Hard Fault Analysis of Trivium

Fault analysis is a powerful attack to stream ciphers. Up to now, the major idea of fault analysis is to simplify the cipher system by injecting some soft faults. We call it soft fault analysis. As a hardware--oriented stream cipher, Trivium is weak under soft fault analysis. In this paper we consider another type of fault analysis of stream cipher, which is to simplify the cipher system by injecting some hard faults. We call it hard fault analysis. We present the following results about such attack to Trivium. In Case 1 with the probability not smaller than 0.2396, the attacker can obtain 69 bits of 80--bits--key. In Case 2 with the probability not smaller than 0.2291, the attacker can obtain all of 80--bits--key. In Case 3 with the probability not smaller than 0.2291, the attacker can partially solve the key. In Case 4 with non--neglectable probability, the attacker can obtain a simplified cipher, with smaller number of state bits and slower non--linearization procedure. In Case 5 with non--neglectable probability, the attacker can obtain another simplified cipher. Besides, these 5 cases can be checked out by observing the key--stream

Effect of supercritical CO2 extraction on pore characteristics of coal and its mechanism

Abundant pore space in coal is not only the place for the accumulation of coalbed methane (CBM), but also the tunnel for gas migration. In this study, five sets of coal samples before and after the second coalification were selected from the eastern margin of Ordos Basin to simulate supercritical CO2 (Sc-CO2) extraction in supercritical extraction equipment. The evolutions of pore structure and porosity were tested by mercury intrusion porosimetry and nuclear magnetic resonance spectroscopy to compare the changes of pore structure and porosity due to the Sc-CO2 extraction, and to explain the related mechanism. The results show that: (1) Pore volume, pore specific surface area, and connectivity characteristics changed significantly due to Sc-CO2 extraction, and the increment of pore volume and pore specific surface area presented a law of increase–decrease–increase with the increase in the coal rank, and the turning point was near the second coalification. (2) The porosity increment change trend due to Sc-CO2 extraction was increase–decrease–increase with increasing coal rank, and the turning point was again near the second coalification, which supports the mercury intrusion porosimetry results. (3) The changes were observed in the porosity characteristics due to Sc-CO2 extraction through pore-increasing and expanding effects. Before the second coalification, the pore-increasing and expanding effects co-existed in the micropores, and after the second coalification, the pore-expanding effect mainly existed in the transitional pores and above. (4) The variation model for the pore structure of coal due to Sc-CO2 extraction was established. The conclusions offer not only important theoretical significance for the CO2-enhanced CBM (CO2-ECBM) mechanism but also important significance for CO2-ECBM engineering

An Urban Neo-Poverty Population-Based Quality of Life and Related Social Characteristics Investigation from Northeast China

OBJECTIVE: To investigate quality of life (QOL) and related characteristics among an urban neo-poverty population in northeast China, and to compare this population with a traditional poverty cohort. DESIGN: The research was a cross-sectional survey executed from June 2005 to October 2007, with a sample of 2940 individuals ages 36 to 55 in three different industrial cities of northeast China. Data were collected on QOL status and sociodemographic characteristics. QOL was assessed using the 36-item Short Form Health Survey (Chinese version). Multiple regression analysis was employed to analyze association between sociodemographic variables and QOL. RESULTS: The scores for QOL in the neo-poverty group were higher than those in the traditional poverty group, but lower than those in the general population. When the neo-poverty population was divided into two subgroups by age, 36-45 years and 46-55 years, the differences in QOL scores were not significant. However, there were significant differences in several dimensions between two subgroups according to unemployment time (<5 years and >5 years). Additionally, stepwise regression analysis indicated that disease burden, including disease and medical expenditures, was a common risk factor for declining QOL in the neo-poverty group. CONCLUSIONS: Despite some limitations, this study provides initial evidence that the QOL of the urban neo-poverty population lies between that of the general population and traditional poverty. QOL of the neo-poverty group approached QOL of the traditional poverty group with increased unemployment years. In addition to decreased income, disease burden is the most important factor influencing QOL status in urban neo-poverty

MicroRNA Let-7f Inhibits Tumor Invasion and Metastasis by Targeting MYH9 in Human Gastric Cancer

BACKGROUND: MicroRNAs (miRNAs) are important regulators that play key roles in tumorigenesis and tumor progression. A previous report has shown that let-7 family members can act as tumor suppressors in many cancers. Through miRNA array, we found that let-7f was downregulated in the highly metastatic potential gastric cancer cell lines GC9811-P and SGC7901-M, when compared with their parental cell lines, GC9811 and SGC7901-NM; however, the mechanism was not clear. In this study, we investigate whether let-7f acts as a tumor suppressor to inhibit invasion and metastasis in gastric cancers. METHODOLOGY/PRINCIPAL: Real-time PCR showed decreased levels of let-7f expression in metastatic gastric cancer tissues and cell lines that are potentially highly metastatic. Cell invasion and migration were significantly impaired in GC9811-P and SGC7901-M cell lines after transfection with let-7f-mimics. Nude mice with xenograft models of gastric cancer confirmed that let-7f could inhibit gastric cancer metastasis in vivo after transfection by the lentivirus pGCsil-GFP- let-7f. Luciferase reporter assays demonstrated that let-7f directly binds to the 3'UTR of MYH9, which codes for myosin IIA, and real-time PCR and Western blotting further indicated that let-7f downregulated the expression of myosin IIA at the mRNA and protein levels. CONCLUSIONS/SIGNIFICANCE: Our study demonstrated that overexpression of let-7f in gastric cancer could inhibit invasion and migration of gastric cancer cells through directly targeting the tumor metastasis-associated gene MYH9. These data suggest that let-7f may be a novel therapeutic candidate for gastric cancer, given its ability to reduce cell invasion and metastasis

Comparison of two functional kappa light‐chain transcripts amplified from a hybridoma

Three heavy‐chain and three kappa (κ)‐chain transcripts were amplified from hybridoma cells secreting a monoclonal antibody (m A b) against transferrin receptor. Sequence analysis via IMGT / V ‐ QUEST yielded the functional/aberrant prediction. Two functional κ‐chain transcripts, V κ2 and V κ3, and one functional V H 1 were revealed. Comprehensive bioinformatics analyses including sequence alignment, phylogenetic tree, somatic hypermutation prediction, and three‐dimensional‐molecular structure modeling were used to predict the origin of the two κ‐chain transcripts. The results of bioinformatics analysis suggest that V κ3 is derived from the myeloma partner of the hybridoma; V κ2 is derived from B‐cell. Functional transcripts V H 1 and V κ2 and V κ3 were then used to construct two chimeric antibodies chi‐ C 2 ( V κ2– V H 1) and chi‐ C 3 ( V κ3–V H 1), respectively. Antigen‐binding experiments showed that only chi‐ C 2 remained the same affinity as its parental mAb. Possible explanations for the coexistence of two functional κ‐chain transcripts and the different affinity of the two chimeric antibodies are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98790/1/bab1080.pd