LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 14

Search options

  1. Article ; Online: Opinion: What models can and cannot tell us about COVID-19.

    Siegenfeld, Alexander F / Taleb, Nassim N / Bar-Yam, Yaneer

    Proceedings of the National Academy of Sciences of the United States of America

    2020  Volume 117, Issue 28, Page(s) 16092–16095

    MeSH term(s) Behavior ; Betacoronavirus ; COVID-19 ; Coronavirus Infections/epidemiology ; Coronavirus Infections/transmission ; Data Accuracy ; Humans ; Models, Statistical ; Pandemics ; Pneumonia, Viral/epidemiology ; Pneumonia, Viral/transmission ; SARS-CoV-2 ; Uncertainty
    Keywords covid19
    Language English
    Publishing date 2020-06-24
    Publishing country United States
    Document type Journal Article
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.2011542117
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 1148: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article ; Online: Modeling Complex Systems

    Alexander F. Siegenfeld / Pratyush K. Kollepara / Yaneer Bar-Yam

    Complexity, Vol

    A Case Study of Compartmental Models in Epidemiology

    2022  Volume 2022

    Abstract: Compartmental epidemic models have been widely used for predicting the course of epidemics, from estimating the basic reproduction number to guiding intervention policies. Studies commonly acknowledge these models’ assumptions but less often justify ... ...

    Abstract Compartmental epidemic models have been widely used for predicting the course of epidemics, from estimating the basic reproduction number to guiding intervention policies. Studies commonly acknowledge these models’ assumptions but less often justify their validity in the specific context in which they are being used. Our purpose is not to argue for specific alternatives or modifications to compartmental models, but rather to show how assumptions can constrain model outcomes to a narrow portion of the wide landscape of potential epidemic behaviors. This concrete examination of well-known models also serves to illustrate general principles of modeling that can be applied in other contexts.
    Keywords Electronic computers. Computer science ; QA75.5-76.95
    Language English
    Publishing date 2022-01-01T00:00:00Z
    Publisher Hindawi-Wiley
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article ; Online: Unraveling the flaws of estimates of the infection fatality rate for COVID-19.

    Shen, Chen / VanGennep, Derrick / Siegenfeld, Alexander F / Bar-Yam, Yaneer

    Journal of travel medicine

    2021  Volume 28, Issue 2

    Language English
    Publishing date 2021-01-04
    Publishing country England
    Document type Editorial ; Comment
    ZDB-ID 1212504-0
    ISSN 1708-8305 ; 1195-1982
    ISSN (online) 1708-8305
    ISSN 1195-1982
    DOI 10.1093/jtm/taaa239
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 4120: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Book ; Online: Modeling complex systems

    Siegenfeld, Alexander F. / Kollepara, Pratyush K. / Bar-Yam, Yaneer

    A case study of compartmental models in epidemiology

    2021  

    Abstract: Compartmental epidemic models have been widely used for predicting the course of epidemics, from estimating the basic reproduction number to guiding intervention policies. Studies commonly acknowledge these models' assumptions but less often justify ... ...

    Abstract Compartmental epidemic models have been widely used for predicting the course of epidemics, from estimating the basic reproduction number to guiding intervention policies. Studies commonly acknowledge these models' assumptions but less often justify their validity in the specific context in which they are being used. Our purpose is not to argue for specific alternatives or modifications to compartmental models, but rather to show how assumptions can constrain model outcomes to a narrow portion of the wide landscape of potential epidemic behaviors. This concrete examination of well-known models also serves to illustrate general principles of modeling that can be applied in other contexts.
    Keywords Quantitative Biology - Populations and Evolution ; Quantitative Biology - Quantitative Methods
    Publishing date 2021-10-06
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Article ; Online: The impact of travel and timing in eliminating COVID-19

    Alexander F. Siegenfeld / Yaneer Bar-Yam

    Communications Physics, Vol 3, Iss 1, Pp 1-

    2020  Volume 8

    Abstract: Large-scale containment measures that reduce the spread of COVID-19 have proven to have too large an impact on both the economy and our mental health to be sustainable in the long term. Here, the authors show that travel reductions between geographical ... ...

    Abstract Large-scale containment measures that reduce the spread of COVID-19 have proven to have too large an impact on both the economy and our mental health to be sustainable in the long term. Here, the authors show that travel reductions between geographical regions and timely local control measures can reduce the region-to-region reproduction number below one, thus eliminating the epidemic and preventing recurrent waves without the need for long-term lockdown measures.
    Keywords Astrophysics ; QB460-466 ; Physics ; QC1-999 ; covid19
    Language English
    Publishing date 2020-11-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Article ; Online: An Introduction to Complex Systems Science and Its Applications

    Alexander F. Siegenfeld / Yaneer Bar-Yam

    Complexity, Vol

    2020  Volume 2020

    Abstract: The standard assumptions that underlie many conceptual and quantitative frameworks do not hold for many complex physical, biological, and social systems. Complex systems science clarifies when and why such assumptions fail and provides alternative ... ...

    Abstract The standard assumptions that underlie many conceptual and quantitative frameworks do not hold for many complex physical, biological, and social systems. Complex systems science clarifies when and why such assumptions fail and provides alternative frameworks for understanding the properties of complex systems. This review introduces some of the basic principles of complex systems science, including complexity profiles, the tradeoff between efficiency and adaptability, the necessity of matching the complexity of systems to that of their environments, multiscale analysis, and evolutionary processes. Our focus is on the general properties of systems as opposed to the modeling of specific dynamics; rather than provide a comprehensive review, we pedagogically describe a conceptual and analytic approach for understanding and interacting with the complex systems of our world. This paper assumes only a high school mathematical and scientific background so that it may be accessible to academics in all fields, decision-makers in industry, government, and philanthropy, and anyone who is interested in systems and society.
    Keywords Electronic computers. Computer science ; QA75.5-76.95
    Subject code 501
    Language English
    Publishing date 2020-01-01T00:00:00Z
    Publisher Hindawi-Wiley
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  7. Article ; Online: Unmasking the mask studies: why the effectiveness of surgical masks in preventing respiratory infections has been underestimated.

