bluuebunny/crossref_metadata_2025 huggingface dataset:
Porcine β-Defensin 2 Attenuates Inflammation and Mucosal Lesions in Dextran Sodium Sulfate–Induced Colitis
Authors: Han Feifei , Zhang Haiwen , Xia Xi , Xiong Haitao , Song Deguang , Zong Xin , Wang Yizhen
Published: January 2015

Intestinal permeability plays a critical role in the etiopathogenesis of ulcerative colitis. Defensins, including porcine β-defensin (pBD)2, are crucial antimicrobial peptides for gut protection owing to their antibacterial and immunomodulatory activities. The purpose of this study was to investigate the protective effects of pBD2 on mucosal injury and the disruption of the epithelial barrier during the pathological process of dextran sodium sulfate (DSS)–induced colitis. The effects and mechanism of pBD2 were evaluated both using a DSS-induced C57BL/6 mouse model and, in vitro, using Caco-2 and RAW264.7 cells. DSS-induced colitis was characterized by higher disease activity index, shortened colon length, elevated activities of myeloperoxidase and eosinophil peroxidase, histologic evidence of inflammation, and increased expression levels of TNF-α, IL-6, and IL-8. pBD2 increased the expression of zonula occludens-1, zonula occludens-2, claudin-1, mucin-1, and mucin-2 mRNA and proteins, and it decreased permeability to FITC-D, as well as apoptosis, in DSS-treated mice. pBD2 also decreased inflammatory infiltrates of the colon epithelium. In Caco-2 cells, pBD2 increased transepithelial electrical resistance and mucin mRNA expression, and it decreased the permeability of FITC-D while preserving the structural integrity of the tight junctions. The effects of pBD2 appeared to be through upregulation of the expression of genes associated with tight junctions and mucins, and by suppressing DSS-induced increases in inflammation, inducible NO synthase, cyclooxygenase-2, and apoptosis. These results show that pBD2 improves DSS-induced changes in mucosal lesions and paracellular permeability, possibly by affecting the activation of NF-κB signaling. The present study demonstrates that intrarectal administration of pBD2 may be a novel preventive option for ulcerative colitis.
Reconnaissance geological mapping and thematic studies of northern Brock Inlier, Northwest Territories
Authors: Rainbird R H , Ielpi A , Turner E C , Jackson V A
Published: January 2015

Foreword
The Geo-mapping for Energy and Minerals (GEM) program is laying the foundation for sustainable economic development in the North. The Program provides modern public geoscience that will set the stage for long-term decision making related to investment in responsible resource development. Geoscience
knowledge produced by GEM supports evidence-based exploration for new energy and mineral resources and enables northern communities to make informed decisions about their land, economy and society. Building upon the success of its first five-years, GEM has been renewed until 2020 to continue
producing new, publically available, regional-scale geoscience knowledge in Canada's North.
During the summer 2014, GEM's new research program has been launched with 14 field activities that include geological, geochemical and geophysical surveying. These activities have been undertaken in collaboration with provincial and territorial governments, northerners and their institutions,
academia and the private sector. GEM will continue to work with these key collaborators as the program advances.
The Brock Inlier project is an activity within the Shield to Selwyn geo-transect: studying the evolution of sedimentary rocks of the northern mainland NWT to improve exploration success: This activity will initiate the first regional integrated effort to place Proterozoic to Cenozoic strata of
Mackenzie Platform, Selwyn Basin, and adjacent regions into a fully modern tectono-stratigraphic and metallogenic framework, and will better enable industry and Northerners to responsibly find and develop energy and mineral natural resources, maximizing their economic and societal
impact.
Antibacterial and smear layer removal capability of oregano extract solution
Authors: Ok Evren , Adanir Necdet , Ozturk Tuba
Published: January 2015

Objective: The aim of this in vitro study was to evaluate the antimicrobial effect of oregano extract solution (OES) against Enterococcus faecalis within root canals and dentin tubules, and its effect on smear layer. Materials and Methods: A total of 180 human maxillary central incisors was selected. After removal of coronal part of the teeth, root canals were prepared using ProTaper rotary files (Dentsply, Tulsa Endodontics, OK, USA) to #F3 with the crown-down manner. The roots were randomly assigned to 15 groups (n = 12 for each). In the first seven groups, the antimicrobial effects of the test groups were evaluated. Suspensions of E. faecalis cultures were adjusted to 1.0 McFarland (1 × 108 colony-forming unit [CFU]/ml), and sterilized teeth were placed in Eppendorf tubes and kept at 37°C for 4 weeks. Samples were then taken from the root canals before irrigation using three sterile paper points. Dentin samples were taken from root canals with ProTaper #F4 and #F5 series rotary instruments after irrigation. The aliquots of samples were placed into the brain heart infusion and incubated at 37°C for 48 h and then the CFUs were counted. In the other eight groups, the efficacy of the irrigation solutions on removing the smear layer was evaluated using scanning electron microscope (Leo 440, Oxford Microscopy Ltd., Cambridge, England) analysis. Statistical evaluation of the microbiological data was performed using the Kruskall–Wallis and Mann– Witney U-test (P < 0.05). Results: There was a statistically difference between the groups (P < 0.05). Chlorhexidine gluconate (CHX), 5% and 2% OES wasn't found to be statistically significant regarding their antibacterial activities against E. faecalis (P > 0.05). 1% OES and NaOCl showed similar antimicrobial effect (P > 0.05), and 1% OES and NaOCl were better than ethylenediaminetetraacetic acid (EDTA) and saline (P < 0.05) but not as successful as CHX. According to the results obtained from dentin, CHX is the most effective solution within dentinal tubules. Different concentrations of OES were not achieved smear layer removal alone but OES in conjunction with 17% EDTA was the final irrigating solution achieved the smear layer removal without dentin erosion. Conclusions: Within the limitations of this study, OES appears to be a possible alternative to NaOCl as a root canal irrigant on the eradication of E. faecalis and removal of smear layer.
Do different bleaching protocols affect the enamel microhardness?
Authors: Mondelli Rafael Francisco Lia , Gabriel Taisa R. Conti Garrido , Rizzante Fabio Antonio Piola , Magalhães Ana Carolina , Bombonatti Juliana Fraga Soares , Ishikiriama Sérgio Kiyoshi
Published: January 2015

