bluuebunny/crossref_metadata_2025 huggingface dataset:
Antiferromagnetic coupling and spin filtering in asymmetrically hydrogenated graphene nanoribbon homojunction
Authors: Kang Jun , Wu Fengmin , Li Shu-Shen , Xia Jian-Bai , Li Jingbo
Published: April 2012

The magnetic and spin transport properties of asymmetrically hydrogenated zigzag graphene nanoribbon homojunction are studied from first-principles calculations. Due to the energy gain obtained from super-exchange interaction, antiferromagnetic coupling is preferred in the homojunction, which makes it a natural not gate in logic operations. Moreover, the homojunction exhibits intrinsic spin filtering effect without the need of doping. It can serve as a spin filter for spin-unpolarized current and as a rectifier for fully spin-polarized current. These characters are related to the overlaps between the electronic states of the electrodes under different bias voltages.
Electrokinetic effects on detection time of nanowire biosensor
Authors: Liu Yaling , Guo Qingjiang , Wang Shunqiang , Hu Walter
Published: April 2012

We develop a multiphysics model to study the contribution of electrokinetics on the biomolecular detection process and provide a physical explanation of the two to three orders of magnitude difference in detection time between experimental results and theoretical predications at ultralow concentration. The electrokinetic effects, including electrophoretic force and electroosmotic flow, have been systematically studied under various sensor design and test conditions. In a typical single nanowire-based sensor, it is found that electrokinetic effects could result in a reduction of detection time over 90 times, compared with that induced by pure biomolecular diffusion. The detection time difference is further enhanced by increasing the applied gate voltage or the number of nanowires. It is proposed that accelerated biomolecular detection at ultralow concentration could be achieved by appropriate combinations of electrokinetic effects and nanowire sensor design.
Iterated function system models in data analysis: Detection and separation
Authors: Alexander Zachary , Meiss James D. , Bradley Elizabeth , Garland Joshua
Published: April 2012

We investigate the use of iterated function system (IFS) models for data analysis. An IFS is a discrete-time dynamical system in which each time step corresponds to the application of one of the finite collection of maps. The maps, which represent distinct dynamical regimes, may be selected deterministically or stochastically. Given a time series from an IFS, our algorithm detects the sequence of regime switches under the assumption that each map is continuous. This method is tested on a simple example and an experimental computer performance data set. This methodology has a wide range of potential uses: from change-point detection in time-series data to the field of digital communications.
Size dependent optical properties of the CdSe-CdS core-shell quantum dots in the strong confinement regime
Authors: Mathew S. , Saran Amit D. , Singh Bhardwaj Bishwajeet , Ani Joseph Santhi , Radhakrishnan P. , Nampoori V. P. N. , Vallabhan C. P. G. , Bellare Jayesh R.
Published: April 2012

We have investigated the third-order optical nonlinearity in CdSe and CdSe-CdS core-shell quantum dots with particle sizes in the range 4.4–5.2 nm by the z-scan technique. Optical absorption and fluorescence properties show quantum confinement effect and the fluorescence peak is shifted when the diameter of the core-shell quantum dots becomes large. Their nonlinear absorption and nonlinear refraction were observed with nanosecond laser radiation of 532-nm wavelength. At an excitation irradiance of 392 MW/cm2, the CdSe-CdS core-shell quantum dots exhibit a reverse saturation and a negative nonlinear refractive index indicating a clear nonlinear behavior. The introduction of CdS shell around CdSe core gives large third-order nonlinearity and third-order optical susceptibility decreases with increasing particle core size in the case of core-shell quantum dots within the range of our investigations. The third-order susceptibility of these quantum dots vary from 3.39 × 10−11 to 5.77 × 10−11 esu. The optical limiting threshold of the quantum dots varies in the range from 0.298 to 0.345 GW/cm2 and this therefore makes CdSe-CdS core-shell quantum dots a promising candidate for reverse-saturable absorption based devices at high laser intensities such as optical limiters.
Diffusion of co-implanted carbon and boron in silicon and its effect on excess self-interstitials
Authors: Uematsu Masashi
Published: April 2012

Diffusion of co-implanted carbon (C) and boron (B) in silicon (Si) and its effect on excess Si self-interstitials (I’s) after annealing at 800 and 1000 °C were investigated by means of secondary ion mass spectrometry. The experimental results showed that C diffusion was not significant at 800 and 1000 °C but later became visible for longer annealing times at 1000 °C. B diffusion was reduced by the presence of C when no significant C diffusion was observed, but it was enhanced when C diffusion was observed. These results indicate that all implanted C atoms form immobile CI clusters with excess I in the amount of implanted C and that these CI clusters are stable and trap I to reduce B diffusion. On the contrary, CI clusters are dissolved to emit I for longer annealing times at 1000 °C and both B and C diffusion are enhanced. Diffusion simulation based on these models fits the experimental profiles of B and C.
Modification of the electrical properties of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) upon doping of ZnO nanoparticles of different content
Authors: Lin Yow-Jon , Su Yu-Chao
Published: April 2012

A photocurrent decay model is presented that addresses the charge trapping and doping mechanisms for composite poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS) films having ZnO nanoparticles of different contents. It is shown that ZnO doping introduced changes in the chemical structure of PEDOT:PSS. Dark current proportional to ZnO doping was observed. For n-type Si/ZnO-doped PEDOT:PSS devices, the high photocurrent density originates from efficient hole transport combined with long-lifetime electron trapping.
Magnetic structure and magnetization process of the glass-coated Fe-based amorphous microwire
Authors: Orlova N. N. , Aronin A. S. , Bozhko S. I. , Kabanov Yu. P. , Gornakov V. S.
Published: April 2012

