bluuebunny/crossref_metadata_2025_split huggingface dataset:
Patterns of foliar δ15N and their control in Eastern Asian forests
Authors: Fang Yunting , Koba Keisuke , Yoh Muneoki , Makabe Akiko , Liu Xueyan 
Published: March 2012

AbstractFoliar δ15N has been used increasingly in research on ecosystem nitrogen (N) cycling, because it can serve as an integrator of ecosystem N cycling and thus has a potential to reveal temporal and spatial patterns of N cycling as well as how the N cycle is altered by disturbances. However, the current understanding on controls of foliar δ15N is based principally on studies from America, Europe, Australia and Africa. Here we compiled data from 65 forests at 33 sites across East Asia to explore regional patterns and what controls foliar δ15N by linking it to climate, species composition, soil depth, slope position, N deposition, and soil N availability. In East Asia, foliar δ15N ranged from −7.1 to +2.7‰. Mean foliar δ15N values for tropical, subtropical and temperate forests were all −3.1‰, which was unexpected. The patterns of foliar δ15N with precipitation, temperature and altitude were not clear. The variation in foliar δ15N among species and between different slope positions appeared to be small within a given forest. The δ15N for both bulk soil N and extractable inorganic N generally increased with soil depth as expected, strengthening the idea that deep‐rooted trees may have access to15N‐enriched N. Different from the positive correlations reported across America and Europe, in East Asia we found that foliar δ15N decreased with increasing N deposition and did not relate to soil N availability. These discrepancies deserve more research to elucidate the mechanisms by which foliar δ15N is affected by ecosystem N availability at a regional scale.
Microbe‐mediated plant–soil feedback and its roles in a changing world
Authors: Miki Takeshi 
Published: March 2012

AbstractPlants affect soil conditions, which in turn alter plant growth and interspecific competition, forming plant–soil feedback (PSF) systems. PSF is a good example of bidirectional interactions between biomes and the non‐living environments, acting as a major driving force of community structure and ecosystem function. Among the major types of PSF mediated by various soil components, there are many holes in our knowledge of the interactions between PSF mediated by plant species‐specific litter and PSF mediated by soil microbes. Here I discuss the role of the functional diversity of microbial decomposers in litter‐mediated PSF and also propose new hypotheses on the role of microbial diversity in PSF mediated by pathogenic and mutualistic soil microbes. I also review how PSF interacts with human‐induced environmental change, i.e., direct drivers of change in the ecosystem (e.g. climate change and the invasion of alien species). Many authors have suggested that the impact of alien plant species on ecosystems is mediated by PSF, which also interacts with other direct drivers, such as climate change. Using a simple model of litter‐mediated PSF with microbial decomposers, I confirm that the interactions between PSF and other direct drivers affect the invasion process of alien species. The model also demonstrates that the functional diversity of microbial decomposers accelerates or decelerates the speed of the invasion depending on the environmental change scenarios. Further theoretical and empirical studies are needed to derive general predictions on how exogenous environmental change induced by human activities alters communities and ecosystems through disturbance or modification of endogenous community–ecosystem interactions, such as the functioning of PSF.
Characterization of Methacrylated Type-I Collagen as a Dynamic, Photoactive Hydrogel
Authors: Gaudet Ian D. , Shreiber David I. 
Published: March 2012

Type-I collagen is an attractive scaffold material for tissue engineering due to its ability to self-assemble into a fibrillar hydrogel, its innate support of tissue cells through bioactive adhesion sites, and its biodegradability. However, a lack of control of material properties has hampered its utility as a scaffold. We have modified collagen via the addition of methacrylate groups to create collagen methacrylamide (CMA) using a synthesis reaction that allows retention of fundamental characteristics of native collagen, including spontaneous fibrillar self-assembly and enzymatic biodegradability. This method allows for a rapid, five-fold increase in storage modulus upon irradiation with 365 nm light. Fibrillar diameter of CMA was not significantly different from native collagen. Collagenolytic degradability of uncrosslinked CMA was minimally reduced, while photocrosslinked CMA was significantly more resistant to degradation. Live/Dead staining demonstrated that a large majority (71%) of encapsulated mesenchymal stem cells remained viable 24 h after photocrosslinking, which further increased to 81% after 72 h. This material represents a novel platform for creating mechanically heterogeneous environments.
Electromigration dispersion in a capillary in the presence of electro-osmotic flow
Authors: Ghosal S. , Chen Z. 
Published: March 2012

