bluuebunny/crossref_metadata_2025 huggingface dataset:
Ovariectomy-Induced Osteoporosis Does Not Impact Fusion Rates in a Recombinant Human Bone Morphogenetic Protein-2–Dependent Rat Posterolateral Arthrodesis Model
Authors: Ghodasra Jason H. , Nickoli Michael S. , Hashmi Sohaib Z. , Nelson John T. , Mendoza Marco , Nicolas Joseph D. , Bellary Sharath S. , Sonn Kevin , Ashtekar Amruta , Park Christian J. , Babu Jacob , Yun Chawon , Ghosh Anjan , Kannan Abhishek , Stock Stuart R. , Hsu Wellington K. , Hsu Erin L.
Published: June 2015

Study Design

Randomized, controlled animal study.

Objective

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is frequently utilized as a bone graft substitute in spinal fusions to overcome the difficult healing environment in patients with osteoporosis. However, the effects of estrogen deficiency and poor bone quality on rhBMP-2 efficacy are unknown. This study sought to determine whether rhBMP-2-induced healing is affected by estrogen deficiency and poor bone quality in a stringent osteoporotic posterolateral spinal fusion model.

Methods

Aged female Sprague-Dawley rats underwent an ovariectomy (OVX group) or a sham procedure, and the OVX animals were fed a low-calcium, low-phytoestrogen diet. After 12 weeks, the animals underwent a posterolateral spinal fusion with 1 μg rhBMP-2 on an absorbable collagen sponge. Representative animals were sacrificed at 1 week postoperative for alkaline phosphatase (ALP) and osteocalcin serum analyses. The remaining animals underwent radiographs 2 and 4 weeks after surgery and were subsequently euthanized for fusion analysis by manual palpation, micro–computed tomography (CT) imaging, and histologic analysis.

Results

The ALP and osteocalcin levels were similar between the control and OVX groups. Manual palpation revealed no significant differences in the fusion scores between the control (1.42 ± 0.50) and OVX groups (1.83 ± 0.36; p = 0.07). Fusion rates were 100% in both groups. Micro-CT imaging revealed no significant difference in the quantity of new bone formation, and histologic analysis demonstrated bridging bone across the transverse processes in fused animals from both groups.

Conclusions

This study demonstrates that estrogen deficiency and compromised bone quality do not negatively influence spinal fusion when utilizing rhBMP-2, and the osteoinductive capacity of the growth factor is not functionally reduced under osteoporotic conditions in the rat. Although osteoporosis is a risk factor for pseudarthrosis/nonunion, rhBMP-2-induced healing was not inhibited in osteoporotic rats.
Singular linear statistics of the Laguerre unitary ensemble and Painlevé. III. Double scaling analysis
Authors: Chen Min , Chen Yang
Published: June 2015

We continue with the study of the Hankel determinant, defined by Dn(t,α)=det∫0∞xj+kw(x;t,α)dxj,k=0n−1, generated by a singularly perturbed Laguerre weight, w(x; t, α) = xαe−xe−t/x, x ∈ ℝ+,  α > 0,  t > 0, and obtained through a deformation of the Laguerre weight function, w(x; 0, α) = xαe−x,  x ∈ ℝ+,  α > 0, via the multiplicative factor e−t/x. An earlier investigation was made on the finite n aspect of such determinants, which appeared in Chen and Its [J. Approx. Theory 162, 270–297 (2010)]. It was found that the logarithm of the Hankel determinant has an integral representation in terms of a particular Painlevé III (PIII, for short) transcendent and its t derivatives. In this paper, we show that under a double scaling, where n, the size of the Hankel matrix tends to ∞, and t tends to 0+, the scaled—and therefore, in some sense, infinite dimensional—Hankel determinant has an integral representation in terms of a C potential. The second order non-linear ordinary differential equation satisfied by C, after a change of variables, is another PIII transcendent, albeit with fewer number of parameters. Expansions of the double scaled determinant for small and large parameters are obtained.
Clathrate structure-type recognition: Application to hydrate nucleation and crystallisation
Authors: Lauricella Marco , Meloni Simone , Liang Shuai , English Niall J. , Kusalik Peter G. , Ciccotti Giovanni
Published: June 2015

For clathrate-hydrate polymorphic structure-type (sI versus sII), geometric recognition criteria have been developed and validated. These are applied to the study of the rich interplay and development of both sI and sII motifs in a variety of hydrate-nucleation events for methane and H2S hydrate studied by direct and enhanced-sampling molecular dynamics (MD) simulations. In the case of nucleation of methane hydrate from enhanced-sampling simulation, we notice that already at the transition state, ∼80% of the enclathrated CH4 molecules are contained in a well-structured (sII) clathrate-like crystallite. For direct MD simulation of nucleation of H2S hydrate, some sI/sII polymorphic diversity was encountered, and it was found that a realistic dissipation of the nucleation energy (in view of non-equilibrium relaxation to either microcanonical (NVE) or isothermal-isobaric (NPT) distributions) is important to determine the relative propensity to form sI versus sII motifs.
Applications of deuterium-tritium equation of state based on density functional theory in inertial confinement fusion
Authors: Wang Cong , Fan Zheng-Feng , He Xian-Tu , Ye Wen-Hua , Zhang Ping
Published: June 2015

