bluuebunny/crossref_metadata_2025 huggingface dataset:
CD36 is Involved in Astrocyte Activation and Astroglial Scar Formation
Authors: Bao Yi , Qin Luye , Kim Eunhee , Bhosle Sangram , Guo Hengchang , Febbraio Maria , Haskew-Layton Renee E , Ratan Rajiv , Cho Sunghee
Published: April 2012

Inflammation is an essential component for glial scar formation. However, the upstream mediator(s) that triggers the process has not been identified. Previously, we showed that the expression of CD36, an inflammatory mediator, occurs in a subset of astcotyes in the peri-infarct area where the glial scar forms. This study investigates a role for CD36 in astrocyte activation and glial scar formation in stroke. We observed that the expression of CD36 and glial fibrillary acidic protein (GFAP) coincided in control and injured astrocytes and in the brain. Furthermore, GFAP expression was attenuated in CD36 small interfering RNA transfected astrocytes or in the brain of CD36 knockout (KO) mice, suggesting its involvement in GFAP expression. Using an in-vitro model of wound healing, we found that CD36 deficiency attenuated the proliferation of astrocytes and delayed closure of the wound gap. Furthermore, stroke-induced GFAP expression and scar formation were significantly attenuated in the CD36 KO mice compared with wild type. These findings identify CD36 as a novel mediator for injury-induced astrogliosis and scar formation. Targeting CD36 may serve as a potential strategy to reduce glial scar formation in stroke.
Refining the Mismatch Concept in Acute Stroke: Lessons Learned from PET and MRI
Authors: Sobesky Jan
Published: April 2012

In ischemic stroke, positron-emission tomography (PET) established the imaging-based concept of penumbra. It defines hypoperfused, but functionally impaired, tissue with preserved viability that can be rescued by timely reperfusion. Diffusion-weighted and perfusion-weighted (PW) magnetic resonance imaging (MRI) translated the concept of penumbra to the concept of mismatch. However, the use of mismatch-based patient stratification for reperfusion therapy remains a matter of debate. The equivalence of mismatch and penumbra, as well as the validity of the classical mismatch concept is questioned for several reasons. First, methodological differences between PET and MRI lead to different definitions of the tissue at risk. Second, the mismatch concept is still poorly standardized among imaging facilities causing relevant variability in stroke research. Third, relevant conceptual issues (e.g., the choice of the adequate perfusion measure, the best quantitative approach to perfusion maps, and the required size of the mismatch) need further refinement. Fourth, the use of single thresholds does not account for the physiological heterogeneity of the penumbra and probabilistic approaches may be more promising. The implementation of this current knowledge into an optimized state-of-the-art mismatch model and its validation in clinical stroke studies remains a major challenge for future stroke research.
Regulation and cellular functions of class II phosphoinositide 3-kinases
Authors: Falasca Marco , Maffucci Tania
Published: April 2012

Class II isoforms of PI3K (phosphoinositide 3-kinase) are still the least investigated and characterized of all PI3Ks. In the last few years, an increased interest in these enzymes has improved our understanding of their cellular functions. However, several questions still remain unanswered on their mechanisms of activation, their specific downstream effectors and their contribution to physiological processes and pathological conditions. Emerging evidence suggests that distinct PI3Ks activate different signalling pathways, indicating that their functional roles are probably not redundant. In the present review, we discuss the recent advances in our understanding of mammalian class II PI3Ks and the evidence suggesting their involvement in human diseases.
Microcontroller based resonance tracking unit for time resolved continuous wave cavity-ringdown spectroscopy measurements
Authors: Votava Ondrej , Mašát Milan , Parker Alexander E. , Jain Chaithania , Fittschen Christa
Published: April 2012

We present in this work a new tracking servoloop electronics for continuous wave cavity-ringdown absorption spectroscopy (cw-CRDS) and its application to time resolved cw-CRDS measurements by coupling the system with a pulsed laser photolysis set-up. The tracking unit significantly increases the repetition rate of the CRDS events and thus improves effective time resolution (and/or the signal-to-noise ratio) in kinetics studies with cw-CRDS in given data acquisition time. The tracking servoloop uses novel strategy to track the cavity resonances that result in a fast relocking (few ms) after the loss of tracking due to an external disturbance. The microcontroller based design is highly flexible and thus advanced tracking strategies are easy to implement by the firmware modification without the need to modify the hardware. We believe that the performance of many existing cw-CRDS experiments, not only time-resolved, can be improved with such tracking unit without any additional modification to the experiment.
Effects of spacer thickness on perpendicular anisotropy L1-FePt/TiN/L1-FePt pseudo spin valves
Authors: Ho P. , Han G. C. , He K. H. , Chow G. M. , Chen J. S.
Published: April 2012

Pseudo spin valves (PSVs) with the structure MgO substrate/L10-Fe50Pt50/TiN/L10-Fe50Pt50 were fabricated with varying TiN spacer thickness from 3 to 7 nm. The giant magnetoresistance (GMR) reached a maximum before diminishing with increasing TiN spacer thickness. The initial enhancement of the GMR was attributed to the reduction in interlayer coupling between the L10-FePt layers. However, a decline in GMR sets in when the current shunting effects negated the enhancement brought about by the improved decoupling. Magnetostatic coupling was the primary source of interlayer coupling in the PSVs. The dependence of interlayer coupling on the remanent state of the hard L10-FePt was also examined based on the magnitude and direction of shift in the center of the minor hysteresis loop. While magnetostatic coupling was present in fully saturated hard L10-FePt, dipolar stray field coupling contributed more significantly to the interlayer coupling strength in partially saturated hard L10-FePt. The stray field coupling strength depended on both the thickness of the spacer and the density of the reversed domains in the hard L10-FePt.
Construction of time-dependent dynamical invariants: A new approach
Authors: Bertin M. C. , Pimentel B. M. , Ramirez J. A.
Published: April 2012

