bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermoelectric and structural characterizations of individual electrodeposited bismuth telluride nanowires
Authors: Mavrokefalos Anastassios , Moore Arden L. , Pettes Michael T. , Shi Li , Wang Wei , Li Xiaoguang
Published: May 2009

The thermoelectric properties and crystal structure of individual electrodeposited bismuth telluride nanowires (NWs) were characterized using a microfabricated measurement device and transmission electron microscopy. Annealing in hydrogen was used to obtain electrical contact between the NW and the supporting Pt electrodes. By fitting the measured Seebeck coefficient with a two-band model, the NW samples were determined to be highly n-type doped. Higher thermal conductivity and electrical conductivity were observed in a 52 nm diameter monocrystalline NW than a 55 nm diameter polycrystalline NW. The electron mobility of the monocrystalline NW was found to be about 19% lower than that of bulk crystal at a similar carrier concentration and about 2.5 times higher than that of the polycrystalline NW. The specularity parameter for electron scattering by the NW surface was determined to be about 0.7 and partially specular and partially diffuse, leading to a reduction in the electron mean-free path from 61 nm in the bulk to about 40 nm in the 52 nm NW. Because of the already short phonon mean-free path of about 3 nm in bulk bismuth telluride, diffuse phonon-surface scattering is expected to reduce the lattice thermal conductivity of the 52–55 nm diameter NWs by only about 20%, which is smaller than the uncertainty in the extracted lattice thermal conductivity based on the measured total thermal conductivity and calculated electron thermal conductivity. Although the lattice thermal conductivity of the polycrystalline NW is likely lower than the bulk values, the lower thermal conductivity observed in this polycrystalline sample is mainly caused by the lower electron concentration and mobility. For both samples, the thermoelectric figure of merit (ZT) increases with temperature and is about 0.1 at a temperature of 400 K. The low ZT compared to that of bulk crystals is mainly caused by a high doping level, suggesting the need for better control of the chemical composition in order to improve the ZT of the electrodeposited NWs. Moreover, bismuth telluride NWs with diameter less than 10 nm would be required for substantial suppression of the lattice thermal conductivity as well as experimental verification of theoretical predictions of power factor enhancement in quantum wires. Such stringent diameter requirement can be relaxed in other NW systems with longer bulk phonon mean-free path or smaller effective mass and thus longer electron wavelength than those in bulk bismuth telluride.
Enthalpy diffusion in multicomponent flows
Authors: Cook Andrew W.
Published: May 2009

The enthalpy diffusion flux in the multicomponent energy equation is a well-known yet frequently neglected term. It accounts for energy changes associated with compositional changes resulting from species diffusion. The term prevents local violations of the entropy condition in flows where significant mixing occurs between species of dissimilar molecular weight. In simulations of nonpremixed combustion, omission of the enthalpy flux can lead to anomalous temperature gradients, which may cause mixing regions to exceed ignition conditions. The term can also play a role in generating acoustic noise in turbulent mixing layers. Euler solvers that rely on numerical diffusion to blend fluids at the grid scale cannot reliably predict temperatures in mixing regions. On the other hand, Navier–Stokes solvers that incorporate enthalpy diffusion can provide much more accurate results. In constructing turbulence closures for high Reynolds number mixing, the same turbulent diffusion model that appears in the species mass transport equation should also appear in the energy equation as part of a “turbulent enthalpy diffusion;” otherwise the energy and species transport equations will not be consistent.
Discrete self-similarity in type-II strong explosions
Authors: Oren Yonatan , Sari Re’em
Published: May 2009

We present new solutions to the strong explosion problem in a nonpower law density profile. The unperturbed self-similar solutions discovered by Waxman and Shvarts describe strong Newtonian shocks propagating into a cold gas with a density profile falling off as r−ω, where ω>3 (type-II solutions). The perturbations we consider are spherically symmetric and log periodic with respect to the radius. While the unperturbed solutions are continuously self-similar, the log periodicity of the density perturbations leads to a discrete self-similarity of the perturbations, i.e., the solution repeats itself up to a scaling at discrete time intervals. We discuss these solutions and verify them against numerical integrations of the time dependent hydrodynamic equations. Finally we show that this method can be generalized to treat any small, spherically symmetric density perturbation by employing Fourier decomposition.
Behavior of a chemically doped graphene junction
Authors: Farmer Damon B. , Lin Yu-Ming , Afzali-Ardakani Ali , Avouris Phaedon
Published: May 2009

Polyethylene imine and diazonium salts are used as complementary molecular dopants to engineer a doping profile in a graphene transistor. Electronic transport in this device reveals the presence of two distinct resistance maxima, alluding to neutrality point separation and subsequent formation of a spatially abrupt junction. Carrier mobility in this device is not significantly affected by molecular doping or junction formation, and carrier transmission is found to scale inversely with the effective channel length of the device. Chemical dilutions are used to modify the dopant concentration and, in effect, alter the properties of the junction.
Geometric effect on surface enhanced Raman scattering of nanoporous gold: Improving Raman scattering by tailoring ligament and nanopore ratios
Authors: Lang X. Y. , Chen L. Y. , Guan P. F. , Fujita T. , Chen M. W.
Published: May 2009

