78 research outputs found

    In vitro FRAP reveals the ATP-dependent nuclear mobilization of the exon junction complex protein SRm160

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    We present a new in vitro system for characterizing the binding and mobility of enhanced green fluorescent protein (EGFP)-labeled nuclear proteins by fluorescence recovery after photobleaching in digitonin-permeabilized cells. This assay reveals that SRm160, a splicing coactivator and component of the exon junction complex (EJC) involved in RNA export, has an adenosine triphosphate (ATP)-dependent mobility. Endogenous SRm160, lacking the EGFP moiety, could also be released from sites at splicing speckled domains by an ATP-dependent mechanism. A second EJC protein, RNPS1, also has an ATP-dependent mobility, but SRm300, a protein that binds to SRm160 and participates with it in RNA splicing, remains immobile after ATP supplementation. This finding suggests that SRm160-containing RNA export, but not splicing, complexes have an ATP-dependent mobility. We propose that RNA export complexes have an ATP-regulated mechanism for release from binding sites at splicing speckled domains. In vitro fluorescence recovery after photobleaching is a powerful tool for identifying cofactors required for nuclear binding and mobility

    New directions in the ransomware phenomenon

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    Ransomware is a type of malware that blocks an user’s access to files and requests him/her a ransom. The main approach of an attacker is to encrypt the user’s files and give him/her the decrypting tool only after he/she pays the requested amount of money. The payment is usually done in difficult to trace currencies. In this paper, we provide a review of the ransomware phenomenon, making a clear distinction between the threats before and after WannaCry (which appeared in May 2017). Initially, we give two taxonomy examples from the literature and one designed by us. The first two taxonomies use ”Platform”, ”Cryptosystem”/”Crypto”, ”Severity”, ”Attack” and ”Target” as criteria (the terms appear in one of them or both), but we have chosen ”Target Zone”, ”Propagation”, ”Payment” and ”Weakness”. We further describe/compare ransomware programs, taking into account several aspects including how they work (e.g., encryption methods), whom they target (e.g., individuals/organizations), what impact they have and what weaknesses can be used to provide countermeasures (besides the general prevention techniques that we mention briefly)

    Quantum-Safe Protocols and Application in Data Security of Medical Records

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    The use of traditional cryptography based on symmetric keys has been replaced with the revolutionary idea discovered by Diffie and Hellman in 1976 that fundamentally changed communication systems by ensuring a secure transmission of information over an insecure channel. Nowadays public key cryptography is frequently used for authentication in e-commerce, digital signatures and encrypted communication. Most of the public key cryptosystems used in practice are based on integer factorization (the famous RSA cryptosystem proposed by Rivest, Shamir and Adlemann), respectively on the discrete logarithm (in finite curves or elliptic curves). However these systems suffer from two potential drawbacks like efficiency because they must use large keys to maintain security and of course security breach with the advent of the quantum computer as a result of Peter Shor\u27s discovery in 1999 of the polynomial algorithm for solving problems such factorization of integers and discrete logarithm

    Low charge noise quantum dots with industrial CMOS manufacturing

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    Silicon spin qubits are among the most promising candidates for large scale quantum computers, due to their excellent coherence and compatibility with CMOS technology for upscaling. Advanced industrial CMOS process flows allow wafer-scale uniformity and high device yield, but off the shelf transistor processes cannot be directly transferred to qubit structures due to the different designs and operation conditions. To therefore leverage the know-how of the micro-electronics industry, we customize a 300mm wafer fabrication line for silicon MOS qubit integration. With careful optimization and engineering of the MOS gate stack, we report stable and uniform quantum dot operation at the Si/SiOx interface at milli-Kelvin temperature. We extract the charge noise in different devices and under various operation conditions, demonstrating a record-low average noise level of 0.61 Ό{\mu}eV/Hz{\sqrt{Hz}} at 1 Hz and even below 0.1 Ό{\mu}eV/Hz{\sqrt{Hz}} for some devices and operating conditions. By statistical analysis of the charge noise with different operation and device parameters, we show that the noise source can indeed be well described by a two-level fluctuator model. This reproducible low noise level, in combination with uniform operation of our quantum dots, marks CMOS manufactured MOS spin qubits as a mature and highly scalable platform for high fidelity qubits.Comment: 22 pages, 13 figure

    Gastrointestinal stromal tumors: a focus on the impact of interstitial cells of Cajal in disease development

