bluuebunny/crossref_metadata_2025 huggingface dataset:
Simple convergent-nozzle aerosol injector for single-particle diffractive imaging with X-ray free-electron lasers
Authors: Kirian R. A. , Awel S. , Eckerskorn N. , Fleckenstein H. , Wiedorn M. , Adriano L. , Bajt S. , Barthelmess M. , Bean R. , Beyerlein K. R. , Chavas L. M. G. , Domaracky M. , Heymann M. , Horke D. A. , Knoska J. , Metz M. , Morgan A. , Oberthuer D. , Roth N. , Sato T. , Xavier P. L. , Yefanov O. , Rode A. V. , Küpper J. , Chapman H. N.
Published: June 2015

A major challenge in high-resolution x-ray free-electron laser-based coherent diffractive imaging is the development of aerosol injectors that can efficiently deliver particles to the peak intensity of the focused X-ray beam. Here, we consider the use of a simple convergent-orifice nozzle for producing tightly focused beams of particles. Through optical imaging we show that 0.5 μm particles can be focused to a full-width at half maximum diameter of 4.2 μm, and we demonstrate the use of such a nozzle for injecting viruses into a micro-focused soft-X-ray FEL beam.
Complex mixed-mode oscillatory patterns in a periodically forced excitable Belousov-Zhabotinsky reaction model
Authors: Español Malena I. , Rotstein Horacio G.
Published: June 2015

The Oregonator is the simplest chemically plausible model for the Belousov-Zhabotinsky reaction. We investigate the response of the Oregonator to sinusoidal inputs with amplitudes and frequencies within plausible ranges. We focus on a regime where the unforced Oregonator is excitable (with no sustained oscillations). We use numerical simulations and dynamical systems tools to both characterize the response patterns and explain the underlying dynamic mechanisms.
Study of the switching rate of gas-discharge devices based on the open discharge with counter-propagating electron beams
Authors: Bokhan P. A. , Gugin P. P. , Lavrukhin M. A. , Zakrevsky Dm. E.
Published: June 2015

The switching rate of gas-discharge devices “kivotrons” based on the open discharge with counter-propagating electron beams has been experimentally studied. Structures with 2-cm2 overall cathode area were examined. The switching time was found to show a monotonic decrease with increasing the working-gas helium pressure and with increasing the voltage across the discharge gap at breakdown. The minimum switching time was found to be ∼240 ps at 17 kV voltage, and the maximum rate of electric-current rise limited by the discharge-circuit inductance was 3 × 1012 A/s.
Study of structural and ferromagnetic resonance properties of spinel lithium ferrite (LiFe5O8) single crystals
Authors: Pachauri Neha , Khodadadi Behrouz , Althammer Matthias , Singh Amit V. , Loukya B. , Datta Ranjan , Iliev Milko , Bezmaternykh Leonard , Gudim Irina , Mewes Tim , Gupta Arunava
Published: June 2015

The effect of B-site cation ordering on the room temperature structural and ferromagnetic resonance (FMR) properties of single crystal spinel lithium ferrite (LiFe5O8, LFO) have been investigated. A detailed microstructural analysis is done through X-ray diffraction, polarized Raman spectroscopy, and transmission electron microscopy (TEM) to examine the effect of post-annealing on the B-site cation ordering. The X-ray diffraction pattern of the as-grown crystal indicates a disordered state of the crystal. However, the annealed sample shows additional superlattice reflections corresponding to the ordered phase. This ordering is further confirmed by Raman spectra and TEM images, which reveal ordering of Li and Fe ions at the octahedral sites contrasting with the relatively high degree of octahedral site disorder in the as-grown crystal. To study the effect of B-site ordering on the magnetic properties and FMR linewidth, vibrating sample magnetometry and broadband FMR measurements have been performed for both the ordered and disordered phases of lithium ferrite. The value of saturation magnetization for both phases is ∼290 emu/cm3. A single mode FMR profile is observed for both phases with little distortion. The linewidth characteristics of the ordered and disordered phases of lithium ferrite phases are compared, and it is observed that the linewidth is independent of the cation ordering. Both the phases exhibit a low linewidth (∼26 Oe at 30 GHz) and the effective damping parameter for the as-grown and annealed samples is determined to be 0.0021 ± 0.0001.
Chaos control of the brushless direct current motor using adaptive dynamic surface control based on neural network with the minimum weights
Authors: Luo Shaohua , Wu Songli , Gao Ruizhen
Published: June 2015

This paper investigates chaos control for the brushless DC motor (BLDCM) system by adaptive dynamic surface approach based on neural network with the minimum weights. The BLDCM system contains parameter perturbation, chaotic behavior, and uncertainty. With the help of radial basis function (RBF) neural network to approximate the unknown nonlinear functions, the adaptive law is established to overcome uncertainty of the control gain. By introducing the RBF neural network and adaptive technology into the dynamic surface control design, a robust chaos control scheme is developed. It is proved that the proposed control approach can guarantee that all signals in the closed-loop system are globally uniformly bounded, and the tracking error converges to a small neighborhood of the origin. Simulation results are provided to show that the proposed approach works well in suppressing chaos and parameter perturbation.
Real-time imaging, spectroscopy, and structural investigation of cathodic plasma electrolytic oxidation of molybdenum
Authors: Stojadinović Stevan , Tadić Nenad , Šišović Nikola M. , Vasilić Rastko
Published: June 2015

