bluuebunny/crossref_metadata_2025 huggingface dataset:
Unsteady, Half-Annulus CFD Calculations of Thermal Migration Through a Cooled, 2.5 Stage High-Pressure Turbine
Authors: Tallman James A.
Published: November 2013

This paper presents an industrial perspective on the potential use of multiple-airfoil row, unsteady CFD calculations in high-pressure turbine design cycles. A sliding-mesh unsteady CFD simulation is performed for a high-pressure turbine section of a modern aviation engine at conditions representative of engine take-off. The turbine consists of two stages plus a center-frame strut upstream of the low-pressure turbine. The airfoil counts per row are such that a half-annulus model domain must be simulated for periodicity. The total model domain size is 170MM computational grid points, and the solution requires approximately 9 days of clock time on 6,288 processing cores of a Cray XE6 supercomputer. Airfoil and endwall cooling flows are modeled via source term additions to the flow. The endwall flowpath cavities and their purge/leakage flows are resolved in the computational meshes to an extent. The time-averaged temperature profile solution is compared with static rake data taken in engine tests. The unsteady solution shows a considerable improvement in agreement with the rake data, compared with a steady-state solution using circumferential mixing planes. Passage-to-passage variations in gas temperature prediction are present in the 2nd stage, due to non-periodic alignment between the nozzle vanes and rotor blades. These passage-to-passage differences are quantified and contrasted.
Optimization of a Sawmill-Based Polygeneration Plant
Authors: Salomón Marianne , Gómez María F. , Spelling James , Martin Andrew
Published: November 2013

Biomass-based fuels have attracted worldwide interest due to their plentiful supply and their environmentally friendly characteristics. In many cases they are still considered waste but for most industries in Sweden, biomass has changed from being simply a disposal problem to become an important part of the energy supply, thanks to the long-term efforts made by the government, researchers and industry, where energy policies have played an important role. However, the amount of power that could be generated from biomass resources is much greater than that which is currently used. To effectively capture this resource requires a new generation of biomass power plants and their effective integration into already existing industrial processes.

The implementation of an integrated polygeneration scheme requires the simultaneous consideration of technical, economic and environmental factors to find optimum solutions. With this in mind, a unified modeling approach that takes into account thermodynamic as well as economic and environmental aspects was used. The analysis was done using ASPEN Utilities and the MATLAB optimization toolbox. A specific case of a sawmill in Sweden, with an annual capacity of 130’000 m3 of sawn wood, has been analyzed and different options for generating electricity and process heat (for the sawmill and for a district heating network) as well as densified biofuels was analyzed. Optimization was then applied for different configurations and operational parameters.

The results show that the sawmill has the capability to not only supply its own energy needs, but also to export from 0.4 to 1MW of electricity to the grid, contribute 5 to 6 MWth of district heating and 20 000 ton/y of biomass pellets. The production of pellets helps to maintain the electricity production throughout the year when the district heating demand is lower. However, the levelized electricity cost is higher than the usual electricity price in the Nordic electricity market and may have difficulty to competing with low-cost electricity sources, such as nuclear energy and hydropower. In spite of this, polygeneration remains attractive for covering the energy demands of the sawmill and pelletization plant.
The Role of Dense Gas Dynamics on ORC Turbine Performance
Authors: Wheeler Andrew P. S. , Ong Jonathan
Published: November 2013

In this paper we investigate the real gas flows which occur within Organic Rankine Cycle (ORC) turbines. A new method for the design of nozzles operating with dense gases is discussed, and applied to the case of a high pressure ratio turbine vane. A Navier-Stokes method which uses equations of states for a variety of working fluids typical of ORC turbines is then applied to the turbine vanes to determine the vane performance. The results suggest that the choice of working fluid has a significant influence on the turbine efficiency.
MEMS-Scale Turbomachinery Based Vacuum Roughing Pump
Authors: Gannon Anthony J. , Hobson Garth V. , Shea Michael J. , Clay Christopher S. , Millsaps Knox T.
Published: November 2013

This study forms part of a program to develop a micro-electro-mechanical-systems (MEMS) scale turbomachinery based vacuum pump and investigates the roughing portion of such a system. Such a machine would have many radial stages with the exhaust stages operating near atmospheric conditions while the inlet stages operate at near vacuum conditions. In low vacuum such as those to the inlet of a roughing pump the flow can still be treated as a continuum however the no-slip boundary condition is not accurate. The Knudsen number becomes a dominant non-dimensional parameter in these machines due to their small size and low pressures. As the Knudsen number increases slip flow becomes present at the walls. The study begins with a basic overview on implementing the slip wall boundary condition in a commercial code by specifying the wall shear stress based on the mean-free-path of the gas molecules. This is validated against an available micro-Poiseuille classical solution at Knudsen numbers between 0.001–0.1 with reasonable agreement found.

