bluuebunny/crossref_metadata_2025 huggingface dataset:
Length and site of the small intestine exposed to fat influences hunger and food intake
Authors: Maljaars P. W. Jeroen , Peters Harry P. F. , Kodde Andrea , Geraedts Maartje , Troost Fred J. , Haddeman Edward , Masclee Ad A. M.
Published: June 2011

The site of intestinal fat delivery affects satiety and may affect food intake in humans. Animal data suggest that the length of the small intestine exposed to fat is also relevant. The aim of the present study was to investigate whether increasing the areas of intestinal fat exposure and the way it is exposed would affect satiety parameters and food intake. In the present single-blind, randomised, cross-over study, fifteen volunteers, each intubated with a naso-ileal tube, received four treatments on consecutive days. The oral control (control treatment) was a liquid meal (LM) containing 6 g fat ingested att = 0 min, with saline infusion att = 30–120 min. Experimental treatments were a fat-free LM att = 0 min, with either 6 g oil delivered sequentially (2 g duodenal,t = 30–60 min; 2 g jejunal,t = 60–90 min; 2 g ileal,t = 90–120 min), simultaneously (2 g each to all sites,t = 30–120 min) or ileal only (6 g ileal,t = 30–120 min). Satiety parameters (hunger and fullness) and cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), peptide YY (PYY) secretion were measured untilt = 180 min, whenad libitumfood intake was assessed. Only the ileum treatment reduced food intake significantly over the control treatment. The ileum and simultaneous treatments significantly reduced hunger compared with the control treatment. Compared with control, no differences were observed for PYY, CCK and GLP-1 with regard to 180 min integrated secretion. Ileal fat infusion had the most pronounced effect on food intake and satiety. Increasing the areas of intestinal fat exposure only affected hunger when fat was delivered simultaneously, not sequentially, to the exposed areas. These results demonstrate that ileal brake activation offers an interesting target for the regulation of ingestive behaviour.
Positive outcomes of oil palm phenolics on degenerative diseases in animal models
Authors: Sambanthamurthi Ravigadevi , Tan YewAi , Sundram Kalyana , Hayes Kenneth C. , Abeywardena Mahinda , Leow Soon-Sen , Devi Sekaran Shamala , Sambandan T. G. , Rha ChoKyun , Sinskey Anthony J. , Subramaniam Krishnan , Fairus Syed , Basri Wahid Mohd
Published: June 2011

It is well established that plant phenolics elicit various biological activities, with positive effects on health. Palm oil production results in large volumes of aqueous by-products containing phenolics. In the present study, we describe the effects of oil palm phenolics (OPP) on several degenerative conditions using various animal models. OPP reduced blood pressure in a NO-deficient rat model, protected against ischaemia-induced cardiac arrhythmia in rats and reduced plaque formation in rabbits fed an atherogenic diet. In Nile rats, a spontaneous model of the metabolic syndrome and type 2 diabetes, OPP protected against multiple aspects of the syndrome and diabetes progression. In tumour-inoculated mice, OPP protected against cancer progression. Microarray studies on the tumours showed differential transcriptome profiles that suggest anti-tumour molecular mechanisms involved in OPP action. Thus, initial studies suggest that OPP may have potential against several chronic disease outcomes in mammals.
Supplement of bamboo extract lowers serum monocyte chemoattractant protein-1 concentration in mice fed a diet containing a high level of saturated fat
Authors: Higa Jason K. , Liu Wanyu , Berry Marla J. , Panee Jun
Published: June 2011

Monocyte chemoattractant protein-1 (MCP-1) is an inflammatory chemokine up-regulated in obese subjects, contributing to the development of type 2 diabetes. The present study investigated the inhibitory effect of an ethanol–water extract from bamboo (BEX,Phyllostachys edulis) on the blood concentration of MCP-1. C57BL/6J mice were fed a standard diet or a high-fat diet with or without the BEX supplement (11 g dry mass/17 000 kJ) for 6 months. A total of ten mice were used in each group. Body weight and food consumption were measured weekly. After euthanisation, the weight of visceral fat and circulating MCP-1 concentration were measured. In comparison with the standard control group, the high-fat control group had increased body weight, abdominal fat storage and serum MCP-1 concentration by 60 % (P < 0·001), 266 % (P < 0·001) and 180 % (P < 0·01), respectively. In comparison with the high-fat control group, the high-fat BEX group showed a 3 % decrease in body weight (P < 0·01), 24 % decrease in mesenteric fat depot (P < 0·01) and 49 % decrease in serum MCP-1 concentration (P < 0·05). The present study suggests that the BEX supplement in the high-fat diet ameliorates elevated MCP-1 concentrations in the blood, and whether this is related to modulated endocrine properties of the visceral fat is to be studied.
An Extended Macro-Finance Model with Financial Factors
Authors: Dewachter Hans , Iania Leonardo
Published: June 2011

This paper extends the benchmark macro-finance (MF) model by introducing, next to the standard macroeconomic factors, additional liquidity-related and return-forecasting factors. Liquidity factors are obtained from a decomposition of the money market spread, while the return-forecasting (risk premium) factor is extracted by imposing a single-factor structure on the 1-period expected excess holding return. The model is estimated on U.S. data using Markov chain Monte Carlo techniques. Two findings stand out. First, the model significantly outperforms most structural and nonstructural MF yield curve models in terms of the cross-sectional fit of the yield curve. Second, financial shocks have a statistically and economically significant impact on the yield curve.
Non-viral genetic transfection of rat Schwann cells with FuGENE HD©lipofection and AMAXA©nucleofection is feasible but impairs cell viability
Authors: Kraus Armin , Täger Joachim , Kohler Konrad , Haerle Max , Werdin Frank , Schaller Hans-Eberhard , Sinis Nektarios
Published: June 2011

Purpose:

To determine transfection efficiency of FuGENE HD©lipofection and AMAXA©nucleofection on rat Schwann cells (SC).

