1,030 research outputs found

    Mind the numt: Finding informative mitochondrial markers in a giant grasshopper genome

    Get PDF
    H2020 Marie Sklodowska-Curie Actions, Grant/Award Number: 658706; Ministerio de Ciencia, Innovacion y Universidades, Grant/Award Number: PID2019-104952GB-I00/AEI/10.13039/501100011033The barcoding of the mitochondrial COX1 gene has been instrumental in cataloguing the tree of life, and in providing insights in the phylogeographic history of species. Yet, this strategy has encountered difficulties in major clades characterized by large genomes, which contain a high frequency of nuclear pseudogenes originating from the mitochondrial genome (numts). Here, we use the meadow grasshopper (Chorthippus parallelus), which possesses a giant genome of ~13 Gb, to identify mitochondrial genes that are underrepresented as numts, and test their use as informative phylogeographic markers. We recover the same full mitochondrial sequence using both whole genome and transcriptome sequencing, including functional protein‐coding genes and tRNAs. We show that a region of the mitogenome containing the COX1 gene, typically used in DNA barcoding, has disproportionally higher diversity and coverage than the rest of the mitogenome, consistent with multiple insertions of that region into the nuclear genome. By designing new markers in regions of less elevated diversity and coverage, we identify two mitochondrial genes that are less likely to be duplicated as numts. We show that, while these markers show high levels of incomplete lineage sorting between subspecies, as expected for mitochondrial genes, genetic variation reflects their phylogeographic history accurately. These findings allow us to identify useful mitochondrial markers for future studies in C. parallelus, an important biological system for evolutionary biology. More generally, this study exemplifies how non‐PCR‐based methods using next‐generation sequencing can be used to avoid numts in species characterized by large genomes, which have remained challenging to study in taxonomy and evolution.H2020 Marie Sklodowska-Curie Actions 658706Ministerio de Ciencia, Innovacion y Universidades PID2019-104952GB-I00/AEI/10.13039/50110001103

    Solitary lower lumbar osteochondroma (spinous process of L3 involvement): a case report

    Get PDF
    Solitary osteochondromas, which are the most common benign bone tumors of long bones, are rarely found in the vertebral column. A 16-year-old female patient presented with a hard palpable mass at lower lumbar region like a congenital deformity. Plain radiography illustrated a well-defined solid mass arising from the posterior elements of the L3 and ruled out any congenital anomalies. A computed tomography scan further determined a mass that arose from the spinous process of L3. The tumor was excised en bloc through a posterior approach and histopathological examination verified the diagnosis of osteocondroma

    How and When Socially Entrepreneurial Nonprofit Organizations Benefit From Adopting Social Alliance Management Routines to Manage Social Alliances?

    Get PDF
    Social alliance is defined as the collaboration between for-profit and nonprofit organizations. Building on the insights derived from the resource-based theory, we develop a conceptual framework to explain how socially entrepreneurial nonprofit organizations (SENPOs) can improve their social alliance performance by adopting strategic alliance management routines. We test our framework using the data collected from 203 UK-based SENPOs in the context of cause-related marketing campaign-derived social alliances. Our results confirm a positive relationship between social alliance management routines and social alliance performance. We also find that relational mechanisms, such as mutual trust, relational embeddedness, and relational commitment, mediate the relationship between social alliance management routines and social alliance performance. Moreover, our findings suggest that different types of social alliance motivation can influence the impact of social alliance management routines on different types of the relational mechanisms. In general, we demonstrate that SENPOs can benefit from adopting social alliance management routines and, in addition, highlight how and when the social alliance management routines–social alliance performance relationship might be shaped. Our study offers important academic and managerial implications, and points out future research directions

    The systemic lupus erythematosus IRF5 risk haplotype is associated with systemic sclerosis

    Get PDF
    Systemic sclerosis (SSc) is a fibrotic autoimmune disease in which the genetic component plays an important role. One of the strongest SSc association signals outside the human leukocyte antigen (HLA) region corresponds to interferon (IFN) regulatory factor 5 (IRF5), a major regulator of the type I IFN pathway. In this study we aimed to evaluate whether three different haplotypic blocks within this locus, which have been shown to alter the protein function influencing systemic lupus erythematosus (SLE) susceptibility, are involved in SSc susceptibility and clinical phenotypes. For that purpose, we genotyped one representative single-nucleotide polymorphism (SNP) of each block (rs10488631, rs2004640, and rs4728142) in a total of 3,361 SSc patients and 4,012 unaffected controls of Caucasian origin from Spain, Germany, The Netherlands, Italy and United Kingdom. A meta-analysis of the allele frequencies was performed to analyse the overall effect of these IRF5 genetic variants on SSc. Allelic combination and dependency tests were also carried out. The three SNPs showed strong associations with the global disease (rs4728142: P = 1.34×10<sup>−8</sup>, OR = 1.22, CI 95% = 1.14–1.30; rs2004640: P = 4.60×10<sup>−7</sup>, OR = 0.84, CI 95% = 0.78–0.90; rs10488631: P = 7.53×10<sup>−20</sup>, OR = 1.63, CI 95% = 1.47–1.81). However, the association of rs2004640 with SSc was not independent of rs4728142 (conditioned P = 0.598). The haplotype containing the risk alleles (rs4728142*A-rs2004640*T-rs10488631*C: P = 9.04×10<sup>−22</sup>, OR = 1.75, CI 95% = 1.56–1.97) better explained the observed association (likelihood P-value = 1.48×10<sup>−4</sup>), suggesting an additive effect of the three haplotypic blocks. No statistical significance was observed in the comparisons amongst SSc patients with and without the main clinical characteristics. Our data clearly indicate that the SLE risk haplotype also influences SSc predisposition, and that this association is not sub-phenotype-specific