Objective: Tooth bleaching tends to increase enamel roughness and porosity, in addition to reducing surface microhardness. The aim of this in vitro study was to evaluate the effects of bleaching treatments using different hydrogen peroxide (HP) concentrations, with and without light activation on bovine enamel microhardness. Materials and Methods: The buccal surfaces of sixty bovine incisors were flattened and polished and the enamel specimens were divided into six groups: G1: Control, exposed to artificial saliva; G2: 35% HP applied in two sessions (45’ each); G3: 35% HP applied in two sessions (3 × 15’ each); G4: 35% HP applied in one session (3 × 7’30”) plus hybrid light (HL); G5: 25% HP applied in one session (3 × 7’30”) plus HL; and G6: 15% HP applied in one session (3 × 7’30”) plus HL. After the treatment, the enamel specimens were stored in artificial saliva. The surface microhardness (Knoop) was measured at the baseline, 24 h and 7 days after bleaching. The data was analyzed using the ANOVA test, followed by the Tukey–Krummer test (P < 0.05). Results: All bleaching procedures lead to a decrease in surface microhardness when compared with the control group after 24 h. The lowest change in surface microhardness was found in the specimens treated with 15% HP plus HL. However, 35% HP plus HL induced the highest decrease in surface microhardness. After 7 days of remineralization, the surface microhardness returned to normal levels for all bleached specimens. Conclusion: Therefore, it can be concluded that the bleaching protocols caused a slight enamel surface alteration. However, the remineralization process minimized these effects.
Impact of metronidazole and amoxicillin combination on matrix metalloproteinases-1 and tissue inhibitors of matrix metalloproteinases balance in generalized aggressive periodontitis
Authors: Cifcibasi Emine , Kantarci Alpdogan , Badur Selim , Issever Halim , Cintan Serdar
Published: January 2015

Objective: Generalized aggressive periodontitis (GAgP) is a complex periodontal disease affecting the entire dentition with a rapid destruction of the periodontium and resulting in loss of teeth. We hypothesized that better clinical healing of adjunctive use of amoxicillin plus metronidazole combination may be related to the effect of this combination therapy to restore imbalance between matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) which is associated with connective tissue and alveolar bone destruction in patients with GAgP. Materials and Methods: Twenty-eight subjects diagnosed with GAgP were recruited. Patients were randomly assigned to test or control groups. MMP-1/TIMP-1 ratio was compared between groups receiving scaling and root planning (SRP) alone (control) or in combination with amoxicillin plus metronidazole (test). Clinical periodontal variables were measured. Gingival crevicular fluid samples were obtained and analyzed for MMP-1 and TIMP-1. Measurements were taken at baseline and repeated at 3 and 6 months after therapy. Results: Total MMP-1 levels were significantly decreased in both groups (P < 0.05) at 3 and 6 months. MMP-1 concentration levels showed a similar pattern to MMP-1 total levels decreasing significantly at 3 months (P < 0.05). TIMP-1 concentration levels increased in the test group throughout the study period, while the difference did not reach statistical significance (P > 0.05). TIMP-1/MMP-1 balance was restored in test group at 6 months significantly better than the control group (P < 0.05). Conclusion: The results of this study suggest that metronidazole and amoxicillin combination as an adjunct to SRP results in better clinical healing through restoring TIMP-1/MMP-1 balance.
Effect of ultraviolet light irradiation on bond strength of fiber post: Evaluation of surface characteristic and bonded area of fiber post with resin cement
Authors: Reza Fazal , Ibrahim Nur Sukainah
Published: January 2015