Methods:

The ischiadic and median nerves of 6-8 week old Lewis rats were cultured in modified melanocyte-growth medium. SCs were genetically transfected with green fluorescent protein (GFP) as reporter gene using FuGENE HD©lipofection and AMAXA©nucleofection. Transfection rates were determined by visualization of GFP fluorescence under fluorescence microscopy and cell counting. Transfected cell to non-transfected cell relation was determined.

Results:

Purity of Schwann cell culture was 88% as determined by immunohistologic staining. Transfection rate of FuGENE HD©lipofection was 2%, transfection rate of AMAXA©nucleofection was 10%. With both methods, Schwann cells showed pronounced aggregation behavior which made them unfeasible for further cultivation. Settling of Schwann cells on laminin and poly-l-ornithine coated plates was compromised by either method.

Conclusion:

Non-viral transfection of rat SC with FuGENE HD©lipofection and AMAXA©nucleofection is basically possible with a higher transfection rate for nucleofection than for lipofection. As cell viability is compromised by either method however, viral transfection is to be considered if higher efficiency is required.
Cerebrospinal Fluid Biomarkers and Cerebral Morphometry in Mild Cognitive Impairment
Authors: Kaiser Elmar , Thomann Anne K. , Thomann Philipp A.
Published: June 2011

Neurocognitive deficits that surpass changes occurring within physiological aging are classified as mild cognitive impairment (MCI). MCI can be regarded as a risk syndrome for the development of manifest dementia. Subjects with MCI present with variable degrees of organic and neuropsychological changes, and show a heterogeneous risk for conversion to dementia. By using specific neuropsychological and laboratory tests as well as methods of brain imaging, we can characterize MCI subjects with early changes, occurring within the course of neurodegenerative diseases such as Alzheimer’s disease, in detail. It is primarily in these patients that early therapeutic interventions seem to be of some use.
Dissociable Age Effects in Focus-Switching
Authors: Dorbath Lara , Titz Cora
Published: June 2011

Focus-switching has recently been identified as an executive control process with differential age sensitivity. To date, the assumption of dissociable age effects is based on only two kinds of tasks constricting its conclusiveness. In a study with 85 younger (19–35 years) and 91 older adults (59–80 years), age effects were again dissociable in two alternative tasks with respect to the availability and the accessibility of representations. The results validate earlier findings that focus-switching is primarily affected in maintaining representations rather than in accessing them.
Evaluation of a TEACCH- and Music Therapy-Based Psychological Intervention in Mild to Moderate Dementia
Authors: Fischer-Terworth Christian , Probst Paul
Published: June 2011

Background: A multicomponent psychological intervention designed to alleviate neuropsychiatric symptoms and to improve communication in mild to moderate dementia was evaluated in a controlled trial. Components were (1) TEACCH (Treatment and Education of Autistic and related Communication handicapped Children)-based cognitive-behavioral and environmental interventions adapted for dementia and (2) music therapy. Methods: In a Pre-post design, the treatment group (n = 26) received the program for 6 months, whereas controls (n = 23) participated in nonspecific occupational therapy. Statistical analyses included t-tests, effect sizes, and two-way ANOVAs. Results: Relative to controls, the treatment group showed partly significant reductions of agitation, aggression, apathy, and anxiety, and improvement of communication, emotional expression, and activity. Conclusion: The intervention can help to increase psychological well-being in patients with dementia.
Der Cognitive Emotion Regulation Questionnaire (CERQ)
Authors: Loch Noelle , Hiller Wolfgang , Witthöft Michael
Published: June 2011

Zusammenfassung. Theoretischer Hintergrund: Der Cognitive Emotion Regulation Questionnaire (CERQ; Garnefski, Kraaij & Spinhoven, 2001 ) erfasst neun Dimensionen kognitiver Emotionsregulation. Fragestellung: Es wurde eine deutsche Adaption des CERQ entwickelt und hinsichtlich Reliabilität, Dimensionalität und Zusammenhängen mit Depressivität und Angstsensitivität getestet. Methode: Die Studie wurde als postalische Fragebogenstudie durchgeführt. Von den zufällig ausgewählt und angeschriebenen 3000 Personen, sendeten 423 den Fragebogen zurück, die finale Stichprobe umfasste N = 414. Angstsensitivität und Depressivität wurden mit dem ASI-3 und dem PHQ-9 erfasst. Ergebnisse: Das 9-Faktorenmodell des CERQ konnte nach einer Verringerung auf drei Items pro Faktor zufriedenstellend repliziert werden. Angstsensitivität und Depressivität zeigten stärkere Zusammenhänge mit dysfunktionalen als mit funktionalen ER-Strategien. Am stärksten waren sie mit Katastrophisierung, Selbstbeschuldigung, Rumination, Neubewertung und Positiver Refokussierung, am schwächsten mit Akzeptanz und Refokussierung auf Planung. Schlussfolgerungen: Der deutsche CERQ ist hinsichtlich Skalenstruktur, Reliabilität und Zusammenhängen mit psychopathologischen Merkmalen vergleichbar mit der niederländischen Originalversion. Obwohl weitere Untersuchungen, insbesondere zur Konstruktvalidität, nötig sind, erscheint der CERQ geeignet für den Einsatz in der Emotionsregulationsforschung.
Active tectonics of the South Chilean marine fore arc (35°S–40°S)
Authors: Geersen Jacob , Behrmann Jan H. , Völker David , Krastel Sebastian , Ranero César R. , Diaz‐Naveas Juan , Weinrebe Wilhelm
Published: June 2011

