A synthetic control chart for monitoring the process mean and variance

Purpose - The aim of this paper is to present a synthetic chart based on the non-central chi-square statistic that is operationally simpler and more effective than the joint X̄ and R chart in detecting assignable cause(s). This chart will assist in identifying which (mean or variance) changed due to the occurrence of the assignable causes. Design/methodology/approach - The approach used is based on the non-central chi-square statistic and the steady-state average run length (ARL) of the developed chart is evaluated using a Markov chain model. Findings - The proposed chart always detects process disturbances faster than the joint X̄ and R charts. The developed chart can monitor the process instead of looking at two charts separately. Originality/value - The most important advantage of using the proposed chart is that practitioners can monitor the process by looking at only one chart instead of looking at two charts separately. © Emerald Group Publishing Limted.

Synthetic control charts with two-stage sampling for monitoring bivariate processes

In this article, we consider the synthetic control chart with two-stage sampling (SyTS chart) to control bivariate processes. During the first stage, one item of the sample is inspected and two correlated quality characteristics (x;y) are measured. If the Hotelling statistic T1 2 for these individual observations of (x;y) is lower than a specified value UCL 1 the sampling is interrupted. Otherwise, the sampling goes on to the second stage, where the remaining items are inspected and the Hotelling statistic T2 2 for the sample means of (x;y) is computed. When the statistic T2 2 is larger than a specified value UCL2, the sample is classified as nonconforming. According to the synthetic control chart procedure, the signal is based on the number of conforming samples between two neighbor nonconforming samples. The proposed chart detects process disturbances faster than the bivariate charts with variable sample size and it is from the practical viewpoint more convenient to administer.

Curauá fibers in the automobile industry - a sustainability assessment

Replacing glass fibers with natural fibers in the automobile industry can yield economic, environmental and social benefits. This article evaluates the prospective environmental impacts of automobile applications of curauá fiber (Ananas erectifolius), which nearly equates the physical properties of glass fibers. The study identified economic and social advantages of applying curauá fiber composites in car parts. Besides costing 50% less than fiber glass, the use of curauá fibers can promote regional development in the Amazon region. In order to realize significant environmental benefits, however, the curauá-based composites would have to be lighter than their glass fiber-based counterparts. © 2006 Elsevier Ltd. All rights reserved.

Use of a synthetic lethal screen to identify genes related to TIF51A in Saccharomyces cerevisiae

The putative eukaryotic translation initiation factor 5A (eIF5A) is an essential protein for cell viability and the only cellular protein known to contain the unusual amino acid residue hypusine. eIF5A has been implicated in translation initiation, cell proliferation, nucleocytoplasmic transport, mRNA decay, and actin polarization, but the precise biological function of this protein is not clear. However, eIF5A was recently shown to be directly involved with the translational machinery. A screen for synthetic lethal mutations was carried out with one of the temperature-sensitive alleles of TIF51A (tif51A-3) to identify factors that functionally interact with eIF5A and revealed the essential gene YPT1. This gene encodes a small GTPase, a member of the rab family involved with secretion, acting in the vesicular trafficking between endoplasmatic reticulum and the Golgi. Thus, the synthetic lethality between TIF51A and YPT1 may reveal the connection between translation and the polarized distribution of membrane components, suggesting that these proteins work together in the cell to guarantee proper protein synthesis and secretion necessary for correct bud formation during G1/ S transition. Future studies will investigate the functional interaction between eIF5A and Ypt1 in order to clarify this involvement of eIF5A with vesicular trafficking. ©FUNPEC-RP.

Influence of endogenous and synthetic female sex hormones on human blood cells in vitro studied with comet assay

The comet assay has been conducted with numerous cell lines to assess in vitro genotoxicity. In order to use the comet assay as part of an in vitro test for evaluating genotoxicity, however, there are cell-specific factors that need to be better understood. In this present study we have evaluated some factors that may impact upon the DNA damage detected in whole blood (WB) cells and lymphocytes (ILs). Experiments were conducted comparing responses of both cells, and investigating the effects of the female hormonal cycle, and oral contraceptive (OC) use on DNA damage detection in the in vitro comet assay, at three sampling time. No significant differences were detected in the basal levels of DNA damage detected in ILs and WB cells from women OC users and non-users and from men. Basal DNA damage in ILs was unaffected by gender and stage of the menstrual cycle or the stage of the treatment schedule. Our results also indicated that the H2O2 induces DNA damage in human lymphocytes independently of gender, low-dose OC use and hormonal fluctuation. However, data showed that in 3rd sampling of menstrual cycle, lymphocytes were more resistant to H2O2-induced DNA damage than those from OC users and men. © 2007 Elsevier Ltd. All rights reserved.

