968 resultados para ROLLING
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Die Materialverfolgung gewinnt in der Metallindustrie immer mehr an Bedeutung:rnEs ist notwendig, dass ein Metallband im Fertigungsprozess ein festgelegtes Programm durchläuft - erst dann ist die Qualität des Endprodukts garantiert. Die bisherige Praxis besteht darin, jedem Metallband eine Nummer zuzuordnen, mit der dieses Band beschriftet wird. Bei einer tagelangen Lagerung der Bänder zwischen zwei Produktionsschritten erweist sich diese Methode als fehleranfällig: Die Beschriftungen können z.B. verloren gehen, verwechselt, falsch ausgelesen oder unleserlich werden. 2007 meldete die iba AG das Patent zur Identifikation der Metallbänder anhand ihres Dickenprofils an (Anhaus [3]) - damit kann die Identität des Metallbandes zweifelsfrei nachgewiesen werden, eine zuverlässige Materialverfolgung wurde möglich.Es stellte sich jedoch heraus, dass die messfehlerbehafteten Dickenprofile, die als lange Zeitreihen aufgefasst werden können, mit Hilfe von bisherigen Verfahren (z.B. L2-Abstandsminimierung oder Dynamic Time Warping) nicht erfolgreich verglichen werden können.Diese Arbeit stellt einen effizienten feature-basierten Algorithmus zum Vergleichrnzweier Zeitreihen vor. Er ist sowohl robust gegenüber Rauschen und Messausfällen als auch invariant gegenüber solchen Koordinatentransformationen der Zeitreihen wie Skalierung und Translation. Des Weiteren sind auch Vergleiche mit Teilzeitreihen möglich. Unser Framework zeichnet sich sowohl durch seine hohe Genauigkeit als auch durch seine hohe Geschwindigkeit aus: Mehr als 99.5% der Anfragen an unsere aus realen Profilen bestehende Testdatenbank werden richtig beantwortet. Mit mehreren hundert Zeitreihen-Vergleichen pro Sekunde ist es etwa um den Faktor 10 schneller als die auf dem Gebiet der Zeitreihenanalyse etablierten Verfahren, die jedoch nicht im Stande sind, mehr als 90% der Anfragen korrekt zu verarbeiten. Der Algorithmus hat sich als industrietauglich erwiesen. Die iba AG setzt ihn in einem weltweit einzigartigen dickenprofilbasierten Überwachungssystemrnzur Materialverfolgung ein, das in ersten Stahl- und Aluminiumwalzwerkenrnbereits erfolgreich zum Einsatz kommt.
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Dendritic cells (DCs) within the CNS are recognized to play an important role in the effector phase and propagation of the immune response in experimental autoimmune encephalomyelitis (EAE), a mouse model for multiple sclerosis. However, the mechanisms regulating DC trafficking into the CNS still need to be characterized. In this study, we show by performing intravital fluorescence videomicroscopy of the inflamed spinal cord white-matter microvasculature in SJL mice with EAE that immature, and to a lesser extent, LPS-matured, bone marrow-derived DCs efficiently interact with the CNS endothelium by rolling, capturing, and firm adhesion. Immature but not LPS-matured DCs efficiently migrated across the wall of inflamed parenchymal microvessels into the CNS. Blocking alpha4 integrins interfered with the adhesion but not the rolling or capturing of immature and LPS-matured DCs to the CNS microvascular endothelium, inhibiting their migration across the vascular wall. Functional absence of beta1 integrins but not of beta7 integrins or alpha4beta7 integrin similarly reduced the adhesion of immature DCs to the CNS microvascular endothelium, demonstrating that alpha4beta1 but not alpha4beta7 integrin mediates this step of immature DCs interaction with the inflamed blood-brain barrier during EAE. Our study shows that during EAE, especially immature DCs migrate into the CNS, where they may be crucial for the perpetuation of the CNS-targeted autoimmune response. Thus therapeutic targeting of alpha4 integrins affects DC trafficking into the CNS and may therefore lead to the resolution of the CNS autoimmune inflammation by reducing the number of CNS professional APCs.
