bluuebunny/crossref_metadata_2025 huggingface dataset:
PVDFBaTiO3/carbon nanotubes ternary nanocomposites: Effect of nanofillers and processing
Authors: Sanchez Freddy A. , González‐Benito Javier
Published: May 2015

Ternary thermoplastic systems based on poly(vinylidene fluoride), PVDF, filled with barium titanate, BaTiO3, submicrometric particles and carbon nanotubes, CNT, were prepared. Their structure and morphology were studied as a function of composition and finally correlated with thermal and mechanical properties. High energy ball milling, HEBM, under cryogenic conditions and subsequent hot pressing were used to obtain films with quite uniform dispersion of the nanofillers. The presence of BaTiO3 particles and CNT did not modify the thermodegradation mechanism of the PVDF. However, enough amount of BaTiO3 seemed to inhibit the volatility of the products of pyrolysis, hindering the decomposition of PVDF. The presence of CNT favored the PVDF thermodegradation probably due to improved heat transmission by an increase in the thermal conductivity. Variations in PVDF thermal transitions were more dependent of processing conditions. Improvements in the mechanical properties of PVDF were ascribed to a reinforcing effect of the fillers. This effect only happened below the fraction of percolation of CNT, pointing out that CNT reinforce through an optimum load transfer from the PVDF matrix to the nanofillers. POLYM. COMPOS., 38:227–235, 2017. © 2015 Society of Plastics Engineers
Chemical cross‐linking and native mass spectrometry: A fruitful combination for structural biology
Authors: Sinz Andrea , Arlt Christian , Chorev Dror , Sharon Michal
Published: May 2015

Mass spectrometry (MS) is becoming increasingly popular in the field of structural biology for analyzing protein three‐dimensional‐structures and for mapping protein–protein interactions. In this review, the specific contributions of chemical crosslinking and native MS are outlined to reveal the structural features of proteins and protein assemblies. Both strategies are illustrated based on the examples of the tetrameric tumor suppressor protein p53 and multisubunit vinculin‐Arp2/3 hybrid complexes. We describe the distinct advantages and limitations of each technique and highlight synergistic effects when both techniques are combined. Integrating both methods is especially useful for characterizing large protein assemblies and for capturing transient interactions. We also point out the future directions we foresee for a combination of in vivo crosslinking and native MS for structural investigation of intact protein assemblies.
Electronic structure of threading dislocations in wurtzite GaN
Authors: Belabbas I. , Chen J. , Nouet G.
Published: May 2015

We have carried out atomistic simulations, based on density functional theory, to investigate the atomic and electronic structures of the three types of prismatic threading dislocations in hexagonal gallium nitride. Screw and mixed threading dislocations were demonstrated to introduce both deep and shallow gap states, while most of core configurations of the edge dislocation introduce solely shallow states. The higher electrical activity of both screw and mixed dislocations, compared to the edge one, is correlated with the high dispersion of their energy levels, within the GaN bandgap. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of O2 flow rate on the electrochromic response of WO3 grown by LPCVD
Authors: Psifis Konstantinos , Louloudakis Dimitris , Vernardou Dimitra , Spanakis Emmanuel , Papadimitropoulos George , Davazoglou Dimitris , Katsarakis Nikolaos , Koudoumas Emmanuel
Published: May 2015

Tungsten trioxide coatings were grown on fluorine doped tin dioxide glass substrate at 465 oC by low pressure chemical vapor deposition. Monoclinic tungsten oxide with low crystallinity containing agglomeration of grains was obtained irrespective of the O2 flow rate utilized. It was only observed an increase of grain size to 75 from 25 nm as the O2 raised to 100 from 25 sccm. In addition, the current density was similar among the samples irrespective of the growth conditions performed. Finally, the coloration efficiency was estimated to be 83 cm2 C‐1 at 670 nm, which is higher than other grown samples using greater deposition temperatures. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hot‐wire vapor deposition of amorphous MoS2 thin films
Authors: Papadimitropoulos Georgios , Vourdas Nikolaos , Kontos A. , Vasilopoulou Maria , Kouvatsos Dimitrios N. , Boukos Nicolas , Gasparotto Alberto , Barreca Davide , Davazoglou Dimitrios
Published: May 2015

Amorphous, as shown by X‐ray diffraction measurements, MoS2 films (a‐MoS2) were deposited by heating a molybdenum wire at temperatures between 500 and 700 °C in H2S at 1 Torr. As shown by Scanning Electron Microscopy measurements, the morphology of samples depends significantly on the filament temperature; at low temperature samples are homogeneous and smooth, at intermediate temperatures they exhibit a granular microstructure and at high temperatures a columnar one. X‐ray photoelectron spectroscopy measurements have shown S/Mo ratios in films varying between 2.5 and 1.5 dependent on filament temperature. Films also contain oxygen at atomic contents of 8 to 12%. As shown by XPS and Raman spectroscopy, at a filament temperature of 600 °C films are mainly composed of MoS2 also containing oxygen at an atomic ratio of 8%. Spectroscopic ellipsometry measurements made on a‐MoS2 films have shown that their band gap is of the order of 1.4 eV, slightly higher than that for the bulk crystalline material. Photoluminescence spectroscopy measurements have shown that samples exhibit a doublet of peaks at 2.8 and 3 eV blue shifted relatively to MoS2 samples composed of one or two mono‐layers. The above indicate that the electronic structure of crystalline atomic‐layer thick MoS2 is preserved in a‐MoS2 films. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural characterization of flavonoid C‐ and O‐glycosides in an extract of Adhatoda vasica leaves by liquid chromatography with quadrupole time‐of‐flight mass spectrometry
Authors: Singh Awantika , Kumar Sunil , Bajpai Vikas , Reddy T. Jagadeshwar , Rameshkumar K. B. , Kumar Brijesh
Published: May 2015

Rationale

Adhatoda vasica Nees is a well‐known Ayurvedic medicinal plant, belonging to the family Acanthaceae. This study aims to seek identification and characterization of flavonoid C‐ and O‐glycosides in the aqueous fraction of the plant leaves.

