Contact Patterns Research Articles

Application of 3D digital smile design based on virtual articulation analysis in esthetic dentistry: A technique

A technique for the application of a virtual articulation system in 3-dimensional digital smile design (DSD) during esthetic restoration is described. To acquire stable occlusion and a smooth jaw movement pattern without premature contacts or interference, a digital facebow and a virtual articulator were used to collect and analyze a patient’s occlusal data and jaw movement information. The original pattern of occlusal contacts and jaw movements were diagnosed as stable and copied to the digital design of the new prostheses. Preparation of the abutments, crown lengthening surgery, and definitive crown fabrication and cementation were performed according to the design. After 9 months, the occlusion remained stable, and the patient was satisfied with the outcome.

Solar-driven biomass chemical looping gasification using Fe3O4 for syngas and high-purity hydrogen production

A novel solar-driven biomass chemical looping gasification (SBCLG) system was proposed and experimentally demonstrated for the co-production of pure hydrogen and syngas from biomass wastes using high-flux solar irradiation. In this system, a steam reactor and a solar fuel reactor were adopted to replace the air and fuel reactors in a typical biomass chemical looping gasification (BCLG) system, respectively. The SBCLG exhibits two advantages over BCLG: (1) the syngas yield is raised as the high-temperature process heat is provided by solar radiation rather than biomass combustion, and (2) a pure hydrogen stream is generated in addition to the syngas stream, which allows a flexible adjustment of the carbon-to-hydrogen ratio for downstream chemical processes. This study marked the first demonstration of a complete cycle of SBCLG in a cavity-type packed-bed solar reactor under simulated high-flux solar irradiation. Magnetite (Fe3O4) was circulated between the steam reactor and the solar fuel reactor as the oxygen carrier (OC). The optimal operational parameters, the reaction temperature and solid contact pattern, were first determined in preliminary experiments in an electric furnace. Then, the effect of biomass to oxygen carrier mass ratio (mRH:mOC) on the key performance indicators was also investigated in a solar reactor. When mRH:mOC = 1:2, the highest values of the average carbon-gas yield of 0.69 ± 0.05 and energy upgrade factor of 0.71 ± 0.04 were achieved. The solar fuel reactor produced CH4, CO, CO2 and H2 at 0.63, 11.86, 8.85, and 18.53 mmol/g biomass, respectively, with the steam reactor yielding high-purity H2 at 7.17 mmol/g biomass. The results indicated that the SBCLG is a viable method for co-production of pure hydrogen and syngas in separate streams.

Structural trends in antibody-antigen binding interfaces: a computational analysis of 1833 experimentally determined 3D structures

Antibodies are attractive therapeutic candidates due to their ability to bind cognate antigens with high affinity and specificity. Still, the underlying molecular rules governing the antibody-antigen interface remain poorly understood, making in silico antibody design inherently difficult and keeping the discovery and design of novel antibodies a costly and laborious process. This study investigates the characteristics of antibody-antigen binding interfaces through a computational analysis of more than 850,000 atom-atom contacts from the largest reported set of antibody-antigen complexes with 1833 nonredundant, experimentally determined structures. The analysis compares binding characteristics of conventional antibodies and single-domain antibodies (sdAbs) targeting both protein- and peptide antigens. We find clear patterns in the number antibody-antigen contacts and amino acid frequencies in the paratope. The direct comparison of sdAbs and conventional antibodies helps elucidate the mechanisms employed by sdAbs to compensate for their smaller size and the fact that they harbor only half the number of complementarity-determining regions compared to conventional antibodies. Furthermore, we pinpoint antibody interface hotspot residues that are often found at the binding interface and the amino acid frequencies at these positions. These findings have direct potential applications in antibody engineering and the design of improved antibody libraries.

新한류 속 언어차용과 문화교류

The purpose of this paper is to discuss the changing aspects of language and cultural contact, focusing on the case of Chinese translation of fandom terminology in the new Korean Wave. Following the craze of the new Korean Wave, new cases of language contact and translation are emerging, focusing on fandom terminology and expressions. Fragmentary Korean expressions, which used to be nothing more than a temporary trend among young people, have now been used for years. Furthermore, it is becoming established as a unique expression showing derivative expressions and formalized translation patterns. This paper first analyzed the translation cases of Chinese, which had a strong influence on the formation of the Chinese character cultural sphere, and as a result, several meaningful characteristics were derived. Based on this, it is worth noting that the formation of global fandom and the new language contact pattern centered on fandom terms have broken down Asian cultural boundaries and acted as an important medium for globalization.