An accurate equation of state for deuterium-tritium mixture is of crucial importance in inertial confinement fusion. The equation of state can determine the compressibility of the imploding target and the energy deposited into the fusion fuel. In the present work, a new deuterium-tritium equation of state, which is calculated according to quantum molecular dynamic and orbital free molecular dynamic simulations, has been used to study the target implosion hydrodynamics. The results indicate that the peak density predicted by the new equation of state is ∼10% higher than the quotidian equation of state data. During the implosion, the areal density and neutron yield are also discussed.
Self-crowding induced phase separation in protein dispersions
Authors: Stegen J. , van der Schoot P.
Published: June 2015

The coupling between protein conformation, molecular volume, and solution phase behaviour is studied theoretically for a two-state, coarse-grained protein model in which protein molecules can reversibly switch between a native and a non-native excited state. In the model, native and non-native conformers are represented by perfect spheres with different hard-core diameters. We presume the larger, non-native species to attract each other through some unspecified potential. We find that at low concentrations the native state is stabilised energetically and that at high concentrations the native state is again stabilised but this time by self-crowding, i.e., a lack of free volume. These two regimes are separated by two first-order transitions from a region where the non-native conformational state is prevalent, stabilised by attractive interactions between the proteins. The calculated phase diagram is very sensitive to even quite small differences in particle volumes and has unusual features, including the loss of a critical point if the size difference is sufficiently large.
Characterization of midwave infrared InSb avalanche photodiode
Authors: Abautret J. , Perez J. P. , Evirgen A. , Rothman J. , Cordat A. , Christol P.
Published: June 2015

This paper focuses on the InSb material potential for the elaboration of Avalanche Photodiodes (APD) for high performance infrared imaging applications, both in passive or active mode. The first InSb electron-APD structure was grown by molecular beam epitaxy, processed and electrically characterized. The device performances are at the state of the art for the InSb epi-diode technology, with a dark current density J(−50 mV) = 32 nA/cm2 at 77 K. Then, a pure electron injection was performed, and an avalanche gain, increasing exponentially, was observed with a gain value near 3 at −4 V at 77 K. The Okuto–Crowell model was used to determine the electron ionization coefficient α(E) in InSb, and the InSb gain behavior is compared with the one of InAs and MCT APDs.
Communication: Rotational excitation of HCl by H: Rigid rotor vs. reactive approaches
Authors: Lique François
Published: June 2015

We report fully quantum time-independent calculations of cross sections for the collisional excitation of HCl by H, an astrophysically relevant process. Our calculations are based on the Bian-Werner ClH2 potential energy surface and include the possibility of HCl destruction through reactive collisions. The strongest collision-induced rotational HCl transitions are those with Δj = 1, and the magnitude of the HCl-H inelastic cross sections is of the same order of magnitude as the HCl-H2 ones. Results of exact calculations, i.e., including the reactive channels, are compared to pure inelastic calculations based on the rigid rotor approximation. A very good agreement is found between the two approaches over the whole energy range 10–3000 cm−1. At the highest collisional energies, where the reaction takes place, the rigid rotor approach slightly overestimates the cross sections, as expected. Hence, the rigid rotor approach is found to be reliable at interstellar temperatures.
Strain mapping at nanometer resolution using advanced nano-beam electron diffraction
Authors: Ozdol V. B. , Gammer C. , Jin X. G. , Ercius P. , Ophus C. , Ciston J. , Minor A. M.
Published: June 2015

We report on the development of a nanometer scale strain mapping technique by means of scanning nano-beam electron diffraction. Only recently possible due to fast acquisition with a direct electron detector, this technique allows for strain mapping with a high precision of 0.1% at a lateral resolution of 1 nm for a large field of view reaching up to 1 μm. We demonstrate its application to a technologically relevant strain-engineered GaAs/GaAsP hetero-structure and show that the method can even be applied to highly defected regions with substantial changes in local crystal orientation. Strain maps derived from atomically resolved scanning transmission electron microscopy images were used to validate the accuracy, precision and resolution of this versatile technique.
The influence of AlN buffer over the polarity and the nucleation of self-organized GaN nanowires
Authors: Auzelle Thomas , Haas Benedikt , Minj Albert , Bougerol Catherine , Rouvière Jean-Luc , Cros Ana , Colchero Jaime , Daudin Bruno
Published: June 2015

We experimentally investigate the influence of AlN buffer growth on the nucleation and the polarity of a self-organized assembly of GaN nanowires (NWs) grown on Si. Two complementary growth mechanisms for AlN buffer deposited on Si are demonstrated. Both emphasize the aggregation of Si on the AlN surface and the growth of large cubic crystallites, namely, AlN pedestals. Further growths of GaN NWs assembly reveal that the GaN 2D layer found at the bottom of the NW assembly is the result of the coalescence of Ga-polar pyramids, whereas AlN pedestals are observed as preferential but not exclusive NW nucleation sites. NWs are N-polar or exhibit inversion domains with a Ga-polar core/N-polar shell structure. This suggests that N-polarity is a necessary condition to trigger NW self-organized nucleation due to a different facets energy hierarchy between the Ga- and the N-polar sides.
Direct spontaneous growth and interfacial structural properties of inclined GaN nanopillars on r-plane sapphire
Authors: Adikimenakis A. , Lotsari A. , Dimitrakopulos G. P. , Kehagias Th. , Aretouli K. E. , Tsagaraki K. , Androulidaki M. , Komninou Ph. , Georgakilas A.
Published: June 2015

