bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Simulation of High Efficient MEMS Electrothermal Actuator
Authors: Song Rong Chang , Wang Gui Lei , Wang Jun Bo , Shen Yue Yue , Lv Chao
Published: July 2013

The paper mainly designs an efficient MEMS electrothermal actuator, with lower voltage input but large displacement output. The calculation method of the actuator considers the convection and radiation besides heat conduction mentioned in most literatures. With the multiphysics simulation by the software Comsol of electrothermal bimorph actuator, the transient effects of thermal convection and thermal radiation on the actuator displacement and the response characteristics of an actuator with a separate heating layer were studied.
Parametric Identification of Bouc-Wen Hysteresis Model for Piezoelectric Ceramic Actuator Based on Immune Particle Swarm Optimization Algorithm
Authors: Dong Ning , Li Hong Juan , Liu Xiang Dong , Cai Chun Xia
Published: July 2013

This paper is concerned with the parametric identification based on immune particle swarm optimization (IPSO) algorithm for Bouc-Wen model of piezoelectric ceramic actuators (PCA). IPSO algorithm is an algorithm that introduces the immunological memory and selection mechanism of concentration of antibody of immune system to PSO algorithm. It is used to identify unknown parameters of Bouc-Wen model, one of the most widely used parametric models of hysteresis in mechanics. The experimental results reveal that IPSO algorithm has better precision and convergence.
Heat Transfer-Fluid Coupled Simulation for Smart Meteorological Microsystems
Authors: Ding Xu Ran , Lou Wen Zhong , Hong Rong Sen
Published: July 2013

The Smart Meteorological Microsystems (SMM) is a kind of microsystems for meteorological information acquisition. SMM consists of two MEMS temperature and humidity sensors, a shell, a micro processor, a communication module, a GPS module, two pressure sensors and their peripheral circuits. The shell is built for protecting the sensors from being damaged when the sensors working in the harsh environment. However the shell also prevents the heat from transferring, leading to the appearance of temperature difference between the areas inside and outside the shell. The environment factors can lead to some temperature measurement errors. In order to solve these problems, this paper has designed an innovative structure of SMM shell. To improve the accuracy of temperature measurement, this paper has analyzed the heat transfer-fluid coupled simulations of temperature field in SMM under the working condition by using COMSOL Multiphysics. According to the results of the simulations, the structure of the SMM shell has been optimized. Either the structure or analysis has been reported in neither domestic nor international papers. As a result, what this paper has done is of a great value.
A Parallel Computing Dynamic Task Scheduling System for Nano-Materials Design and Simulation
Authors: Zeng Xiao Hui , Li Jing Zhong , Bo Deng Li , Zhang Chen , Luo Wen Lang
Published: July 2013

Available task scheduling systems can not support MPI parallel computing applications to be suspended for quickly inserting the emergency parallel computing tasks. By modifying TCP/IP protocol, this paper proposes a new method to solve the processes’ communication synchronization for suspending parallel application; moreover, by modifying the signal mechanism of the Linux operating system, this paper also proposes a method to solve the problems of consistently suspending and recovering parallel application. A Parallel computing dynamic task scheduling prototype system is implemented, and the experiment results show that the prototype system can suspend running parallel computing application, and also support dynamic insertion of emergency MPI parallel computing application.
Characteristic Research of SOI Rib Waveguide Resonators with SiO2 Deposited
Authors: Zang Jun Bin , Xue Chen Yang , Wei Li Ping , Wang Yong Hua , Cui Dan Feng , Zhang Wen Dong
Published: July 2013

With the extensive research and application of SOI nano-optical ring resonators, the problem of high integration becomes the bottleneck restricting its development. To research the effect of deposited SiO2 insulating layer on the resonance characteristic of SOI nano-waveguid ring cavity while integrating, a rib waveguide ring resonator with 500nm SiO2 insulating layer deposited was designed and fabricated in this paper. By testing the resonance transmission spectrum power of this structure, it is found that SiO2 insulating layer deposited has no effect on the grating vertical coupling efficiency while improves the quality factor to 14.000±1.000.
Combined Torsional Buckling of Carbon Nanotubes Subjected to Thermo-Electro-Mechanical Loadings with Consideration of Scale Effect
Authors: Yao Xiao Hu , Sun Yu Gang , Li Han Zhou
Published: July 2013

The present study has theoretically investigated the combined torsional buckling behavior of carbon nanotubes (CNTs) with consideration of scale effect in the multi-field coupling condition. The generalized governing equation of buckling for CNTs subjected to thermo-electro-mechanical loadings has been established based on an elastic shell model of continuum mechanics, in which scale effect is taken account of through the nonlocal elasticity theory. Except the applied torque and torsion-related axial load, the Van der Waals forces between adjacent nanotubes, as well as effects of temperature change and voltage load, is taken into consideration at the meantime. Numerical experiments are conducted to demonstrate the influences of different factors. The conclusions provided herein will be helpful and valuable for the dependent designs and related applications of CNT-based nano-structures serving in the complex thermal and electrical environment.
A Study on Size Effect of Indenter in Nanoindentation via Molecular Dynamics Simulation
Authors: Zhang Lin , Zhao Hong Wei , Ma Zhi Chao , Huang Hu , Geng Chun Yang , Ma Zhi Chao
Published: July 2013

