bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic factors associated with mating system cause a partial reproductive barrier between two parapatric species of Leavenworthia (Brassicaceae)
Authors: Koelling Vanessa A. , Mauricio Rodney
Published: January 2010

Reproductive barriers play a major role in the origin and maintenance of biodiversity by restricting gene flow between species. Although both pre‐ and postzygotic barriers often isolate species, prezygotic barriers are thought to contribute more to reproductive isolation. We investigated possible reproductive barriers between Leavenworthia alabamica and L. crassa, parapatric species with high morphological and ecological similarity and the ability to hybridize. Using greenhouse and field experiments, we tested for habitat isolation and genetic incompatibilities. From controlled crosses, we identified unilateral incompatibility (a partial prezygotic barrier associated with the self‐incompatibility system), but no evidence of other genetic incompatibilities. We found a small reduction in pollen viability of F1 hybrids and early germination of F1, F2, and BC hybrids relative to L. alabamica and L. crassa in a common garden experiment, but the effect on fitness was not tested. Field studies of hybrid pollen viability and germination are needed to determine if they contribute to reproductive isolation. In a reciprocal transplant, we found no evidence of habitat isolation or reduced hybrid survival (from seedling to adult stage) or reproduction. These data suggest unilateral incompatibility partially reproductively isolates L. alabamica and L. crassa, but no other reproductive barriers could be detected.
Phenotypic plasticity and precipitation response in Sonoran Desert winter annuals
Authors: Angert Amy L. , Horst Jonathan L. , Huxman Travis E. , Venable D. Lawrence
Published: January 2010

Temporal environmental variation has profound influences on population dynamics and community structure. Examination of functional traits that influence resource uptake and allocation can illuminate how co‐occurring species translate environmental variation into different demographic outcomes, yet few studies have considered interspecific differences in trait plasticity. We experimentally manipulated soil moisture to test the hypothesis that differences in morphological plasticity contribute to species differences in demographic response to unpredictable precipitation in Sonoran Desert winter annual plants. We compared plasticity of leaf traits and biomass allocation between Pectocarya recurvata (Boraginaceae) and Stylocline micropoides (Asteraceae), co‐occurring species that differ in long‐term demographic patterns. The species with highly variable population dynamics, Stylocline, had striking increases in leaf area and root biomass in response to an experimental increase in soil moisture. In contrast, the species with buffered long‐term population dynamics, Pectocarya, did not differ in leaf morphology or biomass allocation between soil moisture treatments. Regardless of water treatment, Pectocarya had earlier reproductive phenology and greater fecundity than Stylocline, suggesting that differences in the timing of the phenological transitions from vegetative to reproductive growth may affect species’ responses to precipitation pulses. Combining long‐term observations with experimental manipulations provides a window into the functional underpinnings and demographic consequences of trait plasticity.
Microsatellite primers in Rhamnus cathartica (Rhamnaceae) and applicability in related taxa to assess hybridization events
Authors: Culley Theresa M. , Stewart J. Ryan
Published: January 2010

• Premise of the study: Microsatellite primers were developed in the introduced shrub Rhamnus cathartica L., to investigate potential hybridization events with related taxa as a stimulus of invasive spread.

• Methods and Results: Using a non‐radioactive protocol, 15 primer sets were identified in North American and European populations of R. cathartica. The primers amplified di‐, tri‐ and pentanucelotide repeats with 1–14 alleles per locus. Most primers also amplified in R. lanceolata, R. smithii, and/or Frangula alnus (previously R. frangula).

• Conclusions: These results indicate the utility of primers in R. cathartica for future genetic studies as well as their potential applicability in other related taxa.
NEW EPHEMERIDAE FROM ILLINOIS
Authors: Mcdunnough J.
Published: February 2010

Through the courtesy of Dr. S. Forbes I have recently had the opportunity of working over the Ephemerid material contained in the collection of the Illinois State Natural History Survey at Urbana, Ill. In this connection I offer the following descriptions of species which appear to be undescribed, as well as a note on a Mexican species, the identity of which has been doubtful.
Pollen-Induced Oxidative Stress Influences Both Innate and Adaptive Immune Responses via Altering Dendritic Cell Functions
Authors: Csillag Aniko , Boldogh Istvan , Pazmandi Kitti , Magyarics Zoltan , Gogolak Peter , Sur Sanjiv , Rajnavolgyi Eva , Bacsi Attila
Published: January 2010

It has been demonstrated that pollen grains contain NAD(P)H oxidases that induce oxidative stress in the airways, and this oxidative insult is critical for the development of allergic inflammation in sensitized mice. On the basis of this observation, we have examined whether pollen grain exposure triggers oxidative stress in dendritic cells (DCs), altering their functions. To test this hypothesis, human monocyte-derived DCs were treated with ragweed pollen grains. Our findings show that exposure to pollen grains induces an increase in the intracellular levels of reactive oxygen species in DCs. Our data also indicate that besides the NAD(P)H oxidases, other component(s) of pollen grains contributes to this phenomenon. Elevated levels of intracellular reactive oxygen species triggered the production of IL-8 as well as proinflammatory cytokines, such as TNF-α and IL-6. Treatment with pollen grains initiated the maturation of DCs, strongly upregulated the membrane expression of CD80, CD86, CD83, and HLA-DR, and caused only a slight increase in the expression of CD40. The pollen-treated DCs induced the development of naive T lymphocytes toward effector T cells with a mixed profile of cytokine production. Antioxidant inhibited both the phenotypic and functional changes of DCs, underlining the importance of oxidative stress in these processes. Collectively, these data show that pollen exposure-induced oxidative stress may contribute to local innate immunity and participate in the initiation of adaptive immune responses to pollen Ags.
Evolution of Recognition of Ligands from Gram-Positive Bacteria: Similarities and Differences in the TLR2-Mediated Response between Mammalian Vertebrates and Teleost Fish
Authors: Ribeiro Carla M. S. , Hermsen Trudi , Taverne-Thiele Anja J. , Savelkoul Huub F. J. , Wiegertjes Geert F.
Published: January 2010

