2,771 research outputs found
Program Verification by Using DISCOVERER
Recent advances in program verification indicate that various verification problems can be reduced to semi-algebraic system (SAS for short) solving. An SAS consists of polynomial equations and polynomial inequalities. Algorithms for quantifier elimination of real closed fields are the general method for those problems. But the general method usually has low efficiency for specific problems. To overcome the bottleneck of program verification with a symbolic approach, one has to combine special techniques with the general method. Based on the work of complete discrimination systems of polynomials [33,31], we invented new theories and algorithms [32,30,35] for SAS solving and partly implemented them as a real symbolic computation tool in Maple named DISCOVERER. In this paper, we first summarize the results that we have done so far both on SAS-solving and program verification with DISCOVERER, and then discuss the future work in this direction, including SAS-solving itself, termination analysis and invariant generation of programs, and reachability computation of hybrid systems etc. ? IFIP International Federation for Information Processing 2008.EI
Differential Proteomic Analysis of Human Saliva using Tandem Mass Tags Quantification for Gastric Cancer Detection.
Novel biomarkers and non-invasive diagnostic methods are urgently needed for the screening of gastric cancer to reduce its high mortality. We employed quantitative proteomics approach to develop discriminatory biomarker signatures from human saliva for the detection of gastric cancer. Salivary proteins were analyzed and compared between gastric cancer patients and matched control subjects by using tandem mass tags (TMT) technology. More than 500 proteins were identified with quantification, and 48 of them showed significant difference expression (p < 0.05) between normal controls and gastric cancer patients, including 7 up-regulated proteins and 41 down-regulated proteins. Five proteins were selected for initial verification by ELISA and three were successfully verified, namely cystatin B (CSTB), triosephosphate isomerase (TPI1), and deleted in malignant brain tumors 1 protein (DMBT1). All three proteins could differentiate gastric cancer patients from normal control subjects, dramatically (p < 0.05). The combination of these three biomarkers could reach 85% sensitivity and 80% specificity for the detection of gastric cancer with accuracy of 0.93. This study provides the proof of concept of salivary biomarkers for the non-invasive detection of gastric cancer. It is highly encouraging to turn these biomarkers into an applicable clinical test after large scale validation
Speckle interferometry at the Blanco and SOAR telescopes in 2008 and 2009
The results of speckle interferometric measurements of binary and multiple
stars conducted in 2008 and 2009 at the Blanco and SOAR 4-m telescopes in Chile
are presented. A total of 1898 measurements of 1189 resolved pairs or
sub-systems and 394 observations of 285 un-resolved targets are listed. We
resolved for the first time 48 new pairs, 21 of which are new sub-systems in
close visual multiple stars. Typical internal measurement precision is 0.3 mas
in both coordinates, typical companion detection capability is at 0\farcs15 separation. These data were obtained with a new
electron-multiplication CCD camera; data processing is described in detail,
including estimation of magnitude difference, observational errors, detection
limits, and analysis of artifacts. We comment on some newly discovered pairs
and objects of special interest.Comment: Accepted for publication in Astronomical Journal. Tables 4,5,7 will
be published electronically, they are available in full from the author
Cold War in Space: Reconnaissance Satellites and US-Soviet Security Competition
This article traces the history of US and Soviet reconnaissance satellites during the Cold War. It fills the gap in historiography of the Space Race that has inadequately studied military space programs and focused largely on civilian spaceflight, with the Apollo Moon landings being a prime example. It argues that the military satellites employed by both the US and Soviets offered unprecedented amounts of information on the other side and eliminated the issue of lacking intelligence that characterized the early Cold War. This in turn allowed for a more peaceful coexistence between these two ideologically opposed superpowers. Spy satellites allowed for a better assessment of the other side’s military strength, created a system of early warning for nuclear attacks, and offered a non-invasive way of verifying arms control treaties. These reconnaissance satellites and their successors play this important role up to this day
Special Algorithm for Stability Analysis of Multistable Biological Regulatory Systems
We consider the problem of counting (stable) equilibriums of an important
family of algebraic differential equations modeling multistable biological
regulatory systems. The problem can be solved, in principle, using real
quantifier elimination algorithms, in particular real root classification
algorithms. However, it is well known that they can handle only very small
cases due to the enormous computing time requirements. In this paper, we
present a special algorithm which is much more efficient than the general
methods. Its efficiency comes from the exploitation of certain interesting
structures of the family of differential equations.Comment: 24 pages, 5 algorithms, 10 figure
Proteomic characterization reveals that MMP-3 correlates with bronchiolitis obliterans syndrome following allogeneic hematopoietic cell and lung transplantation
Improved diagnostic methods are needed for bronchiolitis obliterans
syndrome (BOS), a serious complication after allogeneic hematopoietic cell
transplantation (HCT) and lung transplantation. For proteins candidate
discovery, we compared plasma pools from HCT transplantation recipients with:
BOS at onset (n=12), pulmonary infection (n=16), chronic graft-versus-host
disease without pulmonary involvement (n=15), and no chronic complications
post-HCT (n=15). Pools were labeled with different tags [isobaric Tags for
Relative and Absolute Quantification (iTRAQ)], and two software tools identified
differentially expressed proteins (≥1.5-fold change). Candidate proteins
were further selected using a six-step computational biology approach. The
diagnostic value of the lead candidate, matrix metalloproteinase-3 (MMP-3), was
evaluated by ELISA in plasma of a verification cohort (n=112) with and without
BOS following HCT (n=76) or lung transplantation (n=36). MMP-3 plasma
concentrations differed significantly between patients with and without BOS
(AUC=0.77). Thus, MMP-3 represents a potential non-invasive blood test for
diagnosis of BOS
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