Methods

A method was developed for simultaneous characterization of flavonoids and their glycosides using high‐pressure liquid chromatography with quadrupole time‐of‐flight mass spectrometry (HPLC/ESI‐QTOF‐MS/MS). The chromatographic separation was carried on an Agilent Poroshell 120 EC‐C18 column (4.6 × 150 mm, 2.7 µm) operated with 0.1% formic acid aqueous solution and methanol as the mobile phase.

Results

The fragmentations of the studied [M–H]− ions of C‐glycosides were shown to be cross‐ring cleavages of the glycoside moiety [M–H–(60/90/120)]− whereas O‐glycosides were shown to eliminate the sugar moiety (Y0− or [Y0–H]−) from the aglycone unit; 6‐C‐glycosides exhibited [M–H–18]−, a characteristic ion, and also a higher abundance of 0,3X6 or 8 ions in comparison to 8‐C glycosides; flavonoid 6,8‐di‐C‐glycosides exhibited cross‐ring cleavages of the sugar attached to the C‐6 position preferentially.

Conclusions

This method was successfully applied for analysis of flavonoids and their glycosides in Adhatoda vasica leaves. A total of 29 compounds were tentatively identified including 17 C‐, nine O‐glycosides and three flavonoids. Copyright © 2015 John Wiley & Sons, Ltd.
Determining the suitability of mass spectrometry for understanding the dissolution processes involved with pharmaceutical tablets
Authors: Lewis Claire , Ray Andrew , Bristow Tony , Wren Stephen
Published: May 2015

Rationale

A current challenge for analytical chemists is the development of the measurement systems and approaches required to understand dynamic processes such as tablet dissolution. The design and development of oral tablets could be improved by the availability of detailed information about the rates of release of the individual tablet components. Small footprint mass spectrometry (MS) systems are gaining use for on‐line reaction monitoring because of their ability to rapidly determine multiple reactant, intermediate, and product species. We have therefore assessed the utility of such MS systems to the study of dissolution processes.

Methods

Aqueous dissolution media containing phosphate and other non‐volatile buffer salts were pumped from a standard USPII dissolution vessel through an active splitter and back. The splitter sampled the dissolution stream and diluted it into a make‐up flow which was pumped to a small single quadrupole mass spectrometer. Single ion monitoring was used to quantify the ions of interest. Three different bio‐relevant dissolution media were studied to gauge the effect of the sample matrix.

Results

Individual dissolution profiles were obtained from a tablet containing three drugs, and lactose as the soluble filler. This was successfully demonstrated with three different bio‐relevant media designed to reflect the pH of the different sections of the human gastro‐intestinal tract. Component concentrations as low as 0.06 µg/mL (representing 1% dissolution) were detected. The MS dissolution profiles correlated with the visual observation of tablet dissolution. MS gave linear responses with concentration for the individual components, although analysis of the tablet solution indicated that ion suppression is an area for further investigation.

Conclusions

An on‐line MS system was used to determine the individual dissolution profiles of three drugs and lactose as they were released from the same tablet. The level of each of these components in solution was determined every 10 seconds, and each had a similar release profile. The dissolution profiles were determined using inorganic buffer solutions at three different bio‐relevant pHs. Copyright © 2015 John Wiley & Sons, Ltd.
Effect of Adverse Pressure Gradient and Different Vegetated Banks on Flow
Authors: Afzalimehr H. , Moradian M. , Gallichand J. , Sui J.
Published: May 2015

This study examines velocity components in 3D and shear stress distributions in flows with adverse pressure gradient over a gravel‐bed channel using three types of vegetation on banks, rice, straw and Typha stems. Results of this experimental study are compared with those for flows in the bare bank channel. Results show that the flows with adverse pressure gradient are not self‐similar in vegetated and bare banks channels. The logarithmic law and parabolic law can be used to well describe flow in the inner and outer regions, respectively, but with different relative flow depths. Shear stress distributions depend on nature of bank roughness and the secondary flow effects because of small values of the aspect ratio and adverse pressure gradient. Quadrant analysis is performed to investigate the effect of different vegetation covers on the Reynolds stress distributions at the central axis of channel and near the vegetated banks. Vegetation covers influence the contributions of different quadrants to the shear stress distribution, showing that sweeps and ejections are dominant events for all vegetated banks for near bed region. However, near the water surface the contributions of outwards and inwards for banks with Typha stems are more important than those for rice and straw. Instead of using a single value for friction factor, for different vegetated banks, a range of friction factor has to be applied in river restoration projects. Vegetated banks result in an increase of more than 60% in friction factor in comparison with that for bare banks under adverse pressure gradient flows. Copyright © 2015 John Wiley & Sons, Ltd.
Effects of pH on the silk fibroin coating of CoCrMo alloy
Authors: Türkan Uğur , Arpaçay Pınar
Published: May 2015

