bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibrational activation in direct and precursor-mediated chemisorption of SiH4 on Si(100)
Authors: Bisson Régis , Dang Tung T. , Sacchi Marco , Beck Rainer D.
Published: August 2008

The quantum state-resolved reactivity S0 of SiH4 on Si(100)-2×1 has been measured for the first time for two vibrationally excited Si–H stretch local mode states (|2000⟩ and |1100⟩) as well the ground state S0 as a function of translational energy En and surface temperature Ts. We observe evidence for both direct and precursor-mediated chemisorption pathways. As expected, increasing En (or Ts) decreases S0 for the precursor-mediated reaction and increases S0 for the direct chemisorption. However, vibrational excitation of the incident SiH4 increases S0 for both the direct and the precursor-mediated pathway with a higher S0 for the |2000⟩ state than for the |1100⟩ state, indicating a nonstatistical reaction mechanism.
Fast domain wall motion in nanostripes with out-of-plane fields
Authors: Kunz Andrew , Reiff Sarah C.
Published: August 2008

Controlling domain wall motion is important due to the impact on the viability of proposed nanowire devices. One hurdle is slow domain wall speed when driven by fields greater than the Walker field due to nucleation of vortices in the wall. We present simulation results detailing the dynamics of these vortices including the nucleation and subsequent fast ejection of the vortex core leading to fast domain wall speeds. The ejection is due to the reversal of the core moments by an out-of-plane field. The technique can be used to produce domain walls of known orientation, independent of the initial state.
Tall wheat grass (Thinopyrum ponticum) and puccinellia (Puccinellia ciliata) may not be the answer for all saline sites: a case study from the Central Western Slopes of New South Wales
Authors: Semple W. S. , Dowling P. M. , Koen T. B.
Published: August 2008

Emergence and survival of Thinopyrum ponticum cv. Dundas, Puccinellia ciliata cv. Meneman, and Trifolium fragiferum cv. Palestine were observed over three seasons (2004–06) on part of a salinised area in Central Western New South Wales. Grid sampling of topsoils in August 2003 indicated that the site was acidic (mean pHwater 6.05), sodic (exchangeable sodium percentage 29), and saline (estimated ECe 18 dS/m). The site comprised a mosaic of low-salinity (ECe ~6 dS/m) vegetated patches and high-salinity (ECe ~30 dS/m) bare patches where EC was highly variable seasonally (exceeding 100 dS/m) and spatially. Despite suboptimal rainfall, emergence of the grasses was satisfactory on bare patches in all seasons but T. fragiferum failed to emerge in 2004 and was omitted from subsequent sowings. Various methods of ‘engineering’ the bare patches, viz. ditching, mounding, straw mulching, liming, or hand weeding, failed to promote optimum growth of the grasses, although survival was generally enhanced in treatments that included a shallow ditch. Results of the experiments, and observations elsewhere on the salinised area (where some patches supported optimal performance of the three species), suggested that high salinity was the main reason for poor performance on the bare patches. It was concluded that comprehensive site definition, both spatial and temporal, is important before attempting revegetation. Nevertheless the response of T. ponticum and P. ciliata in ditches will be limited on high-salinity sites. In addition, it was observed that surface disturbance and reduced grazing promoted establishment and growth of pre-existing species, particularly Cynodon dactylon and Lolium rigidum. There are many salinised sites in the Central West of NSW where neither P. ciliata nor T. ponticum has performed well, nor would be expected to do so, and where management of native and naturalised species already present may provide the best option for enhancing ground cover and herbage production.
Symbiotic competence of rose clover (Trifolium hirtum All.)
Authors: Brockwell J. , Fettell N. A. , Bowman Alison M. , Smith W. , Sweeney G. , Charman N. , Ballard R. A.
Published: August 2008

Rose clover (Trifolium hirtum All.) is a forage plant that is well adapted to acidic and mildly alkaline soils of low natural fertility in southern Australia and to climates with a winter-dominant annual rainfall of 300 mm and above. Reports of low concentrations of nitrogen in rose clover foliage have been attributed to poor N2 fixation and may have discouraged its use in Australia. This investigation, conducted in tube culture, examined the ability of four lines of rose clover to nodulate and fix N2 with effective strains of clover rhizobia (Rhizobium leguminosarum bv. trifolii) and with soils (as a source of naturalised rhizobia) collected from field sites in New South Wales and South Australia. Comparisons with other Trifolium spp. were also made. It was confirmed that there was a low concentration of N in the shoots of the rose clover cvv. SARDI Rose and Hykon. This occurred even where rose clover nodulated and fixed N2 effectively with well known inoculant strains of clover rhizobia and with soil samples collected in the field (provided that the populations of resident clover rhizobia in the soil were at least 150/g). Individual plants were uniform in response to inoculation. Rose clover cv. SARDI Rose was closely related to six of the nine other lines of clover with which it was compared. It was concluded that the registered cultivars of rose clover, cvv. SARDI Rose and Hykon, are symbiotically competent plants. It appears that low N in rose clover foliage is an intrinsic characteristic of the species unconnected with its symbiotic characteristics.
The epidemiology of Wheat streak mosaic virus in Australia: case histories, gradients, mite vectors, and alternative hosts
Authors: Coutts B. A. , Strickland G. R. , Kehoe M. A. , Severtson D. L. , Jones R. A. C.
Published: August 2008

