464 research outputs found
Hyaluronan Rafts on Airway Epithelial Cells
Many cells, including murine airway epithelial cells, respond to a variety of inflammatory stimuli by synthesizing leukocyte-adhesive hyaluronan cables that remain attached to their cell surfaces. This study shows that air-liquid interface cultures of murine airway epithelial cells (AECs) also actively synthesize and release a majority of their HA onto their ciliated apical surfaces to form a heavy chain-hyaluronan (HC-HA) matrix in the absence of inflammatory stimuli. These matrices do not resemble the rope-like HA cables, but occur in distinct sheets, or rafts, that can capture and embed leukocytes from cell suspensions. The HC-HA modification involves the transfer of heavy chains from the inter-a-inhibitor (IaI) proteoglycan, which has 2 heavy chains (HC1 and HC2) on its chondroitin sulfate (CS) chain. The tranesterification transfer of HCs from CS to HA is mediated by tumor-necrosis-factor-induced-gene 6 (TSG-6), which is upregulated in inflammatory reactions. Because the AEC cultures do not have TSG-6 nor serum, which is the source of IaI, assays for HCs and TSG-6 were done and showed that AECs synthesize TSG-6 and their own heavy chain donor (pre-IaI) with a single heavy chain 3 (HC3), which is the substrate for transfer to HA to form the H3-HA rafts. This HC3 pre-IaI is also constitutively expressed by human renal proximal tubular epithelial cells. These leukocyte adhesive HC3-HA structures were also found in the bronchoalveolar lavage (BAL) of naive mice, and were observed on their apical ciliated surfaces. Thus, these leukocyte-adhesive HA rafts are now identified as HC3-HA complexes that could be part of a host defense mechanism filling some important gaps in our current understanding of murine airway epithelial biology and secretion
Hyaluronan Rafts on Airway Epithelial Cells
Many cells, including murine airway epithelial cells, respond to a variety of inflammatory stimuli by synthesizing leukocyte-adhesive hyaluronan cables that remain attached to their cell surfaces. This study shows that air-liquid interface cultures of murine airway epithelial cells (AECs) also actively synthesize and release a majority of their HA onto their ciliated apical surfaces to form a heavy chain-hyaluronan (HC-HA) matrix in the absence of inflammatory stimuli. These matrices do not resemble the rope-like HA cables, but occur in distinct sheets, or rafts, that can capture and embed leukocytes from cell suspensions. The HC-HA modification involves the transfer of heavy chains from the inter-a-inhibitor (IaI) proteoglycan, which has 2 heavy chains (HC1 and HC2) on its chondroitin sulfate (CS) chain. The tranesterification transfer of HCs from CS to HA is mediated by tumor-necrosis-factor-induced-gene 6 (TSG-6), which is upregulated in inflammatory reactions. Because the AEC cultures do not have TSG-6 nor serum, which is the source of IaI, assays for HCs and TSG-6 were done and showed that AECs synthesize TSG-6 and their own heavy chain donor (pre-IaI) with a single heavy chain 3 (HC3), which is the substrate for transfer to HA to form the H3-HA rafts. This HC3 pre-IaI is also constitutively expressed by human renal proximal tubular epithelial cells. These leukocyte adhesive HC3-HA structures were also found in the bronchoalveolar lavage (BAL) of naive mice, and were observed on their apical ciliated surfaces. Thus, these leukocyte-adhesive HA rafts are now identified as HC3-HA complexes that could be part of a host defense mechanism filling some important gaps in our current understanding of murine airway epithelial biology and secretion
variation of genetic diversity over time in local italian chicken breeds undergoing in situ conservation
ABSTRACT The aim of this study was to analyze the variation of different genetic diversity measures in 5 Italian local chicken breeds over a 4-yr period of conservation. The local breeds were Ermellinata di Rovigo, Padovana, Pepoi, Robusta Lionata, and Robusta Maculata. A total of 368 samples were chosen for the analysis among the birds hatched in the years 2002 and 2006. Genetic variation over 30 microsatellite loci was analyzed. All 30 microsatellites were polymorphic, with a total number of alleles equal to 251, a mean (±SD) of 8.367 ± 3.378 across populations and 3.233 ± 1.338 within population. After 4 yr of conservation, a loss of alleles occurred for all the microsatellites, with the exception of 4 loci. The total number of alleles and expected heterozygosity estimates significantly decreased during the 4 yr of conservation, whereas no significant differences were detected for the microsatellites polymorphism information content or for the observed heterozygosity estimates. A decrease of the inbreeding coefficient occurred for all the breeds, with the exception of Padovana and Robusta Lionata. All populations showed evidence of a persistent significant deviation from Hardy-Weinberg equilibrium caused by an excess of homozygotes, except Robusta Maculata, which reached the equilibrium in 2006. For Pepoi, Padovana, Ermellinata di Rovigo, and Robusta Maculata, molecular coancestry increased significantly (
