103 research outputs found
On the Geometry of Virtual Knots
The Dehn complex of prime, alternating virtual links has been shown to be non-positively curved in the paper Generalized knot complements and some aspherical ribbon disc complements by J. Harlander and S. Rosebrock (2003) [7]. This thesis investigates the geometry of an arbitrary alternating virtual link. A method is constructed for which the Dehn complex of any alternating virtual link may be decomposed into Dehn complexes with non-positive curvature. We further study the relationship between the Dehn space and Wirtinger space, and we relate their fundamental groups using generating curves on surfaces. We conclude with interesting examples of Dehn complexes of virtual link diagrams, which illustrate our findings
Recommended from our members
A case of bullous Sézary syndrome
Sézary syndrome is a rare leukemic subtype of cutaneous T cell lymphoma that is characterized by erythroderma, lymphadenopathy, and malignant T cells in the peripheral blood. Poor prognostic factors of Sézary syndrome include advanced disease stage, older age at onset, and large cell transformation. Presentation with bullous lesions, though rare, has been reported in a few patients. We present an elderly woman with bullous Sézary syndrome who presented with a two-month history of progressive rash. Upon admission, the patient had pruritic, erythematous, edematous plaques with overlying flaccid bullae and erosions involving the scalp, neck, torso, and extremities. Despite treatment, the patient died two months after presentation. Although rare, bullous lesions associated with Sézary syndrome may indicate poor prognosis
Effects of commercial fishing regulations on stranding rates of bottlenose dolphin (Tursiops truncatus).
Fisheries management actions taken to protect one species
can have unintended, and sometimes positive, consequences on other species. For example, regulatory measures to reduce fishing effort in the winter gillnet fishery for spiny dogfish (Squalus acanthias) off North Carolina (NC) also led to decreases in the number of bycaught bottlenose
dolphins (Tursiops truncatus). This study found that a marked decrease in fishing effort for spiny dogfish in
NC also corresponded with a marked decrease in winter stranding rates of bottlenose dolphins with entanglement
lesions (P= 0.002). Furthermore, from 1997 through 2002, there was a significant positive correlation (r2 = 0.79;
P= 0.0003) between seasonal bycatch estimates of bottlenose dolphins in gill nets and rates of stranded dolphins
with entanglement lesions. With this information, stranding thresholds were developed that would enable the detection of those increases in bycatch in near real-time. This approach is valuable because updated bycatch estimates from observer data usually have a time-lag of two or more
years. Threshold values could be used to detect increases in stranding rates, triggering managers immediately to direct observer effort to areas of potentially high bycatch or to institute mitigation measures. Thus, observer
coverage and stranding investigations can be used in concert for more effective fishery management
Presentation of body mass index within an electronic health record to improve weight assessment and counselling in children and adolescents
Background Assessment of weight and counselling on nutrition and physical activity is infrequently conducted during well child visits, despite recent expert recommendations.
Objective We investigated whether automatic calculation of body mass index (BMI) in an electronic health record improved assessment of weight and counselling on nutrition and physical activity.
Methods Retrospective review of well child visit records of children between two and 18 years of age (n=550) before and after implementation of an electronic health record system at an academic medical centre's paediatric clinic. Body mass index was automatically calculated and presented within the electronic health record. We measured clinicians' documentation of assessment of weight status, and assessment of and counselling for nutrition and physical activity risk factors.
Results Documentation of assessment of BMI and weight status did not increase. There were no consistent increases in assessment for or counselling on specific nutrition and physical activity behaviours, except with respect to high calorie food intake. Although overall assessment of physical activity decreased, physical activity counselling significantly increased. Documentation of the presence of highrisk family history increased significantly; the provision of counselling for high-risk family history did not show any corresponding increase. Patients with higher BMI percentile scores were more completely assessed for weight status. Completeness of weight status assessment was associated with increased counselling for nutrition and physical activity.
Conclusions Passive changes, such as automatic calculation of BMI, are insufficient to result in systematic improvements in assessment of weight and counselling for nutrition and physical activity
Characterizing Long COVID: Deep Phenotype of a Complex Condition
BACKGROUND: Numerous publications describe the clinical manifestations of post-acute sequelae of SARS-CoV-2 (PASC or long COVID ), but they are difficult to integrate because of heterogeneous methods and the lack of a standard for denoting the many phenotypic manifestations. Patient-led studies are of particular importance for understanding the natural history of COVID-19, but integration is hampered because they often use different terms to describe the same symptom or condition. This significant disparity in patient versus clinical characterization motivated the proposed ontological approach to specifying manifestations, which will improve capture and integration of future long COVID studies.
METHODS: The Human Phenotype Ontology (HPO) is a widely used standard for exchange and analysis of phenotypic abnormalities in human disease but has not yet been applied to the analysis of COVID-19.
