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Distinct Boundaries (distinct + boundary)
Selected AbstractsA complex, young subduction zone imaged by three-dimensional seismic velocity, Fiordland, New ZealandGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2001Donna Eberhart-Phillips Summary The Fiordland subduction zone, where subduction developed in the late Miocene, has been imaged with P and S,P arrival-time data from 311 earthquakes in a simultaneous inversion for hypocentres and 3-D VP and VP/VS models. The three-month microearthquake survey, recorded with 24 portable seismographs, provides excellent coverage, and, since earthquakes to depths of 130 km are included, parts of the model are well-resolved to depths of 100 km. The crustal features are generally consistent with geology. The low velocity in the upper 10 km is associated with the Te Anau and Waiau basins. The Western Fiordland Orthogneiss is associated with a prominent feature from near-surface to over 40 km depth, which includes the residue from the basaltic source rocks. It is defined by high VP (7.4 km s,1 at 15 km depth) and slightly low VP/VS, and has distinct boundaries on its southern and eastern margins. Adjacent to the deepest earthquakes, there is high-velocity Pacific mantle below 80 km depth, inferred to be the mantle expression of ongoing shortening since the early Miocene. As the subducting slab moves down and northeast, it is hindered by the high-velocity body and bends to near-vertical. Bending is accommodated by distributed fracturing evidenced by high VP/VS and persistent deep earthquake activity. Buckling of the subducted plate pushes up the Western Fiordland Orthogneiss. In the transition to the Alpine fault in northern Fiordland, a prominent low-velocity crustal root is consistent with ductile thickening in combination with downwarp of the subducted plate. [source] Collagenolytic (necrobiotic) granulomas: part II , the ,red' granulomasJOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2004Jane M. Lynch The altered fibers lose their distinct boundaries and exhibit new staining patterns, becoming either more basophilic or eosinophilic. Within the area of altered collagen, there may be deposition of acellular substances such as mucin (blue) or fibrin (red), or there may be neutrophils with nuclear dust (blue), eosinophils (red), or flame figures (red). These color distinctions can be used as a simple algorithm for the diagnosis of collagenolytic granulomas, i.e. ,blue' granulomas vs. ,red' granulomas. Eight diagnoses are included within these two groupings, which are discussed in this two-part article. In the previously published first part, the clinical presentation, pathogenesis and histologic features of the ,blue' collagenolytic granulomas were discussed. These are the lesions of granuloma annulare, Wegener's granulomatosis, and rheumatoid vasculitis. In this second half of the series, the ,red' collagenolytic granulomas are discussed; these are the lesions of necrobiosis lipoidica, necrobiotic xanthogranuloma, rheumatoid nodules, Churg,Strauss syndrome, and eosinophilic cellulitis (Well's Syndrome). [source] Collagenolytic (necrobiotic) granulomas: part 1 , the ,blue' granulomasJOURNAL OF CUTANEOUS PATHOLOGY, Issue 5 2004Jane M. Lynch A collagenolytic or necrobiotic non-infectious granuloma is one in which a granulomatous infiltrate develops around a central area of altered collagen and elastic fibers. The altered fibers lose their distinct boundaries and exhibit new staining patterns, becoming either more basophilic or eosinophilic. Within the area of altered collagen, there may be deposition of acellular substances such as mucin (blue) or fibrin (red), or there may be neutrophils with nuclear dust (blue), eosinophils (red), or flame figures (red). These color distinctions can be used as a simple algorithm for the diagnosis of collagenolytic granulomas, i.e. ,blue' granulomas vs. ,red' granulomas. Eight diagnoses are included within these two groupings, which are discussed in this two-part article. In this first part, the clinical presentation, pathogenesis, and histologic features of the ,blue' collagenolytic granulomas are discussed. These are the lesions of granuloma annulare, Wegener's granulomatosis, and rheumatoid vasculitis. In the subsequent half of this two-part series, the ,red' collagenolytic granulomas will be discussed; these are the lesions of necrobiosis lipoidica, necrobiotic xanthogranuloma, rheumatoid nodules, Churg,Strauss syndrome, and eosinophilic cellulitis (Well's syndrome). [source] Generation and Characterization of Embryonic Stem-Like Cell Lines Derived from In Vitro Fertilization Buffalo (Bubalus bubalis) EmbryosREPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2010B Huang Contents In the present study, buffalo embryonic stem-like (ES-like) cell lines