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Introduction: Mathematical models of HIV have been uniquely important in directing and evaluating HIV policy. Transgender and nonbinary people are disproportionately impacted by HIV; however, few mathematical models of HIV transmission have been published that are inclusive of transgender and nonbinary populations. This commentary discusses current structural challenges to developing robust and accurate trans‐inclusive models and identifies opportunities for future research and policy, with a focus on examples from the United States. Discussion: As of April 2024, only seven published mathematical models of HIV transmission include transgender people. Existing models have several notable limitations and biases that limit their utility for informing public health intervention. Notably, no models include transgender men or nonbinary individuals, despite these populations being disproportionately impacted by HIV relative to cisgender populations. In addition, existing mathematical models of HIV transmission do not accurately represent the sexual network of transgender people. Data availability and quality remain a significant barrier to the development of accurate trans‐inclusive mathematical models of HIV. Using a community‐engaged approach, we developed a modelling framework that addresses the limitations of existing model and to highlight how data availability and quality limit the utility of mathematical models for transgender populations. Conclusions: Modelling is an important tool for HIV prevention planning and a key step towards informing public health interventions, programming and policies for transgender populations. Our modelling framework underscores the importance of accurate trans‐inclusive data collection methodologies, since the relevance of these analyses for informing public health decision‐making is strongly dependent on the validity of the model parameterization and calibration targets. Adopting gender‐inclusive and gender‐specific approaches starting from the development and data collection stages of research can provide insights into how interventions, programming and policies can distinguish unique health needs across all gender groups. Moreover, in light of the data structure limitations, designing longitudinal surveillance data systems and probability samples will be critical to fill key research gaps, highlight progress and provide additional rigour to the current evidence. Investments and initiatives like Ending the HIV Epidemic in the United States can be further expanded and are highly needed to prioritize and value transgender populations across funding structures, goals and outcome measures. [ABSTRACT FROM AUTHOR]

Background: To reduce the burden from the COVID-19 pandemic in the United States, federal and state local governments implemented restrictions such as limitations on gatherings, restaurant dining, and travel, and recommended non-pharmaceutical interventions including physical distancing, mask-wearing, surface disinfection, and increased hand hygiene. Resulting behavioral changes impacted other infectious diseases including enteropathogens such as norovirus and rotavirus, which had fairly regular seasonal patterns prior to the COVID-19 pandemic. The study objective was to project future incidence of norovirus and rotavirus gastroenteritis as contacts resumed and other NPIs are relaxed. Methods: We fitted compartmental mathematical models to pre-pandemic U.S. surveillance data (2012–2019) for norovirus and rotavirus using maximum likelihood estimation. Then, we projected incidence for 2022–2030 under scenarios where the number of contacts a person has per day varies from70%, 80%, 90%, and full resumption (100%) of pre-pandemic levels. Results: We found that the population susceptibility to both viruses increased between March 2020 and November 2021. The 70–90% contact resumption scenarios led to lower incidence than observed pre-pandemic for both viruses. However, we found a greater than two-fold increase in community incidence relative to the pre-pandemic period under the 100% contact scenarios for both viruses. With rotavirus, for which population immunity is driven partially by vaccination, patterns settled into a new steady state quickly in 2022 under the 70–90% scenarios. For norovirus, for which immunity is relatively short-lasting and only acquired through infection, surged under the 100% contact scenario projection. Conclusions: These results, which quantify the consequences of population susceptibility build-up, can help public health agencies prepare for potential resurgence of enteric viruses. [ABSTRACT FROM AUTHOR]

Autism spectrum disorder (ASD) is defined as a neurodevelopmental disorder that results in impairments in social communications and interactions as well as repetitive behaviours. Despite current estimates showing that approximately 2.2% of children are affected in the United States, relatively little about ASD pathophysiology is known in part due to the highly heterogenous presentation of the disorder. Given the limited knowledge into the biological mechanisms governing its aetiology, the diagnosis of ASD is performed exclusively based on an individual's behaviour assessed by a clinician through psychometric tools. Although there is no readily available biochemical test for ASD diagnosis, multivariate statistical methods show considerable potential for effectively leveraging multiple biochemical measurements for classification and characterization purposes. In this work, markers associated with the folate dependent one‐carbon metabolism and transsulfuration (FOCM/TS) pathways analyzed via both Fisher discriminant analysis and support vector machine showed a strong capability to distinguish between ASD and typically developing peers (TD) cohorts. Furthermore, using kernel partial least squares regression it was possible to assess some degree of behavioural severity from metabolomic data. While the results presented need to be replicated in independent future studies, they represent a promising avenue for uncovering clinically relevant ASD biomarkers. [ABSTRACT FROM AUTHOR]

