bluuebunny/crossref_metadata_2025 huggingface dataset:
Controls on in situ oxygen and dissolved inorganic carbon dynamics in peats of a temperate fen
Authors: Estop‐Aragonés Cristian , Knorr Klaus‐Holger , Blodau Christian
Published: February 2012

Changes in hydrological conditions are expected and may alter carbon cycling in peatlands. Peat aeration with water table change has not commonly been investigated, and the water table is often assumed to constitute the oxic‐anoxic boundary in peat. We analyzed temperature, moisture, oxygen (O2), and carbon dioxide (CO2) concentrations in profiles of a temperate fen during two seasons. A drying‐rewetting cycle and flooding were induced and compared to controls. The response of moisture and water table position varied greatly and was related to gradients of peat compaction and ash content. Background drought raised air‐filled porosity (AFP) to a maximum of 15%–38% in shallow peat and experimental drought up to 50%. Decline in water table and soil moisture broadly led to O2 penetration and CO2 degassing, and rewetting and flooding led to anoxic conditions and CO2 accumulation in peat pore water. In dense peat with ≥20% ash content the unsaturated zone remained partly low in oxygen, however, and up to 5% AFP and 20 cm above water table O2 concentrations frequently remained below 50 μmol L−1. Moderately intense and short drying did not induce substantial oxygen penetration in the compacted soil profiles. The likelihood of the presence of oxygen in the peat was predicted by logistic regression using water table and ash content or bulk density as predictors (p < 0.0005). The model is potentially useful for predicting the position of the redoxcline in peat deposits and may assist in improving statistical models of trace gas emission from peatlands.
Skinner's Walden Two: An Anticipation of Positive Psychology?
Authors: Adams Nelson
Published: February 2012

B. F. Skinner's, 1948 novel, Walden Two has some remarkable parallels to the growing Positive Psychology movement which emphasizes the promotion of subjective well being, the development of character strengths, and establishing positive institutions. Despite Skinner's reputation for neglecting emotion and subjective well being, one finds the opposite in the Walden Two community. Misunderstandings of Skinner's views have obscured the common themes between his ideas and Positive Psychology including positive use of leisure, value of positive emotions, and seeking happiness through engagement or gratification rather than through pleasure. Moreover, at Walden Two, the community develops Positive Psychology's character strengths such as creativity, persistence, humility, love, fairness, and communal gratitude. Particularly memorable was the shaping of self-regulation. The consequences of comparing Walden Two and Positive Psychology may be to shed some of the myths about contemporary behaviorism and Skinner's ideas, and to remind workers in Positive Psychology of the power of the empirically documented methods for building the automaticity of behavioral skills which may underlie character strengths advocated by Positive Psychology. Finally, this paper suggests the need for finding common ground in current psychology rather than emphasizing divisions.
Applying Psychometric Theory and Research to Developing a Continuously Distributed Approach to Making Research Funding Decisions
Authors: De Los Reyes Andres , Wang Mo
Published: February 2012

Scientists and funding agencies have long struggled with identifying optimal methods for allocating scarce research dollars to pools of research funding proposals. Much of the research has focused on the unreliability of the subjective peer review ratings used to estimate the scholarly merit of funding proposals. Yet, psychologists are uniquely positioned to aid in improving the validity of the funding decisions based on subjective peer review evaluations. Importantly, no federal funding agency currently implements a decision-making method that goes beyond a traditional dichotomous system for allocating support (i.e., “fund” vs. “not fund” a proposal). However, a robust line of psychometric research indicates the superiority of continuous, relative to dichotomous, rating systems for reliably and validly estimating the kinds of constructs of interest in peer review evaluations (i.e., domains relevant to estimating the scholarly merit of research proposals). In this paper, we illustrate how applying psychometric research and theory informs the development of a continuously distributed approach to making research funding decisions. This approach allocates a specific degree of support to proposals, commensurate with the continuously distributed peer review ratings used at major funding agencies to estimate the scholarly merit of proposals. Importantly, we illustrate a hypothetical use of the continuously distributed funding approach that—relative to a dichotomous funding approach and using the same amount of funding resources—allocates funding dollars to 260% more funding proposals. We also discuss the strengths and limitations of a continuously distributed funding approach, as well as its implications for scientists and funding agencies.
Neural Information Processing: between synchrony and chaos
Authors: Rossello Josep , Canals Vincent , Morro Antoni
Published: February 2012

The brain is characterized by performing many different processing tasks ranging from elaborate processes such as pattern recognition, memory or decision-making to more simple functionalities such as linear filtering in image processing. Understanding the mechanisms by which the brain is able to produce such a different range of cortical operations remains a fundamental problem in neuroscience. Some recent empirical and theoretical results support the notion that the brain is naturally poised between ordered and chaotic states. As the largest number of metastable states exists at a point near the transition, the brain therefore has access to a larger repertoire of behaviours. Consequently, it is of high interest to know which type of processing can be associated with both ordered and disordered states. Here we show an explanation of which processes are related to chaotic and synchronized states based on the study of in-silico implementation of biologically plausible neural systems. The measurements obtained reveal that synchronized cells (that can be understood as ordered states of the brain) are related to non-linear computations, while uncorrelated neural ensembles are excellent information transmission systems that are able to implement linear transformations (as the realization of convolution products) and to parallelize neural processes. From these results we propose a plausible meaning for Hebbian and non-Hebbian learning rules as those biophysical mechanisms by which the brain creates ordered or chaotic ensembles depending on the desired functionality. The measurements that we obtain from the hardware implementation of different neural systems endorse the fact that the brain is working with two different states, ordered and chaotic, with complementary functionalities that imply non-linear processing (synchronized states) and information transmission and convolution (chaotic states).
The oligomer plasticity of the small heat-shock protein Lo18 from Oenococcus oeni influences its role in both membrane stabilization and protein protection
Authors: Maitre Magali , Weidmann Stéphanie , Rieu Aurélie , Fenel Daphna , Schoehn Guy , Ebel Christine , Coves Jacques , Guzzo Jean
Published: February 2012