In this paper, the results of the investigation of cathodic plasma electrolytic oxidation (CPEO) of molybdenum at 160 V in a mixed solution of borax, water, and ethylene glycol are presented. Real-time imaging and optical emission spectroscopy were used for the characterization of the CPEO. During the process, vapor envelope is formed around the cathode and strong electric field within the envelope caused the generation of plasma discharges. The spectral line shape analysis of hydrogen Balmer line Hβ (486.13 nm) shows that plasma discharges are characterized by the electron number density of about 1.4 × 1021 m−3. The electron temperature of 15 000 K was estimated by measuring molybdenum atomic lines intensity. Surface morphology, chemical, and phase composition of coatings formed by CPEO were characterized by scanning electron microscopy with energy dispersive x-ray spectroscopy and x-ray diffraction. The elemental components of CPEO coatings are Mo and O and the predominant crystalline form is MoO3.
On numerical and approximate solutions for stagnation point flow involving third order fluid
Authors: Ahmad M. , Sajid M. , Hayat T. , Ahmad I.
Published: June 2015

This article addresses the two-dimensional boundary layer flow of third order fluid in the region of a stagnation point over a surface lubricated with a power law fluid. The lubricant is assumed to have a thin layer of variable thickness over the surface. The third order fluid experiences a partial slip due to this lubrication layer. Mathematical model of the flow problem is represented through a system of nonlinear partial differential equations with nonlinear boundary conditions. The non-similar numerical and analytic solutions of the transformed ordinary differential equation are obtained using hybrid homotopy analysis method based on the combination of homotopy analysis and shooting methods. It is observed that extra drag force is required in order to achieve no-slip regime from full slip and thus slip has suppressed the effects of free stream velocity. The results varying from no-slip to full slip case are discussed under the influence of pertinent parameters.
Proposal of a novel compact P-band magnetically insulated transmission line oscillator with inclined vanes
Authors: Zhang Xiaoping , Dang Fangchao , Li Yangmei , Jin Zhenxing
Published: June 2015

In this paper, we present a novel compact P-band magnetically insulated transmission line oscillator (MILO) with specially inclined slow-wave-structure (SWS) vanes to decrease its total dimension and weight. The dispersion characteristics of the inclined SWS are investigated in detail and made comparisons with that of the traditional straight SWS. The results show that the inclined SWS is more advantageous in operating on a steady frequency in a wide voltage range and has a better asymmetric mode segregation and a relatively large band-gap between the TM00 and TM01 modes which are in favor of avoiding the asymmetric and transverse mode competition. Besides, the transverse dimension of the proposed novel inclined SWS with the same operation frequency is decreased by about 50%, and correspondingly the device volume shrinks remarkably to its 0.35 times. In particle-in-cell simulation, the electron bunching spokes are obviously formed in the inclined SWS, and a P-band high-power microwave with a power of 5.8 GW, frequency of 645 MHz, and efficiency of 17.2% is generated by the proposed device, which indicates the feasibility of the compact design with the inclined vanes at the P-band.
A nano universal joint made from curved double-walled carbon nanotubes
Authors: Cai Kun , Cai Haifang , Shi Jiao , Qin Qing H.
Published: June 2015

A nano universal joint is constructed from curved double-wall carbon nanotubes with a short outer tube as stator and a long inner tube as a rotor. When one end of the rotor is driven (by a rotary motor) to rotate, the same rotational speed but with different rotational direction will be induced at the other end of the rotor. This mechanism makes the joint useful for designing a flexible nanodevice with an adjustable output rotational signal. The motion transmission effect of the universal joint is analyzed using a molecular dynamics simulation approach. In particular, the effects of three factors are investigated. The first factor is the curvature of the stator, which produces a different rotational direction of the rotor at the output end. The second is the bonding conditions of carbon atoms on the adjacent tube ends of the motor and the rotor, sp1 or sp2 atoms, which create different attraction between the motor and the rotor. The third is the rotational speed of the motor, which can be considered as the input signal of the universal joint. It is noted that the rotor's rotational speed is usually the same as that of the motor when the carbon atoms on the adjacent ends of the motor and the rotor are sp1 carbon atoms. When they become the new sp2 atoms, the rotor experiences a jump in rotational speed from a lower value to that of the motor. The mechanism of drops in potential of the motor is revealed. If the carbon atoms on the adjacent ends are sp2 atoms, the rotor rotates more slowly than the motor, whereas the rotational speed is stable when driven by a higher speed motor.
Linguistic landscapes in an era of multiple globalizations
Authors: Ben-Rafael Eliezer , Ben-Rafael Miriam
Published: June 2015

