bluuebunny/crossref_metadata_2025 huggingface dataset:
Poster — Thur Eve — 43: Monte Carlo Modeling of Flattening Filter Free Beams and Studies of Relative Output Factors
Authors: Zhan Lixin , Jiang Runqing , Osei Ernest K.
Published: September 2014

Flattening filter free (FFF) beams have been adopted by many clinics and used for patient treatment. However, compared to the traditional flattened beams, we have limited knowledge of FFF beams. In this study, we successfully modeled the 6 MV FFF beam for Varian TrueBeam accelerator with the Monte Carlo (MC) method. Both the percentage depth dose and profiles match well to the Golden Beam Data (GBD) from Varian. MC simulations were then performed to predict the relative output factors. The in‐water output ratio, Scp, was simulated in water phantom and data obtained agrees well with GBD. The in‐air output ratio, Sc, was obtained by analyzing the phase space placed at isocenter, in air, and computing the ratio of water Kerma rates for different field sizes. The phantom scattering factor, Sp, can then be obtained from the traditional way of taking the ratio of Scp and Sc. We also simulated Sp using a recently proposed method based on only the primary beam dose delivery in water phantom. Because there is no concern of lateral electronic disequilibrium, this method is more suitable for small fields. The results from both methods agree well with each other. The flattened 6 MV beam was simulated and compared to 6 MV FFF. The comparison confirms that 6 MV FFF has less scattering from the Linac head and less phantom scattering contribution to the central axis dose, which will be helpful for improving accuracy in beam modeling and dose calculation in treatment planning systems.
Sci—Thur AM: YIS ‐ 06: An EPID‐based 3D patient dose verification method for SBRT‐VMAT delivery
Authors: McCowan P. , vanUytven E , vanBeek T , McCurdy B
Published: September 2014

Purpose:

Stereotactic body radiation therapy (SBRT) delivered via volumetric modulated arc therapy (VMAT) can strongly benefit from an in vivo patient dose verification due to the large doses per fraction. Electronic portal imaging devices (EPIDs) can be utilized as a patient dose dosimeter. In this work we present a physics‐based model which utilizes on‐treatment EPID images to reconstruct the dose delivered to an anthropomorphic phantom during SBRT‐VMAT delivery.

Methods:

An SBRT linac beam was modeled using Monte Carlo methods and verified with measured data. Our dose reconstruction model back‐projects EPID measured focal fluence upstream of the patient and adds a predicted extra‐focal fluence component. This fluence is forward projected onto the patient's density matrix and convolved with dose kernels to calculate dose. The model was validated for two prostate, three lung, and two spine SBRT‐VMAT treatments. Results were compared to the treatment planning system's calculation.

Results:

2%/2 mm chi comparison calculations gave pass rates for the whole volume, infield, and high dose region respectively, and no lower than: 98%, 95%, 99% for the prostate plans, 99%, 92%, 85% for the lung plans, and 91%, 85%, 81% for the spine plans. A 3%/3mm calculation gave pass rates no lower than 99%, 94%, and 90% for all dose regions for the prostate, lung, and spine respectively.

Conclusions:

We have developed a physics‐based model which calculates delivered dose to phantom (or patient) for SBRT‐VMAT delivery using on treatment EPID images. The accuracy of the results has allowed us to test this model clinically.
Sci—Thur AM: YIS ‐ 07: Design and production of 3D printed bolus for electron radiation therapy
Authors: Su Shiqin , Moran Kathryn , Robar James L.
Published: September 2014

This is a proof‐of‐concept study demonstrating the capacity for modulated electron radiation therapy (MERT) using 3D printed bolus. Previous reports have involved bolus design using an electron pencil beam model and fabrication using a milling machine. In this study, an in‐house algorithm is presented that optimizes the dose distribution with regard to dose coverage, conformity and homogeneity within planning target volume (PTV). The algorithm uses calculated result of a commercial electron Monte Carlo dose calculation as input. Distances along ray lines from distal side of 90% isodose to distal surface of PTV are used to estimate the bolus thickness. Inhomogeneities within the calculation volume are accounted for using coefficient of equivalent thickness method. Several regional modulation operators are applied to improve dose coverage and uniformity. The process is iterated (usually twice) until an acceptable MERT plan is realized, and the final bolus is printed using solid polylactic acid. The method is evaluated with regular geometric phantoms, anthropomorphic phantoms and a clinical rhabdomyosarcoma pediatric case. In all cases the dose conformity is improved compared to that with uniform bolus. The printed boluses conform well to the surface of complex anthropomorphic phantoms. For the rhabdomyosarcoma patient, the MERT plan yields a reduction of mean dose by 38.2% in left kidney relative to uniform bolus. MERT using 3D printed bolus appears to be a practical, low cost approach to generating optimized bolus for electron therapy. The method is effective in improving conformity of prescription isodose surface and in sparing immediately adjacent normal tissues.
Sci—Thur PM: Imaging — 01: Position‐sensitive noise characteristics in multi‐pinhole cardiac SPECT imaging
Authors: Cuddy‐Walsh SG , Wells RG
Published: September 2014