Objective: Fiber post is cemented to a root canal to restore coronal tooth structure. This research aims to evaluate the effect of ultraviolet (UV) irradiation on bond strength of fiber post with resin cement. Materials and Methods: A total of 40 of the two types of fiber posts, namely, FRC Prostec (FRC) and Fiber KOR (KOR), were used for the experiment. UV irradiation was applied on top of the fiber post surface for 0, 15, 20, and 30 min. The irradiated surface of the fiber posts (n = 5) were immediately bonded with resin cement (Rely X U200) after UV irradiation. Shear bond strength (SBS) MPa was measured, and the dislodged area of post surfaces was examined with scanning electron microscopes. Changes in surface roughness (Ra) of the FRC group after UV irradiation were observed (n = 3) using atomic force microscopy. Data of SBS were statistically analyzed using one-way analysis of variance, followed by multiple comparisons (P < 0.05). Results: SBS was significantly higher for 20 min of UV irradiation of the FRC group while significantly higher SBS was observed with 15 min of UV irradiation of the KOR group. Resin cement was more evident (cohesive failure) on the dislodged post surface of the UV treated groups compared with the control. The surface roughness of the FRC post was Ra = 175.1 nm and Ra = 929.2 nm for the control and the 20 min group, respectively. Conclusions: Higher surface roughness of the UV irradiated group indicated formation of mechanical retention on the fiber post surface. Evidence of cohesive failure was observed which indicated higher SBS of fiber post with the UV irradiated group.
Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments
Authors: Celik Cigdem , Cehreli Sevi Burcak , Arhun Neslihan
Published: January 2015

Objective: The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. Materials and Methods: A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the restorations were removed out leaving only middle part. One side of the cavity was finished with course diamond bur and the other was air-abraded with 50 μm Al2O3. They were randomly divided into four groups (n = 10) to receive: Group 1: Adper Single Bond 2; Group 2: All Bond 3; Group 3: ClearfilSE; Group 4: BeautiBond, before being repaired with the same resin composite (Filtek Z250). The specimens were re-thermocycled (1000×), sealed with nail varnish, stained with 0.5% basic fuchsin, sectioned mesiodistally and photographed digitally. The extent of dye penetration was measured by image analysis software (ImageJ) for both bur-finished and air-abraded surfaces at resin-tooth and resin-resin interfaces. The data were analyzed statistically. Results: BeautiBond exhibited the most microleakage at every site. Irrespective of adhesive and initial composite type, air-abrasion showed less microleakage except for BeautiBond. The type of initial repaired restorative material did not affect the microleakage. BeautiBond adhesive may not be preferred in resin composite repair in terms of microleakage prevention. Conclusions: Surface treatment with air-abrasion produced the lowest microleakage scores, independent of the adhesive systems and the pre-existing resin composite type. Pre-existing composite type does not affect the microleakage issue. All-in-one adhesive resin (BeautiBond) may not be preferred in resin composite repair in terms of microleakage prevention.
Evaluation of intrabony defects treated with platelet-rich fibrin or autogenous bone graft: A comparative analysis
Authors: Mathur Ashish , Bains Vivek Kumar , Gupta Vivek , Jhingran Rajesh , Singh G. P.
Published: January 2015

Objective: The primary objective of this study was to compare clinically and radiographically the efficacy of autologous platelet rich fibrin (PRF) and autogenous bone graft (ABG) obtained using bone scrapper in the treatment of intrabony periodontal defects. Materials and Methods: Thirty-eight intrabony defects (IBDs) were treated with either open flap debridement (OFD) with PRF or OFD with ABG. Clinical parameters were recorded at baseline and 6 months postoperatively. The defect-fill and defect resolution at baseline and 6 months were calculated radiographically (intraoral periapical radiographs [IOPA] and orthopantomogram [OPG]). Results: Significant probing pocket depth (PPD) reduction, clinical attachment level (CAL) gain, defect fill and defect resolution at both PRF and ABG treated sites with OFD was observed. However, inter-group comparison was non-significant (P > 0.05). The bivariate correlation results revealed that any of the two radiographic techniques (IOPA and OPG) can be used for analysis of the regenerative therapy in IBDs. Conclusion: The use of either PRF or ABG were effective in the treatment of three wall IBDs with an uneventful healing of the sites.
Microleakage under orthodontic brackets bonded with different adhesive systems
Authors: Alkis Huseyin , Turkkahraman Hakan , Adanir Necdet
Published: January 2015

Objective: This in vitro study aimed to compare the microleakage of orthodontic brackets between enamel-adhesive and adhesive-bracket interfaces at the occlusal and gingival margins bonded with different adhesive systems. Materials and Methods: A total of 144 human maxillary premolar teeth extracted for orthodontic reasons was randomly divided into four groups. Each group was then further divided into three sub-groups. Three total-etching bonding systems (Transbond XT, Greengloo and Kurasper F), three one-step self-etching bonding systems (Transbond Plus SEP, Bond Force and Clearfil S3), three two-step self-etching bonding systems (Clearfil SE Bond, Clearfil Protectbond and Clearfil Liner Bond), and three self-adhesive resin cements (Maxcem Elite, Relyx U 100 and Clearfil SA Cement) were used to bond the brackets to the teeth. After bonding, all teeth were sealed with nail varnish and stained with 0.5% basic fuchsine for 24 h. All samples were sectioned and examined under a stereomicroscope to score for microleakage at the adhesive–enamel and adhesive–bracket interfaces from both occlusal and gingival margins. Statistical Analysis Used: Statistical analyses were performed with Kruskal–Wallis and Wilcoxon signed-rank tests. Results: The results indicate no statistically significant differences between the microleakage scores of the adhesives; microleakage was detected in all groups. Comparison of the average values of the microleakage scores in the enamel–adhesive and adhesive–bracket interfaces indicated statistically significant differences (P < 0.05). The amount of the microleakage was higher at the enamel–adhesive interface than at the bracket-adhesive interface. Conclusions: All of the brackets exhibited some amount of microleakage. This result means that microleakage does not depend on the type of adhesive used.
Root canal morphology of South Asian Indian maxillary molar teeth
Authors: Singh Shishir , Pawar Mansing
Published: January 2015

