A new approach to mass spectrometer measurements of thermospheric density

The gas sampling problem in satellite and high velocity probes was investigated by applying the theory of a drifting Maxwellian gas. A lens system using a free stream ion source was developed and experimentally evaluated over the pressure range of 0.00001 to 0.01 N/m sq (approx. 10 to the minus 7th power to 0.0001 torr). The source has high beam transparency, which minimizes gas-surface collisions within, or near, the ionization volume. It is shown that for high ion energy (60 eV), the extracted ion beam has an on-axis energy spread of less than 4 eV, and that 90 percent of the ions are within 2.5 deg of the beam axis. It is concluded that the molecular beam mass spectrometer concept, developed for gas density measurements in the upper atmosphere, substantially reduces gas-surface scattering and gas-surface reactions in the sample, and preserves the integrity of the gas sample during the analysis process. Studies show that both the Scout and Delta launch vehicles have adequate volume, control, velocity, and data acquisition capability necessary to obtain thermospheric number density in real time

Radiocarbon dates from the Oxford AMS system: archaeometry datelist 35

This is the 35th list of AMS radiocarbon determinations measured at the Oxford Radiocarbon Accelerator Unit (ORAU). Amongst some of the sites included here are the latest series of determinations from the key sites of Abydos, El Mirón, Ban Chiang, Grotte de Pigeons (Taforalt), Alepotrypa and Oberkassel, as well as others dating to the Palaeolithic, Mesolithic and later periods. Comments on the significance of the results are provided by the submitters of the material

Absence of an embryonic stem cell DNA methylation signature in human cancer.

BackgroundDifferentiated cells that arise from stem cells in early development contain DNA methylation features that provide a memory trace of their fetal cell origin (FCO). The FCO signature was developed to estimate the proportion of cells in a mixture of cell types that are of fetal origin and are reminiscent of embryonic stem cell lineage. Here we implemented the FCO signature estimation method to compare the fraction of cells with the FCO signature in tumor tissues and their corresponding nontumor normal tissues.MethodsWe applied our FCO algorithm to discovery data sets obtained from The Cancer Genome Atlas (TCGA) and replication data sets obtained from the Gene Expression Omnibus (GEO) data repository. Wilcoxon rank sum tests, linear regression models with adjustments for potential confounders and non-parametric randomization-based tests were used to test the association of FCO proportion between tumor tissues and nontumor normal tissues. P-values of < 0.05 were considered statistically significant.ResultsAcross 20 different tumor types we observed a consistently lower FCO signature in tumor tissues compared with nontumor normal tissues, with 18 observed to have significantly lower FCO fractions in tumor tissue (total n = 6,795 tumor, n = 922 nontumor, P < 0.05). We replicated our findings in 15 tumor types using data from independent subjects in 15 publicly available data sets (total n = 740 tumor, n = 424 nontumor, P < 0.05).ConclusionsThe results suggest that cancer development itself is substantially devoid of recapitulation of normal embryologic processes. Our results emphasize the distinction between DNA methylation in normal tightly regulated stem cell driven differentiation and cancer stem cell reprogramming that involves altered methylation in the service of great cell heterogeneity and plasticity

Don't bleach chaotic data

A common first step in time series signal analysis involves digitally filtering the data to remove linear correlations. The residual data is spectrally white (it is ``bleached''), but in principle retains the nonlinear structure of the original time series. It is well known that simple linear autocorrelation can give rise to spurious results in algorithms for estimating nonlinear invariants, such as fractal dimension and Lyapunov exponents. In theory, bleached data avoids these pitfalls. But in practice, bleaching obscures the underlying deterministic structure of a low-dimensional chaotic process. This appears to be a property of the chaos itself, since nonchaotic data are not similarly affected. The adverse effects of bleaching are demonstrated in a series of numerical experiments on known chaotic data. Some theoretical aspects are also discussed.Comment: 12 dense pages (82K) of ordinary LaTeX; uses macro psfig.tex for inclusion of figures in text; figures are uufile'd into a single file of size 306K; the final dvips'd postscript file is about 1.3mb Replaced 9/30/93 to incorporate final changes in the proofs and to make the LaTeX more portable; the paper will appear in CHAOS 4 (Dec, 1993

Elevated levels of interleukin-12/23p40 may serve as a potential indicator of dysfunctional heart rate variability in type 2 diabetes

