3,518 research outputs found
A study on the variable sampling interval EWMA X chart when the process parameters are unknown
Detection of viable bacteria in environmental water samples using DNase I and PCR method. International Journal of Environmental Studies
In this study, we tested the potential application of a previously developed method in detecting Escherichia coli in environmental water samples. To increase the sensitivity of the method, and the recovery of microbial cells, water samples were filtered before being subjected to DNase treatment and polymerase chain reaction amplification. Results showed that DNase I treatment and PCR reaction were not affected by inhibitors as the expected amplicon was successfully amplified in autoclaved environmental waters spiked with E. coli. Then, we applied this method to naturally contaminated environmental water samples. We firstly confirmed the presence of coliforms and E. coli in these water samples by plating in eosin methylene blue agar. Simultaneous PCR amplification targeting Lac Z and uidR gene of total coliforms and E. coli respectively demonstrated that this developed method is potentially applicable for routine microbial assessment of health risks related to viable microorganisms in environmental or drinking waters
EXACT RUN LENGTH DISTRIBUTION OF THE DOUBLE SAMPLING X CHART WITH ESTIMATED PROCESS PARAMETERS
Since the run length distribution is generally highly skewed, a significant concern about focusing too much on the average run length (ARL) criterion is that we may miss some crucial information about a control chart’s performance. Thus it is important to investigate the entire run length distribution of a control chart for an in-depth understanding before implementing the chart in process monitoring. In this paper, the percentiles of the run length distribution for the double sampling (DS) X chart with estimated process parameters are computed. Knowledge of the percentiles of the run length distribution provides a more comprehensive understanding of the expected behaviour of the run length. This additional information includes the early false alarm, the skewness of the run length distribution, and the median run length (MRL). A comparison of the run length distribution between the optimal ARL-based and MRL-based DS X chart with estimated process parameters is presented in this paper. Examples of applications are given to aid practitioners to select the best design scheme of the DS X chart with estimated process parameters, based on their specific purpose
EXACT RUN LENGTH DISTRIBUTION OF THE DOUBLE SAMPLING X CHART WITH ESTIMATED PROCESS PARAMETERS
Since the run length distribution is generally highly skewed, a significant concern about focusing too much on the average run length (ARL) criterion is that we may miss some crucial information about a control chart’s performance. Thus it is important to investigate the entire run length distribution of a control chart for an in-depth understanding before implementing the chart in process monitoring. In this paper, the percentiles of the run length distribution for the double sampling (DS) X chart with estimated process parameters are computed. Knowledge of the percentiles of the run length distribution provides a more comprehensive understanding of the expected behaviour of the run length. This additional information includes the early false alarm, the skewness of the run length distribution, and the median run length (MRL). A comparison of the run length distribution between the optimal ARL-based and MRL-based DS X chart with estimated process parameters is presented in this paper. Examples of applications are given to aid practitioners to select the best design scheme of the DS X chart with estimated process parameters, based on their specific purpose
Optical Coherence Tomography Angiography Findings in Dengue-Related Maculopathy:A Case Report
The ophthalmic manifestations of dengue fever include a visually impairing maculopathy, where patients are left with a central or paracentral relative scotoma. The authors present a case of a 26-year-old female patient returning from Thailand with unilateral reduction in visual acuity and a central scotoma associated with dengue fever. The authors report the use of the optical coherence tomography angiography (OCTA) as a noninvasive imaging platform to demonstrate its value in showing the persistent changes corresponding to the functional central scotoma in dengue-related maculopathy, which often cannot be visualized clinically or by standard OCT and fundus fluorescein angiography
Aged-senescent cells contribute to impaired heart regeneration
Aging leads to increased cellular senescence and is associated with decreased potency of tissue-specific stem/progenitor cells. Here, we have done an extensive analysis of cardiac progenitor cells (CPCs) isolated from human subjects with cardiovascular disease, aged 32-86 years. In aged subjects (>70 years old), over half of CPCs are senescent (p16INK4A , SA-β-gal, DNA damage γH2AX, telomere length, senescence-associated secretory phenotype [SASP]), unable to replicate, differentiate, regenerate or restore cardiac function following transplantation into the infarcted heart. SASP factors secreted by senescent CPCs renders otherwise healthy CPCs to senescence. Elimination of senescent CPCs using senolytics abrogates the SASP and its debilitative effect in vitro. Global elimination of senescent cells in aged mice (INK-ATTAC or wild-type mice treated with D + Q senolytics) in vivo activates resident CPCs and increased the number of small Ki67-, EdU-positive cardiomyocytes. Therapeutic approaches that eliminate senescent cells may alleviate cardiac deterioration with aging and restore the regenerative capacity of the heart
Seven- to 11-year-olds’ developing ability to recognize natural facial expressions of basic emotions
Being able to recognize facial expressions of basic emotions is of great importance to social development. However, we still know surprisingly little about children’s developing ability to interpret emotions that are expressed dynamically, naturally and subtly, despite real-life expressions having such appearance in the vast majority of cases. The current research employs a new technique of capturing dynamic, subtly expressed natural emotional displays (happy, sad, angry, shocked and disgusted). Children aged 7, 9 and 11 years (and adults) were systematically able to discriminate each emotional display from alternatives in a 5-way choice. Children were most accurate in identifying the expression of happiness and were also relatively accurate in identifying the expression of sadness; they were far less accurate than adults in identifying shocked and disgusted. Children who performed well academically also tended to be the most accurate in recognizing expressions and this relationship maintained independently of chronological age. Generally, the findings testify to a well-developed ability to recognize very subtle naturally occurring expressions of emotions
How accurately can other people infer your thoughts -- and does culture matter?
