scholarly journals Spin Experimentation with Unpolarized Colliding Beams at the LHC

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1886
Author(s):  
Sergey Troshin
Keyword(s):  
Pp Collisions ◽  
Dynamical Mechanism ◽  
General Role ◽  
Hyperon Production ◽  
Polarized Beams ◽  
Model Predictions ◽  
Polarization Studies ◽  
The Impact ◽  
Colliding Beams

A brief recollection of the problems related to a significant hyperon polarization observed in pp-collisions is given with an emphasis on the general role of spin in the dynamics of hadron interactions. The old, unsolved problem of the observation of a significant hyperon polarization can provide new insights as a result of the measurements of energies at the LHC; in combination with other measurements, these can be used to tag the QGP formation in pp-collisions with colliding beams. Polarization studies in the processes of hyperon production do not require the use of polarized beams or targets and can be performed in the existing experimental environment at the LHC. Model predictions based on the chiral dynamics and pictures of the impact parameter are presented for the illustration of a possible dynamical mechanism that leads to a hyperon polarization.

Major Extratropical Cyclones of the Northwest United States: Historical Review, Climatology, and Synoptic Environment

2010 ◽  
Vol 138 (7) ◽  
pp. 2499-2527 ◽  
Author(s):  
Clifford Mass ◽  
Brigid Dotson
Keyword(s):  
United States ◽  
Conceptual Model ◽  
Large Scale ◽  
Historical Review ◽  
Extratropical Cyclones ◽  
Past Century ◽  
Discussion Section ◽  
General Role ◽  
The Impact

Abstract The northwest United States is visited frequently by strong midlatitude cyclones that can produce hurricane-force winds and extensive damage. This article reviews these storms, beginning with a survey of the major events of the past century. A climatology of strong windstorms is presented for the area from southern Oregon to northern Washington State and is used to create synoptic composites that show the large-scale evolution associated with such storms. A recent event, the Hanukkah Eve Storm of December 2006, is described in detail, with particular attention given to the impact of the bent-back front/trough and temporal changes in vertical stability and structure. The discussion section examines the general role of the bent-back trough, the interactions of such storms with terrain, and the applicability of the “sting jet” conceptual model. A conceptual model of the evolution of Northwest windstorm events is presented.

scholarly journals A network modelling approach to assess non-pharmaceutical disease controls in a worker population: An application to SARS-CoV-2

2021 ◽  
Vol 17 (6) ◽  
pp. e1009058
Author(s):  
Edward M. Hill ◽  
Benjamin D. Atkins ◽  
Matt J. Keeling ◽  
Louise Dyson ◽  
Michael J. Tildesley
Keyword(s):  
Network Model ◽  
Significant Proportion ◽  
Disease Spread ◽  
Contact Tracing ◽  
Work Patterns ◽  
General Role ◽  
Work From Home ◽  
Working Practices ◽  
The Impact

As part of a concerted pandemic response to protect public health, businesses can enact non-pharmaceutical controls to minimise exposure to pathogens in workplaces and premises open to the public. Amendments to working practices can lead to the amount, duration and/or proximity of interactions being changed, ultimately altering the dynamics of disease spread. These modifications could be specific to the type of business being operated. We use a data-driven approach to parameterise an individual-based network model for transmission of SARS-CoV-2 amongst the working population, stratified into work sectors. The network is comprised of layered contacts to consider the risk of spread in multiple encounter settings (workplaces, households, social and other). We analyse several interventions targeted towards working practices: mandating a fraction of the population to work from home; using temporally asynchronous work patterns; and introducing measures to create ‘COVID-secure’ workplaces. We also assess the general role of adherence to (or effectiveness of) isolation and test and trace measures and demonstrate the impact of all these interventions across a variety of relevant metrics. The progress of the epidemic can be significantly hindered by instructing a significant proportion of the workforce to work from home. Furthermore, if required to be present at the workplace, asynchronous work patterns can help to reduce infections when compared with scenarios where all workers work on the same days, particularly for longer working weeks. When assessing COVID-secure workplace measures, we found that smaller work teams and a greater reduction in transmission risk reduced the probability of large, prolonged outbreaks. Finally, following isolation guidance and engaging with contact tracing without other measures is an effective tool to curb transmission, but is highly sensitive to adherence levels. In the absence of sufficient adherence to non-pharmaceutical interventions, our results indicate a high likelihood of SARS-CoV-2 spreading widely throughout a worker population. Given the heterogeneity of demographic attributes across worker roles, in addition to the individual nature of controls such as contact tracing, we demonstrate the utility of a network model approach to investigate workplace-targeted intervention strategies and the role of test, trace and isolation in tackling disease spread.

