bluuebunny/crossref_metadata_2025 huggingface dataset:
Reconsidering the Relationship between Inflation and Relative Price Variability
Authors: CHOI CHI‐YOUNG
Published: July 2010

It has long been popularly believed that the relationship between inflation and relative price variability (RPV) is positive and stable. Using disaggregated CPI data for the United States and Japan, however, this study finds that the relationship is neither linear nor stable over time. The overall relationship is approximately U‐shaped around a nonzero threshold inflation rate. RPV therefore changes not with the inflation rate per se, but with the deviation of inflation from the threshold inflation rate. More importantly, the relationship is by no means stable over time but instead varies significantly in a way that coincides with regime changes of inflation or monetary policy. The relationship was positive during the period of high inflation of the 1970s and the early 1980s, as has been documented by a number of previous studies, whereas it takes a U‐shape profile during the Great Moderation. The results are robust to the use of core inflation, which excludes the traditionally volatile prices of food and energy. This paper then presents a modified version of the Calvo‐type sticky price model to describe the observed empirical regularities. Simulation experiments show that the modified Calvo model fits the data well, and that the underlying relationship hinges upon the degree of price rigidity, which is systematically related to inflation regime. For countries and periods with low inflation rates, the relationship takes a U‐shape as price adjustment is more sticky. In a high‐inflation environment, when price setting becomes more flexible, the U‐shaped profile vanishes.
The Taylor Rule and “Opportunistic” Monetary Policy
Authors: BUNZEL HELLE , ENDERS WALTER
Published: July 2010

We investigate the possibility that the Taylor rule should be formulated as a threshold process such that the Federal Reserve acts more aggressively in some circumstances than in others. It seems reasonable that the Federal Reserve would act more aggressively when inflation is high than when it is low. Similarly, it might be expected that the Federal Reserve responds more to a negative than a positive output gap. Although these specifications receive some empirical support, we find that a modified threshold model that is consistent with “opportunistic” monetary policy makes significant progress toward explaining Federal Reserve behavior.
Measuring a Dynamic Price Index Using Consumption Data
Authors: AOKI SHUHEI , KITAHARA MINORU
Published: July 2010

We propose a new method of constructing a dynamic price index (DPI). Under standard assumptions, our DPI is as stable as the Consumer Price Index (CPI). In certain periods, the DPI differs sharply from the CPI.
Institutions and Bank Behavior: Legal Environment, Legal Perception, and the Composition of Bank Lending
Authors: HASELMANN RAINER , WACHTEL PAUL
Published: July 2010

This paper explores how the legal environment affects bank behavior in 20 transition economies. Based on a newly constructed data set we find that banks’ loan portfolio composition depends on the legal environment. If banks operate in a well‐functioning legal environment they lend relatively more to SMEs and provide more mortgages. On the other hand, banks lend more to large enterprises and to the government if the legal system is unsound. As a transmission channel we identify the banks’ willingness to accept collateral which depends on the bankers’ perceptions of the prevailing laws regarding collateral.
Disagreement and Learning: Dynamic Patterns of Trade
Authors: BANERJEE SNEHAL , KREMER ILAN
Published: July 2010

The empirical evidence on investor disagreement and trading volume is difficult to reconcile in standard rational expectations models. We develop a dynamic model in which investors disagree about the interpretation of public information. We obtain a closed‐form linear equilibrium that allows us to study which restrictions on the disagreement process yield empirically observed volume and return dynamics. We show that when investors have infrequent but major disagreements, there is positive autocorrelation in volume and positive correlation between volume and volatility. We also derive novel empirical predictions that relate the degree and frequency of disagreement to volume and volatility dynamics.
Intraday Patterns in the Cross‐section of Stock Returns
Authors: HESTON STEVEN L. , KORAJCZYK ROBERT A. , SADKA RONNIE
Published: July 2010

Motivated by the literature on investment flows and optimal trading, we examine intraday predictability in the cross‐section of stock returns. We find a striking pattern of return continuation at half‐hour intervals that are exact multiples of a trading day, and this effect lasts for at least 40 trading days. Volume, order imbalance, volatility, and bid‐ask spreads exhibit similar patterns, but do not explain the return patterns. We also show that short‐term return reversal is driven by temporary liquidity imbalances lasting less than an hour and bid‐ask bounce. Timing trades can reduce execution costs by the equivalent of the effective spread.
Why Do Foreign Firms Leave U.S. Equity Markets?
Authors: DOIDGE CRAIG , KAROLYI G. ANDREW , STULZ RENÉ M.
Published: July 2010

Foreign firms terminate their Securities and Exchange Commission registration in the aftermath of the Sarbanes–Oxley Act (SOX) because they no longer require outside funds to finance growth opportunities. Deregistering firms’ insiders benefit from greater discretion to consume private benefits without having to raise higher cost funds. Foreign firms with more agency problems have worse stock‐price reactions to the adoption of Rule 12h‐6 in 2007, which made deregistration easier, than those firms more adversely affected by the compliance costs of SOX. Stock‐price reactions to deregistration announcements are negative, but less so under Rule 12h‐6, and more so for firms that raise fewer funds externally.
QTc Prolongation and Family History of Sudden Death in a Patient with Desmin Cardiomyopathy
Authors: SUNG RAPHAEL K. , URSELL PHILIP C. , RAME J. EDUARDO , BAILEY HELEN , CALESHU COLLEEN , NUSSBAUM ROBERT L. , SCHEINMAN MELVIN M.
Published: July 2010

