bluuebunny/crossref_metadata_2025 huggingface dataset:
Doubly photoresponsive and water‐soluble block copolymers: Synthesis and thermosensitivity
Authors: Zhao Yi , Tremblay Luc , Zhao Yue
Published: August 2010

We report the synthesis and investigation of a new type of photoresponsive block copolymers (BCPs). They were designed to comprise two water‐soluble polymers containing two different photoisomerizable moieties (either azobenzene and spiropyran or two different azobenzenes), with the two constituting blocks that, when separated, exhibit a lower critical solution temperature (LCST) in water and can shift their LCST in opposite directions upon photoisomerization (decrease of LCST for one polymer and increase for the other). A variety of such doubly photoresponsive BCPs were synthesized using either azobenzene‐ or spiropyran‐containing poly(N,N‐dimethylacrylamide) (PDMA), poly(N‐isopropylacrylamide) (PNIPAM) and poly[methoxydi(ethylene glycol) methacrylate] (PDEGMMA). Their thermal phase transition behaviors in aqueous solution before and after simultaneous photoreactions on the two blocks were investigated in comparison with their constituting blocks, by means of solution transmittance (turbidity) and variable‐temperature 1H NMR measurements. The results show that BCPs displayed a single LCST whose shift upon two photoisomerizations appeared to be determined by the competing and opposing photoinduced effects on the two blocks. Moreover, optically controlling the relative photoisomerization degrees of trans azobenzene‐to‐cis azobenzene and spiropyran‐to‐merocyanine could be used to tune the LCST of BCP solution. This study demonstrates the potential of exploring a more complex photoreaction scheme to optically control the solution properties of water‐soluble thermosensitive BCPs. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4055–4066, 2010
Mesoporous Silica Nanoparticles for Intracellular Controlled Drug Delivery
Authors: Vivero‐Escoto Juan L. , Slowing Igor I. , Trewyn Brian G. , Lin Victor S.‐Y.
Published: August 2010

The application of nanotechnology in the field of drug delivery has attracted much attention in the latest decades. Recent breakthroughs on the morphology control and surface functionalization of inorganic‐based delivery vehicles, such as mesoporous silica nanoparticles (MSNs), have brought new possibilities to this burgeoning area of research. The ability to functionalize the surface of mesoporous‐silica‐based nanocarriers with stimuli‐responsive groups, nanoparticles, polymers, and proteins that work as caps and gatekeepers for controlled release of various cargos is just one of the exciting results reported in the literature that highlights MSNs as a promising platform for various biotechnological and biomedical applications. This review focuses on the most recent progresses in the application of MSNs for intracellular drug delivery. The latest research on the pathways of entry into live mammalian and plant cells together with intracellular trafficking are described. One of the main areas of interest in this field is the development of site‐specific drug delivery vehicles; the contribution of MSNs toward this topic is also summarized. In addition, the current research progress on the biocompatibility of this material in vitro and in vivo is discussed. Finally, the latest breakthroughs for intracellular controlled drug release using stimuli‐responsive mesoporous‐silica‐based systems are described.
The role of lateral-entry Steinmann pins in the treatment of pediatric supracondylar humerus fractures
Authors: Weinberg Jacob , Belthur Mohan V.
Published: August 2010

Purpose

Loss of pin fixation in supracondylar fractures can occur with failure to achieve bicortical fixation. Bicortical fixation may be challenging for those pins that attempt to penetrate the diaphyseal cortex, where the bone is thick. Lateral-entry Steinmann pins may allow for better penetration through cortical bone because they are more rigid than typical Kirschner wires.

Methods

A retrospective review of 16 children with type III supracondylar fractures treated by a single surgeon using Steinmann pins was undertaken. The average age at presentation was 6 years. Following closed reduction, all fractures were maintained with three lateral-entry pins. At least one Steinmann pin was placed in the lateral column of the distal humerus in each pin construct.

Results

Follow-up radiographs indicated a mean Baumann's angle of 72.9° (range 64°–82°). There was no statistically significant change in the Baumann's angle or axial alignment at final follow-up. All but one fracture healed in an anatomic position on the lateral view.

Conclusions

Steinmann pins placed through a lateral-entry point are effective in controlling the reduction of high-grade supracondylar fractures. The fixation is excellent and avoids potential ulnar nerve complications of medial entry.
Developmental PCB exposure induces hypothyroxinemia and sex‐specific effects on cerebellum glial protein levels in rats
Authors: Miller V.M. , Kahnke T. , Neu N. , Sanchez‐Morrissey S.R. , Brosch K. , Kelsey K. , Seegal R.F.
Published: August 2010