The South Chilean marine fore arc (35°S–40°S) is separated into four tectonic segments, Concepción North, Concepción South, Nahuelbuta, and Tolten (from north to south). These are each characterized by their individual tectonic geomorphology and reflect different ways of mechanical and kinematic interaction of the convergent Nazca and South American plates. Splay faults that cut through continental framework rock are seismically imaged in both Concepción segments and the Tolten Segment. Additionally, the Concepción South Segment exhibits prominent upper plate normal faults. Normal faults apparently relate to uplift caused by sediment underthrusting at depth. This has led to oversteepening and gravitational collapse of the marine fore arc. There is also evidence for sediment underthrusting and basal accretion to the overriding plate in the Tolten Segment. There, uplift of the continental slope has created a landward inclined seafloor over a latitudinal distance of 50 km. In the Nahuelbuta Segment transpressive upper plate faults, aligned oblique to the direction of plate motion, control the seafloor morphology. Based on a unique acoustic data set including >90% of bathymetric coverage of the continental slope we are able to reveal an along‐strike heterogeneity of a complexly deformed marine fore arc which had escaped attention in previous studies that only considered the structure along transects normal to the plate margin.
SAP suppresses the development of experimental autoimmune encephalomyelitis in C57BL/6 mice
Authors: Ji Zhe , Ke Zun‐Ji , Geng Jian‐Guo
Published: June 2011

Experimental autoimmune encephalomyelitis (EAE) is a CD4+ T cell‐mediated disease of the central nervous system. Serum amyloid P component (SAP) is a highly conserved plasma protein named for its universal presence in amyloid deposits. Here we report that SAP‐transgenic mice had unexpectedly attenuated EAE due to impaired encephalitogenic responses. Following induction with myelin oligodendroglial glycoprotein (MOG) peptide 35–55 in complete Freund's adjuvant, SAP‐transgenic mice showed reduced spinal cord inflammation with lower severity of EAE attacks as compared with control C57BL/6 mice. However, in SAP‐Knockout mice, the severity of EAE is enhanced. Adoptive transfer of Ag‐restimulated T cells from wild type to SAP‐transgenic mice, or transfer of SAP‐transgenic Ag‐restimulated T cells to control mice, induced milder EAE. T cells from MOG‐primed SAP‐transgenic mice showed weak proliferative responses. Furthermore, in SAP‐transgenic mice, there is little infiltration of CD45‐positive cells in the spinal cord. In vitro, SAP suppressed the secretion of interleukin‐2 stimulated by P‐selectin and blocked P‐selectin binding to T cells. Moreover, SAP could change the affinity between α4‐integrin and T cells. These data suggested that SAP could antagonize the development of the acute phase of inflammation accompanying EAE by modulating the function of P‐selectin.
Age-Related Benefits of Digital Noise Reduction for Short-Term Word Learning in Children With Hearing Loss
Authors: Pittman Andrea
Published: June 2011

Purpose

To determine the rate of word learning for children with hearing loss (HL) in quiet and in noise compared to normal-hearing (NH) peers. The effects of digital noise reduction (DNR) were examined for children with HL.

Method

Forty-one children with NH and 26 children with HL were grouped by age (8–9 years and 11–12 years). The children learned novel words associated with novel objects through a process of trial and error. Functions relating performance across trials were calculated for each child in each listening condition and were compared.

Results

Significant effects were observed for age (older > younger) in the children with NH and listening condition (quiet > noise) in the children with HL. Significant effects of hearing status were also observed across groups (NH > HL), indicating that the children with HL required more trials to learn the new words. However, word learning improved significantly in noise with the use of DNR for the older but not for the younger children with HL. Hearing aid history and signal-to-noise ratio did not contribute to performance.

