bluuebunny/crossref_metadata_2025 huggingface dataset:
A system-level neural model of the brain mechanisms underlying instrumental devaluation in rats
Authors: Mannella Francesco , Mirolli Marco , Baldassarre Gianluca
Published: March 2011

Goal-directed behaviours are defined by the presence of two kinds of effect on instrumental learning. First, degrading the contingencies between produced actions and desired outcomes diminishes the number of instrumental responses; second, devaluing a reward results in a lower production of instrumental actions to obtain it. We present a computational model of the neural processes underlying instrumental devaluation in rats. The model reproduces the interaction between the basolateral complex of the amygdala (BLA) and the limbic, associative and somatosensory striato-cortical loops. Firing-rate units are used to abstract the activity features of neural populations. Learning is reproduced through the use of dopamine-dependent simple and differential hebbian rules. Constraints from anatomy of the projections between neural systems are taken into account. The central hypothesis implemented in the model is that pavlovian associations learned within the BLA between manipulanda and rewards modulate goal selection through the activation of the nucleus accumbens core (NaccCo). Selection processes happening in the limbic basal ganglia with the activation of the NaccCo decide which outcome is choosen as a goal within the prelimbic cortex (PL). Connections between the BLA and the NaccCo are learned through hebbian associations mediated by feedbacks from the PL to the NaccCo. Information about selected goals from the limbic striato-cortical loop influences action selection in the sensorimotor loop both through cortico-cortical projections and through a striato-nigro-striatal dopaminergic pathway passing through the associative striato-cortical loop. The model is tested as part of the control system of a simulated rat. Instrumental devaluation tasks are reproduced. Simulated lesions of the BLA, the NaccCo, the PL and the dorsomedial striatum (DMS) both before and after training reproduce the behavioural effect of lesions in real rats. The model provides predictions about the effects of still undocumented lesions.
A soft and dexterous motor
Authors: Anderson Iain A. , Tse Tony Chun Hin , Inamura Tokushu , O’Brien Benjamin M. , McKay Thomas , Gisby Todd
Published: March 2011

We present a soft, bearing-free artificial muscle motor that cannot only turn a shaft but also grip and reposition it through a flexible gear. The bearing-free operation provides a foundation for low complexity soft machines, with multiple degree-of-freedom actuation, that can act simultaneously as motors and manipulators. The mechanism also enables an artificial muscle controlled gear change. Future work will include self-sensing feedback for precision, multidegree-of-freedom operation.
Meandering collimated beam of surface acoustic waves on a trigonal crystal ball
Authors: Yanagisawa Takayuki , Ohgi Tsuneo , Akao Shingo , Nakaso Noritaka , Tsukahara Yusuke , Ohara Yoshikazu , Tsuji Toshihiro , Yamanaka Kazushi
Published: March 2011

To fully exploit high-quality piezoelectric crystals in acoustic wave devices, it is necessary to remove limitations not related to the crystal quality. Among them, the “diffraction loss” is most serious. Previously, we have developed the ball surface acoustic wave (SAW) sensor using crystal ball. However, because of the piezoelectric crystal’s strong anisotropy, we could not control the propagation route of SAWs on a ball. Here, we report a discovery that the beam propagates along a meander route, identical at every turn. Consequently, we succeeded in completely removing the diffraction loss. Since it can fully exploit the quality of crystals, it will stimulate progress of crystal technology.
Stable high conductive amorphous InGaZnO driven by hydrogenation using hot isostatic pressing
Authors: Kim Won-Kyung , Lee Seunghun , Cho Yong Chan , Koinuma Hideomi , Jeong Se-Young , Shin Jong Moon , Cho Chae Ryong , Bae Jong-Seong , Kim Tae-Young , Park Sungkyun
Published: March 2011

We carried out hydrogen injection in amorphous InGaZnO (a-IGZO) by hot isostatic pressing (HIP) treatment under different pressures ranging from 10 to 1000 bar and investigated the stable site of hydrogen in a-IGZO. The HIP process efficiently injected hydrogen in the whole sample without the formation of indium clusters. Despite oxygen annealing, hydrogenated a-IGZO maintained a high electrical conductivity (n∼1019 cm−3 and μ∼16 cm2/V s) without any noticeable physical degradation. In this paper, we discuss the dependence of the preferential position of hydrogen in a-IGZO on the magnitude of pressure and its contribution on the electrical characteristics.
Scattering-based hole burning mediated by localized surface plasmon resonance in photoreactive random media containing Ag nanoparticles
Authors: Murai Shunsuke , Fujimoto Yutaka , Iwata Koji , Fujita Koji , Tanaka Katsuhisa
Published: March 2011

Photoreactive random media containing silver nanoparticles (Ag NPs) have been fabricated, and hole burning effects based on the interference of multiply scattered light have been investigated. Through the analysis of hole profiles, transport mean free path ℓ is estimated for the light with the wavelength of 585 nm. We find that ℓ in the samples embedded with Ag NPs is much shorter compared with that in a medium containing the same amount of titania (TiO2) NPs, indicating that Ag NPs scatter 585 nm lightwaves much stronger than TiO2 NPs because of their larger scattering cross sections due to the localized surface plasmon resonance.
Polarization Coulomb field scattering in AlGaN/AlN/GaN heterostructure field-effect transistors
Authors: Lv Yuanjie , Lin Zhaojun , Zhang Yu , Meng Lingguo , Luan Chongbiao , Cao Zhifang , Chen Hong , Wang Zhanguo
Published: March 2011