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    Introduction. Interstitial Cells of Cajal (ICCs) play a critical role in the regulation of gastrointestinal motility and have been implicated in various functional gastrointestinal disorders. Recent research indicates a possible association between ICCs and the tumor risk of Gastrointestinal Stromal Tumors (GISTs). This research aims to examine the clinical, histopathological, and biomolecular characteristics of ICCs and their relevance in assessing GIST risk. Materials and Methods. This study examined fourteen GIST patients who underwent surgical intervention at the Surgery Department of Carol Davila Nephrology Hospital in Bucharest. Parameters including age, gender, tumor location/ dimensions were scrutinized. Immunohistochemistry employing markers CD117, DOG-1, and CD34 was employed to ascertain the presence of ICCs and GISTs. Results. The GIST risk stratification revealed distribution with 35.71% very low-risk, 21.42% low-risk, 14.28% intermediate-risk, and 28.57% high-risk categories. Predominantly, 57.14% of cases fell within the very low-risk and low-risk categories. Positive immunoreactivity for CD117 and DOG-1 was noted in 92.86% of patients, while CD34 exhibited positivity in 85.71% of cases. Gastric GISTs manifested heightened marker expression. Notably, immunohistochemistry unveiled robust positivity for CD117, DOG-1, and CD34, illustrating a positive correlation between elevated ICC levels and high-risk GISTs. Conclusions. The findings propose an association between ICC levels and high-risk GISTs, accentuating the diagnostic utility of CD117, DOG-1, and CD34 markers in GIST assessment

    Indoor radon related with the geology in romanian urban agglomerations (cluj-napoca)

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    Radon is a natural radioactive gas that occurs due to the radioactive decay of radium (226Ra) present in rocks which, in turn, cames from the radioactive decay of uranium (238U), a primordial natural element. Along with factors such as porosity, permeability and humidity of the rocks and soils, pressure and temperature, geology setting plays one of the most important roles in the release of radon into the environment. Depending on the mineralogical compositions and characteristics of the bedrock from a certain area, a higher or lower concentration of radioactive minerals can be found in the rocks, which will directly influence the level of radon in the atmosphere, implicitly the concentration of radon measured in houses. In this study, a six months concentration of radon (222Rn) was assessed in 256houses from Cluj-Napoca area using CR-39 nuclear track detectors. Correlations between the indoor radon levels and the geological setting was further analyzed. The aim is to better understand the influence of geology on the concentration of radon levels in homes, in order to further identify other risk areas in terms of exposure to radon. Further investigation is needed on other factors influencing the accumulation of radon in high concentrations indoor, such as ventilation, occupation patterns or constructive and architectural features for typical houses. Therefore, the results of this work are considered to be important for indoor radon management in Romania

    Humidity-tolerant ultrathin NiO gas-sensing films

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    When the gas sensor active layer film thickness is decreased, increased sensitivity to changes in the adsorbate concentration is expected when measuring the resistance of the layer, in particular when this thickness is on the order of the Debye length of the material (one–tens of nanometers); however, this is demonstrated only for a limited number of materials. Herein, ultrathin NiO films of different thicknesses (8–21 nm) have been deposited via chemical vapor deposition to fabricate gas sensor devices. Sensor performance for a range of NO2 concentrations (800 part-per-billion to 7 part-per-million) was evaluated and an optimum operating temperature of 125 °C determined. The dependence of the potential relative changes with respect to the NO2 concentration and of the sensor signal with respect to the geometrical parameters was qualitatively evaluated to derive a transduction model capable of fitting the experimental results. The selective sensitivity toward NO2 was confirmed by the limited response for different reducing gases, CO, CH4, NH3, and SO2, under optimum operating conditions, and the sensor signal toward NO2 increased with decreasing thickness, demonstrating that the concept of a Debye length dependence of sensitivity is applicable for the p-type semiconductor NiO. In addition, these NiO sensors were exposed to different relative levels of humidity over a wide range of operating temperatures and were found to display humidity tolerance far superior to those in previous reports on SnO2 materials

    Haplotype divergence supports long-term asexuality in the oribatid mite Oppiella nova

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    Sex strongly impacts genome evolution via recombination and segregation. In the absence of these processes, haplotypes within lineages of diploid organisms are predicted to accumulate mutations independently of each other and diverge over time. This so-called "Meselson effect" is regarded as a strong indicator of the long-term evolution under obligate asexuality. Here, we present genomic and transcriptomic data of three populations of the asexual oribatid mite species Oppiella nova and its sexual relative Oppiella subpectinata We document strikingly different patterns of haplotype divergence between the two species, strongly supporting Meselson effect-like evolution and long-term asexuality in O. nova: I) variation within individuals exceeds variation between populations in O. nova but vice versa in O. subpectinata; II) two O. nova sublineages feature a high proportion of lineage-specific heterozygous single-nucleotide polymorphisms (SNPs), indicating that haplotypes continued to diverge after lineage separation; III) the deepest split in gene trees generally separates the two haplotypes in O. nova, but populations in O. subpectinata; and IV) the topologies of the two haplotype trees match each other. Our findings provide positive evidence for the absence of canonical sex over evolutionary time in O. nova and suggest that asexual oribatid mites can escape the dead-end fate usually associated with asexual lineages
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