bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of selective breeding for differential rates of 50‐kHz ultrasonic vocalizations on emotional behavior in rats
Authors: Burgdorf Jeffrey , Panksepp Jaak , Brudzynski Stefan M. , Beinfeld Margery C. , Cromwell Howard C. , Kroes Roger A. , Moskal Joseph R.
Published: September 2008

Fifty‐kHz ultrasonic vocalizations have previously been shown to be positively correlated with reward and appetitive social behavior in rats, and to reflect a positive affective state. In this study, rats selectively bred for high and low rates of 50‐kHz vocalizations as juveniles were tested as adults in a battery of behavioral tests for social/emotional behaviors. We found that animals selectively bred for high rates of 50‐kHz vocalizations exhibited more crosses into the center area of the open field apparatus, were more likely to show a preference for a dilute sucrose solution (.8%) compared to tap water, and were less aggressive than randomly bred animals. Conversely, animals bred for low rates of 50‐kHz calls produced more fecal boli during both open field testing and “tickling” stimulation, and made less contact with conspecifics in a social interaction test compared to randomly bred animals. We also observed that low line rats have elevated brain levels of cholecystokinin (CCK) in the cortex, which is consistent with literature showing that CCK content in the cortex is positively correlated with rates of aversive 22‐kHz USVs. Conversely, high line animals had elevated levels of met‐enkephalin in several brain regions, which is consistent with the role of endogenous‐opioids in the generation 50‐kHz USVs and positive affect. These results suggest that animals bred for high rates of 50‐kHz may show a stress resilient phenotype, whereas low line rats may show a stress prone phenotype. As such these animals could provide novel insights into the neurobiology of emotion. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 51: 34–46, 2009
Mouse Fem1b interacts with the Nkx3.1 homeoprotein and is required for proper male secondary sexual development
Authors: Wang Xi , Desai Nishita , Hu Ya‐Ping , Price Sandy M. , Abate‐Shen Cory , Shen Michael M.
Published: September 2008

Previous studies of epithelial cell growth and differentiation in the prostate gland have identified the homeodomain protein Nkx3.1 as a central regulator of prostate development and carcinogenesis. To understand the molecular mechanisms of Nkx3.1 function, we have used yeast two‐hybrid analysis to identify Nkx3.1 interacting proteins, and have isolated Fem1b, a mammalian homolog of the C. elegans sex‐determining gene Fem‐1. In mice, the Fem1b and Nkx3.1 genes encode proteins that interact in glutathione‐S‐transferase (GST) pull‐down and co‐immunoprecipitation assays, and are co‐expressed in the prostate and testis of neonatal mice. Null mutants for Fem1b generated by gene targeting display defects in prostate ductal morphogenesis and secretory protein expression, similar to phenotypes found in Nkx3.1 mutants. We propose that Fem1b may have a conserved role in the generation of sexual dimorphism through its interaction with Nkx3.1 in the developing prostate gland. Developmental Dynamics 237:2963–2972, 2008. © 2008 Wiley‐Liss, Inc.
How degrading: Cyp26s in hindbrain development
Authors: White Richard J. , Schilling Thomas F.
Published: September 2008

The vitamin A derivative retinoic acid performs many functions in vertebrate development and is thought to act as a diffusible morphogen that patterns the anterior–posterior axis of the hindbrain. Recent work in several systems has led to insights into how the spatial distribution of retinoic acid is regulated. These have shown local control of synthesis and degradation, and computational models suggest that degradation by the Cyp26 enzymes plays a critical role in the formation of a morphogen gradient as well as its ability to compensate for fluctuations in RA levels. Developmental Dynamics 237:2775–2790, 2008. © 2008 Wiley‐Liss, Inc.
Primer and interview: Epithelial to mesenchymal transition
Authors: Kiefer Julie C.
Published: September 2008

A complex body plan would not be possible without the evolution of the epithelial to mesenchymal (EMT) transition. This primer introduces the hallmarks of EMT, molecular mechanisms underlying the process, and its role in development and disease. Accompanying the primer is a discussion of current topics in the field with EMT experts Angela Nieto, Ph.D., and Jean Paul Thiery, Ph.D. Developmental Dynamics 237:2769–2774, 2008. © 2008 Wiley‐Liss, Inc.
Baf60c is a component of the neural progenitor‐specific BAF complex in developing retina
Authors: Lamba Deepak A. , Hayes Susan , Karl Mike O. , Reh Thomas
Published: September 2008

Remodeling of the chromatin network plays an important role regulating embryonic development as well as differentiation. The SWI/SNF complex is an ATP‐dependent chromatin‐remodeling complex. It consists of several proteins, including an ATPase subunit, either Brg1 or Brm. Two subunits of this complex, Baf53a and Baf45, have been previously identified as being neural progenitor‐specific. In this study, we show that Baf60c, another important part of this large complex, acts in a similar neural progenitor–specific manner. We show that during development Baf60c is expressed in neural progenitors in human retinas as well as mouse retina, cortex and spinal cord. Baf60c expression is lost during neural differentiation and its overexpression keeps the progenitors in a proliferative state through its interaction with the Notch pathway. Finally, we show that Baf60c is re‐expressed in the Müller glial cells that re‐enter the cell cycle after neurotoxic damage. Developmental Dynamics 237:3016–3023, 2008. © 2008 Wiley‐Liss, Inc.
Androgen receptor gene expression in the developing and adult zebrafish brain
Authors: Gorelick Daniel A. , Watson William , Halpern Marnie E.
Published: September 2008