Using the measured capacitance-voltage curves of Ni Schottky contacts with different contact areas and the current-voltage characteristics for the circular and rectangular AlGaN/AlN/GaN heterostructure field-effect transistors (HFETs) at low drain-source voltage, we found that the polarization Coulomb field scattering has an important influence on the two-dimensional electron gas (2DEG) electron mobility in both the circular and rectangular AlGaN/AlN/GaN HFETs. Moreover, the polarization Coulomb field scattering in AlGaN/AlN/GaN heterostructures is relatively weaker compared to that in AlGaN/GaN heterostructures, which is attributed to the AlN interlayer in AlGaN/AlN/GaN heterostructures to enlarge the average distance between the 2DEG electrons and the polarization charges.
Highly sensitive ion detection using Si single-electron transistors
Authors: Kudo Takashi , Nakajima Anri
Published: March 2011

Si single-electron transistors (SETs) were used for highly sensitive ion detection. A multiple-island channel structure was adapted in the SET for room-temperature operation. Clear Coulomb oscillation and diamonds were observed at room temperature. Using the Coulomb oscillation, clear pH responses of drain current (Id)-gate voltage (Vg) characteristics were obtained despite the existence of Id noise. Because Coulomb oscillations have a possibility to increase the slope of Id over Vg near the half-maximum current of the peaks, high resolving power of ion, and/or biomolecule concentration can be expected. A Si-structure will make it possible to integrate the sensors on a single chip.
Nano-Schottky barrier diodes based on Sb-doped ZnS nanoribbons with controlled p-type conductivity
Authors: Peng Qiang , Jie Jiansheng , Xie Chao , Wang Li , Zhang Xiwei , Wu Di , Yu Yongqiang , Wu Chunyan , Wang Zhi , Jiang Peng
Published: March 2011

ZnS nanoribbons (NRs) with controlled p-type doping were synthesized by using Sb as dopant. The p-type conductivity of the ZnS:Sb NRs could be tuned in a wide range of seven orders of magnitude by adjusting the Sb doping level. Nano-Schottky barrier diodes based on Al/p-ZnS NRs junctions exhibited excellent device performances with a high rectification ratio >107 and a small ideality factor of ∼1.22. The diodes also showed the potential as high-sensitive UV detectors. The p-ZnS NRs are expected to act as key building blocks in nano-optoelectronics.
Measurement of valley splitting in high-symmetry Si/SiGe quantum dots
Authors: Borselli M. G. , Ross R. S. , Kiselev A. A. , Croke E. T. , Holabird K. S. , Deelman P. W. , Warren L. D. , Alvarado-Rodriguez I. , Milosavljevic I. , Ku F. C. , Wong W. S. , Schmitz A. E. , Sokolich M. , Gyure M. F. , Hunter A. T.
Published: March 2011

We have demonstrated few-electron quantum dots in Si/SiGe and InGaAs, with occupation number controllable from N=0. These display a high degree of spatial symmetry and identifiable shell structure. Magnetospectroscopy measurements show that two Si-based devices possess a singlet N=2 ground state at low magnetic field, and therefore, the twofold valley degeneracy is lifted. The valley splittings in these two devices were 270 and 120 μeV, suggesting the presence of atomically sharp interfaces in our heterostructures.
Band structures and optical gain of strained GaAsxP1−x−yNy/GaP quantum wells
Authors: Zhu Yuan-Hui , Yu Hong-Yu , Fan Wei-Jun
Published: March 2011

In the framework of effective mass Hamiltonian of semiconductor quantum well structures and band anticrossing model, we investigated the band structures of fully strained GaAsxP1−x−yNy/GaP quantum wells. The GaAsxP1−x−yNy could be widely modified to be direct-band gap or indirect-band gap by changing the mole fraction of As and N in the well layer. We found that an increase in the N mole fraction in the well layer increases the TE mode optical gain very slightly.
Superhard diamond/tungsten carbide nanocomposites
Authors: Lin Z. J. , Zhang J. Z. , Li B. S. , Wang L. P. , Mao Ho-Kwang , Hemley Russell J. , Zhao Yusheng
Published: March 2011

We investigated the processing conditions of diamond/tungsten carbide (WC) composites using in situ synchrotron x-ray diffraction (XRD) and reactive sintering techniques at high pressure and high temperatures. The as-synthesized composites were characterized by synchrotron XRD, scanning electron microscopy, high-resolution transmission electron microscopy, and indentation hardness measurements. Through tuning of the reaction temperature and time, we produced fully reacted, well-sintered, and nanostructured diamond composites with Vickers hardness of about 55 GPa and the grain size of WC binding matrix smaller than 50 nm. A specific set of orientation relationships between WC and tungsten is identified to gain microstructural insight into the reaction mechanism between diamond and tungsten.
Electric fields induced by energy level pinning at organic heterojunctions
Authors: Wilke A. , Amsalem P. , Frisch J. , Bröker B. , Vollmer A. , Koch N.
Published: March 2011

We investigated the energy levels at organic heterojunctions comprising the donor diindenoperylene (DIP) on top of the acceptor C60 with photoelectron spectroscopy. The intermolecular interaction is weak as evidenced on a moderate work function electrode by a small interface dipole of 0.15 eV and flat energy levels on both sides of the junction. When a high work function electrode is used, the DIP levels become Fermi-level pinned and an electric field drops within the C60 layer underneath. The electric field distribution within an organic opto-electronic device may thus be adjusted by employing interfacial energy level pinning, even at physisorptive organic/organic interfaces.
Theoretical discussion for electron-density distribution in multicusp ion source
Authors: Zhan Hualin , Hu Chundong , Xie Yahong , Wu Bin , Wang Jinfang , Liang Lizheng , Wei Jianglong
Published: March 2011

