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Search Results: 1 - 10 of 297994 matches for " J?rg Schmidtke "
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Transgenic Mouse Studies to Understand the Regulation, Expression and Function of the Testis-Specific Protein Y-Encoded (TSPY) Gene
Stephanie Schubert,Jrg Schmidtke
Genes , 2010, DOI: 10.3390/genes1020244
Abstract: The TSPY gene, which encodes the testis- specific protein, Y-encoded, was first discovered and characterized in humans, but orthologous genes were subsequently identified on the Y chromosome of many other placental mammals. TSPY is expressed in the testis and to a much lesser extent in the prostate gland, and it is assumed that TSPY serves function in spermatogonial proliferation and/or differentiation. It is further supposed that TSPY is involved in male infertility and exerts oncogenic effects in gonadal and prostate tumor formation. As a member of the TSPY/SET/NAP protein family, TSPY is able to bind cyclin B types, and stimulates the cyclin B1-CDK1 kinase activity, thereby accelerating the G 2/M phase transition of the cell cycle of target cells. Because the laboratory mouse carries only a nonfunctional Y-chromosomal Tspy-ps pseudogene, a knockout mouse model for functional research analyses is not a feasible approach. In the last decade, three classical transgenic mouse models have been developed to contribute to our understanding of TSPY regulation, expression and function. The different transgenic mouse approaches and their relevance for studying TSPY regulation, expression and function are discussed in this review.
Fluorescent 2,7-Dialkylamino-[1,8]-Naphthyridines: Preparation and Spectroscopic Properties
Christoph Hoock,Jrg Reichert,M. Schmidtke
Molecules , 1999, DOI: 10.3390/41000264
Abstract: Substitution of 4-methyl-[1,8]-naphthyridine in 2 and 7 position by alkylamines leads to highly fluorescent compounds. The arrangement of hydrogen donor and acceptor groups of these naphthyridines allows interactions with guanine and guanine cytosine base pairs. The described synthesis offers easy access to these small and stable fluorescent probes.
Expression of the Viral Antigen VP60 in Transgenic Potatoes and its Effect on the Nutritional Composition of Tubers  [PDF]
Heike Mikschofsky, Anja Hartmann, Pawel Janczyk, Günther M. Keil, Patricia K?nig, Horst Schirrmeier, Martin Hammer, Holger Junghans, Kerstin Schmidt, Jrg Schmidtke, Wolfgang B. Souffrant, Manfred Schwerin, Inge Broer
Food and Nutrition Sciences (FNS) , 2011, DOI: 10.4236/fns.2011.22010
Abstract: Recombinant plant-derived pharmaceuticals have been investigated for the last two decades and some products will soon be brought to market. Since veterinary pharmaceuticals seem to be the front-runners of plant-derived vaccines, we selected one model subunit vaccine, the structural capsid protein VP60 against rabbit haemorrhagic disease, and ana-lyzed the expression of three different sequences representing the vp60 open reading frame in potato plants. The gen-eration of antigenic VP60 molecules in the leaf and tuber tissue of potato was tremendously enhanced by replacing virus-derived sequences with plant-optimized codons. In order to identify potentially undesirable alterations in the composition of these genetically modified food components, we studied their nutrient composition and nutritional value in comparison to two parental conventional breeding varieties (Albatros and Desiree). The largest differences in nutrient composition were found between the two conventional breeds and between conventional Desiree and its near-isogenic genetically modified potato plant, indicating that genetic modification as well as conventional breeding can influence nutrient composition. Nevertheless, most parameters of nutritional value seemed to be more affected by conventional breeding than by genetic modification.
Observational Cohort Study of Ventricular Arrhythmia in Adults with Marfan Syndrome Caused by FBN1 Mutations
Ali Aydin, Baran A. Adsay, Sara Sheikhzadeh, Britta Keyser, Meike Rybczynski, Claudia Sondermann, Christian Detter, Daniel Steven, Peter N. Robinson, Jürgen Berger, Jrg Schmidtke, Stefan Blankenberg, Stephan Willems, Yskert von Kodolitsch, Boris A. Hoffmann
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0081281
Abstract: Background Marfan syndrome is associated with ventricular arrhythmia but risk factors including FBN1 mutation characteristics require elucidation. Methods and Results We performed an observational cohort study of 80 consecutive adults (30 men, 50 women aged 42±15 years) with Marfan syndrome caused by FBN1 mutations. We assessed ventricular arrhythmia on baseline ambulatory electrocardiography as >10 premature ventricular complexes per hour (>10 PVC/h), as ventricular couplets (Couplet), or as non-sustained ventricular tachycardia (nsVT), and during 31±18 months of follow-up as ventricular tachycardia (VT) events (VTE) such as sudden cardiac death (SCD), and sustained ventricular tachycardia (sVT). We identified >10 PVC/h in 28 (35%), Couplet/nsVT in 32 (40%), and VTE in 6 patients (8%), including 3 with SCD (4%). PVC>10/h, Couplet/nsVT, and VTE exhibited increased N-terminal pro–brain natriuretic peptide serum levels(P<.001). All arrhythmias related to increased NT-proBNP (P<.001), where PVC>10/h and Couplet/nsVT also related to increased indexed end-systolic LV diameters (P = .024 and P = .020), to moderate mitral valve regurgitation (P = .018 and P = .003), and to prolonged QTc intervals (P = .001 and P = .006), respectively. Moreover, VTE related to mutations in exons 24–32 (P = .021). Kaplan–Meier analysis corroborated an association of VTE with increased NT-proBNP (P<.001) and with mutations in exons 24–32 (P<.001). Conclusions Marfan syndrome with causative FBN1 mutations is associated with an increased risk for arrhythmia, and affected persons may require life-long monitoring. Ventricular arrhythmia on electrocardiography, signs of myocardial dysfunction and mutations in exons 24–32 may be risk factors of VTE.
