bluuebunny/crossref_metadata_2025 huggingface dataset:
Computed Tomographic Evaluation of Bone Quality of the Mandible Reconstructed by Particular Cellular Bone and Marrow Combined with Platelet Rich Plasma
Authors: Iwamoto Muneharu , Matsuo Akira , Kato Noriko , Takeuchi Sawako , Takahashi Hidetoshi , Hojo Satoru , Chiba Hiroshige
Published: August 2012

Concerning the bone structures of the mandible reconstructed by particular cellular bone and marrow (PCBM), platelet rich plasma (PRP) and tray, we have examined the possibility of implant insertion by clarifying the morphological conditions in each compact and cancellous bone on computed tomography (CT), and by observing the differences in their CT values.

Using the computer software program Sim Plant (Materialize Dental, Leuven, Belgium), we morphologically observed 6 cases of implant inserted area after mandibular reconstruction and 11 cases of native bone, and examined the differences in their CT values. The osseointegration rate of each inserted implant was also evaluated.

Compared with the native bone group, the PCBM reconstruction group had generally thin compact bone. In the over‐3 cm‐length PCBM reconstruction group, the average CT value was 259.7 ± 94.4 HU (n = 3) in the cancellous bone, whereas in the native bone group, the average CT value was 528.9 ± 140.1 HU (n = 10). Therefore, the PCBM reconstruction group showed significantly lower CT value than the native bone group. However, in the under‐3 cm‐length group, the PCBM reconstruction group showed no significant difference compared with the native bone group. The osseointegration rate of the inserted implants almost 6 months after insertion was 100% in the PCBM reconstruction group and 94.1% in the native bone group.

Although the PCBM reconstructed bone had thinner cortical bone and showed lower CT value compared with the native bone, implant insertion was possible.
Side‐to‐side Asymmetry in Trigeminal Neuralgia
Authors: Toda Katsuhiro
Published: August 2012

The right side was affected in 61% of reported cases and the left side was affected in 39% of approximately 30,000 patients with trigeminal neuralgia (TN) affected on only one side. side‐to‐side asymmetry of neurovascular compression in healthy persons cannot account for side‐to‐side asymmetry in TN. Size asymmetry and shape asymmetry of the rotundum and ovale foramens may account for the higher incidence of TN on the right side. This paper proposes a multiple factors theory: the summation of multiple factors reaches a critical level at which TN occurs. It is rational that entrapment of the maxillary and mandibular nerves when they cross the ovale and rotundum foramens is one of the factors which cause TN. The multiple factors theory can account for a TN patient without neurovascular compression and a healthy person with neurovascular compression.
Fibroma of the Tendon Sheath Arising from the Synovial Membrane of the Temporomandibular Joint
Authors: Toyoda Nagataka , Sato Toru , Asada Koichi , Satomura Kazuhito
Published: August 2012

Fibroma of the tendon sheath (FTS) involving the temporomandibular joint (TMJ) is very rare. A case of FTS arising from the synovial membrane of the TMJ is presented. The patient was a 17‐year‐old male with jaw opening pain and clicking in the left TMJ. MRI, arthrotomography, and arthroscopy showed a well‐circumscribed mass that was localized in the superior articular cavity of the left TMJ. The tumor was removed with the attached synovial membrane. Macroscopic, histological and immunohistological features of the intra‐articular tumor were identical to FTS. There have been no signs of recurrence in the 6 years since surgery.
A Case of Impacted Supernumerary Fourth Molar in the Bilateral Mandibular Ramus
Authors: Sumida Tomoki , Murase Ryuichi , Yoshimura Tomohide , Aramoto Takayoshi , Ishikawa Akiko , Hamakawa Hiroyuki
Published: August 2012

The occurrence of multiple supernumerary teeth in individuals without any associated syndrome is rare. In this report, a rare case of a 48‐year‐old woman who had an impacted supernumerary fourth molar in the bilateral mandibular ramus is described. She presented with a swelling in the left cheek region. Radiographic examination revealed an impacted supernumerary tooth in the left mandibular ramus with pericoronal resorption of the bone, suggesting peripheral inflammation. She also had an impacted supernumerary tooth on the right side. After administering an antibiotic and antiinflammatory drug, tooth extraction was performed under general anesthesia.
Inflammation and Atrial Fibrillation
Authors: Endoh Yasumi , Endoh Ikuko , Geczy Carolyn , Nakagomi Akihiro , Kusama Yoshiki , Atarashi Hirotsugu
Published: August 2012

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice. Accumulating evidence indicates a link between inflammation and AF, and important advances in understanding mechanisms of AF are arising from studies of the critical components involved in the modulation of the immunoinflammatory balance within the atrium. However, molecular mechanisms remain unclear. Indeed, although preclinical and clinical studies suggest that chronic inflammation may promote development of AF, the roles of inflammation in the process are complex and incompletely understood. The purpose of this review is to briefly highlight current evidence on relationships between inflammation and AF, and to discuss possible mechanisms of development of AF and/or possible therapeutic approaches targeting components of the inflammatory response.
What Can We Expect from the ISSUE 3 Trial?
Authors: Sutton Richard , Brignole Michele
Published: August 2012

