Moist turbulent Rayleigh-Benard convection with Neumann and Dirichlet boundary conditions

Turbulent Rayleigh-Benard convection with phase changes in an extended layer between two parallel impermeable planes is studied by means of three-dimensional direct numerical simulations for Rayleigh numbers between 10^4 and 1.5\times 10^7 and for Prandtl number Pr=0.7. Two different sets of boundary conditions of temperature and total water content are compared: imposed constant amplitudes which translate into Dirichlet boundary conditions for the scalar field fluctuations about the quiescent diffusive equilibrium and constant imposed flux boundary conditions that result in Neumann boundary conditions. Moist turbulent convection is in the conditionally unstable regime throughout this study for which unsaturated air parcels are stably and saturated air parcels unstably stratified. A direct comparison of both sets of boundary conditions with the same parameters requires to start the turbulence simulations out of differently saturated equilibrium states. Similar to dry Rayleigh-Benard convection the differences in the turbulent velocity fluctuations, the cloud cover and the convective buoyancy flux decrease across the layer with increasing Rayleigh number. At the highest Rayleigh numbers the system is found in a two-layer regime, a dry cloudless and stably stratified layer with low turbulence level below a fully saturated and cloudy turbulent one which equals classical Rayleigh-Benard convection layer. Both are separated by a strong inversion that gets increasingly narrower for growing Rayleigh number.Comment: 19 pages, 13 Postscript figures, Figures 10,11,12,13, in reduced qualit

Identification of subpopulations with characteristics of mesenchymal progenitor cells from human osteoarthritic cartilage using triple staining for cell surface markers

We first identified and isolated cellular subpopulations with characteristics of mesenchymal progenitor cells (MPCs) in osteoarthritic cartilage using fluorescence-activated cell sorting (FACS). Cells from osteoarthritic cartilage were enzymatically isolated and analyzed directly or after culture expansion over several passages by FACS using various combinations of surface markers that have been identified on human MPCs (CD9, CD44, CD54, CD90, CD166). Culture expanded cells combined and the subpopulation derived from initially sorted CD9(+), CD90(+), CD166(+ )cells were tested for their osteogenic, adipogenic and chondrogenic potential using established differentiation protocols. The differentiation was analyzed by immunohistochemistry and by RT-PCR for the expression of lineage related marker genes. Using FACS analysis we found that various triple combinations of CD9, CD44, CD54, CD90 and CD166 positive cells within osteoarthritic cartilage account for 2–12% of the total population. After adhesion and cultivation their relative amount was markedly higher, with levels between 24% and 48%. Culture expanded cells combined and the initially sorted CD9/CD90/CD166 triple positive subpopulation had multipotency for chondrogenic, osteogenic and adipogenic differentiation. In conclusion, human osteoarthritic cartilage contains cells with characteristics of MPCs. Their relative enrichment during in vitro cultivation and the ability of cell sorting to obtain more homogeneous populations offer interesting perspectives for future studies on the activation of regenerative processes within osteoarthritic joints

Efficient generation of neural stem cell-like cells from adult human bone marrow stromal cells

Clonogenic neural stem cells (NSCs) are self-renewing cells that maintain the capacity to differentiate into brain-specific cell types, and may also replace or repair diseased brain tissue. NSCs can be directly isolated from fetal or adult nervous tissue, or derived from embryonic stem cells. Here, we describe the efficient conversion of human adult bone marrow stromal cells (hMSC) into a neural stem cell-like population (hmNSC, for human marrow-derived NSC-like cells). These cells grow in neurosphere-like structures, express high levels of early neuroectodermal markers, such as the proneural genes NeuroD1, Neurog2, MSl1 as well as otx1 and nestin, but lose the characteristics of mesodermal stromal cells. In the presence of selected growth factors, hmNSCs can be differentiated into the three main neural phenotypes: astroglia, oligodendroglia and neurons. Clonal analysis demonstrates that individual hmNSCs are multipotent and retain the capacity to generate both glia and neurons. Our cell culture system provides a powerful tool for investigating the molecular mechanisms of neural differentiation in adult human NSCs. hmNSCs may therefore ultimately help to treat acute and chronic neurodegenerative diseases