We propose a new way to obtain polynomial dynamical invariants of the classical and quantum time-dependent harmonic oscillator from the equations of motion. We also establish relations between linear and quadratic invariants, and discuss how the quadratic invariant can be related to the Ermakov invariant.
Bandgap properties of diamond structure photonic crystals with line defects
Authors: Dai Wei , Wang Hong , Chen Shibin
Published: April 2012

Three dimensional diamond structure photonic crystals with line defects fabricated by rapid prototyping and gel casting with alumina were studied. The influence of the line defect shapes, which include rectangular, ellipse, circle, and square shapes of the cross section, on the transmission properties of the electromagnetic wave was first studied. The resonant mode of the rectangular line defect is the strongest with the guiding band from 11.0 to 11.75 GHz and the normalized resonant intensity is 0.8. If the TE10 mode of the propagating electromagnetic wave is parallel to the polarization direction of the rectangular line defect, the property of the line defect will be strengthened. Two separate line defects with a point defect between them can realize the properties of a straight complete line defect through the coupling between them. The bending properties of the line defect were investigated with the bending angle from 0° to 90° at 15° interval. With the increasing of the bending angle, the guiding bandwidth was reduced slowly while the resonant intensity did not change too much.
Modeling of current gain compression in common emitter mode of a transistor laser above threshold base current
Authors: Basu Rikmantra , Mukhopadhyay Bratati , Basu P. K.
Published: April 2012

We have obtained the expressions for the terminal currents in a heterojunction bipolar transistor laser the base of which contains a quantum well (QW). The emitter-base junction is assumed to be abrupt, leading to abrupt discontinuity in quasi-Fermi level at the interface. The expressions for the terminal currents as a function of collector-emitter and base-emitter voltages are obtained from the solution of the continuity equation. The current density in the QW located at an arbitrary position in the base is related to the virtual state current density. The threshold current density in the QW is calculated by using the expression for gain obtained from Fermi golden rule. The plot of collector current (IC) versus collector-emitter voltage (VCE) for different values of base current shows the usual transistor characteristics, i.e., a rising portion after a cut-in VCE, and then a saturation behavior. The dc current gain remains constant. However, as the base current exceeds the threshold, a stimulated recombination rate is added to the spontaneous recombination rate and the plots of collector currents become closer for the same increase in base current. This current gain compression is in agreement with the experimental observation. Our calculated values qualitatively agree with other experimental findings; however some features like Early effect do not show up in the calculation.
Calculation of the lattice dynamics and Raman spectra of copper zinc tin chalcogenides and comparison to experiments
Authors: Khare Ankur , Himmetoglu Burak , Johnson Melissa , Norris David J. , Cococcioni Matteo , Aydil Eray S.
Published: April 2012

The electronic structure, lattice dynamics, and Raman spectra of the kesterite, stannite, and pre-mixed Cu-Au (PMCA) structures of Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) were calculated using density functional theory (DFT). Differences in longitudinal and transverse optical (LO-TO) splitting in kesterite, stannite, and PMCA structures can be used to differentiate them. The Γ-point phonon frequencies, which give rise to Raman scattering, exhibit small but measurable shifts, for these three structures. Experimentally measured Raman scattering from CZTS and CZTSe thin films were examined in light of DFT calculations and deconvoluted to explain subtle shifts and asymmetric line shapes often observed in CZTS and CZTSe Raman spectra. Raman spectroscopy in conjunction with ab initio calculations can be used to differentiate between kesterite, stannite, and PMCA structures of CZTS and CZTSe.
Tailoring electrically induced properties by stretching relaxor polymer films
Authors: Bobnar V. , Li X. , Casar G. , Eršte A. , Glinšek S. , Qian X. , Zhang Q. M.
Published: April 2012

Electrically induced behavior was investigated and compared in the non-stretched and uniaxially stretched poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene), P(VDF-TrFE-CFE) terpolymer—a member of the P(VDF-TrFE)-based relaxor polymers family that exhibits fast response speeds, giant electrostriction, high electric energy density, and large electrocaloric effect. Although the temperature dependence of the low-field complex dielectric constant is almost identical in the non-stretched and stretched samples, the dc bias electric field via higher nonlinear contribution more heavily alters the dielectric response of the non-stretched terpolymer. The polarization response and, particularly, the induced electrostrictive strain are, on the other hand, much higher in the more-oriented stretched films. The changes in polar-correlation range induced by film stretching also strongly influence the directly measured electrocaloric response, which shows more pronounced temperature dependence in the stretched terpolymer. These results suggest that electrically induced properties of relaxor polymer films can be tailored by controlling the preparation conditions.
Source fabrication and lifetime for Li+ ion beams extracted from alumino-silicate sources
Authors: Roy Prabir K. , Greenway Wayne G. , Kwan Joe W.
Published: April 2012

