bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evening methane emission pulses from a boreal wetland correspond to convective mixing in hollows
Authors: Godwin Casey M. , McNamara Patrick J. , Markfort Corey D. 
Published: June 2013

AbstractSpatial and temporal heterogeneity of methane flux from boreal wetlands makes prediction and up‐scaling challenging, both within and among wetland systems. Drivers of methane production and emissions are also highly variable, making empirical model development difficult and leading to uncertainty in methane emissions estimates from wetlands. Previous studies have examined this problem using point‐scale (static chamber method) and ecosystem‐scale (flux tower methods) measurements, but few studies have investigated whether different processes are observed at these scales. We analyzed methane emissions from a boreal fen, measured by both techniques, using data from the Boreal Ecosystem‐Atmosphere Study. We sought to identify driving processes associated with methane emissions at two scales and explain diurnal patterns in emissions measured by the tower. The mean methane emission rates from flux chambers were greater than the daytime, daily mean rates measured by the tower, but the nighttime, daily mean emissions from the tower were often an order of magnitude greater than emissions recorded during the daytime. Thus, daytime measurements from either the tower or chambers would lead to a biased estimate of total methane emissions from the wetland. We found that the timing of nighttime emission events was coincident with the cooling and convective mixing within hollows, which occurred regularly during the growing season. We propose that diurnal thermal stratification in shallow pools traps methane by limiting turbulent transport. This methane stored during daytime heating is later released during evening cooling due to convective turbulent mixing.
Hydroclimatic assessment of water resources of low Pacific islands: evaluating sensitivity to climatic change and variability
Authors: de Freitas C. R. , Helbig M. , Matzarakis A. 
Published: June 2013

AbstractFor many of the low islands of the tropical Pacific, freshwater is a scarce resource. Water catchment areas are small and groundwater storage is a shallow fresh water lens. The high hydraulic conductivities of the coral and sand substrate means surface water is limited. Realization of the possible impact of climate change has highlighted the sensitivity of island communities to the availability of water. However, impact evaluation requires specialized data as well as appropriate sensitivity assessment methodologies. This is the second of a two part study. The first addressed the data problem by assembling and validating a suitable database. The second develops an island water balance model and applies a sensitivity assessment. Data are at a 2.5° × 2.5° latitude–longitude grid resolution for the Pacific bounded by coordinates 30°S to 30°N and 155°E to 120°W. Output is in the form of Climate Change Sensitivity Index maps that show the impact on the spatial redistribution of climate‐determined freshwater resources under various climate scenarios. The method allows for estimation of water deficits or surpluses for low islands located in any part of the study area. Areas of high sensitivity to climatic change are those that sit between margins of very wet and very dry zones. Their extent is determined by the gradients at the margins. Steep gradients define small areas of high sensitivity, whereas gentle gradients appear as large areas of high sensitivity. Adjustments to the model for differing local surface conditions on different islands can be easily made, which allows a sensitivity assessment of individual islands, even for islands with no climate station data. The approach could be a powerful tool to gain useful information on the influence of climate change on freshwater resources of low islands. Planning decision‐making is possible without knowing precisely the magnitude of climate change that might occur.
The effect of driving climate data on the simulated terrestrial carbon pools and fluxes over North America
Authors: Garnaud C. , Sushama L. , Arora V. K. 
Published: June 2013

AbstractDynamic vegetation models provide the ability to simulate terrestrial carbon pools and fluxes and a useful tool to study how these are affected by climate variability and climate change. At the continental scale, the spatial distribution of climate, in particular temperature and precipitation, strongly determines surface vegetation characteristics. Model validation exercises typically consist of driving a model with observation‐based climate data and then comparing simulated quantities with their observation‐based counterparts. However, observation‐based datasets themselves may not necessarily be consistent with each other. Here, we compare simulated terrestrial carbon pools and fluxes over North America with observation‐based estimates. Simulations are performed using the dynamic vegetation model Canadian Terrestrial Ecosystem Model (CTEM) coupled to the Canadian Land Surface Scheme (CLASS) when driven with two reanalysis‐based climate datasets. The driving ECMWF reanalysis data (ERA40) and NCEP/NCAR reanalysis I data (NCEP) show differences when compared to each other, as well as when compared to the observation‐based climate research unit (CRU) data. Most simulated carbon pools and fluxes show important differences, particularly over eastern North America, primarily due to differences in precipitation and temperature in the two reanalysis. However, despite very different gross fluxes, the model yields fairly similar estimates of the net atmosphere‐land CO2 flux when driven with the two forcing datasets. The ERA40 driven simulation produces terrestrial pools and fluxes that compare better with observation‐based estimates. These simulations do not take into account land use change or nitrogen deposition, both of which have been shown to enhance the land carbon sink over North America. The simulated sink of 0.5 Pg C year−1 during the 1980s and 1990s is therefore lower than inversion‐based estimates. The analysis of spatial distribution of trends in simulated carbon pools and fluxes shows that the simulated carbon sink is driven primarily by NPP enhancements over eastern United States. © 2013 The Authors and Her Majesty the Queen in Right of Canada. International Journal of Climatology published by John Wiley & Sons Ltd
on behalf of the Royal Meteorological Society.
microRNAs and cartilage
Authors: Gibson Gary , Asahara Hiroshi 
Published: June 2013

