bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of bite-jumping appliances on mandibular advancement in growing rats: A radiographic study
Authors: Oksayan Ridvan , Sokucu Oral , Ucuncu Neslihan
Published: July 2014

Objective: The aim was to evaluate the effects of the use of mandibular advancement appliances on mandibular growth in growing rats. Materials and Methods: Twenty-four 8-week-old male Wistar albino rats were randomly divided into two experimental groups (12 rats each): Group I was a control group, and Group II was the mandibular advancement appliance group. A functional bite-jumping appliance was used in Group II to promote mandibular advancement. Anatomical changes in the condyle and mandible were evaluated by comparing radiographic results from before and after the study, with angular and linear measurements. Friedman and Mann-Whitney U-tests were used in statistical analysis. Results: According to the radiographic results, the growth of mandibles and condyles in Group II was significantly greater than with the length of the condylar process (A-B) and distance from condyle to menton (A-D) variables (P < 0.05). In addition, Group I showed greater mandibular base growth than did Group II (P < 0.05). Conclusions: We conclude that the use of an intraoral bite-jumping appliance can stimulate condylar growth and increase sagittal mandibular advancement in growing rats.
A cone-beam computed tomography study of the root canal morphology of anterior teeth in a Turkish population
Authors: Altunsoy Mustafa , Ok Evren , Nur Bilge Gulsum , Aglarci Osman Sami , Gungor Enes , Colak Mehmet
Published: July 2014

Objective: The aim of this study was to determine the root and canal morphology of the maxillary and mandibular anterior teeth in a Turkish population by analyzing cone-beam computed tomography (CBCT) images. Materials and Methods: CBCT images of 417 females and 410 males with a mean age of ranging from 14 to 70 years were examined in this study. A total of 1453 maxillary central incisors, 1504 maxillary lateral incisors, 1523 maxillary canines, 1582 mandibular central incisors, 1603 mandibular lateral incisors, and 1604 mandibular canines were analyzed. The number of root canals and the canal configurations were investigated and then were classified according to Vertucci's classification. The data were analyzed with the Pearson Chi-square test. Results: The Type 1 canal configuration was most prevalent in the maxillary anterior teeth (96.8-99.7%). The Types 2, 3, 4, and 5 canal configurations were observed within the range of 0-1.3%, 0-0.8%, 0-0.7%, and 0-1.8%, respectively. In the mandibular anterior teeth, the Type 1 canal configuration was most prevalent (77-95%). The Types 2, 3, 4, and 5 canal configurations were observed within a range of 0.2-2.7%, 0.2-1.6%, 0.9-5.9%, and 1.8-14.4%, respectively. The prevalence of two canals was higher in males than in females both in the maxillary and mandibular anterior teeth (P < 0.05). Conclusions: Type 1 was the most prevalent canal configuration of maxillary and mandibular anterior teeth in the Turkish population. Type 5 was the most frequently observed canal configuration of the two canalled teeth. The incidence of root canal numbers and configurations differed with sex.
The effect of drinks on color stability and surface roughness of nanocomposites
Authors: Leite Maria Luísa de Alencar e Silva , Silva Fábia Danielle Sales da Cunha Medeiros e , Meireles Sônia Saeger , Duarte Rosângela Marques , Andrade Ana Karina Maciel
Published: July 2014

Objective: The aim was to evaluate the color and surface roughness of nanoparticle (C1) and nanohybrid (C2) composites after immersion in distilled water, acai juice, grape juice and red wine and repolishing. Materials and Methods: After recording the initial surface roughness and color, the specimens were divided into four groups according to the storage solution. The specimens were reassessed after immersion for 1, 2, 4, 8, and 12 weeks and after repolishing. Results: The results showed that after 2 weeks, there were statistically significant changes in color of both resins in all groups, with the exception of the specimens stored in distilled water (P > 0.05). Only 12 weeks of immersion in red wine changed the roughness of composite C1 (P = 0.009). Conclusions: Red wine produced the greatest color change in nanocomposites, followed by grape juice. Acai juice made the color unacceptable clinically only after 12 weeks. Repolishing reduced the color change in all groups.
Radiopacity evaluation of contemporary resin composites by digitization of images
Authors: Ermis R. Banu , Yildirim Derya , Yildiz Gul , Gormez Ozlem
Published: July 2014

Objective: The aim of this study was to evaluate the radiopacity of different composite resins and compare the values to those of human enamel and dentine. Materials and Methods: Five specimens of each material with thicknesses of 2 mm were prepared and radiographed alongside aluminum step wedge and human enamel and dentin. Three occlusal radiographs for each material were taken and digitized using a desktop scanner. Mean gray values of the test materials were measured using Image J software. Then a conversion was performed according to establish the radiopacity of the test materials, in millimeters of equivalent Al. Data were analyzed using one-way analysis of variance and Duncan multiple range tests (P < 0.05). Results: The radiopacity values varied among the restorative materials (P < 0.05). The radiopacity values of the materials tested were, in decreasing order: Enamel Plus HRI > Z250 > Filtek Ultimate ≥ Z550 > Nexcomp ≥ Nanoceram Bright > enamel ≥ Estelite Sigma Quick > Clearfil Majesty Esthetic ≥ Reflexions XLS ≥ Aelite LS Posterior ≥ dentin ≥ 2 mm Al. Conclusion: All resin composite materials investigated in this study presented different radiopacity values. However, all materials had radiopacity values greater than dentin and had sufficient radiopacity to meet International Organization for Standardization 4049 standard.
Push-out bond strength of different mineral trioxide aggregates
Authors: Ertas Huseyin , Kucukyilmaz Ebru , Ok Evren , Uysal Banu
Published: July 2014