This case report describes a pregnant female patient who presented with new‐onset congestive heart failure symptoms and prolonged QTc, with strong family history of sudden death. Endomyocardial biopsy and genetic testing revealed myocardial desmin accumulation and a previously described mutation in the DES (desmin) gene, as well as variants in two LQT genes, SCN5A and KCNH2. The case highlights the phenotypic variability for a particular desmin genotype, and the possible interaction of desminopathy with LQT variants not independently associated with large differences in current properties or QT prolongation from wild type. (PACE 2011; 34:e105–e108)
Ventricular Tachycardia Complicating Head‐up Tilt Test: The role of Coronary Artery Spasm
Authors: YIU KAI‐HANG , TSE HUNG‐FAT , LAU CHU‐PAK
Published: July 2010

Head‐up tilt test (HUT) is frequently used for diagnosis of neurocardiogenic syncope. It mimics orthostatic stress resulting in venous pooling, central hypovolemia with compensated left ventricular hypercontraction, and sympathetic stimulation. Although generally considered to be a safe procedure, we hereby present a rare complication of HUT in a 50‐year‐old woman with isoproterenol infusion inducing coronary spasm that resulted in ventricular tachycardia. (PACE 2011; 34:e109–e111)
Evidence for an Intramural Origin of Idiopathic Premature Ventricular Contractions Successfully Ablated within the Great Cardiac Vein
Authors: YAMADA TAKUMI , McELDERRY H. THOMAS , DOPPALAPUDI HARISH , KAY G. NEAL
Published: July 2010

A 37‐year‐old woman with idiopathic premature ventricular contractions (PVCs), exhibiting a right bundle branch block and inferior axis QRS morphology, underwent electrophysiological testing. The earliest ventricular activation with an isolated prepotential was observed within the great cardiac vein during the PVCs. Pacing from this site with an output of 10 mA produced an excellent pace map, whereas that with an output of 2 mA produced a wider QRS with notches in the early phase. A radiofrequency application delivered at this site eliminated the PVCs. These findings suggested that the PVC origin might have been intramural rather than epicardial. (PACE 2011; 34:e112–e114)
Enhanced Sintering Rate of Zirconia (3Y‐TZP) Through the Effect of a Weak dc Electric Field on Grain Growth
Authors: Yang Di , Raj Rishi , Conrad Hans
Published: July 2010

We show, for the first time, that a dc electric field of 20 V/cm shifts the densification curve to a lower temperature in constant heating rate experiments with yttria‐stabilized tetragonal zirconia powder (3Y‐TZP). The enhanced sintering rate is ascribed, at least in part, to the reduced rate of grain growth under the applied field, consistent with earlier experiments on the influence of such fields on grain size in superplastic deformation and isothermal grain growth in zirconia polycrystals.
Piezoelectric and Dielectric Properties of (Ba1−xCax)(Ti0.95Zr0.05)O3 Lead‐Free Ceramics
Authors: Li Wei , Xu Zhijun , Chu Ruiqing , Fu Peng , Zang Guozhong
Published: July 2010

Lead‐free (Ba1−xCax)(Ti0.95Zr0.05)O3 (x=0.02–0.20) ceramics were prepared successfully using a solid‐state reaction technique. The polymorphic phase transitions from orthorhombic to tetragonal phase around room temperature were identified in the composition range of 0.06<x<0.10. A high piezoelectric coefficient of d33=365 pC/N and high planar electromechanical coupling factor of kp=48.5% were obtained for the sample of x=0.08. With the doping of Ca content, the orthorhombic–tetragonal phase transition point shifted toward room temperature while the relative high Curie temperature (Tc) was still maintained about 110°C.
Forming Silver Conductive Thick Films by Microwave Heating
Authors: Hwang Seongjin , Veronesi Paolo , Leonelli Cristina , Kim Hyungsun
Published: July 2010

This study investigated a microwave‐assisted processing route for the synthesis of conductive thick films on dielectric substrates starting from silver (Ag) and a glass frit powder mixture paste. A single mode microwave (2.45 GHz) applicator was used to reduce the processing time and improve the energy efficiency compared with conventional heating. The microstructures of the Ag‐based conductive thick films that were fired using conventional and microwave heating were observed. After 300 s of microwave treatment, the shrinkage of the microwave‐fired Ag conductive thick films was similar to the conventionally processed films at 580°C for 30 min. The results suggested that the drastic reduction of the substrate temperature and the rapid processing time were significant advantages because both helped to minimize the Ag diffusion into the glass, thus reducing the unwanted yellowing phenomena.
Microstructure and Microwave Dielectric Properties of xCa(Al0.5Nb0.5)O3+(1−x)SrTiO3 Solid Solutions
Authors: Hu Mingzhe , Fu Yang , Luo Chunya , Gu Haoshuang , Lei Wen , Shen Qiang
Published: July 2010

