scholarly journals Modelling Heterogeneity and Super Spreaders of the COVID-19 Spread through Malaysian Networks

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1954
Author(s):  
Fatimah Abdul Razak ◽  
Zamira Hasanah Zamzuri
Keyword(s):  
Compartmental Model ◽  
Initial Conditions ◽  
Realistic Model ◽  
Infected Person ◽  
Epidemic Spread ◽  
Sense Of Security ◽  
False Sense ◽  
Underlying Network ◽  
Population Interactions ◽  
Definition Of

Malaysia is multi-ethnic and diverse country. Heterogeneity, in terms of population interactions, is ingrained in the foundation of the country. Malaysian policies and social distancing measures are based on daily infections and R0 (average number of infections per infected person), estimated from the data. Models of the Malaysian COVID-19 spread are mostly based on the established SIR compartmental model and its variants. These models usually assume homogeneity and symmetrical full mixing in the population; thus, they are unable to capture super-spreading events which naturally occur due to heterogeneity. Moreover, studies have shown that when heterogeneity is present, R0 may be very different and even possibly misleading. The underlying spreading network is a crucial element, as it introduces heterogeneity for a more representative and realistic model of the spread through specific populations. Heterogeneity introduces more complexities in the modelling due to its asymmetrical nature of infection compared to the relatively symmetrical SIR compartmental model. This leads to a different way of calculating R0 and defining super-spreaders. Quantifying a super-spreader individual is related to the idea of importance in a network. The definition of a super-spreading individual depends on how super-spreading is defined. Even when the spreading is defined, it may not be clear that a single centrality always correlates with super-spreading, since centralities are network dependent. We proposed using a measure of super-spreading directly related to R0 and that will give a measure of ‘spreading’ regardless of the underlying network. We captured the vulnerability for varying degrees of heterogeneity and initial conditions by defining a measure to quantify the chances of epidemic spread in the simulations. We simulated the SIR spread on a real Malaysian network to illustrate the effects of this measure and heterogeneity on the number of infections. We also simulated super-spreading events (based on our definition) within the bounds of heterogeneity to demonstrate the effectiveness of the newly defined measure. We found that heterogeneity serves as a natural curve-flattening mechanism; therefore, the number of infections and R0 may be lower than expected. This may lead to a false sense of security, especially since heterogeneity makes the population vulnerable to super-spreading events.

Love, Inc.

2019 ◽  
Author(s):  
Laurie Essig
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Structural Changes ◽  
Global Climate ◽  
Dating Apps ◽  
Sense Of Security ◽  
True Love ◽  
The Future ◽  
False Sense ◽  
Global Movements

In Love, Inc., Laurie Essig argues that love is not all we need. As the future became less secure—with global climate change and the transfer of wealth to the few—Americans became more romantic. Romance is not just what lovers do but also what lovers learn through ideology. As an ideology, romance allowed us to privatize our futures, to imagine ourselves as safe and secure tomorrow if only we could find our "one true love" today. But the fairy dust of romance blinded us to what we really need: global movements and structural changes. By traveling through dating apps and spectacular engagements, white weddings and Disney honeymoons, Essig shows us how romance was sold to us and why we bought it. Love, Inc. seduced so many of us into a false sense of security, but it also, paradoxically, gives us hope in hopeless times. This book explores the struggle between our inner cynics and our inner romantic.

scholarly journals Is a reduction in viability enough to determine biofilm susceptibility to a biocide?

2021 ◽  
pp. 1-7
Author(s):  
Katarzyna Ledwoch ◽  
Maddalena Magoga ◽  
Dulcie Williams ◽  
Stefania Fabbri ◽  
James Walsh ◽  
...  
Keyword(s):  
Mechanical Action ◽  
Atmospheric Plasma ◽  
Sense Of Security ◽  
Biocidal Products ◽  
False Sense ◽  
Sodium Dichloroisocyanurate ◽  
430 Stainless Steel ◽  
Cross Transmission ◽  
Product Test ◽  
Cleaning And Disinfection

Abstract Objective: The abundance and prevalence of dry-surface biofilms (DSBs) in hospitals constitute an emerging problem, yet studies rarely report the cleaning and disinfection efficacy against DSBs. Here, the combined impact of treatments on viability, transferability, and recovery of bacteria from DSBs has been investigated for the first time. Methods: Staphylococcus aureus DSBs were produced in alternating 48-hour wet–dry cycles for 12 days on AISI 430 stainless steel discs. The efficacy of 11 commercially available disinfectants, 4 detergents, and 2 contactless interventions were tested using a modified standardized product test. Reduction in viability, direct transferability, cross transmission (via glove intermediate), and DSB recovery after treatment were measured. Results: Of 11 disinfectants, 9 were effective in killing and removing bacteria from S. aureus DSBs with >4 log10 reduction. Only 2 disinfectants, sodium dichloroisocyanurate 1,000 ppm and peracetic acid 3,500 ppm, were able to lower both direct and cross transmission of bacteria (<2 compression contacts positive for bacterial growth). Of 11 disinfectants, 8 could not prevent DSB recovery for >2 days. Treatments not involving mechanical action (vaporized hydrogen peroxide and cold atmospheric plasma) were ineffective, producing <1 log10 reduction in viability, DSB regrowth within 1 day, and 100% transferability of DSB after treatment. Conclusions: Reduction in bacterial viability alone does not determine product performance against biofilm and might give a false sense of security to consumers, manufacturers and regulators. The ability to prevent bacterial transfer and biofilm recovery after treatment requires a better understanding of the effectiveness of biocidal products.