FINDINGS: We identified 303 articles published before April 29, 2021, curated 59 relevant manuscripts that described clinical manifestations in 81 cohorts three weeks or more following acute COVID-19, and mapped 287 unique clinical findings to HPO terms. We present layperson synonyms and definitions that can be used to link patient self-report questionnaires to standard medical terminology. Long COVID clinical manifestations are not assessed consistently across studies, and most manifestations have been reported with a wide range of synonyms by different authors. Across at least 10 cohorts, authors reported 31 unique clinical features corresponding to HPO terms; the most commonly reported feature was Fatigue (median 45.1%) and the least commonly reported was Nausea (median 3.9%), but the reported percentages varied widely between studies.
INTERPRETATION: Translating long COVID manifestations into computable HPO terms will improve analysis, data capture, and classification of long COVID patients. If researchers, clinicians, and patients share a common language, then studies can be compared/pooled more effectively. Furthermore, mapping lay terminology to HPO will help patients assist clinicians and researchers in creating phenotypic characterizations that are computationally accessible, thereby improving the stratification, diagnosis, and treatment of long COVID.
FUNDING: U24TR002306; UL1TR001439; P30AG024832; GBMF4552; R01HG010067; UL1TR002535; K23HL128909; UL1TR002389; K99GM145411
2015 Proceedings: Religious Values
Paving the Way to Global Christian Citizenshiphttps://knowledge.e.southern.edu/reysymp/1003/thumbnail.jp
Bordetella pertussis Autotransporter Vag8 Binds Human C1 Esterase Inhibitor and Confers Serum Resistance
Bordetella pertussis employs numerous strategies to evade the immune system, including the ability to resist killing via complement. Previously we have shown that B. pertussis binds a complement regulatory protein, C1 esterase inhibitor (C1inh) to its surface in a Bvg-regulated manner (i.e. during its virulence phase), but the B. pertussis factor was not identified. Here we set out to identify the B. pertussis C1inh-binding factor. Using a serum overlay assay, we found that this factor migrates at approximately 100 kDa on an SDS-PAGE gel. To identify this factor, we isolated proteins of approximately 100 kDa from wild type strain BP338 and from BP347, an isogenic Bvg mutant that does not bind C1inh. Using mass spectrometry and bioinformatics, we identified the autotransporter protein Vag8 as the putative C1inh binding protein. To prove that Vag8 binds C1inh, vag8 was disrupted in two different B. pertussis strains, namely BP338 and 18–323, and the mutants were tested for their ability to bind C1inh in a surface-binding assay. Neither mutant strain was capable of binding C1inh, whereas a complemented strain successfully bound C1inh. In addition, the passenger domain of Vag8 was expressed and purified as a histidine-tagged fusion protein and tested for C1inh-binding in an ELISA assay. Whereas the purified Vag8 passenger bound C1inh, the passenger domain of BrkA (a related autotransporter protein) failed to do so. Finally, serum assays were conducted to compare wild type and vag8 mutants. We determined that vag8 mutants from both strains were more susceptible to killing compared to their isogenic wild type counterparts. In conclusion, we have discovered a novel role for the previously uncharacterized protein Vag8 in the immune evasion of B. pertussis. Vag8 binds C1inh to the surface of the bacterium and confers serum resistance
Recommended from our members
Implementing the package of CDC and WHO recommended linkage services: Methods, outcomes, and costs of the Bukoba Tanzania Combination Prevention Evaluation peer-delivered, linkage case management program, 2014-2017
Although several studies have evaluated one or more linkage services to improve early enrollment in HIV care in Tanzania, none have evaluated the package of linkage services recommended by the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO). We describe the uptake of each component of the CDC/WHO recommended package of linkage services, and early enrollment in HIV care and antiretroviral therapy (ART) initiation among persons with HIV who participated in a peer-delivered, linkage case management (LCM) program implemented in Bukoba, Tanzania, October 2014 –May 2017. Of 4206 participants (88% newly HIV diagnosed), most received recommended services including counseling on the importance of early enrollment in care and ART (100%); escort by foot or car to an HIV care and treatment clinic (CTC) (83%); treatment navigation at a CTC (94%); telephone support and appointment reminders (77% among clients with cellphones); and counseling on HIV-status disclosure and partner/family testing (77%), and on barriers to care (69%). During three periods with different ART-eligibility thresholds [CD4<350 (Oct 2014 –Dec 2015, n = 2233), CD4≤500 (Jan 2016 –Sept 2016, n = 1221), and Test & Start (Oct 2016 –May 2017, n = 752)], 90%, 96%, and 97% of clients enrolled in HIV care, and 47%, 67%, and 86% of clients initiated ART, respectively, within three months of diagnosis. Of 463 LCM clients who participated in the last three months of the rollout of Test & Start, 91% initiated ART. Estimated per-client cost was 18 USD for a facility-only model with task shifting. Well accepted by persons with HIV, peer-delivered LCM services recommended by CDC and WHO can achieve near universal early ART initiation in the Test & Start era at modest cost and should be considered for implementation in facilities and communities experiencing <90% early enrollment in ART care
- …