Direct in-vial collection for liquid-scintillation assay of carbon-14 and tritium

Dissolution of biological materials combines the simplicity of oxygen-flask combustion with the reproducibility and purity of the final product, and convenience of direct in-vial collection of the sample by the sealed-tube method. It assures quantitative and reproducible recoveries

Combustion method for assay of biological materials labeled with carbon-14 or tritium, or double-labeled

Dry catalytic combustion at high temperatures is used for assaying biological materials labeled carbon-14 and tritium, or double-labeled. A modified oxygen-flask technique is combined with standard vacuum-line techniques and includes convenience of direct in-vial collection of final combustion products, giving quantitative recovery of tritium and carbon-14

Results of ultra-low level 71ge counting for application in the Gallex-solar neutrino experiment at the Gran Sasso Underground Physics Laboratory

It has been experimentally verified that the Ultra-Low-Level Counting System for the Gallex solar neutrino experiment is capable of measuring the expected solar up silon-flux to plus or minus 12% during two years of operation

Size and the City: The potential of downsizing in reducing energy demand and increasing quality of life

Recent decades have seen a tremendous growth in the population, particularly in cities. London, for example, has increased from about 6.8 million to 8.2 million over 20 years from 1991 to 2011. Additionally, we have seen substantial demographic change, with an increasing life expectancy and other factors resulting in a larger number of households with only one or two people. One consequence of this is that older people can end up living in inappropriate housing being too large for their needs, with high heating bills and stairs restricting mobility. In addition, this also contributes to the decreasing availability of housing for the growing population. Ultimately, this can lead to unnecessary use of energy and carbon emissions. One potential approach would be to promote downsizing amongst those who live in larger-than-needed properties (defined in relationship to a standard). Some people might choose to live in large properties – for those the question might be for whom could downsizing be rendered an attractive option. For those keen on downsizing, the question is more how it can be realized, i.e. what barriers need to be removed and what help given. In any case, for those who downsize, this could result in significant release of equity (for home owners) or reduced rent, in addition to lower bills and potentially more suitable accommodation in terms of access and mobility. Potential benefits for the wider population would be greater availability of housing stock. This paper will address this issue in different ways. Firstly, empirical data will be presented on the effect of housing size on energy consumption. A sample of N = 991 households, approximately representative for the English population, is analysed with regard to the impact of housing size and housing type on energy consumption. Results show that those two predictors are of greatest importance, and together explain about 29% of the variability in the log-transformed annual energy consumption, surpassing all other variables. In addition, the analysis calculates the amount of under- and overpopulation of housing to give an estimate of the distribution of living space. Secondly, the paper will discuss the benefits of downsizing for the population. A detailed literature review is performed. The results address the benefits of downsizing and highlight which factors would promote downsizing. One issue that has been shown previously, was that those who could downsize felt that little adequate alternative housing was available. Also, general potential effects are discussed, such as freed up living space, and issues of intergenerational justice. Thirdly, the paper will look beyond downsizing at other options such as co-housing, creating multiple-generation homes, or taking a lodger. The prevalence of these schemes will be discussed, and their potential highlighted

Low noise cryogenic system for the measurement of Casimir energy in rigid cavities

We report on preliminary results on the measurement of variations of the Casimir energy in rigid cavities through its influence on the superconducting transition of in-cavity aluminium (Al) thin films. After a description of the experimental apparatus we report on a measurement made with thermal photons, discussing its implications for the zero-point photons case. Finally we show the preliminary results for the zero-point case.Comment: 9 pages, 7 figures, Talk given at QFEXT07 Conference in Liepzig: Quantum Field Theory Under the Influence of External Condition

The vulnerability of refrigerated food to unstable power supplies

This paper describes a simplified model for estimating the vulnerability to spoilage of a number of refrigerated foods in households, resulting from interruptions to the electricity power grid. The tool is demonstrated on a sample of three foods (milk, chicken and fish) in India, which historically has suffered significant interruptions. The effect of interruptions is quantified in terms of tonnage and monetary value of potential losses, in a number of simple scenarios. These losses are estimated for rural and urban areas of each Indian state. Our model indicates that extensions to the duration of power supply interruptions increases potential losses in domestic refrigerators, and that these losses are considerable when compared to losses expected in previous stages of the food supply chain. The current model’s estimation of weight of food lost may be converted to a nutritional value, which opens an opportunity for new multidisciplinary areas of research

Four-qubit device with mixed couplings

We present the first experimental results on a device with more than two superconducting qubits. The circuit consists of four three-junction flux qubits, with simultaneous ferro- and antiferromagnetic coupling implemented using shared Josephson junctions. Its response, which is dominated by the ground state, is characterized using low-frequency impedance measurement with a superconducting tank circuit coupled to the qubits. The results are found to be in excellent agreement with the quantum-mechanical predictions.Comment: REVTeX 4, 5pp., 7 EPS figure files. N.B.: "Alec" is my first, and "Maassen van den Brink" my family name. v2: final published version, with changed title, different sample micrograph, and several clarification

The RNA Helicase DDX6 Controls Cellular Plasticity by Modulating P-Body Homeostasis

Post-transcriptional mechanisms have the potential to influence complex changes in gene expression, yet their role in cell fate transitions remains largely unexplored. Here, we show that suppression of the RNA helicase DDX6 endows human and mouse primed embryonic stem cells (ESCs) with a differentiation-resistant, “hyper-pluripotent” state, which readily reprograms to a naive state resembling the preimplantation embryo. We further demonstrate that DDX6 plays a key role in adult progenitors where it controls the balance between self-renewal and differentiation in a context-dependent manner. Mechanistically, DDX6 mediates the translational suppression of target mRNAs in P-bodies. Upon loss of DDX6 activity, P-bodies dissolve and release mRNAs encoding fate-instructive transcription and chromatin factors that re-enter the ribosome pool. Increased translation of these targets impacts cell fate by rewiring the enhancer, heterochromatin, and DNA methylation landscapes of undifferentiated cell types. Collectively, our data establish a link between P-body homeostasis, chromatin organization, and stem cell potency