    Kollepara, Pratyush K / Siegenfeld, Alexander F / Taleb, Nassim Nicholas / Bar-Yam, Yaneer

    Journal of travel medicine

    2021  Volume 28, Issue 7

    Abstract: Background: Pre-pandemic empirical studies have produced mixed statistical results on the effectiveness of masks against respiratory viruses, leading to confusion that may have contributed to organizations such as the WHO and CDC initially not ... ...

    Abstract Background: Pre-pandemic empirical studies have produced mixed statistical results on the effectiveness of masks against respiratory viruses, leading to confusion that may have contributed to organizations such as the WHO and CDC initially not recommending that the general public wear masks during the coronavirus disease 2019 pandemic.
    Methods: A threshold-based dose-response curve framework is used to analyse the effects of interventions on infection probabilities for both single and repeated exposure events. Empirical studies on mask effectiveness are evaluated with a statistical power analysis that includes the effect of adherence to mask usage protocols.
    Results: When the adherence to mask usage guidelines is taken into account, the empirical evidence indicates that masks prevent disease transmission: all studies we analysed that did not find surgical masks to be effective were under-powered to such an extent that even if masks were 100% effective, the studies in question would still have been unlikely to find a statistically significant effect. We also provide a framework for understanding the effect of masks on the probability of infection for single and repeated exposures. The framework demonstrates that masks can have a disproportionately large protective effect and that more frequently wearing a mask provides super-linearly compounding protection.
    Conclusions: This work shows (1) that both theoretical and empirical evidence is consistent with masks protecting against respiratory infections and (2) that non-linear effects and statistical considerations regarding the percentage of exposures for which masks are worn must be taken into account when designing empirical studies and interpreting their results.
    MeSH term(s) COVID-19 ; Humans ; Masks ; Pandemics ; Respiratory Tract Infections/prevention & control ; SARS-CoV-2
    Language English
    Publishing date 2021-08-19
    Publishing country England
    Document type Journal Article
    ZDB-ID 1212504-0
    ISSN 1708-8305 ; 1195-1982
    ISSN (online) 1708-8305
    ISSN 1195-1982
    DOI 10.1093/jtm/taab144
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 4120: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  9. Article: CTCF/cohesin organize the ground state of chromatin-nuclear speckle association.

    Yu, Ruofan / Roseman, Shelby / Siegenfeld, Allison P / Nguyen, Son C / Joyce, Eric F / Liau, Brian B / Krantz, Ian D / Alexander, Katherine A / Berger, Shelley L

    bioRxiv : the preprint server for biology

    2023  

    Abstract: The interchromatin space in the cell nucleus contains various membrane-less nuclear bodies. Recent findings indicate that nuclear speckles, comprising a distinct nuclear body, exhibit interactions with certain chromatin regions in a ground state. Key ... ...

    Abstract The interchromatin space in the cell nucleus contains various membrane-less nuclear bodies. Recent findings indicate that nuclear speckles, comprising a distinct nuclear body, exhibit interactions with certain chromatin regions in a ground state. Key questions are how this ground state of chromatin-nuclear speckle association is established and what are the gene regulatory roles of this layer of nuclear organization. We report here that chromatin structural factors CTCF and cohesin are required for full ground state association between DNA and nuclear speckles. Disruption of ground state DNA-speckle contacts via either CTCF depletion or cohesin depletion had minor effects on basal level expression of speckle-associated genes, however we show strong negative effects on stimulus-dependent induction of speckle-associated genes. We identified a putative speckle targeting motif (STM) within cohesin subunit RAD21 and demonstrated that the STM is required for chromatin-nuclear speckle association. In contrast to reduction of CTCF or RAD21, depletion of the cohesin releasing factor WAPL stabilized cohesin on chromatin and DNA-speckle contacts, resulting in enhanced inducibility of speckle-associated genes. In addition, we observed disruption of chromatin-nuclear speckle association in patient derived cells with Cornelia de Lange syndrome (CdLS), a congenital neurodevelopmental diagnosis involving defective cohesin pathways, thus revealing nuclear speckles as an avenue for therapeutic inquiry. In summary, our findings reveal a mechanism to establish the ground organizational state of chromatin-speckle association, to promote gene inducibility, and with relevance to human disease.
    Language English
    Publishing date 2023-10-24
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.07.22.550178
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  10. Article ; Online: What models can and cannot tell us about COVID-19

    Siegenfeld, Alexander F. / Taleb, Nassim N. / Bar-Yam, Yaneer

    PNAS

    2020  

    Abstract: The coronavirus disease 2019 (COVID-19) pandemic, caused by the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has already claimed more than 470,000 deaths worldwide at the time of this writing (1) and is likely to claim ... ...

    Abstract The coronavirus disease 2019 (COVID-19) pandemic, caused by the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has already claimed more than 470,000 deaths worldwide at the time of this writing (1) and is likely to claim many more. Models can help us determine how to stop the spread of the virus.
    Keywords covid19
    Publisher National Academy of Sciences
    Publishing country us
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top