We have synthesized nanoporous gold (NPG) films with a nanostructure consisting of small nanopores and large gold ligaments by the combination of chemical dealloying and electroless plating. The NPG films exhibit dramatic improvement in surface enhanced Raman scattering (SERS) in comparison with the conventional NPG. The superior SERS effect of the NPG films results from the confluence effect of enhanced local surface plasmon fields and electromagnetic coupling between ligaments, as well as the weak plasmon damping with increasing gold ligament sizes.
A large aperture electro-optic deflector
Authors: Bosco A. , Boogert S. T. , Boorman G. E. , Blair G. A.
Published: May 2009

An electro-optic laser beam deflector with a clear optical aperture of 8.6 mm has been designed, realized, and tested. The electro-optic material used to implement the device was a MgO:LiNbO3 crystal. The exceptionally large aperture makes the device suitable for applications where fast scanning of high power laser beams is needed. The measured deflection angle was 120 μrad/kV for a total length of electro-optic material of 90 mm. A mode quality analysis of the laser beam revealed that the M2 of the laser is affected by less than 4% during scan operation when maximum driving voltage is applied.
Divergence or Convergence? Devolution and Transport Policy in the United Kingdom
Authors: Shaw Jon , MacKinnon Danny , Docherty Iain
Published: May 2009

We examine the impact of devolution in the United Kingdom on transport policies in the first two terms of devolved government, from 1999/2000 to 2007/08. In particular, we discuss the nature and extent of policy convergence and divergence between the devolved territories (Scotland, Wales, Northern Ireland, and London) and England (wherein responsibility for policy formulation remains with the UK government at Westminster), and between the devolved territories themselves. Our analysis builds on existing work on devolution and public policy not only through its focus on transport policy, but also by distinguishing between ‘horizontal’ and ‘vertical’ dimensions of policy divergence and convergence, referring to relations between territories and to links to previous policies adopted within the same territory, respectively. Findings point to a convergence of overarching transport strategies and a complex picture of both convergence and divergence in terms of specific policy measures. The latter provides evidence of a devolution effect on transport policy.
Field metabolic rate and water turnover of red kangaroos and sheep in an arid rangeland: an empirically derived dry-sheep-equivalent for kangaroos
Authors: Munn A. J. , Dawson T. J. , McLeod S. R. , Croft D. B. , Thompson M. B. , Dickman C. R.
Published: May 2009

Sustainable management of pastures requires detailed knowledge of total grazing pressure, but this information is critically lacking in Australia’s rangelands where livestock co-occur with large herbivorous marsupials. We present the first comparative measure of the field metabolic rate (an index of food requirement) of Australia’s largest marsupial, the red kangaroo (Macropus rufus), with that of domestic sheep (Ovis aries; merino breed). We tested the assumption that the grazing pressure of red kangaroos is equivalent to 0.7 sheep, and show this to be a two-fold overestimation of their contribution to total grazing. Moreover, kangaroos had extraordinarily lower rates of water turnover, being only 13% that of sheep. Consequently, our data support arguments that the removal of kangaroos may not markedly improve rangeland capacity for domestic stock. Furthermore, given the low resource requirements of kangaroos, their use in consumptive and non-consumptive enterprises can provide additional benefits for Australia’s rangelands than may occur under traditional rangeland practices.
Use of genetic methods to establish male-biased dispersal in a cryptic mammal, the swamp wallaby (Wallabia bicolor)
Authors: Paplinska Justyna Zofia , Eldridge Mark D. B. , Cooper Desmond W. , Temple-Smith Peter D. M. , Renfree Marilyn B.
Published: May 2009

Mammalian dispersal tends to be male-biased although female-biased dispersal has also been reported in a range of taxa. Most of our knowledge on mammalian sex-biased dispersal is based on studies of eutherians and less work has been done on the direction and causes of sex-biased dispersal in marsupials. This study investigated dispersal of swamp wallabies between two habitat patches in South Gippsland, Victoria, using genetic methods. A Bayesian clustering test showed a high level of genetic exchange between the two habitat patches despite their separation by 10–17 km of cleared land, a creek and a highway. Females in the overall sample were more closely related to each other than males were to each other and females within habitat patches were more closely related than females between habitat patches whereas the converse was true for males. Bayesian inference showed that more males were migrating from the east to the west habitat patch whereas the converse was true for females and the male migration rate was higher than the female migration rate. The differential migration rate did not cause a significant difference in relatedness between patches in females but it did in males. These relatedness and migration patterns indicate that dispersal in the swamp wallaby is male-biased.
Unconventional myosin traffic in cells reveals a selective actin cytoskeleton
Authors: Brawley Crista M. , Rock Ronald S.
Published: May 2009

