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  1. Article ; Online: Weighted ensemble: Recent mathematical developments.

    Aristoff, D / Copperman, J / Simpson, G / Webber, R J / Zuckerman, D M

    The Journal of chemical physics

    2023  Volume 158, Issue 1, Page(s) 14108

    Abstract: Weighted ensemble (WE) is an enhanced sampling method based on periodically replicating and pruning trajectories generated in parallel. WE has grown increasingly popular for computational biochemistry problems due, in part, to improved hardware and ... ...

    Abstract Weighted ensemble (WE) is an enhanced sampling method based on periodically replicating and pruning trajectories generated in parallel. WE has grown increasingly popular for computational biochemistry problems due, in part, to improved hardware and accessible software implementations. Algorithmic and analytical improvements have played an important role, and progress has accelerated in recent years. Here, we discuss and elaborate on the WE method from a mathematical perspective, highlighting recent results that enhance the computational efficiency. The mathematical theory reveals a new strategy for optimizing trajectory management that approaches the best possible variance while generalizing to systems of arbitrary dimension.
    MeSH term(s) Algorithms ; Software
    Language English
    Publishing date 2023-01-06
    Publishing country United States
    Document type Journal Article
    ZDB-ID 3113-6
    ISSN 1089-7690 ; 0021-9606
    ISSN (online) 1089-7690
    ISSN 0021-9606
    DOI 10.1063/5.0110873
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Book ; Online: Weighted ensemble

    Aristoff, D. / Copperman, J. / Simpson, G. / Webber, R. J. / Zuckerman, D. M.

    Recent mathematical developments

    2022  

    Abstract: The weighted ensemble (WE) method, an enhanced sampling approach based on periodically replicating and pruning trajectories in a set of parallel simulations, has grown increasingly popular for computational biochemistry problems, due in part to improved ... ...

    Abstract The weighted ensemble (WE) method, an enhanced sampling approach based on periodically replicating and pruning trajectories in a set of parallel simulations, has grown increasingly popular for computational biochemistry problems, due in part to improved hardware and the availability of modern software. Algorithmic and analytical improvements have also played an important role, and progress has accelerated in recent years. Here, we discuss and elaborate on the WE method from a mathematical perspective, highlighting recent results which have begun to yield greater computational efficiency. Notable among these innovations are variance reduction approaches that optimize trajectory management for systems of arbitrary dimensionality.

    Comment: 12 pages, 10 figures
    Keywords Physics - Computational Physics ; Computer Science - Computational Engineering ; Finance ; and Science
    Publishing date 2022-06-29
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article: The need to improve informed consent for breast cancer patients.

    Zuckerman, D M

    Journal of the American Medical Women's Association (1972)

    2000  Volume 55, Issue 5, Page(s) 285–289

    Abstract: Many of the more than 182,000 women who will be newly diagnosed with breast cancer this year will not have access to all the information they need to make the surgical and treatment choices that are most appropriate for them. Research clearly shows that ... ...

    Abstract Many of the more than 182,000 women who will be newly diagnosed with breast cancer this year will not have access to all the information they need to make the surgical and treatment choices that are most appropriate for them. Research clearly shows that lumpectomy and other breast-conserving surgeries are just as safe as mastectomy for most women with early stage disease, and yet approximately half will undergo the more disfiguring procedures. Choices about breast implants and autologous tissue reconstruction are based, at best, on a few published studies that provide limited information about the long-term safety of these procedures. Many healthy women who have strong family histories of breast cancer consider prophylactic mastectomies, and their decisions are also based on very limited information, because there are few studies showing the effectiveness of that procedure. This paper delineates how limited information and biased recommendations can undermine breast cancer patients' ability to make informed choices.
    MeSH term(s) Adult ; Breast Neoplasms/pathology ; Breast Neoplasms/prevention & control ; Breast Neoplasms/surgery ; Decision Making ; Female ; Humans ; Information Services ; Informed Consent ; Mastectomy ; Mastectomy, Segmental ; Physician-Patient Relations ; Reconstructive Surgical Procedures
    Language English
    Publishing date 2000
    Publishing country United States
    Document type Journal Article
    ZDB-ID 121272-2
    ISSN 1551-8221 ; 0098-8421 ; 0091-7427
    ISSN (online) 1551-8221
    ISSN 0098-8421 ; 0091-7427
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Media violence, gun control, and public policy.