scholarly journals On Lagrangian and vortex-surface fields for flows with Taylor–Green and Kida–Pelz initial conditions

2010 ◽  
Vol 661 ◽  
pp. 446-481 ◽  
Author(s):  
YUE YANG ◽  
D. I. PULLIN
Keyword(s):  
Incompressible Flows ◽  
Initial Conditions ◽  
Scalar Fields ◽  
Local Geometry ◽  
Optimization Approach ◽  
Vortex Reconnection ◽  
Barotropic Flow ◽  
Lagrangian Surfaces ◽  
Definition Of ◽  
Surface Fields

For a strictly inviscid barotropic flow with conservative body forces, the Helmholtz vorticity theorem shows that material or Lagrangian surfaces which are vortex surfaces at time t = 0 remain so for t > 0. In this study, a systematic methodology is developed for constructing smooth scalar fields φ(x, y, z, t = 0) for Taylor–Green and Kida–Pelz velocity fields, which, at t = 0, satisfy ω·∇φ = 0. We refer to such fields as vortex-surface fields. Then, for some constant C, iso-surfaces φ = C define vortex surfaces. It is shown that, given the vorticity, our definition of a vortex-surface field admits non-uniqueness, and this is presently resolved numerically using an optimization approach. Additionally, relations between vortex-surface fields and the classical Clebsch representation are discussed for flows with zero helicity. Equations describing the evolution of vortex-surface fields are then obtained for both inviscid and viscous incompressible flows. Both uniqueness and the distinction separating the evolution of vortex-surface fields and Lagrangian fields are discussed. By tracking φ as a Lagrangian field in slightly viscous flows, we show that the well-defined evolution of Lagrangian surfaces that are initially vortex surfaces can be a good approximation to vortex surfaces at later times prior to vortex reconnection. In the evolution of such Lagrangian fields, we observe that initially blob-like vortex surfaces are progressively stretched to sheet-like shapes so that neighbouring portions approach each other, with subsequent rolling up of structures near the interface, which reveals more information on dynamics than the iso-surfaces of vorticity magnitude. The non-local geometry in the evolution is quantified by two differential geometry properties. Rolled-up local shapes are found in the Lagrangian structures that were initially vortex surfaces close to the time of vortex reconnection. It is hypothesized that this is related to the formation of the very high vorticity regions.

scholarly journals A false sense of security

2008 ◽  
Vol 183 (7) ◽  
pp. 1317-1317
Author(s):  
Mike Rossner
Keyword(s):  
Sense Of Security ◽  
False Sense

Opening forces or failure of commercially available equine headcollars and other safety devices

2021 ◽  
pp. 175433712110396
Author(s):  
David J Marlin ◽  
Kirstie Pickles ◽  
Roberta Ferro de Godoy ◽  
Jane M Williams
Keyword(s):  
Safety Devices ◽  
Risk Of Injury ◽  
Sense Of Security ◽  
Increased Risk ◽  
Custom Made ◽  
False Sense ◽  
Breaking Points ◽  
Horse Owners ◽  
Very High ◽  
Increasing Load

A recent survey by the authors of the present study indicated that headcollar (halter, USA) related incidents resulting in horse injuries may be common. From the survey, 134 incidents involving horse fractures and 167 fatalities were reported. Headcollar design and materials vary markedly from traditional leather to “safety” headcollars and safety devices. Despite their almost universal use, there has been minimal study as to how these items function or specifications for performance. The aim of the present study was to select a range of commercially available standard headcollars and a number of safety devices, to test the force required to break or release them. Safety devices selected included baler twine, which is widely used by equestrians to attach a horse by a headcollar to a lead rope and in turn to a fixture. This system practice is perceived to increase safety. Devices were subjected to increasing load in the poll to lead-rope attachment axis (i.e. to simulate a horse pulling backward) using a custom-made steel rig incorporating an electric 1000 kg winch. The force was increased incrementally until either the headcollar or device opened or failed. The lowest mean opening force of 357 ± 50 N was for a safety headcollar, which is equivalent to a load of approximately 36 kg. The highest breaking force was 5798 ± 265 N for one of the eight different webbing headcollars tested. Breaking for safety devices ranged from 354 ± 121 N for “fine” baler twine to 1348 ± 307 N for a “heavy duty” baler twine. Variability in opening force was lowest in two of the webbing headcollars (CV < 5%) despite these having very high breaking points (>3500 N). The greatest variability was found for fine baler twine (CV = 34%) and one of the commercial safety devices (CV = 38%). The range of opening forces and variability in opening forces for standard headcollars, safety headcollars and safety devices is a cause for concern and may give horse owners/handlers a false sense of security with regards to safety, and actually predispose horses and handlers to an increased risk of injury.