Magnetic structure of amorphous Fe73,9B13,2Si10,9C2 microwires was studied. The magnetic structure of the as-prepared microwire was found to consist of a magnetic core and a ring-shaped surface magnetic layer made up by radially magnetized small ring domains. The geometric characteristics of microwire magnetic structure were first experimentally determined. The width of the surface ring domains is about 5 μm, and the thickness of the surface magnetic layer is 2 μm. The magnetic core of the as-prepared microwire has been shown to consist of extensive domains, no less than 500 μm in size, and their spontaneous magnetization vector deviating from the microwire axis. The effect of magnetostriction on magnetic structure and its changes induced by magnetization has been established. The magnetic structure model for microwires with positive magnetostriction constant is proposed.
Anomaly and defects characterization by I-V and current deep level transient spectroscopy of Al0.25Ga0.75N/GaN/SiC high electron-mobility transistors
Authors: Saadaoui Salah , Ben Salem Mohamed Mongi , Gassoumi Malek , Maaref Hassen , Gaquière Christophe
Published: April 2012

In this paper, we report static electric drain-source current-voltage measurements for different gate voltages and at different temperatures, performed on Al0.25Ga0.75N/GaN/SiC high electron-mobility transistors (HEMT). The results show the presence of kink and collapse effects. We have demonstrated that these effects are significant in the temperature range varying from 150 to 400 K with a maximum around 300 K. This parasitic effect was correlated with the presence of deep levels in our transistor. Indeed, we have noticed the presence of two electron traps named A1 and A2, and one hole trap named H1; their respective activation energies, which are determined using current deep level transient spectroscopy (CDLTS), are, respectively, 0.56, 0.82, and 0.75 eV. Traps H1 and A1 are shown to be extended defects in the Al0.25Ga0.75N/GaN heterostructure; they are supposed to be the origin of the kink and collapse effects. However, the punctual defect A2 seems to be located either in the free gate-drain surface, in the metal/AlGaN interface, or in the AlGaN/GaN interface.
Electrocaloric effect in low-crystallinity ferroelectric polymers
Authors: Moreira R. L.
Published: April 2012

The role of the sample crystallinity on the electrocaloric effect (ECE) of ferroelectric polymers was investigated in miscible blends of poly(vinylidene fluoride-trifluoroethylene) and poly(methyl methacrylate). Polarization switching measurements gave the electric field required to realize full dipole realignment. Conformational entropy and temperature changes were obtained from the thermal dependence of the dielectric permittivity in the paraelectric phase. The obtained ECE values were relatively high: they reached 18.6 J/kgK and 4.7 K for the pure copolymer and decreased ca. 74% for a 70% crystallinity decreasing. The sample crystallinity appears clearly as a key parameter controlling the ECE in non-oriented ferroelectric polymers.
Microstrip direct current superconducting quantum interference device radio frequency amplifier: Noise data
Authors: Schmidt Bernd , Mück Michael
Published: April 2012

A series of about twenty superconducting quantum interference devices (SQUIDs) has been operated as microstrip-SQUID amplifiers (MSAs) at frequencies ranging from 100 MHz to 2 GHz to study the dependence of their gain and noise temperature on bias current and flux. The measured values were in good agreement with theory. The observed dependence of MSA gain and noise temperature on bias current and flux resembled the static transfer function of the SQUIDs. The gains are relatively insensitive to changes in bias current and bias flux; the noise temperature is strongly dependent on the bias flux.
Low cost and high performance Al nanoparticles for broadband light trapping in Si wafer solar cells
Authors: Zhang Yinan , Ouyang Zi , Stokes Nicholas , Jia Baohua , Shi Zhengrong , Gu Min
Published: April 2012

In this paper low cost and earth abundant Al nanoparticles are simulated and compared with noble metal nanoparticles Ag and Au for plasmonic light trapping in Si wafer solar cells. It has been found tailored Al nanoparticles enable broadband light trapping leading to a 28.7% photon absorption enhancement in Si wafers, which is much larger than that induced by Ag or Au. Once combined with the SiNx anti-reflection coating, Al nanoparticles can produce a 42.5% enhancement, which is 4.3% higher than the standard SiNx due to the increased absorption in both the blue and near-infrared regions.
The effect of sucrose addition on intake of a tropical grass hay by sheep
Authors: de Vega A. , Poppi D. P.
Published: April 2012

