Comparative Studies of Some Polypores Using High Performance Liquid Chromatography

Isolates of four polypores; Ganoderma colossum, Ganoderma lucidum, Trametes cingulata and Daedalea quercina were compared using the High performance liquid chromatographic profiles of their triterpenoids. A higher abundance of colossolactone E was found in Ganoderma colossum isolate (FC 876) when compared with FC 872 obtained at different periods and dried differently and 23- hydroxycolossolactone E found in FC 876 was not observed in FC 872. Equal abundance of constituents was also found in Ganoderma lucidum isolates (FC 871 and FC 875) collected from different hosts and geographical locations. The isolates of Trametes cingulata that were of different ages showed predominance of the major constituents in FC 873 and FC 885 isolates when compared with FC 870. The abundance of the triterpenoid in the isolates of Daedalea quercina was almost doubled in FC 882 when compared with that of FC 878. These conform with the chemical spot test results on these polypores in a previous work. The ability of the polypores to produce triterpenoids is affected by their age, period of collection, geographical location and method of drying, which also affected the High Performance Liquid Chromatography characteristics of their secondary metabolites. African Research Review Vol. 1 (1) 2007: pp. 77-9

Dynamics of thermoelastic thin plates: A comparison of four theories

Four distinct theories describing the flexural motion of thermoelastic thin plates are compared. The theories are due to Chadwick, Lagnese and Lions, Simmonds, and Norris. Chadwick's theory requires a 3D spatial equation for the temperature but is considered the most accurate as the others are derivable from it by different approximations. Attention is given to the damping of flexural waves. Analytical and quantitative comparisons indicate that the Lagnese and Lions model with a 2D temperature equation captures the essential features of the thermoelastic damping, but contains systematic inaccuracies. These are attributable to the approximation for the first moment of the temperature used in deriving the Lagnese and Lions equation. Simmonds' model with an explicit formula for temperature in terms of plate deflection is the simplest of all but is accurate only at low frequency, where the damping is linearly proportional to the frequency. It is shown that the Norris model, which is almost as simple as Simmond's, is as accurate as the more precise but involved theory of Chadwick.Comment: 2 figures, 1 tabl

Improved survival at low lung function in cystic fibrosis: cohort study from 1990 to 2007

Objectives To evaluate the survival of patients with cystic fibrosis whose lung function has deteriorated to a forced expiratory volume in one second (FEV1) below 30% predicted in the recent treatment era and to explore factors associated with any change in survival

Optically Selected BL Lacertae Candidates from the Sloan Digital Sky Survey Data Release Seven

We present a sample of 723 optically selected BL Lac candidates from the SDSS DR7 spectroscopic database encompassing 8250 deg^2 of sky; our sample constitutes one of the largest uniform BL Lac samples yet derived. Each BL Lac candidate has a high-quality SDSS spectrum from which we determine spectroscopic redshifts for ~60% of the objects. Redshift lower limits are estimated for the remaining objects utilizing the lack of host galaxy flux contamination in their optical spectra; we find that objects lacking spectroscopic redshifts are likely at systematically higher redshifts. Approximately 80% of our BL Lac candidates match to a radio source in FIRST/NVSS, and ~40% match to a ROSAT X-ray source. The homogeneous multiwavelength coverage allows subdivision of the sample into 637 radio-loud BL Lac candidates and 86 weak-featured radio-quiet objects. The radio-loud objects broadly support the standard paradigm unifying BL Lac objects with beamed radio galaxies. We propose that the majority of the radio-quiet objects may be lower-redshift (z<2.2) analogs to high-redshift weak line quasars (i.e., AGN with unusually anemic broad emission line regions). These would constitute the largest sample of such objects, being of similar size and complementary in redshift to the samples of high-redshift weak line quasars previously discovered by the SDSS. However, some fraction of the weak-featured radio-quiet objects may instead populate a rare and extreme radio-weak tail of the much larger radio-loud BL Lac population. Serendipitous discoveries of unusual white dwarfs, high-redshift weak line quasars, and broad absorption line quasars with extreme continuum dropoffs blueward of rest-frame 2800 Angstroms are also briefly described.Comment: 24 pages, 14 figures, 8 tables. Accepted for publication in A

Genetics, recombination and clinical features of human rhinovirus species C (HRV-C) infections; interactions of HRV-C with other respiratory viruses

