bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase transition in orthorhombic perovskite Sm1−xLuxMnO3: Evidenced by the emergence of ferroelectric polarization
Authors: Zhang Na , Dong Shuai , Liu Meifeng , Fu Zhaoming , Chang Fanggao , Liu Jun-Ming
Published: April 2015

A series of polycrystalline orthorhombic manganites Sm1−xLuxMnO3 have been synthesized in order to study the magnetism-induced ferroelectricity. Detailed measurements of the magnetic and electric properties of Sm1−xLuxMnO3 (0 ≤ x ≤ 0.3) compounds have been performed. The obtained Mn-O-Mn bond angle and the Néel temperature decrease with increasing x, indicating the strengthened frustration of original A-type antiferromagnetic (A-AFM) order of Mn spins. For lower x concentrations, no ferroelectricity is detected, implying the stability of the A-AFM ordering. Further increasing x, a dielectric anomaly begins to develop at 28 K since x = 0.15 which is not observed in SmMnO3. Coinciding with this dielectric anomaly, a ferroelectric polarization emerges, implying the multiferroicity. For intermediate compositions, a possible complex phase separation exists.
Stakeholders' appraisal of biomass-based energy development at local scale
Authors: Nikodinoska Natasha , Mattivi Michela , Notaro Sandra , Paletto Alessandro
Published: April 2015

Bioenergy has a key role in the European Union (EU) policy aimed at enhancing energy security and mitigating climate change. In the implementation of EU policy at national, and—especially—at regional and local levels, the inclusion of stakeholders' opinions is crucial to increase social acceptance and to reduce conflicts between the parties. This study analyzes stakeholders' opinions of biomass-based energy development at the local level (Sarentino valley, South Tyrol region, Italy) by using the SWOT (Strengths, Weaknesses, Opportunities, Threats)-AHP (Analytical Hierarchy Process) approach. SWOT-AHP methodology was implemented in three stages: stakeholders analysis, identification of the SWOT factors, and evaluation of the SWOT factors. Strategic factors were evaluated using the outcomes of a questionnaire administered to five groups of stakeholders (public administrations, NGO and associations, academia, farmers, and forest-wood chain actors). The results showed a firm prevalence for the strengths (33.3%) and opportunities (32.9%) over the potential threats (18.8%) and weaknesses (15%) of the actual bioenergy supply chain in Sarentino valley. SWOT-AHP methodology could be useful in the development and implementation of a local and regional participatory decision making process in the forest-wood-energy supply chain as it can provide structural and quantified analysis of the subjective preferences of the stakeholders.
A multi-functional high voltage experiment apparatus for vacuum surface flashover switch research
Authors: Zeng Bo , Su Jian-cang , Cheng Jie , Wu Xiao-long , Li Rui , Zhao Liang , Fang Jin-peng , Wang Li-min
Published: April 2015

A multifunctional high voltage apparatus for experimental researches on surface flashover switch and high voltage insulation in vacuum has been developed. The apparatus is composed of five parts: pulse generating unit, axial field unit, radial field unit, and two switch units. Microsecond damped ringing pulse with peak-to-peak voltage 800 kV or unipolar pulse with maximum voltage 830 kV is generated, forming transient axial or radial electrical field. Different pulse waveforms and field distributions make up six experimental configurations in all. Based on this apparatus, preliminary experiments on vacuum surface flashover switch with different flashover dielectric materials have been conducted in the axial field unit, and nanosecond pulse is generated in the radial field unit which makes a pulse transmission line in the experiment. Basic work parameters of this kind of switch such as lifetime, breakdown voltage are obtained.
Magnetoimpedance studies on (Fe70Co30)80B20−xSix amorphous ribbons
Authors: Manna Subhendu Kumar , Srinivas V.
Published: April 2015

In the present work, magnetic and magnetoimpedance (MI) properties of (Fe70Co30)80B20−xSix (x = 0, 3, 5, and 10) amorphous ribbons in the frequency range of 500 kHz–13 MHz are reported. Our studies show that the thermal stability, magnetic behavior, and MI profiles have been strongly influenced by the Si content in amorphous ribbons. The magnetic isotherms show that all the samples of present study attain magnetic saturation values well below 500 Oe with coercivity values in the range of 0.2–0.09 Oe, which suggest ultrasoft nature of the samples. Interestingly, MI follows the magnetization variations with Si content. A maximum MI and field sensitivity of 46% and 4.3%, respectively, have been achieved for 10% B replacement by Si. The results show that the skin depth is strongly modified by the addition of Si, which in turn affects the impedance. The MI profiles show double peak and triple peak nature, which indicates the presence of transverse magnetic domain in all samples.
Correlations in rare-earth transition-metal permanent magnets
Authors: Skomski R. , Manchanda P. , Kashyap A.
Published: April 2015