The ISSUE 3 Trial is designed to demonstrate which patients with vasovagal syncope over the age of 40 years will benefit from pacing dual chamber with the rate drop response. The trial has completed its recruitment of 521 patients and 78 have now been randomized in Phase 2, which is the Pacing ON versus Pacing OFF comparison. During this Phase the end‐points are recurrence of syncope or two years of follow‐up without recurrence. It has been calculated that 27 early end‐points will be sufficient to determine a significant difference between the groups. The background, details and design of the trial are explained. Some early findings are presented. Definitive results are expected by the end of 2011.
Non-recurrence sets for weakly mixing linear dynamical systems
Authors: GRIVAUX SOPHIE
Published: August 2012

We study non-recurrence sets for weakly mixing dynamical systems by using linear dynamical systems. These are systems consisting of a bounded linear operator acting on a separable complex Banach space$X$, which becomes a probability space when endowed with a non-degenerate Gaussian measure. We generalize some recent results of Bergelson, del Junco, Lemańczyk and Rosenblatt, and show in particular that sets$\{n_{k}\}$such that$n_{k+1}/n_{k}\to +\infty $, or such that$n_{k}$divides$n_{k+1}$for each$k\ge 0$, are non-recurrence sets for weakly mixing linear dynamical systems. We also give examples, for each$r\ge 1$, of$r$-Bohr sets which are non-recurrence sets for some weakly mixing systems.
Experimental study of particle-driven secondary flow in turbulent pipe flows
Authors: Belt R. J. , Daalmans A. C. L. M. , Portela L. M.
Published: August 2012

In fully developed single-phase turbulent flow in straight pipes, it is known that mean motions can occur in the plane of the pipe cross-section, when the cross-section is non-circular, or when the wall roughness is non-uniform around the circumference of a circular pipe. This phenomenon is known as secondary flow of the second kind and is associated with the anisotropy in the Reynolds stress tensor in the pipe cross-section. In this work, we show, using careful laser Doppler anemometry experiments, that secondary flow of the second kind can also be promoted by a non-uniform non-axisymmetric particle-forcing, in a fully developed turbulent flow in a smooth circular pipe. In order to isolate the particle-forcing from other phenomena, and to prevent the occurrence of mean particle-forcing in the pipe cross-section, which could promote a different type of secondary flow (secondary flow of the first kind), we consider a simplified well-defined situation: a non-uniform distribution of particles, kept at fixed positions in the ‘bottom’ part of the pipe, mimicking, in a way, the particle or droplet distribution in horizontal pipe flows. Our results show that the particles modify the turbulence through ‘direct’ effects (associated with the wake of the particles) and ‘indirect’ effects (associated with the global balance of momentum and the turbulence dynamics). The resulting anisotropy in the Reynolds stress tensor is shown to promote four secondary flow cells in the pipe cross-section. We show that the secondary flow is determined by the projection of the Reynolds stress tensor onto the pipe cross-section. In particular, we show that the direction of the secondary flow is dictated by the gradients of the normal Reynolds stresses in the pipe cross-section, $\partial {\tau }_{rr} / \partial r$ and $\partial {\tau }_{\theta \theta } / \partial \theta $. Finally, a scaling law is proposed, showing that the particle-driven secondary flow scales with the root of the mean particle-forcing in the axial direction, allowing us to estimate the magnitude of the secondary flow.
On flow in weakly precessing cylinders: the general asymptotic solution
Authors: Liao Xinhao , Zhang Keke
Published: August 2012

We investigate, through both asymptotic and numerical analysis, precessionally driven flow of a homogeneous fluid confined in a fluid-filled circular cylinder that rotates rapidly about its symmetry axis and precesses slowly about a different axis that is fixed in space. After demonstrating that the inviscid approximation is always divergent even far away from resonance, we derive a general asymptotic solution for an asymptotically small Ekman number in the rotating frame of reference describing the weakly precessing flow that satisfies the no-slip boundary condition and that is valid at or near or away from resonance. Numerical analysis of the same problem using the Galerkin method in terms of a Chebyshev polynomial expansion is also carried out, showing satisfactory agreement between the general asymptotic solution and the corresponding numerical solution at or near or away from resonance.
Benchmarking across Borders: Electoral Accountability and the Necessity of Comparison
Authors: KAYSER MARK ANDREAS , PERESS MICHAEL
Published: August 2012

When the economy in a single country contracts, voters often punish the government. When many economies contract, voters turn against their governments much less frequently. This suggests that the international context matters for the domestic vote, yet most research on electoral accountability assumes that voters treat their national economies as autarkic. We decompose two key economic aggregates—growth in real gross domestic product and unemployment—into their international and domestic components and demonstrate that voters hold incumbents more electorally accountable for the domestic than for the international component of growth. Voters in a wide variety of democracies benchmark national economic growth against that abroad, punishing (rewarding) incumbents for national outcomes that underperform (outperform) an international comparison. Tests suggest that this effect arises not from highly informed voters making direct comparisons but from “pre-benchmarking” by the media when reporting on the economy. The effect of benchmarked growth exceeds that of aggregate national growth by up to a factor of two and outstrips the international component of growth by an even larger margin, implying that previous research may have underestimated the strength of the economy on the vote.
The Role of the Sheldon Family in Establishing the Tapestry-Weaving Workshops Associated with Their Name
Authors: Guinness John
Published: August 2012

