At a close distance: Dropouts, teachers, and joking relationships

2015 ◽  
Vol 3 (2) ◽  
pp. 280-308 ◽  
Author(s):  
Anna Lund
Keyword(s):  
Joking Relationships ◽  
Close Distance

scholarly journals Survey of Saliva Components and Virus Sensors for Prevention of COVID-19 and Infectious Diseases

Biosensors ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 14
Author(s):  
Priya Dave ◽  
Roberto Rojas-Cessa ◽  
Ziqian Dong ◽  
Vatcharapan Umpaichitra
Keyword(s):  
Infectious Diseases ◽  
Dental Health ◽  
The United States ◽  
Human Saliva ◽  
Field Application ◽  
Future Research ◽  
Prevention Measures ◽  
Control And Prevention ◽  
Close Distance

The United States Centers for Disease Control and Prevention considers saliva contact the lead transmission mean of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes the coronavirus disease 2019 (COVID-19). Saliva droplets or aerosols expelled by sneezing, coughing, breathing, and talking may carry this virus. People in close distance may be exposed directly to these droplets or indirectly when touching the droplets that fall on surrounding surfaces and ending up contracting COVID-19 after touching the mucosa tissue of their faces. It is of great interest to quickly and effectively detect the presence of SARS-CoV-2 in an environment, but the existing methods only work in laboratory settings, to the best of our knowledge. However, it may be possible to detect the presence of saliva in the environment and proceed with prevention measures. However, detecting saliva itself has not been documented in the literature. On the other hand, many sensors that detect different organic components in saliva to monitor a person’s health and diagnose different diseases, ranging from diabetes to dental health, have been proposed and they may be used to detect the presence of saliva. This paper surveys sensors that detect organic and inorganic components of human saliva. Humidity sensors are also considered in the detection of saliva because a large portion of saliva is water. Moreover, sensors that detect infectious viruses are also included as they may also be embedded into saliva sensors for a confirmation of the presence of the virus. A classification of sensors by their working principles and the substances they detect is presented, including the sensors’ specifications, sample size, and sensitivity. Indications of which sensors are portable and suitable for field application are presented. This paper also discusses future research and challenges that must be resolved to realize practical saliva sensors. Such sensors may help minimize the spread of not only COVID-19 but also other infectious diseases.

scholarly journals Call them COVIDiots: Exploring the effects of aggressive communication style and psychological distance in the communication of COVID-19

2021 ◽  
pp. 096366252198919
Author(s):  
Haoran Chu ◽  
Shupei Yuan ◽  
Sixiao Liu
Keyword(s):  
Social Norm ◽  
Distance Perception ◽  
Negative Influence ◽  
Public Understanding ◽  
Communication Style ◽  
Communication Styles ◽  
Positive Outcomes ◽  
The Public ◽  
Aggressive Communication ◽  
Close Distance

This study examined the influences of perceived distance to communicator on the effects of aggressive style (i.e. personal attacks and intense languages) in communicating scientific issues such as COVID-19 to the public. With a multi-site experiment ( N = 464), we found that aggression led to a heightened violation of expected social norm regarding communication styles. However, the interpretation of violation varied depending on the individual’s perceived distance to the communicator. Close distance articulated the urgency and severity of COVID-19 risks conveyed with aggression, which further increased compliance with the message. Far distance perception amplified aggression’s negative influence on writer likeability. The findings showed that aggressive communication may generate positive outcomes when dealing with public understanding of scientific issues such as COVID-19, but communicators need to build a closer connection with their audience.