The spontaneous growth of GaN nanopillars (NPs) by direct plasma-assisted molecular beam epitaxy on nitridated r-plane sapphire substrates has been studied. The emanation of metal-polarity NPs from inside an a-plane nonpolar GaN film was found to depend on both the substrate nitridation and the growth conditions. The density of NPs increased with increasing the duration of the nitridation process and the power applied on the radio-frequency plasma source, as well as the III/V flux ratio, while variation of the first two parameters enhanced the roughness of the substrate's surface. Transmission electron microscopy (TEM) techniques were employed to reveal the structural characteristics of the NPs and their nucleation mechanism from steps on the sapphire surface and/or interfacial semipolar GaN nanocrystals. Lattice strain measurements showed a possible Al enrichment of the first 5–6 monolayers of the NPs. By combining cross-sectional and plan-view TEM observations, the three-dimensional model of the NPs was constructed. The orientation relationship and interfacial accommodation between the NPs and the nonpolar a-plane GaN film were also elucidated. The NPs exhibited strong and narrow excitonic emission, suggesting an excellent structural quality.
Study on GaN buffer leakage current in AlGaN/GaN high electron mobility transistor structures grown by ammonia-molecular beam epitaxy on 100-mm Si(111)
Authors: Ravikiran L. , Radhakrishnan K. , Munawar Basha S. , Dharmarasu N. , Agrawal M. , Manoj kumar C. M. , Arulkumaran S. , Ng G. I.
Published: June 2015

The effect of carbon doping on the structural and electrical properties of GaN buffer layer of AlGaN/GaN high electron mobility transistor (HEMT) structures has been studied. In the undoped HEMT structures, oxygen was identified as the dominant impurity using secondary ion mass spectroscopy and photoluminescence (PL) measurements. In addition, a notable parallel conduction channel was identified in the GaN buffer at the interface. The AlGaN/GaN HEMT structures with carbon doped GaN buffer using a CBr4 beam equivalent pressure of 1.86 × 10−7 mTorr showed a reduction in the buffer leakage current by two orders of magnitude. Carbon doped GaN buffers also exhibited a slight increase in the crystalline tilt with some pits on the growth surface. PL and Raman measurements indicated only a partial compensation of donor states with carbon acceptors. However, AlGaN/GaN HEMT structures with carbon doped GaN buffer with 200 nm thick undoped GaN near the channel exhibited good 2DEG characteristics.
Linearly to radially polarized light conversion and tight focus
Authors: Wang Xiahui , Ren Hongwen , Nah Changwoon
Published: June 2015

We report a polarization-conversion lens (PCL), which consists of a polarization-conversion part and a lens part. The polarization-conversion part is prepared using a twisted-radial liquid crystal gel and the lens part is made using a polymer droplet. The two solidified parts are integrated with a compact structure. The former part can convert a linearly polarized light to a radially polarized light and the latter part can focus the radially polarized light at a spot. At the focused spot, a large component of the electric field is in the longitudinal direction due to the destructive interference of the transverse components. Owing to this unique feature, a tight focus with high power can be obtained. Such a PCL has potential applications in material processing, phase modulation, polarization compensating, and polarization imaging.
Note: Using fast digitizer acquisition and flexible resolution to enhance noise cancellation for high performance nanosecond transient absorbance spectroscopy
Authors: Rimshaw A. , Grieco C. , Asbury J. B.
Published: June 2015

We demonstrate a nanosecond transient absorbance spectrometer that utilizes flexible resolution and rapid data acquisition triggering modes. The instrument features signal-to-noise (S/N) levels enhanced by an order of magnitude especially within the first 100 ns. The primary gain in S/N comes from our sequential subtraction method, which requires a fast digitizer trigger rearm time to detect every laser trigger event.
Photoluminescence enhancement in few-layer WS2 films via Au nanoparticles
Authors: Choi Sin Yuk , Yip Cho Tung , Li Guang-Can , Lei Dang Yuan , Fung Kin Hung , Yu Siu Fung , Hao Jianhua
Published: June 2015

Nano-composites of two-dimensional atomic layered WS2 and Au nanoparticles (AuNPs) have been fabricated by sulfurization of sputtered W films followed by immersing into HAuCl4 aqueous solution. The morphology, structure and AuNPs distribution have been characterized by electron microscopy. The decorated AuNPs can be more densely formed on the edge and defective sites of triangle WS2. We have compared the optical absorption and photoluminescence of bare WS2 and Au-decorated WS2 layers. Enhancement in the photoluminescence is observed in the Au-WS2 nano-composites, attributed to localized surface plasmonic effect. This work provides the possibility to develop photonic application in two-dimensional materials.
All-dielectric periodic terajet waveguide using an array of coupled cuboids
Authors: Minin I. V. , Minin O. V. , Pacheco-Peña V. , Beruete M.
Published: June 2015