A space-charge-limited beam with current densities (J) exceeding 1 mA/cm2 have been measured from lithium alumino-silicate ion sources at a temperature of ∼1275 °C. At higher extraction voltages, the source appears to become emission limited with J ⩾ 1.5 mA/cm2, and J increases weakly with the applied voltage. A 6.35 mm diameter source with an alumino-silicate coating, ⩽0.25 mm thick, has a measured lifetime of ∼40 h at ∼1275 °C, when pulsed at 0.05 Hz and with pulse length of ∼6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. The source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be further extended if the temperature is reduced between pulses.
Gyrokinetic turbulent transport simulation of a high ion temperature plasma in large helical device experiment
Authors: Nunami M. , Watanabe T.-H. , Sugama H. , Tanaka K.
Published: April 2012

Ion temperature gradient turbulent transport in the large helical device (LHD) is investigated by means of gyrokinetic simulations in comparison with the experimental density fluctuation measurements of ion-scale turbulence. The local gyrokinetic Vlasov simulations are carried out incorporating full geometrical effects of the LHD configuration, and reproduce the turbulent transport levels comparable to the experimental results. Reasonable agreements are also found in the poloidal wavenumber spectra of the density fluctuations obtained from the simulation and the experiment. Numerical analysis of the spectra of the turbulent potential fluctuations on the two-dimensional wavenumber space perpendicular to the magnetic field clarifies the spectral transfer into a high radial wavenumber region which correlates with the regulation of the turbulent transport due to the zonal flows. The resultant transport levels at different flux surfaces are expressed in terms of a simple linear relation between the transport coefficient and the ratio of the squared turbulent potential fluctuation to the averaged zonal flow amplitude.
Detection of sulfur dioxide gas with graphene field effect transistor
Authors: Ren Yujie , Zhu Chaofu , Cai Weiwei , Li Huifeng , Ji Hengxing , Kholmanov Iskandar , Wu Yaping , Piner Richard D. , Ruoff Rodney S.
Published: April 2012

Graphene grown by chemical vapor deposition on a Cu foil and transferred onto a Si wafer has been used to fabricate a field effect transistor device that was used to study the sensing of SO2 gas. It was found by in-situ measurements that the SO2 strongly p-dopes the graphene and dramatically shifts its Dirac point. This effect was used to monitor the SO2 gas. The detector can be completely reset by thermal annealing at 100 °C in high vacuum. The response and recovery of the detector are faster at higher temperatures. Moreover, the sensitivity of the SO2 graphene detector increases proportionally with increasing temperature.
Vimentin networks at tunable ion-concentration in microfluidic drops
Authors: Dammann Christian , Nöding Bernd , Köster Sarah
Published: April 2012

The structure and function of biological systems, for example, cells and proteins, depend strongly on their chemical environment. To investigate such dependence, we design a polydimethylsiloxane-based microfluidic device to encapsulate biological systems in picoliter-sized drops. The content of each individual drop is tuned in a defined manner. As a key feature of our method, the individual chemical composition is determined and related to the drop content. In our case, the drop content is imaged using microscopy methods, while the drops are immobilized to allow for long-time studies. As an application of our device, we study the influence of divalent ions on vimentin intermediate filament networks in a quantitative way by tuning the magnesium concentration from drop to drop. This way we are able to directly image the effect of magnesium on the fluorescently tagged protein in a few hundreds of drops. Our study shows that with increasing magnesium concentration in the drops, the compaction of the networks becomes more pronounced. The degree of compaction is characterized by different morphologies; freely fluctuating networks are observed at comparatively low magnesium concentrations of 5–10 mM, while with increasing magnesium concentration reaching 16 mM they develop into fully aggregated networks. Our approach demonstrates how a systematic study of interactions in biological systems can benefit from the exceptional controllability of microfluidic methods.
Dynamic migration of γδ intraepithelial lymphocytes requires occludin
Authors: Edelblum Karen L. , Shen Le , Weber Christopher R. , Marchiando Amanda M. , Clay Bryan S. , Wang Yingmin , Prinz Immo , Malissen Bernard , Sperling Anne I. , Turner Jerrold R.
Published: April 2012

γδ intraepithelial lymphocytes (IELs) are located beneath or between adjacent intestinal epithelial cells and are thought to contribute to homeostasis and disease pathogenesis. Using in vivo microscopy to image jejunal mucosa of GFP γδ T-cell transgenic mice, we discovered that γδ IELs migrate actively within the intraepithelial compartment and into the lamina propria. As a result, each γδ IEL contacts multiple epithelial cells. Occludin is concentrated at sites of γδ IEL/epithelial interaction, where it forms a ring surrounding the γδ IEL. In vitro analyses showed that occludin is expressed by epithelial and γδ T cells and that occludin derived from both cell types contributes to these rings and to γδ IEL migration within epithelial monolayers. In vivo TNF administration,which results in epithelial occludin endocytosis, reduces γδ IEL migration. Further in vivo analyses demonstrated that occludin KO γδ T cells are defective in both initial accumulation and migration within the intraepithelial compartment. These data challenge the paradigm that γδ IELs are stationary in the intestinal epithelium and demonstrate that γδ IELs migrate dynamically to make extensive contacts with epithelial cells. The identification of occludin as an essential factor in γδ IEL migration provides insight into the molecular regulation of γδ IEL/epithelial interactions.
Juvenile hominoid cranium from the late Miocene of southern China and hominoid diversity in Asia
Authors: Kelley Jay , Gao Feng
Published: April 2012