    Zuckerman, D M

    The American journal of orthopsychiatry

    1996  Volume 66, Issue 3, Page(s) 378–389

    Abstract: Public concern with the national level of violence is discussed, and the complexity of the issue delineated. Research findings in two key areas of the topic, media violence and availability of firearms, are examined, as is their applicability to public ... ...

    Abstract Public concern with the national level of violence is discussed, and the complexity of the issue delineated. Research findings in two key areas of the topic, media violence and availability of firearms, are examined, as is their applicability to public policy efforts and recommendations for the prevention of violence. An approach that combines efforts to counteract media violence with those aimed at effective gun control is outlined in terms of bringing about changes in attitudes toward violence and firearm possession.
    MeSH term(s) Adolescent ; Adult ; Firearms/legislation & jurisprudence ; Humans ; Legislation as Topic ; Male ; Mass Media ; Middle Aged ; Public Policy ; Violence
    Language English
    Publishing date 1996-07
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 280031-7
    ISSN 1939-0025 ; 0002-9432
    ISSN (online) 1939-0025
    ISSN 0002-9432
    DOI 10.1037/h0080188
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Thermal motions of the E. coli glucose-galactose binding protein studied using well-sampled, semi-atomistic simulations.

    Cashman, D J / Mamonov, A B / Bhatt, D / Zuckerman, D M

    Current topics in medicinal chemistry

    2010  Volume 11, Issue 2, Page(s) 211–220

    Abstract: The E. coli glucose-galactose chemosensory receptor is a 309 residue, 32 kDa protein consisting of two distinct structural domains. We used two computational methods to examine the protein's thermal fluctuations, including both the large-scale ... ...

    Abstract The E. coli glucose-galactose chemosensory receptor is a 309 residue, 32 kDa protein consisting of two distinct structural domains. We used two computational methods to examine the protein's thermal fluctuations, including both the large-scale interdomain movements that contribute to the receptor's mechanism of action, as well as smaller-scale motions. We primarily employ extremely fast, "semi-atomistic" Library-Based Monte Carlo (LBMC) simulations, which include all backbone atoms but "implicit" side chains. Our results were compared with previous experiments and all-atom molecular dynamics (MD) simulation. Both LBMC and MD simulations were performed using both the apo and glucose-bound form of the protein, with LBMC exhibiting significantly larger fluctuations. The LBMC simulations are in general agreement with the disulfide trapping experiments of Careaga & Falke (J. Mol. Biol., 1992, Vol. 226, 1219-35), which indicate that distant residues in the crystal structure (i.e. beta carbons separated by 10 to 20 angstroms) form spontaneous transient contacts in solution. Our simulations illustrate several possible "mechanisms" (configurational pathways) for these fluctuations. We also observe several discrepancies between our calculations and experimental rate constants. Nevertheless, we believe that our semi-atomistic approach could be used to study fluctuations in other proteins, perhaps for ensemble docking or other analyses of protein flexibility in virtual screening studies.
    MeSH term(s) Amino Acids/metabolism ; Apoenzymes/chemistry ; Apoenzymes/metabolism ; Calcium-Binding Proteins/chemistry ; Calcium-Binding Proteins/metabolism ; Crystallography, X-Ray ; Differential Thermal Analysis ; Disulfides/chemistry ; Escherichia coli ; Galactose/metabolism ; Glucose/metabolism ; Holoenzymes/chemistry ; Holoenzymes/metabolism ; Models, Molecular ; Molecular Dynamics Simulation ; Monosaccharide Transport Proteins/chemistry ; Monosaccharide Transport Proteins/metabolism ; Periplasmic Binding Proteins/chemistry ; Periplasmic Binding Proteins/metabolism ; Protein Binding ; Protein Conformation
    Chemical Substances Amino Acids ; Apoenzymes ; Calcium-Binding Proteins ; Disulfides ; Holoenzymes ; Monosaccharide Transport Proteins ; Periplasmic Binding Proteins ; galactose-binding protein ; Glucose (IY9XDZ35W2) ; Galactose (X2RN3Q8DNE)
    Language English
    Publishing date 2010-10-13
    Publishing country United Arab Emirates
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2064823-6
    ISSN 1873-4294 ; 1568-0266
    ISSN (online) 1873-4294
    ISSN 1568-0266
    DOI 10.2174/156802611794863607
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Efficient dynamic importance sampling of rare events in one dimension.