By introducing some ideas of magnetohydrodynamics (MHD) and kinetic theories, some useful solutions for electron-density distribution in the radial direction in multicusp ion source are obtained. Therefore, some conclusions are made in this perspective: 1, the electron-density distributions in a specific region in the sheath are the same with or without magnetic field; 2, the influence of magnetic field on the electron density obeys exponential law, which should take into account the collision term as well if the magnetic field is strong; 3, the result derived from the Boltzmann equation is qualitatively consistent with some given experimental results.
Influences of surface reconstruction on the atomic-layer-deposited HfO2/Al2O3/n-InAs metal-oxide-semiconductor capacitors
Authors: Lin Hau-Yu , Wu San-Lein , Cheng Chao-Ching , Ko Chih-Hsin , Wann Clement H. , Lin You-Ru , Chang Shoou-Jinn , Wu Tai-Bor
Published: March 2011

We report the characteristics of HfO2/Al2O3/n-InAs metal-oxide-semiconductor capacitors on different reconstructed surface InAs substrates. The HfO2/Al2O3 gate dielectric films deposited on InAs were used to study the interfacial reaction. Compared with (2×4)-surface sample, improvements of capacitance-voltage characteristics for (1×1)-surface sample with lower frequency-dependent capacitance dispersion and higher inversion capacitance are attributed to lower indium composition and less arsenic oxide at Al2O3/InAs interface, as confirmed by x-ray photoelectron spectroscopy. It indicates that the equivalent dangling bond of cations and anions on (1×1)-surface sample tends to avoid the oxidization process and become less pinning.
Pyroelectric, piezoelectric, and photoeffects in hydroxyapatite thin films on silicon
Authors: Lang S. B. , Tofail S. A. M. , Gandhi A. A. , Gregor M. , Wolf-Brandstetter C. , Kost J. , Bauer S. , Krause M.
Published: March 2011

Hydroxyapatite (HA) is the major component of bone and is used in artificial form in many biomedical applications. It was once believed to have a centrosymmetric crystal structure. In theoretical and experimental studies published in 2005, it was shown to have a monoclinic P21 structure. In the work reported here, 500 nm films of HA were spin-coated on silicon wafers. The materials were not poled. They had a nonuniform polarization distribution and exhibited pyroelectricity, piezoelectricity, and photoeffects. Structures of this type may have a number of technological applications.
The effect of trimethylgallium flows in the AlInGaN barrier on optoelectronic characteristics of near ultraviolet light-emitting diodes grown by atmospheric pressure metalorganic vapor phase epitaxy
Authors: Fu Yi-Keng , Jiang Ren-Hao , Lu Yu-Hsuan , Chen Bo-Chun , Xuan Rong , Fang Yen-Hsiang , Lin Chia-Feng , Su Yan-Kuin , Chen Jenn-Fang
Published: March 2011

The letter reports a theoretical and experimental study on the device performance of near ultraviolet light-emitting diodes (LEDs) with quaternary AlInGaN quantum barrier (QB). The indium mole fraction of AlInGaN QB could be enhanced as we increased the trimethylgallium flow rate. It was found the AlInGaN/InGaN LEDs can reduce forward voltage and improve light output power, compared with conventional GaN QB. By using advanced device simulation, it should be attributed to a reduction in lattice mismatch induced polarization mismatch in the active layer, which results in the suppression of electron overflow.
Role of ZrO2 incorporation in the suppression of negative bias illumination-induced instability in Zn–Sn–O thin film transistors
Authors: Yang Bong Seob , Huh Myung Soo , Oh Seungha , Lee Ung Soo , Kim Yoon Jang , Oh Myeong Sook , Jeong Jae Kyeong , Hwang Cheol Seong , Kim Hyeong Joon
Published: March 2011

Thin film transistors (TFTs) with In and Ga-free multicomponent Zn–Sn–Zr–O (ZTZO) channel layers were fabricated using the cosputtering approach. The incorporation of ZrO2 into the Zn–Sn–O (ZTO) films increased the contact resistance, which led to the degradation of the transport properties. In contrast, the threshold voltage shift under negative bias illumination stress (NBIS) was largely improved from −12.5 V (ZTO device) to −4.2 V (ZTZO device). This improvement was attributed to the reduction in the oxygen vacancy defects in the ZTZO film, suggesting that the photoinduced transition from VO to VO2+ was responsible for the NBIS-induced instability.
Efficient blocking of planar defects by prismatic stacking faults in semipolar (112¯2)-GaN layers on m-sapphire by epitaxial lateral overgrowth
Authors: Lacroix B. , Chauvat M. P. , Ruterana P. , Nataf G. , de Mierry P.
Published: March 2011

For the next-generation solid state lighting, the production of high quality semipolar (112¯2) GaN layers on sapphire obtained using asymmetric epitaxial lateral overgrowth (ELO) method has been investigated. This type of ELO leads to efficient blocking of the basal stacking faults (BSFs) in the bulk, and enables the formation of nondefective layers at the surface. The BSFs terminate due to generation of prismatic stacking faults along a well defined boundary. The corresponding intensity of GaN band edge photoluminescence emission is increased by more than four orders of magnitude in comparison to that from semipolar templates.
Direct observation of N-(group V) bonding defects in dilute nitride semiconductors using hard x-ray photoelectron spectroscopy
Authors: Ishikawa F. , Fuyuno S. , Higashi K. , Kondow M. , Machida M. , Oji H. , Son J.-Y. , Trampert A. , Umeno K. , Furukawa Y. , Wakahara A.
Published: March 2011

