Cropland physical disturbance intensity： plot-scale measurement and its application for soil erosion reduction in mountainous areas

Various kinds of human disturbances on cropland are the main reasons for soil erosion and land degradation.Farming practices in mountainous areas vary greatly among cropland plots because of the heterogeneity of biophysical conditions and differences in farmers'management behavior.The main purpose of this paper is to develop a composite index of cropland physical disturbance intensity(CLDI)to reflect the plot-scale discrepancy of potential soil erosion in mountainous areas.The study was based on both plot survey and household interview data,collected from six typical catchments in mountainous areas of southwestern China.Four kinds of physical disturbance practices and two kinds of conservation practices during one crop rotation period were synthesized to develop the CLDI index.The rough set theory was referenced to avoid subjectivity during weight allocation.The results show that conventional tillage,deep fertilization,and manual weeding are the main causes of cropland soil erosion,whereas manure application in combination with seasonal fallow reduces soil erosion.Different crop types as well as cropland location factors determine the spatial pattern of CLDI.Crop rotation modes with major crops of tobacco and maize resulted in a maximal CLDI,and cropland plots with a distance radius of 150 meters away from households received the most intensive physical disturbance.These results are critical to help better protect rural environments in mountainous areas.Based on the results,methods to reduce cropland soil erosion are suggested.

Analysis of Enterobacteriaceae Producing Broad-Spectrum Beta-Lactamases in the Intensive Care Unit Setting

Strains of the Enterobacteriaceae family producing ESBL and AmpC broad-spectrum beta-lactamases that may survive in the hospital setting potentially cause infection in hospitalized patients due to contaminated objects or health care workers’ hands. Over a period of two months (November-December 2010), a single epidemiological study of microbial contamination of air, surfaces and health care workers (swabs from both nostrils and the right hand without a glove) was carried out at two intensive care units of the University Hospital Olomouc, Czech Republic. The bacteria were identified using standard microbiological methods. Phenotypic detection of ESBL and AmpC enzymes and basic genetic analysis of ESBL- and AmpC-positive isolates was performed. The same approach was used to identify and analyze bacteria isolated from clinical samples of patients hospitalized at the above departments over the study period. From a total of 140 environmental samples collected over the study period, 21 isolates of the Enterobacteriaceae family were identified, with ESBL and AmpC production being detected in 4 and 7 isolates, respectively. Among patients’ clinical samples, 10 ESBL- and 6 AmpC-positive isolates were detected. No similarity was found between environmental isolates and strains isolated from patients.