Objective: This study was aimed to evaluate and to compare the push-out bond strength of different brands of mineral trioxide aggregate (MTA) with a calcium enriched mixture cement (CEM). Materials and Methods: Fifteen extracted, single-rooted human teeth were used. The middle-third of the roots were sliced perpendicular to the long axis into 1.00 ± 0.05 mm thick serial slices (15 root × 4 slice = 60 specimen). The specimens were then divided into three groups (n = 20). The standardized root discs were filled with white CEM, ProRoot MTA, MTA-Angelus and wrapped in a serum-soaked gauze. After 3 days at relative humidity, the push-out bond strengths were measured with a universal testing machine. Data were analyzed using one-way analysis of variance and post hoc Tukey tests. Results: The mean push-out bond strength value of the ProRoot MTA group (12.7 ± 2.5 MPa) was the highest and statistically significant difference was recorded between ProRoot MTA and other groups (P < 0.001). There was no significant difference between the mean bond strength of CEM cement (4.6 ± 1.1 MPa) and MTA-Angelus (4.5 ± 1.5 MPa) (P = 0.982). Conclusion: The push-out bond strength of MTA was changed with the brands and ProRoot MTA had the highest push-out bond strength.
The reparability of contemporary composite resins
Authors: Spyrou Maria , Koliniotou-Koumpia Eugenia , Kouros Pantelis , Koulaouzidou Elisabeth , Dionysopoulos Pavlos
Published: July 2014

Objective: The objective was to investigate the way that various surface treatments could influence the bond strength of the repair of methacrylate (MC) and silorane (SIL) composites. Materials and Methods: A total of 160 MC and SIL cylindrical specimens were polymerized and aged in artificial saliva solution for 7 days. Depending on the following surface treatment (diamond bur or air abrasion), and the conditioning procedure (orthophosphoric acid or sodium hypochlorite), 16 groups were formed and repaired either with MC, either with SIL composite. Repaired specimens were subjected to an additional aging procedure in artificial saliva for 7 days, followed by thermo-cycling and then stressed in shear at a rate of 0.5 mm/min until failure. Failure patterns were analyzed using stereomicroscope and scanning electron microscopy. Results: MC composite showed statistically significant higher bond strength both as a base or repair material than SIL (P < 0.001). Statistically significant differences were not observed, when grinding and conditioning procedures was compared. Pretest failures were observed when aged MC-based composite was repaired with SIL-based. Conclusions: Type of composite seems to be the main factor influencing the bond strength of the repair. MC-based composite showed better repairability than SIL composite. Optimum repair conditions should include knowledge of the composite's composition.
Evaluation of gingival bleeding awareness by comparison of self-reports and clinical measurements of freshman dental students
Authors: Baser Ulku , Germen Meliha , Erdem Yelda , Issever Halim , Yalcin Funda
Published: July 2014

Objective: The aims of this descriptive, cross-sectional investigation were to evaluate the gingival health awareness of dental students by comparing their clinical gingival bleeding scores and self-reports, and to compare differences in awareness between males and females. Methods: In total, 100 (51 males, 49 females) freshman dental students were included in the study. Periodontal indices recorded were: Presence of plaque percentage (plaque index [PI], %), percentage of sites of bleeding on probing (BOP, %), probing depth, and community periodontal index (CPI). Percent agreement, kappa agreement, sensitivity, and specificity were calculated by comparing their self-reported gingival bleeding and BOP%. Results: The self-reports of gingival bleeding exhibited statistically significant correlations with BOP% in females (r = 0.42, P = 0.003). Female students showed a higher degree of awareness when kappa agreement, 0.23 (males: 0.16, females: 0.39), sensitivity, 48% (males: 42%, females: 51%), and specificity, 95% (males: 90%, females: 100%) were calculated. Although male dental students had higher PI and CPI scores, there was no significant difference by gender in the clinical measurements. Conclusions: According to our results, the validity of self-reported gingival bleeding was higher among dental students than in previous population-based studies. Female dental students showed a higher degree of awareness than males of their gingival health. Half of the included dental students could not differentiate whether they had gingival bleeding when there was actual bleeding. More emphasis should be given to the education of dental students regarding the relationship between gingival bleeding and active periodontal disease.
Effect of erbium, chromium: yttrium, scandium, gallium, garnet laser and casein phosphopeptide-amorphous calcium phosphate on surface micro-hardness of primary tooth enamel
Authors: Subramaniam Priya , Pandey Annu
Published: July 2014