It is investigated how electron-electron correlations affect the intrinsic properties of rare-earth transition-metal magnets. Focusing on orbital moment and anisotropy, we perform model calculations for 3d-4f alloys and density-functional theory (DFT) calculations for NdCo5. On an independent-electron level, the use of a single Slater determinant with broken spin symmetry introduces Hund's rule correlations, which govern the behavior of rare-earth ions and of alloys described by the local spin density approximation (LSDA) and LSDA + U approximations to DFT. By contrast, rare-earth ions in intermetallics involve configuration interactions between two or more Slater determinants and lead to phenomena such as spin-charge distribution. Analyzing DFT as a Legendre transformation and using Bethe's crystal-field theory, we show that the corresponding density functionals are very different from familiar LSDA-type expressions and outline the effect of spin-charge separation on the magnetocrystalline anisotropy.
Influence of low optical frequencies on actuation dynamics of microelectromechanical systems via Casimir forces
Authors: Sedighi Mehdi , Palasantzas George
Published: April 2015

The role of the Casimir force on the analysis of microactuators is strongly influenced by the optical properties of interacting materials. Bifurcation and phase portrait analysis were used to compare the sensitivity of actuators when the optical properties at low optical frequencies were modeled using the Drude and Plasma models. Indeed, for metallic systems, which have strong Casimir attraction, the details of the modeling of the low optical frequency regime can be dramatic, leading to predictions of either stable motion or stiction instability. However, this difference is strongly minimized for weakly conductive systems as are the doped insulators making actuation modeling more certain to predict.
Pulmonary monoclonal antibody delivery via a portable microfluidic nebulization platform
Authors: Cortez-Jugo Christina , Qi Aisha , Rajapaksa Anushi , Friend James R. , Yeo Leslie Y.
Published: April 2015

Nebulizers have considerable advantages over conventional inhalers for pulmonary drug administration, particularly because they do not require coordinated breath actuation to generate and deliver the aerosols. Nevertheless, besides being less amenable to miniaturization and hence portability, some nebulizers are prone to denature macromolecular drugs due to the large forces generated during aerosolization. Here, we demonstrate a novel portable acoustomicrofluidic device capable of nebulizing epidermal growth factor receptor (EGFR) monoclonal antibodies into a fine aerosol mist with a mass median aerodynamic diameter of approximately 1.1 μm, optimal for deep lung deposition via inhalation. The nebulized monoclonal antibodies were tested for their stability, immunoactivity, and pharmacological properties, which confirmed that nebulization did not cause significant degradation of the antibody. In particular, flow cytometry demonstrated that the antigen binding capability of the antibody is retained and able to reduce phosphorylation in cells overexpressing the EGFR, indicating that the aerosols generated by the device were loaded with stable and active monoclonal antibodies. The delivery of antibodies via inhalation, particularly for the treatment of lung cancer, is thus expected to enhance the efficacy of this protein therapeutic by increasing the local concentration where they are needed.
Weak-antilocalization and surface dominated transport in topological insulator Bi2Se2Te
Authors: Gopal Radha Krishna , Singh Sourabh , Chandra Ramesh , Mitra Chiranjib
Published: April 2015

We explore the phase coherence of thin films of the topological insulator material Bi2Se2Te grown through pulsed laser deposition (PLD) technique. The films were characterised using various techniques for phase and composition. The films were found to be of good quality. We carried out extensive magneto-transport studies of these films and found that they exhibit two dimensional weak antilocalization behaviour. A careful analysis revealed a relatively high phase coherence length (58nm at 1.78K) for a PLD grown film. Since PLD is an inexpensive technique, with the possibility to integrate with other materials, one can make devices which can be extremely useful for low power spintronics and topological quantum computation.
Anarchism, Geohistory, and the Annales: Rethinking Elisée Reclus's Influence on Lucien Febvre
Authors: Ferretti Federico
Published: April 2015

It has been hypothesized that the celebrated geographer and anarchist Elisée Reclus was a decisive influence on several concepts that are characteristic of the Annales School, the historical French school of the Annales d'histoire économique et sociale, such as longue durée, material history, space-movement, and geohistory. Yet no systematic research exists on the topic. In this paper, on the basis of textual analysis and new archival materials recently published in France, I argue that Reclus's influence particularly affected the Annales's founder Lucien Febvre, and that it springs from not only Febvre's scholarly interest in Reclus, but also his early engagement in socialist milieus and sympathies for both anarchism and figures like Pierre-Joseph Proudhon. Finally, I show how these topics could be useful for present debates on critical social theory and radical geographies.
Effects of wildfire and topography on soil nitrogen availability in a boreal larch forest of northeastern China
Authors: Kong Jian-jian , Yang Jian , Chu Haiyan , Xiang Xingjia
Published: April 2015

Both topography and wildfire can strongly affect soil nitrogen (N) availability. Although many studies have examined the individual effects of fire and topography on N, few have investigated their combined influences and relative importance. In this study, we measured soil extractable inorganic N concentrations, N mineralisation rates, and in situ soil inorganic N supply rates at 36 plots in three topographic positions (north-facing, south-facing and flat valley bottom) of burned and unburned sites in a boreal larch forest of northeastern China. Our data showed that wildfire significantly increased soil N availability, with mean soil extractable inorganic N concentrations, N mineralisation rates and N supply rates being 63, 310 and 270% higher in the burned site 1 year following fire. Additionally, soil N availability in the unburned site was significantly greater on the north-facing slope than on the south-facing slope, though this pattern was reversed at the burned site. Wildfire and topography together explained ~50% of the variance in soil N availability, with wildfire explaining three times more than topography. Our results demonstrate that wildfire and topography jointly affected spatial variations of soil N availability, and that wildfire decreased the influence of topography in the early successional stage of this boreal larch ecosystem.
Landscape Prediction and Mapping of Game Fish Biomass, an Ecosystem Service of Michigan Rivers
Authors: Esselman Peter C. , Stevenson R. Jan , Lupi Frank , Riseng Catherine M. , Wiley Michael J.
Published: April 2015

