scholarly journals Sequentially calibrating a Bayesian microsimulation model to incorporate new information and assumptions

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Maria DeYoreo ◽  
Carolyn M. Rutter ◽  
Jonathan Ozik ◽  
Nicholson Collier
Keyword(s):  
Sojourn Time ◽  
Population Level ◽  
Microsimulation Model ◽  
Sequential Approach ◽  
New Information ◽  
Key Population ◽  
History Of ◽  
Colon And Rectum ◽  
Event Histories ◽  
Microsimulation Models

Abstract Background Microsimulation models are mathematical models that simulate event histories for individual members of a population. They are useful for policy decisions because they simulate a large number of individuals from an idealized population, with features that change over time, and the resulting event histories can be summarized to describe key population-level outcomes. Model calibration is the process of incorporating evidence into the model. Calibrated models can be used to make predictions about population trends in disease outcomes and effectiveness of interventions, but calibration can be challenging and computationally expensive. Methods This paper develops a technique for sequentially updating models to take full advantage of earlier calibration results, to ultimately speed up the calibration process. A Bayesian approach to calibration is used because it combines different sources of evidence and enables uncertainty quantification which is appealing for decision-making. We develop this method in order to re-calibrate a microsimulation model for the natural history of colorectal cancer to include new targets that better inform the time from initiation of preclinical cancer to presentation with clinical cancer (sojourn time), because model exploration and validation revealed that more information was needed on sojourn time, and that the predicted percentage of patients with cancers detected via colonoscopy screening was too low. Results The sequential approach to calibration was more efficient than recalibrating the model from scratch. Incorporating new information on the percentage of patients with cancers detected upon screening changed the estimated sojourn time parameters significantly, increasing the estimated mean sojourn time for cancers in the colon and rectum, providing results with more validity. Conclusions A sequential approach to recalibration can be used to efficiently recalibrate a microsimulation model when new information becomes available that requires the original targets to be supplemented with additional targets.

scholarly journals Microsimulation Modeling in Oncology

2018 ◽  
pp. 1-11 ◽  
Author(s):  
Çağlar Çağlayan ◽  
Hiromi Terawaki ◽  
Qiushi Chen ◽  
Ashish Rai ◽  
Turgay Ayer ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Microsimulation Model ◽  
Alternative Interventions ◽  
Oncology Research ◽  
Optimal Intervention ◽  
Potential Applications ◽  
History Of ◽  
Microsimulation Modeling ◽  
Microsimulation Models ◽  
Over Time

Purpose Microsimulation is a modeling technique that uses a sample size of individual units (microunits), each with a unique set of attributes, and allows for the simulation of downstream events on the basis of predefined states and transition probabilities between those states over time. In this article, we describe the history of the role of microsimulation in medicine and its potential applications in oncology as useful tools for population risk stratification and treatment strategy design for precision medicine. Methods We conducted a comprehensive and methodical search of the literature using electronic databases—Medline, Embase, and Cochrane—for works published between 1985 and 2016. A medical subject heading search strategy was constructed for Medline searches by using a combination of relevant search terms, such as “microsimulation model medicine,” “multistate modeling cancer,” and “oncology.” Results Microsimulation modeling is particularly useful for the study of optimal intervention strategies when randomized control trials may not be feasible, ethical, or practical. Microsimulation models can retain memory of prior behaviors and states. As such, it allows an explicit representation and understanding of how various processes propagate over time and affect the final outcomes for an individual or in a population. Conclusion A well-calibrated microsimulation model can be used to predict the outcome of the event of interest for a new individual or subpopulations, assess the effectiveness and cost effectiveness of alternative interventions, and project the future disease burden of oncologic diseases. In the growing field of oncology research, a microsimulation model can serve as a valuable tool among the various facets of methodology available.

scholarly journals The Ocular Gene Delivery Landscape

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1135
Author(s):  
Bhubanananda Sahu ◽  
Isha Chug ◽  
Hemant Khanna
Keyword(s):  
Gene Therapy ◽  
Genetic Diseases ◽  
Gene Therapies ◽  
Advantages And Disadvantages ◽  
Fda Approval ◽  
New Information ◽  
Efficient Delivery ◽  
Delivery Routes ◽  
History Of ◽  
Different Parts