were successfully isolated, cultured and characterized. From a total of 92 normal buffalo embryos obtained by in vitro fertilization, 18 were morulae, 33 were blastocyst and 41 were hatched blastocyst, the inside of morulae or inner cell masses of blastocysts were isolated mechanically and cultured onto mitomocin-C-inactivated buffalo embryonic fibroblasts as feeder layers. Alkaline phosphatase (AP) of ES-like cells, as well as the specific stage embryonic antigen SSEA-1, SSEA-3, SSEA-4 and transcription factor OCT-4, was used to evaluate the characterization of the cells. The spontaneous differentiation of ES-like cells was induced by culturing on leukaemia inhibitory factor-free medium for more than 2 weeks without passage. To evaluate mark gene expression, total RNA was extracted from cells, and specific primers were used for reverse transcriptase-polymerase chain reaction (RT-PCR). After 8,10 days of culture, primary ES-like cell colonies were formed in 0% (0/18) of morulae, 24.24% (8/33) of blastocysts and 60.98% (25/41) of hatched blastocysts, respectively. The forming rate of primary ES-like cells colonies in hatched blastocyst group was significantly (p < 0.05) higher than the obtained for other groups. Two ES-like cell lines could survive to eight passages at least by using the method of mechanical dissociation, but just three passages by using the method of enzymatic dissociation. The cells formed large, multicellular colonies with distinct boundaries, exhibited many important features of ES/ES-like cells, including positive AP, SSEA-1, SSEA-3 and SSEA-4 activity. Undifferentiated buffalo ES-like cells expressed Oct-4, Nanog, Sox2 gene mRNA. In vitro differentiation experiments had demonstrated that those cells were pluripotent. [source] Coordinated regulation of dorsal bone morphogenetic protein 4 and ventral Sonic hedgehog signaling specifies the dorso-ventral polarity in the optic vesicle and governs ocular morphogenesis through fibroblast growth factor 8 upregulationDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 4 2010Takuma Kobayashi Dorsal and ventral specification in the early optic vesicle plays a crucial role in vertebrate ocular morphogenesis, and proper dorsal-ventral polarity in the optic vesicle ensures that distinct structures develop in separate domains within the eye primordium. The polarity is determined progressively during development by coordinated regulation of extraocular dorsal and ventral factors. In the present study, we cultured discrete portions of embryonic chick brains by preparing anterior cephalon, anterior dorsal cephalon and anterior ventral cephalon, and clearly demonstrate that bone morphogenetic protein 4 (BMP4) and Sonic hedgehog (Shh) constitute a dorsal-ventral signaling system together with fibroblast growth factor 8 (FGF8). BMP4 and Shh upregulate Tbx5 and Pax2, as reported previously, and at the same time Shh downregulates Tbx5, while BMP4 affects Pax2 expression to downregulate similarly. Shh induces Fgf8 expression in the ventral optic vesicle. This, in turn, determines the distinct boundary of the retinal pigmented epithelium and the neural retina by suppressing Mitf expression. The lens develops only when signals from both the dorsal and ventral regions come across together. Inverted deposition of Shh and BMP4 signals in organ-cultured optic vesicle completely re-organized ocular structures to be inverted. Based on these observations we propose a novel model in which the two signals govern the whole of ocular development when they encounter each other in the ocular morphogenic domain. [source] Application of ground-penetrating radar to determine the thickness of Pleistocene periglacial slope depositsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 6 2004Daniela Sauer Abstract Wide areas of the mountainous regions of Germany have rock covered by Pleistocene periglacial slope deposits (PPSD), formed by gelifluction during the cold periods of the ice ages in non-glaciated areas. The PPSD provide the parent material for soil development, and their physical characteristics affect several stabile soil properties. Because the PPSD play a significant ecological role, we studied the spatial distribution and properties of the PPSD in order to assess the distribution of the stabile soil properties. The high stone content of the PPSD greatly hinders augering and digging. Hence, we tested the use of ground-penetrating radar (GPR) as a potentially time-saving, non-destructive method to determine the thickness of the PPSD. In several study areas of the Rhenish Massif, GPR investigations of single soil profiles and soil transects along an exposed gas-pipeline ditch were carried out. The GPR images were compared to the actual thickness of the layers of the PPSD exposed in the profiles and the ditch. In the GPR images usually at least