The increased integration of ecosystem service concepts into natural resource management places renewed emphasis on prediction and mapping of fish biomass as a major provisioning service of rivers. The goals of this study were to predict and map patterns of fish biomass as a proxy for the availability of catchable fish for anglers in rivers and to identify the strongest landscape constraints on fish productivity. We examined hypotheses about fish responses to total phosphorus (TP), as TP is a growth-limiting nutrient known to cause increases (subsidy response) and/or decreases (stress response) in fish biomass depending on its concentration and the species being considered. Boosted regression trees were used to define nonlinear functions that predicted the standing crops of Brook Trout Salvelinus fontinalis, Brown Trout Salmo trutta, Smallmouth Bass Micropterus dolomieu, panfishes (seven centrarchid species), and Walleye Sander vitreus by using landscape and modeled local-scale predictors. Fitted models were highly significant and explained 22–56% of the variation in validation data sets. Nonlinear and threshold responses were apparent for numerous predictors, including TP concentration, which had significant effects on all except the Walleye fishery. Brook Trout and Smallmouth Bass exhibited both subsidy and stress responses, panfish biomass exhibited a subsidy response only, and Brown Trout exhibited a stress response. Maps of reach-specific standing crop predictions showed patterns of predicted fish biomass that corresponded to spatial patterns in catchment area, water temperature, land cover, and nutrient availability. Maps illustrated predictions of higher trout biomass in coldwater streams draining glacial till in northern Michigan, higher Smallmouth Bass and panfish biomasses in warmwater systems of southern Michigan, and high Walleye biomass in large main-stem rivers throughout the state. Our results allow fisheries managers to examine the biomass potential of streams, describe geographic patterns of fisheries, explore possible nutrient management targets, and identify habitats that are candidates for species management.

Received May 20, 2014; accepted November 6, 2014
The Interaction between Self-Bias and Reward: Evidence for Common and Distinct Processes
Authors: Sui Jie , Humphreys Glyn W.
Published: April 2015

The perceptual matching of shapes and labels can be affected by both self- and reward-biases when shapes are linked either to labels referring to particular individuals (you, friend, stranger) or to different reward values (£8, £2, £0). We investigated the relations between these biases by varying the reward value associated with particular shape–label pairs (circle–you, square–friend, triangle–stranger). Self shape–label pairs (circle–you) always received no reward, while friend shape–label pairs (square–friend) received high reward and stranger shape–label pairs low reward (triangle–stranger), or the reverse (friend—low reward; stranger—high reward). Despite receiving no reward, responses to self-related pairs were advantaged relative to those to low-reward stimuli and did not differ from those to high-reward items. There was also an advantage for responses to high-reward friend pairs relative to low-reward stranger stimuli, and for high-reward stranger stimuli compared to low-reward friends. Correlations across individuals were found across trial blocks for both the self-advantage and the high-reward advantage, but the self- and reward-advantages were uncorrelated. This suggests that the self- and reward-advantage effects have different origins. In addition, the magnitude of the self-advantage varied according to the rated personal distance between a participant and a stranger. For individuals manifesting a close personal distance to strangers, the self-advantage was smaller, and sensitivity to reward influenced the difference between the self- and high-reward conditions. For individuals manifesting a large personal distance to strangers, sensitivity to reward did not affect self-matching. We suggest that self-advantages on perceptual matching arise independent of reward for individuals with a large personal distance to strangers. On the other hand, in individuals with a weak self-bias, high reward and the self modulate a common subjective value system.
Women outperform men in remembering to remember
Authors: Palermo Liana , Cinelli Maria Cristina , Piccardi Laura , Ciurli Paola , Incoccia Chiara , Zompanti Laura , Guariglia Cecilia
Published: April 2015

The study of gender differences in prospective memory (i.e., remembering to remember) has received modest attention in the literature. The few reported studies investigating either subjective or objective evaluations of prospective memory have shown inconsistent data. In this study, we aimed to verify the presence of gender differences during the performance of an objective prospective memory test by considering the weight of specific variables such as length of delay, type of response, and type of cue. We submitted a sample of 100 healthy Italian participants (50 men and 50 women) to a test expressly developed to assess prospective memory: The Memory for Intentions Screening Test. Women performed better than men in remembering to do an event-based task (i.e., prompted by an external event) and when the task required a physical response modality. We discuss the behavioural differences that emerged by considering the possible role of sociological, biological, neuroanatomical, and methodological variables.
Striking the balance between budgetary discretion and performance accountability: the case of the US Forest Service's approach to integrated restoration
Authors: Schultz Courtney A. , Moseley Cassandra , Mattor Katherine
Published: April 2015

