67 research outputs found

    New primitives of controlled elements F2/4 for block ciphers

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    This paper develops the cipher design approach based on the use of data-dependent operations (DDOs). A new class of DDO based on the advanced controlled elements (CEs) is introduced, which is proven well suited to hardware implementations for FPGA devices. To increase the hardware implementation efficiency of block ciphers, while using contemporary FPGA devices there is proposed an approach to synthesis of fast block ciphers, which uses the substitution-permutation network constructed on the basis of the controlled elements F2/4 implementing the 2 x 2 substitutions under control of the four-bit vector. There are proposed criteria for selecting elements F2/4 and results on investigating their main cryptographic properties. It is designed a new fast 128-bit block cipher MM-128 that uses the elements F2/4 as elementary building block. The cipher possesses higher performance and requires less hardware resources for its implementation on the bases of FPGA devices than the known block ciphers. There are presented result on differential analysis of the cipher MM-12

    Performance Evaluation of Pre-foamed Ultra-lightweight Composites Incorporating Various Proportions of Slag

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    This research examines the feasibility of using a mixture of cement, fly ash, ground granulated blast-furnace slag, and river sand to manufacture pre-foamed ultra-lightweight composite (PULC). Four PULC specimens were prepared with the substitution of cement by slag at 0, 10, 20, and 30 % by weight. The engineering properties of PULC samples were evaluated through the tests of compressive strength, dry density, water absorption, drying shrinkage, and thermal conductivity. Besides, numerical simulation of heat transfer through the PULC brick wall and the microstructure observation were performed. The performance of PULC mixtures incorporating slag showed higher effectiveness than merely used cement. The substitution of 20 % cement by slag resulted in the highest compressive strength as well as the lowest value of water absorption of the PULC samples. Also, the efficiency of the thermal conductivity was in inverse proportion with the density of PULC specimens and it was right for water absorption and drying shrinkage. Moreover, numerical simulations showed that the temperature distribution values in the wall made by PULC material were smaller than in the wall made by the normal clay brick in the same position. Besides, the microstructure analysis revealed that the existence of slag generated a more dense structure of PULC samples with the addition of calcium-silicate-hydrate (C-S-H) gel, especially for a mix containing 20 % slag. Thus, the results of this study further demonstrated that a 20 % slag was the optimal content for the good engineering properties of the PULC samples

    Isolation and production of polyhydroxybutyrate (PHB) from Bacillus pumilus NMG5 strain for bioplastic production and treatment of wastewater from paper factories

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    Polyhydroxybutyrate (PHB) has the potential to replace traditional plastics and limit environmental pollution caused by plastic waste. This study combined wastewater treatment with PHB production to reduce costs. Bacteria capable of synthesizing PHB were isolated from paper mill wastewater and identified using Matrix Assisted Laser Desorption/Ionization–Time of Flight (MALDI-TOF) mass spectrometry and 16S rRNA gene analysis. Bacillus pumilus NMG5 strain was found to have a good yield in modified Nutrient Broth culture, reaching 42.28% of dry biomass. The PHB product was analyzed using FTIR spectroscopy and 1H NMR spectroscopy. The bacterial strain was also tested for its ability to treat paper mill wastewater, and it showed impressive results in terms of biochemical oxygen demand (COD), total nitrogen, and total phosphorus, with efficiencies of 95.93%, 79.36%, and 83.55%, respectively. The study found that wastewater treatment combined with PHB production was a promising solution to reduce costs and limit environmental pollution. The bacterial strain B. pumilus NMG5 had a high yield of PHB, and the PHB product was of high quality, as confirmed by FTIR and 1H NMR spectroscopy. Furthermore, the bacterial strain showed impressive results in treating paper mill wastewater with high COD, total nitrogen, and total phosphorus efficiencies. These results suggest that this harmless bacterium could be used in paper mill wastewater treatment systems to produce PHB, providing a sustainable and environmentally friendly solution

    On the Out of Distribution Robustness of Foundation Models in Medical Image Segmentation

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    Constructing a robust model that can effectively generalize to test samples under distribution shifts remains a significant challenge in the field of medical imaging. The foundational models for vision and language, pre-trained on extensive sets of natural image and text data, have emerged as a promising approach. It showcases impressive learning abilities across different tasks with the need for only a limited amount of annotated samples. While numerous techniques have focused on developing better fine-tuning strategies to adapt these models for specific domains, we instead examine their robustness to domain shifts in the medical image segmentation task. To this end, we compare the generalization performance to unseen domains of various pre-trained models after being fine-tuned on the same in-distribution dataset and show that foundation-based models enjoy better robustness than other architectures. From here, we further developed a new Bayesian uncertainty estimation for frozen models and used them as an indicator to characterize the model's performance on out-of-distribution (OOD) data, proving particularly beneficial for real-world applications. Our experiments not only reveal the limitations of current indicators like accuracy on the line or agreement on the line commonly used in natural image applications but also emphasize the promise of the introduced Bayesian uncertainty. Specifically, lower uncertainty predictions usually tend to higher out-of-distribution (OOD) performance.Comment: Advances in Neural Information Processing Systems (NeurIPS) 2023, Workshop on robustness of zero/few-shot learning in foundation model

