scholarly journals Levels of SARS-CoV-2 population exposure are considerably higher than suggested by seroprevalence surveys

2021 ◽  
Vol 17 (9) ◽  
pp. e1009436
Author(s):  
Siyu Chen ◽  
Jennifer A. Flegg ◽  
Lisa J. White ◽  
Ricardo Aguas
Keyword(s):  
New Method ◽  
Population Exposure ◽  
Multiple Datasets ◽  
Accurate Knowledge ◽  
Past Exposure ◽  
Recent Transmission ◽  
Serological Studies ◽  
Antibody Titers ◽  
Exposure Levels ◽  
Over Time

Accurate knowledge of prior population exposure has critical ramifications for preparedness plans for future SARS-CoV-2 epidemic waves and vaccine prioritization strategies. Serological studies can be used to estimate levels of past exposure and thus position populations in their epidemic timeline. To circumvent biases introduced by the decay in antibody titers over time, methods for estimating population exposure should account for seroreversion, to reflect that changes in seroprevalence measures over time are the net effect of increases due to recent transmission and decreases due to antibody waning. Here, we present a new method that combines multiple datasets (serology, mortality, and virus positivity ratios) to estimate seroreversion time and infection fatality ratios (IFR) and simultaneously infer population exposure levels. The results indicate that the average time to seroreversion is around six months, IFR is 0.54% to 1.3%, and true exposure may be more than double the current seroprevalence levels reported for several regions of England.

scholarly journals Hepatitis B antibody titers in Indonesian adolescents who received the primary hepatitis B vaccine during infancy

2013 ◽  
Vol 53 (3) ◽  
pp. 160
Author(s):  
Hartono Gunardi ◽  
Adra Firmansyah ◽  
Sri Rezeki S Harun ◽  
Sudigdo Sastroasmoro
Keyword(s):  
Hepatitis B ◽  
Booster Dose ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Blood Tests ◽  
Vaccination History ◽  
Antibody Titers ◽  
Hb Vaccine ◽  
Over Time

Backgi-ound Hepatitis B (HB) has been classified as moderate-tohighlyendemic in Indonesia. HB vaccination, the most effectivemethod to prevent HB viral transmission, induces protectiveantibodies against HB surface antigen (anti-HBs). However, theseantibodies decline in titer over time. Studies on the duration ofprotection and the prevalence of n on-responders in Indonesianadolescents have been limited.Objectives To determine anti-HBs titers in 15-17-year oldIndonesian adolescents given primary HB vaccine during infancyand the prevalence of non-responders after a HB vaccine boosterdosage.Methods This cross-sectional study was performed from Februaryto September 2008 on adolescents aged 15-17 years in threesenior high schools in Jakarta who received complete primary HBvaccines during infancy, based on parents' recall. Investigationsincluded HB vaccination history, anthropometric measurements,and blood tests for anti-HBs before and 4-6 weeks after a boosterdose ofHB vaccine.Results Of 94 subjects, 35 had protective anti-HBs and 59 hadundetectable anti-HBs. A booster dose was administered to 5 8 of then on-protected subjects, of which 33 showed anamnestic responses.However, 25 subjects failed to generate protective anti-HBs. Takinginto consideration the adolescents with protective anti-HBs beforeand after the booster dose, serologic protection was demonstratedin 73%. Non-responder prevalence was 27%. The high prevalenceof non-responders may indicate bias of parents' recall.Conclusion Protective anti-HBs is detected in less than half ofIndonesian adolescents given primary HB vaccine during infancy.Following booster dosage, anamnestic responses are n oted in onethirdof subjects. The prevalence of non-responders is 27%, butconfirmation with further study is needed.