The fossil ape
Lufengpithecus
is known from a number of late Miocene sites in Yunnan Province in southern China. Along with other fossil apes from South and Southeast Asia, it is widely considered to be a relative of the extant orangutan,
Pongo pygmaeus
. It is best represented at the type site of Shihuiba (Lufeng) by several partial to nearly complete but badly crushed adult crania. There is, however, an additional, minimally distorted cranium of a young juvenile from a nearly contemporaneous site in the Yuanmou Basin, which affords the opportunity to better assess the relationships between
Lufengpithecus
and
Pongo
. Comparison with similarly aged juvenile skulls of extant great apes reveals no features suggesting clear affinities to orangutans, and instead reveals a morphological pattern largely consistent with a stem member of the hominid (great ape and human) clade. The existence at this time of other hominids in South Asia (
Sivapithecus
) and Southeast Asia (
Khoratpithecus
) with clear craniofacial affinities to
Pongo
suggests both more diversity among Asian Late Miocene apes and more complex patterns of dispersal than previously supposed. Major differences in the associated mammal faunas from the southern China sites and those from South and Southeast Asia are consistent with these findings and suggest more than one dispersal route of apes into East Asia earlier in the Miocene.
Tissue deformation spatially modulates VEGF signaling and angiogenesis
Authors: Rivron Nicolas C. , Vrij Erik J. , Rouwkema Jeroen , Le Gac Severine , van den Berg Albert , Truckenmüller Roman K. , van Blitterswijk Clemens A.
Published: April 2012

Physical forces play a major role in the organization of developing tissues. During vascular development, physical forces originating from a fluid phase or from cells pulling on their environment can alter cellular signaling and the behavior of cells. Here, we observe how tissue deformation spatially modulates angiogenic signals and angiogenesis. Using soft lithographic templates, we assemble three-dimensional, geometric tissues. The tissues contract autonomously, change shape stereotypically and form patterns of vascular structures in regions of high deformations. We show that this emergence correlates with the formation of a long-range gradient of Vascular Endothelial Growth Factor (VEGF) in interstitial cells, the local overexpression of the corresponding receptor VEGF receptor 2 (VEGFR-2) and local differences in endothelial cells proliferation. We suggest that tissue contractility and deformation can induce the formation of gradients of angiogenic microenvironments which could contribute to the long-range patterning of the vascular system.
The possible selves of international students and their cross‐cultural adjustment in Canada
Authors: Yang Ruby Pi‐Ju , Noels Kimberly A.
Published: April 2012

We assessed 93 international students’ reports of their expected and feared possible selves in terms of their thematic content and configuration, and examined the relations between possible selves and cultural adjustment in Canada. The results showed that international students mostly envisioned possible selves in career, education, intrapersonal, and interpersonal domains, and reported more balanced configurations than matched configurations of possible selves. Balanced possible selves in the educational domain were associated with better psychological well‐being, but balanced selves in the intrapersonal domains were linked with more frequent sociocultural difficulties. The findings suggest that the content of international students’ possible selves reflects not only their academic‐focused and career‐inspired sojourn, but also their intercultural experiences with various ethnic groups in the Canadian multicultural society. As well, they speak to the motivational significance of possible selves, particularly the balanced possible selves, for supporting international students’ motivation to pursue an international education and for facilitating a successful cross‐cultural sojourn.
The Republika Srpska as a strong nationalizing state and the consequences for postethnic activism
Authors: Touquet Heleen
Published: April 2012

This paper explores the limits and possibilities for postethnic mobilization in Bosnia-Herzegovina. It employs and critically assesses Tarrow's classic concept of political opportunity structure for the explaining the variations in the occurrence of postethnic mobilization in Bosnia-Herzegovina, a deeply divided society. While the main cleavages in the country run along ethnic lines, a number of groups and NGOs attempt to mobilize alternative identities across ethnic boundaries. These groups are mostly based in the Federation entity of Bosnia-Herzegovina and not in the Republika Srpska. My analysis shows that the concept of political opportunity structure only partly explains this difference. I thus suggest an alternative perspective, which takes into account the cultural environment in which the mobilization happens. The first part of the paper expands on the definition of postethnic activism, explaining what it is and how I proceeded in researching postethnic groups in Bosnia-Herzegovina. The second part uses the framework of political opportunity structure for assessing the influence of environmental factors on the emergence and development of postethnic activism. The third part of the paper evaluates the relevance of the political opportunity structure framework, considers the merits of an approach which takes into account the cultural context, and suggests some further avenues for research.
The birth of modern Circassian nationalism
Authors: Zhemukhov Sufian
Published: April 2012

This article focuses on problems of the national movement of the Circassians – a small nation in the Caucasus, most of whose population is dispersed all over the world. The paper researches the development of the Circassian movement from 1989–2000 and its contemporary structure since 2005. The modern Circassian movement as a whole has never been approached from a political science viewpoint. This research aims to answer several core questions: What are the different strands of the movement? What principles are they based on? Who are the participants? What political forces support them? How do these political forces interact with each other?
The efficacy and safety of lixivaptan in outpatients with heart failure and volume overload: results of a multicentre, randomized, double‐blind, placebo‐controlled, parallel‐group study
Authors: Ghali Jalal K. , Orlandi Cesare , Abraham William T. ,   for the CK‐LX2401 Study Investigators
Published: April 2012

Aims

Volume overload is the dominant feature of decompensated heart failure (HF) and it often results in adverse clinical outcomes. Vasopressin receptor antagonists such as lixivaptan may provide effective volume unloading. This study assessed weight loss after 1 day and 8 weeks of treatment with lixivaptan in outpatients with HF and volume overload.