Eukaryotic cells have a self-organizing cytoskeleton where motors transport cargoes along cytoskeletal tracks. To understand the sorting process, we developed a system to observe single-molecule motility in a cellular context. We followed myosin classes V, VI, and X on triton-extracted actin cytoskeletons fromDrosophilaS2, mammalian COS-7, and mammalian U2OS cells. We find that these cells vary considerably in their global traffic patterns. The S2 and U2OS cells have regions of actin that either enhance or inhibit specific myosin classes. U2OS cells allow for 1 motor class, myosin VI, to move along stress fiber bundles, while motility of myosin V and X are suppressed. Myosin X motors are recruited to filopodia and the lamellar edge in S2 cells, whereas myosin VI motility is excluded from the same regions. Furthermore, we also see different velocities of myosin V motors in central regions of S2 cells, suggesting regional control of motor motility by the actin cytoskeleton. We also find unexpected features of the actin cytoskeletal network, including a population of reversed filaments with the barbed-end toward the cell center. This myosin motor regulation demonstrates that native actin cytoskeletons are more than just a collection of filaments.
IpaB–IpgC interaction defines binding motif for type III secretion translocator
Authors: Lunelli Michele , Lokareddy Ravi Kumar , Zychlinsky Arturo , Kolbe Michael
Published: May 2009

The delivery of virulence factors into host cells through type III secretion systems is essential for enterobacterial pathogenesis. Molecular chaperones bind specifically to virulence factors in the bacterial cytosol before secretion. Invasion plasmid gene C (IpgC) is a chaperone that binds 2 essential virulence factors of
Shigella
: invasion plasmid antigens (Ipa) B and C. Here, we report the crystal structure of IpgC alone and in complex with the chaperone binding domain (CBD) of IpaB. The chaperone captures the CBD in an extended conformation that is stabilized by conserved residues lining the cleft. Analysis of the cocrystal structure reveals a sequence motif that is functional in the IpaB translocator class from different bacteria as determined by isothermal titration calorimetry. Our results show how translocators are chaperoned and may allow the design of inhibitors of enterobacterial diseases.
Gag- and Nef-specific CD4+T cells recognize and inhibit SIV replication in infected macrophages early after infection
Authors: Sacha Jonah B. , Giraldo-Vela Juan P. , Buechler Matthew B. , Martins Mauricio A. , Maness Nicholas J. , Chung Chungwon , Wallace Lyle T. , León Enrique J. , Friedrich Thomas C. , Wilson Nancy A. , Hiraoka Atsunobu , Watkins David I.
Published: May 2009

The precise immunological role played by CD4+T cells in retroviral infections is poorly defined. Here, we describe a new function of these cells, the elimination of retrovirus-infected macrophages. After experimental CD8+cell depletion, elite controlling macaques with set-point viral loads ≤500 viral RNA copies/mL mounted robust Gag- and Nef-specific CD4+T cell responses during reestablishment of control with ≥54% of all virus-specific CD4+T cells targeting these 2 proteins. Ex vivo, these simian immunodeficiency virus (SIV)-specific CD4+T cells neither recognized nor suppressed viral replication in SIV-infected CD4+T cells. In contrast, they recognized SIV-infected macrophages as early as 2 h postinfection because of presentation of epitopes derived from virion-associated Gag and Nef proteins. Furthermore, virus-specific CD4+T cells displayed direct effector function and eliminated SIV-infected macrophages. These results suggest that retrovirus-specific CD4+T cells may contribute directly to elite control by inhibiting viral replication in macrophages.
Stem cells are dispensable for lung homeostasis but restore airways after injury
Authors: Giangreco Adam , Arwert Esther N. , Rosewell Ian R. , Snyder Joshua , Watt Fiona M. , Stripp Barry R.
Published: May 2009

Local tissue stem cells have been described in airways of the lung but their contribution to normal epithelial maintenance is currently unknown. We therefore developed aggregation chimera mice and a whole-lung imaging method to determine the relative contributions of progenitor (Clara) and bronchiolar stem cells to epithelial maintenance and repair. In normal and moderately injured airways chimeric patches were small in size and not associated with previously described stem cell niches. This finding suggested that single, randomly distributed progenitor cells maintain normal epithelial homeostasis. In contrast we found that repair following severe lung injury resulted in the generation of rare, large clonal cell patches that were associated with stem cell niches. This study provides evidence that epithelial stem cells are dispensable for normal airway homeostasis. We also demonstrate that stem cell activation and robust clonal cellular expansion occur only during repair from severe lung injury.
Unphosphorylated STAT1 prolongs the expression of interferon-induced immune regulatory genes
Authors: Cheon HyeonJoo , Stark George R.
Published: May 2009

In normal human cells treated with interferons (IFNs), the concentration of tyrosine-phosphorylated STAT1 (YP-STAT1), which drives the expression of a large number of genes, increases quickly but then decreases over a period of several hours. Because the STAT1 gene is activated by YP-STAT1, IFNs stimulate a large increase in the concentration of unphosphorylated STAT1 (U-STAT1) that persists for several days. To test the significance of high U-STAT1 expression, we increased its concentration exogenously in the absence of IFN treatment. In response, the expression of many immune regulatory genes (e.g., IFI27, IFI44, OAS, and BST2) was increased. In human fibroblasts or mammary epithelial cells treated with low concentrations of IFN-β or IFN-γ, the expression of the same genes increased after 6 h and continued to increase after 48 or 72 h, long after the concentration of YP-STAT1 had returned to basal levels. Consistent with its activity as a transcription factor, most U-STAT1 was present in the nuclei of these cells before IFN treatment, and the fraction in nuclei increased 48 h after treatment with IFN. We conclude that the nuclear U-STAT1 that accumulates in response to IFNs maintains or increases the expression of a subset of IFN-induced genes independently of YP-STAT1, and that many of the induced proteins are involved in immune regulation.
CD34 is a Key Regulator of Hematopoietic Stem Cell Trafficking to Bone Marrow and Mast Cell Progenitor Trafficking in the Periphery
Authors: NIELSEN JULIE S. , MCNAGNY KELLY M.
Published: May 2009

