2,168 research outputs found

    Comparison of Matrix Methods for Elastic Wave Scattering Problems

    Get PDF
    In the last ten years several numerical methods have been developed for the solution of elastic wave scattering problems that have found application in quantitative flaw definition. Before the development of these methods, due to the complexity of Navier’s equation which governs wave motion in an elastic continuum, numerical results were available only for circular cylinders and spheres. The elastic wave equation is separable only in polar and spherical coordinates. For other geometries, three types of numerical methods have been developed. They were all originally developed for acoustic and electromagnetic problems governed by the scalar and vector wave equations respectively

    QCD Approach to B->D \pi Decays and CP Violation

    Full text link
    The branching ratios and CP violations of the BDπB\to D\pi decays, including both the color-allowed and the color-suppressed modes, are investigated in detail within QCD framework by considering all diagrams which lead to three effective currents of two quarks. An intrinsic mass scale as a dynamical gluon mass is introduced to treat the infrared divergence caused by the soft collinear approximation in the endpoint regions, and the Cutkosky rule is adopted to deal with a physical-region singularity of the on mass-shell quark propagators. When the dynamical gluon mass μg\mu_g is regarded as a universal scale, it is extracted to be around μg=440\mu_g = 440 MeV from one of the well-measured BDπB\to D\pi decay modes. The resulting predictions for all branching ratios are in agreement with the current experimental measurements. As these decays have no penguin contributions, there are no direct CPCP asymmetries. Due to interference between the Cabibbo-suppressed and the Cabibbo-favored amplitudes, mixing-induced CP violations are predicted in the BD±πB\to D^{\pm}\pi^{\mp} decays to be consistent with the experimental data at 1-σ\sigma level. More precise measurements will be helpful to extract weak angle 2β+γ2\beta+\gamma.Comment: 21pages,5 figures,3 tables, typos corrected and numerical result for one of decay channels is improve

    Ventral root re-implantation is better than peripheral nerve transplantation for motoneuron survival and regeneration after spinal root avulsion injury

    Get PDF
    published_or_final_versio

    Characterisation and expression of SPLUNC2, the human orthologue of rodent parotid secretory protein

    Get PDF
    We recently described the Palate Lung Nasal Clone (PLUNC) family of proteins as an extended group of proteins expressed in the upper airways, nose and mouth. Little is known about these proteins, but they are secreted into the airway and nasal lining fluids and saliva where, due to their structural similarity with lipopolysaccharide-binding protein and bactericidal/permeability-increasing protein, they may play a role in the innate immune defence. We now describe the generation and characterisation of novel affinity-purified antibodies to SPLUNC2, and use them to determine the expression of this, the major salivary gland PLUNC. Western blotting showed that the antibodies identified a number of distinct protein bands in saliva, whilst immunohistochemical analysis demonstrated protein expression in serous cells of the major salivary glands and in the ductal lumens as well as in cells of minor mucosal glands. Antibodies directed against distinct epitopes of the protein yielded different staining patterns in both minor and major salivary glands. Using RT-PCR of tissues from the oral cavity, coupled with EST analysis, we showed that the gene undergoes alternative splicing using two 5' non-coding exons, suggesting that the gene is regulated by alternative promoters. Comprehensive RACE analysis using salivary gland RNA as template failed to identify any additional exons. Analysis of saliva showed that SPLUNC2 is subject to N-glycosylation. Thus, our study shows that multiple SPLUNC2 isoforms are found in the oral cavity and suggest that these proteins may be differentially regulated in distinct tissues where they may function in the innate immune response

    Transurethral resection of the prostate in Northern Nigeria, problems and prospects

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Benign prostatic hyperplasia (BPH) is the commonest disease of the urinary tract afflicting the ageing male and is the commonest neoplastic disease in men aged 50 years and above.</p> <p>Transurethral prostatectomy (TURP) is the ultimate treatment of choice for benign prostatic hyperplasia (BPH) due mainly to the preference of minimally invasive surgery, long term relief of symptoms and cost effectiveness. It is however not available to the majority of Nigerians in need of prostatic surgery in Public Health Institutions.</p> <p>Methods</p> <p>The records of patients who underwent prostatectomy in Aminu Kano Teaching Hospital, over the period June 2001 to July 2007 were examined. The bio data of patients and laboratory investigations performed were retrieved.</p> <p>Results</p> <p>Five Hundred and forty two patients were operated upon, out of which 40 were excluded due to open prostatectomy (22 patients), bladder neck stenosis (16 patients) or bladder tumour around the trigon (2 patients). The age range of the patients was 47–110 years with a mean of 67.2 years. 289 patients (80.1%) had urethral catheter in situ at presentation and 11 (3%) patients had suprapubic cystostomy of which only 3 (0.85%) had combined urethral stricture and BPH.</p> <p>Only 131 (26%) had their PSA measured which ranged from 2–100 ng/ml out of which 39(29.8% n = 131) patients had more than 4 ng/ml and cancer of the prostate and 1(0.8%, n = 131) patient had a PSA level of 4 ng/ml and malignant prostate.</p> <p>Hospital stay was 1–32 days (mean 7.9) and the mean follow up period was 5.6 months (range 0–60) and there were 17.5% complications comprising of urinary tract infection (UTI) 7.2%, Orchitis 2.2%, urinary incontinence 0.6%, atonic bladder 1%, erectile dysfunction 0.6%, cerebrovascular accident 0.4%, myocardial infarction 0.4%, deep vein thrombosis 0.4% and disseminated intravascular coagulopathy (DIC) 0.6% and 1.2% mortality. The cost of treatment inclusive of pre-admission investigations was US615.00(rangeUS 615.00 (range US 300–1,300)</p> <p>Conclusion</p> <p>Despite advances in minimally invasive therapy for LUTH/BPH, TURP is the optimum treatment of choice for the ageing male of sub-Saharan Africa. It is however not available to the majority of patients in this region due to poor health allocation and inadequate facilities and training.</p