Methods and results

This phase II, 8‐week, multicentre, double‐blind, parallel‐group study randomized participants (2:1) to receive lixivaptan 100 mg or placebo once daily (in addition to standard HF therapy). Body weight and cardiovascular assessments were made at baseline, Day 1 (not cardiovascular), Weeks 1, 2, 4, and 8, and 7 days post‐treatment. The Trail‐making Test, part B (TMT‐B) and the Medical Outcomes Survey 6‐item cognitive function scale (MOS‐6) were assessed at baseline and Week 4. The study randomized 170 participants (lixivaptan, n = 111; placebo, n = 59). Most (97.1%) were receiving pharmacological therapy for HF at baseline. Demographic characteristics were generally similar between the two groups. Body weight decreased significantly from baseline to Day 1 with lixivaptan vs. placebo (least‐square mean change ± standard error: − 0.38 ± 0.08 kg vs. +0.13 ± 0.11 kg; P < 0.001) and at Weeks 1, 2, and 4 (P < 0.01). Cardiovascular changes were generally similar in both groups, though orthopnoea and dyspnoea improved in the lixivaptan group vs. placebo. The TMT‐B and MOS‐6 showed no significant differences between groups. Lixivaptan was well tolerated—thirst and polyuria occurred more frequently vs. placebo.

Conclusions

In outpatients with HF and volume overload, lixivaptan 100 mg once daily, when added to standard therapy, reduced body weight, improved dyspnoea and orthopnoea, and was well tolerated.

Trial registration: NCT01055912
SALSEA North America: a pelagic ecosystem survey targeting Atlantic salmon in the Northwest Atlantic
Authors: Sheehan Timothy F. , Reddin David G. , Chaput Gérald , Renkawitz Mark D.
Published: April 2012

Sheehan, T. F., Reddin, D. G., Chaput, G., and Renkawitz, M. D. 2012. SALSEA North America: a pelagic ecosystem survey targeting Atlantic salmon in the Northwest Atlantic. – ICES Journal of Marine Science, 69: 1580–1588. Pelagic ecosystem surveys were conducted in the Labrador Sea during 2008 and 2009 as part of SALSEA North America. In total, 107 Atlantic salmon (Salmo salar) were captured using a pelagic surface trawl and multipanel surface gillnets. Surface trawling provided a broad spatial sampling of the fish and macroinvertebrate communities in the upper 10 m of the water column, but caught few salmon (23). Gillnetting was more effective at capturing post-smolt (60) and adult (24) salmon. Multiple smolt cohorts were captured, indicating that post-smolts and returning adults from different rivers in North America have similar autumnal habitat requirements. Post-smolts were caught at night and in water temperatures exceeding 10°C, both novel results. Post-smolts and adults consumed similar and diverse prey species, although Themisto compressa was the most important prey item. Intestinal macroparasite loads were substantial and could be a significant source of mortality. Concurrent planktonic assemblage and oceanographic conditions were also quantified. A full exploration of these data, historical datasets, and parallel data collected during SALSEA Greenland and SALSEA-Merge will further understanding of the ecology of marine-phase Atlantic salmon and inform investigations into stock-specific differences in marine productivity.
Tinnitus: Diagnosis and Management
Authors: Butcher Aurelia C. R. , Davies Michael R. L.
Published: April 2012

‘Tinnitus’ stems from the Latin tinnire, meaning ‘to ring’. Tinnitus is the perception of sound in the absence of any corresponding external auditory stimulation. It is a very common symptom presented to general practice; this is not surprising as approximately 1 in 10 adults in the UK experience tinnitus. This article aims to provide information for professionals working in general practice and help them care for patients with tinnitus. A practical aid to ‘consulting a patient with tinnitus’ is included to help clinicians (and therefore their patients) with this common problem.
Trichoderma harzianum Enhances Antioxidant Defense of Tomato Seedlings and Resistance to Water Deficit
Authors: Mastouri Fatemeh , Björkman Thomas , Harman Gary E.
Published: April 2012

Some plant-symbiotic strains of the genus Trichoderma colonize roots and induce profound changes in plant gene expression that lead to enhanced growth, especially under biotic and abiotic stresses. In this study, we tested the hypothesis that one of the protective mechanisms enhanced by T. harzianum T22 colonization is the antioxidant defense mechanism. Having established that strain T22 modulates the expression of the genes encoding antioxidant enzymes, the status of antioxidant defense of tomato seedlings in response to colonization by T22 and water deficit was investigated. Total ascorbate or glutathione levels were not affected by either stimuli, but under water deficit, antioxidant pools became more oxidized (lower ratios of reduced to oxidized forms), whereas colonized plants maintained redox state as high as or higher than unstressed and untreated plants. The enhanced redox state of colonized plants could be explained by their higher activity of ascorbate and glutathione-recycling enzymes, higher activity of superoxide dismutase, catalase, and ascorbate peroxidase, in both root and shoot throughout the experiment. Similar enzymes were induced in uncolonized plants in response to water-deficit stress but to a lower extent when compared with colonized plants. This orchestrated enhancement in activity of reactive oxygen species (ROS)-scavenging pathways in colonized plants in response to stress supports the hypothesis that enhanced resistance of colonized plants to water deficit is at least partly due to higher capacity to scavenge ROS and recycle oxidized ascorbate and glutathione, a mechanism that is expected to enhance tolerance to abiotic and biotic stresses.
Prediction of invasion from the early stage of an epidemic
Authors: Pérez-Reche Francisco J. , Neri Franco M. , Taraskin Sergei N. , Gilligan Christopher A.
Published: April 2012

