405 research outputs found

    L∞-norm and energy quantization for the planar Lane–Emden problem with large exponent

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    For any smooth bounded domain (Formula presented.), we consider positive solutions to (Formula presented.)which satisfy the uniform energy bound (Formula presented.)for (Formula presented.). We prove convergence to (Formula presented.) as (Formula presented.) of the (Formula presented.)-norm of any solution. We further deduce quantization of the energy to multiples of (Formula presented.), thus completing the analysis performed in De Marchis et al. (J Fixed Point Theory Appl 19:889–916, 2017)

    Phaseolin expression in tobacco chloroplast reveals an autoregulatory mechanism in heterologous protein translation

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    Plastid DNA engineering is a well-established research area of plant biotechnology, and plastid transgenes often give high expression levels. However, it is still almost impossible to predict the accumulation rate of heterologous protein in transplastomic plants, and there are many cases of unsuccessful transgene expression. Chloroplasts regulate their proteome at the post-transcriptional level, mainly through translation control. One of the mechanisms to modulate the translation has been described in plant chloroplasts for the chloroplast-encoded subunits of multiprotein complexes, and the autoregulation of the translation initiation of these subunits depends on the availability of their assembly partners [control by epistasy of synthesis (CES)]. In Chlamydomonas reinhardtii, autoregulation of endogenous proteins recruited in the assembly of functional complexes has also been reported. In this study, we revealed a self-regulation mechanism triggered by the accumulation of a soluble recombinant protein, phaseolin, in the stroma of chloroplast-transformed tobacco plants. Immunoblotting experiments showed that phaseolin could avoid this self-regulation mechanism when targeted to the thylakoids in transplastomic plants. To inhibit the thylakoid-targeted phaseolin translation as well, this protein was expressed in the presence of a nuclear version of the phaseolin gene with a transit peptide. Pulse-chase and polysome analysis revealed that phaseolin mRNA translation on plastid ribosomes was repressed due to the accumulation in the stroma of the same soluble polypeptide imported from the cytosol. We suggest that translation autoregulation in chloroplast is not limited to heteromeric protein subunits but also involves at least some of the foreign soluble recombinant proteins, leading to the inhibition of plastome-encoded transgene expression in chloroplast

    Ischemic cardiovascular disease in workers occupationally exposed to urban air pollution – A systematic review

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    Introduction. Cardiovascular disease is the first cause of morbidity and mortality worldwide. Among several known risk factors, researchers also focus their attention on the chronic exposure to air pollution. There is much evidence that exposure to air pollution, especially to ultrafine particles, can damage the endothelium and can favour cardiovascular diseases in the general population. Occupational exposition could be an additive risk factor for the cardiovascular system. This article presents a scientific review of the linkage between occupational exposure to air pollution and ischemic heart disease. Materials and method. A scientific review was undertaken, followed by PRISMA Statements. Observational studies were selected from several scientific databases, likesuch as Pubmed, Google Scholar, Nioshtic-2 and Reserchgate, searching for selected key words: police workers, professional drivers, mail carriers, filling station attendants, road cleaners, garage workers, motor vehicles and engine maintenance. All the key words were combined with “Boolean Operators” with the following words: cardiovascular (or cardiac) disease, cardiovascular function, cardiovascular system, ischemic heart disease, coronary disease, myocardial infarction. During the systematic research, the focus was on retrospective and prospective studies from January 1990 – December 2014. Results. Both the retrospective and prospective studies showed an increased risk of ischemic heart disease in occupationally occupied people exposed to air pollution. Only one study presented a ly minor risk. Conclusions. The findings of this systematic review suggest a possible linkage between occupational exposure to urban air pollution, especially to motor exhaust and particulate, and ischemic heart disease

    Rapid detection of copy number variations and point mutations in BRCA1/2 genes using a single workflow by ion semiconductor sequencing pipeline

