PCT-TEE: Trajectory-based Private Contact Tracing System with Trusted Execution Environment

Existing Bluetooth-based private contact tracing (PCT) systems can privately detect whether people have come into direct contact with patients with COVID-19. However, we find that the existing systems lack functionality and flexibility , which may hurt the success of contact tracing. Specifically, they cannot detect indirect contact (e.g., people may be exposed to COVID-19 by using a contaminated sheet at a restaurant without making direct contact with the infected individual); they also cannot flexibly change the rules of “risky contact,” such as the duration of exposure or the distance (both spatially and temporally) from a patient with COVID-19 that is considered to result in a risk of exposure, which may vary with the environmental situation. In this article, we propose an efficient and secure contact tracing system that enables us to trace both direct contact and indirect contact. To address the above problems, we need to utilize users’ trajectory data for PCT, which we call trajectory-based PCT . We formalize this problem as a spatiotemporal private set intersection that satisfies both the security and efficiency requirements. By analyzing different approaches such as homomorphic encryption, which could be extended to solve this problem, we identify the trusted execution environment (TEE) as a candidate method to achieve our requirements. The major challenge is how to design algorithms for a spatiotemporal private set intersection under the limited secure memory of the TEE. To this end, we design a TEE-based system with flexible trajectory data encoding algorithms. Our experiments on real-world data show that the proposed system can process hundreds of queries on tens of millions of records of trajectory data within a few seconds.

From Contact to Enact: Reducing Prejudice Toward Physical Disability Using Engagement Strategies

The contact hypothesis has dominated work on prejudice reduction and is often described as one of the most successful theories within social psychology. The hypothesis has nevertheless been criticized for not being applicable in real life situations due to unobtainable conditions for direct contact. Several indirect contact suggestions have been developed to solve this “application challenge.” Here, we suggest a hybrid strategy of both direct and indirect contact. Based on the second-person method developed in social psychology and cognition, we suggest working with an engagement strategy as a hybrid hypothesis. We expand on this suggestion through an engagement-based intervention, where we implement the strategy in a theater performance and investigate the effects on prejudicial attitudes toward people with physical disabilities. Based on the results we reformulate our initial engagement strategy into the Enact (Engagement, Nuancing, and Attitude formation) hypothesis. To deal with the application challenge, this hybrid hypothesis posits two necessary conditions for prejudice reduction. Interventions should: (1) work with engagement to reduce prejudice, and (2) focus on the second-order level of attitudes formation. Here the aim of the prejudice reduction is not attitude correction, but instead the nuancing of attitudes.

Association of Common Zoonotic Pathogens With Concentrated Animal Feeding Operations

Animal farming has intensified significantly in recent decades, with the emergence of concentrated animal feeding operations (CAFOs) in industrialized nations. The congregation of susceptible animals in CAFOs can lead to heavy environmental contamination with pathogens, promoting the emergence of hyper-transmissible, and virulent pathogens. As a result, CAFOs have been associated with emergence of highly pathogenic avian influenza viruses, hepatitis E virus, Escherichia coli O157:H7, Streptococcus suis, livestock-associated methicillin-resistant Staphylococcus aureus, and Cryptosporidium parvum in farm animals. This has led to increased transmission of zoonotic pathogens in humans and changes in disease patterns in general communities. They are exemplified by the common occurrence of outbreaks of illnesses through direct and indirect contact with farm animals, and wide occurrence of similar serotypes or subtypes in both humans and farm animals in industrialized nations. Therefore, control measures should be developed to slow down the dispersal of zoonotic pathogens associated with CAFOs and prevent the emergence of new pathogens of epidemic and pandemic potential.

Transmission of Respiratory Viral Diseases to Health Care Workers: COVID-19 as an Example

Health care workers (HCWs) can acquire infectious diseases, including coronavirus disease 2019 (COVID-19), from patients. Herein, COVID-19 is used with the source–pathway–receptor framework as an example to assess evidence for the role of aerosol transmission and indirect contact transmission of viral respiratory infectious diseases. Evidence for both routes is strong for COVID-19 and other respiratory viruses, but aerosol transmission is likely dominant for COVID-19. Key knowledge gaps about transmission processes and control strategies include the distribution of viable virus among respiratory aerosols of different sizes, the mechanisms and efficiency by which virus deposited on the facial mucous membrane moves to infection sites inside the body, and the performance of source controls such as face coverings and aerosol containment devices. To ensure that HCWs are adequately protected from infection, guidelines and regulations must be updated to reflect the evidence that respiratory viruses are transmitted via aerosols. Expected final online publication date for the Annual Review of Public Health, Volume 43 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Source attribution of salmonellosis by time and geography in New South Wales, Australia