Long-term vaccination strategies to mitigate the impact of SARS-CoV-2 transmission: A modelling study.

Vaccines have reduced severe disease and death from Coronavirus Disease 2019 (COVID-19). However, with evidence of waning efficacy coupled with continued evolution of the virus, health programmes need to evaluate the requirement for regular booster doses, considering their impact and cost-effectiveness in the face of ongoing transmission and substantial infection-induced immunity. We developed a combined immunological-transmission model parameterised with data on transmissibility, severity, and vaccine effectiveness. We simulated Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) transmission and vaccine rollout in characteristic global settings with different population age-structures, contact patterns, health system capacities, prior transmission, and vaccine uptake. We quantified the impact of future vaccine booster dose strategies with both ancestral and variant-adapted vaccine products, while considering the potential future emergence of new variants with modified transmission, immune escape, and severity properties. We found that regular boosting of the oldest age group (75+) is an efficient strategy, although large numbers of hospitalisations and deaths could be averted by extending vaccination to younger age groups. In countries with low vaccine coverage and high infection-derived immunity, boosting older at-risk groups was more effective than continuing primary vaccination into younger ages in our model. Our study is limited by uncertainty in key parameters, including the long-term durability of vaccine and infection-induced immunity as well as uncertainty in the future evolution of the virus. Our modelling suggests that regular boosting of the high-risk population remains an important tool to reduce morbidity and mortality from current and future SARS-CoV-2 variants. Our results suggest that focusing vaccination in the highest-risk cohorts will be the most efficient (and hence cost-effective) strategy to reduce morbidity and mortality.

Influence of assembly errors on meshing characteristics of spiral bevel gear and compensation approach of misalignment

Based on the spatial position relationship of spiral bevel gear, mathematical model and mesh model applied with finite element analysis (FEA) approach has been established. The influence of axial position errors of pinion and wheel, offset error, and shaft angle error on the meshing characteristics has been investigated. A method has been proposed to compensate the gear assembly errors by the axial displacement of the pinion and wheel, and the correctness of this method verified by numerical examples. The performed results indicate that the existence of assembly errors can cause contact pattern on the tooth surface to deviate from its design position, resulting in poor meshing quality and having a certain impact on transmission error (TE) and peak-to-peak transmission error (PPTE). The pinion and wheel’s axial positioning errors can be offset by each other, whereas the offset error and shaft angle error can be mitigated by the interplay between the axial positioning of the pinion and wheel. By compensating for assembly errors with axial displacement, the position of the contact pattern can be precisely controlled, and TE will not significant changes.

Families With Early History of Parental Abuse and Neglect: Midlife Adult Children’s Relationships With Their Parents During COVID-19

For families with an early history of parental abuse and neglect (EHPAN), personal and situational stressors can increase relational vulnerabilities. We examined relationship dynamics between midlife adults with EHPAN and their parents during the first year of the COVID-19 pandemic. Analysis of semi-structured qualitative interviews with 31 participants (aged 44–50), examined patterns of contact and support to provide insights into relationship dynamics and relational changes experienced during the pandemic. Three relational themes characterized midlife adult child-parent relationships during COVID-19: tightening ties with parents while taking few COVID-19 precautions; keeping customary ties to maintain the status quo centered around instrumental support; loosening ties in which the relationship drifted. We found areas of resilience and vulnerabilities within each type of relationship. Recognizing that past adversity continues to shape relationship dynamics throughout the life course underscores the need for further research to identify factors that contribute to long-term family resilience and challenges.