The crystal structure evolution and microwave (MW) dielectric properties of xCa(Al0.5Nb0.5)O3+(1−x)SrTiO3 (xCAN+(1−x)ST, 0≤x≤1.0, ) dielectric ceramics were investigated. X‐ray diffraction patterns illustrated that a single perovskite solid solution could be formed between the two end members; however, minor amount of pyrochlore phase was also detected in the composition range of 0.5≤x≤0.9. With the increase of x value, the crystal structure gradually evolved from a simple Pm3m cubic to a monoclinic P21/n space group with the octahedral tilting and the B‐site ordering structure transition subsequently developed. The MW dielectric properties of xCAN+(1−x)ST solid solutions were elaborately investigated and correlated to their crystal structures. The microscopic structure‐related thermal parameters in the xCAN+(1−x)ST solid solution were analyzed in terms of the Claussius–Mossotti equation to reveal the original contributors in temperature coefficients. Temperature coefficient‐compensated ceramic could be obtained in the xCAN+(1−x)ST system in the range of 0.5<x<0.6. When sintered at 1500°C for 4 h, a dielectric constant ɛr of 37.32, a Qf product of 25 430 GHz, and a τf value of −22.4 ppm/°C MW dielectric ceramic could be obtained in the 0.6Ca(Al0.5Nb0.5)O3+0.4SrTiO3 composition.
A Promising Lu2−xHoxO3 Laser Nanoceramic:Synthesis and Characterization
Authors: Galceran Montserrat , Pujol Maria Cinta , Gluchowski Pawel , Stręk Wieslaw , Carvajal Joan Josep , Mateos Xavier , Aguiló Magdalena , Díaz Francesc
Published: July 2010

Lu2−xHoxO3 (x=0.015–0.211) nanocrystals were synthesized by the modified Pechini method, and their nanoceramics were produced by the high‐pressure low‐temperature technique. Structural, morphological studies, and distribution particle size of nanocrystals and sintered pellets were carried out using X‐ray powder diffraction, Raman spectroscopy, electron microscopy, and electron diffraction. The optical spectroscopy studies of Ho3+ were carried out using optical absorption and emission, as well as lifetime measurements.
Densification and Mechanical Properties of Spark Plasma Sintered B4C with Si as a Sintering Aid
Authors: Ye Feng , Hou Zhaoping , Zhang Haijiao , Liu Limeng
Published: July 2010

B4C ceramics doped with different Si contents were fabricated by the spark plasma sintering technique. Pure B4C ceramic could be densified to 99% of the theoretical density. The sinterability could be further improved by the addition of a small amount of Si due to the formation of liquid Si during sintering. The incorporation of Si could also remarkably increase the mechanical properties of B4C ceramics. The Vickers hardness, flexural strength, and fracture toughness of the sample with 8 wt% Si could reach 41.8 GPa, 640 MPa, and 6.1 MPa·m1/2. The improvement in hardness and strength was attributed to grain refinement. Crack deflection due to the thermal expansion mismatch between the B4C and SiC was found to be the main toughening mechanism.
Clinical and community risk models of incident tooth loss in postmenopausal women from the Buffalo Osteo Perio Study
Authors: Bole Christopher , Wactawski‐Wende Jean , Hovey Kathleen M. , Genco Robert J. , Hausmann Ernest
Published: July 2010

Bole C, Wactawski‐Wende J, Hovey KM, Genco RJ, Hausmann E. Clinical and community risk models of incident tooth loss in postmenopausal women from the Buffalo Osteo Perio Study. Community Dent Oral Epidemiol 2010; 38: 487–497. © 2010 John Wiley & Sons A/S

Abstract – Objective:  While risk factors for tooth loss in adults have been identified, limited studies describing factors associated with incident tooth loss in postmenopausal women exist. This study assessed both clinical and non‐clinical risk factors for incident tooth loss.

Methods:  Postmenopausal women (N = 1341) were recruited between 1997 and 2000 from 1847 eligible Observational Study participants of the Buffalo, NY center of the Women’s Health Initiative who had complete dental examinations to assess alveolar bone height, soft tissue attachment and general oral health, and completed questionnaires concerning demographics, general health, lifestyle and oral health (72.6% participation rate). Five years later (2002–2005), 1021 women (76.1%) repeated these examinations and questionnaires. Incident tooth loss was determined by oral examination.

Results:  After an average 5.1 years of follow‐up (SD, 0.38), a total of 323 teeth were lost in 293 women, resulting in 28.7% of women with incident loss of at least one tooth. In multivariable models, diabetes history, gum disease history, smoking, previous tooth loss, BMI and plaque index, baseline clinical measures including alveolar crestal height (ACH) (OR = 1.22 per mm loss, 95% CI 1.11, 1.35), clinical attachment loss (CAL) (OR = 1.13 per mm loss, 95% CI 1.05, 1.23), and pocket depth (PD) (OR = 1.26 per mm loss, 95% CI 1.13, 1.41) were significant risk factors of incident tooth loss. In a community model that included no clinical measures, diabetes history (OR = 2.45, 95% CI 1.26, 4.77), prior gum disease (OR = 1.97, 95% CI 1.43, 2.70), ever smoking (OR = 1.42, 95% CI 1.06, 1.89), number of teeth lost at baseline (OR = 1.05 per tooth, 95% CI 1.02, 1.08), and BMI (OR = 1.15 per 5 km/m2 increase, 95% CI 1.01, 1.33) were associated with an increased risk of incident tooth loss.

