bluuebunny/crossref_metadata_2025 huggingface dataset:
Symbiont acquisition alters behaviour of stinkbug nymphs
Authors: Hosokawa Takahiro , Kikuchi Yoshitomo , Shimada Masakazu , Fukatsu Takema
Published: December 2007

In parasitic associations, the evolutionary interest of a symbiont contradicts that of a host, which sometimes causes the phenomena so-called ‘parasite manipulation’ wherein symbiont infection alters host behaviour to facilitate its vertical/horizontal transmission. In mutualistic associations, meanwhile, symbiont-induced alteration of host behaviour that enhances its transmission has been little described. Here we report such a case in the stinkbugMegacopta punctatissimaassociated with an obligate gut bacterium. When female stinkbugs lay eggs, small particles called ‘symbiont capsules’ are deposited underside of the egg mass. Newborn nymphs immediately acquire the symbiont from the capsule, and then aggregate and become quiescent. By manipulating the levels of symbiont supply to newborn nymphs experimentally, we demonstrated that (i) experimental depletion of the symbiont resulted in the occurrence of wandering nymphs, (ii) the less symbiont supply, the more wandering nymphs, and (iii) almost all wandering nymphs were either symbiont-free or symbiont-depleted, whereas the majority of resting nymphs were infected with sufficient titres of the symbiont. These results strongly suggest that the nymphal behaviour is strongly influenced by the success/failure of the symbiont acquisition, thereby ensuring transmission of the essential symbiont and minimizing the energy and time spent for the activity.
Agonistic signals received by an arthropod filiform hair allude to the prevalence of near-field sound communication
Authors: Santer Roger D , Hebets Eileen A
Published: December 2007

Arthropod filiform hairs respond to air particle movements and are among the most sensitive animal sensory organs. In many species, they are tuned to detect predators or prey and trigger escape or prey capture behaviours. Here we show for the first time that these hairs also receive intraspecific near-field sound signals in an arachnid. During agonistic encounters, whip spiders (Arachnida, Amblypygi) perform antenniform leg vibration (ALV) displays that have significantly longer duration in contest winners than losers. During an ALV display: (i) the vibrating antenniform leg of the displaying whip spider is positioned close to the trichobothria (filiform hairs) on its opponent's walking legs, (ii) the vibrating antenniform leg can excite these trichobothria via air movements and without direct contact, (iii) the antenniform leg of the displaying whip spider vibrates at a frequency that causes particularly strong, sustained excitation and little adaptation in the trichobothria, and (iv) the duration of an ALV display can be extracted from the response of a trichobothrium. Since filiform hairs are widespread among arthropods, communication via such hairs could be extremely prevalent.
Experimental Study of
Pressure Drop and Heat Transfer in a Single-Phase Micropin-Fin Heat
Sink
Authors: Siu-Ho Abel , Qu Weilin , Pfefferkorn Frank
Published: December 2007

The pressure drop and heat transfer characteristics of a single-phase micropin-fin heat sink were investigated experimentally. Fabricated from 110 copper, the heat sink contained an array of 1950 staggered square micropin fins with 200×200μm2 cross section by 670μm height. The ratios of longitudinal pitch and transverse pitch to pin-fin equivalent diameter are equal to 2. De-ionized water was employed as the cooling liquid. A coolant inlet temperature of 25°C, and two heat flux levels, qeff″=50W∕cm2 and qeff″=100W∕cm2, defined relative to the platform area of the heat sink, were tested. The inlet Reynolds number ranged from 93 to 634 for qeff″=50W∕cm2, and from 127 to 634 for qeff″=100W∕cm2. The measured pressure drop and temperature distribution were used to evaluate average friction factor and local averaged heat transfer coefficient/Nusselt number. Predictions of the previous friction factor and heat transfer correlations that were developed for low Reynolds number (Re<1000) single-phase flow in short pin-fin arrays were compared to the present micropin-fin data. Moores and Joshi’s friction factor correlation (2003, “Effect of Tip Clearance on the Thermal and Hydrodynamic Performance of a Shrouded Pin Fin Array,” ASME J. Heat Transfer, 125, pp. 999–1006) was the only one that provided acceptable predictions. Predictions from the other friction factor and heat transfer correlations were significantly different from the experimental data collected in this study. These findings point to the need for further fundamental study of single-phase thermal/fluid transport process in micropin-fin arrays for electronic cooling applications.
Gene therapy in head and neck cancer: a review
Authors: Chisholm E , Bapat U , Chisholm C , Alusi G , Vassaux G
Published: December 2007

Gene therapy for cancer is a rapidly evolving field with head and neck squamous cell cancer being one of the more frequently targeted cancer types. The number of clinical trials in the UK is growing and there is already a commercially available agent in China. Various gene therapy strategies along with delivery mechanisms for targeting head and neck cancer are reviewed.
Leptin increases endothelin type A receptor levels in vascular smooth muscle cells
Authors: Juan Chi-Chang , Chuang Tung-Yueh , Lien Chih-Chen , Lin Yen-Jie , Huang Seng-Wong , Kwok Ching Fai , Ho Low-Tone
Published: December 2007