Bacteria related infections are still cited as a major problem for the implant materials resulting in failure of device especially knee and hip replacement. Two main approaches are focused for inhibiting the bacterial adhesion to the surface. These involve bactericidal substances and anti‐adhesive coatings. Silk fibroin is one of the promising materials due to its good drug loading capacity and efficiency. In this study, the effects of pH on the silk fibroin coating of CoCrMo alloy, prepared by means of layer by layer, was investigated thoroughly using scanning electron microscope (SEM), Atomic Force Microscope (AFM) Attenuated Total Reflectance Fourier Transform Infrared (ATR‐FTIR) Spectroscopy. A medical grade CoCrMo was coated with variable number of silk fibroin up to 14 layers at pH 3.0, 3.5, and 5.5 at room temperature. As a result, only silk fibroin films prepared at pH 3.0 and 3.5 were found to convey the general characteristics of the mixture of silk I and II, while the samples prepared at pH 5.5 exhibited the lack of some specific amide structures which influence the general characteristics of silk I and II. Moreover, regardless of pH, the surface roughness was determined to increase with the increasing number of layers. However, as the pH increases the surface roughness decreases at 6, 10 and 14 layers. SCANNING 38:80–88, 2016. © 2015 Wiley Periodicals, Inc.
Polymeric Micelle‐Mediated Delivery of DNA‐Targeting Organometallic Complexes for Resistant Ovarian Cancer Treatment
Authors: Duan Xiaopin , Liu Demin , Chan Christina , Lin Wenbin
Published: May 2015

Three half‐sandwich iridium and ruthenium organometallic complexes with high cytotoxicity are synthesized, and their anticancer mechanisms are elucidated. The organometallic complexes can interact with DNA through coordination or intercalation, thereby inducing apoptosis and inhibiting proliferation of resistant cancer cells. The organometallic complexes are then incorporated into polymeric micelles through the polymer‐metal coordination between poly(ethylene glycol)‐b‐poly(glutamic acid) [PEG‐b‐P(Glu)] and organometallic complexes to further enhance their anticancer effects as a result of the enhanced permeability and retention effect. The micelles with particle sizes of ≈60 nm are more efficiently internalized by cancer cells than the corresponding complexes, and selectively dissociate and release organometallic anticancer agents within late endosomes and lysosomes, thereby enhancing drug delivery to the nuclei of cancer cells and facilitating their interactions with DNA. Thus, the micelles display higher antitumor activity than the organometallic complexes alone with a lack of the systemic toxicity in a mouse xenograft model of cisplatin‐resistant human ovarian cancer. These results suggest that the polymeric micelles carrying anticancer organometallic complexes provide a promising platform for the treatment of resistant ovarian cancer and other hard‐to‐treat solid tumors.
Efficient Radioisotope Energy Transfer by Gold Nanoclusters for Molecular Imaging
Authors: Volotskova Olga , Sun Conroy , Stafford Jason H. , Koh Ai Leen , Ma Xiaowei , Cheng Zhen , Cui Bianxiao , Pratx Guillem , Xing Lei
Published: May 2015

Beta‐emitting isotopes Fluorine‐18 and Yttrium‐90 are tested for their potential to stimulate gold nanoclusters conjugated with blood serum proteins (AuNCs). AuNCs excited by either medical radioisotope are found to be highly effective ionizing radiation energy transfer mediators, suitable for in vivo optical imaging. AuNCs synthesized with protein templates convert beta‐decaying radioisotope energy into tissue‐penetrating optical signals between 620 and 800 nm. Optical signals are not detected from AuNCs incubated with Technetium‐99m, a pure gamma emitter that is used as a control. Optical emission from AuNCs is not proportional to Cerenkov radiation, indicating that the energy transfer between the radionuclide and AuNC is only partially mediated by Cerenkov photons. A direct Coulombic interaction is proposed as a novel and significant mechanism of energy transfer between decaying radionuclides and AuNCs.
Concise Review: CXCR4/CXCL12 Signaling in Immature Hematopoiesis—Lessons From Pharmacological and Genetic Models
Authors: Karpova Darja , Bonig Halvard
Published: May 2015

Dominant, although nonexclusive roles of CXCR4 and its chief ligand CXCL12 in bone marrow (BM) retention and preservation of the relative quiescence of hematopoietic stem/progenitor cells (HSPCs), along with their involvement in human immunodeficiency virus infection, in trafficking of mature hematopoietic cells to sites of inflammation and in orderly migration of nonhematopoietic cells during embryogenesis, explain the significant interest of the scientific community in the mode of action of this receptor–ligand pair. In this focused review, we seek to distil from the large body of information that has become available over the years some of the key findings about the role of CXCR4/CXCL12 in normal immature hematopoiesis. It is hoped that understanding the mechanistic insights gained there from will help generate hypotheses about potential avenues in which cancer/leukemia cell behavior can be modified by interference with this pathway. Stem Cells  2015;33:2391–2399
Effects of TRPV1 on the hippocampal synaptic plasticity in the epileptic rat brain
Authors: Saffarzadeh Fatemeh , Eslamizade Mohammad J. , Ghadiri Tahereh , Modarres Mousavi Sayed Mostafa , Hadjighassem Mahmoudreza , Gorji Ali
Published: May 2015