ABSTRACTmicroRNAs are small non‐coding RNAs that in the last decade have emerged as overarching regulators of gene expression. Their abundance, ability to repress a large number of target genes and overlapping target specificity indicate a complex network of interactions that is still being defined. A number of studies focused on the role of microRNAs in cartilage have identified a small number, including miR‐140 and ‐675 as playing important roles in regulation of cartilage homeostasis and together with the broader description of the activity of microRNAs in other tissues are beginning to define the function of microRNAs in cartilage development and homeostasis. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1333–1344, 2013.
Distal attachment of flexor tendon allograft: A biomechanical study of different reconstruction techniques in human cadaver hands
Authors: Wei Zhuang , Thoreson Andrew R. , Amadio Peter C. , An Kai‐Nan , Zhao Chunfeng 
Published: June 2013

ABSTRACTWe compared the mechanical force of tendon‐to‐bone repair techniques for flexor tendon reconstruction. Thirty‐six flexor digitorum profundus (FDP) tendons were divided into three groups based upon the repair technique: (1) suture/button repair using FDP tendon (Pullout button group), (2) suture bony anchor using FDP tendon (Suture anchor group), and (3) suture/button repair using FDP tendon with its bony attachment preserved (Bony attachment group). The repair failure force and stiffness were measured. The mean load to failure and stiffness in the bony attachment group were significantly higher than that in the pullout button and suture anchor groups. No significant difference was found in failure force and stiffness between the pullout button and suture anchor groups. An intrasynovial flexor tendon graft with its bony attachment has significantly improved tensile properties at the distal repair site when compared with a typical tendon‐to‐bone attachment with a button or suture anchor. The improvement in the tensile properties at the repair site may facilitate postoperative rehabilitation and reduce the risk of graft rupture. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1720–1724, 2013
Quality assessment of comparative diagnostic accuracy studies: our experience using a modified version of the QUADAS‐2 tool
Authors: Wade Ros , Corbett Mark , Eastwood Alison 
Published: June 2013

Assessing the quality of included studies is a vital step in undertaking a systematic review. The recently revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool (QUADAS‐2), which is the only validated quality assessment tool for diagnostic accuracy studies, does not include specific criteria for assessing comparative studies.As part of an assessment that included comparative diagnostic accuracy studies, we used a modified version of QUADAS‐2 to assess study quality. We modified QUADAS‐2 by duplicating questions relating to the index test, to assess the relevant potential sources of bias for both the index test and comparator test. We also added review‐specific questions.We have presented our modified version of QUADAS‐2 and outlined some key issues for consideration when assessing the quality of comparative diagnostic accuracy studies, to help guide other systematic reviewers conducting comparative diagnostic reviews.Until QUADAS is updated to incorporate assessment of comparative studies, QUADAS‐2 can be used, although modification and careful thought is required. It is important to reflect upon whether aspects of study design and methodology favour one of the tests over another. © 2013 Crown copyright.
Deep subsurface cavities in skin utilizing mechanical optical clearing and femtosecond laser ablation
Authors: Qiu Jinze , Neev Joseph , Wang Tianyi , Milner Thomas E. 
Published: June 2013

AbstractBackground and ObjectivesHigh precision subsurface ablation can be produced in transparent materials using femtosecond laser pulses and multiphoton absorption. Light scattering limits application of the same technique to most biological tissues. Previously, subsurface ablation was demonstrated at superficial depths (50–250 µm) in highly scattering tissues including murine skin and human sclera. We report application of mechanical optical clearing to produce deeper subsurface femtosecond ablation in rodent skin. Ability to target deeper structures in skin using subsurface ablation may allow novel clinical applications for dermatological laser surgery.Study Design/Materials and MethodsOperation of a prototype tissue optical clearing device (TOCD) was verified with white light photography in ex vivo rodent skin. A focused femtosecond beam transmitted through the TOCD and was scanned across rodent skin to produce subsurface ablation at increasing focal depths. Histological sections with H&E staining of the laser irradiated rodent skin were examined for subsurface ablation features following laser irradiation.ResultsSubsurface cavities were observed as deep as 1.7 mm below the skin surface in histological tissue sections. Diameter of subsurface cavities varied from tens of microns to over 100 μm. Subsurface cavities produced by scanning the focused femtosecond beam were contiguous and formed a continuous cut. Mechanical disruption of the overlying tissues was not observed.ConclusionsMechanical optical clearing can be applied directly to in situ rodent skin and produces an optical clearing effect. High precision subsurface ablation can be produced at positions substantially deeper than previously demonstrated. Future studies may be targeted in in vivo human skin to investigate potential clinical applications of subsurface femtosecond ablation using mechanical optical clearing. Lasers Surg. Med. 45:383–390, 2013. © 2013 Wiley Periodicals, Inc.
Transforming the Self‐Assembled Structures of Diblock Copolymer/POSS Nanoparticle Composites Through Complementary Multiple Hydrogen Bonding Interactions
Authors: Wu Yu‐Rong , Wu Yi‐Chen , Kuo Shiao‐Wei 
Published: June 2013