Androgens play a central role in the regulation of male sexual differentiation and behavior in many vertebrates, including zebrafish. Their signaling is mediated by activation of the androgen receptor. A single androgen receptor (ar) gene was recently identified in zebrafish, which encodes a protein that binds androgens in vitro. However, the tissue‐specific expression pattern of this receptor in vivo has not been described. Using whole‐mount RNA in situ hybridization, we characterized expression of the ar gene in developing zebrafish and in the adult brain. In embryos, transcripts were found in the presumptive pronephros and in olfactory placodes. By 3–5 days postfertilization, ar transcripts were also detected in the pineal organ anlage and the retina. In the adult brain, ar was expressed in discrete regions of the telencephalon, in the preoptic area, and throughout the periventricular hypothalamus, regions previously implicated in the regulation of sexually dimorphic behaviors in mammals. Developmental Dynamics 237:2987–2995, 2008. © 2008 Wiley‐Liss, Inc.
Generation of oocyte‐specifically expressed cre transgenic zebrafish for female germline excision of loxp‐flanked transgene
Authors: Liu Xingjun , Li Zhen , Emelyanov Alexander , Parinov Serguei , Gong Zhiyuan
Published: September 2008

In this communication, we report the generation of a cre transgenic zebrafish line under an oocyte‐specific promoter, zp3. The transgenic line Tg(zp3:cre; krt8:rfp) also contains a co‐integrated rfp transgene under the skin epithelial promoter krt8 to allow selection of cre transgenic fish based on RFP fluorescence in the skin. We demonstrated in this transgenic line that cre mRNA was specifically expressed in growing oocytes like endogenous zp3 mRNA. When Tg(zp3:cre; krt8:rfp) was crossed with a loxP transgenic line, the floxed DNA was specifically eliminated from female, but not male, germline. Tg(zp3:cre; krt8:rfp) fish also have maternal cre mRNA in early embryos to cause Cre‐mediated recombination; this feature can be used to activate other loxP transgenic lines in early embryos. Furthermore, after crossing with another loxP transgenic line, Tg(EF:loxP‐mCherry‐loxP‐egfp), we confirmed that our cre line was capable of activating a loxP‐blocked EGFP reporter gene by both maternal and oocyte‐expressed Cre. Developmental Dynamics 237:2955–2962, 2008. © 2008 Wiley‐Liss, Inc.
Dynamic GATA6 expression in primitive endoderm formation and maturation in early mouse embryogenesis
Authors: Cai Kathy Q. , Capo‐Chichi Callinice D. , Rula Malgorzata E. , Yang Dong‐Hua , Xu Xiang‐Xi
Published: September 2008

The derivation of the primitive endoderm layer from the pluripotent cells of the inner cell mass is one of the earliest differentiation and morphogenic events in embryonic development. GATA4 and GATA6 are the key transcription factors in the formation of extraembryonic endoderms, but their specific contribution to the derivation of each endoderm lineage needs clarification. We further analyzed the dynamic expression and mutant phenotypes of GATA6 in early mouse embryos. GATA6 and GATA4 are both expressed in primitive endoderm cells initially. At embryonic day (E) 5.0, parietal endoderm cells continue to express both GATA4 and GATA6; however, visceral endoderm cells express GATA4 but exhibit a reduced expression of GATA6. By and after E5.5, visceral endoderm cells no longer express GATA6. We also found that GATA6 null embryos did not form a morphologically recognizable primitive endoderm layer, and subsequently failed to form visceral and parietal endoderms. Thus, the current study establishes that GATA6 is essential for the formation of primitive endoderm, at a much earlier stage then previously recognized, and expression of GATA6 discriminates parietal endoderm from visceral endoderm lineages. Developmental Dynamics 237:2820–2829, 2008. © 2008 Wiley‐Liss, Inc.
Essential role for fibrillin‐2 in zebrafish notochord and vascular morphogenesis
Authors: Gansner John M. , Madsen Erik C. , Mecham Robert P. , Gitlin Jonathan D.
Published: September 2008

Recent studies demonstrate that lysyl oxidase cuproenzymes are critical for zebrafish notochord formation, but the molecular mechanisms of copper‐dependent notochord morphogenesis are incompletely understood. We, therefore, conducted a forward genetic screen for zebrafish mutants that exhibit notochord sensitivity to lysyl oxidase inhibition, yielding a mutant with defects in notochord and vascular morphogenesis, puff daddygw1 (pfdgw1). Meiotic mapping and cloning reveal that the pfdgw1 phenotype results from disruption of the gene encoding the extracellular matrix protein fibrillin‐2, and the spatiotemporal expression of fibrillin‐2 is consistent with the pfdgw1 phenotype. Furthermore, each aspect of the pfdgw1 phenotype is recapitulated by morpholino knockdown of fibrillin‐2. Taken together, the data reveal a genetic interaction between fibrillin‐2 and the lysyl oxidases in notochord formation and demonstrate the importance of fibrillin‐2 in specific early developmental processes in zebrafish. Developmental Dynamics 237:2844–2861, 2008. © 2008 Wiley‐Liss, Inc.
Maternal Tgif1 regulates nodal gene expression in Xenopus
Authors: Kerr Tyler C. , Cuykendall Tawny N. , Luettjohann Laura C. , Houston Douglas W.
Published: September 2008