    Disinfection performance of an ultraviolet lamp: a CFD investigation

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    Ultraviolet (UV)-based devices have shown their effectiveness on various germicidal purposes. To serve their design optimisation, the disinfection effectiveness of a vertically cylindrical UV lamp, whose wattage ranges from P = 30 − 100 W, is numerically investigated in this work. The UV radiation is solved by the Finite Volume Method together with the Discrete Ordinates model. Various results for the UV intensity and its bactericidal effects against several popular virus types, i.e., Corona-SARS, Herpes (type 2), and HIV, are reported and analysed in detail. Results show that the UV irradiance is greatly dependent on the lamp power. Additionally, it is indicated that the higher the lamp wattage employed, the larger the bactericidal rate is observed, resulting in the greater effectiveness of the UV disinfection process. Nevertheless, the wattage of P ≤ 100W is determined to be insufficient for an effective disinfection performance in a whole room; higher values of power must hence be considered in case intensive sterilization is required. Furthermore, the germicidal effect gets reduced with the viruses less sensitive to UV rays, e.g, the bactericidal rate against the HIV virus is only ∼8.98% at the surrounding walls

    Cloning, expression and purification of fructosyl amino acid oxidase (FAOX) in Escherichia Coli

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    Introduction: The level of serum HbA1c is an indicator of the average blood sugar level in the last three months. HbA1c can be quantified using assays involving the enzyme fructosyl amino acid oxidase (FAOX). This study aims to produce GST-tagged FAOX-TE (GST/FAOX-TE), a thermal stable and specific variant of FAOX, for future application studies. Materials and methods: The E. coli strains DH5α and BL21 (DE3) were used as cloning and expression hosts, respectively. The FAOX-TE sequence was synthesized at IDT (US) and clonned into pGEX-4T3 vector, which was confirmed by Colony PCR. The expression was induced at 16°C, 0.5 mM IPTG in LB media containing 50 µg/ml ampicilin. The protein expression profile was analyzed by SDS-PAGE. The cell pellet was sonicated and purified by Glutathione Sepharose 4 Fast Flow (Cytiva, US). The catalytic activity of GST/FAOX-TE with fructosyl valine was determined using high performance anion exchange chromatography with pulsed amperometry detection (HPAEC-PAD). Results: The fusion protein was successfully expressed in Escherichia coli using the plasmid pGEX-4T3 and purified to high purity 93%. Recombinant GST/FAOX-TE was shown to be active on fructosyl valine. Conclusions: Active GST/FAOX-TE was successfully expressed in E. coli BL21 (DE3) and purified, which will be used for future development of biosensors for fructosyl valine quantification

    Genetic Interaction Between Two VNTRs in the SLC6A4 Gene Regulates Nicotine Dependence in Vietnamese Men

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    Nicotine dependence is an addiction to tobacco products and a global public health concern. Association between the SLC6A4 polymorphisms and nicotine dependence is controversial. Two variable number tandem repeat (VNTR) domains, termed HTTLPR and STin2, in the SLC6A4 gene are well characterized transcriptional regulatory elements. Their polymorphism in the copy number of the repeat correlates with the particular personality and psychiatric traits. We analyzed nicotine dependence in 1,804 participants from Central Vietnam. The Fagerström Test (FTND) was used to evaluate the nicotine dependence and PCR was used to determine the SLC6A4 HTTLPR and STin2 VNTRs. The HTTLPR VNTR was associated with difficulties to refrain from smoking in a prohibiting environment. The STIn2 10/10 genotype was associated with (1) years of smoking, (2) difficulties to quit the first cigarette, and (3) higher number of cigarettes smoked per day (CPD). Stratification analysis was used to find the genetic interaction between these two VNTRs in nicotine dependence as they may synergistically regulate the SLC6A4 expression. Smokers with the S/S HTTLPR genotypes showed a much stronger association between STin2 10/10 variant and CPD. This finding is consistent with the molecular evidence for the functional interaction between HTTLPR and STin2 in cell line models, where STin2 has described as a stronger expressional regulator. Similarly, we found that STin2 is a much stronger modifier of smoking with 10/10 genotype related to higher nicotine dependence. The present study supports genetic interaction between HTTLPR and STin2 VNTRs in the regulation of nicotine dependence with the dominance of the STin2 effects. This finding could be explained by their differential effect on the SLC6A4 expression

