bluuebunny/crossref_metadata_2025 huggingface dataset:
Periodontal and Microbiological Profile of Intensive Care Unit Inpatients
Authors: Tonetto Mateus R , Rocatto Grace , Matos Fernanda Z , Pedro FL Miranda , Lima Suellen L , Aranha AM Fabio
Published: November 2016

Introduction

The bidirectional relationship between the periodontal diseases and systemic diseases was attributed to the focal infection concept. The aims of this study were to assess the periodontal and microbiological profile of intensive care unit (ICU) inpatients submitted to orotracheal intubation, and classify them regarding gender, age group, ethnic, hospitalization reason and period, nosocomial infection occurrence, and death.

Materials and methods

Inpatients were assessed, distributed into toothed and toothless groups. The periodontal clinical condition was assessed 24 hours after the ICU admission through plaque index, gum index, probing depth, and clinical level of insertion. All microbiological samples were collected on the 6th day of admission. These samples were collected from different intraoral sites, depending on the group: In the toothed group, samples were collected from gingival sulcus and in the toothless group, from buccal mucosa and tongue. Identification for Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Tannerella forsythia (Tf) was accomplished and analyzed, using absolute quantification and specific primer pairs through an amplification system with probes.

Results

Forty subjects composed the sample: Gender characterized by 60% of male, 27.5% of all patients were older than 60, and 22.5% were hospitalized due to cerebrovascular accident. Regarding hospitalization period, 55% of patients were hospitalized for 6 days and 70% of them died during the period of hospitalization. Of inpatients, 40% presented periodontal disease and 100% presented dental biofilm on assessed sites. When assessing the microbiota, statistical significance was observed between Aa, Pg, and Tf, for both toothed and toothless group (p < 0.0001).

Conclusion

Large quantities of Aa were found in samples of toothless inpatients, a fact that suggests that the oral environment, even without teeth, presents favorable conditions for bacterial biofilm formation with a related pathogenic potential.

Clinical significance

The dental biofilm may comprise pulmonary pathogen colonies, promoting a perfect environment for their growth and development, facilitating the colonization of the lower airways, as well as colonization by bacteria originally from the oral cavity.

How to cite this article

Porto AN, Borges AH, Rocatto G, Matos FZ, Borba AM, Miranda Pedro FL, Lima SL, Tonetto MR, Bandéca MC, Aranha AMF. Periodontal and Microbiological Profile of Intensive Care Unit Inpatients. J Contemp Dent Pract 2016;17(10):807-814.
Reasons for not using Implants to retain Complete Denture: Patients’ Survey
Authors: Amri Mohammad D Al , Al-Johany Sulieman , AlOtaibi Hanan , Alzoman Hamad , Alkindi Mohammed , Alqahtani Fahad , Alwadei Farhan
Published: November 2016

Objective

This study aimed to gain more information from complete denture (CD) wearers who did not receive dental implants, of the reasons preventing them from using implants to retain their CD in a selected sample of dental patients in Riyadh, Saudi Arabia.

Materials and methods

A paper-and-pencil questionnaire containing 20 direct questions of the possible reasons preventing CD wearers from receiving implants to retain their dentures was distributed in three different places in Riyadh, Saudi Arabia.

Results

A total of 270 subjects were included in this survey. The results showed that 180 (66.7%) patients indicated that the fear of pain associated with implant placement was the main reason preventing them from receiving an implant treatment, followed by fear of the surgical procedure (175, 64.8%), fear of postoperative complications (166, 61.5%), information from other people about the various problems associated with implant treatment (154, 57%), and finally cost of the implant (141, 52.2%).

Conclusion

Fear is the main reason preventing CD wearers from receiving implant treatment. Therefore, it is essential for dentists to be familiar with the reasons for implant refusal to overcome a common, yet an influential obstacle.

How to cite this article

Al-Johany S, AlOtaibi H, Al Amri MD, Alzoman H, Alkindi M, Alqahtani F, Alwadei F. Reasons for not using Implants to retain Complete Denture: Patients’ Survey. J Contemp Dent Pract 2016;17(10):826-829.
Status of Endodontic Treatment and the Correlations to the Quality of Root Canal Filling and Coronal Restoration
Authors: Semenoff-Segundo Alex , Kuga Milton C , Tonetto Mateus R , Pedro Fabio M , Marques ATC , Pereira Thiago M , Lima SNL , Borges Alvaro H
Published: November 2016

Introduction

This cross-sectional study evaluated the prevalence and quality of root canal treatment in 1,977 digital radiological files.

Materials and methods

Data were statistically analyzed using descriptive analysis, and the chi-square test was performed with a 5% significance level.

Results

The mean age of the study population was 34.9 years. The endodontic treatment frequency was 6.14%, significantly higher in premolars. Adequate endodontic treatment was observed in 39.7% of analyzed cases. Molars were significantly more frequent with regard to inadequate filling quality. In 47.6% of cases, the filling's apical limit was classified as adequate, and there was a higher incidence of molars that were inadequate. Restorations were classified as adequate in 79.0% of cases, and molars were responsible for the highest frequency of inadequate restorations. The frequency of teeth with endodontic treatment that showed no periapical changes was 47.7%. There was no significant difference in the presence of periapical change according to gender. An increased presence of periapical change was observed with increasing age. The periapical lesions were observed in 45% of cases and related to inadequate filling quality. The apical limit was considered inadequate and related to periapical changes in 42% of cases. Periapical changes were present in 52% of cases, regardless of the quality of the filling and apical limit. Such changes were present in 42% of cases with adequate coronal restoration.