The method of specifying the wall-shear stress is then applied to a generic MEMS scale roughing pump stage that consists of two stators and a rotor operating at a nominal absolute pressure of 500 Pa. The zero flow case was simulated in all cases as the pump down time for these machines is small due to the small volume being evacuated. Initial transient two-dimensional simulations are used to evaluate three boundary conditions, classical no-slip, specified-shear and slip-flow. It is found that the stage pressure rise increased as the flow began to slip at the walls. In addition it was found that at lower pressures the pure slip boundary condition resulted in very similar predictions to the specified shear simulations. As the specified-shear simulations are computationally expensive it is reasonable to use slip-flow boundary conditions. This approach was used to perform three-dimensional simulations of the stage. Again the stage pressure increased when slip-flow was present compared with the classical no-slip boundaries. A characteristic of MEMS scale turbomachinery are the large relative tip gaps requiring three-dimensional simulations. A tip gap sensitivity study was performed and it was found that when no-slip boundaries were present the pressure ratio increased significantly with decreasing tip gap. When slip-flow boundaries were present this relationship was far weaker.
Aerodynamic Interaction Effects From Upstream and Downstream on the Down-Flow Type Exhaust Diffuser Performance in a Low Pressure Steam Turbine
Authors: Tanuma Tadashi , Sasao Yasuhiro , Yamamoto Satoru , Niizeki Yoshiki , Shibukawa Naoki , Saeki Hiroshi
Published: November 2013

The purpose of this paper is to explain aerodynamic interaction effects from upstream and downstream on the down-flow type exhaust diffuser performance in a low pressure steam turbine. To increase exhaust diffuser performance, design data related to the aerodynamic interaction effects from upstream turbine stages and downstream exhaust hood geometry on the exhaust diffuser performance would be very useful. This paper presents numerical investigation of three dimensional wet steam flows in a down-flow type exhaust diffuser with non-uniform inlet flow from a typical last stage with long transonic blades designed with recent aerodynamic and mechanical design technology. Previous studies show that small scale model tests and CFD analyses of exhaust diffusers with uniform inlet flow conditions are not enough to investigate diffuser efficiency and detail diffuser flow mechanism because inlet flow structures including tip leakage flows and blade wakes superimposed from a last stage and several other upstream turbine stages in low pressure turbines affect flow separations that reduce the exhaust diffuser performance. Recent studies by the authors show that the introduction of radial distributions of velocities and flow angles at the inlet section of exhaust diffuser measured in a full scale development steam turbine increased the accuracy of numerical analysis of diffuser flow. In the present study, the computational domain was enhanced and the method of boundary condition definition was improved to increase the accuracy of boundary layer separation and separation vortex generation in wet steam flows. Using the improved method, the calculation results explained the aerodynamic interaction effects from upstream and downstream on the down-flow type exhaust diffuser performance.
Engine Design Strategy for Boundary Layer Ingesting Propulsion Systems With Multiple Non-Symmetric Engine Inlet Conditions
Authors: Gladin Jonathan C. , Kestner Brian K. , Schutte Jeff S. , Mavris Dimitri N.
Published: November 2013

Boundary layer ingesting inlets for hybrid wing body aircraft have been investigated at some depth in recent years due to the theoretical potential for fuel burn savings. Such savings derive from the ingestion of a portion of the low momentum wake into the propulsor to reenergize the flow, thus yielding total power savings and reducing required block fuel burn.

A potential concern for BLI is that traditional concepts such as “thrust” and “drag” become less clearly defined due to the interaction between the vehicle aerodynamics and the propulsive thrust achieved. One such interaction for the HWB concept is the lateral location of the inlet on the upper surface which determines the effective Reynolds number at the point of ingestion. This is an important factor in determining the amount of power savings achieved by the system, since the boundary layer, displacement, and momentum thicknesses are functions of the local chord length and airfoil shape which are all functions of the lateral location of the engine. This poses a design challenge for engine layouts with more than two engines as at least one or more of the total engines will be operating at a different set of changing inlet conditions throughout the flight envelope.

As a result, the engine operating point and propulsive performance will be different between outboard and inboard engines at flight conditions with appreciable boundary layer influence including key flight conditions for engine design: takeoff, top of climb, and cruise. The optimal engine design strategy in terms of performance to address this issue is to design separate engines with similar thrust performance. This strategy has significant challenges such as requiring the manufacturing and certification of two different engines for one vehicle. A more practical strategy is to design a single engine that performs adequately at the different inlet conditions but may not achieve the full benefits of BLI.

This paper presents a technique for cycle analysis which can account for the disparity between inlet conditions. This technique was used for two principal purposes: first to determine the effect of the inlet disparity on the performance of the system; second, to analyze the various design strategies that might mitigate the impact of this effect. It is shown that a single engine can be sized when considering both inboard and outboard engines simultaneously. Additionally, it is shown that there is a benefit to ingesting larger mass flows in the inboard engine for the case with large disparity between the engine inlets.
Monte Carlo and analytical model predictions of leakage neutron exposures from passively scattered proton therapy
Authors: Pérez‐Andújar Angélica , Zhang Rui , Newhauser Wayne
Published: November 2013

Purpose:

Stray neutron radiation is of concern after radiation therapy, especially in children, because of the high risk it might carry for secondary cancers. Several previous studies predicted the stray neutron exposure from proton therapy, mostly using Monte Carlo simulations. Promising attempts to develop analytical models have also been reported, but these were limited to only a few proton beam energies. The purpose of this study was to develop an analytical model to predict leakage neutron equivalent dose from passively scattered proton beams in the 100‐250‐MeV interval.