To estimate the frequency, molecular epidemiological and clinical associations of infection with the newly described species C variants of human rhinoviruses (HRV), 3243 diagnostic respiratory samples referred for diagnostic testing in Edinburgh were screened using a VP4-encoding region-based selective polymerase chain reaction (PCR) for HRV-C along with parallel PCR testing for 13 other respiratory viruses. HRV-C was the third most frequently detected behind respiratory syncytial virus (RSV) and adenovirus, with 141 infection episodes detected among 1885 subjects over 13 months (7.5%). Infections predominantly targeted the very young (median age 6–12 months; 80% of infections in those &#60;2 years), occurred throughout the year but with peak incidence in early winter months. HRV-C was detected significantly more frequently among subjects with lower (LRT) and upper respiratory tract (URT) disease than controls without respiratory symptoms; HRV-C mono-infections were the second most frequently detected virus (behind RSV) in both disease presentations (6.9% and 7.8% of all cases respectively). HRV variants were classified by VP4/VP2 sequencing into 39 genotypically defined types, increasing the current total worldwide to 60. Through sequence comparisons of the 5′untranslated region (5′UTR), the majority grouped with species A (n = 96; 68%, described as HRV-Ca), the remainder forming a phylogenetically distinct 5′UTR group (HRV-Cc). Multiple and bidirectional recombination events between HRV-Ca and HRV-Cc variants and with HRV species A represents the most parsimonious explanation for their interspersed phylogeny relationships in the VP4/VP2-encoding region. No difference in age distribution, seasonality or disease associations was identified between HRV-Ca and HRV-Cc variants. HRV-C-infected subjects showed markedly reduced detection frequencies of RSV and other respiratory viruses, providing evidence for a major interfering effect of HRV-C on susceptibility to other respiratory virus infections. HRV-C's disease associations, its prevalence and evidence for interfering effects on other respiratory viruses mandates incorporation of rhinoviruses into future diagnostic virology screening

Pinhole calculations of the Josephson effect in 3He-B

We study theoretically the dc Josephson effect between two volumes of superfluid 3He-B. We first discuss how the calculation of the current-phase relationships is divided into a mesoscopic and a macroscopic problem. We then analyze mass and spin currents and the symmetry of weak links. In quantitative calculations the weak link is assumed to be a pinhole, whose size is small in comparison to the coherence length. We derive a quasiclassical expression for the coupling energy of a pinhole, allowing also for scattering in the hole. Using a selfconsistent order parameter near a wall, we calculate the current-phase relationships in several cases. In the isotextural case, the current-phase relations are plotted assuming a constant spin-orbit texture. In the opposite anisotextural case the texture changes as a function of the phase difference. For that we have to consider the stiffness of the macroscopic texture, and we also calculate some surface interaction parameters. We analyze the experiments by Marchenkov et al. We find that the observed pi states and bistability hardly can be explained with the isotextural pinhole model, but a good quantitative agreement is achieved with the anisotextural model.Comment: 20 pages, 21 figures, revtex

Effectiveness of stress control large group psychoeducation for anxiety and depression : systematic review and meta-analysis

Objectives This review sought to evaluate the effectiveness of the ‘Stress Control’ (SC) large psychoeducational 6‐session group programme developed to increase access to treatment for patients with anxiety and depression. Design Systematic review and meta‐analysis (Prospero registration: CRD42020173676). Methods Pre–post and post‐treatment follow‐up effect sizes were extracted and synthesized in a random effects meta‐analysis, and variations in effect sizes were investigated via moderator analyses. Secondary analyses synthesized between‐group effect sizes from controlled studies containing comparator treatments and calculated the average dropout rate. The quality of the meta‐analysis was assessed using the GRADE approach. Results Nineteen studies with pre–post treatment outcomes were included. The average group size was N = 39, and the average dropout rate was 34%. Pooled effect sizes indicated moderate pre–post treatment reductions in anxiety (ES = 0.58; CI 0.41 to 0.75; N = 5597; Z = 7.13; p < .001), moderate reductions in depression (ES = 0.62; CI 0.44 to 0.80; N = 5538, Z = 7.30; p < .001), and large reductions in global distress (ES = 0.86; CI 0.61 to 1.11; N = 591; Z = 7.41; p < .001). At follow‐up, improvements in anxiety, depression, and global distress were maintained. When SC was compared to active and passive controls, outcomes were equivalent for anxiety (ES = 0.12, 95% CI −0.25 to 0.49, Z = −0.70; p = .482) and depression (ES = 0.15, 95% CI −0.24 to 0.54, Z = 0.84; p = .401). Conclusions SC appears to be a clinically effective and durable low‐intensity group intervention that facilitates access to treatment for large patient numbers. However, conclusions are limited by the low methodological quality of the evidence. Practitioner points - The stress control version of large group psychoeducation is appropriate and effective for mild‐to‐moderate anxiety and depression - The evidence base for stress control is predominantly made up of practice‐based studies - Stress control needs to form one component of the overall offer made to patients presenting with mild‐to‐moderate anxiety and depression - The competencies required to deliver such groups need better specification

Growth variations and scattering mechanisms in metamorphic In0.75Ga0.25As/In-0.75 Al0.25As quantum wells grown by molecular beam epitaxy

Modulation doped metamorphic In0.75Ga0.25As/In0.75Al0.25As quantum wells (QW) were grown on GaAs substrates by molecular beam epitaxy (MBE) with step-graded buffer layers. The electron mobility of the QWs has been improved by varying the MBE growth conditions, including substrate temperature, arsenic over pressure and modulation doping level. By applying a bias voltage to SiO2 insulated gates, the electron density in the QW can be tuned from 1×1011 to 5.3×1011 cm−2. A peak mobility of 4.3×105 cm2V−1s−1 is obtained at 3.7×1011 cm−2 at 1.5 K before the onset of second subband population. To understand the evolution of mobility, transport data is fitted to a model that takes into account scattering from background impurities, modulation doping, alloy disorder and interface roughness. According to the fits, scattering from background impurities is dominant while that from alloy disorder becomes more significant at high carrier density