    Zuckerman, D M / Woolf, T B

    Physical review. E, Statistical, nonlinear, and soft matter physics

    2001  Volume 63, Issue 1 Pt 2, Page(s) 16702

    Abstract: Exploiting stochastic path-integral theory, we obtain by simulation substantial gains in efficiency for the computation of reaction rates in one-dimensional, bistable, overdamped stochastic systems. Using a well-defined measure of efficiency, we compare ... ...

    Abstract Exploiting stochastic path-integral theory, we obtain by simulation substantial gains in efficiency for the computation of reaction rates in one-dimensional, bistable, overdamped stochastic systems. Using a well-defined measure of efficiency, we compare implementations of "dynamic importance sampling" (DIMS) methods to unbiased simulation. The best DIMS algorithms are shown to increase efficiency by factors of approximately 20 for a 5k(B)T barrier height and 300 for 9k(B)T, compared to unbiased simulation. The gains result from close emulation of natural (unbiased), instantonlike crossing events with artificially decreased waiting times between events that are corrected for in rate calculations. The artificial crossing events are generated using the closed-form solution to the most probable crossing event described by the Onsager-Machlup action. While the best biasing methods require the second derivative of the potential (resulting from the "Jacobian" term in the action, which is discussed at length), algorithms employing solely the first derivative do nearly as well. We discuss the importance of one-dimensional models to larger systems, and suggest extensions to higher-dimensional systems.
    MeSH term(s) Algorithms ; Computer Simulation ; Mathematical Computing ; Models, Theoretical ; Selection Bias ; Stochastic Processes
    Language English
    Publishing date 2001-01
    Publishing country United States
    Document type Comparative Study ; Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S. ; Research Support, U.S. Gov't, P.H.S.
    ISSN 1539-3755
    ISSN 1539-3755
    DOI 10.1103/PhysRevE.63.016702
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Book ; Online: Rapid sampling of all-atom peptides using a library-based polymer-growth approach

    Mamonov, A. B. / Zhang, X. / Zuckerman, D. M.

    2009  

    Abstract: We adapted existing polymer growth strategies for equilibrium sampling of peptides described by modern atomistic forcefields with implicit solvent. The main novel feature of our approach is the use of pre-calculated statistical libraries of molecular ... ...

    Abstract We adapted existing polymer growth strategies for equilibrium sampling of peptides described by modern atomistic forcefields with implicit solvent. The main novel feature of our approach is the use of pre-calculated statistical libraries of molecular fragments. A molecule is sampled by combining fragment configurations -- of single residues in this study -- which are stored in the libraries. Ensembles generated from the independent libraries are reweighted to conform with the Boltzmann factor distribution of the forcefield describing the full molecule. In this way, high-quality equilibrium sampling of small peptides (4-8 residues) typically requires less than one hour of single-processor wallclock time and can be significantly faster than Langevin simulations. Furthermore, approximate but clash-free ensembles can be generated for larger peptides (e.g., 16 residues) in less than a minute of single-processor computing. We also describe an application to free energy calculation, a "multi-resolution" implementation of the growth procedure and application to fragment assembly protein-structure prediction protocols.
    Keywords Physics - Biological Physics ; Physics - Computational Physics
    Subject code 612
    Publishing date 2009-10-13
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article: Asymmetric primitive-model electrolytes: Debye-Hückel theory, criticality, and energy bounds.