The eye is at the forefront of developing therapies for genetic diseases. With the FDA approval of the first gene-therapy drug for a form of congenital blindness, numerous studies have been initiated to develop gene therapies for other forms of eye diseases. These examinations have revealed new information about the benefits as well as restrictions to using drug-delivery routes to the different parts of the eye. In this article, we will discuss a brief history of gene therapy and its importance to the eye and ocular delivery landscape that is currently being investigated, and provide insights into their advantages and disadvantages. Efficient delivery routes and vehicle are crucial for an effective, safe, and longer-lasting therapy.

scholarly journals Patterns of Weight Change in Aging and Dying

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 491-491
Author(s):  
Stephen Thielke
Keyword(s):  
Older Adults ◽  
Weight Loss ◽  
Risk Factor ◽  
Weight Change ◽  
Population Level ◽  
Chronological Age ◽  
Average Weight ◽  
Remaining Life ◽  
Entire Cohort ◽  
History Of

Abstract Little research has characterized the natural history of weight change in older adults. Different changes may occur during aging and dying. We analyzed 18 years of weight measures from a cohort of 736,361 Veterans, all of whom had died at age 70 or older. We produced summary measures that accounted for both chronological age and number of years before death. Several clear population-level trends appeared. (1) The average weight of the sample declined across all ages at a rate of about 0.18 BMI points per year. (2) Starting about seven years before death, the amount of loss began to accelerate, reaching a decline of 0.75 BMI points in the year before death. (3) Changes in weight relative to years of remaining life were independent of chronologic age. People who died at age 70 experienced, on average, the same type and duration of terminal decline as did those who died at age 95. (4) The dying process involved a cumulative loss of about 1.3 BMI points. (5) The distribution of weights during advancing age both declined and narrowed. (6) Disproportionate deaths occurred at the lower BMI ranges (below a BMI of 24), and especially below 18, regardless of age. (7) The finding in #5 is explained by the entire cohort losing weight, with death of the thinnest members. These findings argue for examining survival time in studies of weight change. They indicate that weight loss may be a natural part of dying, rather than a risk factor for it.

Reply to T.M. Simbirtseva and S.V. Volkov: Facts Against Fantasies

2021 ◽  
pp. 127
Author(s):  
Bella Pak
Keyword(s):  
East Asia ◽  
Scientific Research ◽  
Russian Government ◽  
New Information ◽  
History Of ◽  
The Impact ◽  
Specific Contribution

This article provides an analysis of scientific research on the life and activities of the first Russian charge d’ affaires and consul general in Korea Karl I. Waeber, shows the specific contribution of scholars to the study of the professional biography of this outstanding diplomat. Despite the fact that the activity of K.I. Weber in Korea is partially reflected in the works of Boris D. Pak and Bella B. Pak on the history of Russo-Korean relations, as well as in several separate articles, the first special monographic work on this topic belongs to the pen of the author of this article. The monographic research focuses on a detailed coverage of the tasks, goals facing Waeber in Korea, the specific forms and conditions for their implementation, the impact he exerts on the course of the Russian government towards Korea; analysis of the most complex international circumstances, against the background of which he made certain decisions.   This article contains answers to T.M. Simbirtseva and S.V. Volkov’s critical remarks regarding some of the information and photographic documents given in the work concerning K.I. Waeber and the accusations against the author of the article in connection with the publication in Germany in the summer of 2021 of Dr. S. Braezel's photobook "Pictures of the life of a diplomat between Europe and East Asia: Karl von Waeber (1841-1910)". The author of the article drew attention to some erroneous judgments in the article by T.M. Simbirtseva and S.V. Volkov, formed due to ignorance and bias, analyzed and refuted the most unfounded accusations, clarified the position regarding new information about K.I. Waeber.

scholarly journals Erichthonius or Theseus, who established the Panathenaea?