In this paper, the recently proposed technique to produce photonic jets (terajets at terahertz (THz) frequencies) using 3D dielectric cuboids is applied in the design of a mesoscale cuboid-chain waveguide. The chains are basically designed with several dielectric cubes with side λ0 placed periodically along the axial z-axis and separated by an air-gap. Based on this, a systematic study of the focusing properties and wave guiding of this chain is performed when the air-gap between the dielectric cubes is changed from 0.25λ0 to 3λ0 with the best performance achieved at 2.5λ0. An analysis when losses are included in the cubes is also done, demonstrating a robust performance. Finally, the wave guiding is experimentally demonstrated at sub-THz frequencies with a good agreement with numerical results. The simulation results of focusing and transport properties are carried out using Finite Integration Technique. The results here presented may be scaled to any frequency ranges such as millimeter, sub-millimeter, and optical frequencies.
Graphene as a transparent electrode for amorphous silicon-based solar cells
Authors: Vaianella F. , Rosolen G. , Maes B.
Published: June 2015

The properties of graphene in terms of transparency and conductivity make it an ideal candidate to replace indium tin oxide (ITO) in a transparent conducting electrode. However, graphene is not always as good as ITO for some applications, due to a non-negligible absorption. For amorphous silicon photovoltaics, we have identified a useful case with a graphene-silica front electrode that improves upon ITO. For both electrode technologies, we simulate the weighted absorption in the active layer of planar amorphous silicon-based solar cells with a silver back-reflector. The graphene device shows a significantly increased absorbance compared to ITO-based cells for a large range of silicon thicknesses (34.4% versus 30.9% for a 300 nm thick silicon layer), and this result persists over a wide range of incidence angles.
Combined stress of low temperature and flooding affects physiological activities and insecticidal protein content in transgenic Bt cotton
Authors: Zhou Guisheng , Wang Yonghui , Zhai Fuyan , Lu Shiyuan , Nimir A. E. , Yu Linlin , Pan Hui , Lv Dongmei
Published: June 2015

Low temperature and flooding are severe stresses to cotton plant growth and development in some parts of the world. This study was conducted to determine the interactive effects of low temperature and flooding on physiological and growth parameters of cotton plants, and yield of seed cotton. Transgenic Bt cotton plants at the boll-setting stage were treated with low temperature, flooding, and their combinations. The stresses decreased photosynthetic rate, stomatal conductance, transpiration rate, and intercellular CO2 concentration by up to 37%, 71%, 52%, and 60%, respectively. The content of soluble protein and insecticidal protein was also decreased by up to 65% and 53%, respectively. By contrast, malondialdehyde (MDA) content increased by up to 114%. The length of fruiting branch was shortened by combined low temperature and flooding stress. Boll number and weight were decreased by 3.2% and 28.1%, respectively. Seed cotton yield was decreased by up to 43.2%. Our results suggest that concurrent low temperature and flooding at the boll-setting stage negatively influenced leaf photosynthetic activities and insecticidal protein production, leading to poor protection and yield. We recommend that agronomic measures be designed to stabilise physiological activities and insecticidal protein production in Bt cotton plants under stress conditions.
QTL mapping for plant height and yield components in common wheat under water-limited and full irrigation environments
Authors: Li Xingmao , Xia Xianchun , Xiao Yonggui , He Zhonghu , Wang Desen , Trethowan Richard , Wang Huajun , Chen Xinmin
Published: June 2015

Plant height (PH) and yield components are important traits for yield improvement in wheat breeding. In this study, 207 F2:4 recombinant inbred lines (RILs) derived from the cross Jingdong 8/Aikang 58 were investigated under limited and full irrigation environments at Beijing and Gaoyi, Hebei province, during the 2011–12 and 2012–13 cropping seasons. The RILs were genotyped with 149 polymorphic simple sequence repeat (SSR) markers, and quantitative trait loci (QTLs) for PH and yield components were analysed by inclusive composite interval mapping. All traits in the experiment showed significant genetic variation and interaction with environments. The range of broad-sense heritabilities of PH, 1000-kernel weight (TKW), number of kernels per spike (KNS), number of spikes per m2 (NS), and grain yield (GY) were 0.97–0.97, 0.87–0.89, 0.59–0.61, 0.58–0.68, and 0.23–0.48. The numbers of QTLs detected for PH, TKW, KNS, NS, and GY were 3, 10, 8, 7 and 9, respectively, across all eight environments. PH QTLs on chromosomes 4D and 6A, explaining 61.3–80.2% of the phenotypic variation, were stably expressed in all environments. QPH.caas-4D is assumed to be the Rht-D1b locus, whereas QPH.caas-6A is likely to be a newly discovered gene. The allele from Aikang 58 at QPH.caas-4D reduced PH by 11.5–18.2% and TKW by 2.6–3.8%; however, KNS increased (1.2–3.7%) as did NS (2.8–4.1%). The QPH.caas-6A allele from Aikang 58 reduced PH by 8.0–11.5% and TKW by 6.9–8.5%, whereas KNS increased by 1.2–3.6% and NS by 0.9–4.5%. Genotypes carrying both QPH.caas-4D and QPH.caas-6A alleles from Aikang 58 showed reduced PH by 28.6–30.6%, simultaneously reducing TKW (13.8–15.2%) and increasing KNS (3.4–4.9%) and NS (6.5–10%). QTKW.caas-4B and QTKW.caas-5B.1 were stably detected and significantly associated with either KNS or NS. Major KNS QTLs QKNS.caas-4B and QKNS.caas-5B.1 and the GY QTL QGY.caas-3B.2 were detected only in water-limited environments. The major TKW QTKW.caas-6D had no significant effect on either KNS or NS and it could have potential for improving yield.
DC-SIGN activation mediates the differential effects of SAP and CRP on the innate immune system and inhibits fibrosis in mice
Authors: Cox Nehemiah , Pilling Darrell , Gomer Richard H.
Published: June 2015