We investigated the role of the TLR2 receptor in the recognition of ligands from Gram-positive bacteria in fish. Comparative sequence analysis showed a highly conserved Toll/IL-1 receptor domain. Although the leucine-rich repeat domain was less conserved, the position of the critical peptidoglycan (PGN)-binding residues in the leucine-rich repeat domain of carp TLR2 were conserved. Transfection of human embryonic kidney 293 cells with TLR2 corroborated the ability of carp TLR2 to bind the prototypical mammalian vertebrate TLR2 ligands lipoteichoic acid (LTA) and PGN from Staphylococcus aureus. The synthethic triacylated lipopeptide N-palmitoyl-S-(2,3-bis(palmitoyloxy)-(2RS)-propyl)-(R)-Cys-(S)-Ser-(S)-Lys4 trihydrochloride (Pam3CSK4) but not the diacylated lipopeptide macrophage-activating lipopeptide-2 (MALP-2) also activated TLR2 transfected human cells. We identified clear differences between the mammalian vertebrates and carp TLR2-mediated response. The use of the same ligands on carp macrophages indicated that fish cells require high concentrations of ligands from Gram-positive bacteria (LTA, PGN) for activation and signal transduction, react less strongly (Pam3CSK4) or do not react at all (MALP-2). Overexpression of TLR2 in carp macrophages confirmed TLR2 reactivity of the response to LTA and PGN, low-responsiveness to Pam3CSK4 and nonresponsiveness to MALP-2. A putative relation with the apparent absence of accessory proteins such as CD14 from the fish TLR2-containing receptor complex is discussed. Moreover, activation of carp macrophages by PGN resulted in increased TLR2 gene expression and enhanced TLR2 mRNA stability, MAPK-p38 phosphorylation and increased radical production. Finally, we could show that NADPH oxidase-derived radicals and MAPK-p38 activation cooperatively determine the level of PGN-induced TLR2 gene expression. We propose that the H2O2-MAPK-p38–dependent axis is crucial for regulation of TLR2 gene expression in fish macrophages.
Receptor Activator of NF-κB (RANK) Ligand Induces Ectodomain Shedding of RANK in Murine RAW264.7 Macrophages
Authors: Hakozaki Akihiro , Yoda Masaki , Tohmonda Takahide , Furukawa Mitsuru , Hikata Tomohiro , Uchikawa Shinichi , Takaishi Hironari , Matsumoto Morio , Chiba Kazuhiro , Horiuchi Keisuke , Toyama Yoshiaki
Published: January 2010

Osteoclastogenesis is a highly sophisticated process that involves a variety of membrane-bound proteins expressed in osteoblasts and osteoclast precursors. Over the past several years, proteolytic cleavage and release of the ectodomain of membrane-bound proteins, also referred to as ectodomain shedding, has emerged as an important posttranslational regulatory mechanism for modifying the function of cell surface proteins. In line with this notion, several membrane-bound molecules involved in osteoclastogenesis, including CSF-1R and receptor activator of NF-κB ligand (RANKL), are proteolytically cleaved and released from the cell surface. In this study, we investigated whether receptor activator of NF-κB (RANK), one of the most essential molecules in osteoclastogenesis, undergoes ectodomain shedding. The results showed that RANK is released in the form of a soluble monomeric protein and that TNF-α–converting enzyme is involved in this activity. We also identified potential cleavage sites in the juxtamembrane domain of RANK and found that rRANKL induces RANK shedding in a macrophage-like cell line RAW264.7 via TNFR-associated factor 6 and MAPK pathways. Furthermore, we found that RANKL-induced osteoclastogenesis is accelerated in TNF-α–converting enzyme-deficient osteoclast precursors. These observations suggest the potential involvement of ectodomain shedding in the regulation of RANK functions and may provide novel insights into the mechanisms of osteoclastogenesis.
Regulatory T Cells Attenuate Th17 Cell-Mediated Nigrostriatal Dopaminergic Neurodegeneration in a Model of Parkinson’s Disease
Authors: Reynolds Ashley D. , Stone David K. , Hutter Jessica A. L. , Benner Eric J. , Mosley R. Lee , Gendelman Howard E.
Published: January 2010

Nitrated α-synuclein (N–α-syn) immunization elicits adaptive immune responses to novel antigenic epitopes that exacerbate neuroinflammation and nigrostriatal degeneration in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinson’s disease. We show that such neuroimmune degenerative activities, in significant measure, are Th17 cell-mediated, with CD4+CD25+ regulatory T cell (Treg) dysfunction seen among populations of N–α-syn–induced T cells. In contrast, purified vasoactive intestinal peptide induced and natural Tregs reversed N–α-syn T cell nigrostriatal degeneration. Combinations of adoptively transferred N–α-syn and vasoactive intestinal peptide immunocytes or natural Tregs administered to MPTP mice attenuated microglial inflammatory responses and led to robust nigrostriatal protection. Taken together, these results demonstrate Treg control of N–α-syn–induced neurodestructive immunity and, as such, provide a sound rationale for future Parkinson’s disease immunization strategies.
Insulin Modulates Protease-Activated Receptor 2 Signaling: Implications for the Innate Immune Response
Authors: Hyun Eric , Ramachandran Rithwik , Cenac Nicolas , Houle Steeve , Rousset Perrine , Saxena Amit , Liblau Roland S. , Hollenberg Morley D. , Vergnolle Nathalie
Published: January 2010