Methods:

To develop and validate the analytical model, the authors used values of equivalent dose per therapeutic absorbed dose (H/D) predicted with Monte Carlo simulations. The authors also characterized the behavior of the mean neutron radiation‐weighting factor, , as a function of depth in a water phantom and distance from the beam central axis.

Results:

The simulated and analytical predictions agreed well. On average, the percentage difference between the analytical model and the Monte Carlo simulations was 10% for the energies and positions studied. The authors found that was highest at the shallowest depth and decreased with depth until around 10 cm, where it started to increase slowly with depth. This was consistent among all energies.

Conclusion:

Simple analytical methods are promising alternatives to complex and slow Monte Carlo simulations to predict H/D values. The authorsˈ results also provide improved understanding of the behavior of which strongly depends on depth, but is nearly independent of lateral distance from the beam central axis.
Three independent one‐dimensional margins for single‐fraction frameless stereotactic radiosurgery brain cases using CBCT
Authors: Zhang Qinghui , Chan Maria F. , Burman Chandra , Song Yulin , Zhang Mutian
Published: November 2013

Purpose:

Setting a proper margin is crucial for not only delivering the required radiation dose to a target volume, but also reducing the unnecessary radiation to the adjacent organs at risk. This study investigated the independent one‐dimensional symmetric and asymmetric margins between the clinical target volume (CTV) and the planning target volume (PTV) for linac‐based single‐fraction frameless stereotactic radiosurgery (SRS).

Methods:

The authors assumed a Dirac delta function for the systematic error of a specific machine and a Gaussian function for the residual setup errors. Margin formulas were then derived in details to arrive at a suitable CTV‐to‐PTV margin for single‐fraction frameless SRS. Such a margin ensured that the CTV would receive the prescribed dose in 95% of the patients. To validate our margin formalism, the authors retrospectively analyzed nine patients who were previously treated with noncoplanar conformal beams. Cone‐beam computed tomography (CBCT) was used in the patient setup. The isocenter shifts between the CBCT and linac were measured for a Varian Trilogy linear accelerator for three months. For each plan, the authors shifted the isocenter of the plan in each direction by ±3 mm simultaneously to simulate the worst setup scenario. Subsequently, the asymptotic behavior of the CTV V80% for each patient was studied as the setup error approached the CTV‐PTV margin.

Results:

The authors found that the proper margin for single‐fraction frameless SRS cases with brain cancer was about 3 mm for the machine investigated in this study. The isocenter shifts between the CBCT and the linac remained almost constant over a period of three months for this specific machine. This confirmed our assumption that the machine systematic error distribution could be approximated as a delta function. This definition is especially relevant to a single‐fraction treatment. The prescribed dose coverage for all the patients investigated was 96.1% ± 5.5% with an extreme 3‐mm setup error in all three directions simultaneously. It was found that the effect of the setup error on dose coverage was tumor location dependent. It mostly affected the tumors located in the posterior part of the brain, resulting in a minimum coverage of approximately 72%. This was entirely due to the unique geometry of the posterior head.

Conclusions:

Margin expansion formulas were derived for single‐fraction frameless SRS such that the CTV would receive the prescribed dose in 95% of the patients treated for brain cancer. The margins defined in this study are machine‐specific and account for nonzero mean systematic error. The margin for single‐fraction SRS for a group of machines was also derived in this paper.
Potential of the Synthetic Lethality Principle
Authors: Nijman Sebastian M. B. , Friend Stephen H.
Published: November 2013

Elucidating the first principles of synthetic lethality in cancer, including biological context, will assist clinical translation.
Transposons Up the Dosage
Authors: Chuong Edward B. , Feschotte Cédric
Published: November 2013

A family of transposable elements have played an important role in the evolution of dosage compensation in fruit flies.

[Also see Report by
Ellison and Bachtrog
]
Can Cancer Drugs Treat Immunodeficiency?
Authors: Conley Mary Ellen , Fruman David A.
Published: November 2013

Genome sequencing has defined the genetic basis for a primary immunodeficiency disease.

[Also see Report by

Angulo
et al.

]
Goal of Ending AIDS Gains Traction
Authors: Cohen Jon
Published: November 2013

Impressive gains against HIV have led to the concept of an AIDS-free world, but a San Francisco meeting maps the challenging route ahead.
Culturing Patient Cells for Cancer Immunotherapy: Challenges and Opportunities
Authors: Levine Bruce , Minger Stephen
Published: November 2013

Immunotherapy that uses autologous cells has recently shown increasing success. This procedure, however, requires the generation of sufficient, high-quality cells for infusion into patients. Functionally closed, automated, single use cell culture systems have significant advantages over the open, static systems that are commonly used. Keeping these systems small and efficient, while at the same time producing a sufficient number of cells is a challenge. Enabling high cell density culture is very important in order to minimize the total space required in a manufacturing or clinical development laboratory setting. However, achieving these high cell densities without compromising the quality of cells can be a challenge. This webinar will examine the conditions contributing to a healthy cell culture environment and explore ways to optimize high cell density culture.
Retrovirus-Specific Differences in Matrix and Nucleocapsid Protein-Nucleic Acid Interactions: Implications for Genomic RNA Packaging
Authors: Sun Meng , Grigsby Iwen F. , Gorelick Robert J. , Mansky Louis M. , Musier-Forsyth Karin
Published: November 2013