Alternative methods for the treatment of post-menopausal troubles

[english] Menopause is described as the transition from the reproductive phase of a women to the non reproductive. Changes in hormone levels might lead to complaints and health consequences especially during peri- and postmenopause. Hormone therapy has a potential damaging health risk profile and is recommended for temporal limited therapy for acute vasomotor symptoms only.The present HTA-report aims to assess the effectiveness and the cost-effectiveness of alternative treatment methods for women with postmenopausal symptoms in Germany regarding patient relevant endpoints (reduction of symptoms and frequency of adverse events and improvement of quality of life).A systematic literature search was carried out in 33 relevant databases in September 2010. Citations were selected according to pre-defined criteria and were extracted and evaluated.In the systematic research 22 studies are identified for the effectiveness evaluation, 22 primary studies and one review.High doses of isolated genistein reduce the frequency/intensity of hot flashes while low doses of genistein show no significant effect. Intake of isoflavone extract such as genistein, daidzein, glycitein in various combinations does not have an effect on improvement of cognitive function or vaginal dryness. The effect of black cohosh and hop extract for menopausal complaints cannot be determined since results are heterogenous. The combination of isoflavone, black cohosh, monk’s pepper, valerian and vitamin E has a positive effect on menopause symptoms. Ginkgo biloba shows no significant effect on menopause symptoms and cognitive improvement beside mental flexibility. Acupuncture has a significant influence on hot flashes especially in severe cases.No final statement can be drawn regarding the effectiveness of alter­ne treatment methods due to qualitative shortcomings of included studies and a general limited availability of studies in this field. Furthermore, the generalization of the present HTA is limited due to the inclusion of only postmenopausal women.<br><br>[german] Als Wechseljahre wird der Übergang von der reproduktiven Phase der Frau zur nicht-reproduktiven beschrieben. Insbesondere in der Peri- und Postmenopause können Beschwerden aufgrund des sich veränderten Hormonspiegels auftreten. Aktuell wird die Hormontherapie wegen der mit dieser verbundenen Risiken nur noch zur kurzfristigen Behandlung akuter vasomotorischer Symptome empfohlen. Von den betroffenen Frauen werden alternative und komplementäre Heilmethoden eingesetzt.Im vorliegenden Health Technology Assessment (HTA) sollen die Effektivität und Kosteneffektivität alternativer Behandlungsmethoden von postmenopausalen Wechseljahresbeschwerden in Deutschland hinsichtlich der patientenrelevanten Endpunkte Verringerung der Symptomatik, Häufigkeit unerwünschter Ereignisse sowie Verbesserung der Lebensqualität bewertet werden. In 33 relevanten Datenbanken wird im September 2010 eine systematische Literatursuche durchgeführt. Gefundene und relevante Literaturstellen werden gemäß vorab definierter Kriterien selektiert. Die Daten der Literaturstellen werden gezielt herausgesucht, bewertet und zusammenfassend beurteilt.Aus der systematischen Recherche werden 22 Studien, davon 15 Primärstudien und ein Review zur Bewertung der Effektivität identifiziert.Hochdosiertes isoliertes Genistein reduziert die Anzahl/Schwere von Hitzewallungen, während niedrig dosiertes Genistein keinen signifikanten Effekt zeigt. Die Gabe von Isoflavonextrakten, die Genistein, Daidzein, Glycitein in unterschiedlicher Zusammensetzung enthalten, hat keinen signifikanten Einfluss auf die Verbesserung kognitiver Fähigkeiten oder vaginale Trockenheit. Traubensilberkerzen- und Hopfenextrakt führen zu unterschiedlichen Ergebnissen bezüglich der Wirksamkeit bei postmenopausalen Beschwerden, sodass keine abschließende Aussage zur Effektivität getroffen werden kann. Die Kombination von Isoflavonen, Traubensilberkerze, Mönchspfeffer, Baldrian und Vitamin E hat eine positive Wirkung auf postmenopausale Symptome. Ginkgo biloba zeigt keinen signifikanten Effekt auf postmenopausale Symptome und eine kognitive Verbesserung mit Ausnahme der mentalen Flexibilität. Akupunktur hat einen signifikanten Einfluss auf Hitzewallungen, insbesondere auf deren Schweregrad.Aufgrund der qualitativen Mängel (Concealment, Randomisierung, Fallzahlplanung) der eingeschlossenen Studien und der begrenzten Anzahl an Studien kann keine abschließende zusammenfassende Bewertung zur Wirksamkeit alternativer Heilmethoden gegeben werden. Die Verallgemeinerbarkeit des vorliegenden HTA wird durch die Beschränkung auf postmenopausale Frauen reduziert