Temporal lobe epilepsy is often presented by medically intractable recurrent seizures due to dysfunction of temporal lobe structures, mostly the temporomesial structures. The role of transient receptor potential vaniloid 1 (TRPV1) activity on synaptic plasticity of the epileptic brain tissues was investigated. We studied hippocampal TRPV1 protein content and distribution in the hippocampus of epileptic rats. Furthermore, the effects of pharmacologic modulation of TRPV1 receptors on field excitatory postsynaptic potentials have been analyzed after induction of long term potentiation (LTP) in the hippocampal CA1 and CA3 areas after 1 day (acute phase) and 3 months (chronic phase) of pilocarpine‐induced status epilepticus (SE). A higher expression of TRPV1 protein in the hippocampus as well as a higher distribution of this channel in CA1 and CA3 areas in both acute and chronic phases of pilocarpine‐induced SE was observed. Activation of TRPV1 using capsaicin (1 µM) enhanced LTP induction in CA1 region in non‐epileptic rats. Inhibition of TRPV1 by capsazepine (10 µM) did not affect LTP induction in non‐epileptic rats. In acute phase of SE, activation of TRPV1 enhanced LTP in both CA1 and CA3 areas but TRPV1 inhibition did not affect LTP. In chronic phase of SE, application of TRPV1 antagonist enhanced LTP induction in CA1 and CA3 regions but TRPV1 activation had no effect on LTP. These findings indicate that a higher expression of TRPV1 in epileptic conditions is accompanied by a functional impact on the synaptic plasticity in the hippocampus. This suggests TRPV1 as a potential target in treatment of seizure attacks. Synapse 69:375–383, 2015. © 2015 Wiley Periodicals, Inc.
Deletion of Gαq in the telencephalon alters specific neurobehavioral outcomes
Authors: Graham Devon L. , Buendia Matthew A. , Chapman Michelle A. , Durai Heather H. , Stanwood Gregg D.
Published: May 2015

Gαq‐coupled receptors are ubiquitously expressed throughout the brain and body, and it has been shown that these receptors and associated signaling cascades are involved in a number of functional outputs, including motor function and learning and memory. Genetic alterations to Gαq have been implicated in neurodevelopmental disorders such as Sturge‐Weber syndrome. Some of these associated disease outcomes have been modeled in laboratory animals, but as Gαq is expressed in all cell types, it is difficult to differentiate the underlying circuitry or causative neuronal population. To begin to address neuronal cell type diversity in Gαq function, we utilized a conditional knockout mouse whereby Gαq was eliminated from telencephalic glutamatergic neurons. Unlike the global Gαq knockout mouse, we found that these conditional knockout mice were not physically different from control mice, nor did they exhibit any gross motor abnormalities. However, similarly to the constitutive knockout animal, Gαq conditional knockout mice demonstrated apparent deficits in spatial working memory. Loss of Gαq from glutamatergic neurons also produced enhanced sensitivity to cocaine‐induced locomotion, suggesting that cortical Gαq signaling may limit behavioral responses to psychostimulants. Screening for a variety of markers of forebrain neuronal architecture revealed no obvious differences in the conditional knockouts, suggesting that the loss of Gαq in telencephalic excitatory neurons does not result in major alterations in brain structure or neuronal differentiation. Taken together, our results define specific modulation of spatial working memory and psychostimulant responses through disruptions in Gαq signaling within cerebral cortical glutamatergic neurons. Synapse 69:434–445, 2015. © 2015 Wiley Periodicals, Inc.
Salivary gland development and disease
Authors: Mattingly Aaron , Finley Jennifer K. , Knox Sarah M.
Published: May 2015

Mammalian salivary glands synthesize and secrete saliva via a vast interconnected network of epithelial tubes attached to secretory end units. The extensive morphogenesis required to establish this organ is dependent on interactions between multiple cell types (epithelial, mesenchymal, endothelial, and neuronal) and the engagement of a wide range of signaling pathways. Here we describe critical regulators of salivary gland development and discuss how mutations in these impact human organogenesis. In particular, we explore the genetic contribution of growth factor pathways, nerve‐derived factors and extracellular matrix molecules to salivary gland formation in mice and humans. WIREs Dev Biol 2015, 4:573–590. doi: 10.1002/wdev.194

This article is categorized under:

Signaling Pathways > Global Signaling Mechanisms

Vertebrate Organogenesis > From a Tubular Primordium: Branched

Birth Defects > Organ Anomalies
Lebensmitteldiscounter und Supermarkt. Untersuchung zu Verkehrseffekten, Einzugsgebieten, Vorlieben der Kunden und zum Genehmigungsprozess vor dem Hintergrund der Regelungen des § 11 Abs. 3 BauNVO
Authors: Anders Sascha
Published: May 2015

For the location of new food markets in Germany, the provisions of article 11 sector 3 BauNVO (Federal Land Utilisation Ordinance) and the corresponding jurisdictions are of great importance. The expected impacts of new markets are always object of controversial discussions.

Against this backdrop, the study on qualified local supply, based on a nationwide household survey conducted by telephone, analyzed among others the catchment areas and traffic impacts of the different types of business in food retail — in correlation with the demands and preferences of customers. Unlike common surveys, related to a particular case and carried out within the course of urban land-use planning considerations, the presented study tries to provide general evidence. This shall provide the responsible public authorities and agencies of public interest with a reliable basis for necessary considerations and the balance of interests. Our empirical studies show that the in article 11 sector 3 BauNVO formulated general presumption of urban impacts from a sales area of 800 m2 onwards cannot be confirmed — at least not for the food retail sector. But there also is no other empirically robust sales area limit instead.