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    Molecular analysis of BRCA1 (MIM# 604370) and BRCA2 (MIM #600185) genes is essential for familial breast and ovarian cancer prevention and treatment. An efficient, rapid, cost-effective accurate strategy for the detection of pathogenic variants is crucial. Mutations detection of BRCA1/2 genes includes screening for single nucleotide variants (SNVs), small insertions or deletions (indels), and Copy Number Variations (CNVs). Sanger sequencing is unable to identify CNVs and therefore Multiplex Ligation Probe amplification (MLPA) or Multiplex Amplicon Quantification (MAQ) is used to complete the BRCA1/2 genes analysis. The rapid evolution of Next Generation Sequencing (NGS) technologies allows the search for point mutations and CNVs with a single platform and workflow. In this study we test the possibilities of NGS technology to simultaneously detect point mutations and CNVs in BRCA1/2 genes, using the OncomineTM BRCA Research Assay on Personal Genome Machine (PGM) Platform with Ion Reporter Software for sequencing data analysis (Thermo Fisher Scientific). Comparison between the NGS-CNVs, MLPA and MAQ results shows how the NGS approach is the most complete and fast method for the simultaneous detection of all BRCA mutations, avoiding the usual time consuming multistep approach in the routine diagnostic testing of hereditary breast and ovarian cancers

    Olive fruits infested with olive fly larvae respond with an ethylene burst and the emission of specific volatiles

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    Olive fly (Bactrocera oleae R.) is the most harmful insect pest of olive (Olea europaea L.) which strongly affects fruits and oil production. Despite the expanding economic importance of olive cultivation, up to now, only limited information on plant responses to B. oleae is available. Here, we demonstrate that olive fruits respond to B. oleae attack by producing changes in an array of different defensive compounds including phytohormones, volatile organic compounds (VOCs), and defense proteins. Bactrocera oleae-infested fruits induced a strong ethylene burst and transcript levels of several putative ethylene-responsive transcription factors became significantly upregulated. Moreover, infested fruits induced significant changes in the levels of 12-oxo-phytodienoic acid and C12 derivatives of the hydroperoxide lyase. The emission of VOCs was also changed quantitatively and qualitatively in insect-damaged fruits, indicating that B. oleae larval feeding can specifically affect the volatile blend of fruits. Finally, we show that larval infestation maintained high levels of trypsin protease inhibitors in ripe fruits, probably by affecting post-transcriptional mechanisms. Our results provide novel and important information to understand the response of the olive fruit to B. oleae attack; information that can shed light onto potential new strategies to combat this pes

    Prevalence, virulence and antimicrobial susceptibility of Salmonella spp., Yersinia enterocolitica and Listeria monocytogenes in european wild boar (Sus scrofa) hunted in Tuscany (central Italy)

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    Wild boar is an animal the population of which constantly increases in Europe. This animal plays an important role as a reservoir for several pathogens, including three of the most important zoonoses: salmonellosis, yersiniosis and listeriosis. The aim of this investigation was to eval-uate the occurrence of antimicrobial-resistant and virulence factor genes of Salmonella spp., Yersinia enterocolitica and Listeria monocytogenes isolated from wild boar in Tuscany (Central Italy). During two consequent hunting seasons (2018/2019 and 2019/2020), rectal swabs, spleens and livers were collected from 287 hunted wild boar to isolate strains. Each isolate was tested to investigate its an-timicrobial resistance and to detect virulence factor genes by PCR. Eighteen Salmonella strains (6.27%) were isolated. Of these, 66.7% were resistant to streptomycin, 13.4% to cephalothin, 6.67% to imipenem and one isolate (6.67%) was resistant simultaneously to five antimicrobials. Moreover, the most detected genes were sopE (73.4%), pipB (66.7%), sodCI (53.3%), spvR and spvC (46.7%). In total, 54 (17.8%) Yersinia enterocolitica were isolated; of them, 26 (48.1%), 9 (16.7%), 17 (31.5%), 1 (1.85%) and 1 (1.85%) belonged to biotypes 1, 2, 3, 4 and 5, respectively. All strains (100%) demon-strated resistance to cephalothin and 70.4% to amoxicillin-clavulanic acid, 55.6% to ampicillin, and 37.0% to cefoxitin. Additionally, the most detected genes were ystA (25.9%), inv (24.1%), ail (22.2%), ystB (18.5%) and virF (14.8%). Finally, only one Listeria monocytogenes isolate (0.35%) was obtained, belonging to serogroup IVb, serovar 4b, and it was found to be resistant to cefoxitin, cefotaxime and nalidixic acid. The results highlighted the role of wild boar as a carrier for pathogenic and antimi-crobial-resistant Salmonella spp., Yersinia enterocolitica and Listeria monocytogens, representing a possible reservoir for domestic animals and human pathogens