The Role of Uncertainty Analysis in Model Validation

2003 ◽  
Author(s):  
Richard G. Hills ◽  
Ian H. Leslie
Keyword(s):  
Uncertainty Analysis ◽  
Model Validation ◽  
Correlation Coefficients ◽  
Physical Processes ◽  
Graph Norm ◽  
Thermally Induced ◽  
Test Models ◽  
Model Predictions ◽  
The Impact

Our increased dependence on mathematical models for engineering design, coupled with our decreased dependence on experimental observation, leads to the obvious question — how do we know that our models are valid representations of physical processes? We test models by comparisons between model predictions and experimental observations. As our models become more complex (i.e., multiphysics models), our ability to test models over the range of possible applications becomes more difficult. This difficulty is compounded by the uncertainty that is invariably present in the experimental data used to test the model, the uncertainties in the parameters that are incorporated into the model, and the uncertainties in the model structure itself. When significant uncertainties of these types are present, evaluating model validity through graphical comparisons of model predictions to experimental observations becomes very subjective. Here we consider the impact of uncertainty and the role of uncertainty analysis in model validation. We focus on uncertainty in the model predictions due to parameter uncertainty, and on experimental uncertainty due to measurement noise. We show that characterizing these uncertainties allows us to use a meaningful metric for model testing that is less subjective than the traditional “view graph norm” or the evaluation of correlation coefficients. We demonstrate this methodology through its application to a model and experimental observations of thermally induced foam decomposition.

scholarly journals A network modelling approach to assess non-pharmaceutical disease controls in a worker population: An application to SARS-CoV-2

2020 ◽  
Author(s):  
Edward M Hill ◽  
Benjamin D Atkins ◽  
Matt J Keeling ◽  
Louise Dyson ◽  
Michael J Tildesley
Keyword(s):  
Network Model ◽  
Significant Proportion ◽  
Disease Spread ◽  
Contact Tracing ◽  
Work Patterns ◽  
General Role ◽  
Work From Home ◽  
Working Practices ◽  
The Impact

Background: As part of a concerted pandemic response to protect public health, businesses can enact non-pharmaceutical controls to minimise exposure to pathogens in workplaces and premises open to the public. Amendments to working practices can lead to the amount, duration and/or proximity of interactions being changed, ultimately altering the dynamics of disease spread. These modifications could be specific to the type of business being operated. Methods: We use a data-driven approach to parameterise an individual-based network model for transmission of SARS-CoV-2 amongst the working population, stratified into work sectors. The network is comprised of layered contacts to consider risk of spread in multiple encounter settings (workplaces, households, social and other). We analyse several interventions targeted towards working practices: mandating a fraction of the population to work from home, using temporally asynchronous work patterns and introducing measures to create `COVID-secure' workplaces. We also assess the general role of adherence to (or effectiveness of) isolation and test and trace measures and demonstrate the impact of all these interventions across a variety of relevant metrics. Results: The progress of the epidemic can be significantly hindered by instructing a significant proportion of the workforce to work from home. Furthermore, if required to be present at the workplace, asynchronous work patterns can help to reduce infections when compared with scenarios where all workers work on the same days, particularly for longer working weeks. When assessing COVID-secure workplace measures, we found that smaller work teams and a greater reduction in transmission risk led to a flatter temporal profile for both infections and the number of people isolating, and reduced the probability of large, long outbreaks. Finally, following isolation guidance and engaging with contact tracing alone is an effective tool to curb transmission, but is highly sensitive to adherence levels. Conclusions: In the absence of sufficient adherence to non-pharmaceutical interventions, our results indicate a high likelihood of SARS-CoV-2 spreading widely throughout a worker population. Given the heterogeneity of demographic attributes across worker roles, in addition to the individual nature of controls such as contact tracing, we demonstrate the utility of a network model approach to investigate workplace-targeted intervention strategies and the role of test, trace and isolation in tackling disease spread.

Intergroup Threat and Outgroup Attitudes

2013 ◽  
Vol 44 (5) ◽  
pp. 311-319 ◽  
Author(s):  
Marco Brambilla ◽  
David A. Butz
Keyword(s):  
Gay Men ◽  
Social Group ◽  
Welfare Recipients ◽  
Intergroup Attitudes ◽  
Social Policies ◽  
Intergroup Threat ◽  
Economic Threat ◽  
The Impact ◽  
General Climate

Two studies examined the impact of macrolevel symbolic threat on intergroup attitudes. In Study 1 (N = 71), participants exposed to a macrosymbolic threat (vs. nonsymbolic threat and neutral topic) reported less support toward social policies concerning gay men, an outgroup whose stereotypes implies a threat to values, but not toward welfare recipients, a social group whose stereotypes do not imply a threat to values. Study 2 (N = 78) showed that, whereas macrolevel symbolic threat led to less favorable attitudes toward gay men, macroeconomic threat led to less favorable attitudes toward Asians, an outgroup whose stereotypes imply an economic threat. These findings are discussed in terms of their implications for understanding the role of a general climate of threat in shaping intergroup attitudes.

Sign in / Sign up

Export Citation Format

Share Document