This short note is intended as a response to the paper by Dr Hilary Turner published in Vol 88 of the Antiquaries Journal, entitled: ‘Tapestries once at Chastleton and their influence on the image of tapestries called Sheldon: a reassessment’. It seeks to give an alternative account to that given by Dr Turner of the role of the Sheldon family in establishing the tapestry-weaving workshops associated with their name during the reign of Elizabeth i.
Influence of non-thermal shielding on the Ramsauer phenomena for the electron–atom-induced dipole scattering in Lorentzian plasmas
Authors: KI DAE-HAN , JUNG YOUNG-DAE
Published: August 2012

The non-thermal shielding effects on the Ramsauer phenomena for the electron–atom-induced dipole scattering are investigated in Lorentzian plasmas. The phase theory and the modified Buckingham-type potential are employed to obtain phase shift and collision cross section as functions of spectral index, scattering length, polarizability, collision energy, and the Debye radius. It is found that the non-thermal effect enhances the collision cross section below the Ramsauer energy and suppresses the collision cross section above the Ramsauer energy. In addition, it is found that the non-thermal effect enhances the Ramsauer energy in Lorentzian plasmas.
Species delimitation, bioclimatic range, and conservation status of the threatened lichen Fuscopannaria confusa
Authors: CARLSEN Tor , BENDIKSBY Mika , HOFTON Tom H. , REISO Sigve , BAKKESTUEN Vegar , HAUGAN Reidar , KAUSERUD Håvard , TIMDAL Einar
Published: August 2012

Fuscopannaria confusa is a rare lichen restricted to very humid localities in boreal forests. Two Fuscopannaria species, F. ahlneri and F. mediterranea, and Parmeliella parvula are morphologically problematic to distinguish from F. confusa. Our aim with the present study was to evaluate the taxonomic status of F. confusa and thereby clarify its conservation status in Norway. By phylogenetic analysis of multi-locus DNA sequences, we show that F. confusa is genetically well distinguished from F. ahlneri,F. mediterranea, and P. parvula. Fuscopannaria confusa should therefore be treated as a separate species. A species distribution modelling analysis indicates that F. confusa has a slightly continental but potentially wide geographic distribution in Norway. However, suitable localities are continuously being destroyed by clear-cut logging and hydroelectric power development. Because of the decline in suitable habitats, F. confusa should be regarded as highly threatened in Norway and listed as EN (endangered) at the national level.
Diversity ofRamalina sinensisand its photobiont in local populations
Authors: FRANCISCO DE OLIVEIRA P. M. , TIMSINA B. , PIERCEY-NORMORE M. D.
Published: August 2012

Ramalina sinensisis a widespread lichen in the Northern Hemisphere with sparse local populations, and its potential to adapt to changing environmental conditions is unknown. The objectives of this study were to determine whether geographical distance reflects fungal phylogenetic patterns, and to infer algal identity and its pattern of geographical distribution. Twenty-three samples ofR. sinensiswere collected from three geographical regions in Manitoba. The internal transcribed spacer of ribosomal DNA (ITS rDNA) was sequenced from each of the algal and fungal partners, and phylogenetic analyses were performed. Algal haplotypes were estimated and placed on a map of the geographical regions. Although the fungal partner showed no geographical segregation within Manitoba, the divergence of three samples added to the phylogeny from GenBank suggested that a pattern may be evident if broader geographical distances were examined. The photobiont sequence was determined to be most similar to that ofTrebouxia impressaandT. potteri,two widely distributed algal species. The algal partner showed no geographical structure with sequence polymorphism or haplotype analyses. The abundance of sexual reproduction might explain widespread occurrence and the absence of geographical segregation of the fungus. This study suggests that the diversity in each of the symbionts ofR. sinensisshould not be a limiting factor for adaptation.
Six new species of Pyrenula from the tropics
Authors: APTROOT André , SCHUMM Felix , CÁCERES Marcela E. S.
Published: August 2012

Six new species of the genus Pyrenula are described as new to science from various countries in the tropics. Pyrenula borneensis is described from Borneo, P. endocrocea from the Philippines, P. hawaiiensis from Hawaii, P. rinodinospora from Papua New Guinea, P. rubrojavanica from Java, and P. thailandica from Papua New Guinea, India and Thailand.
The lichen genusUsnea(Parmeliaceae) in tropical South America: species with a pigmented medulla, reacting C+ yellow
Authors: TRUONG Camille , CLERC Philippe
Published: August 2012

In tropical South America (Venezuela, Colombia, Ecuador, Peru, Bolivia and Brazil), we investigated the diversity ofUsneaspecies with a pigmented, C+ yellow medulla. Four species are treated: the sorediateU. ceratinaandU. entoviolata, the latter being new for South America, and the non-sorediateU. cristatulaandU. flavorubescens, the latter being newly described here. A detailed description is provided for each species together with an identification key.
Parasite epidemiology in a changing world: can molecular phylogeography help us tell the wood from the trees?
Authors: MORGAN E.R. , CLARE E.L. , JEFFERIES R. , STEVENS J. R.
Published: August 2012

