Retrospective Estimation Research Articles

High immunity and low mortality after Omicron and mass event in Cameroon despite low vaccination

Background: Little is known about the evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity in African communities.Aim: We evaluated changes in anti-SARS-CoV-2 antibodies, mortality and vaccination status in Cameroon between August 2021 and September 2022 to begin describing the evolution of the pandemic in Africa.Setting: The study was conducted across Cameroon’s 10 regional capitals, between 2021 and 2022 as the country hosted a mass gathering.Methods: We conducted a cross-sectional population-based survey in 2022, including SARS-CoV-2 seroprevalence testing and retrospective mortality estimation using two-stage cluster sampling. We estimated and compared seroprevalence and crude mortality rates (CMR) to a survey conducted in 2021 using the same methodology.Results: We performed serologic testing on 8400 individuals and collected mortality data from 22 314 individuals. Approximately 5% in each survey reported SARS-CoV-2-vaccination. Rapid diagnostic test-based seroprevalence increased from 11.2% (95% confidence interval [CI]: 10–12.5) to 59.8% (95% CI: 58.3–61.2) between 2021 and 2022, despite no increase in the proportion vaccinated. The CMR decreased from 0.17 to 0.06 deaths per 10 000 persons per day between 2021 and 2022. In 2022, no deaths were reportedly attributable to COVID-19 as compared to 17 deaths in 2021.Conclusion: Over a 12-month period encompassing two waves of omicron variant SARS-CoV-2 and a mass gathering, SARS-CoV-2 seropositivity in Cameroon approached 60%, and deaths declined despite low vaccination coverage.Contribution: This study challenges the assumption that high immunisation coverage is the sole determinant of epidemic control in the African context and encourages policymakers to increasingly rely on local research when designing response strategies for more effective outbreak management.

Assessment of individual external exposure doses based on environmental radiation in areas affected by the Fukushima Daiichi Nuclear Power Station accident

Assessing individual external exposure doses from ambient dose equivalents is valuable for predictive and retrospective purposes when personal dosimeters are impractical. This study developed a model to assess individual external exposure doses from ambient dose equivalents, considering daily life patterns (location and time spent in various places), and evaluated parameters associated with individual external exposure doses, such as the reduction effects of radiation due to buildings and vehicles. The model parameters were evaluated using the robust datasets of environmental radiation measured in areas affected by the Fukushima Daiichi Nuclear Power Station (FDNPS) accident. The effective dose estimated by the model was compared to 106 daily personal dose equivalents measured using personal dosimeters in the residents’ living environments near the FDNPS. The estimated effective dose well consists with the measured personal dose equivalents, particularly when considering natural radiation in indoor dose estimation. This model is adequate for radiation protection, enabling the predictive and retrospective estimation of individual external exposure doses using environmental radiation monitoring data.

Coherent long-term average indoor radon concentration estimates obtained by electronic and solid state nuclear track detectors

Despite the rapid development of consumer-grade electronic radon monitors, their capabilities to assess long-term average radon concentrations are not systematically investigated. We present the results of a year-long measurement campaign in 32 dwellings and workplaces in two areas with typical and high radon concentrations in Bulgaria. A systematic comparison was made between electronic monitors and the gold standard — solid-state nuclear track detectors (SSNTDs). RadonEye Plus2 (RE) monitors were used, calibrated and metrologically tested at the three participating laboratories. Two SSNTD-based detectors were utilized: passive radon detectors (PRDs) developed by UKHSA, and CDs/DVDs, developed at SU. Two PRDs for quarterly radon measurements, a RE, a CD and a DVD were placed at each location. Additional old CDs/DVDs were collected for retrospective radon estimates. The results for the annual average radon concentrations, estimated by the four methods are presented. The average difference between the REs and PRDs estimate was 8% (median 4%), between the REs and CDs was 5% (median 0.4%) and between REs and DVDs was −10% (median −12%). The Z-score, representing the difference normalized to its uncertainty, in most cases fell within −1 and 1, indicating excellent agreement. The retrospective estimates also demonstrated excellent agreement with the other data. However, in some cases, small but statistically significant biases were identified between REs and SSNTDs or between different SSNTDs, requiring an inclusion of a reference instrument in future studies. Overall, the results imply that with sound metrological assurance, RadonEye Plus2 monitors can assess long-term average radon concentrations with sufficient accuracy.