Using bulk sensitive hard x-ray photoelectron spectroscopy, we directly observe a spectrum related to N–As bonding defects in (Ga,In)(N,As)/Ga(N,As) heterostructure. The defects are most likely attributed to split interstitials. Their concentration is in the order of 1019 cm−3, close to the detection limit of the measurement. Rapid thermal annealing eliminates the defects, leading to those undetectable. Similar phenomenon is observed for N–P bonding defects in In(N,P). The results indicate common features in dilute nitride semiconductor system: existence of N-(group V) bonding defects and their behavior on postgrowth annealing.
Why the Causal View of Fitness Survives
Authors: Otsuka Jun , Turner Trin , Allen Colin , Lloyd Elisabeth A.
Published: March 2011

We critically examine Denis Walsh's latest attack on the causalist view of fitness. Relying on Judea Pearl's Sure-Thing Principle and geneticist John Gillespie's model for fitness, Walsh has argued that the causal interpretation of fitness results in a reductio. We show that his conclusion only follows from misuse of the models, that is, (1) the disregard of the real biological bearing of the population-size parameter in Gillespie's model and (2) the confusion of the distinction between ordinary probability and Pearl's causal probability. Properly understood, the models used by Walsh do not threaten the causalist view of fitness.
Direct and Indirect Roles for Values in Science
Authors: Elliott Kevin C.
Published: March 2011

Although many philosophers have employed the distinction between “direct” and “indirect” roles for values in science, I argue that it merits further clarification. The distinction can be formulated in several ways: as a logical point, as a distinction between epistemic attitudes, or as a clarification of different consequences associated with accepting scientific claims. Moreover, it can serve either as part of a normative ideal or as a tool for policing how values influence science. While various formulations of the distinction may (with further clarification) contribute to a normative ideal, they have limited effectiveness for regulating how values influence science.
Modeling and experimental verification of low-frequency MEMS energy harvesting from ambient vibrations
Authors: Miller L M , Halvorsen E , Dong T , Wright P K
Published: March 2011

Micro-fabricated piezoelectric vibration energy harvesters with resonance frequencies of 31–232 Hz are characterized and deployed for testing on ambient vibration sources in the machine room of a large building. A survey of 23 ambient vibration sources in the machine room is presented. A model is developed which uses a discretization method to accept measured arbitrary acceleration data as an input and gives harvester response as output. The modeled and measured output from the energy harvesters is compared for both vibrometer and ambient vibration sources. The energy harvesters produced up to 43 nWrms g−2 on a laboratory vibrometer and 10 nW g−2 on ambient vibration sources typically in large buildings.
On convergence of the proximal point algorithm in Banach spaces
Authors: Matsushita Shin-ya , Xu Li
Published: March 2011

In this paper, we give a sufficient condition which guarantees that the sequence generated by the proximal point algorithm terminates after a finite number of iterations.
A note on the topological stable rank of an ideal
Authors: Ji You , Zhang Yuan
Published: March 2011

We show that if

J

\mathfrak {J}

is an ideal of a Banach algebra

A

\mathfrak {A}

, then the left (right) topological stable rank of

J

\mathfrak {J}

is no greater than the left (right) topological stable rank of

A

\mathfrak {A}

.
Bowel Habits and Behaviors Related to Defecation in 10‐ to 16‐year‐olds: Impact of Socioeconomic Characteristics and Emotional Stress
Authors: Devanarayana Niranga Manjuri , Rajindrajith Shaman
Published: March 2011

Objectives:

Bowel habits vary depending on food consumption and genetic factors. The knowledge regarding this physiological phenomenon is limited. Thorough understanding of normal bowel habits is essential for correct diagnosis of defecation disorders. This study evaluated the normal bowel habits of Sri Lankan children.

Patients and Methods:

Children ages 10 to 16 years were randomly selected from 5 schools in 4 districts. Those without defecation disorders were recruited. Details regarding their bowel habits during previous 2 months were collected using a validated, self‐administered questionnaire.

Results:

A total of 2273 children were enrolled (mean age 13.2 years, SD 1.7 years, boys 49.7%). Of them, 1748 (76.9%) opened bowels once daily, whereas 149 (6.6%) and 11 (0.5%) had <3/week and >3/day defecations, respectively. Stool consistency was normal in 1997 (87.9%), hard in 86 (3.8%), and changing consistency in 163 (7.1%). Straining was present in 639 (28.1%), painful defecation in 241 (10.6%), and bleeding in 49 (2.2%). One hundred six (4.7%) children reported stool withholding. Bulky stool was present in 158 (7.0%). Straining, bulky stools, and withholding posture were more common in boys, whereas painful defecation and bleeding were reported more often in girls (P<0.05). Defecation frequency was lower in those from a poor socioeconomic background and war‐affected areas (P < 0.05). Bowel frequency < 3/week, bulky stools, painful defecation, straining, and withholding posture were more common in those exposed to stressful life events (P < 0.05).