The ability of the small Hsp (heat-shock protein) Lo18 from Oenococcus oeni to modulate the membrane fluidity of liposomes or to reduce the thermal aggregation of proteins was studied as a function of the pH in the range 5–9. We have determined by size-exclusion chromatography and analytical ultracentrifugation that Lo18 assembles essentially as a 16-mer at acidic pH. Its quaternary structure evolves to a mixture of lower molecular mass oligomers probably in dynamic equilibrium when the pH increases. The best Lo18 activities are observed at pH 7 when the particle distribution contains a major proportion of dodecamers. At basic pH, particles corresponding to a dimer prevail and are thought to be the building blocks leading to oligomerization of Lo18. At acidic pH, the dimers are organized in a double-ring of stacked octamers to form the 16-mer as shown by the low-resolution structure determined by electron microscopy. Experiments performed with a modified protein (A123S) shown to preferentially form dimers confirm these results. The α-crystallin domain of Methanococcus jannaschii Hsp16.5, taken as a model of the Lo18 counterpart, fits with the electron microscopy envelope of Lo18.
Direct release of synthetic antiferromagnetic nanoparticles fabricated by defect-free thermal imprinting
Authors: Zhang Wei , Krishnan Kannan M.
Published: February 2012

We report an improved process, using a defect-free thermal imprinting process that directly releases homogeneously patterned lithographic nanoparticles from a large-area wafer to water. Our method has a substantially larger yield and avoids all the pitfalls that are associated with the sacrificial layers in the traditional imprinting methods. By using an ethylene tetrafluoroethylene mold and a bi-layer resist lift-off, defect-free imprints were achieved in areas larger than 1 × 1 cm2. Illustrating the effectiveness of this method, high-quality planar Fe/Ta multi-layered magnetic nanoparticles, 300 nm in diameter, were deposited by ion-beam sputtering and their basic magnetic properties are characterized. These particles prepared by direct release with tunable magnetic properties and good engineering possibilities are ideal for a wide range of applications, including those specifically for biomedicine.
Effect of the number of interfaces on the magnetic properties of [SnO2/Cu-Zn ferrite] multilayer
Authors: Saipriya S. , Kurian Joji , Singh R.
Published: February 2012

The [SnO2/Cu-Zn ferrite (CZF)]n (n = 5, 10, 15, and 20) multilayer (ML) were deposited by rf-magnetron sputtering to study their magnetic properties. The magnetization and ferromagnetic resonance (FMR) measurements were undertaken to understand the effect of interfaces on the magnetic properties of these ML. FMR signal line shape changes from asymmetric to symmetric as n increases. The FMR signal peak to peak intensity, FMR linewidth, effective and saturation magnetization and coercivity exhibit oscillations as a function of n. In the parallel configuration the resonance field increases with increase in n, presumably due to the decrease in the active layer to dead layer thickness ratio. The interlayer coupling is strong in the ML with n = 5 leading to the formation of spin waves. The ML interlayer coupling and anisotropy decreases with increasing n. The oscillatory behavior of the magnetic properties can be ascribed to the nonmonotonic variations in the structure and the geometry of the interfaces.
Correlation between magnetic ordering and electric polarization in YMn1−xFexO3 nanocrystalline materials
Authors: Han Tai-Chun , Wu Pei-Jung , Shih Yi-Lun
Published: February 2012

We have synthesized a series of pure hexagonal YMn1−xFexO3 (0 ≤ x ≤ 0.2) nanocrystalline materials by a modified Pechini method and study the effect of substituting Fe for Mn on the antiferromagnetic (AFM) phase transition in YMnO3 nanocrystalline materials using magnetic and dielectric measurements. The magnetic characterization indicates that with increasing Fe-content, up to 0.2, the AFM transition temperature increases from 60 to 72 K. Variable temperature dielectric measurements show an anomaly in the dielectric constant at temperatures close to the AFM ordering temperature for all of the compositions. A corresponding shift of the peak-positions of the dielectric anomaly and magnetic ordering indicates a unique correlation between the magnetic ordering and the electric polarization. The enhancement of the multiferroic ordering temperature in YMn1−xFexO3 nanocrystalline materials is explained on the basis of an increase in the covalence of the Mn/Fe-O-Mn/Fe bonds with iron doping.
Anomalous low-temperature magnetic and magnetotransport properties in Ru-deficient SrRuO3
Authors: Sow Chanchal , Samal D. , Anil Kumar P. S.
Published: February 2012