Leptin, one of the adipocyte-secreted peptides, is involved in the control of appetite and body weight. Several studies have demonstrated that plasma leptin levels are elevated in obese subjects and are positively correlated with body weight. The arterial endothelin (ET) system plays an important role in the regulation of vascular tone, and ET-1 overexpression may be involved in the pathogenesis of the hypertension associated with insulin resistance. This study was performed to explore the regulatory effects of leptin on ET receptor expression and ET binding in A10 vascular smooth muscle cells (VSMCs) by use of Northern blotting, immunoblotting, and a 125I-labeled ET-1 binding assay. The effect of leptin on ET receptor-mediated cell proliferation was also tested. The results showed that leptin caused a significant increase in [125I]-ET-1 binding, which was time- and dose-dependent. Immunoblotting showed that expression of the ET type A receptor (ETAR) in leptin (10−7 M)-treated cells was increased by up to 2.3-fold compared with controls. Levels of ETAR mRNA measured by Northern blotting were also increased by up to 2.2-fold in leptin (10−7 M)-treated cells. Pretreatment with an ERK inhibitor, PD-98059 (2.5 × 10−5 M), blocked the leptin-induced increase in 125I-ET-1 binding. Finally, ET-1 (10−7 M)-stimulated cell proliferation was enhanced by leptin (10−7 M) pretreatment, with a maximal increase of twofold compared with controls. In conclusion, leptin increases ETAR expression in VSMCs in a time- and dose-dependent manner. This effect is ERK dependent and is associated with increased ET-1-stimulated cell proliferation. These findings provide support for roles for leptin and the ET system in the pathogenesis of obesity-associated hypertension.
Diabetes models by screen for hyperglycemia in phenotype-driven ENU mouse mutagenesis projects
Authors: Aigner Bernhard , Rathkolb Birgit , Herbach Nadja , de Angelis Martin Hrabé , Wanke Rüdiger , Wolf Eckhard
Published: December 2007

More than 150 million people suffer from diabetes mellitus worldwide, and this number is expected to rise substantially within the next decades. Despite its high prevalence, the pathogenesis of diabetes mellitus is not completely understood. Therefore, appropriate experimental models are essential tools to gain more insight into the genetics and pathogenesis of the disease. Here, we describe the current efforts to establish novel diabetes models derived from unbiased, phenotype-driven, large-scale N-ethyl- N-nitrosourea (ENU) mouse mutagenesis projects started a decade ago using hyperglycemia as a high-throughput screen parameter. Mouse lines were established according to their hyperglycemia phenotype over several generations, thereby revealing a mutation as cause for the aberrant phenotype. Chromosomal assignment of the causative mutation and subsequent candidate gene analysis led to the detection of the mutations that resulted in novel alleles of genes already known to be involved in glucose homeostasis, like glucokinase, insulin 2, and insulin receptor. Additional ENU-induced hyperglycemia lines are under genetic analysis. Improvements in screen for diabetic animals are implemented to detect more subtle phenotypes. Moreover, diet challenge assays are being employed to uncover interactions between genetic and environmental factors in the pathogenesis of diabetes mellitus. The new mouse mutants recovered in phenotype-driven ENU mouse mutagenesis projects complement the available models generated by targeted mutagenesis of candidate genes, all together providing the large resource of models required for a systematic dissection of the pathogenesis of diabetes mellitus.
Sevoflurane-mediated TGF-β1 signaling in renal proximal tubule cells
Authors: Lee H. Thomas , Kim Mihwa , Song Joseph H. , Chen Sean W. C. , Gubitosa Gina , Emala Charles W.
Published: December 2007

Several volatile anesthetics, including sevoflurane, protect against renal ischemia-reperfusion injury in vivo by reducing necrosis and inflammation. Furthermore, in cultured renal tubule cells, sevoflurane directly induced the phosphorylation of the cytoprotective kinases (ERK and Akt), upregulated 70-kDa heat shock protein (HSP70), and attenuated nuclear translocation of the proinflammatory transcription factor NF-κB. It has been shown that sevoflurane increases the release of transforming growth factor-β1 (TGF-β1) in human proximal tubule (HK-2) cells via externalization of plasma membrane phosphatidylserine (PS), and this increase in TGF-β1 protected HK-2 cells against hydrogen peroxide-mediated necrosis. In this study, we aimed to determine whether the sevoflurane-mediated phosphorylation of ERK and Akt, induction of HSP70, and reduction in NF-κB activation are due to TGF-β1 receptor-mediated signaling after PS externalization in HK-2 cells. Exogenous TGF-β1 and a liposome mixture containing PS mimicked sevoflurane-mediated ERK and Akt phosphorylation and HSP70 induction in HK-2 cells. Sevoflurane and TGF-β1 caused the nuclear translocation of the SMAD3 transcription factor in HK-2 cells. Furthermore, a neutralizing TGF-β1 antibody or exogenous annexin V to bind PS prevented sevoflurane-induced ERK and Akt phosphorylation and HSP70 induction in HK-2 cells. Finally, a TGF-β1 antibody and annexin V attenuated the reduction in nuclear translocation of NF-κB by sevoflurane. Therefore, we demonstrate in this study that sevoflurane-mediated cytoprotective and anti-inflammatory effects in HK-2 cells are at least partially due to the externalization of PS and activation of TGF-β1 signaling pathways.
Deletion of Tandem Repeats Causes Flocculation Phenotype Conversion from Flo1 to NewFlo in Saccharomyces cerevisiae
Authors: Liu Nan , Wang Dong-li , Wang Zhao-yue , He Xiu-ping , Zhang Bo-run
Published: December 2007

