2,285 research outputs found
Evaluating the immediate and longer term impact of a refusal conversion strategy in a large scale longitudinal study
Refusal conversion is one of the fieldwork strategies commonly used to minimise non-response in surveys. There is, however, relatively little evidence about the effectiveness of this strategy, particularly for face-to-face longitudinal surveys. Moreover, much of the existing evidence is based on observational studies. This paper evaluates the effectiveness of a fieldwork strategy – intensive re-issuing - to convert refusals using evidence from an intervention on a random sub-sample of refusals implemented in wave four of a large scale longitudinal study in the UK: the Millennium Cohort Study. We show that intensive re-issuing is an effective way of reducing the refusal rate. We also show that refusal conversion led to a modest reduction in non-response bias in the survey estimates for several key variables. The longer term impact of refusal conversion is also a key concern in longitudinal surveys. We demonstrate that, although the majority of converted refusals go on to participate in the subsequent wave of the study, there is no overall effect of intensive re-issuing on sample size at this wave
Interferon- γ receptor-1 gene promoter polymorphisms and susceptibility for brucellosis in Makkah region
Background: Genetic polymorphisms that affect the production levels of certain cytokines and/or their receptors may determine the risk, severity or protection in some infectious diseases like brucellosis.Objectives: The aim of this study was to investigate the association of certain known Interferon-γ Receptor-1 (IFN-γ R1) gene promoter polymorphisms and the susceptibility to infection with Brucellosis in Saudi population.Methods: A cases-control association study was conducted in 69 individuals with human brucellosis and 94 healthy individuals. Genotyping of IFN-γ R1 – 56 C>T and IFN-γ R1 – 611 A>G polymorphism in both patients and healthy controls was done by PCR- restriction enzyme length polymorphisms (PCR-RFLP) and PCR- confronting two primer pairs (PCR-CTPP) methods and were assessed for potential associations with susceptibility for human brucellosis and their mode of penetrance.Results: Interestingly, we have designed a PCR-CTPP system to be used for genotyping of IFN-γ R1 – 611 A > G polymorphism. The PCR-CTPP is an accurate method for genotyping of SNPs. Moreover, it is time-saving, inexpensive and easy to perform.Conclusion: Both tested polymorphisms, IFN-γ R1 – 56 C>T and IFN-γ R1 -611 A>G polymorphism had no role in genetic susceptibility to human brucellosis in the study population. The PCR-CTPP can be used for genotyping IFN-γ R1 – 611 A > G polymorphism and other types of mutation.Keywords: Brucellosis; susceptibility; IFN-γ R1 gene promoter polymorphisms
Comparative Transcriptomics and Genomics from Continuous Axenic Media Growth Identifies
Coxiella burnetii (Cb) is an obligate intracellular pathogen in nature and the causative agent of acute Q fever as well as chronic diseases. In an effort to identify genes and proteins crucial to their normal intracellular growth lifestyle, we applied a Reverse evolution approach where the avirulent Nine Mile Phase II strain of Cb was grown for 67 passages in chemically defined ACCM-D media and gene expression patterns and genome integrity from various passages was compared to passage number one following intracellular growth. Transcriptomic analysis identified a marked downregulation of the structural components of the type 4B secretion system (T4BSS), the general secretory (sec) pathway, as well as 14 out of 118 previously identified genes encoding effector proteins. Additional downregulated pathogenicity determinants genes included several chaperones, LPS, and peptidoglycan biosynthesis. A general marked downregulation of central metabolic pathways was also observed, which was balanced by a marked upregulation of genes encoding transporters. This pattern reflected the richness of the media and diminishing anabolic and ATP-generation needs. Finally, genomic sequencing and comparative genomic analysis demonstrated an extremely low level of mutation across passages, despite the observed Cb gene expression changes following acclimation to axenic media
Pre-emptive nebulization of lidocaine epinephrine before anesthesia for rigid bronchoscopy in pediatric: a randomized controlled study
Background: Foreign body aspiration in pediatrics is usually managed by rigid bronchoscopy, which is associated with plenty of adverse events. Objective: We tried to compare the effect of nebulized saline, lidocaine or combined lidocaine with epinephrine on postoperative respiratory complications.Patients and methods: This prospective study included 90 children, who were divided into three groups according to the nebulized solution; NS group (normal saline 0.9%), L group (lidocaine 1% 4 mg.kg- 1) and LA group [4 mg.kg- 1 lidocaine 1% and adrenaline (1:1000) 3 mg). Our primary outcome was the incidence of post-operative respiratory complications, while the secondary ones included hemodynamic changes and the incidence of intraoperative cough or desaturation. Results: All pre-procedural data were insignificant among the three groups. The LA group expressed higher heart rates, while the L group showed a significant reduction when compared to NS group. Propofol consumption showed a significant decline in two studied groups compared to the NS group. Intraoperative cough was higher in NS group in comparison to L and LA groups. Although, intraoperative desaturation per case along with post-operative sedation showed no significant difference among the three groups, post-operative cough frequency attacks and severity were higher in NS group when compared to L and LA group and when L group were compared to LA group. Post-operative stridor was insignificant among the three groups.Conclusion: Nebulized lidocaine/adrenaline combination is appropriate option to achieve proper intraoperative sedation and upper airway conditions with reduction of post-operative negative respiratory outcomes together with minor hemodynamic changes