EPIDEMIOLOGICAL CONTACT (EPICONTACT) INVESTIGATION OF COVID-19 AT ISLAMIC BOARDING SCHOOLS IN KUNINGAN REGENCY, INDONESIA

Introduction: COVID-19 has spread throughout the world with more than 61, 27 million patients infected, including in education clusters that implement boarding schools. Contact investigations on the cluster are necessary to control the spread of the virus. Aims: To describe the epidemiological contact pattern of investigation results in the Islamic Boarding School cluster in Kuningan Regency. Methods: The design of this study is descriptive with epidemiological approach. The population is all students of Pondok Pesantren X, as many as 164 students, a sample of 157 students who are positive for COVID-19, and research instrument for the COVID-19 outbreak is investigation form, the variables studied included age, gender, symptoms, duration of contact, number of contacts, number of contact groups and place of contact. Result: Univariate data analysis with epi-contact analysis show: sex: 33.3% male, 60.03% female, average age 15.05 years, the average number of contacts 3.25 people, the average number of male contacts 2.62 and female 3.39, number of male contact groups 41, number of female contact groups 91. Age of value p=0.037. Conclusions: Contact pattern conclusions are mostly in female with the number of contacts between 3-4 people and age is related to the number of contacts. Limiting contact when there is suspicion is necessary to prevent transmission.

Changing social contact patterns among US workers during the COVID-19 pandemic: April 2020 to December 2021

Non-pharmaceutical interventions minimize social contacts, hence the spread of respiratory pathogens such as influenza and SARS-CoV-2. Globally, there is a paucity of social contact data from the workforce. In this study, we quantified two-day contact patterns among USA employees. Contacts were defined as face-to-face conversations, involving physical touch or proximity to another individual and were collected using electronic self-kept diaries. Data were collected over 4 rounds from 2020 to 2021 during the COVID-19 pandemic. Mean (standard deviation) contacts reported by 1456 participants were 2.5 (2.5), 8.2 (7.1), 9.2 (7.1) and 10.1 (9.5) across round 1 (April–June 2020), 2 (November 2020–January 2021), 3 (June–August 2021), and 4 (November–December 2021), respectively. Between round 1 and 2, we report a 3-fold increase in the mean number of contacts reported per participant with no major increases from round 2–4. We then modeled SARS-CoV-2 transmission at home, work, and community settings. The model revealed reduced relative transmission in all settings in round 1. Subsequently, transmission increased at home and in the community but remained exceptionally low in work settings. To accurately parameterize models of infection transmission and control, we need empirical social contact data that capture human mixing behavior across time.

Insights from exact social contagion dynamics on networks with higher-order structures

Abstract Recently, there has been an increasing interest in studying dynamical processes on networks exhibiting higher-order structures, such as simplicial complexes, where the dynamics acts above and beyond dyadic interactions. Using simulations or heuristically derived epidemic spreading models, it was shown that new phenomena can emerge, such as bi-stability/multistability. Here, we show that such new emerging phenomena do not require complex contact patterns, such as community structures, but naturally result from the higher-order contagion mechanisms. We show this by deriving an exact higher-order Susceptible-Infected-Susceptible model and its limiting mean-field equivalent for fully connected simplicial complexes. Going beyond previous results, we also give the global bifurcation picture for networks with 3- and 4-body interactions, with the latter allowing for two non-trivial stable endemic steady states. Differently from previous approaches, we are able to study systems featuring interactions of arbitrary order. In addition, we characterize the contributions from higher-order infections to the endemic equilibrium as perturbations of the pairwise baseline, finding that these diminish as the pairwise rate of infection increases. Our approach represents a first step towards a principled understanding of higher-order contagion processes beyond triads and opens up further directions for analytical investigations.

Trisomies Reorganize Human 3D Genome.

Trisomy is the presence of one extra copy of an entire chromosome or its part in a cell nucleus. In humans, autosomal trisomies are associated with severe developmental abnormalities leading to embryonic lethality, miscarriage or pronounced deviations of various organs and systems at birth. Trisomies are characterized by alterations in gene expression level, not exclusively on the trisomic chromosome, but throughout the genome. Here, we applied the high-throughput chromosome conformation capture technique (Hi-C) to study chromatin 3D structure in human chorion cells carrying either additional chromosome 13 (Patau syndrome) or chromosome 16 and in cultured fibroblasts with extra chromosome 18 (Edwards syndrome). The presence of extra chromosomes results in systematic changes of contact frequencies between small and large chromosomes. Analyzing the behavior of individual chromosomes, we found that a limited number of chromosomes change their contact patterns stochastically in trisomic cells and that it could be associated with lamina-associated domains (LAD) and gene content. For trisomy 13 and 18, but not for trisomy 16, the proportion of compacted loci on a chromosome is correlated with LAD content. We also found that regions of the genome that become more compact in trisomic cells are enriched in housekeeping genes, indicating a possible decrease in chromatin accessibility and transcription level of these genes. These results provide a framework for understanding the mechanisms of pan-genome transcription dysregulation in trisomies in the context of chromatin spatial organization.