AbstractWell‐defined self‐assembled structures are obtained in the form of block copolymer (BCP) nanocomposites, prepared by blending octuply adenine (A)‐functionalized polyhedral oligomeric silsesquioxane (OBA‐POSS) nanoparticles (NPs) with a thymine (T)‐containing BCP (PS‐b‐PVBT); these nanocomposites are stabilized through complementary multiple hydrogen bonding interactions between the A and T units. A transition from one ordered morphology to another occurs upon increasing the content of OBA‐POSS NPs in the PS‐b‐PVBT diblock copolymer, namely lamellar structures at relatively low OBA‐POSS NP contents (<25 wt%) and cylindrical structures at higher OBA‐POSS NP contents (>25 wt%), with concomitant variations in the effective interaction parameter and the overall volume fractions of the two microphase‐separated domains.magnified image
Forming of Polymer Nanofibers by a Pressurised Gyration Process
Authors: Mahalingam Suntharavathanan , Edirisinghe Mohan 
Published: June 2013

AbstractA new route consisting of simultaneous centrifugal spinning and solution blowing to form polymer nanofibers is reported. The fiber diameter (60–1000 nm) is shown to be a function of polymer concentration, rotational speed, and working pressure of the processing system. The fiber length is dependent on the rotational speed. The process can deliver 6 kg of fiber per hour and therefore offers mass production capabilities compared with other established polymer nanofiber generation methods such as electrospinning, centrifugal spinning, and blowing.magnified image
Expected impacts and value of improvements in weather forecasting on the road transport sector
Authors: Nurmi Pertti , Perrels Adriaan , Nurmi Väinö 
Published: June 2013

AbstractAtmospheric predictability has improved by approximately 1 day per decade during the last 20 years based on verification results of ECMWF forecast output. In Finland, locally applied accuracy measures indicate marked improvements in the quality of forecasts for the general public since the late 1980s. It is assumed that similar trends will continue to the foreseeable future. Use of weather information will allow for better options in the decision‐making of various stake holders in the transport sector, such as commuters or tourists, transport infrastructure owners and transport service and maintenance operators. This paper discusses the economic impacts and value of weather forecasts on different transport modes (road, rail, air) highlighting the effects of potential improvements in forecast quality in the expected future climates in Europe. It is not only the improved quality of available weather forecasts that will define the value of information. The way in which the information is communicated and how it is being utilized by decision‐makers are highly relevant steps in a weather service value chain. Rather than applying the traditional Cost‐Loss model, which would relate improved forecast accuracy to increased expected utility, an alternative approach is being applied. This ‘Weather Service Chain Analysis’ (WSCA) accounts for imperfect features in the communication chain and in the use of weather information by analysing the decay of the total potential benefits via decomposing the information flow from original forecast generation to final benefit realization. Concrete estimates are provided for the road transport modes both in Finland and in Europe. Copyright © 2013 Royal Meteorological Society
Factors affecting the quality of QPF: a multi‐method verification of multi‐configuration BOLAM reforecasts against MAP D‐PHASE observations
Authors: Casaioli Marco , Mariani Stefano , Malguzzi Piero , Speranza Antonio 
Published: June 2013