BACKGROUND: Systemic inflammatory processes plausibly contribute to the development of cardiovascular complications, causing increased morbidity and mortality in type 2 diabetes. Circulating inflammatory markers, i.e., interleukin (IL)-6 and tumour necrosis factor-α, are associated with neurocardiac measures. We examined a broad panel of various inflammatory and inflammation-related serum markers to obtain more detailed insight into the possible neuro-immune interaction between cardiovascular regulation and systemic level of inflammation. METHODS: Serum samples from 100 participants with type 2 diabetes were analysed. Heart rate variability, cardiovascular autonomic reflex tests, and cardiac vagal tone tests were performed based on electrocardiographic readings. Data regarding covariates (demographic-, diabetes-, and cardiovascular risk factors) were registered. RESULTS: Increased serum levels of IL-12/IL-23p40 (p  < 0.01) and intercellular adhesion molecule (ICAM)-1 (p  < 0.007) were associated with diminished heart rate variability measures. After all adjustments, the associations between IL-12/23p40, SDANN and VLF persisted (p  = 0.001). Additionally, serum levels of vascular endothelial growth factor (VEGF)-C were associated with response to standing (p  = 0.005). DISCUSSION: The few but robust associations between neurocardiac regulation and serum markers found in this study suggest systemic changes in proinflammatory, endothelial, and lymphatic function, which collectively impacts the systemic cardiovascular function. Our results warrant further exploration of IL-12/IL-23p40, ICAM-1, and VEGF-C as possible cardiovascular biomarkers in T2D that may support future decisions regarding treatment strategies for improved patient care. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12933-021-01437-w

OC /EFSA /SCER /2014/02‐Lot 1 “Specialised training courses on certain aspects of food safety risk assessment for members of EFSA 's Scientific Committee/Panels and their working groups, open to EFSA staff” –final report

This final report evaluates the training courses delivered under the contract OC/EFSA/SCER/2014/02- Lot 1. Two types of specialised training courses were delivered: a training course addressing uncertainty in EFSA’s scientific assessments and a training course on Environmental Risk Assessment. Both trainings were evaluated as very good by the participants. In addition to its primary aim of supporting the understanding and practical implementation of best risk assessment practices, the uncertainty training was used to obtain feedback on the draft guidance document. Therefore, only invited participants could follow the training and selection ensured that each unit was represented in the training. The training course now has to be updated in line with the final version of the guidance document. One of the objectives of the training was to strengthen the dissemination of ERA guidance and modelling practises and to ensure the uptake of guidance on cross-cutting risk assessment approaches amongst members of EFSA’s Scientific Committee/Panels, their working groups and EFSA staff. This aim is partly achieved as participants of different backgrounds joined the trainings. It was noted however, that only a few panel member participated and participants with a background in pesticide risk assessment were over-represented as compared to the other work fields of EFSA

On the two-dimensional rotational body of maximal Newtonian resistance

We investigate, by means of computer simulations, shapes of nonconvex bodies that maximize resistance to their motion through a rarefied medium, considering that bodies are moving forward and at the same time slowly rotating. A two-dimensional geometric shape that confers to the body a resistance very close to the theoretical supremum value is obtained, improving previous results.Comment: This is a preprint version of the paper published in J. Math. Sci. (N. Y.), Vol. 161, no. 6, 2009, 811--819. DOI:10.1007/s10958-009-9602-

System data communication structures for active-control transport aircraft, volume 2

The application of communication structures to advanced transport aircraft are addressed. First, a set of avionic functional requirements is established, and a baseline set of avionics equipment is defined that will meet the requirements. Three alternative configurations for this equipment are then identified that represent the evolution toward more dispersed systems. Candidate communication structures are proposed for each system configuration, and these are compared using trade off analyses; these analyses emphasize reliability but also address complexity. Multiplex buses are recognized as the likely near term choice with mesh networks being desirable for advanced, highly dispersed systems

System data communication structures for active-control transport aircraft, volume 1

Candidate data communication techniques are identified, including dedicated links, local buses, broadcast buses, multiplex buses, and mesh networks. The design methodology for mesh networks is then discussed, including network topology and node architecture. Several concepts of power distribution are reviewed, including current limiting and mesh networks for power. The technology issues of packaging, transmission media, and lightning are addressed, and, finally, the analysis tools developed to aid in the communication design process are described. There are special tools to analyze the reliability and connectivity of networks and more general reliability analysis tools for all types of systems