Conclusions:

The present study provides data on normal bowel habits of Sri Lankan schoolchildren and provides a firm platform to evaluate defecation disorders in them.
Granulocyte Macrophage‐Colony‐stimulating Factor Autoantibodies and Increased Intestinal Permeability in Crohn Disease
Authors: Nylund Cade M , D'Mello Sharon , Kim Mi‐Ok , Bonkowski Erin , Däbritz Jan , Foell Dirk , Meddings Jon , Trapnell Bruce C , Denson Lee A
Published: March 2011

Background:

Alterations in intestinal permeability have been implicated in the pathogenesis of Crohn disease (CD). We have reported that granulocyte macrophage‐colony‐stimulating factor (GM‐CSF) is required for mucosal barrier function in mice, and elevated neutralizing GM‐CSF autoantibodies (Ab) are associated with stricturing ileal disease and surgery in patients with CD. We hypothesized that children with CD with elevated GM‐CSF Ab would exhibit increased intestinal permeability.

Patients and Methods:

Subjects were divided into 3 groups: 15 with CD and high GM‐CSF Ab (≥1.6 μg/mL, GM‐CSF Ab Hi), 12 with CD and low GM‐CSF Ab (<1.6 μg/mL, GM‐CSF Ab Lo), and 15 healthy controls. Subjects ingested a lactulose:mannitol (L:M) solution, and urinary excretion of LM was measured by high‐performance liquid chromatography. Serum GM‐CSF Ab, endotoxin core Ab (EndoCAb), and lipopolysaccharide‐binding protein (LBP), and fecal S100A12 were determined by enzyme‐linked immunosorbent assay.

Results:

The CD groups did not vary by age, sex, disease location, or activity. Neither systemic (serum LBP) nor mucosal (fecal S100A12) inflammation differed between the CD groups. Intestinal permeability as measured by the urine L:M ratio and endotoxin exposure as measured by serum EndoCAb were increased in the GM‐CSF Ab Hi group compared to the GM‐CSF Ab Lo group and controls.

Conclusions:

Patients with CD with elevated GM‐CSF Ab exhibit an increase in bowel permeability relative to patients with CD with lower levels of GM‐CSF Ab in the absence of differences in systemic or intestinal inflammation. Therapies that target the mucosal barrier may be of particular benefit in this subgroup of patients with CD.
Cell-surface nucleolin is sequestered into EPEC microcolonies and may play a role during infection
Authors: Dean Paul , Kenny Brendan
Published: March 2011

Nucleolin is a prominent nucleolar protein that is mobilized into the cytoplasm during infection by enteropathogenicEscherichia coli(EPEC). Nucleolin also exists at low levels at the cell surface of eukaryotic cells and here we show that upon infection of an intestinal cell model, EPEC recruits and subsequently sequesters cell-surface EGFP-nucleolin into extracellularly located bacterial microcolonies. The recruitment of nucleolin was evident around bacteria within the centre of the microcolonies that were not directly associated with actin-based pedestals. Incubation of host intestinal cells with different ligands that specifically bind nucleolin impaired the ability of EPEC to disrupt epithelial barrier function but did not inhibit bacterial attachment or other effector-driven processes such as pedestal formation or microvilli effacement. Taken together, this work suggests that EPEC exploits two spatially distinct pools of nucleolin during the infection process.
Synergistic effect of non‐transmissible Sendai virus vector encoding the c‐myc suppressor FUSE‐binding protein‐interacting repressor plus cisplatin in the treatment of malignant pleural mesothelioma
Authors: Kitamura Atsushi , Matsushita Kazuyuki , Takiguchi Yuichi , Shimada Hideaki , Tada Yuji , Yamanaka Makako , Hiroshima Kenzo , Tagawa Masatoshi , Tomonaga Takeshi , Matsubara Hisahiro , Inoue Makoto , Hasegawa Mamoru , Sato Yasunori , Levens David , Tatsumi Koichiro , Nomura Fumio
Published: March 2011

Human malignant pleural mesothelioma (HMPM) is highly resistant to conventional therapy, and therefore novel therapies are required. We previously reported that overexpression of the FUSE‐binding protein‐interacting repressor (FIR), a c‐myc transcriptional repressor, induces apoptosis via c‐Myc suppression, and is thus a suitable cancer therapy. In the current preclinical trial, a fusion gene deleted non‐transmissible Sendai virus vector encoding FIR (SeV/ΔF/FIR) was prepared and its cytotoxic activity against an orthotopic xenograft model of HMPM, in combination with cisplatin, was assessed. SeV/ΔF/FIR and a fusion gene deleted non‐transmissible Sendai virus vector encoding green fluorescent protein (SeV/ΔF/GFP) were prepared. The transduction efficiency of these agents in terms of dose‐dependent cytotoxicity and/or apoptosis induction was then assessed in a few HMPM cells. Combination therapy with SeV/ΔF/FIR plus cisplatin was evaluated in vitro and in a mouse model. SeV/ΔF/FIR significantly reduced cell viability in three HMPM cell lines but was less effective in non‐tumor immortalized mesothelial cells. SeV/ΔF/FIR cytotoxicity was partly due to apoptosis induction via c‐Myc suppression. In addition, SeV/ΔF/FIR showed synergistic antitumor effects in combination with cisplatin, as was revealed by isobologram analysis in MSTO‐211H. Moreover, combination therapy with SeV/ΔF/FIR plus cisplatin demonstrated significant tumor reduction and improvement in survival rate in an animal model. Combination therapy with SeV/ΔF/FIR plus cisplatin has therapeutic potential against HMPM. SeV/ΔF/FIR plus cisplatin will be an attractive modality against HMPM in the future. (Cancer Sci 2011; 102: 1366–1373)
Methamphetamine users show greater than normal age‐related cortical gray matter loss
Authors: Nakama Helenna , Chang Linda , Fein George , Shimotsu Ryan , Jiang Caroline S. , Ernst Thomas
Published: March 2011

Background  Methamphetamine (Meth) abuse continues to be a major illicit drug of abuse. Neuroimaging findings suggest that Meth is neurotoxic and may alter various brain structures, but the effect of Meth on the aging brain has not been studied.