Budgetary discretion affords agencies flexibility to accomplish complex goals but must be balanced with accountability. Recently, Congress increased budgetary discretion and changed performance measures to support integrated forest restoration. We use this experiment to explore how an agency utilizes budgetary discretion and how this discretion interacts with performance measurement. We find that while the flexibility has allowed the agency to pursue integrated goals, performance measures divert attention from addressing complex problems. Our findings suggest that performance measures are not a panacea for accountability and need to be combined with other mechanisms, such as internal guidance and oversight from collaborative partners.
Assessing the Influence of Salmon Farming through Total Lipids, Fatty Acids, and Trace Elements in the Liver and Muscle of Wild Saithe Pollachius virens
Authors: Arechavala-Lopez P. , Sæther B.-S. , Marhuenda-Egea F. , Sanchez-Jerez P. , Uglem I.
Published: April 2015

Saithe Pollachius virens are attracted to uneaten salmon feed underneath cages at open-cage salmon farms in Norway. The aggregated Saithe have modified their feeding habits as they have switched from wild prey to uneaten food pellets, which could lead to physiological and biochemical changes in the Saithe. Variations in profiles of total lipids, fatty acids, and trace elements in Saithe liver and muscle were measured to evaluate the influence of fish feed from salmon farms on wild Saithe populations. Farm-aggregated Saithe had higher fat content in liver tissues than did individuals captured more than 25 km away from farms, but no clear differences were found in muscle tissues. High proportions of fatty acids of terrestrial origin, such as oleic, linoleic, and linolenic acids, in liver and muscle tissues of farm-aggregated Saithe reflected the presence of wild Saithe at farms. Accordingly, low proportions of arachidonic, eicosapentaenoic, and docosahexaenoic acids in Saithe tissues mirrored the feeding activity at farms. Variations in specific trace element signatures among fish groups also revealed the farming influence on wild Saithe. High levels of Fe, As, Se, Zn, and B in liver, but also As, B, Li, Hg, and Sr in muscle of Saithe captured away from farms indicated the absence of feeding at farms.

Received March 26, 2014; accepted December 10, 2014
The semigroup of metric measure spaces and its infinitely divisible probability measures
Authors: Evans Steven , Molchanov Ilya
Published: April 2015

A metric measure space is a complete, separable metric space equipped with a probability measure that has full support. Two such spaces are equivalent if they are isometric as metric spaces via an isometry that maps the probability measure on the first space to the probability measure on the second. The resulting set of equivalence classes can be metrized with the Gromov–Prohorov metric of Greven, Pfaffelhuber and Winter. We consider the natural binary operation

⊞
\boxplus

on this space that takes two metric measure spaces and forms their Cartesian product equipped with the sum of the two metrics and the product of the two probability measures. We show that the metric measure spaces equipped with this operation form a cancellative, commutative, Polish semigroup with a translation invariant metric. There is an explicit family of continuous semicharacters that is extremely useful for, inter alia, establishing that there are no infinitely divisible elements and that each element has a unique factorization into prime elements.

We investigate the interaction between the semigroup structure and the natural action of the positive real numbers on this space that arises from scaling the metric. For example, we show that for any given positive real numbers

a
a

,

b
b

,

c
c

the trivial space is the only space

X

\mathcal {X}

that satisfies

a

X

⊞
b

X

=
c

X

a \mathcal {X} \boxplus b \mathcal {X} = c \mathcal {X}

.

We establish that there is no analogue of the law of large numbers: if

X

1

\mathbf {X}_1

,

X

2

\mathbf {X}_2

, … is an identically distributed independent sequence of random spaces, then no subsequence of

1
n

⊞

k
=
1

n

X

k

\frac {1}{n} \boxplus _{k=1}^n \mathbf {X}_k

converges in distribution unless each

X

k

\mathbf {X}_k

is almost surely equal to the trivial space. We characterize the infinitely divisible probability measures and the Lévy processes on this semigroup, characterize the stable probability measures and establish a counterpart of the LePage representation for the latter class.
Sorting nexin 27 regulates basal and stimulated brush border trafficking of NHE3
Authors: Singh Varsha , Yang Jianbo , Cha Boyoung , Chen Tiane-e , Sarker Rafiquel , Yin Jianyi , Avula Leela Rani , Tse Ming , Donowitz Mark
Published: April 2015

Sorting nexin 27 (SNX27) contains a PDZ domain that is phylogenetically related to the PDZ domains of the NHERF proteins. Studies on nonepithelial cells have shown that this protein is located in endosomes, where it regulates trafficking of cargo proteins in a PDZ domain–dependent manner. However, the role of SNX27 in trafficking of cargo proteins in epithelial cells has not been adequately explored. Here we show that SNX27 directly interacts with NHE3 (C-terminus) primarily through the SNX27 PDZ domain. A combination of knockdown and reconstitution experiments with wild type and a PDZ domain mutant (GYGF → GAGA) of SNX27 demonstrate that the PDZ domain of SNX27 is required to maintain basal NHE3 activity and surface expression of NHE3 in polarized epithelial cells. Biotinylation-based recycling and degradation studies in intestinal epithelial cells show that SNX27 is required for the exocytosis (not endocytosis) of NHE3 from early endosome to plasma membrane. SNX27 is also required to regulate the retention of NHE3 on the plasma membrane. The findings of the present study extend our understanding of PDZ-mediated recycling of cargo proteins from endosome to plasma membrane in epithelial cells.
Asymmetric formation of coated pits on dorsal and ventral surfaces at the leading edges of motile cells and on protrusions of immobile cells
Authors: Kural Comert , Akatay Ahmet Ata , Gaudin Raphaël , Chen Bi-Chang , Legant Wesley R. , Betzig Eric , Kirchhausen Tom
Published: April 2015