AbstractThe differential migration of ions in an applied electric field is the basis for the separation of chemical species by capillary electrophoresis. Axial diffusion of the concentration peak limits the separation efficiency. Electromigration dispersion is observed when the concentration of sample ions is comparable to that of the background ions. Under such conditions, the local electrical conductivity is significantly altered in the sample zone making the electric field, and, therefore, the ion migration velocity, concentration dependent. The resulting nonlinear wave exhibits shock-like features and, under certain simplifying assumptions, is described by Burgers’ equation (Ghosal & Chen Bull. Math. Biol., vol. 72, 2010, p. 2047). In this paper, we consider the more general situation where the walls of the separation channel may have a non-zero zeta potential and are therefore able to sustain an electro-osmotic bulk flow. The main result is a one-dimensional nonlinear advection diffusion equation for the area averaged concentration. This homogenized equation accounts for the Taylor–Aris dispersion resulting from the variation in the electro-osmotic slip velocity along the wall. It is shown that in a certain range of parameters, the electro-osmotic flow can actually reduce the total dispersion by delaying the formation of a concentration shock. However, if the electro-osmotic flow is sufficiently high, the total dispersion is increased because of the Taylor–Aris contribution.
Tularaemia presenting as parapharyngeal abscess: case presentation
Authors: Koc S , Gürbüzler L , Yaman H , Eyibilen A , Salman N , Ekici A 
Published: March 2012

AbstractObjective:We report an extremely rare case of the oropharyngeal form of tularaemia, causing a parapharyngeal abscess.Case report:A 48-year-old woman presented with fever, sore throat, breathing difficulty and a right-sided neck swelling. This mass had previously been treated with penicillin without response, and had already been surgically drained once in another hospital. On physical examination, the tonsils were exudative and hypertrophic and the pharynx was hyperaemic. A fluctuant, 4 × 4 cm mass was seen on endoscopic examination, originating from the left parapharyngeal area and protruding towards the pyriform sinus, and partly obstructing the airway. Microagglutination test antibody titres for Francisella tularensis were positive (1/1280). The patient healed completely after definitive drainage of the abscess and antimicrobial therapy for 14 days (streptomycin, 2 × 1 g intramuscularly).Conclusion:Tularaemia should be considered in the differential diagnosis of patients presenting with tonsillopharyngitis, cervical lymphadenitis and parapharyngeal abscess who do not respond to treatment with penicillin, even if they do not live in an endemic region.
Diagnostic difficulties of plunging ranula: case series
Authors: Jain R , Morton R P , Ahmad Z 
Published: March 2012

AbstractObjectives:To evaluate common pitfalls in diagnosing complicated plunging ranula, either due to misidentification of plunging ranula or alternative pathology (i.e. false negatives or false positives, respectively).Methods:A review of cases of plunging ranula seen in Middlemore Hospital, New Zealand, was performed. Diagnostically uncertain cases were identified and reviewed, taking particular note of clinical, radiological and surgical findings.Results:From our database, 12 cases were found to have had a complicated diagnosis of plunging ranula. Ten cases were false negatives: four were treated as abscesses, four as simple cysts, one as a thyroglossal cyst and one as a cystic hygroma. Two cases were false positives: one was found to be a thyroglossal cyst and the other a lipoma.Conclusion:The diagnosis of plunging ranula is usually straightforward, with simple surgical management. Misdiagnosis can lead to recurrence of symptoms and inappropriate management, with the associated risks, complications and frustrations of surgery.
2D analysis of direct-drive shock-ignited HiPER-like target implosions with the full laser megajoule
Authors: Canaud B. , Laffite S. , Brandon V. , Temporal M. 
Published: March 2012