SrRuO3 is a well-known itinerant ferromagnet with many intriguing characteristics. The Ru deficiency in this system is believed to play a pivotal role in influencing many of its magnetic and transport properties. The present study involves the magnetic and transport properties of the Ru-deficient SrRu0.93O3 sample to gain more insight into the unusual low-temperature behavior. The ac susceptibility study reveals a sharp ferromagnetic transition at 150 K followed by a hump at Th ∼ 50 K, which has anomalous frequency dependence. Besides, the Th shifts to lower temperatures with an increase in the superposed dc-biasing field and adheres to H2 dependence, in accordance with the Gabay and Toulouse line for the Heisenberg spin glass systems. We also observe a pronounced memory effect toward the low-temperature side, signifying the characteristic of glassy behavior. The temperature-dependent magnetoresistance indicates the signature of an additional ordering toward the low-temperature side. All of the interesting findings combined unveil the existence of low-temperature cryptic magnetic phase in SrRu0.93O3.
Multiferroic response of nanocrystalline lithium niobate
Authors: Díaz-Moreno Carlos , Farias Rurik , Hurtado-Macias Abel , Elizalde-Galindo Jose , Hernandez-Paz Juan
Published: February 2012

In this research work the multiferroic nature of nanocrystalline lithium niobate (NLN) was investigated. The NLN samples were prepared by mechanochemical alloying followed by calcination; after that, the samples were annealed in Ar-5% H atmosphere in order to generate oxygen vacancies in the surface of the nanoparticles. X-ray diffraction (XRD) spectrum showed the formation of a single crystalline phase of LN with an average size of 25 nm. This was confirmed by high-resolution transmission electron microscopy (HRTEM). Ferroelectric hysteresis loop measurements showed a maximum polarization of Ps = 0.21 μC/mm2, remnant polarization Pr = 0.11 μC/mm2 and coercive field Ec = 5.1 kV/cm. Ferromagnetic measurements showed a magnetic remanence of Mr = 0.35 × 10−3 emu/g and a coercive field of HC = 0.75 kOe. Thus, confirming the multiferroic nature of nanometer-scale particles of LN.
Low temperature magnetic force microscope study of magnetization reversal in patterned nanoislands of SrRuO3
Authors: Landau Livnat , Reiner James W. , Klein Lior
Published: February 2012

SrRuO 3 is an itinerant ferromagnet (Tc∼150K) characterized by large uniaxial magnetocrystalline anisotropy (K1∼7.7×106erg/cm3) and relatively low saturation magnetization (Ms=213emu/cm3) - properties which make SrRuO3 an extremely hard magnetic material. We have patterned arrays of rectangular nanoislands of a high quality epitaxial film of SrRuO3 with sides ranging between 50 and 500 nm, and studied their magnetization reversal at 4 K using a low temperature magnetic force microscope. We find that the nucleation field for many of the nanoislands is very close to that expected by the Stoner-Wohlfarth model (∼3.8T) and from nanoislands which exhibit partial reversals we can determine an upper bound for the nucleation volume on the order of 100×100×10nm3. We also find that domain wall pinning in the nanoislands is extremely high and in some cases the depinning field exceeds ∼3T.
Simulation on initial growth stages of graphene on Pt (111) surface
Authors: Guo J. Y. , Xu C. X. , Sheng F. Y. , Shi Z. L. , Dai J. , Li Z. H. , Hu X.
Published: February 2012

Epitaxial growth process and morphology evolution in the initial growth stages of graphene on Pt (111) surface have been studied by means of canonical Monte Carlo simulation. It is found that the nucleation, carbon chains, carbon rings, and then graphene domain are formed orderly in the early growth stages during the annealing process. The dynamic processes of the morphology evolution are visualized through the simulation. The formed structures of graphene are investigated quantitatively by pair distribution function, atomic intervals, and the bend angles among the three contiguous carbon atoms. The lattice mismatch between graphene and the Pt (111) surface is accommodated by the main structure of hcp-fcc. These simulation results are consistent with experimental observations and may give further insights to the epitaxial growth of graphene in the atomic scale.
In-situ x-ray characterization of wurtzite formation in GaAs nanowires
Authors: Krogstrup Peter , Hannibal Madsen Morten , Hu Wen , Kozu Miwa , Nakata Yuka , Nygård Jesper , Takahasi Masamitu , Feidenhans’l Robert
Published: February 2012

In-situ monitoring of the crystal structure formation during Ga-assisted GaAs nanowire growth on Si(111) substrates has been performed in a combined molecular beam epitaxy growth and x-ray characterization experiment. Under Ga rich conditions, we show that an increase in the V/III ratio increases the formation rate of the wurtzite structure. Moreover, the response time for changes in the structural phase formation to changes in the beam fluxes is observed to be much longer than predicted time scales of adatom kinetics and liquid diffusion. This suggests that the morphology of the growth interface plays the key role for the relative growth structure formation rates.
Detecting optically synthesized quasi-monochromatic sub-terahertz phonon wavepackets by ultrafast x-ray diffraction
Authors: Herzog M. , Bojahr A. , Goldshteyn J. , Leitenberger W. , Vrejoiu I. , Khakhulin D. , Wulff M. , Shayduk R. , Gaal P. , Bargheer M.
Published: February 2012