A series of three-dimensional molecular dynamics (MD) simulations of nanoindentation are conducted to investigate the deformation behavior and phase transformation of monocrystalline silicon with different size hemispherical diamond indenters on (010) crystal plane. The technique of coordination number (CN) is employed to elucidate the detailed mechanism of phase transformation in the monocrystalline silicon. The simulation results show that the phase transformation varies according to the different radii indenters. In the phase transformation region beneath the indenter, the crystalline structures of Si-II, Si-XIII, and amorphous phase structures are observed. In addition, the results indicate that phase transformation with large indenters is not same with the small indenter. The six-coordinated silicon phase, Si-XIII, transformed from Si-I is identified. The phases of Si-II and Si-XIII, which have the same coordinate number, are successfully extracted from the transformation region during nanoindentation and amorphous phase will emerge upon unloading.
Preparation of Composite Spherical Alumina Nanoparticles and Study on their CMP Performance
Authors: Tian Li , Zhang Zong Tao , Zhang Jing , Sun Qiu Xia , Jia Xiao Lin
Published: July 2013

The properties of abrasives have great influences on the surface qualities of glass substrate, hard disk, etc[1], during the chemical mechanical planarization (CMP) process. α-Al2O3 particles, as one of the most widely used abrasives in CMP slurries, often cause great surface defects because of its high hardness and unfeasible control of agglomeration during the synthesizing process [2,3]. In this paper, spherical nanocomposite alumina powders with particle sizes of 10-50 nm were prepared, via a homogeneous precipitation method. The structures and surface morphologies of the alumina nanopowders were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM). The results showed that the nanopowders composed of both alpha and theta phase alumina, which had a small particle size and narrow size distributions. The CMP investigations performed on glass substrate showed that the nanocomposite alumina abrasives exhibited a better surface planarization performance than the pure single alpha phase Al2O3 nanopowders, with lower surface roughnesses and less scratches after CMP process. The results indicated that the current processing for the synthesis of nanocomposite Al2O3 powders were of great potentials for practical applications of Al2O3 based abrasives.
The Fabrication of Piezoelectric Vibration Energy Harvester Arrays Based on AlN Thin Film
Authors: Shang Zheng Guo , Li Dong Ling , Wen Zhi Yu , Zhao Xing Qang
Published: July 2013

This paper describes the fabrication and measurement results of piezoelectric energy harvester arrays based on aluminum nitride (AlN) as a piezoelectric material. The AlN piezoelectric thin film with crystal orientation (002) and crystal orientation (101) is deposited respectively by pulsed_DC sputtering on the different bottom electrode materials. Based on the AlN thin film, the piezoelectric vibration energy harvester arrays with 5 cantilever beams were developed. Then the load characteristics, frequency characteristics, harvester connected in series and parallel properties of harvester were investigated. In addition, we compare the properties of piezoelectric vibration energy harvester arrays with crystal orientation (101) and (002), where a record max power output of 0.23 μW and 0.38μW are obtained respectively when the value of acceleration was 1 g, while for the latter, the maximum power is 9.13 μW at the acceleration of 5.0g with the optimized resistance of 15 kΩ.
The Study of Porous Anodic Alumina as Template for the Pit Initiation on Electrode Aluminum Foils
Authors: Zheng Hong Mei , Wu Yu Cheng , Huang Xin Min , Shu X. , Zheng Yu Chun , Liu M.C.
Published: July 2013

To obtain a large surface area, the aluminum electrode foils (AEF) were etched by direct current (DC) in hot chloride solution to get lots of vertical [001] tunnels. Whereas, because of the defects as rolling trace, distorted oxidation film, non-uniform organization, pollution layer on the surface of the aluminum foil, and the easy corrosion in hot Cl- acid solution, the etch pits are disorder and merged. These merged pits cause laterally directed dissolution and excessive dissolution on the aluminum surface, which limited the surface enlarging and decreased the strength of the aluminum foils. In this paper, we adopted anodic oxidation to fabricate the porous anodic alumina (PAA) on the high-purity electronic aluminum foils with 99.99% purity, and polarized by a negative voltage in the KCl solution. The result showed that several nanopores combined together to form a large open holes without barrier layers. With this membrane on, the foils were etched in 70°C HCl+H2SO4 solution, and the etch pits were just generated in the combining-nanopores. The etch pits grew into tunnels respectively without merged, and the surface was also smooth.
Experimental Study on Single-Layer Laser Cladding Feeding by Micro/Nano Composite Powders
Authors: Wang Ming Di , Shi Shi Hong , Wang Hong Yu , Sun Cheng Feng , Liu X.B.
Published: July 2013

Aimed at the lack of the cladding materials such as micro or nanopowder, the micro/nanocomposite powders prepared for experiment are feed directly, the key process parameters on the quality of the surface quality and microstructure analysis of the single-layer of laser cladding are studied in detail. Compared to the ordinary laser micro-cladding layer feeding by the micro powder, the cladding layer is more refined, which has more good mechanical properties. The results showed that: using reasonable parameters, the microstructure and macro-morphology of cladding layer with micro-nanocomposite powders feed directly are better than of micron powders.
Heligmosomoides polygyrus bakeri Infection Activates Colonic Foxp3+ T Cells Enhancing Their Capacity To Prevent Colitis
Authors: Hang Long , Blum Arthur M. , Setiawan Tommy , Urban Joseph P. , Stoyanoff Korynn M. , Weinstock Joel V.
Published: July 2013

