bluuebunny/crossref_metadata_2025 huggingface dataset:
Design space exploration of adaptive beamforming acceleration for bedside and portable medical ultrasound imaging
Authors: Chen Junying , Yiu Billy Y.S. , Hamilton Brandon K. , Yu Alfred C.H. , So Hayden K.-H.
Published: December 2011

The use of adaptive beamforming is a viable solution to provide high-resolution real-time medical ultrasound imaging. However, the increase in image resolution comes at an expense of a significant increase in compute requirement over conventional algorithms. In a bedside diagnosis setting where plug-in power is available, GPUs are promising accelerators to address the processing demand. However, in the case of point-of-care diagnostics where portable ultrasound imaging devices must be used, alternative power-efficient computer systems must be employed, possibly at the expense of lower image resolution in order to maintain real-time performance. This paper presents an initial design space exploration on viable compute architectures that might address the drastically different requirements between bedside and portable medical ultrasound imaging systems using adaptive beamforming. The design and implementation of a GPU accelerator that provides over 45x performance improvement over the equivalent C implementation on a single CPU is presented. Furthermore, and implementation of the beamforming algorithm on a high-performance mobile platform based on an ARM Cortex A8 mobile processor in combination with the built-in NEON accelerator is also presented. The mobile platform delivers over 270x reduction in power consumption when compared to the GPU platform at an expense of much reduced performance. The tradeoffs between power, performance and image quality among the target platforms are studied and future research directions in power-efficient architectures for high-performance medical ultrasound systems are presented.
Domain-specific programmable design of scalable streaming-array for power-efficient stencil computation
Authors: Sano Kentaro , Yamamoto Satoru , Hatsuda Yoshiaki
Published: December 2011

This paper presents the domain-specific programmable design of custom computing machines for high-performance stencil computation. Stencil computation is one of the typical kernels in scientific computations, however its low operational-intensity makes the sustained performance limited by memory bandwidth on recent microprocessors and GPUs. So far we have proposed a scalable streaming-array (SSA) of processing elements, which provides almost linear scalability by increasing FPGAs with a constant externalmemory bandwidth. In order to facilitate custom computing and efficiently utilize hardware resources for various and complex stencil-computations, we design programmable SSA with limited but necessary functionality. We show the design concept, the programmable structure and the SIMD instruction set for SSA. Prototype implementation with nine FPGAs demonstrates that our programmable design with a lot of floating-point units exploits hardware resources well, efficiently achieving 260 GFlop/s, which is 87.4% of the peak, at 1295 MFlop/sW.
The performance of the Haskell containers package
Authors: Straka Milan
Published: December 2011

In this paper, we perform a thorough performance analysis of the
containers
package, the de facto standard Haskell containers library, comparing it to the most of existing alternatives on HackageDB. We then significantly improve its performance, making it comparable to the best implementations available. Additionally, we describe a new persistent data structure based on hashing, which offers the best performance out of available data structures containing
Strings
and
ByteStrings
.
An llVM backend for GHC
Authors: Terei David A. , Chakravarty Manuel M.T.
Published: December 2011

In the presence of ever-changing computer architectures, high-quality optimising compiler backends are moving targets that require specialist knowledge and sophisticated algorithms. In this paper, we explore a new backend for the Glasgow Haskell Compiler (GHC) that leverages the
Low Level Virtual Machine (LLVM)
, a new breed of compiler written explicitly for use by other compiler writers, not high-level programmers, that promises to enable outsourcing of low-level and architecture-dependent aspects of code generation. We discuss the conceptual challenges and our backend design. We also provide an extensive quantitative evaluation of the performance of the backend and of the code it produces.
Hoopl
Authors: Ramsey Norman , Dias João , Peyton Jones Simon
Published: December 2011

Dataflow analysis and transformation of control-flow graphs is pervasive in optimizing compilers, but it is typically entangled with the details of a
particular
compiler. We describe Hoopl, a reusable library that makes it unusually easy to define new analyses and transformations for
any
compiler written in Haskell. Hoopl's interface is modular and polymorphic, and it offers unusually strong static guarantees. The implementation encapsulates state-of-the-art algorithms (interleaved analysis and rewriting, dynamic error isolation), and it cleanly separates their tricky elements so that they can be understood independently.
Species and functors and types, oh my!
Authors: Yorgey Brent A.
Published: December 2011

The theory of
combinatorial species
, although invented as a purely mathematical formalism to unify much of combinatorics, can also serve as a powerful and expressive language for talking about data types. With potential applications to automatic test generation, generic programming, and language design, the theory deserves to be much better known in the functional programming community. This paper aims to teach the basic theory of combinatorial species using motivation and examples from the world of functional programming. It also introduces the
species
library, available on Hackage, which is used to illustrate the concepts introduced and can serve as a platform for continued study and research.
New powder diffraction data of some N-derivatives of 4-chloro-3,5-dimethylphenoxyacetamide-potential pesticides
Authors: Olszewska E. , Tarasiuk B. , Pikus S.
Published: December 2011