Clathrin/AP2-coated vesicles are the principal endocytic carriers originating at the plasma membrane. In the experiments reported here, we used spinning-disk confocal and lattice light-sheet microscopy to study the assembly dynamics of coated pits on the dorsal and ventral membranes of migrating U373 glioblastoma cells stably expressing AP2 tagged with enhanced green fluorescence (AP2-EGFP) and on lateral protrusions from immobile SUM159 breast carcinoma cells, gene-edited to express AP2-EGFP. On U373 cells, coated pits initiated on the dorsal membrane at the front of the lamellipodium and at the approximate boundary between the lamellipodium and lamella and continued to grow as they were swept back toward the cell body; coated pits were absent from the corresponding ventral membrane. We observed a similar dorsal/ventral asymmetry on membrane protrusions from SUM159 cells. Stationary coated pits formed and budded on the remainder of the dorsal and ventral surfaces of both types of cells. These observations support a previously proposed model that invokes net membrane deposition at the leading edge due to an imbalance between the endocytic and exocytic membrane flow at the front of a migrating cell.
The human 18S rRNA base methyltransferases DIMT1L and WBSCR22-TRMT112 but not rRNA modification are required for ribosome biogenesis
Authors: Zorbas Christiane , Nicolas Emilien , Wacheul Ludivine , Huvelle Emmeline , Heurgué-Hamard Valérie , Lafontaine Denis L. J.
Published: April 2015

At the heart of the ribosome lie rRNAs, whose catalytic function in translation is subtly modulated by posttranscriptional modifications. In the small ribosomal subunit of budding yeast, on the 18S rRNA, two adjacent adenosines (A1781/A1782) are N6-dimethylated by Dim1 near the decoding site, and one guanosine (G1575) is N7-methylated by Bud23-Trm112 at a ridge between the P- and E-site tRNAs. Here we establish human DIMT1L and WBSCR22-TRMT112 as the functional homologues of yeast Dim1 and Bud23-Trm112. We report that these enzymes are required for distinct pre-rRNA processing reactions leading to synthesis of 18S rRNA, and we demonstrate that in human cells, as in budding yeast, ribosome biogenesis requires the presence of the modification enzyme rather than its RNA-modifying catalytic activity. We conclude that a quality control mechanism has been conserved from yeast to human by which binding of a methyltransferase to nascent pre-rRNAs is a prerequisite to processing, so that all cleaved RNAs are committed to faithful modification. We further report that 18S rRNA dimethylation is nuclear in human cells, in contrast to yeast, where it is cytoplasmic. Yeast and human ribosome biogenesis thus have both conserved and distinctive features.
Effects of elevated CO2 levels on eggs and larvae of a North Pacific flatfish
Authors: Hurst Thomas P. , Laurel Benjamin J. , Mathis Jeremy T. , Tobosa Lauren R.
Published: April 2015

The Bering Sea and Gulf of Alaska support a number of commercially important flatfish fisheries. These high latitude ecosystems are predicted to be most immediately impacted by ongoing ocean acidification, but the range of responses by commercial fishery species has yet to be fully explored. In this study, we examined the growth responses of northern rock sole (Lepidopsetta polyxystra) eggs and larvae across a range of CO2 levels (ambient to 1500 µatm) to evaluate the potential sensitivity to ocean acidification. Laboratory-spawned eggs and larvae were reared at 8°C in a flow-through culture system in which CO2 levels were maintained via computer-controlled injection of CO2 into a seawater conditioning tank. Overall, we observed only minor effects of elevated CO2 level on sizes of northern rock sole larvae. Size at hatch differed among offspring from four different females, but there was no significant effect of CO2 level on egg survival or size at hatch. In three separate larval growth trials, there was little effect of CO2 level on growth rates through the first 28 d post-hatch (DPH). However, in the one trial extended to 60 DPH, fish reared at the highest CO2 level had lower condition factors after 28 DPH, suggesting that larvae undergoing metamorphosis may be more sensitive to environmental hypercapnia than earlier pre-flexion stages. These results suggest that while early life stages of northern rock sole are less sensitive to ocean acidification than previously examined flatfish, they may be more sensitive to elevated CO2 levels than a previously studied gadid with a similar geographic range.
Measuring and assessing the physical impact of beam trawling
Authors: Depestele Jochen , Ivanović Ana , Degrendele Koen , Esmaeili Moosa , Polet Hans , Roche Marc , Summerbell Keith , Teal Lorna R. , Vanelslander Bart , O'Neill Finbarr G.
Published: April 2015

