Scattering Properties of Atmospheric Aerosols over Lanzhou City and Applications Using an Integrating Nephelometer

The data, measured by a three-wavelength Integrating Nephelometer over Lanzhou City during the winters of 2001/2002 and 2002/2003 respectively, have been analyzed for investigating the scattering properties of atmospheric aerosols and exploring their relationship and the status of air pollution. The aerosol particle volume distribution is inverted with the measured spectral scattering coe?cients. The results show that the daily variation of the aerosol scattering coe?cients is in a tri-peak shape. The average ratio of backscattering coe?cient to total scattering coe?cient at 550 nm is 0.158; there exists an excellent correlation between the scattering coe?cients and the concentration of PM10. The average ratio of the concentration of PM10 to the scattering coe?cients is 0.37 g m?2, which is contingent on the optical parameters of aerosol particles such as the size distribution, etc.; an algorithm is developed for inverting the volume distribution of aerosol particles by using the histogram and Monte-Carlo techniques, and the test results show that the inversion is reasonable.

Recent Progress of Aerosol Light-scattering Enhancement Factor Studies in China

Assessment of the radiative forcing of aerosols in models still lacks sufficient input data for aerosol hygroscopicity. The light scattering enhancement factor [ f(RH, λ)] is a crucial parameter for describing aerosol hygroscopic growth properties.In this paper, we provide a survey of f(RH, λ) studies in China for the past seven years, including instrument developments of humidified nephelometers, ambient f(RH, λ) measurements in China, f(RH, λ) parameterization schemes, and f(RH, λ)applications in aerosol measurements. Comparisons of different f(RH, λ) parameterizations are carried out to check their performance in China using field measurement datasets. We also summary the parameterization schemes for predicting f(RH, λ)with aerosol chemical compositions. The recently developed methods to observe other aerosol properties using f(RH, λ)measurements, such as calculating the aerosol hygroscopicity parameter, cloud condensation nuclei number concentration,aerosol liquid water content, and aerosol asymmetry factor, are introduced. Suggestions for further research on f(RH, λ) in China are given.

Bacterial Urinary Tract Infections among Males with Lower Urinary Tract Obstruction at Komfo Anokye Teaching Hos-pital, Kumasi, Ghana

Purpose: We describe the commonest pathology responsible for lower urinary tract obstruction (LUTO) and associated symptoms such as UTI, etc. among males at the Komfo Anokye Teaching Hospital (KATH) in Kumasi. Materials and Methods: Between January and December 2009, prospective cross sectional hospital based study was conducted involving 103 subjects. Patients with symptoms of LUTO and who were on short admission (up to 48 hours) at the accident and emergency unit of KATH were identified as potential study subjects. All the patients presented with acute retention of urine at the emergency unit of KATH and urethral catheterization was attempted to relieve them of the retention under sterile conditions. Those patients whose initial catheterization failed went through suprapubic cystostomy (suprapubic catheterization). Urine specimens for culture and sensitivity tests were then collected into sterile urine containers immediately after the catheterization (irrespective of type). Ultrasound Scan was requested for all the patients to assist in diagnosing enlargement of the prostate and other associated urological pathologies. Retrograde urethrogram was however, requested for those patients with suprapubic catheterization and which helped in the diagnosis of the urethral stricture. For a particular child, urethral catheter was passed under sterile condition and Micturicting Cysto-Urethrogram (MCUG) was done to assist in diagnosing posterior urethral valve and other conditions. Those subjects whose urinalysis revealed pyuria and positive urine culture and who had voluntarily agreed to enter the study were enrolled. Subjects whose urine culture had multiple bacteria growth that was deemed to be contaminants were excluded from the study. Results: The mean age for males with LUTO was 62 years. The youngest male with LUTO was aged 2 years whilst the maximum age was 93 years. LUTO due to prostatic hyperplasia was found in 79 (76.7%) men;23 (22.3%) had LUTO due to urethral stricture and 1 (1.0%) (youngest male). The mean age of patients that had LUTO due to urethral stricture was approximately 39 years. The youngest patient with LUTO due to urethral stricture aged 22 years whilst the maximum age was 72 years. Microbiological results indicated that Escherichia coli caused 53 (51.5%) of urinary tract infection (UTI) due to LUTO;Klebsiella = 23 (22.3%);Staphylococcus aureus = 14 (14.6%);Pseudomonas spp. = 8 (7.8%) Proteus = 2 (2.0%);Citrobacter = 1 (1.0%) and Salmonella spp. =1 (1.0%). Conclusion: The most common cause of lower urinary tract obstruction (LUTO) in Kumasi, Ghana is prostatic hyperplasia and the commonest causative organism of the associated UTI symptom is Escherichia coli.