N-derivatives of 4-chloro-3,5-dimethylphenoxyacetamide—2-(4-chloro-3,5-dimethylphenoxy)-N-(4-fluorophenyl)acetamide, 2-(4-chloro-3,5-dimethylphenoxy)-N-(3-chloro-4-fluorophenyl) acetamide, 2-(4-chloro-3,5-dimethylphenoxy)-N-[4-chloro-3-(trifluoromethyl)phenyl] acetamide, 2-(4-chloro-3,5-dimethylphenoxy)-N-[3-chloro-4-methylphenyl]acetamide, 2-(4-chloro-3,5-dimethylphenoxy)-N-(2,4,6-tribromophenyl) acetamide, 2-(4-chloro-3,5-dimethylphenoxy)-N-pyridin-2-ylacetamide, 1-[(4-chloro-3,5-dimethylphenoxy)acetyl]-4-methylpiperazine, and 1-benzyl-4-[(4-chloro-3,5-dimethylphenoxy)acetyl]piperazine—have been characterized by X-ray powder diffraction. These organic compounds are potential pesticides. Experimental 2θ peak positions, relative peak intensities, values of d and Miller indices, and unit-cell parameters are presented.
Ab initio structure determination of 3,4-diaminopyridin-1-ium dihydrogen phosphate
Authors: Le Bail A. , Smrčok L’.
Published: December 2011

The structure of 3,4-diaminopyridin-1-ium dihydrogen phosphate, [C5H3(NH)(NH2)2]+ (H2PO4)−, is solved from conventional X-ray powder diffraction data in direct space (monoclinic unit cell with a = 16.0725(9) Å, b = 7.7301(3) Å, c = 14.6189(9) Å, β = 96.869(1)°, V = 1803.2(2) Å3, Z = 8, and space group I2/c), and optimized by energy minimization in the solid state. In the crystal structure of the title compound, dihydrogenphosphate tetrahedra are linked by strong hydrogen O-H…O bonds forming chains running parallel to the b-axis. Antiparallelly π–π stacked DAP cations form molecular columns in the spaces between the chains. Although the dominant interaction of the molecules with their surroundings is electrostatic, their bonding are further enhanced by N-H…O and C-H…O hydrogen bonds.
Synthesis and Rietveld refinement of the ternary skutterudite RuSb2Te
Authors: Laufek F. , Návrátil J.
Published: December 2011

The RuSb2Te compound has been synthesized and structurally characterized from powder X-ray diffraction data. RuSb2Te has the skutterudite structure, Im3 symmetry, unit-cell parameter a = 9.2665(1) Å, V = 795.70(1) Å3, Z = 8, and Dc = 7.88 g/cm3. The Sb and Te atoms randomly occupy the crystallographic 24g position; no indications of ordering of Te and Sb atoms have been detected.
Biosurfactant-Producing Lactobacilli: Screening, Production Profiles, and Effect of Medium Composition
Authors: Gudiña Eduardo J. , Teixeira José A. , Rodrigues Lígia R.
Published: December 2011

Biosurfactant production was screened in four lactobacilli strains. The highest biosurfactant production (excreted and cell-bound biosurfactants) was achieved withLactobacillus paracaseissp.paracaseiA20, a strain isolated from a Portuguese dairy plant, with a decrease in the surface tension of 6.4 mN m−1and 22.0 mN m−1, respectively. Biosurfactant production by this strain was evaluated under different culture broth compositions. The use of different nitrogen sources revealed that yeast extract is essential for bacterial growth, while peptone is crucial for biosurfactant synthesis. For biosurfactant production, the use of peptone and meat extract yielded a higher production when compared to the standard medium, with a surface tension reduction of 24.5 mN m−1Furthermore, experiments were also conducted in a reactor with pH and temperature control. Biomass and biosurfactant production in bioreactor was higher comparing with the experiments conducted in shake flaks. The optimization procedure adopted in the current work was found to improve the biosurfactant production and opened new perspectives for the use ofL. paracaseissp.paracaseiA20 as a promising biosurfactant-producer.
Intense Pulsed-Light Therapy for Proliferative Haemangiomas of Infancy
Authors: Caucanas Marie , Paquet Philippe , Henry Frédérique , Piérard-Franchimont Claudine , Reginster Marie-Annick , Piérard Gérald E.
Published: December 2011

Infantile haemangioma therapy has long been a wait-and-see policy. Since recent development of laser and light therapy, pulsed dye laser has been successfully used for treating superficial haemangiomas. Few studies have been published about treatment with intense pulsed light (IPL) to assess the risk/benefit of IPL in the treatment of infantile haemangiomas during their early proliferative phase. In the present retrospective cohort study, we retrieved data about a series of 14 Caucasian children (median age: 4.8 months) with infantile haemangiomas treated with Photoderm Vasculight flash lamp. All patients experienced a rapid regression of the haemangiomas after 3 treatments on average. Few adverse events were noted, including ulceration and crusts. No residual scarring and cosmetic damages were noticed. Fast growing haemangiomas should be treated with light therapy as soon as possible. This technology is safe, efficient, inducing regression, and preventing any further functional and aesthetic complications. The benefit-risk ratio favours the treatment of most types of haemangiomas which are out of the scope of betablocker administration.
Onychomadesis Developed Only on the Nails Having Cutaneous Lesions of Severe Hand-Foot-Mouth Disease
Authors: Shikuma Emi , Endo Yuichiro , Fujisawa Akihiro , Tanioka Miki , Miyachi Yoshiki
Published: December 2011