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In the healthy individuum lymphocyte traffic into the central nervous system (CNS) is very low and tightly controlled by the highly specialized blood-brain barrier (BBB). In contrast, under inflammatory conditions of the CNS such as in multiple sclerosis or in its animal model experimental autoimmune encephalomyelitis (EAE) circulating lymphocytes and monocytes/macrophages readily cross the BBB and gain access to the CNS leading to edema, inflammation and demyelination. Interaction of circulating leukocytes with the endothelium of the blood-spinal cord and blood-brain barrier therefore is a critical step in the pathogenesis of inflammatory diseases of the CNS. Leukocyte/endothelial interactions are mediated by adhesion molecules and chemokines and their respective chemokine receptors. We have developed a novel spinal cord window preparation, which enables us to directly visualize CNS white matter microcirculation by intravital fluorescence videomicroscopy. Applying this technique of intravital fluorescence videomicroscopy we could provide direct in vivo evidence that encephalitogenic T cell blasts interact with the spinal cord white matter microvasculature without rolling and that alpha4-integrin mediates the G-protein independent capture and subsequently the G-protein dependent adhesion strengthening of T cell blasts to microvascular VCAM-1. LFA-1 was found to neither mediate the G-protein independent capture nor the G- protein dependent initial adhesion strengthening of encephalitogenic T cell blasts within spinal cord microvessel, but was rather involved in T cell extravasation across the vascular wall into the spinal cord parenchyme. Our observation that G-protein mediated signalling is required to promote adhesion strengthening of encephalitogenic T cells on BBB endothelium in vivo suggested the involvement of chemokines in this process. We found functional expression of the lymphoid chemokines CCL19/ELC and CCL21/SLC in CNS venules surrounded by inflammatory cells in brain and spinal cord sections of mice afflicted with EAE suggesting that the lymphoid chemokines CCL19 and CCL21 besides regulating lymphocyte homing to secondary lymphoid tissue might be involved in T lymphocyte migration into the immuneprivileged CNS during immunosurveillance and chronic inflammation. Here, I summarize our current knowledge on the sequence of traffic signals involved in T lymphocyte recruitment across the healthy and inflamed blood-brain and blood-spinal cord barrier based on our in vitro and in vivo investigations.
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As an important Civil Engineering material, asphalt concrete (AC) is commonly used to build road surfaces, airports, and parking lots. With traditional laboratory tests and theoretical equations, it is a challenge to fully understand such a random composite material. Based on the discrete element method (DEM), this research seeks to develop and implement computer models as research approaches for improving understandings of AC microstructure-based mechanics. In this research, three categories of approaches were developed or employed to simulate microstructures of AC materials, namely the randomly-generated models, the idealized models, and image-based models. The image-based models were recommended for accurately predicting AC performance, while the other models were recommended as research tools to obtain deep insight into the AC microstructure-based mechanics. A viscoelastic micromechanical model was developed to capture viscoelastic interactions within the AC microstructure. Four types of constitutive models were built to address the four categories of interactions within an AC specimen. Each of the constitutive models consists of three parts which represent three different interaction behaviors: a stiffness model (force-displace relation), a bonding model (shear and tensile strengths), and a slip model (frictional property). Three techniques were developed to reduce the computational time for AC viscoelastic simulations. It was found that the computational time was significantly reduced to days or hours from years or months for typical three-dimensional models. Dynamic modulus and creep stiffness tests were simulated and methodologies were developed to determine the viscoelastic parameters. It was found that the DE models could successfully predict dynamic modulus, phase angles, and creep stiffness in a wide range of frequencies, temperatures, and time spans. Mineral aggregate morphology characteristics (sphericity, orientation, and angularity) were studied to investigate their impacts on AC creep stiffness. It was found that aggregate characteristics significantly impact creep stiffness. Pavement responses and pavement-vehicle interactions were investigated by simulating pavement sections under a rolling wheel. It was found that wheel acceleration, steadily moving, and deceleration significantly impact contact forces. Additionally, summary and recommendations were provided in the last chapter and part of computer programming codes wree provided in the appendixes.
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In multiple sclerosis and in its animal model experimental autoimmune encephalomyelitis (EAE), inflammatory cells migrate across the highly specialized endothelial blood-brain barrier (BBB) and gain access to the central nervous system (CNS). It is well established that leukocyte recruitment across this vascular bed is unique due to the predominant involvement of alpha4-integrins in mediating the initial contact to as well as firm adhesion with the endothelium. In contrast, the involvement of the selectins, L-selectin, E- and P-selectin and their respective carbohydrate ligands such as P-selectin glycoprotein (PSGL)-1 in this process has been controversially discussed. Intravital microscopic analysis of immune cell interaction with superficial brain vessels demonstrates a role for E- and P-selectin and their common ligand PSGL-1 in lymphocyte rolling. However, E- and P-selectin-deficient SJL- or C57Bl/6 mice or PSGL-1-deficient C57Bl/6 mice develop EAE indistinguishable from wild-type mice. Considering these apparently discrepant observations, it needs to be discussed whether the molecular mechanisms involved in leukocyte trafficking across superficial brain vessels are irrelevant for EAE pathogenesis or whether the therapeutic efficacy of targeting alpha4-integrins in EAE is truly dependent on the inhibition of leukocyte trafficking across the BBB.