CD34 is a cell‐surface sialomucin widely used for hematopoietic stem cell purification and as a marker of most vascular endothelial cells, including those of capillaries in the majority of tissues. Surprisingly, despite extensive research, the function of this sialomucin has remained elusive, with proposed roles ranging from enhancing proliferation or inhibiting differentiation to acting as a proadhesive L‐selectin ligand. Here, we review our recent studies, which suggest that CD34 does, indeed, play a role in leukocyte and HSC trafficking, but that this is through its action as a regulated blocker of cell adhesion and enhancer of migration.
Cognition and Misrecognition: A Bourdieuian Analysis of Cognitive Strategy Instruction in a Linguistically and Culturally Diverse Classroom
Authors: Handsfield Lara J. , Jiménez Robert T.
Published: May 2009

This study reports data from a year-long ethnographic case study of a third-grade teacher's literacy instruction for her linguistically and culturally diverse students. Specifically, we use Bourdieu's social practice theory (1991, 1998) to examine the teacher's linguistic and literate habitus and the discourses of the field converge in her use of cognitive strategy instruction (CSI). In doing so, we spotlight CSI as a site of “struggle for the monopoly of legitimate discourse” (Bourdieu, 1983, p. 317) of the field of reading instruction and the potential effects for linguistically and culturally diverse students. We adapt Bourdieu's theories, however, by situating both habitus and field as performative (Butler, 1993) “as if” spaces (Holland, et al., 1998). Counter to the intentions of many who have developed and advocated the teaching of cognitive reading strategies, we found that CSI was performed in ways that may legitimize narrow conceptions of what “counts” as reading, and even thinking, or cognizing, about texts. At the same time, we identified a small number of instances in which the teacher's instruction challenged those conceptualizations. While we argue that CSI can benefit students, particularly those who struggle with reading, we are concerned that it may be implemented in ways that support current standardizing efforts in language and literacy education. We end with a discussion of how CSI might be employed in less prescriptive ways that are more closely attuned to the socially, historically, and politically situated literacy practices students may engage with in their daily lives.
Mistaking the instance for the rule: A critical analysis of the truth-table evaluation paradigm
Authors: Schroyens Walter
Published: May 2009

Many studies probe for interpretations of < if A then C> by having people evaluate truth-table cases (, < A and not-C>, < not-A and C>, < not-A and not-C>) as making the rule true or false, or being irrelevant. We argue that a single case can never prove a general rule to be true, as philosophy of science has taught any researcher. Giving participants the impossible “true” option would therefore bias results away from this response. In Experiment 1 people judged instead whether cases make a rule false, do not make the rule false, or are irrelevant to the rule. The experimental group ( N = 44) showed a significant increase in not-false responses compared with true responses of the control group ( N = 39). In Experiments 2 and 3 the experimental groups judged whether cases make a rule true, corroborate it (i.e., make the rule more plausible, but neither true nor false), make it false, or are irrelevant. There was a significant reduction of irrelevant responses as compared to the default true/false/irrelevant task for the control groups. Even < A and C> cases were often no longer considered to make an < if A then C> rule true and were correctly judged to corroborate (vs. verify) rules. Results corroborate our conceptual analyses of the unsuitable “true” response option and put into question arguments that hinge on the presumed likelihood by which people consider truth contingencies to make a rule “true”.
Ecological Conservation: The Problems of Targeting Policies and Designing Instruments
Authors: Clark C. D. , Russell C. S.
Published: May 2009

Three decades of effort to control the obvious and familiar forms of pollution has produced a policy toolkit of theoretical power and practical flexibility. However, the toolkit is not as well-suited to addressing the challenges posed by preserving ecological diversity and integrity. This paper aims to illuminate some of the obstacles to policy design for ‘ecological conservation’ by: (1) identifying a number of analytical characteristics that were key to creating successful policy in the pollution control setting; (2) considering the applicability of these characteristics to the ecological conservation setting; and (3) discussing the implications of these differences for policy design. The paper concludes with recommendations on sidestepping these difficulties.
The fruit of the golden flower
Authors: Davy-Barnes Malcolm
Published: May 2009

As a pioneer in psychologically exploring Eastern religions and philosophies, Jung has been accused of psychologism and fashioning spiritual traditions to confirm his own theories. The author looks at Jung's engagement with the Taoist text,The secret of the golden flower; exploring Jung's writing of a commentary, in the context of his life and interests at the time. In noting some of the concepts he took from his reading, Jung's commentary is placed back in the context of the Chinese alchemical tradition to look at Jung's ambivalence to the East. The arising problematic distinctions between the psychological and spiritual are explored. Finally, the commentary is discussed in the light of Jung's methodology that can be seen as producing valuable insights not only through his technique of amplification, but also through the paradox borne of the shadow of that technique.
Studies on plasma direct energy converters for thermal and fusion-produced ions using slanted cusp magnetic and distributed electric fields
Authors: Yasaka Y. , Goto K. , Taniguchi A. , Tsuji A. , Takeno H.
Published: May 2009