Comparison of the biological behavior of wollastonite bioceramics prepared from synthetic and natural precursors

Wollastonite bioceramics prepared from synthetic and natural precursors were implanted in rats in bone and subcutaneous tissues. The implant sites were excised after 7, 30 and 120 days, fixed, dehydrated, embedded in paraffin wax for serial cutting and examined under transmitted light microscope. It was found a very similar behavior for both wollastonite bioceramics. They were biocompatible, bioactive and biodegradable when implanted in rat bone. The synthetic ceramic was more reabsorbable than the one from natural powder. When implanted in subcutaneous rat tissue, both materials elicited a mild initial inflammatory reaction that practically disappeared after 120 days. Both materials were encapsulated with a very thin fibrous capsule and slightly reabsorbed at their surfaces. None of the materials induced ectopic osteogenesis. According to the results, the studied materials seem to be able for manufacturing reabsorbable bone implants.

Doxazosin reduces cell proliferation and increases collagen fibers in rat prostatic lobes

We investigated the effects of doxazosin (Dox), an alpha-adrenoceptor antagonist used clinically for the treatment of benign prostatic hyperplasia (BPH), on the rat prostatic complex by assessing structural parameters, collagen fiber content, cell proliferation, and apoptosis. Adult Wistar rats were treated with Dox (25 mg/kg per day), and the ventral (VP), dorsolateral, and anterior prostate (AP) regions of the prostate complex were excised at 3, 7, and 30 days after treatment. At 24 h before being killed, the rats were injected once with 5-bromodeoxyuridine (BrdU; thymidine analog) to label mitotically active cells. The prostates were weighed and processed for histochemistry, morphometry-stereology, immunohistochemistry for BrdU, Western blotting for proliferating cell nuclear antigen (PCNA), and the TUNEL reaction for apoptosis. Dox-treated prostate lobes at day 3 presented increased weight, an enlarged ductal lumen, low cubical epithelial cells, reduced epithelial folds, and stretched smooth muscle cells. However, at day 30, the prostates exhibited a weight reduction of ∼20% and an increased area of collagen and reticular fibers in the stromal space. Dox also reduced epithelial cell proliferation and increased apoptosis in the three prostatic lobes. Western blotting for PCNA confirmed the reduction of cell proliferation by Dox, with the AP and VP being more affected than the dorsal prostate. Thus, Dox treatment alters epithelial cell behavior and prostatic tissue mechanical demand, inducing tissue remodeling in which collagen fibers assume a major role. © 2007 Springer-Verlag.

Myotoxic phospholipases A2 isolated from Bothrops brazili snake venom and synthetic peptides derived from their C-terminal region: Cytotoxic effect on microorganism and tumor cells

This paper reports the purification and biochemical/pharmacological characterization of two myotoxic phospholipases A2 (PLA2s) from Bothrops brazili venom, a native snake from Brazil. Both myotoxins (MTX-I and II) were purified by a single chromatographic step on a CM-Sepharose ion-exchange column up to a high purity level, showing Mr ∼ 14,000 for the monomer and 28,000 Da for the dimer. The N-terminal and internal peptide amino acid sequences showed similarity with other myotoxic PLA2s from snake venoms, MTX-I belonging to Asp49 PLA2 class, enzymatically active, and MTX-II to Lys49 PLA2s, catalytically inactive. Treatment of MTX-I with BPB and EDTA reduced drastically its PLA2 and anticoagulant activities, corroborating the importance of residue His48 and Ca2+ ions for the enzymatic catalysis. Both PLA2s induced myotoxic activity and dose-time dependent edema similar to other isolated snake venom toxins from Bothrops and Crotalus genus. The results also demonstrated that MTXs and cationic synthetic peptides derived from their 115-129 C-terminal region displayed cytotoxic activity on human T-cell leukemia (JURKAT) lines and microbicidal effects against Escherichia coli, Candida albicans and Leishmania sp. Thus, these PLA2 proteins and C-terminal synthetic peptides present multifunctional properties that might be of interest in the development of therapeutic strategies against parasites, bacteria and cancer. © 2008 Elsevier Inc. All rights reserved.