Influence du Procede de Fabrication sur la Conformite aux Normes des Produits d’une Boyauderie Industrielle au Centre du Maroc
L'industrie de boyauderie a connu un développement prodigieux ces derniers temps au Maroc. Cette situation exige une conformité des produits de boyauderie destinés à l'exportation, étant donné que les produits de charcuterie sont souvent soumis à de multiples sources de contamination liées à la longueur et à la complexité de leur cheminement, c'est-à -dire, de l'étable à la table. Afin d'évaluer la qualité hygiénique des boyaux, des analyses microbiologiques ont été réalisées sur 7 lots différents de boyaux, à des stades différents de traitement dans une unité de boyauderie, au centre du Maroc. Les résultats montrent que tous les échantillons analysés durant les étapes de mesurage, égouttage et salage ont été conformes. Cependant, les étapes du calibrage, tubage et conditionnement ont présenté un pourcentage de non- conformité de 28,6, 42,9 et 14,3 %, respectivement. La non-conformité des échantillons analysés a été liée principalement à la présence de coliformes totaux et fécaux. Cette contamination fécal a sans doute été causée par le non-respect des règles d'hygiène au niveau des ateliers de production et/ou par les manipulateurs et pourrait être à l'origine d'un risque sanitaire. L'évaluation du microbisme bactérien a révélé que le calibrage, le tubage et le conditionnement sont des étapes critiques, dont la maîtrise est nécessaire pour assurer la conformité du produit fini. Ce qui traduit la nécessité d'instaurer un système de contrôle qualité.Mots clés : Boyaux, qualité hygiénique, analyses, risque sanitaire, conformité, Maro
Hybrid Deep Neural Network for Facial Expressions Recognition
Facial expressions are critical indicators of human emotions where recognizing facial expressions has captured the attention of many academics, and recognition of expressions in natural situations remains a challenge due to differences in head position, occlusion, and illumination. Several studies have focused on recognizing emotions from frontal images only, while in this paper wild images from the FER2013 dataset have been used to make a more generalizing model with the existence of its challenges, it is among the most difficult datasets that only got 65.5 % accuracy human-level. This paper proposed a model for recognizing facial expressions using pre-trained deep convolutional neural networks and the technique of transfer learning. this hybrid model used a combination of two pre-trained deep convolutional neural networks, training the model in multiple cases for more efficiency to categorize the facial expressions into seven classes. The results show that the best accuracy of the suggested models is 74.39%Â for the hybrid model, and 73.33% for Fine-tuned the single EfficientNetB0 model, while the highest accuracy for previous methods was 73.28%. Thus, the hybrid and single models outperform other state of art classification methods without using any additional, the hybrid and single models ranked in the first and second position among these methods. Also, The hybrid model has even outperformed the second-highest in accuracy method which used extra data. The incorrectly labeled images in the dataset unfairly reduce accuracy but our best model recognized their actual classes correctly
Effect of Harvesting Date and Variety of Date Palm on Antioxidant Capacity, Phenolic and Flavonoid Content of Date Palm (Phoenix Dactylifera)
The effect of date palm variety and harvesting date on total phenolic content, total flavonoid content, and antioxidant capacity of seven varieties of date palm fruits collected at different maturation stages obtained from date palm farms located in the Jericho area of the Jordan valley was investigated in this study. During different harvesting times (from June to September 2011), total phenolic content, total flavonoid content, and antioxidant capacity varied between 13.75-231.40 mg gallic acid equivalents (GAE), 1.72-9.6 mg catechin equivalents, and 142.0-719.3 μmol Trolox equivalents per 100 g dry weight sample for the seven varieties of date palm, respectively. Pearson correlation indicated that there is a strong significant correlation between antioxidant capacity and total phenolic content, as well as between antioxidant capacity and total flavonoid content for all date palm varieties investigated in this study. It is expected that these results will be useful to farmers particularly in their selection of harvesting time of the date palm fruits with high content of the bioactive compounds to meet the increasing demand on such healthy products.We are grateful to Beit Jala pharmaceutical company for performing HPLC analyses in their laboratories