Wheat streak mosaic virus (WSMV) infection and infestation with its wheat curl mite (WCM; Aceria tosichella) vector were investigated in wheat crops at two sites in the low-rainfall zone of the central grainbelt of south-west Australia. In the 2006 outbreak, after a preceding wet summer and autumn, high WCM populations and total infection with WSMV throughout a wheat crop were associated with presence of abundant grasses and self-sown ‘volunteer’ wheat plants before sowing the field that became affected. Wind strength and direction had a major effect on WSMV spread by WCM to neighbouring wheat crops, the virus being carried much further downwind than upwind by westerly frontal winds. Following a dry summer and autumn in 2007, together with control of grasses and volunteer cereals before sowing and use of a different seed stock, no WSMV or WCM were found in the following wheat crop within the previously affected area or elsewhere on the same farm. In the 2007 outbreak, where the preceding summer and autumn were wet, a 40% WSMV incidence and WCM numbers that reached 4800 mites/ear at the margin of the wheat crop were associated with abundant grasses and volunteer wheat plants in adjacent pasture. WSMV incidence and WCM populations declined rapidly with increasing distance from the affected pasture. Also, wheat plants that germinated early had higher WSMV infection incidences than those that germinated later. The alternative WSMV hosts identified at these sites were volunteer wheat, annual ryegrass (Lolium rigidum), barley grass (Hordeum sp.), and wild oats (Avena fatua). In surveys outside the growing season at or near these two sites or elsewhere in the grainbelt, small burr grass (Tragus australianus), stink grass (Eragrostis cilianensis), and witch grass (Panicum capillare) were identified as additional alternative hosts.
Mating induces an immune response and developmental switch in theDrosophilaoviduct
Authors: Kapelnikov Anat , Zelinger Einat , Gottlieb Yuval , Rhrissorrakrai Kahn , Gunsalus Kristin C. , Heifetz Yael
Published: August 2008

Mating triggers physiological and behavioral changes in females. To understand how females effect these changes, we used microarray, proteomic, and comparative analyses to characterize gene expression in oviducts of mated and unmatedDrosophilafemales. The transition from non-egg laying to egg laying elicits a distinct molecular profile in the oviduct. Immune-related transcripts and proteins involved in muscle and polarized epithelial function increase, whereas cell growth and differentiation-related genes are down-regulated. Our combined results indicate that mating triggers molecular and biochemical changes that mediate progression from a “poised” state to a mature, functional stage.
Actin-binding cleft closure in myosin II probed by site-directed spin labeling and pulsed EPR
Authors: Klein Jennifer C. , Burr Adam R. , Svensson Bengt , Kennedy Daniel J. , Allingham John , Titus Margaret A. , Rayment Ivan , Thomas David D.
Published: August 2008

We present a structurally dynamic model for nucleotide- and actin-induced closure of the actin-binding cleft of myosin, based on site-directed spin labeling and electron paramagnetic resonance (EPR) in
Dictyostelium
myosin II. The actin-binding cleft is a solvent-filled cavity that extends to the nucleotide-binding pocket and has been predicted to close upon strong actin binding. Single-cysteine labeling sites were engineered to probe mobility and accessibility within the cleft. Addition of ADP and vanadate, which traps the posthydrolysis biochemical state, influenced probe mobility and accessibility slightly, whereas actin binding caused more dramatic changes in accessibility, consistent with cleft closure. We engineered five pairs of cysteine labeling sites to straddle the cleft, each pair having one label on the upper 50-kDa domain and one on the lower 50-kDa domain. Distances between spin-labeled sites were determined from the resulting spin–spin interactions, as measured by continuous wave EPR for distances of 0.7–2 nm or pulsed EPR (double electron–electron resonance) for distances of 1.7–6 nm. Because of the high distance resolution of EPR, at least two distinct structural states of the cleft were resolved. Each of the biochemical states tested (prehydrolysis, posthydrolysis, and rigor), reflects a mixture of these structural states, indicating that the coupling between biochemical and structural states is not rigid. The resulting model is much more dynamic than previously envisioned, with both open and closed conformations of the cleft interconverting, even in the rigor actomyosin complex.
Synthetic glycopeptide vaccines combining β-mannan and peptide epitopes induce protection against candidiasis
Authors: Xin Hong , Dziadek Sebastian , Bundle David R. , Cutler Jim E.
Published: August 2008

The first fully synthetic glycopeptide vaccines against a fungal disease have been used to combat disseminated candidiasis in mice. Six T cell peptides found inCandida albicanscell wall proteins were selected by algorithm peptide epitope searches; each was synthesized and conjugated to the fungal cell wall β-mannan trisaccharide [β-(Man)3] by novel saccharide-peptide linker chemistry to create glycopeptide conjugates. The six proteins were selected because of expression during human candidiasis and cell wall association and included: fructose-bisphosphate aldolase (Fba); methyltetrahydropteroyltriglutamate (Met6); hyphal wall protein-1 (Hwp1); enolase (Enol); glyceraldehyde-3-phosphate dehydrogenase (Gap1); and phosphoglycerate kinase (Pgk1). By immunization protocols favoring production of protective antibody, the β-(Man)3-Fba, β-(Man)3-Met6 and β-(Man)3-Hwp1 induced protection evidenced by survival and reduced kidney fungal burden, the β-(Man)3-Eno1 and β-(Man)3-Gap1 gave moderate protection, and the β-(Man)3-Pgk1 slightly enhanced disease. For the β-(Man)3-Fba conjugate, protection was uniquely acquired through immunity against the carbohydrate and the Fba peptide. This approach based on fully synthetic chemically defined immunogens should be generally useful in vaccine development.
Both maltose-binding protein and ATP are required for nucleotide-binding domain closure in the intact maltose ABC transporter
Authors: Orelle Cedric , Ayvaz Tulin , Everly R. Michael , Klug Candice S. , Davidson Amy L.
Published: August 2008