In Xenopus, the maternal transcription factor VegT is necessary and sufficient to initiate the expression of nodal‐related genes, which are central to many aspects of early development. However, little is known about regulation of VegT activity. Using maternal loss‐of‐function experiments, we show that the maternal homeoprotein, Tgif1, antagonizes VegT and plays a central role in anteroposterior patterning by negatively regulating a subset of nodal‐related genes. Depletion of Tgif1 causes the anteriorization of embryos and the up‐regulation of nodal paralogues nr5 and nr6. Furthermore, Tgif1 inhibits activation of nr5 by VegT in a manner that requires a C‐terminal Sin3 corepressor‐interacting domain. Tgif1 has been implicated in the transcriptional corepression of transforming growth factor‐beta (TGFβ) and retinoid signaling. However, we show that Tgif1 does not inhibit these pathways in early development. These results identify an essential role for Tgif1 in the control of nodal expression and provide insight into Tgif1 function and mechanisms controlling VegT activity. Developmental Dynamics 237:2862–2873, 2008. © 2008 Wiley‐Liss, Inc.
Toward understanding the morphogenesis of siliceous spicules in freshwater sponge: Differential mRNA expression of spicule‐type‐specific silicatein genes in Ephydatia fluviatilis
Authors: Mohri Kurato , Nakatsukasa Mikiko , Masuda Yoshiki , Agata Kiyokazu , Funayama Noriko
Published: September 2008

Siliceous spicules of sponges are morphologically diverse and provide good models for understanding the morphogenesis of biomineralized products. The silica deposition enzyme silicatein is a component of siliceous spicules of sponges and is thought to be the key molecule determining the morphology of spicules. Here, we focused on the silicateins of the freshwater sponge Ephydatia fluviatilis, which has two types of morphologically and functionally different spicules, called megascleres and gemmoscleres. We isolated six isoforms of silicateins and examined their mRNA expression in the cells producing megascleres and gemmoscleres. The spicule‐type‐specific mRNA expression of these isoforms and differential expression during spicule development suggest that the characteristic morphology of spicules is due to the specific properties and combinatory functions of silicatein isoforms. Developmental Dynamics 237:3024–3039, 2008. © 2008 Wiley‐Liss, Inc.
Gli3‐deficient mice exhibit cleft palate associated with abnormal tongue development
Authors: Huang Xi , Goudy Steven L. , Ketova Tatiana , Litingtung Ying , Chiang Chin
Published: September 2008

Palatogenesis depends on appropriate growth, elevation, and fusion of the palatal shelves and aberration in these processes can lead to palatal clefting. We observed a high incidence of palate clefting in mice deficient in Gli3, known for its role as a repressor in the absence of Shh signaling. In contrast with several current mouse models of cleft palate, Meckel's cartilage extension, cranial neural crest migration, palatal shelf proliferation, apoptosis, and key signaling components mediated by Shh, Bmp, Fgf, and Tgfβ, appeared unaffected in Gli3−/− mice. Palatal clefting in Gli3−/− mice was consistently associated with tongue abnormalities such as failure to flatten and improper positioning, implicating a critical role of Gli3 and normal tongue morphogenesis for timely palatal shelf elevation and joining. Furthermore, Gli3−/− palatal shelves grown in roller cultures without tongue can fuse suggesting that the abnormal tongue is likely an impediment for palatal shelf joining in Gli3−/− mutants. Developmental Dynamics 237:3079–3087, 2008. © 2008 Wiley‐Liss, Inc.
Retinoic acid down‐regulates Tbx1 expression and induces abnormal differentiation of tongue muscles in fetal mice
Authors: Okano Junko , Sakai Yasuo , Shiota Kohei
Published: September 2008

Excess retinoic acid (RA) during pregnancy can cause various developmental anomalies in both humans and rodents. We investigated the mechanisms underlying the aberrant differentiation of tongue muscles in fetal mice exposed to exogenous RA in utero. RA‐degrading enzymes (Cyp26a1 and Cyp26b1) were expressed at early stages of normal tongue development, but exogenous RA perturbed their expression in the fetal tongue. RA is normally distributed in the developing tongue muscles but its localization was disrupted by exogenous RA. After RA treatment, myogenic determination factors were reduced and the differentiation was significantly suppressed in tongue muscles. Tbx1, a candidate gene of DiGeorge syndrome, was down‐regulated in the fetal tongue in response to excess RA. Moreover, Tbx1 as well as myogenic determination factors were not observed in tongue muscle primordia of Cyp26b1−/− fetuses. Our study suggests that RA signaling may play an essential role in tongue muscle differentiation via the regulation of Tbx1. Developmental Dynamics 237:3059–3070, 2008. © 2008 Wiley‐Liss, Inc.
Properties of branchiomeric and somite‐derived muscle development in Tbx1 mutant embryos
Authors: Grifone Raphälle , Jarry Thérèse , Dandonneau Mathieu , Grenier Julien , Duprez Delphine , Kelly Robert G.
Published: September 2008

Vertebrate craniofacial and trunk myogenesis are regulated by distinct genetic programs. Tbx1, homologue of the del22q11.2 syndrome candidate gene TBX1, controls branchiomeric craniofacial muscle development. Here, we demonstrate using immunohistochemistry that myogenic regulatory factors are activated in Tbx1‐positive cells within pharyngeal mesoderm. These cells are also Islet1 and Capsulin‐positive and in the absence of Tbx1 persist in the core of the first arch. Sporadic hypoplastic mandibular muscles in Tbx1−/− embryos contain Pax7‐positive myocytes with indistinguishable differentiation properties from wild‐type muscles and have normal tendon attachments and fiber‐type patterning. In contrast to TBX1 haploinsufficient del22q11.2 syndrome patients, no alteration in fiber‐type distribution was detected in Tbx1+/− adult masseter and pharyngeal constrictor muscles. Furthermore, Tbx1‐expressing limb muscles display normal patterning, differentiation, fiber‐type growth, fiber‐type distribution and fetal maturation in the absence of Tbx1. The critical requirement for Tbx1 during muscle development is thus in the robust onset of myogenic specification in pharyngeal mesoderm. Developmental Dynamics 237:3071–3078, 2008. © 2008 Wiley‐Liss, Inc.
Temporal and spatial expression of collagens during murine atrioventricular heart valve development and maintenance
Authors: Peacock Jacqueline D. , Lu Yinhui , Koch Manuel , Kadler Karl E. , Lincoln Joy
Published: September 2008