Beam trawling causes physical disruption of the seabed through contact of the gear components with the sediment and the resuspension of sediment into the water column in the turbulent wake of the gear. To be able to measure and quantify these impacts is important so that gears of reduced impact can be developed. Here we assess the physical impact of both a conventional 4 m tickler-chain beam trawl and a “Delmeco” electric pulse beam trawl. We measure the changes in seabed bathymetry following the passage of these gears using a Kongsberg EM2040 multi-beam echosounder and use a LISST 100X particle size analyser to measure the concentration and particle size distribution of the sediment mobilized into the water column. We also estimate the penetration of the gears into the seabed using numerical models for the mechanical interaction between gears and seabed. Our results indicate that the seabed bathymetry changes between ∼1 and 2 cm and that it is further increased by higher trawling frequencies. Furthermore, our results suggest that the alteration following the passage of the conventional trawl is greater than that following the pulse trawl passage. There was no difference in the quantity of sediment mobilized in the wake of these two gears; however, the numerical model introduced in this study predicted that the tickler-chain trawl penetrates the seabed more deeply than the pulse gear. Hence, greater alteration to the seabed bathymetry by the tickler-chain beam trawling is likely to be a result of its greater penetration. The complimentary insights of the different techniques highlight the advantage of investigating multiple effects such as sediment penetration and resuspension simultaneously and using both field trials and numerical modelling approaches.
Utilizing the “Stable-to-be Vertebra” Saves Motion Segments in Growing Rods Treatment for Early-Onset Scoliosis
Authors: Dede Ozgur , Demirkiran Gokhan , Bekmez Senol , Sturm Peter F. , Yazici Muharrem
Published: April 2015

Background:

There is no consensus on the selection of distal instrumentation levels in growing rod surgery. Many surgeons utilize the stable zone of Harrington, but there is not overwhelming evidence to support this preference. The aim of this study was to determine the value of bending/traction radiographs in selection of distal instrumentation levels of a growing rod construct in children with idiopathic or idiopathic-like early-onset scoliosis (EOS).

Methods:

Twenty-three consecutive patients with idiopathic or idiopathic-like EOS who underwent growing rod surgery at 2 separate institutions between 2006 and 2011 were included. Lengthening procedures were performed periodically at 6-month intervals. Analyses were performed retrospectively for age at index surgery, follow-up period, and radiographic measurements. Lower instrumented levels, neutral vertebra, stable vertebrae (SV), and stable-to-be vertebrae (StbV) were identified on the preoperative radiographs. Coronal Cobb angles, tilt of lower instrumented vertebra (LIV) and LIV+1, and disk wedging under the LIV and LIV+1 were measured on the early postoperative and latest follow-up radiographs.

Results:

Average age at index surgery was 83.6 months. Mean follow-up period was 68.1 months. Initial analysis showed that the relationship of LIV to the StbV was a better predictive of LIV+1 tilt than the SV at the final follow-up. Therefore, the patients were grouped according to the relationship of the LIV to the StbV. LIV was the StbV in 9 patients, proximal to the StbV in 8 patients, and distal to the StbV in 6 patients. At the latest follow-up, tilt of LIV+1 exceeded 10 degrees in 7 of the 8 patients where LIV was proximal to the StbV, whereas only in 1 of 9 patients where LIV was StbV, and in none of the 6 patients where LIV was distal to the StbV. The data indicate that selection of the StbV as the LIV could spare an average of 1.8 vertebral segments when compared with the SV, as StbV is never distal but almost always proximal to the SV.

Conclusions:

Choosing the StbV as the LIV saves motion segments and prevents distal adding on, while providing satisfactory deformity correction in idiopathic and idiopathic-like EOS.

Level of Evidence:

Level III—retrospective comparative study.
Compartment Pressures in Children With Normal and Fractured Forearms: A Preliminary Report
Authors: Tharakan Sasha J. , Subotic Ulrike , Kalisch Markus , Staubli Georg , Weber Daniel M.
Published: April 2015

Introduction:

Acute compartment syndrome (ACS) can lead to irreversible damage if fasciotomy is not performed in a timely manner. Needle manometry is a tool to confirm suspected ACS. The threshold for compartment pressures that can be tolerated has been debated. The aim of this study is to assess the normal compartment pressures in noninjured forearms of children. Further, we sought to quantify the maximum tolerable compartment pressures in fractured forearms of children, thus establishing a baseline and providing guidance in evidence-based decision making to evaluate children with suspected ACS.

Methods:

This prospective study included children up to the age of 16 years with forearm fractures that needed reduction with or without osteosynthesis. Between June 2009 and March 2013, 41 children were included. Mean age was 9.25 years (range, 4 to 15.4 y). We used needle manometry to measure the pressures in the superficial and deep volar as well as in the dorsal compartments (DCs) on both the forearms. The mean pressures between compartments in healthy versus injured arms were analyzed using a 1-sided, paired t test.

Results:

On the injured side, the mean compartment pressure was 19.12 mm Hg (range, 3 to 49 mm Hg) in the deep volar compartment, 15.56 mm Hg (range, 5 to 37 mmHg) in the DC, and 14.8 mm Hg (range, 2 to 35 mm Hg) in the superficial volar compartment. On the noninjured side, the mean compartment pressure was 12.9 mm Hg (range, 6 to 31 mm Hg) in the DC, 10.22 mm Hg (range, 3 to 22 mm Hg) in the deep volar compartment, and 9.66 mm Hg (range, 3 to 21 mm Hg) in the superficial volar compartment. We measured an absolute compartment pressure of >30 mm Hg in 15 patients on the fractured side. Three of them had an absolute compartment pressure of >45 mm Hg. Only 1 had ACS. This patient underwent fasciotomy and was excluded for further analysis. On follow-up (mean, 24.84 mo), no patient was found to have any sequelae of ACS.