Conclusion

It can be concluded that apical periodontitis (AP) is associated with the quality of endodontic treatment. The coronal restoration affects significantly the success rate of endodontic treatment.

Clinical significance

The quality of the root filling and coronal restoration is closely related to periapical health.

How to cite this article

Pedro FM, Marques ATC, Pereira TM, Bandeca MC, Lima SNL, Kuga MC, Tonetto MR, Semenoff- Segundo A, Borges AH. Status of Endodontic Treatment and the Correlations to the Quality of Root Canal Filling and Coronal Restoration. J Contemp Dent Pract 2016;17(10):830-836.
The Role of Economic Policy Uncertainty in Predicting U.S. Recessions: A Mixed-frequency Markov-switching Vector Autoregressive Approach
Authors: Balcilar Mehmet , Gupta Rangan , Segnon Mawuli
Published: November 2016

This paper analyzes the performance of the monthly economic policy uncertainty (EPU) index in predicting recessionary regimes of the (quarterly) U.S. GDP. In this regard, the authors apply a mixed-frequency Markov-switching vector autoregressive (MF-MS-VAR) model, and compare its in-sample and out-of-sample forecasting performances to those of a Markov-switching vector autoregressive model (MS-VAR, where the EPU is averaged over the months to produce quarterly values) and a Markov-switching autoregressive (MS-AR) model. Their results show that the MF-MS-VAR fits the different recession regimes, and provides out-of-sample forecasts of recession probabilities which are more accurate than those derived from the MS-VAR and MS-AR models. The results highlight the importance of using high-frequency values of the EPU, and not averaging them to obtain quarterly values, when forecasting recessionary regimes for the U.S. economy.
Measurement of size-dependent single scattering albedo of fresh biomass
burning aerosols using the extinction-minus-scattering technique with a
combination of cavity ring-down spectroscopy and nephelometry
Authors: Singh Sujeeta , Fiddler Marc N. , Bililign Solomon
Published: November 2016

Abstract. Biomass burning (BB) aerosols have a significant effect on regional climate, and represent a significant uncertainty in our understanding of climate change. Using a combination of cavity ring-down spectroscopy and integrating nephelometry, the single scattering albedo (SSA) and Ångstrom absorption exponent (AAE) were measured for several North American biomass fuels. This was done for several particle diameters for the smoldering and flaming stage of white pine, red oak, and cedar combustion. Measurements were done over a wider wavelength range than any previous direct measurement of BB particles. While the offline sampling system used in this work shows promise, some changes in particle size distribution were observed, and a thorough evaluation of this method is required. The uncertainty of SSA was 6 %, with the truncation angle correction of the nephelometer being the largest contributor to error. While scattering and extinction did show wavelength dependence, SSA did not. SSA values ranged from 0.46 to 0.74, and were not uniformly greater for the smoldering stage than the flaming stage. SSA values changed with particle size, and not systematically so, suggesting the proportion of tar balls to fractal black carbon change with fuel type/state and particle size. SSA differences of 0.15–0.4 or greater can be attributed to fuel type or fuel state for fresh soot. AAE values were quite high (1.59–5.57), despite SSA being lower than is typically observed in wildfires. The SSA and AAE values in this work do not fit well with current schemes that relate these factors to the modified combustion efficiency of a burn. Combustion stage, particle size, fuel type, and fuel condition were found to have the most significant effects on the intrinsic optical properties of fresh soot, though additional factors influence aged soot.
Intercomparison and evaluation of satellite peroxyacetyl nitrate observations in the upper troposphere–lower stratosphere
Authors: Pope Richard J. , Richards Nigel A. D. , Chipperfield Martyn P. , Moore David P. , Monks Sarah A. , Arnold Stephen R. , Glatthor Norbert , Kiefer Michael , Breider Tom J. , Harrison Jeremy J. , Remedios John J. , Warneke Carsten , Roberts James M. , Diskin Glenn S. , Huey Lewis G. , Wisthaler Armin , Apel Eric C. , Bernath Peter F. , Feng Wuhu
Published: November 2016