Retroviral RNA encapsidation involves a recognition event between genomic RNA (gRNA) and one or more domains in Gag. In HIV-1, the nucleocapsid (NC) domain is involved in gRNA packaging and displays robust nucleic acid (NA) binding and chaperone functions. In comparison, NC of human T-cell leukemia virus type 1 (HTLV-1), a deltaretrovirus, displays weaker NA binding and chaperone activity. Mutation of conserved charged residues in the deltaretrovirus bovine leukemia virus (BLV) matrix (MA) and NC domains affects virus replication and gRNA packaging efficiency. Based on these observations, we hypothesized that the MA domain may generally contribute to NA binding and genome encapsidation in deltaretroviruses. Here, we examined the interaction between HTLV-2 and HIV-1 MA proteins and various NAs
in vitro
. HTLV-2 MA displays higher NA binding affinity and better chaperone activity than HIV-1 MA. HTLV-2 MA also binds NAs with higher affinity than HTLV-2 NC and displays more robust chaperone function. Mutation of two basic residues in HTLV-2 MA α-helix II, previously implicated in BLV gRNA packaging, reduces NA binding affinity. HTLV-2 MA binds with high affinity and specificity to RNA derived from the putative packaging signal of HTLV-2 relative to nonspecific NA. Furthermore, an HIV-1 MA triple mutant designed to mimic the basic character of HTLV-2 MA α-helix II dramatically improves binding affinity and chaperone activity of HIV-1 MA
in vitro
and restores RNA packaging to a ΔNC HIV-1 variant in cell-based assays. Taken together, these results are consistent with a role for deltaretrovirus MA proteins in viral RNA packaging.
EBP1, a Novel Host Factor Involved in Primer Binding Site-Dependent Restriction of Moloney Murine Leukemia Virus in Embryonic Cells
Authors: Wang Gary Z. , Wolf Daniel , Goff Stephen P.
Published: November 2013

Mouse embryonic cells are unable to support the replication of Moloney murine leukemia virus (MLV). The integrated viral DNA is transcriptionally silenced, largely due to binding of host transcriptional repressors to the primer binding site (PBS) of the provirus. We have previously shown that a PBS DNA-binding repressor complex contains ZFP809 and TRIM28. Here, we identified ErbB3-binding protein 1 (EBP1) to be a novel component of the ZFP809-TRIM28 silencing complex and show that EBP1 depletion reduces PBS-mediated retroviral silencing.
Virus-Viroid Interactions: Citrus Tristeza Virus Enhances the Accumulation of Citrus Dwarfing Viroid in Mexican Lime via Virus-Encoded Silencing Suppressors
Authors: Serra Pedro , Bani Hashemian Seyed M. , Fagoaga Carmen , Romero Juan , Ruiz-Ruiz Susana , Gorris Maria T. , Bertolini Edson , Duran-Vila Núria
Published: November 2013

An assay to identify interactions between
Citrus Dwarfing Viroid
(CDVd) and
Citrus Tristeza Virus
(CTV) showed that viroid titer was enhanced by the coinfecting CTV in Mexican lime but not in etrog citron. Since CTV encodes three RNA silencing suppressors (RSSs), p23, p20 and p25, an assay using transgenic Mexican limes expressing each RSS revealed that p23 and, to a lesser extent, p25 recapitulated the effect observed with coinfections of CTV and CDVd.
Wheat streak mosaic virus Infects Systemically despite Extensive Coat Protein Deletions: Identification of Virion Assembly and Cell-to-Cell Movement Determinants
Authors: Tatineni Satyanarayana , Kovacs Frank , French Roy
Published: November 2013

Viral coat proteins function in virion assembly and virus biology in a tightly coordinated manner with a role for virtually every amino acid. In this study, we demonstrated that the coat protein (CP) of
Wheat streak mosaic virus
(WSMV; genus
Tritimovirus
, family
Potyviridae
) is unusually tolerant of extensive deletions, with continued virion assembly and/or systemic infection found after extensive deletions are made. A series of deletion and point mutations was created in the CP cistron of wild-type and/or green fluorescent protein-tagged WSMV, and the effects of these mutations on cell-to-cell and systemic transport and virion assembly of WSMV were examined. Mutants with overlapping deletions comprising N-terminal amino acids 6 to 27, 36 to 84, 85 to 100, 48 to 100, and 36 to 100 or the C-terminal 14 or 17 amino acids systemically infected wheat with different efficiencies. However, mutation of conserved amino acids in the core domain, which may be involved in a salt bridge, abolished virion assembly and cell-to-cell movement. N-terminal amino acids 6 to 27 and 85 to 100 are required for efficient virion assembly and cell-to-cell movement, while the C-terminal 65 amino acids are dispensable for virion assembly but are required for cell-to-cell movement, suggesting that the C terminus of CP functions as a dedicated cell-to-cell movement determinant. In contrast, amino acids 36 to 84 are expendable, with their deletion causing no obvious effects on systemic infection or virion assembly. In total, 152 amino acids (amino acids 6 to 27 and 36 to 100 and the 65 amino acids at the C-terminal end) of 349 amino acids of CP are dispensable for systemic infection and/or virion assembly, which is rare for multifunctional viral CPs.
Differential Impact of Magnitude, Polyfunctional Capacity, and Specificity of HIV-Specific CD8
+
T Cell Responses on HIV Set Point
Authors: Riou Catherine , Burgers Wendy A. , Mlisana Koleka , Koup Richard A. , Roederer Mario , Abdool Karim Salim S. , Williamson Carolyn , Gray Clive M.
Published: November 2013