This paper reported a case of onychomadesis which appeared on the nails after heal of cutaneous lesions of hand-foot-mouth disease (HFMD). There were a few reports describing onychomadesis after HFMD; however, the mechanism is still unclear. The present case was prospectively observed, and onychomadesis was found to develop only on the nails having cutaneous lesions of HFMD. We considered that nail dysfunction due to direct inflammation spreading from skin eruptions around nail is one of the causes of onychomadesis linked toHFMD.
Topical Ophthalmic Cyclosporine in the Treatment of Toxic Epidermal Necrolysis
Authors: Onaran Zafer , Usta Gülşah , Koçak Mukadder , Örnek Kemal , Büyükkoçak Ünase
Published: December 2011

Aim. To describe a case of toxic epidermal necrolysis (TEN) with ocular involvement treated with topical ophthalmic cyclosporine.Case Presentation. A 20-year-old woman developed TEN following administration of carbamazepine that was prescribed for epilepsy. Ophthalmic examination revealed bilateral pseudomembranous conjunctivitis. She was hospitalized in the intensive care unit and treated with intravenous corticosteroid and immunoglobulin. Topical cyclosporine was used in combination with topical corticosteroids for ocular surface disease. Following two months of ocular treatment, she recovered without any severe ocular complication. Ocular examination at the four-month followup showed a 2 mm of symblepharon in the lower fornix as the sole pathologic finding.Conclusion. Topical ophthalmic cyclosporine may contribute to decrease the ophthalmic complications of TEN and should be considered in the acute stage of the disease.
Novel Immunotherapeutic Strategies of Gastric Cancer Treatment
Authors: Amedei Amedeo , Benagiano Marisa , della Bella Chiara , Niccolai Elena , D′Elios Mario M.
Published: December 2011

Gastric cancer (GC) is the fourth most common cancer and the second most frequent cause of cancer‐related deaths, accounting for 10.4% of cancer deaths worldwide. Despite the improvements, estimated cure rates for patients with advanced stages remain poor, and in the metastatic setting, chemotherapy is the mainstay of palliative therapy and results in objective response rates (ORRs) of only 20–40% and median overall survivals (OS) of 8–10 months. Therefore, many investigators believe that the potential for making significant progress lies in understanding and exploiting the molecular biology of these tumors to investigate new therapeutic strategies to combat GC, such as specific immunotherapy. In this paper, we analyze the different approaches used for immune‐based (especially dendritic and T cells) therapies to gastric cancer treatment and discuss the results obtained in preclinical models as in clinical trials.
The Effect of Exposed Glass Fibers and Particles of Bioactive Glass on the Surface Wettability of Composite Implants
Authors: Abdulmajeed Aous A. , Lassila Lippo V. , Vallittu Pekka K. , Närhi Timo O.
Published: December 2011

Measurement of the wettability of a material is a predictive index of cytocompatibility. This study was designed to evaluate the effect of exposed E-glass fibers and bioactive glass (BAG) particles on the surface wettability behavior of composite implants. Two different groups were investigated: (a) fiber reinforced composites (FRCs) with different fiber orientations and (b) polymer composites with different wt. % of BAG particles. Photopolymerized and heat postpolymerized composite substrates were made for both groups. The surface wettability, topography, and roughness were analyzed. Equilibrium contact angles were measured using the sessile drop method. Three liquids were used as a probe for surface free energy (SFE) calculations. SFE values were calculated from contact angles obtained on smooth surfaces. The surface with transverse distribution of fibers showed higher () polar () and total SFE () components (16.9 and 51.04 mJ/m2, resp.) than the surface with in-plane distribution of fibers (13.77 and 48.27 mJ/m2, resp.). The increase in BAG particle wt. % increased the polar () value, while the dispersive () value decreased. Postpolymerization by heat treatment improved the SFE components on all the surfaces investigated (). Composites containing E-glass fibers and BAG particles are hydrophilic materials that show good wettability characteristics.
Deuterium Isotope Effects on 14,15N Chemical Shifts of Ammonium Ions: A Solid State NMR Study
Authors: Hansen Poul Erik
Published: December 2011

Deuterium isotope effects on N14,15 chemical shifts are measured in ammonium halides in the solid state using both enriched N15 salts and N14 natural abundance materials. The effects are correlated to N15 chemical shifts and to N···X distances. The deuterium isotope effects on N14,15 chemical shifts in the solid state are discussed in relation to effects observed in solution. No NH couplings are seen due to fast rotation in the solid, which leads to self-decoupling, whereas ND couplings are present.
Primitive Neuroectodermal Tumor of the Liver: A Case Report
Authors: Cambruzzi Eduardo , Guerra Enilde Eloena , Hilgert Hamilton Cardoso , Schmitz Herbert Jorge , Silva Vinícius Lopes , Milani Daniel Marini , Cruz Ricardo Pedrini , Pruinelli Raul
Published: December 2011