Increasing levels of sucrose (15, 30, 45, and 60% of the total dry matter intake, DMI) were added to a Control diet of a tropical grass hay (pangola grass, Digitaria eriantha) to examine the effect on DMI and digestible organic matter intake (DOMI). A pelleted lucerne (Medicago sativa) diet provided a positive Control diet with a higher metabolisable energy intake. There were positive linear and quadratic effects of sucrose addition on DMI and DOMI, reflecting increasing values from Control to 45% sucrose, which then decreased for 60% sucrose. Intake values at 45% sucrose were equivalent to 49% (DMI) and 60% (DOMI) of those shown by animals fed on pelleted lucerne. At the same time there was a decrease in hay intake and neutral detergent fibre digestibility. Rumen concentration of butyric acid increased with sucrose addition. Eating pattern changed with increasing sucrose inclusion in that meals extended over the whole day rather than most food being consumed within 5 h as occurred with the high roughage diet. Intake of sucrose was similar for all diets by 5 h, but by 24 h high sucrose diets had resulted in a higher intake of sucrose. It was suggested that the underlying characteristics of the neutral detergent fibre present in the diet regulate intake by posing a limit, which cannot be overridden.
Using abattoir surveillance and producer surveys to investigate the prevalence and current preventative management of Caseous lymphadenitis in Merino flocks in Australia
Authors: Bush R. D. , Barnett R. , Links I. J. , Windsor P. A.
Published: April 2012

The prevalence of Caseous lymphadenitis (CLA) in Australia was estimated to be 5.2% using 2009 abattoir surveillance data from all States supplied by Animal Health Australia involving 5029 lines comprising 1 339 463 sheep. This is a decrease from the 26% estimated in a similar study in 1995. There was a significant difference (P < 0.001) in CLA prevalence between all states except Tasmania and Victoria (P = 0.75) with prevalences of 12.8 and 12.9%, respectively. Western Australia recorded the lowest prevalence with 1.0%. The average CLA prevalence for New South Wales was 5.3% and within three surveyed Livestock Health and Pest Authority regions (Tablelands, Central North and Central West) was 2.9, 4.9 and 4.4%, respectively. The attitude of the majority of producers surveyed in these three Livestock Health and Pest Authority areas was that CLA was of little or no significance (75%) but were aware of the need for CLA control with ~68% using 6-in-1 vaccine, though only 39.9% as recommended. It appears that the prolonged use of CLA vaccination has been successful in reducing the prevalence of CLA across Australia and particularly in New South Wales. Further improvements in communication of information on preventative management practices associated with lice control, importance of using an approved vaccination program, plus increasing producers’ awareness of the importance of CLA control, are indicated.
Sequential generations of honey bee (Apis mellifera) queens produced using cryopreserved semen
Authors: Hopkins Brandon K. , Herr Charles , Sheppard Walter S.
Published: April 2012

Much of the world’s food production is dependent on honey bees for pollination, and expanding food production will further increase the demand for managed pollination services. Apiculturists outside the native range of the honey bee, in the Americas, Australia and eastern Asia, have used only a few of the 27 described subspecies of honey bees (Apis mellifera) for beekeeping purposes. Within the endemic ranges of a particular subspecies, hybridisation can threaten native subspecies when local beekeepers import and propagate non-native honey bees. For many threatened species, cryopreserved germplasm can provide a resource for the preservation of diversity and recovery of endangered populations. However, although instrumental insemination of queen honey bees is well established, the absence of an effective means to cryopreserve honey bee semen has limited the success of efforts to preserve genetic diversity within the species or to develop repositories of honey bee germplasm for breeding purposes. Herein we report that some queens inseminated with cryopreserved semen were capable of producing a substantial number of fertilised offspring. These diploid female larvae were used to produce two additional sequential generations of new queens, which were then back-crossed to the same stock of frozen semen. Our results demonstrate the ability to produce queens using cryopreserved honey bee spermatozoa and the potential for the establishment of a honey bee genetic repository.
Staying in the middle
Authors: Bischoff Alexander , Kurth Elisabeth , Henley Alix
Published: April 2012

In this age of migration, many societies are characterized by linguistic and cultural diversity. Public institutions, such as health care systems, face the challenge of integrating new arrivals, immigrants, refugees or asylum seekers, into the host society. The purpose of this study was to examine how interpreters see their work within the context of the integration of immigrants into the host society (Switzerland) in general, and into the local health system in particular. We investigated the roles that interpreters working in a Women’s Hospital in Switzerland take on and are aware of in their work. The interpreters described four main roles: word-for-word interpreting, intercultural explanation, building patient–provider relationships, and accompanying immigrant patients. An additional cross-cutting theme emerged: interpreters facilitating the integration of immigration. Only the first of these is generally regarded as their “official” role. The interpreters take on the additional roles as necessary during a consultation, in response to the needs of the patient and the health professionals. Further discussion is needed about whether these additional roles should be recognized and promoted as part of their work since they are important and there is no one else to take them on. Interpreters who take on the additional roles related to integration have the potential to be important actors in health care services whose patient populations that are increasingly linguistically and culturally diverse.
The Public Knowledge Project and Open Journal Systems: open source options for small publishers
Authors: OWEN Brian , STRANACK Kevin
Published: April 2012

This article provides an overview of the Public Knowledge Project (PKP) and its open source software development projects, with a particular focus on Open Journal Systems (OJS), an online journal publishing platform now used by over 11,500 journals around the world. OJS is just one of many examples of software and services that provide new and cost‐effective alternatives, especially for small scholarly societies and commercial publishers. The development of online publishing, open source software, and virtual communities are together opening up new opportunities for scholars, researchers, societies, small publishers, and librarians to reassert their independence and control over the publishing process, and provides a wider range of options than has ever existed before.
Metacognition and reasoning
Authors: Fletcher Logan , Carruthers Peter
Published: April 2012

