bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the morphogenesis and cell proliferation in the retina of a pleuronectiform fish, the turbot psetta maxima (Pleuronectiformes: Teleostei)
Authors: Cid Patricia , Doldán María Jesús , Rodríguez María Soledad , Prego Benjamin , de Miguel Encarnación 
Published: March 2013

ABSTRACTThe morphogenesis and cell proliferation in the retina of turbot (Psetta maxima, Pleuronectiformes: Teleostei) from embryo through metamorphosis have been examined by using proliferating cell nuclear antigen (PCNA)‐immunohistochemistry and general histological procedures. In the embryonic retina, cell proliferation and spatial cell reorganization form the anlage of the pigment epithelium and neural retina. Neurogenesis begins around hatching in the temporal retina, dorsal to the optic nerve exit, and then a wave of cell differentiation spreads to the nasal retina to yield a laminated retina by the end of the prolarval turbot stage. Germinal zones in the differentiated retina persist as a rim at the retinal margin, as well as surrounding the optic fissure in premetamorphic and metamorphic turbot larvae. In these zones, progenitor cells with different morphologies show a similar spatial arrangement, which suggests that they have a similar retinogenic potential. During metamorphosis, asymmetric proliferative activity in turbot germinal zones is associated with a marked expansion of the retinal tissue. Scattered stem cells in the laminated retina, related to the lineage of rod photoreceptors, were also observed both in large premetamorphic larvae and metamorphic turbots. The proliferative activity of these cells increases considerably during metamorphosis, when rod photoreceptors become morphologically differentiated. Microsc. Res. Tech. 76:588–597, 2013. © 2013 Wiley Periodicals, Inc.
Does Low Gas Permeability of Rigid‐Shelled Gekkotan Eggs Affect Embryonic Development?
Authors: ANDREWS ROBIN M. , THOMPSON MICHAEL B. , GREENE VIRGINIA W. 
Published: March 2013

AbstractParchment‐shelled eggs are characteristic of most squamates, including the basal clades of gekkotan lizards. The majority of gekkotan lizards, however, produce rigid‐shelled eggs that are highly impermeable to gas exchange; eggs are laid in dry sites and experience a net loss of water during incubation. We tested the hypothesis that the 1,000‐fold lower rate of oxygen diffusion through the shells of rigid‐ compared to parchment‐shelled eggs imposes a physiological cost on development. To do this, we contrasted species with rigid and with parchment shells with regards to (1) rates of embryonic metabolism and (2) rates and patterns of development of the yolk sac and chorioallantois, the vascularized extra‐embryonic membranes that transport oxygen to embryonic tissues. Metabolic rates of embryos from the rigid‐shelled eggs of Gehyra variegata did not differ from those of the parchment‐shelled eggs of Oedura lesueurii. Moreover, maximum metabolic rates of gekkotans with rigid shells did not differ from those of gekkotan or scincid lizards with parchment shells. In contrast, the yolk sac covered more of the surface area of the egg at oviposition, and the chorioallantois reached its full extent earlier for the species with rigid shelled eggs (Chondrodactylus turneri, G. variegata) than for the species with parchment‐shelled eggs (Eublepharis macularius, O. lesueurii). Differences in the temporal patterns of yolk sac and chorioallantois development would thus serve to compensate for low rates of oxygen diffusion through rigid shells of gekkotans. J. Exp. Zool. 319A:259–267, 2013. © 2013 © 2013 Wiley Periodicals, Inc.
Simulation of six years of carbon fluxes for a sedge‐dominated oligotrophic minerogenic peatland in Northern Sweden using the McGill Wetland Model (MWM)
Authors: Wu Jianghua , Roulet Nigel T. , Sagerfors Jorgen , Nilsson Mats B. 
Published: March 2013