Helminthic infections protect mice from colitis in murine models of inflammatory bowel disease and also may protect people. Helminths like Heligmosomoides polygyrus bakeri can induce regulatory T cells (Treg). Experiments explored whether H. polygyrus bakeri infection could protect mice from colitis through activation of colonic Treg and examined mechanisms of action. We showed that H. polygyrus bakeri infection increased the number of T cells expressing Foxp3 in the colon. More importantly, Foxp3+/IL-10− and Foxp3+/IL-10+ T cell subsets isolated from the colon of H. polygyrus bakeri–infected mice prevented colitis when adoptively transferred into a murine model of inflammatory bowel disease, whereas Treg from uninfected mice could not provide protection. Only the transferred colonic Foxp3+/IL-10− T cells from H. polygyrus bakeri–infected mice readily accumulated in the colon and mesenteric lymph nodes of recipient mice, and they reconstituted the Foxp3+/IL-10− and Foxp3+/IL-10+ T cell subsets. However, transferred Foxp3+/IL-10+ T cells disappeared. IL-10 expression by Foxp3+ T cells was necessary for colitis prevention. Thus, H. polygyrus bakeri infection activates colonic Foxp3+ T cells, making them highly regulatory. The Foxp3+ T cells that fail to express IL-10 may be critical for populating the colon with the Foxp3+/IL-10+ T cells, which are required to control colitis.
Novel Role for Molecular Transporter Importin 9 in Posttranscriptional Regulation of IFN-ε Expression
Authors: Matsumiya Tomoh , Xing Fei , Ebina Masayuki , Hayakari Ryo , Imaizumi Tadaatsu , Yoshida Hidemi , Kikuchi Hideaki , Topham Matthew K. , Satoh Kei , Stafforini Diana M.
Published: July 2013

IFN-ε is a unique type I IFN whose constitutive expression in lung, brain, small intestine, and reproductive tissues is only partially understood. Our previous observation that posttranscriptional events participate in the regulation of IFN-ε mRNA expression led us to investigate whether the 5′ and/or 3′ untranslated regions (UTR) have regulatory functions. Surprisingly, we found that full-length IFN-ε 5′UTR markedly suppressed mRNA expression under basal conditions. Analysis of the secondary structure of this region predicted formation of two stable stem-loop structures, loops 1 and 2. Studies using luciferase constructs harboring various stretches of IFN-ε 5′UTR and mutant constructs in which the conformation of loop structures was disrupted showed that loop 1 is essential for regulation of mRNA expression. Incubation of HeLa cell extracts with agarose-bound RNAs harboring IFN-ε loop structures identified importin 9 (IPO9), a molecular transporter and chaperone, as a candidate that associates with these regions of the 5′UTR. IPO9 overexpression decreased, and IPO9 silencing increased basal IFN-ε expression. Our studies uncover a previously undescribed function for IPO9 as a specific, and negative, posttranscriptional regulator of IFN-ε expression, and they identify key roles for IFN-ε stem-loop structure 1 in this process. IPO9-mediated effects on 5′UTRs appear to extend to additional mRNAs, including hypoxia-inducible factor–1α, that can form specific loop structures.
Conditional Deletion of PTEN in Peripheral T Cells Augments TCR-Mediated Activation but Does Not Abrogate CD28 Dependency or Prevent Anergy Induction
Authors: Locke Frederick L. , Zha Yuan-yuan , Zheng Yan , Driessens Gregory , Gajewski Thomas F.
Published: July 2013

PTEN is thought to play a critical role in T cell activation by negatively regulating the PI3K signaling pathway important for cellular activation, growth, and proliferation. To directly eliminate PTEN in postthymic T cells for studies of functional effects, we used CAR transgenic × PTENflox/flox mice, which enabled gene deletion using a Cre adenovirus in vitro. These mice were also immunized to generate stable Th1 clones that could have PTEN deleted when desired. PTEN-deleted T cells exhibited enhanced IL-2 production, proliferation, and Akt phosphorylation upon TCR/CD28 engagement, whereas T cell survival was not potentiated. Gene expression profiling revealed a small subset of induced genes that were augmented upon PTEN deletion. However, PTEN-deficient T cells still required CD28 costimulation for IL-2 production and remained susceptible to anti-CD3–induced anergy. The absence of PTEN within the CD8 T cell compartment led to markedly increased cytolytic activity following an allogeneic MLR in vitro, without increasing autologous MLR activity. Our results indicate that deletion of PTEN can augment the activation of postthymic T cells but does not mediate CD28 independence or anergy resistance. Nonetheless, PTEN inhibition may be a viable target for immune potentiation owing to increased cytokine production by activated CD4+ cells and increased cytotoxicity by CD8+ T cells.
Human Invariant NKT Cell Subsets Differentially Promote Differentiation, Antibody Production, and T Cell Stimulation by B Cells In Vitro
Authors: Zeng Shijuan Grace , Ghnewa Yasmeen G. , O’Reilly Vincent P. , Lyons Victoria G. , Atzberger Ann , Hogan Andrew E. , Exley Mark A. , Doherty Derek G.
Published: July 2013