A gene, FLONS, conferring NewFlo-type flocculation ability in yeast was cloned. The 3,396-bp ORF encoded a peptide of 1,132 amino acids with high identity to Flo1 protein. Aligned with the FLO1 gene, two repeated regions (675 and 540 bp) were lost in the middle of FLONS, revealing that this gene was a derived form of the FLO1 gene. The missing repeated sequence contained three highly homologous repeat units. Although the flocculation phenotype of the transformant YTS-S with the FLONS gene was inhibited by both mannose and glucose, it exhibited some distinguished physiological characteristics from the reported typical NewFlo-type flocculation during detailed investigation. The deletion of repeats was suspected to cause conversion of the flocculation phenotype from Flo1 to NewFlo, suggesting that intragenic tandem repeats generated functional variability in Flo1 protein.
Mixed Micelle-Template Route to Mesoporous Silica
Authors: Son You-Hwan , Park Man , Kim Sang Tae , Choy Jin-Ho
Published: December 2007

Mesoporous silica materials were prepared through a novel mixed micelle-template method which was employed by alkyl polyethylene oxide (C16E20 and C2-ceramide. X-ray diffraction patterns clearly showed the formation of mesoporous silica by contribution
of mixed micelle-template up to 3/1 weight ratio (C16E20/C2-ceramide). TEM and N2 adsorption isotherms analyses indicated that the mesoporous structure was maintained even after encased C2-ceramides. However, when the weight ratio of C16E20/C2-ceramide
exceeds 2/2, less ordered and irregular pore structure was observed. According to the in-vitro experiment on cancer cells such as MCF-7, HOS, and HepG2, the simultaneously encapsulated C2-ceramide shows apoptosis. Therefore, the present results could provide a new method for mesoporous
material as drug delivery system.
Material and Sensing Properties of Pd-Deposited WO3 Thin Films
Authors: Choi Gwangpyo , Jin Guanghu , Park Si-Hyun , Lee Woonyoung , Park Jinseong
Published: December 2007

The physicochemical and electrical properties of Pd-deposited WO3 thin films were investigated as a function of Pd thickness, annealing temperature, and operating temperature for application as a hydrogen gas sensor. WO3 thin films were deposited on an insulating
material using a thermal evaporator. X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) were used to evaluate the crystal structure, microstructure, surface roughness, and chemical property
of the films, respectively. The deposited films grew into polycrystalline WO3 with a rhombohedral structure after annealing at 500 °C. Adding Pd had no effect on the crystallinity, but suppressed the growth of WO3 grains. The Pd was scattered as isolated small spherical
particles of PdO2 on the WO3 thin film after annealing at 500 °C, while it agglomerated as irregular large particles or diffused into the WO3 after annealing at 600 °C. PdO2 reduction under H2 and reoxidation under air were dependent
on both the Pd deposition thickness and annealing conditions. The WO3 thin film with a 2-nm-thick Pd deposit showed a good response and recovery to H2 gas at a 250 °C operating temperature.
Encapsulation of Pd Complex in Ionic Liquid on Highly Ordered Mesoporous Silica MCM-41
Authors: Sarkar M. S. , Qiu Huili , Jin Myung-Jong
Published: December 2007

Palladium acetate was encapsulated onto highly ordered mesoporous silica MCM-41 with the aid of ionic liquid. The immobilized Pd complex can efficiently catalyze Heck coupling reactions of activated and non-activated aryl halides with acrylates. The Pd catalyst exhibited remarkably
high catalytic activity and outstanding stability. Moreover, the immobilized palladium acetate could be recycled at least six times without significant loss of activity.
Photocatalytic Reduction of Nitrate in Wastewater Using ZnO Nanopowder Synthesized by Solution Combustion Method
Authors: Park Sung , Kim Hee-Joon , Kim Jong Soo , Yoo Kang , Lee Jae Chun , Anderson W. A. , Lee Ju-Hyeon
Published: December 2007

ZnO nanopowder was synthesized by a unique method which is called solution combustion method (SCM). This nanopowder was used for a photocatalyst to decompose nitrate that is a toxic pollutant in wastewater. It has been known that TiO2, the most popular photocatalyst, does
not decompose the nitrate. In this paper, however, the SCM ZnO nanopowder decomposed about 13% of nitrate. Furthermore, adding methanol as a hole scavenger, the decomposition rate was enhanced by about 5 times. On the other hand, it has been reported that the photocatalytic reduction reaction
of nitrate produces ammonia as a final product. The present results, however, suggest that the final product is non-toxic nitrogen gas rather than the toxic ammonia. These results would be very valuable for drinking water purification.
Improved Electrochemical Performance of LiCoPO4 Nanoparticles for Lithium Ion Batteries
Authors: Gu Hal-Bon , Jin Bo , Jun Dae-Kyoo , Han Zhenji
Published: December 2007

Single phase LiCoPO4 nanoparticles were synthesized by solid-state reaction. LiCoPO4/Li batteries were fabricated in an argon-filled glove box, and their electrochemical properties were analyzed by cyclic voltammetry (CV) and charge–discharge tests. The structural
performance of LiCoPO4 nanoparticles was investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD result demonstrated that LiCoPO4 nanoparticles had an orthorhombic olivine-type structure with a space group of Pmnb. The charge–discharge
tests indicated that the initial discharge capacity and coulombic efficiency of LiCoPO4/Li batteries were 110 mA h/g and 48% in cut-off voltage range of 3.0–5.3 V,90 mA h/g and 54% in cut-off voltage range of 3.0–5.1 V, 70 mA h/g and 60% in cut-off voltage range of 3.0–5.0
V, respectively. After 30 cycles, the coulombic efficiency was 78% for 3.0–5.3 V, 88% for 3.0–5.1 V, 91% for 3.0–5.0 V, respectively. These results indicated that the coulombic efficiency of LiCoPO4 /Li battery increased upon cycling and upon decreasing in charge
upper limit voltage, respectively.
Autothermal Reforming of Propane over Hydrotalcite-Like Catalysts Containing Promotor
Authors: Lim You-Soon , Moon Dong-Ju , Park Nam-Cook , Shin Jae-Soon , Kim Jong-Ho , Kim Young-Chul
Published: December 2007

