In this article, we introduce some distribution-free exponentially weighted moving average (EWMA) schemes for phase-II monitoring. Our proposed schemes are based on the well-known Lepage statistic ...and are referred to as the EWMA-Lepage (EL) procedures. These schemes are designed for monitoring the location and the scale parameters of an unknown but continuous univariate process at phase II. A novelty of these schemes is that a single chart can monitor both the location and scale parameters. Moreover, their distribution-free characteristic ensures that the in-control (denoted IC) properties of the proposed procedure remain invariant and known for all univariate continuous distributions. We discuss both the exact and the steady-state control limits. We obtain control limits under different situations for practical implementation of these schemes and examine the IC and out-of-control (denoted OOC) properties of the monitoring schemes through simulation studies in terms of the average, the standard deviation, the median, and some percentiles of the run length distributions. We illustrate the proposed procedure with two sets of data arriving out of manufacturing sector. We also offer some remarks and future research directions.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Generalized nonparametric Shewhart–Lepage chart for joint monitoring is introduced.•Optimal implementation strategy and applications of the proposed chart is discussed.•The new scheme displays ...exceptional performance in detecting complex process shifts.•Post signal follow-up procedures to identify the nature of shifts is addressed.
We generalize popular distribution-free (nonparametric) Shewhart–Lepage scheme for simultaneously monitoring of location and scale parameters using an adaptive approach. This approach is known as percentile modifications of ranks (or adaptive Gastwirth score) in the statistical literature. This is a powerful tool to improve rank tests to detect a shift in the process. The adaptive Gastwirth score is not much familiar among quality control practitioners and therefore rarely used in practice. Nevertheless, such scores are very useful in detecting various types of shifts in the process characteristics. Considering its distinct advantages, we develop a new class of Shewhart-type adaptive Lepage–Gastwirth (ALG) scheme. We discuss optimal implementation strategies of the proposed scheme to achieve lower out-of-control (OOC) average run length (ARL) and false alarm rate (FAR). This scheme is typically designed to monitor service quality where the reference sample may be non-normal. Post signal follow-up procedures of the proposed Shewhart-type optimal ALG chart is discussed. We illustrate the use of optimal ALG charts with a recent data on Vancouver city call centre service quality monitoring.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In recent decades, nano-scale zero valent iron is reported to have plant growth enhancement capacity under laboratory conditions, but till date, there is no report to highlight its effect on the ...growth and yield of field-grown plants. In this study, we have evaluated the potential of nZVI priming on rice yield. A two-year field study has been conducted with different concentrations (10, 20, 40, and 80 mg l
−1
) of nZVI for seed priming. The efficacy of nanopriming was compared with the hydroprimed control set. Seeds were treated for 72 h and sown in nursery beds and after 30 days seedlings were transplanted in the field. Root anatomy and morphology were studied in 7 days old seedlings where no changes were found. RAPD analysis also confirmed that low doses of nZVI were not genotoxic. Nanoprimed plants also had broader leaves, higher growth, biomass, and tiller number than control plants. Maximum yield was obtained from the 20 mg l
−1
nZVI primed set (3.8 fold higher than untreated control) which is achieved primarily because of the increase in fertile tiller numbers (two fold higher than untreated control). Higher values of other agronomic parameters like growth rate, net assimilation rate proved that nZVI priming enhanced photosynthetic efficiency and helped in the proper storage of photo-assimilates. All these attributed to increased accumulation of phytochemicals like starch, soluble sugar, protein, lipid, phenol, riboflavin, thiamine, and ascorbic acid in the grains. The elemental analysis confirmed that nZVI priming also promoted higher accumulations of macro and micronutrients in grains. Thus, nanoprimed seeds showed better crop performance compared to the traditional hydropimed seeds. Hence, nZVI can be considered as ‘pro-fertilizer’ and can be used commercially as a seed treatment agent which is capable of boosting plant growth and yield along with minimum interference to the soil ecosystem.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The use of polystyrene micro and nanoplastics in cosmetics and personal care products continues to grow every day. The harmful effects of their biological accumulation in organisms of all trophic ...levels including humans have been reported by several studies. While we have accumulating evidence on the impact of nanoplastics on different organ systems in humans, only a handful of reports on the impact of polystyrene nanoplastics upon direct contact with the immune system at the cellular level are avialable. The present study offers significant evidence on the cell-specific harmful impact of sulfate-modified nanoplastics (S-NPs) on human macrophages. Here we report that exposure of human macrophages to S-NPs (100 µg/mL) stimulated the accumulation of lipids droplets (LDs) in the cytoplasm resulting in the differentiation of macrophages into foam cells. The observed effect was specific for human and murine macrophages but not for other cell types, especially human keratinocytes, liver, and lung cell models. Furthermore, we found that S-NPs mediated LDs accumulation in human macrophages was accompanied by acute mitochondrial oxidative stress. The accumulated LDs were further delivered and accumulated into lysosomes leading to impaired lysosomal clearance. In conclusion, our study reveals that exposure to polystyrene nanoplastics stabilized with anionic surfactants can be a potent stimulus for dysregulation of lipid metabolism and macrophage foam cell formation, a characteristic feature observed during atherosclerosis posing a serious threat to human health.
