bluuebunny/crossref_metadata_2025 huggingface dataset:
IL-27 Blocks RORc Expression to Inhibit Lineage Commitment of Th17 Cells
Authors: Diveu Caroline , McGeachy Mandy J. , Boniface Katia , Stumhofer Jason S. , Sathe Manjiri , Joyce-Shaikh Barbara , Chen Yi , Tato Cristina M. , McClanahan Terrill K. , de Waal Malefyt René , Hunter Christopher A. , Cua Daniel J. , Kastelein Robert A.
Published: April 2009

IL-27 is secreted by APCs in response to inflammatory stimuli and exerts a proinflammatory Th1-enhancing activity but also has significant anti-inflammatory functions. We examined the molecular mechanism by which IL-27 regulates TGFβ plus IL-6- or IL-23-dependent Th17 development in the mouse and human systems. IL-27 inhibited the production of IL-17A and IL-17F in naive T cells by suppressing, in a STAT1-dependent manner, the expression of the Th17-specific transcription factor RORγt. The in vivo significance of the role of IL-27 was addressed in delayed-type hypersensitivity response and experimental autoimmune encephalomyelitis (EAE). By generating mice deficient for the p28 subunit of IL-27, we showed that IL-27 regulated the severity of delayed-type hypersensitivity response and EAE through its effects on Th17 cells. Furthermore, up-regulation of IL-10 in the CNS, which usually occurs late after EAE onset and plays a role in the resolution of the disease, was notably absent in IL-27p28−/− mice. These results show that IL-27 acts as a negative regulator of the developing IL-17A response in vivo, suggesting a potential therapeutic role for IL-27 in autoimmune diseases.
Bone Marrow-Derived Mast Cells Accumulate in the Central Nervous System During Inflammation but Are Dispensable for Experimental Autoimmune Encephalomyelitis Pathogenesis
Authors: Bennett Jami L. , Blanchet Marie-Renée , Zhao Linlin , Zbytnuik Lori , Antignano Frann , Gold Matthew , Kubes Paul , McNagny Kelly M.
Published: April 2009

Reports showing that W/Wv mice are protected from experimental autoimmune encephalomyelitis (EAE, a murine model of multiple sclerosis), have implicated mast cells as an essential component in disease susceptibility, but the role of mast cell trafficking has not been addressed. In this study, we have used both mast cell transplantation and genetic mutations (Cd34−/−, W/Wv, Wsh/Wsh) to investigate the role of mast cell trafficking in EAE in detail. We show, for the first time, that bone marrow-derived mast cells are actively recruited to the CNS during EAE. Unexpectedly, however, we found that EAE develops unabated in two independent genetic backgrounds in the complete absence of mast cells or bone marrow-derived mast cell reconstitution. We conclude that although mast cells do accumulate in the brain and CNS during demyelinating disease via peripheral mast cell trafficking, they are completely dispensable for development of disease.
Galectin-2 Suppresses Contact Allergy by Inducing Apoptosis in Activated CD8+ T Cells
Authors: Loser Karin , Sturm Andreas , Voskort Maik , Kupas Verena , Balkow Sandra , Auriemma Matteo , Sternemann Carlo , Dignass Axel U. , Luger Thomas A. , Beissert Stefan
Published: April 2009

Galectins, a family of structurally related β-galactoside-binding proteins, are expressed by various cells of the immune systems and seem to be important for the regulation of immune responses and immune cell homeostasis. Since it has been demonstrated that galectin-2 regulates cell-mediated inflammatory bowel disease and colitis in mice, we intended to investigate the role of galectin-2 in inflammatory cutaneous T cell-mediated immune responses. To address this issue, groups of naive mice were sensitized to the contact allergen 2,4-dinitro-1-fluorobenzene and systemically treated with galectin-2 to analyze the effects of galectin-2 on contact allergy. Here we show that galectin-2 is expressed in murine skin and is up-regulated upon cutaneous inflammation. Interestingly, treatment of mice with galectin-2 significantly reduced the contact allergy response. This effect was long-lasting since rechallenge of galectin-2-treated mice after a 14-day interval still resulted in a decreased ear swelling. We were able to demonstrate that galectin-2 induced a reduction of MHC class I-restricted immune responses in the treated animals, which was mediated by the induction of apoptosis specifically in activated CD8+ T cells. Additionally, we report that the galectin-2-binding protein CD29 is up-regulated on the surface of activated CD8+ T cells compared with naive CD8+ T cells or CD4+ T cells, suggesting that increased galectin-2/CD29 signaling might be responsible for the proapoptotic effects of galectin-2 on activated CD8+ T cells. Taken together, these data indicate that galectin-2 may represent a novel therapeutic alternative for the treatment of CD8-mediated inflammatory disorders such as contact allergy.
IL-6 Modulates CD5 Expression in B Cells from Patients with Lupus by Regulating DNA Methylation
Authors: Garaud Soizic , Le Dantec Christelle , Jousse-Joulin Sandrine , Hanrotel-Saliou Catherine , Saraux Alain , Mageed Rizgar A. , Youinou Pierre , Renaudineau Yves
Published: April 2009