Hydrotalcite-like catalysts were synthesized by co-precipitation and then these were promoted by the addition of noble metals, alkaline earth metals and ceria. Reaction tests were conducted using a feed of H2O/C/O2 = 3/1/0.37 at a temperature range from 300 °C
to 700 °C. Catalysts were characterized by XRD, TEM, FESEM, TPR, and BET. Reaction test results confirmed an enhancement of the catalytic activity of the promotor-modified catalysts due to low carbon deposition. Among the alkaline earth metals tested, those with larger atomic number exhibited
higher activity at a lower temperature range.
Work Function Increase of Al-Doped ZnO Thin Films by B+ Ion Implantation
Authors: Hong Sang-Jin , Heo Gi-Seok , Park Jong-Woon , Lee In-Hwan , Choi Bum-Ho , Lee Jong-Ho , Park Se-Yeon , Shin Dong-Chan
Published: December 2007

The work function of an Al-doped ZnO (AZO) thin film can be increased via B+ ion implantation from 3.92 eV up to 4.22 eV. The ion implantation has been carried out with the ion dose of 1 × 1016 cm−2 and ion energy of 5 keV. The resistance
of the B+ implanted AZO films has been a bit raised, while their transmittance is slightly lowered, compared to those of un-implanted AZO films. These behaviors can be explained by the doping profile and the resultant band diagram. It is concluded that the coupling between the B+
ions and oxygen vacancies would be the main reason for an increase in the work function and a change in the other properties. We also address that the work function is more effectively alterable if the defect density of the top transparent conducting oxide layer can be controlled.
A Hydrogen Peroxide Biosensor Based on Peroxidase Activity of Hemoglobin in Polymeric Film
Authors: Kafi A. K. M. , Lee Dong-Yun , Park Sang-Hyun , Kwon Young-Soo
Published: December 2007

A Hydrogen peroxide (H2O2) biosensor, based on hemoglobin (Hb) and ortho-phenylenediamine (o-PD) gold electrode, was fabricated. Hb was immobilized onto the electrode surface by electrochemical polymerize method with o-PD. The designed biosensor
showed a well defined redox peak which was attributed to the direct electrochemical response of Hb. The immobilized Hb exhibited an excellent electrocatalytical response to the reduction of hydrogen peroxide, enabling the sensitivity determination of H2O2. Factors and
performances such as pH, potential, influencing the designed biosensor, were studied carefully. The amperometric detection of H2O2 was carried out at −300 mV in phosphate buffer solution (PBS) (0.1 M) with pH 6.0. This biosensor showed a fast amperometric response
(less then 5 s) to H2O2. The levels of the (Relative standard deviation) RSDs (<3 5%) for the entire analyses reflected a highly reproducible sensor performance. Using the optimized conditions, the detection limit of the biosensor was 1 × 10−7
M and linear range was from 5 × 10−6 to 1.25 × 10−4 M. In addition, this sensor showed long term stability and good sensitivity.
Fabrication of Mesoporous Cerium Dioxide Films by Cathodic Electrodeposition
Authors: Kim Young-Soo , Lee Jin-Kyu , Ahn Jae-Hoon , Park Eun-Kyung , Kim Gil-Pyo , Baeck Sung-Hyeon
Published: December 2007

Mesoporous cerium dioxide (Ceria, CeO2) thin films have been successfully electrodeposited onto ITO-coated glass substrates from an aqueous solution of cerium nitrate using CTAB (Cetyltrimethylammonium Bromide) as a templatingagent. The synthesized films underwent detailed
characterizations. The crystallinity of synthesized CeO2 film was confirmed by XRD analysis and HR-TEM analysis, and surface morphology was investigated by SEM analysis. The presence of mesoporosity in fabricated films was confirmed by TEM and small angle X-ray analysis. As-synthesized
film was observed from XRD analysis and HR-TEM image to have well-crystallized structure of cubic phase CeO2. Transmission electron microscopy and small angle X-ray analysis revealed the presence of uniform mesoporosity with a well-ordered lamellar phase in the CeO2 films
electrodeposited with CTAB templating.
Electrochemical Fabrication of SrTiO3 Nanowires with Nanoporous Alumina Template
Authors: Kang Jinwook , Ryu Jaemin , Ko Eunseong , Tak Yongsug
Published: December 2007

Strontium titanate nanowires were electrochemically synthesized with nanoporous alumina template. Both chemical and electrical variables such as electrolyte pH, temperature, and current wave-form were modulated to investigate the synthesis process of SrTiO3 nanowires. Superimposed
cathodic pulse and diffusion time accelerated the growth of SrTiO3 nanowires, which suggested that the concentration of H+ and Sr2+ ion inside alumina template had a strong influence on the formation of SrTiO3 nanowires. Morphology and crystallinity
of SrTiO3 nanowires were investigated with scanning electron microscope, X-ray diffractometer and energy dispersive X-ray spectroscopy.
Impact of Soil Moisture Anomalies on Summer Rainfall over East Asia: A Regional Climate Model Study
Authors: Kim Jung-Eun , Hong Song-You
Published: December 2007