Abstract. Peroxyacetyl nitrate (PAN) is an important chemical species in the troposphere as it aids the long-range transport of NOx and subsequent formation of O3 in relatively clean remote regions. Over the past few decades observations from aircraft campaigns and surface sites have been used to better understand the regional distribution of PAN. However, recent measurements made by satellites allow for a global assessment of PAN in the upper troposphere–lower stratosphere (UTLS). In this study, we investigate global PAN distributions from two independent retrieval methodologies, based on measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument, on board Envisat from the Institute of Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology, and the Department of Physics and Astronomy, University of Leicester (UoL). Retrieving PAN from MIPAS is challenging due to the weak signal in the measurements and contamination from other species. Therefore, we compare the two MIPAS datasets with observations from the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS), in situ aircraft data and the 3-D chemical transport model TOMCAT. MIPAS shows peak UTLS PAN concentrations over the biomass burning regions (e.g. ranging from 150 to  >  200 pptv at 150 hPa) and during the summertime Asian monsoon as enhanced convection aids the vertical transport of PAN from the lower atmosphere. At 150 hPa, we find significant differences between the two MIPAS datasets in the tropics, where IMK PAN concentrations are larger by 50–100 pptv. Comparisons between MIPAS and ACE-FTS show better agreement with the UoL MIPAS PAN concentrations at 200 hPa, but with mixed results above this altitude. TOMCAT generally captures the magnitude and structure of climatological aircraft PAN profiles within the observational variability allowing it to be used to investigate the MIPAS PAN differences. TOMCAT–MIPAS comparisons show that the model is both positively (UoL) and negatively (IMK) biased against the satellite products. These results indicate that satellite PAN observations are able to detect realistic spatial variations in PAN in the UTLS, but further work is needed to resolve differences in existing retrievals to allow quantitative use of the products.
Global and regional radiative forcing from 20 % reductions in BC, OC and
SO4 – an HTAP2 multi-model study
Authors: Stjern Camilla Weum , Samset Bjørn Hallvard , Myhre Gunnar , Bian Huisheng , Chin Mian , Davila Yanko , Dentener Frank , Emmons Louisa , Flemming Johannes , Haslerud Amund Søvde , Henze Daven , Jonson Jan Eiof , Kucsera Tom , Lund Marianne Tronstad , Schulz Michael , Sudo Kengo , Takemura Toshihiko , Tilmes Simone
Published: November 2016

Abstract. In the Hemispheric Transport of Air Pollution Phase 2 (HTAP2) exercise, a range of global atmospheric general circulation and chemical transport models performed coordinated perturbation experiments with 20 % reductions in emissions of anthropogenic aerosols, or aerosol precursors, in a number of source regions. Here, we compare the resulting changes in the atmospheric load and vertically resolved profiles of black carbon (BC), organic aerosols (OA) and sulfate (SO4) from 10 models that include treatment of aerosols. We use a set of temporally, horizontally and vertically resolved profiles of aerosol forcing efficiency (AFE) to estimate the impact of emission changes in six major source regions on global radiative forcing (RF) pertaining to the direct aerosol effect, finding values between. 51.9 and 210.8 mW m−2 Tg−1 for BC, between −2.4 and −17.9 mW m−2 Tg−1 for OA and between −3.6 and −10.3 W m−2 Tg−1 for SO4. In most cases, the local influence dominates, but results show that mitigations in south and east Asia have substantial impacts on the radiative budget in all investigated receptor regions, especially for BC. In Russia and the Middle East, more than 80 % of the forcing for BC and OA is due to extra-regional emission reductions. Similarly, for North America, BC emissions control in east Asia is found to be more important than domestic mitigations, which is consistent with previous findings. Comparing fully resolved RF calculations to RF estimates based on vertically averaged AFE profiles allows us to quantify the importance of vertical resolution to RF estimates. We find that locally in the source regions, a 20 % emission reduction strengthens the radiative forcing associated with SO4 by 25 % when including the vertical dimension, as the AFE for SO4 is strongest near the surface. Conversely, the local RF from BC weakens by 37 % since BC AFE is low close to the ground. The fraction of BC direct effect forcing attributable to intercontinental transport, on the other hand, is enhanced by one-third when accounting for the vertical aspect, because long-range transport primarily leads to aerosol changes at high altitudes, where the BC AFE is strong. While the surface temperature response may vary with the altitude of aerosol change, the analysis in the present study is not extended to estimates of temperature or precipitation changes.
Aerosol pollution radiative effects on land carbon uptake in China
Authors: Yue Xu , Unger Nadine
Published: November 2016

Abstract. China suffers from frequent haze pollution episodes that alter the surface solar radiation and influence regional carbon uptake by the land biosphere. Here, we apply combined vegetation and radiation modeling and multiple observational datasets to assess the radiative effects of aerosol pollution in China on the regional land carbon uptake for the 2009–2011 period. First, we assess the inherent sensitivity of China's land biosphere to aerosol pollution by defining and calculating two aerosol optical depth (AOD) at 550 nm thresholds (i) AODt1, resulting in the maximum net primary productivity (NPP), and (ii) AODt2, such that if local AOD
An innovative eddy-covariance system with vortex intake for measuring carbon dioxide and water fluxes of ecosystems
Authors: Ma Jingyong , Zha Tianshan , Jia Xin , Sargent Steve , Burgon Rex , Bourque Charles P.-A. , Zhou Xinhua , Liu Peng , Bai Yujie , Wu Yajuan
Published: November 2016