Polychlorinated biphenyls (PCBs) are persistent lipophilic environmental contaminants which are found in fatty tissues of humans and wild‐life alike. Maternal transfer of PCBs to offspring is easily achieved across the placenta and via lactation. In male rats, perinatal PCB exposure induces behavioral abnormalities, in addition to hypothyroxinemia and white matter changes. There are sex differences in white matter volume synthesis and density in adult and aged rodents. Yet whether PCB exposure effects on white matter are sex‐specific is unclear, because the previous studies were conducted in male offspring. Furthermore, although hypothyroxinemia induced by PCB exposure is thought to trigger white matter changes, PCBs also affect interleukin‐6 (IL‐6) expression, and IL‐6 regulates white matter growth. We hypothesized that perinatal PCB exposure would have sex‐specific effects on white matter development associated with altered IL‐6 levels. We found that female offspring had higher levels of myelin basic protein (MBP) than males did, at postnatal day (PND) 7, 18 and 21. PCB exposure induced hypothyroxinemia in males and females at PND7, 14, 21, and 42. PCB exposure also increased MBP and reduced glial fibrillary acidic protein (GFAP) levels in males at PND21, but had the opposite effect in females. In addition, at PND14 and 21, PCB exposure elevated IL‐6 levels in male offspring only. The induction of sex‐specific changes in white matter proteins, in the absence of sex differences in thyroxine levels after PCB exposure, suggests that serum thyroxine levels do not directly contribute to the white matter alterations. Instead, IL‐6 may contribute to increased MBP levels in males, whereas in females estromimetic and thyromimetic PCB metabolites may affect white matter development. This data adds to an increasing body of literature showing that perinatal insults induce sex‐specific effects in offspring.
Geochemical and geophysical evidence of methane release over the East Siberian Arctic Shelf
Authors: Shakhova N. , Semiletov I. , Leifer I. , Salyuk A. , Rekant P. , Kosmach D.
Published: August 2010

The East Siberian Arctic Shelf (ESAS), which includes the Laptev Sea, the East Siberian Sea, and the Russian part of the Chukchi Sea, has not been considered to be a methane (CH4) source to hydrosphere or atmosphere because subsea permafrost, which underlies most of the ESAS, was believed, first, not to be conducive to methanogenesis and, second, to act as an impermeable lid, preventing CH4 escape through the seabed. Here recent observational data obtained during summer (2005–2006) and winter (2007) expeditions indicate the ubiquitous presence of elevated dissolved CH4 and an elevated atmospheric CH4 mixing ratio. The CH4 data were also analyzed together with high resolution seismic (HRS) data obtained by means of a “Sonic M‐141” system consisting of a high‐resolution profiler and side‐scan sonar mounted in a towed fish during the Transdrift‐X Expedition (2004) onboard the R/V Yakov Smirnitskiy. Results show anomalously high concentrations of dissolved CH4 (up to 5 μM) and an episodically (nongradually) increasing atmospheric mixing ratio of CH4 (up to 8.2 ppm) in some areas of the ESAS. A most likely source is year‐round CH4 release through taliks (columns of thawed sediments within permafrost) from seabed CH4 reservoirs such as shallow hydrates and geological sources. Such releases occur not only within the areas underlain by fault zones but also outside of them. This points to permafrost's failure to further preserve CH4 deposits in the ESAS. The total amount of carbon preserved within the ESAS as organic matter and ready to release CH4 from seabed deposits is predicted to be ∼1400 Gt. Release of only a small fraction of this reservoir, which was sealed with impermeable permafrost for thousands of years, would significantly alter the annual CH4 budget and have global implications, because the shallowness of the ESAS allows the majority of CH4 to pass through the water column and escape to the atmosphere.
Observations of storm‐induced mixing and Gulf Stream Ring incursion over the southern flank of Georges Bank: Winter and summer 1997
Authors: Lee Craig M. , Brink Kenneth H.
Published: August 2010

High‐resolution hydrographic measurements collected along the southern edge of Georges Bank during March and June–July 1997 focused on characterizing processes that drive fluxes of material between the slope and bank. Wintertime sampling characterized changes driven by a strong storm. A Scotian Shelf crossover event produced a ribbon of anomalously fresh water along the bank's southern flank that was diluted during the storm. Comparison of prestorm and poststorm sections shows that over the bank changes in heat and salt inventories are consistent with those expected solely from local surface fluxes. In deeper waters, advective effects, likely associated with frontal motion and eddies, are clearly important. Summertime surveys resolve the development of a massive intrusion of Gulf Stream‐like waters onto the bank. East of the intrusion, a thin extrusion of bank water is drawn outward by the developing ring, exporting fresher water at a rate of about 7 × 104 m3/s. A large‐amplitude Gulf Stream meander appears to initiate the extrusion, but it quickly evolves, near the bank edge, into a warm core ring. Ring water intrudes to approximately the 80 m isobath, 40 km inshore from the bank edge. The intrusion process seems analogous to the development of Gulf Stream shingles (a hydrodynamic instability) in the South Atlantic Bight. It appears that, once the intruded water is established on the bank, it remains there and dissipates in place. Although the intrusion is an extremely dramatic event, it is probably not actually a major contributor to shelf edge exchanges over a seasonal time scale.
Simulation of satellite infrared radiances for convective‐scale data assimilation over the Mediterranean
Authors: Duffourg Fanny , Ducrocq Véronique , Fourrié Nadia , Jaubert Geneviève , Guidard Vincent
Published: August 2010