This article considers the cognitive architecture of human meta-reasoning: that is, metacognition concerning one's own reasoning and decision-making. The view we defend is that meta-reasoning is a cobbled-together skill comprising diverse self-management strategies acquired through individual and cultural learning. These approximate the monitoring-and-control functions of a postulated adaptive
system
for metacognition by recruiting mechanisms that were designed for quite other purposes.
The neural basis of metacognitive ability
Authors: Fleming Stephen M. , Dolan Raymond J.
Published: April 2012

Ability in various cognitive domains is often assessed by measuring task performance, such as the accuracy of a perceptual categorization. A similar analysis can be applied to metacognitive reports about a task to quantify the degree to which an individual is aware of his or her success or failure. Here, we review the psychological and neural underpinnings of metacognitive accuracy, drawing on research in memory and decision-making. These data show that metacognitive accuracy is dissociable from task performance and varies across individuals. Convergent evidence indicates that the function of the rostral and dorsal aspect of the lateral prefrontal cortex (PFC) is important for the accuracy of retrospective judgements of performance. In contrast, prospective judgements of performance may depend upon medial PFC. We close with a discussion of how metacognitive processes relate to concepts of cognitive control, and propose a neural synthesis in which dorsolateral and anterior prefrontal cortical subregions interact with interoceptive cortices (cingulate and insula) to promote accurate judgements of performance.
Treatment with the cancer drugs decitabine and doxorubicin induces human skin keratinocytes to express Oct4 and the OCT4 regulator mir‐145
Authors: CHINNATHAMBI Sathivel , WIECHERT Susan , TOMANEK‐CHALKLEY Ann , WINTER Michael C. , BICKENBACH Jackie R.
Published: April 2012

Previously, we showed that transient transfection with OCT4 not only produced high expression of Oct4 in skin keratinocytes, but also caused a generalized demethylation of keratinocyte DNA. We hypothesized that DNA demethylation alone might allow expression of endogenous OCT4. Here, we report that treatment with the cancer drug decitabine results in generalized DNA demethylation in skin keratinocytes, and by 48 h after treatment, 96% of keratinocytes show expression of the endogenous Oct4 protein and the OCT4 repressor mir‐145. This is true for keratinocytes only, as skin fibroblasts treated similarly show no OCT4 or mir‐145 expression. Decitabine‐treated keratinocytes also show increased mir‐302c and proliferation similar to other Oct4+ cells. Treatment with doxorubicin, another cancer drug, induces expression of mir‐145 only in cells that already express OCT4, suggesting that Oct4 regulates its own repressor. Co‐treatment with decitabine and doxorubicin results first in increased OCT4 and mir‐145, then a decrease in both, suggesting that OCT4 and mir‐145 regulate each other. The novel strategy presented here provides a regulatable system to produce Oct4+ cells for transformation studies and provides a unique method to study the effects of endogenous Oct4 in cancer cells and the surrounding somatic cells.
Randomised clinical trial: sustained response to PPI treatment of symptoms resembling functional dyspepsia and irritable bowel syndrome in patients suffering from an overlap with erosive gastro‐oesophageal reflux disease
Authors: Mönnikes H. , Schwan T. , van Rensburg C. , Straszak A. , Theek C. , Sander P. , Lühmann R.
Published: April 2012

Background

Gastro‐oesophageal reflux disease (GERD), functional dyspepsia (FD) and irritable bowel syndrome (IBS) are highly prevalent gastrointestinal conditions with accumulating evidence of overlap in patients. Despite availability of a vast body of research related to individual disorders, major pharmacological breakthrough in treatment of the overlap condition is still lacking.

Aim

To assess sustainability of GERD healing and whether known beneficial effects of proton pump inhibitor treatment on GERD also extend to symptoms suggestive of FD and IBS.

Methods

A total of 626 patients with reflux oesophagitis were treated with pantoprazole for up to 16 weeks depending on healing of GERD, followed by an observational phase of up to 6 months without treatment. Rates of patients suffering from GERD, FD or IBS were assessed at baseline, and at last visits of treatment and observational phase.

Results

Rates of patients with reflux oesophagitis and concomitantly with reflux symptoms, FD or IBS were each significantly lower after pantoprazole treatment (P < 0.0001). While rates of patients with reflux signs or symptoms increased again during observational phase, rates of FD and IBS were maintained at the low level after cessation of medication (P < 0.0001).

Conclusions

Pantoprazole is efficacious in the treatment of patients suffering from signs and symptoms suggesting an overlap of GERD, FD and/or IBS, providing a sustained response post‐treatment in FD and IBS symptom categories. Mechanisms underlying the beneficial effects of improvement in reflux oesophagitis on symptoms suggestive of FD or IBS still need to be determined.
Meta‐analysis: vasoactive medications for the management of acute variceal bleeds
Authors: Wells M. , Chande N. , Adams P. , Beaton M. , Levstik M. , Boyce E. , Mrkobrada M.
Published: April 2012

Background

Vasoactive medications such as vasopressin, somatostatin and their analogues (terlipressin, vapreotide and octreotide) are commonly used for the treatment of acute variceal bleeding. However, the risks and benefits of these interventions are not well understood.

Aim

To undertake a meta‐analysis of the efficacy of vasoactive medications in patients having acute variceal bleeds.

Methods

Randomised controlled trials (RCTs) of vasopressin, somatostatin and their analogues, administered to patients with acute variceal bleeds were identified based on systematic searches of nine electronic databases and multiple sources of grey literature.