B lymphocytes from patients with systemic lupus erythematosus (SLE) are characterized by reduced expression levels of membrane CD5. Recent studies from our laboratory have revealed that the level of membrane CD5 is determined by the relative level of two alternative CD5 isoforms; CD5-E1A, which is expressed on the membrane, and CD5-E1B, which is retained in the cytoplasm. Using bisulfite sequencing and methylation-sensitive endonuclease assays we show that the promoter for the alternative CD5-E1B isoform is demethylated in B cells from patients with SLE but not in healthy controls. We go on to show that differential methylation is more pronounced following BCR engagement. As a result of this demethylation, CD5-E1B mRNA is transcribed at the expense of CD5-E1A mRNA transcription. We provide further evidence that production of high IL-6 levels by SLE B cells abrogates the ability of SLE B cells to induce DNA methyl transferase (DNMT1) and then to methylate DNA, an effect that is reversed in the presence of a blocking Ab to the IL-6 receptor. The pattern of demethylation of CpG islands in the CD5-E1B promoter in SLE B cells is similar to those in B cells from healthy controls stimulated in the presence of IL-6, or treated with the methylation inhibitor PD98059. The study reveals that engagement of the BCR with constitutive IL-6 down-regulates the level of membrane CD5, which negatively regulates BCR signaling, in SLE B cells. This altered signaling could, in turn, promote the activation and expansion of autoreactive B cells in SLE patients.
Regulation of NK Cell Function by Human Granulocyte Arginase
Authors: Oberlies Johanna , Watzl Carsten , Giese Thomas , Luckner Claudia , Kropf Pascale , Müller Ingrid , Ho Anthony D. , Munder Markus
Published: April 2009

The arginine-hydrolyzing enzyme arginase is constitutively expressed by human polymorphonuclear granulocytes (PMN). Upon PMN cell death arginase is liberated and depletes arginine in the microenvironment. This amino acid depletion suppresses T cell proliferation and cytokine secretion and emerges as a key mechanism of immunosuppression during chronic inflammation and tumor growth. Here we show that PMN arginase also severely impairs key functions of primary human NK cells as well as IL-2-activated NK cells. In the absence of arginine, NK cell proliferation and IL-12/IL-18-induced secretion of IFN-γ are severely diminished. In contrast, NK cell viability, granule exocytosis, and cytotoxicity are independent of extracellular arginine. The mechanism of NK cell suppression by arginine depletion is posttranscriptional since mRNA transcript frequency is unaffected upon NK cell activation in the absence of arginine. Finally, we demonstrate that human purulent exudate ex vivo inhibits NK cell functions exclusively due to liberated arginase. Arginase inhibitors are therefore promising pharmacological agents to treat unwanted suppression of the innate (NK cell) as well as the adaptive (T cell) immune system.
Experimental Autoimmune Encephalomyelitis in Lewis rats: IFN-β Acts As a Tolerogenic Adjuvant for Induction of Neuroantigen-Dependent Tolerance
Authors: Mannie Mark D. , Abbott Derek J. , Blanchfield J. Lori
Published: April 2009

Cytokine-Ag fusion proteins represent a novel approach for induction of Ag-specific tolerance and may constitute an efficient therapy for autoimmune disease. This study addressed whether a fusion protein containing rat IFN-β and the encephalitogenic 73–87 determinant of myelin basic protein (i.e., the neuroantigen, or NAg) could prevent or treat experimental autoimmune encephalomyelitis (EAE) in Lewis rats. The optimal structure of the fusion protein was comprised of the rat IFN-β cytokine as the N-terminal domain with an enterokinase (EK) linker to the NAg domain. Both cytokine and NAg domains had full biological activity. Subcutaneous administration of 1 nmol of IFNβ-NAg fusion protein in saline on days −21, −14, and −7 before encephalitogenic challenge on day 0 resulted in a substantial attenuation of EAE. In contrast, administration of IFN-β or NAg alone did not affect susceptibility to EAE. The covalent attachment of IFN-β and NAg was not necessary, because separate injections of IFN-β and NAg at adjacent sites were as effective as injection of IFNβ-NAg for prevention of disease. When treatment was initiated after disease onset, the rank order of inhibitory activity was as follows: the IFNβ-NAg fusion protein ≥ a mixture of IFN-β plus NAg > IFN-β > NAg. The novel finding that IFN-β acts as a tolerogenic adjuvant as well as a tolerogenic fusion partner may have significance for development of tolerogenic vaccines.
Gastrointestinal Nematode Infection Exacerbates Malaria-Induced Liver Pathology
Authors: Helmby Helena
Published: April 2009

Mixed parasite infections are common in many parts of the world, but little is known of the effects of concomitant parasite infections on the immune response or severity of clinical disease. We have used the nonlethal malaria infection model of Plasmodium chabaudi AS in combination with the gastrointestinal nematode Heligmosomoides bakeri polygyrus to investigate the impact of nematode infections on malarial morbidity and antimalarial immunity. The data demonstrate that wild-type C57BL/6 mice coinfected with both parasites simultaneously exhibit a striking increase in mortality, while mice deficient in IFN-γ or IL-23 survive coinfection. The increase in mortality in wild-type mice was associated with severe liver pathology characterized by extensive coagulative necrosis and an increase in hepatic IFN-γ, IL-17, and IL-22 mRNA expression. This is the first demonstration of increased malaria-associated pathology associated with a switch toward a proinflammatory environment, involving not only IFN-γ but also the IL-17/IL-23 axis, as a result of coinfection with a gastrointestinal helminth.
A Functional IL-13 Receptor Is Expressed on Polarized Murine CD4+ Th17 Cells and IL-13 Signaling Attenuates Th17 Cytokine Production
Authors: Newcomb Dawn C. , Zhou Weisong , Moore Martin L. , Goleniewska Kasia , Hershey Gurjit K. K. , Kolls Jay K. , Peebles R. Stokes
Published: April 2009