Defining the characteristics of HIV-specific CD8
+
T cell responses that lead to viral control is crucial for vaccine development. We evaluated the differential impact of magnitude, polyfunctional capacity, and specificity of the CD8
+
response at approximately 6 months postinfection on the viral set point at 12 months in a cohort of HIV-infected individuals. High frequencies of Gag and Nef responses endowed with four functions were the best predictors of a low viral set point.
Novel Treatment with Neuroprotective and Antiviral Properties against a Neuroinvasive Human Respiratory Virus
Authors: Brison Elodie , Jacomy Hélène , Desforges Marc , Talbot Pierre J.
Published: November 2013

Human coronaviruses (HCoVs) are recognized respiratory pathogens with neuroinvasive and neurotropic properties in mice and humans. HCoV strain OC43 (HCoV-OC43) can infect and persist in human neural cells and activate neuroinflammatory and neurodegenerative mechanisms, suggesting that it could be involved in neurological disease of unknown etiology in humans. Moreover, we have shown that HCoV-OC43 is neurovirulent in susceptible mice, causing encephalitis, and that a viral mutant with a single point mutation in the viral surface spike (S) protein induces a paralytic disease that involves glutamate excitotoxicity in susceptible mice. Herein, we show that glutamate recycling via the glial transporter 1 protein transporter and glutamine synthetase are central to the dysregulation of glutamate homeostasis and development of motor dysfunctions and paralytic disease in HCoV-OC43-infected mice. Moreover, memantine, an
N
-methyl-
d
-aspartate receptor antagonist widely used in the treatment of neurological diseases in humans, improved clinical scores related to paralytic disease and motor disabilities by partially restoring the physiological neurofilament phosphorylation state in virus-infected mice. Interestingly, memantine attenuated mortality rates and body weight loss and reduced HCoV-OC43 replication in the central nervous system in a dose-dependent manner. This novel action of memantine on viral replication strongly suggests that it could be used as an antiviral agent to directly limit viral replication while improving neurological symptoms in various neurological diseases with a viral involvement.

IMPORTANCE
Mutations in the surface spike (S) protein of human respiratory coronavirus OC43 appear after persistent infection of human cells of the central nervous system, a possible viral adaptation to this environment. Furthermore, a single amino acid change in the viral S protein modulated virus-induced neuropathology in mice from an encephalitis to a neuropathology characterized by flaccid paralysis, which involves glutamate excitotoxicity. We now show that memantine, a drug that is used for alleviating symptoms associated with neuropathology, such as Alzheimer's disease, can partially restore the physiological state of infected mice by limiting both neurodegeneration and viral replication. This suggests that memantine could be used as an antiviral agent while improving neurological symptoms in various neurological diseases with a viral involvement.
Idiopathic sialectasis of the Stensen's duct treated with marsupialisation
Authors: Lohia Shivangi , Joshi Arjun S
Published: November 2013

Sialectasis is an uncommon medical condition of the salivary glands. Conservative treatments of sialectasis include repeated aspiration, compression, dilation of the papilla and stent placement. This is the first reported case that we know of, using marsupialisation for distal sialectasis. Our case highlights the diagnostic and therapeutic challenges posed by sialectasis and demonstrates the efficacy of marsupialisation for distally based sialectasis when conservative treatments fail.
Children's exposure to second-hand smoke at home in Bangladesh: a community survey
Authors: Zafar Ullah Abu Naser , Huque Rumana , Akter Salma , Nasreen Shammi , Akter Humaira , Thomson Heather , Cameron Ian , Newell James Nicholas , Siddiqi Kamran
Published: November 2013

Objectives

In Bangladesh, second-hand smoke (SHS) is recognised as a principal source of indoor air pollution and a major public health problem. However, we know little about the extent to which people are aware of the risks of second-hand smoking, or restrict smoking indoors or in the presence of children. We report findings of a community survey exploring these questions.

Design and setting

A total of 722 households were surveyed in urban and rural settings, using a multistage cluster random sampling approach and a semistructured questionnaire. In addition, we used qualitative methods to further explore the determinants of smoking-related behaviours inside homes.

Findings

55% of households in our sample had at least one regular smoker. Smoking indoors was common. In 30% of households, smoking occurred in the presence of children, exposing nearly 40% of children to SHS. Overall, we found a lack of awareness about the harms associated with second-hand smoking.

Conclusions

Our study highlights that a sizeable proportion of children and non-smokers are exposed to SHS at homes in Bangladesh, posing a significant and grave public health problem. In the absence of any impetus to legislate against smoking in private places, an educational approach is recommended to change smoking practices at home. Such a shift toward voluntary smoking restrictions at home would require behaviour change among smokers and support from non-smoking family members.
Intention-to-treat analyses and missing data approaches in pharmacotherapy trials for alcohol use disorders
Authors: Del Re A C , Maisel Natalya C , Blodgett Janet C , Finney John W
Published: November 2013

Objectives

Intention to treat (ITT) is an analytic strategy for reducing potential bias in treatment effects arising from missing data in randomised controlled trials (RCTs). Currently, no universally accepted definition of ITT exists, although many researchers consider it to require either no attrition or a strategy to handle missing data. Using the reports of a large pool of RCTs, we examined discrepancies between the types of analyses that alcohol pharmacotherapy researchers stated they used versus those they actually used. We also examined the linkage between analytic strategy (ie, ITT or not) and how missing data on outcomes were handled (if at all), and whether data analytic and missing data strategies have changed over time.