The article focuses on the vaccination of older adults against respiratory syncytial virus (RSV) and discusses key topics such as mathematical modeling, vaccine protection duration, and vaccine efficacy. It authors highlight the need for RSV vaccines due to the high hospitalization rate among older adults and the emergence of new vaccine formulations. Mathematical models play a crucial role in evaluating vaccine impact, taking into account uncertainties in vaccine protection.

Background and aims Effective strategies are needed to address dramatic increases in hepatitis C virus (HCV) infection among people who inject drugs (PWID) in rural settings of the United States. We determined the required scale-up of HCV treatment with or without scale-up of HCV prevention interventions to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025 and 2030 in a rural US setting. Design An ordinary differential equation model of HCV transmission calibrated to HCV epidemiological data obtained primarily from an HIV outbreak investigation in Indiana. Setting Scott County, Indiana (population 24 181), USA, a rural setting with negligible baseline interventions, increasing HCV epidemic since 2010, and 55.3% chronic HCV prevalence among PWID in 2015. Participants PWID. Measurements Required annual HCV treatments per 1000 PWID (and initial annual percentage of infections treated) to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025/30, either with or without scaling-up syringe service programmes (SSPs) and medication-assisted treatment (MAT) to 50% coverage. Sensitivity analyses considered whether this impact could be achieved without re-treatment of re-infections, and whether greater intervention scale-up was required due to the increasing epidemic in this setting. Findings To achieve a 90% reduction in incidence and prevalence by 2030, without MAT and SSP scale-up, 159 per 1000 PWID (initially 24.9% of infected PWID) need to be HCV-treated annually. However, with MAT and SSP scaled-up, treatment rates are halved (89 per 1000 annually or 14.5%). To reach the same target by 2025 with MAT and SSP scaled-up, 121 per 1000 PWID (19.9%) need treatment annually. These treatment requirements are threefold higher than if the epidemic was stable, and the impact targets are unattainable without retreatment. Conclusions Combined scale-up of hepatitis C virus treatment and prevention interventions is needed to decrease the increasing burden of hepatitis C virus incidence and prevalence in rural Indiana, USA, by 90% by 2025/30. [ABSTRACT FROM AUTHOR]

This study investigated the level of injury severity in crashes in right-turn lanes at signalised intersections. It used a dataset of 1900 injuries occurring at 275 signalised intersections in the Las Vegas, NV, USA area in the period 2003 to 2005. An advanced random-parameter binary logit model was used to determine the factors that significantly influence injury severity - categorised as either property damage only or severe injury - in right-turn lanes. A comparison of this model with the traditional fixed-parameter model was made to account for the unobserved heterogeneity. It was comparable to the two-level binary logistic model, which accounts for cross-group heterogeneity. The analysis showed that the following factors lead to a significantly higher likelihood of severe injury: rear-end crashes, the involvement of a vehicle going through the intersection, stopped and parked vehicles on main and minor streets, length of corner clearance, number of through lanes on minor streets and intersection angle. [ABSTRACT FROM AUTHOR]

Choking problems occur in transitions that have a bed rise higher than a maximum allowable value. Due to the complexity of the United States Bureau of Reclamation (USBR) horseshoe cross-section, a time-consuming trial-and-error procedure is inevitable as a way to determine the maximum allowable bed rise. This paper presents straightforward solutions to calculate a choke-free maximum bed rise for practical changes in bed elevations. The maximum relative errors associated with the proposed equations are less than 1%. A graphical solution is presented to obtain the upstream operating ranges based on non-dimensional specific energy curves. In addition, a direct relationship is developed to determine the critical depth in the transition zone which bears less than 1% relative error. Finally, a choking solution is discussed by considering the energy head loss occurred in the channel transition zone. [ABSTRACT FROM AUTHOR]