IL-17A is produced from Th17 cells, and is involved in many autoimmune and inflammatory diseases. IL-13R has not previously been reported to be functionally expressed on T cells; however, we found that purified BALB/c CD4+ cells polarized to Th17 with TGF-β, IL-6, and IL-23 have increased mRNA and protein expression of IL-13Rα1 and mRNA expression of IL-4Rα compared with Th0, Th1, or Th2 polarized cells. The addition of IL-13 at Th17 polarization negatively regulated IL-17A and IL-21 expression, and reduced the number of CD4+ T cells producing IL-17A. Further, adding IL-13 at the time of Th17 cell restimulation attenuated IL-17A expression. CD4+ Th17 polarized cells from IL-4 knockout (KO) mice also had IL-13-induced inhibition of IL-17A production, but this was not observed in IL-4R KO and STAT6 KO mice. Addition of IL-13 at polarization increased IL-13R expression in wild-type Th17 cells. Further, IL-13 administration during Th17 polarization down-regulated retinoic acid-related-γT, the transcription required for Th17 development; increased STAT6 phosphorylation, and up-regulated GATA3, the transcription factor activated during the development of Th2 cells. This IL-13-mediated effect was specific to Th17 cells as IL-13 neither decreased IFN-γ expression by Th1 cells nor affected Th2 cell production of IL-4. Collectively, we have shown that Th17 cells express a functional IL-13R and that IL-13 negatively regulates IL-17A and IL-21 production by decreasing retinoic acid-related-γT expression and while increasing phosphorylation of STAT6 and GATA3 expression. Therefore, therapeutic intervention inhibiting IL-13 production could have adverse consequences by up-regulating Th17 inflammation in certain disease states.
Rapid Up-Regulation and Granule-Independent Transport of Perforin to the Immunological Synapse Define a Novel Mechanism of Antigen-Specific CD8+ T Cell Cytotoxic Activity
Authors: Makedonas George , Banerjee Pinaki P. , Pandey Rahul , Hersperger Adam R. , Sanborn Keri B. , Hardy Gareth A. D. , Orange Jordan S. , Betts Michael R.
Published: April 2009

CTL are endowed with the ability to eliminate pathogens through perforin-mediated cytotoxic activity. The mechanism for perforin-mediated Ag-specific killing has been solely attributed to cytotoxic granule exocytosis from activated CD8+ T cells. In this study, we redefine this mechanism, demonstrating that virus-specific CD8+ T cells rapidly up-regulate perforin in response to stimulation temporally with IFN-γ and CD107a expression. Following Ag-specific activation, newly synthesized perforin rapidly appears at the immunological synapse, both in association with and independent of cytotoxic granules, where it functions to promote cytotoxicity. Our work suggests a novel mechanism of CTL cytotoxicity and identifies a novel correlate of CD8+ T cell-mediated immunity.
Pathogenic Natural Antibodies Recognizing Annexin IV Are Required to Develop Intestinal Ischemia-Reperfusion Injury
Authors: Kulik Liudmila , Fleming Sherry D. , Moratz Chantal , Reuter Jason W. , Novikov Aleksey , Chen Kuan , Andrews Kathy A. , Markaryan Adam , Quigg Richard J. , Silverman Gregg J. , Tsokos George C. , Holers V. Michael
Published: April 2009

Intestinal ischemia-reperfusion (IR) injury is initiated when natural IgM Abs recognize neo-epitopes that are revealed on ischemic cells. The target molecules and mechanisms whereby these neo-epitopes become accessible to recognition are not well understood. Proposing that isolated intestinal epithelial cells (IEC) may carry IR-related neo-epitopes, we used in vitro IEC binding assays to screen hybridomas created from B cells of unmanipulated wild-type C57BL/6 mice. We identified a novel IgM mAb (mAb B4) that reacted with the surface of IEC by flow cytometric analysis and was alone capable of causing complement activation, neutrophil recruitment and intestinal injury in otherwise IR-resistant Rag1−/− mice. mAb B4 was found to specifically recognize mouse annexin IV. Preinjection of recombinant annexin IV blocked IR injury in wild-type C57BL/6 mice, demonstrating the requirement for recognition of this protein to develop IR injury in the context of a complex natural Ab repertoire. Humans were also found to exhibit IgM natural Abs that recognize annexin IV. These data in toto identify annexin IV as a key ischemia-related target Ag that is recognized by natural Abs in a pathologic process required in vivo to develop intestinal IR injury.
An Atypical Protein Kinase C (PKCζ) Plays a Critical Role in Lipopolysaccharide-Activated NF-κB in Human Peripheral Blood Monocytes and Macrophages
Authors: Huang XueSong , Chen Ling-Yu , Doerner Astrid M. , Pan Warren W. , Smith Laura , Huang Shuang , Papadimos Thomas J. , Pan Zhixing K.
Published: April 2009

We have reported that the bacterial LPS induces the activation of NF-κB and inflammatory cytokine gene expression and that this requires the activity of small GTPase, RhoA. In this study, we show that an atypical protein kinase C isozyme, PKCζ, associates functionally with RhoA and that PKCζ acts as a signaling component downstream of RhoA. Stimulation of monocytes and macrophages with LPS resulted in PKCζ activation and that inhibition of PKCζ activity blocks both LPS-stimulated activation of NF-κB and IL-1β gene expression. Our results also indicate that transforming growth factor β-activated kinase 1 acts as a signaling component downstream of PKCζ in cytokine gene transcription stimulated by LPS in human peripheral blood monocytes and macrophages. The specificity of this response suggests an important role for the Rho GTPase/PKCζ/transforming growth factor β-activated kinase 1/NF-κB pathway in host defense and in proinflammatory cytokine synthesis induced by bacterial LPS.
Chronic Lymphocytic Leukemia and B and T Cells Differ in Their Response to Cyclic Nucleotide Phosphodiesterase Inhibitors
Authors: Meyers John A. , Su Derrick W. , Lerner Adam
Published: April 2009

