547 research outputs found

    The diatom-derived aldehyde decadienal affects life cycle transition in the ascidian Ciona intestinalis through nitric oxide/ERK signalling

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    Polyunsaturated aldehydes (PUAs) are fatty-acid-derived metabolites produced by some microalgae, including different diatom species. PUAs are mainly produced as a wound-activated defence mechanism against microalgal predators or released from senescent cells at the end of a bloom. PUAs, including 2,4-trans-decadienal (DD), induce deleterious effects on embryonic and larval development of several planktonic and benthic organisms. Here, we report on the effects of DD on larval development and metamorphosis of the ascidian Ciona intestinalis. Ciona larval development is regulated by the cross-talking of different molecular events, including nitric oxide (NO) production, ERK activation and caspase 3-dependent apoptosis. We report that treatment with DD at the competence larval stage results in a delay in metamorphosis. DD affects redox balance by reducing total glutathione and NO levels. By biochemical and quantitative gene expression analysis, we identify the NO-signalling network affected by DD, including the upregulation of ERK phosphatase mkp1 and consequent reduction of ERK phosphorylation, with final changes in the expression of downstream ERK target genes. Overall, these results give new insights into the molecular pathways induced in marine organisms after exposure to PUAs during larval development, demonstrating that this aldehyde affects key checkpoints of larval transition from the vegetative to the reproductive life stage. & 2015 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited

    Marine Biotechnology: A New Vision and Strategy for Europe

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    Marine Board-ESF The Marine Board provides a pan-European platform for its member organisations to develop common priorities, to advance marine research, and to bridge the gap between science and policy in order to meet future marine science challenges and opportunities. The Marine Board was established in 1995 to facilitate enhanced cooperation between European marine science organisations (both research institutes and research funding agencies) towards the development of a common vision on the research priorities and strategies for marine science in Europe. In 2010, the Marine Board represents 30 Member Organisations from 19 countries. The Marine Board provides the essential components for transferring knowledge for leadership in marine research in Europe. Adopting a strategic role, the Marine Board serves its Member Organisations by providing a forum within which marine research policy advice to national agencies and to the European Commission is developed, with the objective of promoting the establishment of the European Marine Research Area

    Exploring resonantly produced mixed sterile neutrino dark matter models

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    An unidentified 3.55 keV X-ray line in stacked spectra of galaxies and clusters raises the interesting possibility that it originates from the decay of sterile neutrino dark matter. In this work, we explore mixed sterile neutrino dark matter models that combine cold dark matter and warmer sterile neutrino dark matter produced through lepton number-driven active-to-sterile neutrino transformation. We analyze the sensitivity of the sterile neutrino spectra on active-sterile mixing and on initial neutrino lepton numbers. Furthermore, we assess the viability of these models with estimates of the number of subhalos formed as the host sites of satellite galaxies.Comment: 10 pages, 12 figure

    De novo transcriptome assembly and gene expression profiling of the copepod Calanus helgolandicus feeding on the PUA-producing diatom Skeletonema marinoi

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    Diatoms are the dominant component of the marine phytoplankton. Several diatoms produce secondary metabolites, namely oxylipins, with teratogenic effects on their main predators, crustacean copepods. Our study reports the de novo assembled transcriptome of the calanoid copepod Calanus helgolandicus feeding on the oxylipin-producing diatom Skeletonema marinoi. Differential expression analysis was also performed between copepod females exposed to the diatom and the control flagellate Prorocentrum minimum, which does not produce oxylipins. Our results showed that transcripts involved in carbohydrate, amino acid, folate and methionine metabolism, embryogenesis, and response to stimulus were differentially expressed in the two conditions. Expression of 27 selected genes belonging to these functional categories was also analyzed by RT-qPCR in C. helgolandicus females exposed to a mixed solution of the oxylipins heptadienal and octadienal at the concentration of 10 \ub5M, 15 \ub5M, and 20 \ub5M. The results confirmed differential expression analysis, with up-regulation of genes involved in stress response and down-regulation of genes associated with folate and methionine metabolism, embryogenesis, and signaling. Overall, we offer new insights on the mechanism of action of oxylipins on maternally-induced embryo abnormality. Our results may also help identify biomarker genes associated with diatom-related reproductive failure in the natural copepod population at sea

    Magnetic resonance imaging for deep infiltrating endometriosis: current concepts, imaging technique and key findings

