6,222 research outputs found
Strontium and neodymium isotopic variations in early Archean gneisses affected by middle to late Archean high-grade metamorphic processes: West Greenland and Labrador
Relicts of continental crust formed more than 3400 Ma ago are preserved fortuitously in most cratons. The cratons provide the most direct information about crust and mantle evolutionary processes during the first billion years of Earth history. In view of their polymetamorphic character, these terrains are commonly affected by subsequent tectonothermal events. Hence, their isotope systematics may be severely disturbed as a result of bulk chemical change or local isotopic homogenization. This leads to equivocal age and source information for different components within these terrains. The Sr and Nd isotopic data are presented for early Archean gneisses from the North Atlantic Craton in west Greenland and northern Labrador which were affected by younger metamorphic events
Sublinear Estimation of Weighted Matchings in Dynamic Data Streams
This paper presents an algorithm for estimating the weight of a maximum
weighted matching by augmenting any estimation routine for the size of an
unweighted matching. The algorithm is implementable in any streaming model
including dynamic graph streams. We also give the first constant estimation for
the maximum matching size in a dynamic graph stream for planar graphs (or any
graph with bounded arboricity) using space which also
extends to weighted matching. Using previous results by Kapralov, Khanna, and
Sudan (2014) we obtain a approximation for general graphs
using space in random order streams, respectively. In
addition, we give a space lower bound of for any
randomized algorithm estimating the size of a maximum matching up to a
factor for adversarial streams
Temperature dependence of the ohmic conductivity and activation energy of Pb1+y(Zr0.3Ti0.7)O3 thin films
The ohmic conductivity of the sol-gel derived Pb1+y(Zr0.3Ti0.7)O3 thin films
(with the excess lead y=0.0 to 0.4) are investigated using low frequency small
signal alternate current (AC) and direct current (DC) methods. Its temperature
dependence shows two activation energies of 0.26 and 0.12 eV depending on
temperature range and excess Pb levels. The former is associated with Pb3+
acceptor centers, while the latter could be due to a different defect level yet
to be identified.Comment: 13 pages, 3 figures, PostScript. Submitted to Applied Physics Letter
Loss of expression of ATM is associated with worse prognosis in colorectal cancer and loss of Ku70 expression is associated with CIN
Repair of double strand DNA breaks (DSBs) is pivotal in maintaining normal
cell division and disruption of this system has been shown to be a key factor in
carcinogenesis. Loss of expression of the DSB repair proteins have previously been
shown to be associated with poorer survival in colorectal cancer. We wished to
ascertain the relationship of altered expression of the DSB repair proteins γ-H2AX
(gamma-H2AX), ATM and Ku70 with biological and clinico-pathological features
of colorectal cancer. 908 tumours from the VICTOR clinical trial of stage II/III
colorectal cancer were analysed for expression of γ-H2AX, ATM and Ku70 using
immunohistochemistry. Expression levels were correlated with CIN and with diseasefree
survival, correcting for microsatellite instability, BRAF/KRAS mutation status,
Dukes stage, chemo/radiotherapy, age, gender and tumour location. Down-regulated
Ku70 expression was associated with chromosomal instability (p=0.029) in colorectal
cancer. Reduced ATM expression was an independent marker of poor disease-free
survival (HR=1.67, 95% CI 1.11-2.50, p=0.015). For Ku70, further studies are
required to investigate the potential relationship of non-homologous end joining with
chromosomal instability. Loss of ATM expression might serve as a biomarker of poor
prognosis in colorectal cancer
A product line organization using an open development method
Opening access to the source code for a product is a business strategy that is increasingly used as the basis for innovative collaborations with stakeholders. The strategy has been successful at producing a large quantity of high-quality software. A tactic in this strategy is to effectively use the efforts of many widely dispersed professionals. The processes, software tools and the communication mechanisms used to facilitate concurrent development by a large number of people are of as much interest as the software being created. In this position paper we present our view of how a software product line organization might operate if it used an open development method (ODM) but is not necessarily producing open source software. We will describe a hypothetical product line (HPL), which is part speculation, part our experience, and partly the experience of others
MCH Pheromone for Preventing Douglas-Fir Beetle Infestation in Windthrown Trees
A granular controlled-release formulation (98 percent inert, 2 percent 3-methyl-2-cyclohexen-1-one) was applied May 11-13, 1982, at 4.48 kg/ha to 76.9 ha of uninfested windthrown Douglas-fir by helicopter with a modified aerial spreader of 1.13 m³ capacity. Granules measured on treated plots averaged 2.04-2.69 kg/ha, sufficient to reduce Douglas-fir beetle (Dendroctonus pseudotsugae) infestation 96.4 percent by late June. The same MCH treatment reduced spruce beetle (Dendroctonus rufipennis) attacks by 55 percent in fewer, intermingled windthrown Engelmann spruce
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