Molecular phylogeography has revolutionised our ability to infer past biogeographic events from cross-sectional data on current parasite populations. In ecological parasitology, this approach has been used to address fundamental questions concerning host-parasite co-evolution and geographic patterns of spread, and has raised many technical issues and problems of interpretation. For applied parasitologists, the added complexity inherent in adding population genetic structure to perceived parasite distributions can sometimes seem to cloud rather than clarify approaches to control. In this paper, we use case studies firstly to illustrate the potential extent of cryptic diversity in parasite and parasitoid populations, secondly to consider how anthropogenic influences including movement of domestic animals affect the geographic distribution and host associations of parasite genotypes, and thirdly to explore the applied relevance of these processes to parasites of socio-economic importance. The contribution of phylogeographic approaches to deeper understanding of parasite biology in these cases is assessed. Thus, molecular data on the emerging parasitesAngiostrongylus vasorumin dogs and wild canids, and the myiasis-causing fliesLuciliaspp. in sheep andCochliomyia hominovoraxin humans, lead to clear implications for control efforts to limit global spread. Broader applications of molecular phylogeography to understanding parasite distributions in an era of rapid global change are also discussed.
Comparative analysis of ITS1 nucleotide sequence reveals distinct genetic difference between Brugia malayi from Northeast Borneo and Thailand
Authors: FONG MUN-YIK , NOORDIN RAHMAH , LAU YEE-LING , CHEONG FEI-WEN , YUNUS MUHAMMAD HAFIZNUR , IDRIS ZULKARNAIN MD
Published: August 2012

Brugia malayi is one of the parasitic worms which causes lymphatic filariasis in humans. Its geographical distribution includes a large part of Asia. Despite its wide distribution, very little is known about the genetic variation and molecular epidemiology of this species. In this study, the internal transcribed spacer 1 (ITS1) nucleotide sequences of B. malayi from microfilaria-positive human blood samples in Northeast Borneo Island were determined, and compared with published ITS1 sequences of B. malayi isolated from cats and humans in Thailand. Multiple alignment analysis revealed that B. malayi ITS1 sequences from Northeast Borneo were more similar to each other than to those from Thailand. Phylogenetic trees inferred using Neighbour-Joining and Maximum Parsimony methods showed similar topology, with 2 distinct B. malayi clusters. The first cluster consisted of Northeast Borneo B. malayi isolates, whereas the second consisted of the Thailand isolates. The findings of this study suggest that B. malayi in Borneo Island has diverged significantly from those of mainland Asia, and this has implications for the diagnosis of B. malayi infection across the region using ITS1-based molecular techniques.
Social Policy Digest Online
Authors: Bennett Fran , Jones Ken
Published: August 2012

The Social Policy Digest is a major online resource providing up-to-date listings of developments across the whole range of social policy issues - including links to source materials and related commentaries. The Digest is published by Cambridge University Press on behalf of the Social Policy Association.
Infant feeding practices and prevalence of obesity in eight European countries – the IDEFICS study
Authors: Hunsberger Monica , Lanfer Anne , Reeske Anna , Veidebaum Toomas , Russo Paola , Hadjigeorgiou Charalampos , Moreno Luis A , Molnar Dénes , De Henauw Stefaan , Lissner Lauren , Eiben Gabriele
Published: August 2012

Objective

To assess the association between exclusive breast-feeding and childhood overweight.

Design

Cross-sectional data are from the baseline survey of the longitudinal cohort study IDEFICS. Exclusive rather than partial breast-feeding is the focus of the study due to the theoretical relationship between exclusive breast-feeding and development of dietary self-regulation. Children's measured heights and weights were used to calculate weight status, while waist-to-height ratio (WtHR) and skinfold measures were examined as alternative indicators of adiposity and fat patterning.

Setting

Examination centres in eight European countries (Italy, Estonia, Cyprus, Belgium, Sweden, Hungary, Germany and Spain).

Subjects

The analysis included 14 726 children aged 2–9 years for whom early feeding practices were reported by parents in standardized questionnaires.

Results

After controlling for education, income and other potential confounders, breast-feeding exclusively for 4–6 months was protective of overweight (including obesity) when compared with children never exclusively breast-fed (OR = 0·73; 95 % CI 0·63, 0·85) across all measures of overweight. Exclusively breast-feeding for 6 months offered slightly more protection than for 4 and 5 months combined (OR = 0·71; 95 % CI 0·58, 0·85). The associations could not be explained by socio-economic characteristics or maternal overweight.