Abstract: Streptococcus pneumoniae (S. pneumoniae) is a bacterium commonly found in the throat of young children. Pneumococcal serotypes can cause a variety of invasive and non-invasive diseases such as meningitis and pneumonia. In 2000 a vaccine was introduced in the USA that not only prevents vaccine type disease but has also been shown to eliminate carriage of the vaccine serotypes. One key problem with the vaccine is that it has been observed that the same sequence types (genetic material found in the serotypes) are able to manifest in more than one serotype. This is a potential problem if sequence types associated with invasive disease may express themselves in multiple serotypes. We present a basic differential equation mathematical model for exploring the relationship between sequence types and serotypes where a sequence type is able to manifest itself in one vaccine serotype and one non-vaccine serotype. An expression for the effective reproduction number is found and an equilibrium and then a global stability analysis carried out. We illustrate our analytical results by using simulations with realistic parameter values. [ABSTRACT FROM AUTHOR]

Joint opening of concrete pavement is caused by changes in the temperature and humidity of concrete slabs. The joint opening influences the load transfer efficiency between two adjacent slabs and the performance of sealants of the joint. Thus, joints that show larger openings than the predicted size may experience faulting at an early age of the concrete pavement owing to loss of the load transfer efficiency due to pumping of base materials through the failed joint sealants. In addition, because of intrusion of incompressible materials into the joints through the torn sealants, unexpected spalling may develop. In this study, factors influencing variation in the joint openings of concrete pavements were investigated using data of the US Federal Highway Administration long-term pavement performance seasonal monitoring programme sections. A probabilistic joint opening model using the upper bound of the 90% confidence interval of the joint opening was developed in order to mitigate underestimation of the joint opening. The newly developed joint opening model was validated using a series of data pertaining to joint movement measured at the Korea Expressway Corporation test road. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of this study is to investigate online shoppers' adoption of visual sensory enabling technologies, showing that these sensory experience enablers provide a dual role in enhancing online apparel shopping by reducing perceived product risk, and increasing the entertainment value of the online shopping process. Design/methodology/approach - The researchers conducted a focus group interview and pre-test with a college student sample and a main test with a US national sample of online shoppers. The data were analyzed using single- and multiple-group structural equation modeling. Findings - The findings provide empirical support for perceived usefulness and perceived entertainment value as strong predictors of consumers' attitudes towards using all three of the sensory enabling technologies (SETs) - 2D larger view and alternative views, 3D rotation views, and virtual try-on. The impact of perceived ease-of-use was significant only for 3D rotation views, suggesting that the impact of perceived ease-of-use differs by technology. Attitudes towards using sensory enabling technologies had a significant impact on the actual use of all three SETs; however, the impact of technology anxiety and innovativeness on the use of SETs also differed by technology. Originality/value - The results provide empirical validation of the proposed SE-TAM model. Based on the current findings, SETs may provide a valuable tool that online apparel retailers can use to increase online purchases, either by reducing the perceived risk through better online product evaluation, or by enhancing consumers' enjoyment of the shopping process on their web site. [ABSTRACT FROM AUTHOR]

The article focuses on the simplified modelling methodology for numerical prediction of integral abutment (IA) bridges in the U.S. The state departments of transportation in the country suggest the construction of materials with straight alignment and small skew to reduce the size of numerical model and computation time. The authors concluded that the non-linear hysteresis model for soil-structure interaction and connection element was utilized in modelling technique to predict bridge behavior.

Purpose - The aim of this paper is to assess the effects of traditional inputs and firms' R&D capital on labour productivity growth. Design/methodology/approach - The study measures the effects of the traditional inputs on firms' productivity growth, through four procedures: OLS in first differences, within group, GMIvI in first differences and GMrvI system. Findings - Whatever the specification considered, the more efficient estimates obtained from the GMM system show a similar effect of the firm's R&D stock upon its labour productivity performance. Practical implications - The results suggest that physical capital plays a more prominent role for European firms than for US ones, while employees are more productive in the USA. Originality/value - By presenting some empirical evidence on the effects of R&D on labour productivity, at the firm level, the present study makes two main contributions to the existing literature. First, a unique firm-level database for European and US firms is used. It is self evident that firms in these countries operate in different economic and institutional settings; as a consequence the results identify some robust common effects concerning the two areas considered (the USA versus Europe) at the micro level. Second, service and manufacturing sectors are merged. [ABSTRACT FROM AUTHOR]