Myocardial perfusion imaging (MPI) with Single Photon Emission Computed Tomography (SPECT) is invaluable in the diagnosis and management of heart disease. It provides essential information on myocardial blood flow and ischemia. Multi‐pinhole dedicated cardiac‐SPECT cameras offer improved count sensitivity, and spatial and energy resolutions over parallel‐hole camera designs however variable sensitivity across the field‐of‐view (FOV) can lead to position‐dependent noise variations. Since MPI evaluates differences in the signal‐to‐noise ratio, noise variations in the camera could significantly impact the sensitivity of the test for ischemia. We evaluated the noise characteristics of GE Healthcare's Discovery NM530c camera with a goal of optimizing the accuracy of our patient assessment and thereby improving outcomes. Theoretical sensitivity maps of the camera FOV, including attenuation effects, were estimated analytically based on the distance and angle between the spatial position of a given voxel and each pinhole. The standard deviation in counts, σ was inferred for each voxel position from the square root of the sensitivity mapped at that position. Noise was measured experimentally from repeated (N=16) acquisitions of a uniform spherical Tc‐99m‐water phantom. The mean (μ) and standard deviation (σ) were calculated for each voxel position in the reconstructed FOV. Noise increased ∼2.1× across a 12 cm sphere. A correlation of 0.53 is seen when experimental noise is compared with theory suggesting that ∼53% of the noise is attributed to the combined effects of attenuation and the multi‐pinhole geometry. Further investigations are warranted to determine the clinical impact of the position‐dependent noise variation.
Sci—Thur PM: Planning & Delivery — 02: Treatment planning workflow for very high‐energy electron beam radiotherapy
Authors: Bazalova Magdalena , Qu Bradley , Palma Bianey , Hårdemark Bjorn , Hynning Elin , Maxim Peter , Loo Billy
Published: September 2014

Purpose:

To develop treatment planning workflow for rapid radiotherapy delivered with very‐high energy electron (VHEE) scanning beam.

Methods:

VHEE radiotherapy treatment planning was performed by linking Monte Carlo (MC) dose calculations with inverse optimization in a research version of RayStation. In order to study a number of treatment parameters, a Matlab graphical user interface (GUI) for calculation of VHEE beamlet dose was developed. Through the GUI, EGSnrc MC simulations were run for a number of beam energies, number of beams, beamlet spot and grid sizes, and machine bore sizes. VHEE plans for a pediatric patient with a 4.3 cm3 brain target optimized with spot‐scanning algorithm in RayStation were compared to the clinically delivered 6 MV VMAT plan.

Results and Discussion:

VHEE beam energy had the largest effect on the quality of dose distributions. For the same target dose, the mean doses to critical organs decreased by 10–15% when planned with 100 MeV compared to 60 MeV. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams. While beamlet spacing and bore size had a small effect on VHEE dose distributions, 0.1‐3mm beamlet sizes resulted in identical dose distributions. Critical organ doses were by up to 70% lower in the best VHEE plan compared to the clinical 6 MV VMAT plan.

Conclusions:

We have developed a GUI for MC beamlet generation for treatment planning of VHEE radiotherapy. We have demonstrated that pediatric VHEE plans resulted in significant critical organ dose sparing compared to the clinical VMAT plan.
Poster — Thur Eve — 04: Characterizations of image quality for CT with iterative reconstruction algorithm — development of a routine quality control metric
Authors: Yang Chang‐Ying Joseph , Bjarnason Thorarin Albert
Published: September 2014

Iterative reconstruction algorithms (IRA) are available on modern CT systems. We are investigating the feasibility of routinely and objectively characterizing the image quality of CT with IRA. Noise‐equivalent‐quanta (NEQ) conceptually and potentially can be the metric of image quality assessment for system performance. CT images of the third module of an ACR phantom were acquired on a GE LightSpeed VCT system using 5 different mA ranging from 25–400 with 6 different ASiR levels ranging from 0–100. MTF and NPS measurements were obtained from these CT images using the method described by Friedman et al1. It was found that MTF acquired using even low mA is reliable and consistent. MTF from data acquired using 400mA provides decreased MTF performance for the reason yet to be determined. There is incremental improvement in MTF by the incremental increase in ASiR level. While ASiR makes no improvements in NPS and NEQ at low spatial frequency, the ASiR increment level of 25 has the same effect of doubling the dose to the NPS and NEQ performances at frequency 0.5 lp/mm. A yet to be defined way of quantifying the spatial spectrum content shift by ASiR should be required for QC when ASiR is used for dose reduction. This study provides a preliminary understanding and characterization of objective image quality of CT with IRA. Further studies on the scene dependency of the image quality by IRA and different implementations of IRA by other CT manufactures are forthcoming.
Poster — Thur Eve — 07: Simultaneous reconstruction of both true and scattered coincidences using a Generalized Scatter reconstruction algorithm in PET
Authors: Sun H , Pistorious S
Published: September 2014

Introduction:

Scattered coincidences in PET are generally taken as noise, which reduces image contrast and compromises quantification. We have developed a method, with promising results, to reconstruct activity distribution from scattered PET events instead of simply correcting for them. The implementation of this method on clinical PET scanners is however limited by the currently available detector energy resolution. With low energy resolution we lose the ability to distinguish scattered coincidences from true events based on the measured photon energy. In addition the two circular arcs used to confine the source position for a scattered event cannot be accurately defined.

Method:

This paper presents a modification to this approach which accounts for limited energy resolution. A measured event is split into a true and a scattered component each with different probabilities based on the position of the pair of photon energies in the energy spectrum. For the scattered component, we model the photon energy with a Gaussian distribution and the upper and lower energy limits can be estimated and used to define inner and outer circular arcs to confine the source position. The true and scattered components for each measured event were reconstructed using our Generalized Scatter reconstruction algorithm.