Given the anti-inflammatory effects of insulin in human and animal studies done in vivo and given the signaling pathways in common between insulin and the protease-activated receptor 2 (PAR2), a G protein-coupled receptor, we hypothesized that insulin would have an impact on the inflammatory actions of PAR2. We found that low doses or concentrations of insulin in the subnanomolar range reduced PAR2-induced inflammation in a murine paw edema model, attenuated PAR2-induced leukocyte trafficking in mouse intestinal venules, and reduced PAR2 calcium signaling in cultured dorsal root ganglion neurons and endothelial cells. This effect of insulin to attenuate PAR2-mediated inflammation was reversed when cells were preincubated with LY294002 (a PI3K inhibitor) and GF 109203X (a pan-protein kinase C inhibitor). The enhanced inflammatory effect of PAR2 observed in vivo in an insulin-deficient murine type 1 diabetes model was attenuated by the local administration of insulin at the inflammatory site. Our data point to an anti-inflammatory action of insulin that targets the acute innate inflammatory response triggered by PAR2.
Control of α4β7 Integrin Expression and CD4 T Cell Homing by the β1 Integrin Subunit
Authors: DeNucci Christopher C. , Pagán Antonio J. , Mitchell Jason S. , Shimizu Yoji
Published: January 2010

The α4β7 integrin promotes homing of T cells to intestinal sites. The α4 integrin subunit that pairs with β7 integrin can also pair with β1 integrin. In this paper, we show that the preferential pairing of β1 integrin with α4 integrin regulates the expression of α4β7 on T cells. In the absence of β1 integrin, naive mouse CD4 T cells have increased α4β7 expression, resulting in increased adhesion to mucosal addressin cell adhesion molecule-1 and enhanced homing to Peyer’s patches (PP). In a reciprocal manner, overexpression of β1 integrin causes the loss of α4β7 expression and decreased homing to PP. A similar upregulation of β1 integrin and suppression of α4β7 expression occurs rapidly after CD4 T cell activation. β1 integrin thus dominates β7 integrin for α4 integrin pairing, thereby controlling the abundance of unpaired α4 integrin. Increasing the abundance of α4 integrin relative to β1 integrin is critical to retinoic acid-mediated expression of α4β7 integrin during T cell activation. In the absence of β1 integrin, endogenous Ag-specific CD4 T cells uniformly express high levels of α4β7 after Listeria monocytogenes infection. The resulting β1-deficient early memory T cells have decreased localization to the bone marrow and enhanced localization to PP after infection. Thus, the preferential association of β1 integrin with α4 integrin suppresses α4β7 integrin expression and regulates the localization of memory CD4 T cells.
IL-17 Promotes Tumor Development through the Induction of Tumor Promoting Microenvironments at Tumor Sites and Myeloid-Derived Suppressor Cells
Authors: He Donggou , Li Hui , Yusuf Nabiha , Elmets Craig A. , Li Jun , Mountz John D. , Xu Hui
Published: January 2010

The role of immune responses in tumor development is a central issue for tumor biology and immunology. IL-17 is an important cytokine for inflammatory and autoimmune diseases. Although IL-17–producing cells are detected in cancer patients and tumor-bearing mice, the role of IL-17 in tumor development is controversial, and mechanisms remain to be fully elucidated. In the current study, we found that the development of tumors was inhibited in IL-17R–deficient mice. A defect in IFN-γR increased tumor growth, whereas tumor growth was inhibited in mice that were deficient in both IL-17R and IFN-γR compared with wild-type animals. Further experiments showed that neutralization of IL-17 by Abs inhibited tumor growth in wild-type mice, whereas systemic administration of IL-17 promoted tumor growth. The IL-17R deficiency increased CD8 T cell infiltration, whereas it reduced the infiltration of myeloid-derived suppressor cells (MDSCs) in tumors. In contrast, administration of IL-17 inhibited CD8 T cell infiltration and increased MDSCs in tumors. Further analysis indicated that IL-17 was required for the development and tumor-promoting activity of MDSCs in tumor-bearing mice. These data demonstrate that IL-17–mediated responses promote tumor development through the induction of tumor-promoting microenvironments at tumor sites. IL-17–mediated regulation of MDSCs is a primary mechanism for its tumor-promoting effects. The study provides novel insights into the role of IL-17 in tumor development and has major implications for targeting IL-17 in treatment of tumors.
Activation-Induced Cytidine Deaminase Splice Variants Are Defective Because of the Lack of Structural Support for the Catalytic Site
Authors: van Maldegem Febe , Jibodh R. Aarti , van Dijk Remco , Bende Richard J. , van Noesel Carel J. M.
Published: January 2010