Objective: The aim was to evaluate the effect of Er, Cr: YSGG laser and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on surface micro-hardness of primary tooth enamel. Materials and Methods: A total of 30 freshly extracted caries free primary anterior teeth were cleaned and stored in 1% thymol. Teeth were embedded in acrylic resin such that only their buccal surfaces were exposed and were divided into four groups. Group I: Five intact teeth (negative control). The remaining 25 teeth were immersed for 30 min in 1% citric acid for demineralization. Group II: Five demineralized teeth (positive control), Group III: CPP-ACP (GC tooth mousse-GC International, Itabashi-Ku, Tokyo, Japan) application and Group IV: Etching using Er, Cr: YSGG laser + CPP-ACP application. Groups III and IV were subjected to pH cycling for 5 days. Surface micro-hardness of all the teeth was measured using Brinell hardness tester (Fuel Instruments and Engineers Pvt. Ltd.). Data were analyzed using ANOVA. Results: Mean surface micro-hardness of Groups I and II were 177.43 kgf/mm2 and 164.86 kgf/mm2, respectively. Group IV showed a higher mean surface micro-hardness (230.68 kgf/mm2) compared with that of Group III (190.28 kgf/mm2). In comparison to all other groups, laser etching prior to CPP-ACP application increased surface micro-hardness significantly (P < 0.001). Conclusion: Laser irradiation of primary teeth followed by CPP-ACP application increased surface micro-hardness of enamel.
Improvement of an anterior infrabone defect using combined periodontal and orthodontic therapy: A 6-year follow-up case report
Authors: de Molon Rafael Scaf , Kim Yeon Jung , dos Santos-Pinto Ary , Cirelli Joni Augusto
Published: July 2014

Extensive intraosseous lesions represent a clinical challenge for the periodontist. Sites with bone defects have been shown to be at higher risk of periodontitis progression in patients who had not received periodontal therapy. Thus, the aim of this case report was to describe a novel approach for the treatment of 1-walled intraosseous defect by combining nonsurgical periodontal therapy and orthodontic movement toward the bone defect, avoiding regenerative and surgical procedures. A 47-year-old woman underwent the proposed procedures for the treatment of her left central incisor with 9 mm probing depth and 1-walled intraosseous defect in its mesial aspect. Initially, basic periodontal therapy with scaling and root planning was accomplished. Two months later, an orthodontic treatment was planned to eliminate the intraosseous lesion and to improve the interproximal papillary area. Orthodontic root movement toward the osseous defect was performed for 13 months with light forces. After 6 years postoperative it was concluded that combined basic periodontal therapy and orthodontic movement was capable of eliminating the intraosseous defect and improve the esthetics in the interproximal papillary area between the central incisors.
Coronectomy of a lower third molar in combination with vital pulp therapy
Authors: Kim Young-Bin , Joo Woo-Hee , Min Kyung-San
Published: July 2014

Coronectomy is a procedure that intentionally spares the vital root after removal of the crown of the lower third molar to avoid damage to the inferior alveolar nerve. Vital pulp therapy is one option for managing exposed pulp tissue to reduce the risk of pulpal inflammation or necrosis. Among various dental materials, mineral trioxide aggregate (MTA) has been successfully used for vital pulp therapy. Thus, this case report discusses a coronectomy procedure in combination with vital pulp therapy using MTA. This case also attempts to highlight the formation of tertiary dentin, evidence of successful vital pulp therapy.
Integrative Pathway Analysis Using Graph-Based Learning with Applications to TCGA Colon and Ovarian Data
Authors: Dellinger Andrew E. , Nixon Andrew B. , Pang Herbert
Published: July 2014

Recent method development has included multi-dimensional genomic data algorithms because such methods have more accurately predicted clinical phenotypes related to disease. This study is the first to conduct an integrative genomic pathway-based analysis with a graph-based learning algorithm. The methodology of this analysis, graph-based semi-supervised learning, detects pathways that improve prediction of a dichotomous variable, which in this study is cancer stage. This analysis integrates genome-level gene expression, methylation, and single nucleotide polymorphism (SNP) data in serous cystadenocarcinoma (OV) and colon adenocarcinoma (COAD). The top 10 ranked predictive pathways in COAD and OV were biologically relevant to their respective cancer stages and significantly enhanced prediction accuracy and area under the ROC curve (AUC) when compared to single data-type analyses. This method is an effective way to simultaneously predict binary clinical phenotypes and discover their biological mechanisms.
Localization and Completeness in L2(ℝ)
Authors: Olevskii Victor
Published: July 2014

We give a necessary and sufficient condition for a sequence to be a localization set for a determining average sampler.
Nutrient availability affects the response of juvenile corals and the endosymbionts to ocean acidification
Authors: Tanaka Yasuaki , Iguchi Akira , Nishida Kozue , Inoue Mayuri , Nakamura Takashi , Suzuki Atsushi , Sakai Kazuhiko
Published: July 2014