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The purpose of this paper is to investigate the occurrence and character of the vermiculite deposits approximately four miles northwest of Pony; Madison County, Montana. The deposits are situated in rolling foothills at the northern end of the Tobacco Root Mountains.
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The humanized anti-alpha(4) integrin Ab Natalizumab is an effective treatment for relapsing-remitting multiple sclerosis. Natalizumab is thought to exert its therapeutic efficacy by blocking the alpha(4) integrin-mediated binding of circulating immune cells to the blood-brain barrier (BBB). As alpha(4) integrins control other immunological processes, natalizumab may, however, execute its beneficial effects elsewhere. By means of intravital microscopy we demonstrate that natalizumab specifically inhibits the firm adhesion but not the rolling or capture of human T cells on the inflamed BBB in mice with acute experimental autoimmune encephalomyelitis (EAE). The efficiency of natalizumab to block T cell adhesion to the inflamed BBB was found to be more effective in EAE than in acute systemic TNF-alpha-induced inflammation. Our data demonstrate that alpha(4) integrin-mediated adhesion of human T cells to the inflamed BBB during EAE is efficiently blocked by natalizumab and thus provide the first direct in vivo proof of concept of this therapy in multiple sclerosis.
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Beef cow herd owners can benefit from incorporating price signals into their heifer retention decisions. Whereas a perfect forecast of calf prices over the productive life of the heifer added to the herd would be ideal, such information is not available. However, simple decision rules that incorporate current or recent prices and the knowledge that the cattle cycle likely will repeat itself can help producers improve their investment decisions. A dollar cost averaging strategy that retains the same dollar value of heifers each year and a rolling average value strategy that retains a 10-year average value of heifers out performed strategies that sought to maintain a constant herd size or a constant cash flow.
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Schwerpunkt dieser Arbeit ist die Entwicklung und der Test eines auf Consumer-Highspeedkameras basierenden Bewegungserfassungssystems. Consumer-Kameras sind flexibler einsetzbar als kommerzielle Bewegungserfassungssysteme, zugleich kostengünstiger und werden daher oft in der sportwissenschaftlichen Forschung verwendet. Durch ihren Einsatz entstehen jedoch prinzipbedingt höhere Messunsicherheiten, deren Bestimmung in der vorliegenden Arbeit ein besonderer Stellenwert eingeräumt wird. Nach einem Überblick über aktuelle Bewegungserfassungssysteme und deren Genauigkeiten folgt eine Betrachtung der Messunsicherheit aus metrologischer Perspektive. Anschließend werden die Prozesse der Bilderfassung bei digitalen Consumer-Kameras sowie die zur Modellierung des Kameraabbildungsverhaltens notwendigen Parameteridentifikationsmethoden dargestellt. Diese reichen vom häufig genutzten DLT-Verfahren über Methoden mit Verzeichnungskorrektur bis zu Bündelausgleichsverfahren. Im Anschluss werden die für die verwendeten Kameras geeigneten Methoden auf Basis funktionaler Hardwaretests ausgewählt und weitere für das Bewegungserfassungssystem notwendige Softwarekomponenten diskutiert. Dazu gehören neben der automatisierten Video- und Bildverarbeitung, spezielle Verfahren zur Korrektur von Consumer-Kamera-spezifischen Abweichungen, z.B. die Korrektur von Rolling-Shutter-Verzerrungen. Im zweiten Teil der Arbeit richtet sich der Fokus auf die Simulation der Effekte von Parameterungenauigkeiten auf die Systemgenauigkeit sowie auf die Validierung und den Test des implementierten Systems. Dabei konnte die Rekonstruktionsgenauigkeit von 11.86mm bei einer Referenzrahmenkalibration durch den Einsatz der Kalibrationsmethode mit Bündelausgleichsverfahren von Svoboda u. a. (2005) auf maximal 4.126mm (M=0.073 mm; SD=1.486 mm) reduziert werden. Diese Methode erlaubt zudem eine einfachere Kalibration größerer Messvolumen ohne aufwändige Referenzrahmen und ist daher ideal für den sportwissenschaftlichen Einsatz geeignet. Ein weiteres Ergebnis der Arbeit ist die theoretische Ableitung der Fehlerfortpflanzung für die Prozessschritte der Bewegungserfassung. In Kombination mit der entwickelten Simulationsumgebung wird damit die Grundlage für eine Prädiktion der erreichbaren Messunsicherheit bereits vor der eigentlichen Messung gelegt.