The maltose transporter MalFGK
2
of
Escherichia coli
is a member of the ATP-binding cassette superfamily. A periplasmic maltose-binding protein (MBP) delivers maltose to MalFGK
2
and stimulates its ATPase activity. Site-directed spin labeling EPR spectroscopy was used to study the opening and closing of the nucleotide-binding interface of MalFGK
2
during the catalytic cycle. In the intact transporter, closure of the interface coincides not just with the binding of ATP, as seen with isolated nucleotide-binding domains, but requires both MBP and ATP, implying that MBP stimulates ATPase activity by promoting the closure of the nucleotide-binding interface. After ATP hydrolysis, with MgADP and MBP bound, the nucleotide-binding interface resides in a semi-open configuration distinct from the fully open configuration seen in the absence of any ligand. We propose that P
i
release coincides with the reorientation of transmembrane helices to an inward-facing conformation and the final step of maltose translocation into the cell.
Suppression of E-protein activity interferes with the development of
BCR-ABL
-mediated myeloproliferative disease
Authors: Ko Jinkyung , Patel Nihal , Ikawa Tomokatsu , Kawamoto Hiroshi , Frank Oliver , Rivera Richard R. , Van Etten Richard A. , Murre Cornelis
Published: August 2008

E-proteins are a class of helix-loop-helix (HLH) proteins, which play multiple roles throughout lymphoid development. The DNA binding activities of the E-proteins are regulated by a distinct class of antagonistic HLH proteins, named Id1–4. Here we demonstrate that Id2 deficient mice in a C57BL/6 genetic background exhibit increased cellularity in the granulocyte/myeloid progenitor compartment and show significantly higher numbers of maturing neutrophils. Within 6 months of age, Id2 deficient mice succumbed from overwhelming granulocytosis. The disease closely mimicked the distinctive features of human chronic myeloid leukemia: leukocytosis with maturing neutrophils, splenomegaly, hepatomegaly, and myeloid infiltration into peripheral tissues, including spleen, liver, and lungs. Strikingly, forced Id2 expression in murine bone marrow cells substantially delayed the onset of myeloproliferative disease (MPD). Collectively, these studies show that suppression of E-protein activity interferes with the development of
BCR-ABL
-mediated MPD.
Efficient reproduction of cynomolgus monkey using pronuclear embryo transfer technique
Authors: Sun Qiang , Dong Juan , Yang Wenting , Jin Yujuan , Yang Mingying , Wang Yan , Wang Philip L. , Hu Yinghe , Tsien Joe Z.
Published: August 2008

One of the technical bottlenecks in producing nonhuman primate models is that current assisted reproductive techniques, such as
in vitro
culture and frozen conservation of multicell-stage embryos, often result in poor embryo quality and subsequently lead to low birth rates. We investigated whether pronuclear embryo transfer can be used as an effective means for improving pregnancy and live birth rates of nonhuman primates. We collected 174 metaphase II oocytes by laparoscopy from 22 superovulated mature females and then fertilized these eggs using either
in vitro
fertilization or intracytoplasmic sperm injection, resulting in a 33.3% and a 50% fertilization rate, respectively. These 66 fertilized pronuclear-stage embryos were then tubally transferred to 30 recipients and led to 7 births and 1 abortion. Importantly, we observed that the highest live birth rate of ≈64% was obtained when the transfer of pronuclear embryos was performed in the presence of new corpus luteum in the ovary of recipients between 24 h and 36 h after estradiol peak. Therefore, our experiments demonstrate that by matching the critical time window in the recipient's reproductive cycle for achieving optimal embryo-uterine synchrony, pronuclear embryo transfer technology can significantly improve the pregnancy rate and live birth of healthy baby monkeys. This efficient method should be valuable to the systematic efforts in construction of various transgenic primate disease models.
Inhibition of the fungal fatty acid synthase type I multienzyme complex
Authors: Johansson Patrik , Wiltschi Birgit , Kumari Preeti , Kessler Brigitte , Vonrhein Clemens , Vonck Janet , Oesterhelt Dieter , Grininger Martin
Published: August 2008

Fatty acids are among the major building blocks of living cells, making lipid biosynthesis a potent target for compounds with antibiotic or antineoplastic properties. We present the crystal structure of the 2.6-MDa
Saccharomyces cerevisiae
fatty acid synthase (FAS) multienzyme in complex with the antibiotic cerulenin, representing, to our knowledge, the first structure of an inhibited fatty acid megasynthase. Cerulenin attacks the FAS ketoacyl synthase (KS) domain, forming a covalent bond to the active site cysteine C1305. The inhibitor binding causes two significant conformational changes of the enzyme. First, phenylalanine F1646, shielding the active site, flips and allows access to the nucleophilic cysteine. Second, methionine M1251, placed in the center of the acyl-binding tunnel, rotates and unlocks the inner part of the fatty acid binding cavity. The importance of the rotational movement of the gatekeeping M1251 side chain is reflected by the cerulenin resistance and the changed product spectrum reported for
S. cerevisiae
strains mutated in the adjacent glycine G1250. Platensimycin and thiolactomycin are two other potent inhibitors of KSs. However, in contrast to cerulenin, they show selectivity toward the prokaryotic FAS system. Because the flipped F1646 characterizes the catalytic state accessible for platensimycin and thiolactomycin binding, we superimposed structures of inhibited bacterial enzymes onto the
S. cerevisiae
FAS model. Although almost all side chains involved in inhibitor binding are conserved in the FAS multienzyme, a different conformation of the loop K1413–K1423 of the KS domain might explain the observed low antifungal properties of platensimycin and thiolactomycin.
Surfen, a small molecule antagonist of heparan sulfate
Authors: Schuksz Manuela , Fuster Mark M. , Brown Jillian R. , Crawford Brett E. , Ditto David P. , Lawrence Roger , Glass Charles A. , Wang Lianchun , Tor Yitzhak , Esko Jeffrey D.
Published: August 2008

