1,305 research outputs found

    A knowledge based decision support system for tool changeover in CNCs

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    This paper describes an application of an adaptive planning system for automatic tool changers in flexible manufacturing systems. The conventional models of predictive control usually cannot adapt to a real time dynamic environment. The proposed adaptive control model is capable of self adjusting to changing environments. The algorithm is based on a decision logic, which is constructed by breaking up knowledge and converting them into mathematical form in order to cover all possible conditions that can exist during the implementation phase. Expert thoughts and knowledge from decision logic are stored in the decision tree, which consists of circular nodes, arcs and decision nodes. The suggested system is capable of accepting further rules, new nodes and branches to the tree when additional attributes are needed. This whole knowledge is encoded in the form of production rules and each rule represents a small chunk of knowledge relating to the given domain of tool replacement. A number of related rules collectively respond to highly useful conclusions.The system uses VP Expert development shell, contains an inference engine and, a user interface. The originality of the proposed strategy lies in that a knowledge-based expert system is developed to identify and analyze the current conditions and then readjust the output that reflects the real-time environment. Compared with the various classical models, the approach can synthesize and analyze as many variables as possible to adequately and reliably identify the real-time conditions. Simulation results demonstrate the effectiveness and practicality of this tool-change planning and control strategy

    BMP9 is a potent inducer of chondrogenesis, volumetric expansion and collagen type II accumulation in bovine auricular cartilage chondroprogenitors

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    Reconstruction of the outer ear currently requires harvesting of cartilage from the posterior of the auricle or ribs leading to pain and donor site morbidity. An alternative source for auricular reconstruction is in vitro tissue engineered cartilage using stem/progenitor cells. Several candidate cell-types have been studied with tissue-specific auricular cartilage progenitor cells (AuCPC) of particular interest. Whilst chondrogenic differentiation of competent stem cells using growth factor TGFβ1 produces cartilage this tissue is frequently fibrocartilaginous and lacks the morphological features of hyaline cartilage. Recent work has shown that growth factor BMP9 is a potent chondrogenic and morphogenetic factor for articular cartilage progenitor cells, and we hypothesised that this property extends to cartilage-derived progenitors from other tissues. In this study we show monoclonal populations of AuCPCs from immature and mature bovine cartilage cultured with BMP9 produced cartilage pellets have 3-5-fold greater surface area in sections than those grown with TGFβ1. Increased volumetric growth using BMP9 was due to greater sGAG deposition in immature pellets and significantly greater collagen accumulation in both immature and mature progenitor pellets. Polarised light microscopy and immunohistochemical analyses revealed that the organisation of collagen fibrils within pellets is an important factor in the growth of pellets. Additionally, chondrocytes in BMP9 stimulated cell pellets had larger lacunae and were more evenly dispersed throughout the extracellular matrix. Interestingly, BMP9 tended to normalise the response of immature AuCPC monoclonal cell lines to differentiation cues whereas cells exhibited more variation under TGFβ1. In conclusion, BMP9 appears to be a potent inducer of chondrogenesis and volumetric growth for AuCPCs a property that can be exploited for tissue engineering strategies for reconstructive surgery though with the caveat of negligible elastin production following 21-day treatment with either growth factor

    Compact relativistic geometries in f(R,G)f(R,G) gravity

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    One of the possible potential candidates for describing the universe's rapid expansion is modified gravity. In the framework of the modified theory of gravity f(R,G)f(R,G), the present work features the materialization of anisotropic matter, such as compact stars. Specifically, to learn more about the physical behavior of compact stars, the radial, and tangential pressures as well as the energy density of six stars namely HerX1Her X-1, SAXJ1808.43658SAXJ1808.4-3658, 4U1820304U1820-30, PSRJ16142230PSR J 1614 2230, VELAX1VELA X-1, and CenX3Cen X-3 are calculated. Herein, the modified theory of gravity f(R,G)f(R,G) is disintegrated into two parts i.e. the tanh\tanh hyperbolic f(R)f(R) model and the three different f(G)f(G) model. The study focuses on graphical analysis of compact stars wherein the stability aspects, energy conditions, and anisotropic measurements are mainly addressed. Our calculation revealed that, for the positive value of parameter n of the model f(G)f(G), all the six stars behave normally.Comment: Some changes have been made. " To appear in International Journal of Geometric Methods in Modern Physics

    Enhanced Tissue Integration During Cartilage RepairIn VitroCan Be Achieved by Inhibiting Chondrocyte Death at the Wound Edge