PCR testing of traced contacts for SARS-CoV-2 in England, January to July 2021.

BackgroundThe NHS Test and Trace (NHSTT) programme was established in May 2020 in England to deliver SARS-CoV-2 testing and contact tracing in order to identify infected individuals and reduce COVID-19 spread. To further control transmission, people identified as contacts were asked to self-isolate for 10 days and test only if they became symptomatic. From March 2021, eligibility criteria for PCR testing expanded to include asymptomatic contacts of confirmed cases.AimTo analyse testing patterns of contacts before and after the change in testing guidance in England to assess the impact on PCR testing behaviour with respect to symptom status and contact type.MethodsTesting and contact tracing data were extracted from the national data systems and linked. Subsequently, descriptive statistical analysis was applied to identify trends in testing behaviour.ResultsBetween 1 January and 31 July 2021, over 5 million contacts were identified and reached by contact tracers; 42.3% took a PCR test around the time they were traced. Overall positivity rate was 44.3% and consistently higher in symptomatic (60-70%) than asymptomatic (around 20%, March-June) contacts. The proportion of tests taken by asymptomatic contacts increased over time, especially after the change in testing guidance. No link was observed between uptake of PCR tests and vaccination coverage. Fully vaccinated contacts showed lower positivity (23.8%) than those with one dose (37.2%) or unvaccinated (51.0%).ConclusionAlmost 1 million asymptomatic contacts were tested for SARS-CoV-2, identifying 214,056 positive cases, demonstrating the value of offering PCR testing to this group.

Risk Factors and Urogenital Schistomiasis Prevalence among Primary School Children in Makurdi, Nigeria

Urogenital schistosomiasis in humans is an infection of public health importance caused by infection with Schistosoma heamatobium. The study investigated the risk factors and intensity of urogenital schistosomiasis among primary school pupils in Makurdi, Nigeria. Eight hundred (800) school pupils consisting of 200 per school, aged 5 – 20 years in Angwan Jukun, Angwan Reke, Agbo and Ijaha communities, respectively were enrolled for the study. Suitably designed questionnaire was used to document data on the demographics as well as relevant information of the participants. Urine samples were collected from consented participants between 10 am – 2 pm, into pre-labelled plastic sample bottles following aseptic techniques. The samples were subjected to standard parasitological techniques for determination and quantification of parasite in the zoology laboratory of Benue State University, Makurdi. Research data was subjected to chi square analysis to ascertain association of the research variables with schistosomiasis prevalence in the study area. The study filed an overall prevalence of 23.75% (190/800). Infection rates were significantly associated with age as age group 16-20 years had the highest prevalence (P<0.000). Males 25.42% (122/800) were slightly more infected than females 21.25% (68/800) (P>0.05). Water contact pattern of participants revealed a highly significant association with schistosomiasis prevalence (p<0.001)). Grazing activity 50% (1/2) displayed higher infection prevalence followed by > 1 activity 34.65% (79/228) while no infection was seen in snail hunters. The association between the presence and type of livestock sharing open water sources with the communities was statistically significant (P<0.05). Makurdi is endemic for urogenital schistosomiasis and related risk factors. The roles of other definitive hosts in ensuring continual disease transmission and possible zoonosis should be investigated

Numerical simulations of the effect of lateral malleolus fracture malunion on ankle biomechanics: Different offset directions and offsets