Significance

Pentraxins such as serum amyloid P (SAP) and C-reactive protein (CRP) have significant, and for SAP dominant, effects on the innate immune system. This report shows that contrary to the current model of how SAP and CRP are sensed by cells, Fcγ receptors are not necessary for SAP to regulate the innate immune system. This report considerably changes our understanding of the endogenous regulation of the innate immune system and connections between innate immune system signaling and epithelial cell signaling. The identification of DC-SIGN as a SAP receptor, the potential use of anti–DC-SIGN antibodies as a therapeutic, and the observation that remarkably low concentrations of a DC-SIGN ligand are therapeutic in a mouse model of fibrosis, create a new approach to treat fibrosis.
Trp triad-dependent rapid photoreduction is not required for the function of
Arabidopsis
CRY1
Authors: Gao Jie , Wang Xu , Zhang Meng , Bian Mingdi , Deng Weixian , Zuo Zecheng , Yang Zhenming , Zhong Dongping , Lin Chentao
Published: June 2015

Significance

The Trp triad-dependent photoreduction of the flavin chromophore has been widely accepted as the photoexcitation mechanism of cryptochrome photoreceptors. However, the experimental evidence supporting this hypothesis derived primarily from the biophysical studies in vitro, except for one genetics study of
Arabidopsis
cryptochrome 1 (CRY1). In contrast to the previous report, we found that all Trp-triad mutations of
Arabidopsis
CRY1 remained physiologically active in plants, and this result cannot be readily explained by the ATP-dependent enhancement of Trp triad-dependent photoreduction. Our results challenge the widely accepted Trp-triad hypothesis and call for further investigation of alternative electron transport mechanisms to explain cryptochrome photoexcitation.
Rescue of the Stargardt phenotype in
Abca4
knockout mice through inhibition of vitamin A dimerization
Authors: Charbel Issa Peter , Barnard Alun R. , Herrmann Philipp , Washington Ilyas , MacLaren Robert E.
Published: June 2015

Significance

Accumulation of lipofuscin in the retinal pigment epithelium precedes retinal degenerations and dystrophies responsible for blindness-causing retinal diseases. The mechanism behind lipofuscin formation in the retina or in any tissue is poorly understood. Here we show in mice that the dimerization of vitamin A is responsible for triggering the formation of more than 50% of ocular lipofuscin. Replacing three hydrogen atoms on vitamin A with deuterium inhibits vitamin A dimerization, resulting in reduced lipofuscin and transcriptional normalization of genes associated with inflammation without compromising retinal function. Thus, vitamin A deuterated at the carbon 20 position provides a clinically amiable tool to prevent vitamin A dimerization in humans to assess whether impeding such dimerization might prevent retinal degenerations such as Stargardt disease and age-related macular degeneration.
Evaluation of sterol transport from the endoplasmic reticulum to mitochondria using mitochondrially targeted bacterial sterol acyltransferase in Saccharomyces cerevisiae
Authors: Tian Siqi , Ohta Akinori , Horiuchi Hiroyuki , Fukuda Ryouichi
Published: June 2015

To elucidate the mechanism of interorganelle sterol transport, a system to evaluate sterol transport from the endoplasmic reticulum (ER) to the mitochondria was constructed. A bacterial glycerophospholipid: cholesterol acyltransferase fused with a mitochondria-targeting sequence and a membrane-spanning domain of the mitochondrial inner membrane protein Pet100 and enhanced green fluorescent protein was expressed in a Saccharomyces cerevisiae mutant deleted for ARE1 and ARE2 encoding acyl-CoA:sterol acyltransferases. Microscopic observation and subcellular fractionation suggested that this fusion protein, which was named mito-SatA-EGFP, was localized in the mitochondria. Steryl esters were synthesized in the mutant expressing mito-SatA-EGFP. This system will be applicable for evaluations of sterol transport from the ER to the mitochondria in yeast by examining sterol esterification in the mitochondria.
Weighted Hardy spaces associated with elliptic operators. Part I: Weighted norm inequalities for conical square functions
Authors: Martell José María , Prisuelos-Arribas Cruz
Published: June 2015

This is the first part of a series of three articles. In this paper, we obtain weighted norm inequalities for different conical square functions associated with the Heat and the Poisson semigroups generated by a second order divergence form elliptic operator with bounded complex coefficients. We find classes of Muckenhoupt weights where the square functions are comparable and/or bounded. These classes are natural from the point of view of the ranges where the unweighted estimates hold. In doing that, we obtain sharp weighted change of angle formulas which allow us to compare conical square functions with different cone apertures in weighted Lebesgue spaces. A key ingredient in our proofs is a generalization of the Carleson measure condition which is more natural when estimating the square functions below

p
=
2

p=2

.
FoldNucleus: web server for the prediction of RNA and protein folding nuclei from their 3D structures
Authors: Pereyaslavets Leonid B. , Sokolovsky Igor V. , Galzitskaya Oxana V.
Published: June 2015

Motivation: To gain insight into how biopolymers fold as quickly as they do, it is useful to determine which structural elements limit the rate of RNA/protein folding.

