SIGACT News Complexity Theory Column 109

2021 ◽  
Vol 52 (2) ◽  
pp. 45-45
Author(s):  
Lane A. Hemaspaandra
Keyword(s):  
Decision Trees ◽  
Complexity Theory ◽  
Models Of Computation ◽  
Social Distancing ◽  
Time Period

Warmest thanks to Alexander Knop, Shachar Lovett, Sam McGuire, and Weiqiang Yuan for this issue's guest column, \Models of computation between decision trees and communication." (Their article came in early, and I wrote back thanking them for being three days early, mentioning that that happens surprisingly rarely. Then two days later, I said, \Wow!", as I realized that they actually had somehow|even during a remote-teaching, social-distancing time period|prepared and sent in their article a month and three days early.)

scholarly journals How public perceptions of social distancing evolved over a critical time period: communication lessons learnt from the American state of Wisconsin

2020 ◽  
Vol 19 (05) ◽  
pp. A11
Author(s):  
Kaiping Chen ◽  
Luye Bao ◽  
Anqi Shao ◽  
Pauline Ho ◽  
Shiyu Yang ◽  
...  
Keyword(s):  
Public Health ◽  
Computational Methods ◽  
Large Scale ◽  
Critical Time ◽  
Effective Communication ◽  
Public Perceptions ◽  
Social Distancing ◽  
Time Period ◽  
Large Scale Survey ◽  
Main Barrier

Understanding how individuals perceive the barriers and benefits of precautionary actions is key for effective communication about public health crises, such as the COVID-19 outbreak. This study used innovative computational methods to analyze 30,000 open-ended responses from a large-scale survey to track how Wisconsin (U.S.A.) residents' perceptions of the benefits of and barriers to performing social distancing evolved over a critical time period (March 19th to April 1st, 2020). Initially, the main barrier was practical related, however, individuals later perceived more multifaceted barriers to social distancing. Communication about COVID-19 should be dynamic and evolve to address people's experiences and needs overtime.

scholarly journals On a hierarchy of Boolean functions hard to compute in constant depth

2001 ◽  
Vol Vol. 4 no. 2 ◽  
Author(s):  
Anna Bernasconi
Keyword(s):  
Harmonic Analysis ◽  
Complexity Theory ◽  
Lower Bounds ◽  
Boolean Functions ◽  
Combinatorial Property ◽  
Constant Depth ◽  
Models Of Computation ◽  
Mathematical Properties ◽  
International Audience ◽  
Mathematical Techniques

International audience Any attempt to find connections between mathematical properties and complexity has a strong relevance to the field of Complexity Theory. This is due to the lack of mathematical techniques to prove lower bounds for general models of computation.\par This work represents a step in this direction: we define a combinatorial property that makes Boolean functions ''\emphhard'' to compute in constant depth and show how the harmonic analysis on the hypercube can be applied to derive new lower bounds on the size complexity of previously unclassified Boolean functions.

scholarly journals Exploring Sexting and Online Sexual Victimization during the COVID-19 Pandemic Lockdown

2021 ◽  
Vol 18 (12) ◽  
pp. 6662
Author(s):  
Aina M. Gassó ◽  
Katrin Mueller-Johnson ◽  
José R. Agustina ◽  
Esperanza L. Gómez-Durán
Keyword(s):  
Online Survey ◽  
Sexual Victimization ◽  
Routine Activities ◽  
Routine Activities Theory ◽  
Main Hypothesis ◽  
Social Distancing ◽  
Daily Routines ◽  
Time Period ◽  
Alternative Hypotheses ◽  
The Way

The COVID-19 pandemic lockdown has impacted daily routines, forcing people to stop socializing in person and changing the way people express their feelings and their romantic or sexual interactions. Social distancing has changed the way people behave online, and we expect that engagement in sexting and online sexual victimization behaviors have increased during lockdown. The aim of this paper is to study the prevalence of sexting and online sexual victimization behaviors during the COVID-19 lockdown in Spanish adults in order to explore how social distancing has affected these behaviors. The sample comprised 293 Spanish adults (mean age = 30.3; 66.2% female) who took part in an online survey about their engagement in sexting behaviors and online sexual victimization experiences. Overall results were apparently not supportive of our main hypothesis, showing that both sexting engagement and online sexual victimization decreased during lockdown despite the increase in internet use. Apart from differences in time period of reference, some alternative hypotheses relate to the increased presence of capable guardians according to the routine activities theory and to forced distance as a demotivation to sext. Possible explanations and hypotheses for these results are discussed further in the paper.

scholarly journals Modeling COVID-19 Transmission Dynamics With Self-Learning Population Behavioral Change

2021 ◽  
Vol 9 ◽  
Author(s):  
Tsz-Lik Chan ◽  
Hsiang-Yu Yuan ◽  
Wing-Cheong Lo
Keyword(s):  
Behavioral Change ◽  
Feedback Loop ◽  
Transmission Rate ◽  
Behavioral Changes ◽  
Social Distancing ◽  
Delayed Information ◽  
Time Period ◽  
The Social ◽  
Information Delay ◽  
Self Learning