Conclusions

This multi-country investigation indicated that exclusive breast-feeding for 4–6 months may confer protection against overweight in addition to other known benefits. There was no demonstrated benefit of exclusive breast-feeding for more than 6 months or combination feeding for any duration across all measures of overweight examined.
Adiposity indices in the prediction of insulin resistance in prepubertal Colombian children
Authors: Mueller Noel T , Pereira Mark A , Buitrago-Lopez Adriana , Rodríguez Diana C , Duran Alvaro E , Ruiz Alvaro J , Rueda-Clausen Christian F , Villa-Roel Cristina
Published: August 2012

Objective

To compare BMI with abdominal skinfold thickness (ASF), waist circumference and waist-to-height ratio in the prediction of insulin resistance (IR) in prepubertal Colombian children.

Design

We calculated age- and sex-specific Z-scores for BMI, ASF, waist circumference, waist-to-height ratio and three other skinfold-thickness sites. Logistic regression with stepwise selection (P = 0·80 for entry and P = 0·05 for retention) was performed to identify predictors of IR and extreme IR, which were determined by age- and sex-specific Z-scores to identify the ≥ 90th and ≥ 95th percentile of homeostasis model assessment (HOMAIR), respectively. We used receiver operating characteristic curves to compare the area under the curve between models.

Setting

Bucaramanga, Colombia.

Subjects

Children (n 1261) aged 6–10 years in Tanner stage 1 from a population-based study.

Results

A total of 127 children (seventy girls and fifty-seven boys) were classified with IR, including sixty-three children (thirty-three girls and thirty boys) classified with extreme IR. Only ASF and BMI Z-scores were retained as predictors of IR by stepwise selection. Adding ASF Z-score to BMI Z-score improved the area under the curve from 0·794 (95 % CI 0·752, 0·837) to 0·811 (95 % CI 0·770, 0·851; P for contrast = 0·01). In predicting extreme IR, the addition of ASF Z-score to BMI Z-score improved the area under the curve from 0·837 (95 % CI 0·790, 0·884) to 0·864 (95 % CI 0·823, 0·905; P for contrast = 0·01).

Conclusions

ASF Z-score predicted IR independent of BMI Z-score in our population of prepubertal children. ASF and BMI Z-scores together improved IR risk stratification compared with BMI Z-score alone, opening new perspectives in the prediction of cardiometabolic risk in prepubertal children.
Riots, Demonstrations, Strikes and the Coalition Programme
Authors: Taylor-Gooby Peter
Published: August 2012

The current UK government's policies include headlong spending cuts and a far-reaching restructuring of public provision. State welfare arguably contributes to political legitimacy and social stability, as well as to better social conditions and economic prosperity. The fact that current policies bear disproportionately on lower income groups may damage legitimacy.

This article analyses a dataset covering twenty-six countries for more than two decades to show that spending cuts, privatisation and increases in poverty undermine legitimacy. It uses a direct measure of legitimacy in terms of the frequency of riots and political demonstrations and strikes, rather than the usual indirect measures in terms of attitudes and trust in government. Findings in relation to the increased work-centredness of the benefit and labour market reforms are more equivocal: a stricter benefit regime may not undermine legitimacy.
Conservation agriculture systems for Malawian smallholder farmers: long-term effects on crop productivity, profitability and soil quality
Authors: Ngwira Amos Robert , Thierfelder Christian , Lambert Dayton M.
Published: August 2012

Conservation agriculture (CA) systems are based upon minimal soil disturbance; crop residue retention and crop rotation and/or intercrop association are increasingly seen to recycle nutrients, increase yield and reduce production costs. This study examines the effects of CA practices on crop productivity, profitability and soil quality under the conditions encountered by smallholder farmers in two farming communities from 2005 to 2011 in Malawi, as part of the contribution to remedy a lack of supporting agronomic research for these relatively new systems. The drier agroenvironment of Lemu of Bazale Extension Planning Area (EPA) is characterized by sandy clay loam soils and lower rainfall. Here, CA showed positive benefits on maize yield after the first season of experimentation, with highest increases of 2.7 Mg ha−1and 2.3 Mg ha−1more yield in CA monocrop maize and CA maize–legume intercrop, respectively, than the conventional tillage in the driest season of 2009/10. In the high rainfall environment of Zidyana EPA (characterized by sandy loam soils), substantial maize yield benefits resulted in the fifth season of experimentation. Farmers spent at most 50 days ha−1(US$140) producing maize under CA systems compared with 62 days ha−1(US$176) spent under conventional tillage practices. In Lemu, both CA systems resulted in gross margins three times higher than that of the conventional control plot, while in Zidyana, CA monocrop maize and CA maize–legume intercrop resulted in 33 and 23% higher gross margins, respectively, than conventional tillage. In Zidyana, the earthworm population was highest (48 earthworms m−2in the first 30 cm) in CA monocrop maize, followed by a CA maize–legume intercropping (40 earthworms) and lowest (nine earthworms) in conventionally tilled treatment. In both study locations CA monocrop maize and CA maize–legume intercrop gave higher water infiltration than the conventional treatment. Improvements in crop productivity, overall economic gain and soil quality have made CA an attractive system for farmers in Malawi and other areas with similar conditions. However, for extensive adoption of CA by smallholder farmers, cultural beliefs that crop production is possible without the ubiquitous ridge and furrow system and residue burning for mice hunting have to be overcome.
Size distributions of pore water and entrapped air during drying‐infiltration processes of sandstone characterized by water‐expulsion porosimetry
Authors: Nishiyama Naoki , Yokoyama Tadashi , Takeuchi Shingo
Published: August 2012