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    Objective: Experimental wounding of articular cartilage results in cell death at the lesion edge. The objective of this study was to investigate whether inhibition of this cell death results in enhanced integrative cartilage repair. Methods: Bovine articular cartilage discs (6mm) were incubated in media containing inhibitors of necrosis (Necrostatin-1, Nec-1) or apoptosis (Z-VAD-FMK, ZVF) before cutting a 3mm inner core. This core was left in situ to create disc/ring composites, cultured for up to 6 weeks with the inhibitors, and analyzed for cell death, sulfated glycosaminoglycan release, and tissue integration. Results: Creating the disc/ring composites resulted in a significant increase in necrosis. ZVF significantly reduced necrosis and apoptosis at the wound edge. Nec-1 reduced necrosis. Both inhibitors reduced the level of wound-induced sulfated glycosaminoglycan loss. Toluidine blue staining and electron microscopy of cartilage revealed significant integration of the wound edges in disc/ring composites treated with ZVF. Nec-1 improved integration, but to a lesser extent. Push-out testing revealed that ZVF increased adhesive strength compared to control composites. Conclusions: This study shows that treatment of articular cartilage with cell death inhibitors during wound repair increases the number of viable cells at the wound edge, prevents matrix loss, and results in a significant improvement in cartilage-cartilage integration

    Habitat use pattern and conservation status of smooth–coated otters Lutrogale perspicillata in the Upper Ganges Basin, India

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    Modelo de uso del hábitat y estado de conservación de las nutrias lisas Lutrogale perspicillata en la zona alta de la cuenca del Ganges, India Las nutrias lisas habitan en varios sistemas fluviales importantes del Asia meridional y sus necesidades medioambientales las vinculan con problemas de seguridad alimentaria e hídrica, debido a la elevada densidad de humanos. La falta de datos de referencia sobre su distribución y ecología es otra limitación notable que la especie está afrontando en la India. El presente estudio se vio impulsado por el rápido descenso de la población de nutrias en el país y se centra en estimar el estado de conservación, el modelo de uso del hábitat y las amenazas asociadas en la zona alta de la cuenca del río Ganges (Asia septentrional). Nuestros resultados contribuyen a comprender mejor las complejas interacciones ecológicas y a elaborar medidas de conservación eficaces. Junto con las preferencias de hábitat, en el estudio también se informa sobre nuevas ubicaciones en la distribución de la especie. Asimismo se ponen de relieve las deficiencias existentes en la conservación de la especie y se sugieren las zonas cuya ordenación debería ser prioritaria.Smooth–coated otters inhabit several major river systems in southern Asia, and their environmental requirements link them to food and water security issues as the region is so densely populated by humans. The lack of baseline data on their distribution and ecology is another major constraint that the species is facing in India. The present study was stimulated by the rapid decline in the otter’s population in the country and focuses on estimating the conservation status, habitat use pattern, and associated threats in the upper Ganges River Basin (N India). Our findings contribute towards a better understanding of the complex ecological interactions and the design of effective conservation measures. Coupled with the habitat preferences, the study also provides new locations in the species distribution. This paper highlights the gap areas in the conservation of the species and suggests areas that should be prioritized for management.Modelo de uso del hábitat y estado de conservación de las nutrias lisas Lutrogale perspicillata en la zona alta de la cuenca del Ganges, India Las nutrias lisas habitan en varios sistemas fluviales importantes del Asia meridional y sus necesidades medioambientales las vinculan con problemas de seguridad alimentaria e hídrica, debido a la elevada densidad de humanos. La falta de datos de referencia sobre su distribución y ecología es otra limitación notable que la especie está afrontando en la India. El presente estudio se vio impulsado por el rápido descenso de la población de nutrias en el país y se centra en estimar el estado de conservación, el modelo de uso del hábitat y las amenazas asociadas en la zona alta de la cuenca del río Ganges (Asia septentrional). Nuestros resultados contribuyen a comprender mejor las complejas interacciones ecológicas y a elaborar medidas de conservación eficaces. Junto con las preferencias de hábitat, en el estudio también se informa sobre nuevas ubicaciones en la distribución de la especie. Asimismo se ponen de relieve las deficiencias existentes en la conservación de la especie y se sugieren las zonas cuya ordenación debería ser prioritaria