Objective: The objective was to study the root canal morphology of South Asian Indian Maxillary molars using a tooth clearing technique. Materials and Methods: Hundred teeth each comprising of first, second, and third molars collected from different dental schools and clinics in India were subjected to standard dye penetration, decalcification and clearing procedure before being studied. Results: The first molar mesiobuccal roots exhibited 69% Type I, 24% Type II, 4% Type IV, 2% Type V, and 1% exhibited a Vertuccis Type VIII canal anatomy. In the group with three separate roots the second molar mesiobuccal roots in exhibited 80.6% Type I, 15.3% Type II, 2.7% Type IV, and 1.4% Type V canal anatomy while the third molars mesiobuccal roots exhibited 57.4% Type I, 32% Type II, 2.1% Type III, 8.5% Type IV, 1% had a Type V canal anatomy in the similar group. Conclusion: A varied root canal anatomy was seen in the mesiobuccal root canal of the maxillary molars.
Genetic background of supernumerary teeth
Authors: Subasioglu Aslı , Savas Selcuk , Kucukyilmaz Ebru , Kesim Servet , Yagci Ahmet , Dundar Munis
Published: January 2015

Supernumerary teeth (ST) are odontostomatologic anomaly characterized by as the existence excessive number of teeth in relation to the normal dental formula. This condition is commonly seen with several congenital genetic disorders such as Gardner's syndrome, cleidocranial dysostosis and cleft lip and palate. Less common syndromes that are associated with ST are; Fabry Disease, Ellis-van Creveld syndrome, Nance-Horan syndrome, Rubinstein-Taybi Syndrome and Trico–Rhino–Phalangeal syndrome. ST can be an important component of a distinctive disorder and an important clue for early diagnosis. Certainly early detecting the abnormalities gives us to make correct management of the patient and also it is important for making well-informed decisions about long-term medical care and treatment. In this review, the genetic syndromes that are related with ST were discussed.
Effect of radiotherapy on the sealing ability of temporary filling materials
Authors: Bodrumlu Ebru Hazar , Bodrumlu Emre , Avşar Aysun , Meydan Ahmet Deniz
Published: January 2015

Objective: The purpose of this study was to assess the sealing ability of three different temporary restorative materials on endodontic access cavities as compared to radiated and nonirradiated teeth. Materials and Methods: All teeth were randomly divided into two main groups according to the presence or absence of the radiotherapy. The specimens in these groups were then divided into three subgroups of 12 teeth each, and into two control groups of eight teeth each as negative and positive control groups. In radiotherapy groups, radiotherapy (1.8 Gy) was applied daily over 35 days resulting in a total application of 63 Gy. Standardized occlusal endodontic access cavities were prepared in all groups. A cotton pellet was placed on the pulp chamber. The access cavities were restored with three temporary filling materials; first fill, Cavit-G and Cavisol. The specimens were immersed in 2% methylene blue solution and centrifuged at 3000 rpm for 5 min. Results: Although there was no statistical difference among the three materials for the groups in which radiotherapy was not applied (P > 0.05), it was found that the sealing abilities of Cavit-G and Cavisol were not affected by radiotherapy (P > 0.05). However, the leakage values of the light-cured polymerized temporary filling material, first fill, were increased when radiotherapy was performed (P < 0.05). Conclusion: The radiotherapy application reduces the sealing ability of the light-cured temporary filling material, first fill.
Ridge expansion with motor driven bone expanders: A clinical case report
Authors: Rodriguez-Martinez Juan B. , Munoz-Soto Esther , Peres Maria F. S. , Chaves Eros S.
Published: January 2015

Implant placement often requires bone augmentation procedures due to the presence of bone defects on the future implant site. The aim of the present case report is to describe a ridge expansion technique using sequential motor driven bone expanders to allow the implant placement in an atrophic maxillary ridge. The use of the motorized expanders avoided a bone augmentation surgical procedure prior to implant placement and, as a result, reduced the overall treatment time. The results were followed-up for 2 years after the implant supported the crown delivery.
Endodontic management of maxillary first molar with three mesiobuccal root canals using cone beam computerized tomography
Authors: Chalkar Aaditya , Bhagwat Sumita , Mandke Lalitagauri
Published: January 2015