We excite an epitaxial SrRuO3 thin film transducer by a pulse train of ultrashort laser pulses, launching coherent sound waves into the underlying SrTiO3 substrate. Synchrotron-based x-ray diffraction (XRD) data exhibiting separated sidebands to the substrate peak evidence the excitation of a quasi-monochromatic phonon wavepacket with sub-THz central frequency. The frequency and bandwidth of this sound pulse can be controlled by the optical pulse train. We compare the experimental data to combined lattice dynamics and dynamical XRD simulations to verify the coherent phonon dynamics. In addition, we observe a lifetime of 130 ps of such sub-THz phonons in accordance with the theory.
Influence of a depletion layer on localized surface waves in doped semiconductor nanostructures
Authors: Vassant S. , Pardo F. , Bouchon P. , Haïdar R. , Marquier F. , Greffet J. J. , Pelouard J. L.
Published: February 2012

We report THz polarized reflectivity measurements on a doped GaAs grating made of thin walls with subwavelength dimensions and periodicity. A clear dip appears in the TM-polarized reflectivity spectrum, due to the excitation of a localized surface plasmon-phonon mode along the grating walls. The theoretical model used to describe the electromagnetic response of the grating shows the importance of the depletion layer at the GaAs surface and indicates a high sensitivity of the reflectivity dip frequency to the surface potential.
Efficiency enhancement of organic photovoltaics by addition of carbon nanotubes into both active and hole transport layer
Authors: Stylianakis Minas M. , Kymakis Emmanuel
Published: February 2012

We investigate the effect of the incorporation of single walled carbon nanotubes (SWNTs) into both the active layer and the hole transport layer (HTL) on bulk heterojunction organic photovoltaic devices. The overall efficiency gain for such a device is 40%, compared with the pristine device. The observed efficiency gain is attributed to a more efficient exciton dissociation due to the SWNTs presence in the photoactive layer and an overall enhanced hole transport and collection through the SWNTs percolation paths, which are extended in both the active layer and the HTL.
Experimental treatment-control studies of ecologically based rodent management in Africa: balancing conservation and pest management
Authors: Taylor Peter J. , Downs Sarah , Monadjem Ara , Eiseb Seth J. , Mulungu Loth S. , Massawe Apia W. , Mahlaba Themb'a A. , Kirsten Frikkie , Von Maltitz Emil , Malebane Phanuel , Makundi Rhodes H. , Lamb Jennifer , Belmain Steven R.
Published: February 2012

Context Rodent pests severely affect crop production, particularly in monocultures where one or two rodent pest species dominate. We predict higher species richness of native small mammal species in more heterogeneous mosaic (crop–fallow–bush) subsistence agro-ecosystems in Africa. Conservation and agro-ecological imperatives require that such diverse natural communities should be maintained and may benefit crop protection through limiting domination of pest species. Ecologically based rodent-management alternatives to rodenticides are urgently required and one such method (community trapping) is herein advocated. Aims To provide baseline information on rodent and shrew communities in agro-ecosystems in three African countries and to demonstrate efficacy of ecologically based rodent management (EBRM) in Africa (e.g. community household trapping). Methods Removal-trapping in a variety of agro-ecological habitats provided accurate small-mammal species lists. Intensive kill-trapping by rural agricultural communities was carried out experimentally where the efforts of communities were scientifically monitored by kill-trapping to measure impact on rodent numbers and the levels of post-harvest damage to stored grains. Key results Our study revealed a high diversity of endemic species in agricultural habitats in Tanzania and Namibia (but not Swaziland) and the existence of undescribed and possibly rare species, some of which may be at risk of extinction from unchecked habitat transformation for agriculture. Treatment-control studies showed that communities in three African countries could effectively reduce pest rodent populations and rodent damage by intensive trapping on a daily basis in and around the community. Conclusions Community trapping reduced pest rodent populations and damage to stored grains. Unlike the use of indiscriminate rodenticide, this practice is expected to have a negligible effect on beneficial non-target rodent and shrew species. Implications Ecologically based rodent management approaches such as community trapping will conserve beneficial non-pest rodent communities and ultimately improve crop protection.
Typologizing grammatical complexities
Authors: Good Jeff
Published: February 2012

An important theme in work attempting to situate creoles with respect to non-creoles typologically is the extent to which it can be said that creole grammars are relatively simple from a cross-linguistic perspective. Work arguing for and against this position has generally focused on an examination of the synchronic grammars of creoles in order to show that they are either simple or complex in one way or another. By contrast, there has not been a detailed examination of two important related questions: How can we typologize grammatical complexities themselves? And, once we have typologized them, will we find that different types of complexities are affected differently during creolization? This paper examines these questions and proposes that distinguishing between complexities derived from paradigmatic structure as opposed to syntagmatic structure may yield important insights into apparent patterns of simplicity within creoles, in particular with respect to which complexities we might expect to be readily transferred from source languages into an emerging creole.
Lexical and visual choices in the representation of immigration in the Spanish press
Authors: Crespo Fernández Eliecer , Martínez Lirola María
Published: February 2012

Our goal in this paper is to shed some light on the treatment of immigration issues in the current Spanish press via the analysis of the visual and lexical choices used in the journalistic representation of immigration. With this in mind, taking Critical Discourse Analysis and Visual Grammar as theoretical paradigms, we will explore how immigration is represented in a representative sample of multimodal texts found in newspapers from Alicante, a province with a very high percentage of immigrants in Spain. To this end, we will analyse the image and the euphemistic lexical references to immigration in the headlines, subheadings and captions of the pieces of news that constitute our corpus. The findings obtained provide evidence for the fact that, in the majority of the texts analysed, a considerable number of lexical and visual elements do not contribute to a positive representation of immigrants and tend to provoke, whether consciously or not, discriminatory attitudes towards them.
Nuevas perspectivas sobre la variación de las formas presente simple y presente progresivo en español y en inglés
Authors: Fafulas Stephen
Published: February 2012