This paper focuses on linguistic landscapes in present-day urban settings. These spaces consist of numberless establishments riddled with versatile texts or ‘LL items’. They are foci of both the development of globalization that conquers the world through commercial globe-encompassing networks, and of massive migrations from underprivileged countries to privileged ones. In each such city, one distinguishes major ‘downtowns’ and secondary ones in neighbourhoods, whose variety reflects a complex composition. LL investigations help understand how far and in what ways dissonant cleavages divide the public space. Chaos is the rule in this urban landscape, but where it illustrates some permanence and recurrence, it becomes familiar and the feeling of disorder may leave room for a notion of gestalt. Turning from here to the empirical investigation of LLs in Brussels, Berlin, and Tel-Aviv, we ask, as far as LLs can say: (1) if globalization causes the weakening of allegiances to all-societal symbols in favour of supra-national ones; (2) if migratory movements toward megapolises express themselves in the creation of segregated LLs or, on the contrary, indicate some ‘melting’ tendencies of the new populations into society’s mainstream; and (3) to what extent these questions elicit the same answers in different places or contribute to different configurations.
Translanguaging and linguistic landscapes
Authors: Gorter Durk , Cenoz Jasone
Published: June 2015

In this article we discuss the concept of translanguaging in relation to a holistic view of linguistic landscapes that goes beyond the analysis of individual signs. On the one hand, we look at instances of multilingual signage as a combination of linguistic resources. On the other hand, at the neighborhood level the individual signs combine, alternate and mix to shape linguistic landscapes as a whole. We expand our “Focus on Multilingualism” approach from school settings to the multilingual cityscape. One bookshop and its surrounding neighborhoods in Donostia-San Sebastián illustrate how readers navigate between languages and go across linguistic borders. Through translanguaging we foreground the co-occurrence of different linguistic forms, signs and modalities. At the level of neighborhood emerges the space in which translanguaging goes outside the scope of single signs and separate languages. We conclude that translanguaging is an approach to linguistic landscapes that takes the study of multilingualism forward.
Word cities and language objects
Authors: Jaworski Adam
Published: June 2015

The focus of this paper is on language objects in contemporary ‘word cities’, or urban landscapes, shaped by art and consumer culture. I define ‘language objects’ as two- or three-dimensional pieces of writing (e.g. needlework samplers, fridge magnets, wooden or metal sculptures, etc.) that do not serve any apparent informational or utilitarian purpose, i.e. they are not ‘attached’ to or displayed on any objects with identifiable practical functions, e.g. buildings, t-shirts, mugs, paper weights, and so on. Two specific language objects considered here are Robert Indiana’s LOVE sculpture and a Marks & Spencer ‘love letters decoration’. It is suggested that such language objects perform largely Jakobson’s (1960) poetic function with its key focus on form. Yet, they are also instances of linguistic performances with complex trajectories of appropriation and recontextualization of prior cultural and linguistic material (Bauman, 2001; Bauman & Briggs, 1990), while their appropriation for specific ‘personal’ uses is best explained by treating them as ‘shifters’ — referential indexes, or signs constituted by the combination of their symbolic value and the communicative act itself (or ‘rules of use’) (Jakobson, 1971; Silverstein, 1976).
Opening spaces of learning in the linguistic landscape
Authors: Malinowski David
Published: June 2015

In the context of increasing interest in the linguistic landscape as a site of language and literacy learning, this paper outlines a conceptual framework for joining recent innovations in LL theory and methodology with pedagogical practice in second and foreign language education. After a review of current approaches to teaching the linguistic forms, cultural messages, and political actions realized in the linguistic landscape, a spatialized perspective based upon the principle ofthirdnessis proposed as a way for learners to explore, contrast, and reflect upon multiple meanings in the LL. Specifically, the paper adapts methodological innovations in Trumper-Hecht (2010) and other recent research by reinterpreting Henri Lefebvre’s triadic paradigm of conceived, perceived, and lived spaces for the language classroom, such that teachers and learners can design nuanced, multilayered investigations of discourses in place. As qualitative methods cast new light on questions of subjectivity, materiality, and change in the linguistic landscape, it is argued, linguistic landscape research offers valuable tools for pedagogical application, even as language learners open up new interpretive spaces for research.
Why diachronicity matters in the study of linguistic landscapes
Authors: Pavlenko Aneta , Mullen Alex
Published: June 2015

It is commonly argued that the proliferation of urban writing known as linguistic landscapes represents “a thoroughly contemporary global trend” (Coupland, 2010: 78). The purpose of this paper is to show that linguistic landscapes are by no means modern phenomena and to draw on our shared interest in multilingual empires to highlight the importance of diachronic inquiry and productive dialog between sociolinguists of modern and ancient societies. We will argue that while signs do operate in aggregate, the common focus on all signsat a single point in time on one streetis problematic because the interpretation of signs is diachronic in nature, intrinsically linked to the preceding signs in the same environment and to related signs elsewhere, and the process of reading “back from signs to practices to people” (Blommaert, 2013: 51) is not as unproblematic as it is sometimes made to look.
Evacuation Times of Radio Transmitters Consumed by Largemouth Bass
Authors: Thompson Brandon C. , Gwinn Daniel C. , Allen Micheal S.
Published: June 2015

Reduction in transmitter size used in telemetry studies have allowed researchers to tag and track fish that are much smaller than could have been tagged previously. Researchers seek information on juvenile or small fish movement, behavior, and survival to better understand recruitment processes. Juvenile or small-bodied fish that have been tagged have an increased risk of predation, which results in transmitters being consumed. Knowledge about radio transmitter accumulation in a predator's gut and evacuation times are critical for interpreting locations of radio-tagged fish and their predators. Our objective was to determine what factors influenced the evacuation time of transmitters (0.3 g), implanted in juvenile Largemouth Bass Micropterus salmoides through the digestive system of adult Largemouth Bass that had preyed upon those tagged juveniles. All transmitters ingested by the predators were evacuated within 84 h. A Poisson regression model showed that transit time decreased significantly with temperature and increased with prey length and predator length. The results of this study suggest that miniature radio transmitters (e.g., 0.3 g) do not accumulate in the digestive tract of predators and that after consumption, up to 3 d of behavior (i.e., movement and habitat use) by the predator, movements could falsely be attributed to the juvenile fish. Therefore, if a distinction cannot be made between predator and tagged juvenile Largemouth Bass, we recommend not including information from the final 3 d before cessation of movement when analyzing the behavior of tagged fish.

