bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective Priming and Expansion of Antigen-Specific Foxp3−CD4+ T Cells during Listeria monocytogenes Infection
Authors: Ertelt James M. , Rowe Jared H. , Johanns Tanner M. , Lai Joseph C. , McLachlan James B. , Way Sing Sing 
Published: February 2009

Abstract
The Foxp3-expressing subset of regulatory CD4+ T cells have defined Ag specificity and play essential roles in maintaining peripheral tolerance by suppressing the activation of self-reactive T cells. Similarly, during chronic infection, pathogen-specific Foxp3-expressing CD4+ T cells expand and actively suppress pathogen-specific effector T cells. Herein, we used MHC class II tetramers and Foxp3gfp knockin mice to track the kinetics and magnitude whereby pathogen-specific Foxp3+CD4+ and Foxp3−CD4+ cells are primed and expand after acute infection with recombinant Listeria monocytogenes (Lm) expressing the non-“self”-Ag 2W1S52–68. We demonstrate that Lm infection selectively primes proliferation, expansion, and subsequent contraction of Lm-specific Foxp3− effector CD4+ cells, while the numbers of Lm-specific Foxp3+CD4+ regulatory cells remain essentially unchanged. In sharp contrast, purified 2W1S52–68 peptide primes coordinated expansion of both Foxp3+ regulatory and Foxp3− effector T cells with the same Ag specificity. Taken together, these results indicate selective priming and expansion of Foxp3− CD4 T cells is a distinguishing feature for acute bacterial infection.
The Microenvironment of Germ Cell Tumors Harbors a Prominent Antigen-Driven Humoral Response
Authors: Willis Simon N. , Mallozzi Scott S. , Rodig Scott J. , Cronk Katherine M. , McArdel Shannon L. , Caron Tyler , Pinkus Geraldine S. , Lovato Laura , Shampain Kimberly L. , Anderson David E. , Anderson Richard C. E. , Bruce Jeffrey N. , O’Connor Kevin C. 
Published: February 2009

Abstract
Germ cell tumors are a heterogeneous group of neoplasms derived from residual primordial tissue. These tumors are commonly found in the brain, testes, or ovaries, where they are termed germinomas, seminomas, or dysgerminomas, respectively. Like several other tumor types, germ cell tumors often harbor an immune cell infiltrate that can include substantial numbers of B cells. Yet little is known about whether the humoral immune response affects germ cell tumor biology. To gain a deeper understanding of the role B cells play in this tumor family, we characterized the immune cell infiltrate of all three germ cell tumor subtypes and defined the molecular characteristics of the B cell Ag receptor expressed by tumor-associated B cells. Immunohistochemistry revealed a prominent B cell infiltrate in the microenvironment of all tumors examined and clear evidence of extranodal lymphoid follicles with germinal center-like architecture in a subset of specimens. Molecular characterization of the Ig variable region from 320 sequences expressed by germ cell tumor-infiltrating B cells revealed clear evidence of Ag experience, in that the cardinal features of an Ag-driven B cell response were present: significant somatic mutation, isotype switching, and codon insertion/deletion. This characterization also revealed the presence of both B cell clonal expansion and variation, suggesting that local B cell maturation most likely occurs within the tumor microenvironment. In contrast, sequences from control tissues and peripheral blood displayed none of these characteristics. Collectively, these data strongly suggest that an adaptive and specific humoral immune response is occurring within the tumor microenvironment.
Programming for CD8 T Cell Memory Development Requires IL-12 or Type I IFN
Authors: Xiao Zhengguo , Casey Kerry A. , Jameson Stephen C. , Curtsinger Julie M. , Mescher Matthew F. 
Published: February 2009