Numerous modeling studies have shown that soil moisture anomalies in later spring have a significant effect on the summer rainfall anomalies in North America. On the other hand, the role of soil moisture in forming monsoonal precipitation in East Asia has not been identified. This study attempts to clarify the importance of soil moisture on the summer rainfall in late spring in East Asia. The National Centers for Environmental Prediction (NCEP) Regional Spectral Model (RSM) is utilized for 3-month (June–August) simulations in 1998 (above-normal precipitation year) and 1997 (below-normal precipitation year). Initial and boundary conditions are derived from the NCEP–Department of Energy (DOE) reanalysis. The control run uses the initial soil moisture from the reanalysis, whereas it is set as a saturation and wilting point for “wet” and “dry” experiments, respectively.

The impact of soil moisture anomalies on the simulated summer rainfall in East Asia is not significant. The change in precipitation between the wet and dry experiments is about 10%. A conflict between the local feedback of soil moisture and a change in large-scale circulations associated with the summertime monsoonal circulation in East Asia can be attributed as a reason for this anomaly. It is found that enhanced (suppressed) evaporation from the soil to the atmosphere in wet (dry) initial soil moisture reduces (increases) the land–sea contrast between East Asia and the Pacific Ocean, leading to a weakened sensitivity of the monsoonal circulations to the initial soil moisture. It can be concluded that the impact of the initial soil moisture is significant on the dynamic circulation in East Asia.
Multiscale Impacts of Variable Heating in Climate
Authors: Sardeshmukh Prashant D. , Sura Philip
Published: December 2007

While it is obvious that the mean diabatic forcing of the atmosphere is crucial for maintaining the mean climate, the importance of diabatic forcing fluctuations is less evident in this regard. Such fluctuations do not appear directly in the equations of the mean climate but affect the mean indirectly through their effects on the time-mean transient-eddy fluxes of heat, momentum, and moisture. How large are these effects? What are the effects of tropical phenomena associated with substantial heating variations such as ENSO and the MJO? To what extent do variations of the extratropical surface heat fluxes and precipitation affect the mean climate? What are the effects of the rapid “stochastic” components of the heating fluctuations? Most current climate models misrepresent ENSO and the MJO and ignore stochastic forcing; they therefore also misrepresent their mean effects. To what extent does this contribute to climate model biases and to projections of climate change?

This paper provides an assessment of such impacts by comparing with observations a long simulation of the northern winter climate by a dry adiabatic general circulation model forced only with the observed time-mean diabatic forcing as a constant forcing. Remarkably, despite the total neglect of all forcing variations, the model reproduces most features of the observed circulation variability and the mean climate, with biases similar to those of some state-of-the-art general circulation models. In particular, the spatial structures of the circulation variability are remarkably well reproduced. Their amplitudes, however, are progressively underestimated from the synoptic to the subseasonal to interannual and longer time scales. This underestimation is attributed to the neglect of the variable forcing. The model also excites significant tropical variability from the extratropics on interannual scales, which is overwhelmed in reality by the response to tropical heating variability. It is argued that the results of this study suggest a role for the stochastic, and not only the coherent, components of transient diabatic forcing in the dynamics of climate variability and the mean climate.
School Bullying Among Hong Kong Chinese Primary Schoolchildren
Authors: Wong Dennis S. W. , Lok David P. P. , Wing Lo T. , Ma Stephen K.
Published: December 2007

The first comprehensive survey of 7,025 Chinese primary schoolchildren found that 24% of respondents reported that they had sometimes physically bullied another child. When children observed school bullying, 56% said they immediately reported it to their teachers. Another 20% tried to stop the bullying by approaching the bullies. The study also identified factors associated with bullying. These included coming from an adverse psychosocial background and having more contact with violent values through association with deviant peers and exposure to the mass media. On the basis of the research findings, potential methods of bullying intervention are discussed.
An Examination of the Validity of SUS-TAS in Cross-Cultures
Authors: Sirakaya-Turk Ercan , Ekinci Yuksel , Kaya Alp Giray
Published: December 2007

The purpose of this study is to validate the Sustainable Tourism Attitude Scale (SUS-TAS), which measures residents' attitudes toward sustainable tourism development. Using two data sets from Turkey and the Turkish Republic of Northern Cyprus, a confirmatory factor analysis was employed to assess psychometric properties of SUS-TAS. Although the original SUS-TAS items were reduced in number from 44 to 33, the revised scale demonstrated good psychometric properties. The data supported validity of the original seven SUS-TAS dimensions in two samples. Furthermore, the final version of SUS-TAS demonstrated adequate construct validity and good internal consistency. The findings of the study suggest that SUS-TAS can be used to assess resident attitudes toward sustainable tourism development in cross-cultural settings.
In situ monitoring of polyurethane cure using fibre-optical FT-NIR spectroscopy
Authors: Benali S. , Bertrand D. , Dupuy J. , Lachenal G. , Maazouz A.
Published: December 2007