Primary liver sarcomas represent a rare group of neoplasias, with angiosarcoma being the most common histological type. Primitive neuroectodermal tumor (PNET) represents a high malignant neoplasia that usually affects the central nervous system and soft tissues. An 18-year-old male patient was admitted with clinical complains of pain in the right upper abdominal quadrant. The clinical evaluation revealed a solid mass in the right hepatic lobe. On the gross examination of the resected liver specimen, the right lobe of the liver was replaced by a yellow-red solid mass measuring 21 cm in its largest dimension. On the histopathology, a tumor composed of small round blue cells with little cytoplasm and round nuclei was identified. The lesion revealed positive immunoexpression for vimentin and CD99 and negative immunostaining for desmin, CD45, cytokeratin, and neuroblastoma protein, suggesting, then, the diagnosis of PNET. Although it is an unusual tumor, it should be considered in the differential diagnosis of liver masses, especially in young patients.
Performance Evaluation of Stochastic Multi-Echelon Inventory Systems: A Survey
Authors: Simchi-Levi David , Zhao Yao
Published: December 2011

Globalization, product proliferation, and fast product innovation have significantly increased the complexities of supply chains in many industries. One of the most important advancements of supply chain management in recent years is the development of models and methodologies for controlling inventory in general supply networks under uncertainty and their widefspread applications to industry. These developments are based on three generic methods: the queueing-inventory method, the lead-time demand method and the flow-unit method. In this paper, we compare and contrast these methods by discussing their strengths and weaknesses, their differences and connections, and showing how to apply them systematically to characterize and evaluate various supply networks with different supply processes, inventory policies, and demand processes. Our objective is to forge links among research strands on different methods and various network topologies so as to develop unified methodologies.
Dietary Restriction Promotes Vessel Maturation in a Mouse Astrocytoma
Authors: Urits Ivan , Mukherjee Purna , Meidenbauer Joshua , Seyfried Thomas N.
Published: December 2011

Mature vasculature contains an endothelial cell lining with a surrounding sheath of pericytes/vascular smooth muscle cells (VSMCs). Tumor vessels are immature and lack a pericyte sheath. Colocalization of vascular endothelial growth factor receptor 2 (VEGFR-2) and platelet-derived growth factor receptor beta (PDGF-Rβ) reduces pericyte ensheathment of tumor vessels. We found that a 30% dietary restriction (DR) enhanced vessel maturation in the mouse CT-2A astrocytoma. DR reduced microvessel density and VEGF expression in the astrocytoma, while increasing recruitment of pericytes, positive for alpha-smooth muscle actin (α-SMA). Moreover, DR reduced colocalization of VEGF-R2 and PDGF-Rβ, but did not reduce total PDGF-Rβexpression. These findings suggest that DR promoted vessel normalization by preventing VEGF-induced inhibition of the PDGF signaling axis in pericytes. DR appears to shift the tumor vasculature from a leaky immature state to a more mature state. We suggest that vessel normalization could improve delivery of therapeutic drugs to brain tumors.
An Enthusiastic Glance in to the Visible Responsive Photocatalysts for Energy Production and Pollutant Removal, with Special Emphasis on Titania
Authors: Silija Padikkaparambil , Yaakob Zahira , Suraja Viswanathan , Binitha Njarakkattuvalappil Narayanan , Akmal Zubair Shamsul
Published: December 2011

As a consequence of the rapid growth of industry, major problems are created related to energy and environment. Sunlight being one of the most potential alternative source of energy, the development of efficient solar-energy storage systems is an important subject in the fields of science and technology. Here we have reviewed and summarized some of the recent reports on visible responsive photocatalysts. In this review, the influence of various metal oxide photocatalysts on energy production and pollutant removal are presented with special emphasis on titania based photocatalysts. The photoactivity of titania for various pollutant degradation, modified titania (TiO2) systems, their physical and chemical characteristics, and so forth, are described in detail at this juncture. Different methods used to enhance the visible light absorption of TiO2, like doping with metals and nonmetals, coupling with other metal oxides, and so forth, have been discussed. Various applications of photocatalysts including photocatalytic treatment of waste water, pesticide degradation and water splitting to produce hydrogen are summarized. The development of photocatalysts that function under visible light for the efficient utilization of sunlight is an area of current interest and thus the different methods of preparation for the visible active photocatalysts are also explored.
Evaluating Frequency, Diagnostic Quality, and Cost of Lyme Borreliosis Testing in Germany: A Retrospective Model Analysis
Authors: Müller I. , Freitag M. H. , Poggensee G. , Scharnetzky E. , Straube E. , Schoerner Ch. , Hlobil H. , Hagedorn H.-J. , Stanek G. , Schubert-Unkmeir A. , Norris D. E. , Gensichen J. , Hunfeld K.-P.
Published: December 2011

Background. Data on the economic impact of Lyme borreliosis (LB) on European health care systems is scarce. This project focused on the epidemiology and costs for laboratory testing in LB patients in Germany.Materials and Methods. We performed a sentinel analysis of epidemiological and medicoeconomic data for 2007 and 2008. Data was provided by a German statutory health insurance (DAK) company covering approx. 6.04 million members. In addition, the quality of diagnostic testing for LB in Germany was studied.Results. In 2007 and 2008, the incident diagnosis LB was coded on average for 15,742 out of 6.04 million insured members (0.26%). 20,986 EIAs and 12,558 immunoblots were ordered annually for these patients. For all insured members in the outpatient sector, a total of 174,820 EIAs and 52,280 immunoblots were reimbursed annually to health care providers (cost: 2,600,850€). For Germany, the overall expected cost is estimated at 51,215,105€. However, proficiency testing data questioned test quality and standardization of diagnostic assays used.Conclusion. Findings from this study suggest ongoing issues related to care for LB and may help to improve future LB disease management.
Criminal Manifestations of Dementia Patients: Report from the National Forensic Hospital
Authors: Kim Jeong-Min , Chu Kon , Jung Keun-Hwa , Lee Soon-Tae , Choi Sang-Sub , Lee Sang Kun
Published: December 2011