Received June 9, 2014; accepted January 28, 2015
Ethanol extract of Brazilian propolis ameliorates cognitive dysfunction and suppressed protein aggregations caused by hyperhomocysteinemia
Authors: Miyazaki Yuta , Sugimoto Yasushi , Fujita Akikazu , Kanouchi Hiroaki
Published: June 2015

Homocysteine (Hcy) has been proposed to be a risk factor for cognitive dysfunction. We investigated the effects and the underlying mechanisms of action of propolis, which has antioxidant activity on Hcy-induced oxidative stress in vitro and in vivo. For the in vitro assays, neuroblastoma SH-SY5Y and glioblastoma U-251MG cells were cultured with Hcy and various concentrations of propolis. Cell death and reactive oxygen species production were significantly suppressed by propolis in dose-dependent manner, compared with Hcy alone. For the in vivo assays, mice were fed a propolis-containing diet and Hcy thiolactone in water. Cognitive function was evaluated using the Morris water maze test. Propolis suppressed cognitive dysfunction caused by hyperhomocysteinemia. Accumulation of aggregated protein in brain was accelerated in hyperhomocysteinemia, and the accumulation was suppressed by propolis. Hyperhomocysteinemia, however, did not enhance the oxidative stress in brain. In vitro amyloid formation assay showed that Hcy accelerated lysozyme aggregation and propolis inhibited the aggregation.
A diary after dinner: How the time of event recording influences later accessibility of diary events
Authors: Szőllősi Ágnes , Keresztes Attila , Conway Martin A. , Racsmány Mihály
Published: June 2015

Recording the events of a day in a diary may help improve their later accessibility. An interesting question is whether improvements in long-term accessibility will be greater if the diary is completed at the end of the day, or after a period of sleep, the following morning. We investigated this question using an internet-based diary method. On each of five days, participants ( n = 109) recorded autobiographical memories for that day or for the previous day. Recording took place either in the morning or in the evening. Following a 30-day retention interval, the diary events were free recalled. We found that participants who recorded their memories in the evening before sleep had best memory performance. These results suggest that the time of reactivation and recording of recent autobiographical events has a significant effect on the later accessibility of those diary events. We discuss our results in the light of related findings that show a beneficial effect of reduced interference during sleep on memory consolidation and reconsolidation.
Factors Influencing Daily Growth in Young-of-the-Year Winter Flounder along an Urban Gradient Revealed Using Hierarchical Linear Models
Authors: Gallagher Brian K. , Hice Lyndie A. , McElroy Anne E. , Cerrato Robert M. , Frisk Michael G.
Published: June 2015

Growth during early life history plays a key role in the recruitment dynamics of marine fishes; however, the effects of environmental stressors on growth are often difficult to quantify. In this study, increment widths from sagittal otoliths were used as a proxy for daily growth in 102 young-of-the-year Winter Flounder Pseudopleuronectes americanus collected over a 2-year period from three sites in Long Island, New York. We hypothesized that we would observe different growth patterns among bays due to an environmental gradient driven primarily by contaminant loadings and environmental stressors in our study sites. Hierarchical linear models were utilized to associate individual attributes (ontogeny, condition, and gene expression) to daily growth patterns during each year. As expected, daily growth generally displayed a negative relationship with age and daily average temperature, although the effect of temperature was much more variable. Out of 14 individual attributes, the settlement date, the age at capture, the condition indices Fulton's K and hepatosomatic index, and the expression of genes associated with immune response (pleurocidin), contaminant exposure (cytochrome P5401A), and glucose and glycogen metabolism (glycerol-3-phosphate dehydrogenase) were observed to significantly and consistently affect growth. The results provide evidence of differential growth based on the date of settlement and condition, and the molecular indicators of stress suggest that growth is also influenced by habitat quality. There were significantly different relationships between individual attributes and growth among bays, but these did not always reflect the proposed environmental gradient. Together, the results suggest that anthropogenic stressors likely play a role in growth and recruitment processes in Long Island bays and indicate that growth is both spatially and temporally dynamic at multiple scales. Furthermore, this study highlights the utility of hierarchical linear models in analyzing complex daily growth data in juvenile fish, which may be applicable to other species.
Waiting for a flourishing Baltic cod (Gadus morhua) fishery that never comes: old truths and new perspectives
Authors: Svedäng Henrik , Hornborg Sara
Published: June 2015

