bluuebunny/crossref_metadata_2025_split huggingface dataset:
Querkrafttragfähigkeit von Stockschrauben und Solarbefestigern auf Dächern mit Trapezprofileindeckung
Authors: Krüger Helmut , Misiek Thomas , Ummenhofer Thomas 
Published: August 2011

AbstractPhotovoltaik‐ und Solarthermieelemente werden zur energetischen Nutzung sonnenbestrahlter Dachflächen mit unterschiedlichen Befestigungssystemen auf vorhandenen Dachoberflächen montiert. Bei der Installation auf Trapezprofilen kommen hauptsächlich Stockschrauben, Solarbefestiger und Solarkalotten zum Einsatz. Insbesondere für den rechnerischen Nachweis von Stockschrauben und Solarbefestigern sind bisher nur unzureichende Bemessungsansätze verfügbar. Im Mittelpunkt steht hierbei die Einleitung von Querlasten aus Dachschub, Wind und Schnee in die Unterkonstruktion.Die im vorliegenden Aufsatz vorgestellten Bemessungsverfahren ermöglichen die Bestimmung der Querkrafttragfähigkeit unter Beachtung des Einflusses exzentrisch eingeleiteter Druckkräfte. Dem bemessenden Ingenieur müssen hierzu die Drehfedersteifigkeit Ca der Einspannung des Verbindungsmittels in der Unterkonstruktion, die Trapezprofilsteifigkeit in Sickenrichtung Kb und das Fließmoment My,Rk des Verbindungsmittels zur Verfügung stehen. Eine konservative Abschätzung kann auch mit der Querkrafttragfähigkeit des Trapezprofils Fb und dem Fließmoment My,Rk unter Vernachlässigung der Einspannwirkung in der Unterkonstruktion erfolgen.Shear bearing capacity of hanger bolts and solar fasteners on roofs with trapezoidal profiles. For the energetic utilization of sunlit roof areas, photovoltaic and solar thermal plants are installed on the existing roof surface by means of different fastening systems. For the installation on trapezoidal profiles, hanger bolts, solar fasteners and solar calottes are primarily applied. Especially for the application of hanger bolts and solar fasteners, only insufficient design approaches are available up to now. The load bearing behavior due to effects from roof shear, wind and snow loading into the substructure is the main problem.The methods and equations presented within this article facilitate to determine the shear bearing capacity considering the influences of eccentrically induced compressive forces. For this purpose, the torsion spring stiffness Ca of the fastener in the substructure, the trapezoidal profile stiffness Kb and the yield moment My,Rk of the fastener must be provided for the user. An conservative assessment can also be realized by using the shear bearing capacity of the trapezoidal profile Fb and the yield moment My,Rk neglecting the torsion spring stiffness.
Lineage Specific Methylation of the Elf5 Promoter in Mammary Epithelial Cells
Authors: Lee Heather J. , Hinshelwood Rebecca A. , Bouras Toula , Gallego-Ortega David , Valdés-Mora Fátima , Blazek Katrina , Visvader Jane E. , Clark Susan J. , Ormandy Christopher J. 
Published: August 2011

Abstract
Recent characterization of mammary stem and progenitor cells has improved our understanding of the transcriptional network that coordinates mammary development; however, little is known about the mechanisms that enforce lineage commitment and prevent transdifferentiation in the mammary gland. The E-twenty six transcription factor Elf5 forces the differentiation of mammary luminal progenitor cells to establish the milk producing alveolar lineage. Methylation of the Elf5 promoter has been proposed to act as a lineage gatekeeper during embryonic development. We used bisulphite sequencing to investigate in detail whether Elf5 promoter methylation plays a role in lineage commitment during mammary development. An increase in Elf5 expression was associated with decreasing Elf5 promoter methylation in differentiating HC11 mammary cells. Similarly, purified mammary epithelial cells from mice had increased Elf5 expression and decreased promoter methylation during pregnancy. Finally, analysis of epithelial subpopulations revealed that the Elf5 promoter is methylated and silenced in the basal, stem cell-containing population relative to luminal cells. These results demonstrate that Elf5 promoter methylation is lineage-specific and developmentally regulated in the mammary gland in vivo, and suggest that loss of Elf5 methylation specifies the mammary luminal lineage, while continued Elf5 methylation maintains the stem cell and myoepithelial lineages.
Synthesis of One‐Dimensional Tl2O3 Nanostructures from Thermolyses of a New One‐Dimensional Thallium(I) Coordination Polymer Precursor
Authors: Mohammadi Masoomeh , Morsali Ali 
Published: August 2011