Predictability of undesired events is a question of great interest in many scientific disciplines including seismology, economy and epidemiology. Here, we focus on the predictability of invasion of a broad class of epidemics caused by diseases that lead to permanent immunity of infected hosts after recovery or death. We approach the problem from the perspective of the science of complexity by proposing and testing several strategies for the estimation of important characteristics of epidemics, such as the probability of invasion. Our results suggest that parsimonious approximate methodologies may lead to the most reliable and robust predictions. The proposed methodologies are first applied to analysis of experimentally observed epidemics: invasion of the fungal plant pathogenRhizoctonia solaniin replicated host microcosms. We then consider numerical experiments of the susceptible–infected–removed model to investigate the performance of the proposed methods in further detail. The suggested framework can be used as a valuable tool for quick assessment of epidemic threat at the stage when epidemics only start developing. Moreover, our work amplifies the significance of the small-scale and finite-time microcosm realizations of epidemics revealing their predictive power.
A two‐step approach to map quantitative trait loci for meat quality in connected porcine F2 crosses considering main and epistatic effects
Authors: Stratz P. , Baes C. , Rückert C. , Preuss S. , Bennewitz J.
Published: April 2012

The aim of this study was to map QTL for meat quality traits in three connected porcine F2 crosses comprising around 1000 individuals. The three crosses were derived from the founder breeds Chinese Meishan, European Wild Boar and Pietrain. The animals were genotyped genomewide for approximately 250 genetic markers, mostly microsatellites. They were phenotyped for seven meat quality traits (pH at 45 min and 24 h after slaughter, conductivity at 45 min and 24 h after slaughter, meat colour, drip loss and rigour). QTL mapping was conducted using a two‐step procedure. In the first step, the QTL were mapped using a multi‐QTL multi‐allele model that was tailored to analyse multiple connected F2 crosses. It considered additive, dominance and imprinting effects. The major gene RYR1:g.1843C>T affecting the meat quality on SSC6 was included as a cofactor in the model. The mapped QTL were tested for pairwise epistatic effects in the second step. All possible epistatic effects between additive, dominant and imprinting effects were considered, leading to nine orthogonal forms of epistasis. Numerous QTL were found. The most interesting chromosome was SSC6. Not all genetic variance of meat quality was explained by RYR1:g.1843C>T. A small confidence interval was obtained, which facilitated the identification of candidate genes underlying the QTL. Epistasis was significant for the pairwise QTL on SSC12 and SSC14 for pH24 and for the QTL on SSC2 and SSC5 for rigour. Some evidence for additional pairwise epistatic effects was found, although not significant. Imprinting was involved in epistasis.
Circulating ficolin-2 and ficolin-3 in normal pregnancy and pre-eclampsia
Authors: Halmos A , Rigó J , Szijártó J , Füst G , Prohászka Z , Molvarec A
Published: April 2012

Ficolins are soluble molecules of the innate immune system that recognize carbohydrate molecules on microbial pathogens, apoptotic and necrotic cells. They act through two distinct routes: initiating the lectin pathway of complement activation and mediating a primitive opsonophagocytosis. In this study, we measured plasma levels of ficolin-2 and ficolin-3 in 60 pre-eclamptic patients, 60 healthy pregnant women and 59 healthy non-pregnant women by enzyme-linked immunosorbent assay (ELISA). Circulating levels of complement activation products (C4d, C3a, SC5b9), angiogenic factors (soluble fms-like tyrosine kinase-1, placental growth factor) and markers of endothelial activation (von Willebrand factor antigen), endothelial injury (fibronectin) and trophoblast debris (cell-free fetal DNA) were also determined. Plasma levels of ficolin-2 were significantly lower in healthy pregnant than in healthy non-pregnant women, while ficolin-3 levels did not differ significantly between the two groups. Furthermore, pre-eclamptic patients had significantly lower ficolin-2 and ficolin-3 concentrations than healthy non-pregnant and pregnant women. In the pre-eclamptic group, plasma ficolin-2 levels showed a significant positive correlation with serum placental growth factor (PlGF) concentrations and significant inverse correlations with serum levels of soluble fms-like tyrosine kinase-1 (sFlt-1), blood urea nitrogen and creatinine, serum lactate dehydrogenase activities, as well as with plasma VWF:antigen, fibronectin and cell-free fetal DNA concentrations. In conclusion, circulating levels of ficolin-2 are decreased in the third trimester of normal pregnancy. There is a further decrease in plasma ficolin-2 concentrations in pre-eclampsia, which might contribute to the development of the maternal syndrome of the disease through impaired removal of the trophoblast-derived material released into the maternal circulation by the hypoxic and oxidatively stressed pre-eclamptic placenta.
Effects of testosterone therapy on sleep and breathing in obese men with severe obstructive sleep apnoea: a randomized placebo‐controlled trial
Authors: Hoyos Camilla M. , Killick Roo , Yee Brendon J. , Grunstein Ronald R. , Liu Peter Y.
Published: April 2012

Study objectives

High doses of short‐term testosterone have been shown to acutely worsen sleep‐disordered breathing in men with obstructive sleep apnoea (OSA). The effects of lower, near‐conventional doses of testosterone in obese men with OSA may differ over the longer term but have not been systematically studied. We assessed sleep and breathing effects of near‐conventional testosterone treatment as an adjunct to weight loss in obese men with severe OSA.