Can regular blood counts help to prevent drug-induced blood dyscrasias?

1974 ◽  
Vol 12 (18) ◽  
pp. 69-72
Keyword(s):  
Sore Throat ◽  
Cytotoxic Drugs ◽  
Rational Approach ◽  
Drug Induced ◽  
Recent Advances ◽  
Sense Of Security ◽  
False Sense

The practice of performing regular blood counts during therapy with drugs known to cause dyscrasias has varied over the years. For a time they were thought essential during treatment with drugs like thiouracil and phenylbutazone, but they were abandoned when it was realised that blood changes can develop so quickly that a normal count might give only a false sense of security. It seemed better to take a preliminary count to exclude prior abnormality and to warn patients to stop the drug and report at once if they developed symptoms such as sore throat or mouth ulceration, so that a count could be done and the treatment changed if necessary. However, this approach is not satisfactory when either gold or cytotoxic drugs are used because potentially fatal irreversible aplasia may occur before symptoms are noticed. Recent advances in knowledge of the mechanisms of drug-induced blood dyscrasias1 allow a more rational approach to their detection and avoidance. These dyscrasias may be divided into five types.

scholarly journals Continuous assessment and matriculation examination marks – An empirical examination

2015 ◽  
Vol 5 (2) ◽  
pp. 17 ◽  
Author(s):  
Servaas Van der Berg ◽  
Debra Shepherd
Keyword(s):  
South African ◽  
Career Planning ◽  
National Curriculum ◽  
Continuous Assessment ◽  
Empirical Examination ◽  
Sense Of Security ◽  
False Sense ◽  
Matriculation Examination ◽  
School Careers ◽  
Examination Preparation

<p>This study analyses information and feedback from matriculation level continuous assessment in the South African education system. Continuous assessment (CASS) at the time carried a 25% weight in the final matriculation (Grade 12) mark, and it provides feedback that affects examination preparation and effort. Weak assessment in schools sends wrong signals to students that may have important consequences for the way they approach the final examination. Moreover, similarly wrong signals earlier in their school careers may also have affected their subject choice and career planning.<br />This study compares CASS data to the externally assessed matric exam marks for a number of subjects. There are two signalling dimensions to inaccurate assessments: (i) Inflated CASS marks can give students a false sense of security and lead to diminished exam effort. (ii) A weak correlation between CASS and the exam marks could mean poor signalling in another dimension: Relatively good students may get relatively low CASS marks. Such low correlations indicate poor assessment reliability, as the examination and continuous assessment should both be testing mastery of the same national curriculum. The paper analyses the extent of each of these dimensions of weak signalling in South African schools and draws disturbing conclusions for a large part of the school system.</p>

scholarly journals Performance Comparison of SSH Libraries

2021 ◽  
Vol 23 (06) ◽  
pp. 868-873
Author(s):  
Sonali Karki ◽  
◽  
Dr. Kiran V ◽  
Keyword(s):  
Community Development ◽  
Performance Comparison ◽  
Digital Transformation ◽  
Third Party ◽  
Security Measures ◽  
Privileged Access ◽  
Sense Of Security ◽  
False Sense ◽  
Pros And Cons ◽  
Python Package

The business industry is evolving. Enterprises have begun a digital transformation path, adopting innovative technologies that enable them to move quickly and change how they cooperate, lowering costs and improving productivity. However, as a result of these technologies, the conventional perimeter has evaporated, and identification has become the new line of defense. New security concerns necessitate modern security measures. Passwords are no longer appropriate for authenticating privileged access to mission-critical assets. Passwords are notorious for being insecure, causing weariness, and giving the user a false sense of security. Enterprises must use password-less solutions, which is where SSH key-based authentication comes in. The Python language’s numerous applications are the consequence of a mixture of traits that offer this language advantage over others. Some of the advantages of programming with Python are as follows: To enable easy communication between Python and other systems, Python Package Index (PyPI) is used. The package consists of a variety of modules developed by third-party developers. It also has the benefit of being an Open Source and Community Development language, as well as having substantial Support Libraries. There are multiple SSH libraries in python and this paper focuses on each of their pros and cons as well as the time it has taken for each of them to perform.

Sign in / Sign up

Export Citation Format

Share Document