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Activated T cells use very late antigen-4/α4β1 integrin for capture, rolling on, and firm adhesion to endothelial cells, and use leukocyte function-associated antigen-1/αLβ2 integrin for subsequent crawling and extravasation. Inhibition of α4β1 is sufficient to prevent extravasation of activated T cells and is successfully used to combat autoimmune diseases, such as multiple sclerosis. Here we show that effector T cells lacking the integrin activator Kindlin-3 extravasate and induce experimental autoimmune encephalomyelitis in mice immunized with autoantigen. In sharp contrast, adoptively transferred autoreactive T cells from Kindlin-3-deficient mice fail to extravasate into the naïve CNS. Mechanistically, autoreactive Kindlin-3-null T cells extravasate when the CNS is inflamed and the brain microvasculature expresses high levels of integrin ligands. Flow chamber assays under physiological shear conditions confirmed that Kindlin-3-null effector T cells adhere to high concentrations of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1, albeit less efficiently than WT T cells. Although these arrested T cells polarize and start crawling, only few remain firmly adherent over time. Our data demonstrate that the requirement of Kindlin-3 for effector T cells to induce α4β1 and αLβ2 integrin ligand binding and stabilization of integrin-ligand bonds is critical when integrin ligand levels are low, but of less importance when integrin ligand levels are high.
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BACKGROUND AIMS Stem cells participate in vascular regeneration following critical ischemia. However, their angiogenic and remodeling properties, as well as their role in ischemia-related endothelial leukocyte activation, need to be further elucidated. Herein, we investigated the effect of bone marrow-derived mesenchymal stromal cells (BM-MSCs) in a critically ischemic murine skin flap model. METHODS Groups received either 1 × 10(5), 5 × 10(5), or 1 × 10(6) BM-MSCs or cell-free conditioned medium (CM). Controls received sodium chloride. Intravital fluorescence microscopy was performed for morphological and quantitative assessment of micro-hemodynamic parameters over 12 days. RESULTS Tortuosity and diameter of conduit-arterioles were pronounced in the MSC groups (P < 0.01), whereas vasodilation was shifted to the end arteriolar level in the CM group (P < 0.01). These effects were accompanied by angiopoietin-2 expression. Functional capillary density and red blood cell velocity were enhanced in all treatment groups (P < 0.01). Although a significant reduction of rolling and sticking leukocytes was observed in the MSC groups with a reduction of diameter in postcapillary venules (P < 0.01), animals receiving CM exhibited a leukocyte-endothelium interaction similar to controls. This correlated with leukocyte common antigen expression in tissue sections (P < 0.01) and p38 mitogen-activated protein kinase expression from tissue samples. Cytokine analysis from BM-MSC culture medium revealed a 50% reduction of pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-12, tumor necrosis factor-α, interferon-γ) and chemokines (keratinocyte chemoattractant, granulocyte colony-stimulating factor) under hypoxic conditions. DISCUSSION We demonstrated positive effects of BM-MSCs on vascular regeneration and modulation of endothelial leukocyte adhesion in critical ischemic skin. The improvements after MSC application were dose-dependent and superior to the use of CM alone.
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INTRODUCTION Pontocerebellar hypoplasia Type 2 (PCH2) is a rare autosomal recessive condition, defined on MRI by a small cerebellum and ventral pons. Clinical features are severe developmental delay, microcephaly and dyskinesia.Ninety percent carry a p.A307S mutation in the TSEN54-gene. Our aim was to describe the natural course including neurological and developmental features and other aspects of care in a homogeneous group of PCH2 patients all carrying the p.A307S mutation. PATIENTS AND METHODS Patients were recruited via the German patients' organizations. Inclusion criteria were imaging findings of PCH2 and a p.A307S mutation. Data were collected using medical reports and patient questionnaires discussed in a standardized telephone interview. RESULTS Thirty-three patients were included. When considering survival until age 11 years, 53% of children had died Weight, length and head circumference, mostly in the normal range at birth, became abnormal, especially head circumference (-5.58 SD at age 5 yrs). Neurologic symptoms: Choreathetosis was present in 88% (62% with pyramidal signs), 12% had pure spasticity. Epileptic seizures were manifest in 82%, status epilepticus in 39%. Non-epileptic dystonic attacks occurred in 33%. General symptoms: feeding difficulties were recorded in 100%, sleep disorder in 96%, apneas in 67% and recurrent infections in 52%; gastroesophageal reflux disease was diagnosed in 73%, 67% got percutaneous endoscopic gastrostomy and 36% a Nissen-fundoplication. Neurodevelopmental data: All children made progress, but on a low level: such as fixing and following with the eyes was seen in 76%, attempting to grasp objects (76%), moderate head control (73%), social smile (70%), rolling from prone to supine (58%), and sitting without support (9%). Ten percent lost achieved abilities on follow-up. The presence of prenatal symptoms did not correlate with outcome. CONCLUSION Phenotype of this genetically homogeneous group of PCH2 children was severe with reduced survival, but compatible with some developmental progress. Our data support the hypothesis of an early onset degeneration which thereafter stabilizes.