Heart valve function is achieved by organization of matrix components including collagens, yet the distribution of collagens in valvular structures is not well defined. Therefore, we examined the temporal and spatial expression of select fibril‐, network‐, beaded filament‐forming, and FACIT collagens in endocardial cushions, remodeling, maturing, and adult murine atrioventricular heart valves. Of the genes examined, col1a1, col2a1, and col3a1 transcripts are most highly expressed in endocardial cushions. Expression of col1a1, col1a2, col2a1, and col3a1 remain high, along with col12a1 in remodeling valves. Maturing neonate valves predominantly express col1a1, col1a2, col3a1, col5a2, col11a1, and col12a1 within defined proximal and distal regions. In adult valves, collagen protein distribution is highly compartmentalized, with ColI and ColXII observed on the ventricular surface and ColIII and ColVa1 detected throughout the leaflets. Together, these expression data identify patterning of collagen types in developing and maintained heart valves, which likely relate to valve structure and function. Developmental Dynamics 237:3051–3058, 2008. © 2008 Wiley‐Liss, Inc.
The developmental sequence of gene expression within the rod photoreceptor lineage in embryonic zebrafish
Authors: Nelson Steve M. , Frey Ruth A. , Wardwell Sheri L. , Stenkamp Deborah L.
Published: September 2008

In postembryonic zebrafish, rod photoreceptors are continuously generated from progenitors in the inner nuclear layer, which are derived from radial Müller glia that express the transcription factor pax6. We used BrdU incorporation, in combination with in situ hybridization for cell‐specific transcription factors, to establish the patterns of gene expression during rod lineage maturation in the embryonic zebrafish. Downregulation of pax6 expression was accompanied by sporadic upregulation of expression of the transcription factors NeuroD/nrd, rx1, crx, and Nr2e3/pnr. As cells of the rod lineage entered the outer nuclear layer, they became homogeneous, coordinately expressing NeuroD, rx1, crx, and Nr2e3. Postmitotic, maturing rods also expressed nrl, rod opsin, and rod transducin/gnat1. The presence of rx1 within the rod lineage and in maturing rods indicates that rx1 is not cone‐specific, as previously reported, and suggests a high degree of molecular similarity between rod and cone progenitor populations in the zebrafish. Developmental Dynamics 237:2903–1917, 2008. © 2008 Wiley‐Liss, Inc.
Identification and characterization of subpopulations of Pax3 and Pax7 expressing cells in developing chick somites and limb buds
Authors: Galli Lisa M. , Knight Sara R. , Barnes Tiffany L. , Doak Allison K. , Kadzik Rachel S. , Burrus Laura W.
Published: September 2008

Immunostaining of a transverse section of a HH st 18 chick embryo with Pax3 (green), Pax7 (blue), and MyoD (red) is shown in the upper left panel. All other panels display the same markers in different colors. The image was collected by confocal microscopy. See Galli et al., Developmental Dynamics 237:1862‐1874. © 2008 Wiley‐Liss, Inc.
Lack of galectin‐3 alters the balance of innate immune cytokines and confers resistance to Rhodococcus equi infection
Authors: Ferraz Luciana C. , Bernardes Emerson S. , Oliveira Aline F. , Ruas Luciana P. , Fermino Marise L. , Soares Sandro G. , Loyola Adriano M. , Oliver Constance , Jamur Maria C. , Hsu Daniel K. , Liu Fu‐Tong , Chammas Roger , Roque‐Barreira Maria‐Cristina
Published: September 2008

Galectin‐3 is a β‐galactoside‐binding lectin implicated in the fine‐tuning of innate immunity. Rhodococcus equi, a facultative intracellular bacterium of macrophages, causes severe granulomatous bronchopneumonia in young horses and immunocompromised humans. The aim of this study is to investigate the role of galectin‐3 in the innate resistance mechanism against R. equi infection. The bacterial challenge of galectin‐3‐deficient mice (gal3−/−) and their wild‐type counterpart (gal3+/+) revealed that the LD50 for the gal3−/− mice was about seven times higher than that for the gal3+/+ mice. When challenged with a sublethal dose, gal3−/− mice showed lower bacteria counts and higher production of IL‐12 and IFN‐γ production, besides exhibiting a delayed although increased inflammatory reaction. Gal3−/− macrophages exhibited a decreased frequency of bacterial replication and survival, and higher transcript levels of IL‐1β, IL‐6, IL‐10, TLR2 and MyD88. R. equi‐infected gal3+/+ macrophages showed decreased expression of TLR2, whereas R. equi‐infected gal3−/− macrophages showed enhanced expression of this receptor. Furthermore, galectin‐3 deficiency in macrophages may be responsible for the higher IL‐1β serum levels detected in infected gal3−/− mice. Therefore galectin‐3 may exert a regulatory role in innate immunity by diminishing IL‐1β production and thus affecting resistance to R. equi infection.
IFN‐β regulates CD73 and adenosine expression at the blood–brain barrier
Authors: Niemelä Jussi , Ifergan Igal , Yegutkin Gennady G. , Jalkanen Sirpa , Prat Alexander , Airas Laura
Published: September 2008