Software System Architecture for Estimating Software Development Time

The article is devoted to the issues of estimating the duration of software development, the solution of which can significantly improve the efficiency of software projects. The relevance of the topic is conditioned by the rapid development of software development methodologies, on which the existing algorithms of such estimation depend, and, as a consequence, by the rapid obsolescence of approaches to solving this problem. A systematic analysis of the main algorithms for estimating software development duration is carried out. The classification of such algorithms is presented. The algorithm of software development duration estimation and the idea of the system implementing it, which will allow end users to automate this process, are proposed. The approaches to implementation of algorithms of retrospective (historical) estimation, PERT, expert estimation are considered. The prospectivity of researches in the field of implementation of methods of expert evaluation using neural networks is shown. The architecture of the proposed system is described. A prototype of the system implementing the method of retrospective evaluation based on the evaluation of the speed of the development team is developed.

Reconstructing Prospective Intergenerational Educational Mobility in 12 Countries

In this article, we reconstruct prospective intergenerational educational mobility and explore fertility's role in this process for women born between 1925 and 1950 in 12 European countries. We do so by combining high-quality retrospective data (Generations and Gender Survey) and low-requirement prospective datasets using an inferential method developed and advanced in prior research. Our analysis shows that the negative educational fertility gradient partly compensates for the inequality in prospective mobility rates between lower and higher educated women and is most pronounced in high-inequality contexts. However, fertility's role is small and declining and thus does not account for much of the differences in mobility rates between countries. We also explore the relative importance of sibship size effects in mediating the effect of fertility gradient, finding it negligible. Finally, we explore the correspondence between prospective and retrospective estimates in the reconstruction of prospective mobility rates and suggest why the former, when available, must be preferred.

Back to Bernoulli: a simple formula for trans-stenotic pressure gradients and retrospective estimation of flow rates in cerebral venous disease

BackgroundVenous sinus stenosis can be associated with cerebrovascular disorders. Understanding the role of blood flow disturbances in these disorders is often hampered by the lack of patient-specific flow rates. Our...

Can ultrasound-guided medial branch blocks be used to select patients for cervical facet joint radiofrequency neurotomy? A matched retrospective cohort validation study.

Medial branch blocks are used to select patients for cervical facet joint radiofrequency neurotomy (CRFN). Blocks are typically performed under fluoroscopic guidance (ie, fluoroscopy-guided blocks [FLBs]). The validity of ultrasound-guided blocks (USBs) is not well established. No prior research has compared cervical USB validity and FLB validity with CRFN outcome used as the criterion standard. To evaluate cervical USB versus FLB validity with CRFN outcome used as the criterion standard. Demographic and outcome data were extracted from the electronic medical records of 2 affiliated musculoskeletal pain management clinics for all patients between 2015 and 2023 inclusive who had cervical USB leading to CRFN. CRFN outcomes of each USB patient were compared with those of a matched FLB patient from the radiofrequency neurotomy (RFN) outcome database of the same clinics. Matching variables included patient age, sex, pain duration, diagnostic/prognostic block paradigm, and CRFN number. Each patient completed a numeric rating scale (NRS) pain score and Pain Disability Quality-of-Life Questionnaire (PDQQ) just before and 3months after CRFN. At repeat CRFN, patients provided a retrospective estimate of the duration and average magnitude (percentage) of relief after the CRFN. USB and FLB groups were comprised of 27 patients (58 RFNs) and 38 patients (58 RFNs), respectively. Post-RFN NRS pain severity and PDQQ-Spine scores demonstrated comparable (P > .05) absolute improvements, proportion of patients achieving ≥50% improvement, and attainment of the minimum clinically important difference. Retrospective estimates of pain relief magnitude and duration were also comparable. This study finds cervical USB and FLB to be comparably valid as defined by their ability to predict CRFN outcome. Within the limitations of operator competence, USB can be used to select patients for CRFN.