Besides the size of the market especially the location of the market (urban integrated vs. non-integrated), the urban framework (urban vs. rural) and the different retailers themselves (like Aldi, Edeka) have a crucial influence on traffic impacts and purchasing power levies.
Changing channels in pain and epilepsy: Exploiting ion channel gene therapy for disorders of neuronal hyperexcitability
Authors: Snowball Albert , Schorge Stephanie
Published: May 2015

Chronic pain and epilepsy together affect hundreds of millions of people worldwide. While traditional pharmacotherapy provides essential relief to the majority of patients, a large proportion remains resistant, and surgical intervention is only possible for a select few. As both disorders are characterised by neuronal hyperexcitability, manipulating the expression of the most direct modulators of excitability – ion channels – represents an attractive common treatment strategy. A number of viral gene therapy approaches have been explored to achieve this. These range from the up‐ or down‐regulation of channels that control excitability endogenously, to the delivery of exogenous channels that permit manipulation of excitability via optical or chemical means. In this review we highlight the key experimental successes of each approach and discuss the challenges facing their clinical translation.
Cross‐linking analysis reveals the putative dimer structure of the cyanobacterial BLUF photoreceptor PixD
Authors: Ren Shukun , Sugimoto Yuki , Kobayashi Taichi , Masuda Shinji
Published: May 2015

PixD is a blue light using flavin (BLUF)‐type blue‐light photoreceptor controlling phototaxis in the cyanobacterium Synechocystis sp. PCC6803. The crystal structure of PixD shows a decamer, although in solution an equilibrium is maintained between the dimer and decamer. Because the ratio of these two conformers is altered by illumination, the equilibrium state determines photosensitivity. However, no structural information is available for the PixD dimer. Here, we report a predicted structure for the dimer based on docking simulation, mutagenesis, and mass spectrometry‐based cross‐linking analyses. The results indicate the importance of the PixD C‐terminus for dimer preference and photosensitivity.
Effects of Attentional Loadings on Gait Performance Before Turning in Stroke Survivors
Authors: Manaf Haidzir , Justine Maria , Goh Hui‐Ting
Published: May 2015

Background

Attentional loadings have significant impacts on turning performance in individuals with stroke. Improper gait modification before turning may contribute to falls after stroke. Therefore, examination of the changes in temporal‐spatial gait parameters before turning may reveal important deficits in gait control when stroke survivors are challenged by dual‐tasking.

Objective

To compare the effects of 3 attentional loading conditions on spatial‐temporal gait parameters before turning between stroke survivors and healthy control subjects.

Design

Case‐control study design.

Setting

University motion analysis laboratory.

Participants

Ten chronic stroke survivors (mean age = 49 ± 9 years) and 10 healthy control subjects (mean age = 53 ± 5 years) were included.

Methods

Spatial‐temporal gait parameters were obtained by the use of a motion‐capture system while participants performed the Timed‐Up and Go (TUG) test under 3 attentional loading conditions: single, dual‐motor, and dual‐cognitive task conditions. A repeated‐measure analysis of variance was used to analyze the data.

Main outcome measures

We measured gait speed, stride length, and stride time during the straight walking phase (one gait cycle before turn) of the TUG test.

Results

We found that attentional loadings had a differential effect on gait speed measured for both groups (P = .001). The dual‐motor and dual‐cognitive task conditions led to a slower gait speed compared with the single‐task condition in stroke survivors (both P = .02). However, in the TUG scores of healthy control subjects, only the dual‐cognitive condition led to a significantly reduced gait speed compared with the single task condition (P = .001) and dual motor condition (P = .01).

Conclusion

The results demonstrated that attentional loadings resulted in a greater deterioration of gait performance before turning in stroke survivors compared with healthy control subjects. Particularly, temporal gait parameter was more vulnerable to dual‐task interference than the spatial gait parameter.
REASONS FOR REASONS
Authors: Reed Baron
Published: May 2015

Hilary Kornblith explores the prospects for reasons eliminationism, the view that reasons ought not to be regarded as being of central importance in epistemology. I reply by conceding that reasons may not be necessary for knowledge, in at least some cases, but I argue that they are nevertheless vitally important in epistemology more broadly. Their importance stems from being necessary, not for knowledge but for us, given that we are social agents with practical concerns. In that sense, we have (social and practical) reasons for (having a practice of giving and receiving epistemic) reasons.
Interannual variation in the summer diets of harbour seals Phocavitulina at Mousa, Shetland (UK)
Authors: Brown Edward G. , Pierce Graham J. , Hislop John R.G. , Santos M. Begoña
Published: May 2015

The main prey species in the summer (July–September) diets of harbour seals (Phoca vitulina) on the Island of Mousa (Shetland, UK), 1994–1997, were whiting (Merlangius merlangus), herring (Clupea harengus), sandeel (Ammodytidae) and garfish (Belone belone). Norway pout (Trisopterus esmarkii) was numerically important but comprised no more than 11% of prey weight in any year. There were marked between-year fluctuations in the relative importance of these prey, with whiting comprising 16–34% (by weight) of the diet, herring 12–28%, sandeels 7–18% and garfish 7–22%. Additional data on spring (April–June) diet were available for 1995–1997: sandeels were the most important prey (% weight) in all three years (51–60% of the diet), while herring (8–48%) and gadids (2–22%) varied in importance. The average size of fish eaten was larger than that reported in comparable studies from other areas. Harbour seals appear to have selected larger sandeels, whiting and Norway pout than the average size available in the area, as indicated by survey trawls, although between-year changes in the size of Norway pout in the diet did to some extent reflect availability. Interannual variation in the importance of Norway pout in the diet appeared to track trends in abundance, although the short time series precluded detection of a statistically significant correlation. Thus, some of our results are consistent with harbour seals feeding opportunistically while others point to selectivity, particularly for prey size. Estimated consumption of fish by the 500 harbour seals on Mousa during summer ranged from 152–195 tonnes.
Sea slug disperses the invasive Caulerpa taxifolia
Authors: Z˘uljevic Ante , Thibaut Thierry , Elloukal Hind , Meinesz Alexandre
Published: May 2015