IFN‐β treatment reduces the relapse rate in MS but its mechanism of action remains incompletely understood. Our aim was to clarify the beneficial effect of IFN‐β in the treatment of MS. We assessed the influence of IFN‐β treatment on (i) CD73 expression on the surface of primary cultures of human blood–brain barrier endothelial cells (BBB‐EC) and human astrocytes using immunofluorescence staining and flow cytometry, (ii) transmigration of CD4+ T lymphocytes using an in vitro model of BBB and (iii) CD73 enzyme activity, i.e. ecto‐5′‐nucleotidase activity in the serum of MS patients using a radiochemical assay. IFN‐β increases the expression of ecto‐5′‐nucleotidase both on BBB‐EC and astrocytes. As a consequence, lymphocyte transmigration through BBB‐EC is reduced. Importantly, this reduction can be reversed using α,β‐methyleneadenosine‐5′‐diphosphate, a specific inhibitor of ecto‐5′‐nucleotidase. CD73 is strongly expressed in microvasculature in samples of postmortem MS brain and, moreover, in the majority of MS patients there was a clear upregulation both in the soluble serum ecto‐5′‐nucleotidase activity and skin microvascular CD73 expression after IFN‐β treatment. Upregulation of ecto‐5′‐nucleotidase and a subsequent increase in adenosine production might contribute to the beneficial effects of IFN‐β on MS via enhancing the endothelial barrier function.
Slow‐Proton Dynamics within a Zirconium‐Containing Sandwich‐Like Complex Based on the Trivacant Anion α‐[SiW9O34]10– – Synthesis, Structure and NMR Spectroscopy
Authors: Leclerc‐Laronze Nathalie , Marrot Jérôme , Haouas Mohamed , Taulelle Francis , Cadot Emmanuel
Published: September 2008

Reaction of ZrOCl2 with the potassium tungstosilicate A‐α‐[SiW9O34]10– in water at pH = 4 leads to the formation of the sandwich‐type complex [Zr3O(OH)2(SiW9O34)2]12– (H2‐1) which has been structurally characterised by single‐crystal X‐ray diffraction. It consists of a [Zr3O(OH)2] triangular central cluster closely embedded between two A‐α‐[SiW9O34]10– subunits. Inspection of the geometric parameters within the {Zr3O3} core unambiguously reveals the presence of two attached protons giving two hydroxo Zr–OH–Zr bridges and a single oxo Zr–O–Zr junction. The anions Hx‐1 with x = 3, 2 or 1 were obtained in solution at pH = 2, 4 and 7.5, respectively, and were subsequently characterised by 183W and 29Si NMR spectroscopy in aqueous solution. 183W NMR spectra appear strongly dependent upon the protonation state of the trizirconium central core, {HxZr3O3}. 183W NMR spectroscopy of H2‐1 gives a two‐line spectrum, consistent only with the hopping of the two H+ ions over the three bridging Zr–O–Zr oxygen atoms. Interestingly, the resonance attributed to the six tungsten atoms of the belt connected to the zirconium atoms through W–O–Zr junctions exhibits substantial line‐broadening (Δν1/2 = 21 Hz) interpreted as a slow dynamic process involving the H+ ions. Such behaviour contrasts with the fast H+ mobility generally observed in other POM systems and this will be discussed in relation to the peculiar environment of the {Zr3O3} core which hinders structural relaxation consequent with the H+ hopping. Both 183W resonances of the H3‐1 anion remain sharp as usual (Δν1/2 = 1.6 Hz) consistent with the presence of the triprotonated species [Zr3(OH)3(SiW9O34)2]11– whereas for the monoprotanated anion (H‐1), the resonance of the belt becomes broad enough to be indistinguishable. Infrared spectroscopy, elemental analysis, pH titration and polarographic measurements of Hx‐1 were also carried out.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Gas‐Phase Chemistry of Vanadium Oxide Cluster Cations VmOn+ (m = 1–4; n = 1–10) with Water and Molecular Oxygen
Authors: Feyel Sandra , Schröder Detlef , Schwarz Helmut
Published: September 2008

Bare vanadium oxide cluster cations VmOn+ (m = 1–4; n =1–10) generated by electrospray ionization are investigated with respect to their reactivity toward water and molecular oxygen by using mass spectrometric techniques. Besides ion hydration, the ion/molecule reactions of VmOn+ with oxygen‐labeled water (H218O) also lead to 16O/18O exchange reactions of the vanadium oxide clusters cations. Although the probability of degenerate 16O/18O exchange between VmOn+ and water is fairly high for the cluster cations with a medium valence state of vanadium, oxygen‐atom exchange reactions between VmOn+ and 18O2 can only be accomplished by VO+, V3O6+, and V4O8+. Particularly interesting is the fact that not only oxygen atoms from vanadyl units are exchanged in the cluster cations, but bridging oxygen atoms are also most likely involved in the processes. Other reaction channels for the interaction of VmOn+ cluster cations with molecular oxygen are reported as well, such as oxidative degradation of the low‐valent cluster cations upon collision with O2 and formation of association complexes for the high‐valent cluster cations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Green Catalysts: Solid‐Phase Peptide Carbene Ligands in Aqueous Transition‐Metal Catalysis
Authors: Worm‐Leonhard Kasper , Meldal Morten
Published: September 2008