This paper focuses on the simulation of satellite infrared passive observations for their assimilation in high horizontal resolution (2.5 km) numerical weather prediction systems. In order to better represent the sensitivity of the satellite measurement to the whole atmosphere within its footprint, new observation operators are designed. They aggregate the model information contained within the satellite field of view. The different observation operators are evaluated for the simulation of Infrared Atmospheric Sounding Interferometer (IASI) and Atmospheric Infrared Sounder (AIRS) observations over a whole month. The new observation operators are found to improve the simulation of water vapor channels and to have neutral to slightly negative impact for temperature channels. For most channels, the standard deviation of the observation minus guess departures is reduced. The modifications of the simulations are substantial for water vapor channels for which the weighting functions peak at pressures greater than 340 hPa for IASI and between 340 hPa and 800 hPa for AIRS. The most important ones appear where fine‐scale humidity gradients occur in dry sounded layers. The new observation operators improve the simulation of IASI and AIRS observations by filtering out these fine‐scale patterns that are not detected by the instruments. With improvements in observations minus guess reaching 2 K, the new observation operators may avoid the rejection of some observations by quality control procedures during the assimilation process. Single observation assimilation experiments are then carried out using the different observation operators. They show that even large modifications in the observation simulation have almost no impact on the final analysis.
Volcanism and resurfacing on Venus at the full resolution of Magellan SAR data
Authors: Grindrod Peter M. , Stofan Ellen R. , Guest John E.
Published: August 2010

We examine the importance of localized volcanism in resurfacing on Venus by analyzing the results of geologic mapping of a 12° × 12° area at the full resolution of Magellan SAR data. Resurfacing due to corona‐, ridge‐, and small volcano‐related volcanism accounts for 27%, 6%, and 10% respectively of the mapped area. Mapping at the resolution of Magellan data, rather than a regional scale, gives corona‐related flow unit areas that can differ individually by almost an order of magnitude, with a total increase of 28%, and more than three times as many identifiable units. A total of 2919 small volcanoes or vents less than 10 km in diameter were identified in the F‐Map, with a mean diameter of 1.59 (s.d. = 1.08) km and densities of up to 36 small volcanoes per 50 km2. Taken together, coronae, ridge eruptions, and small volcanoes probably make a significant contribution to resurfacing on Venus.
Biophysical feedbacks between the Pleistocene megafauna extinction and climate: The first human‐induced global warming?
Authors: Doughty Christopher E. , Wolf Adam , Field Christopher B.
Published: August 2010

A large increase in Betula during a narrow 1000 year window, ∼13,800 years before present (YBP) in Alaska and Yukon corresponded in time with the extinction of mammoths and the arrival of humans. Pollen data indicate the increase in Betula during this time was widespread across Siberia and Beringia. We hypothesize that Betula increased due to a combination of a warming climate and reduced herbivory following the extinction of the Pleistocene mega herbivores. The rapid increase in Betula modified land surface albedo which climate‐model simulations indicate would cause an average net warming of ∼0.021°C per percent increase in high latitude (53–73°N) Betula cover. We hypothesize that the extinction of mammoths increased Betula cover, which would have warmed Siberia and Beringia by on average 0.2°C, but regionally by up to 1°C. If humans were partially responsible for the extinction of the mammoths, then human influences on global climate predate the origin of agriculture.
Effects of Age on Concurrent Vowel Perception in Acoustic and Simulated Electroacoustic Hearing
Authors: Arehart Kathryn H. , Souza Pamela E. , Muralimanohar Ramesh Kumar , Miller Christi Wise
Published: August 2010

Purpose

In this study, the authors investigated the effects of age on the use of fundamental frequency differences (ΔF
0
) in the perception of competing synthesized vowels in simulations of electroacoustic and cochlear-implant hearing.

Method

Twelve younger listeners with normal hearing and 13 older listeners with (near) normal hearing were evaluated in their use of ΔF
0
in the perception of competing synthesized vowels for 3 conditions: unprocessed synthesized vowels (UNP), envelope-vocoded synthesized vowels that simulated a cochlear implant (VOC), and synthesized vowels processed to simulate electroacoustic stimulation (EAS) hearing. Tasks included (a)
multiplicity,
which required listeners to identify whether a stimulus contained 1 or 2 sounds and (b)
double-vowel identification,
which required listeners to attach phonemic labels to the competing synthesized vowels.

Results

Multiplicity perception was facilitated by ΔF
0
in UNP and EAS but not in VOC, with no age-related deficits evident. Double-vowel identification was facilitated by ΔF
0
, with ΔF
0
benefit largest in UNP, reduced in EAS, and absent in VOC. Age adversely affected overall identification and ΔF
0
benefit on the double-vowel task.

Conclusions

Some but not all older listeners derived ΔF
0
benefit in EAS hearing. This variability may partly be due to how listeners are able to draw on higher-level processing resources in extracting and integrating cues in EAS hearing.
Speech Production Accuracy and Variability in Young Cochlear Implant Recipients: Comparisons With Typically Developing Age-Peers
Authors: Ertmer David J. , Goffman Lisa A.
Published: August 2010

Purpose

The speech production accuracy and variability scores of 6 young cochlear implant (CI) recipients with 2 years of device experience were compared with those of typically developing (TD) age-peers.

Method

Words from the First Words Speech Test (FWST; Ertmer, 1999) were imitated 3 times to assess the accuracy and variability of initial consonants, vowels, and words. The initial consonants in the 4 sets of the FWST followed a typical order of development.