Results

The search identified 3011 citations, and 30 trials with a total of 3111 patients met eligibility criteria. The use of vasoactive agents was associated with a significantly lower risk of 7‐day mortality (RR 0.74; 95% CI 0.57–0.95; P = 0.02; I2 = 0%; moderate quality of evidence), and a significant improvement in haemostasis (RR 1.21, 95% CI 1.13–1.30; P < 0.001; I2 = 28%; very low quality of evidence), lower transfusion requirements (pooled mean difference −0.70 units of blood transfused, 95% CI −1.01 to −0.38; P < 0.001; I2 = 82%; moderate quality of evidence), and a shorter duration of hospitalisation (pooled mean difference −0.71 days; 95% CI −1.23 to −0.19; P = 0.007; I2 = 0%; low quality of evidence). Studies comparing different vasoactive agents did not show a difference in efficacy, although the quality of evidence was very low.

Conclusions

The use of vasoactive agents was associated with a significantly lower risk of acute all‐cause mortality and transfusion requirements, and improved control of bleeding and shorter hospital stay. Studies comparing different vasoactive medications failed to demonstrate a difference in efficacy.
Characterization of α‐smooth muscle actin positive cells during multilineage differentiation of dental pulp stem cells
Authors: Zhao X. , Gong P. , Lin Y. , Wang J. , Yang X. , Cai X.
Published: April 2012

Objectives

Dental pulp tissue contains stem cells that can differentiate into multiple lineages under specific culture conditions; the origin of these dental pulp stem cells, however, is still unknown.

Materials and methods

Here we have utilized an α‐SMA‐GFP transgenic mouse model to characterize expression of a‐smooth muscle actin (SMA)‐GFP in subpassages of pulp‐tissue‐derived dental pulp cells, as perivascular cells express α‐SMA.

Results

During subculturing, percentages of cells expressing a‐SMA increased signi?cantly from passage 1 to 3. α‐SMA‐GFP‐positive cells expanded faster than α‐SMA‐GFP‐negative cells. The dental pulp cells at passage 3 were induced towards osteogenic, adipogenic or chondrogenic differentiation. All three differentiated cell lines expressed high levels of α‐SMA (mineralized nodules, lipid droplets and chondrocyte pellets). GFP expression colocalized with differentiated osteoblasts, adipocytes and chondrocytes. Co‐culturing the α‐SMA‐GFP‐positive cells with human endothelial cells promoted formation of tube‐like structures and robust vascular networks, in 3‐D culture.

Conclusions

Taken together, the a‐SMA‐GFP‐positive cells were shown to have multilieange differentiation ability and to promote vascularization in a co‐culture system with endothelial cells.
Departure behaviour of juvenile southern bluefin tuna (Thunnus maccoyii) from southern Western Australia temperate waters in relation to the Leeuwin Current
Authors: FUJIOKA KO , HOBDAY ALISTAIR J. , KAWABE RYO , MIYASHITA KAZUSHI , TAKAO YOSHIMI , SAKAI OSAMU , ITOH TOMOYUKI
Published: April 2012

The arrival of the warm tropical Leeuwin Current (LC) into southern Western Australia (SWA) may influence the movement timing and foraging habitat of juvenile southern bluefin tuna (SBT). Seasonal and interannual changes in the strength of the LC lead to thermal differences and potential changes in food availability between tropical and temperate waters in SWA. This phenomenon could influence the habitat utilization of SBT in these summer grounds. Movement characteristics determined from SBT tagged with acoustic transmitters (N = 244) using cross‐shelf lines of automated receivers for three summer‐autumn seasons (2004/2005, 2005/2006, 2006/2007) in SWA revealed interannual variability. Each year, the eastward movements of tagged fish increased as temperatures increased, and fish left the region when temperatures exceeded 20.0°C, a temperature indicative of the leading edge of the LC in SWA waters. Interannual fluctuations in the timing of movements were detected. When the LC was narrow and restricted to the shelf edge in 2004/2005, the distribution of SBT in shelf waters did not change before or after LC intrusion. In contrast, long distance eastward movements frequently occurred when the LC intrusion was spread wide over the continental shelf in 2005/2006 and 2006/2007. This suggests that, off SWA, juvenile SBT move quickly out of local foraging habitats defined by cool sub‐tropical temperate waters ahead of the tropical LC intrusion, despite these waters not being physiologically limiting. These results suggest that the behavioural response of SBT may be related to changes in prey availability as a result of changes in oceanographic conditions.
Coupling hydrodynamic and individual‐based models to simulate long‐term larval supply to coastal nursery areas
Authors: ROCHETTE SEBASTIEN , HURET MARTIN , RIVOT ETIENNE , LE PAPE OLIVIER
Published: April 2012