AbstractNorthern peatlands store ~30% of the global soil carbon, despite covering only 3% of the land. To understand the carbon balance of these systems and predict their response to changes in climate, robust and reliable models are needed. The McGill Wetland Model (MWM), originally developed to simulate the carbon dynamics of ombrotrophic bogs, was modified to simulate the CO2 biogeochemistry of sedge‐dominated oligotrophic minerogenic peatlands, a prominent peatland type in boreal and subarctic landscapes. Three modifications were implemented: (1) a function to describe the impact of soil moisture on the optimal gross primary production, (2) a scheme to partition the peat profile into oxic and anoxic compartments based on the “effective root depth” as a function of daily sedge net primary production, and (3) a function to describe the “fen” moss water dynamics. The modified MWM was evaluated using eddy‐covariance net ecosystem production (NEP) from Degero Stormyr in northern Sweden. The root mean square error for daily NEP was ~0.46 g C m−2 d−1, and the index of agreement was 84%. This model adequately captures the magnitude and direction of the CO2 fluxes and simulates the seasonal and inter‐annual variability reasonably well (r2 > 0.8). Sensitivity analysis confirms that specifically water table depth (WTD) and moss water content are key biogeochemical hydrology processes for the carbon biogeochemistry of a sedge‐dominated oligotrophic minerogenic peatland. An increase of WTD by 15 cm or air temperature by 3°C could decrease NEP by up to 200% and make the peatland become a source of CO2.
Satellite observations of terrestrial water storage provide early warning information about drought and fire season severity in the Amazon
Authors: Chen Yang , Velicogna Isabella , Famiglietti James S. , Randerson James T. 
Published: March 2013

AbstractFire risk in the Amazon can be predicted several months before the onset of the dry season using sea surface temperatures in the tropical north Atlantic and tropical Pacific. The lead times between ocean state and the period of maximum burning (4–11 months) may enable the development of forecasts with benefits for forest conservation, yet the underlying physical and biological mechanisms responsible for these temporal offsets are not well known. Here, we examined the hypothesis that year‐to‐year variations in soil water recharge during the wet season modify atmospheric water vapor and fire behavior during the following dry season. We tested this hypothesis by analyzing terrestrial water storage observations from the Gravity Recovery and Climate Experiment (GRACE), active fires from the Moderate Resolution Imaging Spectroradiometer (MODIS), and several other satellite and atmospheric reanalysis datasets during 2002–2011. We found that terrestrial water storage deficits preceded severe fire seasons across the southern Amazon. The most significant relationships between monthly terrestrial water storage and the sum of active fires during the dry season occurred during April–August (p < 0.02), corresponding to 1–5 month lead times before the peak month of burning (September). Analysis of other datasets provided evidence for a cascade of processes during drought events, with lower cumulative precipitation (and higher cumulative evapotranspiration) in the wet season substantially reducing terrestrial water storage, and subsequently, surface and column atmospheric water vapor. Our results suggest that terrestrial water storage observations from GRACE have the potential to improve fire season forecasts for the southern Amazon.
Positive and negative‐mode laser desorption/ionization‐mass spectrometry (LDI‐MS) for the detection of indigoids in archaeological purple
Authors: Ribechini Erika , Pérez‐Arantegui Josefina , Colombini Maria Perla 
Published: March 2013

Laser‐based ionization techniques have demonstrated to be a valuable analytical tool to study organic pigments by mass spectrometric analyses. Though laser‐based ionization techniques have identified several natural and synthetic organic dyes and pigments, they have never been used in the characterization of purple.In this work, positive and negative‐mode laser desorption/ionization mass spectrometry (LDI‐MS) was used for the first time to detect indigoids in shellfish purple. The method was used to study organic residues collected from archaeological ceramic fragments that were known to contain purple, as determined by a classical high‐performance liquid chromatography‐based procedure.LDI‐MS provides a mass spectral fingerprint of shellfish purple, and it was found to be a rapid and successful tool for the identification of purple. In addition, a comparison between positive and negative mode ionization highlighted the complementarity of the two ionization modes. On the one hand, the negative‐ion mode LDI‐MS showed a better selectivity and sensitivity to brominated molecules, such as 6,6'‐dibromoindigo, 6‐monobromoindigo, 6,6'‐dibromoindirubin, 6‐ and 6’‐monobromoindirubin, thanks to their electronegativity, and produced simpler mass spectra. On the other hand, negative‐ion mode LDI‐MS was found to have a lower sensitivity to non‐brominated compounds, such as indigo and indirubin, whose presence can be established in any case by collecting the complementary positive‐ion LDI mass spectrum. Copyright © 2013 John Wiley & Sons, Ltd.
Methods for uncertainty assessment of climate models and model predictions over East Asia
Authors: Heo Ki‐Young , Ha Kyung‐Ja , Yun Kyung‐Sook , Lee Sun‐Seon , Kim Hyung‐Jin , Wang Bin 
Published: March 2013