Aim  The aim was to determine regional volumes of cortical gray matter in the brains of adult Meth users versus healthy control subjects, and their interaction with age and Meth‐usage variables.

Design  Cross‐sectional study

Setting  Magnetic resonance imaging (MRI) Research Center located in a university‐affiliated hospital.

Participants  Thirty‐four Meth‐dependent subjects (21 men and 13 women; ages 33.1 ± 8.9 years), diagnosed according to DSM‐IV criteria, and 31 healthy non‐Meth user comparison subjects (23 men and 8 women ages 35.7 ± 8.4 years).

Measurement  Regional gray matter volumes were segmented automatically in all subjects and evaluated in relation to age, using high‐resolution MRIs at 3.0 Tesla.

Findings  After adjustment for the effects of cranium size, the Meth users showed enhanced cortical gray matter volume loss with age in the frontal (analysis of covariance interaction P = 0.02), occipital (interaction P = 0.01), temporal (interaction P < 0.001) and the insular lobes (interaction P = 0.01) compared to controls, independently of Meth‐usage patterns. Additionally, Meth users showed smaller gray matter volumes than control subjects in several subregions (dorsolateral prefrontal: P = 0.02; orbitofrontal: P = 0.03; prefrontal: P = 0.047; superior temporal: P = 0.04).

Conclusions  Methamphetamine users appear to show increased cortical gray matter loss with age which raises the possibility of accelerated decline in mental functioning.
Similar profile of cognitive impairment and recovery for Aboriginal Australians in treatment for episodic or chronic alcohol use
Authors: Dingwall Kylie M. , Maruff Paul , Cairney Sheree
Published: March 2011

Aims  The cognitive impairment and recovery associated with chronic alcohol abuse and subsequent abstinence is well understood. However, the recovery profile following heavy episodic or ‘binge’ use, which is common among some Australian Aboriginal users, has not been investigated thoroughly and no empirical studies have examined chronic use in this population. The aim of this study was to identify and compare cognitive impairment and recovery associated with chronic and episodic alcohol use among Aboriginal Australians.

Design  Longitudinal case–control design.

Setting  Residential alcohol treatment programmes in northern Australia.

Participants  Forty chronic alcohol users, 24 episodic users and 41 healthy controls [mean age = 34.24; standard deviation (SD) = 9.73].

Measurements  Cognitive assessments of visual motor, attention, memory, learning and executive functions at baseline (start of treatment), then 4 weeks and 8 weeks later. Reassessment of 31% of participants an average of 11 months later (SD = 4.4) comparing those who remained abstinent (n = 5), those who relapsed (n = 11) and healthy controls (n = 19).

Findings  At baseline, chronic and episodic alcohol users showed impaired visual motor, learning, memory and executive functions. With the exception of visual motor impairment, all deficits had improved to normal levels within 4 weeks. Visual motor deficits had normalized within 11 months. Performances did not differ at any time between chronic and episodic alcohol groups.

Conclusions  In Aboriginal Australians, episodic drinking is associated with similar patterns of impairment and recovery as chronic alcohol use. Most cognitive deficits appear to recover within the first month of abstinence, while persisting visual motor problems recover within 1 year.
Gender differences in the impact of families on alcohol use: a lagged longitudinal study of early adolescents
Authors: Kelly Adrian B. , O'Flaherty Martin , Toumbourou John W. , Connor Jason P. , Hemphill Sheryl A. , Catalano Richard F.
Published: March 2011

Aims  From the pre‐teen to the mid‐teen years, rates of alcohol use and misuse increase rapidly. Cross‐sectional research shows that positive family emotional climate (low conflict, high closeness) is protective, and there is emerging evidence that these protective mechanisms are different for girls versus boys. The aim of this study was to explore gender differences in the longitudinal impact of family emotional climate on adolescent alcohol use and exposure to peer drinking networks.

Design  Three‐wave two‐level (individual, within‐individual over time) ordinal logistic regression with alcohol use in the past year as the dependent measure and family variables lagged by 1 year.

Setting  Adolescents completed surveys during school hours.

Participants  A total of 855 Australian students (modal age 10–11 years at baseline) participating in the International Youth Development Study (Victoria, Australia).

Measurements  These included emotional closeness to mother/father, family conflict, parent disapproval of alcohol use and peer alcohol use.

Findings  For girls, the effect of emotional closeness to mothers on alcohol use was mediated by exposure to high‐risk peer networks. Parent disapproval of alcohol use was protective for both genders, but this effect was larger for boys versus girls, and there was no evidence that peer use mediated this effect. Peer drinking networks showed stronger direct risk effects than family variables.

Conclusions  Family factors unidirectionally impact on growth in adolescent alcohol use and effects vary with child gender.
Cannabis and social welfare assistance: a longitudinal study
Authors: Pedersen Willy
Published: March 2011

Aims  To investigate associations between cannabis use and subsequent receipt of social welfare assistance.

Design, setting and participants  The Young in Norway Longitudinal Study. A population‐based Norwegian sample (n = 2606) was followed‐up from adolescence to late 20s. Self‐report data were merged with data from national registers.

Measurements  Data were extracted on the use of alcohol, tobacco and cannabis and other illegal substances. Information was also retrieved on socio‐demographic and family factors, academic achievement, conduct problems and mental health. National registers provided data on social welfare assistance, educational level and crime statistics.