Conclusion

Word learning was significantly reduced in younger children, in noise, and in the presence of hearing loss. Age-related benefits of DNR were apparent for children over 10 years of age.
The simplicity of perfect atoms: Degeneracies in supersymmetric hydrogen
Authors: Rube Tomas , Wacker Jay G.
Published: June 2011

Supersymmetric QED hydrogen-like bound states are remarkably similar to nonsupersymmetric hydrogen, including an accidental degeneracy of the fine structure and is broken by the Lamb shift. This article classifies the states, calculates the leading order spectrum, and illustrates the results in several limits. The relation to other nonrelativistic bound states is explored.
First-principles study of Be doped CuAlS2 for p-type transparent conductive materials
Authors: Huang Dan , Zhao Yu-Jun , Tian Ren-Yu , Chen Di-Hu , Nie Jian-Jun , Cai Xin-Hua , Yao Chun-Mei
Published: June 2011

CuAlS2 has attracted much attention recently as a p-type transparent conductive material. In this paper, we investigate the site preference of substitutional Be in CuAlS2 and the transition level of BeAl using the first-principles calculation. We find that Be would be doped effectively at Al sites in CuAlS2 as a good p-type dopant. In addition, we speculate that Be–Mg or Be–Zn codoped CuAlS2 could have a mobility enhancement and thus a good p-type conductivity due to low lattice distortion.
Electron scattering from polarization charges bound on a rough interface of polar heterostructures
Authors: Quang Doan Nhat , Tung Nguyen Huyen , Tien Nguyen Thanh
Published: June 2011

We present the theory of an ad hoc scattering mechanism for carriers confined in a heterostructure (HS) made of polar materials, such as zinc blends, nitrides, and oxides. We show that the carriers in an actual polar HS must be laterally scattered extra from both piezoelectric and spontaneous polarization charges bound on a rough interface of the system. This is due to roughness-induced fluctuations in the position of interface polarization charges, so referred to as polarization roughness (PR) scattering. The new scattering is combined with the normal surface roughness (SR) scattering, giving rise to an effective roughness-related process, which is referred to as polarization surface roughness (PSR) scattering. The PSR scattering is found to be more important for nearly forward events and at small sheet carrier densities, and it is one of the key mechanisms governing transport in polar HSs. This enables a successful explanation of the mobility data on polar HSs made, e.g., of AlGaN/GaN, which has not been understood so far, starting only from the traditional scattering mechanisms.
Corner effects on phonon-limited mobility in rectangular silicon nanowire metal-oxide-semiconductor field-effect transistors based on spatially resolved mobility analysis
Authors: Lee Yeonghun , Kakushima Kuniyuki , Natori Kenji , Iwai Hiroshi
Published: June 2011

We investigated the phonon-limited electron mobility in rectangular silicon nanowire metal-oxide-semiconductor field-effect transistors (Si NW MOSFETs) using the Kubo-Greenwood formula. Although cross-sectional electrostatics has been actively investigated, the cross-sectional distribution of the spatially resolved mobility has not been studied yet. In this paper, we discuss the corner effects based on spatially resolved mobility analysis. Taking into account the subband composition for local electrons, we could study the cross-sectional spatially resolved carrier transport. A strongly confined Si NW MOSFET showed that mobility hardly fluctuated in the cross-sectional distribution with strong volume inversion. On the other hand, a less-confined Si NW MOSFET showed that the corner mobility was lower than the side mobility; therefore, our result could imply that the corner effects were not positive for improvement in mobility.
Temperature dependent resistance and cryogenic microwave spectroscopy of Au decorated silicon nanowires
Authors: Zhu Xueni , Hasko David G. , Hofmann Stephan , Milne William I.
Published: June 2011

We investigate the electrical transport properties of silicon nanowire arrays grown by Au catalyzed chemical vapor deposition, resulting in prominent Au nanoparticle sidewall decoration. dc electrical measurements show symmetric nonlinear I-V characteristics with a zero field conductivity temperature dependence consistent with nearest neighbor hopping. The characteristic energy for this temperature dependence is similar to the expected charging energy of the Au nanoparticles. The measured resistance is also dependent on the bias voltage history if large electric fields are applied. Random telegraph noise events at low temperature indicate that the measured resistance is dominated by a small number of electrons confined to a single nanowire in the array. With a fixed bias, the resistance can be influenced by indirectly coupled microwave radiation at low temperature. This results in a large number of high quality factor resonant features, indicating significant excitation lifetimes. The origin of these resonances is thought to be due to spatial Rabi oscillations of trapped electrons between pairs of trap sites located close to the channel. Such systems are promising for charge qubit-based quantum information processing.
Ta and Au(Pd) alloy metal film transducers for time-domain thermoreflectance at high pressures
Authors: Hsieh Wen-Pin , Cahill David G.
Published: June 2011

We studied the pressure dependence of the thermoreflectance and piezo-optical coefficients of metal film transducers—Al, Ta, and Au(Pd) alloy (≈5 at. % Pd)—at a laser wavelength, 785 nm, commonly used in time-domain thermoreflectance (TDTR) and picosecond acoustics experiments. Al has exceptionally high thermoreflectance at ambient pressure, dR/dT ≈ 1.3 × 10−4 K−1, but its applicability at high temperatures is limited by the low melting temperature. The thermoreflectance of Al also has an undesirable zero-crossing near 6 GPa. The thermoreflectance values of Ta and Au(Pd) are comparable to that of Al at ambient conditions but independent of pressure in the pressure range 0 < P < 10 GPa. Ta and Au(Pd) thin film transducers also show strong picosecond acoustic echoes at all pressures in this range. We conclude that Ta and Au(Pd) metal film transducers can replace Al in TDTR experiments and thereby facilitate the extension of TDTR methods to high pressures and temperatures.
Temperature dependence of weak localization effects of excitons in ZnCdO/ZnO single quantum well
Authors: Yang W. F. , Chen R. , Liu B. , Wong L. M. , Wang S. J. , Sun H. D.
Published: June 2011