Se presenta un análisis de la variación gramatical de las formas presente simple y presente progresivo en el español monolingüe y bilingüe. Por medio de una encuesta contextualizada y codificada según el aspecto léxico del verbo y el valor semántico de los adverbios de tiempo, se muestran los contextos en los que hay variación de dichas formas. Además de los factores lingüísticos, se incluyen en el análisis los factores extralingüísticos de sexo y nivel de bilingüismo. Los resultados indican que tanto el aspecto léxico del verbo como el valor semántico del adverbio son factores significativos en la predicción de ambas formas. De igual manera, el factor extralingüístico que considera el nivel de bilingüismo de los hablantes tiene un efecto significativo. El instrumento empleado en la investigación contribuye metodológicamente al estudio de la variación de las formas del presente simple y del presente progresivo en cuanto al control de las variables lingüísticas, dado que se evaluaron contextos idénticos y se obtuvo el mismo número de respuestas por participante. Por último, el estudio aporta a la literatura una nueva perspectiva sobre el tema al mostrar que las formas presente simple y presente progresivo aparecen en variación en un número de contextos diferentes a los previamente identificados en otros estudios, lo cual permite definir apropiadamente el ámbito de la variación.
Multistability in auditory stream segregation: a predictive coding view
Authors: Winkler István , Denham Susan , Mill Robert , Bőhm Tamás M. , Bendixen Alexandra
Published: February 2012

Auditory stream segregation involves linking temporally separate acoustic events into one or more coherent sequences. For any non-trivial sequence of sounds, many alternative descriptions can be formed, only one or very few of which emerge in awareness at any time. Evidence from studies showing bi-/multistability in auditory streaming suggest that some, perhaps many of the alternative descriptions are represented in the brain in parallel and that they continuously vie for conscious perception. Here, based on a predictive coding view, we consider the nature of these sound representations and how they compete with each other. Predictive processing helps to maintain perceptual stability by signalling the continuation of previously established patterns as well as the emergence of new sound sources. It also provides a measure of how well each of the competing representations describes the current acoustic scene. This account of auditory stream segregation has been tested on perceptual data obtained in the auditory streaming paradigm.
Multistability, cross-modal binding and the additivity of conjoined grouping principles
Authors: Kubovy Michael , Yu Minhong
Published: February 2012

We present a sceptical view of multimodal multistability—drawing most of our examples from the relation between audition and vision. We begin by summarizing some of the principal ways in which audio-visual binding takes place. We review the evidence that unambiguous stimulation in one modality may affect the perception of a multistable stimulus in another modality. Cross-modal influences of one multistable stimulus on the multistability of another are different: they have occurred only in speech perception. We then argue that the strongest relation between perceptual organization in vision and perceptual organization in audition is likely to be by way of analogous Gestalt laws. We conclude with some general observations about multimodality.
Combinatorial use of bone morphogenetic protein 6, noggin and SOST significantly predicts cancer progression
Authors: Yuen Hiu‐Fung , McCrudden Cian M. , Grills Claire , Zhang Shu‐Dong , Huang Yu‐Han , Chan Ka‐Kui , Chan Yuen‐Piu , Wong Michelle Lok‐Yee , Law Simon , Srivastava Gopesh , Fennell Dean A. , Dickson Glenn , El‐Tanani Mohamed , Chan Kwok‐Wah
Published: February 2012

Emerging evidence has indicated a role of the bone morphogenetic proteins (BMP) in the pathogenesis of certain cancers. The signaling of BMP family members is tightly regulated by their antagonists, including noggin and SOST, which are, in turn, positively regulated by BMP, thereby forming a negative feedback loop. Consequently, the expression of these antagonists should be taken into account in studies on the prognostic significance of BMP. In the present paper, we correlated protein and mRNA expression levels of BMP6, noggin and SOST, alone or in combination, with patient survival in various types of cancer. We found that BMP6 alone was not significantly correlated with esophageal squamous cell carcinoma patient survival. Instead, a high level of inhibitor of differentiation 1, a downstream factor of BMP6, was associated with shorter survival in patients whose tumors stained strongly for BMP6. Knockdown of noggin in esophageal cancer cell line EC109, which expresses BMP6 strongly and SOST weakly, enhanced the non‐adherent growth of the cells. Noggin and SOST expression levels, when analyzed alone, were not significantly correlated with patient survival. However, high BMP6 activity, defined by strong BMP6 expression coupled with weak noggin or SOST expression, was significantly associated with shorter survival in esophageal squamous cell carcinoma patients. We further confirmed that BMP6 activity could be used as a prognostic indicator in prostate, bladder and colorectal cancers, using publicly available data on BMP6, noggin and SOST mRNA expression and patient survival. Our results strongly suggest that BMP6, noggin and SOST could be used in combination as a prognostic indicator in cancer progression. (Cancer Sci 2012; 103: 1145–1154)
MSTN genotypes in Thoroughbred horses influence skeletal muscle gene expression and racetrack performance
Authors: McGivney Beatrice A. , Browne John A. , Fonseca Rita G. , Katz Lisa M. , MacHugh David E. , Whiston Ronan , Hill Emmeline W.
Published: February 2012

