A Study of the Probe Induced Disturbances on the Near-Field Measurement

Numerical simulations were used to investigate the disturbance introduced by placing a small magnetic loop probe in the near field of a driven loop. In the absence of the loop probe, the numerical simulations were compared with an approximate closed-form analytical expression for the magnetic field produced by the driven loop. The agreement between the approximate analytical results and the simulation was good. The next set of simulations was based on a physical model that included the probe and showed that the probe does exert an effect on the field being measured. Examples of these simulations and their implications on measurements will be discussed

Effectiveness of Green Olympic Initiatives on Reasons Affecting Residents’ Actions to Support the Olympic Movement

The world faces major environmental challenges that affect the well-being of human beings, plants, and wildlife. The Olympic Games, one of the most influential sport events, should pay special attention to environmental issues. In 1996, the environmental element became a central factor of the International Olympic Committee’s (IOC) (IOC, 2009). To scientifically and comprehensively evaluate the impact of the Olympics on the host city, the IOC launched the Olympic Games Global Impact (OGGI) study in 2003 (IOC, 2006). This study begins two years before the host city is selected, and terminates two years after hosting the Games (IOC, 2006). One of the reasons to do an 11-year OGGI study is likely because the social, economic, and environmental impact of the Games may vary throughout the whole process. To a great extent, these technical reports remain internal to the IOC. A majority of previous studies on mega sport events have focused on the economic impact (Twynam & Johnston, 2004). Few studies have emphasized the environmental aspect of major sport events. It would be constructive to investigate the environmental impact of the Beijing Games over eight years, from the moment of being named as the host city to one year after hosting the event. Based on the environmental measures applied in Beijing, there were five critical time periods that should be considered in order to comprehensively understand the effectiveness of the Beijing Green Olympic initiatives, including July 2001 (Time 1) when Beijing was named as the host city for the 2008 Olympic Games, August 2007(Time 2) when it was one year before the Games, August 2008 (Time 3) when it was during the Games, December 2008 (Time 4) when it covered close-out and summary period of the Games, and December 2009 (Time 5) when it was one year after the Games. Research has suggested that local residents play an important role in achieving successful and sustainable impact of mega sport events (Deccio & Baloglu, 2002). Therefore, the purpose of this study was to examine residents’ perceived effectiveness of Beijing Green Olympic initiatives, by investigating their awareness, perception, attitude, intention, and actual behavior through conducting a time-series analysis. Based on a comprehensive review of literature, a questionnaire was developed that included the following sections: awareness, perception, attitude, behavior intention, and actual behavior associated with Beijing Green Olympics initiatives. All items were phrased in a 7-point scale (1 = “strongly disagree” to 7 = “strongly agree”). The questionnaire was phrased into five versions, corresponding with the five key time periods. Each version had a different leading statement and, to increase recall accuracy, a historical scenario/picture reflecting a specific time period. Five sets of pictures depicting significant events that happened in China during each time periods were collected and their accuracy of time representation was verified by two professors and three graduate students in sport social science from a leading Chinese university. Items within each time period were put in a random order to reduce carry-over effect in the repeated measure research design. The questionnaire was then double-translated to ensure translation accuracy. A community intercept approach was adopted and data were collected at shopping centers, city libraries, parks, restaurants, municipal offices, and transportation centers in Beijing, China. A total of 119 subjects, who were 18 years or older in 2001 and considered Beijing as his/her primary residential location since 2001, were included in the study. A doubly repeated measure MANOVA was conducted, which revealed that the vector mean scores of the Green Olympics’ effectiveness variables (i.e., awareness, perception, attitude, behavior intention, and actual behaviour) were significantly (p \u3c .05) different over the five time periods. The research findings indicate that the perceived environmental impact by residents had been formed, developed, and altered as a result of different environmental efforts applied in Beijing. To a great extent, these reflected the effectiveness of the Green Olympic programs across five key periods of the Games. Further discussions are conducted on expanding environmental programs and policies beyond 2008 and the city of Beijing, and moving China toward environmentally sustainable development

Nucleation of amorphous shear bands at nanotwins in boron suboxide

The roles of grain boundaries and twin boundaries in mechanical properties are well understood for metals and alloys. However, for covalent solids, their roles in deformation response to applied stress are not established. Here we characterize the nanotwins in boron suboxide (B_6O) with twin boundaries along the {0111} planes using both scanning transmission electron microscopy and quantum mechanics. Then, we use quantum mechanics to determine the deformation mechanism for perfect and twinned B_6O crystals for both pure shear and biaxial shear deformations. Quantum mechanics suggests that amorphous bands nucleate preferentially at the twin boundaries in B_6O because the twinned structure has a lower maximum shear strength by 7.5% compared with perfect structure. These results, which are supported by experimental observations of the coordinated existence of nanotwins and amorphous shear bands in B_6O, provide a plausible atomistic explanation for the influence of nanotwins on the deformation behaviour of superhard ceramics