Findings  We observed prospective bivariate associations between increasing levels of cannabis use and subsequent social welfare assistance (P < 0.0001). The associations were reduced after adjusting for a range of potentially confounding factors, but remained significant. Frequent cannabis users were at highly increased risk for subsequently receiving social welfare assistance. At 28 years, those with 50+ times cannabis use during the previous 12 months and had an odds ratio of 9.3 (95% confidence interval: 4.3–20.1) for receiving social welfare assistance in the following 2‐year span. Users of cannabis also had longer periods of receiving social welfare assistance than others (P < 0.0001) and were less likely to leave the welfare assistance system (P < 0.0001).

Conclusions  In Norway the use of cannabis is linked with subsequent receipt of social welfare assistance whether the consequences are related to use of the substance per se, or to cultural factors and the illegal status of the cannabis. Future research should attempt to understand the interactions of factors behind these associations.
Does the introduction of comprehensive smoke‐free legislation lead to a decrease in population smoking prevalence?
Authors: Bajoga Ummulkhulthum , Lewis Sarah , McNeill Ann , Szatkowski Lisa
Published: March 2011

Aims  To investigate changes in population smoking prevalence in jurisdictions which have implemented comprehensive smoke‐free legislation, taking into account long‐term trends in smoking behaviour.

Design  Interrupted time series analysis of population‐level survey data using segmented regression.

Setting  Twenty‐one countries, American states or Canadian provinces which have implemented comprehensive smoke‐free legislation.

Participants   Respondents sampled in large representative surveys of smoking prevalence.

Measurements  For each jurisdiction, segmented regression models quantify any upwards or downwards trend in smoking prevalence prior to the introduction of smoke‐free legislation, any immediate change in the level of smoking prevalence at the time smoke‐free legislation was introduced, and any change in the trend in smoking prevalence post‐legislation compared to the pre‐legislation period.

Findings  In all but three locations there was a statistically significant decline in smoking prevalence prior to the introduction of smoke‐free legislation. In two locations, Washington and the Republic of Ireland, there was an immediate decline in the level of smoking prevalence at the introduction of legislation. In six American states there was a significant change in the rate of decline in smoking prevalence, with smoking prevalence declining more steeply in the post‐legislation period compared to the pre‐legislation period. No change in the level or trend of population smoking prevalence was seen in 13 of the 21 locations studied.

Conclusions  The introduction of comprehensive smoke‐free legislation has increased the rate at which smoking prevalence was declining in some locations, but in the majority of jurisdictions had no measureable impact on existing trends in smoking prevalence.
Social participation of youths with cerebral palsy differed based on their self‐perceived competence as a friend
Authors: Kang L‐J. , Palisano R. J. , King G. A. , Chiarello L. A. , Orlin M. N. , Polansky M.
Published: March 2011

Background  Social participation with friends fosters development of meaningful relationships, life skills and psychosocial well‐being. Youths with cerebral palsy (CP) face challenges to establishing social relationships with friends. The aim of this study was to explore whether social participation with friends differs among youths with CP based on their self‐perceived competence as a friend.

Methods  A total of 135 youths with CP, 13–21 years old (mean age 16 years, 50% were male), completed the measures Fulfillment in Social Roles and Children's Assessment of Participation and Enjoyment. Youths were assigned to high, middle and low groups defined by their self‐perceived competence as a friend. Differences among the three groups in the number, total frequency and enjoyment of activities done with friends was examined by Kruskal–Wallis one‐way analyses of variance. Post hoc analysis of significant effects was performed using a Mann–Whitney U‐test or Kolmogorov–Smirnov test.

Results  The number (χ2= 17.07, d.f. = 2, P < 0.001) and total frequency (χ2= 18.35, d.f. = 2, P < 0.001) of activities done with friends differed based on youths' self‐perceived competence as a friend. Youths with high self‐perceived competence as a friend did the greatest number of activities and participated most often with friends. Youths with low self‐perceived competence did the fewest activities and participated least often with friends. No differences were found in the enjoyment of activities done with friends among the three groups (χ2= 1.86, d.f. = 2, P > 0.05).

Conclusions  For youths with CP, the number and frequency of activities done with friends differed based on self‐perceived competence as a friend, but not enjoyment of activities. The results suggest a positive link between social participation and self‐perceived competence. Healthcare providers have a role to support youths' efforts to engage with friends by enhancing community opportunities, developing and providing interventions in natural social environments and incorporating peer support into service delivery.
The relation between health‐related quality of life, treatment adherence and disease severity in a paediatric sickle cell disease sample
Authors: Fisak B. , Belkin M. H. , von Lehe A. C. , Bansal M. M.
Published: March 2011

Background  The purpose of this study was to provide a comprehensive examination of the potential factors associated with health‐related quality of life (HRQOL) in a paediatric sickle cell disease sample.

Methods  Caregivers of 78 paediatric sickle cell disease patients completed surveys, which included measures of HRQOL, treatment adherence and barriers to treatment adherence. Medical chart reviews were also conducted to assess disease severity.

Results  Barriers to treatment adherence and pain crisis frequency were found to be the most robust factors associated with HRQOL.