IntroductionAnkle fractures account for approximately 10 % of all fractures. Approximately 5–68 % of patients with ankle fractures may suffer from malunion. Besides, suboptimal reduction of fracture fragments can affect the biomechanics of the ankle joint, ultimately leading to damage to the ankle joint. However, there are certain controversies over the conclusion of previous cadaveric studies. MethodsIn this study, a three-dimensional model of the ankle joint was established based on CT image data. In addition, the effects of backward offset (1–2 mm) and outward offset (0.5–1 mm) of the fracture fragment on the contact area, contact pressure, and ligament force of the ankle joint were investigated via the finite element method. Moreover, lateral malleolus fracture malunion in five ankle positions (neutral, 10° dorsiflexion, 10° plantarflexion, 20° dorsiflexion, and 20° plantarflexion) was investigated. ResultsThis model predicted an overall increased contact area in the ankle joint in patients with lateral malleolus fracture malunion compared with the normal ankle joint. The results demonstrated that the outward offset had a more significant effect than the backward one. The larger the dorsiflexion-plantarflexion angle, the more pronounced the effect of malunion. Further, an outward offset can cause the fibula to lose its function. ConclusionPost-traumatic osteoarthritis occurs under the action of unaccustomed cartilage forces due to altered tibial talar joint contact patterns, rather than increased contact pressure reported in previous studies. Malunion leads to an increase or decrease in force on the affected ligament, while the cause of malunion can be envisioned based on a decrease in the force on the ligaments.

Mapping of neuronal and glial primary cilia contactome and connectome in the human cerebral cortex

Primary cilia act as antenna receivers of environmental signals and enable effective neuronal or glial responses. Disruption of their function is associated with circuit disorders. To understand the signals these cilia receive, we comprehensively mapped cilia's contacts within the human cortical connectome using serial-section EM reconstruction of a 1mm3 cortical volume, spanning the entire cortical thickness. We mapped the "contactome" of cilia emerging from neurons and astrocytes in every cortical layer. Depending on the layer and cell type, cilia make distinct patterns of contact. Primary cilia display cell-type- and layer-specific variations in size, shape, and microtubule axoneme core, which may affect their signaling competencies. Neuronal cilia are intrinsic components of a subset of cortical synapses and thus a part of the connectome. This diversity in the structure, contactome, and connectome of primary cilia endows each neuron or glial cell with a unique barcode of access to the surrounding neural circuitry.

Social contact patterns among employees in U.S. long-term care facilities during the COVID-19 pandemic, December 2020 to June 2021

ObjectiveWe measured contact patterns using social contact diaries for 157 U.S. long-term care facility employees from December 2020 - June 2021. These data are crucial for analyzing mathematical transmission models and for informing healthcare setting infection control policy.ResultsThe median number of daily contacts was 10 (IQR 8–11). Household contacts were more likely partially masked than fully masked, more likely to involve physical contact, and longer in duration compared to facility contacts.

Patterns of Mental Health Service Contacts for Young People Deemed Eligible for Court Diversion

Past research suggests that diverting young people away from the criminal justice system and into mental health services can reduce subsequent reoffending, but the impact of such programs on the rates of timely mental health service contact are largely unknown. In this study, we examined a sample of 523 young people who were deemed eligible for mental health diversion between 2008 and 2015. Around half (47%) of these young people were granted diversion by a Magistrate. Overall, the levels of timely mental health service contact after court finalization, even for those who were granted diversion, appeared low given that the purpose of diversion is to facilitate such contact for all those diverted. Specifically, only 22% of those who were granted community-based diversion and 62% of individuals granted inpatient-based diversion had mental health service contact within 7 days of court finalization. Rates of health contact were much lower for those who were not granted either type of diversion (8% and 23%, respectively). Diversion was associated with a significant reduction in reoffending rates, but the impact of early mental health service contact was less clear. There is a need to understand the reasons why many young people are not accessing appropriate mental health services following diversion in order to improve outcomes and fully realize the intended benefits of mental health court diversion.

