures of ectodermal origin like brain and skin. This may disturb neurodevelopment that in turn may cause these subjects to be at increased risk for the development of schizophrenia and related disorders. The precise confirmation of this theory, at least in some cases, will provide further understanding of these illnesses, allowing easy and inexpensive identification of subjects at risk and providing guidelines for the development of new pharmacological interventions for early treatment and even for primary prevention of the illness

Post-transcriptional control of gene expression : therapeutic targeting in human diseases

SUMMARY RNA has become a promising target for pharmacological purposes. In this study, evidence are provided of the up-regulation of messenger RNA in a sequence-specific manner by targeting a destabilizing element. Adenine-uridine rich elements (AREs) play an important role in modulating mRNA stability, being the target site of many ARE Binding Proteins (AUBPs) that are involved in the decay process. The bcl-2 (b)-ARE, located in the 3 -UTR of the b-RNA, regulates the rate of bcl-2 RNA degradation. The b-ARE has been targeted with three 2 -O-methyl oligoribonucleotides designed in the antisense orientation (asORNs) and, afterwards, with three 2 -O-Me-ORNs, homologous to the core region of ARE of bcl-2 mRNA. Both asORNs and sense-ORNs were studied by a cell-free degradation assay. ORNs inhibited the rate of RNA decay in a dose-response and ORNs sequence dependent fashion, moreover asORNs were specific to the b-ARE. ORNs were then transfected into malignant cells in culture and b-RNA half-life was measured by real-time PCR. We showed that ORNs increased the expression of b-RNA and Bcl-2 protein in a dose-response fashion, while asORNs were Bcl-2 specific and affected also cell survival and phenotype, sORNs up-regulated the expression ARE-transcripts other than bcl-2. In fact, sORNs, tested for decoy-aptamer activity in UVx-linking and RNA-IP assays, competed with the ARE motif for the interaction with AUBPs shared by different ARE-transcript, hence their activity is bcl-2 independent

Proposta per l'insegnamento della relatività speciale in un liceo scientifico

Viene presentato il materiale elaborato in una esperienza di insegnamento della Relatività speciale nel triennio di un liceo scientifico e riportati brevemente i risultati emersi dalla sperimentazione in classe

Wine and tumors: study of resveratrol

In modern industrial societies the attention to public health, especially in relation to food habits, is increasing day by day. Considering this, it's no wonder that wine, the voluptuary drink that best represents human history, is the most interesting compound. The main and best known wine effects on the human body are caused by alcohol, but several other active compounds are present in wine. Above all, resveratrol is able to neutralize free radicals, which can damage DNA and may lead to cancer onset. In this study, we have indagated resveratrol anticancer action, analyzing its effects on both cell cycle and growing of human lymphoma B (DHL-4) cells. MTT colorimetric test, tripan blue dye exclusion assay, and cell cycle analysis showed that resveratrol has a dose-dependent antiproliferative and antiapoptotic action on DHL-4 cells. These results confirm resveratrol's potential therapeutic role on tumors

Clinical and radiographic evaluation of small-diameter (3.3-mm) implants followed for 1-7 years : a longitudinal study

Implants with a small diameter may be used where bone width is reduced or in single-tooth gaps with limited mesiodistal space, such as for the replacement of lateral maxillary or mandibular incisors. The purpose of the present longitudinal study was to compare the prognosis of narrow implants (3.3-mm-diameter) to standard (4.1-mm-diameter) implants. Over a 7-year period, 122 narrow implants were inserted in 68 patients to support 45 partial fixed prostheses (PFD) and 23 single-tooth prostheses (ST). Furthermore, 120 patients received 208 standard implants and were restored with 70 PFD and 50 ST, respectively. Clinical and radiographic assessment data were provided. Six (1.8%) out of 330 implants failed. Cumulative survival and success rates were calculated with life-table analyses processed by collecting clinical and radiographic data. For narrow implants, the cumulative survival rate was 98.1% in the maxilla and 96.9% in the mandible. The cumulative success rate was 96.1% in the maxilla and 92% in the mandible. Conversely, standard-diameter implants showed a cumulative survival rate of 96.8% in the maxilla and 97.9% in the mandible. The cumulative success rate was 97.6% in the maxilla and 93.8% in the mandible. Cumulative survival and success rates of small-diameter implants and standard-diameter implants were not statistically different (P &rt; 0.05). Type 4 bone was a determining failure factor, while marginal bone loss was not influenced by the different implant diameters. The results suggest that small-diameter implants can be successfully used in the treatment of partially edentulous patients

Interaction of nucleolin with an evolutionary conserved sequence is required for pre-rRNA primary processing in vitro.

International audienceThe first processing event of the precursor ribosomal RNA (pre-rRNA) takes place within the 5' external transcribed spacer. This primary processing requires conserved cia-acting RNA sequence downstream from the cleavage site and several nucleic acids (small nucleolar RNAs) and proteins trans-acting factors including nucleolin, a major nucleolar protein, The specific interaction of nucleolin with the pre-rRNA is required for processing in vitro. Xenopus laevis and hamster nucleolin interact with the same pre-rRNA site and stimulate the processing activity of a mouse cell extract. A highly conserved 11-nucleotide sequence located 5-6 nucleotides after the processing site is required for the interaction of nucleolin and processing. In vitro selection experiments with nucleolin have identified an RNA sequence that contains the UCGA motif present in the 11-nucleotide conserved sequence, The interaction of nucleolin with pre-rRNA is required for the formation of an active processing complex. Our findings demonstrate that nucleolin is a key factor for the assembly and maturation of pre-ribosomal ribonucleoparticles

Interaction of Nucleolin with an Evolutionarily Conserved Pre-ribosomal RNA Sequence Is Required for the Assembly of the Primary Processing Complex*

The first processing event of the precursor ribosomal RNA (pre-rRNA) takes place within the 5' external transcribed spacer. This primary processing requires conserved cia-acting RNA sequence downstream from the cleavage site and several nucleic acids (small nucleolar RNAs) and proteins trans-acting factors including nucleolin, a major nucleolar protein, The specific interaction of nucleolin with the pre-rRNA is required for processing in vitro. Xenopus laevis and hamster nucleolin interact with the same pre-rRNA site and stimulate the processing activity of a mouse cell extract. A highly conserved 11-nucleotide sequence located 5-6 nucleotides after the processing site is required for the interaction of nucleolin and processing. In vitro selection experiments with nucleolin have identified an RNA sequence that contains the UCGA motif present in the 11-nucleotide conserved sequence, The interaction of nucleolin with pre-rRNA is required for the formation of an active processing complex. Our findings demonstrate that nucleolin is a key factor for the assembly and maturation of pre-ribosomal ribonucleoparticles