Abstract
Inflammation can have both positive and negative effects on development of CD8 T cell memory, but the relative contributions and cellular targets of the cytokines involved are unclear. Using CD8 T cells lacking receptors for IL-12, type I IFN, or both, we show that these cytokines act directly on CD8 T cells to support memory formation in response to vaccinia virus and Listeria monocytogenes infections. Development of memory to vaccinia is supported predominantly by IL-12, whereas both IL-12 and type I IFN contribute to memory formation in response to Listeria. In contrast to memory formation, the inability to respond to IL-12 or type I IFN had a relatively small impact on the level of primary expansion, with at most a 3-fold reduction in the case of responses to Listeria. We further show that programming for memory development by IL-12 is complete within 3 days of the initial naive CD8 T cell response to Ag. This programming does not result in formation of a population that expresses killer cell lectin-like receptor G1, and the majority of the resulting memory cells have a CD62Lhigh phenotype characteristic of central memory cells. Consistent with this, the cells undergo strong expansion upon rechallenge and provide protective immunity. These data demonstrate that IL-12 and type I IFN play an essential early role in determining whether Ag encounter by naive CD8 T cells results in formation of a protective memory population.
A Pivotal Role for CD40-Mediated IL-6 Production by Dendritic Cells during IL-17 Induction In Vivo
Authors: Perona-Wright Georgia , Jenkins Stephen J. , O'Connor Richard A. , Zienkiewicz Dimitrios , McSorley Henry J. , Maizels Rick M. , Anderton Stephen M. , MacDonald Andrew S. 
Published: February 2009

Abstract
The costimulatory requirements for Th17 development remain to be defined. In this study, we show that CD40-deficient animals immunized with the Gram-positive bacterium Propionibacterium acnes were specifically impaired in their ability to mount an IL-17 response, but not that of IFN-γ. The same cytokine imbalance resulted from in vivo priming with pathogen-pulsed, CD40-deficient dendritic cells (DC). Engagement of CD40 on P. acnes-conditioned DC stimulated the release of IL-12, IL-23, and IL-6, of which IL-6 alone proved essential for Th17 differentiation. Compared with wild-type DC, priming with those lacking expression of CD40 resulted in reduced disease severity during experimental autoimmune encephalomyelitis, coincident with reduced IL-17 production. Our data delineate sequential requirements for DC expression of CD40 and production of IL-6 during Th17 polarization in vitro and in vivo, and reveal distinct costimulatory requirements for Th1 vs Th17 generation.
Synthesis and Structure–Property Correlation in Shape‐Controlled ZnO Nanoparticles Prepared by Chemical Vapor Synthesis and their Application in Dye‐Sensitized Solar Cells
Authors: Bacsa Revathi R. , Dexpert‐Ghys Jeannette , Verelst Marc , Falqui Andrea , Machado Bruno , Bacsa Wolfgang S. , Chen Peter , Zakeeruddin Shaik M. , Graetzel Michael , Serp Philippe 
Published: February 2009

AbstractHere, the large scale synthesis of nanocrystalline ZnO spheres and tetrapods in the size range of 8–40 nm by chemical vapor synthesis using zinc metal as precursor is described. A detailed study of the effect of experimental parameters on the morphology and yield is presented. High‐resolution transmission electron microscopy images of the tetrapods show that they are formed by the self assembly of four nanorods in the vapor phase. The tetrapods have optical absorption coefficients that are one order of magnitude greater than the spheres and show intense UV luminescence whereas the spheres show only the green emission. The observed differences in the optical properties are related to the presence of surface defects present in the nanospheres. The tetrapods have increased efficiencies for application in dye sensitized solar cells when compared to spheres.
A C1 microkinetic model for methane conversion to syngas on Rh/Al2O3
Authors: Maestri Matteo , Vlachos Dionisios G. , Beretta Alessandra , Groppi Gianpiero , Tronconi Enrico 
Published: February 2009

AbstractA microkinetic model capable of describing multiple processes related to the conversion of natural gas to syngas and hydrogen on Rh is derived. The parameters of microkinetic models are subject to (intrinsic) uncertainty arising from estimation. It is shown that intrinsic uncertainty could markedly affect even qualitative model predictions (e.g., the rate‐determining step). In order to render kinetic models predictive, we propose a hierarchical, data‐driven methodology, where microkinetic model analysis is combined with a comprehensive, kinetically relevant set of nearly isothermal experimental data. The new, thermodynamically consistent model is capable of predicting several processes, including methane steam and dry reforming, catalytic partial oxidation, H2 and CO rich combustion, water‐gas shift and its reverse at different temperatures, space velocities, compositions and reactant dilutions, using the measured Rh dispersion as an input. Comparison with other microkinetic models is undertaken. Finally, an uncertainty analysis assesses the effect of intrinsic uncertainty and catalyst heterogeneity on the overall model predictions. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Feedback control of dissipative PDE systems using adaptive model reduction
Authors: Varshney Amit , Pitchaiah Sivakumar , Armaou Antonios 
Published: February 2009