AbstractA new thallium(I) one‐dimensional coordination polymer, [Tl(2,4,6‐tcp)]n (1) (2,4,6‐tcp– = 2,4,6‐trichlorophenoxide) was synthesized and characterized by elemental analyses and IR spectroscopy. Compound 1 was structurally characterized by single‐crystal X‐ray diffraction and is a one‐dimensional coordination polymer with coordination environment of TlO3. Three different Tl2O3 nano‐structures were prepared by direct calcination, thermal decomposition in oleic acid and sol‐gel method in poly vinyl alcohol (PVA). The nano‐materials were characterized by scanning electron microscopy, X‐ray powder diffraction (XRD), and IR spectroscopy. This study demonstrates the coordination polymers may be suitable precursors for the preparation of nanoscale materials with difference and interesting morphologies.
Ce2[CrN3]: Single Phase Synthesis and Characterization of a Nitridochromate(I)
Authors: Bräunling Daniel , Niewa Rainer 
Published: August 2011

AbstractThe ternary nitridochromate Ce2[CrN3] (orthorhombic Immm, a = 378.56(1) pm, b = 340.88(2) pm, c = 1251.27(4) pm) was synthesized in single phase form from the binary nitrides utilizing the decomposition of CrN to Cr2N. Magnetic susceptibility measurements as well as X‐ray absorption spectroscopy indicate a Ce4+(4f0) electronic state and in turn an oxidation state of +1 for chromium provided –3 for nitrogen.
Topological derivatives for networks of elastic strings
Authors: Leugering G. , Sokolowski J. 
Published: August 2011

AbstractWe consider linear second order differential equations on metric graphs under given boundary and nodal conditions. We are interested in the problem of changing the topology of the underlying graph in that we replace a multiple node by a subgraph or concentrate a subgraph to a single node. We wish to do so in an optimal fashion. More precisely, given a cost function we may look for its sensitivity with respect to these operations in order to find an optimal topology of the graph. Thus, in essence, we are looking for the topological gradient for linear second order problems on metric graphs.
A hyperbolic model for granular flow
Authors: Cattani A. , Colombo R.M. , Guerra G. 
Published: August 2011

AbstractWe present a model that describes the motion of some granular material sliding along a slope. During this movement, both erosion and deposition may take place, depending on the speed of the sliding material. Analytically, this model consists of a hyperbolic system of partial differential equations. In the 1D case, the resulting system of balance laws displays interesting behavior. Its convective part gives rise to a 3 × 3 globally well defined Riemann Problem, in spite of the appearance of vacuum and of the lack of strict hyperbolicity. Several numerical integrations show various features of this model.
Decay estimates for the Brinkman‐Forchheimer equations in a semi‐infinite pipe
Authors: Li Y. , Liu Y. , Luo S. , Lin C. 
Published: August 2011

AbstractIn this paper, we consider the Brinkman‐Forchheimer equations in a semi‐infinite pipe. A second order differential inequality is derived which leads to an exponential decay estimate for the energy E (z,t) defined in (3.1) under appropriate initial and boundary conditions. We also indicate how to establish the explicit bound for the total energy.
Interface delamination of bi‐material structure under time harmonic load. Cohesive behaviour of the interface
Authors: Ivanovna J. , Nikolova G. , Gambin B. 
Published: August 2011