Predicting the sound power and impact of a wastewater treatment plant

2001 ◽  
Vol 44 (2-3) ◽  
pp. 235-242 ◽  
Author(s):  
B. De heyder ◽  
P. Ockier ◽  
R. Jansen ◽  
R. Huiberts
Keyword(s):  
Wastewater Treatment ◽  
Empirical Model ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Empirical Models ◽  
Sound Power ◽  
Water Line ◽  
Model Derivation ◽  
Close Distance

Several process units at a wastewater treatment plant (WWTP) can produce a significant level of sound and thus induce sound nuisance for nearby residents. The risk for sound nuisance should be considered by making a prognosis of sound impact in an early project phase (planning, design). A prognosis requires information with respect to the sound characteristics of the different process units. This paper reports the development of empirical models for the sound power of relevant process units in the water line at Aquafin WWTPs. The used methodology for model derivation and validation allowed us to minimize the required number of measurements. Besides the methodology, the paper describes in detail the derivation and validation of the empirical model for the splashing water of screw pumps. Also the use of all the derived empirical models to determine the sound impact of a wastewater treatment plant at close distance is illustrated with a case-study.

scholarly journals Two-Stage Pursuit Strategy for Incomplete-Information Impulsive Space Pursuit-Evasion Mission Using Reinforcement Learning

Aerospace ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 299
Author(s):  
Bin Yang ◽  
Pengxuan Liu ◽  
Jinglang Feng ◽  
Shuang Li
Keyword(s):  
Reinforcement Learning ◽  
Incomplete Information ◽  
Trajectory Optimization ◽  
Game Problem ◽  
Gradient Algorithm ◽  
Two Stage ◽  
Pursuit Evasion ◽  
Evasion Game ◽  
Close Distance ◽  
Pursuit Strategy

This paper presents a novel and robust two-stage pursuit strategy for the incomplete-information impulsive space pursuit-evasion missions considering the J2 perturbation. The strategy firstly models the impulsive pursuit-evasion game problem into a far-distance rendezvous stage and a close-distance game stage according to the perception range of the evader. For the far-distance rendezvous stage, it is transformed into a rendezvous trajectory optimization problem and a new objective function is proposed to obtain the pursuit trajectory with the optimal terminal pursuit capability. For the close-distance game stage, a closed-loop pursuit approach is proposed using one of the reinforcement learning algorithms, i.e., the deep deterministic policy gradient algorithm, to solve and update the pursuit trajectory for the incomplete-information impulsive pursuit-evasion missions. The feasibility of this novel strategy and its robustness to different initial states of the pursuer and evader and to the evasion strategies are demonstrated for the sun-synchronous orbit pursuit-evasion game scenarios. The results of the Monte Carlo tests show that the successful pursuit ratio of the proposed method is over 91% for all the given scenarios.

scholarly journals Nanohydroxyapatite Application to Osteoporosis Management

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Zairin Noor
Keyword(s):  
Complex Structure ◽  
Bone Matrix ◽  
Bone Cell ◽  
Osteoporotic Bone ◽  
Chemical Formula ◽  
Duration Of Treatment ◽  
Sodium Calcium ◽  
Hydrogen Carbonate ◽  
Close Distance ◽  
Hydroxyapatite Crystals

Hydroxyapatite is chemically related to the inorganic component of bone matrix as a complex structure with the formula of Ca10(OH)2(PO4)6. Previous studies have reported the application of microsized hydroxyapatite to bone regeneration, but the result is not satisfied. The limitation comes from the size of hydroxyapatite. In addition, the duration of treatment is very long. The advantages of hydroxyapatite nanocrystal are the osteoconduction, bioresorption, and contact in close distance. Crystal in osteoporotic bone is calcium phosphate hydroxide with the chemical formula of Ca10(OH)2(PO4)6. Crystal of normal bone issodium calcium hydrogen carbonate phosphate hydratewith the chemical formula of Ca8H2(PO4)6·H2O–NaHCO3–H2O. The recent development is applying nanobiology approach to hydroxyapatite. This is based on the concept that the mineral atoms arranged in a crystal structure of hydroxyapatite can be substituted or incorporated by the other mineral atoms. In conclusion, the basic elements of hydroxyapatite crystals, composed of atomic minerals in a certain geometric pattern, and their relationship to the bone cell biological activity have opened opportunities for hydroxyapatite crystals supplement application on osteoporosis. Understanding of the characteristics of bone hydroxyapatite crystals as well as the behavior of mineral atom in the substitution will have a better impact on the management of osteoporosis.

Sign in / Sign up

Export Citation Format

Share Document