In order to control the spread of the invasive Caulerpa taxifolia (Chlorophyta) in the Mediterranean, in situ experiments were conducted with the specialized predator Lobiger serradifalci (Mollusca: Ascoglossa=Sacoglossa). An unexpected effect of L. serradifalci on C. taxifolia was observed. Instead of destroying the algal frond, the ascoglossan cut fronds into tiny living fragments capable of regenerating. Thus, L. serradifalci may facilitate C. taxifolia dispersal instead of controlling it.
A large Cirroteuthis magna (Cephalopoda: Cirroctopoda) caught on the Cape Verde Terrace (North Atlantic)
Authors: Collins Martin A. , O'Dea Mary , Henriques Camila
Published: May 2015

A large, mature, female cirrate octopod, Cirroteuthis magna, was caught in a research trawl at 3200-m depth on the Cape Verde Terrace off the west African coast in November 1999. It is only the fourth recorded specimen of this species and the largest specimen (1,700 mm TL; 330 mm ML) of cirrate octopod ever caught. Detailed measurements were taken of the fresh and preserved specimen and indicated considerable shrinkage (17–32%) during formalin preservation. Careful dissection revealed large mature eggs (12·5–14 mm long) in the proximal oviduct, and a wide range of egg sizes and development stages in the ovary. The taxonomy and ecology of the species is briefly discussed.
Comparing the diet of cod (Gadus morhua) and grey seals (Halichoerus grypus): an investigation of secondary ingestion
Authors: Arnett Richard T.P. , Whelan John
Published: May 2015

Otoliths from the stomachs of 138 by-caught grey seals (Halichoerus grypus) from the west coast of Ireland were compared with otoliths from the stomachs of 364 commercially caught cod(Gadus morhua) to determine if there were any overlaps in type, number and size of prey that might be attributable to secondary ingestion. A total of 19 species/groups were common to both cod and seal stomachs accounting for 99·6% and 95·8% of the otoliths from cod and seal stomachs respectively. There were significant differences between the otolith/fish lengths of all six species/groups compared but there were overlaps in the size distributions. Analysis of the diet composition of the cod stomachs suggested that larger cod consumed mainly fish and smaller cod consumed mainly crustaceans. Cod and seals were utilizing the same fish prey but the seals were generally consuming larger fish. Overlaps between the size distributions of prey species/groups suggest that secondary ingestion was possible and should be considered in future seal diet studies.
Secondary excitation process for quantitative confocal 3D-XRF analysis
Authors: Tsuji Kouichi , Tabe Atsushi , Wobrauscheck Peter , Streli Christina
Published: May 2015

X-ray fluorescence (XRF) is a well-established method for quantitative elemental analysis. For accurate quantification, secondary excitation has to be taken into account. In this paper, the secondary excitation process was discussed for analysis by confocal micro-XRF. Experimental depth profiles were shown for a layered sample of Co and Cu. An additional peak was observed in the depth profile of Co, and it was explained by secondary excitation process. Additionally, a Mosaic model was proposed for quantification of confocal micro- XRF analysis.
The Evolution of Modern Behaviour and its Implications for Maritime Dispersal During the Palaeolithic
Authors: Leppard Thomas P.
Published: May 2015

Oceans and seas are more frequently thought to have been barriers to than enablers of movement for archaic hominins. This interpretation has been challenged by a revisionist model which suggests that bodies of water facilitated the dispersal of pre-moderns. This paper addresses the revisionist model by defining maritime dispersal as a series of cognitive and organizational problems, the capacity to solve which must have arisen during the evolution of Homo. The central question posed is: knowing the type of social and cognitive configuration necessary for strategic maritime dispersal, and knowing the social and cognitive capacities of hominin species implied in the revisionist dispersal model, how likely is it that such species possessed the capacity to undertake purposive maritime colonization? Available data suggest that the evolution of modern cognitive architecture during the Late Pleistocene correlates positively with increasing evidence for maritime dispersal in the Upper Palaeolithic, and that behavioural modernity is implicated in the appearance of strategic maritime dispersal in Homo. Consequently, it is likely that deliberate trans-oceanic seagoing is restricted to Anatomically Modern Humans, and possibly Neanderthals.
L. G. KOVÁCS AND VARIETIES OF GROUPS
Authors: GROVES J. R. J.
Published: May 2015

This is a short account of some of the work of L. G. (Laci) Kovács on varieties of groups.
Tropical forests and climate change: a critique of green governmentality
Authors: Adelman Sam
Published: May 2015

This paper contains three main arguments. First, tropical forests have become objects of climate and environmental governance under the REDD+ mechanism in the UN Framework Convention on Climate Change that combines legal, market and scientific rationalities with measurement, reporting and verification (MRV) technologies in a neoliberal green governmentality regime. Second, the current structures and institutions of governance are contradictory and international environmental law provides inadequate means for regulating and protecting forests. Third, these deficiencies point to the need for imaginative alternative forms of governance to prevent further deforestation.
Protective Role of Kv7 Channels in Oxygen and Glucose Deprivation-Induced Damage in Rat Caudate Brain Slices
Authors: Barrese Vincenzo , Taglialatela Maurizio , Greenwood Iain A , Davidson Colin
Published: May 2015