A series of functionalized imidazolium ions containing a pyridine moiety and carboxylic acid functionality has been synthesized in solution. These compounds serve asN‐heterocyclic carbene precursors and were attached to a dipeptide on solid support by means of standard peptide coupling techniques. Treatment with base generated the corresponding carbenes, which were directly complexed to palladium(II) and subsequently studied by mass spectrometry and NMR spectroscopy. The supported monocarbene catalyst7was successfully applied in Sonogashira and Suzuki cross‐coupling reactions, and the cross‐coupling products were isolated in excellent yield. Bis(carbene) catalyst8was successfully applied in solution in high‐yielding Suzuki cross‐coupling reactions. Furthermore, the catalysts proved to be stable in aqueous media, which allowed the Suzuki cross‐coupling reactions to be performed in water. No loss of catalytic activity was observed when supported catalyst7was recycled and subjected to repetitive cycles of Suzuki cross‐coupling reactions in water.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Nα‐Fmoc‐Protected ω‐Azido‐ and ω‐Alkynyl‐L‐amino Acids as Building Blocks for the Synthesis of “Clickable” Peptides
Authors: Le Chevalier Isaad Alexandra , Barbetti Francesca , Rovero Paolo , D'Ursi Anna Maria , Chelli Mario , Chorev Michael , Papini Anna Maria
Published: September 2008

The growing interest in the 1,4‐disubstituted‐1,2,3‐triazolyl moiety as an amide bond surrogate and its formation through very mild, chemoselective, and bioorthogonal CuI‐catalyzed Huisgen 1,3‐dipolar [3+2] cycloaddition of an alkynyl to an azido function, presented an unmet need for specifically designed α‐amino‐acid‐derived building blocks. Herein we report the synthesis of unnatural homologous series of Nα‐Fmoc‐protected ω‐yne‐ and ω‐azido‐L‐amino acids compatible with the Fmoc/tBu‐based solid‐phase peptide synthesis. These building blocks can be incorporated into pseudopeptides that can serve as precursors of inter‐ and intramolecular click reactions. The homologous Nα‐Fmoc‐ω‐azido‐L‐amino acids were prepared from either the ω‐amino or the ω‐hydroxy precursors by the respective diazo‐transfer reactions and sequential nucleophilic substitutions initially by halide followed by azide. The homologous Nα‐Fmoc‐ω‐yne‐L‐amino acids were prepared by alkylation of a chiral auxiliary, which is a NiII complex of Schiff base derived from glycine and (S)‐2‐(N‐benzylprolyl)aminobenzophenone, with ω‐bromoalkynes. These building blocks will be instrumental for constructing side‐chain modified peptides, interside‐chain peptide chimera, peptide small molecule conjugates, and cyclopeptides, which were cyclized through 1,4‐disubstituted 1,2,3‐triazolyl‐containing side‐chain‐to‐side‐chain bridges. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Nucleophilic Trifluoromethylation of Imines under Acidic Conditions
Authors: Levin Vitalij V. , Dilman Alexander D. , Belyakov Pavel A. , Struchkova Marina I. , Tartakovsky Vladimir A.
Published: September 2008

A general method for the trifluoromethylation of imines by using Me3SiCF3 under acidic conditions is described. The reaction is promoted by hydrofluoric acid generated in situ from KHF2 and either TFA or TfOH. A new chemoselectivity pattern was achieved, as the C=N bond was found to be more reactivate than the carbonyl group. The trifluoromethylation reaction is believed to proceed by concerted transfer of the CF3 group from the silicon atom to the iminium electrophile. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The Intermolecular Pauson–Khand Reaction of meso‐Substituted Porphyrins (Eur. J. Org. Chem. 29/2008)
Authors: Horn Sabine , Senge Mathias O.
Published: September 2008

The cover picture shows the products of the intermolecular Pauson–Khand reaction of meso‐substituted porphyrins. In addition to various monomers, this method offers easy access to porphyrin dimers with well‐defined stereochemistries. Details are discussed in the article by S. Horn and M. O. Senge from Trinity College Dublin on p. 4881 ff.
Probabilistic risk modeling at the wildland urban interface: the 2003 Cedar Fire
Authors: Brillinger D. R. , Autrey B. S. , Cattaneo M. D.
Published: September 2008

The October 2003 Cedar Fire in San Diego County was a tragedy involving 15 deaths, the burning of some 280 000 acres of land, the destruction of approximately 2227 homes, and costs of suppression near $30 million. It was the largest fire in California history. The data associated with the fire, however, do provide an opportunity to carry out probabilistic risk modeling of a wildland‐urban interface (WUI) event. WUI's exist where humans and their development interface with wildland fuel. As home building expands from urban areas to nearby forest areas, these homes become more likely to burn.

Wildfires are an exceedingly complex phenomenon with uncertainty and unpredictability abounding, hence a statistical approach to gaining insight appears useful. In this research, spatial stochastic models are developed. These relate risk probabilities and losses measures to a variety of available explanatory quantities. There is a consideration of economic aspects and a discussion of the difficulties that arose in developing the data and of carrying out the analyses. Purposes of the work include highlighting a statistical method, developing variates associated with a destruction probability and employing the fitted risk probability to estimate future and possible losses. Copyright © 2008 John Wiley & Sons, Ltd.
Long‐term stability of biological denitrification process for high strength nitrate removal from wastewater of uranium industry
Authors: Biradar Prashant M. , Dhamole Pradip B. , Nair Rashmi R. , Roy S.B. , Satpati S.K. , D'Souza Stanislaus F. , Lele S.S. , Pandit A.B.
Published: September 2008

The aim of the present study was to biologically denitrify uranium nitrate raffinate (UNR) from nuclear industry, which is a principle source of high strength nitrate waste. To denitrify the high nitrate waste, a pilot‐scale continuous stirred tank reactor was designed with two inbuilt settlers. Acclimatization of mixed culture with synthetic waste was carried out prior to the inoculation of the acclimatized sludge into the reactor. Initial concentration of nitrate in uranium raffinate was 77,000 mg/L NO3. It was diluted and used as a feed to the reactor. Concentration of nitrate in feed was increased gradually from 10,000 mg/L NO3 to 40,000 mg/L NO3 with hydraulic retention time (HRT) maintained at 34.4 h. Complete denitrification of 40,000 mg/L NO3 was achieved in a specified HRT.