The interactive effects of nutrient availability and ocean acidification on coral calcification were investigated using post‐settlement juvenile corals of Acropora digitifera cultured in nutrient‐sufficient or nutrient‐depleted seawater for 4 d and then exposed to seawater with different partial pressure of carbon dioxide (PCO2) conditions (38.8 or 92.5 Pa) for 10 d. After the nutrient pretreatment, corals in the high nutrient condition (HN corals) had a significantly higher abundance of endosymbiotic algae than did those in the low nutrient condition (LN corals). The high abundance of endosymbionts in HN corals was reduced as a result of subsequent seawater acidification, and the chlorophyll a per algal cell increased. The photosynthetic oxygen production rate by endosymbionts was enhanced by the acidified seawater regardless of the nutrient treatment, indicating that the reduction in endosymbiont density in HN corals due to acidification was compensated for by the increase in chlorophyll a per cell. Though the photosynthetic rate increased in the acidified conditions for both LN and HN corals, the calcification rate significantly decreased for LN corals but not for HN corals. The acquisition of nutrients from seawater, rather than the increase in alkalinity caused by photosynthesis, might effectively alleviate the negative response of coral calcification to seawater acidification, suggesting that the response of corals and their endosymbionts to ocean acidification can be influenced by nutrient conditions.
Community succession in hydrothermal vent habitats of the Eastern Lau Spreading Center and Valu Fa Ridge, Tonga
Authors: Sen Arunima , Podowski Elizabeth L. , Becker Erin L. , Shearer Erica A. , Gartman Amy , Yücel Mustafa , Hourdez Stéphane , Luther George W. , III , Fisher Charles R.
Published: July 2014

Patterns of succession in Lau Basin hydrothermal vent communities determined with high‐resolution imagery and in situ physico—chemical data collected over 4 yr and analyzed within a Geographic Information System show that Alviniconcha snails are a pioneering group, the snail Ifremeria nautilei is a mid‐successional species, and the heat‐intolerant mussel Bathymodiolus brevior dominates when venting declines. The associated fauna also changes as communities progress through the successional stages, and eventually non‐vent—endemic deep‐sea species appear when venting has mostly subsided. This is a unique example of primary succession in which the primary producers form symbiotic associations with mobile animals, resulting in successional patterns not observed in other systems. I. nautilei dominates newly formed substrates or venting sources where both I. nautilei and Alviniconcha spp. are already established (e.g., by migration), while Alviniconcha spp. seem to be better at colonizing newly active vents (e.g., by settlement) that are remote from colonized vents. Thus, on the scale of a 5–39 m2 diffuse flow area or a single edifice, the mid‐successional species dominates new substrates instead of the pioneering group. These communities are remarkably stable over long time periods relative to other hydrothermal vent regions. In addition to the sequential replacements of species as sites age and overall conditions change, Lau vent animals track changes in vent fluids and relocate themselves when local hydrothermal plumbing changes over small spatial scales.
Anxiety in Preadolescent Children: What Happens If We Don't Treat It, and What Happens If We Do?
Authors: Simon Ellin , van der Sluis Cathy , Muris Peter , Thompson Ellen , Cartwright-Hatton Sam
Published: July 2014

In this paper, we review the area of anxiety in children under the age of 11 years. We explore the literature examining the continuity of anxiety symptoms and behavioral inhibition when they appear in children of this age, and show that when these are present, there is a high likelihood of significant anxiety in later childhood, adolescence, and beyond. We then focus on the growing area of treatment research. We show that there are a number of promising new avenues for managing anxiety disorders in this young age group. Many of these interventions involve a key role for parents in the treatment process, but others have demonstrated success employing modified cognitive behavior therapy directed at the child. Limitations to the conclusions, caused by the limited amounts research, small sample sizes and significant methodological difficulties, are discussed.
Gauss-Seidel Limb Scattering (GSLS) radiative transfer model development in support of the Ozone Mapping and Profiler Suite (OMPS) Limb Profiler mission
Authors: Loughman R. , Flittner D. , Nyaku E. , Bhartia P. K.
Published: July 2014

Abstract. The Gauss-Seidel Limb Scattering (GSLS) radiative transfer (RT) model simulates the transfer of solar radiation through the atmosphere, and is imbedded in the retrieval algorithm used to process data from the Ozone Mapping and Profiler Suite (OMPS) Limb Profiler (LP), which was launched on the Suomi NPP satellite in October 2011. A previous version of this model has been compared with several other limb scattering RT models in previous studies, including Siro, MCC++, CDIPI, LIMBTRAN, SASKTRAN, VECTOR, and McSCIA. To address deficiencies in the GSLS radiance calculations revealed in earlier comparisons, several recent changes have been added that improve the accuracy and flexibility of the GSLS model, including: 1. Improved treatment of the variation of the extinction coefficient with altitude, both within atmospheric layers and above the nominal top of the atmosphere (TOA). 2. Addition of multiple scattering source function calculations at multiple zeniths along the line of sight (LOS). 3. Re-introduction of the ability to simulate vector (polarized) radiances. 4. Introduction of variable surface properties along the limb LOS, with minimal effort required to add variable atmospheric properties along the LOS as well. 5. Addition of the ability to model multiple aerosol types within the model atmosphere. The model improvements numbered 1–3 above are verified by comparison to previously published results (using standard radiance tables whenever possible), demonstrating significant improvement in cases for which previous versions of the GSLS model performed poorly. The single-scattered radiance errors that were as high as 4% in earlier studies are now generally reduced to < 0.5%, while total radiance errors generally decline from > 10% to 1–2%. In all cases, the height dependence of the GSLS radiance error is greatly reduced.
Tropospheric vertical column densities of NO2 over managed dryland ecosystems (Xinjiang, China): MAX-DOAS measurements vs. 3-D dispersion model simulations based on laboratory derived NO emission from soil samples
Authors: Mamtimin B. , Behrendt T. , Badawy M. M. , Wagner T. , Qi Y. , Wu Z. , Meixner F. X.
Published: July 2014