ABSTRACTModel performance and uncertainty have been assessed using simulations of the climate in the 20th century based on the 21 models of the Intergovernmental Panel on Climate Change's Fourth Assessment Report (IPCC AR4) and NCEP/NCAR reanalysis data. To evaluate the fidelity and reliability of the simulations of East Asian climate change, the following approaches are compared to assess the uncertainty of East Asian monsoon and climate projection in conjunction with global warming: Taylor diagrams using correlation and standard deviation of model results over East Asia (100°E–150°E, 20°N–45°N), signal‐to‐noise ratio (SNR), and principal‐mode comparison identified by empirical orthogonal function (EOF) analysis. On the basis of the Taylor diagram and SNR results, good performance models with statistically high fidelity produce higher values of warming over East Asia and an enhancement of the northwest–southeast temperature gradient between the land and ocean. This enhanced temperature gradient may strengthen the East Asian summer monsoon flow, resulting in a greater increase in precipitation along the East Asian summer rain band on the continental side of East Asia. However, the good performance models as determined by the principal‐mode comparison produce lower values of warming over the East Asia region during winter; these values are clearly different from the corresponding values obtained from the Taylor diagram and SNR approaches. These results suggest that the models that give priority to the signal associated with the first leading mode of EOF or the principal mode may predict less warming than other models. The models that predict an El Niño‐like state in response to greenhouse warming produce less warming over East Asia, corresponding to the results of the principal‐mode comparison.
Locally injection of cell sheet fragments enhances new bone formation in mandibular distraction osteogenesis: A rabbit model
Authors: Ma Dongyang , Ren Liling , Yao Hong , Tian Wenyan , Chen Fulin , Zhang Junrui , Liu Yanpu , Mao Tianqiu 
Published: March 2013

ABSTRACTEffective methods to shorten the treatment period of distraction osteogenesis (DO) are needed. To investigate whether injections of osteogenic bone marrow stromal cell (BMSC) sheet fragments could be used to facilitate new bone formation during DO, 30 rabbits underwent bilateral mandibular osteotomy and their mandibles were lengthened at a rate of 0.75 mm/12 h for 6 days after a 5‐day latency period. There were three treatment groups (n = 10 for each group): Serum‐free medium, dissociated BMSCs, and BMSC sheet fragments. A local injection was conducted with a needle directly into the distracted areas immediately after distraction. Rabbits were sacrificed for examination at 3 and 6 weeks after injection. Gross examination, radiographic evaluation, and micro‐CT scanning indicated a significant increase in bony union in the BMSC sheet fragment group, compared with the medium group and the dissociated cell group. The histomorphometric analysis showed more intensive bone formation in the sheet fragment group than the other two groups at each time point. Additionally, the peak load was significantly higher in the fragment group than those in the others. The results show that injection of BMSC sheet fragments promotes bone formation in DO and indicate a promising approach to shorten the treatment period of osteodistraction. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1082–1088, 2013
Impingement and stability of total hip arthroplasty versus femoral head resurfacing using a cadaveric robotics model
Authors: Colbrunn R.W. , Bottros J.J. , Butler R.S. , Klika A.K. , Bonner T.F. , Greeson C. , van den Bogert A.J. , Barsoum W.K. 
Published: March 2013

AbstractWe identified and compared the impingent‐free range of motion (ROM) and subluxation potential for native hip, femoral head resurfacing (FHR), and total hip arthroplasty (THA). These constructs were also compared both with and without soft tissue to elucidate the role of the soft tissue. Five fresh‐frozen bilateral hip specimens were mounted to a six‐degree of freedom robotic manipulator. Under load‐control parameters, in vivo mechanics were recreated to evaluate impingement free ROM, and the subluxation potential in two “at risk” positions for native hip, FHR, and THA. Impingement‐free ROM of the skeletonized THA was greater than FHR for the anterior subluxation position. For skeletonized posterior subluxations, stability for THA and FHR constructs were similar, while a different pattern was observed for specimens with soft tissues intact. FHR constructs were more stable than THA constructs for both anterior and posterior subluxations. When the femoral neck is intact the joint has an earlier impingement profile placing the hip at risk for subluxation. However, FHR design was shown to be more stable than THA only when soft tissues were intact. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1108–1115, 2013
Genotypic variation for potassium efficiency in wild and domesticated watermelons under ample and limited potassium supply
Authors: Fan Molin , Bie Zhilong , Xie Huiying , Zhang Fang , Zhao Shuang , Zhang Hongyan 
Published: March 2013