Results and Conclusion:

The results show that the contrast and noise properties were improved by 6–9% and 2–4% respectively. This demonstrates that the performance of the algorithm is less sensitive to the energy resolution and that incorporating scattered photons into reconstruction brings more benefits than simply rejecting them.
Poster — Thur Eve — 13: Inter‐Fraction Target Movement in Image‐Guided Radiation Therapy of Prostate Cancer
Authors: Cui Congwu , Zeng Grace G.
Published: September 2014

We investigated the setup variations over the treatment courses of 113 patients with intact prostate treated with 78Gy/39fx. Institutional standard bladder and bowel preparation and image guidance protocols were used in CT simulation and treatment. The RapidArc treatment plans were optimized in Varian Eclipse treatment planning system and delivered on Varian 2100X Clinacs equipped with On‐Board Imager to localize the target before beam‐on. The setup variations were calculated in terms of mean and standard deviation of couch shifts. No correlation was observed between the mean shift and standard deviation over the treatment course and patient age, initial prostate volume and rectum size. The mean shifts in the first and last 5 fractions are highly correlated (P < 10−10) while the correlation of the standard deviations cannot be determined. The Mann‐Kendall tests indicate trends of the mean daily Ant‐Post and Sup‐Inf shifts of the group. The target is inferior by ∼1mm to the planned position when the treatment starts and moves superiorly, approaching the planned position at 10th fraction, and then gradually moves back inferiorly by ∼1mm in the remain fractions. In the Ant‐Post direction, the prostate gradually moves posteriorly during the treatment course from a mean shift of ∼2.5mm in the first fraction to ∼1mm in the last fraction. It may be related to a systematic rectum size change in the progress of treatment. The biased mean shifts in Ant‐Post and Sup‐Inf direction of most patients suggest systematically larger rectum and smaller bladder during the treatment than at CT simulation.
Poster — Thur Eve — 15: Improvements in the stability of the tomotherapy imaging beam
Authors: Belec J
Published: September 2014

Use of helical TomoTherapy based MVCT imaging for adaptive planning requires the image values (HU) to remain stable over the course of treatment. In the past, the image value stability was suboptimal, which required frequent change to the image value to density calibration curve to avoid dose errors on the order of 2–4%. The stability of the image values at our center was recently improved by stabilizing the dose rate of the machine (dose control servo) and performing daily MVCT calibration corrections. In this work, we quantify the stability of the image values over treatment time by comparing patient treatment image density derived using MVCT and KVCT. The analysis includes 1) MVCT ‐ KVCT density difference histogram, 2) MVCT vs KVCT density spectrum, 3) multiple average profile density comparison and 4) density difference in homogeneous locations. Over two months, the imaging beam stability was compromised several times due to a combination of target wobbling, spectral calibration, target change and magnetron issues. The stability of the image values were analyzed over the same period. Results show that the impact on the patient dose calculation is 0.7% +− 0.6%.
Structure and selectivity in bestrophin ion channels
Authors: Yang Tingting , Liu Qun , Kloss Brian , Bruni Renato , Kalathur Ravi C. , Guo Youzhong , Kloppmann Edda , Rost Burkhard , Colecraft Henry M. , Hendrickson Wayne A.
Published: September 2014

Human bestrophin-1 (hBest1) is a calcium-activated chloride channel from the retinal pigment epithelium, where mutations are associated with vitelliform macular degeneration, or Best disease. We describe the structure of a bacterial homolog (KpBest) of hBest1 and functional characterizations of both channels. KpBest is a pentamer that forms a five-helix transmembrane pore, closed by three rings of conserved hydrophobic residues, and has a cytoplasmic cavern with a restricted exit. From electrophysiological analysis of structure-inspired mutations in KpBest and hBest1, we find a sensitive control of ion selectivity in the bestrophins, including reversal of anion/cation selectivity, and dramatic activation by mutations at the cytoplasmic exit. A homology model of hBest1 shows the locations of disease-causing mutations and suggests possible roles in regulation.
Complete Genome Sequence of a Field Strain of Peste des Petits Ruminants Virus Isolated during 2010-2014 Epidemics in Senegal
Authors: Salami Habib , Croville Guillaume , Kwiatek Olivier , Mariette Jérôme , Klopp Christophe , Valière Sophie , Guérin Jean-Luc , Lo Moustapha , Thiongane Yaya , Albina Emmanuel , Libeau Geneviève
Published: September 2014

Peste des petits ruminants virus (PPRV) infection is expanding and results in regular epizootic activities in Africa, the Middle East, and Asia. Here, we report the complete genome sequence of a field strain of PPRV isolated in Senegal (SnDk11I13) in 2013.
Draft Genome Sequences of Three Escherichia coli Strains Investigated for the Effects of Lysogeny on Niche Diversification
Authors: Lai Jennifer Y. H. , Zhang Hao , Chiang Miranda H. Y. , Yu Min , Zhang Rui , Lau Stanley C. K.
Published: September 2014

During the course of investigating the effects of lysogeny on niche diversification of
Escherichia coli
, we used the temperate phages induced from one
E. coli
strain to infect another and created an isogenic lysogen of the latter. The draft genome sequences of the three
E. coli
strains are reported herein.
Childhood meningitis in the conjugate vaccine era: a prospective cohort study
Authors: Sadarangani Manish , Willis Louise , Kadambari Seilesh , Gormley Stuart , Young Zoe , Beckley Rebecca , Gantlett Katherine , Orf Katharine , Blakey Sarah , Martin Natalie G , Kelly Dominic F , Heath Paul T , Nadel Simon , Pollard Andrew J
Published: September 2014