Measurement and Prediction of Sound Exposure Levels by University Wind Bands

2010 ◽  
Vol 25 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Kris Chesky
Keyword(s):  
Linear Regression Analysis ◽  
Critical Role ◽  
Significant Proportion ◽  
Sound Exposure ◽  
Sound Levels ◽  
Wind Bands ◽  
Exposure Levels ◽  
The Mean ◽  
Over Time

The purpose of this study was to determine sound exposure levels generated in two college wind bands. Dosimeter data from a large sample of ensemble-based instructional activities (n = 43) was collected over time and processed to assess associations with predictor variables that may be relevant to this context, including indicators of time spend at various intensity levels, maximum and peak sound levels, degree of variability of sound levels over time, and the percentage of time playing music. The mean dose per event for the entire sample was 109.5% and ranged from 53.8% to 166.9%. Results of linear regression analysis revealed that regressors accounted for a significant proportion of the variance in dose (F = 128.42, p < 0.000) and a statistically significant and very large (96% variance accounted for) contribution to the prediction of dose. Findings implicate the critical role of the instructor and teaching pedagogy.

scholarly journals The prospectively-reported implementation update and score (PRIUS): a new method for capturing implementation-related developments over time

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Edward J. Miech ◽  
Nicholas A. Rattray ◽  
Dawn M. Bravata ◽  
Barbara J. Homoya ◽  
Jennifer Myers ◽  
...  
Keyword(s):  
New Method ◽  
Over Time

Incidence and Cumulative Incidence as Supplemental Measures of the Scale of Imprisonment

2017 ◽  
Vol 64 (7) ◽  
pp. 888-916 ◽  
Author(s):  
William Rhodes ◽  
Gerald G. Gaes ◽  
Jeremy Luallen ◽  
Ryan Kling ◽  
Tom Rich ◽  
...  
Keyword(s):  
Administrative Data ◽  
Cumulative Incidence ◽  
Inflection Point ◽  
Estimation Method ◽  
New Method ◽  
Blacks And Whites ◽  
Over Time

Prison growth has primarily been measured as a prevalence over time. We propose cohort-specific supplemental measures: incidence based on the age of first adult admission into prison, and cumulative incidence, based on the proportion of people who will be imprisoned during their lifetime. We present a new estimation method using administrative data. Prior research derived estimates from inmate surveys. The main advantages of this new method are that estimates can be updated every year with little cost and minimal imputation. We present results showing that we have likely reached an inflection point in the growth of cumulative incidence, and the ratio between Blacks and Whites is declining although the disparity is still large—roughly 4.5 to 1.

Analysis of CTBT IMS Hydroacoustic hydrophone station underwater system electronics calibration sequences

2020 ◽  
Author(s):  
Mario Zampolli ◽  
Georgios Haralabus ◽  
Jerry Stanley ◽  
Peter Nielsen
Keyword(s):  
Cross Talk ◽  
The Other ◽  
System Response ◽  
Electronic Noise ◽  
Laboratory Environment ◽  
Accurate Knowledge ◽  
Ascension Island ◽  
Element Input ◽  
The Stability ◽  
Over Time

&lt;p&gt;The end-to-end calibration from the hydrophone ceramic element input to the digitizer output of CTBT IMS Hydroacoustic (HA) hydrophone stations is measured in a laboratory environment before deployment. After the hydrophones are deployed permanently with the Underwater System (UWS) hydrophone triplets, the response of the digitizer component can be measured by activating remotely a relay which excludes the hydrophone ceramic, preamplifier and riser cable, and feeds a pre-stored known waveform into the digitizer circuit via a digital-to-analogue converter. Analysis of these underwater calibration sequences makes it possible to verify the stability of the digitizer response over time and obtain useful information for investigations which require an accurate knowledge of the system response. Results are presented showing the stability of the UWS electronics response over time and one case, pertaining to the H10S triplet of HA10 Ascension Island, where changes in the calibration response appeared after the onset of electronic noise in one hydrophone channel with cross-talk to the other two channels.&lt;/p&gt;