Retrospective estimation of the time-varying effective reproduction number for a COVID-19 outbreak in Shenyang, China: An observational study.

The time-varying effective reproduction number Re(t) is essential for designing and adjusting public health responses. Retrospective analysis of Re(t) helps to evaluate health emergency capabilities. We conducted this study to estimate the Re(t) of the Corona Virus Disease 2019 (COVID-19) outbreak caused by SARS-CoV-2 Omicron in Shenyang, China. Data on the daily incidence of this Corona Virus Disease 2019 outbreak between March 5, 2022, and April 25, 2022, in Shenyang, China, were downloaded from the Nationwide Notifiable Infectious Diseases Reporting Information System. Infector-infectee pairs were identified through epidemiological investigation. Re(t) was estimated by R-studio Package "EpiEstim" based on Bayesian framework through parameter and nonparametric method, respectively. About 1134 infections were found in this outbreak, with 20 confirmed cases and 1124 asymptomatic infections. Fifty-four infector-infectee pairs were identified and formed a serial interval list, and 15 infector-infectee pairs were included in the generation time table. Re(t) calculated by parameter and nonparametric method all peaked on March 17, 2022, with a value of 2.58 and 2.54 and decreased to <1 after March 28, 2022. There was no statistical difference in the Re(t) distribution calculated using the 2 methods (t = 0.001, P > .05). The present study indicated that the decisive response of Shenyang, China, played a significant role in preventing the spread of the epidemic, and the retrospective analysis provided novel insights into the outbreak response to future public health emergencies.

STUDYING THE AGE OF ONSET AND DETECTION OF CHRONIC MYELOID LEUKEMIA USING A THREE-STAGE STOCHASTIC MODEL

Chronic Myeloid Leukemia (CML) is a biphasic malignant clonal disorder that progresses, first with a chronic phase, where the cells have enhanced proliferation only, and then to a blast phase, where the cells have the ability of self-renewal. It is well recognized that the Philadelphia chromosome (which contains the BCR-ABL fusion gene) is the “hallmark of CML”. However, empirical studies have shown that the mere presence of BCR-ABL may not be a sufficient condition for the development of CML, and further modifications related to tumor suppressors may be necessary. Accordingly, we develop a three-mutation stochastic model of CML progression, with the three stages corresponding to the non-malignant cells with BCR-ABL presence, the malignant cells in the chronic phase, and the malignant cells in the blast phase. We demonstrate that the model predictions agree with age incidence data from the United States. Finally, we develop a framework for the retrospective estimation of the time of onset of malignancy, from the time of detection of the cancer.

Direct medical cost related to the management of pemphigus: A pilot Tunisian study.

Pemphigus is a therapeutically challenging disease with high morbidity and economic burden. First-line prescription of rituximab remains limited in Tunisia due to its high cost. Systemic steroids remain the standard of care but are associated with a major risk of morbidities and higher treatment costs. To assess the direct medical costs of pemphigus in Tunisia. Retrospective estimation of direct medical costs during the 18 months following the diagnosis using the "bottom-up approach" in the Dermatology Department of Hedi Chaker Hospital, Sfax, Tunisia. Total medical costs were estimated at 38745.7 €, with an average cost of 1 210 € per patient and per year: paraclinical investigations (46%), medical treatment (30%), hospitalization (21%) and outpatient visits (3%). The average cost was the highest in the age group of 15-24 years (1553 €). Treatment costs related to corticosteroid-induced morbidity were estimated at 1208 €. The management of pemphigus in Tunisia needs to be adapted to take into account the health economic analysis in order to reduce overall disease costs and the burden of steroid-induced morbidities.