Results

The TD group produced targets with high accuracy and low variability. Their scores across FWST sets reflected the expected order of development. The CI group produced most targets less accurately and with more variability than the TD children. Relatively high accuracy for the consonants of Sets 1 and 2 indicated that these phonemes were acquired early and in a typical developmental order. A trend toward greater accuracy for Set 4 as compared with Set 3 suggested that later-emerging consonants were not acquired in the expected order. Variability was greatest for later-emerging initial consonants and whole words.

Discussion

Although considerable speech production proficiency was evident, age-level performance was not attained after 2 years of CI experience. Factors that might influence the order of consonant acquisition are discussed.
Cross-Modulation Interference With Lateralization of Mixed-Modulated Waveforms
Authors: Hsieh I-Hui , Petrosyan Agavni , Gonçalves óscar F. , Hickok Gregory , Saberi Kourosh
Published: August 2010

Purpose

This study investigated the ability to use spatial information in mixed-modulated (MM) sounds containing concurrent frequency-modulated (FM) and amplitude-modulated (AM) sounds by exploring patterns of interference when different modulation types originated from different loci as may occur in a multisource acoustic field.

Method

Interaural delay thresholds were measured from 5 normal-hearing adults for an AM sound in the presence of interfering FM and vice versa as a function of interferer modulation rate. In addition, the effects of near versus remote interferer rates, and fixed versus randomized interferer interaural delay, were investigated.

Results

AM interfered with lateralization of FM at all modulation rates. However, the FM interfered with AM lateralization only when the FM rate was higher than the AM rate. This rate asymmetry was surprising given the prevalence of low-frequency dominance in lateralization, but was predicted by a cross-correlation model of binaural interaction. Effects were similar for fixed and randomized interferer interaural delays.

Conclusions

The results suggest that in multisource environments, sources containing different modulation types significantly interfere with localization in complex ways that reveal interactions between modulation type and rate. These findings contribute to the understanding of auditory object formation and localization.
Contact mechanisms and design principles for (Schottky and Ohmic) metal contacts to semiconductor nanowires
Authors: Mohammad S. Noor
Published: August 2010

Contact mechanisms and design principles for (Ohmic and Schottky) metal (M) contacts to semiconductor nanowires (NWs) have been studied. The NWs have been assumed to be cylindrical. A unified model has been developed for the contacts. The model takes into consideration the amorphicity of the M/NW interface structure, the diameter dependence of the energy band gap, the barrier height modulation, and the fluctuations in both the barrier height and the applied bias. While the fluctuations in the barrier height are assumed to involve band tails, the fluctuations in applied bias are assumed to involve tiny Gaussian peaks. Several different features of the Ohmic and the Schottky contacts have been addressed. These include temperature and dimension dependencies of the current-voltage characteristics, the influence of the M/NW interface on the contact characteristics, the relationship between the barrier height and the ideality factor, and the barrier height reduction as a function of temperature. The model appears to be very general. It seems to explain all experimental results available to date in the literature. The calculated results are almost always in good correspondence with the experimental results. The study seemingly demonstrates an alternative to the doping dependence of the Ohmic contacts. It elucidates the fundamental physics underlying M/NW contacts. It highlights means to yield low-resistivity Ohmic contacts by thermionic emission. It describes design criteria for both Ohmic and Schottky contacts. The design criteria for Ohmic contacts tend to address the long-term reliability concerns for devices. They explain also the behavior of both good and bad Ohmic contacts. All these may be the most striking attributes of the study. These attributes explain why Schottky contacts to NWs, with proper gate modulation, may act also as Schottky barrier transistors.
Magnetoresistive effect in graphene nanoribbon due to magnetic field induced band gap modulation
Authors: Kumar S. Bala , Jalil M. B. A. , Tan S. G. , Liang Gengchiau
Published: August 2010

The electronic properties of armchair graphene nanoribbons (AGNRs) can be significantly modified from semiconducting to metallic states by applying a uniform perpendicular magnetic field (B-field). Here, we theoretically study the band gap modulation induced by a perpendicular B-field. The applied B-field causes the lowest conduction subband and the topmost valence subband to move closer to one another to form the n=0 Landau level. We exploit this effect to realize a device relevant magnetoresistive (MR) modulation. Unlike in conventional spin-valves, this intrinsic MR effect is realized without the use of any ferromagnetic leads. The AGNRs with number of dimers, Na=3p+1[p=1,2,3,…] show the most promising behavior for MR applications with large conductance modulation, and hence, high MR ratio at the optimal source-drain bias. However, the MR is suppressed at higher temperature due to the spread of the Fermi function distribution. We also investigate the importance of the source-drain bias in optimizing the MR. Lastly, we show that edge roughness of AGNRs has the unexpected effect of improving the magnetic sensitivity of the device and thus increasing the MR ratio.
Controlling charge balance and exciton recombination by bipolar host in single-layer organic light-emitting diodes
Authors: Qiao Xianfeng , Tao Youtian , Wang Qiang , Ma Dongge , Yang Chuluo , Wang Lixiang , Qin Jingui , Wang Fosong
Published: August 2010