Two types of direct energy converters, cusp direct energy converter (CUSPDEC) and travelling-wave (TW) DEC, used to produce electricity from thermal ions and fusion products in an advanced fuelled fusion, are investigated using small-scale devices. In CUSPDEC, magnetized electrons are deflected along the field lines of the cusp magnetic field to the line cusp region and collected by an electron collector, while weakly magnetized ions can traverse the separatrix and enter into the point cusp region. Thus, ions are separated from electrons, and flow into an ion collector to produce dc power. Efficiencies of energy conversion of separated ions with large thermal spread of energy are measured to be ∼55%. An additional lateral electrode, together with the existing collector, constitutes a two-stage ion collector that provides distributed ion-decelerating fields. From the measured voltage–current characteristics, the efficiency of this collector is estimated to be improved to 65–70%, which is consistent with the calculation. Fusion-produced fast ions enter into TWDEC and are velocity-modulated by RF fields, bunched and then decelerated by RF travelling-wave fields on the decelerator to produce RF power. The TWDEC device has shown that the energies of ions of 3–6 keV can be decreased by 10–15% for a one-wavelength decelerator. This would give a total efficiency of 60–70% for a full-length decelerator. A novel system is being investigated for further improvement, in which the incoming ions are deflected transversely, according to each energy, to form a fan-shaped beam and a distributed electrode array for modulation and deceleration generates travelling-waves appropriate to each ion path depending on the energy.
Behaviour of turbulent transport in the vicinity of a magnetic island
Authors: Poli E. , Bottino A. , Peeters A.G.
Published: May 2009

The influence of a static magnetic island on the behaviour of the electrostatic turbulence in a tokamak is investigated numerically employing global nonlinear gyrokinetic particle-in-cell simulations. The excitation of turbulence is modified by the magnetic topology of the island. Low mode numbers in the energy spectrum of the potential disturbances, corresponding to the island perturbation, are amplified by nonlinear coupling with the microinstabilities, particularly in the presence of strong turbulence. The associated large-scale flows affect the transport directly and through strain of small-scale eddies. The temperature profile determined numerically in the island region agrees qualitatively with analytic estimates; however, quantitative discrepancies are found.
Epigenetic silencing of transposable elements: A trade-off between reduced transposition and deleterious effects on neighboring gene expression
Authors: Hollister Jesse D. , Gaut Brandon S.
Published: May 2009

Transposable elements (TEs) are ubiquitous genomic parasites. The deleterious consequences of the presence and activity of TEs have fueled debate about the evolutionary forces countering their expansion. Purifying selection is thought to purge TE insertions from the genome, and TE sequences are targeted by hosts for epigenetic silencing. However, the interplay between epigenetic and evolutionary forces countering TE expansion remains unexplored. Here we analyze genomic, epigenetic, and population genetic data from Arabidopsis thaliana to yield three observations. First, gene expression is negatively correlated with the density of methylated TEs. Second, the signature of purifying selection is detectable for methylated TEs near genes but not for unmethylated TEs or for TEs far from genes. Third, TE insertions are distributed by age and methylation status, such that older, methylated TEs are farther from genes. Based on these observations, we present a model in which host silencing of TEs near genes has deleterious effects on neighboring gene expression, resulting in the preferential loss of methylated TEs from gene-rich chromosomal regions. This mechanism implies an evolutionary tradeoff in which the benefit of TE silencing imposes a fitness cost via deleterious effects on the expression of nearby genes.
Crystallography Open Database – an open-access collection of crystal structures
Authors: Gražulis Saulius , Chateigner Daniel , Downs Robert T. , Yokochi A. F. T. , Quirós Miguel , Lutterotti Luca , Manakova Elena , Butkus Justas , Moeck Peter , Le Bail Armel
Published: May 2009

The Crystallography Open Database (COD), which is a project that aims to gather all available inorganic, metal–organic and small organic molecule structural data in one database, is described. The database adopts an open-access model. The COD currently contains ∼80 000 entries in crystallographic information file format, with nearly full coverage of the International Union of Crystallography publications, and is growing in size and quality.
Association of polymorphisms in genes involved in lipoprotein metabolism with plasma concentrations of remnant lipoproteins and HDL subpopulations before and after hormone therapy in postmenopausal women
Authors: Lamon‐Fava Stefania , Asztalos Bela F. , Howard Timothy D. , Reboussin David M. , Horvath Katalin V. , Schaefer Ernst J. , Herrington David M.
Published: May 2009

Objective  A high degree of inter‐individual variability in plasma lipid level response to hormone therapy (HT) has been reported. Variations in the oestrogen receptor α gene (ESR1) and in genes involved in lipid metabolism may explain some of the variability in response to HT.

Subjects  Postmenopausal Caucasian women (n = 208) participating in a placebo‐controlled randomized trial of 3·2 years of hormone therapy (HT).