In a search for small molecule antagonists of heparan sulfate, we examined the activity of
bis
-2-methyl-4-amino-quinolyl-6-carbamide, also known as surfen. Fluorescence-based titrations indicated that surfen bound to glycosaminoglycans, and the extent of binding increased according to charge density in the order heparin > dermatan sulfate > heparan sulfate > chondroitin sulfate. All charged groups in heparin (
N
-sulfates,
O
-sulfates, and carboxyl groups) contributed to binding, consistent with the idea that surfen interacted electrostatically. Surfen neutralized the anticoagulant activity of both unfractionated and low molecular weight heparins and inhibited enzymatic sulfation and degradation reactions
in vitro
. Addition of surfen to cultured cells blocked FGF2-binding and signaling that depended on cell surface heparan sulfate and prevented both FGF2- and VEGF
165
-mediated sprouting of endothelial cells in Matrigel. Surfen also blocked heparan sulfate-mediated cell adhesion to the Hep-II domain of fibronectin and prevented infection by HSV-1 that depended on glycoprotein D interaction with heparan sulfate. These findings demonstrate the feasibility of identifying small molecule antagonists of heparan sulfate and raise the possibility of developing pharmacological agents to treat disorders that involve glycosaminoglycan–protein interactions.
Electron injection into organic semiconductor devices from high work function cathodes
Authors: Hoven Corey V. , Yang Renqiang , Garcia Andres , Crockett Victoria , Heeger Alan J. , Bazan Guillermo C. , Nguyen Thuc-Quyen
Published: August 2008

We show that polymer light-emitting diodes with high work-function cathodes and conjugated polyelectrolyte injection/transport layers exhibit excellent efficiencies despite large electron-injection barriers. Correlation of device response times with structure provides evidence that the electron-injection mechanism involves redistribution of the ions within the polyelectrolyte electron-transport layer and hole accumulation at the interface between the emissive and electron-transport layers. Both processes lead to screening of the internal electric field and a lowering of the electron-injection barrier. The hole and electron currents are therefore diffusion currents rather than drift currents. The response time and the device performance are influenced by the type of counterion used.
Dynamics of ligand substitution in labile cobalt complexes resolved by ultrafast T-jump
Authors: Ma Hairong , Wan Chaozhi , Zewail Ahmed H.
Published: August 2008

Ligand exchange of hydrated metal complexes is common in chemical and biological systems. Using the ultrafast T-jump, we examined this process, specifically the transformation of aqua cobalt (II) complexes to their fully halogenated species. The results reveal a stepwise mechanism with time scales varying from hundreds of picoseconds to nanoseconds. The dynamics are significantly faster when the structure is retained but becomes rate-limited when the octahedral-to-tetrahedral structural change bottlenecks the transformation. Evidence is presented, from bimolecular kinetics and energetics (enthalpic and entropic), for a reaction in which the ligand assists the displacement of water molecules, with the retention of the entering ligand in the activated state. The reaction time scale deviates by one to two orders of magnitude from that of ionic diffusion, suggesting the involvement of a collisional barrier between the ion and the much larger complex.
Neural correlates of partial lexical activation
Authors: Pirog Revill Kathleen , Aslin Richard N. , Tanenhaus Michael K. , Bavelier Daphne
Published: August 2008

As a spoken word unfolds over time, it is temporarily consistent with the acoustic forms of multiple words. Previous behavioral research has shown that, in the face of temporary ambiguity about how a word will end, multiple candidate words are briefly activated. Here, we provide neural imaging evidence that lexical candidates only temporarily consistent with the input activate perceptually based semantic representations. An artificial lexicon and novel visual environment were used to target human MT/V5 and an area anterior to it which have been shown to be recruited during the reading of motion words. Participants learned words that referred to novel objects and to motion or color/texture changes that the objects underwent. The lexical items corresponding to the change events were organized into phonologically similar pairs differing only in the final syllable. Upon hearing spoken scene descriptions in a posttraining verification task, participants showed greater activation in the left hemisphere anterior extent of MT/V5 when motion words were heard than when nonmotion words were heard. Importantly, when a nonmotion word was heard, the level of activation in the anterior extent of MT/V5 was modulated by whether there was a phonologically related competitor that was a motion word rather than another nonmotion word. These results provide evidence of activation of a perceptual brain region in response to the semantics of a word while lexical competition is in process and before the word is fully recognized.
Think, blink or sleep on it? The impact of modes of thought on complex decision making
Authors: Newell Ben R. , Wong Kwan Yao , Cheung Jeremy C. H. , Rakow Tim
Published: August 2008