AbstractPotassium (K) is an important nutrient for watermelon (Citrullus lanatus Thunb. Matsum. & Nakai). However, there is little knowledge about genetic variations in K efficiency in watermelon. Sixty‐four watermelon genotypes were grown under conditions of ample (6 mM) and limited (0.1 mM) K supply in a glasshouse. Thirty‐eight wild genotypes (C. lanatus var. citroide) and 26 domesticated genotypes (C. lanatus var. lanatus) were cultivated hydroponically for 30 d. Shoot dry weight, shoot K concentration, K uptake, K‐use index (shoot dry weight / shoot K concentration), relative shoot dry weight (shoot dry weight under limited K / shoot dry weight under ample K), and relative shoot K concentration (shoot K concentration under limited K / shoot K concentration under ample K) were determined. Significant differences were observed among genotypes. The K efficiency was classified based on a medium‐efficiency interval which is equivalent to the 95% confidence interval of the mean relative shoot dry weight and relative shoot K concentration. Genotypic data above or below this interval were classified as either K‐efficient or K‐inefficient. We identified eight K‐efficient genotypes, of which four were wild types. Thus, wild watermelons can be used in breeding programs to improve the K efficiency of domesticated watermelons.
Additive Prozesskette zur Instandsetzung von Bauteilen
Authors: Bergmann André , Grosser Henrik , Graf Benjamin , Uhlmann Eckart , Rethmeier Michael , Stark Rainer 
Published: March 2013

AbstractKomplexe Bauteile ohne Fügestellen sind die Spezialität additiver Verfahren. Immer deutlicher wird der Wert dieser Technologie für den Turbomaschinenbau, etwa bei der Fertigung von Turbinenschaufeln mit inneren Kühlstrukturen. Wichtig für vorbildgetreue Turbinenkomponenten: Die Technologie ermöglicht die Fertigung von Freiformen und Hinterschnitten, von außen‐ und innenliegenden filigranen, komplexen Strukturen als Einzelteil – und das in einem einzigen Arbeitsschritt. Des Weiteren benötigen additive Verfahren keine formgebenden Werkzeuge und weisen demnach kürzere Prozessketten im Vergleich zu konventionellen Herstellungsverfahren auf. Wirtschaftliche Vorteile kommen vor allem bei kleinen Losgrößen und Bauteilabmessungen zur Geltung.In diesem Artikel werden am Beispiel einer Turbinenschaufel Schlüsseltechnologien einer additiven Prozesskette gezeigt. Zunächst erfolgt die additive Fertigung einer Turbinenschaufel mittels Selective Laser Melting (SLM). Das Verfahren ermöglicht die Integration innenliegender Kühlkanäle. An dieser Schaufel wird anschließend mittels Laser‐PulverAuftragschweißen (LPA) die Reparatur unterschiedlicher Beschädigungen demonstriert. Im nächsten Schritt der Prozesskette bietet ein optischer 3D‐Scan der Schaufel die Möglichkeit zur Qualitätskontrolle und zum Vergleich der Bauteilabmessungen mit der Sollgeometrie.
Dauerfestigkeit nach dem Laserstrahlbeschichten
Authors: Köhler Henry , Seefeld Thomas , Vollertsen Frank 
Published: March 2013

AbstractDas Laserstrahlbeschichten wird seit langem erfolgreich für eine Vielzahl von Anwendungen eingesetzt, um beispielsweise funktionale Randschichten bzw. schadhafte Ausgangsgeometrien wiederherzustellen. Einem großen Feld steht das Verfahren jedoch bis heute nicht bzw. nur sehr eingeschränkt zur Verfügung: Bauteile, die dynamischen Lasten ausgesetzt sind. Grund dafür ist, dass bisher wenige Untersuchungen systematisch nachweisen, inwiefern der Schweißprozess entsprechende Bauteileigenschaften beeinflusst.
Selective Detection of NADPH among Four Pyridine‐Nucleotide Cofactors by a Fluorescent Probe Based on Aggregation‐Induced Emission
Authors: Noguchi Takao , Dawn Arnab , Yoshihara Daisuke , Tsuchiya Youichi , Yamamoto Tatsuhiro , Shinkai Seiji 
Published: March 2013