Methods  Plasma triglyceride (TG), remnant lipoprotein cholesterol (RLP‐C), and high‐density lipoprotein cholesterol (HDL‐C) levels and HDL subpopulations were assessed at baseline and at follow up. Single nucleotide polymorphisms (SNPs) in ESR1 and in the ATP binding cassette A1 (ABCA1), cholesteryl ester transfer protein (CETP), hepatic lipase (LIPC), lipoprotein lipase (LPL), and scavenger receptor class B type I (SRB1) genes were assessed for their association with baseline plasma levels and HT‐related changes in levels of RLP‐C and HDL subpopulations.

Results  Carriers of the ESR1 PvuII or IVS1‐1505 variants had lower plasma TG concentrations and higher plasma HDL‐C and α‐1 and preα‐1 HDL particle levels at baseline and showed greater increases in HDL‐C, apo A‐I and α‐1 particle levels after HT than wild‐type carriers. Carriers of the N291S and D9N variants in the LPL gene had significantly higher remnant lipoproteins and lower α‐2 HDL particle levels at baseline. The CETP TaqIB SNP was a significant determinant of baseline plasma HDL‐C and HDL subpopulation profile.

Conclusions  Single nucleotide polymorphisms in ESR1, CETP and LPL had significant effects on baseline plasma levels of TG‐rich and HDL subpopulations. With the exception of ESR1 SNPs, variation in genes involved in lipid metabolism has a very modest effect on lipoprotein response to HT.
Population history in social spiders repeated: colony structure and lineage evolution in Stegodyphus mimosarum (Eresidae)
Authors: JOHANNESEN JES , WICKLER WOLFGANG , SEIBT UTA , MORITZ ROBIN F. A.
Published: May 2009

Social cooperative spiders from diverse taxonomic families share life‐history and demographic traits, including highly inbred colony structure. The combination of traits suggests constrained pathways for social evolution in spiders. The genus Stegodyphus has three independently evolved social species, which can be used as replicate samples to analyse population constraints in evolutionary time. We tested colony structure and population history of the social S. mimosarum from South and East Africa using mitochondrial DNA variation, and we compared the results to published data for the independently evolved social congener S. dumicola. S. mimosarum had many and diverse haplotypes (5–7% sequence divergence for ND1) but colonies were monomorphic and genealogically similar haplotypes occurred in abutting regions. These findings are nearly identical to results for S. dumicola and imply similar colony‐level processes over evolutionary time in independently evolved social species. These population dynamics are discussed with respect to the apparent lack of cladogenesis in social spiders.
Is the Future more or less Human? Differing Views of Humanness in the Posthumanism Debate
Authors: WILSON SAMUEL , HASLAM NICK
Published: May 2009

A debate has emerged in the bioethics literature about the use of biotechnology to modify human nature. A failure to define humanness has produced conceptual confusion in this debate. We draw upon recent social psychological work on folk concepts of humanness and dehumanization to analyse the understandings of humanness that underpin the rival positions. We argue that advocates and opponents of human nature modification employ distinct conceptions of humanness, and that their differing evaluations of modification make sense in light of these conceptions. Advocates view modification as the enhancement of a non‐essentialist sense of humanness that takes us further from animal nature. Opponents view it as the loss of an essentialist sense of humanness that takes us closer to a robotic state. Recognition that humanness has multiple senses implies that there is no mutually exclusive choice between seeing the outcome of modification as a quantitative gain in humanness or a fundamental, qualitative loss of it.
Bateson, Double Description, Todes, and Embodiment: Preparing Activities and Their Relation to Abduction
Authors: SHOTTER JOHN
Published: May 2009

Does all understanding consist in our using concepts to relate to the things around us, or do we also possess a more direct, spontaneous, bodily way of doing so? I explore this second possibility via Bateson's (1979) notion of “double description.” These phenomena are dynamic phenomena, in that they have their existence only in our embodied relations to the temporal unfolding of events in the two or more relevant sources. As such, as Bateson (1979) put it, they are of a different “logical type” (Russell, 1908) to their source events. Bateson did not, however, extend this important insight out into the ways in which can make ourselves ready to relate to the others and othernesses around us, not only in such a way as to intertwine our outgoing activities towards them in with the incoming activities from them in a subtlety responsive manner, but also come to use the relational understandings created in such dynamic interplays in an anticipatory fashion—thus to provide us with embodied, perceptual skills that enable us to go out to meet familiar circumstances with appropriate kinds of response “at the ready”, so to speak. Below, following Todes (2001) and Merleau‐Ponty (1962), I outline the kind of preparing activities required if we are to acquire new embodied “readinesses” that enable us to become more “at home” in surroundings which are in fact in continual change—a process that connects with Bateson's (1979) account of abduction, the process in which we can sense the existence of a “pattern that connects.” Overall, my purpose in all of this is to bring to the fore the ineradicable role of our bodies in spontaneously arriving at what counts as real for us, and which although unnamable by us, determines that of “which knowledge always speaks” (Merleau‐Ponty, 1962, p. ix).
Critical Realism and Causality: Tracing the Aristotelian Legacy
Authors: PRATTEN STEPHEN
Published: May 2009