Invariant NK T (iNKT) cells can provide help for B cell activation and Ab production. Because B cells are also capable of cytokine production, Ag presentation, and T cell activation, we hypothesized that iNKT cells will also influence these activities. Furthermore, subsets of iNKT cells based on CD4 and CD8 expression that have distinct functional activities may differentially affect B cell functions. We investigated the effects of coculturing expanded human CD4+, CD8α+, and CD4−CD8α− double-negative (DN) iNKT cells with autologous peripheral B cells in vitro. All iNKT cell subsets induced IgM, IgA, and IgG release by B cells without needing the iNKT cell agonist ligand α-galactosylceramide. Additionally, CD4+ iNKT cells induced expansions of cells with phenotypes of regulatory B cells. When cocultured with α-galactosylceramide–pulsed B cells, CD4+ and DN iNKT cells secreted Th1 and Th2 cytokines but at 10–1000-fold lower levels than when cultured with dendritic cells. CD4+ iNKT cells reciprocally induced IL-4 and IL-10 production by B cells. DN iNKT cells expressed the cytotoxic degranulation marker CD107a upon exposure to B cells. Remarkably, whereas iNKT cell subsets could induce CD40 and CD86 expression by B cells, iNKT cell–matured B cells were unable to drive proliferation of autologous and alloreactive conventional T cells, as seen with B cells cultured in the absence of iNKT cells. Therefore, human CD4+, CD8α+, and DN iNKT cells can differentially promote and regulate the induction of Ab and T cell responses by B cells.
Control of In Vivo Collateral Damage Generated by T Cell Immunity
Authors: Thangavelu Govindarajan , Gill Ronald G. , Boon Louis , Ellestad Kristofor K. , Anderson Colin C.
Published: July 2013

An ongoing dilemma faced during an immune response is generating an effective, often proinflammatory response to eliminate pathogens and/or infected cells while also minimizing collateral damage to adjacent noninfected tissues. The factors limiting bystander cell injury during an Ag-specific immune response in vivo are largely unknown. In this study, using an in vivo model of islet transplants in TCR transgenic mice, we show that both CD4 and CD8 T cells do have the capacity to inflict adjacent tissue damage and that this injury is greatly enhanced in sensitized hosts. CD4 T cell–mediated killing of specific and bystander cells occurred via different mechanisms. Unlike specific target cell killing, CD4-mediated bystander injury required tissue Fas expression and was inhibited with anti–IFN-γ Ab treatment in vivo. Moreover, bystander cell injury was not entirely nonspecific but rather required, in naive recipients, that the MHC allele expressed by the bystanders was self. Importantly, the coinhibitor programmed death-1 plays an important role in restraining bystander cell injury mediated either by defined TCR transgenic T cells or by polyclonal T cell populations. Thus, the differential requirements for specific versus bystander cell injury suggest that there are opportunities for inhibiting immune pathology without compromising Ag-specific immunity in vivo.
HLA-F and MHC-I Open Conformers Cooperate in a MHC-I Antigen Cross-Presentation Pathway
Authors: Goodridge Jodie P. , Lee Ni , Burian Aura , Pyo Chul-Woo , Tykodi Scott S. , Warren Edus H. , Yee Cassian , Riddell Stanley R. , Geraghty Daniel E.
Published: July 2013

Peptides that are presented by MHC class I (MHC-I) are processed from two potential sources, as follows: newly synthesized endogenous proteins for direct presentation on the surface of most nucleated cells and exogenous proteins for cross-presentation typically by professional APCs. In this study, we present data that implicate the nonclassical HLA-F and open conformers of MHC-I expressed on activated cells in a pathway for the presentation of exogenous proteins by MHC-I. This pathway is distinguished from the conventional endogenous pathway by its independence from TAP and tapasin and its sensitivity to inhibitors of lysosomal enzymes, and further distinguished by its dependence on MHC-I allotype-specific epitope recognition for Ag uptake. Thus, our data from in vitro experiments collectively support a previously unrecognized model of Ag cross-presentation mediated by HLA-F and MHC-I open conformers on activated lymphocytes and monocytes, which may significantly contribute to the regulation of immune system functions and the immune defense.
Membrane-Type 6 Matrix Metalloproteinase Regulates the Activation-Induced Downmodulation of CD16 in Human Primary NK Cells
Authors: Peruzzi Giovanna , Femnou Laurette , Gil-Krzewska Aleksandra , Borrego Francisco , Weck Jennifer , Krzewski Konrad , Coligan John E.
Published: July 2013