We report on the optical properties of high-quanlity ZnCdO/ZnO single quantum well (SQW) grown on c-sapphire substrates by pulsed laser deposition. The temperature dependent photoluminescence (PL) of ZnO/ZnCdO SQWs exhibits an inconspicuous S-shaped property due to the weak carrier localization effect, as a consequence of the slightly inhomogeneous Cd distribution in the well layer as well as the smooth interfaces. The integrated PL intensity of the higher Cd SQW decreases faster than that of the lower sample with increasing temperature, indicating the presence of interface barrier in high Cd content SQWs.
Dynamics of the reference layer driven by spin-transfer torque: Analytical versus simulation model
Authors: Hou Zhiwei , Liu Yaowen , Cardoso Susana , Freitas Paulo P. , Chen Haohsun , Chang Ching-Ray
Published: June 2011

The magnetization orientation of the polarizing reference layer would fluctuate between the parallel and antiparallel states when the reference layer loses stability. In this paper, a combined analytical and simulation study is presented to predict the magnetic dynamics of the spin valve element with single-domain magnets as the free and reference layers. We acquire a complete phase diagram that includes the normal spin-torque switching and random magnetization fluctuations by tuning the spin torque strength between the free and reference layers. The phase dynamics strongly depends on the magnetization state of the reference layer, showing that the instability of the reference layer could be responsible for the random fluctuation events.
Formation and structural characterization of Ni nanoparticles embedded in SiO2
Authors: Sprouster D. J. , Giulian R. , Araujo L. L. , Kluth P. , Johannessen B. , Kirby N. , Ridgway M. C.
Published: June 2011

Face-centered cubic Ni nanoparticles were formed in SiO2 by ion implantation and thermal annealing. Small-angle x-ray scattering in conjunction with transmission electron microscopy was used to determine the nanoparticle size as a function of annealing temperature, whereas the local atomic structure was measured with x-ray absorption spectroscopy. The influence of finite-size effects on the nanoparticle structural properties was readily apparent and included a decrease in coordination number and bond length and an increase in structural disorder for decreasing nanoparticle size. Such results are consistent with the non-negligible surface-to-volume ratio characteristic of nanoparticles. In addition, temperature-dependent x-ray absorption spectroscopy measurements showed the mean vibrational frequency (as obtained from the Einstein temperature) decreased with decreasing nanoparticle size. This reduction was attributed to the greater influence of the loosely bound, under-coordinated surface atoms prevailing over the effects of capillary pressure, the former enhancing the low frequency modes of the vibrational density of states.
Product energy deposition of CN + alkane H abstraction reactions in gas and solution phases
Authors: Glowacki David R. , Orr-Ewing Andrew J. , Harvey Jeremy N.
Published: June 2011

In this work, we report the first theoretical studies of post-transition state dynamics for reaction of CN with polyatomic organic species. Using electronic structure theory, a newly developed analytic reactive PES, a recently implemented rare-event acceleration algorithm, and a normal mode projection scheme, we carried out and analyzed quasi-classical and classical non-equilibrium molecular dynamics simulations of the reactions CN + propane (R1) and CN + cyclohexane (R2). For (R2), we carried out simulations in both the gas phase and in a CH2Cl2 solvent. Analysis of the results suggests that the solvent perturbations to the (R2) reactive free energy surface are small, leading to product energy partitioning in the solvent that is similar to the gas phase. The distribution of molecular geometries at the respective gas and solution phase variational association transition states is very similar, leading to nascent HCN which is vibrationally excited in both its CH stretching and HCN bending coordinates. This study highlights the fact that significant non-equilibrium energy distributions may follow in the wake of solution phase bimolecular reactions, and may persist for hundreds of picoseconds despite frictional damping. Consideration of non-thermal distributions is often neglected in descriptions of condensed-phase reactivity; the extent to which the present intriguing observations are widespread remains an interesting question.
Mesophase formation in a system of top-shaped hard molecules: Density functional theory and Monte Carlo simulation
Authors: de las Heras Daniel , Varga Szabolcs , Vesely Franz J.
Published: June 2011

We present the phase diagram of a system of mesogenic top-shaped molecules based on the Parsons-Lee density functional theory and Monte Carlo simulation. The molecules are modeled as a hard spherocylinder with a hard sphere embedded in its center. The stability of five different phases is studied, namely, isotropic, nematic, smectic A, smectic C, and columnar phases. The positionally ordered phases are investigated only for the case of parallel alignment. It is found that the central spherical unit destabilizes the nematic with respect to the isotropic phase, while increasing the length of the cylinder has the opposite effect. Also, the central hard sphere has a strong destabilizing effect on the smectic A phase, due the inefficient packing of the molecules into layers. For large hard sphere units the smectic A phase is completely replaced by a smectic C structure. The columnar phase is first stabilized with increasing diameter of the central unit, but for very large hard sphere units it becomes less stable again. The density functional results are in good agreement with the simulations.
Correlation of the change in transfer characteristics with the interfacial trap densities of amorphous In–Ga–Zn–O thin film transistors under light illumination
Authors: Kim Jeong Hwan , Kim Un Ki , Chung Yoon Jang , Hwang Cheol Seong
Published: June 2011