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    Endometriosis is an estrogen-dependent chronic disease affecting about 10% of reproductive-age women with symptoms like pelvic pain and infertility. Pathologically, it is defined by the presence of endometrial tissue outside the uterine cavity responsible for a chronic inflammatory process. For decades the diagnosis of endometriosis was based on surgical exploration and biopsy of pelvic lesions. However, laparoscopy is not a risk-free procedure with possible false negative diagnosis due to an underestimate of retroperitoneal structures such as ureters and nerves. For these reasons nowadays, the diagnosis of endometriosis is based on a noninvasive approach where clinical history, response to therapy and imaging play a fundamental role. Trans-vaginal ultrasound and magnetic resonance imaging are suitable for recognizing most of endometriotic lesions; nevertheless, their accuracy is strictly determined by operators’ experience and imaging technique. This review paper aims to make radiologists aware of the diagnostic possibilities of pelvic MRI and familial with the MR acquisition protocols and image interpretation for women with endometriosis

    The multifaceted covid-19: Ct aspects of its atypical pulmonary and abdominal manifestations and complications in adults and children. a pictorial review

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    Our daily experience in a COVID hospital has allowed us to learn about this disease in many of its changing and unusual aspects. Some of these uncommon manifestations, however, appeared more frequently than others, giving shape to a multifaceted COVID-19 disease. This pictorial review has the aim to describe the radiological aspects of atypical presentations and of some complications of COVID-19 disease in adults and children and provide a simple guide for radiologists to become familiar with the multiform aspects of this disease

    The Role of Multiparametric Magnetic Resonance in Volumetric Modulated Arc Radiation Therapy Planning for Prostate Cancer Recurrence After Radical Prostatectomy: A Pilot Study

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    Background and Purpose: Volumetric modulated arc radiotherapy (RT) has become pivotal in the treatment of prostate cancer recurrence (RPC) to optimize dose distribution and minimize toxicity, thanks to the high-precision delineation of prostate bed contours and organs at risk (OARs) under multiparametric magnetic resonance (mpMRI) guidance. We aimed to assess the role of pre-treatment mpMRI in ensuring target volume coverage and normal tissue sparing. Material and Methods: Patients with post-prostatectomy RPC eligible for salvage RT were prospectively recruited to this pilot study. Image registration between planning CT scan and T2w pre-treatment mpMRI was performed. Two sets of volumes were outlined, and DWI images/ADC maps were used to facilitate precise gross tumor volume (GTV) delineation on morphological MRI scans. Two rival plans (mpMRI-based or not) were drawn up. Results: Ten patients with evidence of RPC after prostatectomy were eligible. Preliminary data showed lower mpMRI-based clinical target volumes than CT-based RT planning (p = 0.0003): median volume difference 17.5 cm3. There were no differences in the boost volume coverage nor the dose delivered to the femoral heads and penile bulb, but median rectal and bladder V70Gy was 4% less (p = 0.005 and p = 0.210, respectively) for mpMRI-based segmentation. Conclusions: mpMRI provides high-precision target delineation and improves the accuracy of RT planning for post-prostatectomy RPC, ensures better volume coverage with better OARs sparing and allows non-homogeneous dose distribution, with an aggressive dose escalation to the GTV. Randomized phase III trials and wider datasets are needed to fully assess the role of mpMRI in optimizing therapeutic strategies

    High-quality RNA extraction from copepods for Next Generation Sequencing: A comparative study

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    Despite the ecological importance of copepods, few Next Generation Sequencing studies (NGS) have been performed on small crustaceans, and a standard method for RNA extraction is lacking. In this study, we compared three commonly-used methods: TRIzol®, Aurum Total RNA Mini Kit and Qiagen RNeasy Micro Kit, in combination with preservation reagents TRIzol® or RNAlater®, to obtain high-quality and quantity of RNA from copepods for NGS. Total RNA was extracted from the copepods Calanus helgolandicus, Centropages typicus and Temora stylifera and its quantity and quality were evaluated using NanoDrop, agarose gel electrophoresis and Agilent Bioanalyzer. Our results demonstrate that preservation of copepods in RNAlater® and extraction with Qiagen RNeasy Micro Kit were the optimal isolation method for high-quality and quantity of RNA for NGS studies of C. helgolandicus. Intriguingly, C. helgolandicus 28S rRNA is formed by two subunits that separate after heat-denaturation and migrate along with 18S rRNA. This unique property of protostome RNA has never been reported in copepods. Overall, our comparative study on RNA extraction protocols will help increase gene expression studies on copepods using high-throughput applications, such as RNA-Seq and microarrays
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