Mechanisms Underlying Hypoxia Tolerance in <i>Drosophila melanogaster</i>: <i>hairy</i> as a Metabolic Switch

Hypoxia-induced cell injury has been related to multiple pathological conditions. In order to render hypoxia-sensitive cells and tissues resistant to low O2 environment, in this current study, we used Drosophila melanogaster as a model to dissect the mechanisms underlying hypoxia-tolerance. A D. melanogaster strain that lives perpetually in an extremely low-oxygen environment (4% O2, an oxygen level that is equivalent to that over about 4,000 m above Mt. Everest) was generated through laboratory selection pressure using a continuing reduction of O2 over many generations. This phenotype is genetically stable since selected flies, after several generations in room air, survive at this low O2 level. Gene expression profiling showed striking differences between tolerant and naïve flies, in larvae and adults, both quantitatively and qualitatively. Up-regulated genes in the tolerant flies included signal transduction pathways (e.g., Notch and Toll/Imd pathways), but metabolic genes were remarkably down-regulated in the larvae. Furthermore, a different allelic frequency and enzymatic activity of the triose phosphate isomerase (TPI) was present in the tolerant versus naïve flies. The transcriptional suppressor, hairy, was up-regulated in the microarrays and its binding elements were present in the regulatory region of the specifically down-regulated metabolic genes but not others, and mutations in hairy significantly reduced hypoxia tolerance. We conclude that, the hypoxia-selected flies: (a) altered their gene expression and genetic code, and (b) coordinated their metabolic suppression, especially during development, with hairy acting as a metabolic switch, thus playing a crucial role in hypoxia-tolerance.</p

Network analysis of skin tumor progression identifies a rewired genetic architecture affecting inflammation and tumor susceptibility

11 páginas, 5 figuras, 1 tabla.-- et al.[Background]: Germline polymorphisms can influence gene expression networks in normal mammalian tissues and can affect disease susceptibility. We and others have shown that analysis of this genetic architecture can identify single genes and whole pathways that influence complex traits, including inflammation and cancer susceptibility. Whether germline variants affect gene expression in tumors that have undergone somatic alterations, and the extent to which these variants influence tumor progression, is unknown. [Results]: Using an integrated linkage and genomic analysis of a mouse model of skin cancer that produces both benign tumors and malignant carcinomas, we document major changes in germline control of gene expression during skin tumor development resulting from cell selection, somatic genetic events, and changes in the tumor microenvironment. The number of significant expression quantitative trait loci (eQTL) is progressively reduced in benign and malignant skin tumors when compared to normal skin. However, novel tumor-specific eQTL are detected for several genes associated with tumor susceptibility, including IL18 (Il18), Granzyme E (Gzme), Sprouty homolog 2 (Spry2), and Mitogen-activated protein kinase kinase 4 (Map2k4). [Conclusions]: We conclude that the genetic architecture is substantially altered in tumors, and that eQTL analysis of tumors can identify host factors that influence the tumor microenvironment, mitogen-activated protein (MAP) kinase signaling, and cancer susceptibility.This work was supported by the National Cancer Institute. AB acknowledges support from the Barbara Bass Bakar Chair of Cancer Genetics. MDT was supported in part by a Sandler Foundation postdoctoral research fellowship. JS was supported by the Swedish Research Council and the Tegger Foundation. KKL was supported by an NIH Kirschstein-NRSA postdoctoral research fellowship. JPL is partially supported by Carlos III (FIS)/FEDER, MICIIN/plan-E 2009, JCyL (’Biomedicina y Educación’) and CSIC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Nanowired three-dimensional cardiac patches