Recently, conflicting results were reported on the hypermutation activity of activation-induced cytidine deaminase (AID) splice variants. With the generation of single point mutations, we studied the structure-function relationship of the amino acids that are commonly absent from all described splice variants. The results from this analysis pointed to several amino acids that are required for class switch recombination (CSR), without perturbing cellular localization or nucleocytoplasmic shuttling. A defect in deaminase activity was found to underlie this CSR deficiency. Interestingly, the most debilitating mutations concentrated on hydrophobic amino acids, suggesting a structural role for this part of the protein. Indeed, by generating homologous amino acid replacements, CSR activity could be restored. These results are in agreement with recent reports on the protein structure of the AID homolog APOBEC3G, suggesting a similar protein composition. In addition, the findings underscore that AID splice variants are unlikely to have preservation of catalytic activity.
Aggressive behavior, related conduct problems, and variation in genes affecting dopamine turnover
Authors: Grigorenko Elena L. , DeYoung Colin G. , Eastman Maria , Getchell Marya , Haeffel Gerald J. , Klinteberg Britt af , Koposov Roman A. , Oreland Lars , Pakstis Andrew J. , Ponomarev Oleg A. , Ruchkin Vladislav V. , Singh Jay P. , Yrigollen Carolyn M.
Published: February 2010

A number of dopamine‐related genes have been implicated in the etiology of violent behavior and conduct problems. Of these genes, the ones that code for the enzymes that influence the turnover of dopamine (DA) have received the most attention. In this study, we investigated 12 genetic polymorphisms in four genes involved with DA functioning (COMT, MAOA and MAOB, and DβH) in 179 incarcerated male Russian adolescents and two groups of matched controls: boys without criminal records referred to by their teachers as (a) “troubled‐behavior‐free” boys, n=182; and (b) “troubled‐behavior” boys, n=60. The participants were classified as (1) being incarcerated or not, (2) having the DSM‐IV diagnosis of conduct disorder (CD) or not, and (3) having committed violent or nonviolent crimes (for the incarcerated individuals only). The findings indicate that, although no single genetic variant in any of the four genes differentiated individuals in the investigated groups, various linear combinations (i.e., haplotypes) and nonlinear combinations (i.e., interactions between variants within and across genes) of genetic variants resulted in informative and robust classifications for two of the three groupings. These combinations of genetic variants differentiated individuals in incarceration vs. nonincarcerated and CD vs. no‐CD groups; no informative combinations were established consistently for the grouping by crime within the incarcerated individuals. This study underscores the importance of considering multiple rather than single markers within candidate genes and their additive and interactive combinations, both with themselves and with nongenetic indicators, while attempting to understand the genetic background of such complex behaviors as serious conduct problems. Aggr. Behav. 36:158–176, 2010. © 2010 Wiley‐Liss, Inc.
Synthesis of PEOlated Fe3O4@SiO2 Nanoparticles via Bioinspired Silification for Magnetic Resonance Imaging
Authors: Tan Happy , Xue Jun Min , Shuter Borys , Li Xu , Wang John
Published: February 2010

Inspired by the biosilification process, a highly benign synthesis strategy is successfully developed to synthesize PEOlated Fe3O4@SiO2 nanoparticles (PEOFSN) at room temperature and near‐neutral pH. The success of such a strategy lies in the simultaneous encapsulation of Fe3O4 nanocrystals and silica precursors into the core of PEO‐based polymeric micelles. The encapsulation results in the formation of a silica shell being confined to the interface between the core and corona of the Fe3O4‐nanocrystal‐loaded polymeric micelles. Consequently, the surface of the Fe3O4@SiO2 nanoparticle is intrinsically covered by a layer of free PEO chains, which enable the PEOFSN to be colloidally stable not only at room temperature, but also upon incubation in the presence of proteins under physiological conditions. In addition, the silica shell formation does not cause any detrimental effects to the encapsulated Fe3O4 nanocrystals with respect to their size, morphology, crystallinity, and magnetic properties, as shown by their physicochemical behavior. The PEOFSN are shown to be good candidates for magnetic resonance imaging (MRI) contrast agents as demonstrated by the high r2/r1 ratio with long‐term stability under high magnetic field, as well as the lack of cytotoxicity.
Solvent‐Stabilized Photoconductive Metal Phthalocyanine Nanoparticles: Preparation and Application in Single‐Layered Photoreceptors
Authors: Wang Yuan , Liang Dejian
Published: February 2010

This article features solvent‐stabilized nanoparticles of photoconductive metal phthalocyanines (MPcs) with small particle sizes and narrow size distributions, which are tractable building blocks for photoelectric devices. The preparation and stabilization mechanism of 1,2‐dichloroethane (DCE)‐stabilized oxovanadium phthalocyanine (VOPc) and oxotitanium phthalocyanine (TiOPc) nanoparticles are discussed. It is found for the first time that the DCE‐stabilized TiOPc and VOPc nanoparticles are positively charged with zeta potentials of about +66 mV, which is ascribed to the electron transfer from the nanoparticles to DCE molecules. The excellent xerographic properties of the single‐layered photoreceptors based on TiOPc or VOPc nanoparticles and the charge transport mechanism of these photoreceptors are discussed. The strategy for further improving the xerographic properties of single‐layered photoreceptors is proposed.
Solar‐Energy Production and Energy‐Efficient Lighting: Photovoltaic Devices and White‐Light‐Emitting Diodes Using Poly(2,7‐fluorene), Poly(2,7‐carbazole), and Poly(2,7‐dibenzosilole) Derivatives
Authors: Beaupré Serge , Boudreault Pierre‐Luc T. , Leclerc Mario
Published: February 2010