AbstractThe interface cohesive behaviour and interface delamination in a bi‐material structure consisting of two plates and material interface with zero thickness under time harmonic load is studied. Previously, the authors studied the elasto‐brittle interface behaviour, from both sides of a crack, initially normal to the interface, when the elastic‐brittle interface debonding appeared. Now, it is again assumed that the restriction for the ratio of energy release rates of the second plate and interface allowing the occurrence of an interface cohesive delamination before the initiation of the normal crack in the second plate is satisfied. The shear lag model is adopted and applied to find the dynamic response of the considered structure, assuming the cohesive interface behaviour, accompanied before of the elastic‐brittle one. In both cases, the growth of debond length is not considered e.g. at a given loading condition the corresponding single debond length is found. The inertia forces of the already debonded interface elasto‐brittle cracks (mode II) are neglected. The appropriate contact conditions are proposed in order to fit together both elastic and cohesive solutions. The Laplace inverse transform is applied to obtain the original of cohesive debond length by the aid of the already obtained elastic value of debond length at the same loading condition. Parametric analysis of the results obtained is illustrated by examples of the modern ceramic‐metal composite on metal substrate. The influence of frequencies and amplitude fluctuations on the cohesive debond length and the interface shear stress distribution are discussed.
Linear plane wave propagation and normal transmission and reflection at discontinuity surfaces in second gradient 3D continua
Authors: dell'Isola F. , Madeo A. , Placidi L. 
Published: August 2011

AbstractWe study plane waves in second gradient solids and their reflection and transmission at plane displacement discontinuity surfaces. The needed extension of the treatment adopted to study plane wave propagation in Cauchy continua is not straightforward and is developed here. In particular, the balance of mechanical energy valid for second gradient continua is deduced. The presented results may be of interest as many boundary layer phenomena can be accounted for by second gradient models. We prove that second gradient elastic moduli may influence, in a measurable manner, how planar waves behave at discontinuity surfaces: the novel results presented here can be the basis of experimental procedures to estimate some among these moduli. We explicitly remark that reflection and transmission coefficients which we have estimated show a significant dependence on frequency, which indeed makes easier to conceive effective measurement methods.
Providers’ Perceptions and Practices Regarding BRCA1/2 Genetic Counseling and Testing in African American Women
Authors: Graves Kristi D. , Christopher Juleen , Harrison Toni Michelle , Peshkin Beth N. , Isaacs Claudine , Sheppard Vanessa B. 
Published: August 2011

AbstractWe examined healthcare providers’ perceptions of genetic counseling and testing in African American women at moderate to high‐risk of carrying a BRCA1/2 mutation. We conducted 20 in‐depth interviews with genetic counselors (n = 5), medical oncologists (n = 8), obstetrician/gynecologists (n = 2) and surgeons (n = 5). Interviews were audiotaped, transcribed and independently coded by two individuals using a content analysis approach. Seven themes emerged relevant to providers’ perceptions of African American women's use of BRCA1/2 genetic services: access factors, cultural beliefs and preferences, effects of testing, patient motivators for genetic counseling and testing, patient‐provider communication, reasons for provider referral, and reasons for patient refusal. Providers identified individual‐ and system‐level barriers to African American women's use of genetic services, including lack of follow‐up after referrals to genetic specialists and challenges to obtaining financial coverage for under‐ and uninsured high‐risk women. Results have implications for physician and patient education regarding appropriate referrals to and uptake of genetic services in at‐risk African American women.
Uneven Distribution of Ceramides, Sphingomyelins and Glycerophospholipids Between Heads and Tails of Rat Spermatozoa
Authors: Oresti Gerardo M. , Luquez Jessica M. , Furland Natalia E. , Aveldaño Marta I. 
Published: August 2011