For many marine fish species, recruitment is strongly related to larval survival and dispersal to nursery areas. Simulating larval drift should help assessing the sensitivity of recruitment variability to early life history. An individual‐based model (IBM) coupled to a hydrodynamic model was used to simulate common sole larval supply from spawning areas to coastal and estuarine nursery grounds at the population scale in the eastern Channel on a 14‐yr time series, from 1991 to 2004. The IBM allowed each particle released to be transported by currents from the hydrodynamic model, to grow with temperature, to migrate vertically giving stage development, and possibly to die according to drift duration, representing the life history from spawning to metamorphosis. Despite sensitivity to the larval mortality rate, the model provided realistic simulations of cohort decline and spatio‐temporal variability of larval supply. The model outputs were analysed to explore the effects of hydrodynamics and life history on the interannual variability of settled sole larvae in coastal nurseries. Different hypotheses of the spawning spatial distribution were also tested, comparing homogeneous egg distribution to observation and potential larval survival (PLS) maps. The sensitivity analyses demonstrated that larval supply is more sensitive to the life history along larval drift than to the phenology and volume of spawning, providing explanations for the lack of significant stock–recruitment relationship. Nevertheless, larval supply is sensitive to spawning distribution. Results also suggested a very low connectivity between supposed different sub‐populations in the eastern Channel.
Model‐based assessment of local‐scale fish larval connectivity in a network of marine protected areas
Authors: BASTERRETXEA GOTZON , JORDI ANTONI , CATALÁN IGNACIO A. , SABATÉS ANA
Published: April 2012

We assessed by numerical modeling the coastal fish larval dispersion along the southern coast of Mallorca (Balearic Islands, NW Mediterranean) with the objective of determining the factors that contribute to successful recruitment. We assumed that fish larvae dispersal is mainly regulated by physical transport. Currents are mainly wind driven in this area; therefore, changes in wind forcing have a first‐order impact on larval transport. The synoptic wind patterns were systematically analyzed based on self‐organizing map analysis. The wind fields were clustered using a neural network pattern recognition approach into two modes, producing opposite along‐shelf flow. The seasonal changes between spring and summer in the dominance of either mode modulate the along‐shelf circulation, producing flow shifts under some circumstances. This variability in the wind regime was consistent throughout the 10 years analyzed (2000–2009). Using the Princeton Ocean Model (POM) and a particle‐tracking algorithm, we analyzed the effect of wind‐forced currents in the connectivity among near‐shore habitats. We show that, at the spatial scale considered, the coastal morphology and stochastic wind forcing favor local recruitment (mean of 30% self‐recruitment). Maximum transport distances of 20–30 km were typically associated with particles left to drift for 21 days. The implications for the performance of the four marine protected areas near SW Mallorca Island are discussed. Our results suggest that, although wind episodes determine the fate of short‐time spawning events, on a seasonal basis, regular larval supply to coastal zones is ensured by wind stochasticity.
Noncalcifying larvae in a changing ocean: warming, not acidification/hypercapnia, is the dominant stressor on development of the sea star Meridiastra calcar
Authors: Nguyen Hong D. , Doo Steve S. , Soars Natalie A. , Byrne Maria
Published: April 2012

Climate change driven ocean warming and acidification is potentially detrimental to the sensitive planktonic life stages of benthic marine invertebrates. Research has focused on the effects of acidification on calcifying larvae with a paucity of data on species with alternate developmental strategies and on the interactive effects of warming and acidification. To determine the impact of climate change on a conspicuous component of the intertidal fauna of southeast Australia, the development of the noncalcifying lecithotrophic larvae of the sea star Meridiastra calcar was investigated in the setting of predicted ocean warming (+2 to 4 °C) and acidification (−0.4 to 0.6 pH units) for 2100 and beyond in all combinations of stressors. Temperature and pH were monitored in the habitat of M. calcar to place experiments in context with current environmental conditions. There was no effect of temperature or pH on cleavage stage embryos but later development (gastrula‐larvae) was negatively effected by a +2 to 4 °C warming and there was a negative effect of −0.6 pH units on embryos reaching the hatched gastrula stage. Mortality and abnormal development in larvae increased significantly even with +2 °C warming and larval growth was impaired at +4 °C. For the range of temperature and pH conditions tested, there were no interactive effects of stressors across all stages monitored. For M. calcar, warming not acidification was the dominant stressor. A regression model incorporating data from this study and projected increasing SST for the region suggests an increase in larval mortality to 70% for M. calcar by 2100 in the absence of acclimation and adaptation. The broad distribution of this species in eastern Australia encompassing subtropical to cold temperate thermal regimes provides the possibility that local M. calcar populations may be sustained in a warming world through poleward migration of thermotolerant propagules, facilitated by the strong southward flow of the East Australian Current.
Comparison of visual and automated assessment of HER2 status and their impact on outcome in primary operable invasive ductal breast cancer
Authors: Mohammed Zahra M A , Going James J , McMillan Donald C , Orange Clare , Mallon Elizabeth , Doughty Julie C , Edwards Joanne
Published: April 2012

Mohammed Z M A, Going J J, McMillan D C, Orange C, Mallon E, Doughty J C & Edwards J  (2012) Histopathology 61, 675–684

Comparison of visual and automated assessment of HER2 status and their impact on outcome in primary operable invasive ductal breast cancer

Aims:  To compare visual and computerized image analysis of HER2 immunohistochemistry (IHC) with fluorescence in‐situ hybridization (FISH) for HER2 status, and to examine the relationships with outcome in patients with primary operable invasive ductal breast cancer.

Methods and results:  Tissue microarrays for 431 breast cancer patients were used to compare different approaches to the assessment of HER2 status. The cores were scored visually and with the Slidepath Tissue IA system, using the NICE‐approved scoring system for the HercepTest, as well as by FISH. The agreement between visual and image analysis of HER2 IHC was excellent [interclass correlation coefficient (ICCC) = 0.95, rs = 0.90, r = 0.91, k = 0.81, and P < 0.001]. The agreement of HER2 FISH with visual and image analysis of HER2 IHC was also excellent (ICCC = 0.95 and ICCC = 0.92, respectively). Univariate survival analysis showed equivalent associations of visual and image analysis of HER2 and HER2 FISH with both recurrence‐free survival (all P < 0.01) and cancer‐specific survival (all P < 0.05) in patients with invasive ductal breast cancer.