World energy needs grow each year. To address global warming and climate changes the search for renewable energy sources with limited greenhouse gas emissions and the development of energy‐efficient lighting devices are underway. This Review reports recent progress made in the synthesis and characterization of conjugated polymers based on bridged phenylenes, namely, poly(2,7‐fluorene)s, poly(2,7‐carbazole)s, and poly(2,7‐dibenzosilole)s, for applications in solar cells and white‐light‐emitting diodes. The main strategies and remaining challenges in the development of reliable and low‐cost renewable sources of energy and energy‐saving lighting devices are discussed.
Applications of Ultrasound to the Synthesis of Nanostructured Materials
Authors: Bang Jin Ho , Suslick Kenneth S.
Published: February 2010

Recent advances in nanostructured materials have been led by the development of new synthetic methods that provide control over size, morphology, and nano/microstructure. The utilization of high intensity ultrasound offers a facile, versatile synthetic tool for nanostructured materials that are often unavailable by conventional methods. The primary physical phenomena associated with ultrasound that are relevant to materials synthesis are cavitation and nebulization. Acoustic cavitation (the formation, growth, and implosive collapse of bubbles in a liquid) creates extreme conditions inside the collapsing bubble and serves as the origin of most sonochemical phenomena in liquids or liquid‐solid slurries. Nebulization (the creation of mist from ultrasound passing through a liquid and impinging on a liquid‐gas interface) is the basis for ultrasonic spray pyrolysis (USP) with subsequent reactions occurring in the heated droplets of the mist. In both cases, we have examples of phase‐separated attoliter microreactors: for sonochemistry, it is a hot gas inside bubbles isolated from one another in a liquid, while for USP it is hot droplets isolated from one another in a gas. Cavitation‐induced sonochemistry provides a unique interaction between energy and matter, with hot spots inside the bubbles of ∼5000 K, pressures of ∼1000 bar, heating and cooling rates of >1010 K s−1; these extraordinary conditions permit access to a range of chemical reaction space normally not accessible, which allows for the synthesis of a wide variety of unusual nanostructured materials. Complementary to cavitational chemistry, the microdroplet reactors created by USP facilitate the formation of a wide range of nanocomposites. In this review, we summarize the fundamental principles of both synthetic methods and recent development in the applications of ultrasound in nanostructured materials synthesis.
Multidimensional Architectures for Functional Optical Devices
Authors: Arpin Kevin A. , Mihi Agustin , Johnson Harley T. , Baca Alfred J. , Rogers John A. , Lewis Jennifer A. , Braun Paul V.
Published: February 2010

Materials exhibiting multidimensional structure with characteristic lengths ranging from the nanometer to the micrometer scale have extraordinary potential for emerging optical applications based on the regulation of light–matter interactions via the mesoscale organization of matter. As the structural dimensionality increases, the opportunities for controlling light–matter interactions become increasingly diverse and powerful. Recent advances in multidimensional structures have been demonstrated that serve as the basis for three‐dimensional photonic‐bandgap materials, metamaterials, optical cloaks, highly efficient low‐cost solar cells, and chemical and biological sensors. In this Review, the state‐of‐the‐art design and fabrication of multidimensional architectures for functional optical devices are covered and the next steps for this important field are described.
One‐dimensional model of vacuum filtration of compressible flocculated suspensions
Authors: Stickland Anthony D. , de Kretser Ross G. , Scales Peter J.
Published: February 2010

This work details the one‐dimensional modeling of the different processes that may occur during the vacuum filtration of compressible flocculated suspensions. Depending on the operating conditions of the applied pressure and the initial solids concentration relative to the material properties of the compressive yield stress and the effective capillary pressure at the air–liquid interface, the dewatering process undergoes a combination of cake formation, consolidation, and/or desaturation. Mathematical models for these processes based on the compressional rheology approach are presented and appropriate solution methods outlined. Results using customary material properties are given for different operating conditions to illustrate the three dewatering processes. This approach lays the theoretical basis for further work understanding two‐ and three‐dimensional effects during desaturation, such as cracking and wall detachment. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Natural rectorite mineral: A promising substitute of kaolin for in‐situ synthesis of fluid catalytic cracking catalysts
Authors: Wei Baoying , Liu Haiyan , Li Tiesen , Cao Liyuan , Fan Yu , Bao Xiaojun
Published: February 2010

Fabrication of high‐performance fluid catalytic cracking (FCC) catalysts is suffering from the shortage of high‐quality kaolin that has long been used as matrix or starting material for synthesizing FCC catalysts. This work aimed at exploring the potential of rectorite, a natural aluminosilicate mineral, to substitute kaolin for preparing FCC catalysts through in‐situ synthesis technique. The physicochemical properties of a rectorite mineral, including its chemical composition, structure, thermal behavior, and chemical reactivity, were systemically investigated and compared with those of commercial kaolin. The results showed that the rectorite mineral suitably treated could substitute kaolin for synthesizing FCC catalysts. Moreover, we had shown that a hydrothermally stable ZSM‐5/rectorite composite in which ZSM‐5 crystals of ca. 2 μm in size were overgrown on preformed rectorite substrate could be synthesized using the rectorite mineral calcined at 800°C as raw material. When used as FCC additive, the obtained ZSM‐5/rectorite composite demonstrated enhanced light olefin (ethylene and propylene) yields. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Comparative study of hydrogen, argon, and xenon uptake into a propane hydrate
Authors: Abbondondola Joanne A. , Fleischer Everly B. , Janda Kenneth C.
Published: February 2010