Contrary to the declared recovery of the stock, the density-dependent growth of Eastern Baltic cod (Gadus morhua, Gadidae), probably related to increased gear selectivity, may have disrupted the size structure and substantially lowered the productivity of the stock. This naturally affects the profitability and future development of industry as well as ecosystem objectives in relation to policies such as the Marine Strategy Framework Directive. As a result, current management frameworks need to be reconsidered with a clear priority on setting objectives related to both socio-economic and ecosystem considerations. We explore various management options, using bioeconomic modelling to visualize potential trade-offs, and form an integrated decision support to inform managers regarding potential yield in biomass, revenue at both the fleet and individual levels, and environmental impact of fishing. We also investigate the consequences of preventing density-dependence by lowering selectivity, Lc, while optimizing for economic revenue and minimizing ecosystem impacts. Our findings indicate that new strategies need to be adopted by reducing Lc as well as fishing mortality, F, to restore individual growth and, hence, stock productivity. We also note that these more risk-averting strategies are positively linked to better profitability at both the individual and fleet levels as well as with enhanced ecosystem functioning and lower ecological stress.
Swift/XRT view of S5 0716+714 during a flare
Authors: Wierzcholska A. , Siejkowski H.
Published: June 2015

The blazar S5 0716+714 has been monitored in its flaring state between 2015 January 19 and February 22 with the Swift X-Ray Telescope (Swift/XRT). During this period, an exceptional flux level was observed in the X-ray range as well as at other wavelengths, e.g. optical, near-infrared and very-high-energy γ rays. Here, we report X-ray observations of S5 0716+714 carried out during the outburst. The observed X-ray spectra, well described by a broken power-law model, disentangle both synchrotron and inverse Compton components. The break energy shifts towards higher energies with increasing flux, revealing the dominance of synchrotron radiation in the X-ray spectrum observed. We also report spectrum softening with increasing flux. During the recent flare, significant temporal intranight variability is observed in the X-ray range.
Black hole accretion versus star formation rate: theory confronts observations
Authors: Volonteri Marta , Capelo Pedro R. , Netzer Hagai , Bellovary Jillian , Dotti Massimo , Governato Fabio
Published: June 2015

We use a suite of hydrodynamical simulations of galaxy mergers to compare star formation rate (SFR) and black hole accretion rate (BHAR) for galaxies before the interaction (‘stochastic’ phase), during the ‘merger’ proper, lasting ∼0.2–0.3 Gyr, and in the ‘remnant’ phase. We calculate the bivariate distribution of SFR and BHAR and define the regions in the SFR–BHAR plane that the three phases occupy. No strong correlation between BHAR and galaxy-wide SFR is found. A possible exception are galaxies with the highest SFR and the highest BHAR. We also bin the data in the same way used in several observational studies, by either measuring the mean SFR for AGN in different luminosity bins, or the mean BHAR for galaxies in bins of SFR. We find that the apparent contradiction or SFR versus BHAR for observed samples of AGN and star-forming galaxies is actually caused by binning effects. The two types of samples use different projections of the full bivariate distribution, and the full information would lead to unambiguous interpretation. We also find that a galaxy can be classified as AGN-dominated up to 1.5 Gyr after the merger-driven starburst took place. Our study is consistent with the suggestion that most low-luminosity AGN hosts do not show morphological disturbances.
Four Weeks in a Single-Leg Weight-Bearing Hip Spica Cast is Sufficient Treatment for Isolated Femoral Shaft Fractures in Children Aged 1 to 3 Years
Authors: Jaafar Sami , Sobh Ali , Legakis Julie E. , Thomas Ronald , Buhler Kelsey , Jones Eric T.
Published: June 2015

Background:

Hip spica casting regimens for the treatment of femoral shaft fractures in a pediatric population aged 1 to 3 years vary. Patient charts were reviewed to determine if there are any clinical differences between 3 and 4 weeks in an ambulatory single-leg hip spica (SLHS) cast versus 6 to 8 weeks in a standard double-leg, non–weight-bearing hip spica cast.

Methods:

The medical records of 109 patients with femoral shaft fractures treated with a hip spica casting from January 1, 2008 to December 31, 2011 were examined. After exclusions, 94 patients were eligible for inclusion in the study. Patient records were assessed, noting age, weight, type of cast, time in cast, and complications. All casts were applied by senior pediatric orthopaedic surgeons at a single institution.

Results:

Two groups were evaluated: 59 patients in the SLHS group and 35 in the double-leg hip spica group. The 2 groups were demographically similar with an average age of 2 years, 70.2% of patients were male, 45.7% were black, and 35.1% were white. The average time to cast removal was 4.1 weeks for the single-leg group and 5.3 weeks for the double-leg group (P<0.001). Both groups had similar low rates of loss of reduction. The double-leg group had a significantly higher incidence of clinically significant limb-length discrepancy (7/35, 20%), compared with the single-leg group (1/59, 1.7%, P=0.004). In addition, the double-leg group also had more skin problems (11/35, 31.4%) compared with the single-leg group (6/59, 10.2%, P=0.013). Seventeen patients in the single-leg group were documented as walking in the cast as compared with no patients in the double-leg group (P<0.001).

Conclusions:

Patients treated with a single-leg spica cast for 4 weeks had fewer complications than patients treated in a traditional double-leg cast. Femoral shaft fractures in patients less than 4 years old can be treated in a weight-bearing SLHS casts for approximately 4 weeks with fewer alignment and skin complications.