Abstract. We report on MAX-DOAS observations of NO2 over an oasis-ecotone-desert ecosystem in NW-China. There, local ambient NO2 concentrations originate from enhanced biogenic NO emission of intensively managed soils. Our target oasis "Milan" is located at the southern edge of the Taklimakan desert, very remote and well isolated from other potential anthropogenic and biogenic NOx sources. Four observation sites for MAX-DOAS measurements were selected, at the oasis center, downwind and upwind of the oasis, and in the desert. Biogenic NO emissions in terms of (i) soil moisture and (ii) soil temperature of Milan oasis' (iii) different land-cover type sub-units (cotton, Jujube trees, cotton/Jujube mixture, desert) were quantified by laboratory incubation of corresponding soil samples. Net potential NO fluxes were up-scaled to oasis scale by areal distribution and classification of land-cover types derived from satellite images using GIS techniques. A Lagrangian dispersion model (LASAT, Lagrangian Simulation of Aerosol-Transport) was used to calculate the dispersion of soil emitted NO into the atmospheric boundary layer over Milan oasis. Three dimensional NO concentrations (30 m horizontal resolution) have been converted to 3-D NO2 concentrations, assuming photostationary state conditions. NO2 column densities were simulated by suitable vertical integration of modeled 3-D NO2 concentrations at those downwind and upwind locations, where the MAX-DOAS measurements were performed. Downwind-upwind differences (a direct measure of Milan oasis' contribution to the areal increase of ambient NO2 concentration) of measured and simulated slant (as well as vertical) NO2 column densities show excellent agreement. This agreement is considered as the first successful attempt to prove the validity of the chosen approach to up-scale laboratory derived biogenic NO fluxes to ecosystem field conditions, i.e. from the spatial scale of a soil sample (cm2) to the size of an entire agricultural ecosystem (km2).
Scavenging ratio of polycyclic aromatic compounds in rain and snow at the Athabasca oil sands region
Authors: Zhang L. , Cheng I. , Muir D. , Charland J.-P.
Published: July 2014

Abstract. Athabasca oil sands industry in northern Alberta, Canada is a possible source of polycyclic aromatic compounds (PACs). Monitored PACs, including polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and dibenzothiophenes, in precipitation and in air at three near-source sites in the Fort MacKay and Fort McMurray area during May 2011 to August 2012 were analyzed to generate a database of scavenging (or washout) ratios (Wt) for PACs scavenged by both snow and rain. Median precipitation and air concentrations of parent PAHs over the May 2011 to August 2012 period ranged from 0.3–184.9 (chrysene) ng L−1 and 0.01–3.9 (naphthalene) ng m−3, respectively, which were comparable to literature values. Higher concentrations in precipitation and air were observed for alkylated PAHs and dibenzothiophenes. The median precipitation and air concentrations were 11.3–646.7 (C3-fluoranthene/pyrene) ng L−1 and 0.21–16.9 (C3-naphthalene) ng m−3, respectively, for alkylated PAHs, and 8.5–530.5 (C4-dibenzothiophene) ng L−1 and 0.13–6.6 (C2-dibenzothiophene) ng m−3 for dibenzothiophenes and their alkylated derivatives. Median Wt over the measurement period were 6100–1.1 × 106 from snow scavenging and 350–2.3 × 105 from rain scavenging depending on the PAC species. Median Wt for parent PAHs were within the range of those observed at other urban and suburban locations. But Wt for acenaphthylene in snow samples was 2–7 times higher. Some individual snow and rain samples exceeded literature values by a factor of 10. Wt for benzo(a)pyrene, dibenz(a,h)anthracene, and benzo(g,h,i)perylene in snow samples had reached 107, which is the maximum for PAH snow scavenging ratios reported in literature. From the analysis of data subsets, Wt for particulate-phase dominant PACs were 14–20 times greater than gas-phase dominant PACs in snow samples and 7–20 times greater than gas-phase dominant PACs in rain samples. Wt from snow scavenging was ∼9 times greater than rain scavenging for particulate-phase dominant PACs and 4–9.6 times greater than rain scavenging for gas-phase dominant PACs. Gas-particle fractions of each PAC, particle size distributions of particulate-phase dominant PACs, and Henry's Law constant of gas-phase dominant PACs explained, to a large extent, the different Wt values among the different PACs and precipitation types. This study verified findings from a previous study of Wang et al. (2014) which suggested that snow scavenging is more efficient than rain scavenging of particles for equivalent precipitation amount, and also provided new knowledge on the scavenging of gas-phase PACs by snow and rain.
The Orbiting Carbon Observatory (OCO-2): spectrometer performance evaluation using pre-launch direct sun measurements
Authors: Frankenberg C. , Pollock R. , Lee R. A. M. , Rosenberg R. , Blavier J.-F. , Crisp D. , O'Dell C. W. , Osterman G. B. , Roehl C. , Wennberg P. O. , Wunch D.
Published: July 2014