Design

Descriptive statistics were generated for reported and actual data analytic strategy and for missing data strategy. In addition, generalised linear models determined changes over time in the use of ITT analyses and missing data strategies.

Participants

165 RCTs of pharmacotherapy for alcohol use disorders.

Results

Of the 165 studies, 74 reported using an ITT strategy. However, less than 40% of the studies actually conducted ITT according to the rigorous definition above. Whereas no change in the use of ITT analyses over time was found, censored (last follow-up completed) and imputed missing data strategies have increased over time, while analyses of data only for the sample actually followed have decreased.

Conclusions

Discrepancies in reporting versus actually conducting ITT analyses were found in this body of RCTs. Lack of clarity regarding the missing data strategy used was common. Consensus on a definition of ITT is important for an adequate understanding of research findings. Clearer reporting standards for analyses and the handling of missing data in pharmacotherapy trials and other intervention studies are needed.
Development of an evaluation framework for African–European hospital patient safety partnerships
Authors: Rutter Paul , Syed Shamsuzzoha B , Storr Julie , Hightower Joyce D , Bagheri-Nejad Sepideh , Kelley Edward , Pittet Didier
Published: November 2013

Background

Patient safety is recognised as a significant healthcare problem worldwide, and healthcare-associated infections are an important aspect. African Partnerships for Patient Safety is a WHO programme that pairs hospitals in Africa with hospitals in Europe with the objective to work together to improve patient safety.

Objective

To describe the development of an evaluation framework for hospital-to-hospital partnerships participating in the programme.

Methods

The framework was structured around the programme's three core objectives: facilitate strong interhospital partnerships, improve in-hospital patient safety and spread best practices nationally. Africa-based clinicians, their European partners and experts in patient safety were closely involved in developing the evaluation framework in an iterative process.

Results

The process defined six domains of partnership strength, each with measurable subdomains. We developed a questionnaire to measure these subdomains. Participants selected six indicators of hospital patient safety improvement from a short-list of 22 based on their relevance, sensitivity to intervention and measurement feasibility. Participants proposed 20 measures of spread, which were refined into a two-part conceptual framework, and a data capture tool created.

Conclusion

Taking a highly participatory approach that closely involved its end users, we developed an evaluation framework and tools to measure partnership strength, patient safety improvements and the spread of best practice.
Normal and anomalous densities in Bose–Einstein condensates with optical lattices
Authors: Bendacha M. , Boudjemâa A.
Published: November 2013

We study the quantum phase transition from the superfluid to the Mott insulator state in two- and three-dimensional Bose–Einstein condensate with optical lattices using Bose–Hubbard Hamiltonian within the generalized Hatree–Fock–Bogoliubov approximation. The behavior of the depletion and the anomalous fraction has been investigated in the Mott insulator phase. We found that at T = 0, these quantities become significant in two and three dimensions. It is shown also that the dimensionality of the lattice enhances the anomalous density.
Influence of experimental diabetes and insulin treatment on the enantioselective pharmacokinetics of mexiletine and its metabolites
Authors: Pardo Campos Godoy Ana Leonor , Martinez Edson Z. , Marques Maria Paula , de Carvalho Leone Andréia , Barbosa Coelho Eduardo , Lucia Lanchote Vera
Published: November 2013

This study evaluates the influence of streptozotocin-induced diabetes on the kinetic disposition and metabolism of mexiletine (MEX) enantiomers in rats. Animals in the control (n = 6 for each blood collection time), diabetic (single intravenous dosage of 45 mg·(kg body mass)−1 of streptozotocin), and insulin-treated groups (diabetic rats treated daily with 2 IU insulin) received by gavage a single dose of 10 mg·(kg body mass)−1 racemic MEX. MEX enantiomers and the metabolites hydroxymethylmexiletine (HMM) and p-hydroxymexiletine PHM) were analyzed by LC-MS/MS. Statistical analysis was based on a serial sacrifice design, and parameter estimation was performed using a Bayesian modeling procedure. Area under the curve (AUC) for the (−)-(R) enantiomers of MEX, HMM, and PHM did not differ between the control and diabetic groups. However, AUC for (+)-(S)-MEX and (+)-(S)-HMM were lower in the diabetic than in the control group. Insulin treatment recovered glucose levels to normal and the (+)-(S)-MEX AUC and (+)-(S)-HMM AUC became similar to the AUCs observed in the nondiabetic animals.
AN ASYMPTOTIC STABILITY THEOREM FOR QUASILINEAR DELAY DIFFERENTIAL EQUATIONS WITH OSCILLATING COEFFICIENTS
Authors: DUNG NGUYEN TIEN
Published: November 2013