The change in the transfer characteristics of amorphous In–Ga–Zn–O thin film transistors (TFTs) was investigated under light illumination at various wavelengths. The variations in the interfacial trap density (Dit) were also studied using metal-insulator-semiconductor capacitors. The transfer characteristics of the TFTs were dependent on the wavelength of illuminated light. The increase in subthreshold swing observed under light illumination of wavelengths below 550 nm (∼2.3 eV) was confirmed to be related to the increase in Dit near the conduction band edge. This Dit increase is caused by doubly ionized oxygen vacancies (VO2+) that are temporarily generated under light illumination.
Induced magnetic anisotropy in lifted (Ga,Mn)As thin films
Authors: Greullet F. , Ebel L. , Münzhuber F. , Mark S. , Astakhov G. V. , Kießling T. , Schumacher C. , Gould C. , Brunner K. , Ossau W. , Molenkamp L. W.
Published: June 2011

We demonstrate the ability to release the growth-induced strain in (Ga,Mn)As layers and (In,Ga)As/(Ga,Mn)As bilayers by lifting them from the GaAs substrate. The lifted (bi)layers are then deposited back onto various substrates. The change in strain before and after processing has been studied by means of x-ray diffraction. Magnetic characterization demonstrates the efficiency of our lift-off process to reorient the magnetization to the direction normal to the layer plane.
Real time demonstration of high bitrate quantum random number generation with coherent laser light
Authors: Symul T. , Assad S. M. , Lam P. K.
Published: June 2011

We present a random number generation scheme that uses broadband measurements of the vacuum field contained in the radio-frequency sidebands of a single-mode laser. Even though the measurements may contain technical noise, we show that suitable algorithms can transform the digitized photocurrents into a string of random numbers that can be made arbitrarily correlated with a subset of the quantum fluctuations (high quantum correlation regime) or arbitrarily immune to environmental fluctuations (high environmental immunity). We demonstrate up to 2 Gbps of real time random number generation that were verified using standard randomness tests.
Relational and Dialectical Spaces of Knowing: Knowledge, Practice, and Work in Economic Geography
Authors: Vallance Paul
Published: June 2011

Recent work in economic geography suggests the emergence of a distinctive relational and practice-centred set of perspectives on knowledge, based around concepts including communities of practice and relational proximity. This paper will argue that, despite the significant advances in understanding this work contributes, it does not yet provide a complete account of knowing-in-practice, and proposes a stronger focus on work activity as a first step in addressing this gap. The first half critically reviews this economic geography literature, focusing on how it articulates a view of practice in relation to knowledge, organisation, and space. The second half develops an alternative conceptualisation of knowing as work practice, particularly drawing on cultural–historical activity theory. This is organised around the dual spatially inflected concepts of situated and distributed knowledge. The paper concludes by arguing that, far from being mutually exclusive, the situated and distributed parts of knowing coexist in a dialectical relationship, and their interaction in work practice leads to the production of spaces of collective knowing.
Privatization, Marketization, and Deprivation: Interpreting the Homeownership Paradox in Postreform Urban China
Authors: Chen Guo
Published: June 2011

The paper examines the nature of the housing predicaments faced by China's urban poor since the advent of pro-ownership housing marketization in the 1990s. It is argued that housing deprivation in today's urban China is a complex problem which is difficult to disentangle based solely on the material outcomes of housing distribution and housing inequalities. Therefore, an integrative framework is proposed to examine the issue from the perspective of structure–agency interaction. Statistical methods are employed to identify the concrete market and nonmarket factors which constrain the housing decisions of Nanjing's poor families, based on census and household-survey data. Qualitative interviews are then utilized to help reconstruct and interpret different storylines of homeownership transition under the identified constraints. Findings suggest that the ownership-based housing model has been promoted among the poor in exploitative ways, which has resulted in profound deprivation—for both poor owners and nonowners. Alternative, nonownership housing options are urgently needed to address the problem.
Aphids alter host-plant nitrogen isotope fractionation
Authors: Wilson Alex C. C. , Sternberg Leonel da S. L. , Hurley Katherine B.
Published: June 2011

Plant sap-feeding insects and blood-feeding parasites are frequently depleted in
15
N relative to their diet. Unfortunately, most fluid-feeder/host nitrogen stable-isotope studies simply report stable-isotope signatures, but few attempt to elucidate the mechanism of isotopic trophic depletion. Here we address this deficit by investigating the nitrogen stable-isotope dynamics of a fluid-feeding herbivore-host plant system: the green peach aphid,
Myzus persicae
, feeding on multiple brassicaceous host plants.
M. persicae
was consistently more than 6‰ depleted in
15
N relative to their hosts, although aphid colonized plants were 1.5‰ to 2.0‰ enriched in
15
N relative to uncolonized control plants. Isotopic depletion of aphids relative to hosts was strongly related to host nitrogen content. We tested whether the concomitant aphid
15
N depletion and host
15
N enrichment was coupled by isotopic mass balance and determined that aphid
15
N depletion and host
15
N enrichment are uncoupled processes. We hypothesized that colonized plants would have higher nitrate reductase activity than uncolonized plants because previous studies had demonstrated that high nitrate reductase activity under substrate-limiting conditions can result in increased plant δ
15
N values. Consistent with our hypothesis, nitrate reductase activity in colonized plants was twice that of uncolonized plants. This study offers two important insights that are likely applicable to understanding nitrogen dynamics in fluid-feeder/host systems. First, isotopic separation of aphid and host depends on nitrogen availability. Second, aphid colonization alters host nitrogen metabolism and subsequently host nitrogen stable-isotope signature. Notably, this work establishes a metabolic framework for future hypothesis-driven studies focused on aphid manipulation of host nitrogen metabolism.
Nonlinear effect of climate on plague during the third pandemic in China
Authors: Xu Lei , Liu Qiyong , Stige Leif Chr. , Ben Ari Tamara , Fang Xiye , Chan Kung-Sik , Wang Shuchun , Stenseth Nils Chr. , Zhang Zhibin
Published: June 2011