Demand and Supply of Water for Agriculture: Influence of Topography and Climate in Pre-Alpine, Mesoscale Catchments  [PDF]
Jürg Fuhrer, Karsten Jasper
Natural Resources (NR) , 2012, DOI: 10.4236/nr.2012.33019
Abstract: With climate change, water may become limited for intensive agriculture even in regions presently considered “water-rich”. Information about the potential water requirement and its temporal and spatial variability can help to develop future water management plans. A case study was carried out for Switzerland with its highly complex pre-alpine topography and steep gradients in climate. The hydrological model WaSiM-ETH was used to simulate net irrigation requirement (NIR) for cropland, grassland and orchards using criteria to define irrigation periods based either on the water stress level (expressed by the ratio of actual (aET) to potential evapotranspiration ((pET) (Method 1) or on thresholds for soil water potential (Method 2). Simulations for selected catchments were carried out with a daily time step for the period 1981-2010 using a 500 × 500 m spatial resolution. Catchment-scale NIR ranged between 0 and 4.3 million m3 and 0 and 7.3 million m3 for the two methods, respectively, with no trend over the observation period in any catchment. During the heat wave in 2003, NIR increased by a factor of 1.5 to 2.3 relative to the mean, and in catchments where discharge is directly dependent on precipitation, NIR in the summer of 2003 reached the limits of river water availability. In contrast, in a region with water supply from glacier melt water, highest NIR in 2003 still remained far below total river discharge. The results show that NIR varies strongly between years and across the landscape, and even in a presently cool-temperate climate, irrigation may put pressure on regional water resources under extreme climatic conditions that may become more frequent by the end of the 21st century.
Energy-Minimizing Curve Fitting for High-Order Surface Mesh Generation  [PDF]
Karsten Bock, Jrg Stiller
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.521309
Abstract: We investigate different techniques for fitting Bézier curves to surfaces in context of high-order curvilinear mesh generation. Starting from distance-based least-squares fitting we develop an incremental algorithm, which incorporates approximations of stretch and bending energy. In the process, the algorithm reduces the energy weight in favor of accuracy, leading to an optimized set of sampling points. This energy-minimizing fitting strategy is applied to analytically defined as well as triangulated surfaces. The results confirm that the proposed method straightens and shortens the curves efficiently. Moreover the method preserves the accuracy and convergence behavior of distance-based fitting. Preliminary application to surface mesh generation shows a remarkable improvement of patch quality in high curvature regions.
Photometric Analysis of Variable Stars in NGC 299
R. J. Sanders,I. Serraj,P. C. Schmidtke,A. Udalski
Physics , 2013,
Abstract: We have analyzed OGLE-III photometry for stars in the SMC cluster NGC 299. Two eclipsing binaries and one intrinsic variable (most likely a Be star) are identified. Unlike other young SMC clusters, no low-amplitude pulsating variables are present.