To facilitate understanding of the treatablity and long‐term stability of biological denitrification of UNR, study was carried out for 211 days by periodical perturbation of the system. Furthermore, to find the volume ratio of reactor to settler required for the full‐scale design of the denitrification plant, settling of acclimatized sludge was carried out. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Influence of exhaust hood geometry on the capture efficiency of lateral exhaust and push–pull ventilation systems in surface treatment tanks
Authors: González Enrique , Marzal Francisco , Miñana Agustín , Doval Marta
Published: September 2008

In a local exhaust ventilation system, where the pollutant or the emitted flows are captured near the generated source, the knowledge of the capture efficiency is necessary to evaluate performance. This article reports a study of the influence of the exhaust hood slot height on the capture efficiency. For this study, the emission of gases and vapors from open surface tanks used in industrial treatments has been simulated in an installation fitted with two ventilation systems: lateral exhaust and push–pull. Several configurations were possible by varying the geometrical and operational conditions. Both qualitative and quantitative evaluations have been performed, the former through observations of the flows using smoke and the latter by using sulfur hexafluoride as tracer gas. The results obtained on capture efficiency for both ventilation systems tested with several exhaust slot height and as a function of the operating flows rates, are presented. It was found that varying the exhaust slot height between 15 and 45 cm had no effect on capture efficiency. The results show that there are no significant differences between the exhaust slots heights tested, although, in the case of 60 cm for lateral exhaust ventilation, the efficiency was slightly lower. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Pollution reduction and energy savings of a coupled two‐kiln system for bricks making
Authors: Chavez Rosa‐Hilda
Published: September 2008

Atmospheric pollution is one of the most important current environmental problems, becoming a phenomenon that could reach levels of serious consequences with irreversible environmental impacts. In Mexico, like in several other countries, brickmakers carry out brick production by burning mixtures of different heavy fuels. Because of the wide variety of fuels used, it is necessary to determine what types of residual gases are generated, in order to propose remedial treatments in production or to introduce substitution technologies. These preventive actions need to be put in place in order to comply with the Ecological Balance and Environment Protection Federal Law. Brick kilns emit pollutant gases and particles that remain in the air, causing a serious health hazard to the near‐factory residents. Amongst these pollutants are carbon monoxide (CO), sulfur oxides (SOx), and hydrocarbons. This article presents the results of the analysis of a novel two‐kiln coupled system. This experimental analysis includes the determination of the combustion products for gases and particulate matter generated from the burning of the heavy fuels using gas chromatography and scanning electron microscopy. Field data also allowed the determination of energy savings for this system, mainly because of the reduction of the consumption of fuel. Fortunately, these results show a combined 39% energy savings and a reduction of pollutants and particle emissions, as compared to the standard currently‐in‐use brick‐production systems. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Blind channel identification in Alamouti coded systems: a comparative study of eigendecomposition methods in indoor transmissions at 2.4 GHz
Authors: Pérez‐Iglesias Héctor J. , García‐Naya José A. , Dapena Adriana , Castedo Luis , Zarzoso Vicente
Published: September 2008

This paper focuses on blind channel estimation in Alamouti coded systems with one receiving antenna working in indoor scenarios where the flat fading assumption is reasonable. A comparative study of several channel estimation techniques in both simulated and realistic scenarios is presented. The tested methods exploit the orthogonality property of the Alamouti coded channel matrix, and are based on the eigendecomposition of a square matrix made up of second‐order statistics (SOS) or higher order statistics (HOS) of the observed signals. An experimental evaluation is carried out on a testbed developed at the University of A Coruña (UDC) and operating at 2.4 GHz. The results show the superior performance of the SOS‐based blind channel estimation technique in both line of sight (LOS) and non‐LOS (NLOS) channels. Copyright © 2008 John Wiley & Sons, Ltd.
Modelling the daily banknotes in circulation in the context of the liquidity management of the European Central Bank
Authors: Cabrero Alberto , Camba‐Mendez Gonzalo , Hirsch Astrid , Nieto Fernando
Published: September 2008

The main focus of this paper is to model the daily series of banknotes in circulation. The series of banknotes in circulation displays very marked seasonal patterns. To the best of our knowledge the empirical performance of two competing approaches to model seasonality in daily time series, namely the ARIMA‐based approach and the Structural Time Series approach, has never been put to the test. The application presented in this paper provides valid intuition on the merits of each approach. The forecasting performance of the models is also assessed in the context of their impact on the liquidity management of the Eurosystem.  Copyright © 2008 John Wiley & Sons, Ltd.
Hippocampal, amygdala, and neocortical synchronization of theta rhythms is related to an immediate recall during rey auditory verbal learning test
Authors: Babiloni Claudio , Vecchio Fabrizio , Mirabella Giovanni , Buttiglione Maura , Sebastiano Fabio , Picardi Angelo , Di Gennaro Giancarlo , Quarato Pier P. , Grammaldo Liliana G. , Buffo Paola , Esposito Vincenzo , Manfredi Mario , Cantore Giampaolo , Eusebi Fabrizio
Published: September 2008