Background/Aims: Some dementia patients have profound behavioral and psychological symptoms which might cause legal violation. We illustrate clinical and criminal characteristics of dementia patients who had been incarcerated because of criminal activity. Methods: The National Forensic Hospital is the only hospital-based correctional facility in the Republic of Korea which incarcerates criminals with psychiatric or neurological disease. Between May 2008 and April 2009, those patients who had been diagnosed with dementia in the National Forensic Hospital were included in the study. We reviewed their medical and legal reports. Results: There were 7 dementia patients out of 752 patients, including 2 Alzheimer’s disease (AD) patients, 1 vascular dementia patient, and 4 patients with alcohol-related dementia. Criminal behavior included simple larceny by the 2 AD patients, and multiple violent crimes in a drunken state by the other 5 patients. Conclusions: This study reported diverse criminal behaviors among dementia patients. Inebriation may be related to violent criminal behavior among some dementia patients.
The First Report of a Patient with Probable Variant Creutzfeldt-Jakob Disease in Turkey
Authors: Adapınar Demet Özbabalık , Saylısoy Suzan , Yenilmez Çınar , Aslan Hüseyin , Ertan Bengü , Artan Sevilhan , Güleç Gülcan , Susuz Çiğdem , Adapınar Baki
Published: December 2011

Variant Creutzfeldt-Jakob disease (vCJD) was first reported in the UK in 1996. Here, we report the first Turkish case of vCJD. A 47-year-old man, who has never lived outside of Turkey and had had no transfusion, was admitted to the University Hospital with speech disorder, cognitive decline and ataxia following depression, irritability, and personality change. The immunoassay of the 14-3-3 protein in the cerebrospinal fluid was negative. Brain magnetic resonance imaging revealed high-signal lesions involving the bilateral caudate and lentiform nucleus on T2- and diffusion-weighted imaging. The patient developed akinetic mutism 10 months after disease onset. The clinical presentation and neuroimaging findings were compatible with the vCJD cases reported since 1996 and met the World Health Organization’s case definition for probable vCJD.
Rituximab Treatment for Membranous Nephropathy: A French Clinical and Serological Retrospective Study of 28 Patients
Authors: Michel Pierre-Antoine , Dahan Karine , Ancel Pierre-Yves , Plaisier Emmanuelle , Mojaat Rachid , De Seigneux Sophie , Daugas Eric , Matignon Marie , Mesnard Laurent , Karras Alexandre , François Hélène , Pardon Agathe , Caudwell Valérie , Debiec Hanna , Ronco Pierre
Published: December 2011

The development of well-tolerated and effective therapies that target the pathogenesis of membranous nephropathy (MN) would be useful. Our objective was to evaluate the efficacy of rituximab in MN. We analyzed the outcome of 28 patients treated with rituximab for idiopathic MN. Anti-PLA2R antibodies in serum and PLA2R antigen in kidney biopsy were assessed in 10 and 9 patients, respectively. Proteinuria was significantly decreased by 56, 62 and 87% at 3, 6 and 12 months, respectively. At 6 months, 2 patients achieved complete remission (CR) and 12 partial remission (PR; overall renal response, 50%). At 12 months (n = 23), CR was achieved in 6 patients and PR in 13 patients (overall renal response, 82.6%). Three patients suffered a relapse of nephrotic proteinuria 27–50 months after treatment. Univariate analysis suggested that the degree of renal failure (MDRD estimated glomerular filtration rate <45/ml/min/1.73 m2) is an independent factor that predicts lack of response to rituximab. Anti-PLA2R antibodies were detected in the serum of 10 patients, and PLA2R antigen in immune deposits in 8 of 9 patients. Antibodies became negative in all 5 responsive patients with available follow-up sera. In this retrospective study, a high rate of remission was achieved 12 months after treatment.
Long-Term Follow-Up of Persistent Truncus Arteriosus: Kuwait Experience
Authors: Selvan J.P. , Uthaman B. , Abushaban L. , Qabandi M.A. , Al Hay A. , Al Hassan A. , Thinakarvel M.
Published: December 2011