Bacterial conjugate vaccines have dramatically changed the epidemiology of childhood meningitis; viral causes are increasingly predominant, but the current UK epidemiology is unknown. This prospective study recruited children under 16 years of age admitted to 3 UK hospitals with suspected meningitis. 70/388 children had meningitis—13 bacterial, 26 viral and 29 with no pathogen identified. Group B Streptococcus was the most common bacterial pathogen. Infants under 3 months of age with bacterial meningitis were more likely to have a reduced Glasgow Coma Score and respiratory distress than those with viral meningitis or other infections. There were no discriminatory clinical features in older children. Cerebrospinal fluid (CSF) white blood cell count and plasma C-reactive protein at all ages, and CSF protein in infants <3 months of age, distinguished between bacterial meningitis and viral meningitis or other infections. Improved diagnosis of non-bacterial meningitis is urgently needed to reduce antibiotic use and hospital stay.
A Note on Scheduling Jobs with Extended Sum-of-Processing-Times-Based and Position-Based Learning Effect
Authors: Niu Yu-Ping , Wan Long , Wang Ji-Bo
Published: September 2014

The note deals with machine scheduling problems with a more general learning effect model, i.e., the actual job processing time is a function of the sum of the function of the processing times of the jobs already processed and job position. We show that some single machine scheduling problems are still polynomially solvable under the proposed model. We also show that some special cases of the flow shop scheduling problems can be solved in polynomial time.
Adaptive Interference Suppression Based on Lv Distribution for DSSS Communications
Authors: Luo Shan , Li Xiumei , Li Shenghong , Bi Guoan
Published: September 2014

It is generally difficult to effectively eliminate intentional multiple component interference in any communication systems mainly because of the difficulties in accurately estimating the parameters of interference particularly in low signal-to-noise ratio (SNR) environments. This paper proposes effective methods of adaptive interference suppression based on Lv distribution (AISL) for direct sequence spread spectrum (DSSS) communications. Since the recently reported Lv distribution (LVD) provides better concentration of signal energy in the domain of frequency-chirp rate than other reported methods, it achieves performance improvement on estimating the parameters containing multiple linear frequency modulated (LFM) signals. With the desirable properties of the LVD, the proposed interference suppression methods are able to excise interference of multiple components. The proposed methods firstly examine if the received signal is interfered by using a high-order statistics, known as skewness, to measure the distribution concentration of the received signal in the LVD domain. Then the interference excision process is employed only when the interference is present. Two methods, i.e., AISL-I based on the concept of interference cancellation and AISL-II based on phase cancellation and filtering, are investigated. The merits of these methods are analyzed and compared in terms of bit error rates (BERs). Results of Monte Carlo experiments are also presented to show the effectiveness of suppressing interference by the proposed methods.
NONLINEAR STRAIN GRADIENT THEORY BASED VIBRATION AND INSTABILITY OF BORON NITRIDE MICRO-TUBES CONVEYING FERROFLUID
Authors: GHORBANPOUR ARANI ALI , JALILVAND ABDOLREZA , KOLAHCHI REZA
Published: September 2014

Nonlinear vibration and instability of a boron nitride micro-tube (BNMT) conveying ferrofluid under the combined magnetic and electric fields are investigated. Based on Euler–Bernoulli beam (EBB), piezoelasticity strain gradient theory and Hamilton's principle, high order equations of motion are derived for three boundary conditions namely as clamped–clamped (C–C), simply–simply (S–S) and clamped–simply (C–S). The differential quadrature method (DQM) is applied to discretize the motion equations in order to obtain the nonlinear frequency and critical fluid velocity using a direct iterative method. A detailed parametric study is conducted to elucidate the influences of the various boundary conditions, size diameter and magnetic field on vibrational characteristic of BNMT. Numerical results indicate that the effect of magnetic field appears in higher speed of ferrofluid and increases the critical velocity or enlarges the stability region. The results are in good agreement with the previous researches. The results of this study can be used to manufacture smart micro/nano electromechanical systems in advanced biomechanics applications with magnetic and electric fields as parametric controllers.
Fabrication of Two-Dimensional PEDOT:PSS Nanosheets Through In Situ Formed Complexes
Authors: Zhang Kun , Wang Shiren
Published: September 2014

This paper presents a simple and effective method to fabricate water-soluble two-dimensional (2D) conductive poly(3,4-ethylenedioxythiophene):poly (sodium 4-styrenesulfonate) (PEDOT:PSS) nanosheets. Linear PSS is water-soluble and exhibits a quasi 1D structure in the dilute solution. Addition of 3,4-ethylenedioxythiophene (EDOT) monomers into acidic solutions would form 2D molecular complexes due to charge attraction. In situ polymerization of the ethylenedioxythiophene monomers produces 2D poly EDOT nanosheets. Both transmission electron microscopy and atomic force microscopy characterizations have confirmed the 2D polymeric nanosheets. Further Fourier transform infrared (FTIR) characterization also validated that the 2D nanosheet is composed of EDOT-based units and Raman spectroscopy indicated the strong interactions between ethylenedioxythiophene units in the 2D nanostructures. The electrical conductivity is measured to as high as 551.58 S/m for the thin film of as-produced 2D PEDOT:PSS nanosheets.
Chapter 15 The continental shelf of western India
Authors: Faruque B. M. , Ramachandran K. V.
Published: September 2014