Abstract. Closed-path eddy-covariance (EC) systems are used to monitor exchanges of carbon dioxide (CO2) and water vapor (H2O) between the atmosphere and biosphere. Traditional EC intake systems are equipped with in-line filters to prevent airborne dust particulates from contaminating the optical windows of the sample cell which degrades measurements. In order to preserve fast-frequency response, the in-line filter should be small, but small filters plug quickly and require frequent replacement. This paper reports the test results of a field-performance of an innovative EC system (EC155, Campbell Scientific, Inc.) with a prototype vortex intake replacing the in-line filter of a traditional EC system. The vortex intake design is based on fluid dynamics theory. An air sample is drawn into the vortex chamber, where it spins in a vortex flow. The initially homogenous flow is separated when particle momentum forces heavier particles to the periphery of the chamber, leaving a much cleaner air stream at the center. Clean air (75 % of total flow) is drawn from the center of the vortex chamber, through a tube to the sample cell with optical windows. The remaining 25 % of the flow carries the heavier dust particles away in a separate bypass tube. An EC155-system measured CO2 and H2O fluxes in two urban forest ecosystems in the megalopolis of Beijing, China. These sites present a challenge for EC measurements because of the generally poor air quality with high concentrations of suspended particulate. The closed-path EC system with vortex intake significantly reduced maintenance requirements by preserving optical signal strength and sample cell pressure within acceptable ranges for much longer periods. The system with vortex intake also maintained excellent high-frequency response. For example at the Badaling site, percentage system downtime due to plugged filters was reduced from 26 % with traditional in-line filters to 0 % with the prototype vortex intake. The use of vortex intake could extent the geographical applicability of the EC technique in ecology and allow investigators to acquire more accurate and continuous measurements of CO2 and H2O fluxes in a wider range of ecosystems.
Community Air Sensor Network (CAIRSENSE) project: evaluation of low-cost
sensor performance in a suburban environment in the southeastern United
States
Authors: Jiao Wan , Hagler Gayle , Williams Ronald , Sharpe Robert , Brown Ryan , Garver Daniel , Judge Robert , Caudill Motria , Rickard Joshua , Davis Michael , Weinstock Lewis , Zimmer-Dauphinee Susan , Buckley Ken
Published: November 2016

Abstract. Advances in air pollution sensor technology have enabled the development of small and low-cost systems to measure outdoor air pollution. The deployment of a large number of sensors across a small geographic area would have potential benefits to supplement traditional monitoring networks with additional geographic and temporal measurement resolution, if the data quality were sufficient. To understand the capability of emerging air sensor technology, the Community Air Sensor Network (CAIRSENSE) project deployed low-cost, continuous, and commercially available air pollution sensors at a regulatory air monitoring site and as a local sensor network over a surrounding  ∼ 2 km area in the southeastern United States. Collocation of sensors measuring oxides of nitrogen, ozone, carbon monoxide, sulfur dioxide, and particles revealed highly variable performance, both in terms of comparison to a reference monitor as well as the degree to which multiple identical sensors produced the same signal. Multiple ozone, nitrogen dioxide, and carbon monoxide sensors revealed low to very high correlation with a reference monitor, with Pearson sample correlation coefficient (r) ranging from 0.39 to 0.97, −0.25 to 0.76, and −0.40 to 0.82, respectively. The only sulfur dioxide sensor tested revealed no correlation (r < 0.5) with a reference monitor and erroneously high concentration values. A wide variety of particulate matter (PM) sensors were tested with variable results – some sensors had very high agreement (e.g., r =  0.99) between identical sensors but moderate agreement with a reference PM2.5 monitor (e.g., r =  0.65). For select sensors that had moderate to strong correlation with reference monitors (r > 0.5), step-wise multiple linear regression was performed to determine if ambient temperature, relative humidity (RH), or age of the sensor in number of sampling days could be used in a correction algorithm to improve the agreement. Maximum improvement in agreement with a reference, incorporating all factors, was observed for an NO2 sensor (multiple correlation coefficient R2adj-orig = 0.57, R2adj-final = 0.81); however, other sensors showed no apparent improvement in agreement. A four-node sensor network was successfully able to capture ozone (two nodes) and PM (four nodes) data for an 8-month period of time and show expected diurnal concentration patterns, as well as potential ozone titration due to nearby traffic emissions. Overall, this study demonstrates the performance of emerging air quality sensor technologies in a real-world setting; the variable agreement between sensors and reference monitors indicates that in situ testing of sensors against benchmark monitors should be a critical aspect of all field studies.
Physiology regulates the relationship between coccosphere geometry and growth-phase in coccolithophores
Authors: Sheward Rosie M. , Poulton Alex J. , Gibbs Samantha J. , Daniels Chris J. , Bown Paul R.
Published: November 2016

Abstract. Coccolithophores are an abundant phytoplankton group that exhibit remarkable diversity in their biology, ecology, and calcitic exoskeletons (coccospheres). Their extensive fossil record is testament to their important biogeochemical role and is a valuable archive of biotic responses to environmental change stretching back over 200 million years. However, to realise the potential of this archive requires an understanding of the physiological processes that underpin coccosphere architecture. Using culturing experiments on four modern coccolithophore species (Calcidiscus leptoporus, Calcidiscus quadriperforatus, Helicosphaera carteri and Coccolithus braarudii) from three long-lived families, we investigate how coccosphere architecture responds to shifts from exponential (rapid cell division) to stationary (slowed cell division) growth phases as cell physiology reacts to nutrient depletion. These experiments reveal statistical differences in cell size and the number of coccoliths per cell between these two growth phases, specifically that cells in exponential-phase growth are typically smaller with fewer coccoliths, whereas cells experiencing growth-limiting nutrient depletion have larger coccosphere sizes and greater numbers of coccoliths per cell. Although the exact numbers are species-specific, these growth- phase shifts in coccosphere geometry demonstrate that the core physiological responses of cells to nutrient depletion results in increased cell sizes and coccoliths per cell across four different coccolithophore families (Calcidiscaceae, Coccolithaceae, Isochrysidaceae, Helicosphaeraceae), a representative diversity of this phytoplankton group. Building on this, direct comparison of coccosphere geometries in modern and fossil coccolithophores enables a proxy for growth phase to be developed that allows growth responses to environmental change to be investigated throughout their evolutionary history. Our data also shows that changes in growth rate and coccoliths per cell associated with growth-phase shifts can substantially alter cellular calcite production. Coccosphere geometry is therefore a valuable tool for accessing growth information in the fossil record that provides unprecedented insights into the biotic responses of species to environmental change and its potential biogeochemical consequences.
Annual greenhouse gas budget for a bog ecosystem undergoing
restoration by rewetting
Authors: Lee Sung Ching , Christen Andreas , Black Andy T. , Johnson Mark S. , Jassal Rachhpal S. , Ketler Rick , Nesic Zoran , Merkens Markus
Published: November 2016