Objective: To evaluate the long-term results of patients in Kuwait who were operated for persistent truncus arteriosus (PTA). Subjects and Methods: The following data were collected for retrospective analysis from 24 medical records of consecutive patients with PTA in Kuwait between August 1993 and August 2009: demographics, morphology, management and outcome. Major associated abnormalities included interrupted aortic arch in 1 patient and abnormal coronary artery anatomy in 2. Results: Of the 24 patients, 16 underwent total intracardiac repair. The age at operation ranged from 15 days to 5 years (mean 166.19 ± 438.63 days) and weight ranged from 2.5 to 15 kg (mean 4.3 ± 3.01 kg). The right ventricle to pulmonary artery continuity was established with aortic homograft in 11, pulmonary homograft in 4 and by implantation of a Contegra conduit in 1 patient. Four patients had moderate truncal valve regurgitation requiring concomitant truncal valve repair. After a mean follow-up period of 81.81 ± 61.58 months (range 3–166) there was no death. Eight of the 16 (50%) patients underwent redo homograft operations. One patient who had concomitant truncal valve repair subsequently underwent aortic valve replacement. Conclusion: The data showed that complete repair of PTA in the neonatal and early infancy period was the treatment with the best potential for survival. The homograft remained one of the conduits of choice to establish continuity between the right ventricle and the pulmonary artery in spite of the high incidence of conduit redo operations.
Divergence-Free Spatial Velocity Flow Field Interpolator for Improving Measurements from ADCP-Equipped Small Unmanned Underwater Vehicles
Authors: MacMahan Jamie , Vennell Ross , Beatson Rick , Brown Jenna , Reniers Ad
Published: December 2011

Applying a two-dimensional (2D) divergence-free (DF) interpolation to a one-person deployable unmanned underwater vehicle’s (UUV) noisy moving-vessel acoustic Doppler current profiler (MV-ADCP) measurements improves the results and increases the utility of the UUV in tidal environments. For a 3.5-h MV-ACDP simulation that spatially and temporally varies with the M2 tide, the 2D DF-estimated velocity magnitude and orientation improves by approximately 85%. Next the 2D DF method was applied to velocity data obtained from two UUVs that repeatedly performed seven 1-h survey tracks in Bear Cut Inlet, Miami, Florida. The DF method provides a more realistic and consistent representation of the ADCP measured flow field, improving magnitude and orientation estimates by approximately 25%. The improvement increases for lower flow velocities, when the ADCP measurements have low environmental signal-to-noise ratio. However, near slack tide when flow reversal occurs, the DF estimates are invalid because the flows are not steady state within the survey circuit.
A DRP–4DVar Data Assimilation Scheme for Typhoon Initialization Using Sea Level Pressure Data
Authors: Zhao Ying , Wang Bin , Liu Juanjuan
Published: December 2011

In this study, a new data assimilation system based on a dimension-reduced projection (DRP) technique was developed for the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) modeling system. As an initial step to test the newly developed system, observing system simulation experiments (OSSEs) were conducted using a simulated sea level pressure (SLP) field as “observations” and assimilation experiments using a specified SLP field to evaluate the effects of the new DRP–four-dimensional variational data assimilation (4DVar) method, initialization, and simulation of a tropical storm—Typhoon Bilis (2006) over the western North Pacific. In the OSSEs, the “nature” run, which was assumed to represent the “true” atmosphere, was simulated by the MM5 model, which was initialized with the 1.0° × 1.0° NCEP final global tropospheric analyses and integrated for 120 h. The simulated SLP field was then used as the observations in the data assimilation. It is shown that the MM5 DRP–4DVar system can successfully assimilate the (simulated) model output (used as observations) because the OSSEs resulted in improved storm-track forecasts. In addition, compared with an experiment that assimilated the SLP data fixed at the end of a 6-h assimilation window, the experiment that assimilated the SLP data every 3 min in a 30-min assimilation window further improved the typhoon-track forecasts, especially in terms of the initial vortex location and landfall location. Finally, the assimilation experiments with a specified SLP field have demonstrated the effectiveness of the new method.
Application of a WRF Mesoscale Data Assimilation System to Springtime Severe Weather Events 2007–09
Authors: Wheatley Dustan M. , Stensrud David J. , Dowell David C. , Yussouf Nusrat
Published: December 2011

An ensemble-based data assimilation system using the Weather Research and Forecasting Model (WRF) has been used to initialize forecasts of prolific severe weather events from springs 2007 to 2009. These experiments build on previous work that has shown the ability of ensemble Kalman filter (EnKF) data assimilation to produce realistic mesoscale features, such as drylines and convectively driven cold pools, which often play an important role in future convective development. For each event in this study, severe weather parameters are calculated from an experimental ensemble forecast started from EnKF analyses, and then compared to a control ensemble forecast in which no ensemble-based data assimilation is performed. Root-mean-square errors for surface observations averaged across all events are generally smaller for the experimental ensemble over the 0–6-h forecast period. At model grid points nearest to tornado reports, the ensemble-mean significant tornado parameter (STP) and the probability that STP > 1 are often greater in the experimental 0–6-h ensemble forecasts than in the control forecasts. Likewise, the probability of mesoscale convective system (MCS) maintenance probability (MMP) is often greater with the experimental ensemble at model grid points nearest to wind reports. Severe weather forecasts can be sharpened by coupling the respective severe weather parameter with the probability of measurable rainfall at model grid points. The differences between the two ensembles are found to be significant at the 95% level, suggesting that even a short period of ensemble data assimilation can yield improved forecast guidance for severe weather events.
Choosing a Boundary Layer Parameterization for Tropical Cyclone Modeling
Authors: Kepert Jeffrey D.
Published: December 2011