2021 ◽  
Vol 13 (3) ◽  
pp. 259-268
Author(s):  
Tatiana Borisovna Gvozdeva
Keyword(s):  
Olympic Games ◽  
Urban Community ◽  
Vase Painting ◽  
New Name ◽  
New Information ◽  
History Of ◽  
Two Stages ◽  
Regional Character ◽  
The Olympic Games

The sources know two versions of the establishing of Panathenaia, the main public holiday of the Athenian polis. The earliest version of aition of Panathenaia is associated with the history of the Athenian indigenous king Erichthonius. The son of Gaia and Hephaestus, Erichthonius was raised by the goddess Athena on the Acropolis, and after becoming king of Athens, he dedicated the feast of Panathenaia to the goddess. In the source, he is the first founder of the holiday. However, two types of Panathenaia were known in Athens: the Lesser Panathenaia, which were held annually, and the Greater Panathenaia, which, like the Olympic Games, were held every four years. Gradually, there appear pieces of new information about the history of the establishing of the Panathenaia in the mythological tradition. Now the authors distinguish two stages in the history of the feast, wherein the earlier one was called Athenaia. Gradually Erichthonius was relegated to the background, as founder Athenaeus, whereas the holiday got a new name - Panathenaia. This process was often associated with the synoekismus of Theseus, when he had united all the Athenians into one urban community. The cult of Theseus became especially popular in Athens after the reforms of Cleisthenes. Theseus' exploits are becoming a popular theme in Attic vase painting, especially scenes depicting the struggle, which Theseus was believed to be the founder of in Athens. At the same time, the program of the Panathenaic Games was expanding, the Panathenaia gradually acquired a supra-regional character.

scholarly journals Modelling the HIV-Associated TB Epidemic and the Impact of Interventions Aimed at Epidemic Control

2019 ◽  
pp. 25-55
Author(s):  
P. J. Dodd ◽  
C. Pretorius ◽  
B. G. Williams
Keyword(s):  
Natural History ◽  
Mathematical Models ◽  
Population Level ◽  
Explicit Representation ◽  
Epidemic Control ◽  
Future Directions ◽  
Individual Level ◽  
Tuberculosis Epidemiology ◽  
History Of ◽  
The Impact

Abstract In this chapter, we focus on mathematical models of tuberculosis epidemiology (TB) that include interactions with HIV and an explicit representation of transmission. We review the natural history of TB and illustrate how its features are simplified and incorporated in mathematical models. We then review the ways HIV influences the natural history of TB, the interventions that have been considered in models, and the way these individual-level effects are represented in models. We then go on to consider population-level effects, reviewing the TB/HIV modelling literature. We first review studies whose focus was on purely epidemiological modelling, and then studies whose focus was on modelling the impact of interventions. We conclude with a summary of the uses and achievements of TB/HIV modelling and some suggested future directions.

CERAMIC HISTORY, CERAMIC CHANGE, AND ARCHITECTURAL SEQUENCE AT ACANMUL, CAMPECHE: A LOCAL CHRONICLE AND ITS REGIONAL IMPLICATIONS

2015 ◽  
Vol 26 (2) ◽  
pp. 233-273 ◽  
Author(s):  
Joseph W. Ball ◽  
Jennifer T. Taschek
Keyword(s):  
Architectural History ◽  
Ninth Century ◽  
Medium Size ◽  
State University ◽  
Central Coast ◽  
The North ◽  
New Information ◽  
History Of ◽  
San Diego State University ◽  
The City

AbstractAcanmul is a medium-size center located at the north end of the Bay of Campeche about 25 km northeast of the city of Campeche. Between 1999 and 2005, three independent sets of investigations and major architectural consolidation were carried out at the center by archaeologists from the Universidad Autónoma de Campeche (UAC), the Instituto Nacional de Antropología e Historia (INAH), Centro Regional de Campeche, and UAC in collaboration with San Diego State University. These efforts produced a wealth of new information on the archaeology of the central Campeche coast, including new insights into the emergence and evolution of the northern slateware tradition and the architectural history of the central coast from Preclassic through Postclassic times. New data concerning changing relationships through time of the central coast Maya to both the interior central and southern lowlands and to the northern plains also were documented, as was the mid ninth century sacking of the center. This article synthesizes the findings of the three separate institutional efforts at Acanmul and offers a number of new cultural historical scenarios and hypotheses based on them.