The west coast of India, extending from Sir Creek in the north to Kanyakumari in the south, is a trailing passive margin that bears the imprint of generally shore-parallel and less common orthogonal structural elements. The geomorphology of the marginal part of western India, mostly controlled by the three principal structural trends of NNW–SSE Dharwar, NE–SW Aravalli orogenies and west–east Narmada graben, displays a straight coastline. The coastal ocean current operates from April to October and the net sediment transport is from north to south with the longshore current. The continental shelf width varies from 345 km off Daman in the north to 120 km off Goa and tapers to 60 km off Kochi in the south. The western continental shelf of India has an area of about 310 000 km
2
, and is divided into an inner shelf with modern clayey silt and silty clay sediments with high organic matter and low carbonate content, and an outer shelf having relict carbonate sediments, coarse sands with low organic matter and high carbonates. The mid-shelf is rather uneven topographically, and the outer shelf is commonly interrupted by shore-parallel ridges and reefs with a relief of 2–18 m. Phosphatic limestone micronodules occur in the outer shelf.
Chapter 19 Carbonate shelf sediments of the western continental margin of Australia
Authors: Collins Lindsay B. , James Noel P. , Bone Yvonne
Published: September 2014

Australia's western margin is adjacent to a low–moderate-relief, semi-arid hinterland extending from northern tropical to southern temperate latitudes. Swell waves occur throughout, and cyclonic storms and tidal influences decline from north to south. The margin is influenced by the poleward-flowing, warm, nutrient-poor Leeuwin Current. There is limited upwelling and localized downwelling of saline water on to the shelf. The North West Shelf (NWS) is an ocean-facing ramp with palimpsest sediments – formed during Marine Isoptope Stage (MIS) 3 and 4; stranded ooids and peloids formed early during the post-Last Glacial Maximum (LGM) sea-level rise – and Holocene particles. Changing oceanography during sea-level rise profoundly affected sediment character.

The SW Shelf (SWS) comprises the subtropical sediment-starved Carnarvon Ramp in the north and the incipiently rimmed, flat-topped, steep-fronted Rottnest Shelf in the south. The inner Carnarvon Ramp includes the Ningaloo Reef and hypersaline Shark Bay. The mid ramp is relict or stranded foraminifer-dominated sand, and represents attenuated carbonate production due to downwelling incursions of Shark Bay water on to the ramp; the outer ramp is planktic foraminiferal sand or spiculitic mud. Rottnest Shelf has coralline algal-encrusted hardgrounds, larger symbiont-bearing foraminifers with abundant cool-water elements including bryzoans, molluscs and smaller foraminifers. The SWS is transitional between warm- and cool-water carbonate realms.
Estimating instantaneous energetic cost during non-steady-state gait
Authors: Selinger Jessica C. , Donelan J. Maxwell
Published: September 2014

Respiratory measures of oxygen and carbon dioxide are routinely used to estimate the body's steady-state metabolic energy use. However, slow mitochondrial dynamics, long transit times, complex respiratory control mechanisms, and high breath-by-breath variability obscure the relationship between the body's instantaneous energy demands (instantaneous energetic cost) and that measured from respiratory gases (measured energetic cost). The purpose of this study was to expand on traditional methods of assessing metabolic cost by estimating instantaneous energetic cost during non-steady-state conditions. To accomplish this goal, we first imposed known changes in energy use (input), while measuring the breath-by-breath response (output). We used these input/output relationships to model the body as a dynamic system that maps instantaneous to measured energetic cost. We found that a first-order linear differential equation well approximates transient energetic cost responses during gait. Across all subjects, model fits were parameterized by an average time constant (τ) of 42 ± 12 s with an average R2of 0.94 ± 0.05 (mean ± SD). Armed with this input/output model, we next tested whether we could use it to reliably estimate instantaneous energetic cost from breath-by-breath measures under conditions that simulated dynamically changing gait. A comparison of the imposed energetic cost profiles and our estimated instantaneous cost demonstrated a close correspondence, supporting the use of our methodology to study the role of energetics during locomotor adaptation and learning.
Congenital Factor V Deficiency: Comparison of the Severity of Clinical Presentations among Patients with Rare Bleeding Disorders
Authors: Naderi Majid , Tabibian Shadi , Alizadeh Shaban , Hosseini Soudabeh , Zaker Farhad , Bamedi Taregh , Shamsizadeh Morteza , Dorgalaleh Akbar
Published: September 2014

Background: Factor V deficiency (FVD) is a rare bleeding disorder (RBD) mostly present in regions with a high rate of consanguinity. FVD after FXIII deficiency is the next more prevalent RBD in Sistan and Baluchistan (S&B) in southeastern Iran. The aim of this study was to evaluate the clinical manifestations and severity of bleeding diathesis in patients with FVD. Methods: This descriptive study was conducted on 23 patients with FVD in S&B province. FVD was diagnosed by clinical findings and routine laboratory tests. Bleeding diatheses were classified into three grades (I-III) depending on the severity of symptoms. The severity of bleeding episodes in our patients was compared with other RBDs. Result: Based on residual plasma FV activity, 6 (26%), 16 (69.5%) and 1 (4.5%) patients had mild, moderate and severe factor deficiency, respectively. 24% of the patients had grade III life-threatening bleeding episodes which in comparison with FVII deficiency (17.4%) and FI deficiency (21%) had a higher incidence, and in comparison with FX deficiency (41.7%) and FXIII deficiency (63.1) had a lower incidence. Grade II and grade I bleeding diathesis were observed in 56.2 and 16.7% of the patients, respectively. Conclusion: FVD is the second most common type of RBD in S&B province and grade II bleeding episodes were the major bleeding presentation and observed in more than half of the patients.
N3-Substituted Temozolomide Analogs Overcome Methylguanine-DNA Methyltransferase and Mismatch Repair Precipitating Apoptotic and Autophagic Cancer Cell Death
Authors: Zhang Jihong , Hummersone Marc , Matthews Charles S. , Stevens Malcolm F.G. , Bradshaw Tracey D.
Published: September 2014