Many regions observed recurrent outbreaks of COVID-19 cases after relaxing social distancing measures. It suggests that maintaining sufficient social distancing is important for limiting the spread of COVID-19. The change of population behavior responding to the social distancing measures becomes an important factor for the pandemic prediction. In this paper, we develop a SEAIR model for studying the dynamics of COVID-19 transmission with population behavioral change. In our model, the population is divided into several groups with their own social behavior in response to the delayed information about the number of the infected population. The transmission rate depends on the behavioral changes of all the population groups, forming a feedback loop to affect the COVID-19 dynamics. Based on the data of Hong Kong, our simulations demonstrate how the perceived cost after infection and the information delay affect the level and the time period of the COVID-19 waves.

scholarly journals Global projections of lives saved from COVID-19 with universal mask use

2020 ◽  
Keyword(s):  
Low Cost ◽  
Health Benefits ◽  
Health Impacts ◽  
Transmission Model ◽  
Reference Scenario ◽  
Economic Costs ◽  
Social Distancing ◽  
Time Period ◽  
Economic Downturns ◽  
The Difference

ABSTRACTBACKGROUNDSocial distancing mandates (SDM) have reduced health impacts from COVID-19 but also resulted in economic downturns that have led many nations to relax SDM. Until deployment of an efficacious and equitable vaccine, intervention options to reduce COVID-19 mortality and minimize restrictive SDM are sought by society.METHODSA susceptible-exposed-infectious-recovered (SEIR) deterministic transmission model was parameterized with data on reported deaths, cases, and select covariates to predict infections and deaths from COVID-19 through March 01, 2021. We explore three scenarios: a “non-adaptive” scenario where neither mask use or SDM adapt to changing conditions, a “reference” where current national levels of mask use are maintained and SDM reintroduced when deaths rise, and an increase in mask use to 95% coverage levels (“universal mask”). We reviewed published studies to set priors on the magnitude of reduction in transmission through increasing mask use.RESULTSMask use was estimated at 59.0% of people globally on October 19, 2020. Universal mask use could avert 733,310 deaths (95% UI 385,981 to 1,107,759) between October 27, 2020 and March 01, 2021, the difference between the predicted 2.95 million deaths (95% UI 2.70 to 3.35) in the reference scenario and 2.22 million deaths (95% UI 2.00 to 2.45) in the universal mask scenario over this time period.CONCLUSIONSThe cumulative toll of the COVID-19 pandemic could be substantially reduced by the universal adoption of masks before the availability of a vaccine. This low-cost, low-barrier policy, whether customary or mandated, has enormous health benefits with presumed marginal economic costs.

scholarly journals New Cases of Syphilis and Molluscum Contagiosum in the COVID-19 Pandemic: A Sign That Social Distancing Guidelines Are Not Being Adhered to?

2021 ◽  
Vol 5 (1) ◽  
pp. 34-36
Author(s):  
Haley Danielle Heibel ◽  
Parneet Dhaliwal ◽  
Clay J. Cockerell
Keyword(s):  
Health Care ◽  
Sexually Transmitted Diseases ◽  
Molluscum Contagiosum ◽  
Medical Providers ◽  
Cutaneous Manifestations ◽  
Health Care Resources ◽  
Social Distancing ◽  
Sexually Transmitted ◽  
Time Period ◽  
Limited Health

Social distancing has played an important role in reducing the transmission of COVID-19, and, if the general public uniformly followed social distancing guidelines, we would theoretically expect no new diagnoses of sexually transmitted diseases (STDs) during this time period.  However, during the COVID-19 era, we have diagnosed multiple cases of syphilis and molluscum contagiosum histopathologically with an increased incidence in our practice from the dates of March 1 to August 28, 2020, compared with these dates in 2019.  The vast majority of these cases were not suspected by referring clinicians.  Dermatologists are experts in the recognition of the cutaneous manifestations of venereal diseases which is critical to appropriate diagnosis and management, and they should continue to provide care during this pandemic.  Individuals who acquire STDs during this time may increase the strain on already limited health care resources by disregarding social distancing recommendations.  All medical providers must consider how we can better encourage individuals to abide by social distancing recommendations, optimize care for patients during the pandemic, and prevent the misallocation of valued health care resources.

scholarly journals Data-driven Optimized Control of the COVID-19 Epidemics

2020 ◽  
Author(s):  
Afroza Shirin ◽  
Yen Ting Lin ◽  
Francesco Sorrentino
Keyword(s):  
Optimal Control ◽  
Control Strategies ◽  
Optimal Solution ◽  
Optimal Level ◽  
Initial Time ◽  
Local Health ◽  
Control Input ◽  
Social Distancing ◽  
Time Period ◽  
The Impact