    A low density of 0.8 g/cc for the Trojan binary asteroid 617 Patroclus

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    The Trojan population consists of two swarms of asteroids following the same orbit as Jupiter and located at the L4 and L5 Lagrange points of the Jupiter-Sun system (leading and following Jupiter by 60 degrees). The asteroid 617 Patroclus is the only known binary Trojan (Merline et al. 2001). The orbit of this double system was hitherto unknown. Here we report that the components, separated by 680 km, move around the system centre of mass, describing roughly a circular orbit. Using the orbital parameters, combined with thermal measurements to estimate the size of the components, we derive a very low density of 0.8 g/cc. The components of Patroclus are therefore very porous or composed mostly of water ice, suggesting that they could have been formed in the outer part of the solar system.Comment: 10 pages, 3 figures, 1 tabl

    Triplicity and Physical Characteristics of Asteroid (216) Kleopatra

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    To take full advantage of the September 2008 opposition passage of the M-type asteroid (216) Kleopatra, we have used near-infrared adaptive optics (AO) imaging with the W.M. Keck II telescope to capture unprecedented high resolution images of this unusual asteroid. Our AO observations with the W.M. Keck II telescope, combined with Spitzer/IRS spectroscopic observations and past stellar occultations, confirm the value of its IRAS radiometric radius of 67.5 km as well as its dog-bone shape suggested by earlier radar observations. Our Keck AO observations revealed the presence of two small satellites in orbit about Kleopatra (see Marchis et al., 2008). Accurate measurements of the satellite orbits over a full month enabled us to determine the total mass of the system to be 4.64+/-0.02 10^18 Kg. This translates into a bulk density of 3.6 +/-0.4 g/cm3, which implies a macroscopic porosity for Kleopatra of ~ 30-50%, typical of a rubble-pile asteroid. From these physical characteristics we measured its specific angular momentum, very close to that of a spinning equilibrium dumbbell.Comment: 35 pages, 3 Tables, 9 Figures. In press to Icaru

    Presence and characterization of zoonotic bacterial pathogens in wild boar hunting dogs (Canis lupus familiaris) in tuscany (italy)

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    Domestic dogs (Canis lupus familiaris) used for wild boar (Sus scrofa) hunting may represent incidental hosts for several zoonotic pathogens. This investigation aimed to evaluate the presence of anti-Leptospira antibodies and the occurrence, antimicrobial resistance, and virulence of Salmonella spp., Yersinia enterocolitica, and Listeria monocytogenes in sera and rectal swabs collected from 42 domestic hunting dogs in the Tuscany region (Italy). Regarding Leptospira, 31 out of 42 serum samples (73.8%) were positive and serogroup Pomona was the most detected (71.4%) at titers between 1:100 and 1:400. Four Salmonella isolates (9.52%) were obtained, all belonging to serotype Infantis; two of them showed antimicrobial resistance to streptomycin, while pipB and sopE presence was assessed in all but one isolate. Concerning Yersinia enterocolitica, seven isolates (16.7%) were obtained, six belonging to biotype 1 and one to biotype 4. Resistance to amoxicillin–clavulanic acid, cephalothin, and ampicillin was detected. Biotype 4 presented three of the virulence genes searched (ystA, ystB, inv), while isolates of biotype 1 showed only one gene. No Listeria monocytogenes was isolated from dog rectal swabs. The results suggest that hunting dogs are exposed to different bacterial zoonotic agents, potentially linked to their work activity, and highlight the possible health risks for humans
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