Endodontic treatment of maxillary first molar with three canals in mesiobuccal root using cone beam computerized tomography (CBCT). This case report presents a maxillary first molar with three mesiobuccal canals. Missing a canal during root canal therapy is one of the main causes of endodontic failure. The frequency of detection of extra canals has increased with better techniques in instrumentation, magnification and illumination. The present case shows three canals in the mesiobuccal root, which is an aberrant and rare anatomical presentation. CBCT proved to be an important tool in confirming the presence and location of the extra canals.
Management of C-shaped root canal configuration with three different obturation systems
Authors: Elumalai Deenadayalan , Kumar Ashok , Tewari Rajendra Kumar , Mishra Surendra Kumar , Andrabi Syed Mukhtar-Un-Nisar , Iftekhar Huma , Alam Sharique
Published: January 2015

Unusual root canal anatomy always poses a diagnostic and treatment challenge. Identification of such variation is important for the success of the root canal treatment outcome. The C-shaped root canal configuration is one of the aberrant morphology of molar teeth, commonly the mandibular second molar. In this configuration, the canals are connected by slit or web. The presence of fin, slit and web makes through debridement obstacle for the clinician. This case reports present successful management of C-shaped mandibular molars with three different obturation systems.
The Ongoing Revolution of MALDI-TOF Mass Spectrometry for Microbiology Reaches Tropical Africa
Authors: Fall Bécaye , Lo Cheikh Ibrahima , Samb-Ba Bissoume , Perrot Nadine , Diawara Silman , Gueye Mamadou Wague , Sow Kowry , Aubadie-Ladrix Maxence , Mediannikov Oleg , Sokhna Cheikh , Diemé Yaya , Chatellier Sonia , Wade Boubacar , Raoult Didier , Fenollar Florence
Published: January 2015

Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) represents a revolution in routine pathogen identification in clinical microbiology laboratories. A MALDI-TOF MS was introduced to tropical Africa in the clinical microbiology laboratory of the Hôpital Principal de Dakar (Senegal) and used for routine pathogen identification. Using MS, 2,429 bacteria and fungi isolated from patients were directly assayed, leading to the identification of 2,082 bacteria (85.7%) and 206 fungi (8.5%) at the species level, 109 bacteria (4.5%) at the genus level, and 16 bacteria (0.75%) at the family level. Sixteen isolates remained unidentified (0.75%). Escherichia coli was the most prevalent species (25.8%) followed by Klebsiella pneumoniae (14.8%), Streptococcus agalactiae (6.2%), Acinetobacter baumannii (6.1%), Pseudomonas aeruginosa (5.9%), and Staphylococcus aureus (5.9%). MALDI-TOF MS has also enabled the detection of rare bacteria and fungi. MALDI-TOF MS is a powerful tool for the identification of bacterial and fungal species involved in infectious diseases in tropical Africa.
Electrodynamic balance measurements of thermodynamic, kinetic, and optical aerosol properties inaccessible to bulk methods
Authors: Steimer S. S. , Krieger U. K. , Te Y.-F. , Lienhard D. M. , Huisman A. J. , Ammann M. , Peter T.
Published: January 2015

Abstract. Measurements of a single, levitated particle in an electrodynamic balance are an established tool for deriving thermodynamic and material data such as density, refractive index and activities of components of an aqueous solution under supersaturated conditions, where bulk measurements are not possible. The retrieval relies on combining mass-to-charge data and size data from light scattering. Here, we use a combination of low- and high-resolution Mie resonance spectroscopy to obtain radius data, enabling an accurate size determination not only when the particle is in equilibrium, but also when it is out of equilibrium due to kinetic limitation of mass transport. With the data measured under non-equilibrium conditions, it is possible to retrieve the water diffusivity. A challenge is that the radius retrieval by comparing measured light scattering with Mie theory requires the knowledge of refractive index as a function of concentration. Here, we show an iterative retrieval of refractive index and size for compounds for which data cannot be obtained in the bulk either due to lack of sufficient amounts of sample or limited solubility. We demonstrate the measurement strategy and the retrieval of water activity, density, refractive index and water diffusivity for aqueous shikimic acid. Water diffusivity in concentrated shikimic acid decreases by 6 orders of magnitude at 250 K compared to that at room temperature.
Quantifying residual ionospheric errors in GNSS radio occultation bending angles based on ensembles of profiles from end-to-end simulations
Authors: Liu C. L. , Kirchengast G. , Zhang K. , Norman R. , Li Y. , Zhang S. C. , Fritzer J. , Schwaerz M. , Wu S. Q. , Tan Z. X.
Published: January 2015

