Investigation of the EXAFS Cumulants of Silicon and Germanium Semiconductors by Statistical Moment Method: Pressure Dependence

Pressure dependence of Extended X-ray Absorption Fine Structure (EXAFS) cumulants of silicon and germanium have been investigated using the statistical moment method (SMM). Analytical expressions of the first and second cumulants of silicon and germanium have been derived. The equations of states for silicon and germanium semiconductors have been also obtained using which the pressure dependence of lattice constants and volume of these semiconductors have been estimated. Numerical results using the developed theories for these semiconductors are found to be in good and reasonable agreement with those of the other theories and with experiment

Pressure Dependence of EXAFS Debye-Waller Factors in Crystals

In present article the pressure dependence of Debye-Waller factors in crystals has been investigated by using statistical moment method and anharmonic correlated Einstein model. These two methods provide similar results which indicate that the Debye-Waller factors of crystals decreases slightly under high pressure. Our numerical results for several crystals are compared to other theoretical and experimental values and showed a good agreement

Integration of an RSA-2048-bit public key cryptography solution in the development of secure voice recognition processing applications

The authors initially employs the fast Fourier transform (FFT) approach to transforming voice inputs into digital signals before integrating a speech recognition solution (which includes two models: the hidden Markov model (HMM) and the artificial neural network (ANN)). To achieve standard-tone identification of voice signals and digitally store speech, the authors then incorporated a 2048-bit Rivest-Shamir-Adleman (RSA) encryption method to encrypt and decrypt digital speech. The authors’ building team constructed the program using a 256-bit advanced encryption standard - Galois counter mode (AES-GCM) encryption method to assure the application’s effectiveness. The authors successfully created a voice recognition application according to the HMM of ANN. The collected findings suggest that the authors’ secure speech recognition program (named soft voice - RSA) has improved in terms of safety, keeping speech material secret, and speed. It takes roughly 0.2 s to generate a 2048-bit RSA key pair that exceeds the National Institute of Standards and Technology (NIST) standard, 700-1070 ms to process speech, 1-4 ms to encrypt 2048-bit RSA, 6-8 ms to decrypt 2048-bit RSA

Serotypes, virulence genes, and PFGE profiles of Escherichia coli isolated from pigs with postweaning diarrhoea in Slovakia

BACKGROUND: Postweaning diarrhoea (PWD) in pigs is usually the main infectious problem of large-scale farms and is responsible for significant losses worldwide. The disease is caused mainly by enterotoxigenic E. coli (ETEC) and Shiga-toxin producing E. coli (STEC). In this study a total of 101 E. coli isolated from pigs with PWD in Slovakia were characterized using phenotypic and genotypic methods. RESULTS: These 101 isolates belonged to 40 O:H serotypes. However, 57% of the isolates belonged to only six serotypes (O9:H51, O147:H-, O149:H10, O163:H-, ONT:H-, and ONT:H4), including two new serotypes (O163:H- and ONT:H4) not previously found among porcine ETEC and STEC isolated in other countries. Genes for EAST1, STb, STa, LT and Stx2e toxins were identified in 64%, 46%, 26%, 20%, and 5% of isolates, respectively. PCR showed that 35% of isolates carried genes for F18 colonization factor, and further analyzed by restriction endonuclease revealed that all of them were F18ac. Genes for F4 (K88), F6 (P987), F17, F5 (K99), F41, and intimin (eae gene) adhesins were detected in 19 %, 5%, 3%, 0.9%, 0.9%, and 0.9% of the isolates, respectively. The study of genetic diversity, carried out by PFGE of 46 representative ETEC and STEC isolates, revealed 36 distinct restriction profiles clustered in eight groups. Isolates of the same serotype were placed together in the dendrogram, but high degree of polymorphism among certain serotypes was detected. CONCLUSION: Seropathotype O149:H10 LT/STb/EAST1/F4 (14 isolates) was the most commonly detected followed by O163:H- EAST1/F18 (six isolates), and ONT:H4 STa/STb/Stx2e/F18 (five isolates). Interestingly, this study shows that two new serotypes (O163:H- and ONT:H4) have emerged as pig pathogens in Slovakia. Furthermore, our results show that there is a high genetic variation mainly among ETEC of O149:H10 serotype

Vertical transmission and early diagnosis of the microsporidian Enterocytozoon hepatonaei in Whiteleg Shrimp Penaeus vannamei

Microsporidia, which are ubiquitous obligate intracellular parasites responsible for a variety of diseases and economic losses in farming, have different transmission strategies. While horizontal transmission relies on sufûcient parasite numbers released into environment, vertical transmission requires host reproduction to occur leading to a lower virulence, and also induces a sex ratio distortion. The second strategy has been reported in a broad range of hosts from protists to mammals, in which insects and amphipod crustaceans as the most common. The present study shows the first evidence of vertical transmission of a microsporidia in decapod crustaceans via an experimental description of the infection by Enterocytozoon hepatopenaei (EHP) in whiteleg shrimp Penaeus vannamei. The group of healthy shrimp was infected with EHP by feeding with infected-shrimp tissue and sharing habitat. The presence of EHP in the infected shrimps was detected by using Polymerase Chain Reaction (PCR) method with specific primers EHP-510F/EHP-510R and histopathological analysis. The Nauplius, Zoae 1 and Zoae 2 stages collected from the infected female broodstocks demonstrated that EHP can infect offspring from their parental shrimp, and interestingly EHP can be detected from Nauplius stage of shrimp by the use of PCR method