The transport of pore water in a rock during drying‐infiltration processes was characterized by water‐expulsion porosimetry. In this method, pore water is expelled by increasing gas pressure in a stepwise fashion, and the amounts of water in each pore size class are determined. Fontainebleau sandstone, having an open porosity of 6% and main pore radii of 1–20 μm, was used. The change in size distribution of pore water was determined as a function of the degree of drying. As the drying proceeded, the amount of water decreased first in the larger pores followed by the smaller pores. Next, water was infiltrated into the sample preliminarily adjusted to various water saturations (Spre‐flow), and the entrapped air saturation, hydraulic conductivity (K), and size distribution of pore water were measured. As Spre‐flow decreased, the entrapped air saturation increased and K decreased as approximated by K ∝ Sflow4.5, where Sflow is the water saturation after the infiltration. A comparison of the size distributions of pore water before and after the infiltration revealed that the ease of water infiltration (air entrapment) depends on pore size. If pores of >8 μm radii were emptied by drying, they were readily refilled with water, whereas smaller pores were only partially refilled because air was trapped in them. The experimentally measured K‐Sflowrelationship generally agreed with those predicted by the Mualem‐van Genuchten model and its modified version accounting for air entrapment, but some differences in the size distribution of pore water were observed between the experiment and the models.
Biodegradability of dissolved organic carbon in the Yukon River and its tributaries: Seasonality and importance of inorganic nitrogen
Authors: Wickland K. P. , Aiken G. R. , Butler K. , Dornblaser M. M. , Spencer R. G. M. , Striegl R. G.
Published: August 2012

Northern high‐latitude rivers transport large amounts of terrestrially derived dissolved organic matter (DOM) from boreal and arctic ecosystems to coastal areas and oceans. Current knowledge of the biodegradability of DOM in these rivers is limited, particularly for large rivers discharging to the Arctic Ocean. We conducted a seasonally comprehensive study of biodegradable dissolved organic carbon (BDOC) dynamics in the Yukon River and two of its tributaries in Alaska, USA. Distinct seasonal patterns of BDOC, consistent across a wide range of watershed size, indicate BDOC is transported year‐round. Relative biodegradability (%BDOC) was greatest during winter, and decreased into spring and summer. Due to large seasonal differences in DOC concentration, the greatest concentrations of BDOC (mg C L−1) occurred during spring freshet, followed by winter and summer. While chemical composition of DOM was an important driver of BDOC, the overriding control of BDOC was mineral nutrient availability due to wide shifts in carbon (C) and nitrogen (N) stoichiometry across seasons. We calculated seasonal and annual loads of BDOC exported by the Yukon River by applying measured BDOC concentrations to daily water discharge values, and also by applying an empirical correlation between %BDOC and the ratio of DOC to dissolved inorganic N (DIN) to total DOC loads. The Yukon River exports ∼0.2 Tg C yr−1 as BDOC that is decomposable within 28 days. This corresponds to 12–18% of the total annual DOC export. Furthermore, we calculate that the six largest arctic rivers, including the Yukon River, collectively export ∼2.3 Tg C yr−1 as BDOC to the Arctic Ocean.
The transition of dynamic rupture styles in elastic media under velocity‐weakening friction
Authors: Gabriel A.‐A. , Ampuero J.‐P. , Dalguer L. A. , Mai P. M.
Published: August 2012

Although kinematic earthquake source inversions show dominantly pulse‐like subshear rupture behavior, seismological observations, laboratory experiments and theoretical models indicate that earthquakes can operate with different rupture styles: either as pulses or cracks, that propagate at subshear or supershear speeds. The determination of rupture style and speed has important implications for ground motions and may inform about the state of stress and strength of active fault zones. We conduct 2D in‐plane dynamic rupture simulations with a spectral element method to investigate the diversity of rupture styles on faults governed by velocity‐and‐state‐dependent friction with dramatic velocity‐weakening at high slip rate. Our rupture models are governed by uniform initial stresses, and are artificially initiated. We identify the conditions that lead to different rupture styles by investigating the transitions between decaying, steady state and growing pulses, cracks, sub‐shear and super‐shear ruptures as a function of background stress, nucleation size and characteristic velocity at the onset of severe weakening. Our models show that small changes of background stress or nucleation size may lead to dramatic changes of rupture style. We characterize the asymptotic properties of steady state and self‐similar pulses as a function of background stress. We show that an earthquake may not be restricted to a single rupture style, but that complex rupture patterns may emerge that consist of multiple rupture fronts, possibly involving different styles and back‐propagating fronts. We also demonstrate the possibility of a super‐shear transition for pulse‐like ruptures. Finally, we draw connections between our findings and recent seismological observations.
Acute Schmorl's Node during Strenuous Monofin Swimming: A Case Report and Review of the Literature
Authors: Paterakis Konstantinos N. , Brotis Alexandros G. , Dardiotis Efthimios , Hadjigeorgiou Georgios M. , Karachalios Theofilos , Fountas Kostas N. , Karantanas Apostolos
Published: August 2012

Study Design

This case report describes an acute Schmorl's node (SN) in an elite monofin athlete during exercise. The patient presented with severe back pain and leg numbness and was managed successfully with conservative treatment.