The boundary layer in a tropical cyclone is in some respects unlike that elsewhere in the atmosphere. It is therefore necessary to evaluate boundary layer parameterizations for their suitability for use in tropical cyclone simulation. Previous work has shown substantial sensitivity to the choice of scheme and identified specific shortcomings in some schemes, but without recommending which schemes are most suitable. Here, several schemes, representative of those available in popular modeling systems, are reviewed and applied in a simplified modeling framework. Based on a comparison with observations and on theoretical grounds, one popular class of schemes is shown to be badly flawed in that it incorrectly predicts the near-surface wind profile, and therefore should not be used. Another is shown to be sensitive to diagnosis of the boundary layer depth, a difficult problem in the core of the tropical cyclone, and caution is advised. The Louis boundary layer scheme and a higher-order closure scheme are, so far as can be discerned, without major problems, and are recommended. The recommendations and discussion herein should help users make a more informed choice of boundary layer parameterization, and to better understand the results that they obtain.
Assimilation of F-16 Special Sensor Microwave Imager/Sounder Data in the NCEP Global Forecast System
Authors: Yan Banghua , Weng Fuzhong
Published: December 2011

The Special Sensor Microwave Imager/Sounder (SSMIS) on board the Defense Meteorological Satellite Program (DMSP) F-16 satellite is the first conically scanning sounding instrument that provides information on atmospheric temperature and water vapor profiles. The SSMIS data were preprocessed by the Naval Research Laboratory (NRL) using its Unified Preprocessor Package (UPP) and then distributed to the numerical weather prediction centers by the Fleet Numerical Meteorology and Oceanography Center (FNMOC). This dataset was assimilated into the Global Forecast System (GFS) using gridpoint statistical interpolation (GSI). The initial assimilation of the SSMIS data into the GFS did not improve the medium-range (5–7 days) forecast skill. The SSMIS bias (O-B) still changes with location and time after the GSI bias-correction scheme is implemented. This bias characteristic is related to residual calibration errors in the correction of the SSMIS antenna emission and warm target contamination. The large O-B standard deviation is probably due to the large instrument noise in the SSMIS UPP data. The large O-B and its standard deviation for several surface sensitive channels are also caused by uncertainty in surface emissivity. In this study, a new scheme is developed to remove regionally dependent bias using a weekly composite O-B. The SSMIS noise is reduced through a Gaussian function filter. A new emissivity database for snow and sea ice is developed for the SSMIS surface sensitive channels. After applying these algorithms, the quality of the SSMIS low-atmospheric sounding (LAS) data is improved; the surface-sensitive channels can be effectively assimilated, and the impacts of SSMIS LAS data on the medium-range forecast in the GFS are positive and similar to those from Advanced Microwave Sounding Unit-A (AMSU-A) data.
A Method for Calibrating Deterministic Forecasts of Rare Events
Authors: Marsh Patrick T. , Kain John S. , Lakshmanan Valliappa , Clark Adam J. , Hitchens Nathan M. , Hardy Jill
Published: December 2011

Convection-allowing models offer forecasters unique insight into convective hazards relative to numerical models using parameterized convection. However, methods to best characterize the uncertainty of guidance derived from convection-allowing models are still unrefined. This paper proposes a method of deriving calibrated probabilistic forecasts of rare events from deterministic forecasts by fitting a parametric kernel density function to the model’s historical spatial error characteristics. This kernel density function is then applied to individual forecast fields to produce probabilistic forecasts.
Why Split? Organizational Splits among Ethnopolitical Organizations in the Middle East
Authors: Asal Victor , Brown Mitchell , Dalton Angela
Published: December 2011

Why do political organizations split? Drawing insight from organizational theory and social movement literature, this article explores the effect of organizational factors on group schism. Using a new data set of 112 ethnopolitical organizations in the Middle East, the article examines to what extent organizational factors such as leadership structure, organizational legality, and tactical intensity, as well as contextual variables such as state violence and external support for the organization, influence group schism. Findings show that organizations with a factional or competing leadership structure and those that use violence as a tactic are at a greater risk to split. Contrary to research on political parties, which highlight the importance of factional leadership structure in relation to the maintenance and growth of the party organization, findings suggest that competing leadership structure, along with the employment of tactical violence, precipitates ethnopolitical organizational fission and eventual splintering.
Negotiating towards a Next Turn: Phonetic Resources for ‘Doing the Same’
Authors: Sikveland Rein Ove
Published: December 2011

This paper investigates hearers’ use of response tokens (back-channels), in maintaining and differentiating their actions. Initial observations suggest that hearers produce a sequence of phonetically similar responses to disengage from the current topic, and dissimilar responses to engage with the current topic. This is studied systematically by combining detailed interactional and phonetic analysis in a collection of naturally-occurring talk in Norwegian. The interactional analysis forms the basis for labeling actions as maintained (‘doing the same’) and differentiated (‘NOT doing the same’), which is then used as a basis for phonetic analysis. The phonetic analysis shows that certain phonetic characteristics, including pitch, loudness, voice quality and articulatory characteristics, are associated with ‘doing the same’, as different from ‘NOT doing the same’. Interactional analysis gives further evidence of how this differentiation is of systematic relevance in the negotiations of a next turn. This paper addresses phonetic variation and variability by focusing on the relationship between sequence and phonetics in the turn-by-turn development of meaning. This has important implications for linguistic/phonetic research, and for the study of back-channels.
Design and modeling magnetorheological directional control valve
Authors: Salloom Maher Yahya , Samad Zahurin
Published: December 2011