Ischemic stroke can cause striatal dopamine efflux that contributes to cell death. Since Kv7 potassium channels regulate dopamine release, we investigated the effects of their pharmacological modulation on dopamine efflux, measured by fast cyclic voltammetry (FCV), and neurotoxicity, in Wistar rat caudate brain slices undergoing oxygen and glucose deprivation (OGD). The Kv7 activators retigabine and ICA27243 delayed the onset, and decreased the peak level of dopamine efflux induced by OGD; and also decreased OGD-induced damage measured by 2,3,5-triphenyltetrazolium chloride (TTC) staining. Retigabine also reduced OGD-induced necrotic cell death evaluated by lactate dehydrogenase activity assay. The Kv7 blocker linopirdine increased OGD-evoked dopamine efflux and OGD-induced damage, and attenuated the effects of retigabine. Quantitative-PCR experiments showed that OGD caused an ~ 6-fold decrease in Kv7.2 transcript, while levels of mRNAs encoding for other Kv7 subunits were unaffected; western blot experiments showed a parallel reduction in Kv7.2 protein levels. Retigabine also decreased the peak level of dopamine efflux induced by L-glutamate, and attenuated the loss of TTC staining induced by the excitotoxin. These results suggest a role for Kv7.2 in modulating ischemia-evoked caudate damage.
The Effects of Delayed Reduction of Tonic Inhibition on Ischemic Lesion and Sensorimotor Function
Authors: Lake Evelyn MR , Chaudhuri Joydeep , Thomason Lynsie , Janik Rafal , Ganguly Milan , Brown Mary , McLaurin JoAnne , Corbett Dale , Stanisz Greg J , Stefanovic Bojana
Published: May 2015

To aid in development of chronic stage treatments for sensorimotor deficits induced by ischemic stroke, we investigated the effects of GABA antagonism on brain structure and fine skilled reaching in a rat model of focal ischemia induced via cortical microinjections of endothelin-1 (ET-1). Beginning 7 days after stroke, animals were administered a gamma-aminobutyric acid (GABAA) inverse agonist, L-655,708, at a dose low enough to afford α5-GABAA receptor specificity. A week after stroke, the ischemic lesion comprised a small hypointense necrotic core (6 ± 1 mm3) surrounded by a large (62 ± 11 mm3) hyperintense perilesional region; the skilled reaching ability on the Montoya staircase test was decreased to 34% ± 2% of the animals' prestroke performance level. On L-655,708 treatment, animals showed a progressive decrease in total stroke volume (13 ± 4 mm3 per week), with no change in animals receiving placebo. Concomitantly, treated animals' skilled reaching progressively improved by 9% ± 1% per week, so that after 2 weeks of treatment, these animals performed at 65% ± 6% of their baseline ability, which was 25% ± 11% better than animals given placebo. These data indicate beneficial effects of delayed, sustained low-dose GABAA antagonism on neuroanatomic injury and skilled reaching in the chronic stage of stroke recovery in an ET-1 rat model of focal ischemia.
Eccentricity Mapping of the Human Visual Cortex to Evaluate Temporal Dynamics of Functional T1ρ Mapping
Authors: Heo Hye-Young , Wemmie John A , Johnson Casey P , Thedens Daniel R , Magnotta Vincent A
Published: May 2015

Recent experiments suggest that T1 relaxation in the rotating frame ( T1ρ) is sensitive to metabolism and can detect localized activity-dependent changes in the human visual cortex. Current functional magnetic resonance imaging (fMRI) methods have poor temporal resolution due to delays in the hemodynamic response resulting from neurovascular coupling. Because T1ρ is sensitive to factors that can be derived from tissue metabolism, such as pH and glucose concentration via proton exchange, we hypothesized that activity-evoked T1ρ changes in visual cortex may occur before the hemodynamic response measured by blood oxygenation level-dependent (BOLD) and arterial spin labeling (ASL) contrast. To test this hypothesis, functional imaging was performed using BOLD, and ASL in human participants viewing an expanding ring stimulus. We calculated eccentricity phase maps across the occipital cortex for each functional signal and compared the temporal dynamics of T1ρ versus BOLD and ASL. The results suggest that T1ρ changes precede changes in the two blood flow-dependent measures. These observations indicate that T1ρ detects a signal distinct from traditional fMRI contrast methods. In addition, these findings support previous evidence that T1ρ is sensitive to factors other than blood flow, volume, or oxygenation. Furthermore, they suggest that tissue metabolism may be driving activity-evoked T1ρ changes.
Inhibition of Histone Methyltransferases SUV39H1 and G9a Leads to Neuroprotection in an in vitro Model of Cerebral Ischemia
Authors: Schweizer Sophie , Harms Christoph , Lerch Heike , Flynn Jennifer , Hecht Jochen , Yildirim Ferah , Meisel Andreas , Märschenz Stefanie
Published: May 2015

Cerebral ischemia induces a complex transcriptional response with global changes in gene expression. It is essentially regulated by transcription factors as well as epigenetic players. While it is well known that the inhibition of transcriptionally repressive histone deacetylases leads to neuroprotection, the role of histone methyltransferases in the postischemic transcriptional response remains elusive. We investigated the effects of inhibition of the repressive H3K9 histone methyltransferases SUV39H1 and G9a on neuronal survival, H3K9 promoter signatures and gene expression. Their inhibition either with the specific blocker chaetocin or by use of RNA interference promoted neuronal survival in oxygen glucose deprivation (OGD). Brain-derived neurotrophic factor (BDNF) was upregulated and BDNF promoter regions showed an increase in histone marks characteristic for active transcription. The BDNF blockade with K252a abrogated the protective effect of chaetocin treatment. In conclusion, inhibition of histone methyltransferases SUV39H1 and G9a confers neuroprotection in a model of hypoxic metabolic stress, which is at least in part mediated by BDNF.
Recovery from severe H7N9 disease is associated with diverse response mechanisms dominated by CD8+ T cells
Authors: Wang Zhongfang , Wan Yanmin , Qiu Chenli , Quiñones-Parra Sergio , Zhu Zhaoqin , Loh Liyen , Tian Di , Ren Yanqin , Hu Yunwen , Zhang Xiaoyan , Thomas Paul G. , Inouye Michael , Doherty Peter C. , Kedzierska Katherine , Xu Jianqing
Published: May 2015