Purpose — This paper seeks to develop and test a model that enables examination of the cross-cultural comparative influence of the meets expectations versus feeling state perspectives of consumer satisfaction for a product or brand. Design/methodology/approach — New measures were developed for the meets expectations and feeling state constructs, leading to a survey that was administered to Chinese and Americans. The data were analyzed using structural equation modeling in order to test hypotheses that were developed from the extant literature. Findings — The study found that meets expectations and feeling state are two distinct separate constructs with Americans and Chinese, and that their influence on future purchase intent differs between cultures, and between brands. Research limitations/implications — Only two brands were used in the study. The survey was completed with university students in the USA and China versus a broader range of age groups. The dissimilar nuances of English and Chinese may lead to different understandings of the measurement items. Practical implications — This study provides a foundation for future cross-cultural consumer research, and provides empirical insights into the ongoing standardization versus localization marketing strategy debate. Originality/value — This study is a benchmark comparative cross-cultural consumer satisfaction study with vastly disparate American and Chinese consumers. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of this article is to examine the existence of underwriting cycles in property-liability insurance for Switzerland, the USA, and Japan over a period of 40 years (1957-1997), it aims to overcome some of the limitations of a pure autoregressive process of second order (AR(2)). Design/methodology/approach - Loss-ratio data for the three countries are used for the recent period 1957-1997. To test for the existence of cycles and calculate their length, we start with autoregressive processes of second order and include more variables that should be taken into account. We also estimate a cointegration model in order to separate long-term and short-term dynamics. Findings - The hypothesis of cycles of six years in length no longer holds globally and it is necessary to go further than estimating simple AR(2) processes. Different models or specifications seem adequate for different countries because of the varying structure of the insurance markets. Cycles are still found for the USA and most estimations for Switzerland, whereas most specifications for Japan have not revealed cycles. Originality/value - Most empirical work on underwriting cycles has so far been done on US data. This study investigates insurance cycles for three countries on three continents. Based on the autoregressive process of second order and the estimations presented in the companion to this article (i.e. Part I), the model is extended by inclusion of more variables and some of the time-series characteristics that were ignored in many previous studies are dealt with. [ABSTRACT FROM AUTHOR]

Background: Multiple SARS-CoV-2 variants are still rampant across the United States (US). We aimed to evaluate the impact of vaccination scale-up and potential reduction in the vaccination effectiveness on the COVID-19 epidemic and social restoration in the US. Methods: We extended a published compartmental model and calibrated the model to the latest US COVID-19 data. We estimated the vaccine effectiveness against the variant and evaluated the impact of a potential reduction in vaccine effectiveness on the epidemics. We explored the epidemic trends under different levels of social restoration. Results: We estimated the overall existing vaccine effectiveness against the variant as 88.5% (95% CI: 87.4-89.5%) with the vaccination coverage of 70% by the end of August, 2021. With this vaccine effectiveness and coverage, there would be 498,972 (109,998-885,947) cumulative infections and 15,443 (3,828-27,057) deaths nationwide over the next 12 months, of which 95.0% infections and 93.3% deaths were caused by the variant. Complete social restoration at 60, 65, 70% vaccination coverage would increase cumulative infections to 1.6 (0.2-2.9) million 0.7 (0.1-1.2) million, and 511,159 (110,578-911,740), respectively. At same time it would increase cumulative deaths to 39,040 (5,509-72,570), 19,562 (3,873-35,250), 15,739 (3,841-27,638), respectively. However, if the vaccine effectiveness were reduced to 75%, 50% or 25% due to new SARS-CoV-2 variants, there would be 667,075 (130,682-1,203,468), 1.7 (0.2-3.2) million, 19.0 (5.3-32.7) million new infections and 19,249 (4,281-34,217), 42,265 (5,081-79,448), 426,860 (117,229-736,490) cumulative deaths to occur over the next 12 months. Further, social restoration at a lower vaccination coverage would lead to even greater secondary outbreaks. Conclusion: Current COVID-19 vaccines remain effective against the SARS-CoV-2 variant, and 70% vaccination coverage would be sufficient to restore social activities to a pre-pandemic level. Further reduction in vaccine effectiveness against SARS-CoV-2 variants would result in a potential surge of the epidemic. Multiple measures, including public health interventions, vaccination scale-up and development of a new vaccine booster, should be integrated to counter the new challenges of new SARS-CoV-2 variants., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Li, Li, Zou, Liu, Li, Zhuang, Shen and Zhang.)