Abstract. The radio occultation (RO) technique using signals from the Global Navigation Satellite System (GNSS), in particular from the Global Positioning System (GPS) so far, is meanwhile widely used to observe the atmosphere for applications such as numerical weather prediction and global climate monitoring. The ionosphere is a major error source in RO measurements at stratospheric altitudes and a linear ionospheric correction of dual-frequency RO bending angles is commonly used to remove the first-order ionospheric effect. However, the residual ionopheric error (RIE) can still be significant so that it needs to be further mitigated for high accuracy applications, especially above about 30 km altitude where the RIE is most relevant compared to the magnitude of the neutral atmospheric bending angle. Quantification and careful analyses for better understanding of the RIE is therefore important towards enabling benchmark-quality stratospheric RO retrievals. Here we present such an analysis of bending angle RIEs covering the stratosphere and mesosphere, using quasi-realistic end-to-end simulations for a full-day ensemble of RO events. Based on the ensemble simulations we assessed the variation of bending angle RIEs, both biases and SDs, with solar activity, latitudinal region, and with or without the assumption of ionospheric spherical symmetry and of co-existing observing system errors. We find that the bending angle RIE biases in the upper stratosphere and mesosphere, and in all latitudinal zones from low- to high-latitudes, have a clear negative tendency and a magnitude increasing with solar activity, in line with recent empirical studies based on real RO data. The maximum RIE biases are found at low latitudes during daytime, where they amount to with in −0.03 to −0.05 μrad, the smallest at high latitudes (0 to −0.01 μrad; quiet space weather and winter conditions). Ionospheric spherical symmetry or asymmetries about the RO event location have only a minor influence on RIE biases. The RIE SDs are markedly increased both by ionospheric asymmetries and increasing solar activity and amount to about 0.3 to 0.7 μrad in the upper stratosphere and mesosphere. Taking into account also realistic observation errors of a modern RO receiving system, amounting globally to about 0.4 μrad (un-biased; SD), shows that the random RIEs are typically comparable to the total observing system error. The results help to inform future RIE mitigation schemes that will improve upon the use of the linear ionospheric correction of bending angles and that will also provide explicit uncertainty estimates.
Par@Graph – a parallel toolbox for the construction and analysis of large complex climate networks
Authors: Ihshaish H. , Tantet A. , Dijkzeul J. C. M. , Dijkstra H. A.
Published: January 2015

Abstract. In this paper, we present Par@Graph, a software toolbox to reconstruct and analyze complex climate networks having a large number of nodes (up to at least O (106)) and of edges (up to at least O (1012)). The key innovation is an efficient set of parallel software tools designed to leverage the inherited hybrid parallelism in distributed-memory clusters of multi-core machines. The performance of the toolbox is illustrated through networks derived from sea surface height (SSH) data of a global high-resolution ocean model. Less than 8 min are needed on 90 Intel Xeon E5-4650 processors to construct a climate network including the preprocessing and the correlation of 3 × 105 SSH time series, resulting in a weighted graph with the same number of vertices and about 3 × 106 edges. In less than 5 min on 30 processors, the resulted graph's degree centrality, strength, connected components, eigenvector centrality, entropy and clustering coefficient metrics were obtained. These results indicate that a complete cycle to construct and analyze a large-scale climate network is available under 13 min. Par@Graph therefore facilitates the application of climate network analysis on high-resolution observations and model results, by enabling fast network construction from the calculation of statistical similarities between climate time series. It also enables network analysis at unprecedented scales on a variety of different sizes of input data sets.
Assessment of impact of mass movements on the upper Tayyah valley's bridge along Shear escarpment highway, Asir region (Saudi Arabia) using remote sensing data and field investigation
Authors: Youssef A. M. , Al-Kathery M. , Pradhan B.
Published: January 2015

Abstract. Escarpment highways, roads and mountainous areas in Saudi Arabia are facing landslide hazards that are frequently occurring from time to time causing considerable damage to these areas. Shear escarpment highway is located in the north of the Abha city. It is the most important escarpment highway in the area, where all the light and heavy trucks and vehicle used it as the only corridor that connects the coastal areas in the western part of the Saudi Arabia with the Asir and Najran Regions. More than 10 000 heavy trucks and vehicles use this highway every day. In the upper portion of Tayyah valley of Shear escarpment highway, there are several landslide and erosion potential zones that affect the bridges between tunnel 7 and 8 along the Shear escarpment Highway. In this study, different types of landslides and erosion problems were considered to access their impacts on the upper Tayyah valley's bridge along Shear escarpment highway using remote sensing data and field investigation. These landslides and erosion problems have a negative impact on this section of the highway. Results indicate that the areas above the highway and bridge level between bridge 7 and 8 have different landslides including planar, circular, rockfall failures and debris flows. In addition, running water through the gullies cause different erosional (scour) features between and surrounding the bridge piles and culverts. A detailed landslides and erosion features map was created based on intensive field investigation (geological, geomorphological, and structural analysis), and interpretation of Landsat image 15 m and high resolution satellite image (QuickBird 0.61 m), shuttle radar topography mission (SRTM 90 m), geological and topographic maps. The landslides and erosion problems could exhibit serious problems that affect the stability of the bridge. Different mitigation and remediation strategies have been suggested to these critical sites to minimize and/or avoid these problems in the future.
Forest damage and snow avalanche flow regime
Authors: Feistl T. , Bebi P. , Christen M. , Margreth S. , Diefenbach L. , Bartelt P.
Published: January 2015

Abstract. Snow avalanches break, uproot and overturn trees causing damage to forests. The extent of forest damage provides useful information on avalanche frequency and intensity. However, impact forces depend on avalanche flow regime. In this paper, we define avalanche loading cases representing four different avalanche flow regimes: powder, intermittent, dry and wet. In the powder regime, the blast of the cloud can produce large bending moments in the tree stem because of the impact area extending over the entire tree crown. We demonstrate that intermittent granular loadings are equivalent to low-density uniform dry snow loadings under the assumption of homogeneous particle distributions. In the wet snow case, avalanche pressure is calculated using a quasi-static model accounting for the motion of plug-like wet snow flows. Wet snow pressure depends both on avalanche volume and terrain features upstream of the tree. Using a numerical model that simulates both powder and wet snow avalanches, we study documented events with forest damage. We find (1) powder clouds with velocities over 20 m s−1 can break tree stems, (2) the intermittent regime seldom controls tree breakage and (3) quasi-static pressures of wet snow avalanches can be much higher than pressures calculated using dynamic pressure formulas.
Predictive analysis of landslide susceptibility in the Kao-Ping watershed, Taiwan under climate change conditions
Authors: Shou K. J. , Wu C. C. , Lin J. F.
Published: January 2015