Highly efficient single-layer organic light-emitting diodes with reduced efficiency roll-off are demonstrated by using a bipolar host material of 2,5-bis(2-(9H-carbazol-9-yl)phenyl)-1,3,4-oxadiazole (o-CzOXD) doped with iridium complexes as the emissive layer. For example, the green single-layer device, employing fac-tris(2-phenylpyridine)iridium Ir(ppy)3 as dopant, shows a peak current efficiency of 45.57 cd A−1, corresponding to external quantum efficiency (EQE) of 12.42%, and still exhibits efficiencies of 45.26 cd A−1 and 40.42 cd A−1 at luminance of 1000 and 10 000 cd m−2, respectively. In addition, the yellow and red single-layer devices, with bis(2-(9,9- diethyl-9H-fluoren-2-yl)-1-phenyl-1H-benzoimidazol-N,C3)iridium(acetylacetonate) (fbi)2Ir(acac) and bis(1-phenylisoquinolinolato-C2,N)iridium(acetylacetonate) (piq)2Ir(acac) as emitter, also show high EQE of 7.04% and 7.28%, respectively. The transport properties of o-CzOXD film are well investigated by current-voltage measurement, from which both hole and electron mobility are determined. It is found that the o-CzOXD shows appealing bipolar transport character, which is favor for the balanced charge distribution in the whole doped zone. More importantly, the multifunctional role of hole trapping and electron transporting of the iridium complex in o-CzOXD further balances the charge carriers and broadens the recombination zone. As a result, the recombination of electrons and holes is significantly improved and the triplet-triplet annihilation and triplet-polaron quenching processes are effectively suppressed, eventually leading to the high efficiency as well as the reduced efficiency roll-off.
Effect of ferromagnetic film thickness on magnetoresistance of thin-film superconductor-ferromagnet hybrids
Authors: Aladyshkin A. Yu. , Volodin A. P. , Moshchalkov V. V.
Published: August 2010

We study the influence of the thickness Df of the plain ferromagnetic (F) film on the electrical resistance of the flux-coupled hybrids, consisting of superconducting (S) Al film and multilayer [Co/Pt] F film with out-of-plain magnetization. The behavior of such hybrids at high and low temperatures is found to be different as follows: the nucleation of superconductivity at high temperatures is governed mainly by the typical lateral dimensions of the magnetic domains, while low-temperature properties are determined by topology of the magnetic template. We show that an increase in the Df value leads to a broadening of the field-intervals and temperature intervals where nonmonotonous dependence of the superconducting critical temperature Tc on the applied magnetic field H is observed (for demagnetized F films). Further increase in the Df value results in a global suppression of superconductivity. Thus, we determined an optimal thickness, when the nonmonotonous dependence Tc(H) can be observed in rather broad T and H range, what can be interesting for further studies of the localized superconductivity in planar Al-based S/F hybrids and for development of the devices which can exploit the localized superconductivity.
Effects of ferroelectric-poling-induced strain on the transport and magnetic properties of La7/8Ba1/8MnO3 thin films
Authors: Zheng R. K. , Wang Y. , Chan H. L. W. , Choy C. L. , Habermeier H.-U. , Luo H. S.
Published: August 2010

We have investigated the effects of the strain induced by ferroelectric poling on the transport and magnetic properties of La7/8Ba1/8MnO3 (LBMO) thin films epitaxially grown on ferroelectric 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 (PMN–PT) single-crystal substrates. The ferroelectric poling reduces the in-plane tensile strain of the film, giving rise to a decrease in the resistivity and an increase in the magnetization, Curie temperature, and magnetoresistance of the LBMO film. These strain effects are explained within the framework of coexisting phases whose volume fractions are modified as a result of the reduction in the tetragonal distortion of MnO6 octahedra induced by ferroelectric poling. An investigation of the effects of polarization reversal on the transport properties of the LBMO film indicates that the ferroelectric-poling-induced strain effects dominate over the ferroelectric field effects in the LBMO/PMN–PT structure.
In vitro and in vivo reconstitution of the cadherin–catenin–actin complex from
Caenorhabditis elegans
Authors: Kwiatkowski Adam V. , Maiden Stephanie L. , Pokutta Sabine , Choi Hee-Jung , Benjamin Jacqueline M. , Lynch Allison M. , Nelson W. James , Weis William I. , Hardin Jeff
Published: August 2010

The ternary complex of cadherin, β-catenin, and α-catenin regulates actin-dependent cell–cell adhesion. α-Catenin can bind β-catenin and F-actin, but in mammals α-catenin either binds β-catenin as a monomer or F-actin as a homodimer. It is not known if this conformational regulation of α-catenin is evolutionarily conserved. The
Caenorhabditis elegans
α-catenin homolog HMP-1 is essential for actin-dependent epidermal enclosure and embryo elongation. Here we show that HMP-1 is a monomer with a functional C-terminal F-actin binding domain. However, neither full-length HMP-1 nor a ternary complex of HMP-1–HMP-2(β-catenin)–HMR-1(cadherin) bind F-actin in vitro, suggesting that HMP-1 is auto-inhibited. Truncation of either the F-actin or HMP-2 binding domain of HMP-1 disrupts
C. elegans
development, indicating that HMP-1 must be able to bind F-actin and HMP-2 to function in vivo. Our study defines evolutionarily conserved properties of α-catenin and suggests that multiple mechanisms regulate α-catenin binding to F-actin.
Halolamina pelagica gen. nov., sp. nov., a new member of the family Halobacteriaceae
Authors: Cui Heng-Lin , Gao Xia , Yang Xin , Xu Xue-Wei
Published: August 2010