AbstractPrevious work showed that rat germ cells and spermatozoa contain ceramides and sphingomyelins with high proportions of nonhydroxy and 2‐hydroxy (2‐OH) polyunsaturated fatty acids (PUFA) with very long chains (VLCPUFA). The aim of this study was to assess how these lipids are distributed between the heads and tails of mature spermatozoa in comparison with other membrane lipid classes. In addition to quantitative differences due to the fact that these gametes have a long, voluminous tail and a minute head, several compositional dissimilarities emerged between these two regions. The total cholesterol/total phospholipid ratio, the choline/ethanolamine glycerophospholipid (ChoGpl/EtnGpl) ratio, and the proportion of plasmalogens within these two classes, were much larger in the head than in the tail. Whereas EtnGpl was rich in 22:5n‐6 in both regions, ChoGpl had plenty of 22:4n‐9, especially in the heads. An important proportion of the head EtnGpl‐ 22:5n‐6 and ChoGpl 22:4n‐9 was in plasmenyl‐ (rather than in phosphatidyl‐) subclasses. The heads concentrated all of the sphingomyelin species with nonhydroxy‐ and 2‐OH VLCPUFA, and the tails most of the saturated fatty acids that are present in total sperm sphingomyelin. Unexpectedly, virtually all of the abundant spermatozoal ceramides, predominantly made up by species with 2‐OH VLCPUFA, was located in the tail. The fact that intact rat spermatozoa constitutively have much more VLCPUFA‐containing ceramide than sphingomyelin is explained by the present findings, since the former are mostly lipids of the large tail while the latter mostly collect in the small head.
Perialveolar bacterial microbiota and bacteraemia after dental alveolitis in adult rats that had been subjected to neonatal malnutrition
Authors: Gonçalves de Araújo Flávia Regina , Machado Barbosa de Castro Célia Maria , Advíncula Rocha Judith , Sampaio Bruno , de Fátima Alves Diniz Maria , Baratella Evêncio Liriane , Ramos Montarroyos Ulisses 
Published: August 2011

The aim of the present study was to analyse the bacteriological factors during the process of dental alveolitis, relating it to a higher incidence of bacteraemia in adult rats subjected to neonatal malnutrition. We used forty male Wistar rats, suckled by mothers fed a diet during lactation containing 17 % protein in the nourished group (N) or 8 % protein in the undernourished group (UN). After weaning, the animals were given the Labina standard diet. After 90 d, these animals underwent upper right incisor extraction and induction of alveolitis. The oral microbiota was obtained using a swab and blood culture through venous blood. These procedures were performed before the extraction, 5 min after extraction, on the 21st day after alveolitis for groups N-21 and UN-21 and on the 28th day after alveolitis for groups N-28 and UN-28. Data were expressed as means and standard deviations for parametric data, and as medians and interquartile intervals for non-parametric data. Statistical significance was considered by assuming a critical level of 5 %. Before and after extraction, lower bacterial growth was observed per colony-forming unit (CFU) in the perialveolar region of the upper right incisors of undernourished animals, while the opposite was true after alveolitis, when a larger number of CFU was observed in these animals. The percentage of positive blood cultures obtained after alveolitis was greater in the undernourished animals. The present study thus demonstrated the influence of neonatal malnutrition in the perialveolar microbiota and in the development of bacteraemia after dental alveolitis.
Geomorphic evidence for ancestral drainage patterns in the Zagros Simple Folded Zone and growth of the Iranian plateau
Authors: WALKER RICHARD T. , RAMSEY LUCY A. , JACKSON JAMES 
Published: August 2011

AbstractWe describe the geomorphology of a large (~10000 km2) internally draining region within the Zagros fold-and-thrust belt of Fars province, Iran. A series of wind gaps through fold crests and a continuous line of low-slope pixels in digital elevation models indicate the presence of an older, and now abandoned, through-going river system. We suggest, from the presence of the wind gaps, that the original through-going river system was abandoned as a direct result of fold growth. At present, through-going drainage in Fars is restricted to only two major rivers, the Kul and the Mand, which bound the margins of the internally drained region. The low gradients of the Kul and the Mand rivers are similar to those in topographic profiles drawn along the course of the abandoned drainage. The Mand and Kul rivers may be defeated in the future, causing an expansion of the internally drained region, and resulting in a profound change in the distribution of sediment and surface elevations within the Zagros. The internally draining part of the Zagros resembles the Central Iranian Plateau both in its geomorphology and in the apparently slow rates of deformation within it. We speculate that the development of internally drained basins and distribution of shortening within the range may be causally linked. The geomorphology that we describe might, therefore, record a stage in the southward expansion of the non-deforming and topographically high Central Iranian Plateau.
Effects of strobilurin fungicide programmes and fertilizer nitrogen rates on winter wheat: severity ofSeptoria tritici, leaf senescence and yield
Authors: ISHIKAWA S. , HARE M. C. , KETTLEWELL P. S. 
Published: August 2011