Over the years, plague has caused a large number of deaths worldwide and subsequently changed history, not the least during the period of the Black Death. Of the three plague pandemics, the third is believed to have originated in China. Using the spatial and temporal human plague records in China from 1850 to 1964, we investigated the association of human plague intensity (plague cases per year) with proxy data on climate condition (specifically an index for dryness/wetness). Our modeling analysis demonstrates that the responses of plague intensity to dry/wet conditions were different in northern and southern China. In northern China, plague intensity generally increased when wetness increased, for both the current and the previous year, except for low intensity during extremely wet conditions in the current year (reflecting a dome-shaped response to current-year dryness/wetness). In southern China, plague intensity generally decreased when wetness increased, except for high intensity during extremely wet conditions of the current year. These opposite effects are likely related to the different climates and rodent communities in the two parts of China: In northern China (arid climate), rodents are expected to respond positively to high precipitation, whereas in southern China (humid climate), high precipitation is likely to have a negative effect. Our results suggest that associations between human plague intensity and precipitation are nonlinear: positive in dry conditions, but negative in wet conditions.
Loss of the
miR-21
allele elevates the expression of its target genes and reduces tumorigenesis
Authors: Ma Xiaodong , Kumar Munish , Choudhury Saibyasachi N. , Becker Buscaglia Lindsey E. , Barker Juanita R. , Kanakamedala Keerthy , Liu Mo-Fang , Li Yong
Published: June 2011

MicroRNA 21 (miR-21) is overexpressed in virtually all types of carcinomas and various types of hematological malignancies. To determine whether miR-21 promotes tumor development in vivo, we knocked out the
miR-21
allele in mice. In response to the 7,12-dimethylbenz[
a
]anthracene (DMBA)/12-
O
-tetradecanoylphorbol-13-acetate mouse skin carcinogenesis protocol,
miR-21
-null mice showed a significant reduction in papilloma formation compared with wild-type mice. We revealed that cellular apoptosis was elevated and cell proliferation was decreased in mice deficient of miR-21 compared to wild-type animals. In addition, we found that a large number of validated or predicted miR-21 target genes were up-regulated in
miR-21
-null keratinocytes, which are precursor cells to skin papillomas. Specifically, up-regulation of
Spry1
,
Pten
, and
Pdcd4
when miR-21 was ablated coincided with reduced phosphorylation of ERK, AKT, and JNK, three major downstream effectors of Ras activation that plays a predominant role in DMBA-initiated skin carcinogenesis. These results provide in vivo evidence that miR-21 exerts its oncogenic function through negatively regulating its target genes.
Value-driven attentional capture
Authors: Anderson Brian A. , Laurent Patryk A. , Yantis Steven
Published: June 2011

Attention selects which aspects of sensory input are brought to awareness. To promote survival and well-being, attention prioritizes stimuli both voluntarily, according to context-specific goals (e.g., searching for car keys), and involuntarily, through attentional capture driven by physical salience (e.g., looking toward a sudden noise). Valuable stimuli strongly modulate voluntary attention allocation, but there is little evidence that high-value but contextually irrelevant stimuli capture attention as a consequence of reward learning. Here we show that visual search for a salient target is slowed by the presence of an inconspicuous, task-irrelevant item that was previously associated with monetary reward during a brief training session. Thus, arbitrary and otherwise neutral stimuli imbued with value via associative learning capture attention powerfully and persistently during extinction, independently of goals and salience. Vulnerability to such value-driven attentional capture covaries across individuals with working memory capacity and trait impulsivity. This unique form of attentional capture may provide a useful model for investigating failures of cognitive control in clinical syndromes in which value assigned to stimuli conflicts with behavioral goals (e.g., addiction, obesity).
2D NMR-spectroscopic screening reveals polyketides in ladybugs
Authors: Deyrup Stephen T. , Eckman Laura E. , McCarthy Patrick H. , Smedley Scott R. , Meinwald Jerrold , Schroeder Frank C.
Published: June 2011