Design

An 18‐week randomized, double‐blind, placebo‐controlled, parallel group trial in 67 men.

Interventions

All subjects were placed on a hypocaloric diet and then received intramuscular injections of 1000 mg testosterone undecanoate or placebo at 0, 6 and 12 weeks.

Measurements and Results

Sleep and breathing were measured by nocturnal polysomnography at 0, 7 and 18 weeks. Testosterone, compared to placebo, worsened the oxygen desaturation index (ODI) by 10·3 events/h (95%CI, 0·8–19·8 events/h; P = 0·03) and nocturnal hypoxaemia (sleep time with oxygen saturation <90%, SpO2T90%) by 6·1% (95%CI, 1·5–10·6; P = 0·01) at 7 weeks. Testosterone therapy did not alter ODI (4·5, −5·4 to 14·4 events/h; P = 0·36) or SpO2T90% at 18 weeks (2·9, −1·9–7·7%; P = 0·23) compared to placebo. The testosterone treatment effects on ODI and SpO2T90% were not influenced by baseline testosterone concentrations (testosterone by treatment interactions, all P > 0·35). Blood testosterone concentrations did not correlate with ODI or SpO2T90% (all P > 0·19).

Conclusions

Testosterone therapy in obese men with severe OSA mildly worsens sleep‐disordered breathing in a time‐limited manner, irrespective of initial testosterone concentrations. This time‐dependency was not related to testosterone concentrations.

Trial Registration

www.anzctr.org.au Identifier: ACTRN1260‐6000404527.
Lower incidence and severity of tomato virus in elevated CO2 is accompanied by modulated plant induced defence in tomato
Authors: Huang L. , Ren Q. , Sun Y. , Ye L. , Cao H. , Ge F.
Published: April 2012

Elevation in atmospheric CO2 concentration broadly affects plant phenology and physiology, and these effects may alter the performance of plant viruses. The effects of elevated CO2 on the susceptibility of tomato plants to Tomato yellow leaf curl virus (TYLCV) were examined for two successive years in open top chambers (OTC) in the field. We experimentally tested the hypothesis that elevated CO2 would reduce the incidence and severity of TYLCV on tomato by altering plant defence strategies. Our results showed that elevated CO2 decreased TYLCV disease incidence (by 14.6% in 2009 and 11.8% in 2010) and decreased disease severity (by 20.0% in 2009 and 10.4% in 2010). Elevated CO2 also decreased the level of TYLCV coat protein in tomato leaves. Regardless of virus infection, elevated CO2 increased plant height and aboveground biomass. Additionally, elevated CO2 increased the leaf C:N ratio of tomato, but decreased soluble protein content in leaves. Notably, elevated CO2 increased the salicylic acid (SA) level in uninfected and infected plants. In contrast, elevated CO2 reduced jasmonic acid (JA) in uninfected plants while it increased JA and abscisic acid (ABA) in virus‐infected plants. Furthermore, combined exogenous SA and JA application enhanced resistance to TYLCV more than application of either SA or JA alone. Our results suggest that the modulated antagonistic relationship between SA and JA under elevated CO2 makes a great contribution to increased tomato resistance to TYLCV, and the predicted increases in tomato productivity may be enhanced by reduced plant virus susceptibility under projected rising CO2 conditions.
Effects of prohydrojasmon‐treated corn plants on attractiveness to parasitoids and the performance of their hosts
Authors: Mandour N. S. , Kainoh Y. , Ozawa R. , Uefune M. , Takabayashi J.
Published: April 2012

We investigated the effect of prohydrojasmon [propyl (1RS,2RS)‐(3‐oxo‐ 2‐pentylcyclopentyl) acetate] (PDJ) treatment of intact corn plants, on their attractiveness to the specialist endoparasitoid, Cotesia kariyai Watanabe (Hymenoptera: Braconidae), and on the performance of the common armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae) under laboratory conditions. Attractiveness of C. kariyai to PDJ‐treated plants was studied in a wind tunnel, whereas performance of M. separata larvae was tested in plastic cages. The attractiveness of the treated plants increased with concentrations of PDJ increasing to 2 mm, which was equivalent to the attractiveness of host‐infested plants. PDJ‐treated corn plants emitted 16 volatile compounds (α‐pinene, β‐myrcene, (Z)‐3‐hexenyl acetate, limonene, (E)‐β‐ocimene, linalool, (E)‐4,8‐dimethyl‐1,3,7‐nonatriene, (+)‐cyclosativene, ylangene, (E)‐β‐farnesene, (E, E)‐4,8,12‐trimethyl‐1,3,7,11‐tridecatetraene, α‐bergamotene, γ‐cadinene, δ‐cadinene, α‐muulolene and nerolidol), most of which were observed in the headspace of host‐infested corn plants with some quantitative and qualitative differences. We also tested the effects of PDJ treatment on the performance of M. separata larvae. The survival rates of the larval and pupal stages were significantly lower at 2 mm level of PDJ. A significant decrease in weight at 6th stadium larvae was observed only at 2 mm level of PDJ. In contrast, PDJ treatment at all PDJ concentration levels caused significant reduction in weight of pupal stage as compared to control. These data suggested that PDJ, originally developed as a plant growth regulator, especially to induce coloring of fruits, has the potential to induce direct and indirect defenses in corn plants against common armyworm, M. separata.
Site occupancy and detection probability of Argentine ant populations
Authors: Ward D. F. , Stanley M. C.
Published: April 2012