Abstract. Many peatlands have been drained and harvested for peat mining, which has turned them from carbon (C) sinks into C emitters. Rewetting of disturbed peatlands facilitates their ecological recovery, and may help them revert to carbon dioxide (CO2) sinks. However, rewetting may also cause substantial emissions of the more potent greenhouse gas (GHG) methane (CH4). Our knowledge on the exchange of CO2 and CH4 following rewetting during restoration of disturbed peatlands is currently limited. This study quantifies annual fluxes of CO2 and CH4 in a disturbed and rewetted area located in the Burns Bog Ecological Conservancy Area in Delta, BC, Canada. Burns Bog is recognized as the largest raised bog ecosystem on North America's West Coast. Burns Bog was substantially reduced in size and degraded by peat mining and agriculture. Since 2005, the bog has been declared a conservancy area, with restoration efforts focusing on rewetting disturbed ecosystems to recover Sphagnum and suppress fires. Using the eddy-covariance (EC) technique, we measured year-round (16th June 2015 to 15th June 2016) turbulent fluxes of CO2 and CH4 from a tower platform in an area rewetted for the last 8 years. The study area, dominated by sedges and Sphagnum, experienced a varying water table position that ranged between 7.7 (inundation) and −26.5 cm from the surface during the study year. The annual CO2 budget of the rewetted area was −179 g CO2-C m−2 year−1 (CO2 sink) and the annual CH4 budget was 16 g CH4-C m−2 year−1 (CH4 source). Gross ecosystem productivity (GEP) exceeded ecosystem respiration (Re) during summer months (June–August), causing a net CO2 uptake. In summer, high CH4 emissions (121 mg CH4-C m−2 day−1) were measured. In winter (December–February), while roughly equal magnitudes of GEP and Re made the study area CO2 neutral, very low CH4 emissions (9 mg CH4-C m−2 day−1) were observed. The key environmental factors controlling the seasonality of these exchanges were downwelling photosynthetically active radiation and 5-cm soil temperature. It appears that the high water table caused by ditch blocking which suppresses Re. With low temperatures in winter, CH4 emission was more suppressed than Re. Annual net GHG flux from CO2 and CH4 expressed in terms of CO2 equivalents (CO2e) during the study period totaled to −55 g CO2e m−2 year−1 (net CO2e sink) and 1147 g CO2e m−2 year−1 (net CO2e source) by using 100-year and 20-year global warming potential values, respectively. Consequently, the ecosystem was almost CO2e neutral during the study period expressed on a 100-year time horizon but was a significant CO2e source on a 20-year time horizon.
Transient simulations of the present and the last interglacial climate using the Community Climate System Model version 3: effects of orbital acceleration
Authors: Varma Vidya , Prange Matthias , Schulz Michael
Published: November 2016

Abstract. Numerical simulations provide a considerable aid in studying past climates. Out of the various approaches taken in designing numerical climate experiments, transient simulations have been found to be the most optimal when it comes to comparison with proxy data. However, multi-millennial or longer simulations using fully coupled general circulation models are computationally very expensive such that acceleration techniques are frequently applied. In this study, we compare the results from transient simulations of the present and the last interglacial with and without acceleration of the orbital forcing, using the comprehensive coupled climate model CCSM3 (Community Climate System Model version 3). Our study shows that in low-latitude regions, the simulation of long-term variations in interglacial surface climate is not significantly affected by the use of the acceleration technique (with an acceleration factor of 10) and hence, large-scale model–data comparison of surface variables is not hampered. However, in high-latitude regions where the surface climate has a direct connection to the deep ocean, e.g. in the Southern Ocean or the Nordic Seas, acceleration-induced biases in sea-surface temperature evolution may occur with potential influence on the dynamics of the overlying atmosphere.
A Hydrological Prediction System Based on the SVS Land–Surface Scheme: Implementation and Evaluation of the GEM-Hydro platform on the watershed of Lake Ontario
Authors: Gaborit Étienne , Fortin Vincent , Xu Xiaoyong , Seglenieks Frank , Tolson Bryan , Fry Lauren M. , Hunter Tim , Anctil François , Gronewold Andrew D.
Published: November 2016