ABSTRACTThis paper discusses the results of a quantitative precipitation forecast (QPF) verification study aimed at comparing different alternative new configurations of the meteorological BOlogna Limited Area Model (BOLAM) to be implemented in 2013 into the ISPRA's Hydro‐Meteo‐Marine forecasting system (SIMM) in place of the currently operational version, dated 2009. Five new configurations are defined after considering several combinations of the following model settings: horizontal grid spacing, domain extension, initial and boundary conditions, nesting design and the BOLAM code version. Such testing configurations are inter‐compared with the operational BOLAM version following a multi‐method approach including Fourier spectral analysis, several categorical scores, quasi‐relative operating characteristic diagram and visual inspection of the spatial distributions of the contingency table elements. Rain gauge measurements available between June and November 2007 within the international initiative ‘Demonstration of Probabilistic Hydrological and Atmospheric Simulation of flood Events in the Alpine region’ of the Mesoscale Alpine Programme (MAP D‐PHASE) are considered as observational dataset. A 6 month reforecast campaign is performed in order to produce, for each compared configuration, the corresponding forecast series. Results show that decreasing model grid spacing and simultaneously increasing model domain extension is effective in improving the QPF quality when higher‐resolution initial and boundary conditions are directly applied to BOLAM, without using a coarser‐resolution parent model run. Therefore, such skilful configuration has been deployed in late 2012 within the international research programme ‘HYdrological cycle in Mediterranean EXperiment’ (HyMeX). On the contrary, when keeping the low‐resolution, double nesting configuration, improving input data decreases the QPF performance. Copyright © 2013 Royal Meteorological Society
A unified verification system for operational models from Regional Meteorological Centres of China Meteorological Administration
Authors: Chen Jing , Wang Yu , Li Li , Zhao Bin , Chen Fajing , Li Yinglin , Cui Yingjie 
Published: June 2013

ABSTRACTA new unified verification system was set up for evaluating operational models from Regional Meteorological Centres (RMC) of the China Meteorological Administration (CMA) using traditional verification methods. The functionality of the system includes data transmission and processing, forecast verification, new product validation and operational monitoring. Eight limited‐area models from different regions of China were verified in this study, including Weather Research and Forecasting (WRF) models from four RMCs. Global/Regional Assimilation and Prediction System (GRAPES) models from two RMCs, Mesoscale Model version 5 (MM5) and Advanced Regional Eta‐co‐ordinate Model (AREM) from the remaining two RMCs. Real time ground observations and model analysis are used as truth for surface and upper‐air variables, respectively. The variables verified are 500 hPa geopotential height, wind and temperature at 850 hPa, wind at 250 hPa, 24 and 3 h accumulated precipitation, and 2 m temperature. The results of the RMCs' models were also compared with those from a limited‐area version of the GRAPES model (GRAPES‐MESO) run operationally at the Numerical Weather Prediction Center (NWPC)/CMA. A new score called ‘relative improvement ratio’ was defined for continuous variables in the comparison. The preliminary results for the year 2011 showed that forecast error varied from one RMC to another, e.g., performance is more stable with relatively lower error for the regional centres of Shanghai, Beijing, Guangzhou and Shenyang than others. These centres provide also more accurate predictions of the rain‐shine category and of precipitation amount, especially the moderate rain forecast in 3 h accumulation. Copyright © 2013 Royal Meteorological Society
Comparative skill assessment of consensus and physically based tercile probability seasonal precipitation forecasts for Brazil
Authors: Coelho Caio A. S. 
Published: June 2013

ABSTRACTThis study aimed to perform a comparative skill assessment of consensus and physically based tercile probability seasonal precipitation forecasts for Brazil produced during the last decade. Two fundamental forecast attributes have been examined: discrimination and reliability. The discrimination assessment revealed that forecast quality is seasonally dependent and that consensus and physically based forecasts are complementary. During spring and summer consensus forecasts were generally found to have better discrimination ability than physically based forecasts. During autumn and winter physically based forecasts were found to have better discrimination ability than consensus forecasts. However, discrimination is a necessary but not sufficient forecast skill attribute, and therefore only provides indication of potential forecast quality provided forecasts are reliable (i.e. well calibrated). The analysis of tendency diagrams has revealed that both consensus and physically based forecasts suffer from systematic errors (biases) for the three forecast categories. Both forecasts under‐forecasted the below‐normal category and over‐forecasted the above normal category. This over‐forecasting feature was stronger for physically based forecasts when compared to consensus forecasts. The normal category was more severely over‐forecast for consensus forecasts when compared to physically based forecasts. The assessment through the computation of the reliability component of the Brier Score has revealed that consensus forecasts are better calibrated than CPTEC/AGCM physically based forecasts. Copyright © 2013 Royal Meteorological Society
Characteristic decompositions and boundary value problems for two‐dimensional steady relativistic Euler equations
Authors: Lai Geng , Shen Chun 
Published: June 2013

AbstractIn this paper, we investigate Goursat problems, and mixed initial and boundary value problems for the two‐dimensional steady relativistic Euler equations. The global existence of classical solutions to these problems are obtained by using the characteristic decomposition method. Some applications of these results in supersonic flow in two‐dimensional ducts and the two‐dimensional relativistic jet are discussed. Copyright © 2013 John Wiley & Sons, Ltd.