This paper examines controversial claims about the merit of “unconscious thought” for making complex decisions. In four experiments, participants were presented with complex decisions and were asked to choose the best option immediately, after a period of conscious deliberation, or after a period of distraction (said to encourage “unconscious thought processes”). In all experiments the majority of participants chose the option predicted by their own subjective attribute weighting scores, regardless of the mode of thought employed. There was little evidence for the superiority of choices made “unconsciously”, but some evidence that conscious deliberation can lead to better choices. The final experiment suggested that the task is best conceptualized as one involving “online judgement” rather than one in which decisions are made after periods of deliberation or distraction. The results suggest that we should be cautious in accepting the advice to “stop thinking” about complex decisions.
Exploring the time course of semantic interference and associative priming in the picture–word interference task
Authors: Sailor Kevin , Brooks Patricia J. , Bruening Paul R. , Seiger-Gardner Liat , Guterman Mark
Published: August 2008

The picture–word interference (PWI) task is a widely used technique for exploring effects of semantic context on lexical access. In this task, printed words are superimposed over pictures to be named, with the timing of the interfering word relative to the picture systematically manipulated. Two experiments ( N = 24 adults in each) explored the time course of effects of associates (e.g., CARROT superimposed on a picture of a rabbit) versus coordinates (e.g., CHIPMUNK superimposed on a picture of a rabbit) on naming latencies. Associates led to faster picture naming than did unrelated words, with facilitative effects occurring at stimulus onset asynchronies (SOAs, in ms) ranging from –450 to 0. Coordinates led to slower naming latencies, with the interference effect restricted to SOAs of –150 and 0. The overlapping time course of associative priming and coordinate interference provides important constraints on models of lexical access in speech production.
A critical role for Apc in hematopoietic stem and progenitor cell survival
Authors: Qian Zhijian , Chen Lina , Fernald Anthony A. , Williams Bart O. , Le Beau Michelle M.
Published: August 2008

The adenomatous polyposis coli (Apc) tumor suppressor is involved in the initiation and progression of colorectal cancer via regulation of the Wnt signaling cascade. In addition, Apc plays an important role in multiple cellular functions, including cell migration and adhesion, spindle assembly, and chromosome segregation. However, its role during adult hematopoiesis is unknown. We show that conditional inactivation of Apc in vivo dramatically increases apoptosis and enhances cell cycle entry of hematopoietic stem cells (HSCs)/ hematopoietic progenitor cells (HPCs), leading to their rapid disappearance and bone marrow failure. The defect in HSCs/HPCs caused by Apc ablation is cell autonomous. In addition, we found that loss of Apc leads to exhaustion of the myeloid progenitor pool (common myeloid progenitor, granulocyte-monocyte progenitor, and megakaryocyte-erythroid progenitor), as well as the lymphoid-primed multipotent progenitor pool. Down-regulation of the genes encoding Cdkn1a, Cdkn1b, and Mcl1 occurs after acute Apc excision in candidate HSC populations. Together, our data demonstrate that Apc is essential for HSC and HPC maintenance and survival.
Selective miRNA disruption in T reg cells leads to uncontrolled autoimmunity
Authors: Zhou Xuyu , Jeker Lukas T. , Fife Brian T. , Zhu Shirley , Anderson Mark S. , McManus Michael T. , Bluestone Jeffrey A.
Published: August 2008

A new regulatory T (T reg) cell–specific, FoxP3-GFP-hCre bacterial artificial chromosome transgenic mouse was crossed to a conditional Dicer knockout (KO) mouse strain to analyze the role of microRNAs (miRNAs) in the development and function of T reg cells. Although thymic T reg cells developed normally in this setting, the cells showed evidence of altered differentiation and dysfunction in the periphery. Dicer-deficient T reg lineage cells failed to remain stable, as a subset of cells down-regulated the T reg cell–specific transcription factor FoxP3, whereas the majority expressed altered levels of multiple genes and proteins (including Neuropilin 1, glucocorticoid-induced tumor necrosis factor receptor, and cytotoxic T lymphocyte antigen 4) associated with the T reg cell fingerprint. In fact, a significant percentage of the T reg lineage cells took on a T helper cell memory phenotype including increased levels of CD127, interleukin 4, and interferon γ. Importantly, Dicer-deficient T reg cells lost suppression activity in vivo; the mice rapidly developed fatal systemic autoimmune disease resembling the FoxP3 KO phenotype. These results support a central role for miRNAs in maintaining the stability of differentiated T reg cell function in vivo and homeostasis of the adaptive immune system.
Did the Protestant Ethic Disappear? The Virtue of Thrift on the Cusp of Postwar Affluence
Authors: Steigerwald David
Published: August 2008

After World War II, the United States moved into what historians are now recognizing as a full-blown consumer society. Consumer society carried with it vast cultural changes, including shifts in fundamental values. Not least important were shifts in the practices of thrift, as seen in how Americans regarded personal savings and debt. Traditionally seen as opposites, those two economic behaviors became intertwined in the 1950s, as Americans continued to save, not to accumulate wealth but to spend and often even as they took on consumer debt. Thus, the 1950s were a tipping point between industrial capitalism and consumer capitalism.
Structural evidence for substrate‐induced synergism and half‐sites reactivity in biotin carboxylase
Authors: Mochalkin Igor , Miller J. Richard , Evdokimov Artem , Lightle Sandra , Yan Chunhong , Stover Charles Ken , Waldrop Grover L.
Published: August 2008