Level of Evidence:

Level III—clinical retrospective comparative study.
Incidence and Risk Factors for Extensor Pollicis Longus Rupture in Elastic Stable Intramedullary Nailing of Pediatric Forearm Shaft Fractures
Authors: Lee Adam K. , Beck John D. , Mirenda William M. , Klena Joel C.
Published: June 2015

Background:

Elastic stable intramedullary nailing (ESIN) is an effective means of fixation for unstable, pediatric forearm shaft fractures with the benefit of smaller incisions, less soft tissue manipulation, and ease of removal. This study was designed to evaluate the incidence of and risk factors for extensor pollicis longus (EPL) rupture after fixation of pediatric radial shaft fractures with ESIN.

Methods:

A retrospective review of all patients younger than 19 years who had a repair of a forearm fracture with flexible intramedullary nailing between 2006 and 2011 was performed. Nineteen consecutive patients were identified from the electronic medical record. All patients were treated with a titanium elastic nailing system using a dorsal approach to the radius. The patients were followed postoperatively for at least 2 years, and all fractures healed. An extensive chart review assessing for persistent pain, EPL function, and risk factors for EPL rupture was performed. Implants were removed in all but 1 patient.

Results:

Seventeen records were available for review. Fourteen (82%) were male, and the mean age at time of fracture was 10 years old (range, 5 to 14 y). Follow-up averaged 5.5 years (range, 2.9 to 7.8 y). The mean weight was 32.7 kg for males and 50.6 kg for females corresponding to the 61st and 60th percentile respectively of weight-for-age (range, 8th to 99.9th percentile). Hardware was removed in all but 1 case, and the median time from surgery to hardware removal was 21 weeks (range, 8 to 63). Three of the 17 patients (18%) experienced rupture of the EPL. Two were treated with additional surgery following hardware removal, and one was untreated due to patient preference. None of the 17 patients (including those with rupture) had independent risk factors for tendon rupture: inflammatory arthritis, diabetes, or prior steroid use. Time to removal, patient age, and percentile of weight-for-age did not correlate with EPL rupture.

Conclusions:

Although ESIN of pediatric forearm shaft fractures has gained acceptance as a treatment option, our series of 17 patients revealed an 18% rate of EPL rupture. With this small patient cohort, no patient characteristics proved to be significant risk factors for predicting tendon rupture. However, awareness should be raised for an increased risk of EPL rupture with this fixation method.

Level of Evidence:

Level IV—Therapeutic.
Closed Reduction and Percutaneous Pinning Versus Open Reduction and Internal Fixation for Type II Lateral Condyle Humerus Fractures in Children Displaced >2 mm
Authors: Pennock Andrew T. , Salgueiro Lissette , Upasani Vidyadhar V. , Bastrom Tracey P. , Newton Peter O. , Yaszay Burt
Published: June 2015

Background:

The optimal treatment for pediatric lateral condyle fractures displaced >2 mm, but with little joint displacement is unclear. The purpose of this study was to assess clinical and radiographic outcomes and complication rates of patients undergoing open reduction internal fixation (ORIF) versus closed reduction and percutaneous pin fixation (CRPP) of lateral condyle fractures with >2 mm of displacement and no obvious articular surface incongruity.

Methods:

A retrospective review of all children with acute lateral condyle fractures with 2.1 to 5.0 mm of displacement treated from 2006 to 2014 was performed. A total of 74 patients were treated who met inclusion criteria; 51 underwent ORIF and 23 underwent CRPP. No differences existed between the 2 groups with respect to age, sex, extremity, mechanism of injury, time to treatment, fracture displacement, or fracture classification. Charts and radiographs were reviewed and the following parameters were documented: operating room time, time to union, return to activities, magnitude of lateral spurring, and complications. Major complications were defined as those with presumptive long-term effects or requiring reoperation.

Results:

All fractures healed within 12 weeks of surgery, regardless of treatment type and no differences were observed in time to union between groups. OR time averaged 30 minutes faster for the CRPP group (P<0.001). Nearly 10% of patients in each group developed elbow stiffness, requiring formal therapy. The overall complication rates were 25% for the ORIF group and 13% for the CRPP group (P=0.36). No major complications were observed in the CRPP group, whereas 3 (6%) were observed in the ORIF group, including 1 case of avascular necrosis, 1 case of osteomyelitis with an associated premature physeal closure, and 1 refracture requiring surgery.

Conclusions:

Surgical treatment of lateral condyle fractures displaced >2 mm, but with no significant articular surface incongruity has good outcomes with both CRPP and ORIF. CRPP, however, minimizes surgical time, avoids an incision and is thus our preferred treatment approach when joint congruity can be confirmed.

Level of Evidence:

Level III—therapeutic study.
Effect of Casting Material on the Cast Pressure After Sequential Cast Splitting
Authors: Roberts Aaron , Shaw K. Aaron , Boomsma Shawn E. , Cameron Craig D.
Published: June 2015

Background:

Circumferential casting is a vital component of nonoperative fracture management. These casts are commonly valved to release pressure and decrease the risk of complications from swelling. However, little information exists regarding the effect of different casting supplies on the pressure within the cast.