Conclusions:  Computerized image analysis of HER2 IHC gives results comparable to those obtained with visual assessment, with possible advantages in diagnostic pathology.
Primary cardiac sarcomas may develop from resident or bone marrow‐derived mesenchymal stem cells: use of immunohistochemistry including CD44 and octamer binding protein 3/4
Authors: Hegyi Laszlo , Thway Khin , Fisher Cyril , Sheppard Mary N
Published: April 2012

Hegyi L, Thway K, Fisher C & Sheppard M N  (2012) Histopathology 61, 966–973

Primary cardiac sarcomas may develop from resident or bone marrow‐derived mesenchymal stem cells: use of immunohistochemistry including CD44 and octamer binding protein 3/4

Aims:  To provide evidence that cardiac sarcomas ‘not otherwise specified’ express markers that might indicate their cellular origin or identify any lines of differentiation.

Methods and results:  We reviewed all 11 cases of primary undifferentiated cardiac sarcomas found in the archives of the Royal Marsden and Royal Brompton Hospitals, London, UK during the period 2000–2009. Five cases with appropriate consent and archived material were investigated using immunohistochemistry. We found that the spindle, pleomorphic or occasionally epithelioid cell sarcomas showed no lineage‐specific differentiation other than partial myofibroblastic or ‘myoid’ differentiation (all cases). All tumours showed some degree of cytoplasmic positivity for the mesenchymal stem cell marker CD44. In contrast, no nuclear octamer binding protein 3/4 (Oct3/4) expression was seen in any of the tumours, although very patchy cytoplasmic positivity was seen in some tumours.

Conclusions:  The cytoplasmic positivity for CD44 and the absence of nuclear Oct3/4 suggest that the cells of these sarcomas may represent ‘daughter’ stem cells that no longer have the capacity for tumour initiation, but have subsequently developed new lines of partial differentiation. Primary cardiac sarcomas may arise from mesenchymal stem cells with the ability to generate tumours with multilineage differentiation.
Impairment of Fear‐Conditioning Responses and Changes of Brain Neurotrophic Factors in Diet‐Induced Obese Mice
Authors: Yamada‐Goto N. , Katsuura G. , Ochi Y. , Ebihara K. , Kusakabe T. , Hosoda K. , Nakao K.
Published: April 2012

Recent epidemiological studies demonstrate that obesity is related to a high incidence of cognitive impairment. In the present study, cognitive behaviours in diet‐induced obese (DIO) mice fed 60% high‐fat diet for 16 weeks were compared with those in mice fed a control diet (CD) in fear‐conditioning tests including both contextual and cued elements that preferentially depend on the hippocampus and amygdala, respectively. Furthermore, brain‐derived neurotrophic factor (BDNF) and neurotrophin‐3 (NT‐3) content in the brain areas was examined in both CD and DIO mice. In fear‐conditioning tests, the freezing percentages of both contextual fear and cued fear responses in DIO mice were significantly lower than in CD mice. BDNF content in the cerebral cortex and hippocampus of DIO mice was significantly lower than that in CD mice. Its receptor, full‐length TrkB, in the amygdala of DIO mice was significantly decreased compared to that in CD mice, although not in the cerebral cortex, hippocampus and hypothalamus. By contrast, NT‐3 content in the hippocampus, amygdala and hypothalamus of DIO mice was significantly higher than that in CD mice. Its receptor, full‐length TrkC, was not significantly different between CD and DIO mice. The present study demonstrates that DIO mice show impairment of both hippocampus‐dependent contextual and amygdala‐dependent cued responses in the fear‐conditioning tests, as well as an imbalance in the interaction between the BDNF and NT‐3 systems in the cerebral cortex, hippocampus and amygdala related to cognition and fear.
Expression of Aromatase and Two Isozymes of 5α‐Reductase in the Developing Green Anole Forebrain
Authors: Cohen R. E. , Wade J.
Published: April 2012

Neural steroids, as well as the enzymes that produce these hormones, are important for sexual differentiation of the brain during development. Aromatase converts testosterone into oestradiol. 5α‐reductase converts testosterone to 5α‐dihydrotestosterone and occurs in two isozymes: type 1 (5αR1) and type 2 (5αR2). Each of these enzymes is present in the developing brain in many species, although no work has been carried out examining the expression of all three enzymes in non‐avian reptiles with genetic sex determination. In the present study, we evaluated mRNA expression of neural aromatase, 5αR1 and 5αR2, on the day of hatching and at day 50 in one such lizard, the green anole. We describe the distribution of these enzymes throughout the brain and the quantification of mRNA expression in three regions that control adult sexual behaviours: the preoptic area (POA) and ventromedial amygdala (AMY), which are involved in male displays, as well as the ventromedial hypothalamus, which regulates female receptivity. Younger animals had a greater number (POA) and density (AMY) of 5αR1 mRNA expressing cells. We detected no effects of sex or age on aromatase or 5αR2. In comparison with data from adults, the present results support the idea that the green anole forebrain has not completely differentiated by 50 days after hatching and that 5αR1 may play a role in the early development of regions important for masculine function.
Two‐body wear of occlusal splint materials
Authors: KURT H. , ERDELT K.‐J. , CILINGIR A. , MUMCU E. , SÜLÜN T. , TUNCER N. , GERNET W. , BEUER F.
Published: April 2012