Objective

The aim of our communication was to describe a rare presentation of a common pathological condition during an intense sport.

Background

Swimming is not generally considered to be a sport activity that leads to spinal injuries. SNs are usually asymptomatic lesions, incidentally found on imaging studies. There is no correlation between swimming and symptomatic SN formation.

Case Report

A 16-year-old monofin elite athlete suffered from an acute nonradiating back pain during extreme exercise. His back pain was associated with a fracture of the superior L5 end plate and an acute SN at the L5 vertebral body with perilesional bone marrow edema. The pain resolved with nonsteroidal anti-inflammatory drugs and bed rest. The athlete had an excellent outcome and returned to his training activities 6 months after his incident.

Conclusion

SN should be considered in the differential diagnosis of severe back pain, especially in sport-related injuries. SNs present with characteristic imaging findings. Due to the benign nature of these lesions, surveillance-only management may be the best course of action.
Total Disc Arthroplasty and Anterior Cervical Discectomy and Fusion in Cervical Spine: Competitive or Complimentary? Review of the Literature
Authors: Jawahar Ajay , Nunley Pierce
Published: August 2012

Anterior cervical discectomy and arthrodesis has come to represent standard of care for patients with persistent radicular and/or myelopathic symptoms that have failed to improve with conservative treatments. One potential complication of the procedure is the accelerated degeneration of the vertebrae and the intervertebral discs adjacent to the level fused and the effects of fusion on those levels. The concern that fusion may be a contributing factor to accelerated adjacent segment degeneration led to increased interest in cervical disc replacement after anterior decompressive surgery. Several studies analyzing the short-term outcomes of the disc replacement procedure have been published since then, and the pros and cons of both procedures continue to remain a topic of debate among the scientific community. The analysis of published literature and our own experience has convinced us that the overall longer-term clinical outcomes after anterior cervical discectomy and fusion (ACDF) and total disc replacement (TDR) in the general patient population are not significantly different in terms of symptomatic improvement, neurological improvement, and restoration to better quality of life. Age of the patients and number of affected levels may impact the outcomes and hence determine the choice of optimum procedure. To definitely compare the incidence of adjacent segment disease after these procedures, multi-institutional studies with predetermined and unanimously agreed upon clinical and radiological criteria should be undertaken and the results analyzed in an unbiased fashion. Until that time, it is reasonable to assume that ACDF as well as cervical TDR are both safe and effective procedures that may have outcome benefits in specific patient subgroups based upon demographics and clinical/radiological parameters at the time of surgery.
Charcot Arthropathy of the Wrist Associated with Cervical Spondylotic Myelopathy
Authors: Jackson Keith , Ramadorai Uma , Abell Brian , DeVine John
Published: August 2012

Background

Charcot arthropathy is a cascade of destructive changes that can effect joints of both the axial and appendicular skeleton. The pathogenesis of this condition centers around the accumulation of minor traumatic events after the loss of normal joint sensation. The most frequently cited cause of Charcot arthropathy of the upper extremity is syringomyelia, and magnetic resonance imaging of the cervical spine should be obtained at presentation.

Case Report

A 72-year-old woman presented with a painless right wrist deformity. Radiographs demonstrated advanced destructive changes of the radiocarpal joint. Magnetic resonance imaging of the cervical spine revealed multilevel cervical spondylotic stenosis with cord deformation, but no evidence of syringomyelia. Neurological examination confirmed the presence of myelopathy.

Literature Review

The most frequently cited cause of Charcot arthropathy of the upper extremity is syringomyelia, although pathologies such as diabetes mellitus, tabes dorsalis, leprosy, and other disorders affecting the nervous system have been reported to lead to this condition. Neuropathic arthropathy involving the wrist is a rare phenomenon with fewer than 20 published reports in modern literature.

Clinical Relevance

Charcot arthropathy of the wrist is a rare but potentially disabling condition. The diagnosis of spondylotic myelopathy should be considered when evaluating a patient with this presentation. Evaluation consisting of a detailed neurological examination and advanced imaging of the cervical spine is warranted to identify the etiology.
Metal atom (Zn, Cd and Mg) luminescence in solid neon
Authors: Healy Brendan , Kerins Paul , McCaffrey John G.
Published: August 2012