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1898 is a crucial moment in Spain’s cultural history: Losing its last Colonies Cuba and the Philippines to the USA caused an unprecedented crisis in Spanish self-understanding that set a complex process of spiritual reconstruction rolling. To rebuild Spanish cultural identity as isolated state nation without losing touch with those parts of the Colonial past that were felt as belonging to its broader cultural environment required sophisticated reflection. Cultural issues had to take over the function to bridge between national borders. Music got is own part in this recycling of the Colonial into the Hispanic.
Uterine torsion in Brown Swiss cattle: retrospective analysis from an alpine practice in Switzerland
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The incidence of uterine torsion in cattle is 0.5–1 per cent of all calvings and up to 30 per cent of all dystocia cases (Berchtold and Rüsch 1993). The unstable suspension of the bovine uterus is a predisposition cited by different authors (Pearson 1971, Schulz and others 1975, Berchtold and Rüsch 1993). Age of the cow, season and weight and sex of the calf have been inconsistently reported to be associated with uterine torsion (Distl 1991, Frazer and others 1996, Tamm 1997). Small amount of fetal fluids and a large abdomen may contribute to uterine torsion (Berchtold and Rüsch 1993). Furthermore, some authors describe a predisposition in the Brown Swiss breed (Distl 1991, Schmid 1993, Frazer and others 1996) and in cows kept in alpine regions (Schmid 1993). Uterine torsion is predominantly seen under parturition, and the degree of torsion is most often between 180° and 360°. The direction is counter-clockwise in 60–90 per cent of the cases (Pearson 1971, Berchtold and Rüsch 1993, Erteld and others 2012). Vaginal delivery is possible after manual detorsion or after rolling of the cow, whereas caesarean section has to be performed after unsuccessful detorsion or if the cervix is not dilating adequately following successful correction of the torsion (Berchtold and Rüsch 1993, Frazer and others 1996). Out of all veterinary-assisted dystocia cases, 20 per cent (Aubry and others 2008) to 30 per cent (Berchtold and Rüsch 1993) are due to uterine torsion. Many publications describe fertility variables after dystocia, but only Schönfelder and coworkers described that 40 per cent of the cows got pregnant after uterine torsion followed by caesarean section (Schönfelder and Sobiraj 2005).
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PURPOSE OF REVIEW Neutrophil extravasation from the blood into tissues is initiated by tethering and rolling of neutrophils on endothelial cells, followed by neutrophil integrin activation and shear resistant arrest, crawling, diapedesis and breaching the endothelial basement membrane harbouring pericytes. Endothelial intercellular cell adhesion molecule (ICAM)-1 and ICAM-2, in conjunction with ICAM-1 on pericytes, critically contribute to each step. In addition, epithelial ICAM-1 is involved in neutrophil migration to peri-epithelial sites. The most recent findings on the role of ICAM-1 and ICAM-2 for neutrophil migration into tissues will be reviewed here. RECENT FINDINGS Signalling via endothelial ICAM-1 and ICAM-2 contributes to stiffness of the endothelial cells at sites of chronic inflammation and junctional maturation, respectively. Endothelial ICAM-2 contributes to neutrophil crawling and initiation of paracellular diapedesis, which then proceeds independent of ICAM-2. Substantial transcellular neutrophil diapedesis across the blood-brain barrier is strictly dependent on endothelial ICAM-1 and ICAM-2. Endothelial ICAM-1 or ICAM-2 is involved in neutrophil-mediated plasma leakage. ICAM-1 on pericytes assists the final step of neutrophil extravasation. Epithelial ICAM-1 rather indirectly promotes neutrophil migration to peri-epithelial sites. SUMMARY ICAM-1 and ICAM-2 are involved in each step of neutrophil extravasation, and have redundant but also distinct functions. Analysis of the role of endothelial ICAM-1 requires simultaneous consideration of ICAM-2.