Effective sampling and detection plays an important role in the surveillance and management of invasive species. Invasive ants are prime candidates for imperfect detection because of their small size, cryptic nature and also because of their strong association with human transportation around the globe. We examined site occupancy, colonization‐extirpation dynamics and detection probability of Argentine ant populations in the Auckland region of New Zealand. Comparison of 175 sites from 2002 to 2007 shows the dynamic nature of Argentine ants, with an extirpation rate of 33% and a colonization rate of 8%. Baited vials gave relatively poor detection for Argentine ants, despite repeated sampling. If Argentine ants were present at a location, their probability of detection using baited vials was, on average, only P = 0.55 (±SE = 0.04). However, this probability depended on the duration that baited vials were left out. Detectability was highest for vials set out for three (P = 0.52–0.75) or 6 h (P = 0.53–0.82). Detection probability for visual searching was 0.895. We use these data to suggest improvements in the design of surveys for Argentine ants. Research on detection theory and its applications for surveillance and eradication is a major gap for invasive ants.
Fire‐related cues and germination from the soil seed bank of senescent remnants of mallee vegetation on Eastern Kangaroo Island
Authors: RAWSON TESSA , DAVIES RICHARD , WHALEN MOLLY , MACKAY DUNCAN
Published: April 2012

Plant communities dominated by narrow‐leaved mallee (Eucalyptus cneorifolia) are almost entirely confined to north‐eastern Kangaroo Island, South Australia, an area which has been extensively cleared for agriculture. Consequently, surviving examples consist mostly of small remnants which are thought to be senescent due to the exclusion of fire. This senescence is associated with the loss of many native understory species. Prescribed burns have been suggested as a management tool to stimulate the restoration of native plants from the soil seed bank; however, no seed bank studies have previously been conducted on Kangaroo Island and the seed bank literature usually focuses on particular species rather than on plant communities. We conducted an experiment to investigate the effects of the fire‐related cues heat and smoke on the germination of plants from the seed bank in soil sampled from 10 long‐ungrazed narrow‐leaved mallee sites on Kangaroo Island. Eighty trays of soil were monitored in a controlled glasshouse for five months after being subjected to heat and/or smoke treatments. The overall number of native, but not exotic, plant species germinating from the soil seed bank was significantly increased by all three fire‐related treatments (heat, smoke and heat plus smoke) compared with the control (no fire‐related treatment). Different plant life forms exhibited varying responses to heat and smoke treatments. The results of this study illustrate that the application of fire‐related treatments to soil seed banks in controlled glasshouse conditions can stimulate the recruitment of native species, including several species of conservation concern. These findings also indicate the potential of using these treatments for the ex situ germination of fire dependent species for revegetation purposes and indicate aspects of prescribed burns that may be important for restoring different components of native vegetation.
Neuroblast survival depends on mature vascular network formation after mouse stroke: role of endothelial and smooth muscle progenitor cell co‐administration
Authors: Nih Lina R. , Deroide Nicolas , Leré‐Déan Carole , Lerouet Dominique , Soustrat Mathieu , Levy Bernard I. , Silvestre Jean‐Sébastien , Merkulova‐Rainon Tatiana , Pocard Marc , Margaill Isabelle , Kubis Nathalie
Published: April 2012

Pro‐angiogenic cell‐based therapies constitute an interesting and attractive approach to enhancing post‐stroke neurogenesis and decreasing neurological deficit. However, most new stroke‐induced neurons die during the first few weeks after ischemia, thus impairing total recovery. Although the neovascularization process involves different cell types and various growth factors, most cell therapy protocols are based on the biological effects of single‐cell‐type populations or on the administration of heterogeneous populations of progenitors, namely human cord blood‐derived CD34+ cells, with scarce vascular progenitor cells. Tight cooperation between endothelial cells and smooth muscle cells/pericytes is critical for the development of functional neovessels. We hypothesized that neuroblast survival in stroke brain depends on mature vascular network formation. In this study, we injected a combination of endothelial progenitor cells (EPCs) and smooth muscle progenitor cells (SMPCs), isolated from human umbilical cord blood, into a murine model of permanent focal ischemia induced by middle cerebral artery occlusion. The co‐administration of SMPCs and EPCs induced enhanced angiogenesis and vascular remodeling in the peri‐infarct and infarct areas, where vessels exhibited a more mature phenotype. This activation of vessel growth resulted in the maintenance of neurogenesis and neuroblast migration to the peri‐ischemic cortex. Our data suggest that a mature vascular network is essential for neuroblast survival after cerebral ischemia, and that co‐administration of EPCs and SMPCs may constitute a novel therapeutic strategy for improving the treatment of stroke.