Glioblastoma multiforme (GBM) treatment includes temozolomide (TMZ) chemotherapy. O6-Methylguanine lesions are repaired by methylguanine-DNA methyltransferase (MGMT). Response to TMZ requires low MGMT and functional mismatch repair (MMR); resistance, conferred by MGMT or MMR deficiency, represents a barrier to successful treatment. TMZ analogs were synthesized, substituting N3-methyl with propargyl (1) or sulfoxide (2). MTT assays were conducted in SNB19 and U373 isogenic glioma cell lines (V = vector control; M = MGMT-transfected). TMZ potency was reduced >5-fold in SNB19M and U373M cells; in contrast, MGMT-expressing cells were equisensitive as vector controls to analogs 1 and 2. GI50 values <50 VM of analogs 1 or 2 were detected in V cells possessing acquired TMZ resistance: SNB19VR (hMSH6 loss) and U373VR (MGMT upregulation). Analogs 1 and 2 inhibited MMR-deficient colorectal carcinoma cell growth (irrespective of p53); G2/M cell cycle arrest preceded apoptosis. GH2AX foci inferred the generation of DNA double-strand breaks by analogs 1 and 2. Acridine orange-stained vesicles, intracellular punctate GFP-LC3 protein and double-membraned autophagosomes indicate that TMZ, 1 and 2 induce autophagy in apoptotis-resistant GBM cells. Analogs 1 and 2 elicit in vitro antitumor activity irrespective of MGMT, MMR and p53. Such imidazotetrazines may treat MGMT+ GBM and possess broader spectrum activity causing apoptosis and autophagy in malignancies which evade apoptosis. i 2014 S. Karger AG, Basel
Intraplaque Hemorrhage, Fibrous Cap Status, and Microembolic Signals in Symptomatic Patients With Mild to Moderate Carotid Artery Stenosis
Authors: Truijman Martine T.B. , de Rotte Alexandra A.J. , Aaslid Rune , van Dijk Anouk C. , Steinbuch Jeire , Liem Madieke I. , Schreuder Floris H.B.M. , van der Steen Anton F.W. , Daemen Mat J.A.P. , van Oostenbrugge Robert J. , Wildberger Joachim E. , Nederkoorn Paul J. , Hendrikse Jeroen , van der Lugt Aad , Kooi Marianne Eline , Mess Werner H. , Schreuder A.H.C.M.L. , Koudstaal P.J. , Limburg M. , Weisfelt M. , Korten A.G. , Saxena R. , van Orshoven N.P. , Tromp S.C. , Bakker S.L.M. , Kruyt N.D. , de Kruijk J.R. , de Borst G.J. , Meems B.J. , Verhey J.C.B. , Wijnhoud A.D.
Published: September 2014

Background and Purpose—

In patients with mild to moderate symptomatic carotid artery stenosis, intraplaque hemorrhage (IPH) and a thin/ruptured fibrous cap (FC) as evaluated with MRI, and the presence of microembolic signals (MESs) as detected with transcranial Doppler, are associated with an increased risk of a (recurrent) stroke. The objective of the present study is to determine whether the prevalence of MES differs in patients with and without IPH and thin/ruptured FC, and patients with only a thin/ruptured FC without IPH.

Methods—

In this multicenter, diagnostic cohort study, patients with recent transient ischemic attack or minor stroke in the carotid territory and an ipsilateral mild to moderate carotid artery plaque were included. IPH and FC status were dichotomously scored. Analysis of transcranial Doppler data was done blinded for the MRI results. Differences between groups were analyzed with Fisher exact test.

Results—

A total of 113 patients were included. Transcranial Doppler measurements were feasible in 105 patients (average recording time, 219 minutes). A total of 26 MESs were detected in 8 of 105 patients. In 44 of 105 plaques IPH was present. In 92 of 105 plaques FC status was assessable, 36 of these had a thin/ruptured FC. No significant difference in the prevalence of MES between patients with and without IPH (
P
=0.46) or with thick versus thin/ruptured FC (
P
=0.48) was found.