Radiological injuries under low energy x-rays in mice depending on dose and protocol: comparative characterization of lesion severity and impact of the in vivo bone response on retrospective dose estimations

Objective. To improve our knowledge about the biological effects of over exposures involving low-energy x-rays, we developed and characterized a preclinical mouse model allowing to mimic different lesion severity degrees induced by 80 kV x-ray depending on the dose and protocol (single or repeated exposure). Approach. Mice were locally exposed (paw) to 80 kV x-rays in a single (15, 30 or 45 Gy in K air) or repeated exposition (2 × 15 or 3 × 15 Gy in K air) to assess different degrees of lesion severity. Six post-irradiation euthanasia time points (0, 7, 14, 21, 42, and 84 days) were determined to follow up the evolution of lesions based on the lesion score, weighing and cutaneous blood perfusion. The bone dose was estimated at the different time points by electron paramagnetic resonance (EPR) spectroscopy. Main results. The monitoring of the lesion severity allows to classify the exposure protocols according to their severity. EPR spectroscopy measurements allow to determine the bone dose on the day of irradiation which is 7 times higher than the initial dose for single protocols. However, the initial signal measured at the end of the repeated exposure was 27% lower than the signal measured for a single dose. The study of the kinetics of EPR signal showed a decrease of the EPR signal which is dependent on the exposure protocol but not on dose highlighting the impact of bone physiology on the bone dose estimation. Significance: the preclinical model developed allows to assess the impact of the dose and protocol on the lesion severity induced by low-energy x-ray. For the first time, the dynamics of free radicals have been quantified in an in vivo model, highlighting that the doses actually administered can be underestimated if samples are taken weeks or even months after exposure.

Incidence of Strabismus Post–Plaque Brachytherapy in Patients With Uveal Melanoma

PurposeTo determine the incidence and type of strabismus in patients with uveal melanoma treated with plaque brachytherapy. DesignRetrospective incidence estimation study SettingMulticenter Patient Population438 eyes of 438 patients with uveal melanoma treated with plaque brachytherapy between October 2011 to May 2021. InterventionIodine 125 plaque brachytherapy Main Outcome MeasuresVariables reviewed included incidence of non-resolving strabismus post-plaque brachytherapy, type of strabismus developed, extraocular muscles operated, and modality of treatment received. ResultsFour hundred thirty-eight patients underwent plaque brachytherapy treatment for uveal melanoma. Eleven patients developed strabismus post plaque brachytherapy (2.5%, n=11/438). Of these patients, five (1.1%, n=5/438) developed strabismus immediately post-operation. Specifically, two patients (0.5%, n=2/438) developed strabismus immediately post-operation due to slipped muscles, two patients (0.5%, n=2/438) due to decompensated phorias, and one patient (0.5%, n=1/438) due to a fibrotic muscle. Six patients (1.4%, n=6/438) developed late onset sensory strabismus. A total of 355 (81.1%, n=355/438) patients had their extraocular muscles disinserted during surgery, with the lateral rectus being the most common, accounting for 45.4% (n=161/355). Followed by the superior rectus at 26.8% (n=95/355). Strabismus surgery was the most common treatment modality, comprising 72.7% (n=8/11) of patients. ConclusionThe incidence of strabismus following plaque brachytherapy treatment for uveal melanoma was low, and primarily classified as late onset sensory strabismus. Previous studies may underestimate the long-term incidence of strabismus post plaque brachytherapy by focusing primarily on strabismus present immediately post-operatively.

The relationship between the body and air temperature in a terrestrial ectotherm.

Ectotherms make up the majority of terrestrial biodiversity, so it is important to understand their potential responses to climate change. Often, models aiming to achieve this understanding correlate species distributions with ambient air temperature. However, this assumes a constant relationship between the air temperature and body temperature, which determines an ectotherm's thermal performance. To test this assumption, we develop and validate a method for retrospective estimation of ectotherm body temperature using heat exchange equations. We apply the model to predict the body temperature of wild field crickets (Gryllus campestris) in Northern Spain for 1985-2019 and compare these values to air temperature. We show that while air temperature impacts ectotherm body temperature, it captures only a fraction of its thermal experience. Solar radiation can increase the body temperature by more than 20°C above air temperature with implications for physiology and behaviour. The effect of solar radiation on body temperature is particularly important given that climate change will alter cloud cover. Our study shows that the impacts of climate change on species cannot be assumed to be proportional only to changing air temperature. More reliable models of future species distributions require mechanistic links between environmental conditions and thermal ecophysiologies of species.

A refined ICD-10 diagnoses-based approach for retrospective analysis of potential palliative care need and coverage in claims data of deceased.