Myostatin, encoded by the MSTN gene, is a member of the TGF‐β superfamily that regulates skeletal muscle development. A MSTN SNP significantly associated with Thoroughbred horse racing phenotypes has recently been identified as well as significant reductions in Thoroughbred skeletal muscle gene expression for three transcripts 400–1500 base pairs downstream of the MSTN gene following a period of training. Together, these findings indicate that MSTN genotypes may influence MSTN gene expression. To investigate this, MSTN mRNA expression was measured in biopsies from the middle gluteal muscle from 60 untrained yearling Thoroughbreds (C/C, n = 15; C/T, n = 28; T/T, n = 17) using two independent real‐time qRT‐PCR assays. MSTN gene expression was also evaluated in a subset (N = 33) of these animals using samples collected after a ten‐month period of training. A significant association was observed between genotype and mRNA abundance for the untrained horses (assay I, P = 0.0237; assay II, P = 0.003559), with the C/C cohort having the highest MSTN mRNA levels, the T/T group the lowest levels and the C/T group intermediate levels. Following training, there was a significant decrease in MSTN mRNA (−3.35‐fold; P = 6.9 × 10−7), which was most apparent for the C/C cohort (−5.88‐fold, P = 0.001). These data demonstrate the tight relationship between phenotype, genotype and gene expression at the MSTN gene in Thoroughbred racehorses.
Inhibition of CYP2D6‐mediated tramadol O‐demethylation in methadone but not buprenorphine maintenance patients
Authors: Coller Janet K. , Michalakas Jennifer R. , James Heather M. , Farquharson Aaron L. , Colvill Joel , White Jason M. , Somogyi Andrew A.
Published: February 2012

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Management of pain in opioid dependent individuals is problematic due to numerous issues including cross‐tolerance to opioids. Hence there is a need to find alternative analgesics to classical opioids and tramadol is potentially one such alternative.

• Methadone inhibits CYP2D6 in vivo and in vitro.

• We aimed to investigate the effect of methadone on the pathways of tramadol metabolism: O‐demethylation (CYP2D6) to the opioid‐active metabolite M1 and N‐demethylation (CYP3A4) to M2 in subjects maintained on methadone or buprenorphine as a control.

WHAT THIS STUDY ADDS

• Compared with subjects on buprenorphine, methadone reduced the clearance of tramadol to active O‐desmethyl‐tramadol (M1) but had no effect on N‐desmethyltramadol (M2) formation.

• Similar to other analgesics whose active metabolites are formed by CYP2D6 such as codeine, reduced formation of O‐desmethyltramadol (M1) is likely to result in reduced analgesia for subjects maintained on methadone. Hence alternative analgesics whose metabolism is independent of CYP2D6 should be utilized in this patient population.

AIMS To compare the O‐ (CYP2D6 mediated) and N‐ (CYP3A4 mediated) demethylation metabolism of tramadol between methadone and buprenorphine maintained CYP2D6 extensive metabolizer subjects.

METHODS Nine methadone and seven buprenorphine maintained subjects received a single 100 mg dose of tramadol hydrochloride. Blood was collected at 4 h and assayed for tramadol, methadone, buprenorphine and norbuprenorphine (where appropriate) and all urine over 4 h was assayed for tramadol and its M1 and M2 metabolites.

RESULTS The urinary metabolic ratio [median (range)] for O‐demethylation (M1) was significantly lower (P= 0.0002, probability score 1.0) in the subjects taking methadone [0.071 (0.012–0.103)] compared with those taking buprenorphine [0.192 (0.108–0.392)], but there was no significant difference (P= 0.21, probability score 0.69) in N‐demethylation (M2). The percentage of dose [median (range)] recovered as M1 was significantly lower in subjects taking methadone compared with buprenorphine (0.069 (0.044–0.093) and 0.126 (0.069–0.187), respectively, P= 0.04, probability score 0.19), M2 was significantly higher in subjects taking methadone compared with buprenorphine (0.048 (0.033–0.085) and 0.033 (0.014–0.049), respectively, P= 0.04, probability score 0.81). Tramadol was similar (0.901 (0.635–1.30) and 0.685 (0.347–1.04), respectively, P= 0.35, probability score 0.65).

CONCLUSIONS Methadone inhibited the CYP2D6‐mediated metabolism of tramadol to M1. Hence, as the degree of opioid analgesia is largely dependent on M1 formation, methadone maintenance patients may not receive adequate analgesia from oral tramadol.
Challenges to nurse prescribers of a no‐antibiotic prescribing strategy for managing self‐limiting respiratory tract infections
Authors: Rowbotham Samantha , Chisholm Anna , Moschogianis Susie , Chew‐Graham Carolyn , Cordingley Lis , Wearden Alison , Peters Sarah
Published: February 2012

Aims.  To report a qualitative study of the experiences of nurse prescribers in managing patients with self‐limiting respiratory tract infections.

Background.  Patients frequently attend primary care with respiratory tract infections. Although a no‐prescribing strategy is recommended for these consultations, general practitioners frequently prescribe antibiotics, citing non‐clinical reasons such as patient pressure. Nurses increasingly manage people with respiratory tract infections, but research has not yet explored their experiences within such consultations.

Design.  Semi‐structured interviews and focus groups.

Methods.  Fifteen semi‐structured interviews and three focus groups (n = 5, n = 4, and n = 12) with a purposive sample of nurse prescribers (n = 34) and other non‐medical prescribers (n = 2) were conducted between November 2009–November 2010. A qualitative approach was used to develop conceptual categories from the dataset, and emerging themes were explored in subsequent interviews/focus groups.