Small molecules of biological origin continue to yield the most promising leads for drug design, but systematic approaches for exploring nature’s cache of structural diversity are lacking. Here, we demonstrate the use of 2D NMR spectroscopy to screen a library of biorationally selected insect metabolite samples for partial structures indicating the presence of new chemical entities. This NMR-spectroscopic survey enabled detection of novel compounds in complex metabolite mixtures without prior fractionation or isolation. Our screen led to discovery and subsequent isolation of two families of tricyclic pyrones in
Delphastus catalinae
, a tiny ladybird beetle that is employed commercially as a biological pest control agent. The
D. catalinae
pyrones are based on 23-carbon polyketide chains forming 1,11-dioxo-2,6,10-trioxaanthracene and 4,8-dioxo-1,9,13-trioxaanthracene derivatives, representing ring systems not previously found in nature. This study highlights the utility of 2D NMR-spectroscopic screening for exploring nature’s structure space and suggests that insect metabolomes remain vastly underexplored.
Bub1 overexpression induces aneuploidy and tumor formation through Aurora B kinase hyperactivation
Authors: Ricke Robin M. , Jeganathan Karthik B. , van Deursen Jan M.
Published: June 2011

High expression of the protein kinase Bub1 has been observed in a variety of human tumors and often correlates with poor clinical prognosis, but its molecular and cellular consequences and role in tumorigenesis are unknown. Here, we demonstrate that overexpression of Bub1 in mice leads to near-diploid aneuploidies and tumor formation. We found that chromosome misalignment and lagging are the primary mitotic errors responsible for the observed aneuploidization. High Bub1 levels resulted in aberrant Bub1 kinase activity and hyperactivation of Aurora B kinase. When Aurora B activity is suppressed, pharmacologically or via BubR1 overexpression, chromosome segregation errors caused by Bub1 overexpression are largely corrected. Importantly, Bub1 transgenic mice overexpressing Bub1 developed various kinds of spontaneous tumors and showed accelerated Myc-induced lymphomagenesis. Our results establish that Bub1 has oncogenic properties and suggest that Aurora B is a critical target through which overexpressed Bub1 drives aneuploidization and tumorigenesis.
Formation of new alumina by shearing at high pressure
Authors: Furuichi H
Published: June 2011

The structures of inorganic solids sheared at high pressure more frequently persist at ambient conditions than those hydrostatically pressurized to high pressure. Accordingly, we can expect to fabricate materials with high-pressure structure to use them for practical purposes at ambient conditions. I, therefore, sheared α-alumina, at gradually heightened pressure up to 18 GPa at room temperature and took transmission X-ray diffraction patterns from the central area of the specimens on imaging plates, one year after the shearing. They showed broad diffused rings. This indicates that the sheared structure is highly disordered. The rings roughly correspond to a highly disordered structure consisting of simple cubic lattices, with the exception of two rings. Alumina with the former structure has not yet been reported. The latter rings correspond to those of alumina above 90 GPa (the structure is unknown). The fact mentioned above suggests the existence of an intermediate state between α-alumina and the alumina above 90 GPa. The above facts also suggest that the transformation mentioned above and the disordering of lattices contributed to plastic deformation of the specimen during the shearing.
Shapes of tetrahedra with prescribed cone angles
Authors: González Ahtziri , López-López Jorge
Published: June 2011

Given real numbers

4
π
>

θ
0

≥

θ
1

≥

θ
2

≥

θ
3

>
0

4\pi >\theta _0\geq \theta _1\geq \theta _2\geq \theta _3>0

so that

∑

j
=
0

3

θ
j

=
4
π

\sum _{j=0}^3\theta _j=4\pi

, we provide a detailed description of the space of flat metrics on the 2-sphere with 4 conical points of cone angles

θ
0

,

θ
1

,

θ
2

,

θ
3

\theta _0,\theta _1,\theta _2,\theta _3

, endowed with a geometric structure arising from the area function.
Herodas
Authors: Zanker Graham
Published: June 2011

Herodas, a poet of the early third century bce whose name also appears in ancient sources as Herondas and Herodes, is the inventor of mimiambs, mimes in iambic verse, which have come down to us in eight poems, a fragmentary ninth, and quotations. They combine considerable literary sophistication with “low” subject matter. This includes a bawd tempting a young woman to form a liaison with a young man (Mimiamb 1), a brothel keeper suing an alleged kidnapper of one of his girls (2), the beating of an unruly schoolboy by his teacher under the direction of the boy’s desperate mother (3), two women’s admiration of statues and a painting by Apelles during a visit to a temple of Asclepius (4), a sadistic punishment by a female owner of a slave who has shared his sexual favors with another woman (5), an intimate conversation between two women about a missing dildo (6), a visit to a shoemaker who is probably selling dildoes on the sly (7), and a dream of Herodas’s in which he defends his poetic invention (8). Herodas is not known to have written poetry of any other kind.
Etruscan Architecture
Authors: Edlund-Berry Ingrid
Published: June 2011

The study of Etruscan architecture suffers greatly in comparison with its Greek and Roman counterparts because of the building materials used. Whereas Greek temples, such as the Parthenon in Athens, and Roman public buildings, such as the immense bath complex of Caracalla in Rome, immediately catch the attention and admiration of students and travelers, Etruscan architectural remains consist for the most part of underground tombs, foundation walls, models of huts and houses, and fragments of terracotta roof decoration. At the same time, thanks to the description by the Roman architectural historian Vitruvius (Ten Books on Architecture 4.7.1–4), the proportions and layout of the so-called Tuscan temple are well known and have been much admired and studied during the Renaissance and later. The perception of Etruscan architecture has, however, changed much since the advent of large-scale excavations in the late 19th century, and since the 1950s new evidence has produced important results for our understanding of the architectural traditions in ancient Italy.