Phosphodiesterase (PDE)4 inhibitors, which activate cAMP signaling by reducing cAMP catabolism, are known to induce apoptosis in B lineage chronic lymphocytic leukemia (CLL) cells but not normal human T cells. The explanation for such differential sensitivity remains unknown. In this study, we report studies contrasting the response to PDE4 inhibitor treatment in CLL cells and normal human T and B cells. Affymetrix gene chip analysis in the three cell populations following treatment with the PDE4 inhibitor rolipram identified a set of up-regulated transcripts with unusually high fold changes in the CLL samples, several of which are likely part of compensatory negative feedback loops. The high fold changes were due to low basal transcript levels in CLL cells, suggesting that cAMP-mediated signaling may be unusually tightly regulated in this cell type. Rolipram treatment augmented cAMP levels and induced ATF-1/CREB serine 63/133 phosphorylation in both B lineage cell types but not T cells. As treatment with the broad-spectrum PDE inhibitor 3-isobutyl-1-methylxanthine induced T cell CREB phosphorylation, we tested a series of family-specific PDE inhibitors for their ability to mimic 3-isobutyl-1-methylxanthine-induced ATF-1/CREB phosphorylation. Whereas PDE3 inhibitors alone had no effect, the combination of PDE3 and PDE4 inhibitors induced ATF-1/CREB serine 63/133 phosphorylation in T cells. Consistent with this observation, PDE3B transcript and protein levels were low in CLL cells but easily detectable in T cells. Combined PDE3/4 inhibition did not induce T cell apoptosis, suggesting that cAMP-mediated signal transduction that leads to robust ATF-1/CREB serine 63/133 phosphorylation is not sufficient to induce apoptosis in this lymphoid lineage.
Differential Regulation of Foxp3 and IL-17 Expression in CD4 T Helper Cells by IRAK-1
Authors: Maitra Urmila , Davis Sarah , Reilly Christopher M. , Li Liwu
Published: April 2009

Host immune responses are finely regulated by the opposing effects of Th17 and T regulatory (Treg) cells. Treg cells help to dampen inflammatory processes and Th17 cells facilitate various aspects of immune activation. The differentiation of Th cells depends on a unique combination of stimulants and subsequent activation of diverse transcription factors. In particular, cooperative activation of NFAT and Smad3 leads to the induction of Treg cells, and cooperation among STAT3 and Smad3 switches to the induction of Th17 cells. We have previously shown that the IL-1 receptor associated kinase 1 (IRAK-1) selectively activates STAT3 and inactivates NFAT. Physiological studies have shown that IRAK-1−/− mice are protected from developing various inflammatory diseases, including experimental autoimmune encephalomyelitis and atherosclerosis with unknown mechanism. In this study, we demonstrate that IRAK-1 plays a critical modulatory role in the differentiation of Th17 and Treg cells. Following stimulation with TCR agonists and TGFβ, IRAK-1−/− CD4 Th cells display elevated nuclear NFATc2 levels and increased interaction of NFATc2 and Smad3, resulting in increased expression of Foxp3, a key marker for Treg cells. IRAK-1−/− mice have constitutively higher populations of Treg cells. In contrast, when stimulated with TCR agonists together with IL-6 and TGF-β, IRAK-1−/− CD4 Th cells exhibit attenuated STAT3 Ser727 phosphorylation and reduced expression of IL-17 and RORγt compared with wild-type cells. Correspondingly, IRAK-1 deletion results in decreased IL-17 expression and dampened inflammatory responses in acute and chronic inflammatory mice models. Our data provides mechanistic explanation for the anti-inflammatory phenotypes of IRAK-1−/− mice.
Multimedia Video
Authors: Elmagarmid Ahmed K. , Jiang Haitao
Published: April 2009

The sections in this article are

Video Codecs

Jpeg and Mjpeg

Quicktime

Video Databases

Video Data Modeling

Video Cut Detection and Segmentation

Video Indexing

Video Query, Retrieval, and Browsing

Video Authoring and Editing

Video Conferencing

Video‐on‐Demand
Multimedia Audio
Authors: Cook Perry R.
Published: April 2009

The sections in this article are

The Multimedia Audio Subsystem

PCM Wave Storage and Playback

Analog Mixing Versus Digital Filters

Software Streaming Models

Synchronization

Audio Compression

Musical Instrument Digital Interface

Sound and Music Synthesis

Speech

3D Audio and Audio for Virtual Environments
Inspection in Semiconductor Manufacturing
Authors: Sankaran Vijay , Weber Charles M. , Lakhani Fred , Tobin, Jr. Kenneth W.
Published: April 2009

The sections in this article are

Defect Reduction Cycle in Semiconductor Manufacturing

Inspection in the IC Manufacturing Process Life Cycle

Optical Imaging Technology

Laser‐Scattering Technology

Measurement of Optical Scatter from Contaminants on Wafers

Automatic Defect Classification

Future Challenges

Conclusions

Acknowledgments
Emulsion Polymerization
Authors: van Herk A. , Heuts H.
Published: April 2009