Conclusions:  Clinical and questionnaire‐based models were found to provide similar risk estimates for incident tooth loss in postmenopausal women. These models identified high‐risk postmenopausal women where preventive strategies may be targeted.
Antibody‐mediated modulation of immune responses
Authors: Nimmerjahn Falk , Ravetch Jeffrey V.
Published: July 2010

Summary:  Activation of the humoral immune system by microbial infections or self‐antigens results in the initiation of strong pro‐inflammatory reactions. Antibodies of the immunoglobulin G (IgG) isotype play a crucial role in this cascade of reactions, resulting in the clearance of invading microbes and the generation of long lasting immunity. In addition, IgG antibodies feedback on the generation of novel IgG antibodies by activated B cells, impact plasma cell survival, and participate actively in maintaining and returning to the steady state. This review focuses on our current models of how IgG molecules can have this diverse array of activities.
Mechanisms that determine plasma cell lifespan and the duration of humoral immunity
Authors: Amanna Ian J. , Slifka Mark K.
Published: July 2010

Summary:  Humoral immunity following vaccination or infection is mainly derived from two types of cells: memory B cells and plasma cells. Memory B cells do not actively secrete antibody but instead maintain their immunoglobulin in the membrane‐bound form that serves as the antigen‐specific B‐cell receptor. In contrast, plasma cells are terminally differentiated cells that no longer express surface‐bound immunoglobulin but continuously secrete antibody without requiring further antigenic stimulation. Pre‐existing serum or mucosal antibody elicited by plasma cells (or other intermediate antibody‐secreting cells) represents the first line of defense against reinfection and is critical for protection against many microbial diseases. However, the mechanisms involved with maintaining long‐term antibody production are not fully understood. Here, we examine several models of long‐term humoral immunity and present a new model, described as the ‘Imprinted Lifespan’ model of plasma cell longevity. The foundation of this model is that plasma cells are imprinted with a predetermined lifespan based on the magnitude of B‐cell signaling that occurs during the induction of an antigen‐specific humoral immune response. This represents a testable hypothesis and may explain why some antigen‐specific antibody responses fade over time whereas others are maintained essentially for life.
Control of immune response by amino acid metabolism
Authors: Grohmann Ursula , Bronte Vincenzo
Published: July 2010

Summary:  The interaction between pathogenic microorganisms and their hosts is regulated by reciprocal survival strategies, including competition for essential nutrients. Though paradoxical, mammalian hosts have learned to take advantage of amino acid catabolism for controlling pathogen invasion and, at the same time, regulating their own immune responses. In this way, ancient catabolic enzymes have acquired novel functions and evolved into new structures with highly specialized functions, which go beyond the struggle for survival. In this review, we analyze the evidence supporting a critical role for the metabolism of various amino acids in regulating different steps of both innate and adaptive immunity.
Programmed cell death of dendritic cells in immune regulation
Authors: Chen Min , Wang Jin
Published: July 2010

Summary:  Programmed cell death is essential for the maintenance of lymphocyte homeostasis and immune tolerance. Dendritic cells (DCs), the most efficient antigen‐presenting cells, represent a small cell population in the immune system. However, DCs play major roles in the regulation of both innate and adaptive immune responses. Programmed cell death in DCs is essential for regulating DC homeostasis and consequently, the scope of immune responses. Interestingly, different DC subsets show varied turnover rates in vivo. The conventional DCs are relatively short‐lived in most lymphoid organs, while plasmacytoid DCs are long‐lived cells. Mitochondrion‐dependent programmed cell death plays an important role in regulating spontaneous DC turnover. Antigen‐specific T cells are also capable of killing DCs, thereby providing a mechanism for negative feedback regulation of immune responses. It has been shown that a surplus of DCs due to defects in programmed cell death leads to overactivation of lymphocytes and the onset of autoimmunity. Studying programmed cell death in DCs will shed light on the roles for DC turnover in the regulation of the duration and magnitude of immune responses in vivo and in the maintenance of immune tolerance.
The power and the promise of restimulation‐induced cell death in human immune diseases
Authors: Snow Andrew L. , Pandiyan Pushpa , Zheng Lixin , Krummey Scott M. , Lenardo Michael J.
Published: July 2010

Summary:  Controlled expansion and contraction of lymphocytes both during and after an adaptive immune response are imperative to sustain a healthy immune system. Both extrinsic and intrinsic pathways of lymphocyte apoptosis are programmed to eliminate cells at the proper time to ensure immune homeostasis. Genetic disorders of apoptosis described in mice and humans have established Fas and Bim as critical pro‐apoptotic molecules responsible for T‐cell death in response to T‐cell receptor restimulation and cytokine withdrawal, respectively. Emerging evidence prompts revision of this classic paradigm, especially for our understanding of restimulation‐induced cell death (RICD) and its physiological purpose. Recent work indicates that RICD employs both Fas and Bim for T‐cell deletion, dispelling the notion that these molecules are assigned to mutually exclusive apoptotic pathways. Furthermore, new mouse model data combined with our discovery of defective RICD in X‐linked lymphoproliferative disease (XLP) patient T cells suggest that RICD is essential for precluding excess T‐cell accumulation and associated immunopathology during the course of certain infections. Here, we review how these advances offer a refreshing new perspective on the phenomenon of T‐cell apoptosis induced through antigen restimulation, including its relevance to immune homeostasis and potential for therapeutic interventions.
Intertwined pathways of programmed cell death in immunity
Authors: Hedrick Stephen M. , Ch’en Irene L. , Alves Bryce N.
Published: July 2010

Summary:  Programmed cell death (PCD) occurs widely in species from every kingdom of life. It has been shown to be an integral aspect of development in multicellular organisms, and it is an essential component of the immune response to infectious agents. An analysis of the phylogenetic origin of PCD now shows that it evolved independently several times, and it is fundamental to basic cellular physiology. Undoubtedly, PCD pervades all life at every scale of analysis. These considerations provide a backdrop for understanding the complexity of intertwined, but independent, cell death programs that operate within the immune system. In particular, the contributions of apoptosis, autophagy, and necrosis in the resolution of an immune response are considered.
The complex interplay between autophagy, apoptosis, and necrotic signals promotes T‐cell homeostasis
Authors: Walsh Craig M. , Edinger Aimee L.
Published: July 2010