The rate of absorption of hydrogen, argon, and xenon into a Type II propane clathrate hydrate has been studied. The propane hydrate is synthesized from 250‐μm ice grains, is estimated to have a porosity of 65% and has roughly the consistency of chalk. Hydrogen is rapidly absorbed by the hydrate sample and approaches the equilibrium vapor pressure in an hour before a very slow residual absorption process ensues. For an initial hydrogen pressure of 1.5 MPa, about 4.5% of the available 512 cages are occupied by hydrogen after 1 h, and 4.9% after 18 h. In contrast, for both argon and xenon significantly more gas is absorbed by the hydrate but at a much slower rate: about 5% as fast for xenon and 1% as fast for argon. We conclude that hydrogen readily diffuses through the propane hydrate microcrystal structure, while argon and xenon are probably absorbed by growing new double hydrate while consuming the propane hydrate. Although considerably higher pressures would be required to store significant quantities of hydrogen in propane hydrate, it appears that the crystal can be loaded and emptied in relatively short times. © 2010 American Institute of Chemical Engineers AIChE J, 2010
The application of in situ formed mixed iron oxides in the removal of strontium and actinides from nuclear tank waste
Authors: Arafat H. A. , Aase S. B. , Bakel A. J. , Bowers D. L. , Gelis A. V. , Regalbuto M. C. , Vandegrift G. F.
Published: February 2010

This article discusses the experimental program conducted at Argonne National Laboratory to study the performance of in situ formed mixed iron oxides (IS‐MIO) for the removal of strontium (Sr), plutonium (Pu), neptunium (Np), uranium (U), and americium (Am) from the Savannah River Site (SRS) radioactive tank waste. The boundaries for the experimental work were defined in collaboration with SRS. IS‐MIO was actually found to be a mixture of Fe(II) and Fe(III) oxides and hydroxides, including magnetite. Decontamination factor (DF) values were measured for both IS‐MIO and monosodium titanate (MST), the baseline sorbent used by SRS. DF values for IS‐MIO were found to be superior to MST for all isotopes studied. DF values for Pu, Np, and Sr, achieved within 30 min of IS‐MIO formation were orders of magnitude larger than the needed values. DF values for U and Am were less than the former three but still acceptable, and greater than MST. © 2010 American Institute of Chemical Engineers AIChE J, 2010
An interspecific analysis of relative jaw‐joint height in primates
Authors: Armfield Brooke A. , Vinyard Christopher J.
Published: February 2010

Jaw‐joint height (JJH) above the occlusal plane is thought to be influenced by cranial base angle (CBA) and facial angulation during growth. To better understand how JJH relates to midline craniofacial form, we test the hypothesis that relative increases in JJH are correlated with increasing CBA flexion and facial kyphosis (i.e., ventral bending) across primates. We compared JJH above the occlusal plane to CBA and the angle of facial kyphosis (AFK) across adults from 82 species. JJH scales with positive allometry relative to a skull geometric mean in anthropoids and most likely strepsirrhines. Anthropoid regressions for JJH are elevated above strepsirrhines, whereas catarrhines exhibit a higher slope than platyrrhines. Semipartial correlations between relative JJH and both CBA and AFK show no association across a small strepsirrhine sample, limited associations among catarrhines and anthropoids, but strong correlations in platyrrhines. Contrary to our hypothesis, however, increases in relative JJH are correlated with relatively less flexed basicrania and more airorhynch faces (i.e., reduced ventral bending) in platyrrhines. The mosaic pattern of relationships involving JJH across primate clades points to multiple influences on JJH across primates. In clades showing little association with basicranial and facial angles, such as strepsirrhines, the potential morphological independence of JJH may facilitate a relative freedom for evolutionary changes related to masticatory function. Finally, failure to associate relative JJH and basicranial flexion in most clades suggests that the relatively taller JJH and more flexed basicrania of anthropoids compared to strepsirrhines may have evolved as an isolated event during the origin of anthropoids. Am J Phys Anthropol 142:519–530, 2010. © 2010 Wiley‐Liss, Inc.
Anion Binding of N‐(o‐Methoxybenzamido)thioureas: Contribution of the Intramolecular Hydrogen Bond in the N‐Benzamide Moiety
Authors: Jiang Qian‐Qian , Darhkijav Burenkhangai , Liu Hao , Wang Fang , Li Zhao , Jiang Yun‐Bao
Published: February 2010

N‐(o‐Methoxybenzamido)thioureas (2 X/2 Y) are found to show an enhanced anion binding affinity with binding constants over 107 mol−1 L orders of magnitude for AcO− and a redshifted absorption of the anion binding complexes in acetonitrile (MeCN) relative to those of N‐benzamidothioureas (1) that bear no o‐OMe in the N‐benzamide moiety, despite the electron‐donating character of o‐OMe. Absorption of the anion–2 X/2 Y complex was shown to be of the same charge‐transfer nature as that of the anion–1 complex, but its dependence on substituent X is interestingly influenced by the o‐MeO⋅⋅⋅HNCO six‐membered‐ring intramolecular hydrogen bond identified in 2 X/2 Y. Such an intramolecular hydrogen bond is suggested to be responsible for the enhanced anion binding affinity. In the presence of this intramolecular hydrogen bond, the anion binding constant of 2 X was found to be independent of substituent X at the N‐phenyl ring, as in the case of 1, whereas that of 2 Y showed an amplified dependence on substituent Y at the N′‐phenyl ring, but to a lower extent than that of 1. A similar ring intramolecular hydrogen bond was purported to exist in 2 Za, 2 Zd, and 2 Ze, which bear NHMe, F, and Cl as the ortho substituent in the N‐benzamide moiety. In terms of the current roles of thiourea in not only anion recognition and sensing but also organocatalysis and crystal engineering, the present finding would be of significance for a wider structural diversity of smart thiourea derivatives with predesigned functions.
Embryonic systems implementation with FPGA‐based artificial cell network hardware architectures
Authors: Szász Csaba , Chindriş Virgil , Husi Géza
Published: February 2010