The production of polymers is shifting from solvent‐based systems toward water‐based systems. A versatile technique to produce polymer nanoparticles in an aqueous system is emulsion polymerization. Different aspects described in this article are the general mechanism of emulsion polymerization, ingredients in the recipes, emulsion copolymerization and composition drift, process strategies, development of particle morphologies, reactor setups and industrial‐scale operation aspects of mixing and heat transfer, and finally the main applications of latices.
Ion Exchange Technology
Authors: Sarkar Sudipta , Greenleaf John E. , SenGupta Arup K.
Published: April 2009

Since its discovery more than a century ago, the phenomenon of ion exchange has undergone significant evolution in terms of both theory and practice, especially after the synthesis of organic (polymeric) ion exchangers. No specialty thrives in isolation. The field of ion exchange grew over decades by permeating into myriad areas from deionization to drug delivery. There have been continuous development in the synthesis of new ion exchange materials and processes that now cater to various applications in industries as diverse as power and water utilities, biotechnology, chemical purification, food and beverages, agriculture, pharmaceuticals, microelectronics, and also water treatment. Polymeric ion exchangers, viewed as a strongly ionized electrolyte with low dielectric constants, can be made suitable for various uses including trace contaminant removal in environmental separation, hydrometallurgy, catalysis, product purification, and sustainable industrial processes. Many of these specific interactions can be characterized and enhanced by making modifications to the polymer matrix, covalently attached fixed functional groups, degree of cross‐linking, porosity, and morphology. Affinity for specific ions or selectivity of the ion exchangers plays a critical role and allows one to design ion exchange processes in which complete removal of the target ion from the background of other ions is required. Selectivity of the ion exchangers also influences separation of noble metals and chemical purification operations. An understanding of the basic principles of ion exchange equilibrium and kinetics is important for the development of new materials and processes. In order for an ion exchange process to be economically viable, the ion exchangers need to be regenerable so that they may be used for tens of cycles. Such a constraint demands a tradeoff between the high selectivity of the resin and its regenerability with cost‐effective regenerants. Regulations related to the disposal of spent regenerant have also driven new advancements in the field of ion exchange.
Polymer Filtration Membranes
Authors: Asatekin Ayse , Mayes Anne M.
Published: April 2009

Polymer filtration membranes have been a focus of research since the late eighteenth century and became a thriving industry in the twentieth century. Today, membranes are used in commercial applications spanning from drinking water purification to gas separations, with a market that is expected to grow to more than $10 billion by 2010. This article describes the materials and morphologies commonly found in today's commercial membranes, along with their methods of manufacture. Membranes classified according to retentate size as microfiltration, ultrafiltration, nanofiltration, or reverse osmosis are introduced, along with ion exchange and gas separation membranes. The primary mechanisms by which these different membranes achieve separation during filtration are described, as well as example applications. Permeability, molecular weight cutoff, and rejection/retention are introduced as metrics for membrane performance comparisons. Membrane fouling is discussed as a chief obstacle to the more widespread use of membranes in wastewater treatment and other applications involving high concentrations of organics in the feed stream. Mechanisms of membrane fouling are described along with approaches commonly employed to limit fouling, including membrane surface modification, process optimization, and pretreatment of the feed. The future outlook of the polymer filtration membrane industry is touched upon in the context of increasing demand for fresh water and continuing improvements in membrane performance anticipated by research advances.
Modified synthetic aperture algorithm for sonar systems
Authors: Sawa T. , Aoki T. , Yoshida H. , Hyakudome T. , Ishibashi S. , Matsubara S. , Wright S.
Published: April 2009

It is hard to negate the effects of ocean waves on synthetic aperture sonar that has to be operated in the ocean and many efforts to deal with ocean waves have been made. One of these efforts is motion compensation by calculating phase errors with a computer. But the synthetic aperture algorithm with motion compensation is heavy, and remains difficult to be executed on a real‐time basis. Thus, a modified synthetic aperture algorithm is proposed in this paper. This algorithm, which is named a 1.5‐dimensional algorithm, is in between a one‐dimensional and two‐dimensional algorithm. It synthesizes a virtual aperture about 10 times faster than other algorithms in a computer simulation. Copyright © 2009 John Wiley & Sons, Ltd.
Solution Processing of Chalcogenide Semiconductors via Dimensional Reduction
Authors: Mitzi David B.
Published: April 2009

The quest to develop thin‐film solution processing approaches that offer low‐cost and preferably low‐temperature deposition, while simultaneously providing quality semiconductor characteristics, has become an important thrust within the materials community. While inorganic compounds offer the potential for outstanding electronic properties relative to organic systems, the very nature of these materials rendering them good electronic materials—namely strong covalent bonding—also leads to poor solubility. This review presents a “dimensional reduction” approach to improving the solubility of metal chalcogenide semiconductors, which generally involves breaking the extended framework up into discrete metal chalcogenide anions separated by small and volatile cationic species. The resulting soluble precursor may be solution‐processed into thin‐film form and thermally decomposed to yield the desired semiconductor. Several applications of this principle to the solution deposition of high‐performance active layers for transistors (channel mobility >10 cm2 V−1 s−1), solar cells (power conversion efficiency of as high as 12%), and fundamental materials study will be presented using hydrazine as the deposition solvent.
Self‐Assembled Quantum Dot Molecules
Authors: Wang Lijuan , Rastelli Armando , Kiravittaya Suwit , Benyoucef Mohamed , Schmidt Oliver G.
Published: April 2009

