Exploiting dynamic scheduling for VM-based code obfuscation

Code virtualization built upon virtual machine (VM) technologies is emerging as a viable method for implementing code obfuscation to protect programs against unauthorized analysis. State-of-the-art VM-based protection approaches use a fixed scheduling structure where the program follows a single, static execution path for the same input. Such approaches, however, are vulnerable to certain scenarios where the attacker can reuse knowledge extracted from previously seen software to crack applications using similar protection schemes. This paper presents DSVMP, a novel VM-based code obfuscation approach for software protection. DSVMP brings together two techniques to provide stronger code protection than prior VM-based schemes. Firstly, it uses a dynamic instruction scheduler to randomly direct the program to execute different paths without violating the correctness across different runs. By randomly choosing the program execution paths, the application exposes diverse behavior, making it much more difficult for an attacker to reuse the knowledge collected from previous runs or similar applications to perform attacks. Secondly, it employs multiple VMs to further obfuscate the relationship between VM bytecode and their interpreters, making code analysis even harder. We have implemented DSVMP in a prototype system and evaluated it using a set of widely used applications. Experimental results show that DSVMP provides stronger protection with comparable runtime overhead and code size when compared to two commercial VMbased code obfuscation tools

Ecological vulnerability assessment of a China's representative mining city based on hyperspectral remote sensing

Mining cities are clusters of communities that specialized in mining and extractive industries. The extensive mining activities in these cities have stimulated widespread and substantial ecological stresses to the surrounding environment, that significantly jeopardize the health condition of vegetation and human. Given the recent recognition of remote sensing in monitoring large-scale environmental change, we incorporated Ziyuan #1-02D, a recently released hyperspectral remote sensing data, into the ecological vulnerability assessment framework, using Panzhihua city as a case study, which is recognized as one of the most representative mining cities in China. The multi-spectral imaging data was widely applied in previous research. However, with the wide bands, multi-spectral imaging data cannot depict detailed characteristics of spectral targeted. As a result, we introduce indexes from the hyperspectral imaging to ecological vulnerability assessment proposed in this study, which can depict and monitor the growth and restoration of vegetation more accurately. We used the optimum index factor method to select bands from the satellite-based Ziyuan #1-02D data for quantifying vegetation indexes and red edge. Besides, we obtained inventory data, land-use, soil type, and typography of Panzhihua city to reconstruct its ecological vulnerability index (EVI) for 2020 and 2021. Comparing to the multi-spectral data, the ecological vulnerability results from hyperspectral imaging performed better in precision and concentration in EVI values, reaching the conclusions more directly. Specifically, the mining area and the relevant hazard types and impact areas were delineated through intensive fieldwork. Results suggested that the east and west districts, and north of Renhe district suffer great ecological stress, in which we observed intensive coal and metal-related mining industry. The central region, which occupies vanadium titanomagnetite mines, also shows substantial ecological issues, while the other mining industries, such as granite ore did not significantly influence the local environment. Although the newly released satellite-based data only have two-year periods, we still observed improving ecological conditions, with the southeast and west regions showing much lower ecological vulnerability values. The spatial autocorrelation analysis suggested that the high-high clustering region of EVI is located in the east, west, and Renhe districts, primarily due to the mining industries of variations scales. We also found that the clustering of low ecological vulnerable regions, mostly surrounds the vanadium titanomagnetite excavation industry, thanks to the local restoration projects

DISC1 splice variants are upregulated in schizophrenia and associated with risk polymorphisms

Disrupted-In-Schizophrenia-1 (DISC1) is a promising susceptibility gene for major mental illness, but the mechanism of the clinical association is unknown. We searched for DISC1 transcripts in adult and fetal human brain and tested whether their expression is altered in patients with schizophrenia and is associated with genetic variation in DISC1. Many alternatively spliced transcripts were identified, including groups lacking exon 3 (Δ3), exons 7 and 8 (Δ7Δ8), an exon 3 insertion variant (extra short variant-1, Esv1), and intergenic splicing between TSNAX and DISC1. Isoforms Δ7Δ8, Esv1, and Δ3, which encode truncated DISC1 proteins, were expressed more abundantly during fetal development than during postnatal ages, and their expression was higher in the hippocampus of patients with schizophrenia. Schizophrenia risk-associated polymorphisms [non-synonymous SNPs rs821616 (Cys704Ser) and rs6675281 (Leu607Phe), and rs821597] were associated with the expression of Δ3 and Δ7Δ8. Moreover, the same allele at rs6675281, which predicted higher expression of these transcripts in the hippocampus, was associated with higher expression of DISC1Δ7Δ8 in lymphoblasts in an independent sample. Our results implicate a molecular mechanism of genetic risk associated with DISC1 involving specific alterations in gene processing

Photobiocatalytic Strategies for Organic Synthesis

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Lifespan expression of the <i>GAD2</i> alternative transcripts.

<p>Each figure shows the expression patterns of the selected <i>GAD2</i> alternative transcripts across the lifespan in the human DLPFC: (A) The expression of <i>GAD2</i> full length across the lifespan in the human DLPFC. (B) The expression of ENST00000428517 across the lifespan in the human DLPFC. The expression of full length <i>GAD2</i> transcript increases from 14 weeks of gestational age until the first decade of life and levels off throughout the rest of the lifespan. ENST00000428517 expression in the DLPFC is highest in the fetus and then declines gradually. The x-axis shows age: Before birth gestational age is in weeks (wks) and after birth in years (yrs). On the y-axis, the expressions levels were Log2 normalized. Each dot represents an individual subject.</p

Demographic information of our human postmortem samples.

<p>Demographic information of our human postmortem samples.</p

Mapped Reads and Junction Plots from RNA sequencing of <i>GAD2</i>.

<p>Using pooled whole brain, known and putative novel exons for <i>GAD2</i> in both adult and fetal human brain were identified using RNA-Seq. The y-axis is the coverage information, while the x-axis shows the position of the reads. The red arc-shapes between exons represented the splicing junctions. The thickness of the red arc-shapes represented the abundance of the splicing events. We observed the continuously splicing events across all the known junction of the <i>GAD2</i> gene in adult brain but not in fetal brain. These results suggested there isn’t a novel splicing junction for <i>GAD2</i> in the human DLPFC, and potential truncated transcripts composed by several 5’ exons.</p

Alternative transcript map for <i>GAD2</i>.

<p>(A) Alternative transcripts of <i>GAD2</i> in human Brain. Full length <i>GAD2</i> transcript (NM_001134366.1, encoding the 65kDa GAD protein) and a truncated transcript (ENST00000428517) were identified. Key: Black rectangles, known exons. (B) The expression of <i>GAD2</i> transcripts in 20 human tissues. <i>GAD2</i> were mainly expressed in human brain. These two transcripts had opposite developmental expression changes in human brain. All the expression levels were normalized by ACTB, B2M and GUSB.</p