Evaluation of bleach-sedimentation for sterilising and concentrating Mycobacterium tuberculosis in sputum specimens

Chew, Rusheng; Calderón, Carmen; Schumacher, Samuel G; Sherman, Jonathan M.; Caviedes, Luz; Fuentes, Patricia; Coronel, Jorge; Valencia, Teresa; Hererra, Beatriz; Zimic, Mirko; Huaroto, Libio; Sabogal, Iván; Escombe, A. Rod; Gilman, Robert H.; Evans, Carlton A.

doi:10.1186/1471-2334-11-269

Cited by 19 publications

(19 citation statements)

References 18 publications

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“…On the other hand, the SNARC effect clearly shows associations with lateralized response tendencies. If they appear late in the process, it is likely that they are spatial in nature, as in the mental number line account of the SNARC effect ( Restle, 1970 ; Dehaene et al, 1990 ) rather than conceptual, as in the polarity account ( Proctor and Cho, 2006 ). Our conclusions, therefore, are similar to those of Fitousi et al (2009) .…”

Section: Discussionmentioning

confidence: 99%

There’s a SNARC in the Size Congruity Task

et al. 2018

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The size congruity effect involves interference between numerical magnitude and physical size of visually presented numbers: congruent numbers (either both small or both large in numerical magnitude and physical size) are responded to faster than incongruent ones (small numerical magnitude/large physical size or vice versa). Besides, numerical magnitude is associated with lateralized response codes, leading to the Spatial Numerical Association of Response Codes (SNARC) effect: small numerical magnitudes are preferably responded to on the left side and large ones on the right side. Whereas size congruity effects are ascribed to interference between stimulus dimensions in the decision stage, SNARC effects are understood as (in)compatibilities in stimulus-response combinations. Accordingly, size congruity and SNARC effects were previously found to be independent in parity and in physical size judgment tasks. We investigated their dependency in numerical magnitude judgment tasks. We obtained independent size congruity and SNARC effects in these tasks and replicated this observation for the parity judgment task. The results confirm and extend the notion that size congruity and SNARC effects operate in different representational spaces. We discuss possible implications for number representation.

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Section: Discussionmentioning

confidence: 99%

There’s a SNARC in the Size Congruity Task

et al. 2018

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“…Its concentration also varies according to the time and the specimens used [ 6 ]. M. tuberculosis in sputum was successfully sterilized by adding equal volumes of 15% bleach for one minute, 6% for five minutes or 3% for 20 minutes [ 15 ]. Studies revealed that the concentration of bleach and time applied to decontaminate biohazard spill varied from 0.05%-0.5% for 15-20 min [ 16 , 17 ].…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the efficacy of bleach routinely used in health facilities against mycobacterium tuberculosis isolates in Ethiopia

Mekonnen¹,

Admassu²,

Wassie³

et al. 2015

Pan Afr Med J

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IntroductionIn Ethiopia, the most widely used disinfectant is 5% Hypochlorites. However, Ethiopian national health safety and infection prevention guideline recommendation on the use of bleach is not consistent and varying from 0.1%-4%. The purpose of this study was therefore to assess the effective time-concentration relationship of sodium hypochlorite against Mycobacterium tuberculosis complex isolates in the absence of any organic load.MethodsThis experimental study was conducted in Bahir Dar Regional laboratory from February-June 2013. Test suspensions of 1.5 X 108 CFU/ml prepared using normal saline containing 0.5% tween 80. From 5% stock, 0.1%, 0.5%, 1% and 2% bleach was prepared. A 1ml of test strain suspension and 1ml of bleach mixed and allowed to stand until the specified time achieved, neutralized by 48 ml phosphate buffer. 100µl from the diluted sediment were spread on two L-J mediums and incubated at 37°C for 8 weeks.ResultsWhen 0. 1% bleach was used for 10 min, majority 11/20 of isolates showed 3 x 103 CFU/ml growth (ME = 4.4) which was inefficient. However, when the time increased, the log10 reduction was acceptable, ME >5 and it was effective. The bleach solution containing 0.5% and above was effective in all respective times. In this study, there is no difference observed in the tuberculocidal activity of bleach against resistant and sensitive strains.ConclusionOur study showed that in the absence of any organic load, 0.1% bleaches over 15 min and 0.5% bleaches over 10 min was found to be tuberculocidal.

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“…Traditionally, researchers have used the mental number line to explain both CDE and PDE (e.g., Restle, 1970; Dehaene, 1997). According to this perspective, numbers are represented in the brain along a line analogous to the physical number line on paper.…”

Section: Introductionmentioning

confidence: 99%

Different Neural Mechanisms for the Comparison and Priming Distance Effects: An fMRI Study

et al. 2016

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Using functional magnetic resonance imaging, the present study examined whether the comparison distance effect (CDE) and the priming distance effect (PDE) in number processing had the same underlying neural mechanisms. 24 healthy participants completed a number comparison task and a number priming task in the scanner. Imaging data were examined for brain regions selected based on a meta-analysis of previous studies of number processing. Results revealed robust CDE and PDE at both behavioral and neural levels. The CDE had a significant hemodynamic signature in the right parietal cortex but not in the left parietal cortex, although a direct test of this hemispheric laterality did not reach statistical significance. In contrast, the PDE showed significant left-hemisphere laterality with a significant hemodynamic signature in the left parietal cortex but not in the right parietal cortex. These results suggested that the CDE and PDE had different underlying neural mechanisms.

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Evaluation of bleach-sedimentation for sterilising and concentrating Mycobacterium tuberculosis in sputum specimens

Cited by 19 publications

References 18 publications

There’s a SNARC in the Size Congruity Task

There’s a SNARC in the Size Congruity Task

Evaluation of the efficacy of bleach routinely used in health facilities against mycobacterium tuberculosis isolates in Ethiopia

Different Neural Mechanisms for the Comparison and Priming Distance Effects: An fMRI Study

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