CD16 (FcγRIIIa), the low-affinity receptor for IgG, expressed by the majority of human NK cells, is a potent activating receptor that facilitates Ab-dependent cell-mediated cytotoxicity (ADCC). ADCC dysfunction has been linked to cancer progression and poor prognosis for chronic infections, such as HIV; thus, understanding how CD16 expression is regulated by NK cells has clinical relevance. Importantly, CD16 cell-surface expression is downmodulated following NK cell activation and, in particular, exposure to stimulatory cytokines (IL-2 or IL-15), likely owing to the action of matrix metalloproteinases (MMPs). In this article, we identify membrane-type 6 (MT6) MMP (also known as MMP25) as a proteinase responsible for CD16 downmodulation. IL-2–induced upregulation of MT6/MMP25 cell-surface expression correlates with CD16 downmodulation. MT6/MMP25, sequestered in intracellular compartments in unstimulated NK cells, translocates to the cell surface after stimulation; moreover, it polarizes to the effector–target cell interface of the CD16-mediated immunological synapse. siRNA-mediated disruption of MT6/MMP25 expression enhances the ADCC capacity of NK cells, emphasizing the important functional role of MT6/MMP25 in the regulation of ADCC activity. Thus, this study uncovers a previously unknown role of MT6/MMP25 in human NK cells, and suggests that inhibition of MT6/MMP25 activity could improve ADCC efficacy of therapeutically administered NK cells that require IL-2 for culture and expansion.
Cellular and Molecular Requirements for the Selection of In Vitro–Generated CD8 T Cells Reveal a Role for Notch
Authors: Dervović Džana D. , Liang Haydn C.-Y. , Cannons Jennifer L. , Elford Alisha R. , Mohtashami Mahmood , Ohashi Pamela S. , Schwartzberg Pamela L. , Zúñiga-Pflücker Juan Carlos
Published: July 2013

Differentiation of CD8 single-positive (SP) T cells is predicated by the ability of lymphocyte progenitors to integrate multiple signaling cues provided by the thymic microenvironment. In the thymus and the OP9-DL1 system for T cell development, Notch signals are required for progenitors to commit to the T cell lineage and necessary for their progression to the CD4+CD8+ double-positive (DP) stage of T cell development. However, it remains unclear whether Notch is a prerequisite for the differentiation of DP cells to the CD8 SP stage of development. In this study, we demonstrate that Notch receptor–ligand interactions allow for efficient differentiation and selection of conventional CD8 T cells from bone marrow–derived hematopoietic stem cells. However, bone marrow–derived hematopoietic stem cells isolated from Itk−/−Rlk−/− mice gave rise to T cells with decreased IFN-γ production, but gained the ability to produce IL-17. We further reveal that positive and negative selection in vitro are constrained by peptide–MHC class I expressed on OP9 cells. Finally, using an MHC class I–restricted TCR-transgenic model, we show that the commitment of DP precursors to the CD8 T cell lineage is dependent on Notch signaling. Our findings further establish the requirement for Notch receptor–ligand interactions throughout T cell differentiation, including the final step of CD8 SP selection.
Induction of Activation-Induced Cytidine Deaminase–Targeting Adaptor 14-3-3γ Is Mediated by NF-κB–Dependent Recruitment of CFP1 to the 5′-CpG-3′–Rich 14-3-3γ Promoter and Is Sustained by E2A
Authors: Mai Thach , Pone Egest J. , Li Guideng , Lam Tonika S. , Moehlman J’aime , Xu Zhenming , Casali Paolo
Published: July 2013

Class switch DNA recombination (CSR) crucially diversifies Ab biologic effector functions. 14-3-3γ specifically binds to the 5′-AGCT-3′ repeats in the IgH locus switch (S) regions. By interacting directly with the C-terminal region of activation-induced cytidine deaminase (AID), 14-3-3γ targets this enzyme to S regions to mediate CSR. In this study, we showed that 14-3-3γ was expressed in germinal center B cells in vivo and induced in B cells by T-dependent and T-independent primary CSR-inducing stimuli in vitro in humans and mice. Induction of 14-3-3γ was rapid, peaking within 3 h of stimulation by LPSs, and sustained over the course of AID and CSR induction. It was dependent on recruitment of NF-κB to the 14-3-3γ gene promoter. The NF-κB recruitment enhanced the occupancy of the CpG island within the 14-3-3γ promoter by CFP1, a component of the COMPASS histone methyltransferase complex, and promoter-specific enrichment of histone 3 lysine 4 trimethylation (H3K4me3), which is indicative of open chromatin state and marks transcription-competent promoters. NF-κB also potentiated the binding of B cell lineage-specific factor E2A to an E-box motif located immediately downstream of the two closely-spaced transcription start sites for sustained 14-3-3γ expression and CSR induction. Thus, 14-3-3γ induction in CSR is enabled by the CFP1-mediated H3K4me3 enrichment in the promoter, dependent on NF-κB and sustained by E2A.
Tumor-Infiltrating Regulatory T Cells Inhibit Endogenous Cytotoxic T Cell Responses to Lung Adenocarcinoma
Authors: Ganesan Anusha-Preethi , Johansson Magnus , Ruffell Brian , Beltran Adam , Lau Jonathan , Jablons David M. , Coussens Lisa M.
Published: July 2013