Optimizing the impact on the economy of control strategies aiming at containing the spread of COVID-19 is a critical challenge. We use daily new case counts of COVID-19 patients reported by local health administrations from different Metropolitan Statistical Areas (MSAs) within the US to parametrize a simple model that well describes the propagation of the disease in each area. We then introduce a time-varying control input that represents the level of social distancing imposed on the population of a given area and solve an optimal control problem with the goal of minimizing the impact of social distancing on the economy in the presence of relevant constraints, such as a desired level of suppression for the epidemics at a terminal time. We find that with the exception of the initial time and of the final time, the optimal control input is well approximated by a constant variable which is specific to each area. For all the areas considered, this optimal level corresponds to stricter social distancing than the `current' level estimated from data. Proper selection of the time period for application of the control action optimally is important: depending on the particular MSA this period should be either short or long or intermediate. Finally, we see that small deviations from the optimal solution can lead to dramatic violations of the constraints.

scholarly journals Proactive social distancing mitigates COVID-19 outbreaks within a month across 58 mainland China cities

2020 ◽  
Author(s):  
Zhanwei Du ◽  
Xiaoke Xu ◽  
Lin Wang ◽  
Spencer J. Fox ◽  
Benjamin J. Cowling ◽  
...  
Keyword(s):  
Reproduction Number ◽  
Mainland China ◽  
Chinese Cities ◽  
Social Distancing ◽  
Time Period ◽  
Community Transmission

AbstractIn early 2020, cities across China enacted strict social distancing measures to contain emerging coronavirus (COVID-19) outbreaks. We estimated the speed with which these measures contained community transmission in each of 58 Chinese cities. On average, containment was achieved 7.83 days (SD 6.79 days) after the implementation of social distancing interventions, with an average reduction in the reproduction number (Rt) of 54.3% (SD 17.6%) over that time period. A single day delay in the implementation of social distancing led to a 2.41 (95% CI: 0.97, 3.86) day delay in containment. Swift social distancing interventions may thus achieve rapid containment of newly emerging COVID-19 outbreaks.

The Tempo and mode(S) of Prebiotic Evolution

1997 ◽  
Vol 161 ◽  
pp. 419-429 ◽  
Author(s):  
Antonio Lazcano
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Biological Evolution ◽  
Current Evidence ◽  
Early Diversification ◽  
Time Period ◽  
The Galaxy ◽  
History Of ◽  
Widespread Phenomenon ◽  
The Origin Of Life

AbstractDifferent current ideas on the origin of life are critically examined. Comparison of the now fashionable FeS/H2S pyrite-based autotrophic theory of the origin of life with the heterotrophic viewpoint suggest that the later is still the most fertile explanation for the emergence of life. However, the theory of chemical evolution and heterotrophic origins of life requires major updating, which should include the abandonment of the idea that the appearance of life was a slow process involving billions of years. Stability of organic compounds and the genetics of bacteria suggest that the origin and early diversification of life took place in a time period of the order of 10 million years. Current evidence suggest that the abiotic synthesis of organic compounds may be a widespread phenomenon in the Galaxy and may have a deterministic nature. However, the history of the biosphere does not exhibits any obvious trend towards greater complexity or «higher» forms of life. Therefore, the role of contingency in biological evolution should not be understimated in the discussions of the possibilities of life in the Universe.

Alteration of Mitochondria in Oxythiamine-Induced, Acute Thiamine Deficiency in the Mouse

1976 ◽  
Vol 34 ◽  
pp. 284-285
Author(s):  
Itaru Watanabe ◽  
Dante G. Scarpelli
Keyword(s):  
Electron Microscopy ◽  
Adult Male ◽  
Thiamine Deficiency ◽  
Light And Electron Microscopy ◽  
Fatty Change ◽  
Deficient Diet ◽  
Subcutaneous Injections ◽  
Swiss Mice ◽  
Time Period ◽  
Ad Libitum

Acute thiamine deficiency was produced in mice by the administration of oxythiamine, a thiamine analogue, superimposed upon a thiamine deficient diet. Adult male Swiss mice (30 gm. B.W.) were fed with a thiamine deficient diet ad libitumand were injected with oxythiamine (170 mg/Kg B.W.) subcutaneously on days 4 and 10. On day 11, severe lassitude and anorexia developed, followed by death within 48 hours. The animals treated daily with subcutaneous injections of thiamine (300 μg/Kg B.W.) from day 11 through 15 were kept alive. Similarly, feeding with a diet containing thiamine (600 μg/Kg B.W./day) from day 9 through 17 reversed the condition. During this time period, no fatal illness occurred in the controls which were pair-fed with a thiamine deficient diet.The oxythiamine-treated mice showed a significant enlargement of the liver, which weighed approximately 1.5 times as much as that of the pair-fed controls. By light and electron microscopy, the hepatocytes were markedly swollen due to severe fatty change and swelling of the mitochondria.

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