Bacterial acetyl‐CoA carboxylase is a multifunctional biotin‐dependent enzyme that consists of three separate proteins: biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), and carboxyltransferase (CT). Acetyl‐CoA carboxylase is a potentially attractive target for novel antibiotics because it catalyzes the first committed step in fatty acid biosynthesis. In the first half‐reaction, BC catalyzes the ATP‐dependent carboxylation of BCCP. In the second half‐reaction, the carboxyl group is transferred from carboxybiotinylated BCCP to acetyl‐CoA to produce malonyl‐CoA. A series of structures of BC from several bacteria crystallized in the presence of various ATP analogs is described that addresses three major questions concerning the catalytic mechanism. The structure of BC bound to AMPPNP and the two catalytically essential magnesium ions resolves inconsistencies between the kinetics of active‐site BC mutants and previously reported BC structures. Another structure of AMPPNP bound to BC shows the polyphosphate chain folded back on itself, and not in the correct (i.e., extended) conformation for catalysis. This provides the first structural evidence for the hypothesis of substrate‐induced synergism, which posits that ATP binds nonproductively to BC in the absence of biotin. The BC homodimer has been proposed to exhibit half‐sites reactivity where the active sites alternate or “flip‐flop” their catalytic cycles. A crystal structure of BC showed the ATP analog AMPPCF2P bound to one subunit while the other subunit was unliganded. The liganded subunit was in the closed or catalytic conformation while the unliganded subunit was in the open conformation. This provides the first structural evidence for half‐sites reactivity in BC.
Crystal structure of the human receptor activity‐modifying protein 1 extracellular domain
Authors: Kusano Seisuke , Kukimoto‐Niino Mutsuko , Akasaka Ryogo , Toyama Mitsutoshi , Terada Takaho , Shirouzu Mikako , Shindo Takayuki , Yokoyama Shigeyuki
Published: August 2008

Receptor activity‐modifying protein (RAMP) 1 forms a heterodimer with calcitonin receptor‐like receptor (CRLR) and regulates its transport to the cell surface. The CRLR·RAMP1 heterodimer functions as a specific receptor for calcitonin gene‐related peptide (CGRP). Here, we report the crystal structure of the human RAMP1 extracellular domain. The RAMP1 structure is a three‐helix bundle that is stabilized by three disulfide bonds. The RAMP1 residues important for cell‐surface expression of the CRLR·RAMP1 heterodimer are clustered to form a hydrophobic patch on the molecular surface. The hydrophobic patch is located near the tryptophan residue essential for binding of the CGRP antagonist, BIBN4096BS. These results suggest that the hydrophobic patch participates in the interaction with CRLR and the formation of the ligand‐binding pocket when it forms the CRLR·RAMP1 heterodimer.
Prion protein gene polymorphisms in sheep in the state of Paraná, Brazil
Authors: Sotomaior C. S. , Sotomaior V. S. , Madeira H. M. F. , Thomaz‐Soccol V.
Published: August 2008

To determine the polymorphisms of the prion protein gene in sheep from the state of Paraná, Brazil, 323 animals of meat breeds (Suffolk, Hampshire Down, Texel, Ile de France, Dorper, Dorset, Santa Inês and crossbreds) were genotyped by restriction fragment length polymorphism (RFLP) analysis. The most frequent allele was ARQ, with a frequency of 0.61, followed by ARR (0.30). VRQ and AHQ alleles were present at very low frequencies (0.13 and 0.05 respectively), and the ARH allele was not found. Seven genotypes were identified (ARR/ARR, ARR/ARQ, ARQ/ARQ, ARR/VRQ, ARR/AHQ, ARQ/VRQ and ARQ/AHQ), of which ARQ/ARQ was the most frequent (0.41). The Santa Inês breed and crossbred animals showed the highest genotypic variability.
Deficiency of Myo18B in mice results in embryonic lethality with cardiac myofibrillar aberrations
Authors: Ajima Rieko , Akazawa Hiroshi , Kodama Maho , Takeshita Fumitaka , Otsuka Ayaka , Kohno Takashi , Komuro Issei , Ochiya Takahiro , Yokota Jun
Published: August 2008

Myo18B is an unconventional myosin family protein expressed predominantly in muscle cells. Although conventional myosins are known to be localized on the A‐bands and function as a molecular motor for muscle contraction, Myo18B protein was localized on the Z‐lines of myofibrils in striated muscles. Like Myo18A, another 18th class of myosin, the N‐terminal unique domain of the protein and not the motor domain and the coiled‐coil tail is critical for its localization to F‐actin in myocytes. Myo18B expression was induced by myogenic differentiation through the binding of myocyte‐specific enhancer factor‐2 to its promoter. Deficiency of Myo18B caused an embryonic lethality in mice accompanied by disruption of myofibrillar structures in cardiac myocytes at embryonic day 10.5. Thus, Myo18B is a unique unconventional myosin that is predominantly expressed in myocytes and whose expression is essential for the development and/or maintenance of myofibrillar structure.
IMPACT OF MULTIPLE GENE MUTATIONS IN DETERMINING THE SEVERITY OF CARDIOMYOPATHY AND HEART FAILURE
Authors: Tsoutsman Tatiana , Bagnall Richard D , Semsarian Christopher
Published: August 2008

Familial hypertrophic cardiomyopathy (FHC) is a primary cardiac disorder characterized by myocardial hypertrophy that demonstrates substantial diversity in both genetic causes and clinical manifestations.