Virulence factors in Escherichia coli isolated from calves with diarrhea in Vietnam

This study was conducted to determine the prevalence and characteristics of pathogenic Escherichia (E.) coli strains from diarrheic calves in Vietnam. A total of 345 E. coli isolates obtained from 322 diarrheic calves were subjected to PCR and multiplex PCR for detection of the f5, f41, f17, eae, sta, lt, stx1, and stx2 genes. Of the 345 isolates, 108 (31.3%) carried at least one fimbrial gene. Of these 108 isolates, 50 carried genes for Shiga toxin and one possessed genes for both enterotoxin and Shiga toxin. The eae gene was found in 34 isolates (9.8%), 23 of which also carried stx genes. The Shiga toxin genes were detected in 177 isolates (51.3%) and the number of strains that carried stx1, stx2 and stx1/stx2 were 46, 73 and 58, respectively. Among 177 Shiga toxin-producing E. coli isolates, 89 carried the ehxA gene and 87 possessed the saa gene. Further characterization of the stx subtypes showed that among 104 stx1-positive isolates, 58 were the stx1c variant and 46 were the stx1 variant. Of the 131 stx2-positive strains, 48 were stx2, 48 were stx2c, 11 were stx2d, 17 were stx2g, and seven were stx2c/stx2g subtypes. The serogroups most prevalent among the 345 isolates were O15, O20, O103 and O157

Characterizing pig value chains in Vietnam: descriptive analysis from survey data

The traditional pig sector plays a significant role in Vietnam’s economy from production, especially for farmers in rural areas, to consumption (more than 90% of pork consumed is supplied by conventional wet markets). At the same time, the traditional pig sector is under threat from animal health and food safety risks that impact both its profitability and future viability. However, little research exists on defining key intervention points that could manage risks in a propoor, cost-effective manner. Our study highlighted and reviewed the contrast between pig value chains in two provinces (Hung Yen and Nghe An) that represent different levels of economic development in the county. Based on semi-structured questionnaires, 400 pig producing farmers and 400 pork consumers were surveyed in both provinces during July and August 2013, paying particular attention to typologies of production and consumption in rural, semi-urban, and urban zones. We also obtained information on 200 other intermediary value chain actors through semi-structured and in-depth interviews. Preliminary descriptive analysis revealed the main characteristics of various actors in the sampled value chains, including (vet and feed) input suppliers, producers, traders, slaughterhouses (or abattoirs), processors, retailers, and consumers. In particular, we found that actors in Hung Yen are more likely to be active and commercialised in pig value chains than those in Nghe An. At the same time, Nghe An is exposed to operate its chains more ‘self-sufficiently’, with ownproduced inputs, particularly feeds, and has more state-owned farms involved in breed supply. In both study sites, middlemen often perform multiple functions and are generally the most powerful actors in the surveyed chains since they have better access to information and dominate value-added activities. This may imply a potential control point for risk management in response to diseases transmitted in short-term as well as (pro-poor) profit distribution in longerterm. Moreover, the behaviours of actors in these two provinces are dissimilar in terms of production and consumption practices as a result of differences in production scale, knowledge, attitude and habits. Information from this study will provide more insightful understanding of these existing value chains and serve as the base for further economic and risk analysis

Awareness and preparedness of healthcare workers against the first wave of the COVID-19 pandemic: A cross-sectional survey across 57 countries.

BACKGROUND: Since the COVID-19 pandemic began, there have been concerns related to the preparedness of healthcare workers (HCWs). This study aimed to describe the level of awareness and preparedness of hospital HCWs at the time of the first wave. METHODS: This multinational, multicenter, cross-sectional survey was conducted among hospital HCWs from February to May 2020. We used a hierarchical logistic regression multivariate analysis to adjust the influence of variables based on awareness and preparedness. We then used association rule mining to identify relationships between HCW confidence in handling suspected COVID-19 patients and prior COVID-19 case-management training. RESULTS: We surveyed 24,653 HCWs from 371 hospitals across 57 countries and received 17,302 responses from 70.2% HCWs overall. The median COVID-19 preparedness score was 11.0 (interquartile range [IQR] = 6.0-14.0) and the median awareness score was 29.6 (IQR = 26.6-32.6). HCWs at COVID-19 designated facilities with previous outbreak experience, or HCWs who were trained for dealing with the SARS-CoV-2 outbreak, had significantly higher levels of preparedness and awareness (p<0.001). Association rule mining suggests that nurses and doctors who had a 'great-extent-of-confidence' in handling suspected COVID-19 patients had participated in COVID-19 training courses. Male participants (mean difference = 0.34; 95% CI = 0.22, 0.46; p<0.001) and nurses (mean difference = 0.67; 95% CI = 0.53, 0.81; p<0.001) had higher preparedness scores compared to women participants and doctors. INTERPRETATION: There was an unsurprising high level of awareness and preparedness among HCWs who participated in COVID-19 training courses. However, disparity existed along the lines of gender and type of HCW. It is unknown whether the difference in COVID-19 preparedness that we detected early in the pandemic may have translated into disproportionate SARS-CoV-2 burden of disease by gender or HCW type