Abstract. The Orbiting Carbon Observatory-2 (OCO-2), launched on 2 July 2014, is a NASA mission designed to measure the column-averaged CO2 dry air mole fraction, XCO2. Towards that goal, it will collect spectra of reflected sun-light in narrow spectral ranges centered at 0.76, 1.6 and 2.0 μm with a resolving power (λ/Δ λ) of 20 000. These spectra will be used in an optimal estimation framework to retrieve XCO2. About 100 000 cloud free soundings of XCO2 each day will allow estimates of net CO2 fluxes on regional to continental scales to be determined. Here, we evaluate the OCO-2 spectrometer performance using pre-launch data acquired during instrument thermal vacuum tests in April 2012. A heliostat and a diffuser plate were used to feed direct sunlight into the OCO-2 instrument and spectra were recorded. These spectra were compared to those collected concurrently from a nearby high-resolution Fourier Transform Spectrometer that was part of the Total Carbon Column Observing Network (TCCON). Using the launch-ready OCO-2 calibration and spectroscopic parameters, we performed total column scaling fits to all spectral bands and compared these to TCCON results. On 20 April, we detected a CO2 plume from the Los Angeles basin at the JPL site with strongly enhanced short-term variability on the order of 1% (3–4 ppm). We also found good (<0.5 pppm) inter-footprint consistency in retrieved XCO2. The variations in spectral fitting residuals are consistent with signal-to-noise estimates from instrument calibration, while average residuals are systematic and mostly attributable to remaining errors in our knowledge of the CO2 and O2 spectroscopic parameters. A few remaining inconsistencies observed during TVAC may be attributable to the specific instrument setup on the ground and will be re-evaluated with in-orbit data, when the instrument is expected to be in a much more stable environment.
A reduced-complexity model for river delta formation – Part 2: Validation of the flow routing scheme
Authors: Liang M. , Geleynse N. , Edmonds D. A. , Passalacqua P.
Published: July 2014

Abstract. In a companion paper (Liang et al., 2014) we introduced a Reduced-Complexity Model (RCM) for river delta formation, developed using a parcel-based "weighted random walk" method for routing water and sediment flux. This model (referred to as "DeltaRCM") consists of a flow routing scheme as the hydrodynamic component (referred to as "FlowRCM") and a set of sediment transport rules as the morphodynamic component. In this work, we validate the flow routing scheme (FlowRCM) via a series of hydrodynamic tests by comparing the model outputs to Delft3D and theoretical predictions. These tests are designed to reveal the capability of FlowRCM to resolve flow field features that are critical to delta dynamics at the level of channel processes. In particular, we focus on (1) backwater profile, (2) flow around a mouth bar, (3) flow through a single bifurcation, and (4) flow through a distributary channel network. We show that while the simple rules are not able to reproduce all fine-scale flow structures, FlowRCM does capture flow field features that are essential to deltaic processes such as bifurcations and avulsions. Finally, we discuss advantages and limitations of FlowRCM and identify environments most suitable for it.
Stochastic modelling of spatially and temporally consistent daily precipitation time-series over complex topography
Authors: Keller D. E. , Fischer A. M. , Frei C. , Liniger M. A. , Appenzeller C. , Knutti R.
Published: July 2014

Abstract. Many climate impact assessments over topographically complex terrain require high-resolution precipitation time-series that have a spatio-temporal correlation structure consistent with observations. This consistency is essential for spatially distributed modelling of processes with non-linear responses to precipitation input (e.g. soil water and river runoff modelling). In this regard, weather generators (WGs) designed and calibrated for multiple sites are an appealing technique to stochastically simulate time-series that approximate the observed temporal and spatial dependencies. In this study, we present a stochastic multi-site precipitation generator and validate it over the hydrological catchment Thur in the Swiss Alps. The model consists of several Richardson-type WGs that are run with correlated random number streams reflecting the observed correlation structure among all possible station pairs. A first-order two-state Markov process simulates intermittence of daily precipitation, while precipitation amounts are simulated from a mixture model of two exponential distributions. The model is calibrated separately for each month over the time-period 1961–2011. The WG is skilful at individual sites in representing the annual cycle of the precipitation statistics, such as mean wet day frequency and intensity as well as monthly precipitation sums. It reproduces realistically the multi-day statistics such as the frequencies of dry and wet spell lengths and precipitation sums over consecutive wet days. Substantial added value is demonstrated in simulating daily areal precipitation sums in comparison to multiple WGs that lack the spatial dependency in the stochastic process: the multi-site WG is capable to capture about 95% of the observed variability in daily area sums, while the summed time-series from multiple single-site WGs only explains about 13%. Limitation of the WG have been detected in reproducing observed variability from year to year, a component that has not been considered in the WG calibration. Given the obtained performance, the presented stochastic model is expected to be a useful tool to re-sample the observed record and valuable to be used as a statistical downscaling method in a climate change context.
Variability of low flow magnitudes in the Upper Colorado River Basin: identifying trends and relative role of large-scale climate dynamics
Authors: Pournasiri Poshtiri M. , Pal I.
Published: July 2014