Findings.  Although participants reported experiencing numerous challenges within these consultations, they believed that they possessed some of the communication skills to deal effectively with patients without prescribing antibiotics. Participants reported that protocols supported their decision‐making and welcomed the benefits of peer support in dealing with ‘demanding’ patients. However, the newness of nurses and other non‐medical prescribers to the prescribing role meant that some were cautious in dealing with patients with respiratory tract infections.

Conclusion.  Training for nurses and other non‐medical prescribers should focus on building their confidence and skills to manage people with respiratory tract infections without recourse to antibiotics. Further work should seek to explore which strategies are most effective in managing respiratory tract infections while maintaining patient satisfaction with care.
Chronotype and diurnal patterns of positive affect and affective neural circuitry in primary insomnia
Authors: HASLER BRANT P. , GERMAIN ANNE , NOFZINGER ERIC A. , KUPFER DAVID J. , KRAFTY ROBERT T. , ROTHENBERGER SCOTT D. , JAMES JEFFREY A. , BI WENZHU , BUYSSE DANIEL J.
Published: February 2012

While insomnia is a well‐established risk factor for the initial onset, recurrence or relapse of affective disorders, the specific characteristics of insomnia that confer risk remain unclear. Patients with insomnia with an evening chronotype may be one particularly high‐risk group, perhaps due to alterations in positive affect and its related affective circuitry. We explored this possibility by comparing diurnal patterns of positive affect and the activity of positive affect‐related brain regions in morning‐ and evening‐types with insomnia. We assessed diurnal variation in brain activity via the relative regional cerebral metabolic rate of glucose uptake by using [18F]fluorodeoxyglucose‐positron emission tomography during morning and evening wakefulness. We focused on regions in the medial prefrontal cortex and striatum, which have been consistently linked with positive affect and reward processing. As predicted, chronotypes differed in their daily patterns in both self‐reported positive affect and associated brain regions. Evening‐types displayed diurnal patterns of positive affect characterized by phase delay and smaller amplitude compared with those of morning‐types with insomnia. In parallel, evening‐types showed a reduced degree of diurnal variation in the metabolism of both the medial prefrontal cortex and the striatum, as well as lower overall metabolism in these regions across both morning and evening wakefulness. Taken together, these preliminary findings suggest that alterations in the diurnal activity of positive affect‐related neural structures may underlie differences in the phase and amplitude of self‐reported positive affect between morning and evening chronotypes, and may constitute one mechanism for increased risk of mood disorders among evening‐type insomniacs.
Legumes select symbiosis island sequence variants in Bradyrhizobium
Authors: PARKER MATTHEW A.
Published: February 2012

Bradyrhizobium strains sampled from 14 legume genera native to eastern North America showed substantial host‐related phylogenetic clustering at three loci in the symbiotic island (SI) region (nodC, nifD, nifH), indicating selection of distinct suites of SI lineages by different legumes. Bacteria assorted consistently with particular legumes across two regions separated by 800 km, implying recurrent assembly of the same symbiotic combinations. High genetic polymorphism of all three SI loci relative to four nonsymbiotic loci supported the inference that a form of multiple‐niche balancing selection has acted on the SI region, arising from differential symbiont utilization by different legume taxa. Extensive discordance between the tree for SI variants and a phylogenetic tree inferred for four housekeeping loci implied that lateral transfer of the symbiosis island region has been common (at least 26 transfer events among 85 Bradyrhizobium strains analysed). Patterns of linkage disequilibrium also supported the conclusion that recombination has impacted symbiotic and nonsymbiotic regions unequally. The high prevalence of lateral transfer suggests that acquisition of a novel SI variant may often confer a strong selective advantage for recipient cells.
Clinical application of 2.7M Cytogenetics array for CNV detection in subjects with idiopathic autism and/or intellectual disability
Authors: Qiao Y , Tyson C , Hrynchak M , Lopez‐Rangel E , Hildebrand J , Martell S , Fawcett C , Kasmara L , Calli K , Harvard C , Liu X , Holden JJA , Lewis SME , Rajcan‐Separovic E
Published: February 2012

Qiao Y, Tyson C, Hrynchak M, Lopez‐Rangel E, Hildebrand J, Martell S, Fawcett C, Kasmara L, Calli K, Harvard C, Liu X, Holden JJA, Lewis SME, Rajcan‐Separovic E. Clinical application of 2.7M Cytogenetics array for CNV detection in subjects with idiopathic autism and/or intellectual disability.

Higher resolution whole‐genome arrays facilitate the identification of smaller copy number variations (CNVs) and their integral genes contributing to autism and/or intellectual disability (ASD/ID). Our study describes the use of one of the highest resolution arrays, the Affymetrix® Cytogenetics 2.7M array, coupled with quantitative multiplex polymerase chain reaction (PCR) of short fluorescent fragments (QMPSF) for detection and validation of small CNVs. We studied 82 subjects with ASD and ID in total (30 in the validation and 52 in the application cohort) and detected putatively pathogenic CNVs in 6/52 cases from the application cohort. This included a 130‐kb maternal duplication spanning exons 64–79 of the DMD gene which was found in a 3‐year‐old boy manifesting autism and mild neuromotor delays. Other pathogenic CNVs involved 4p14, 12q24.31, 14q32.31, 15q13.2‐13.3, and 17p13.3. We established the optimal experimental conditions which, when applied to select small CNVs for QMPSF confirmation, reduced the false positive rate from 60% to 25%. Our work suggests that selection of small CNVs based on the function of integral genes, followed by review of array experimental parameters resulting in highest confirmation rate using multiplex PCR, may enhance the usefulness of higher resolution platforms for ASD and ID gene discovery.
7q11.23 Microduplication: a recognizable phenotype
Authors: Dixit A , McKee S , Mansour S , Mehta SG , Tanteles GA , Anastasiadou V , Patsalis PC , Martin K , McCullough S , Suri M , Sarkar A
Published: February 2012