Conclusions  This study provides insight into the factors related to paediatric sickle cell disease and informs both clinicians and researchers interested in understanding and improving HRQOL in this population. In particular, the reduction of pain crises frequency and barriers to adherence may be particularly effective strategies to improve HRQOL.
Profiles of language development in pre‐school children: a longitudinal latent class analysis of data from the Early Language in Victoria Study
Authors: Ukoumunne O. C. , Wake M. , Carlin J. , Bavin E. L. , Lum J. , Skeat J. , Williams J. , Conway L. , Cini E. , Reilly S.
Published: March 2011

Background  Pre‐school language impairment is common and greatly reduces educational performance. Population attempts to identify children who would benefit from appropriately timed intervention might be improved by greater knowledge about the typical profiles of language development. Specifically, this could be used to help with the early identification of children who will be impaired on school entry.

Methods  This study applied longitudinal latent class analysis to assessments at 8, 12, 24, 36 and 48 months on 1113 children from a population‐based study, in order to identify classes exhibiting distinct communicative developmental profiles.

Results  Five substantive classes were identified: Typical, i.e. development in the typical range at each age; Precocious (late), i.e. typical development in infancy followed by high probabilities of precocity from 24 months onwards; Impaired (early), i.e. high probabilities of impairment up to 12 months followed by typical language development thereafter; Impaired (late), i.e. typical development in infancy but impairment from 24 months onwards; Precocious (early), i.e. high probabilities of precocity in early life followed by typical language by 48 months. The entropy statistic (0.84) suggested classes were fairly well defined, although there was a non‐trivial degree of uncertainty in classification of children. That half of the Impaired (late) class was expected to have typical language at 4 years and 6% of the numerically large Typical class was expected to be impaired at 4 years illustrates this. Characteristics indicative of social advantage were more commonly found in the classes with improving profiles.

Conclusions  Developmental profiles show that some pre‐schoolers' language is characterized by periods of accelerated development, slow development and catch‐up growth. Given the uncertainty in classifying children into these profiles, use of this knowledge for identifying children who will be impaired on school entry is not straightforward. The findings do, however, indicate greater need for language enrichment programmes among disadvantaged children.
Autophagy in the immune response to tuberculosis: clinical perspectives
Authors: Ní Cheallaigh C , Keane J , Lavelle E C , Hope J C , Harris J
Published: March 2011

A growing body of evidence points to autophagy as an essential component in the immune response to tuberculosis. Autophagy is a direct mechanism of killing intracellular Mycobacterium tuberculosis and also acts as a modulator of proinflammatory cytokine secretion. In addition, autophagy plays a key role in antigen processing and presentation. Autophagy is modulated by cytokines; it is stimulated by T helper type 1 (Th1) cytokines such as tumour necrosis factor (TNF)-α and interferon (IFN)-γ, and is inhibited by the Th2 cytokines interleukin (IL)-4 and IL-13 and the anti-inflammatory cytokine IL-10. Vitamin D, via cathelicidin, can also induce autophagy, as can Toll-like receptor (TLR)-mediated signals. Autophagy-promoting agents, administered either locally to the lungs or systemically, could have a clinical application as adjunctive treatment of drug-resistant and drug-sensitive tuberculosis. Moreover, vaccines which effectively induce autophagy could be more successful in preventing acquisition or reactivation of latent tuberculosis.
Chemokine CXCL11 links microbial stimuli to intestinal inflammation
Authors: Liu Z , Chen X , Wang X , Chen X , Song C-H , Du Y , Su J , Yaseen S A , Yang P-C
Published: March 2011

Interleukin (IL)-17 plays an important role in the pathogenesis in a number of immune inflammatory disorders. This study aims to investigate the mechanism by which microbial product flagellin is involved in the development of T helper type (Th)17 cells. Serum levels of IL-17 and CXCL9-11 in patients with ulcerative colitis (UC) were evaluated. The source and mechanism of CXC11 release in intestinal mucosa were examined with colonic biopsies from UC patients and a colitis mouse model. The role of flagellin in the development of Th17 cells was studied with a cell co-culture system. High serum levels of CXCL11 and IL-17 were observed in UC. Flagellin could induce the production of CXCL11 in CD14+ cells that facilitated the development of Th17 cells. In a skewed Th1 response environment flagellin induces intestinal inflammation, with IL-17 expression predominant. CXCR3/CXCL11 pathway is involved in microbial product flagellin-induced intestinal inflammation in which the Th17 response plays an important role.
Parents Empowering Parents (PEP) Program: understanding its impact on the bleeding disorders community
Authors: DUTREIL S. , RICE J. , MERRITT D. , KUEBLER E. J.
Published: March 2011

Summary.  The Parents Empowering Parents (PEP) Program gives parents tools to improve the lives of children with bleeding disorders. The aim of this study was to evaluate the efficacy of PEP. Eleven haemophilia treatment centres (HTC) participated in the study and 301 participants completed the survey. Parents who did not attend PEP were divided into three groups based on their reasons for not attending: (Not Offered, Bad Time and Don’t Need). Those who attended (Attended) PEP reported less use of yelling, spanking, slapping and giving‐in after attending PEP. The Not Offered group used Praising (P = 0.016), Natural Consequences (P = 0.002), Being Consistent (P = 0.016), Ignoring (P = 0.006), Distracting (P = 0.002), Setting Limits (P = 0.009), Giving Choices (P = 0.049), Being Consistent (P = 0.014) and Distracting (P = 0.019) less than all other groups. The Bad Time group used Time‐Out (P = 0.037) and Ignoring (P = 0.019) more than the other groups that did not attend PEP. The Don’t Need group used Spanking (P = 0.008) and Time‐Out (P = 0.003) and Yelling (P = 0.014) less than all other groups. Attending PEP seems to decrease the use of negative parenting techniques. Those who reported PEP was not offered to them used positive parenting techniques less than all other participants.