Discussion:

This is the first study to report normal compartment pressure measurements in noninjured forearms and in fractured forearms without clinical suspicion of ACS in children.

The mean compartment pressure measured in the deep volar compartment (DVC) in healthy children was 10.22 mm Hg (range, 3 to 22 mm Hg) and therefore slightly higher than in adults. Some children with fractures tolerated absolute compartment pressures >30 mm Hg without clinical signs of ACS. Fasciotomy in children under close observation could eventually be delayed despite surpassing the accepted pressure limits for adults.

Level of Evidence:

Level I—prognostic.
Reliability and Effectiveness of Smartphone Technology for the Diagnosis and Treatment Planning of Pediatric Elbow Trauma
Authors: Paryavi Ebrahim , Schwartz Brandon S. , Meyer Carissa L. , Herman Martin J. , Abzug Joshua M.
Published: April 2015

Background:

Mobile imaging, such as viewing radiographs as text messages, is increasingly prevalent in clinical settings. The purpose of this study was to determine whether remote diagnosis of pediatric elbow fractures using smartphone technology is reliable. In addition, this study aimed to determine whether the assessment regarding the decision for operative treatment is affected by evaluation of images on a mobile device as opposed to standard picture archiving and communication system (PACS).

Methods:

Standard anteroposterior and lateral radiographs of 50 pediatric elbow trauma cases were evaluated by 2 fellowship-trained pediatric orthopaedic surgeons and 2 senior orthopaedic residents. Raters were asked to classify the case as any of 6 diagnoses: supracondylar humerus, lateral condyle, medial epicondyle, radial neck fracture, positive posterior fat pad sign, or normal pediatric elbow. Raters were asked to choose operative or conservative treatment. After 1 week, photographs of the same images were taken from a standardized distance from a computer monitor with an iPhone 5 camera and transmitted by multimedia messaging to each rater. The same questions were again posed to raters. Interobserver and intraobserver reliabilities were calculated by Cohen κ-statistics with bootstrapped 95% confidence intervals.

Results:

Intraobserver reliability of classification of injuries on PACS compared with smartphone images was excellent, with an overall κ of 0.91. Treatment decision also demonstrated excellent intraobserver reliability (PACS vs. smartphones) with a κ of 0.86 for all raters.

Conclusions:

Diagnosis of pediatric elbow injuries can be made equally reliably based on either PACS or transmitted multimedia messaging images taken with an iPhone camera from a computer screen and viewed on a smartphone. Treatment decisions can also be made reliably based on either image modality.

Clinical Relevance:

Using smartphones to transmit and display radiographs, which is common in current clinical practice, is effective and reliable for diagnosis and treatment planning of pediatric elbow injuries.
Accuracy of Percutaneous Pedicle Screw Placement
Authors: Baird Evan O. , McAnany Steven J. , Overley Samuel , Skovrlj Branko , Guzman Javier Z. , Qureshi Sheeraz A.
Published: April 2015

Study Design:

In vitro human cadaveric surgical technique study.

Objective:

To assess the accuracy of percutaneous pedicle screw placement in a human cadaveric model using standard fluoroscopic guidance technique, compared across varying levels of experience.

Summary of Background Data:

The current literature varies widely in the reported frequency of facet violation during placement of percutaneous pedicle screws. However, as of yet there are no studies examining the effect that training level has on accuracy of placement.

Materials and Methods:

Four surgeons with differing levels of training (PGY-2, PGY-4, fellow, attending) were evaluated on their accuracy of percutaneous placement of screws in a uniform manner. Each of the 10 cadavers was instrumented from L1 to S1 bilaterally, for a total of 120 screws. Specimens were dissected to evaluate for facet and pedicle wall violations. These were then recorded and analyzed to evaluate for correlation among participating surgeons, laterality, spinal level, and cadaver body mass index.

Results:

Of 120 screws placed, there were 35 total violations [26 superior articular facet violations (21.7%), 5 intra-articular facet joint violations (4.2%), and 4 pedicle breaches (3.3%)]. Among the trainees there was no difference in the likelihood of causing a violation (P=0.8863) but there was a difference when compared with the attending surgeon (P=0.0175). Laterality (P=0.1598), spinal level (P=0.3536), and body mass index (P=0.8547) did not correlate with the likelihood of a violation.

Conclusions:

Surgeons of differing training levels are able to safely and accurately place lumbar pedicle screws in a percutaneous manner, with a low likelihood of facet and pedicle wall violations.
The Effect of Concomitant Rib Deformity in Congenital Scoliosis on Spinal Curve Correction After Segmental Pedicle Screw Instrumentation
Authors: Ameri Ebrahim , Fouladi Daniel F. , Safari Mir Bahram , Tari Hossein Vahid , Ghandhari Hassan
Published: April 2015

Study Design:

A single-center, prospective study.

Objective:

To investigate the effect of rib anomaly on surgical curve correction outcome in congenital scoliosis.