Directional control valves are designed to control direction of flow, while actuators maintain required speeds and precise positions. Magnetorheological (MR) fluid is a controllable fluid. Utilizing the MR fluid properties, direct interface between magnetic fields and fluid power is possible, without the need for mechanical moving parts like spools. This study proposes a design of a four-way three-position MR directional control valve, presents a method of building, and explains the working principle of the valve. An analysis of the design and finite elements using finite element method of magnetism (FEMM) software was performed on each valve. The magnetic circuit of the MR valve was analyzed and the performance was simulated. The experiment showed the functional working principle of the MR valve. In conclusion, the MR valve proved to be effective in controlling the direction and speed of hydraulic actuators proportionally. The proposed new design has the potential to reduce the complexity of directional control valves in the future.
Privacy by design: Networked computing, 1969–1979
Authors: Braman Sandra
Published: December 2011

Discourse analysis of the technical document series that records the internet design history, the RFCs, shows that those involved during the first decade saw privacy as a multi-dimensional and interactive problem requiring use of a suite of solutions at the network, individual, and data levels that had to take into account the need to balance privacy against experimentation and innovation. Internet designers were sophisticated in their pragmatic thinking about privacy when evaluated vis-a-vis theoretical developments since that time, viewing privacy as a contextual matter involving boundary setting, and using information architecture and metadata as tools for privacy protection. Those in the social science and legal communities think about the privacy effects of communication on humans, while those in the technical design community must focus on privacy as a set of logistical problems. Bringing these diverse communities into a single conversation can considerably enrich and strengthen the work of all.
Long-offset AVO inversion of PP reflections from plane interfaces using effective reflection coefficients
Authors: Skopintseva Lyubov , Ayzenberg Milana , Landrø Martin , Nefedkina Tatyana , Aizenberg Arkady M.
Published: December 2011

A conventional amplitude variation with offset (AVO) inversion is based on geometrical seismics which exploit plane-wave reflection coefficients to describe the reflection phenomenon. Widely exploited linearizations of plane-wave coefficients are mostly valid at pre-critical offsets for media with almost flat and weak-contrast interfaces. Existing linearizations do not account for the seismic frequency range by ignoring the frequency content of the wavelet, which is a strong assumption. Plane-wave reflection coefficients do not fully describe the reflection of seismic waves at near-critical and post-critical offsets, because reflected seismic waves are typically generated by point sources. We propose an improved approach to AVO inversion, which is based on effective reflection coefficients (ERCs). ERCs generalize plane-wave coefficients for seismic waves generated by point sources and therefore more accurately describe near-critical and post-critical reflections where head waves are generated. Moreover, they are frequency-dependent and incorporate the local curvatures of the wavefront and the reflecting interface. In our study, we neglect the effect of interface curvature and demonstrate the advantages of our approach on synthetic data for a simple model with a plane interface separating two isotropic half-spaces. A comparison of the inversion results obtained with our approach and the results from an AVO inversion method based on the exact plane-wave reflection coefficient suggests that our method is superior, in particular for long-offset ranges which extend to and beyond the critical angle. We thus propose that long offsets can be successfully exploited in an AVO inversion under the correct assumption about the reflection coefficient. Such long-offset AVO inversion shows the potential of outperforming a conventional moderate-offset AVO inversion in the accuracy of estimated model parameters.
Full-waveform based complete moment tensor inversion and source parameter estimation from downhole microseismic data for hydrofracture monitoring
Authors: Song Fuxian , Toksöz M. Nafi
Published: December 2011

Downhole microseismic monitoring is a valuable tool in understanding the efficacy of hydraulic fracturing. Inverting for the moment tensor has gained increasing popularity in recent years as a way to understand the fracturing process. Previous studies utilize only part of the information in the waveforms, such as direct P- and S-wave amplitudes, and make far-field assumptions to determine the source mechanisms. The method is hindered in downhole monitoring, when only limited azimuthal coverage is available. In this study, we develop an approach to invert for complete moment tensor using full-waveform data recorded at a vertical borehole. We use the discrete wavenumber integration method to calculate full wavefields in the layered medium. By using synthetic data, we find that, at the near-field range, a stable, complete moment tensor can be retrieved by matching the waveforms without additional constraints. At the far-field range, we discover that the off-plane moment tensor component is poorly constrained by waveforms recorded at one well. Therefore, additional constraints must be introduced to retrieve the complete moment tensor. We study the inversion with three different types of constraints. For each constraint, we investigate the influence of velocity model errors, event mislocations, and data noise on the extracted source parameters by a Monte Carlo study. We test our method using a single well microseismic data set obtained during the hydraulic fracturing of the Bonner sands in East Texas. By imposing constraints on the fracture strike and dip range, we are able to retrieve the complete moment tensor for events in the far-field. Field results suggest that most events have a dominant double-couple component. The results also indicate the existence of a volumetric component in the moment tensor. The derived fracture plane orientation generally agrees with that derived from the multiple event location.