Abstract. This work describes the implementation of the distributed GEM-Hydro runoff modeling platform, developed at Environment and Climate Change Canada (ECCC) over the last decade. The latest version of GEM-Hydro combines the SVS (Soil, Vegetation and Snow) land-surface scheme and the WATROUTE routing scheme in order to provide streamflow predictions on a gridded river network. SVS is designed to be two-way coupled to the GEM (Global Environmental Multi-scale) atmospheric model exploited by ECCC for operational weather and environmental forecasting. Although SVS has been shown to accurately track soil moisture during the warm season, it has never been evaluated before for hydrological prediction. This paper presents a first evaluation of its ability to simulate streamflow for all major rivers flowing into Lake Ontario. The skill level of GEM-Hydro is assessed by comparing the quality of simulated flows to that of two established hydrological models, MESH and WATFLOOD, which share the same routing scheme (WATROUTE) but rely on different land–surface schemes. All models are calibrated using the same meteorological forcings, objective function, calibration algorithm, and watershed delineation. Results show that GEM-Hydro performs well and is competitive with MESH and WATFLOOD. A computationally efficient strategy is proposed to calibrate the land-surface model of GEM-Hydro: a simple unit hydrograph is used for routing instead of its standard distributed routing component. The distributed routing part of the model can then be run in a second step to estimate streamflow everywhere inside the domain. Global and local calibration strategies are compared in order to estimate runoff for ungauged portions of the Lake Ontario watershed. Overall, streamflow predictions obtained using a global calibration strategy, in which a single parameter set is identified for the whole watershed of Lake Ontario, show skills comparable to the predictions based on local calibration. Hence, global calibration provides spatially consistent parameter values, robust performance at gauged locations, and reduces the complexity and computational burden of the calibration procedure. This work contributes to the Great Lakes Runoff Inter-comparison Project for Lake Ontario (GRIP-O) which aims at improving Lake Ontario basin runoff simulations by comparing different models using the same input forcings.
Large-scale vegetation responses to terrestrial moisture storage changes
Authors: Andrew Robert L. , Guan Huade , Batelaan Okke
Published: November 2016

Abstract. The Normalised Difference Vegetation Index (NDVI) is a useful tool for studying vegetation activity and ecosystem performance at a large spatial scale. In this study we use the Gravity Recovery and Climate Experiment (GRACE) total water storage (TWS) estimates to examine temporal variability of NDVI across Australia. We aim to demonstrate a new method that reveals the moisture dependence of vegetation cover at different temporal resolutions. Time series of monthly GRACE TWS anomalies are decomposed into different temporal frequencies using a discrete wavelet transform and analysed against time series of NDVI anomalies in a stepwise regression. Results show that combinations of different frequencies of decomposed GRACE TWS data explain NDVI temporal variations better than raw GRACE TWS alone. Generally, NDVI appears to be more sensitive to inter-annual changes in water storage than shorter changes, though grassland-dominated areas are sensitive to higher frequencies of water storage changes. Different types of vegetation, defined by areas of land use type show distinct differences in how they respond to the changes in water storage which is generally consistent with our physical understanding. This unique method provides useful insight into how NDVI is affected by changes in water storage at different temporal scales across land use types.
High-Resolution Virtual Catchment Simulations of the Subsurface-Land Surface-Atmosphere System
Authors: Schalge Bernd , Rihani Jehan , Baroni Gabriele , Erdal Daniel , Geppert Gernot , Haefliger Vincent , Haese Barbara , Saavedra Pablo , Neuweiler Insa , Hendricks Franssen Harrie-Jan , Ament Felix , Attinger Sabine , Cirpka Olaf A. , Kollet Stefan , Kunstmann Harald , Vereecken Harry , Simmer Clemens
Published: November 2016

Abstract. Combining numerical models, which simulate water and energy fluxes in the subsurface-land surface-atmosphere system in a physically consistent way, becomes increasingly important to understand and study fluxes at compartmental boundaries and interdependencies of states across these boundaries. Complete state evolutions generated by such models, when run at highest possible resolutions while incorporating as many processes as attainable, may be regarded as a proxy of the real world – a virtual reality – which can be used to test hypotheses on functioning of the coupled terrestrial system and may serve as source for virtual measurements to develop data-assimilation methods. Such simulation systems, however, face severe problems caused by the vastly different scales of the processes acting in the compartments of the terrestrial system. The present study is motivated by the development of cross-compartmental data-assimilation methods, which face the difficulty of data scarcity in the subsurface when applied to real data. With appropriate and realistic measurement operators, the virtual reality not only allows taking virtual observations in any part of the terrestrial system at any density, thus overcoming data-scarcity problems of real-world applications, but also provides full information about true states and parameters aimed to be reconstructed from the measurements by data assimilation. In the present study, we have used the Terrestrial Systems Modeling Platform TerrSysMP, which couples the meteorological model COSMO, the land-surface model CLM, and the subsurface model ParFlow, to set up the virtual reality for a regional terrestrial system roughly oriented at the Neckar catchment in southwest Germany. We find that the virtual reality is in many aspects quite close to real observations of the catchment concerning, e.g., atmospheric boundary-layer height, precipitation, and runoff. But also discrepancies become apparent both in the ability of such models to correctly simulate some processes – which still need improvement – and the realism of the results of some observation operators like the SMOS and SMAP sensors, when faced with model states. In a succeeding step, we will use the virtual reality to generate observations in all compartments of the system for coupled data assimilation. The data assimilation will rely on a coarsened and simplified version of the model system.
A Multi-sensor Data-driven methodology for all-sky Passive Microwave Inundation Retrieval
Authors: Takbiri Zeinab , Ebtehaj Ardeshir M. , Foufoula-Georgiou Efi
Published: November 2016

