424 research outputs found
Recommended from our members
Modeling the Influence of Knowledge on Recognition: Connecting visualrecognition behavior across development to PDP computational models ofsemantic knowledge
Recent behavioral findings in children’s selection of a “real” versus “silly” animal demonstrated a developmentalchange wherein younger children select chimeric animals with regular forms (e.g., a seal with four legs, a camel with no hump)as real. To reduce verbal demands while maintaining the same stimuli, we developed a touch screen change-detection task inwhich children (4 – 7-years-old) were instructed to locate a single changing feature (e.g., a rhinoceros with and without a horn)as fast as possible. Children were faster to find changes when the feature appeared on animals with more prototypic animalforms (e.g., a donkey with and without a hump) when compared to animals with atypical forms (e.g., a camel with and withouta hump). Alongside exploration via computational models, these findings suggest that children’s real-world object recognitionis supported by the interplay of semantic knowledge, informed by covariation among visual features, and visual recognition
Enterobacter cloacae infection of an expanded polytetrafluoroethylene femoral-popliteal bypass graft: a case report
<p>Abstract</p> <p>Introduction</p> <p><it>Enterobacter cloacae </it>infections are common among burn victims, immunocompromised patients, and patients with malignancy. Most commonly these infections are manifested as nosocomial urinary tract or pulmonary infections. Nosocomial outbreaks have also been associated with colonization of certain surgical equipment and operative cleaning solutions. Infections of an aortobifemoral prosthesis, an aortic graft, and arteriovenous fistulae are noted in the literature. To our knowledge, this is the first isolated account of an <it>E. cloacae </it>infection of a femoral-popliteal expanded polytetrafluoroethylene bypass graft.</p> <p>Case presentation</p> <p>A 68-year-old Caucasian man presented with fever and rest pain in the right lower extremity five months after the placement of a vascular expanded polytetrafluoroethylene graft for femoral-popliteal bypass. Computed tomography angiography demonstrated peri-graft fluid that was aspirated percutaneously with image guidance and cultured to reveal <it>E. cloacae</it>. The graft was revised and then removed. The patient completed a six-week course of ceftazidime and is currently without signs of infection. There were no other reports of <it>E. cloacae </it>graft infections in any patients receiving treatment in the same surgical suite within a month of this report.</p> <p>Conclusion</p> <p>Isolated cases of <it>E. cloacae </it>infection of surgical bypass grafts are rare (unique in this setting). Clinicians should have a high index of suspicion for device contamination in such cases and should consider testing for possible microbial reservoirs. Graft removal is required due to the formation of biofilm and the recent emergence of Enterobacteriaceae producing extended-spectrum beta-lactamase in community acquired infections.</p
Mycoplasma genitalium among Young, Urban Pregnant Women
Objective. As the consequences of Mycoplasma genitalium in pregnant women are unknown, we examined the relationship between prenatal M. genitalium infection and SAB.
Methods. The presence of M. genitalium was determined by PCR in urine from 82 women who subsequently experienced a SAB and 134 women who maintained their pregnancies past 22 weeks gestation. The relationships between M. genitalium and subsequent SAB, demographic, current pregnancy, and reproductive health history characteristics were evaluated.
Results. Compared to women without M. genitalium, women with M. genitalium were more likely to report nulliparity (41.7% versus 17.4%, P = .04), history of pelvic inflammatory disease (27.3% versus 8.8%, P = .08), prior C. trachomatis infection (63.6% versus 36.9%, P = .11,) and problems getting pregnant (18.2% versus 4.4%, P = .10). M. genitalium was not associated with SAB (AOR 0.9, 95% CI 0.2–3.8).
Conclusions. Pregnant women who test positive for M. genitalium do not have an increased risk of SAB but report a history of reproductive morbidities
Exposure to Stress and Air Pollution from Bushfires during Pregnancy: Could Epigenetic Changes Explain Effects on the Offspring?