Engineered cardiac patches for treating damaged heart tissues after a heart attack are normally produced by seeding heart cells within three-dimensional porous biomaterial scaffolds1, 2, 3. These biomaterials, which are usually made of either biological polymers such as alginate4 or synthetic polymers such as poly(lactic acid) (PLA)5, help cells organize into functioning tissues, but poor conductivity of these materials limits the ability of the patch to contract strongly as a unit6. Here, we show that incorporating gold nanowires within alginate scaffolds can bridge the electrically resistant pore walls of alginate and improve electrical communication between adjacent cardiac cells. Tissues grown on these composite matrices were thicker and better aligned than those grown on pristine alginate and when electrically stimulated, the cells in these tissues contracted synchronously. Furthermore, higher levels of the proteins involved in muscle contraction and electrical coupling are detected in the composite matrices. It is expected that the integration of conducting nanowires within three-dimensional scaffolds may improve the therapeutic value of current cardiac patches.National Institutes of Health (U.S.) (NIH, grant GM073626)National Institutes of Health (U.S.) (NIH, grant DE13023)National Institutes of Health (U.S.) (NIH, grant DE016516)American Heart Association (Postdoctoral Fellowship)National Institutes of Health (U.S.) (Ruth L. Kirschstein National Research Service Award (no. F32GM096546)

Adenosine receptor expression and function in rat striatal cholinergic interneurons

1. Cholinergic neurons were identified in rat striatal slices by their size, membrane properties, sensitivity to the NK(1) receptor agonist (Sar(9), Met(O(2))(11)) Substance P, and expression of choline acetyltransferase mRNA. A(1) receptor mRNA was detected in 60% of the neurons analysed, and A(2A) receptor mRNA in 67% (n=15). 2. The A(1) receptor agonist R-N(6)-(2-phenylisopropyl)adenosine (R-PIA) hyperpolarized cholinergic neurons in a concentration dependent manner sensitive to the A(1) antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 100 nM). 3. In dual stimulus experiments, the A(2A) receptor antagonist 8-(3-chlorostyryl)caffeine (CSC, 500 nM) decreased release of [(3)H]-acetylcholine from striatal slices (S2/S1 0.78±0.07 versus 0.95±0.05 in control), as did adenosine deaminase (S2/S1 ratio 0.69±0.05), whereas the A(1) receptor antagonist DPCPX (100 nM) had no effect (S2/S1 1.05±0.14). 4. In the presence of adenosine deaminase the adenosine A(2A) receptor agonist 2-p-((carboxyethyl)phenylethylamino)-5′-N-ethylcarboxamidoadenosine (CGS21680, 10 nM) increased release (S2/S1 ratio 1.03±0.05 versus 0.88±0.05 in control), an effect blocked by the antagonist CSC (500 nM, S2/S1 0.68±0.05, versus 0.73±0.08 with CSC alone). The combined superfusion of bicuculline (10 μM), saclofen (1 μM) and naloxone (10 μM) had no effect on the stimulation by CGS21680 (S2/S1 ratio 0.99±0.04). 5. The A(1) receptor agonist R-PIA (100 nM) inhibited the release of [(3)H]-acetylcholine (S2/S1 ratio 0.70±0.03), an effect blocked by DPCPX (S2/S1 ratio 1.06±0.07). 6. It is concluded that both A(1) and A(2A) receptors are expressed on striatal cholinergic neurons where they are functionally active

B-RAF kinase drives developmental axon growth and promotes axon regeneration in the injured mature CNS

Activation of intrinsic growth programs that promote developmental axon growth may also facilitate axon regeneration in injured adult neurons. Here, we demonstrate that conditional activation of B-RAF kinase alone in mouse embryonic neurons is sufficient to drive the growth of long-range peripheral sensory axon projections in vivo in the absence of upstream neurotrophin signaling. We further show that activated B-RAF signaling enables robust regenerative growth of sensory axons into the spinal cord after a dorsal root crush as well as substantial axon regrowth in the crush-lesioned optic nerve. Finally, the combination of B-RAF gain-of-function and PTEN loss-of-function promotes optic nerve axon extension beyond what would be predicted for a simple additive effect. We conclude that cell-intrinsic RAF signaling is a crucial pathway promoting developmental and regenerative axon growth in the peripheral and central nervous systems

A Model of Trust, Moods, and Emotions in Multiagent Systems and its Empirical Evaluation

Abstract We study the interplay of moods, emotions, and trust in decisionmaking contexts characterized by commitments among agents. We develop a general approach representing the relationships among these concepts via a Bayesian network model. Our approach incorporates insights from the literature and provides a computational methodology for identifying improved Bayesian models. Based on observations from an empirical study, we motivate a refined Bayesian model involving the above-mentioned concepts that goes beyond the relationships known in the literature. Our findings include (1) the violation of a commitment affects trust more than its satisfaction; (2) goal satisfaction affects mood and emotion more than commitment satisfaction, but the outcome of a commitment affects trust more than the outcome of a goal; and (3) an agent&apos;s prior mood and trust affect whether it satisfies its commitments