Abstract. Low flow magnitude in a head water basin is important for planners because minimum available amount of water in a given time period often leads to concerns regarding serious repercussions, in both up and downstream regions. This is a common scenario in arid region like Colorado River basin located in the southwestern US. Low flow variability in Colorado River is due to complex interactions between several natural and anthropogenic factors; but we aim to identify the relative role of climate on varying low flow magnitudes at different spatial locations. The research questions we aim to answer are: Is there a systematic variability in water availability during the driest time of a year or season? How does that vary across locations and is there a link between large-scale climate and low flow variations? Towards that aim we select 17 stream gauge locations, which are identified as "undisturbed" meaning that these stations represent near-natural river flow regimes in the headwater region of Colorado River, which provides a useful resource for assessment of climate and hydrology associations without the confounding factor of major direct (e.g. water abstraction) or indirect (e.g. land-use change) human modification of flows. A detailed diagnostic analysis gives us fair understanding on the variability of low flow magnitude that is explained by climate. We also present spatial heterogeneity of hydro-climatological linkages that is important for suitable adaptive management measures.
Recharge estimation and soil moisture dynamics in a Mediterranean karst aquifer
Authors: Ries F. , Lange J. , Schmidt S. , Puhlmann H. , Sauter M.
Published: July 2014

Abstract. Knowledge of soil moisture dynamics in the unsaturated soil zone provides valuable information on the temporal and spatial variability of groundwater recharge. This is especially true for the Mediterranean region, where a substantial fraction of long-term groundwater recharge is expected to occur during high magnitude precipitation events of above-average wet winters. To elucidate process understanding of infiltration processes during these extreme events, a monitoring network of precipitation gauges, meteorological stations, and soil moisture plots was installed in an area with a steep climatic gradient in the Jordan Valley region. In three soil moisture plots, Hydrus-1D was used to simulate water movement in the unsaturated soil zone with soil hydraulic parameters estimated by the Shuffled Complex Evolution Metropolis algorithm. To generalize our results, we modified soil depth and rainfall input to simulate the effect of the pronounced climatic gradient and soil depth variability on percolation fluxes and applied the calibrated model to a time series with 62 years of meteorological data. Soil moisture measurements showed a pronounced seasonality and suggested rapid infiltration during heavy rainstorms. Hydrus-1D successfully simulated short and long-term soil moisture patterns, with the majority of simulated deep percolation occurring during a few intensive rainfall events. Temperature drops in a nearby groundwater well were observed synchronously with simulated percolation pulses, indicating rapid groundwater recharge mechanisms. The 62 year model run yielded annual percolation fluxes of up to 66% of precipitation depths during wet years and of 0% during dry years. Furthermore, a dependence of recharge on the temporal rainfall distribution could be shown. Strong correlations between depth of recharge and soil depth were also observed.
An interdisciplinary approach to volcanic risk reduction under conditions of uncertainty: a case study of Tristan da Cunha
Authors: Hicks A. , Barclay J. , Simmons P. , Loughlin S.
Published: July 2014

Abstract. The uncertainty brought about by intermittent volcanic activity is fairly common at volcanoes worldwide. While better knowledge of any one volcano's behavioural characteristics has the potential to reduce this uncertainty, the subsequent reduction of risk from volcanic threats is only realised if that knowledge is pertinent to stakeholders and effectively communicated to inform good decision making. Success requires integration of methods, skills and expertise across disciplinary boundaries. This research project develops and trials a novel interdisciplinary approach to volcanic risk reduction on the remote volcanic island of Tristan da Cunha (South Atlantic). For the first time, volcanological techniques, probabilistic decision support and social scientific methods were integrated in a single study. New data were produced that (1) established no spatio-temporal pattern to recent volcanic activity; (2) quantified the high degree of scientific uncertainty around future eruptive scenarios; (3) analysed the physical vulnerability of the community as a consequence of their geographical isolation and exposure to volcanic hazards; (4) evaluated social and cultural influences on vulnerability and resilience; and (5) evaluated the effectiveness of a scenario planning approach, both as a method for integrating the different strands of the research and as a way of enabling on-island decision makers to take ownership of risk identification and management, and capacity building within their community. The paper provides empirical evidence of the value of an innovative interdisciplinary framework for reducing volcanic risk. It also provides evidence for the strength that comes from integrating social and physical sciences with the development of effective, tailored engagement and communication strategies in volcanic risk reduction.
Geohazard risk assessment using high resolution SAR interferometric techniques: a case study of Larissa National Airport Central Greece
Authors: Fakhri F. , Kalliola R.
Published: July 2014