SUMMARYFour field experiments were conducted over 3 years to study whether adding a strobilurin fungicide to a triazole fungicide programme for disease control in winter wheat had any influence, in combination with different rates of fertilizer nitrogen (N), on the severity of foliar diseases, the degree of leaf senescence and consequently on yield.Septoria triticiwas the dominant foliar disease observed in all experiments. The area under the disease progress curve (AUDPC) tended to be greater for untreated plots than those treated with fungicides; however, the performance of the programme containing a strobilurin fungicide did not always exceed that of the triazole-only programme. Fitting a quadratic equation to relationships between leaf N concentration and the proportion of leaf area covered withS. triticion a relative scale across the four experiments indicated a possibility that there could be an optimum N concentration in host plants forS. triticito develop, rather than a simple increase or decrease with a rise in plant N concentration. Plant height tended to be reduced following an application of a mixture of epoxiconazole and trifloxystrobin; however, it was not clear whether there was any association between plant height and the severity ofS. tritici. S. triticicaused a reduction in mean grain weight (MGW) in most of the experiments. It was concluded that an optimum leaf N concentration may exist forS. triticiin winter wheat.
Seasonal development and pathological changes associated with the parasitic nematodePhilometroides sanguineusin wild crucian carpCarassius carassius(L.) in England
Authors: Williams C.F. , Moravec F. , Turnbull J.F. , Ferguson H.W. 
Published: August 2011

AbstractPathological changes associated with the parasitic nematodePhilometroides sanguineus(Rudolphi, 1819) are described for the first time from observations of infections in wild crucian carpCarassius carassius(L.) in England. The damage caused byP. sanguineuswas influenced strongly by host size, parasite development and the seasonal migrations of female nematodes within host tissues. Male and unfertilized female nematodes located on the swim-bladder wall caused only minor, localized changes. In contrast, the migration of gravid female nematodes into the fins during autumn provoked an acute inflammatory response comprising neutrophils, eosinophils and lymphocytes. This was accompanied by fin distortion, swelling of the dorsal and caudal tissues, degenerative changes and localized oedema. The encapsulation of female nematodes in connective tissue throughout winter limited additional tissue damage. The emergence of gravid nematodes from the fins in spring to facilitate larval dispersal caused necrosis, hyperplasia and loss of skin integrity. This activity was again accompanied by acute inflammatory reactions. Pathological changes were more severe in crucian carp measuring less than 60 mm in length, with no signs of debilitation in larger fish. These observations suggest that any impact ofP. sanguineusis strictly seasonal and may be limited to fry. Lesions caused by this parasite, only recently recorded in Britain, may represent an additional pressure upon wild crucian carp populations already threatened by hybridization, competition and habitat loss.
The impact of political crisis on smallholder pig farmers in western Kenya, 2006–2008
Authors: Dewey Cate E. , Wohlgemut Jared M. , Levy Mike , Mutua Florence K. 
Published: August 2011

ABSTRACTFarmers and families in western Kenya have grown increasingly dependent on the pig industry as a primary resource for savings and income. The post-election crisis in 2008 had a serious impact on people living in western Kenya because the region was the stronghold of the opposition Orange Democratic Movement (ODM). The pig industry was affected in a number of ways, including an increase in the price of food and farm inputs, sale of pigs to provide food and other essentials for the family, or because of forced migration, leading to a drastic decrease in numbers of pigs. This will have a negative effect on the long-term viability of the pig industry due to decreased availability of growing, breeding and market weight animals.
‘Even if I am not here, there are so many eyes’: surveillance and state reach in Rwanda
Authors: Purdeková Andrea 
Published: August 2011

ABSTRACTBased on seven months of fieldwork research, the present article explores the nature and ‘reach’ of the state in post-genocide Rwanda, and its effects on decentralisation, participation and assertion of voice at the local level. Rwanda as a case of a ‘strong’ African state is explored through a number of lenses: the vertical structure (administrative and information apparatuses of the state); the lateral structure (multiple responsibilities, imihigo, indirect control); the spectrum of state-led ‘local’ activities; and, last but not least, the ‘counterweights’ to the state. The article suggests an increasing penetration of state in terms of surveillance as well as exactions (couched in terms of umusanzu or contribution) and control over voice at local level. Decentralisation amounts to mere ‘dispatching of control’, making central power more, not less, effective.