Summary  This study investigates the wear resistance of four different types of occlusal splint materials based on two‐body wear simulations under wet and dry conditions. Twenty specimens of each splint material (Dentalon Plus, Orthoplast, Biocryl C, and Eclipse), each with a diameter of 16 mm and a thickness of 3 mm, were tested, half under wet and half under dry conditions. Each wear test was performed using a device called chewing simulator CS‐4 (n = 10; test load: 50 N; number of cycles: 10 000, 20 000, and 30 000; continuous rinsing with 30 °C water for wet conditions); the antagonists were simulated using steel balls. Wear was determined using a 3D laser scanner and a surface analysis program. To detect significant statistical differences, wear data after 10 000; 20 000; and 30 000 cycles were compared using the Kruskal–Wallis test and the Mann–Whitney U‐test. The level of significance was set at 5%. Significant differences were found between the groups of different materials tested under wet conditions (P < 0·05), whereas no differences between them were found under dry conditions (P > 0·05). No significant difference was found between the wet and dry conditions for all materials and cycles (P > 0·05). For groups of different materials tested under wet conditions, the degree of volume loss generated in the Chewing Simulator CS‐4 was found to differ significantly for different numbers of cycles. The presence of water had no effect on the volume loss in the different material groups that were tested.
Estimating the prevalence of infections in vector populations using pools of samples
Authors: SPEYBROECK N. , WILLIAMS C. J. , LAFIA K. B. , DEVLEESSCHAUWER B. , BERKVENS D.
Published: April 2012

Several statistical methods have been proposed for estimating the infection prevalence based on pooled samples, but these methods generally presume the application of perfect diagnostic tests, which in practice do not exist. To optimize prevalence estimation based on pooled samples, currently available and new statistical models were described and compared. Three groups were tested: (a) Frequentist models, (b) Monte Carlo Markov‐Chain (MCMC) Bayesian models, and (c) Exact Bayesian Computation (EBC) models. Simulated data allowed the comparison of the models, including testing the performance under complex situations such as imperfect tests with a sensitivity varying according to the pool weight. In addition, all models were applied to data derived from the literature, to demonstrate the influence of the model on real‐prevalence estimates. All models were implemented in the freely available R and OpenBUGS software and are presented in Appendix S1.

Bayesian models can flexibly take into account the imperfect sensitivity and specificity of the diagnostic test (as well as the influence of pool‐related or external variables) and are therefore the method of choice for calculating population prevalence based on pooled samples. However, when using such complex models, very precise information on test characteristics is needed, which may in general not be available.
Cactin is essential for G1 progression in Toxoplasma gondii
Authors: Szatanek Tomasz , Anderson‐White Brooke R. , Faugno‐Fusci David M. , White Michael , Saeij Jeroen P. J. , Gubbels Marc‐Jan
Published: April 2012

Toxoplasma gondii is an obligate intracellular protozoan parasite whose rapid lytic replication cycles define its pathogenicity. We identified a temperature‐sensitive growth mutant, FV‐P6, which irreversibly arrests before the middle of the G1 stage of the tachyzoite cell cycle. This arrest is caused by a point mutation in a gene conserved across eukaryotes, Cactin, whose product localizes to the nucleus. To elucidate the role of TgCactin we performed genome‐wide expression profiling. Besides the expected G1 expression profile, many genes associated with the extracellular state as well as with the bradyzoite cyst stage were identified. Consistent with these profiles were the expression of AP2 transcription factors typically associated with extracellular and bradyzoite stage parasites. This suggests a role for TgCactin in control of gene expression. As TgCactin does not contain any functionally defined domains we reasoned TgCactin exerts its function through interactions with other proteins. In support of this model we demonstrated that TgCactin is present in a protein complex and can oligomerize. Taken together, these results suggest that TgCactin acts as a pivotal protein potentially regulating gene expression at several transition points in parasite development.
Mast Cell Activation by Conidia of Sporothrix schenckii: Role in the Severity of Infection
Authors: Romo‐Lozano Y. , Hernández‐Hernández F. , Salinas E.
Published: April 2012

Mast cells are abundant in the skin and other peripheral tissues, where they are one of the first immune cells to make contact with invading pathogens. As a result of pathogen recognition, mast cells can be activated and release different preformed and de novo‐synthesized mediators. Sporothrix schenckii is the fungus that causes sporotrichosis, a worldwide‐distributed subcutaneous mycosis considered as an important emerging health problem. It remains unknown whether or not mast cells are activated by S. schenckii. Here, we investigated the in vitro response of mast cells to conidia of S. schenckii and their in vivo involvement in sporotrichosis. Mast cells became activated after interaction with conidia, releasing early response cytokines as TNF‐α and IL‐6. Although histamine release was not significantly stimulated by S. schenckii, we determined that conidia potentiate histamine secretion induced by compound 48/80. Furthermore, functional depletion of peritoneal mast cells before S. schenckii infection significantly reduced the severity of cutaneous lesions of the sporotrichosis. These data demonstrate that mast cells are important contributors in the host response to S. schenckii infection, suggesting a role of these cells in the progress of clinical manifestations in sporotrichosis.