Abstract. Among the most critical issues, climatic abnormalities caused by global warming also affect Taiwan significantly for the past decade. The increasing frequency of extreme rainfall events, in which concentrated and intensive rainfalls generally cause geohazards including landslides and debris flows. The extraordinary Typhoon Morakot hit Southern Taiwan on 8 August 2009 and induced serious flooding and landslides. In this study, the Kao-Ping River watershed was adopted as the study area, and the typical events 2007 Krosa Typhoon and 2009 Morakot Typhoon were adopted to train the susceptibility model. This study employs rainfall frequency analysis together with the atmospheric general circulation model (AGCM) downscaling estimation to understand the temporal rainfall trends, distributions, and intensities in the Kao-Ping River watershed. The rainfall estimates were introduced in the landslide susceptibility model to produce the predictive landslide susceptibility for various rainfall scenarios, including abnormal climate conditions. These results can be used for hazard remediation, mitigation, and prevention plans for the Kao-Ping River watershed.
A novel method for analyzing the process of abrupt climate change
Authors: Yan P. C. , Feng G. L. , Hou W.
Published: January 2015

Abstract. A climate system which is transitioning from one state to another is known as an abrupt climate change. Most of the recent studies regarding abrupt climate change have focused on the changes occurring before and after the abrupt change point, while little attention has been given to the "transition process" which occurs when the system breaks away from the original state to a new state. In this study, a novel method for analyzing the process of abrupt climate change was presented. By using the mathematical model based on the Logistic model, the process of the abrupt change could be analyzed and divided into different phases which include start moment, end moment, stable state, and unstable transition state. Meanwhile, the method was confirmed to be effective by testing in a study of Pacific decadal oscillation (PDO) time sequence, and the results of this study specify that this abrupt change process of PDO has a relationship with global warming.
Numerical simulation of extreme snow melt observed at the SIGMA-A site, northwest Greenland, during summer 2012
Authors: Niwano M. , Aoki T. , Matoba S. , Yamaguchi S. , Tanikawa T. , Kuchiki K. , Motoyama H.
Published: January 2015

Abstract. The surface energy balance (SEB) from 30 June to 14 July 2012 at site SIGMA (Snow Impurity and Glacial Microbe effects on abrupt warming in the Arctic)-A, (78°03' N, 67°38' W; 1490 m a.s.l.) on the northwest Greenland Ice Sheet (GrIS) was investigated by using in situ atmospheric and snow measurements, as well as numerical modeling with a one-dimensional, multi-layered, physical snowpack model called SMAP (Snow Metamorphism and Albedo Process). At SIGMA-A, remarkable near-surface snowmelt and continuous heavy rainfall (accumulated precipitation between 10 and 14 July was estimated to be 100 mm) were observed after 10 July 2012. Application of the SMAP model to the GrIS snowpack was evaluated based on the snow temperature profile, snow surface temperature, surface snow grain size, and shortwave albedo, all of which the model simulated reasonably well. However, comparison of the SMAP-calculated surface snow grain size with in situ measurements during the period when surface hoar with small grain size was observed on-site revealed that it was necessary to input air temperature, relative humidity, and wind speed data from two heights to simulate the latent heat flux into the snow surface and subsequent surface hoar formation. The calculated latent heat flux was always directed away from the surface if data from only one height were input to the SMAP model, even if the value for roughness length of momentum was perturbed between the possible maximum and minimum values in numerical sensitivity tests. This result highlights the need to use two-level atmospheric profiles to obtain realistic latent heat flux. Using such profiles, we calculated the SEB at SIGMA-A from 30 June to 14 July 2012. Radiation-related fluxes were obtained from in situ measurements, whereas other fluxes were calculated with the SMAP model. By examining the components of the SEB, we determined that low-level clouds accompanied by a significant temperature increase played an important role in the melt event observed at SIGMA-A. These conditions induced a remarkable surface heating via cloud radiative forcing in the polar region.
Histology of Failed Metal-on-Metal Hip Arthroplasty; Three Distinct Sub-Types
Authors: Berstock James R. , Baker Richard P. , Bannister Gordon C. , Case C. Patrick
Published: January 2015

The histological specimens from 29 failed metal-on-metal (MoM) hip arthroplasties treated at our institution were reviewed. Five patients had a failed MoM total hip arthroplasty (THA), and 24 patients a failed hip resurfacing. Clinical and radiographic features of each hip were correlated with the histological findings.

