15 research outputs found

    Effects of arbuscular mycorrhizal fungal inoculations on the growth and polyphenol levels of garden leek (Allium porrum)

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    Arbuscular mycorrizal (AM) fungi may enhance plant growth and polyphenol production, however, there have been limited studies on the relationships between root colonization of different fungal species and polyphenol production on cultivated Allium porrum (garden leek). The effects of inoculation of AM fungi spores from Rhizophagus intraradices, Giga -spora margarita, Glomus geosporum, Paraglomus occultum, Claroideoglomus claroideum, and Glomus species on colonization of garden leek roots and symbiotic changes in polyphenol production and plant growth were evaluated in greenhouse experiments. There were significant differences (p < 0.05) in colonization of leek roots by AM fungi species. The greatest level of root colonization was recorded on plants inoculated with R. intraradices (73%) and the lowest level on C. claroideum (3.2%). Significant differences (p < 0.05) in plant height were recorded between AM inoculated plants and the controls. Polyphenol levels differed significantly (p < 0.05) between garden leek plants inoculated with AM fungi and the non-inoculated controls. The percentage increases in polyphenol (a derivative of kaempferol) on garden leeks inoculated with G. geosporum relative to the untreated controls ranged from 28 to 1123%. Due to symbiosis with different AM species, other polyphenols decreased in some instances (negative values) and increased in others for values of up to 590%. Results showed that AM fungi species exhibited remarkable differences in polyphenol levels in garden leeks. The high polyphenol production by garden leek plants inoculated with G. geosporum, and Glomus species could be exploited for enhanced resistance of garden leeks to insects and diseases. This research highlights an understudied area, notably the relationships between AM fungal inoculations, root colonizations and polyphenol production in garden leeks. The findings can be utilized to improve pest resistance and the quality of garden leek plants

    <em>In silico</em> characterization of a novel pathogenic deletion mutation identified in <em>XPA</em> gene in a Pakistani family with severe xeroderma pigmentosum.

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    BACKGROUND: Xeroderma Pigmentosum (XP) is a rare skin disorder characterized by skin hypersensitivity to sunlight and abnormal pigmentation. The aim of this study was to investigate the genetic cause of a severe XP phenotype in a consanguineous Pakistani family and in silico characterization of any identified disease-associated mutation. RESULTS: The XP complementation group was assigned by genotyping of family for known XP loci. Genotyping data mapped the family to complementation group A locus, involving XPA gene. Mutation analysis of the candidate XP gene by DNA sequencing revealed a novel deletion mutation (c.654del A) in exon 5 of XPA gene. The c.654del A, causes frameshift, which pre-maturely terminates protein and result into a truncated product of 222 amino acid (aa) residues instead of 273 (p.Lys218AsnfsX5). In silico tools were applied to study the likelihood of changes in structural motifs and thus interaction of mutated protein with binding partners. In silico analysis of mutant protein sequence, predicted to affect the aa residue which attains coiled coil structure. The coiled coil structure has an important role in key cellular interactions, especially with DNA damage-binding protein 2 (DDB2), which has important role in DDB-mediated nucleotide excision repair (NER) system. CONCLUSIONS: Our findings support the fact of genetic and clinical heterogeneity in XP. The study also predicts the critical role of DDB2 binding region of XPA protein in NER pathway and opens an avenue for further research to study the functional role of the mutated protein domain

    Identification of recurrent c.742G&gt;T nonsense mutation in <em>ECM1</em> in Pakistani families suffering from lipoid proteinosis.

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    Lipoid proteinosis (LP) is one of the rare, recessive autosomal disorders clinically characterized by widespread deposition of hyaline-like material in the skin, mucosa and viscera. Classical features include beaded eyelid papules, laryngeal infiltration and hoarseness of voice caused by pathogenic mutations in the ECM1gene located on 1q21.2. In present study ethnically different, three consanguineous Pakistani families with typical cutaneous features of LP were analysed to investigate the underlying molecular basis. PCR based linkage analysis using microsatellite markers localized the families to locus 1q21.2, harboring ECM1 gene. To identify the mutation in the candidate gene (ECM1), Sanger sequencing was carried out. All the families were found to carry c.742&nbsp;G&gt;T nonsense mutation in exon 7 of the ECM1 gene that resulted in a truncated ECM1 protein containing 247 amino acids instead of 540 (p.E248X). To further investigate the impact and importance of mutation in LP pathogenesis we applied different bioinformatics tools. In silico studies has predicted lack of functional domains and 65&nbsp;% shorter ECM1 mutant protein. It is the first report of recurrence mutation from Pakistan as c.742G&gt;T nonsense mutation was found in three ethnically different Pakistani families with LP. Study strengthens the conclusion that c.742G&gt;T mutation is the pathological cause of LP. Furthermore, data also support the fact that exon 7 is one of the most common hot spots of pathological mutations in ECM1. The absence of functional domains and truncated sequence most likely contribute to the lack of ECM1 function and thereby influence several aspects of dermal homeostasis that leads to LP pathogenesis