Immune cells comprise a substantial proportion of the tumor mass in human nonsmall cell lung cancers (NSCLC), but the precise composition and significance of this infiltration are unclear. In this study, we examined immune complexity of human NSCLC as well as NSCLC developing in CC10-TAg transgenic mice, and revealed that CD4+ T lymphocytes represent the dominant population of CD45+ immune cells, and, relative to normal lung tissue, CD4+Foxp3+ regulatory T cells (Tregs) were significantly increased as a proportion of total CD4+ cells. To assess the functional significance of increased Tregs, we evaluated CD8+ T cell–deficient/CC10-TAg mice and revealed that CD8+ T cells significantly controlled tumor growth with antitumor activity that was partially repressed by Tregs. However, whereas treatment with anti-CD25–depleting mAb as monotherapy preferentially depleted Tregs and improved CD8+ T cell–mediated control of tumor progression during early tumor development, similar monotherapy was ineffective at later stages. Because mice bearing early NSCLC treated with anti-CD25 mAb exhibited increased tumor cell death associated with infiltration by CD8+ T cells expressing elevated levels of granzyme A, granzyme B, perforin, and IFN-γ, we therefore evaluated carboplatin combination therapy resulting in a significantly extended survival beyond that observed with chemotherapy alone, indicating that Treg depletion in combination with cytotoxic therapy may be beneficial as a treatment strategy for advanced NSCLC.
Using Conversation Topics for Predicting Therapy Outcomes in Schizophrenia
Authors: Howes Christine , Purver Matthew , McCabe Rose
Published: July 2013

Previous research shows that aspects of doctor-patient communication in therapy can predict patient symptoms, satisfaction and future adherence to treatment (a significant problem with conditions such as schizophrenia). However, automatic prediction has so far shown success only when based on low-level lexical features, and it is unclear how well these can generalize to new data, or whether their effectiveness is due to their capturing aspects of style, structure or content. Here, we examine the use of topic as a higher-level measure of content, more likely to generalize and to have more explanatory power. Investigations show that while topics predict some important factors such as patient satisfaction and ratings of therapy quality, they lack the full predictive power of lower-level features. For some factors, unsupervised methods produce models comparable to manual annotation.
SoFi, an Igor based interface for the efficient use of the generalized multilinear engine (ME-2) for source apportionment: application to aerosol mass spectrometer data
Authors: Canonaco F. , Crippa M. , Slowik J. G. , Baltensperger U. , Prévôt A. S. H.
Published: July 2013

Abstract. Source apportionment using the bilinear model through the multilinear engine (ME-2) was successfully applied to non-refractory organic aerosol (OA) mass spectra collected during winter 2011 and 2012 in Zurich, Switzerland using the aerosol chemical speciation monitor ACSM. Five factors were identified: low-volatility oxygenated OA (LV-OOA), semivolatile oxygenated OA (SV-OOA), hydrocarbon-like OA (HOA), cooking OA (COA) and biomass burning OA (BBOA). A graphical user interface SoFi (Source Finder) was developed at PSI in order to facilitate the testing of different rotational techniques available within the ME-2 engine by providing a priori factor profiles for some or all of the expected factors. ME-2 was used to test the positive matrix factorization (PMF) model, the fully constrained chemical mass balance (CMB) model, and partially constrained models utilizing a values and pulling equations. Within the set of model solutions determined to be environmentally reasonable, BBOA and SV-OOA factor mass spectra and time series showed the greatest variability. This variability represents uncertainty in the model solution and indicates that analysis of model rotations provides a useful approach for assessing the uncertainty of bilinear source apportionment models.
Diagenesis and benthic fluxes of nutrients and metals during experimentally induced anoxia in the Gulf of Trieste (northern Adriatic Sea)
Authors: Koron N. , Ogrinc N. , Metzger E. , Riedel B. , Faganeli J.
Published: July 2013

Abstract. Sequential nutrient regeneration and organic matter (OM) degradation in surface sediments of the Gulf of Trieste (northern Adriatic Sea) were examined using in situ benthic chambers under normoxic, anoxic and reoxic conditions. Intensive NH4+ and PO4− anoxic regeneration was subsequently slower in prolonged anoxia. NH4+ production was probably also a consequence of dissimilatory nitrate reduction to NH4+. The presence of anammox and laterally pumping of oxygenated water by benthic infauna explained the presence of NO3− in anoxia. Anoxic phases were characterized by enhanced dissolution of Sibiog, decreasing pore water Ca and Mg concentrations indicating carbonate precipitation and higher Fe and Mn concentrations as a result of reduction/respiration. Reoxygenation was characterized by enhanced bioturbation. Nitrification caused NH4+ decrease and P precipitated quickly as carbonate fluorapatite and FePO4. In addition adsorption of P onto Fe-hydroxides could also occur since Fe (and Mn) reoxidized quickly. Increased Ca levels suggested enhanced carbonate dissolution. Diffusive fluxes at the sediment–water interface (SWI), calculated from pore water modelling using diffusion-reaction model, revealed high anoxic NH4+ effluxes and Ca (and Mg) influxes. PO4− fluxes were very low and high NH4+/PO4− flux ratios in anoxic and reoxic phases suggested an excess of benthic inorganic N. Nutrient budgets at the SWI showed intensive anoxic recycling of inorganic N but low P and Si cycling in all redox phases.
CUDA-C implementation of the ADER-DG method for linear hyperbolic PDEs
Authors: Castro C. E. , Behrens J. , Pelties C.
Published: July 2013