Time Series Model Based Earning Forecasting

2013 ◽  
Vol 791-793 ◽  
pp. 2147-2150
Author(s):  
Xiang Rong Jiang ◽  
Ying Ying Cui
Keyword(s):  
Time Series ◽  
Empirical Study ◽  
Relative Stability ◽  
Listed Companies ◽  
Time Series Model ◽  
New Method ◽  
Time Series Models ◽  
Seasonal Patterns ◽  
Model Based ◽  
Over Time

We propose a procedure to forecast earning of listed companies. It is a modification of method developed for forecasting series with stable seasonal patterns. The new method is motivated by the observations that seasonal patterns, which may be evolving over time and remain relative stability, arise in finance market. The method can be applied to forecast individual observations as well as the end-of-season totals. Empirical study will be conducted with data from finance market to evaluate the performance of the proposed method. The new method is proved more effective than traditional time series models.

scholarly journals Detection, prevalence, and duration of humoral responses to SARS-CoV-2 under conditions of limited population exposure.

2020 ◽  
Author(s):  
Tyler J Ripperger ◽  
Jennifer L Uhrlaub ◽  
Makiko Watanabe ◽  
Rachel Wong ◽  
Yvonne Castaneda ◽  
...  
Keyword(s):  
Local Community ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Population Level ◽  
Population Exposure ◽  
Antibody Titers ◽  
Asymptomatic Individuals ◽  
Humoral Responses ◽  
Antibody Levels ◽  
Antibody Kinetics

We conducted an extensive serological study to quantify population-level exposure and define correlates of immunity against SARS-CoV-2. We found that relative to mild COVID-19 cases, individuals with severe disease exhibited elevated authentic virus-neutralizing titers and antibody levels against nucleocapsid (N) and the receptor binding domain (RBD) and the S2 region of spike protein. Unlike disease severity, age and sex played lesser roles in serological responses. All cases, including asymptomatic individuals, seroconverted by 2 weeks post-PCR confirmation. RBD- and S2-specific and neutralizing antibody titers remained elevated and stable for at least 2-3 months post-onset, whereas those against N were more variable with rapid declines in many samples. Testing of 5882 self-recruited members of the local community demonstrated that 1.24% of individuals showed antibody reactivity to RBD. However, 18% (13/73) of these putative seropositive samples failed to neutralize authentic SARS-CoV-2 virus. Each of the neutralizing, but only 1 of the non-neutralizing samples, also displayed potent reactivity to S2. Thus, inclusion of multiple independent assays markedly improved the accuracy of antibody tests in low seroprevalence communities and revealed differences in antibody kinetics depending on the viral antigen. In contrast to other reports, we conclude that immunity is durable for at least several months after SARS-CoV-2 infection.

scholarly journals Detecting Transient Trapping from a Single Trajectory: A Structural Approach

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 1044
Author(s):  
Yann Lanoiselée ◽  
Jak Grimes ◽  
Zsombor Koszegi ◽  
Davide Calebiro
Keyword(s):  
Plasma Membrane ◽  
Single Particle ◽  
Adrenergic Receptors ◽  
Particle Trajectory ◽  
Temporal Structure ◽  
Structural Approach ◽  
New Method ◽  
Trajectory Data ◽  
Receptor Stimulation ◽  
Over Time

In this article, we introduce a new method to detect transient trapping events within a single particle trajectory, thus allowing the explicit accounting of changes in the particle’s dynamics over time. Our method is based on new measures of a smoothed recurrence matrix. The newly introduced set of measures takes into account both the spatial and temporal structure of the trajectory. Therefore, it is adapted to study short-lived trapping domains that are not visited by multiple trajectories. Contrary to most existing methods, it does not rely on using a window, sliding along the trajectory, but rather investigates the trajectory as a whole. This method provides useful information to study intracellular and plasma membrane compartmentalisation. Additionally, this method is applied to single particle trajectory data of β2-adrenergic receptors, revealing that receptor stimulation results in increased trapping of receptors in defined domains, without changing the diffusion of free receptors.

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