Methods:

Seventy-five long-arm casts were performed on human volunteers, divided between 5 experimental groups with 15 casts in each groups. Testing groups consisted of 2 groups with a plaster short-arm cast overwrapped with fiberglass to a long arm with either cotton or synthetic cast padding. The 3 remaining groups included fiberglass long-arm casts with cotton, synthetic, or waterproof cast padding. A pediatric blood pressure cuff bladder was placed within the cast and inflated to 100 mm Hg. After inflation, the cast was sequentially released with pressure reading preformed after each stage. Order of release consisted of cast bivalve, cast padding release, and cotton stockinet release. After release, the cast was overwrapped with a loose elastic bandage. Difference in pressure readings were compared based upon the cast material.

Results:

Pressures within the cast were found to decrease with sequential release of cast. The cast type had no effect of change in pressure. Post hoc testing demonstrated that the type of cast padding significantly affected the cast pressures with waterproof padding demonstrating the highest pressure readings at all time-points in the study, followed by synthetic padding. Cotton padding had the lowest pressure readings at all time-points.

Discussion:

Type of cast padding significantly influences the amount of pressure within a long-arm cast, even after bivalving the cast and cutting the cast padding. Cotton cast padding allows for the greatest change in pressure.

Clinical Relevance:

Cotton padding demonstrates the greatest change in pressure within a long-arm cast after undergoing bivalve. Synthetic and waterproof cast padding should not be used in the setting of an acute fracture to accommodate swelling.
Early Results of Drilling and/or Microfracture for Grade IV Osteochondritis Dissecans of the Capitellum
Authors: Lewine Eliza B. , Miller Patricia E. , Micheli Lyle J. , Waters Peter M. , Bae Donald S.
Published: June 2015

Background:

Surgical treatment is recommended for patients with unstable osteochondritis dissecans (OCD) of the elbow. However, little information is available comparing the anticipated results from the host of techniques. In this investigation, clinical and radiographic resolution as well as return to sports rates were assessed in adolescent patients following loose body (LB) removal and drilling/microfracture of grade IV lesions.

Methods:

We reviewed 21 adolescents treated with LB removal and drilling/microfracture for grade IV elbow OCD. Patients with additional elbow pathology, prior elbow surgery, or <1 year follow-up were excluded. Clinical resolution was defined as resolution of tenderness and radiographic resolution as resolution of edema on magnetic resonance imaging (MRI). Return to sport rates and Timmerman scores were assessed. Mean clinical and MRI follow-up times were 2.2±1.19 and 2.4±1.54 years, respectively. Clinical and radiographic parameters associated with clinical and/or radiographic resolution or return to sports were determined using penalized likelihood logistic regression. Wilcoxon signed-rank tests were used to evaluate the change in range of motion and in Timmerman scores.

Results:

Fifteen (71.4%) patients had either clinical or radiographic resolution at most recent follow-up. Nine (50%) had complete resolution on MRI, whereas 13 (61.9%) were nontender at their follow-up. Four patients with recurrent LBs underwent revision surgery. There were no complications in the 21 index procedures. Eighteen (85.7%) patients returned to any sport, whereas 14 (66. 7%) returned to their primary sport. Elbow flexion and extension improved by medians of 12 and 21 degrees, respectively (P=0.002, 0.01). Timmerman scores improved by a median of 30 (P=0.001). Shorter duration of symptoms correlated with smaller OCD lesions (P=0.03) and with improved clinical or radiographic resolution and return to sport rates.

Conclusions:

The majority of patients with grade IV elbow OCD achieves clinical and/or radiographic resolution and return to sports 2 years after LB removal and drilling/microfracture. Recurrence may be seen, however, and further investigation is needed to assess the efficacy of this technique compared with other treatment strategies.

Level of Evidence:

Level IV.
Bioabsorbable Pin Fixation in Late Presenting Pediatric Radial Neck Fractures
Authors: Fuller Corey B. , Guillen Phillip T. , Wongworawat Montri D. , Riedel Barth B.
Published: June 2015

Background:

Current treatment algorithms for pediatric radial neck fractures reserve open treatment for severe residual angulation. There is a paucity of literature guiding treatment for delayed presentation resulting in malunion. Bioabsorbable pins have been used successfully for many other fracture types in the upper extremity. The purpose of this study is to determine whether open reduction, bioabsorbable fixation with an osteotomy when necessary is a reasonable treatment option in delayed pediatric radial neck fractures by assessing pain, range of motion, functional, and radiographic outcomes.

Methods:

Radial neck fractures were evaluated in 7 children, 4 to 12 years old, with delayed initial presentation averaging 20 days. Patients presented with an average angular deformity of 63 degrees and translational deformity of 57% (6.1 mm) in the AP plane, all with painful and reduced range of motion. Patients underwent open reduction and fixation with Self-Reinforced Poly-L-Lactic Acid pins after failed closed reduction. Four patients required formal osteotomies. Postoperative follow-up averaged 9.2 months and consisted of radiographic and clinical evaluation with Wong-Baker FACES Visual Analog scale and the Mayo Elbow Performance (MEP) score.