"Sportstudentin beim Diskuswurf". Die Konstruktion des Frauenk rpers in der Fotografie des Nationalsozialismus "Sportstudentin beim Diskuswurf" ["Discus-throwing Female Sports Student"]. The Construction of the Female Body in National Socialism "Sportstudentin beim Diskuswurf" ["Lanzamiento de disco. Mujeres estudiantes deportistas"]. La construcción del cuerpo femenino en la fotografía nacional socialista
Adrian Schmidtke
Forum : Qualitative Social Research , 2008,
Abstract: Fotografien waren zur Zeit des Nationalsozialismus ein wesentliches Machtinstrument, welches sowohl der propagandistischen Inszenierung von Idealtypen, als auch der Lenkung der visuellen Wahrnehmung diente. Anhand von historischen Fotografien untersucht der Artikel mittels ikonografisch-ikonologischer und serieller Fotoanalysen die Genese der jeweiligen Idealtypen am Beispiel des Frauenbildes und zeigt dabei Brüche und Ambivalenzen bei der Darstellung auf. URN: urn:nbn:de:0114-fqs0802152 During the time of National Socialism, photography was an essential tool of power for conducting propagandistic ideal types as well as directing visual perception. On the basis of an iconographic-iconologic analysis of historical photographs, this article investigates the genesis of particular ideal types by taking the conception of women as an example and points out antagonisms and ambivalences in the representation and illustration of this conception. URN: urn:nbn:de:0114-fqs0802152 Durante el tiempo del nazismo, la fotografía fue una herramienta central del poder tanto para dirigir tipos ideales propagandísticos como para manejar la percepción visual. Desde un análisis iconológico e iconográfico de fotografías históricas, este artículo investiga la génesis de tipos ideales particulares al tomar la concepción de la mujer como un ejemplo y se ala antagonismos y ambivalencias en la representación e ilustración de esta concepción. URN: urn:nbn:de:0114-fqs0802152
Review: Günter Mey & Katja Mruck (Hrsg.) (2007). Grounded Theory Reader Review: Günter Mey & Katja Mruck (Eds.) (2007). Grounded Theory Reader Rese a: Günter Mey & Katja Mruck (Eds.) (2007). Grounded Theory Reader
Adrian Schmidtke
Forum : Qualitative Social Research , 2009,
Abstract: Der vorliegende Band, der zum vierzigsten Geburtstag der Grounded-Theory-Methodologie (GTM) zusammengestellt wurde, untergliedert sich in zwei Abschnitte. Der erste reflektiert die Genese und Grundpositionen der GTM und bietet Raum für die exemplarische Darstellung zentraler Kontroversen. Der zweite Abschnitt nimmt die Forschungspraxis in den Blick, wobei einzelne Problemstellungen der praktischen Arbeit mit der GTM im Mittelpunkt stehen. In der Summe ist der "Grounded Theory Reader" ein hervorragend zusammengestellter Band, der allerdings weniger für einen ersten Einblick in die GTM geeignet ist, als vielmehr einen überblick zum gegenw rtigen Stand der Dinge bietet, für den grundlegende Kenntnisse der methodologischen Pr missen und Forschungspraxis vorteilhaft sind. URN: urn:nbn:de:0114-fqs0903286 The volume was published to mark the 40th anniversary of the publication of "The Discovery of Grounded Theory." The first part describes the emergence and fundamental positions of grounded theory methodology (GTM) in methodological and theoretical terms; the second part focuses on research practices. The "Grounded Theory Reader" is an excellent compilation that doesn’t claim to be a standard textbook for newcomers to GTM. Rather, it is a reflection of the state of the art in GTM and enables insights in complex research practices. A basic understanding of GTM is recommended in order to get the most from the book. URN: urn:nbn:de:0114-fqs0903286 Este volumen fue publicado para conmemorar el 40avo aniversario de la publicación de "El descubrimiento de teoría fundamentada". La primera parte describe la emergencia y posiciones fundamentales de la metodología de teoría fundamentada (MTF) en términos metodológicos y teóricos; la segunda parte se enfoca en las prácticas de investigación. El libro titulado "Grounded Theory Reader" es una excelente compilación que no pretende ser un libro de texto estándar para quienes se inician en la MTF. Por el contrario, es una reflexión sobre el estado del arte en la MTF y facilita la comprensión en prácticas de investigación compleja. Es recomendable un entendimiento básico de la MTF para obtener más provecho de la lectura del libro. URN: urn:nbn:de:0114-fqs0903286
LDA Study of Particulate Flow in a Channel with Deformed Surface Locations and with Flow Conditioner  [PDF]
Mehdi Azimian, Hans-Jrg Bart
Open Journal of Fluid Dynamics (OJFD) , 2015, DOI: 10.4236/ojfd.2015.54035
Abstract: Hydroabrasion in particulate flows plays an important role in various industrial and natural processes. To predict the effects of particulate flow and the resulting phenomena such as erosion/abrasion in a pipeline, channel or a fitting, it is essential to characterize the effects in a simple standardized geometry. For this purpose, it is vital to initially understand the particulate flow behavior and motion in such geometries. In the present work, two series of experimental works by application of the LDA measurement technique were successfully conducted. First, the particulate flow behavior at downstream of a flow conditioner inside a channel with square cross-section was investigated. Shorter lengths for fully development of velocity profile by using the self-constructed flow conditioner were observed. Moreover, the flow at downstream of the conditioner was modeled with the CFD tool (ANSYS-CFX V. 14.57) and the simulation results were compared and validated by the LDA experimental data. Better agreement between the simulation results and experimental data was observed in the fully developed region. However, there are some deviations due to the actual pressure loss through the experimental loop and the calculated pressure loss value, which includes some assumptions for the loss coefficients. Furthermore, the particulate flow behavior and vortex generation inside the deformed locations of a channel surface were studied in detail. With the help of the Matlab program, it was possible to calculate and visualize the velocity vectors for each measured point inside the channel accurately.
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