Abstract. The possibility of use the productions of Earth Resource Satellite (ERS-1/2) and Advanced Environment Satellite ENVISAT SAR (Synthetic Aperture Radar) C-band have given the potential to detect and estimate the time series of dynamic ground deformation within high spatial and temporal resolution. The Larissa National Airport is suffering from continued ground deformation as evidenced by the presence of ground fissures and sinkholes as well as observed land subsidence. This study uses two Synthetic Aperture Radar interferometric techniques (InSAR) to detect short- and long-term ground deformation dynamics in the airport using the GAMMA Software (S/W). The results indicate complex subsidence and uplift processes at ranges between −15 and 25 mm a−1 to co-occur in different parts of the study region. Some of these changes may be attributed to tectonic fault movements but some of the observed ground deformation processes are more likely to result from human induced changes in the groundwater level and expansive soils.
Deriving a sea surface climatology of CO2 fugacity in support of air–sea gas flux studies
Authors: Goddijn-Murphy L. M. , Woolf D. K. , Land P. E. , Shutler J. D. , Donlon C.
Published: July 2014

Abstract. Climatologies, or long-term averages, of essential climate variables are useful for evaluating models and providing a baseline for studying anomalies. The Surface Ocean Carbon Dioxide (CO2) Atlas (SOCAT) has made millions of global underway sea surface measurements of CO2 publicly available, all in a uniform format and presented as fugacity, fCO2. fCO2 is highly sensitive to temperature and the measurements are only valid for the instantaneous sea surface temperature (SST) that is measured concurrent with the in-water CO2 measurement. To create a climatology of fCO2 data suitable for calculating air–sea CO2 fluxes it is therefore desirable to calculate fCO2 valid for climate quality SST. This paper presents a method for creating such a climatology. We recomputed SOCAT's fCO2 values for their respective measurement month and year using climate quality SST data from satellite Earth observation and then extrapolated the resulting fCO2 values to reference year 2010. The data were then spatially interpolated onto a 1° × 1° grid of the global oceans to produce 12 monthly fCO2 distributions for 2010. The partial pressure of CO2 (pCO2) is also provided for those who prefer to use pCO2. The CO2 concentration difference between ocean and atmosphere is the thermodynamic driving force of the air–sea CO2 flux, and hence the presented fCO2 distributions can be used in air–sea gas flux calculations together with climatologies of other climate variables.
Spatial self-selection in land-use–travel behavior interactions: accounting simultaneously for attitudes and socioeconomic characteristics
Authors: De Abreu e Silva João
Published: July 2014

Spatial self-selection can be ascribed to two main factors: socioeconomic characteristics or attitudinal aspects towards travel and location choices. Several studies have investigated the influence of self-selection on the relations between travel behavior and land-use patterns. So far the results could be considered mixed.

The model proposed herein uses data collected in 2009 for the Lisbon Metropolitan Area. A structural equations model was built to study the effects of spatial self-selection due to both socioeconomic and attitudinal effects. Three model specifications were considered: one treating attitudes toward travel as exogenous and two others considering them as endogenous. The preferred specification considered attitudes as exogenous. The land-use patterns are described by factors both at the residence and employment zones of each individual. The travel behavior variables included here are multidimensional and include commuting distance, car ownership, the number of trips by mode, and the total amount of time between the first and last trips. On account of the data characteristics and sample size, Bayesian estimation, as implemented in AMOSTM software, was used. The results obtained show that although the attitudinal variables significantly influence travel behavior, they do not annul the effects of land-use patterns in also contributing to shape the same behavior.
Temporal transferability of models of mode-destination choice for the Greater Toronto and Hamilton Area
Authors: Fox James , Daly Andrew , Hess Stephane , Miller Eric
Published: July 2014

Transport planning relies extensively on forecasts of traveler behavior over horizons of 20 years and more. Implicit in such forecasts is the assumption that travelers’ tastes, as represented by the behavioral model parameters, are constant over time. In technical terms, this assumption is referred to as the "temporal transferability" of the models. This paper summarizes the findings from a literature review that demonstrates there is little evidence about the transferability of mode-destination models over typical forecasting horizons. The literature review shows a relative lack of empirical studies given the importance of the issue. To provide further insights and evidence, models of commuter mode-destination choice been developed from household interview data collected across the Greater Toronto and Hamilton Area in 1986, 1996, 2001, and 2006. The analysis demonstrates that improving model specification improves the transferability of the models, and in general the transferability declines as the transfer period increases. The transferability of the level-of-service parameters is higher than transferability of the cost parameters, which has important implications when considering the accuracy of forecasts for different types of policy. The transferred models over-predict the key change in mode share over the transfer period—specifically, the shift from local transit to auto driver between 1986 and 1996—but under-predict the growth in commuting tour lengths over the same period.
What Hope Means to Parents of Children with Cancer?
Authors: Chinchilla-Salcedo Tania Catalina ,   Universidad de La Sabana
Published: July 2014

Objetivo: describir el concepto de la esperanza que tienen los padres de niños entre 0 y 15 años de edad con diagnóstico de cáncer. Método: investigación cualitativa de tipo descriptivo exploratorio; la información se recolectó en cuatro ciudades de Colombia, a través de entrevistas semiestructuradas a once padres de niños con diagnóstico de cáncer. Resultados: se identificaron doce categorías que describen las experiencias de los padres y cómo estas los llevan vivir y a describir la esperanza como virtud y estado de ánimo. Conclusiones: la esperanza termina siendo el eje fundamental que mueve la vida de los padres; las experiencias alrededor del cáncer de sus hijos transforman el significado de la enfermedad y de su propias vidas, en las cuales se redescubren estrategias y mecanismos positivos de afrontamiento.