Abstract. We present a multi-sensor Bayesian passive microwave retrieval algorithm for flood inundation mapping at high spatial and temporal resolutions. The algorithm takes advantage of observations from multiple sensors in optical, short-infrared, and microwave bands, thereby allowing detection and mapping of the sub-pixel fraction of inundated areas under almost all-sky conditions. The method relies on a nearest neighbor search and a modern sparsity-promoting inversion method that make use of an a priori database in the form of two joint dictionaries. These dictionaries contain almost overlapping observations by the Special Sensor Microwave Imager and Sounder (SSMIS) on board the Defense Meteorological Satellite Program (DMSP) F17 satellite and the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Aqua and Terra satellites. Evaluation of the retrieval algorithm over the Mekong delta shows that it is capable of capturing to a good degree the diurnal variability (i.e., morning and evening) of inundation due to localized convective precipitation. At longer time-scales, the results demonstrate consistency with the ground-based water level observations, denoting that the method is properly capturing inundation seasonal patterns in response to regional monsoonal rain. The calculated Euclidean distance, rank-correlation and also Copula quantile analysis demonstrate a good agreement between the outputs of the algorithm and the observed water levels at monthly and daily time scales.
Compound extremes in a changing climate – a Markov chain approach
Authors: Sedlmeier Katrin , Mieruch Sebastian , Schädler Gerd , Kottmeier Christoph
Published: November 2016

Abstract. Studies using climate models and observed trends indicate that extreme weather has changed and may continue to change in the future. The potential impact of extreme events such as heat waves or droughts depends not only on their number of occurrences but also on "how these extremes occur", i.e., the interplay and succession of the events. These quantities are quite unexplored, for past changes as well as for future changes and call for sophisticated methods of analysis. To address this issue, we use Markov chains for the analysis of the dynamics and succession of multivariate or compound extreme events. We apply the method to observational data (1951–2010) and an ensemble of regional climate simulations for central Europe (1971–2000, 2021–2050) for two types of compound extremes, heavy precipitation and cold in winter and hot and dry days in summer. We identify three regions in Europe, which turned out to be likely susceptible to a future change in the succession of heavy precipitation and cold in winter, including a region in southwestern France, northern Germany and in Russia around Moscow. A change in the succession of hot and dry days in summer can be expected for regions in Spain and Bulgaria. The susceptibility to a dynamic change of hot and dry extremes in the Russian region will probably decrease.
Technical Note: Volume Transport Equations in Combined Sverdrup-Stommel-Munk Dynamics without Level of no Motion
Authors: Chu Peter C.
Published: November 2016

Abstract. The cornerstone theories of ocean dynamics proposed by Sverdrup (1947), Stommel (1948), and Munk (1950) are based on the assumption of level of no motion. Such an assumption is the same as the assumption of no meridional geostrophic transport. Ever since Sverdrup (1947) however, verification of the accuracy of the Sverdrup balance theory is based on the comparison of the Sverdrup meridional transport with the meridional transport calculated directly from the geostrophic currents based on hydrographic data. To overcome the mismatch between theory (no meridional geostrophic transport in Sverdrup transport) and verification (comparison of Sverdrup transport to meridional geostrophic transport), extended Sverdrup-Stommel-Munk transport equations are derived in this note with replacing the level of no motion by the ocean bathymetry and in consequence one forcing function (surface wind stress) in the classical transport equations (with level of no motion assumption) is replaced by five forcing functions: density, surface wind stress, bottom meridional current, bottom stresses due to vertical and horizontal viscosities. The first two forcing functions (density and surface wind stress) are more than an order of magnitude stronger than the other three forcing functions using the world ocean bathymetry, climatological annual mean hydrographic and surface wind stress data. The extended Sverdrup volume transport streamfunctions under wind forcing, density forcing, and combined wind and density forcing are presented.
Statistical characterization of roughness uncertainty and impact on wind resource estimation
Authors: Kelly Mark , Jørgensen Hans Ejsing
Published: November 2016

Abstract. In this work we relate uncertainty in background roughness length (z0) to uncertainty in wind speeds, where the latter are predicted at a wind farm location based on wind statistics observed at a different site. Sensitivity of predicted winds to roughness is derived analytically for the industry-standard European Wind Atlas method, which is based on the geostrophic drag law. We consider roughness statistically and its corresponding uncertainty, in terms of both z0 derived from measured wind speeds, as well as that chosen in practice by wind engineers. We show the combined effect of roughness uncertainty arising from differing wind-observation and turbine-prediction sites; this is done for the case of roughness bias, as well as for the general case. For estimation of uncertainty in annual energy production (AEP), we also develop a generalized analytical turbine power curve, from which we derive a relation between mean wind speed and AEP. Following from our developments we provide guidance on approximate roughness uncertainty magnitudes to be expected in industry practice, and also find that sites with larger background roughness incur relatively larger uncertainties.
Design and Simulation Analysis of Multi-Agent Online Dissemination Model on the Basis of "The Spiral of Silence" Theory
Authors: Miao Qiuyun , Shen Yang
Published: November 2016

This article studies the classical theory of communications—the Spiral of Silence. The key factors are extracted for multi-agent modeling and simulation with Netlogo. It turns out that opinion climate is the external formation of the Spiral of Silence. Besides, the size of opinion climate has no direct effects on the Spiral of Silence.
Simulating the Performance Characteristic of Passband Modulation Techniques in MATLAB Environment
Authors: Thuneibat Saed Ali
Published: November 2016

Now days, digital communication systems become complex and sophisticated. Not all vendors, if any, can understand the system and components of system that represent different modulation techniques, line and block coding, multiplexing and multiple access.

