854 research outputs found

    The fundamental group and torsion group of Beauville surfaces

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    We give a survey on the fundamental group of surfaces isogenous to a higher product. If the surfaces are regular, e.g. if they are Beauville surfaces, the first homology group is a finite group. We present a MAGMA script which calculates the first homology groups of regular surfaces isogenous to a product.Comment: 14 pages; MAGMA script included; v2: minor corrections, final version to appear in the Proceedings of the Conference "Beauville Surfaces and Groups", Newcastle University (UK), 7-9th June 201

    High species diversity in Colletotrichum associated with citrus diseases in Europe

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    Species of Colletotrichum are considered important plant pathogens, saprobes, and endophytes on a wide range of plant hosts. Several species are well-known on citrus, either as agents of pre- or post-harvest infections, such as anthracnose, postbloom fruit drop, tear stain and stem-end rot on fruit, or as wither-tip of twigs. In this study we explored the occurrence, diversity and pathogenicity of Colletotrichum spp. associated with Citrus and allied genera in European orchards, nurseries and gardens. Surveys were carried out during 2015 and 2016 in Greece, Italy, Malta, Portugal and Spain. A total of 174 Colletotrichum strains were isolated from symptomatic leaves, fruits, petals and twigs. A multi-locus phylogeny was established based on seven genomic loci (ITS, GAPDH, ACT, CAL, CHS-1, HIS3 and TUB2), and the morphological characters of the isolates determined. Preliminary pathogenicity tests were performed on orange fruits with representative isolates. Colletotrichum strains were identified as members of three major species complexes. Colletotrichum gloeosporioides s.str. and two novel species (C. helleniense and C. hystricis) were identified in the C. gloeosporioides species complex. Colletotrichum karstii, C. novae-zelandiae and two novel species (C. catinaense and C. limonicola) in the C. boninense species complex, and C. acutatum s.str. was also isolated as member of C. acutatum species complex. Colletotrichum gloeosporioides and C. karstii were the predominant species of Colletotrichum isolated. This study represents the first report of C. acutatum on citrus in Europe, and the first detection of C. novae-zelandiae from outside New Zealand. Pathogenicity tests revealed C. gloeosporioides s.str. to be the most virulent species on fruits. The present study improves our understanding of species associated with several disease symptoms on citrus fruits and plants, and provides useful information for effective disease management

    Tools for engineering coordinated system behaviour in synthetic microbial consortia

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    Advancing synthetic biology to the multicellular level requires the development of multiple cell-to-cell communication channels that propagate information with minimal signal interference. The development of quorum-sensing devices, the cornerstone technology for building microbial communities with coordinated system behaviour, has largely focused on cognate acyl-homoserine lactone (AHL)/transcription factor pairs, while the use of non-cognate pairs as a design feature has received limited attention. Here, we demonstrate a large library of AHL-receiver devices, with all cognate and non-cognate chemical signal interactions quantified, and we develop a software tool that automatically selects orthogonal communication channels. We use this approach to identify up to four orthogonal channels in silico, and experimentally demonstrate the simultaneous use of three channels in co-culture. The development of multiple non-interfering cell-to-cell communication channels is an enabling step that facilitates the design of synthetic consortia for applications including distributed bio-computation, increased bioprocess efficiency, cell specialisation and spatial organisation

    A study of maternal competence in preterm birth condition, during the transition from hospital to home: An early intervention program’s proposal

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    The study was conducted with 104 mothers (average age 32.5 years, SD 6.1) of preterm infants (very and moderately preterm but still healthy) to monitor the perceived maternal role competence from the time of hospitalisation to post-discharge, in order to define an intervention program to support mothers during this transition. A targeted Q-Sort tool (Maternal Competence Q-Sort in preterm birth) was applied at two different times as a self-observation tool for parenting competence in neonatology. A tendency towards dysregulation of the maternal role competence was detected, mainly in terms of low self-assessment and was found to worsen during post-discharge, particularly with regard to caregiving ability. This study suggests the importance of accompanying parenting competence in preterm birth conditions, not only during hospitalisation in the Neonatal Intensive Care Unit (NICU) but also following discharge in order to promote the development of premature infants. This paper reports in the last part a specific integrated psychoeducational intervention program (psychologist and nurses), which we defined precisely in light of the suggestions offered by the study data on perceived maternal competence created with the Q-sort

    Cardiovascular magnetic resonance (CMR) in restrictive cardiomyopathies

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    The restrictive cardiomyopathies constitute a heterogeneous group of myocardial diseases with a different pathogenesis and overlapping clinical presentations. Diagnosing them frequently poses a challenge. Echocardiography, electrocardiograms and laboratory tests may show non-specific changes. In this context, cardiac magnetic resonance (CMR) may play a crucial role in defining the diagnosis and guiding treatments, by offering a robust myocardial characterization based on the inherent magnetic properties of abnormal tissues, thus limiting the use of endomyocardial biopsy. In this review article, we explore the role of CMR in the assessment of a wide range of myocardial diseases causing restrictive patterns, from iron overload to cardiac amyloidosis, endomyocardial fibrosis or radiation-induced heart disease. Here, we emphasize the incremental value of novel relaxometric techniques such as T1 and T2 mapping, which may recognize different storage diseases based on the intrinsic magnetic properties of the accumulating metabolites, with or without the use of gadolinium-based contrast agents. We illustrate the importance of these CMR techniques and their great support when contrast media administration is contraindicated. Finally, we describe the useful role of cardiac computed tomography for diagnosis and management of restrictive cardiomyopathies when CMR is contraindicated

    Parental Resources in Parents of Children with Special Needs (SNs) at the Time of COVID-19

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    Background. The limitations imposed by governments for containing the spread of COVID-19 have affected familial relationships, especially those of families dealing with children with special needs or chronic illness conditions. The current study aims to better understand what pathological/disability condition has impacted parental resources, sense of competence, and perception of children's executive functioning the most. Methods. A sample of 648 parents was asked to answer a survey assessing children's condition (typical development, specific learning disorder, autism spectrum syndrome, chronic illness), parental resources, parenting sense of competence (distinguished into parental satisfaction and self-efficacy), and parents' perception of their children's executive functioning. A MANOVA model was performed to assess differences in parental resources, sense of competence, and perception of the children's executive functions according to their condition. A path analysis model was performed to examine the impact of sense of competence and children's condition on parental resources and children's executive functions. Results. Parents with children with specific learning disorder reported lower scores of parental resources in terms of total scores, common antecedents, and specific antecedents compared to parents with typically developed children (total scores: MD = 56.45, p < 0.001; common antecedents: MD = 22.28, p < 0.00; specific antecedents: MD = 34.17, p < 0.001), parents with autistic children (total scores: MD = 62.79, p = 0.01; common antecedents: MD = 24.03, p = 0.01; specific antecedents: MD = 38.76, p = 0.02) and parents of children with chronic illness (total scores: MD = 37.42, p = 0.04; common antecedents: MD = 16.59, p = 0.01). The path analysis model shows a direct effect of parental satisfaction (beta = 0.26) and pathology/disability (beta = -0.10) on parental resources that, in turn, influence parents' perception of their children's executive functioning (beta = 0.24). Conclusion. Although no data about the prepandemic situation is available, the current study highlights that parental stress influence children's cognition. Moreover, parents of children with special needs seemed to be challenged during COVID-19, especially parents of children with specific learning disorders, that are already stressed out by their children's condition. Therefore, academic services should undertake preventive measures to preserve parental well-being and to provide a supportive environment for children, especially for those with atypical development
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