Two extremely halophilic archaeal strains, TBN21T and TBN49, were isolated from the Taibei marine solar saltern near Lianyungang city, Jiangsu province, China. Cells of the two strains were pleomorphic and Gram-negative and colonies were red. Strains TBN21T and TBN49 were able to grow at 25–50 °C (optimum 37 °C), at 1.4–5.1 M NaCl (optimum 3.4–3.9 M) and at pH 5.5–9.5 (optimum pH 7.0–7.5) and neither strain required Mg2+ for growth. Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). The major polar lipids of the two strains were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and eight glycolipids; three of these glycolipids (GL3, GL4 and GL5) were chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1), galactosyl mannosyl glucosyl diether (TGD-1) and mannosyl glucosyl diether (DGD-1), respectively. Phylogenetic analysis revealed that strains TBN21T and TBN49 formed a distinct clade with their closest relative, Halobaculum gomorrense JCM 9908T (89.0–89.5 % 16S rRNA gene sequence similarity). The DNA G+C contents of strains TBN21T and TBN49 were 64.8 and 62.7 mol%, respectively. DNA–DNA hybridization between strains TBN21T and TBN49 was 90.1 %. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strains TBN21T and TBN49 represent a novel species in a new genus within the family Halobacteriaceae, for which the name Halolamina pelagica gen. nov., sp. nov. is proposed. The type strain of Halolamina pelagica is TBN21T ( = CGMCC 1.10329T  = JCM 16809T).
Comparison of endodontic bacterial community structures in root-canal-treated teeth with or without apical periodontitis
Authors: Zoletti Gustavo O. , Carmo Flávia L. , Pereira Eliezer M. , Rosado Alexandre S. , Siqueira José F. , Santos Kátia R. N.
Published: August 2010

Bacterial occurrence in treated root canals, even in patients without post-treatment apical periodontitis, raises the possibility that factors other than mere bacterial presence can be determinants for a favourable outcome of endodontic treatment. Because these factors may be related to the bacterial communities colonizing the root canal, including virulence, density and interactions, the objective of this study was to compare the community structures found in root-canal-treated teeth with (12 samples) and without (11 samples) apical periodontitis lesions by means of a PCR-denaturing gradient gel electrophoresis fingerprinting approach. Results confirmed a polymicrobial composition even in treated patients without post-treatment disease. A large microbial community diversity was observed for treated teeth both with or without disease, but no specific pattern was detected for diseased teeth. Nevertheless, the number of bands from samples with apical periodontitis lesions was statistically significantly higher (P=0.04) than that from samples collected from root-canal-treated teeth without post-treatment apical periodontitis. Furthermore, predominant bands in samples from patients with apical disease were also observed.
Successful treatment of pan-resistant Klebsiella pneumoniae pneumonia and bacteraemia with a combination of high-dose tigecycline and colistin
Authors: Humphries Romney M. , Kelesidis Theodoros , Dien Bard Jennifer , Ward Kevin W. , Bhattacharya Debika , Lewinski Michael A.
Published: August 2010

The spread of antimicrobial resistance among members of the Enterobacteriaceae is a significant clinical threat. We report the treatment of pan-resistant Klebsiella pneumoniae bacteraemia with combination tigecycline and colistin in a 49-year-old male and review available therapeutic options. Despite a poor prognosis, the patient recovered, but remains colonized with the pan-resistant isolate.
Molecular pathogenesis of Listeria monocytogenes in the alternative model host Galleria mellonella
Authors: Joyce Susan A. , Gahan Cormac G. M.
Published: August 2010

Larvae ofGalleria mellonella, the greater wax moth, provide an alternative infection model for many human pathogens as they are amenable to use at elevated incubation temperatures (37 °C). This study and a parallel study by Mukherjeeet al.[Mukherjee, K., Altincicek, B., Hain, T., Domann, E., Vilcinskas, A. & Chakraborty, T. (2010).Appl Environ Microbiol76, 310–317] establish this insect host as an appropriate model to investigate the pathogenesis ofListeriaspecies. In this study we show that inoculation withListeria monocytogenesinitiates a dynamic infection inG. mellonellaand that production of the cytolysin listeriolysin O (LLO) is necessary for toxicity and bacterial growth. Production of LLO by the non-pathogenic speciesLactococcus lactisis sufficient to induce mortality in the insect model. We employed real-time bioluminescence imaging to examine the dynamics of listerial growth and virulence gene expression in theG. mellonellamodel. Analysis ofluxpromoter fusions demonstrated significant induction of virulence gene expression upon introduction of the pathogen into insects at both 30 and 37 °C. The host response to listerial infection was examined which demonstrated that haemocyte destruction accompaniesL. monocytogenespathogenesis and is preceded by activation of the phenoloxidase system. Furthermore, we demonstrate thatListeria innocuais pathogenic toG. mellonellathrough a persistence mechanism that implicates an alternative mechanism for pathogenicity in this model.
Evaluation of a spacecraft attitude and rate estimation algorithm
Authors: Filipski M.N. , Varatharajoo R.
Published: August 2010

Purpose

This paper aims to present the development and performance evaluation of an attitude and rate estimation algorithm using an extended Kalman filter structure based on a body‐referenced representation of the state.