In-line monitoring of the reaction extent of polyurethane during a reactive injection moulding (RIM) process is carried out using fibre-optic near infrared (NIR) spectroscopy. Up to 250 transmission spectra are recorded during the reaction. Univariate and multivariate analysis of transmittance spectra were used to calculate the chemical conversion. A good agreement is observed between first principal component of principal component analysis (PCA), and univariate (Beer—Lambert) results. It is observed that, in this case, the PCA method can provide a good practical estimation of the time-concentration profile during the reaction, without the need of the time-consuming calibration methods. The scores of PC1 are merely linearly correlated to the level of conversion and contain enough information for the quantitative analysis. As expected interactions and hydrogen-bonding play an important role. Hence the spectral region of PCA analysis has to be carefully selected to obtain a good agreement with the Beer—Lambert law. The NIR spectroscopy and the PCA are easy-to-use techniques for on line monitoring of polyurethane reactions and these results open up a low cost effective opportunity for monitoring the fast RIM process.
Enhancing process insight in polymer extrusion by grey box modelling
Authors: McAfee M.
Published: December 2007

Owing to the complexity and inherent instability in polymer extrusion there is a need for process models which can be run on-line to optimize settings and control disturbances. First-principle models demand computationally intensive solution, while `black box' models lack generalization ability and physical process insight. This work examines a novel `grey box' modelling technique which incorporates both prior physical knowledge and empirical data in generating intuitive models of the process. The models can be related to the underlying physical mechanisms in the extruder and have been shown to capture unpredictable effects of the operating conditions on process instability. Furthermore, model parameters can be related to material properties available from laboratory analysis and as such, lend themselves to retuning for different materials without extensive remodelling work.
Real-time process monitoring of micromoulding using integrated ultrasonic sensors
Authors: Ono Y. , Whiteside B.R. , Brown E.C. , Kobayashi M. , Cheng C.-C. , Jen C.-K. , Coates P.D.
Published: December 2007

Real-time, non-intrusive and non-destructive process monitoring of micromoulding has been performed using novel ultrasonic sensors integrated onto the barrel and mould insert with an ultrasonic pulse-echo technique. The relative variation of the polymer melt temperature inside the extrusion barrel can be obtained using the ultrasonic velocities of the melt measured at the barrel during extrusion. Melt flow arrival in the mould, and solidification, shrinkage and detachment of the polymer inside the mould cavity are also successfully monitored. The presented ultrasonic sensors and technique enable optimizing the micromoulding process, and improving quality of the moulded parts and process efficiency.
Chemical properties and biodegradability of waste paper mill sludges to be used for landfill covering
Authors: Zule Janja , Černec Franc , Likon Marko
Published: December 2007

Waste paper mill sludges originating from different effluent treatment and de-inking installations are complex mixtures of inorganic and organic particles. Due to their favourable physico-chemical, and microbiological characteristics, they may be conveniently reused for different purposes as such or after appropriate pretreatment. Sludges from the Slovenian paper industry were extensively tested for their chemical, stability and sealing properties. During the biodegradability tests, evolutions of greenhouse gases CO2, CH4 and H2 S as well as the concentrations of released volatile organic acids, such as acetic, propionic, butyric, lactic and glycollic acids as the typical degradation products of organic materials, were measured. Some other important parameters of water leachates such as pH, redox potential, content of starch and leachable ions were also evaluated. The results indicate that most of them can be efficiently applied as alternative hydraulic barrier layers for landfill construction and covering instead of the more expensive clay due to their good geomechanical properties, chemical inertness and microbiological stability. Such replacement brings about considerable economical and ecological benefits as the waste is reprocessed as secondary raw material.
The use of alum, ferric chloride and ferrous sulphate as coagulants in removing suspended solids, colour and COD from semi-aerobic landfill leachate at controlled pH
Authors: Hamidi Abdul Aziz  , Alias Salina , Assari Faridah , Mohd Nordin Adlan
Published: December 2007

Suspended solids, colour and chemical oxygen demand (COD) are among the main pollutants in landfill leachate. Application of physical or biological processes alone is normally not sufficient to remove these constituents, especially for leachate with a lower biochemical oxygen demand (BOD)/ COD ratio. The main objective of this research was to investigate the efficiency of coagulation and flocculation processes for removing suspended solids, colour and COD from leachate produced in a semi-aerobic landfill in Penang, Malaysia. A 12-month characterization study of the leachate indicated that it had a mean annual BOD/COD ratio of 0.15 and was partially stabilized, with little further biological degradation likely to occur. Particle size analysis of the raw leachate indicated that its 50th percentile ( d50) was 11.68 µm. Three types of coagulants were examined in bench scale jar test studies: aluminium sulphate (alum), ferric chloride (FeCl3) and ferrous sulphate (FeSO4). The effects of agitation speed, settling time, pH, coagulant dosages and temperature were examined. At 300 rpm of rapid mixing, 50 rpm of slow mixing, and 60 min settling time, higher removals of suspended solids (over 95%), colour (90%) and COD (43%) were achieved at pH 4 and 12. FeCl 3 was found to be superior to other coagulants tested. At pH 4 and 12, fair removal of suspended solids was observed at a reasonably low coagulant dose, i.e., 600 mg L—1; hHowever, about 2500 mg L—1 of coagulant was required to achieve good removals at pH 6. Better removals were achieved at higher temperature. The d50 of sludge after coagulation at pH 4 with a 2500 mg L —1 FeCl3 dose was 60.16 µm, which indicated that the particles had been removed effectively from the leachate. The results indicate that coagulation and flocculation processes can be used effectively in integrated semi-aerobic leachate treatment systems, especially for removing suspended solids, colour and COD.
Metal fractionation in soil profiles at automobile mechanic waste dumps
Authors: Iwegbue Chukwujindu M.A.
Published: December 2007