It is well known that theta rhythms (3–8 Hz) are the fingerprint of hippocampus, and that neural activity accompanying encoding of words differs according to whether the items are later remembered or forgotten [“subsequent memory effect” (SME)]. Here, we tested the hypothesis that temporal synchronization of theta rhythms among hippocampus, amygdala, and neocortex is related to immediate memorization of repeated words. To address this issue, intracerebral electroencephalographic (EEG) activity was recorded in five subjects with drug‐resistant temporal lobe epilepsy (TLE), under presurgical monitoring routine. During the recording of the intracerebral EEG activity, the subjects performed a computerized version of Rey auditory verbal learning test (RAVLT), a popular test for the clinical evaluation of the immediate and delayed memory. They heard the same list of 15 common words for five times. Each time, immediately after listening the list, the subjects were required to repeat as many words as they could recall. Spectral coherence of the intracerebral EEG activity was computed in order to assess the temporal synchronization of the theta (about 3–8 Hz) rhythms among hippocampus, amygdala, and temporal‐occipital neocortex. We found that theta coherence values between amygdala and hippocampus, and between hippocampus and occipital‐temporal cortex, were higher in amplitude during successful than unsuccessful immediate recall. A control analysis showed that this was true also for a gamma band (40–45 Hz). Furthermore, these theta and gamma effects were not observed in an additional (control) subject with drug‐resistant TLE and a wide lesion to hippocampus. In conclusion, a successful immediate recall to the RAVLT was associated to the enhancement of temporal synchronization of the theta (gamma) rhythms within a cerebral network including hippocampus, amygdala, and temporal–occipital neocortex. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Strong resemblance in the amplitude of oscillatory brain activity in monozygotic twins is not caused by “trivial” similarities in the composition of the skull
Authors: van 't Ent Dennis , van Soelen Inge L.C. , Stam Cornelis J. , De Geus Eco J.C. , Boomsma Dorret I.
Published: September 2008

Previous twin studies have shown strong heritability of electroencephalogram amplitude characteristics, such as power spectra. However, it has been suggested that these high heritabilities may reflect “trivial” twin resemblance in intervening tissues such as the skull. Here we demonstrate strong monozygotic twin correlation (0.79 < r < 0.88) of eyes‐closed resting‐state magnetoencephalogram power, which is insensitive to intervening tissues. These results confirm that brain activity itself is highly heritable. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Extensions to decomposition of the redistributive effect of health care finance
Authors: Zhong Hai
Published: September 2008

The total redistributive effect (RE) of health‐care finance has been decomposed into vertical, horizontal and reranking effects. The vertical effect has been further decomposed into tax rate and tax structure effects. We extend this latter decomposition to the horizontal and reranking components of the RE. We also show how to measure the vertical, horizontal and reranking effects of each component of the redistributive system, allowing analysis of the RE of health‐care finance in the context of that system. The methods are illustrated with application to the RE of health‐care financing in Canada. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation, characterization, and evaluation of radiopaque hydrogel filaments for endovascular embolization
Authors: Constant Michael J. , Keeley Edward M. , Cruise Gregory M.
Published: September 2008

Radiopaque hydrogel filaments were prepared, characterized, and evaluated for potential use as implants for endovascular embolization of vascular defects. Three hydrogel formulations were prepared by free radical polymerization: (i) poly(ethylene glycol) diacrylate with 2,4,6‐triiodophenyl penta‐4‐enoate (PEG‐I), (ii) poly(ethylene glycol) diacrylamide with barium sulfate (PEG‐B), and (iii) poly(propylene glycol) diacrylate with barium sulfate (PPG‐B). The PEG‐B and PPG‐B hydrogels exhibited radiopacity comparable with clinically used platinum coils, whereas the PEG‐I hydrogel did not. In the dry state, the average ultimate tensile strength and strain of the hydrogels ranged from 37 to 128 gf and 21% to 72%, respectively. The PEG‐B hydrogel had significantly higher tensile strength compared with the PEG‐I hydrogel. In the hydrated state, the average ultimate tensile strength and strain ranged from 5 to 15 gf and 7% to 30%, respectively. Statistically significant differences in tensile strength were not present when hydrated. Compared with poly(ethylene) after 4‐week implantation into the subcutaneous space of rabbits, the PEG‐I hydrogel elicited slightly more inflammation, whereas the PEG‐B and PPG‐B hydrogels elicited less inflammation. All three hydrogel formulations elicited less fibrous encapsulation than poly(ethylene). With further development, these materials have potential as embolization devices. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Cephalexin‐loaded injectable macroporous calcium phosphate bone cement
Authors: Hesaraki Saeed , Nemati Roghayeh
Published: September 2008

Different types of calcium phosphate cements (CPCs) have been studied as potential matrices for incorporating different types of antibiotics. All of these matrices were morphologically microporous whereas macroporosity is essential for rapid cement resorption and bone replacement. In this study, liberation of cephalexin monohydrate (CMH) from a macroporous CPC was investigated over 0.5–300 h in simulated body fluid and some mathematical models were fitted to the release profiles. Macroporosity was introduced into the cement matrix by using sodium dodecyl sulfate molecules as air‐entraining agents and the effect of both surfactant and CMH on basic properties of the CPC was studied. Incorporation of CMH into the CPC composition increased the setting time, decreased the crystallinity of the formed apatite phase, and improved the injectability of the paste. The use of both CMH and sodium dodecyl sulfate did not affect the rate of conversion of the reactants into apatite phase while soaking the cements in simulated body fluid. Results showed that the liberation rate of the drug from porous CPC was higher than that of the nonporous CPC but same release patterns were experienced in both types of cements, that is, like to nonporous CPC, a time‐dependent controlled release of the incorporated drug was obtained from macroporous CPC. The Weibull model was the best fitting‐equation for release profiles of all cements. The liberated CMH was as active as fresh cephalexin. It is concluded that this macroporous CPC can be successfully used as drug carrier with controlled release profile for the treatment of bone infections. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009