Clinical heterogeneity can be explained by the causative gene (at least 13 have been identified to date), the position of the amino acid residue affected by a mutation within the protein (over 450 mutations have been reported to date) and modifying genetic and environmental factors.

Multiple mutations are found in up to 5% of human FHC cases, who typically present with a more severe phenotype compared with single‐mutation carriers (i.e. earlier onset of disease, greater left ventricular hypertrophy and a higher incidence of sudden cardiac death events).

Multiple mutations usually involve MYH7, MYBPC3 and, to a lesser extent, TNNI2, reflecting the higher contribution of mutations in these genes to FHC.

Multiple‐mutation mouse models appear to mimic the human multiple‐mutation phenotype and, thus, will help improve our understanding of disease pathogenesis. The models provide a tool for future studies of disease mechanisms and signalling pathways in FHC and its sequelae (i.e. heart failure and sudden death), thereby allowing identification of novel targets for potential therapies and disease prevention strategies.
Transiently increased colocalization of vesicular glutamate transporters 1 and 2 at single axon terminals during postnatal development of mouse neocortex: a quantitative analysis with correlation coefficient
Authors: Nakamura Kouichi , Watakabe Akiya , Hioki Hiroyuki , Fujiyama Fumino , Tanaka Yasuyo , Yamamori Tetsuo , Kaneko Takeshi
Published: August 2008

In the published paper of Nakamura et al. (2007), the double primes referred to in Figs 1, 2, 7 and 8 were corrupted throughout the text and legends at an early conversion stage of production. We apologise for any inconvenience caused and, for clarity, reproduce the whole paper again here on pages 1033–1046.

Reference

Nakamura, K.,
Watakabe, A.,
Hioki, H.,
Fujiyama, F.,
Tanaka, Y.,
Yamamori, T. &
Kaneko, T. (2007) .
Eur. J. Neurosci., 26, 3054–3067.

Vesicular glutamate transporter 1 (VGLUT1) and VGLUT2 show complementary distribution in neocortex; VGLUT1 is expressed mainly in axon terminals of neocortical neurons, whereas VGLUT2 is located chiefly in thalamocortical axon terminals. However, we recently reported a frequent colocalization of VGLUT1 and VGLUT2 at a subset of axon terminals in postnatal developing neocortex. We here quantified the frequency of colocalization between VGLUT1 and VGLUT2 immunoreactivities at single axon terminals by using the correlation coefficient (CC) as an indicator in order to determine the time course and spatial extent of the colocalization during postnatal development of mouse neocortex. The colocalization was more frequent in the primary somatosensory (S1) area than in both the primary visual (V1) and the motor areas; of area S1 cortical layers, colocalization was most evident in layer IV barrels at postnatal day (P) 7 and in adulthood. CC in layer IV showed a peak at P7 in area S1, and at P10 in area V1 though the latter peak was much smaller than the former. These results suggest that thalamocortical axon terminals contained not only VGLUT2 but also VGLUT1, especially at P7–10. Double fluorescence in situ hybridization confirmed coexpression of VGLUT1 and VGLUT2 mRNAs at P7 in the somatosensory thalamic nuclei and later in the thalamic dorsal lateral geniculate nucleus. As VGLUT1 is often used in axon terminals that show synaptic plasticity in adult brain, the present findings suggest that VGLUT1 is used in thalamocortical axons transiently during the postnatal period when plasticity is required.
DIONYSIUS IN HANS URS VON BALTHASAR AND JEAN‐LUC MARION
Authors: JONES TAMSIN
Published: August 2008

This article evaluates Jean‐Luc Marion's retrieval of Dionysius against the backdrop of the debate in recent continental philosophy over the identity and meaning of “negative theology”. Marion's interpretation and use of Dionysius draws heavily on that of Hans Urs von Balthasar, both in his manner of approaching Dionysius and with the central elements of the Corpus Dionysiacum upon which he focuses. Through this comparison, it is clear that different polemical and apologetic interests shape their similar but distinct retrievals. Marion, like Balthasar before him, is translating Dionysius for a new audience. With this translation, I argue that Marion provides a richer and more complex confrontation with Dionysius than has previously been offered within the contemporary discussions of “negative theology”.
Redistribution and Inequality in a Heterogeneous Society
Authors: HODLER ROLAND
Published: August 2008

This paper analyses how income redistribution affects inequality in a society in which individuals differ in their earning abilities and their preferences for consumption and leisure. After discussing the shortcomings of various standard approaches, I measure inequality in such a heterogeneous society by the inequality in individuals' so‐called equivalent wages. This approach suggests that redistribution tends to reduce inequality by transferring income from high‐ability to low‐ability individuals, but to increase inequality by transferring income from consumption‐loving to leisure‐loving individuals. These countervailing effects lead in all my simulations to a U‐shaped relationship between redistribution and inequality.
Endogenous Acquisition of Information and the Equity Home Bias
Authors: LUNDTOFTE FREDERIK
Published: August 2008

This paper investigates the extent to which differences in information costs can explain the equity home bias puzzle. In a model where information costs are higher for the Foreign asset than for the Home asset, I show that, if cost functions are convex and the assets have identical return characteristics, the expected size of the home bias in terms of differences in expected demands is positive and increasing in expected excess returns and risk, but decreasing in risk aversion. However, a calibration to US data suggests that information costs can explain only a small fraction of the observed home bias.
A ‘Leaky Bucket’ in the Real World: Estimating Inequality Aversion using Survey Data
Authors: PIRTTILÄ JUKKA , UUSITALO ROOPE
Published: August 2008