We report three major histological subtypes. Patients either have a macrophage response to metal debris, a lymphocytic response (ALVAL) or a mixed picture of both. In addition we observe that the ALVAL response is located deep within tissue specimens, and can occur in environments of low wear debris. The macrophage response is limited to the surface of tissue specimens, with normal underlying tissue. Patients with subsequently confirmed ALVAL underwent revision surgery sooner than patients whose histology confirms a macrophage response (3.8 vs. 6.9 years p<0.05). Both histological subtypes (ALVAL and macrophage dominant) are responsible for abnormal soft tissue swellings.
Acetabular Component Orientation in Total Hip Arthroplasty: The Impact of Obesity
Authors: McArthur Benjamin A. , Vulcano Ettore , Cross Michael , Nguyen Joseph , Della Valle Alejandro G. , Salvati Eduardo
Published: January 2015

Introduction

Acetabular component position can be an important determinant of joint stability and bearing surface wear after THA. Nonetheless, the incidence of malpositioning is high. Patient obesity, low surgeon volume, and minimally invasive approaches are known risk factors for malposition. As the incidence of obesity continues to increase, it is important to recognise its effect on intraoperative component positioning in THA.

Objectives

Our goal was to assess the impact of obesity on component position for a high-volume surgeon using a standard postero-lateral approach.

Methods

A consecutive series of 120 obese (BMI >30, mean BMI 34.4) and 120 non-obese patients (mean BMI 25.4), who had undergone primary THA by a single surgeon, were included in our retrospective study. AP pelvis and cross-table radiographs obtained at the first postoperative visit were analysed using EBRA software to determine inclination and anteversion angles. Optimal position was defined as 30-45° of inclination and 5-25° of anteversion.

Results

Mean inclination and anteversion were 40.6 (+/-5.4°) and 16.6 (+/-5.5°) respectively, in the obese group and 39° (+/-5.0°) and 16.2° (+/-7.5°) in the non-obese group. In the obese group 89 (74%) patients were within the desired range for both measurements, 31 (26%) were out of range in at least one, compared to 91 (76%) and 29 (24%) in the non-obese group, respectively. The overall incidence of malpositioning was 25% for both groups. Among outliers, mean deviation from the optimal range was ≤3.8° in both groups.

Conclusions

The risk of component malpositioning in THA may be reduced when surgery is performed by an experienced, high volume surgeon utilising a standard posterolateral approach. In this setting the deleterious effect of obesity may be overcome.
Functional Treatment of Developmental Hip Dysplasia with the Tübingen Hip Flexion Splint
Authors: Atalar Hakan , Gunay Cuneyd , Komurcu Mahmut
Published: January 2015

Objective

Developmental dysplasia of the hip (DDH) is a deformity that may cause to serious disability. Early diagnosis and early treatment are very important. Our aim is to report the outcomes of infants with DDH who were treated with the Tübingen hip flexion splint.

Materials and methods

Retrospectively, 49 patients (45 female, four male; 60 hips) diagnosed with DDH were included in the study. For diagnosis, all patients underwent ultrasonography of the hip performed according to the Graf method. Infants whose hips were Graf type 2b or worse underwent orthotic treatment. Treatment success was defined as development into a mature hip (Graf type 1 on ultrasonography and no acetabular dysplasia apparent on the latest radiograph).

Results

Overall median age at the start of treatment was 18 weeks (14-25). Median total treatment time (from initial application of the splint to the end of weaning) was 17 weeks (14-20). Median duration of follow up was 13.5 months (8.5-31.5). Treatment was successful in 56/60 hips (93.3%). Of the 56 successfully treated patients, acetabular dysplasia was present early in follow up but later resolved in 4 patients. No complications were encountered in any patients in the study.

Conclusion

The Tübingen splint provides abduction, but due to its different design it offers the advantages of preventing hip adduction and leaving the knee and ankle joints free. Our findings suggest that in infants with DDH, the Tübingen hip flexion splint is an effective form of treatment.
Novel Artificial Anal Sphincter System Based on Transcutaneous Energy Transmission System Tested in vivo
Authors: Wang Yongbing , Liu Hua , Xu Qianqian , Yan Guozheng
Published: January 2015

This paper proposes a novel artificial anal sphincter system (AASS) for severe fecal incontinence. The AASS is composed of an artificial anal sphincter (AAS), an external transcutaneous energy transmission system (TETS), and an external control device. The AAS is composed of a cuff, a micropump, a reservoir, and a remote control device. It is designed to be implanted into the body of the patient. The function of the AAS is to open and close the patient's natural anus. Patients suffering from loss of their natural sphincter lose rectal sensation and are thus unable to perceive imminent fecal incontinence. In order to restore rectal sensation, a pressure sensor in the AAS cuff is designed to detect pressure in the colon. The pressure reflects the present quantity of colon contents, allowing patients to control the AAS to open or close the anus according to the pressure. The TETS is designed to provide electrical energy to the implanted AAS without wire connections. The external control device is designed to receive the pressure information from the AAS and send the patient's command to the implanted device. This paper provides a thorough discussion of the design of the novel AASS and describes the performance of the AASS when tested in vivo on two Beagle dogs who were chosen to be the subjects for receiving the implant. The experimental results verified that the performance of the AASS met the functional requirements it was designed for; however, the trial also revealed some challenges to be further studied.