Morphology of collagen fibers and elastic system fibers in actinic cheilitis

Background: Actinic cheilitis (AC) is a premalignant condition intimately related to exposure of the lips to sun rays. Aim: The objective of this study was to evaluate the elastic and collagen fibers in the lamina propria of AC. The degree of epithelial atypia was correlated with the quantity of elastic and collagen fibers. Materials and Methods: Fifty-one cases were investigated. One slide was stained with hematoxylin-eosin for the evaluation of atypia, the second was stained with Weigert′s resorcin-fuchsin for the assessment of elastic fibers, and the third slide was stained with Mallory′s trichrome for the analysis of collagen fibers. Results: Ordinal logistic regression analysis revealed a significant correlation between the presence of atypia and collagen fibers (P<0.05). Conclusions: It was concluded that there seems to be a reduction in the quantity of collagen fibers in cases of moderate and severe atypia. No correlation was observed between the degradation of elastic system fibers and the grade of dysplasia.

Thermal tunability of photonic bandgaps in photonic crystal fibers selectively filled with nematic liquid crystal

We address the bandgap effect and the thermo-optical response of high-index liquid crystal (LC) infiltrated in photonic crystal fibers (PCF) and in hybrid photonic crystal fibers (HPCF). The PCF and HPCF consist of solid-core microstructured optical fibers with hexagonal lattice of air-holes or holes filled with LC. The HPCF is built from the PCF design by changing its cladding microstructure only in a horizontal central line by including large holes filled with high-index material. The HPCF supports propagating optical modes by two physical effects: the modified total internal reflection (mTIR) and the photonic bandgap (PBG). Nevertheless conventional PCF propagates light by the mTIR effect if holes are filled with low refractive index material or by the bandgap effect if the microstructure of holes is filled with high refractive-index material. The presence of a line of holes with high-index LC determines that low-loss optical propagation only occurs on the bandgap condition. The considered nematic liquid crystal E7 is an anisotropic uniaxial media with large thermo-optic coefficient; consequently temperature changes cause remarkable shifts in the transmission spectrums allowing thermal tunability of the bandgaps. Photonic bandgap guidance and thermally induced changes in the transmission spectrum were numerically investigated by using a computational program based on the beam propagation method. © 2010 SPIE.

Morphological and molecular analysis of the collagen fibers in inflammatory process

Collagen makes up one third of the total protein in humans, being formed by the connection of three polypeptide chains arranged in a triple helix. This protein has fundamental importance in the formation of extracellular matrix of connective tissue. This study aimed to analyze the structural changes of collagen, which are resulting from inflammatory processes in oral mucosa, and to make the comparative analysis between the histopathology and the Raman spectra. The samples of tissues with inflammatory fibrous hyperplasia (IFH) and normal mucosa (NM) were evaluated by Raman Spectroscopy, hematoxylin-eosin and Massons trichrome stain. The histological analysis in both stains showed differences in collagen fibers, which was presented as thin fibers and arranged in parallel direction in NM and as collagen fibers are thick, mature and not organized, showing that these types of stain show morphological changes of collagen in IFH. The Raman Spectroscopy discriminate the groups of NM and IFH based on vibrational modes of proline, hydroxiproline and CH3, CH2. The histological stains only shows information from morphological data, and can be complemented by Raman spectra. This technique could demonstrate that inflammatory process caused some changes in collagen structure which is related to aminoacids such as proline and hidroxyproline. © 2011 SPIE-OSA.