Transplantation of Renal Allografts From Organ Donors Reactive for HCV Antibodies to HCV-Negative Recipients: Safety and Clinical Outcome

IntroductionBecause of the shortage of available organs for renal transplantation, strategies enabling the safe use of organs from donors with potential chronic infections such as hepatitis C are necessary. The aim of this study was to analyze the outcome of renal transplant donation from hepatitis C virus (HCV)-positive donors.MethodsBetween September 2002 and May 2007, 51 kidneys (34 donors) reactive for HCV antibodies were further evaluated. Six kidneys (5 donors) were transplanted to 6 recipients with known chronic HCV infection. The remaining 29 donors underwent extended virological testing. Nine donors were HCV RNA positive and thus not suitable for HCV-negative patients. Twenty donors (21 kidneys) did not have detectable HCV RNA copies and were transplanted into 21 HCV-negative recipients. Clinical outcomes focusing on safety, allograft function, and de novo HCV infection in the recipient were collected.ResultsThere were no de novo HCV infections detected in recipients who were HCV negative before transplantation. The extended virological donor screening did not have an impact on median cold ischemia time. Five-year graft survival was 75%.DiscussionOrgans from anti-HCV-reactive, nonviremic donors can be transplanted safely to HCV-negative recipients

Vermischungsvorgänge in der unteren Troposphäre über orographisch strukturiertem Gelände. Ein Beitrag zum EUROTRAC-Teilprojekt TRACT

Meteorologische und luftchemische Messungen, die während der TRACT Feldmeßkampagne im September 1992 in Südwestdeutschland, Ostfrankreich und der Nordschweiz durchgeführt wurden, zeigen einen starken Einfluß der Orographie auf die vertikale Durchmischung und den Horizontaltransport von Luftmassen in der unteren Troposphäre während Schönwetterlagen. Detaillierte Untersuchungen der konvektiven Grenzschichtentwicklung werden sowohl anhand von Meßdaten als auch mittels einfacher Modellrechnungen durchgeführt. Es werden verschiedene Parametrisierungen der Grenzschichtentwicklung diskutiert, die orographisch bedingte Advektionseffekte berücksichtigen und somit zu einer besseren Beschreibung der Grenzschichthöhe über unebenem Gelände beitragen. Über hügeligem Gelände wird der Austausch zwischen der atmosphärischen Grenzschicht und der freien Troposphäre (Handover) durch Stufen in der Grenzschichthöhe und Durchbrüche in der Grenzschichtinversion verstärkt. Regionale Windsysteme entlang der großen Täler zwischen den Gebirgen bewirken einen Transport von Luftverunreinigungen zwischen verschiedenen städtischen Ballungszentren. Diesen regionalen Luftströmungen sind thermisch induzierte Zirkulationssysteme an den Berghängen und in den Seitentälern der Gebirge überlagert, die zu einem Luftmassenaustausch zwischen den dicht besiedelten Tälern mit hohen Emissionen und den ländlichen Bergregionen führen. Es wird gezeigt, daß hierbei die nächtlichen Bergwinde zu sekundären Ozonmaxima an Talstationen führen können. Geländebeeinflußte Nebelverteilungen bewirken starke räumliche Unterschiede in den Spurengasverteilungen und in der Grenzschichthöhe und begünstigen somit das Handover an Grenzschichtstufen

ПРИНЦИПИ ПЛАНУВАННЯ ТА ОРГАНІЗАЦІЇ ІННОВАЦІЙНОЇ ДІЯЛЬНОСТІ НА ВУГІЛЬНИХ ШАХТАХ

Розглянуто особливості галузевого планування та організації виробництва як фактора, що впливає на інноваційну діяльність вугільних підприємств, напрямки планування та оцінки економічної ефективності інновацій у вугільному виробництві, питання формування звітності впровадження іннова-цій та використання результатів його аналізу. The article focuses on the peculiarities of the branch planning and organisation of manufacture as the factor, which influences the innovation activity of coal mining enterprises. The article also deals with planning and evaluation of economic efficiency of the innovations in coal industry. It also covers the issues of reporting on the introduction of innovations and applying the results of its analysis

Pervasive Communities in the Internet of People

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