To better understand the influence of environmental conditions on the adsorption of extracellular chromosomal DNA and its availability for natural transformation, the amount and conformation of adsorbed DNA were monitored under different conditions in parallel with transformation assays using the soil bacterium Azotobacter vinelandii. DNA adsorption was monitored using the technique of quartz c...

Natural organic matter (NOM) in source water originated from Luan River and Yellow River, North China was isolated and fractionated with XAD resins and ultra-filtration membranes. The raw water samples and fractions were disinfected with sufficient monochloramine to determine their N-nitrosamines formation potentials. Fluorescence Excitation-Emission Matrix (EEM), molecular weight (MW), dissolv...

Metals are present in aquatic environments as a result of natural and anthropogenic inputs, and may induce toxicity to organisms. One of the main factors that influence this toxicity in fresh water is natural organic matter (NOM) but all NOMs are not the same in this regard. In sea water, possible protection by marine NOMs is not well understood. Thus, our study isolated marine NOMs by solid-ph...

OBJECTIVES  To identify the  predictive factors of successful non-operative  management  of patients  with intraperitoneal bleeding following blunt abdominal trauma. METHODS This was cross-sectional study being performed in our Level I trauma center in southern  Iran between 2010 and 2011. We included adult (>14 years) patients with blunt  abdominal trauma  and intra-peritoneal hemorrhage  de...

Fuzzy set based methods have been proved to be effective in handling many types of uncertainties in different fields, including reliability engineering. This paper presents a new approach on fuzzy reliability, based on the use of beta type distribution as membership function. Considering experts' ideas and by asking operators linguistic variables, a rule base is designed to determine the level ...

This study investigates the fractions of natural organic matter (NOM) and trihalomethane (THM) formation after chlorination in samples of raw water and the outputs from ozonation, coagulation-flocculation, and conventional filtration treatment units. All the water samples are passed through various ultrafiltration (UF) membranes. UF membranes with different molecular size ranges based on appare...

Due to the unique antibacterial activities, silver nanoparticles (AgNPs) have been extensively used in commercial products. Anthropogenic activities have released considerable AgNPs as well as highly toxic silver ion (Ag(+)) into the aquatic environment. Our recent study revealed that ubiquitous natural organic matter (NOM) could reduce Ag(+) to AgNP under natural sunlight. However, the toxic e...

The present paper continues a series of comprehensive taxonomic treatments of cercosporoid fungi (formerly Cercospora s. lat.), belonging to the Mycosphaerellaceae (Ascomycota). The fourth contribution of this series initiates treatments of cercosporoid fungi on dicots and comprises species occurring on hosts belonging the the families Acanthaceae, Actinidiaceae, Adoxaceae, Aizoaceae, Altingiac...

Free chlorine has been used extensively as a primary and secondary disinfectant for potable water. Where it is difficult to maintain a free chlorine residual or when disinfection by-products (DBPs) are of concern, monochloramine has been used to provide a stable disinfectant residual in distributions systems. Reactions of disinfectants, free chlorine or monochloramine, with natural organic matt...

Contamination of soil interstitial waters by labile heavy metals such as Cu(II), Cd(II), and Ni(II) is of worldwide concern. Carbonaceous materials such as char and activated carbon have received considerable attention in recent years as soil amendment for both sequestering heavy metal contaminants and releasing essential nutrients like sulfur. Information is currently lacking in how aging impa...