ICD-10-based approaches often provide the basis for retrospective estimation of potential palliative care need. Applying the ICD-10-based Murtagh et al. classification from 2014 (Murtagh classification), developed using mortality data, to administrative claims data leads to inconsistencies in estimating palliative care need. The aim of the study was to refine the classification for palliative care need estimation in deceased individuals with cancer and non-cancer diagnosis. A retrospective population-based study comparing Murtagh classification to a new ICD-10-based classification (revised by expert opinion) was conducted using outpatient and inpatient claims data, including billing codes for palliative care. Palliative care need was estimated for diagnoses groups and was contrasted with palliative care utilization rates in the last year of life. Our dataset included records of 417,405 individuals who deceased in 2016-2019. Out of individuals deceased in 2019 (n = 117,436), 81.4% had at least one diagnosis from the new classification, while 97.0% had at least one diagnosis from the Murtagh classification. Classification revision thus identified fewer individuals as potentially in need of palliative care. Among individuals with cancer, 70.7% (vs. 55.7% via Murtagh classification) received palliative care. In non-cancer subgroups, the utilization rate was considerably lower, with a maximum of 36.7% (vs. 33.7% via Murtagh classification) in 2019. Similar results were observed for the other years. Compared to the ICD10-based Murtagh classification, the revised ICD-10-based classification enables more realistic estimations if the cause of death is unavailable and reveals higher rates of palliative care coverage and differences especially in cancer versus non-cancer diseases. German Clinical Trials Register (DRKS00024133).

Applicability of Food Monitoring Data for Assessing Relative Exposure Contributions of Pyrethroids in Retrospective Human Biomonitoring Risk Estimations.

The use of pyrethroids is very broad and shows increasing trends. Human biomonitoring studies represent the best approach for realistic risk estimations, but their interpretation requires a tiered approach. A previous HBM4EU study indicated levels in European children groups just around the threshold for concern, requiring further refinement. The main difficulty is that several pyrethroids with different toxicity potencies generate the same urinary metabolites. As diet is the main pyrethroid source for the general population, EU food monitoring data reported by EFSA have been used to estimate the relative contribution of each pyrethroid. The main contributors were cypermethrin for DCCA and 3-PBA and lambda-cyhalothrin for CFMP. Urinary levels predicted from food concentration according to the EFSA diets were mostly within the range of measured levels, except 3-PBA and CFMP levels in children, both below measured levels. The predicted lower levels for 3-PBA can be explained by the very low Fue value, initially proposed as conservative, but that seems to be unrealistic. The discrepancies for CFMP are mostly for the highest percentiles and require further assessments. The refined assessments included the revision of the previously proposed human biomonitoring guidance values for the general population, HBM-GV Gen Pop, following recent toxicological reevaluations, and the estimation of hazard quotients (HQs) for each individual pyrethroid and for the combined exposure to all pyrethroids. All HQs were below 1, indicating no immediate concern, but attention is required, particularly for children, with HQs in the range of 0.2-0.3 for the highly exposed group. The application of probabilistic methods offers assessments at the population level, addressing the variability in exposure and risk and providing relevant information for Public Health impact assessments and risk management prioritization.

İleriye Yönelik ve Geriye Dönük Zamanlama Süreçleri: Teoriler ve Yöntemler

We experience a flow of time in everyday life. However, according to modern physics, time does not flow. In the psychology and neuroscience literature, different models and explanations have been made to try to answer the question of what time is besides an illusion of flow and to figure out how time is perceived. Different methods have also been used to learn how time is handled and to test how accurate these models are. People process time in two ways: implicitly and explicitly. We are talking about explicit timing when estimating the time interval length. Another distinction, according to the measurement method of time perception paradigms, is between prospective and retrospective time estimations. Although there are theorists who claim that these two methods involve similar cognitive processes, it is thought that different cognitive processes serve to experience and remember a time, depending on whether time perception is measured by the prospective or retrospective time estimation methods. This brings to mind different method-dependent constraints and advantages. As with any other kind of perception study, the method chosen for time perception research should fit the question being asked. This review presents a selective review of time perception studies to make it easier for a researcher planning to study time perception to choose the appropriate method for the study question. The time perception processes and related evidence were examined using prospective and retrospective time estimation measurement methods. But it's important to note that the time perception models and methods talked about in this review are only a small part of a very large field.