Conclusions—

In patients with a symptomatic mild to moderate carotid artery stenosis, IPH and FC status are not associated with MES. This suggests that MRI and transcranial Doppler provide different information on plaque vulnerability.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT01709045.
The Widow-Ascetic under Hindu Law
Authors: Brick David
Published: September 2014

This article constitutes a fairly comprehensive, largely diachronic analysis of the restrictions placed upon the non-sexual behavior of widows by works of the classical Hindu legal tradition known as Dharmaśāstra. As such, it systematically examines an array of texts belonging to virtually all periods of Dharmaśāstra, beginning with the earliest surviving Dharmaśāstric works and proceeding chronologically forward. This article, therefore, provides a more detailed and reliable account of the rise of widow-asceticism within the orthodox Brahmanical communities that produced these texts than is hitherto available. In this way, it significantly contributes to our broader understanding of how Brahmanical attitudes toward women changed between roughly 300bce and 1500ce.
The Impact of Subtidal Circulation on Internal-Tide-Induced Mixing in the Philippine Sea
Authors: Kerry Colette G. , Powell Brian S. , Carter Glenn S.
Published: September 2014

This study uses a primitive equation model to estimate the time-varying M2 internal tide dissipation in the Philippine Sea in the presence of the subtidal circulation. The time-mean diapycnal diffusivity due to the M2 internal tide is estimated to be 4.0–4.8 × 10−4 m2 s−1 at the Luzon Strait and 2–9 × 10−5 m2 s−1 in the Philippine Sea basin. The variability in internal tides and their interactions with the subtidal ocean circulation results in significant spatial and temporal variability in the energy available for mixing. The subtidal circulation influences internal-tide-induced mixing in two ways: by introducing variability in internal tide generation and by increased dissipation of baroclinic energy associated with greater velocity shear. Close to the generation site, mixing is dominated by high-mode internal tide dissipation, while in the far field the influence of the mesoscale energy on internal tide dissipation is significant, resulting in increased dissipation. This study presents model-based estimates of the important and relatively unknown effect of mesoscale circulation on internal-tide-induced mixing away from internal tide generation sites in a region of high eddy kinetic energy.
Rainy-Season Precipitation over the Sichuan Basin and Adjacent Regions in Southwestern China
Authors: Qian Tingting , Zhao Ping , Zhang Fuqing , Bao Xinghua
Published: September 2014

The spatial variability and diurnal propagation of mean precipitation in the summer rainy seasons (from 2003 to 2010) over the Sichuan basin (SCB) and adjacent mountainous regions are examined using high spatiotemporal resolution satellite-derived precipitation estimates. The SCB is located just east of the Tibetan Plateau (TP) and is prone to heavy precipitation that often peaks over nighttime and early morning. The large-scale environment over the SCB during the rainy season is characterized by weak low- to midtropospheric convergence in the lee of the TP and by the upper-tropospheric jet stream to the north. Under this flow configuration, the study links the unique diurnal variations in the precipitation pattern and propagation to the unique topography in this region. It is found that during the rainy season, the local diurnal precipitation maximum moves primarily downslope and southeastward, from over the TP in the daytime to SCB at night. A secondary maximum moves northeastward downslope of the Yunnan–Guizhou Plateau toward the SCB from late evening to the early morning. The movement of precipitation over the SCB and the adjacent regions is closely tied to multiple regional-scale mountain–plain solenoids because of the large contrast in terrain heights between the basin and surrounding mountain ranges.
Improved Outcomes in Auditory Brainstem Implantation with the Use of Near‐Field Electrical Compound Action Potentials
Authors: Mandalà Marco , Colletti Liliana , Colletti Giacomo , Colletti Vittorio
Published: September 2014

Objective

To compare the outcomes (auditory threshold and open‐set speech perception at 48‐month follow‐up) of a new near‐field monitoring procedure, electrical compound action potential, on positioning the auditory brainstem implant electrode array on the surface of the cochlear nuclei versus the traditional far‐field electrical auditory brainstem response.

Study Design

Retrospective study.

Setting

Tertiary referral center.

Subjects and Methods

Among the 202 patients with auditory brainstem implants fitted and monitored with electrical auditory brainstem response during implant fitting, 9 also underwent electrical compound action potential recording. These subjects were matched retrospectively with a control group of 9 patients in whom only the electrical auditory brainstem response was recorded. Electrical compound action potentials were obtained using a cotton‐wick recording electrode located near the surface of the cochlear nuclei and on several cranial nerves.

Results

Significantly lower potential thresholds were observed with the recording electrode located on the cochlear nuclei surface compared with the electrical auditory brainstem response (104.4 ± 32.5 vs 158.9 ± 24.2, P =. 0030). Electrical brainstem response and compound action potentials identified effects on the neighboring cranial nerves on 3.2 ± 2.4 and 7.8 ± 3.2 electrodes, respectively (P =. 0034). Open‐set speech perception outcomes at 48‐month follow‐up had improved significantly in the near‐ versus far‐field recording groups (78.9% versus 56.7%; P =. 0051).

Conclusions

Electrical compound action potentials during auditory brainstem implantation significantly improved the definition of the potential threshold and the number of auditory and extra‐auditory waves generated. It led to the best coupling between the electrode array and cochlear nuclei, significantly improving the overall open‐set speech perception.
Loneliness in the Daily Lives of Adolescents
Authors: van Roekel Eeske , Scholte Ron H. J. , Engels Rutger C. M. E. , Goossens Luc , Verhagen Maaike
Published: September 2014

The main aim of the present study was to examine state levels of loneliness in adolescence. Both concurrent associations and temporal dynamics between social contexts and state levels of loneliness were examined. Data were collected from 286 adolescents ( Mage = 14.19 years, 59% girls) by using the Experience Sampling Method. Results showed that adolescents had higher levels of state loneliness when they were alone, compared with being with company. When adolescents were with others, they were most lonely at school and with classmates. Adolescents showed a relief effect when they entered the company of friends after being alone, whereas a spillover effect of solitude was found when adolescents entered the company of family after being alone. Our findings show the dynamics of state loneliness, in that being with classmates increases state loneliness, whereas being with friends reduces loneliness after being alone.
Human papillomavirus DNA and mRNA prevalence and association with cervical cytological abnormalities in the Irish HIV population
Authors: Loy Aisling , McInerney Jamie , Pilkington Loretto , Keegan Helen , Delamere Sandra , Martin Cara M , Sheils Orla , O’Leary John J , Mulcahy Fiona
Published: September 2014