In this paper, we provide new necessary and sufficient conditions of the asymptotic stability for a class of quasilinear differential equations with several delays and oscillating coefficients. Our results are established by means of fixed point theory and improve those obtained in [J. R. Graef, C. Qian and B. Zhang, Asymptotic behavior of solutions of differential equations with variable delays, Proc. London Math. Soc.81 (2000) 72–92; B. Zhang, Fixed points and stability in differential equations with variable delays, Nonlinear Anal.63 (2005) e233–e242].
CONVERGENCE ANALYSIS OF COEFFICIENT-BASED REGULARIZATION UNDER MOMENT INCREMENTAL CONDITION
Authors: WANG CHENG , CAI JIA
Published: November 2013

In this paper, we investigate coefficient-based regularized least squares regression problem in a data dependent hypothesis space. The learning algorithm is implemented with samples drawn by unbounded sampling processes and the error analysis is performed by a stepping-stone technique. A new error decomposition technique is proposed for the error analysis. The regularization parameters in our setting provide much more flexibility and adaptivity. Sharp learning rates are addressed by means of l2-empirical covering numbers under a moment hypothesis condition.
On the Global Stability Properties and Boundedness Results of Solutions of Third-Order Nonlinear Differential Equations
Authors: Ateş Muzaffer
Published: November 2013

We studied the global stability and boundedness results of third-order nonlinear differential equations of the form . Particular cases of this equation have been studied by many authors over years. However, this particular form is a generalization of the earlier ones. A Lyapunov function was used for the proofs of the two main theorems: one with and the other with . The results in this paper generalize those of other authors who have studied particular cases of the differential equations. Finally, a concrete example is given to check our results.
Influence of Annealing on Properties of Spray Deposited ZnO Thin Films
Authors: Nadarajah Kalyani , Yern Chee Ching , Tan Chou Yong
Published: November 2013

Zinc Oxide (ZnO) thin films were deposited on glass substrates via the spray pyrolysis technique. The films were subsequently annealed in ambient air from 300°C to 500°C. The morphology and structural properties of the thin films were studied by field emission scanning electron microscope (FESEM), atomic force microscopy (AFM), and X‐ray diffractometry (XRD) techniques. Electrical resistivity of the thin films was measured using a data acquisition unit. The optical properties of the films were characterized by UV‐vis spectroscopy and photoluminescence (PL) technique. X‐ray diffraction data showed that the films were grown in the (002) direction with a hexagonal wurtzite structure. The average grain size ranged from 15 to 27 nm. Increasing annealing temperatures resulted in larger grain sizes and higher crystallinity, with the surface roughness of annealed films being more than twice if compared to unannealed film. The electrical resistivity of the films decreased with the increasing annealing temperature. The UV and visible band emissions were observed in the photoluminescence spectra, due to exciton and defect‐related emissions, respectively. The transmission values of the films were as high as 90% within the visible range (400–700 nm).
Risk Factors for Chronic Mastitis in Morocco and Egypt
Authors: Oltean Hanna N. , Soliman Amr S. , Omar Omar S. , Youssef Tamer F. , Karkouri Mehdi , Abdel-Aziz Azza , Hablas Ahmad , Blachley Taylor , Tahri Ali , Merajver Sofia D.
Published: November 2013

Chronic mastitis is a prolonged inflammatory breast disease, and little is known about its etiology. We identified 85 cases and 112 controls from 5 hospitals in Morocco and Egypt. Cases were women with chronic mastitis (including periductal, lobular, granulomatous, lymphocytic, and duct ectasia with mastitis). Controls had benign breast disease, including fibroadenoma, benign phyllodes, and adenosis. Both groups were identified from histopathologically diagnosed patients from 2008 to 2011, frequency-matched on age. Patient interviews elicited demographic, reproductive, breastfeeding, and clinical histories. Cases had higher parity than controls (OR = 1.75, 1.62–1.90) and more reported history of contraception use (OR = 2.73, 2.07–3.61). Cases were less likely to report wearing a bra (OR = 0.56, 0.47–0.67) and less often used both breasts for breastfeeding (OR = 4.40, 3.39–5.72). Chronic mastitis cases were significantly less likely to be employed outside home (OR = 0.71, 0.60–0.84) and more likely to report mice in their households (OR = 1.63, 1.36–1.97). This is the largest case-control study reported to date on risk factors for chronic mastitis. Our study highlights distinct reproductive risk factors for the disease. Future studies should further explore these factors and the possible immunological and susceptibility predisposing conditions.
Does a History of Migraine Affect the Rate of Thrombolysis in Young Stroke Patients?
Authors: Øygarden Halvor , Elnan Kvistad Christopher , Thomassen Lars , Waje-Andreassen Ulrike , Naess Halvor
Published: November 2013