AbstractWe present a 2D analysis of direct-drive shock ignition for the laser Megajoule. First, a target design is chosen in the HiPER-like target family generated by scale up and down of the original HiPER target. A first analysis is done considering the 1D fuel assembly and 2D shock ignition by means of the ring at polar angle of 33°2. The intensity profile is top-hat and calculations are done for several different radii. It is shown that larger the radius, lower the minimum spike power is. In addition, the intensity in each quad can stay below 4 × 1014 W/cm2 and is considered non crucial for parametric instabilities such as two plasmons. A 2D analysis of the fuel assembly is done in a second step by considering the two rings located at 49° and 59°5 and their symmetric by the equatorial plane symmetry. It is shown that low mode asymmetries are important at the stagnation and can significantly affect the areal density obtained. Finally, full 2D calculations of shock ignition is done, using all the beams of the LMJ and show that the spike power needed for ignition and gain is increased by a factor greater than 3 regarding the power needed in perfectly isotropic fuel assembly. This increase is mainly due to high level low mode asymmetries generated during fuel assembly.
Ultrahigh acceleration of plasma by picosecond terawatt laser pulses for fast ignition of fusion
Authors: Lalousis P. , Földes I.B. , Hora H. 
Published: March 2012

AbstractA fundamental different mechanism dominates laser interaction with picosecond-terawatt pulses in contrast to the thermal-pressure processes with ns pulses. At ps-interaction, the thermal effects are mostly diminished and the nonlinear (ponderomotive) forces convert laser energy instantly with nearly 100% efficiency into the space charge neutral electron cloud, whose motion is determined by the inertia of the attached ion cloud. These facts were realized only by steps in the past and are expressed by the ultrahigh plasma acceleration, which is more than few thousand times higher than observed by any thermokinetic mechanism. The subsequent application for side-on ignition of uncompressed fusion fuel by the ultrahigh accelerated plasma blocks is studied for the first time by using the genuine two-fluid hydrodynamics. Details of the shock-like flame propagation can be evaluated for the transition to ignition conditions at velocities near 2000 km/s for solid deuterium-tritium.
Collisional effects on fast electron generation and transport in fast ignition
Authors: Sakagami H. , Okada K. , Kaseda Y. , Taguchi T. , Johzaki T. 
Published: March 2012

AbstractAs the binary collision process requires much more computation time, a statistical electron-electron collision model based on modified Langevin equation is developed to reduce it. This collision model and a simple electron-ion scattering model are installed into one-dimensional PIC code, and collisional effects on fast electron generation and transport in fast ignition are investigated. In the collisional case, initially thermal electrons are heated up to a few hundred keV due to direct energy transfer by electron-electron collision, and they are also heated up to MeV by Joule heating induced by electron-ion scattering. Thus the number of low energy component of fast electrons increase than that in the collisionless case.
Superficial changes on the Inconel 600 superalloy by picosecond Nd:YAG laser operating at 1064, 532, and 266 nm: Comparative study
Authors: Stašić J. , Gaković B. , Trtica M. , Desai T. , Volpe L. 
Published: March 2012

AbstractA comparative study of superficial changes on the superalloy Inconel 600, induced by a picosecond Nd:YAG laser operating at 1064, 532, and 266 nm, is presented. All of the laser wavelengths, as well as the used fluences of 2.5 (1064 nm), 4.3 (532 nm), and 0.6 J/cm2 (266 nm) were found to be adequate for inducing surface variations. Quite different surface features were produced depending on the laser wavelength used. The measured surface damage thresholds were 0.25, 0.13 and 0.10 J/cm2 for 1064, 532, and 266 nm, respectively. Drastic differences, in function of the wavelength used, were recorded for the crater depths, as well the appearance of hydrodynamic effects and periodic surface structures. Differences in crater depths were explained via an easier propagation of the first harmonic laser radiation (1064 nm) through the ejected material and plasma compared to a radiation at 532 and 266 nm. Finally, changes in the surface oxygen content caused by ultrashort laser pulses were considered.
Investigation of magnesium laser ablated plumes with Thomson scattering
Authors: Nedanovska E. , Nersisyan G. , Lewis C.L.S. , Riley D. 
Published: March 2012