    5-[(E)-(2,6-Dichloro­benzyl­idene)amino]-2-hy­droxy­benzoic acid

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    There are two geometrically different mol­ecules in the asymmetric unit of the title compound, C14H9Cl2NO3. The 5-amino-2-hy­droxy­benzoic acid units [r.m.s. deviations of 0.0323 and 0.0414 Å] and 2,6-dichloro­benzaldehyde groups [r.m.s. deviations of 0.0285 and 0.0226 Å] are roughly planar and oriented at dihedral angles of 11.69 (13) and 83.12 (6)° in the two mol­ecules. An intra­molecular O—H⋯O hydrogen bond completes an S(6) ring motif in each mol­ecule. The two mol­ecules form dimers with each other through inter­molecular O—H⋯N and C—H⋯O hydrogen bonds, completing an R 2 2(8) ring motif. The dimers are inter­linked via inter­molecular O—H⋯N and C—H⋯O hydrogen bonds, forming polymeric sheets

    Association of Physical Activity with Co-morbid Conditions in Geriatric Population

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    To find out association of physical activity with co-morbid conditions in geriatric population, a cross-sectional study was conducted in different cties of Pakistan in 2015. A total of 114 participants were inducted by non-probability convenience sampling technique. Data was collected after informed verbal consent by a validated questionnaire that is Rapid Assessment of Physical Activity (RAPA). Participants were categorized into two groups i.e. physically active and physically inactive. Data was entered and analyzed in SPSS version 20. There were 66 (57.9%) males and 48 (42.1%) females with mean age of 57.04±7.348 years. Among hypertensive individuals (n=43, 37.7%) there were 39 (90.7%) physically inactive, among individuals having angina (n=17, 14.9%) there were 15 (88.2%) physically inactive. Out of 37 (32.5%) diabetics, 35 (94.6%) were physically inactive. Among individuals suffering from arthritis (n=40, 35.1%), there were 38 (95%) physically inactive. A significant association was found between physical activity and diabetes and arthritis with p-value of 0.048 and 0.029 respectively. Physical activity is significantly associated with diabetes and arthritis in geriatric population. Adequate physical activity should be performed to reduce the risk of co-morbid conditions and improve the quality of life in geriatric population

    Three dimensional printed degradable and conductive polymer scaffolds promote chondrogenic differentiation of chondroprogenitor cells

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    Conductive polymers have been used for various biomedical applications including biosensors, tissue engineering and regenerative medicine. However, the poor processability and brittleness of these polymers hinder the fabrication of three-dimensional structures with desirable geometries. Moreover, their application in tissue engineering and regenerative medicine has been so far limited to excitable cells such as neurons and muscle cells. To enable their wider adoption in tissue engineering and regenerative medicine, new materials and formulations that overcome current limitations are required. Herein, a biodegradable conductive block copolymer, tetraaniline-b-polycaprolactone-b-tetraaniline (TPT), is synthesised and 3D printed for the first time into porous scaffolds with defined geometries. Inks are formulated by combining TPT with PCL in solutions which are then directly 3D printed to generate porous scaffolds. TPT and PCL are both biodegradable. The combination of TPT with PCL increases the flexibility of the hybrid material compared to pure TPT, which is critical for applications that need mechanical robustness of the scaffolds. The highest TPT content shows the lowest tensile failure strain. Moreover, the absorption of a cell adhesion-promoting protein (fibronectin) and chondrogenic differentiation of chondroprogenitor cells are found to be dependent on the amount of TPT in the blends. Higher content of TPT in the blends increases both fibronectin adsorption and chondrogenic differentiation, though the highest concentration of TPT in the blends is limited by its solubility in the ink. Despite the contradicting effects of TPT concentration on flexibility and chondrogenic differentiation, a concentration that strikes a balance between the two factors is still available. It is worth noting that the effect on chondrogenic differentiation is found in scaffolds without external electric stimulation. Our work demonstrates the possibility of 3D printing flexible conductive and biodegradable scaffolds and their potential use in cartilage tissue regeneration, and opens up future opportunities in using electric stimulation to control chondrogenesis in these scaffolds

    Dataset of why inclusion matters for Alzheimer's disease biomarker discovery in plasma

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    Here we present a plasma proteomics dataset that was generated to understand the importance of self-reported race for biomarker discovery in Alzheimer's disease. This dataset is related to the article “Why inclusion matters for Alzheimer's disease biomarker discovery in plasma” [1]. Plasma samples were obtained from clinically diagnosed Alzheimer's disease and cognitively normal adults of African American/Black and non-Hispanic White racial and ethnic backgrounds. Plasma was immunodepleted, digested, and isobarically tagged with commercial reagents. Tagged peptides were fractionated using high pH fractionation and resulting fractions analysed by liquid chromatography – mass spectrometry (LC-MS/MS & MS3) analysis on an Orbitrap Fusion Lumos mass spectrometer. The resulting data was processed using Proteome Discoverer to produce a list of identified proteins with corresponding tandem mass tag (TMT) intensity information
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