Design/methodology/approach

The algorithm requires only geomagnetic field data and can be used as a low‐cost alternative or as a back‐up estimator in the case of attitude sensor failures. The satellite rate is estimated as a part of the filter state and thus no gyroscope is necessary. The assessment of the algorithm performance is realized through a Monte Carlo simulation using a low‐Earth orbit, nadir‐pointing satellite.

Findings

Given some attitude and rate error requirements, the range of admissible initial errors on the filter state and the effect of un‐modelled disturbance torque are determined, along with the achievable attitude and rate accuracies.

Practical implications

Because the simulation set‐up is clearly stated, the results of this evaluation can be used as a benchmark for other estimation algorithms.

Originality/value

The necessary assumptions and approximations used to derive the filter equations are explicitly pointed out for the benefit of the readers. Well‐defined filter initial conditions are used in an extensive series of tests resulting into a unique set of findings.
Profiling European traditional food consumers
Authors: Vanhonacker Filiep , Lengard Valérie , Hersleth Margrethe , Verbeke Wim
Published: August 2010

Purpose

The paper seeks to provide a picture of the profile of European traditional food consumers (TFC) in terms of their socio‐demographics, attitudes, life‐style orientations and behavioural characteristics.

Design/methodology/approach

Cross‐sectional data were collected through a pan‐European consumer survey (n=4,828) conducted in November and December 2007, with samples representative for gender, age and region, collected from six European countries: Spain, Italy, France, Belgium, Poland and Norway. First, information about the consumption of traditional food and the image of a typical TFC was provided through descriptive analysis. Next, the actual characteristics of TFC were assessed using partial least squares regression and these were discussed in the context of the theory of self‐image congruity.

Findings

Traditional food consumption patterns are stronger in the south than in the north of Europe. TFC across Europe are typically middle‐aged to elderly, health‐conscious, ethnocentric, food connoisseurs, who are attached to familiarity in their food choices and who very much enjoy cooking.

Practical implications

The information about the profile, the image and the actual characteristics of TFC has practical implications for marketing and communicating about traditional foods, including their identification, differentiation, research and development and positioning in the European food market.

Originality/value

Traditional food is currently undergoing a revival, with increased sales, consumer and regulatory interest. This paper provides cross‐cultural results from a large pan‐European consumer sample that provides highly relevant and useful information about the market potentials of the traditional food industry, which mostly consists of small‐and medium‐sized enterprises. The application of the self‐image congruity theory to validate the results contributes to the originality of the paper.
Information‐seeking behavior of the social sciences faculty at Kuwait University
Authors: Marouf Laila , Anwar Mumtaz A.
Published: August 2010

Purpose

The purpose of this paper is to investigate the information‐seeking behavior of the social sciences faculty at Kuwait University.

Design/methodology/approach

A survey method was used for this study. The data were collected using a structured, peer‐reviewed questionnaire self‐administered to 77 faculty members, with 54 returns.

Findings

It was found that these respondents heavily depend on books and journals for teaching and on a larger variety of materials for research purposes. Their use of informal sources is comparatively less than formal sources. Journals and books are considered the most important sources to meet their needs. Among the informal sources, conferences, subject experts, and colleagues are given higher importance than librarians and government officials. Journals and books are used more frequently than raw data, technical reports, and manuscripts and primary materials. Their satisfaction level with all the sources is positive but higher for journals and books. The level of satisfaction with informal sources is slightly higher than formal sources. Their library use is very low with complaints about the quality of staff, resources, especially in Arabic, and access to international resources.

Research limitations/implications

The research is limited to faculty in the college of Social Sciences, Kuwait University.

Practical implications

Understanding the information‐seeking behavior of social science scholars and developing information resources and designing systems and services that are appropriate for their needs.

Originality/value

This paper contributes to the very limited research literature on the topic in the Arab countries.
Strategy types of service firms: evidence from Greece
Authors: Salavou Helen
Published: August 2010

Purpose

The purpose of this study is to empirically examine different types of service firms, featuring strategy orientations and the performance of different emphases.

Design/methodology/approach

To answer the questions the paper raises, data of 80 Greek firms of the services sector are analysed with the help of factor analysis, cluster analysis and analysis of variance.

Findings

The findings reveal three types of firms pursuing different strategy orientations for dealing with competition (i.e. the hybridists: 44 firms, the confused strategists: 25 firms and the non‐strategists: 11 firms). Furthermore, they suggest that performance is dependent on these strategy types.

Research limitations/implications

The study provides new evidence outside the manufacturing industry and the US context, which dominates the literature. Nonetheless, further empirical research will help to generalise the findings within the services sector in Greece and/or comparable national contexts, especially within the European Union.

Practical implications

The empirical results highlight the discussion of pure vs hybrid forms of competitive advantage pursued by service firms operating at home. A message of the utmost importance for practitioners is that the hybrid form of competitive advantage, which places high emphasis on low cost, is the prevailing and the best‐performing strategic choice.