Histochemical and ultrastructural analysis of hepatic glycogen and collagen fibers in alloxan-induced diabetic rats submitted to long-term physical training

Alterations in liver functions are common among diabetic patients, and many symptoms in the liver have been reported, including changes in glycogen stores and in the amount of collagen fibers. The practice of physical training and its morphological effects in this organ, however, are scarcely studied. In order to observe the morphological effects of alloxan-induced diabetes and the alterations arising from the practice of long-term chronic physical training in the liver, samples were collected and processed, and then analyzed by means of the histochemical techniques Periodic Acid-Schiff and Picrosirius-Hematoxylin, and ultrastructural cytochemical test of Afzelius. Through evaluation of the tissue, it was observed a drastic reduction in hepatic glycogen stores of sedentary diabetics, recovered in trained diabetic rats. Furthermore, it was detected a decrease in the content of perisinusoidal collagen fibers in the diabetic liver, also recovered due to the development of a training protocol. On ultrastructural level, cytochemical analysis confirmed the loss of glycogen and the recovery obtained by training. In conclusion, the practice of a long-term chronic physical training protocol may be considered an important assistant in the treatment of diabetes, mitigating the occurrence of possible damages to liver tissue. © 2011 Elsevier Ltd.

Improving synthetic aperture image by image compounding in beamforming process

In this work, signal processing techniques are used to improve the quality of image based on multi-element synthetic aperture techniques. Using several apodization functions to obtain different side lobes distribution, a polarity function and a threshold criterium are used to develop an image compounding technique. The spatial diversity is increased using an additional array, which generates complementary information about the defects, improving the results of the proposed algorithm and producing high resolution and contrast images. The inspection of isotropic plate-like structures using linear arrays and Lamb waves is presented. Experimental results are shown for a 1-mm-thick isotropic aluminum plate with artificial defects using linear arrays formed by 30 piezoelectric elements, with the low dispersion symmetric mode S0 at the frequency of 330 kHz. © 2011 American Institute of Physics.

Influence of enclosure size on growth of breast and leg muscle fibers in domestic fowl

This experiment evaluated the growth of breast and leg muscle fibers of domestic fowl raised in two enclosure sizes (SE: Small Enclosure, 1.125 m2/10 birds; LE: Large Enclosure, 5.25 m2/10 birds). In breast muscles, the number of fibers per area decreased over time and higher values were observed in broilers housed in SE compared to LE. The fiber size increased with age and was greater in LE than SE at 56 days of age, suggesting greater hypertrophic growth of fibers in breast muscle for broilers maintained in LE. In leg muscles, the muscle cross-sectional area was greater for broilers raised in LE than SE at 56 days of age and decreased from 42 to 56 days of age in broilers raised in SE, suggesting leg muscle atrophy in these birds. The Fast Glycolytic (FG), Fast Oxidative-Glycolytic (FOG) and Slow Oxidative (SO) fibers grew until 42 days of age in both enclosure sizes. The area of FOG fibers was greater in broilers raised in LE than those in SE at 28 and 56 days of age; in LE-raised broilers, the SO area was greater at 28, 42 and 56 days of age, suggesting that the muscles of broilers housed in LE are more oxidative. The BW gain was greater for broilers raised in LE than SE, whereas BW, feed intake and feed conversion were not influenced by enclosure size. Thus, the enclosure space affected hypertrophic growth and metabolic characteristics of breast and leg muscle fibers. © Asian Network for Scientific Information, 2012.

Dispersed hydroxyapatite bioglass 45S5 composites: Comparative evaluation of the use of bovine bone and synthetic hydroxyapatite

The bovine bone and sintetic hydroxyapatite (HA) bioceramics are reference materials to employment as a bone substitute, however, their slow rate of degradation and its low rate of bioactivity index (Ib) are presented as limiting factors for application as bone graft. In contrast, the bioglass is a resorbable and osteoinductive material. the present work objective the development of composites of dispersed bovine bone or sintetic HA in silicate-phosphate bioglass, seeking to obtain a biomaterial with properties suitable for application as bone grafts. The composites were prepared by mixing between the powder components followed by sintering for 1h. Were used HA and bioglass (45S5) with particle size <240μm. The tested proportions of HA/45S5 were 20/80, 30/70 and 40/60 (wt%). The composites characterization was made employing scanning electron microscopy, Infra-Red Spectrometry and hydrolytic resistance test. The test results indicate the potential use of the materials developed for applications such as bone graft. © (2012) Trans Tech Publications, Switzerland.