Socioeconomic differences in SARS-CoV-2-antigen contacts after one year of the vaccination campaign

Abstract Background Evidence on the SARS-CoV-2 serological status of the German population by socioeconomic position (SEP) is still limited for the vaccine era of the pandemic, but could contribute to the understanding of the unequal risks of severe COVID-19. This study aims to evaluate the socioeconomic patterns of antigen contacts through infection, vaccination or both (‘hybrid immunity’) after one year of vaccination campaign in Germany. Methods We used nationwide serological and self-reported data from the population-based German seroepidemiological Corona Monitoring Nationwide study (RKI-SOEP-2, November 2021-February 2022) to estimate prevalence ratios (PR) of SARS-CoV-2 infection, COVID-19 vaccination (at least one dose of vaccine), basic immunization (at least two SARS-CoV-2 antigen contacts), and three antigen contacts by education and income. Estimates were derived from Poisson regression models adjusted for age, sex, migration status, urban-rural residence, federal state and date of participation. Results Across 10,448 adult participants, low-education groups had a 1.35-fold greater risk of SARS-CoV-2 infection compared to high-education groups (95% CI 1.01-1.82, p = 0.045). COVID-19 vaccination and basic immunization decreased with lower education and income. Low-education and low-income groups were less likely to have had at least three SARS-CoV-2 antigen contacts (PR low vs. high education: 0.74, 95% CI 0.65-0.84, p < 0.001; PR low vs. high income: 0.66, 95% CI 0.57-0.77, p < 0.001) Conclusions The results show socioeconomic inequalities in SARS-CoV-2 infections, COVID-19 vaccinations and antigen contacts, suggesting a lower level of protection against severe COVID-19 for individuals with low and medium SEP. The majority of the German population exhibits further prevention potential, which could be addressed via more targeted interventions. Future research, pandemic response and vaccination campaigns should address the specific needs and barriers of these groups. Key messages • Multiple antigen contacts, especially through vaccination, are less prevalent in groups with low or medium socioeconomic position. • Potential to prevent severe COVID-19 exists in the majority of the German population after one year of vaccination campaign.

Temporal and Probabilistic Comparisons of Epidemic Interventions.

Forecasting disease spread is a critical tool to help public health officials design and plan public health interventions. However, the expected future state of an epidemic is not necessarily well defined as disease spread is inherently stochastic, contact patterns within a population are heterogeneous, and behaviors change. In this work, we use time-dependent probability generating functions (PGFs) to capture these characteristics by modeling a stochastic branching process of the spread of a disease over a network of contacts in which public health interventions are introduced over time. To achieve this, we define a general transmissibility equation to account for varying transmission rates (e.g. masking), recovery rates (e.g. treatment), contact patterns (e.g. social distancing) and percentage of the population immunized (e.g. vaccination). The resulting framework allows for a temporal and probabilistic analysis of an intervention's impact on disease spread, which match continuous-time stochastic simulations that are much more computationally expensive. To aid policy making, we then define several metrics over which temporal and probabilistic intervention forecasts can be compared: Looking at the expected number of cases and the worst-case scenario over time, as well as the probability of reaching a critical level of cases and of not seeing any improvement following an intervention. Given that epidemics do not always follow their average expected trajectories and that the underlying dynamics can change over time, our work paves the way for more detailed short-term forecasts of disease spread and more informed comparison of intervention strategies.

Face gear drive manufacturing: Pinion/cutter design for a crowned contact pattern

Face gear drives are special angular gears in which an involute pinion and face gear wheel mesh. They enable high transmission ratios in small construction spaces. The face gear is typically manufactured by gear hobbing or gear shaping using an involute pinion-type cutter. Face gear drives with identical pinion and cutter parameters form a conjugated pairing. Conjugate pairings tend to have unfavourable edge contact, which is usually counteracted by geometric flank modifications during manufacture. A common modification technique is the crowning of the flanks. This usually requires changes to the machine kinematics. Due to their geometry and manufacturing process, face gear drives offer an easy way to achieve a crowned contact pattern in the facewidth direction without changing the machine kinematics, making them promising for multiple applications. Using a pinion with fewer teeth than the cutter results in a crowned contact pattern (lead crowning). The position of the contact point along the facewidth can be adjusted by varying the profile shift coefficient of the pinion or the cutter. This paper presents a straightforward method for selecting proper design parameters depending on the contact distances. The contact distances can be estimated analytically to evaluate the chosen design parameters. Example calculations are given as proof of the developed method presented in this paper. Overall, this study offers a novel evaluation strategy for an ideal cutter/pinion design for manufacturing durable face gear drives with optimised contact patterns.