4,466 research outputs found
Efficient long-pulse fully-loaded CTF3 linac operation
An efficient RF to beam energy transfer in the accelerating structures of the drive beam is one of the key points of the Compact Linear Collider (CLIC) RF power source. For this, the structures are fully beam-loaded, i.e. the accelerating gradient is nearly zero at the downstream end of each structure. In this way, about 96 % of the RF energy can be transferred to the beam. To demonstrate this mode of operation, 1.5 ..s long beam pulses are accelerated in six fully loaded structures in the CLIC Test Facility (CTF3) Linac. The final beam energy is compared to the input RF power of the structures, proving the efficient energy transfer
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Social Context in Developmental Psychopathology: Recommendations for Future Research from the MacArthur Network on Psychopathology and Development
Accumulating evidence suggests that social contexts in early life have important and complex effects on childhood psychopathology. Spurred by the lack of an explicit operational definition that could guide the study of such effects, we define a social context operationally as “a set of interpersonal conditions, relevant to a particular behavior or disorder and external to, but shaped and interpreted by, the individual child.” Building on this definition, we offer a series of recommendations for future research, based on five theoretically derived propositions: (a) Contexts are nested and multidimensional; (b) contexts broaden, differentiate, and deepen with age, becoming more specific in their effects; (c) contexts and children are mutually determining; (d) a context's meaning to the child determines its effects on the child and arises from the context's ability to provide for fundamental needs; and (e) contexts should be selected for assessment in light of specific questions or outcomes. As reflected in an increasingly rich legacy of literature on child development and psychopathology, social contexts appear to influence emerging mental disorders through dynamic, bidirectional interactions with individual children. Future research will benefit from examining not only statistical interactions between child- and context-specific factors, but also the actual transactions between children and contexts and the transduction of contextual influences into pathways of biological mediation. Because adverse contexts exert powerful effects on the mental health of children, it is important for the field to generate new, more theoretically grounded research addressing the contextual determinants of psychological well-being and disorder
The glutamate transport inhibitor DL-Threo-β-Benzyloxyaspartic acid (DL-TBOA) differentially affects SN38- and oxaliplatin-induced death of drug-resistant colorectal cancer cells
BACKGROUND: Colorectal cancer (CRC) is a leading cause of cancer death globally and new biomarkers and treatments are severely needed. METHODS: Here, we employed HCT116 and LoVo human CRC cells made resistant to either SN38 or oxaliplatin, to investigate whether altered expression of the high affinity glutamate transporters Solute Carrier (SLC)-1A1 and -1A3 (EAAT3, EAAT1) is associated with the resistant phenotypes. Analyses included real-time quantitative PCR, immunoblotting and immunofluorescence analyses, radioactive tracer flux measurements, and biochemical analyses of cell viability and glutathione content. Results were evaluated using one- and two-way ANOVA and Students two-tailed t-test, as relevant. RESULTS: In SN38-resistant HCT116 and LoVo cells, SLC1A1 expression was down-regulated ~60 % and up-regulated ~4-fold, respectively, at both mRNA and protein level, whereas SLC1A3 protein was undetectable. The changes in SLC1A1 expression were accompanied by parallel changes in DL-Threo-β-Benzyloxyaspartic acid (TBOA)-sensitive, UCPH101-insensitive [(3)H]-D-Aspartate uptake, consistent with increased activity of SLC1A1 (or other family members), yet not of SLC1A3. DL-TBOA co-treatment concentration-dependently augmented loss of cell viability induced by SN38, while strongly counteracting that induced by oxaliplatin, in both HCT116 and LoVo cells. This reflected neither altered expression of the oxaliplatin transporter Cu(2+)-transporter-1 (CTR1), nor changes in cellular reduced glutathione (GSH), although HCT116 cell resistance per se correlated with increased cellular GSH. DL-TBOA did not significantly alter cellular levels of p21, cleaved PARP-1, or phospho-Retinoblastoma protein, yet altered SLC1A1 subcellular localization, and reduced chemotherapy-induced p53 induction. CONCLUSIONS: SLC1A1 expression and glutamate transporter activity are altered in SN38-resistant CRC cells. Importantly, the non-selective glutamate transporter inhibitor DL-TBOA reduces chemotherapy-induced p53 induction and augments CRC cell death induced by SN38, while attenuating that induced by oxaliplatin. These findings may point to novel treatment options in treatment-resistant CRC. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12885-015-1405-8) contains supplementary material, which is available to authorized users
Updated CLIC parameters 2005
This note presents the CLIC parameter set as of mid 2005 and describes the different sub-systems, stressing how the design of the different components is driven. This design emerged from a better understanding of limitations for normal conducting accelerating structures, which led to a new optimised design for the CLIC 30 GHz accelerating structure. The structure parameters and improvements in other sub-systems have resulted in a major revision of the parameters. The overall layout and efciencies for CLIC with this updated parameter-set are presented
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Predictions of the equation of state of cerium yield interesting insights into experimental results
There has been much interest in the past in understanding the dynamic properties of phase changing materials. In this paper we begin to explore the dynamic properties of the complex material of cerium. Cerium metal is a good candidate material to explore capabilities in determining a dynamic phase diagram on account of its low dynamic phase boundaries, namely, the {gamma}-{alpha}, and {alpha}-liquid phase boundaries. Here we present a combination of experimental results with calculated results to try to understand the dynamic behavior of the material. Using the front surface impact technique, we performed a series of experiments which displayed a rarefaction shock upon release. These experiments show that the reversion shock stresses occur at different magnitudes, allowing us to plot out the {gamma}-{alpha} phase boundary. Applying a multiphase equation of state a broader understanding of the experimental results will be discussed
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