Background Salmonella is a major cause of zoonotic illness around the world, arising from direct or indirect contact with a range of animal reservoirs. In the Australian state of New South Wales (NSW), salmonellosis is believed to be primarily foodborne, but the relative contribution of animal reservoirs is unknown. Methods The analysis included 4543 serotyped isolates from animal reservoirs and 30,073 serotyped isolates from domestically acquired human cases in NSW between January 2008 and August 2019. We used a Bayesian source attribution methodology to estimate the proportion of foodborne Salmonella infections attributable to broiler chickens, layer chickens, ruminants, pigs, and an unknown or unsampled source. Additional analyses included covariates for four time periods and five levels of rurality. Results A single serotype, S. Typhimurium, accounted for 65–75% of included cases during 2008–2014 but < 50% during 2017–2019. Attribution to layer chickens was highest during 2008–2010 (48.7%, 95% CrI 24.2–70.3%) but halved by 2017–2019 (23.1%, 95% CrI 5.7–38.9%) and was lower in the rural and remote populations than in the majority urban population. The proportion of cases attributed to the unsampled source was 11.3% (95% CrI 1.2%–22.1%) overall, but higher in rural and remote populations. The proportion of cases attributed to pork increased from approximately 20% in 2009–2016 to approximately 40% in 2017–2019, coinciding with a rise in cases due to Salmonella ser. 4,5,12:i:-. Conclusion Layer chickens were likely the primary reservoir of domestically acquired Salmonella infections in NSW circa 2010, but attribution to the source declined contemporaneously with increased vaccination of layer flocks and tighter food safety regulations for the handling of eggs.

One Health Genomic Study of Human and Animal Klebsiella pneumoniae Isolated at Diagnostic Laboratories on a Small Caribbean Island

Klebsiella pneumoniae causes a variety of infections in both humans and animals. In this study, we characterised the genomes of human and animal isolates from two diagnostic laboratories on St. Kitts, a small Caribbean island inhabited by a large population of vervet monkeys. In view of the increased chances of direct or indirect contact with humans and other animal species, we used the One Health approach to assess transmission of K. pneumoniae across host species by sequencing 82 presumptive K. pneumoniae clinical isolates from humans (n = 51), vervets (n = 21), horses (n = 5), dogs (n = 4) and a cat (n = 1). Whole genome sequencing (WGS) was carried out using Illumina technology. De novo assembly was performed in CLC Genomics Workbench v.11.0. Single nucleotide polymorphisms were detected using NASP followed by phylogenetic analysis using IQ-TREE. Virulence and antimicrobial resistance gene contents were analysed using the Kleborate and CGE pipelines. WGS-based analysis showed that 72 isolates were K. pneumoniae sensu stricto and five K. quasipneumoniae and five K. variicola. K. pneumoniae isolates belonged to 35 sequence types (ST), three of which were occasionally shared between humans and animals: ST23, ST37 and ST307. The ST23 strains from vervets formed a separate cluster amongst publicly available sequenced ST23 strains, indicating the presence of a specific vervet sublineage. Animal strains harbored fewer resistance genes and displayed distinct virulence traits that appeared to be host-specific in vervet isolates. Our results show that K. pneumoniae infections on this Caribbean island are usually caused by host-specific lineages.

Impact of Persian Sufi Thoughts on D. H. Lawrence’s Writing

In this paper, we have argued that Lawrence’s interest in what is ancient wisdom brings him in direct or indirect contact with Sufi metaphysics. This outlook on the world brings him closer to a Sufi universe in two ways. Firstly, Lawrence portrays romantic relationships in a mystical language, he presents the sensuous relationships as sacred activities through which the characters aspire to self-discovery. Lawrence`s portrayal of romantic love corresponds with the higher concept of love in Sufi literature. Secondly, this paper takes a closer look at some of Lawrence’s spiritual works including his Study of Thomas Hardy to compare his sustained argument regarding spiritualism and transcendental motifs in comparison with Sufi cosmology. Moreover, the following discussion also includes a detailed engagement with Lawrence`s correspondence and biographical information of the time when Lawrence was writing his essays and novels which contain transcendental motifs. His correspondence and biographical information suggest he had some direct exposure to Sufi literature in translation. Keywords: mysticism, divinity, holistic vision, physical and spiritual connection, cosmology, transcendental, metaphysics, ontology