one distinct boundary could be identified, which occurs at the transition between the loose material and the hard rock, mostly ranging between 50 and 150,cm depth. In some cases, in which stone content changed abruptly between different layers of the PPSD, also the boundaries between these layers could be identified in the GPR image. On the other hand, in areas where remnants of the Mesozoic-Tertiary weathering mantle are preserved, the boundary between the saprolite and the overlying basal layer of the PPSD is ambiguous or not at all visible. Einsatz von Georadar zur Bestimmung der Mächtigkeit periglaziärer Lagen In den deutschen Mittelgebirgen sind die Gesteine weitflächig von periglaziären Lagen überzogen. Diese entstanden durch Gelifluktion während der Kaltzeiten in den unvergletscherten Bereichen. Sie stellen das Ausgangssubstrat der Bodenbildung dar und bestimmen eine Reihe stabiler Bodeneigenschaften. Die ökologische Bedeutung der periglaziären Lagen gab den Anlass, ihre Verbreitung und Eigenschaften zu erfassen, um daraus flächenhafte Aussagen über diese Eigenschaften abzuleiten. Da Bohrungen und Grabungen in den periglaziären Lagen häufig durch hohe Skelettgehalte erschwert werden, wurde untersucht, ob Georadar zur zeitsparenden, zerstörungsfreien Erfassung der Lagenmächtigkeiten eingesetzt werden kann. In verschiedenen Teilen des Rheinischen Schiefergebirges wurden Georadar-Messungen an Bodenprofilen sowie an Transekten entlang eines Gasleitungsgrabens durchgeführt, die jeweils mit den Mächtigkeiten der periglaziären Lagen verglichen wurden, die an der Graben- bzw. Profilwand aufgeschlossen waren. In den Radargrammen ist in der Regel mindestens eine deutliche Grenze zu erkennen. Diese tritt am Übergang vom Lockermaterial zum Festgestein auf, der in der Regel zwischen 50 und 150,cm Tiefe liegt. In einigen Fällen, in denen sich der Skelettgehalt an den Lagengrenzen abrupt stark verändert, sind auch Grenzen zwischen verschiedenen Lagen im Radargramm zu erkennen. Dagegen ist in Gebieten, in denen Reste der mesozoisch-tertiären Verwitterungsdecke im Untergrund anstehen, die Grenze zwischen der Basislage und dem Gestein im Radargramm nur diffus oder nicht ausgeprägt. [source] Seasonal Foraging Activity and Bait Preferences of Ants on Barro Colorado Island, Panama1BIOTROPICA, Issue 3 2002Daniel A. Hahn ABSTRACT A yearlong arboreal baiting survey of ants was conducted during 1983 on Barro Colorado Island, Panama. Because of a severe El Nino event, the 1983 dry season in Panama was exceptionally long and dry with a distinct boundary between the dry and wet seasons. Baits, located on tree trunks, attracted both terrestrial and arboreal ants, allowing comparisons between the two groups. Species composition at baits changed dramatically with season. Baits were primarily occupied by arboreal species during the dry season, while wet season baits were occupied mostly by terrestrial species. Arboreal and terrestrial ants differed markedly in their preferences for protein- or carbohydrate-based baits; arboreal ants preferred protein-based baits and terrestrial ants preferred carbohydrate-based baits. Foraging preference for protein suggests that protein resources were limiting for arboreal ants, particularly during the dry season, and that carbohydrate resources were limiting for terrestrial ants. Fundamental differences in arboreal and terrestrial habitats may promote the differences in foraging strategies observed during an annual cycle in a seasonal tropical forest. RESUMEN Durante el año de 1983 se realizó un estudio mirmecológico en la isla de Barro Colorado, Panamá. Debido a que el fenómeno"El Niño" fue muy severe ese año, la estacion seca fue excepcionalmente intensa y larga; además, se observó una diferencia marcada entre la estación seca y la húmeda. Se colocaron cebos en los troncos de los árboles que atrajeron hormigas terrestres y arbóreas, lo que permitió la comparación de estos dos grupos. La composición de las especies atraidas por los cebos varió notablemente de acuerdo a la temporada; durante la estación seca predominaron las especies arbóreas, mientras que en la húmeda predominaron las terrestres. Las hormigas arbóreas y las terrestres difirieron notablemente en su preferencias por cebos preparados con proteinas o carbohidratos. Las hormigas arbóreas prefirieron las proteinas, mientras que las terrestres prefirieron los carbohidratos. La inclinación por proteinas sugiere que éstas son un recurso limitante para las hormigas arbóreas, particularmente durante la estación seca; mientras que los carbohidratos lo son para las hormigas terrestres. Las diferencias fundamentales entre los ambientes arbóreo y terrestre puede promover diferencias en las estrategias de forrajeo observadas durante el ciclo anual del bosque tropical. 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