AbstractThe problem of feedback control of spatially distributed processes described by highly dissipative partial differential equations (PDEs) is considered. Typically, this problem is addressed through model reduction, where finite dimensional approximations to the original infinite dimensional PDE system are derived and used for controller design. The key step in this approach is the computation of basis functions that are subsequently utilized to obtain finite dimensional ordinary differential equation (ODE) models using the method of weighted residuals. A common approach to this task is the Karhunen‐Loève expansion combined with the method of snapshots. To circumvent the issue of a priori availability of a sufficiently large ensemble of PDE solution data, the focus is on the recursive computation of eigenfunctions as additional data from the process becomes available. Initially, an ensemble of eigenfunctions is constructed based on a relatively small number of snapshots, and the covariance matrix is computed. The dominant eigenspace of this matrix is then utilized to compute the empirical eigenfunctions required for model reduction. This dominant eigenspace is recomputed with the addition of each snapshot with possible increase or decrease in its dimensionality; due to its small dimensionality the computational burden is relatively small. The proposed approach is applied to representative examples of dissipative PDEs, with both linear and nonlinear spatial differential operators, to demonstrate its effectiveness of the proposed methodology. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Approximate dynamic programming based optimal control applied to an integrated plant with a reactor and a distillation column with recycle
Authors: Tosukhowong Thidarat , Lee Jay H. 
Published: February 2009

AbstractAn approximate dynamic programming (ADP) method has shown good performance in solving optimal control problems in many small‐scale process control applications. The offline computational procedure of ADP constructs an approximation of the optimal “cost‐to‐go” function, which parameterizes the optimal control policy with respect to the state variable. With the approximate “cost‐to‐go” function computed, a multistage optimization problem that needs to be solved online at every sample time can be reduced to a single‐stage optimization, thereby significantly lessening the real‐time computational load. Moreover, stochastic uncertainties can be addressed relatively easily within this framework. Nonetheless, the existing ADP method requires excessive offline computation when applied to a high‐dimensional system. A case study of a reactor and a distillation column with recycle was used to illustrate this issue. Then, several ways were proposed to reduce the computational load so that the ADP method can be applied to high‐dimensional integrated plants. The results showed that the approach is much more superior to NMPC in both deterministic and stochastic cases. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Noninvasive collection of fresh hairs from free‐ranging howler monkeys for DNA extraction
Authors: Améndola‐Pimenta Monica , García‐Feria Luis , Serio‐Silva Juan Carlos , Rico‐Gray Victor 
Published: February 2009

AbstractThe use of noninvasive collected samples as source of DNA in studies of wild primate populations has increased in recent years. Fresh‐plucked hairs represent an important source of DNA, with relatively high quality and concentration. In this study, we describe a low‐cost noninvasive technique for collecting fresh‐plucked hairs used to obtain DNA samples from free‐ranging black howler monkey populations (Alouatta pigra). We designed and manufactured darts made of wooden dowels, with the anterior part smeared with glue, which were projected with blowpipes to trap howler monkey hairs. All of the materials to make the darts are inexpensive and are available locally. We collected 89 samples from 76 individuals residing in 15 troops, and the total number of hairs obtained was 754. We found no differences in the number of hairs collected among sex–age classes or among localities but the percentage of darts recovered with sample varied among localities. Preliminary results indicate that over 96% of samples yielded DNA suitable for polymerase chain reaction‐based microsatellite marker analysis. The technique proved successful for collecting fresh‐plucked hairs of free‐ranging black howler monkeys without any trauma to the animals and can be easily adapted to obtain samples from other wild primate and mammal species. Am. J. Primatol. 71:359–363, 2009. © 2009 Wiley‐Liss, Inc.
Selective neuronal nitric oxide synthase inhibitors and the prevention of cerebral palsy
Authors: Ji Haitao , Tan Sidhartha , Igarashi Jotaro , Li Huiying , Derrick Matthew , Martásek Pavel , Roman Linda J. , Vásquez‐Vivar Jeannette , Poulos Thomas L. , Silverman Richard B. 
Published: February 2009