Summary:  Intense research efforts over the last two decades have focused on establishing the significance of apoptotic signaling in adaptive immunity. Without doubt, caspase‐dependent apoptosis plays vital roles in many immune processes, including lymphocyte development, positive and negative selection, homeostasis, and self‐tolerance. Cell biologists have developed new insights into cell death, establishing that other modes of cell death exist, such as programmed necrosis and type II/autophagic cell death. Additionally, immunologists have identified a number of immunological processes that are highly dependent upon cellular autophagy, including antigen presentation, lymphocyte development and function, pathogen recognition and destruction, and inflammatory regulation. In this review, we provide detailed mechanistic descriptions of cellular autophagy and programmed necrosis induced in response to death receptor ligation, including methods to identify them, and compare and contrast these processes with apoptosis. The crosstalk between these three processes is emphasized as newly formulated evidence suggests that this interplay is vital for efficient T‐cell clonal expansion. This new evidence indicates that in addition to apoptosis, autophagy and programmed necrosis play significant roles in the termination of T‐cell‐dependent immune responses.
The immortality of humoral immunity
Authors: Elgueta Raul , De Vries Victor C. , Noelle Randolph J.
Published: July 2010

Summary:  Decades of high‐titered antibody are sustained due to the persistence of memory B cells and long‐lived plasma cells (PCs). The differentiation of each of these subsets is antigen‐ and T‐cell driven and is dependent on signals acquired and integrated during the germinal center response. Inherent in the primary immune response must be the delivery of signals to B cells to create these populations, which have virtual immortality. Differences in biology and chemotactic behavior disperse memory B cells and long‐lived PCs to a spectrum of anatomic sites. Each subset must rely on survival factors that can support their longevity. This review focuses on the generation of each of these subsets, their survival, and renewal, which must occur to sustain serological memory. In this context, we discuss the role of antigen, bystander inflammation, and cellular niches. The contribution of BAFF (B‐cell activating factor belonging to the tumor necrosis factor family) and APRIL (a proliferation‐inducing ligand) to the persistence of memory B cells and PCs are also detailed. Insights that have been provided over the past few years in the regulation of long‐lived B‐cell responses will have profound impact on vaccine development, the treatment of pre‐sensitized patients for organ transplantation, and therapeutic interventions in both antibody‐ and T‐cell‐mediated autoimmunity.
Transcription factor regulation of CD8+ T‐cell memory and exhaustion
Authors: Angelosanto Jill M. , Wherry E. John
Published: July 2010

Summary:  During an infection, antigen‐specific CD8+ T cells undergo numerous cellular and transcriptional changes as they develop from naive T cells into effector and memory cells. However, when the antigen persists in a chronic infection, the cellular programs governing effector and memory development are influenced by chronic stimulation, and dysfunctional or exhausted CD8+ T cells are generated. Recently, exhausted CD8+ T cells were found to differ dramatically from naive and functional memory CD8+ T cells on a transcriptional level, demonstrating that exposure to chronic antigen can impact T cells at a fundamental level. While transcriptional changes in CD8+ T cells during memory development is currently a topic of particular interest, the transcriptional changes related to exhaustion and other forms of T‐cell dysfunction have received less attention. New computational methods are not only uncovering important transcription factors in these developmental processes but are also going further to define and connect these transcription factors into transcriptional modules that work in parallel to control cell fate and state. Understanding the molecular processes behind the development of CD8+ T‐cell memory and exhaustion should not only increase our understanding of the immune system but also could reveal therapeutic targets and treatments for infectious and immunological diseases. Here, we provide a basic overview of acute and chronic viral infections and the transcription factors known to influence the development of virus‐specific T cells in both settings. We also discuss recent innovations in genomic and computational tools that could be used to enhance the way we understand the development of T‐cell responses to infectious disease.
The Testosterone Metabolite 3α-Diol Enhances Female Rat Sexual Motivation When Infused in the Nucleus Accumbens Shell
Authors: Sánchez Montoya Eliana L. , Hernández Lizaida , Barreto-Estrada Jennifer L. , Ortiz José G. , Jorge Juan Carlos
Published: July 2010

Aim

The purpose of this study was to provide a quantitative assessment of female rat sexual behaviors after acute exposure to the A-ring reduced testosterone metabolite, androstanediol (3α-Diol), through the nucleus accumbens (NA) shell.

Main Outcome Measures

Quantitative analyses of female rat sexual behaviors and assessment of protein levels for the enzyme glutamic acid decarboxylase isoform 67 (GAD67) and gephyrin, a protein that participates in the clustering of GABA-A receptors in postsynaptic cells, were accomplished.

Methods

Female rats were ovariectomized and primed with estrogen and progesterone to induce sexual behaviors. Females received a 3α-Diol infusion via guided cannula that aimed to the NA shell five minutes prior to a sexual encounter with a stud male. The following parameters were videotaped and measured in a frame by frame analysis: lordosis quotient (LQ), Lordosis rating (LR), frequency and duration of proceptive behaviors (hopping/darting and ear wiggling). Levels of GAD67 and gephyrin were obtained by Western blot analysis two or twenty-four hours after the sexual encounter.