Results:

Final radiographs demonstrate an improvement in angular deformity by 56 degrees and translational deformity by 51%. Final clinical outcomes demonstrated significantly improved pain-free range of motion with excellent MEP scores in 6 of the 7 patients. One patient developed a radioulnar synostosis, subsequently undergoing synostosis excision with a final MEP score of 80/100. There was no evidence of physeal closure or avascular necrosis and no cases requiring hardware removal or complicated by local inflammatory reactions.

Conclusions:

This small series shows encouraging results in the treatment of pediatric radial neck fractures with delayed presentation using open reduction, bioabsorbable fixation, and when necessary an osteotomy. Bioabsorbable fixation may eliminate issues surrounding subsequent hardware removal and pin-site infections. Despite these encouraging results, radioulnar synostosis after open surgery is still a concern.

Level of Evidence:

Level IV—case series.
Rate and Risk Factors for Delayed Healing Following Surgical Treatment of Lateral Condyle Humerus Fractures in Children
Authors: Salgueiro Lissette , Roocroft Joanna H. , Bastrom Tracey P. , Edmonds Eric W. , Pennock Andrew T. , Upasani Vidyadhar V. , Yaszay Burt
Published: June 2015

Background:

Lateral condyle humerus fracture nonunion after surgical fixation has been reported to be <1%. The purpose of this study was to evaluate the rate and risk factors for delayed healing of pediatric lateral condyle fractures after surgical fixation.

Methods:

Retrospective study of all operatively treated lateral condyle fractures at a single institution from 2006 to 2013 was performed. Radiographic evaluation included: measured fracture displacement at both presentation and after surgical fixation, fracture classification, and multiple parameters of pin configuration. Patients who had delayed healing were defined as those not healed by the eighth week of follow-up and were compared with those fractures that healed in <8 weeks to identify risk factors associated with delayed healing. Purposeful selection was utilized to identify factors for entry into a multivariate binary logistic regression model.

Results:

A total of 210 children were evaluated. Mean follow-up was 25 weeks (4 wk to 5 y). Distribution of Weiss classification was as follows: type 1, 8 (4%); type 2, 61 (29%); and type 3, 141 (67%). There were 33 (16%) delayed unions and 7 of these (3% of the entire cohort) required further surgery to achieve healing. Weiss classification, intraoperative fluoroscopy time, and intraoperative displacement after fixation met criteria for entry into the regression. While Weiss classification did not remain significant within the model, its removal resulted in a 30% change in the parameter estimate for intraoperative fluoroscopy time. For each second increase in fluoroscopy time, there is a 3% increase in the risk of delayed healing. Patients with >1 mm displacement of the lateral cortex after fixation had an increased risk of delayed healing (OR=4.78, P=0.007).

Conclusions:

Delayed union of lateral condyle fractures is a matter of concern, and the rate of secondary surgery to achieve healing appears to be higher than previously reported. Risks for delayed healing include amount of residual displacement after reduction and the difficulty in attaining that reduction, as defined by fluoroscopy time.

Level of Evidence:

Level IV—therapeutic study, case series.
The discovery, distribution and evolution of viruses associated withDrosophila melanogaster
Authors: Webster Claire L. , Waldron Fergal M. , Robertson Shaun , Crowson Daisy , Ferrari Giada , Quintana Juan F. , Brouqui Jean-Michel , Bayne Elizabeth H. , Longdon Ben , Buck Amy H. , Lazzaro Brian P. , Akorli Jewelna , Haddrill Penelope R. , Obbard Darren J.
Published: June 2015

Abstract

Drosophila melanogasteris a valuable invertebrate model for viral infection and antiviral immunity, and is a focus for studies of insect-virus coevolution. Here we use a metagenomic approach to identify more than 20 previously undetected RNA viruses and a DNA virus associated with wildD. melanogaster. These viruses not only include distant relatives of known insect pathogens, but also novel groups of insect-infecting viruses. By sequencing virus-derived small RNAs we show that the viruses represent active infections ofDrosophila.We find that the RNA viruses differ in the number and properties of their small RNAs, and we detect both siRNAs and a novel miRNA from the DNA virus. Analysis of small RNAs also allows us to identify putative viral sequences that lack detectable sequence similarity to known viruses. By surveying >2000 individually collected wild adultDrosophilawe show that more than 30% ofD. melanogastercarry a detectable virus, and more than 6% carry multiple viruses. However, despite a high prevalence of theWolbachiaendosymbiont—which is known to be protective against virus infections inDrosophila—we were unable to detect any relationship between the presence ofWolbachiaand the presence of any virus. Using publicly available RNA-seq datasets we show that the community of viruses inDrosophilalaboratories is very different from that seen in the wild, but that some of the newly discovered viruses are nevertheless widespread in laboratory lines and are ubiquitous in cell culture. By sequencing viruses from individual wild-collected flies we show that some viruses are shared betweenD. melanogasterandD. simulans. Our results provide an essential evolutionary and ecological context for host-virus interaction inDrosophila, and the newly reported viral sequences will help developD. melanogasterfurther as a model for molecular and evolutionary virus research.

DataAvailability

All of the relevant data can be found within the paper and its Supporting Information files, with the exception of raw metagenomic sequence data which are deposited at NCBI Sequence Read Archive (SRP056120), and sequence data which are deposited at Genbank (KP714070-KP714108,KP757922-KP757936andKP757937-KP757993)