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•S-NPs induce accumulation of neutral lipids selectively in macrophages•Exposure to S-NPs induces acute oxidative stress•S-NPs exposed macrophages display impaired lysosomal clearance
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•ZnO-np treatment let to a decrease in MI, increase in CA and MN formation.•Increase in DNA fragmentation noted.•Accumulation of cells in G2/M phase, increase in sub G0 ...population.•ZnO-np induced oxidative stress response.•TEM images revealed alteration of cellular organization and nanoparticle uptake.
Cytotoxicity, genotoxicity, and biochemical effects were evaluated in the plants Allium cepa, Nicotiana tabacum, and Vicia faba following exposure to ZnO nanoparticles (np; diameter, ∼85nm). In the root meristems of Allium cepa cells, we observed loss of membrane integrity, increased chromosome aberrations, micronucleus formation, DNA strand breaks, and cell-cycle arrest at the G2/M checkpoint. In Vicia faba and Nicotiana tabacum, we observed increased intracellular ROS production, lipid peroxidation, and activities of some antioxidant enzymes. TEM images revealed gross morphological alterations and internalization of the np. Our findings provide evidence of ZnO np toxicity, characterized by deregulation of components of ROS-antioxidant machinery, leading to DNA damage, cell-cycle arrest, and cell death. These plants, especially Allium cepa, are reliable systems for assessment of np toxicology.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The digestive enzyme of plant are generally α-amylase. They functions enzyme that breakdown starch into maltose and sugars. This happens in the endosperm of the seed. Due to pollutants, this process ...get happened one of emergent xenobiotics are micro and nano plastics. This study involves the interaction 100 nm size of polystyrene nano plastic (PSNPs) on α-amylase. The hyperchromism of α-amylase – PSNPs conjugate’s revealed that ground-state complex in a microenvironment. Fluorescence quenching happened when the concentration of PSNPs was increased. The Stern Volmer plot revealed binding constant (Ka) was 1.904 × 1019 M-1. S-1 while the quenching constant (Kq) was 1.036 × 1011 M-1, the blue shift of the peak showed static quenching. The binding constant was KA = 4.2 × 1012, the number of binding site on PSNPs for α-amylase was n = 1.12. The synchronous result showed a gradual reduction in the intensity of Trp residues because when the α-amylase interacts with PSNPs short-range π-π interaction happens around the Trp163 residues. The enzyme activity of α-amylase by 44 % and its IC50 value was found to be 100 µg/mL. The enzyme kinetics (Vmax) analysis showed the type of inhibition with and without PSNPs Vmax 769 and Vmax 303 µg/mL/min, uncompetitive inhibition respectively. The effect of PSNPs on the enzymatic activity of α-amylase showed structural alterations of the protein. Therefore the in vitro and in silico studies were shown evidence of interaction between α-amylase and PSNPs leads to conformational structural changes in α-amylase.