Rom Harré's generative account of causality has been drawn on heavily by advocates of critical realism. Yet Harré argues that critical realists often exaggerate the extent to which powerful causal explanations of social phenomena can be developed. Certain proponents of critical realism have responded to Harré's criticisms by suggesting that it is useful to consider the relevant issues in relation to the familiar Aristotelian classification of four causes. In this paper I contribute to this debate and pursue a similar strategy. The paper adds to existing contributions in two ways. Firstly, I outline how Harré sees his generative account of causality as linking up with Aristotelian themes. It emerges that Harré at times conceives of his generative theory as part of an alternative to the Aristotelian system while at other times he draws connections between it and a reformulated account of formal causality. Secondly, I argue that when we consider the positions of Harré and proponents of critical realism on the scope of causal explanation in the social realm in relation to the interpretation of final causes offered by another philosopher profoundly influenced by the Aristotelian tradition, namely Charles Peirce, we can see both as limited in certain respects.
Identification of a regulatory loop for the synthesis of neurosteroids: a steroidogenic acute regulatory protein‐dependent mechanism involving hypothalamic‐pituitary‐gonadal axis receptors
Authors: Meethal Sivan Vadakkadath , Liu Tianbing , Chan Hsien W. , Ginsburg Erika , Wilson Andrea C. , Gray Danielle N. , Bowen Richard L. , Vonderhaar Barbara K. , Atwood Craig S.
Published: May 2009

Brain sex steroids are derived from both peripheral (primarily gonadal) and local (neurosteroids) sources and are crucial for neurogenesis, neural differentiation and neural function. The mechanism(s) regulating the production of neurosteroids is not understood. To determine whether hypothalamic‐pituitary‐gonadal axis components previously detected in the extra‐hypothalamic brain comprise a feedback loop to regulate neuro‐sex steroid (NSS) production, we assessed dynamic changes in expression patterns of steroidogenic acute regulatory (StAR) protein, a key regulator of steroidogenesis, and key hypothalamic‐pituitary‐gonadal endocrine receptors, by modulating peripheral sex hormone levels in female mice. Ovariectomy (OVX; high serum gonadotropins, low serum sex steroids) had a differential effect on StAR protein levels in the extrahypothalamic brain; increasing the 30‐ and 32‐kDa variants but decreasing the 37‐kDa variant and is indicative of cholesterol transport into mitochondria for steroidogenesis. Treatment of OVX animals with E2, P4, or E2 + P4 for 3 days, which decreases OVX‐induced increases in GnRH/gonadotropin production, reversed this pattern. Suppression of gonadotropin levels in OVX mice using the GnRH agonist leuprolide acetate inhibited the processing of the 37‐kDa StAR protein into the 30‐kDa StAR protein, confirming that the differential processing of brain StAR protein is regulated by gonadotropins. OVX dramatically suppressed extra‐hypothalamic brain gonadotropin‐releasing hormone 1 receptor expression, and was further suppressed in E2‐ or P4‐treated OVX mice. Together, these data indicate the existence of endocrine and autocrine/paracrine feedback loops that regulate NSS synthesis. Further delineation of these feedback loops that regulate NSS production will aid in developing therapies to maintain brain sex steroid levels and cognition.
Decrease of optic disc cupping and pallor of ocular hypertensives with timolol therapy
Authors: Schwartz Bernard , Lavin Philip , Takamoto Takenori , Araujo Daniel F. , Smits Gerard
Published: May 2009

Abstract. Purpose: The purpose of this study was to determine whether timolol drops compared to placebo drops had a significant effect on optic disc cupping and pallor in ocular hypertensives.

Methods: Thirty‐seven ocular hypertensives were randomly assigned to placebo or 0.5% timolol drops to both eyes in a double masked clinical trial. Measurements of ocular pressure and photographs of the optic disc for cupping by photogrammetry and pallor by computerized image analysis were made at about 3 month intervals, for 18 to 24 months of follow‐up.

Results: None of the subjects developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals. Subjects treated with timolol developed a significant decrease in ocular pressure and a significant decrease in optic disc cupping with a smaller decrease in pallor compared to subjects treated with placebo. Multivariate analyses indicated that the decrease of optic disc cupping and pallor was not associated with the ocular pressure on treatment or the decrease in ocular pressure during the trial.

Conclusion: Timolol treatment was associated with a decrease in optic disc cupping and pallor. The effect of timolol appears to be related to mechanisms other than the decrease in ocular pressure.
Increase of retinal nerve fiber layer thickness in ocular hypertensives with timolol therapy
Authors: Schwartz Bernard , Takamoto Takenori , Lavin Philip , Smits Gerard
Published: May 2009

Abstract. Purpose: The purpose of this study was to determine whether timolol drops compared to placebo drops had a significant effect on retinal nerve fiber layer thickness in ocular hypertensives.

Methods: Thirty‐seven ocular hypertensives were randomly assigned to receive placebo or 0.5% timolol drops to both eyes for 18 to 24 months in a double masked clinical trial. Measurements of ocular pressure and photographs of retinal nerve fiber layer using stereophotogrammetric techniques were made at about 3 month intervals for 18 to 24 months of follow‐up.

Results: None of the subjects developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals. Subjects treated with timolol had a significant decrease in ocular pressure and developed a significant increase in retinal nerve fiber layer thickness compared to subjects treated with placebo. Multivariate analyses indicated that the increase of retinal nerve layer thickness was not associated either with the ocular pressure on treatment or the decrease in ocular pressure on treatment.