    The Surgical Infection Society revised guidelines on the management of intra-abdominal infection

    Get PDF
    Background: Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations. Methods: Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council. Results: This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included. Summary: The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline

    Low-temperature ageing of zirconia-toughened alumina ceramics and its implication in biomedical Implants

    Get PDF
    Abstract Changes in crystalline phases resulting from low-temperature ageing of different yttria doped and non-doped zirconia-toughened alumina composites and nanocomposites were investigated under controlled humidity and temperature conditions in autoclave. A classical powder mixing processing route and a new modified colloidal processing route were used to process the composites. Different compositions ranging from 2.5 wt.% zirconia in a matrix of alumina to pure zirconia (3Y-TZP) were studied. It was observed that Al 2 O 3 +yttria stabilised ZrO 2 composites exhibited significant ageing. However, ageing was much slower than traditionally observed for Y-TZP ceramics, due to the presence of the alumina matrix. Ageing was clearly limited for zirconia content beyond 25 wt.%. On the other side of the spectrum, Al 2 O 3 +2.5 wt.% ZrO 2 initially presented a monoclinic fraction but did not show any ageing degradation. These composites seem to represent the best choice between slow crack growth and ageing resistance.

    Barium yttrium fluoride based upconversion nanoparticles as dual mode image contrast agents

    Get PDF
    Dual labeled contrast agents could provide better complementary information for bioimaging than available solely from a single modality. In this paper we investigate the suitability of Yb3+ and Er3+-doped BaYF5 upconversion nanoparticles (UCNPs) as both optical and X-ray micro computed tomography (μCT) contrast agents. Stable, aqueous UCNP dispersions were synthesised using a hydrothermal method with the addition of polyethyleneimine (PEI). UCNPs were single crystal and had a truncated cuboidal morphology, with average particle size of 47 ± 9 nm from transmission electron microscopy which was further used to characterize the structure and composition in detail. A zeta potential value of +51 mV was measured for the aqueous nanoparticle dispersions which is beneficial for cell permeability. The outer hydrated PEI layer is also advantageous for the attachment of proteins for targeted delivery in biological systems. The prepared UCNPs were proven to be non-toxic to endothelial cells up to a concentration of 3.5 mg/mL, when assessed using an MTT assay. The particles showed intense green upconversion photoluminescence when excited at a wavelength of 976 nm using a diode laser. Quantitative X-ray μCT contrast imaging confirmed the potential of these UCNPs as X-ray contrast agents and confirming their dual modality for bioimaging

    Human hippocampal neurogenesis drops sharply in children to undetectable levels in adults.

    Get PDF
    New neurons continue to be generated in the subgranular zone of the dentate gyrus of the adult mammalian hippocampus. This process has been linked to learning and memory, stress and exercise, and is thought to be altered in neurological disease. In humans, some studies have suggested that hundreds of new neurons are added to the adult dentate gyrus every day, whereas other studies find many fewer putative new neurons. Despite these discrepancies, it is generally believed that the adult human hippocampus continues to generate new neurons. Here we show that a defined population of progenitor cells does not coalesce in the subgranular zone during human fetal or postnatal development. We also find that the number of proliferating progenitors and young neurons in the dentate gyrus declines sharply during the first year of life and only a few isolated young neurons are observed by 7 and 13 years of age. In adult patients with epilepsy and healthy adults (18-77 years; n = 17 post-mortem samples from controls; n = 12 surgical resection samples from patients with epilepsy), young neurons were not detected in the dentate gyrus. In the monkey (Macaca mulatta) hippocampus, proliferation of neurons in the subgranular zone was found in early postnatal life, but this diminished during juvenile development as neurogenesis decreased. We conclude that recruitment of young neurons to the primate hippocampus decreases rapidly during the first years of life, and that neurogenesis in the dentate gyrus does not continue, or is extremely rare, in adult humans. The early decline in hippocampal neurogenesis raises questions about how the function of the dentate gyrus differs between humans and other species in which adult hippocampal neurogenesis is preserved

    Kahler Moduli Inflation Revisited

    Get PDF
    We perform a detailed numerical analysis of inflationary solutions in Kahler moduli of type IIB flux compactifications. We show that there are inflationary solutions even when all the fields play an important role in the overall shape of the scalar potential. Moreover, there exists a direction of attraction for the inflationary trajectories that correspond to the constant volume direction. This basin of attraction enables the system to have an island of stability in the set of initial conditions. We provide explicit examples of these trajectories, compute the corresponding tilt of the density perturbations power spectrum and show that they provide a robust prediction of n_s approximately 0.96 for 60 e-folds of inflation.Comment: 27 pages, 9 figure
    corecore