Originality/value

The study focuses on strategy types of firms to offer a view on the basis of competitive advantage within the services sector of a dynamic European Union member state. By excluding the well‐known pure and stuck‐in‐the‐middle alternatives, the evidence highlights the lack of a strategy and combined choices of strategic orientations, which differ in terms of performance. It appears that the dominant argument of strategic purity is not applicable to all firms in all countries.
A “new” view on “traditional” strategic alliances' formation paradigms
Authors: Arturo Lowensberg Daniel
Published: August 2010

Purpose

This paper seeks to argue that managers need to apply a holistic and long‐term approach in their understanding of strategic alliances' paradigms to inform decisions. Owing to the complexity of strategic alliance scenarios it is often a difficult task for management to know what information is required in order to take such decisions. It is suggested here that six widely used motivational paradigms in the formation of interorganisational relationships (transaction cost economics, resource dependence, strategic choice, stakeholder theory, organizational learning, and institutional theory) can be used not only during the formation stages of alliances but also during an alliance's lifecycle to help in decision making.

Design/methodology/approach

The paper proposes a discussion of possible shortcomings in the literature on motivational paradigms based on a review of the pertinent literature and, with the help of previously published cases/examples, suggests a new conceptual perspective of the paradigms.

Findings

The paper explains how and why motivational paradigms could be viewed as an interrelated web of issues throughout a strategic alliance's entire lifecycle – and not just at their formation stage when, often, they are used singly and in isolation of one another. It is proposed that their continuous and holistic use contributes to a manager's awareness of possible issues and helps his/her strategic management and decision taking. This new perspective is presented conceptually in a model.

Practical implications

For decision makers and managers: the proposed perspective will enhance their management and decision‐taking processes by increasing their awareness and acting as an aide‐mémoire of issues they need to consider/investigate and will reduce the possibility of alliance failure. For educators, it will expand the scope of traditional alliance formation paradigms and inform their teaching and research.

Originality/value

This is a novel approach to a traditional theory that expands its scope and usefulness.
Bile secretion and palm oil diets in Wistar rats
Authors: Obembe A.O. , Antai A.B. , Owu D.U. , Okwari O.O. , Eteng M.U. , Osim E.E.
Published: August 2010

Purpose

Chronic feeding with thermoxidized palm oil causes tissue damage. The purpose of this paper is to ascertain whether chronic feeding of oxidized and fresh palm oil affects biliary secretion.

Design/methodology/approach

Albino Wistar rats were divided into three groups of ten rats each. The first group was the control and were fed on normal rat chow, while the second (FPO) and third group (TPO) were fed diet containing either fresh or thermoxidized palm oil (15per cent (w/w)) for 14 weeks. Biliary secretion, bilirubin, electrolytes, cholesterol and serum levels of alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase enzymes were measured.

Findings

Biliary secretion in TPO was significantly (p < 0.05) lower compared with the control or FPO. Electrolytes (Na+, Cl− and HCO3−) content of bile were significantly (p < 0.05) lower in TPO compared with control or FPO group. Conjugated and un‐conjugated bilirubin levels were significantly (p < 0.05) elevated in TPO compared with control or FPO. The levels of serum liver enzymes were significantly (p < 0.001) higher in TPO than control or FPO. The cholesterol level in the TPO was significantly higher (p < 0.001) than in control or FPO.

Research limitations/implications

The non‐clinical approach and use of experimental animals present limitations to the study.

Originality/value

These results suggest that long‐term feeding of thermally oxidized palm oil alters bile composition and decreases biliary flow due to its hazardous free radicals.
Evaluation of nutritional and anti‐nutritional compounds from tania (XanthosomaSchott) corms
Authors: de Almeida Lima Thaina , Luiz Franco Octávio , Gomes Gonçalves Eduardo , Pereira Sales Maurício , Borghetti Fabian
Published: August 2010

Purpose

Tuber crops are extremely important for humans, being extensively used in many cultures and mainly in poor and developing countries. Tanias (XanthosomaSchott) belong to the Aracea family and have been commonly used as a staple food since pre‐Columbian times. Nowadays, tanias are integrated in the staple diet of several countries in the Americas, West Africa, Asia and the Pacific. In order to shed light on their potential and possible risks for human nutrition, nutritional and anti‐nutritional evaluations of different compounds synthesized by tania corms were carried out by using seven tropical species.

Design/methodology/approach

Classical analyses for non‐structural carbohydrates and nitrogenated compounds as well inhibitory assays towards α‐amylases and proteases were employed.

Findings

Tests for quantitation of reducing sugars, soluble polysaccharides, free amino acid content and total protein amounts presented variable scores among studied species. Nevertheless, the amounts of non‐starchy polysaccharides and sugars were less than those observed in other tuber crops, such as potato, cassava, sweet potato and yam. Otherwise, when anti‐nutritional compounds were evaluated, no digestive enzyme inhibitory activity was detected in performed assays. Moreover,Xanthosoma atrovirens,Xanthosoma brasilienseandXanthosoma mafaffashowed agglutination activity towards blood type B, probably due to the presence of lectins.

Research limitations/implications

In summary, data here presented suggest that it is not possible to indicate a single tania candidate as the best choice for human consumption.

Originality/value

The paper presents a pioneer comparison of nutritional and antinutritional compounds between different species of tania corms.