Due to climate change, bushfires are becoming a more frequent and more severe phenomenon which contributes to poor health effects associated with air pollution. In pregnancy, environmental exposures can have lifelong consequences for the fetus, but little is known about these consequences in the context of bushfire smoke exposure. In this review we summarise the current knowledge in this area, and propose a potential mechanism linking bushfire smoke exposure in utero to poor perinatal and respiratory outcomes in the offspring. Bushfire smoke exposure is associated with poor pregnancy outcomes including reduced birth weight and an increased risk of prematurity. Some publications have outlined the adverse health effects on young children, particularly in relation to emergency department presentations and hospital admissions for respiratory problems, but there are no studies in children who were exposed to bushfire smoke in utero. Prenatal stress is likely to occur as a result of catastrophic bushfire events, and stress is known to be associated with poor perinatal and respiratory outcomes. Changes to DNA methylation are potential epigenetic mechanisms linking both smoke particulate exposure and prenatal stress to poor childhood respiratory health outcomes. More research is needed in large pregnancy cohorts exposed to bushfire events to explore this further, and to design appropriate mitigation interventions, in this area of global public health importance.Vanessa Murphy is supported by an Investigator Grant from the Medical Research Future Fund (grant ID 1196252)
Identification of a Pseudomonas aeruginosa PAO1 DNA methyltransferase, its Targets, and physiological roles
DNA methylation is widespread among prokaryotes, and most DNA methylation reactions are catalyzed by adenine DNA methyltransferases, which are part of restriction-modification (R-M) systems. R-M systems are known for their role in the defense against foreign DNA; however, DNA methyltransferases also play functional roles in gene regulation. In this study, we used single-molecule real-time (SMRT) sequencing to uncover the genome-wide DNA methylation pattern in the opportunistic pathogen Pseudomonas aeruginosa PAO1. We identified a conserved sequence motif targeted by an adenine methyltransferase of a type I R-M system and quantified the presence of N(6)-methyladenine using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Changes in the PAO1 methylation status were dependent on growth conditions and affected P. aeruginosa pathogenicity in a Galleria mellonella infection model. Furthermore, we found that methylated motifs in promoter regions led to shifts in sense and antisense gene expression, emphasizing the role of enzymatic DNA methylation as an epigenetic control of phenotypic traits in P. aeruginosa Since the DNA methylation enzymes are not encoded in the core genome, our findings illustrate how the acquisition of accessory genes can shape the global P. aeruginosa transcriptome and thus may facilitate adaptation to new and challenging habitats.IMPORTANCE With the introduction of advanced technologies, epigenetic regulation by DNA methyltransferases in bacteria has become a subject of intense studies. Here we identified an adenosine DNA methyltransferase in the opportunistic pathogen Pseudomonas aeruginosa PAO1, which is responsible for DNA methylation of a conserved sequence motif. The methylation level of all target sequences throughout the PAO1 genome was approximated to be in the range of 65 to 85% and was dependent on growth conditions. Inactivation of the methyltransferase revealed an attenuated-virulence phenotype in the Galleria mellonella infection model. Furthermore, differential expression of more than 90 genes was detected, including the small regulatory RNA prrF1, which contributes to a global iron-sparing response via the repression of a set of gene targets. Our finding of a methylation-dependent repression of the antisense transcript of the prrF1 small regulatory RNA significantly expands our understanding of the regulatory mechanisms underlying active DNA methylation in bacteria
TCRpMHCmodels: Structural modelling of TCR-pMHC class I complexes