AbstractOptical Thomson scattering has been implemented as a diagnostic of laser ablated plumes generated with second harmonic Nd:YAG laser radiation at 532 nm. Thomson scattering data with both spatial and temporal resolution has been collected, giving both electron density, and temperature distributions within the plume as a function of time. Although the spatial profiles do not match very well for simple models assuming either isothermal or isentropic expansion, consideration of the measured ablated mass indicates an isothermal expansion fits better than an isentropic expansion and indeed, at late time, the spatial profile of temperature is almost consistent with an isothermal approximation.
Population densities and conservation status of Norfolk Island forest birds
Authors: DUTSON GUY 
Published: March 2012

SummaryThree weeks of intensive surveys in Norfolk Island National Park in 2009 failed to find White-chested White-eye Zosterops albogularis and it was calculated that there was a less than 17% probability that a population of 10 birds had been overlooked. The last multi-observer record of this species was in 1978, and it is recommended that the species’ IUCN Red List status of “Critically Endangered” is tagged as “Possibly Extinct”. During these surveys, the population densities of seven bird species were calculated from 352 independent point counts. Causes of imprecision and bias were investigated, suggesting a small underestimation. Other species were recorded too infrequently, or their distributions were too biased, for analysis. The population densities of the extant endemic taxa were relatively high and suggest no current declines, and the population estimates were consistent with previous studies. This study recommends monitoring most species by point counts, or line transects if resources are limited, supplemented with specific monitoring of Tasman (Norfolk Island) Parakeet Cyanoramphus cookii, Pacific Robin Petroica multicolor, Southern Boobook Ninox novaeseelandiae and seabirds. Ongoing monitoring of these birds is needed to help inform management of the National Park and the island in general, given their small population sizes and their likely susceptibility to rat and cat predation, competition from alien species and drought.
The use and interpretation of serum retinol distributions in evaluating the public health impact of vitamin A programmes
Authors: Palmer Amanda C , West Keith P , Dalmiya Nita , Schultink Werner 
Published: March 2012

AbstractObjectiveDeveloping countries have adopted universal, high-potency vitamin A (VA) supplementation and food fortification as major strategies to control deficiency, prevent nutritional blindness and reduce child mortality. Yet questions persist regarding how best to measure impact and when to phase out supplementation. The present paper provides guidance on the use and interpretation of serum retinol (SROL) distributions as indicators of both programme impact and adequate VA intake in a population.DesignWe reviewed extant data on SROL's response to high-potency VA supplementation and VA-fortified foods in children.ResultsSupplementation virtually eliminates xerophthalmia and reduces child mortality; however, it shifts the SROL distribution only transiently (<2 months). Regular consumption of VA-fortified foods prevents xerophthalmia, lowers mortality and sustainably improves SROL distributions, from which both compliance and public health impact can be inferred.ConclusionsGiven SROL's limited responsiveness to high-potency VA supplementation, target population coverage remains the preferred performance indicator. However, periodic SROL surveys do reflect underlying dietary risk and can guide programming: low or marginal SROL distributions in areas with high supplementation coverage do not signify programme failure, but rather suggest the need to continue supplementation while working to effectively raise dietary VA intakes. We propose that a sustained rise in the SROL distribution, defined as ≤5 % prevalence of SROL < 0·70 μmol/l among vulnerable population groups in at least two consecutive surveys (≥1 year apart), be used as an indicator of stable and adequate dietary VA intake and status in a population, at which point programmes may re-evaluate the need for continued universal supplementation.
Critical Evaluation of Mouse Models Used to Study Pain and Loss of Pain Perception in Diabetic Neuropathy
Authors: Bierhaus A. , Nawroth P. 
Published: March 2012