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•The interaction of PSNPs against diastase α-amylase was investigated in the microenvironment system.•A static quenching mechanism was shown by the hypochromic action of UV–vis and Fluorescence Spectroscopy.•A molecular docking study was determined to affect aromatic residues.•The inhibition efficiency of the α-amylase on PSNPs was IC50 tested.•The PSNPs against α-amylase inhibition activity and enzyme kinetics were performed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Nanoremediation of soil, ground and surface water using nanoscale zerovalent iron particles (nZVI) has facilitated their direct environmental exposure posing ecotoxicological concerns. Numerous ...studies elucidate their phytotoxicity in terms of growth and their fate within the plant system. However, their potential genotoxicity and cytotoxicity mechanisms are not known in plants. This study encompasses the physico-chemical characterisation of two forms of nZVI (nZVI-1 and nZVI-2) with different surface chemistries and their influence on uptake, root morphology, DNA damage, oxidative stress and cell death in Allium cepa roots after 24 h. To our knowledge, this is the first report on the cyto-genotoxicity of nZVI in plants. The adsorption of nZVI on root surfaces caused root tip, epidermal and root hair damage as assessed by Scanning Electron Microscopy. nZVI-1, due to its colloidal destabilisation (low zeta potential, conductivity and high polydispersity index), smaller size and high uptake imparted enhanced DNA damage, chromosome/nuclear aberrations (CAs/NAs) and micronuclei formation compared to nZVI-2. Although nZVI-2 exhibited high zeta potential and conductivity, its higher dissolution and substantial uptake induced genotoxicity. nZVI incited the generation of reactive oxygen species (ROS) (hydrogen peroxide, superoxide and hydroxyl radicals) leading to membrane lipid peroxidation, electrolyte leakage and mitochondrial depolarisation. The inactivation of catalase and insignificant glutathione levels marked the onset of oxidative stress. Increased superoxide dismutase and guaiacol peroxidase enzyme activities, and proline content indicated the activation of antioxidant defence machinery to alleviate ROS. Moreover, ROS-mediated apoptotic and necrotic cell death occurred in both nZVI-1 and nZVI-2-treated roots. Our results open up further possibilities in the environmental safety appraisal of bare and modified nZVI in correlation with their physico-chemical characters.
A new single distribution-free Phase-II CUSUM procedure based on the Cucconi statistic for simultaneously monitoring shifts in the unknown location and scale parameters of a process is proposed. The ...procedure does not require the assumption of normal data. Control limits are tabulated for practical implementation of the procedure. The in-control and out-of-control performance of the procedure are comprehensively examined in terms of mean, median, variability and some percentiles of the corresponding run length distribution. A thorough comparison with the Shewhart-type procedures based on the Cucconi and Lepage statistics as well as with the CUSUM procedure based on the Lepage statistic is presented. The proposed procedure is illustrated by analysing the service quality of the Vancouver City Call Centre.
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BFBNIB, IZUM, KILJ, NUK, PILJ, SAZU, UL, UM, UPUK
•This paper introduces a distribution-free Phase I scheme for location and scale.•This is a one-chart scheme based on the multi-sample Lepage statistic.•This scheme does not require the restriction ...of equal sizes for each subgroup.•A variety of patterned shifts are considered in simulation study.•This scheme is superior to or comparable to several existing two-chart schemes in most cases.
In this paper, we introduce an exactly distribution-free procedure for Phase I analysis which is capable of assessing stability of both location and scale parameters of the process using a single plotting statistic. A large proportion of literature on Phase I or retrospective analysis assumes normality. The normality assumption is often invalid in practice. In recent years, researchers have proposed some distribution-free (nonparametric) Phase I schemes. Most of these schemes facilitate assessing either the location or the scale, individually but not both simultaneously. Practitioners often consider a two-chart scheme, one for monitoring the location parameter and the other the scale parameter in tandem. Nevertheless, such two-chart schemes have certain practical disadvantages. There is a plethora of literature on distribution-free Phase II schemes for simultaneously monitoring the location and scale parameters of a process distribution using a single statistic. To the best of our knowledge, there is no literature on Phase I or retrospective analysis of both location and scale adopting a single statistic. To fill this research gap, we propose a distribution-free Phase I monitoring scheme for both location and scale parameters based on the multi-sample Lepage statistic. The proposed Phase I scheme can be implemented even if subgroup sizes are unequal. Unlike, most of the existing schemes, it does not require the restriction of equal sizes for each subgroup. The design and implementation of the proposed scheme is simple. We clearly outline and illustrate the implementation steps with an example. Compared to several existing two-chart schemes, the proposed one-chart scheme has performance advantages in a variety of cases, especially for skewed and heavy-tailed data. We also study certain interesting features of the proposed scheme.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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