The cell‐based structure, which makes up the majority of biological organisms, offers the ability to grow with fault‐tolerance abilities and self‐repair. By adapting these mechanisms and capabilities to nature, scientific approaches have promoted research for understanding related phenomena and associated principles to engine complex novel digital systems and improve their capability. Founded by these observations, the paper is focused on computer‐aided modeling, simulation and experimental research of embryonic systems, with the purpose to implement very large scale integrated hardware structures which are able to imitate cells or artificial organism operation mode, with similar robustness and fault‐tolerance properties like their biological equivalents from nature. Field Programmable Gate Array (FPGA)‐based artificial cell model configuration provided with strongly network communication capabilities is proposed and developed. The presented theoretical and simulation approaches were tested on a laboratory prototype embryonic system (embryonic machine), for study and implementation of basic abilities of living organisms. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Strongly autonomous interconnections and stabilization of 2D behaviors
Authors: Napp Diego , Rocha Paula
Published: February 2010

In this paper we study linear discrete two‐dimensional systems in the behavioral context where control is viewed as interconnection. Within this framework the natural concept of regular interconnection has been introduced by J.C.Willems. Here we investigate regular interconnections that yield finite dimensional behaviors using tools previously developed to analyze almost implementation problems. We prove that when a finite dimensional (sub‐) behavior can be achieved from a given behavior by regular interconnection then the controllable part of the original behavior is rectifiable, moreover, in this case all the other sub‐behaviors are almost regularly implementable. We apply these results to characterize all stabilizable behaviors. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
What causes the extremely heavy rainfall in Taiwan during Typhoon Morakot (2009)?
Authors: Ge Xuyang , Li Tim , Zhang Shengjun , Peng Melinda
Published: February 2010

Despite its category‐2 intensity only, Typhoon (tropical cyclone in the Western Pacific) Morakot produced a record‐breaking rainfall in Taiwan. A cloud‐resolving model is used to simulate this extreme rainfall event and understand the dynamic aspect under this event. Due to the interaction between Morakot and a monsoon system, a peripheral gale force monsoon surge appears to the south of Taiwan. The monsoon surge remains even in a sensitivity experiment in which Taiwan terrain is reduced. However, the rainfall amount in Taiwan is greatly reduced without high topography over Taiwan, suggesting the important role the local topography plays in producing heavy rainfall. The overall numerical results indicate that it is the interaction among the typhoon, monsoon system, and local terrain that led to this extreme event. Copyright © 2010 Royal Meteorological Society
Hydrological seasonal forecast over France: feasibility and prospects
Authors: Céron J.‐P. , Tanguy G. , Franchistéguy L. , Martin E. , Regimbeau F. , Vidal J.‐P.
Published: February 2010

This article presents a first evaluation of a hydrological forecasting suite at seasonal time scales over France. The hydrometeorological model SAFRAN‐ISBA‐MODCOU is forced by seasonal forecasts from the DEMETER project for the March–April–May period. Despite a simple downscaling method, the atmospheric forcings are reasonably well represented at the finest scale. The computed soil moisture shows some predictability with large regions of correlation above 0.3. Probabilistic scores for soil moisture and river flows for four different catchments are higher than that for atmospheric variables. These results suggest to go further for building an operational hydrological seasonal forecast system. Copyright © 2010 Royal Meteorological Society
Cardiac malformations and alteration of TGFβ signaling system in diabetic embryopathy
Authors: Zhao Zhiyong
Published: February 2010

BACKGROUND: Cardiovascular defects are the most common anomalies in diabetic embryopathy. The mechanisms underlying the manifestation of the defects remain to be addressed. METHODS: Female mice were administered streptozotocin to induce diabetes. Embryos from euglycemic (control) and hyperglycemic groups were examined for morphological and histological evaluation of malformations. Cell proliferation and programmed cell death (apoptosis) were assessed using mitotic markers (BrdU and Ki67) and TUNEL assay, respectively. Expression of eight four genes in the TGFβ signaling system was analyzed using real‐time RT‐PCR. RESULTS: Structural abnormalities were observed in the heart and neural tube in diabetic groups, with significantly higher malformation rates than in control groups. Moreover, malformation rates in the heart were higher than those in the neural tube. Cardiac abnormalities including dilated heart tube, smaller ventricles, conotruncal stenosis, and abnormal heart looping were seen during early morphogenesis prior to cardiac septation [embryonic day (E) 9.5–11.5]. Histological examinations showed hypoplastic myocardium and endocardial cushions. After cardiac septation (E15.5), ventricular septal defects were observed, which were manifested in the non‐muscular portion of the septum. Significant decreases in cell proliferation with no differences in apoptosis were observed in the myocardium and endocardial cushions in diabetic compared to control groups. Factors in the TGFβ signaling that regulate heart development were downregulated by maternal diabetes. CONCLUSIONS: Maternal diabetes causes malformations in the heart of the embryo. The heart is more susceptible to maternal diabetic insults than the neural tube. Malformations in the heart prior to septation are associated with decreased cell proliferation, but not increased apoptosis. The TGFβ signaling is involved in cardiac malformations in diabetic embryopathy. Birth Defects Res (Part B) 89:97–105, 2010. © 2010 Wiley‐Liss, Inc.
Hyperglycemia and hypoxia are interrelated in their teratogenic mechanism: studies on cultured rat embryos
Authors: Ornoy Asher , Rand Shiran Bahat , Bischitz Noa
Published: February 2010