From Blood to Bone—The Osteogenic Activity of L-PRF Membranes on the Ex Vivo Embryonic Chick Femur Development Model

(1) Background: To evaluate the effects of the direct and indirect contact of leukocyte and platelet-rich fibrin (L-PRF) on bone development, in an ex vivo embryonic chick femur model. (2) Methods: Both sections of L-PRF membranes (red and yellow portions) were evaluated with scanning electron microscopy and histochemical staining. The in vivo angiogenic activity was evaluated using a chorioallantoic membrane model. The osteogenic activity was assessed with an organotypic culture of embryonic chick femora through direct and indirect contact, and assessment was conducted by microtomographic and histological analysis. Descriptive statistics, One-Way ANOVA and Tukey’s multiple comparisons tests were performed for datasets that presented a normal distribution, and Kruskal-Wallis tests were performed for non-parametric datasets. A significance level of 0.05 was considered. (3) Results: The L-PRF induced angiogenesis reflected by a higher number and a larger and more complex gauge in the vessels that invaded the membrane. The physical presence of the membrane over the bone (direct contact) unleashes the full potential of the L-PRF effects on bone growth enhancement. The greatest increase in mineral content was observed in the diaphysis region. (4) Conclusion: The L-PRF direct contact group presented higher values on mineral content for bone volume, bone surface and bone mineral density than the indirect contact and control groups.

Cryptocurrency as Epidemiologically Safe Means of Transactions: Diminishing Risk of SARS-CoV-2 Spread

In comparison with other respiratory viruses, the current COVID-19 pandemic’s rapid seizing the world can be attributed to indirect (contact) way of transmission of SARS-CoV-2 virus in addition to the regular airborne way. A significant part of indirect transmission is made through cash bank notes. SARS-CoV-2 remains on cash paper money for period around four times larger than influenza A virus and is absorbed by cash notes two and a half times more effectively than influenza A (our model). During the pandemic, cryptocurrencies have gained attractiveness as an “epidemiologically safe” means of transactions. On the basis of the authors’ gallop polls performed online with social networks users in 44 countries in 2020–2021 (the total number of clear responses after the set repair 32,115), around 14.7% of surveyed participants engaged in cryptocurrency-based transactions during the pandemic. This may be one of the reasons of significant rise of cryptocurrencies rates since mid-March 2020 till the end of 2021. The paper discusses the reasons for cryptocurrency attractiveness during the COVID-19 pandemic. Among them, there are fear of SARS-CoV-2 spread via cash contacts and the ability of the general population to mine cryptocurrencies. The article also provides a breakdown of the polled audience profile to determine the nationalities that have maximal level of trust to saving and transacting money as cryptocurrencies.

The Cultural Dimension of SLA Attitudes of Philological and Non-Philological Learners to English Language Speakers

Attitudes towards target language (TL) speakers present an aspect pertaining to the cultural dimension of learning a foreign language. Consequently, the main goals of the study were to determine the participants’ attitudes towards the British and Americans, and the degree of social distance the participants felt towards these groups by comparing evaluations of their willingness to identify with TL and L1 speakers. The participants included in the study (N=239) represented two age groups (secondary and tertiary students), and two educational profiles: philological (Phil) and non-philological (Non-Phil) groups. The main research instruments were an adapted Bogardus Social Distance Scale, which showed good internal consistency on all the subscales, and an English language contact scale, whose aim was to test the participants’ actual interaction with the target language speakers (the length of stay in a TL community, potential mobility via school/university exchange programmes). The main finding suggests that Phil groups, being more familiar with the TL culture, evaluated its speakers much more positively and were generally more willing to identify with TL members, even at the most intimate level (spouse). Accordingly, the practical implications would be to encourage foreign language teachers to keep acquainting learners with different cultural elements and work towards fostering positive attitudes to the TL and its culture. What our study has failed to determine, though, is whether the actual contact with real, flesh-and-blood people in contrast to indirect contact with ‘imaginary TL speakers’ that are the product of one’s perception makes a difference in attitudes.