Summary: We have created a new web server, FoldNucleus. Using this server, it is possible to calculate the folding nucleus for RNA molecules with known 3D structures—including pseudoknots, tRNAs, hairpins and ribozymes—and for protein molecules with known 3D structures, as long as they are smaller than 200 amino acid residues. Researchers can determine and understand which elements of the structure limit the folding process for various types of RNAs and protein molecules. Experimental Ф values for 21 proteins can be found and compared with those determined by our method: http://bioinfo.protres.ru/resources/phi_values.htm.

Availability and implementation:  http://bioinfo.protres.ru/foldnucleus/.

Contact:  ogalzit@vega.protres.ru
Improving prediction of fall risk among nursing home residents using electronic medical records
Authors: Marier Allison , Olsho Lauren E.W. , Rhodes William , Spector William D.
Published: June 2015

Objective Falls are physically and financially costly, but may be preventable with targeted intervention. The Minimum Data Set (MDS) is one potential source of information on fall risk factors among nursing home residents, but its limited breadth and relatively infrequent updates may limit its practical utility. Richer, more frequently updated data from electronic medical records (EMRs) may improve ability to identify individuals at highest risk for falls.

Methods The authors applied a repeated events survival model to analyze MDS 3.0 and EMR data for 5129 residents in 13 nursing homes within a single large California chain that uses a centralized EMR system from a leading vendor. Estimated regression parameters were used to project resident fall probability. The authors examined the proportion of observed falls within each projected fall risk decile to assess improvements in predictive power from including EMR data.

Results In a model incorporating fall risk factors from the MDS only, 28.6% of observed falls occurred among residents in the highest projected risk decile. In an alternative specification incorporating more frequently updated measures for the same risk factors from the EMR data, 32.3% of observed falls occurred among residents in the highest projected risk decile, a 13% increase over the base MDS-only specification.

Conclusions Incorporating EMR data improves ability to identify those at highest risk for falls relative to prediction using MDS data alone. These improvements stem chiefly from the greater frequency with which EMR data are updated, with minimal additional gains from availability of additional risk factor variables.
Interaction between an emerging flux region and a pre-existing fan-spine dome observed by IRIS and SDO
Authors: Jiang Fayu , Zhang Jun , Yang Shuhong
Published: June 2015

We present multiwavelength observations of a fan-spine dome in the active region NOAA 11996 with the Interface Region Imaging Spectrograph (IRIS) and the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory (SDO) on 2014 March 9. The destruction of the fan-spine topology owing to the interaction between its magnetic fields and a nearby emerging flux region (EFR) is observed for the first time. The line-of-sight magnetograms from the Helioseismic and Magnetic Imager on board the SDO reveal that the dome is located on the mixed magnetic fields, with its rim rooted in the redundant positive polarity surrounding the minority parasitic negative fields. The fan surface of the dome consists of a filament system and recurring jets are observed along its spine. The jet occurring around 13:54 UT is accompanied by a quasi-circular ribbon that brightens in the clockwise direction along the bottom rim of the dome, which may indicate an occurrence of slipping reconnection in the fan-spine topology. The EFR emerges continuously and meets with the magnetic fields of the dome. Magnetic cancellations take place between the emerging negative polarity and the outer positive polarity of the dome's fields, which lead to the rise of the loop connecting the EFR and brightenings related to the dome. A single Gaussian fit to the profiles of the IRIS Si IV 1394 Å line is used in the analysis. It appears that there are two rising components along the slit, in addition to the rise in the line-of-sight direction. The cancellation process repeats again and again. Eventually the fan-spine dome is destroyed and a new connectivity is formed. We suggest that magnetic reconnection between the EFR and the magnetic fields of the fan-spine dome is responsible for the destruction of the dome.
Effect of Nitrogen Rate and the Environment on Physicochemical Properties of Selected High‐Amylose Rice Cultivars
Authors: Bryant Rolfe J. , M. Yeater Kathleen , McClung Anna M.
Published: June 2015

Genetic marker haplotypes for the Waxy and alk genes are associated with amylose content and gelatinization temperature, respectively, and are used by breeders to develop rice cultivars that have physicochemical properties desired by the parboiling and canning industries. Cultivars that provide consistent processing quality across diverse production environments are important to the industry. This study determined if measures of processing quality differed among cultivars, fertility treatments, and production environments. Nine cultivars having high amylose content (>23.0%) but with different Waxy and alk haplotypes were evaluated in three environments and using three nitrogen fertility levels. Although environment and fertility levels significantly (P < 0.05) impacted protein content, gelatinization temperatures, and peak, trough, and final paste viscosities, cultivars performed consistently across production environments and fertility applications. Differences were observed among cultivars in paste viscosity measures and gelatinization temperatures that corresponded with their Waxy and alk haplotypes. However, discriminant analysis revealed subgroupings within the same Waxy and alk haplotypes that were primarily differentiated by trough paste viscosity. The results of this study demonstrated that although these high‐amylose cultivars had consistent ranking across environments and nitrogen fertility regimes, there were differences in rice processing quality traits that were not apparent from their Waxy and alk haplotypes.
Effect of Dark, Hard, and Vitreous Kernel Content on Protein Molecular Weight Distribution and on Milling and Breadmaking Quality Characteristics for Hard Spring Wheat Samples from Diverse Growing Regions
Authors: Baasandorj Tsogtbayar , Ohm Jae‐Bom , Simsek Senay
Published: June 2015