The effects of emotion on retrospective duration memory using virtual reality.

Our memories for temporal duration may be colored by the emotions we experience during an event. While emotion generally enhances some aspects of memory, temporal duration has been shown to be particularly susceptible to emotion-induced distortions. However, prior work has faced difficulty when studying this phenomenon, having to make some trade-offs on ecological validity or experimental control. Here, we sought to bridge this gap by studying the effects of emotion on temporal duration memory using virtual reality. In the present study, a final sample of 69 participants experienced a series of negative-emotional and neutral worlds within virtual reality. Following this, participants provided ratings of emotionality (arousal, valence, pleasantness) and retrospective duration estimates (i.e., remembered time). We hypothesized that negative events would be recalled as having a greater duration than neutral events (H1). We additionally hypothesized that negative, but not neutral, events would be recalled as being longer than the true duration (H2). The results supported H1 while failing to provide evidence in support of H2. Together, the results bolster the importance of emotion, especially negative emotion, in shaping how we remember the temporal unfolding of the past.

Multidimensional assessment of time perception along the continuum of Alzheimer’s Disease and evidence of alterations in subjective cognitive decline

Timing alterations occur in Alzheimer’s disease (AD), even in early stages (mild cognitive impairment, MCI). Moreover, a stage named subjective cognitive decline (SCD), in which individuals perceive a change in cognitive performance not revealed by neuropsychological tests, has been identified as a preclinical phase of AD. However, no study to date has investigated different dimensions of time processing along the continuum from physiological to pathological aging, and whether timing alterations occur in SCD. Here a sample of participants with SCD, MCI, AD and healthy controls (HC) performed tasks assessing prospective duration estimation, production, reproduction, implicit temporal learning in conditions dependent from external cues (externally-cued learning, ECL) or independent from external cues (internally-based learning, IBL), retrospective duration estimation, the subjective experience of time and the temporal collocation of events. AD patients performed worse than HC and SCD in prospective timing, and in collocating events in time. The subjective experience of time did not differ between groups. Concerning temporal learning, AD performed worse in ECL than in IBL, whereas SCD performed worse in IBL than in ECL. SCD, MCI and AD patients all showed errors greater than HC in retrospective duration estimation. Results point to implicit temporal learning in externally-cued conditions and retrospective time estimation as possible early markers of cognitive decline.

14C IN TREE RINGS IN THE VICINITY OF THE RBMK REACTOR NUCLEAR POWER PLANT

ABSTRACTThe paper presents the results of radiocarbon (14C) concentration measurements in tree rings in the vicinity of Kursk NPP (Russia) with four operating RBMK reactors. The sampling was carried out from the site with the highest expected accumulation of radiocarbon in vegetation. The site was determined with long-term meteorological data. The measurements of 14C concentration carried out with accelerator-mass spectrometer in Budker Institute of Nuclear Physics, Novosibirsk, Russia. The obtained results demonstrated the influence of exploitation of Kursk NPP to the concentration of 14C in tree rings. Based on the equilibrium between the 14C ratio in the tree rings and the surrounding air, retrospective estimates of the radiocarbon discharge and effective doses were made. Effective doses were calculated with two approaches: IAEA methodology and less conservative approach, considering the real food consumption in the Kursk region. The values of calculated doses by the second method (0.08–2.58 μSv) are more than 2 times less than IAEA approach (0.17–5.30 μSv). The highest difference between measured and background 14C in tree ring is 41.7 ± 5.8 pMC in 2014 during the restoration of graphite stack. The main contribution to 14С exposure in the considering period is caused by background – from 70 to 99%.

Cardiac MR modelling of systolic and diastolic blood pressure

AimsBlood pressure (BP) is a crucial factor in cardiovascular health and can affect cardiac imaging assessments. However, standard outpatient cardiovascular MR (CMR) imaging procedures do not typically include BP measurements...