    Chronic Toxoplasma Infection Modifies the Structure and the Risk of Host Behavior

    Get PDF
    The intracellular parasite Toxoplasma has an indirect life cycle, in which felids are the definitive host. It has been suggested that this parasite developed mechanisms for enhancing its transmission rate to felids by inducing behavioral modifications in the intermediate rodent host. For example, Toxoplasma-infected rodents display a reduction in the innate fear of predator odor. However, animals with Toxoplasma infection acquired in the wild are more often caught in traps, suggesting that there are manipulations of intermediate host behavior beyond those that increase predation by felids. We investigated the behavioral modifications of Toxoplasma-infected mice in environments with exposed versus non-exposed areas, and found that chronically infected mice with brain cysts display a plethora of behavioral alterations. Using principal component analysis, we discovered that most of the behavioral differences observed in cyst-containing animals reflected changes in the microstructure of exploratory behavior and risk/unconditioned fear. We next examined whether these behavioral changes were related to the presence and distribution of parasitic cysts in the brain of chronically infected mice. We found no strong cyst tropism for any particular brain area but found that the distribution of Toxoplasma cysts in the brain of infected animals was not random, and that particular combinations of cyst localizations changed risk/unconditioned fear in the host. These results suggest that brain cysts in animals chronically infected with Toxoplasma alter the fine structure of exploratory behavior and risk/unconditioned fear, which may result in greater capture probability of infected rodents. These data also raise the possibility that selective pressures acted on Toxoplasma to broaden its transmission between intermediate predator hosts, in addition to felid definitive hosts

    Patient and family involvement in adult critical and intensive care settings : a scoping review

    Get PDF
    BACKGROUND: Despite international bodies calling for increased patient and family involvement, these concepts remain poorly defined within literature on critical and intensive care settings. OBJECTIVE: This scoping review investigates the extent and range of literature on patient and family involvement in critical and intensive care settings. Methodological and empirical gaps are identified, and a future agenda for research into optimizing patient and family involvement is outlined. METHODS: Searches of MEDLINE, CINAHL, Social Work Abstracts and PsycINFO were conducted. English‐language articles published between 2003 and 2014 were retrieved. Articles were included if the studies were undertaken in an intensive care or critical care setting, addressed the topic of patient and family involvement, included a sample of adult critical care patients, their families and/or critical care providers. Two reviewers extracted and charted data and analysed findings using qualitative content analysis. FINDINGS: A total of 892 articles were screened, 124 were eligible for analysis, including 61 quantitative, 61 qualitative and 2 mixed‐methods studies. There was a significant gap in research on patient involvement in the intensive care unit. The analysis identified five different components of family and patient involvement: (i) presence, (ii) having needs met/being supported, (iii) communication, (iv) decision making and (v) contributing to care. CONCLUSION: Three research gaps were identified that require addressing: (i) the scope, extent and nature of patient involvement in intensive care settings; (ii) the broader socio‐cultural processes that shape patient and family involvement; and (iii) the bidirectional implications between patient/family involvement and interprofessional teamwork

    Acquisition of the Sda1-encoding bacteriophage does not enhance virulence of the serotype M1 Streptococcus pyogenes strain SF370

    Get PDF
    The resurgence of invasive disease caused by Streptococcus pyogenes (group A Streptococcus [GAS]) in the past 30 years has paralleled the emergence and global dissemination of the highly virulent M1T1 clone. The GAS M1T1 clone has diverged from the ancestral M1 serotype by horizontal acquisition of two unique bacteriophages, encoding the potent DNase Sda1/SdaD2 and the superantigen SpeA, respectively. The phage-encoded DNase promotes escape from neutrophil extracellular traps and is linked to enhanced virulence of the M1T1 clone. In this study, we successfully used in vitro lysogenic conversion to transfer the Sda1-encoding phage from the M1T1 clonal strain 5448 to the nonclonal M1 isolate SF370 and determined the impact of this horizontal gene transfer event on virulence. Although Sda1 was expressed in SF370 lysogens, no capacity of the phage-converted strain to survive human neutrophil killing, switch to a hyperinvasive covRS mutant form, or cause invasive lethal infection in a humanized plasminogen mouse model was observed. This work suggests that the hypervirulence of the M1T1 clone is due to the unique synergic effect of the M1T1 clone bacteriophage-specific virulence factor Sda1 acting in concert with the M1T1 clone-specific genetic scaffold
    corecore