AbstractObjectiveTo design a new class of selective neuronal nitric oxide synthase (NOS) inhibitors, and demonstrate that administration in a rabbit model for cerebral palsy (CP) prevents hypoxia‐ischemia–induced deaths and reduces the number of newborn kits exhibiting signs of CP.MethodsWe used a novel computer‐based drug design method called fragment hopping to identify new chemical entities, synthesized them, and conducted in vitro enzyme inhibition studies with the three isozymes of NOS and in vivo experiments to monitor cardiovascular effects on pregnant rabbit dams, NOS activity, and NOx (NO and NO2) concentration in fetal brain, and assess neurobehavioral effects on kits born to saline‐ and compound treated dams.ResultsThe computer‐based design led to the development of powerful and highly selective compounds for inhibition of neuronal NOS over the other isozymes. After maternal administration in a rabbit model of CP, these compounds were found to distribute to fetal brain, to be nontoxic, without cardiovascular effects, inhibit fetal brain NOS activity in vivo, reduce NO concentration in fetal brain, and dramatically ameliorate deaths and number of newborn kits exhibiting signs of CP.InterpretationThis approach may lead to new preventive strategies for CP. Ann Neurol 2008
Dynamics of 1,3‐Dipolar Cycloaddition Reactions of Diazonium Betaines to Acetylene and Ethylene: Bending Vibrations Facilitate Reaction
Authors: Xu Lai , Doubleday Charles E. , Houk K. N. 
Published: February 2009

AbstractGetting the bends: The dynamics of 1,3‐dipolar cycloaddition reactions have been explored by decomposing transition vector, quasi‐classical trajectories, and single trajectories. Dipole bending (see picture) makes the largest contribution to the TS distortion energy and constitutes the major part of transition‐state distortion energy in the favored concerted pathway.magnified image
Synthesis of Single‐Crystal Tetra(4‐pyridyl)porphyrin Rectangular Nanotubes in the Vapor Phase
Authors: Yoon Seok Min , Hwang In‐Chul , Kim Kwang S. , Choi Hee Cheul 
Published: February 2009

AbstractStacking up: One‐dimensional single‐crystalline rectangular nanotubes (RNTs) of 5,10,15,20‐tetra(4‐pyridyl)porphyrin (H2TPyP, see picture) are synthesized by a vaporization–condensation–recrystallization process. The single‐crystal X‐ray diffraction and selected‐area electron diffraction data reveal that the H2TPyP RNTs form by self‐stacking of H2TPyP units through hydrogen‐bonding, H–π, and π–π intermolecular interactions.magnified image
Membrane reformer PEM cogeneration systems for residential applications–Part A: full load and partial load simulation
Authors: Campanari Stefano , Macchi Ennio , Manzolini Giampaolo 
Published: February 2009

AbstractThis two‐part paper investigates the performances and economic potential benefits of a fuel cell cogeneration system based on a membrane reformer (MREF), using polymer electrolyte membrane (PEM) fuel cells, applied to residential cogeneration. Part A of this work focuses on the thermodynamic analysis and simulation of the system at full and partial load conditions, discussing its performance by means of a sensitivity analysis carried out under different operating conditions. Part B presents the technoeconomic analysis of the proposed system integrated into a real residential application, dealing with the energy savings and the economic balances, and proposes a preliminary design of the cogeneration unit.The system is based upon a PEM fuel cell, integrated with a membrane reformer (MREF) to form a small‐scale, highly efficient cogeneration unit, potentially suitable for application to distributed generation in the residential field. The high purity hydrogen fuel required by the PEM fuel cell is produced in the membrane reformer through hydrogen selective membranes based on a Pd‐Ag alloy. The analysis is carried out aiming to define the system energy balances in all the conditions occurring under real operation, including the influence of ambient temperature and of the expected fuel cell efficiency decay with time. The discussion reveals the relevant potential advantages of the MREF solution with respect to fuel cell units based on steam reforming (SR) or auto‐thermal reforming (ATR): when compared to these solutions, MREF exhibits a 10% points higher electrical efficiency and requires a much simpler plant layout. These results are the basis for the detailed system technoeconomic analysis carried out in Part B of the work. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Membrane reformer PEM cogeneration systems for residential applications—Part B: techno‐economic analysis and system layout
Authors: Campanari Stefano , Macchi Ennio , Manzolini Giampaolo 
Published: February 2009