This research investigated how accurately people infer what others are thinking after observing a brief sample of their behaviour and whether culture/similarity is a relevant factor. Target participants (14 British and 14 Mediterraneans) were cued to think about either positive or negative events they had experienced. Subsequently, perceiver participants (16 British and 16 Mediterraneans) watched videos of the targets thinking about these things. Perceivers (both groups) were significantly accurate in judging when targets had been cued to think of something positive versus something negative, indicating notable inferential ability. Additionally, Mediterranean perceivers were better than British perceivers in making such inferences, irrespective of nationality of the targets, something that was statistically accounted for by corresponding group differences in levels of independently measured collectivism. The results point to the need for further research to investigate the possibility that being reared in a collectivist culture fosters ability in interpreting others’ behaviour
Nicotiana benthamiana as a Production Platform for Artemisinin Precursors
Background Production of pharmaceuticals in plants provides an alternative for chemical synthesis, fermentation or natural sources. Nicotiana benthamiana is deployed at commercial scale for production of therapeutic proteins. Here the potential of this plant is explored for rapid production of precursors of artemisinin, a sesquiterpenoid compound that is used for malaria treatment. Methodology/Principal Findings Biosynthetic genes leading to artemisinic acid, a precursor of artemisinin, were combined and expressed in N. benthamiana by agro-infiltration. The first committed precursor of artemisinin, amorpha-4,11-diene, was produced upon infiltration of a construct containing amorpha-4,11-diene synthase, accompanied by 3-hydroxy-3-methylglutaryl-CoA reductase and farnesyl diphosphate synthase. Amorpha-4,11-diene was detected both in extracts and in the headspace of the N. benthamiana leaves. When the amorphadiene oxidase CYP71AV1 was co-infiltrated with the amorphadiene-synthesizing construct, the amorpha-4,11-diene levels strongly decreased, suggesting it was oxidized. Surprisingly, no anticipated oxidation products, such as artemisinic acid, were detected upon GC-MS analysis. However, analysis of leaf extracts with a non-targeted metabolomics approach, using LC-QTOF-MS, revealed the presence of another compound, which was identified as artemisinic acid-12-ß-diglucoside. This compound accumulated to 39.5 mg.kg-1 fwt. Apparently the product of the heterologous pathway that was introduced, artemisinic acid, is further metabolized efficiently by glycosyl transferases that are endogenous to N. benthamiana. Conclusion/Significance This work shows that agroinfiltration of N. bentamiana can be used as a model to study the production of sesquiterpenoid pharmaceutical compounds. The interaction between the ectopically introduced pathway and the endogenous metabolism of the plant is discussed
Dimensionality of Carbon Nanomaterials Determines the Binding and Dynamics of Amyloidogenic Peptides: Multiscale Theoretical Simulations
Experimental studies have demonstrated that nanoparticles can affect the rate of protein self-assembly, possibly interfering with the development of protein misfolding diseases such as Alzheimer's, Parkinson's and prion disease caused by aggregation and fibril formation of amyloid-prone proteins. We employ classical molecular dynamics simulations and large-scale density functional theory calculations to investigate the effects of nanomaterials on the structure, dynamics and binding of an amyloidogenic peptide apoC-II(60-70). We show that the binding affinity of this peptide to carbonaceous nanomaterials such as C60, nanotubes and graphene decreases with increasing nanoparticle curvature. Strong binding is facilitated by the large contact area available for π-stacking between the aromatic residues of the peptide and the extended surfaces of graphene and the nanotube. The highly curved fullerene surface exhibits reduced efficiency for π-stacking but promotes increased peptide dynamics. We postulate that the increase in conformational dynamics of the amyloid peptide can be unfavorable for the formation of fibril competent structures. In contrast, extended fibril forming peptide conformations are promoted by the nanotube and graphene surfaces which can provide a template for fibril-growth
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