Background. Migraine is prevalent in young patients and a frequent stroke mimic. To distinguish stroke mimics from true stroke can be difficult, and there is a possibility of misdiagnosing a stroke as a migrainous attack in patients with migraine. We aimed to investigate if a history of migraine affects the rate of thrombolytic therapy in young stroke patients.Methods. All patients below 50 years of age admitted in the period 2006–2013 to the Bergen Stroke Centre with acute ischaemic stroke were included. The rate of thrombolytic therapy in patients with migraine was compared to patients with no history of migraine. A multivariate analysis was performed to adjust confounding factors.Results. A total of 170 young stroke patients were enrolled, 49 with migraine and 121 with no migraine. In total, 10.2% of young patients with migraine received thrombolytic therapy, compared with 26.5% of young patients with nomigraine (P=0.02). Migraine was associated with a low rate of thrombolytic therapy when adjusting for possible confounding factors (OR 0.19 CI: 0.05–0.72,P=0.02).Conclusion. Migraine is associated with a low rate of thrombolytic therapy in young patients admitted with acute ischaemic stroke. Migraine patients admitted with acute ischaemic stroke are at risk of maltreatment.
The Development of SONAR as a Tool in Marine Biological Research in the Twentieth Century
Authors: Fornshell John A. , Tesei Alessandra
Published: November 2013

The development of acoustic methods for measuring depths and ranges in the ocean environment began in the second decade of the twentieth century. The two world wars and the “Cold War” produced three eras of rapid technological development in the field of acoustic oceanography. By the mid-1920s, researchers had identified echoes from fish, Gadus morhua, in the traces from their echo sounders. The first tank experiments establishing the basics for detection of fish were performed in 1928. Through the 1930s, the use of SONAR as a means of locating schools of fish was developed. The end of World War II was quickly followed by the advent of using SONAR to track and hunt whales in the Southern Ocean and the marketing of commercial fish finding SONARs for use by commercial fisherman. The “deep scattering layer” composed of invertebrates and fish was discovered in the late 1940s on the echo sounder records. SONARs employing high frequencies, broadband, split beam, and multiple frequencies were developed as methods for the detection, quantification and identification of fish and invertebrates. The study of fish behavior has seen some use of passive acoustic techniques. Advancements in computer technology have been important throughout the last four decades of the twentieth century.
On Some Sampling-Related Frames inU-Invariant Spaces
Authors: Fernández-Morales H. R. , García A. G. , Hernández-Medina M. A. , Muñoz-Bouzo M. J.
Published: November 2013

This paper is concerned with the characterization as frames of some sequences inU-invariant spaces of a separable Hilbert spaceℋwhereUdenotes an unitary operator defined onℋ; besides, the dual frames having the same form are also found. This general setting includes, in particular, shift-invariant or modulation-invariant subspaces inL2ℝ, where these frames are intimately related to the generalized sampling problem. We also deal with some related perturbation problems. In doing so, we need the unitary operatorUto belong to a continuous group of unitary operators.
Four-Pointn-Ary Interpolating Subdivision Schemes
Authors: Mustafa Ghulam , Bashir Robina
Published: November 2013

We present an efficient and simple algorithm to generate 4-pointn-ary interpolating schemes. Our algorithm is based on three simple steps: second divided differences, determination of position of vertices by using second divided differences, and computation of new vertices. It is observed that 4-pointn-ary interpolating schemes generated by completely different frameworks (i.e., Lagrange interpolant and wavelet theory) can also be generated by the proposed algorithm. Furthermore, we have discussed continuity, Hölder regularity, degree of polynomial generation, polynomial reproduction, and approximation order of the schemes.
Mature Cytotoxic CD56bright/CD16+Natural Killer Cells Can Infiltrate Lymph Nodes Adjacent to Metastatic Melanoma
Authors: Messaoudene Meriem , Fregni Giulia , Fourmentraux-Neves Emmanuelle , Chanal Johan , Maubec Eve , Mazouz-Dorval Sarra , Couturaud Benoit , Girod Angelique , Sastre-Garau Xavier , Albert Sebastien , Guédon Charles , Deschamps Lydia , Mitilian Delphine , Cremer Isabelle , Jacquelot Nicolas , Rusakiewicz Sylvie , Zitvogel Laurence , Avril Marie-Francoise , Caignard Anne
Published: November 2013

Melanomas are characterized by high metastatic potential, with regional lymph node representing the most frequent site of early dissemination in this disease. These regional lymph nodes also represent the primary site for differentiation of natural killer (NK) cells. Although blood-derived NK cells can efficiently lyse melanoma cells isolated from metastatic lymph node (M-LN), there has been no study of the properties of the most disease-relevant NK cells isolated from M-LN in patients with melanoma. Here, we report that M-LN contains 0.5% to 11% of CD56bright NK cells among CD45+ hematopoietic cells present and that this cell population surrounds tumor cell clusters in M-LN. This NK cell population was characterized by expression of CD62L, chemokine receptors, and high levels of natural cytotoxicity receptors (NCR), NK group 2 D (NKG2D), and DNAX accessory molecule 1 (DNAM-1). Expression of NCR-NKp30 and NKG2D correlated negatively with percentages of tumor cells in M-LN. Interestingly, M-LN contained a unique subset of mature CD56brightCD16+ NK cells displaying coregulated expression of NCR and NKG2D activating receptors. Ex vivo analyses suggested that M-LN–derived NK cells were inactive but could be activated by appropriate cytokine signals [interleukin (IL)-2 or IL-15], and could lyse metastatic melanoma cells in a highly efficient manner compared with blood-derived NK cells. Taken together, the results offer evidence that adjuvant immunotherapy that targets NK cells in M-LN for activation may improve treatment of patients with sentinel lymph node–positive melanoma. Cancer Res; 74(1); 81–92. ©2013 AACR.