scholarly journals Cronkhite-Canada Syndrome: A Rare Cause of Chronic Diarrhoea in a Young Man

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Dhrubajyoti Bandyopadhyay ◽  
Adrija Hajra ◽  
Vijayan Ganesan ◽  
Suvrendu Sankar Kar ◽  
Debarati Bhar ◽  
...  
Keyword(s):  
Correct Diagnosis ◽  
Bacterial Overgrowth ◽  
Close Correlation ◽  
Small Intestinal Bacterial Overgrowth ◽  
Clinical Findings ◽  
Careful Examination ◽  
Chronic Diarrhoea ◽  
History Of ◽  
Clostridium Difficile Toxin ◽  
Colon And Rectum

A young Indian man presented with nine-month history of chronic diarrhea, occasionally mixed with blood and intermittent colicky abdominal pain. He also complained of generalized body swelling for the last three months. On examination, he had diffuse hyperpigmentation of the skin and dystrophic nail changes. Upper and lower gastrointestinal endoscopy revealed multiple sessile polyps in the stomach, small bowel, and colon and rectum. Biopsy of polyps showed adenomatous changes with stromal edema and dilated glands. Cronkhite-Canada syndrome (CCS) was diagnosed and treated with glucocorticoids and enteral nutritional supplementation. There was an associated small intestinal bacterial overgrowth (SIBO) and stool was positive for clostridium difficile toxin. After 12 weeks of treatment, the patient achieved remission. Close correlation with clinical findings, including pertinent ectodermal abnormalities, endoscopic studies, and careful examination of biopsies will ensure a timely and correct diagnosis of CCS.

ПУШКИНСКИЙ ДОМ РАН КАК АКАДЕМИЧЕСКИЙ ЦЕНТР ИЗУЧЕНИЯ ТЕМЫ «ПРАВОСЛАВИЕ И РУССКАЯ КУЛЬТУРА». 1991–2021

2021 ◽  
pp. 14-23
Author(s):  
Алексей Маркович Любомудров
Keyword(s):  
Academic Development ◽  
Russian Literature ◽  
Russian Culture ◽  
New Information ◽  
History Of ◽  
The Moment ◽  
Religious Aspects ◽  
Official Status

Статья посвящена тридцатилетней истории изучения религиозных аспектов русской литературы под эгидой Пушкинского Дома. Детально описаны зарождение, цели и состав участников ежегодных конференций «Православие и русская культура», позволивших сказать новое слово об историческом взаимодействии веры и светского творчества. Становление исследований проходило в обстановке противодействия сил, занимавших позиции безоценочного релятивизма и откровенного антихристианства. В работе показано, как стихийно сложившийся в Институте русской литературы центр изучения православных парадигм отечественной словесности в 2008 году получил официальный статус и за годы своего существования подготовил десятки трудов, собраний сочинений классиков, сотни публикаций. Подчеркнута объединяющая и консолидирующая роль пушкинодомцев в академической разработке данной темы. The article is devoted to the thirty-year history of studying the religious aspects of Russian literature at the basis of the Institute of Russian Literature (Pushkin House). The origin, goals and participants of the annual conferences «Orthodoxy and Russian Culture», which provided new information about the historical interaction of faith and secular creativity, are described in details. The formation of the research took place in the atmosphere of confrontation between forces whose positions were relativistic and distinctly anti-christian. The work shows how the spontaneously established Center for the study of the Orthodox paradigm of Russian literature received its own official status in 2008. By the moment the Center has prepared hundreds of publications as well as collective works of classics. The unifying and consolidating role of researchers of Pushkin House in the academic development of subject mentioned above is emphasized.

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