Conclusion: Timolol treatment was associated with an increase of retinal nerve fiber layer thickness. The effect of timolol appears to be related to mechanisms other than the decrease in ocular pressure.
Severe microcornea with anterior segment malformation in a mother and her son
Authors: Russell‐Eggitt I. , Kriss A. , Restori Marie , Speedwell L. , Thompson D. , Timms C. , Yu C.
Published: May 2009

ABSTRACT A male infant with microcornea, anterior segment dysgenesis and congenital cataracts, but with a normal ocular posterior segment is reported. His mother also had extreme microcornea, no useful vision from birth, but had globes of grossly normal size.
Corneal deepithelialization caused by acute deficiency of isoleucine during treatment of a patient with Maple Syrup Urine Disease
Authors: Tornqvist Kristina , Tornqvist Hans
Published: May 2009

ABSTRACT Classical Maple Syrup Urine Disease is a serious, autosomal recessive and rare metabolic disorder due to a completely inactive enzyme complex for metabolizing the branched amino acids leucine, valine and isoleucine. If untreated the disease is lethal. Metabolic control achieved by strict dietary treatment results in normal development. In this paper we describe deepithelialization of the cornea together with skin and intestinal symptoms as the result of isolated deficiency of isoleucine during treatment of a critically ill, newborn infant with this unusual disease.
Temporal corneal phacoemulsification combined with separate‐incision superior trabeculectomy vs standard phacotrabeculectomy. A comparative study
Authors: Rossetti L. , Bucci L. , Miglior S. , Orzalesi N.
Published: May 2009

The aim of the study was to compare functional and refractive outcome after temporal approach phacoemulsification combined with superior trabeculectomy against that of standard superior phacotrabeculectomy in patients affected by cataract and uncontrolled glaucoma.

Fifty patients undergoing combined surgery were randomly allocated to receive either a standard superior phacotrabeculectomy (group A) or a temporal via clear cornea phacoemulsification combined with a separate superior trabeculectomy (group B).

Short‐term and long‐term mean IOP reductions were similar in the two groups though, at 2 years, more patients in the standard phacotrabeculectomy group had need of medical therapy to control their ocular pressure (p=0.04). Group B had less surgically induced astigmatism than group A (p=0.05). There was no significant difference in ocular inflammation and complication rates between the 2 groups.
Ultrabiomicroscopic study of the effects of brimonidine, apraclonidine, latanoprost and ibopamine on the chamber angle and ciliary body
Authors: Presti L. Lo , Morgese A. , Ravot M. , Brogliatti B. , Carenini B. Boles
Published: May 2009

The authors used the Zeiss Humphrey (Mod840, 50MHz) ultrabiomicroscope to evaluate the changes that Brimonidine, Apraclonidine, Latanoprost and Ibopamine cause in the anterior chamber and on the ciliary body of healthy subjects. The eyes of 60 volunteers, separated into 4 groups according to drug instilled, were studied and the parameters analyzed were: anterior chamber depth (ACD), pupillary diameter (PD), angle opening at 500 microns from the scleral spur (AOD500), trabecular iris angle (TIA) and iris thicknesses (ID1 and ID3).

The study showed the miotic effect of Brimonidine (S) that was accompanied by an angle opening (S). Apraclonidine and Latanoprost caused no statistically significant changes in the angle or in the ciliary body. Ibopamine caused mydriasis (S).

The UBM, therefore, showed itself to be useful also in the study of the mechanism of action of drugs on the angular structures and on the ciliary body.
Role of orexin in the regulation of glucose homeostasis
Authors: Tsuneki H. , Wada T. , Sasaoka T.
Published: May 2009

Orexin‐A (hypocretin‐1) and orexin‐B (hypocretin‐2) are hypothalamic neuropeptides that play key roles in the regulation of wakefulness, feeding, reward, autonomic functions and energy homeostasis. To control these functions indispensable for survival, orexin‐expressing neurones integrate peripheral metabolic signals, interact with many types of neurones in the brain and modulate their activities via the activation of orexin‐1 receptor or orexin‐2 receptor. In addition, a new functional role of orexin is emerging in the regulation of insulin and leptin sensitivities responsible for whole‐body glucose metabolism. Recent evidence indicates that orexin efficiently protects against the development of peripheral insulin resistance induced by ageing or high‐fat feeding in mice. In particular, the orexin receptor‐2 signalling appears to confer resistance to diet‐induced obesity and insulin insensitivity by improving leptin sensitivity. In fact, the expression of orexin gene is known to be down‐regulated by hyperglycaemia in the rodent model of diabetes, such as ob/ob and db/db mice. Moreover, the levels of orexin receptor‐2 mRNA have been shown to decline in the brain of mice along with ageing. These suggest that hyperglycaemia due to insulin insensitivity during ageing or by habitual consumption of a high‐fat diet leads to the reduction in orexin expression in the hypothalamus, thereby further exacerbating peripheral insulin resistance. Therefore, orexin receptor controlling hypothalamic insulin/leptin actions may be a new target for possible future treatment of hyperglycaemia in patients with type 2 diabetes.