The interaction between the class I major histocompatibility complex (MHC), the peptide presented by the MHC and the T-cell receptor (TCR) is a key determinant of the cellular immune response. Here, we present TCRpMHCmodels, a method for accurate structural modelling of the TCR-peptide-MHC (TCR-pMHC) complex. This TCR-pMHC modelling pipeline takes as input the amino acid sequence and generates models of the TCR-pMHC complex, with a median Cα RMSD of 2.31 Å. TCRpMHCmodels significantly outperforms TCRFlexDock, a specialised method for docking pMHC and TCR structures. TCRpMHCmodels is simple to use and the modelling pipeline takes, on average, only two minutes. Thanks to its ease of use and high modelling accuracy, we expect TCRpMHCmodels to provide insights into the underlying mechanisms of TCR and pMHC interactions and aid in the development of advanced T-cell-based immunotherapies and rational design of vaccines. The TCRpMHCmodels tool is available at http://www.cbs.dtu.dk/services/TCRpMHCmodels/.Fil: Jensen, Kamilla Kjærgaard. Technical University of Denmark; DinamarcaFil: Rantos, Vasileios. Technical University of Denmark; DinamarcaFil: Jappe, Emma Christine. Technical University of Denmark; DinamarcaFil: Olsen, Tobias Hegelund. Technical University of Denmark; DinamarcaFil: Jespersen, Martin Closter. Technical University of Denmark; DinamarcaFil: Jurtz, Vanessa. Technical University of Denmark; DinamarcaFil: Jessen, Leon Eyrich. Technical University of Denmark; DinamarcaFil: Lanzarotti, Esteban Omar. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Mahajan, Swapnil. La Jolla Institute for Allergy and Immunology; Estados UnidosFil: Peters, Bjoern. La Jolla Institute for Allergy and Immunology; Estados UnidosFil: Nielsen, Morten. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; Argentina. Technical University of Denmark; DinamarcaFil: Marcatili, Paolo. Technical University of Denmark; Dinamarc
Bismuth molybdate catalysts prepared by mild hydrothermal synthesis: Influence of pH on the selective oxidation of propylene
A series of bismuth molybdate catalysts with relatively high surface area was prepared via mild hydrothermal synthesis. Variation of the pH value and Bi/Mo ratio during the synthesis allowed tuning of the crystalline Bi-Mo oxide phases, as determined by X-ray diffraction (XRD) and Raman spectroscopy. The pH value during synthesis had a strong influence on the catalytic performance. Synthesis using a Bi/Mo ratio of 1/1 at pH ≥ 6 resulted in γ-Bi2MoO6, which exhibited a better catalytic performance than phase mixtures obtained at lower pH values. However, a significantly lower catalytic activity was observed at pH = 9 due to the low specific surface area. γ-Bi2MoO6 synthesized with Bi/Mo = 1/1 at pH = 6 and 7 exhibited relatively high surface areas and the best catalytic performance. All samples prepared with Bi/Mo = 1/1, except samples synthesized at pH = 1 and 9, showed better catalytic performance than samples synthesized with Bi/Mo = 2/3 at pH = 4 and 9 and γ-Bi2MoO6 synthesized by co-precipitation at pH = 7. At temperatures above 440 °C, the catalytic activity of the hydrothermally synthesized bismuth molybdates started to decrease due to sintering and loss of surface area. These results support that a combination of the required bismuth molybdate phase and a high specific surface area is crucial for a good performance in the selective oxidation of propylene
Experiences of patients with traumatic brain injury and their carers during transition from in-patient rehabilitation to the community: a qualitative study
Purpose: To explore the experiences of individuals who have had a severe traumatic brain injury (TBI) and their carers in the first month post-discharge from in-patient rehabilitation into living in the community.
Method: Using a qualitative approach underpinned by critical realism, we explored the narratives of 10 patients and nine carers using semi-structured interviews approximately one month post-discharge. Thematic analysis was carried out independently by two researchers.
Results: Firstly, perceptions of support were mixed but many patients and carers felt unsupported in the inpatient phase, during transitions between units and when preparing for discharge. Secondly, they struggled to accept a new reality of changed abilities, loss of roles and loss of autonomy. Thirdly, early experiences post-discharge exacerbated fears for the future.
Conclusions: Most patients and carers struggled to identify a cohesive plan that supported their transition to living in the community. Access to services required much persistence on the part of carers and tended to be short-term, and therefore did not meet their long-term needs. We propose the need for a case manager to be involved at an early stage of their rehabilitation and act as a key point for information and access to on-going rehabilitation and other support services
- …