Dixit A, McKee S, Mansour S, Mehta SG, Tanteles GA, Anastasiadou V, Patsalis PC, Martin K, McCullough S, Suri M, Sarkar A. 7q11.23 Microduplication: a recognizable phenotype.

Williams‐Beuren syndrome is a well‐known microdeletion syndrome with a recognizable clinical phenotype. The subtle phenotype of the reciprocal microduplication of the Williams‐Beuren critical region has been described recently. We report seven further patients, and a transmitting parent, with 7q11.23 microduplication. All our patients had speech delay, autistic features and facial dysmorphism consistent with the published literature. We conclude that the presence of specific dysmorphic features, including straight, neat eyebrows, thin lips and a short philtrum, in our patients with speech delay and autistic features provides further evidence that the children with 7q11.23 microduplication have a recognizable phenotype.
Chemical‐Mediated Predator Avoidance in the European House Cricket (Acheta domesticus) is Modulated by Predator Diet
Authors: Hoefler Chad D. , Durso Lisa C. , McIntyre Kyle D.
Published: February 2012

Chemical information often mediates interactions between predators and prey, and threat‐sensitivity theory includes predictions that prey species should respond to chemical signatures of predators in a manner that is commensurate with the level of the assessed threat. Using the European house cricket (Acheta domesticus), we explored the influence of diet‐derived cues from the centipede Scolopocryptops sexspinosus on anti‐predator behavior in three laboratory experiments. In experiment 1, we compared the amount of time that adult female crickets spent on untreated filter paper and filter paper exposed to centipedes fed either the larvae of Hermetia illucens (black soldier fly), crickets, or a mixture of fly larvae and crickets. We discovered that crickets spent significantly less time on filter paper exposed to centipedes fed crickets only or a mixture of crickets and fly larvae compared with blank filter paper or filter paper exposed to centipedes fed fly larvae only. In our second experiment, we compared the amount of time that crickets spent on blank filter paper and filter paper exposed to adult female conspecifics to rule out the possibility that crickets simply avoid all filter paper exposed to metabolic by‐products, and crickets exhibited no discrimination. In our third experiment, we tested the potential effects of diet order on anti‐predatory behaviors. Specifically, we compared the amount of time that adult female crickets spent on filter paper exposed to centipedes fed fly larvae followed by crickets and filter paper exposed to centipedes fed crickets followed by fly larvae. We discovered no diet sequence effect. Our study demonstrates that European house crickets are sensitive to the chemical cues of their centipede predators, but only when centipedes have fed upon crickets.
Quantitative trait locus analysis of spot blotch and leaf rust resistance in the BCD47 × Baronesse barley mapping population
Authors: Castro Ariel J. , Gamba Fernanda , German Silvia , Gonzalez Silvana , Hayes Patrick M. , Pereyra Silvia , Perez Carlos
Published: February 2012

With 2 figures and 6 tables

We studied the genetics of the resistance to leaf rust (LR) (caused by Puccinia hordei) and spot blotch (SB) (caused by Cochliobolus sativus) in barley using a doubled‐haploid population derived from the cross BCD47 × Baronesse. BCD47 has low SB severity and high susceptibility to LR, while Baronesse is susceptible to SB and has low LR severity. Resistance to both diseases is expressed at the adult plant stage. The population was phenotyped in eight field environments for SB and nine for LR. Ten quantitative trait loci (QTLs) were detected for SB. None were significant in more than three environments, and both parents contributed resistance alleles. Five QTLs were detected for LR. The most consistent quantitative trait locus (QTL) (significant in seven environments) was on chromosome 6H (located on the Bmag173‐Bmag009 interval) with Baronesse contributing the resistance allele. Coincident QTL effects for SB were also detected in this region with resistance alleles to the two diseases in repulsion. These results illustrate the difficulties of resistance gene detection in the complex disease environments found under field conditions.
Targeted therapy of hepatocellular carcinoma: Present and future
Authors: Chan Stephen L , Yeo Winnie
Published: February 2012

Following the encouraging results of sorafenib in advanced hepatocellular carcinoma (HCC), targeted therapy has become a new direction of research in the treatment of HCC. Emerging data provide evidence that the pathogenesis and progression of HCC are mediated by a number of molecular defects and dysregulated pathways. Novel targeted therapies are designed to inhibit the aberrant pathways at a molecular level with an aim to improve the clinical outcome. For the past few years, an increasing number of targeted agents have been tested in HCC in the clinical setting. This review aims to summarize the current status of clinical development of targeted therapy in HCC, with focus on novel agents targeting angiogenesis, signal transduction and epigenetic dysregulation of tumors. The review also discusses the lessons learned from outcomes of completed clinical trials and provides perspectives on future clinical trials in HCC.