Kernel vitreousness is an important grading characteristic for segregation of subclasses of hard red spring (HRS) wheat in the United States. This research investigated the protein molecular weight distribution (MWD) and the flour and baking quality characteristics of different HRS wheat market subclasses. The U.S. regional crop quality survey samples obtained from six regions for three consecutive growing years were used for subclass segregation based on the dark, hard, and vitreous (DHV) kernel percentage. Flour milled from HRS wheat with greater percentages of DHV kernel showed higher water absorption capacity for breadmaking. Protein MWD parameters could be related to the association between DHV kernel level and water absorption. Specifically, flour protein fractions rich in gliadins and high‐molecular‐weight polymeric proteins in the SDS‐unextractable fraction were identified to have significant and positive correlations with both DHV kernels and flour water absorption levels. An example further showed the importance of flour water absorption on potential economic incentives that can be gained with having a greater percentage of vitreous kernels. This information could help the flour milling and baking industry to segregate the different subclasses of HRS wheat with varying DHV content for their intended end‐use applications.
Limited Genetic Variability Among American Isolates ofGrapevine virus EfromVitisspp.
Authors: Vargas-Asencio J. , Al Rwahnih M. , Rowhani A. , Celebi-Toprak F. , Thompson J. R. , Fuchs M. , Perry K. L.
Published: June 2015

A survey for the presence of Grapevine virus E (GVE, genus Vitivirus, family Betaflexiviridae) in vineyards in New York and California was conducted using macroarray hybridization or reverse-transcription polymerase chain reaction (RT-PCR) assays. In New York, GVE was detected in 10 of 46 vines of Vitis labrusca, one V. riparia, and one Vitis hybrid. All GVE-infected New York vines were coinfected with Grapevine leafroll-associated virus-3. In California, GVE was detected in 8 of 417 vines of V. vinifera. All GVE-infected California vines were also coinfected by one of the leafroll-associated viruses and other vitiviruses. In order to assess the genetic diversity among GVE isolates, a viral cDNA was amplified by RT-PCR, and a 675-nucleotide region that included the 3′ terminus of the coat protein gene, a short intergenic region, and the 5′ terminus of the putative nucleic acid binding protein gene was sequenced. All 20 GVE isolates sequenced in this study were very closely related, with >98% nucleotide identity to the SA94 isolate from South Africa. These findings confirm the presence of GVE in major grape-growing regions of the United States and indicate a very low level of genetic diversity.
Customized “In-Office” Three-Dimensional Printing for Virtual Surgical Planning in Craniofacial Surgery
Authors: Mendez Bernardino M. , Chiodo Michael V. , Patel Parit A.
Published: June 2015

Background:

Virtual surgical planning using three-dimensional (3D) printing technology has improved surgical efficiency and precision.1–4 A limitation to this technology is that production of 3D surgical models requires a third-party source, leading to increased costs (up to $4000) and prolonged assembly times (averaging 2–3 weeks).4,5 The purpose of this study is to evaluate the feasibility, cost, and production time of customized skull models created by an “in-office” 3D printer for craniofacial reconstruction.

Methods:

Two patients underwent craniofacial reconstruction with the assistance of “in-office” 3D printing technology. Three-dimensional skull models were created from a bioplastic filament with a 3D printer using computed tomography (CT) image data. The cost and production time for each model were measured.

Results:

For both patients, a customized 3D surgical model was used preoperatively to plan split calvarial bone grafting and intraoperatively to more efficiently and precisely perform the craniofacial reconstruction. The average cost for surgical model production with the “in-office” 3D printer was $25 (cost of bioplastic materials used to create surgical model) and the average production time was 14 hours.

Conclusions:

Virtual surgical planning using “in office” 3D printing is feasible and allows for a more cost-effective and less time consuming method for creating surgical models and guides. By bringing 3D printing to the office setting, we hope to improve intraoperative efficiency, surgical precision, and overall cost for various types of craniofacial and reconstructive surgery.
Extradural Ossification Following Epidural Hematoma in Children
Authors: Claiborne Jeffrey R. , Hoge Margaret K. , Wood Benjamin C. , Couture Daniel E. , David Lisa R.
Published: June 2015

There has been a profound increase in the number of patients undergoing head computed tomography after minor injuries and the identification of epidural hematomas has risen concurrently. Although emergent craniotomy and evacuation has been the conventional standard for management, some epidural hematomas can be managed nonoperatively in carefully selected patients. Because of the difficulty in clinically monitoring epidural hematoma absorption and resolution because of the attributed risks of imaging radiation exposure in pediatric patients, the exact incidence of epidural hematoma ossification is unknown.