AbstractA number of studies have addressed diabetic neuropathy (DN) in transgenic and knock out mouse models to unravel the molecular mechanisms underlying metabolic pain and loss of pain perception. However, it is difficult to compare these studies with each other or even with human DN due to experimental differences including the type of diabetes, the background strain of the respective mouse model, the methods of diabetes induction and the duration of diabetes, animal age and gender. To receive useful information for DN from genetically modified mice, it is therefore mandatory to first define the appropriate model and – if necessary – to backcross transgenic strains into the respective background to allow a reliable (and at least in part translatable to human DN) interpretation of the results.
Understanding Diabetic Polyneuropathy and Longevity: What Can We Learn from the Nematode Caenorhabditis Elegans?
Authors: Mendler M. , Schlotterer A. , Morcos M. , Nawroth P. 
Published: March 2012

AbstractPathogenesis of late diabetic complications is influenced by a complex interplay of multiple exogenous and intrinsic factors. The well characterised nematode Caenorhabditis elegans is an ideal model to study causes of diabetic polyneuropathy because of its easily accessible nervous system. A repertoire of methods allows the assessment of both morphological and functional glucotoxic damages as well as reduction of lifespan, thereby helping to examine the influence of different pathways and mechanisms on neurodegeneration. Its insulin signalling system allows to directly visualize effects of insulin on high glucose induced neuronal damage, leading to a better understanding of diabetic polyneuropathy.
Crosstalk in the Retinal Neurovascular Unit – Lessons for the Diabetic Retina
Authors: Feng Y. , Busch S. , Gretz N. , Hoffmann S. , Hammes H.-P. 
Published: March 2012

AbstractDiabetic retinopathy shares important features with neurodegenerative retinal diseases, including loss of ganglion cells and retinal thinning. The impact on vasoregression and subsequent ischemia-driven changes such as macular edema and proliferative retinopathy are not established. Studies using adult neurodegenerative animal models such as the transgenic TGR(CMV-PKD2(1/703)HA) rat imply early activation of the innate immunity system and the complement system as well as microglia playing a role in the damage of the retinal neurovascular unit.
Macrovascular Disease in Diabetes: Is the Mouse a Suitable Model?
Authors: Müller O. , Katus H. , Backs J. 
Published: March 2012

AbstractTo elucidate the pathogenesis of macrovascular disease in diabetes, animal models are widely used. Diabetic mice are of particular interest because they can be crossed to knockout mice lacking specific genes that are under consideration to contribute to diabetic vascular complications. However, the mouse is relative resistant to develop atherosclerosis. Therefore, we review some commonly used mouse models and discuss their advantages and disadvantages.
Lignin synthesis, transcriptional regulation and potential for useful modification in plants.
Authors: Bedon F. , Legay S. 
Published: March 2012

Abstract
Lignin, the second most abundant plant polymer on earth, has always been of great interest for research with regard to its biological roles and potential for useful modification. Over the last few decades, numerous studies have considerably enriched our knowledge of lignin biosynthesis. In the first part, a revision of lignin composition and synthesis is described, highlighting the key genes shown to be implicated in the lignification process occurring during secondary cell wall (SCW) formation in plants. Availability of genome sequencing data has brought about useful information concerning the different gene families of the lignin biosynthesis pathway. These data can be exploited to isolate the members that are more specific to the SCW formation process through combination of sequence homology or specific transcript-profiling techniques. This review also summarizes our current knowledge on the transcriptional regulation of lignin biosynthesis, particularly the R2R3-MYB and NAC transcription factor (TF) families. Strategies of lignin modification for the production of second-generation biofuels are also discussed.