Soil profiles at five automobile mechanic waste dumps in Port-Harcourt, Nigeria were investigated to assess the spatial distribution, chemical speciation, and likely mobility of Cd, Cu, Pb, Zn, Cr and Ni in the soil as a function of the soil properties. A sequential fractionation protocol was used that generated six different fractions into which soil metal could partition. Cadmium was associated with non-residual fractions at surface horizons, but at lower depths it was in the residual fractions. Copper and Cr partitioned into organic and residual fractions, while Pb was associated with an Fe—Mn oxide fraction and the residual fractions. Zinc in surface horizons partitioned into an Fe—Mn oxide fraction and a fraction that captured carbonate-bound species, but in subsurface horizons, it was mainly in the residual fractions. Ni was predominantly found in the residual fractions. Mobility factors were calculated, and their values tended to decrease with increasing profile depth, indicating that these metals are relatively mobile in the surface horizons compared the subsurface except for chromium in the 15—30 cm depths. The mobility factors for the heavy metals follow the order: Cd > Zn > Pb > Cu > Cr > Ni. The results suggest that there is serious contamination hazard with Cd, Pb, and Zn in the soil profiles.
Exercise Distributed across Day and Night Does Not Alter Circadian Period in Humans
Authors: Cain Sean W. , Rimmer David W. , Duffy Jeanne F. , Czeisler Charles A.
Published: December 2007

In rodents, increased activity due to running-wheel access is associated with a change in observed circadian period. In humans, exposure to exercise has failed to demonstrate similar effects on period. Methodological issues with prior studies such as light exposure during exercise, length of study, and method of measuring period confounded those evaluations of the effect of exercise on period in humans. In the present experiment, the authors examined the effect of exercise on period in 8 subjects using a 44-day within-subjects inpatient study. They used a 20-h forced desynchrony protocol, in which subjects were exposed to exercise across circadian phases under dim light conditions. Exercise consisted of three 45-min sessions per wake period on an ergometer. Target exercise intensity was ~65% of maximal heart rate. Intrinsic circadian period was measured using both core body temperature and hourly plasma melatonin samples. Consistent with previous reports, the authors find no effect of exercise on endogenous circadian period as measured by either core body temperature or melatonin. Exercise distributed across biological day and night does not appear to affect circadian period.
Cis-Combination of the Classic perS and perL Mutations Results in Arrhythmic Drosophila with Ectopic Accumulation of Hyperphosphorylated PERIOD Protein
Authors: Hyuk Wan Ko  , DiMassa Suzanne , Eun Young Kim  , Bae Kiho , Edery Isaac
Published: December 2007

The 1st circadian “clock” gene identified was the X-linked period ( per) gene in Drosophila melanogaster. In the pioneering initial report, Konopka and Benzer (1971) characterized 3 alleles of per that shortened ( perS; ~19 h), lengthened ( perL; ~29 h), or abolished ( per0) circadian behavioral rhythms. They also showed that transheterozygotes carrying the perS and perL mutations exhibit robust behavioral rhythms with nearly normal periods of ~23 h, highlighting the semidominant nature of many clock mutants. In this study, per0 flies bearing a doubly mutated per transgene that carries both the perS and perL alleles ( per0; perS/L) were analyzed for behavioral and molecular rhythms. Unlike singly mutated versions, the per0; per S/L transgenic flies are arrhythmic in constant dark conditions and exhibit little, if any, entrainment to daily light—dark cycles. In a wildtype per+ background, expression of per S/L abolishes behavioral rhythms, indicating that it functions in a transdominant negative fashion. Biochemical analysis of head extracts revealed that only hyperphosphorylated isoforms of the PERS/L protein are detected throughout a daily cycle, and the levels remain constant. Intriguingly, little if any PERS/L is observed in key pacemaker neurons that control daily activity rhythms, consistent with the notion that hyperphosphorylated isoforms of PER are unstable. Nonetheless, PERS/L is detected in ectopic cells in the brain, in which it exhibits an unusual localization, mainly staining the periphery of the nucleus. These results suggest that posttranslational mechanisms play a key role in limiting the accumulation of PER to specific cells. On a broader scope, our results indicate that the semidominant effects of period-altering alleles observed in trans are not necessarily preserved in the cis-configuration and that novel phenotypes can emerge.
Computational Analysis of Mammalian Cell Division Gated by a Circadian Clock: Quantized Cell Cycles and Cell Size Control
Authors: Zámborszky Judit , Hong Christian I. , Csikász Nagy Attila
Published: December 2007