Luminescence spectroscopy of the metal atoms Mg, Zn and Cd isolated in solid neon is recorded using pulsed synchrotron radiation excitation of the ns1np1 1P1-ns2 1S0 resonance (n = 3, 4 and 5 respectively) transitions. Two features, a dominant band and a red-shoulder, are identified in the UV absorption spectra of Zn/Ne and Cd/Ne. Excitation of these features yields distinct emission bands with the red-shoulder absorption producing the smaller, Stokes-shifted emission. Nanosecond decaytime measurements, made with the time correlated single photon counting technique indicate the emission bands arise from the spin singlet  1P1→1S0 transition. Hence, it is concluded that the duplication of absorption and emission features in the Cd/Ne and Zn/Ne systems arises from metal atom occupancy in two distinct sites. In contrast, Mg/Ne luminescence consists of single excitation and emission bands, indicative of occupancy in just one site. The occurrence of distinct photophysical characteristics of the linewidths, Stokes shift and lifetimes in the Mg/Ne system, compared with those recorded for Zn/Ne and Cd/Ne, is rationalized in terms of a different site occupancy for atomic Mg. Accurate interaction potentials for the ground states of the M · Ne diatomics are used to analyse site occupancies and interpret this contrasting behavior.
Optical spectroscopy and microscopy of radiation-induced light-emitting point defects in lithium fluoride crystals and films
Authors: Montereali R. M. , Bonfigli F. , Menchini F. , Vincenti M. A.
Published: August 2012

Broad-band light-emitting radiation-induced F2 and F3+ electronic point defects, which are stable and laser-active at room temperature in lithium fluoride crystals and films, are used in dosimeters, tuneable color-center lasers, broad-band miniaturized light sources and novel radiation imaging detectors. A brief review of their photoemission properties is presented, and their behavior at liquid nitrogen temperatures is discussed. Some experimental data from optical spectroscopy and fluorescence microscopy of these radiation-induced point defects in LiF crystals and thin films are used to obtain information about the coloration curves, the efficiency of point defect formation, the effects of photo-bleaching processes, etc. Control of the local formation, stabilization, and transformation of radiation-induced light-emitting defect centers is crucial for the development of optically active micro-components and nanostructures. Some of the advantages of low temperature measurements for novel confocal laser scanning fluorescence microscopy techniques, widely used for spatial mapping of these point defects through the optical reading of their visible photoluminescence, are highlighted.
X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility
Authors: Reverdin Charles , Thais Frédéric , Loisel Guillaume , Busquet M. , Bastiani-Ceccotti S. , Blenski T. , Caillaud T. , Ducret J. E. , Foelsner W. , Gilles D. , Gilleron F. , Pain J. C. , Poirier M. , Serres F. , Silvert V. , Soullie G. , Turck-Chieze S. , Villette B.
Published: August 2012

An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution ⟨E/δE⟩ ∼ 50. It has been used at the LULI-2000 laser facility at École Polytechnique (France) to measure the Δn = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.
Inner valence excitations of condensed neon
Authors: Kassühlke B. , Feulner P.
Published: August 2012

Applying two-dimensional electron spectroscopy, we investigated bound and continuum excitations of neon films condensed onto clean metal surfaces, in the energy range of the [Ne 2s] singly and [Ne 2p2] doubly excited states. Precise energy values of excitons and ionization potentials were obtained for the surface and for the bulk and compared to data for the isolated neon atom. In addition, valuable information on the mobility and decay of excitons in this energy range was accessible with our technique.
The radiation-induced chemistry in solid xenon matrices
Authors: Feldman V. I. , Kobzarenko A. V. , Orlov A. Y. , Sukhov F. F.
Published: August 2012

The paper presents an overview of recent studies of the radiation-chemical transformations of guest molecules in solid xenon induced by fast electrons and x-ray irradiation. Specific features of the experimental approach based on the combination of matrix isolation IR and EPR spectroscopy are briefly outlined (with a particular emphasis on monoisotopic and isotopically enriched xenon matrices). The results reveal rich and diverse radiation-induced chemistry in solid xenon, which is considered in the following major aspects: (1) matrix-induced and matrix-assisted transformations of the primary guest radical cations; (2) production and dynamics of hydrogen atoms; (3) formation of xenon hydrides. Finally, preliminary results on the radiation-induced generation of oxygen atoms and ions in solid xenon are presented.
Impurity and vacancy effects in graphene
Authors: Loktev V. M. , Pogorelov Yu. G.
Published: August 2012

A Green function analysis is developed for the quasiparticle spectrum of 2D graphene sheets with different types of substitutional disorder, including vacancies. Impurity effects in this system are found to be anomalous, are compared to those in well-known doped semiconductors, and are explained in terms of conical singularities in the band spectrum of pure graphene. Criteria for the appearance of localized states on clusters of impurity scatterers and for qualitative restructuring of the band spectrum are established and the possibility of a distinctive metal/insulator transition when vacancies are present is discussed.
Temperature effect of metastable atom desorption from solid Ne by low-energy electron impact
Authors: Kato Haruaki , Tachibana Takayuki , Hirayama Takato
Published: August 2012

We studied desorption of metastable atoms induced by electronic transitions in solid Ne by low energy electron impact. Time-of-flight spectra and the angular distribution of metastable atoms desorbed from the surface of an annealed sample showed increased kinetic energy, higher signal intensity, and a narrower angular distribution compared with those measured using an unannealed sample. These results were explained by considering the sample’s surface conditions in the framework of the cavity ejection mechanism. Our results for annealed solid Ne showed that when the sample temperature increased from 5 to 7 K, the width of the angular distribution increased by about 10%. A simple trajectory calculation qualitatively reproduced our experimental results.