The avian origin A/H7N9 influenza virus causes high admission rates (>99%) and mortality (>30%), with ultimately favourable outcomes ranging from rapid recovery to prolonged hospitalization. Using a multicolour assay for monitoring adaptive and innate immunity, here we dissect the kinetic emergence of different effector mechanisms across the spectrum of H7N9 disease and recovery. We find that a diversity of response mechanisms contribute to resolution and survival. Patients discharged within 2–3 weeks have early prominent H7N9-specific CD8+ T-cell responses, while individuals with prolonged hospital stays have late recruitment of CD8+/CD4+ T cells and antibodies simultaneously (recovery by week 4), augmented even later by prominent NK cell responses (recovery >30 days). In contrast, those who succumbed have minimal influenza-specific immunity and little evidence of T-cell activation. Our study illustrates the importance of robust CD8+ T-cell memory for protection against severe influenza disease caused by newly emerging influenza A viruses.
Neuronal development is promoted by weakened intrinsic antioxidant defences due to epigenetic repression of Nrf2
Authors: Bell Karen F.S. , Al-Mubarak Bashayer , Martel Marc-André , McKay Sean , Wheelan Nicola , Hasel Philip , Márkus Nóra M. , Baxter Paul , Deighton Ruth F. , Serio Andrea , Bilican Bilada , Chowdhry Sudhir , Meakin Paul J. , Ashford Michael L.J. , Wyllie David J.A. , Scannevin Robert H. , Chandran Siddharthan , Hayes John D. , Hardingham Giles E.
Published: May 2015

Forebrain neurons have weak intrinsic antioxidant defences compared with astrocytes, but the molecular basis and purpose of this is poorly understood. We show that early in mouse cortical neuronal development in vitro and in vivo, expression of the master-regulator of antioxidant genes, transcription factor NF-E2-related-factor-2 (Nrf2), is repressed by epigenetic inactivation of its promoter. Consequently, in contrast to astrocytes or young neurons, maturing neurons possess negligible Nrf2-dependent antioxidant defences, and exhibit no transcriptional responses to Nrf2 activators, or to ablation of Nrf2’s inhibitor Keap1. Neuronal Nrf2 inactivation seems to be required for proper development: in maturing neurons, ectopic Nrf2 expression inhibits neurite outgrowth and aborization, and electrophysiological maturation, including synaptogenesis. These defects arise because Nrf2 activity buffers neuronal redox status, inhibiting maturation processes dependent on redox-sensitive JNK and Wnt pathways. Thus, developmental epigenetic Nrf2 repression weakens neuronal antioxidant defences but is necessary to create an environment that supports neuronal development.
Active graphene–silicon hybrid diode for terahertz waves
Authors: Li Quan , Tian Zhen , Zhang Xueqian , Singh Ranjan , Du Liangliang , Gu Jianqiang , Han Jiaguang , Zhang Weili
Published: May 2015

Controlling the propagation properties of the terahertz waves in graphene holds great promise in enabling novel technologies for the convergence of electronics and photonics. A diode is a fundamental electronic device that allows the passage of current in just one direction based on the polarity of the applied voltage. With simultaneous optical and electrical excitations, we experimentally demonstrate an active diode for the terahertz waves consisting of a graphene–silicon hybrid film. The diode transmits terahertz waves when biased with a positive voltage while attenuates the wave under a low negative voltage, which can be seen as an analogue of an electronic semiconductor diode. Here, we obtain a large transmission modulation of 83% in the graphene–silicon hybrid film, which exhibits tremendous potential for applications in designing broadband terahertz modulators and switchable terahertz plasmonic and metamaterial devices.
Climate variability modulates western US ozone air quality in spring via deep stratospheric intrusions
Authors: Lin Meiyun , Fiore Arlene M. , Horowitz Larry W. , Langford Andrew O. , Oltmans Samuel J. , Tarasick David , Rieder Harald E.
Published: May 2015

Evidence suggests deep stratospheric intrusions can elevate western US surface ozone to unhealthy levels during spring. These intrusions can be classified as ‘exceptional events’, which are not counted towards non-attainment determinations. Understanding the factors driving the year-to-year variability of these intrusions is thus relevant for effective implementation of the US ozone air quality standard. Here we use observations and model simulations to link these events to modes of climate variability. We show more frequent late spring stratospheric intrusions when the polar jet meanders towards the western United States, such as occurs following strong La Niña winters (Niño3.4<−1.0 °C). While El Niño leads to enhancements of upper tropospheric ozone, we find this influence does not reach surface air. Fewer and weaker intrusion events follow in the two springs after the 1991 volcanic eruption of Mt. Pinatubo. The linkage between La Niña and western US stratospheric intrusions can be exploited to provide a few months of lead time during which preparations could be made to deploy targeted measurements aimed at identifying these exceptional events.