Existing evidence of inequality aversion relies on data from class‐room experiments where subjects face hypothetical questions. This paper estimates the magnitude of inequality aversion using representative survey data, with questions related to the real‐economy situations the respondents face. The results reveal that inequality aversion can be measured in a meaningful way using survey data, but the magnitudes of the estimates depend dramatically on how inequality aversion is measured. No matter how measured, the revealed inequality aversion predicts opinions on a wide range of questions related to the welfare state, such as the level of taxation, tax progressivity and the structure of unemployment benefits.
Novel exon 1 progranulin gene variant in Alzheimer’s disease
Authors: Cortini F. , Fenoglio C. , Guidi I. , Venturelli E. , Pomati S. , Marcone A. , Scalabrini D. , Villa C. , Clerici F. , Dalla Valle E. , Mariani C. , Cappa S. , Bresolin N. , Scarpini E. , Galimberti D.
Published: August 2008

Background and purpose:  Progranulin (PGRN) expression is increased in activated microglia in Alzheimer's disease (AD) brain, suggesting a potential role in this pathology.

Methods:  A mutation scanning of exons and flanking regions of PGRN was carried out in 120 patients with sporadic frontotemporal lobar degeneration and 145 with sporadic AD.

Results:  Amongst variants not yet deposited, a novel allelic variant was identified in Exon 1 (g100169G > A). It leads to an amino acidic change (p.Gly35Arg) and was observed in a patient with late onset AD. In silico analysis predicted that this mutation is possibly damaging. A second variant (g.100165C > T), resulting in a silent mutation (pAsp33Asp), was found in a patient with semantic dementia and in another with early onset AD. Both variants were absent in 226 controls. In addition, two rare non‐pathogenic variants lying very close to PGRN splice‐site regions (IVS2 + 7→G > A and IVS7 + 7→G > A) were observed. Transcriptional analysis in peripheral blood mononuclear cells from patients demonstrated they do not affect exon splicing.

Conclusions:  A novel putative PGRN mutation leading to an amino acidic substitution was identified in a patient with clinical AD.
Migration and Transnational Families in Fiji: Comparing Two Ethnic Groups
Authors: Voigt‐Graf Carmen
Published: August 2008

In the past two decades, international migration patterns out of Fiji have undergone changes with important implications for the formation of transnational families. The focus of this paper is on a comparison between the formation of Indo‐Fijian transnational extended families and indigenous Fijian transnational nuclear families. These are discussed within the framework of “transnational corporations of kin.”

For several decades, Indo‐Fijians have permanently migrated to the Pacific Rim as a consequence of the economic and political situation in Fiji. They have resettled in complete nuclear family units and have subsequently attempted to sponsor the migration of their extended family members. Recent years have witnessed an increasing number of indigenous Fijians migrating temporarily for work. In contrast to Indo‐Fijians, indigenous Fijian migrate as individuals, leaving their spouses and children behind in Fiji. Women migrate autonomously as caregivers and nurses while men find employment as soldiers and security officers. The main purpose of their mostly temporary migration is to send remittances. However, these economic benefits have to be contrasted with the social and psychological costs associated with the separation of nuclear families. The paper also discusses policy implications arising from the comparative analysis, especially in the light of the current situation in Fiji which is characterised by a lack of policies addressing the implications of migration.
Philippine Women on the Move: Marriage across Borders
Authors: Lauser Andrea
Published: August 2008

This paper discusses how Philippine transnational marriage migration is intertwined in complex and paradoxical ways with global, local and personal matters. My argument will blur the artificial and still dominant analytical division between marriage migrants (wives or “mail order” brides) and labour migrants (workers – mainly domestic workers). Focusing on the life histories of different Filipina women, the paper illustrates the intersections and multiplicity of their roles as wives, mistresses, workers, mothers, daughters and citizens in a transnational migratory space.

Furthermore, I go along with those scholars who argue that women do not only marry in order to migrate, but that they also migrate in order to marry, as marriage is seen as an important aspect of social fulfilment. By carefully investigating these emerging transnational or even global marriage‐scapes, I analyze the different motives, logics and desires that come into play. While women from the Philippines may look for “modern husbands” and “modern marriages” because of local constraints on their marriage opportunities, many western men turn to Asia and the Philippines for “traditional” wives whom they imagine to be more “conservative” and “less demanding.” Both often discover that their gender stereotypes are more imagined than real.

The stories illustrate how Filipina migrants use different socio‐cultural and socio‐economic situations across transnational space – and at times against local gender constructions – in order to renegotiate and reclaim a respectable and desired marital status. On the one hand, these women are subject to manifold localised, legal and religious‐moral definitions as women and wives. On the other hand, they creatively and actively utilise structural differences and new opportunities across transnational space to redefine themselves. The stories thus show both the women’s agency and the importance of structural factors.
Dye and fibre discoveries of the twentieth century. Part 4: Oil crisis… fibres crisis… dyes crisis
Authors: Park James , Shore John
Published: August 2008

The oil crisis in the 1970s struck the supplies and users of dyes and chemicals with the impact of a tsunami. Rationalisation and diversification transformed the producer industry worldwide. Increasing concern regarding the environmental effects of chemical pollution greatly modified and limited the scope for developing and marketing novel dyes and effect chemicals.