Abstract. We implement the ADER-DG numerical method using the CUDA-C language to run the code in a Graphic Processing Unit (GPU). We focus on solving linear hyperbolic partial differential equations where the method can be expressed as a combination of precomputed matrix multiplications becoming a good candidate to be used on the GPU hardware. Moreover, the method is arbitrarily high-order involving intensive work on local data, a property that is also beneficial for the target hardware. We compare our GPU implementation against CPU versions of the same method observing similar convergence properties up to a threshold where the error remains fixed. This behaviour is in agreement with the CPU version but the threshold is larger that in the CPU case. We also observe a big difference when considering single and double precision where in the first case the threshold error is significantly larger. Finally, we did observe a speed up factor in computational time but this is relative to the specific test or benchmark problem.
Landslides and slope stability evaluation in the historical town of Kruja, Albania
Authors: Muceku Y. , Korini O.
Published: July 2013

Abstract. This paper describes the landslides and slope stability evaluation in the urban area of Kruja town, Albania. Kruja is a~historical and heritage center, due to the existence of many important cultural monuments including Skanderbeg castle and Bazaar square etc. The urban area of Kruja town has been affected from the Landslides effects, in the past and also present. From this phenomenon many engineering objects such as buildings, roads etc. are damaged and demolished. From the engineering geological mapping at scale 1 : 5000 it is observed that many active landslides have dramatically increased in activity after 1980s. The landslide types found in the studied area are earth slides, debris flow, as well as rock fall and rock rolling. Also, from field works and laboratory analysis, the slope stability of whole urban areas has been determined; for this purpose the studied zone is divided into the stable and unstable areas, which helps to better understand the mass movement's activity as one of the most harmful hazards of the geodynamics' phenomena.
The value of integrating information from multiple hazards for flood risk management
Authors: Castillo-Rodríguez J. T. , Escuder-Bueno I. , Altarejos-García L. , Serrano-Lombillo A.
Published: July 2013

Abstract. This article presents a methodology for estimating flood risk in urban areas integrating pluvial flooding, river flooding and failure of both small and large dams. The first part includes a review of basic concepts and existing methods on flood risk analysis, evaluation and management. Traditionally, flood risk analyses have focused on specific site studies and qualitative or semi-quantitative approaches. However, in this context, a general methodology to perform a quantitative flood risk analysis including different flood hazards was still required. The second part describes the proposed methodology, which presents an integrated approach – combining pluvial, river flooding and dam failure, as applied to a case study: a urban area located downstream a dam under construction. Such methodology represents an upgrade of the methodological piece developed within the SUFRI project. This article shows how outcomes from flood risk analysis provide better and more complete information to inform authorities, local entities and the stakeholders involved on decision-making with regard to flood risk management.
Mapping air temperature using time series analysis of LST: the SINTESI approach
Authors: Alfieri S. M. , De Lorenzi F. , Menenti M.
Published: July 2013

Abstract. This paper presents a new procedure to map time series of air temperature (Ta) at fine spatial resolution using time series analysis of satellite-derived land surface temperature (LST) observations. The method assumes that air temperature is known at a single (reference) location such as in gridded climate data with grid size of the order of 35 km × 35 km. The LST spatial and temporal pattern within a grid cell has been modelled by the pixel-wise ratios r (x,y,t) of the LST at any location to the LST at a reference location. A preliminary analysis of these patterns over a decade has demonstrated that their intra-annual variability is not negligible, with significant seasonality, even if it is stable throughout the years. The intra-annual variability has been modeled using Fourier series. We have evaluated the intra-annual variability by theoretically calculating the yearly evolution of LST (t) for a range of cases as a function of terrain, land cover and hydrological conditions. These calculations are used to interpret the observed LST (x,y,t) and r (x,y,t). The inter-annual variability has been evaluated by modeling each year of observations using Fourier series and evaluating the interannual variability of Fourier coefficients. Because of the negligible interannual variability of r (x,y,t), LST (x,y,t) can be reconstructed in periods of time different from the ones when LST observations are available. Time series of Ta are generated using the ratio r (x,y,t) and a linear regression between LST and Ta. Such linear regression is applied in two ways: (a) to estimate LST at any time from observations or forecasts of Ta at the reference location; (b) to estimate Ta from LST at any location. The results presented in this paper are based on the analysis of daily MODIS LST observations over the period 2001–2010. The Ta at the reference location was gridded data at a node of a 35 km × 35 km grid. Only one node was close to our study area and was used for the work presented here. The regression of Ta on LST was determined using concurrent observations of Ta at the four available weather stations in the Valle Telesina (Italy), our study area. The accuracy of our estimates is consistent with literature and with the combined accuracy of LST and Ta. We obtained comparable error statistics when applying our method to LST data during periods different but adjacent to the periods used to model of r (x,y,t). The method has also been evaluated against Ta observations for earlier periods of time (1984–1988), although available data are rather sparse in space and time. Slightly larger deviation were obtained. In all cases five days of averages from estimated and observed Ta were compared, giving a better accuracy.
A balanced water layer concept for subglacial hydrology in large-scale ice sheet models
Authors: Goeller S. , Thoma M. , Grosfeld K. , Miller H.
Published: July 2013