AbstractThis two‐part paper investigates the performances and potential economic benefits of a membrane reformer (MREF)‐based fuel cell cogeneration system, using polymer electrolyte membrane (PEM) fuel cells, applied to residential cogeneration. Part A of the work focuses on the thermodynamic analysis and simulation of the system at full and partial load conditions, discussing its performance by means of a sensitivity analysis carried out under different operating conditions. Part B presents the techno‐economic analysis of the proposed system integrated into a real residential application, dealing with the energy savings and the economic balances, and proposes a preliminary design of the cogeneration unit.The higher electric efficiency of the innovative MREF system proposed in this work allows a yearly cost savings about 50% higher than cost savings allowed by fuel cell cogeneration units based on conventional fuel processors. Moreover, CO2 emissions savings, calculated for an average northern Italy single‐family load, is about 1.6 tCO2/year.The paper also presents a proposed system layout, discussing the preliminary design of all the required components and analyzing with particular care the issues related to the heat recovery loop and to the arrangement of the system key component: the membrane reforming reactor. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
The role of trust belief and its antecedents in a community‐driven knowledge environment
Authors: Kim Byoungsoo , Han Ingoo 
Published: February 2009

AbstractGiven the prevalence of community‐driven knowledge sites (CKSs), such as Naver Knowledge In and Yahoo! Answers, it has become important to understand the key drivers of user decision‐making processes. In the online environment, building and maintaining user trust belief is a significant challenge to the continuing growth and long‐term viability of information systems (IS), due to the open nature of the Internet. This study develops a theoretical framework to examine the role of trust belief in the CKS post‐adoption phenomenon. This study also presents an investigation of the key antecedents of trust belief to understand the mechanism of building user trust belief in a CKS. Based on the multidimensional trust formation model, this study posits user satisfaction, perceived reputation, disposition to trust, and information quality as the trust belief antecedents. Data collected from 258 users who have direct experiences with Naver Knowledge In was used to test the research model using structural equation modeling. This study preliminarily confirms the salience of user trust belief in the CKS post‐adoption phenomenon. The findings also indicate that the cognitive‐based, affective‐based, and personality‐oriented trust antecedents play a significant role in enhancing trust belief in a CKS. Theoretical and practical implications of the findings are described.
Collective indexing of emotions in images. A study in emotional information retrieval
Authors: Schmidt Stefanie , Stock Wolfgang G. 
Published: February 2009

AbstractSome documents provoke emotions in people viewing them. Will it be possible to describe emotions consistently and use this information in retrieval systems? We tested collective (statistically aggregated) emotion indexing using images as examples. Considering psychological results, basic emotions areanger,disgust,fear,happiness, andsadness. This study follows an approach developed by Lee and Neal (2007) for music emotion retrieval and applies scroll bars for tagging basic emotions and their intensities. A sample comprising 763 persons tagged emotions caused by images (retrieved fromwww.Flickr.com) applying scroll bars and (linguistic) tags. Using SPSS, we performed descriptive statistics and correlation analysis. For more than half of the images, the test persons have clear emotion favorites. There are prototypical images for given emotions. The document‐specific consistency of tagging using a scroll bar is, for some images, very high. Most of the (most commonly used) linguistic tags are on the basic level (in the sense of Rosch's basic level theory). The distributions of the linguistic tags in our examples follow an inverse power‐law. Hence, it seems possible to apply collective image emotion tagging to image information systems and to present a new search option for basic emotions. This article is one of the first steps in the research area of emotional information retrieval (EmIR).