Cell cycle and circadian rhythms are conserved from cyanobacteria to humans with robust cyclic features. Recently, molecular links between these two cyclic processes have been discovered. Core clock transcription factors, Bmal1 and Clock (Clk), directly regulate Wee1 kinase, which inhibits entry into the mitosis. We investigate the effect of this connection on the timing of mammalian cell cycle processes with computational modeling tools. We connect a minimal model of circadian rhythms, which consists of transcription—translation feedback loops, with a modified mammalian cell cycle model from Novak and Tyson (2004). As we vary the mass doubling time (MDT) of the cell cycle, stochastic simulations reveal quantized cell cycles when the activity of Wee1 is influenced by clock components. The quantized cell cycles disappear in the absence of coupling or when the strength of this link is reduced. More intriguingly, our simulations indicate that the circadian clock triggers critical size control in the mammalian cell cycle. A periodic brake on the cell cycle progress via Wee1 enforces size control when the MDT is quite different from the circadian period. No size control is observed in the absence of coupling. The issue of size control in the mammalian system is debatable, whereas it is well established in yeast. It is possible that the size control is more readily observed in cell lines that contain circadian rhythms, since not all cell types have a circadian clock. This would be analogous to an ultradian clock intertwined with quantized cell cycles (and possibly cell size control) in yeast. We present the first coupled model between the mammalian cell cycle and circadian rhythms that reveals quantized cell cycles and cell size control influenced by the clock.
The Dorsomedial Hypothalamic Nucleus Is Not Necessary for the Expression of Circadian Food-Anticipatory Activity in Rats
Authors: Landry Glenn J. , Yamakawa Glenn R. , Webb Ian C. , Mear Rhiannon J. , Mistlberger Ralph E.
Published: December 2007

Restricted daytime feeding generates food-anticipatory activity (FAA) by entrainment of a circadian pacemaker separate from the light-entrainable pacemaker located in the SCN. The dorsomedial hypothalamic nucleus (DMH) has been proposed as the site of food-entrainable oscillators critical for the expression of FAA, but another study found no effects of complete DMH ablation on FAA. To account for these different results, the authors examined methodological factors, including (1) cage configuration and feeding method and (2) use of social cues. Intact and DMH-ablated rats were maintained on one 4-h daily meal in the middle of the light period, using caging and feeding methods matching those of Gooley et al. (2006). Rats with partial or complete DMH ablation were less nocturnal during ad lib food access but exhibited normal FAA during restricted feeding, as quantified by FAA magnitude, ratios, latency to appearance, duration, and precision. To evaluate the use of social cues, intact rats naive to restricted-feeding schedules were food deprived for 72 h on 4 tests. Daytime activity increased during food deprivation, but the magnitude and waveform of this activity was not influenced by the presence of food-entrained rats exhibiting robust FAA in adjacent cages. Thus, hungry intact rats do not use social cues to anticipate a daily mealtime, suggesting that DMH-ablated rats do not anticipate meals by reacting to sounds from food-entrained intact rats in adjacent cabinets. These results confirm our previous finding that the DMH is not critical for normal expression of FAA in rats, and this observation is extended to food restriction methodologies used by other labs. The methodological differences that do underlie discrepant results remain unresolved, as does the location of food-entrainable oscillators, input pathways, and output pathways critical for FAA.
Performing the Self
Authors: Hutchinson Rachael
Published: December 2007

This article analyzes the quick-response binary combat game genre, suggesting that so-called "finger-twitch" games, often maligned by academics, are both complex and significant for cultural studies. While the game structure of binary combat is most often seen in terms of simple entertainment, lacking narrative power and encouraging an apathetic and passive attitude to violence, the author argues that games such as Mortal Kombat, Street Fighter, and Soul Calibur are complex in terms of their construction of stereotyped identity and in the binary structure of combative play. Further, the significance of the genre lies in the performative aspects of gameplay, which problematize accepted models of identification and immersion. Once the player is introduced into the superficial binary structure of combat, then that player's choice and agency become the primary factors in gameplay, ultimately creating space for the inversion of stereotype, the subversion of gender roles and the possible transcendence of the binary system.
Remembering (Forgetting) Baudrillard
Authors: Crogan Patrick
Published: December 2007

Baudrillard, the “most famous theorist of simulation,” exists on the margins of the emerging field of computer game studies where he most often appears as a perfunctory reference to “postmodern” theory that the emerging discourse supercedes in its passage to specificity. By turns strange and symptomatic, the relegation of his thought to marginality where it could have been considered as central enables the unfolding of orthodox positions in game studies of both instrumental and conventionally critical hue. This article remembers the profound challenge to conceptual work in the era of computer simulation that Baudrillard posed in his writings, a challenge perhaps too quickly forgotten in the model-building race of games studies' early years.
Radical Illusion (A Game Against)
Authors: Galloway Alexander R.
Published: December 2007

There are two voices in the work of Jean Baudrillard, the early voice, which lasted less than 10 years, and the mature voice, which lasted about 30. The first voice is younger and more conventionally leftist. It was fully embedded in the intellectual debates of the late 1960s. A committed Marxist, the younger Baudrillard wrote on labor and needs, use-value and production. But after this period as a young man, Baudrillard transitioned into a very different thinker in the middle to late 1970s. He developed a whole new theoretical vocabulary that was completely in tune with that decade's historical transformation into digitization, postindustrial economies, immaterial labor, mediation, and simulation. His theories of play and games are at the very heart of this transformation. Through a close reading of several texts, this essay explores Baudrillard's interest in play and games through the concepts of seduction, the fatal strategy, illusion, and what he called the “principle of separation.”
Toward a (Kin)Aesthetic of Video Gaming
Authors: Behrenshausen Bryan G.
Published: December 2007

Against the hegemony of ocularcentrism currently pervading video game theory, the author situates the practice of video gaming for further inquiry by performance studies to account for it as a wholly embodied phenomenon. Personal narratives of players engaging in performances of the game Dance Dance Revolution indicate the necessity of accounting for both the intersubjective and interobjective elements of video game play. The performativity of video gaming insists on a consideration of its material and discursive dimensions that not only refuses to metonymically reduce the gamer's body to a pair of eyes but also complicates popular dualistic understandings of the player—game relationship.