Abstract. There is currently no doubt about the existence of a widespread hydrological network under the Antarctic Ice Sheet, which lubricates the ice base and thus leads to increased ice velocities. Consequently, ice models should incorporate basal hydrology to obtain meaningful results for future ice dynamics and their contribution to global sea level rise. Here, we introduce the balanced water layer concept, covering two prominent subglacial hydrological features for ice sheet modeling on a continental scale: the evolution of subglacial lakes and balance water fluxes. We couple it to the thermomechanical ice-flow model RIMBAY and apply it to a synthetic model domain. In our experiments we demonstrate the dynamic generation of subglacial lakes and their impact on the velocity field of the overlaying ice sheet, resulting in a negative ice mass balance. Furthermore, we introduce an elementary parametrization of the water flux–basal sliding coupling and reveal the predominance of the ice loss through the resulting ice streams against the stabilizing influence of less hydrologically active areas. We point out that established balance flux schemes quantify these effects only partially as their ability to store subglacial water is lacking.
Factors Influencing the Utilisation of Maternal Health Services: The Perspective of Rural Women in Ghana
Authors: Daniels Anita Anima , Ahenkan Albert , Poku Kwabena Adu
Published: July 2013

Maternal mortality is a global issue and WHO recommends the use of maternal health services to help improve the health of women and babies during pregnancy and childbirth. Considering global and national interest in improving maternal health and the fact that Ghana is still battling with reducing maternal mortality, understanding the factors affecting the use of maternal services in rural areas is crucial as the women are seen as more vulnerable due to inequity issues. This study sets to examine the factors that influence the utilisation of antenatal and delivery services among rural women in Ghana, focusing on individual and area factors. A descriptive cross sectional study was carried out in three rural communities using Akuapim North District of Ghana as a case study.. The study adopted the quantitative approach. Structured interviews were used in data collection with the help of interview schedules. Two hundred and ninety-six (296) respondents were sampled using both probability and non probability techniques. Findings reveal that the use of the MHS is inadequate in relation to the WHO standards. Individual characteristics such as age, marital status and family size and the cost and time taken to a health facility were significantly associated with all the maternal health outcomes. Poor access to vehicles hindered women from delivery in a health institution and getting assistance from trained medical personnels. However, no significant association was established between education of respondents and the maternal health outcomes. It is recommended that the Ministry of Health engages in inter-sectoral collaboration to help ensure health equity.Effective integration of TBAs in providing care is needed to help improve utilisation of maternal services in rural areas
Principle-Based Governance: Infuence Outcomes through Values and Beliefs
Authors: Horswill Russell Alan
Published: July 2013

This article examines how public and not-for-profit governance boards can influence outcomes by asserting their values and beliefs on all levels of an organization. The purpose of this article is to present and apply a governance model call Principle-based Governance developed for public and not-for-profit organizations to a theoretical model calling for the creation of a hybrid/vector model of governance. The governance model presented focuses on providing assurance to constituents, fostering an organization that maintains sustainable balance, and engaged constituents in shared governance processes. Through the articulation of board governance (direct control), guiding the system (shared influence) and administrative empowerment (delegated authority) functions, the governance model provides clear demarcation between the role of the CEO and the board. It draws upon published research pertaining to effective governance and applied experience in implementing aspects of the Principle-Based Governance Model (Assurance). The article concludes that the governance model does address fully the primary intent of the hybrid/vector governance model.
Multijurisdictional Industrial Parks and Revenue Sharing: An Application of Growth Pole Theory
Authors: Jolley G. Jason , Paynter Sharon R.
Published: July 2013

Rural communities often lack the fiscal capacity to make the necessary investments to differentiate their industrial and technology parks in a crowded marketplace. This case study examines Triangle North, a multi-jurisdictional industrial/technology park in North Carolina. The study discusses the application of growth pole theory as the intellectual underpinnings of the joint park, its innovative financing and revenue sharing arrangement, and lessons learned from its implementation that can be applied to other locales.
Performance Contract and Performance Evaluation of State-Owned Enterprises: Insights from the Goal Setting Theory
Authors: Simpson Samuel Nana Yaw
Published: July 2013

Performance contract (PC) is one of the initiatives under the impulse of reforming State-Owned Enterprises (SOEs) to among other things, ensure improved SOE performance. Studies however show mixed results in relation to improved SOE performance, and the general perception is that targets in PCs are not challenging enough. Drawing on the goal setting theory, this article provides further theoretical explanations for the application and impact of PCs using evidence from Ghana, the first Anglophone nation in Africa to adopt and implement the PC reform programmes. Relying primarily on data from PCs, SOE evaluation reports, and interviews, findings suggest that the quality of targets in PCs has been improving over the years. Moreover, the goal setting theory element, commitment, is crucial to achieving desirable outcome from PC as a performance evaluation tool.
Local Economic Development Initiatives in Ghana: The Challenges and the Way Forward
Authors: Mensah James Kwame , Bawole Justice Nyigmah , Ahenkan Albert
Published: July 2013

This case study presents and analyses Local Economic Development (LED) initiatives and challenges from two districts in Ghana. The study is a qualitative case study that uses individual interviews through purposive selection from officials who are directly involved in the formulation and implementation of district development initiatives. The study found that the district does not have a LED policy in place but have initiated and implemented a number of programmes that are pro-LED. These programmes are in the area of agriculture, human resource development, financing and infrastructure development. However, the implementation of these initiatives has encountered many challenges such as inadequate human resource, finance, absence of LED policy and improper collaboration among local level actors. The paper provides the way forward for the initiation and implementation of LED at the local level.