ABSTRACT
Anatomists and radiologists use the Zaidi-Dayal and Richards-Jabbour scales to study the shape of the foramen magnum. Our aim is to measure the interrater and intrarater agreement and reliability of ratings made using the two scales. We invited 16 radiology residents to attend two sessions, four weeks apart. During each session, we asked the residents to classify the shape of the foramen magnum in 35 images using both scales. We used Fleiss' κ to measure interrater reliability and Cohen's κ to measure intrarater reliability. The interrater reliability of ratings made using the Zaidi-Dayal scale was 0.34 (0.26-0.46) for session one and 0.30 (0.24-0.39) for session two, and the intrarater reliability was 0.39 (0.34-0.44). The interrater reliability of ratings made using the Richards-Jabbour scale was 0.14 (0.10-0.19) for session one and 0.12 (0.09-0.17) for session two, and the intrarater reliability was 0.11 (0.07-0.15). In conclusion, the interrater and intrarater agreement and reliability of ratings made using the Zaidi-Dayal and Richards-Jabbour scales are inadequate. We recommend an objective method by Zdilla et al. to researchers interested in studying the shape of the foramen magnum.
ABSTRACT
Phytoremediation is considered as a novel environmental friendly technology, which uses plants to remove or immobilize heavy metals. The use of metal-resistant plant growth-promoting bacteria (PGPB) constitutes an important technology for enhancing biomass production as well as tolerance of the plants to heavy metals. In this study, we isolated twenty seven (NF1-NF27) chromium resistant bacteria. The bacteria were tested for heavy metals (Cr, Zn, Cu, Ni, Pb and Co) resistance, Cr(VI) reduction and PGPB characters (phosphate solubilization, production of IAA and siderophores). The results showed that the bacterial isolates resist to heavy metals and reduce Cr(VI), with varying capabilities. 37.14% of the isolates have the capacity of solubilizing phosphate, 28.57% are able to produce siderophores and all isolates have the ability to produce IAA. Isolate NF2 that showed high heavy metal resistance and plant growth promotion characteristics was identified by 16S rDNA sequence analysis as a strain of Cellulosimicrobium sp.. Pot culture experiments conducted under greenhouse conditions showed that this strain was able to promote plant growth of alfalfa in control and in heavy metals (Cr, Zn and Cu) spiked soils and increased metal uptake by the plants. Thus, the potential of Cellulosimicrobium sp. for both bioremediation and plant growth promotion has significance in the management of environmental pollution.
ABSTRACT
AIM: Localization of Cr(VI) removal activity in Candida tropicalis strain and the study of its Cr(VI) removal capacity in soil. METHODS AND RESULTS: Candida tropicalis strain HE650140 showed a remarkable capacity to completely reduce 50 mg l(-1) of Cr(VI) in 48 h under aerobic conditions; however, a small change in total content of chromium in the culture liquid was detected, which can be explained by the formation of Cr(III). Fractionation of the cells showed that chromium removal activity was present in both the cytoplasm and membrane. The bioaugmentation of Cr(VI)-contaminated soil microcosms by live and dead biomass showed that yeast inoculation diminishes phytoavailable chromium from soils, improving different growth parameters of clover. CONCLUSION: The Cr(VI) removal activity was found in both cytoplasmic and membrane fractions. Both live and dead biomass of C. tropicalis were capable to reduce Cr(VI) in the soil and limit the toxicity of this metal to clover seedlings. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is one of the few documents that present the ability of dead yeast to limit phytoavailability of Cr(VI) from soil. This is of great significance in bioremediation of Cr(VI)-contaminated soil.