BACKGROUND: Hyperglycemia and hypoxia are well‐known teratogens that may affect many animal species, including man. One of the main mechanisms of teratogenic action of both seems to be increased oxidative stress. The purpose of this study was to evaluate the hypothesis that in the developing embryo hyperglycemia also leads to hypoxia, both resulting in oxidative damage. METHODS: The study was performed on 10.5‐day‐old rat embryos of the regular Sabra strain cultured for 28 hours in hyperglycemic or hypoxic conditions. Embryonic growth and rate of anomalies was assessed at the end of the culture period. The embryonic oxidative damage was investigated by studying the levels of Malondialdehyde (MDA) to determine the lipid peroxidation. The redox status was studied by measuring the activity of Catalase‐like (CAT) and Super Oxide Dismutase (SOD) enzymes and the amount of Low Molecular Weight Antioxidants (LMWA). In addition, we studied by immunohistochemistry in the embryos and yolk sacs the amount of nitrotyrosine as an additional marker for the extent of oxidative stress. The amounts of the redox and hypoxia sensitive transcription factors HIF1α, NFkB, and IkB were also studied by immunohistochemistry. RESULTS: Both hyperglycemia and hypoxia increased the rate of congenital anomalies mainly of the heart, neural tube, and brain. Embryonic growth and scoring were decreased only by hypoxia. Both hyperglycemia and hypoxia increased embryonic oxidative stress as evidenced by increased lipid peroxidation, increased nitrotyrosine and LMWA, but only minimal changes in CAT and SOD activity. Severe hyperglycemia also caused hypoxia, as evidenced by increased HIF1α. Thus, there seems to be an interrelation between hyperglycemia and hypoxia, both resulting in embryonic damage apparently by enhanced oxidative stress. CONCLUSIONS: Both hyperglycemia and hypoxia seem to exert their embryotoxicity through a similar mechanism of increased oxidative stress in the embryo in a stage when its antioxidant capacity is still weak. Moreover, hyperglycemia also seems to induce hypoxia, intensifying diabetes‐induced embryopathy. Birth Defects Res (Part B) 89:106–115, 2010. © 2010 Wiley‐Liss, Inc.
Imaginal discs: Renaissance of a model for regenerative biology
Authors: Bergantiños Cora , Vilana Xavier , Corominas Montserrat , Serras Florenci
Published: February 2010

Many animals display a capacity to regenerate tissues or even a complete body. One of the main goals of regenerative biology is to identify the genes and genetic networks necessary for this process. Drosophila offers an ideal model system for such studies. The wide range of genetic and genomic approaches available for use in flies has helped in initiating the deciphering of the mechanisms underlying regeneration, and the results may be applicable to other organisms, including mammals. Moreover, most models of regeneration require experimental manipulation, whereas in Drosophila discrete domains can be ablated by genetically induced methods. Here, we present a summary of current research into imaginal disc regeneration and discuss the power of this tissue as a tool for understanding the genetics of regeneration.
When metabolism meets topology: Reconciling metabolite and reaction networks
Authors: Montañez Raul , Medina Miguel Angel , Solé Ricard V. , Rodríguez‐Caso Carlos
Published: February 2010

The search for a systems‐level picture of metabolism as a web of molecular interactions provides a paradigmatic example of how the methods used to characterize a system can bias the interpretation of its functional meaning. Metabolic maps have been analyzed using novel techniques from network theory, revealing some non‐trivial, functionally relevant properties. These include a small‐world structure and hierarchical modularity. However, as discussed here, some of these properties might actually result from an inappropriate way of defining network interactions. Starting from the so‐called bipartite organization of metabolism, where the two meaningful subsets (reactions and metabolites) are considered, most current works use only one of the subsets by means of so‐called graph projections. Unfortunately, projected graphs often ignore relevant biological and chemical constraints, thus leading to statistical artifacts. Some of these drawbacks and alternative approaches need to be properly addressed.
Electrophoresis today and tomorrow: Helping biologists' dreams come true
Authors: Klepárník Karel , Boček Petr
Published: February 2010

Intensive research and development of electrophoresis methodology and instrumentation during past decades has resulted in unique methods widely implemented in bioanalysis. While two‐dimensional electrophoresis and denaturing polyacrylamide gel electrophoresis in sodium dodecylsulfate are still the most frequently used electrophoretic methods applied to analyses of proteins, new miniaturized capillary and microfluidic versions of electromigrational methods have been developed. High‐throughput electrophoretic instruments with hundreds of capillaries for parallel separations and laser‐induced fluorescence detection of labeled DNA strands have been of key importance for the scientific and commercial success of the Human Genome Project. Another powerful method, capillary isoelectric focusing with pressurized and pH‐driven mobilization, provides efficient separations and on‐line sensitive detection of proteins, bacteria and viruses. Electrophoretic microfluidic devices can integrate single‐cell injection, cell lysis, separation of its components and fluorescence or mass spectrometry detection. These miniaturized devices also proved the capability of single‐molecule detection.