N -butyldeoxynojirimycin reduces growth and ganglioside content of experimental mouse brain tumours
Abnormalities in glycosphingolipid (GSL) biosynthesis have been implicated in the oncogenesis and malignancy of brain tumours. GSLs comprise the gangliosides and the neutral GSLs and are major components of the cell surface glycocalyx. N -butyldeoxynojirimycin (N B-DNJ) is an imino sugar that inhibits the glucosyltransferase catalysing the first step in GSL biosynthesis. The influence of N B-DNJ was studied on the growth and ganglioside composition of two 20-methylcholanthrene-induced experimental mouse brain tumours, EPEN and CT-2A, which were grown in vitro and in vivo. N B-DNJ (200 μM) inhibited the proliferation of the EPEN and CT-2A cells by 50%, but did not reduce cell viability. The drug, administered in the diet (2400 mg kg−1) to adult syngeneic C57BL/6 mice, reduced the growth and ganglioside content of subcutaneous and intracerebral EPEN and CT-2A tumours by at least 50% compared to the untreated controls. N B-DNJ treatment also shifted the relative distribution of tumour gangliosides in accordance with the depletion of metabolic substrates. Side effects of N B-DNJ treatment were generally mild and included reductions in body and spleen weights and intestinal distension. We conclude that N B-DNJ may inhibit tumour growth through an effect on ganglioside biosynthesis and may be useful as a new chemotherapy for brain tumours. © 2001 Cancer Research Campaign http://www.bjcancer.co
Understanding the control of a vitamin B12 riboswitch
Within the life sciences switching mechanisms are pervasive at all levels, from molecules to cells and tissues. Their operation can be a key determinant of health or disease. Whilst the existence and importance of switches is widely acknowledged within the biological literature, many life scientists do not deal explicitly with the switching behaviour. Frequently, steady-state behaviour before and after switching is the primary focus. Here methods for analysis of switched systems from control engineering are applied to the modelling and analysis of a riboswitch. The model has been developed by studying the dynamics of the vitamin B12 riboswitch. The simulation results have been validated using in vivo experiments by checking the bacterial growth when using Escherichia coli and Salmonella enterica where the action of the vitamin B12 riboswitch is known to be a determinant of system behaviour. The paper first describes a simple model for the B12-riboswitch regulatory network in E. coli and applies the same analysis when changing the strain to S. enterica. Validation of the simulation results has been undertaken by linking the dynamics of the riboswitch to bacterial growth
Wind shear coefficients and energy yield for Dhahran, Saudi Arabia
Abstract This study presents calculated values of wind shear coefficients (WSE) using measured values of wind speed at 20, 30, and 40m above ground level (AGL), for Dhahran, Saudi Arabia. The study also includes the air density estimated using measured air temperature and surface pressure and effect of wind shear coefficient on energy yield from a wind farm of 60MW installed capacity developed using 40 wind turbines of 1500kW size. The data used in the determination of wind shear coefficient covered a period of almost 5 years between 4 October 1995 and 30 November 2000. The study suggests a value of 0.189 of wind shear coefficient for the calculation of wind speed at different heights if measured values are known at one height. No regular seasonal trend was observed in the values of wind shear coefficients. In case of diurnal variation, higher values were observed during nighttime and early hours of the day and comparatively smaller values during day light hours. The air density, calculated using measured temperature and pressure was found to be 1.18 kg/m3. The energy yield obtained using RetScreen software, showed that the actual wind shear coefficient presented in this paper produced around 11–12% more energy compared to that obtained using 1/7 power law. Accordingly, 2–3% higher plant capacity factors were achieved using actual sitedependent wind shear coefficient instead of 1/7th wind power law exponent for the calculation of wind speed at hub-height. r 2006 Elsevier Ltd. All rights reserved. Keywords: Wind shear coefficients; Air density; Wind power potential; Wind farm; Wind speed; Wind energ
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