    Pyrrolizidine Alkaloids and their Biological Properties from Indian Heliotropium Species

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    Direct observation of the dead-cone effect in quantum chromodynamics

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    At particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD) [1]. The vacuum is not transparent to the partons and induces gluon radiation and quark pair production in a process that can be described as a parton shower [2]. Studying the pattern of the parton shower is one of the key experimental tools in understanding the properties of QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass m and energy E, within a cone of angular size m/E around the emitter [3]. A direct observation of the dead-cone effect in QCD has not been possible until now, due to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible bound hadronic states. Here we show the first direct observation of the QCD dead-cone by using new iterative declustering techniques [4, 5] to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD, which is derived more generally from its origin as a gauge quantum field theory. Furthermore, the measurement of a dead-cone angle constitutes the first direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.The direct measurement of the QCD dead cone in charm quark fragmentation is reported, using iterative declustering of jets tagged with a fully reconstructed charmed hadron.In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD). These partons subsequently emit further partons in a process that can be described as a parton shower which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass mQm_{\rm{Q}} and energy EE, within a cone of angular size mQm_{\rm{Q}}/EE around the emitter. Previously, a direct observation of the dead-cone effect in QCD had not been possible, owing to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible hadrons. We report the direct observation of the QCD dead cone by using new iterative declustering techniques to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics

    Underlying-event properties in pp and p–Pb collisions at √sNN = 5.02 TeV

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    We report about the properties of the underlying event measured with ALICE at the LHC in pp and p−Pb collisions at sNN−−−√=5.02 TeV. The event activity, quantified by charged-particle number and summed-pT densities, is measured as a function of the leading-particle transverse momentum (ptrigT). These quantities are studied in three azimuthal-angle regions relative to the leading particle in the event: toward, away, and transverse. Results are presented for three different pT thresholds (0.15, 0.5, and 1 GeV/c) at mid-pseudorapidity (|η|10 GeV/c, whereas for lower ptrigT values the event activity is slightly higher in p−Pb than in pp collisions. The measurements are compared with predictions from the PYTHIA 8 and EPOS LHC Monte Carlo event generators

    Dielectron production at midrapidity at low transverse momentum in peripheral and semi-peripheral Pb–Pb collisions at √sNN = 5.02 TeV

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    The first measurement of the e+e− pair production at low lepton pair transverse momentum (pT,ee) and low invariant mass (mee) in non-central Pb−Pb collisions at sNN−−−√=5.02 TeV at the LHC is presented. The dielectron production is studied with the ALICE detector at midrapidity (|ηe|<0.8) as a function of invariant mass (0.4≤mee<2.7 GeV/c2) in the 50−70% and 70−90% centrality classes for pT,ee<0.1 GeV/c, and as a function of pT,ee in three mee intervals in the most peripheral Pb−Pb collisions. Below a pT,ee of 0.1 GeV/c, a clear excess of e+e− pairs is found compared to the expectations from known hadronic sources and predictions of thermal radiation from the medium. The mee excess spectra are reproduced, within uncertainties, by different predictions of the photon−photon production of dielectrons, where the photons originate from the extremely strong electromagnetic fields generated by the highly Lorentz-contracted Pb nuclei. Lowest-order quantum electrodynamic (QED) calculations, as well as a model that takes into account the impact-parameter dependence of the average transverse momentum of the photons, also provide a good description of the pT,ee spectra. The measured ⟨p2T,ee⟩−−−−−√ of the excess pT,ee spectrum in peripheral Pb−Pb collisions is found to be comparable to the values observed previously at RHIC in a similar phase-space region
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