The complex interplay between HIV and human papillomavirus and its link to cervical dysplasia is poorly understood. This is the first study to assess the prevalence of oncogenic human papillomavirus mRNA in HIV-positive women, its relationship to HIV and its potential use in the triage of cervical cancer screening in HIV-positive women. In this cross-sectional study, we included 321 HIV-positive women. In all, 28.7% had abnormal cervical cytology, 51.1% were human papillomavirus DNA-positive and 21.8% tested positive for human papillomavirus mRNA. Women with a CD4 count of <200 × 106/L were more likely to test positive for human papillomavirus DNA and mRNA. Virally suppressed women were less likely to be human papillomavirus DNA-positive; however, the same did not hold true for human papillomavirus mRNA. We found the human papillomavirus mRNA screening to be more specific when screening for low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion than human papillomavirus DNA at 84.53% compared to 57.36%. However, the sensitivity was less at 51.59% versus 91.07% for human papillomavirus DNA. It may be possible in the future to use human papillomavirus mRNA/DNA testing within a triage algorithm for the screening and management of cervical cancer in the HIV-positive patient.
Transformational Leadership, Interactional Justice, and Organizational Citizenship Behavior
Authors: Carter Min Z. , Mossholder Kevin W. , Feild Hubert S. , Armenakis Achilles A.
Published: September 2014

We examined the mediating influence of interactional justice on relations between transformational leadership and organizational citizenship behavior (OCB). Because the relational context in which supervisors and subordinates interact could influence the mediated effect of transformational leadership on OCB, we developed a first stage moderation model and examined supervisor–subordinate dissimilarities in race and gender as potential moderating variables. Analyses performed using 230 supervisor–subordinate dyads showed that racial dissimilarity moderated the mediated effect of transformational leadership on OCB transmitted through interactional justice. As hypothesized, the mediated effect of transformational leadership on OCB was stronger for subordinates who were racially dissimilar to their supervisors. Gender dissimilarity did not moderate the mediation model.
Goddess with a Picasso face: Art markets, collectors and sacred things in the circulation of Korean shaman paintings
Authors: Kendall Laurel , Yang Jongsung
Published: September 2014

In the well-known story of how ‘primitive art’ came to be recognized as such, things once regarded as sacred or empowered circulate as art collected for reasons far removed from their original intention. In the case of Korean shaman paintings, the authors interpret this process as a kind of ‘purification’ in Bruno Latour’s sense, a translation and transformation of old practices (paintings as the seats of gods) into things that are deployed in acceptably modern ways (paintings as art commodities). The authors recognize, also following Latour, that this is necessarily an incomplete and unstable process. Their discussion assumes two parallel purifications, a discursive purification that recuperates the paintings as art market commodities and a more literal purification by shamans when, in particular circumstances, they deem it appropriate to release paintings to the art market. The authors are concerned with both thickening and broadening the discussion of art market circulation: thickening, by showing how, within a particular history in a particular place, at some distance from Paris or New York, things once sacred came to be revalued as ‘art’. They broaden the discussion by setting it among collectors and dealers in South Korea and thus outside the familiar dichotomy of the West and the rest that has heretofore organized discussions of the commodification and circulation of once sacred goods. A seemingly familiar story about art markets and the social life of things unfolds within the unfamiliar context of an alternative or Other modernity.
Propylthiouracil-Induced Vasculitis With Antineutrophil Cytoplasmic Antibody
Authors: Criado Paulo Ricardo , Grizzo Peres Martins Ana Claudia , Gaviolli Camila Fatima , Alavi Afsaneh
Published: September 2014

Propylthiouracil (PTU)-associated vasculitis is a potentially life-threatening disease with a recent increase in the reported cases in the medical literature. This increase may suggest that some earlier cases have been unrecognized or assigned to an alternative nosology category. Although the skin can be the only organ affected by PTU-associated vasculitis, there are many reports with multiple-system involvement. Classically, the symptoms appear under a tetrad of fever, sore throat, arthralgia, and skin lesions. Cutaneous lesions in reported cases of PTU vasculitis have most commonly consisted of retiform acral, purpuric plaques, or nodules. We report a case of perinuclear antineutrophil cytoplasmic antibody–associated vasculitis developed during treatment with PTU for Grave’s disease.
Talking about alcohol: communities of practice and patient pathways
Authors: Whiteford Martin , Byrne Paula
Published: September 2014

It is widely argued in policy circles and academic research that the health and social care needs of people with multiple and complex needs are greatly enhanced through a shared commitment to inter-professional practice and transformational learning. We take this assumption to task by examining a ‘community of practice’ (a working group for high-impact users facilitated by a large inner-city GP surgery), which brings together frontline practitioners and statutory commissioners working at the interface between homelessness, health and substance use. We then go on to identify four areas: (1) knowledge exchange and critical reflection; (2) networks of intervention; (3) inequality in relations and resources and (4) competition and congruence – that demand critical attention if we are to understand more fully the potential role of ‘communities of practice’ in acting as bridgeheads to health and social care integration.