A neuroimaging study in childhood autism
Background: Childhood autism is now widely viewed as being of developmental neurological origin. Abnormality in neuroimaging is reported in autism.Objectives: To delineate the proportion of structural magnetic resonance imaging (MRI) and electro encephalography (EEG) abnormality among the children with Autism and to assess any association of MRI and EEG changes with co morbid mental illness.Methods: It was a cross sectional descriptive study done at a child and adolescent consultation centre, Dhaka. The study was Carried out from January 2009 to December 2009. Both boys and girls were included in the study. A total of 42 children with childhood autism aged between two and 12 years participated in this study. Diagnosis of autism was based on ICD-10(DCR) criteria. Results: Abnormalities were found to be 35.7% in MRI and 42.9% in EEG. EEG abnormalities were found in the form of defuse slow waves activities, generalized faster activities, epileptogenic discharge and mixed discharge. The abnormalities in MRI was found in the form of diffuse cortical atrophic changes, focal cortical atrophy in frontal and temporal cortex with widening of major sulci, prominent ventricles, periventricular degeneration and abnormal basal ganglia. EEG changes were significantly associated with increased number of co-morbid illness (mental retardation, epilepsy and others). Conclusion: A number of abnom1alities that observed in the present study indicative of relations between structural and physiological dysfunctions and childhood autism. Further exploratory and in-depth researches are certainly required in this field. Intervention of autism needs to address co morbidities for better outcome
Latent effect of gamma irradiation on reproductive potential and ultrastructure of males' testes of Culex pipiens (Diptera; Culicidae)
AbstractLaboratory male pupae of Culex pipiens were exposed to 23, 41, 74 and 128 Gy doses of gamma radiation according to the LD25, LD50, LD75 and LD90 calculation, respectively. The inherited deleterious effects of gamma radiation were observed in the F1, F2 and F3 generations. Levels of sterility index in the F1 and F2 were higher than those of untreated control but in the F3 generation there was a semi-sterility compared with the control. Ultrastructure of normal males' testes of C. pipiens was studied using transmission electron microscopy. Histopathological responses were observed in the irradiated testes of C. pipiens. Gamma radiation had greatly affected the testes, such as (i) rupture, necrosis, degeneration and small vacuoles were reported in the testicular wall (ii) an abnormal distribution of the developmental stages of spermatogonia and spermatocytes leading to a general decrease in the rate of spermatogenesis; and (iii) deformity of sperm inhibitting the movements and the fertility of the sperm led to the decrease in the reproductive potential of C. pipiens. Consequently, these radiation doses are consistent with those used in the already established Sterile Insect Technique (SIT) programmes against Culex pipiens
New Mixed Ligand Complexes of Ditertiary Phosphanes with Ni(II) Alkylxanthates
Mixed Iigand complexes of Ni(II) with alkylxanthates and
ditertiary phosphanes of the composition Ni(ROCSSb(diphoshhave
been prepared, where R = methyl, ethyl, propyl, butyl, and cyclohexyl
and diphos = bis(diphenylphosphino)ethane (dpe) and bis-
(diphenylphosphino)butane (dpb). The newly prepared compounds
were characterized on the basis of chemical analyses, infrared and
electronic spectra, lH-NMR, molar conductance, and thermal analysis.
A square planar structure was proposed for the complexes
Factors affecting cellulase production by trichoderma koningii
Because of the need for renewable energy resources, cellulose, which can be enzymatically hydrolyzed to glucose, has drawn lot of attention during the past decade. However, the process of cellulose conversion using cellulase is not yet economically feasible because of the high cost of enzymes. Factors influencing the cellulase production of Trichoderma koningii using both acid and steam treated sugar cane bagasse and rice straw as carbon sources were investigated. The highest levels of cellulase activities were obtained using a culture medium containing urea and (NH4)2SO4 together as nitrogen sources at 0.217% and 0.241% for both carbon sources. When the culture medium was supplemented either with 0.5% Tween 60 or Tween 80, the rate of cellulase production was increased considerably. Maximum levels of both filter paper and CMC-ase activities produced on both media were obtained at 25 °C and 100 r.p.m., while the highest level of â -glucosidase production was obtained at 30 °C and 200 r.p.m
Small size boundary effects on two-pion interferometry
The Bose-Einstein correlations of two identically charged pions are derived
when these particles, the most abundantly produced in relativistic heavy ion
collisions, are confined in finite volumes. Boundary effects on single pion
spectrum are also studied. Numerical results emphasize that conventional
formulation usually adopted to describe two-pion interferometry should not be
used when the source size is small, since this is the most sensitive case to
boundary effects. Specific examples are considered for better illustration.Comment: more discussion on Figure4 and diffuse boundar
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