They need the conclusion about which of modulation techniques is the suitable for transmission and in the same time can save the power and bandwidth.

Engineers can study and analyze the modulation techniques and then compare between them to give such conclusion using modeling and simulation.

MATLAB is a high level mathematical language for technical computing.

In this paper we use MATLAB environment as simulation software to give on display a clear result that used to compare between two digital Passband modulation techniques BPSK and QPSK, and pinpoint the performance of the two techniques over selected parameters.
Aplikace metody ukotvujících vinět v pedagogickém výzkumu: přehled literatury a metodologická doporučení
Authors: Voňková Hana , Papajoanu Ondřej , Bendl Stanislav
Published: November 2016

Dotazníková šetření se (sebe)hodnoticími položkami jsou v pedagogickém výzkumu využívána často. Respondenti však mohou na tyto položky odpovídat rozdílně, tj. volit jiné škálové kategorie, přestože jejich objektivní situace je stejná. Metoda ukotvujících vinět nabízí řešení tohoto problému. Odpovědi na tyto položky koriguje o rozdílné užívání škály a činí je tak porovnatelné. Tento příspěvek si klade dva cíle. Zaprvé poskytnout přehled do této chvíle publikovaných prací z oblastí pedagogického výzkumu, ve kterých byla tato metoda aplikována. Zadruhé shrnout metodologická doporučení týkající se správné formulace a užití ukotvujících vinět. Metoda byla zatím úspěšně aplikována při měření nečestného chování žáků, ICT znalostí a dovedností, spokojenosti rodičů se školou, řízení třídy učitelem a podpory žáků ze strany učitele. Ukazuje se, že respondenti s různými charakteristikami skutečně užívají škálu rozdílným způsobem a že korigování dat s využitím metody ukotvujících vinět může pomoci vysvětlit některá paradoxní zjištění o vztahu vybraných proměnných. Naše metodologická doporučení pro využívání vinět se týkají podpory základních předpokladů metody, diskriminační síly vinět, počtu vinět, obsahové relevance a jazykové složky vinět. Na základě shrnutí dosavadního rozšíření a přínosu této metody pedagogickému výzkumu diskutují autoři možnosti jejího dalšího využití pro měření pedagogických konceptů.
Analytika učení: nový přístup ke zkoumání učení (nejen) ve virtuálním prostředí
Authors: Juhaňák Libor , Zounek Jiří
Published: November 2016

Cílem studie je představit a popsat nově se formující výzkumnou oblast označovanou jako analytika učení (learning analytics), která se zaměřuje na využití kvantitativních metod v rámci výzkumu učení (převážně) ve virtuálním prostředí. V první části příspěvku se věnujeme historickým kořenům analytiky ve vzdělávání a mapujeme různé inspirační zdroje, ze kterých analytika učení jakožto svébytná oblast výzkumů vychází a čerpá. Dáváme analytiku učení do souvislosti s příbuznými výzkumnými oblastmi v kontextu výzkumů technologiemi podporovaného učení (technology enhanced learning). Druhá část studie se zaměřuje na samotné vymezení analytiky učení a zpřesnění pojmů. Zároveň přibližuje a srovnává některé z užívaných konceptů (úrovně analytiky ve vzdělávání, proces analytiky učení). Třetí část prezentuje hlavní výzkumné směry analytiky učení, které lze identifikovat v doposud publikovaných odborných zdrojích.
A Paley-Wiener Theorem for the Spherical Transform Associated with the Generalized Gelfand Pair $(U(p,q),H_{n})$, $p+q=n$
Authors: Campos Silvina
Published: November 2016

In this work we prove a Paley-Wiener theorem for the spherical transform associated to the generalized Gelfand pair $(H_n\ltimes U(p,q),H_n)$, where $H_n$ is the $2n+1$-dimensional Heisenberg group. In particular, by using the identification of the spectrum of $(U(p,q),H_n)$ with a subset $\Sigma$ of $\mathbb{R}^2$, we prove that the restrictions of the spherical transforms of functions in $C_{0}^{\infty}(H_n)$ to appropriated subsets of $\Sigma$, can be extended to holomorphic functions on $\mathbb{C}^2$. Also, we obtain a real variable characterizations of such transforms.
Definiendo la hipertextualidad. Análisis cuantitativo y cualitativo de la evolución del concepto
Authors: Arias-Robles Félix , García-Avilés José Alberto
Published: November 2016

Pese a las múltiples referencias a la hipertextualidad, todavía existen confusiones sobre su significado. Ahora que cumple medio siglo, resulta pertinente recopilar y aclarar el significado de un término todavía esencial para entender la naturaleza de los contenidos digitales. Por eso, esta investigación realiza un análisis documental y de contenido de un conjunto de 155 referencias en 136 trabajos seleccionados a partir de una muestra inicial de 4.750. El estudio de variables como el año de publicación, el tipo de mención o los elementos presentes en las definiciones permite estudiar la evolución, desviaciones y, sobre todo, puntos en común. Este proceso pone de manifiesto la juventud de la mayoría de las referencias conceptuales, su estabilidad en el tiempo y la tendencia a la concreción. Pero, sobre todo, demuestra la necesidad de incluir en su definición elementos como estructura, contenido multimedia, interfaz digital y, especialmente, enlace y usuario.