Semiconductor quantum dot molecules (QDMs) are systems composed of two or more closely spaced and interacting QDs. QDMs are receiving much attention both as playground for studying coupling and energy transfer processes between “artificial atoms” and as new systems, which substantially extend the range of possible applications of QDs. QDMs can be conveniently fabricated by self‐assembly either through chemical synthesis or epitaxial growth. Although QDMs relying on the random occurrence of nearby QDs can be used for fundamental studies, special fabrication protocols must be used to create QDMs with well‐defined properties. In this article, we focus on self‐assembled QDMs obtained by epitaxial growth and embedded in a semiconductor matrix, which are appealing for the possible realization of quantum gates based on two‐level systems defined in QDs. We provide a comprehensive overview of the development and current stage of the research on QDMs composed of vertically (in the growth direction) or laterally (in the growth plane) aligned QDs. The review highlights some recent milestone works and points out the challenges and future directions in the field.
Socioeconomic variation in the growth status of urban school children 6–13 years in Oaxaca, Mexico, in 1972 and 2000
Authors: Malina Robert M. , Peña Reyes Maria Eugenia , Little Bertis B.
Published: April 2009

Socioeconomic variation in the growth status of urban school children 6–13 years of age in 1972 and 2000 was compared. The children were resident in the city of Oaxaca and were students in the same primary school in each year. Socioeconomic status (SES) was based on parental occupation. Height, sitting height, estimated leg length, weight, and the body mass index in 218 boys and 191 girls in 1972 and 173 boys and 166 girls in 2000 were compared. Sex‐specific MANCOVA was used to evaluate SES differences within each year, while sex‐ and SES‐specific MANCOVA was used to evaluate differences between years. The prevalence of stunting, overweight and obesity was estimated. There were no SES differences among boys and girls in 1972 and boys in 2000; low‐middle and middle SES girls were significantly taller and heavier with longer legs than low SES girls in 2000. Within each SES group, children in 2000 were significantly larger in body size and segment lengths except for sitting height in low SES children of both sexes. Estimated secular gains increased from low to low‐middle to middle SES in both sexes. Inequitable gains by SES contributed to an increase in the magnitude of differences between SES groups, especially between low SES children on one hand and low‐middle and middle SES children on the other hand. The prevalence of stunting declined while the prevalence of overweight and to a lesser extent in obesity increased from 1972 to 2000, more so in low‐middle and middle SES than in low SES children. Am. J. Hum. Biol. 2009. © 2009 Wiley‐Liss, Inc.
The Garífuna (Black Carib) people of the Atlantic coasts of Honduras: Population dynamics, structure, and phylogenetic relations inferred from genetic data, migration matrices, and isonymy
Authors: Herrera‐Paz Edwin‐Francisco , Matamoros Mireya , Carracedo Ángel
Published: April 2009

The aim of this study is to assess population dynamics, structure, and phylogenetic relations of the populations that inhabit the Caribbean coasts of Honduras: the Garífuna (or Black Carib) people, an admixture of Black Africans and Red Carib Native Amerindians. Thirteen autosomal tetranucleotide microsatellite markers of the DNA (namely short tandem repeats) were genotyped in samples from the Garifuna communities of Bajamar, in the Department of Cortés; Corozal, in the Department of Atlántida; and Iriona, in the Department of Gracias a Dios. Each subject in the study filled a questionnaire with the following information: complete name and surname of participant, and places of birth of the participant, his/her parents, and grandparents. We performed analyses that included determination of migration rates and residence patterns from information of places of birth, fixation indices from genetic data, and analysis of surnames of the sampled subjects (isonymy). Migration matrices showed a migration wave from east to west in the parents and grandparents of the subjects. A raise in migration rates and a shift in predominating residence pattern from neolocality to matrilocality from grandparents to parents were observed. Analysis of isonymy conjunctly with values for FIS in each community showed high endogamy in Bajamar, and recent, high immigration in Iriona. A dendrogram constructed with allele frequencies of the Garifuna and other populations from the Americas, Africa, and Europe revealed the close relationships of this ethnic group with Afro‐Caribbean and African Populations. Am. J. Hum. Biol. 2010. © 2009 Wiley‐Liss, Inc.
Fetal signaling through placental structure and endocrine function: Illustrations and implications from a nonhuman primate model
Authors: Rutherford Julienne N.
Published: April 2009

The placenta is a transmitter of fetal need and fetal quality, interfacing directly with maternal physiology and ecology. Plasticity of placental structure and function across the developmental timeframe of gestation may serve as an important tool by which a fetus calibrates its growth to shifting maternal ecology and resource availability, and thereby signals its quality and adaptability to a changing environment. Signals of this quality may be conveyed by the size of the placental interface, an important marker of fetal access to maternal resources, or by production of placental insulin‐like growth factor‐II, a driver of fetoplacental growth. Litter size variation in the common marmoset monkey offers the opportunity to explore intrauterine resource allocation and placental plasticity in an important nonhuman primate model. Triplet marmosets are born at lower birth weights and have poorer postnatal outcomes and survivorship than do twins; triplet placentas differ in placental efficiency, microscopic morphology, and endocrine function. Through placental plasticity, triplet fetuses are able to adjust functional access to maternal resources in a way that allows pregnancy to proceed. However, the costs of such mechanisms may relate to reduced fetal growth and altered postnatal outcomes, with the potential to lead to adverse adult health consequences, suggesting an important link between the placenta itself and the developmental origins of health and disease. Am. J. Hum. Biol. 2009. © 2009 Wiley‐Liss, Inc.
Age at first reproduction and economic change in the context of differing kinship ecologies
Authors: Leonetti Donna L. , Nath Dilip C.
Published: April 2009