Summary of Background Data:

The presence of rib anomalies may complicate surgical correction of congenital scoliosis. The outcome of surgical correction, however, has not been documented in scoliotic patients with and without rib deformity.

Methods:

Percent Cobb angle decrease (CAD) after operation was calculated in 94 patients with congenital scoliosis. Posterior segmental pedicle screw instrumentation (posterior approach) with or without previous anterior spinal release and fusion (anterior approach) was the method of correction. The impact of vertebral anomaly and rib deformity on CAD was examined.

Results:

Although the type of vertebral anomaly had no significant effect on the mean CAD, it was significantly lower in 56 patients with rib deformity compared with that in the remaining patients without rib deformity (35.14%±15.83% vs. 51.54%±17.82%, P<0.001); particularly in those with complex, unilateral rib abnormalities, and in those with same-level vertebral and rib deformities. Patients’ sex and age at the time of operation, rib number abnormality, and the type of operation (ie, posterior-only approach vs. anterior and posterior approach) did not contribute significantly to Cobb angle change after operation.

Conclusions:

Concomitant rib deformities, particularly of complex and unilateral types, significantly compromise operative curve correction outcome in congenital scoliosis.
The Quantitated Internal Suture Browpexy: Comparison of Two Brow-Lifting Techniques in Patients Undergoing Upper Blepharoplasty
Authors: Baker Meredith S. , Shams Pari N. , Allen Richard C.
Published: April 2015

Purpose:

To describe and evaluate 1) the quantitated internal suture browpexy (ISB), which combines the advantages of a browpexy and “brassiere suture,” 2) the endoscopic Endotine browplasty, and 3) to compare these two techniques in patients undergoing simultaneous upper blepharoplasty.

Methods:

Retrospective review of patients undergoing bilateral upper blepharoplasty alone, bilateral ISB with upper blepharoplasty, and bilateral Endotine (MicroAire, Charlottesville, VA, U.S.A.) browplasty with upper blepharoplasty by one surgeon was performed. ImageJ 1.47v software (Wayne Rasband, National Institutes of Health, Bethesda, MD, U.S.A.) and standardized photographs were used to measure pre- and postoperative brow position at three positions (central, medial, lateral). Statistical analysis was performed using Sigmaplot version 12.5 for Windows (Systat Software, Inc., San Jose, CA, U.S.A.).

Results:

Thirty-three patients undergoing ISB with blepharoplasty, 33 undergoing Endotine browplasty with blepharoplasty, and 30 patients undergoing blepharoplasty alone were included. The 3 groups were matched for age and gender. Patients undergoing upper blepharoplasty alone showed statistically significant brow descent at all three brow positions (mean: -1.7 mm [p ≤ 0.04]). The quantitated ISB prevented brow descent but provided minimal brow elevation (mean lateral elevation: right eye (OD) +1.3 mm [p = 0.03]; OS +0.9 mm [p = 0.08]). Endotine browplasty with upper blepharoplasty provided significant brow elevation at all brow positions, particularly laterally (OD +4.0 mm [p < 0.001]; OS +3.5 mm [p < 0.001]). There were no complications.

Conclusions:

Upper blepharoplasty alone is associated with brow descent; performing ISB simultaneously effectively prevents this descent. Endotine browplasty with upper blepharoplasty achieves significant brow elevation. Quantitation of the browpexy allows reproducible placement of the suture thereby producing consistent and symmetrical results.
A retrospective review of sudden onset severe headache and subarachnoid haemorrhage on the clinical decision unit: looking for a needle in a haystack?
Authors: Cooper Jamie G. , Smith Benedict , Hassan Tajek B.
Published: April 2015

Introduction

Patients commonly present to the Emergency Department with sudden onset acute severe headache, but exclusion of significant secondary causes, particularly subarachnoid haemorrhage (SAH), is vital. The misdiagnosis of SAH is most likely in patients with a normal neurological examination, and the consequences can be disastrous. A noncontrast computed tomography (CT) brain scan is the initial investigation of choice, and most would recommend that, if negative, this be followed by a lumbar puncture (LP) and cerebrospinal fluid (CSF) analysis. Many hospitals in the UK have developed Clinical Decision Unit (CDU) pathways to provide a standardized approach to the investigation and management of neurologically normal patients with headache suggestive of SAH.

Aims

The aims of this study were to describe the prevalence of SAH and to evaluate the performance of CT and LP in a CDU population with sudden onset acute severe headache.

Methods

A retrospective review of neurologically pristine patients admitted to a CDU pathway for exclusion of SAH was conducted. Structured case notes were reviewed; patient demographics, investigation results and clinical outcomes were recorded in each case.

Results

The overall prevalence of SAH in this population was 14/517 (2.7%). A noncontrast CT of the brain had a negative predictive value of 99.8%, reducing the post-test probability of having an angiogram-positive SAH detected by LP and CSF analysis to 0.21% (95% confidence interval 0.04–0.36%).

Conclusion

The management of neurologically pristine patients with sudden onset severe headache on a CDU pathway is feasible. In light of the low prevalence of SAH in this population, the decision to follow a negative CT with an LP in all cases needs careful consideration, as CSF results may only rarely confer therapeutic benefit to patients suspected of SAH.