Results

Acute exposure to 3α-Diol in the NA shell enhanced LR, ear wiggling, and hopping/darting but not LQ. Some of these behavioral effects were counteracted by co-infusion of 3α-Diol plus the GABAA-receptor antagonist GABAzine. A transient reduction of GAD67 levels in the NA shell was detected.

Conclusions

The testosterone metabolite 3α-Diol enhances sexual proceptivity, but not receptivity, when infused into the NA shell directly. The GABAergic system may participate in the androgen-mediated enhancement of female rat sexual motivation.
Research Article: Effective and Specific Inhibition of the CD40–CD154 Costimulatory Interaction by a Naphthalenesulphonic Acid Derivative
Authors: Margolles‐Clark Emilio , Kenyon Norma S. , Ricordi Camillo , Buchwald Peter
Published: July 2010

Costimulatory interactions are important regulators of T‐cell activation and, hence, promising therapeutic targets in autoimmune diseases as well as in transplant recipients. Following our recent identification of the first small‐molecule inhibitors of the CD40–CD154 costimulatory protein–protein interaction (J Mol Med 87, 2009, 1133), we continued our search within the chemical space of organic dyes, and we now report the identification of the naphthalenesulphonic acid derivative mordant brown 1 as a more active, more effective, and more specific inhibitor. Flow cytometry experiments confirmed its ability to concentration‐dependently inhibit the CD154(CD40L)‐induced cellular responses in human THP‐1 cells at concentrations well below cytotoxic levels. Binding experiments showed that it not only inhibits the CD40–CD154 interaction with sub‐micromolar activity, but it also has considerably more than 100‐fold selectivity toward this interaction even when compared to other members of the tumor necrosis factor superfamily pairs such as TNF‐R1–TNF‐α, BAFF‐R(CD268)–BAFF(CD257/BLys), OX40(CD134)–OX40L(CD252), RANK(CD265)–RANKL(CD254/TRANCE), or 4‐1BB(CD137)–4‐1BBL. There is now sufficient structure‐activity relationship information to serve as the basis of a drug discovery initiative targeting this important costimulatory interaction.
Influence of colony size on pup fitness and survival in South American sea lions
Authors: Drago Massimiliano , Cardona Luís , García Néstor , Ameghino Santiago , Aguilar Alex
Published: July 2010

Abstract

Increased terrestrial pup mortality in small colonies due to harassment by subadult males has been proposed as a mechanism to explain the stagnation of South American sea lion populations after sealing ended. To test this hypothesis, pup survival rate was assessed in five northern Patagonia colonies with different sizes. Female diet quality as well as pup growth rate and immune status from the largest and smallest of these colonies were also assessed. Results indicated that the pup survival rate increased with colony size and pup‐to‐subadult male ratio. Furthermore, pups grew faster in the smallest colony, although female diet composition and pup immune status did not differ between the two colonies. Inverse relationship between pup growth rate and survival rate indicated that mortality was independent of food supply. In absence of terrestrial predators, infanticide by subadult males is the only mortality source other than starvation and illness and the relationship between pup survival rate and pup‐to‐subadult male ratio approached a type II functional response curve. Thus, infanticide stands as the most likely reason for the observed positive relationship between colony size and pup survival rate, supporting the hypothesis that post‐sealing population stasis was caused by inverse density dependence.
South American sea lions in Peru have a lek‐like mating system
Authors: Soto Karim H. , Trites Andrew W.
Published: July 2010

Abstract

Five years of behavioral observations revealed significant effects of high air temperatures and breeding site topography on the mating system of South American sea lions in Peru. Unlike most polygynous mammals that defend females or fixed territories, male sea lions in Peru maintained positions along the shoreline where females passed each day to thermoregulate, and where most copulations occurred. Sex ratios (1 male per 17 females) and male mating success were extremely skewed (14% of males achieved 50% of the copulations, and 25% of them did not copulate at all). The mass daily movements of females toward the water and cool substrate of the shoreline, along with a highly skewed sex ratio, accentuated the difficulty for males to monopolize and restrict female movements. Females moved freely and chose their mates, unlike in temperate regions of their range where male South American sea lions control groups of females or access to tide pools. Our observations indicate that the South American sea lion in Peru has a lek‐like breeding system. This is a rare alternative to the common male strategies of defending females and resources, and is likely an evolutionary product of their highly skewed sex ratio, protracted breeding season, and the extreme subtropical climate where they breed.
Microencapsulation of Fish Oil by Spray Granulation and Fluid Bed Film Coating
Authors: Anwar Sri Haryani , Weissbrodt Jenny , Kunz Benno
Published: July 2010

Abstract: The stability of microencapsulated fish oil prepared with 2 production processes, spray granulation (SG) and SG followed by film coating (SG‐FC) using a fluid bed equipment, was investigated. In the 1st process, 3 types of fish oil used were based on the ratios of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (10/50, 33/22, and 18/12). Each type was emulsified with soluble soybean polysaccharide (SSPS) and maltodextrin to produce 25% oil powders. In the 2nd process, 15% film coating of hydroxypropyl betacyclodextrin (HPBCD) was applied to the granules from the 1st process. The powder stability against oxidation was examined by measurement of peroxide values (PV) and headspace propanal after storage at room temperature and at 3 to 4 °C for 6 wk. Uncoated powder containing the lowest concentration of PUFA (18/12) was found to be stable during storage at room temperature with maximum PV of 3.98 ± 0.001 meq/kg oil. The PV increased sharply for uncoated powder with higher concentration of omega‐3 (in 33/22 and 10/50 fish oils) after 3 wk storage. The PVs were in agreement with the concentration of propanal, and these 2 parameters remained constant for most of the uncoated powders stored at low temperature. Unexpectedly, the outcomes showed that the coated powders had lower stability than uncoated powders as indicated by higher initial PVs; more hydroperoxides were detected as well as increasing propanal concentration. The investigation suggests that the film‐coating by HPBCD ineffectively protected fish oil as the coating process might have induced further oxidation; however, SG is a good method for producing fish oil powder and to protect it from oxidation because of the “onion skin” structure of granules produced in this process.
Development of Soybean Protein‐Isolate Edible Films Incorporated with Beeswax, Span 20, and Glycerol
Authors: Chao Zhang , Yue Ma , Xiaoyan Zhao , Dan Ma
Published: July 2010