Kinship systems which tend to be based on ecologies of subsistence also assign differential power, privilege, and control to human connections that present pathways for manipulation of resource access and transfer. They can be used in this way to channel resource concentrations in women and hence their reproductive value. Thus, strategic female life course trade‐offs and their timing are likely to be responsive to changing preferences for qualities in women as economic conditions change. Female life histories are studied in two ethnic groups with differing kinship systems in NE India where the competitive market economy is now being felt by most households. Patrilineal Bengali (599 women) practice patrilocal residence with village exogamy and matrilineal Khasi (656 women) follow matrilocal residence with village endogamy, both also normatively preferring three‐generation extended households. These households have helpful senior women and significantly greater income. Age at first reproduction (AFR), achieved adult growth (height) and educational level (greater than 6 years or less) are examined in reproductive women, ages 16–50. In both groups, women residing normatively are older at AFR and taller than women residing nonnormatively. More education is also associated with senior women. Thus, normative residence may place a woman in the best reproductive location, and those with higher reproductive and productive potential are often chosen as households face competitive market conditions. In both groups residing in favorable reproductive locations is associated with a faster pace of fertility among women, as well as lower offspring mortality among Khasi, to compensate for a later start. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Ritualized combat as an indicator of intrasexual selection effects on male life history evolution
Authors: Graves Brent M.
Published: April 2009

Trade‐offs between survival, growth, current reproduction, and future reproduction influence life history evolution, leading to adaptive timing of investment in various strategies. If engagement in costly intrasexual contests to gain better access to mates is an important form of male reproductive investment, then the expression of characters that promote success in this process should be influenced by their fitness effects across the lifespan. To test this prediction, the ages at which human (Homo sapiens) males exhibit the greatest investment in morphological, behavioral, and physiological characters associated with intrasexual competition was estimated by examining the ages at which males succeed in a form of ritualized combat. The average age of international boxing champions was in the latter half of the twenties, and titles were held for about 2 years on average. Thus, peak investment in traits that enhance intrasexual competition abilities appears to coincide with ages at which males have highest reproductive success. Additionally, larger males reached peak probability of success in this ritualized combat at ages about 2.6 years greater than smaller males. Because body size is highly heritable and there is strong positive assortative mating relative to this character among humans, this may indicate a polymorphic set of reproductive strategies produced through maintenance of coadapted gene complexes. Am. J. Hum. Biol., 2010. © 2009 Wiley‐Liss, Inc.
Enzymkatalyse “in neuem Licht”
Authors: Gärtner Wolfgang
Published: April 2009

Bei Licht betrachtet: Die NADPH:Protochlorophyllid(Pchlid)‐Oxidoreduktase (POR; siehe Struktur; grün Pchlid, gelb NADPH) ist ein gutes Modell für die Untersuchung katalytischer Prozesse in Enzymen, denn ihre Lichtaktivierung ermöglicht einen sofortigen Start der katalysierten Reaktion. Durch Bestrahlung mit schwachen, kurzen Laserpulsen kann man Konformationsänderungen während der Reaktion detektieren und so den Katalyseprozess in seine Einzelschritte zerlegen.

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Enzyme Catalysis “Reilluminated”
Authors: Gärtner Wolfgang
Published: April 2009

In a new light: The NADPH:protochlorophyllide (Pchlide) oxidoreductase (POR; see structure, green Pchlide, yellow NADPH) is a good model to investigate catalytical processes in enzymes, as its light activation allows an immediate start of the catalyzed reaction. By irradiation with weak, short laser pulses it is possible to detect conformation changes during the reaction and thus to uncover the elementary steps of the catalytic process.

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Correlation of the Mitochondrial Activity of Two‐Cell Embryos Produced In Vitro and the Two‐Cell Block In Kunming and B6C3F1 Mice
Authors: Wang Shie , Lin Cuiying , Shi Hexiu , Xie Meirong , Zhang Weiyu , Lv Junjie
Published: April 2009

The correlation between the early embryonic block to development and mitochondrial activity was investigated comparing two‐cell embryos produced in vitro from Kunming (KM) and B6C3F1 mice. One‐cell embryos were obtained from two species of hybrids (female KM mice mated with KM males and female B6C3F1 mice mated with KM males) and cultured for 84 hr in M16 media. The mitochondrial membrane potential, ATP content, and reactive oxygen species levels were measured in the resulting KM and B6C3F1 two‐cell embryos. Mitochondrial membrane potential and ATP content were also determined in KM and B6C3F1 metaphase II eggs. The results showed that the two‐cell block was observed in cultured KM embryos but not in B6C3F1 embryos. Mitochondrial membrane potential and ATP content of KM two‐cell embryos were significantly lower than in B6C3F1 two‐cell embryos (P < 0.01). Interestingly, the reactive oxygen species levels of KM two‐cell embryos were significantly lower than their B6C3F1 counterparts (P < 0.01). There was no difference in mitochondrial membrane potential and ATP content between KM and B6C3F1 metaphase II eggs. It is concluded that KM mice have an early two‐cell embryo block and that a possible “blocking” mechanism is the lower mitochondrial membrane potential and ATP content in these embryos. The results suggest a new approach for overcoming early embryonic development block, that of manipulating mitochondrial activity. Anat Rec, 292:661–669, 2009. © 2009 Wiley‐Liss, Inc.
Geometric Morphometric Investigation of Molar Shape Diversity in Modern Lemurs and Lorises
Authors: White Jess
Published: April 2009