Background: Seasonal influenza poses a significant public health and economic burden, associated with the outcome of infection and resulting complications. The true burden of the disease is difficult to capture due to the wide range of presentation, from asymptomatic cases to non-respiratory complications such as cardiovascular events, and its seasonal variability. An understanding of the magnitude of the true annual incidence of influenza is important to support prevention and control policy development and to evaluate the impact of preventative measures such as vaccination., Methods: We use a dynamic disease transmission model, laboratory-confirmed influenza surveillance data, and randomized-controlled trial (RCT) data to quantify the underestimation factor, expansion factor, and symptomatic influenza illnesses in the US and Canada during the 2011-2012 and 2012-2013 influenza seasons., Results: Based on 2 case definitions, we estimate between 0.42-3.2% and 0.33-1.2% of symptomatic influenza illnesses were laboratory-confirmed in Canada during the 2011-2012 and 2012-2013 seasons, respectively. In the US, we estimate between 0.08-0.61% and 0.07-0.33% of symptomatic influenza illnesses were laboratory-confirmed in the 2011-2012 and 2012-2013 seasons, respectively. We estimated the symptomatic influenza illnesses in Canada to be 0.32-2.4 million in 2011-2012 and 1.8-8.2 million in 2012-2013. In the US, we estimate the number of symptomatic influenza illnesses to be 4.4-34 million in 2011-2012 and 23-102 million in 2012-2013., Conclusions: We illustrate that monitoring a representative group within a population may aid in effectively modelling the transmission of infectious diseases such as influenza. In particular, the utilization of RCTs in models may enhance the accuracy of epidemiological parameter estimation.

Tuberculosis (TB) mortality rates in the USA fell rapidly from 1910 to 1933. However, during this period, racial disparities in TB mortality in the nation's expanding cities grew. Because of long delays between infection and disease, TB mortality is a poor indicator of short-term changes in transmission. We estimated the annual risk of TB infection (ARTI) in 11 large US cities to understand whether rising inequality in mortality reflected rising inequality in ARTI using city-level TB mortality data compiled by the US Department of Commerce from 1910 to 1933. We estimated ARTI for African-Americans and whites using pediatric extrapulmonary TB mortality data for African-Americans and whites in our panel of cities. We also estimated age-adjusted pulmonary TB mortality rates for these cities. We find that the ratio of ARTI for African-Americans vs. whites increased from 2·1 (95% CI = 1·7, 2·4) in 1910 to 4·2 (95% CI = 3·4, 5·2) in 1933. This change mirrored the increasing inequality in age-adjusted pulmonary TB mortality during this period. These findings may reflect the combined effects of migration, inequality in access to care, increasing population density, and racial residential segregation in northern cities during this period.

The mortality patterns in human populations reflect biological, social and medical factors affecting our lives, and mathematical modelling is an important tool for the analysis of these patterns. It is known that the mortality rate in all human populations increases with age after sexual maturity. This increase is predominantly exponential and satisfies the Gompertz equation. Although the exponential growth of mortality rates is observed over a wide range of ages, it excludes early- and late-life intervals. In this work we accept the fact that the mortality rate is an exponential function of age and analyse possible mechanisms underlying the deviations from the exponential law across the human lifespan. We consider the effect of heterogeneity as well as stochastic factors in altering the exponential law and compare our results to publicly available age-dependent mortality data for Swedish and US populations. In a model of heterogeneous populations we study how differences in parameters of the Gompertz equation describing different subpopulations account for mortality dynamics at different ages. Particularly, we show that the mortality data on Swedish populations can be reproduced fairly well by a model comprising four subpopulations. We then analyse the influence of stochastic effects on the mortality dynamics to show that they play a role only at early and late ages, when only a few individuals contribute to mortality. We conclude that the deviations from exponential law at young ages can be explained by heterogeneity, namely by the presence of a subpopulation with high initial mortality rate presumably due to congenital defects, while those for old ages can be viewed as fluctuations and explained by stochastic effects., (Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.)