AbstractA fluorescent sensor based on guanidinium‐tethered tetraphenylethene (TPE) has been investigated toward the differentiation of pyridine nucleotide cofactors (NAD+, NADH, NADP+, and NADPH). TPE selectively recognizes NADPH possessing the higher tetra‐anionic net‐charge, resulting in the steep “turn‐on” fluorescence increase. The comparative aggregation behaviors and fluorescence response studies of TPE on the four cofactors reveal that the critical aggregate concentration of TPE against NADPH correlates directly with the concentration threshold for the fluorescence response. These results establish that TPE can selectively differentiate NADPH over the other three cofactors by the steep aggregation‐induced fluorescence response accompanied by the high signal‐to‐background contrast.magnified image
Photoluminescent Toroids Formed by Temperature‐Driven Self‐Assembly of Rhodamine B End‐Capped Poly(N‐isopropylacrylamide)
Authors: Hsu Chih‐Yuan , Chang Shih‐Chieh , Hsu Keh‐Ying , Liu Ying‐Ling 
Published: March 2013

AbstractIn this paper, self‐assembled polymeric toroids formed by a temperature‐driven process are reported. Rhodamine B (RhB) end‐capped poly(N‐isopropylacrylamide) (PNIPAAm) demonstrating a lower critical solution temperature (LCST) is prepared. In a two‐phase system, the polymer in the aqueous phase could move to the chloroform phase on raising the temperature above its LCST. This temperature‐driven process results in the formation of polymeric toroids in the chloroform phase, and the strategy affords a new pathway to toroidal self‐assembly of polymers. Moreover, the photoluminescent behavior of the RhB end‐capped PNIPAAm species formed by the process is also studied and discussed.magnified image
Magnetoresistance of multi‐walled carbon nanotubes modified with iron
Authors: Ovsienko I. V. , Matzui L.Y. , Yatsenko I. V. , Khrapatiy S. V. , Prylutskyy Y. I. , Ritter U. , Scharff P. , Le Normand F. 
Published: March 2013

AbstractThe dependence of the magnetoresistance of iron‐doped multi‐walled carbon nanotubes (Fe‐MWCNTs) on the carbon nanotubes arrangement, the temperature, the relative orientation of the magnetic field, and the current was investigated. The findings show that the magnetoresistance of partially‐oriented Fe‐MWCNTs is due to a combination of two mechanisms: (1) the giant magnetoresistance (GMR) that takes place in layered or cluster systems consisting of magnetic and nonmagnetic materials, and (2) the anisotropic magnetoresistance which is characteristic of ferromagnetic metals. For array‐oriented Fe‐MWCNTs the dominant mechanism of magnetoresistance depends on the relative orientation of the magnetic field and current through the sample, namely it depends on the localization mechanism at the mutually perpendicular orientation of the magnetic field and current and the GMR effect in mutual parallel orientation of the magnetic field and current.
The role of band structure in electron transfer kinetics in low‐dimensional carbon
Authors: Szroeder P. , Górska A. , Tsierkezos N. , Ritter Uwe , Strupiński W. 
Published: March 2013

AbstractThe role of band structure in heterogeneous electron transfer kinetics at graphene and carbon nanotube electrodes is discussed within Gerischer‐Marcus model. Raman spectroscopy was used to estimate the averaged density of defects in anodized epitaxial graphene, single‐walled carbon nanotube mats, and multi‐walled carbon nanotube carpets. Comparison of the density of defects with cyclic voltammetry data reveals correlation between the defect induced electronic states near the Fermi level and electrochemical efficiency. Electron transfer at low dimensional carbon electrodes is additionally enhanced by layer curvature and doping. Results show that defect induced states are responsible for large dispersion of heterogeneous electron transfer rate constant at different graphitic nanocarbon electrodes.
Physical properties of C60 fullerene nanostructures
Authors: Kolyadina E. Y. , Matveeva L. A. , Neluba P. L. , Shlapatskaya V. V. 
Published: March 2013

AbstractNanoheterostructures of C60 fullerenes were obtained by thermal vacuum sublimation of a C60 fullerene powder onto non‐heated silicon, mica, quartz, and Ti6Al4V alloy substrates. The composition, structure, electronic and optical properties and the internal mechanical stresses of the heterostructures were studied by Raman spectroscopy, atomic force microscopy, electroreflectance modulation spectroscopy, light absorption spectroscopy, photoluminescence, and measurements of the heterostructure bending. The effects of the film sublimation temperature and external actions (γ‐irradiation, helium plasma) on the physical properties were studied. Mainly, the appearance of new carbon (graphite‐ and diamond‐like) phases after the decomposition of C60 molecules was observed at increased film sublimation temperature and after γ‐irradiation or helium plasma.