    Zuckerman, D M / Fisher, M E / Bekiranov, S

    Physical review. E, Statistical, nonlinear, and soft matter physics

    2001  Volume 64, Issue 1 Pt 1, Page(s) 11206

    Abstract: Debye-Hückel (DH) theory is extended to treat two-component size- and charge-asymmetric primitive models, focusing primarily on the 1:1 additive hard-sphere electrolyte with, say, negative ion diameters a(--) larger than the positive ion diameters a(++). ...

    Abstract Debye-Hückel (DH) theory is extended to treat two-component size- and charge-asymmetric primitive models, focusing primarily on the 1:1 additive hard-sphere electrolyte with, say, negative ion diameters a(--) larger than the positive ion diameters a(++). The treatment highlights the crucial importance of the charge-unbalanced "border zones" around each ion into which other ions of only one species may penetrate. Extensions of the DH approach that describe the border zones in a physically reasonable way are exact at high T and low density rho and, furthermore, are also in substantial agreement with recent simulation predictions for trends in the critical parameters, T(c) and rho(c), with increasing size asymmetry. Conversely, the simplest linear asymmetric DH description, which fails to account for physically expected behavior in the border zones at low T, can violate a new lower bound on the energy (which applies generally to models asymmetric in both charge and size). Other theories, including those based on the mean spherical approximation, predict trends in the critical parameters quite opposite to those established by the simulations.
    MeSH term(s) Biophysics/methods ; Diffusion ; Electrolytes ; Evaluation Studies as Topic ; Ions ; Mathematics ; Models, Chemical ; Models, Statistical ; Nonlinear Dynamics ; Solutions ; Static Electricity ; Thermodynamics
    Chemical Substances Electrolytes ; Ions ; Solutions
    Language English
    Publishing date 2001-07
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.
    ISSN 1539-3755
    ISSN 1539-3755
    DOI 10.1103/PhysRevE.64.011206
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: Retrospective study of interests and abilities that predict life goals and sex-role attitudes of college women.

    Zuckerman, D M

    Psychological reports

    1978  Volume 43, Issue 3 Pt 2, Page(s) 1151–1157

    MeSH term(s) Achievement ; Adult ; Attitude ; Female ; Gender Identity ; Goals ; Humans ; Identification (Psychology) ; Retrospective Studies ; Women
    Language English
    Publishing date 1978-12
    Publishing country United States
    Document type Journal Article
    ZDB-ID 205658-6
    ISSN 1558-691X ; 0033-2941
    ISSN (online) 1558-691X
    ISSN 0033-2941
    DOI 10.2466/pr0.1978.43.3f.1151
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Television's impact on children.

    Zuckerman, D M / Zuckerman, B S

    Pediatrics

    1985  Volume 75, Issue 2, Page(s) 233–240

    Abstract: Television has a major impact on children's knowledge, attitudes, and behavior. Research has demonstrated the association between television viewing and four areas: (1) children's aggressive behavior; (2) racial and sex-role stereotypes; (3) decreased ... ...

    Abstract Television has a major impact on children's knowledge, attitudes, and behavior. Research has demonstrated the association between television viewing and four areas: (1) children's aggressive behavior; (2) racial and sex-role stereotypes; (3) decreased interest in reading and school activities; and (4) poorer health habits and attitudes. Methodological limitations make it difficult to draw firm conclusions about a causal relationship between television viewing and children's behavior. Representative studies in these four areas are reviewed, important methodological concerns are pointed out, and conclusions from the research findings are drawn. The implications of the data for pediatricians and other health professionals are discussed.
    MeSH term(s) Advertising as Topic ; Attitude to Health ; Child ; Child Behavior ; Child, Preschool ; Feeding Behavior ; Humans ; Intelligence ; Interpersonal Relations ; Prejudice ; Reading ; Stereotyping ; Television ; Violence
    Language English
    Publishing date 1985-02
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 207677-9
    ISSN 1098-4275 ; 0031-4005
    ISSN (online) 1098-4275
    ISSN 0031-4005
    Database MEDical Literature Analysis and Retrieval System OnLINE

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