    Gallbladder carriage generates genetic variation and genome degradation in Salmonella Typhi

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    Despite recent advances in typhoid fever control, asymptomatic carriage of Salmonella Typhi in the gallbladder remains poorly understood. Aiming to understand if S. Typhi becomes genetically adapted for long-term colonisation in the gallbladder, we performed whole genome sequencing on a collection of S. Typhi isolated from the gallbladders of typhoid carriers. These sequences were compared to contemporaneously sampled sequences from organisms isolated from the blood of acute patients within the same population. We found that S. Typhi carriage was not restricted to any particular genotype or conformation of antimicrobial resistance genes, but was largely reflective of S. Typhi circulating in the general population. However, gallbladder isolates showed a higher genetic variability than acute isolates, with median pairwise SNP distances of 21 and 13 SNPs (p = 2.8x10-9), respectively. Within gallbladder isolates of the predominant H58 genotype, variation was associated with a higher prevalence of nonsense mutations. Notably, gallbladder isolates displayed a higher frequency of non-synonymous mutations in genes encoding hypothetical proteins, membrane lipoproteins, transport/binding proteins, surface antigens, and carbohydrate degradation. Specifically, we identified several gallbladder-specific non-synonymous mutations involved in LPS synthesis and modification, with some isolates lacking the Vi capsular polysaccharide vaccine target due to the 134Kb deletion of SPI-7. S. Typhi is under strong selective pressure in the human gallbladder, which may be reflected phylogenetically by long terminal branches that may distinguish organisms from chronic and acute infections. Our work shows that selective pressures asserted by the hostile environment of the human gallbladder generate new antigenic variants and raises questions regarding the role of carriage in the epidemiology of typhoid fever

    Genetic interaction between two VNTRs in the MAOA gene is associated with the nicotine dependence

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    Nicotine dependence is an addiction to tobacco products and a global public health concern that in part would be influenced by our genetics. Smokers are reported to have reduced MAOA activity, but the results from genetic associations with this gene have been inconclusive. Two functionally relevant variable number tandem repeat (VNTR) domains, termed uVNTR and dVNTR, in the MAOA gene are well characterized transcriptional regulatory elements. In the present study, we analyzed uVNTR and dVNTR polymorphisms in the MAOA gene in the Vietnamese male population of smokers and non-smokers in order to assess the association of MAOA with the nicotine dependence measured by the Fagerström Test for Nicotine Dependence (FTND). Individual analysis of VNTRs separately identified uVNTR to be associated with the F6 question of the FTND indicating the stronger addiction to nicotine. No associations were found between the dVNTR and smoking behavior. The combination of dVNTR and uVNTR, that predicts low expression of MAOA (10–3 haplotypes), was significantly associated with the higher nicotine dependence (FTND score), longer smoking duration, and more persistent smoking behavior (fewer quit attempts). In conclusion, our study confirms that low MAOA expression is genetically predictive to the higher nicotine dependence

    The clinical features of osteogenesis imperfecta in Vietnam

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    Purpose Osteogenesis imperfecta (OI) has not been studied in a Vietnamese population before. The aim of this study was to systematically collect epidemiological information, investigate clinical features and create a clinical database of OI patients in Vietnam for future research and treatment strategy development. Method Participants underwent clinical and physical examinations; also medical records were reviewed. Genealogical information was collected and family members’ phenotypical manifestations recorded. Cases were classified according to the Sillence classification. Results In total, 146 OI patients from 120 families were studied: 46 with OI Type I, 46 with Type III and 54 with Type IV. Almost patients had skeletal deformations. One hundred and forty-two had a history of fractures, 117 blue sclera, 89 dentinogenesis imperfecta and 26 hearing loss. The total number of fractures was 1,932. Thirty-four patients had intra-uterine fractures and nine had perinatal fractures. Surgery was performed 163 times in 58 patients; 100 osteosyntheses and 63 osteotomies. Bisphosphonate treatment was used in 37 patients. The number of affected individuals and predominance of severe forms of OI indicate that the disease is under diagnosed in Vietnam, especially in cases without a family history or with mild form of OI. Deformities appeared in all patients with different severity and localisation, affecting mostly the lower limbs. OI medical and surgical treatment rates are low and in most cases surgery was performed due to fractures. Conclusions Compared to previous studies, our results indicate a lower OI prevalence and greater severity of symptoms in the Vietnamese population when compared with other areas. Further investigation, improved diagnosis and treatment are needed to increase the patients’ quality of life
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