Abstract:  The effect of the beeswax, Span 20, and glycerol content on qualities of soybean‐protein‐isolate edible films was evaluated. Beeswax and Span 20 were selected to improve qualities of soybean‐protein‐isolate films from 11 emulsifiers. The content of beeswax, Span 20, and glycerol was further optimized by response surface analysis. The optimal composite emulsifier was beeswax (1.87% of soybean protein‐isolate), Span 20 (10.25% of soybean protein‐isolate), and glycerol (29.12% of soybean protein‐isolate) with tensile strength of 908 MPa, percentage elongation at break of 25.8%, water vapor permeability of 19.2 g/m·d·MPa, and oxygen permeability of 0 cm3/m·d·MPa. The quality of soybean‐protein‐isolate films incorporated with the optimal composite emulsifier was 2.34 times higher than that of the control. Furthermore, the disulfide bond content of soybean‐protein‐isolate films showed a positive correlation with their quality, which provided a simple and rapid way to rank quality of soybean‐protein‐isolate films. Therefore, our result will not only give an instruction to soybean‐protein‐isolate‐film production, but also give a simple and rapid way to rank film qualities.

Practical Application:  Our results give the optimal composite emulsifiers for the soybean‐protein‐isolate‐film production. The soybean‐protein‐isolate films based on the optimal composite emulsifiers show their tensile strength of 908 MPa, percentage elongation at break of 25.8%, water vapor permeability of 19.2 g/m·d·MPa, and oxygen permeability of 0 cm3/m·d·MPa, being stronger than the control. Moreover, our results give a simple and rapid way to rank film qualities, because the disulfide bond content of soybean‐protein‐isolate films showed a positive correlation with their quality. Hence, the disulfide bond content was an indicator to rank qualities of soybean‐protein‐isolate films.
Development and Evaluation of a Fluidized Bed System for Wheat Grain Disinfection
Authors: Dhillon B. , Wiesenborn D. , Dhillon H. , Wolf‐Hall C.
Published: July 2010

Abstract:  Durum wheat grain from the field is naturally contaminated with bacteria, yeast, and mold. The reduction in aerobic plate count (APC) and yeast and mold count (YMC) is often necessary before processing wheat. Gaseous ozone, ozonated water, and acetic acid solution are nontraditional antimicrobial agents for grains and are safe for humans and the environment. Better disinfection may be possible by applying antimicrobial agents to grain in a fluidized state. Fluidization increases the exposure of grain surfaces, resulting in uniform and quick contact of grain with antimicrobial agents. Therefore, a fluidized bed was developed with automated spraying system (to spray treatment waters), and a port for gaseous ozone injection. The pressures and velocities within the fluidized bed system were measured to characterize the system. The treatments used on fluidized grain were: distilled water (control), gaseous ozone (6 ppm), ozonated water (23 mg/L), gaseous ozone + ozonated water (6 ppm, 23 mg/L), acetic acid solution (0.5%), acetic acid + ozonated water (0.5%, 26 mg/L), and gaseous ozone + acetic acid + ozonated water (6 ppm, 0.5%, 26 mg/L). The last of these treatments was most effective with 1.7 and 3.3 log reduction in APC and YMC, respectively. This combined treatment can be used to replace the chlorinated water that industry uses during tempering of grain. Ozonated water alone resulted in a 0.3 log reduction in both APC and YMC. Gaseous ozone alone did not cause a significant reduction in APC and YMC.
Direct Spectroscopic Observation of Singlet Oxygen Quenching and Kinetic Studies of Physical and Chemical Singlet Oxygen Quenching Rate Constants of Synthetic Antioxidants (BHA, BHT, and TBHQ) in Methanol
Authors: Lee Jun Hyun , Jung Mun Yhung
Published: July 2010

Abstract:  Singlet oxygen quenching by synthetic antioxidants (BHA, BHT, and TBHQ) was directly observed by spectroscopic monitoring of luminescence at 1268 nm. The luminescence data showed unambiguous evidence of singlet oxygen quenching by synthetic phenolic antioxidants with the highest activity for TBHQ, followed by BHA and BHT. The protective activities of these synthetic antioxidants on α‐terpinene oxidation with chemically‐induced singlet oxygen under dark further confirmed their singlet oxygen quenching abilities. Total singlet oxygen quenching rate constants (kr + kq) of BHA, BHT, and TBHQ were determined in a system containing α‐terpinene (as a singlet oxygen trap) and methylene blue (as a sensitizer) during light irradiation, and the values were 5.14 × 107, 3.41 × 106, and 1.99 × 108 M−1s−1, respectively. After the kr value of α‐terpinene was first determined, the kr values of the synthetic antioxidants were calculated by measuring their relative reaction rates with singlet oxygen to that of α‐terpinene under the identical conditions. The kr values of the BHA, BHT, and TBHQ were 3.90 × 105, 1.23 × 105, and 2.93 × 106, M−1s−1. The percent partition of chemical quenching over total singlet oxygen quenching (kr × 100)/(kr + kq) for BHA, BHT, and TBHQ were 0.76%, 3.61%, and 1.47%, respectively. The results showed that the synthetic antioxidants quench singlet oxygen almost exclusively through the mechanism of physical quenching. This represents the first report on the singlet oxygen quenching mechanism of these synthetic antioxidants.