In the study of mammalian adaptation to the environment, teeth are of primary importance due to their role as one of the direct interaction points between an individual and its ecological surroundings. Here, molar shape and function are investigated through traditional multivariate statistics and Thin‐Plate Splines deformations to compare the relative location of lower first molar occlusal structures (protoconid, metaconid, hypoconid, entoconid, cristid obliqua, and protolophid) in modern lemurs, lorises, tarsiers, and a non‐primate outgroup taxon (Tupaia). Results suggest that shape is based both on tooth size and dietary patterns. Small teeth tend to be short (anteroposteriorally) with wide talonids, whereas larger teeth are generally characterized as being long and narrow. In considering non‐size related shape trends, frugivorous and graminivorous taxa generally exhibit a relatively buccal intersection of the cristid obliqua with the base of the protolophid, and a relatively “perpendicular” position of the protolophid in relation to the anteroposterior axis of the tooth (defined as the axis connecting the protolophid and hypoconid). Morphological trends of folivores include a central (midline) position of the cristid obliqua‐protolophid base intersection and an oblique angle of the protolophid. Insectivorous taxa (primate and non‐primate) generally exhibit a central placement of the cristid obliqua‐protolophid base intersection (as in folivores), along with a relatively perpendicular angle of the protolophid (as in frugivores). Omnivorous taxa exhibit shape patterns that are intermediate between these three former groups. This study provides a comparative baseline for the interpretation of morphological trends in fossil primate groups, particularly the Adapiformes. Anat Rec, 292:701–719, 2009. © 2009 Wiley‐Liss, Inc.
Mean–variance efficiency with extended CIR interest rates
Authors: Ferland René , Watier François
Published: April 2009

We study a mean–variance investment problem in a continuous‐time framework where the interest rates follow Cox–Ingersoll–Ross dynamics. We construct a mean–variance efficient portfolio through the solutions of backward stochastic differential equations. We also give sufficient conditions under which an explicit analytic expression is available for the mean–variance optimal wealth of the investor. Copyright © 2009 John Wiley & Sons, Ltd.
Conformational choices for the stereochemically constrained γ‐amino acid residue gabapentin: Theoretical studies and correlation with experimental results
Authors: Vasudev Prema G. , Chatterjee Sunanda , Ramakrishnan Chandrasekharan , Shamala Narayanaswamy , Balaram Padmanabhan
Published: April 2009

Gabapentin (1‐aminomethylcyclohexaneacetic acid, Gpn) is an achiral, conformationally constrained γ amino acid residue. A survey of available crystal structures of Gpn peptides reveals that the torsion angles about the CγCβ (θ1) and CβCα (θ2) bonds are overwhelmingly limited to gauche, gauche (g+g+/g−g−) conformations. The Gpn residue forms C7 and C9 hydrogen bonds in which the donor and acceptor atoms come from the flanking peptide units. In combination with α amino acid residues αγ and γα segments can adopt C12 hydrogen bonded structures. The conformational choices available to the Gpn residue have been probed using energy calculations, adopting a grid search strategy. Ramachandran ϕ–ψ maps have been constructed for fixed values of θ1 and θ2, corresponding to the gauche and trans conformations. The sterically allowed and energetically favorable regions of conformational space have been defined and experimental observations compared. C7 and C9 hydrogen bonded conformational families have been identified using a grid search approach in which θ1 and θ2 values are varied over a range of ±10° about ideal values at 1° intervals. The theoretical analysis together with experimental observations for 59 Gpn residues from 35 crystal structures permits definition of the limited range of conformational possibilities at this γ amino acid residue. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 426–435, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Colonic ischaemia and intra-abdominal hypertension following open repair of ruptured abdominal aortic aneurysm
Authors: Djavani K , Wanhainen A , Valtysson J , Björck M
Published: April 2009

Background

The aim was to investigate the association between colonic ischaemia and intra-abdominal pressure (IAP) after surgery for ruptured abdominal aortic aneurysm (rAAA).

Methods

Sigmoid colon perfusion was monitored with an intramucosal pH (pHi) tonometer. Patients with a pHi of 7·1 or less were treated for suspected hypovolaemia with intravenous colloids and colonoscopy. IAP was measured every 4 h. Patients with an IAP of 20 mmHg or more had neuromuscular blockade, relaparotomy or both.

Results

A total of 52 consecutive patients had open rAAA repair; 30-day mortality was 27 per cent. Eight patients died shortly after surgery. Fifteen were not monitored for practical reasons; mortality in this group was 33 per cent. IAP and pHi were measured throughout the stay in intensive care in the remaining 29 patients. Monitoring led to volume resuscitation in 25 patients, neuromuscular blockade in 16, colonoscopy in 19 and relaparotomy in two. One patient died in this group. Twenty-three of 29 patients had a pHi of 7·1 or less, of whom 15 had a pHi of 6·9 or less. Sixteen had an IAP of 20 mmHg or more, of whom ten also had a pHi below 6·90. Peak IAP values correlated with the simultaneously measured pHi (r = –0·39, P = 0·003).

Conclusion

Raised IAP is an important mechanism behind colonic hypoperfusion after rAAA repair. Monitoring IAP and timely intervention may improve outcome.