Integrating epidural hematoma calcification into management algorithms is not clearly defined in the literature. The authors report a case of a 2-year-old girl with a calcified epidural hematoma requiring surgical treatment. With the incidence of epidural hematomas rising, providers should be aware of the rare but consequential incidence of epidural hematoma ossification. After literature review and discussion of the pathophysiology, the authors present an algorithmic approach to account for this rare entity. For conservative management of asymptomatic epidural hematomas, providers should consider follow-up magnetic resonance imaging to evaluate resolution in 2 to 3 months. If the magnetic resonance imaging indicates a failure to resolve, a computed tomography scan should then be performed to evaluate ossification and possible need for surgical intervention.
Acellular Dermal Matrix Use in Cleft Palate and Palatal Fistula Repair
Authors: Agir Hakan , Eren Gamze G. , Yasar Emrah K.
Published: June 2015

Background:

In cleft palate repair, anatomically oriented, tension free, atraumatic total closure is the key to achieve a normal speech consecutive to a sufficient velopharyngeal closure and also to prevent postoperative fistula development. In this clinical study, we review our experience with acellular dermal matrix (ADM) which was used as an adjunct to facilitate difficult cleft palate and palatal fistula closure.

Methods:

From October 2009 till December 2013, primary cleft palate and fistula repairs in which ADM was used were culled from the cleft surgery files. Acellular dermal matrix was used as an extra layer in between palatal flaps of primary repairs and as a sandwiched sheet separating the flaps used to repair fistulas. In addition to patient, cleft and fistula demographics, records were evaluated for sizes, fistula development, fistula recurrence, extrusion, exposure, and infection.

Results:

Acellular dermal matrix was used in 35 patients with palatal clefts of mean size 15 ± 4 mm and in 15 palatal fistulas. Two-flap palatoplasty technique was the dominant technique for the palate repair. Fistula rate for the palate repair was 8.5% and fistula recurrence rate was 20%. Mean follow-up for the palate and fistula repair patients was 29 ± 15 months and 32 ± 11 months, respectively. In two cases of palatoplasty group and in four cases of fistula repair group, ADM was exposed resulting in total extrusion in two fistula cases.

Conclusions:

In this ongoing experience of application, ADM has been shown to be a simple, safe, and helpful tool to reduce fistula rate mainly in relatively wide and high tension tenuous cleft palate repairs but less favorable in challenging fistula closure attempts particularly along with poorly vascularized surrounding tissues. However, study design and its results are yet far from strongly recommending routine ADM use in cleft palate surgery.
LMO2 at 25 years: a paradigm of chromosomal translocation proteins
Authors: Chambers Jennifer , Rabbitts Terence H.
Published: June 2015

LMO2was first discovered through proximity to frequently occurring chromosomal translocations in T cell acute lymphoblastic leukaemia (T-ALL). Subsequent studies on its role in tumours and in normal settings have highlightedLMO2as an archetypical chromosomal translocation oncogene, activated by association with antigen receptor gene loci and a paradigm for translocation gene activation in T-ALL. The normal function of LMO2 in haematopoietic cell fate and angiogenesis suggests it is a master gene regulator exerting a dysfunctional control on differentiation following chromosomal translocations. Its importance in T cell neoplasia has been further emphasized by the recurrent findings of interstitial deletions of chromosome 11 nearLMO2and ofLMO2as a target of retroviral insertion gene activation during gene therapy trials for X chromosome-linked severe combined immuno-deficiency syndrome, both types of event leading to similar T cell leukaemia. The discovery of LMO2 in some B cell neoplasias and in some epithelial cancers suggests a more ubiquitous function as an oncogenic protein, and that the current development of novel inhibitors will be of great value in future cancer treatment. Further, the role of LMO2 in angiogenesis and in haematopoietic stem cells (HSCs) bodes well for targeting LMO2 in angiogenic disorders and in generating autologous induced HSCs for application in various clinical indications.
Infinite product expansion of the Fokker–Planck equation with steady-state solution
Authors: Martin R. J. , Craster R. V. , Kearney M. J.
Published: June 2015

We present an analytical technique for solving Fokker–Planck equations that have a steady-state solution by representing the solution as an infinite product rather than, as usual, an infinite sum. This method has many advantages: automatically ensuring positivity of the resulting approximation, and by design exactly matching both the short- and long-term behaviour. The efficacy of the technique is demonstrated via comparisons with computations of typical examples.
Decisions reduce sensitivity to subsequent information
Authors: Bronfman Zohar Z. , Brezis Noam , Moran Rani , Tsetsos Konstantinos , Donner Tobias , Usher Marius
Published: June 2015

Behavioural studies over half a century indicate that making categorical choices alters beliefs about the state of the world. People seem biased to confirm previous choices, and to suppress contradicting information. These choice-dependent biases imply a fundamental bound of human rationality. However, it remains unclear whether these effects extend to lower level decisions, and only little is known about the computational mechanisms underlying them. Building on the framework of sequential-sampling models of decision-making, we developed novel psychophysical protocols that enable us to dissect quantitatively how choices affect the way decision-makers accumulate additional noisy evidence. We find robust choice-induced biases in the accumulation of abstract numerical (experiment 1) and low-level perceptual (experiment 2) evidence. These biases deteriorate estimations of the mean value of the numerical sequence (experiment 1) and reduce the likelihood to revise decisions (experiment 2). Computational modelling reveals that choices trigger a reduction of sensitivity to subsequent evidence via multiplicative gain modulation, rather than shifting the decision variable towards the chosen alternative in an additive fashion. Our results thus show that categorical choices alter the evidence accumulation mechanism itself, rather than just its outcome, rendering the decision-maker less sensitive to new information.