Practical Application:  The synthetic antioxidants, especially TBHQ, have been found to have a strong singlet oxygen quenching ability. This article also clearly showed that singlet oxygen quenching by synthetic antioxidants was mainly by the physical quenching mechanism. The results suggested that these synthetic antioxidants, especially TBHQ, could be used practically for the protection of the food components such as edible oils and vitamins against singlet oxygen induced oxidations without significant losses of antioxidant activity during storage under light.
Drivers of Liking for Soy‐Based Indian‐Style Extruded Snack Foods Determined by U.S. and Indian Consumers
Authors: Neely Erika A. , Lee Youngsoo , Lee Soo‐Yeun
Published: July 2010

Abstract:  Although many researchers have studied potential ways to deliver soy in novel forms, little is known about specific sensory attributes associated with soy snacks, or how those attributes drive liking for consumers. The first objective of this study was to use sensory descriptive analysis to characterize 9 extruded soy snacks with varying soy levels and soy grits contents. A total of 12 trained panelists used a descriptive analysis method to evaluate the snacks and found 14 attributes to be significantly different across the samples. Furthermore, it is not known how preferences of Indian snack consumers living in the United States and India may vary for sensory attributes of soy snacks. The 2nd objective was to correlate descriptive profiling data and previously collected consumer data to construct preference maps illustrating consumers’ attitudes toward the snacks. Results indicate that consumers generally accept samples characterized by attributes such as crunchy, cumin, curry, salty, and umami, but dislike samples with wheat, rough, or porous attributes. Indian consumers differed from the U.S. consumers in that their preferences were more varied, and they tended to be more tolerant of wheat and porous attributes. Therefore, different strategies should be utilized when developing products for these groups to cater to their specific inclinations.
Stabilization of a Nutraceutical Omega‐3 Fatty Acid by Encapsulation in Ultrathin Electrosprayed Zein Prolamine
Authors: Torres‐Giner Sergio , Martinez‐Abad Antonio , Ocio Maria J. , Lagaron Jose M.
Published: July 2010

Abstract:  Docosahexaenoic acid (DHA) is a long chain polyunsaturated fatty acid of the omega‐3 series (ω‐3), which exerts strong positive influences on human health. The target of this study was the stabilization by encapsulation of this bioactive ingredient in zein ultrathin capsules produced by electrospraying. The zein ultrathin DHA encapsulation was observed by ATR‐FTIR spectroscopy to be more efficient against degradation under both ambient conditions and in a confined space (so‐called headspace experiment). In the latter case, that more closely simulates a sealed food packaging situation, the bioactive DHA was considerably more stable. By fitting the degradation data to a specific auto‐decomposition food lipids kinetic model, it was seen that the encapsulated ω‐3 fatty acid showed a 2.5‐fold reduction in the degradation rate constant and also had much higher degradation induction time. Moreover, the ultrathin zein‐DHA capsules resulted to be more stable across relative humidity and temperature. Finally, headspace analysis by gas chromatography coupled with mass spectrometry showed that the presence of 3 main flavor‐influencing aldehydes in the headspace was much lower in the zein encapsulated DHA, suggesting that the encapsulated bioactive also releases much less off‐flavors. Electrosprayed ultrathin capsules of zein are shown to exhibit potential in the design of novel functional foods or bioactive packaging strategies to enhance the stability of functional ingredients.

Practical Application: This article presents a novel methodology for the stabilization by encapsulation of omega 3 nutraceuticals via electrospraying and has potential application in the development of functional foods.
Introduction to the Special Section: Perspectives on Sibling Relationships: Advancing Child Development Research
Authors: Conger Katherine Jewsbury , Kramer Laurie
Published: July 2010

Abstract— For the vast majority of individuals, relationships with siblings provide a context for life experiences, yet the influences of these relationships are rarely reflected in studies of child and adolescent development. To encourage researchers to take the role of siblings into account in their studies of child development, this Special Section of Child Development Perspectives presents 3 articles that summarize emerging issues related to how siblings are defined in a world of increasingly diverse family forms and multiple cultures and to the unique role of siblings during the transition to adulthood. The Special Section concludes with a commentary that frames sibling issues within the larger context of research on social relationships and child development across the life course.
Sibling Experiences in Diverse Family Contexts
Authors: McGuire Shirley , Shanahan Lilly
Published: July 2010

Abstract— Sibling experiences provide a proximal context for development and, in turn, are embedded in ecological niches within society. Using an ecological framework, this article reviews the complexity of sibling experiences in diverse family contexts within the United States, focusing on families that vary in ethnic background and family structure and identifying emerging family contexts that have been understudied in sibling research. The article also illustrates that it is essential to consider macrocontextual influences on microlevel sibling processes and emphasizes that sibling experiences cannot be fully understood using samples from a few communities and family types. The article concludes that the sibling context is a largely untapped window into understanding links among children’s development, family context, and culture.