An Online Calculator to Better Understand the Impact of False-Negative COVID-19 Polymerase Chain Reaction Test Results in the Context of Anesthesia Providers

What does the COVID-19 false-negative exposure problem mean in the context of a local anesthesia practice? We present a customizable online calculator designed to quantify and better understand individual and aggregate provider exposure risk.

An Online Calculator to Better Understand the Impact of False-Negative COVID-19 Polymerase Chain Reaction Test Results in the Context of Anesthesia Providers (Preprint)

UNSTRUCTURED What does the COVID-19 false-negative exposure problem mean in the context of a local anesthesia practice? We present a customizable online calculator designed to quantify and better understand individual and aggregate provider exposure risk.

Noise Exposure Monitoring on the Segmental Box Girder Casting Process from a Concrete Casting Yard

Noise exposure monitoring is essential to assess noise exposure circumstances and provide a noise control plan to minimize noise exposure problems in the workplace. In Malaysia, occupational noise exposure problems have been increasing, especially in the construction industry. Hence, this study aims to investigate the noise exposure problem in a construction casting yard in Malaysia. The objectives of the study were to measure the current occupational noise exposure problem and to propose a noise control action. Field measurement was carried out at a segmented box girder casting yard under the Mass Rapid Transit (MRT) construction project in Selangor, Malaysia. A total of six case studies from four different construction trades had been conducted. This study plotted noise maps and measured personal noise exposure levels for the three construction trades. The results showed that the equivalent sound level exceeded the action level of 85 dBA for these trades. Besides, the bar cutting trade with an 8-hour time-weighted average of 92.3 dBA exceeded the permissible exposure limit of 90 dBA. The noise reduction rating of the hearing protection device was evaluated, and appropriate noise control action was proposed. The proposed noise reduction rating was 32 dBA, so it is expected to reduce the time-weighted average sound level below 80 dBA for this workplace. In conclusion, the results could disseminate to construction workers to raise their risk awareness regarding the noise exposure issue in the workplace. The noise mapping information could also be used for the design of the engineering control to reduce the noise exposure level in the construction workplace.

The Exposure Problem and Market Design

Markets have an exposure problem when getting to the optimal allocation requires a sequence of transactions which if started but not completed leaves at least one trader with losses. We use laboratory experiments to evaluate the effect of the exposure problem on alternative market mechanisms. The continuous double auction performs poorly: efficiency is only 20% when exposure is high and 55% when it is low. A package market effectively eliminates the exposure problem: in low and high-exposure treatments efficiency is 82% and 89%, respectively. Building on stability notions from matching theory we introduce the concept of mechanism stability. A model of trade that combines mechanism stability with noisy best responses and imperfect foresight explains the difference in market performance. Finally, decentralized bargaining with contingent contracts performs well with perfect information and communication but not in the more realistic case when traders’ preferences are privately known.

FL-TOHIP (Fractional Lion Algorithm to Topology-Hiding Multipath Routing Protocol) in Mobile ad hoc Network

Due to the dynamic nature of the mobile ad hoc network (MANET), all the nodes are mobile and generously connected to other nodes without the use of any fixed communications. Because of the random movement of nodes, the network topology is not predicted easily. Therefore, routing is one of the major challenging tasks in MANET. Significantly, the topology-hiding multipath routing protocol (TOHIP) is used to eliminate the topological exposure problem by transmitting the information through disjoint paths from the source to the destination. To select the optimal routing path, we have proposed the fractional lion algorithm to TOHIP (FL-TOHIP). Initially, the routing path is designed in MANET based on the existing TOHIP, which generates the number of disjoint routing paths. Then, the optimal path selection is done by the proposed fractional lion algorithm. To improve the solution searching, the fractional lion algorithm is adapted to the mathematical theory called fractional calculus. Finally, the performance of the proposed protocol is compared to the existing protocol using the delay, energy, and cost.

Inventory of Obsolete Pesticide Warehouses in Tajikistan and Implications for Removal of Contaminated Soil

Background. Tajikistan is an agrarian-industrial republic. A large portion of the Tajikistan economy relies on agriculture. With the rise of agriculture, especially cotton production, came the widespread use of pesticides. Abandoned and unsupervised pesticide storage warehouses have become a health and environmental problem. In many cases such sites, as well as significant areas of pesticide-contaminated land, remain accessible to the public. A survey and analysis of 26 former pesticide storage warehouse sites across Tajikistan revealed a country-wide pesticide exposure problem that threatens the health of vulnerable populations. Infrastructure and local governance issues are barriers to addressing this health crisis for rural residents. Objectives. The purpose of this article is to describe the issues surrounding former pesticide storage warehouses and their effect on the health of the population of Tajikistan. Materials and Methods. In 2012, the non-governmental organization (NGO), Pure Earth (formerly Blacksmith Institute), with the financial support of the Food and Agriculture Organization of the United Nations (FAO), Green Cross Switzerland and the European Union conducted surveys of 26 pesticide warehouses located throughout Tajikistan. The survey included detailed site assessments, including analysis of the maintenance of chemicals and soil testing. Results. Soil samples taken from the studied sites exceeded maximum permissible concentrations referenced by Pure Earth by several hundred times for dichlorodiphenyl-trichloroethane (DDT) and hexachlorocyclohexane (HCH), as well as aldrin and dieldrin. Even the most polluted sites had families living on the premises. Conclusions. Pesticide contamination in Tajikistan is a serious and ongoing problem that requires the attention of local, state governments, and international non-governmental organizations. We recommend the development of a government-sponsored public education campaign to inform the population about the potential risks of exposure to obsolete pesticides. The dangers of agricultural use, former storage warehouses and disposal areas should be addressed. In addition, data from the 2012 surveys of 26 warehouses should be used to prioritize the four high-risk sites and develop preliminary clean-up plans for contaminated soil around warehouses to present to government ministries and NGOs. Competing Interests. The authors declare no competing financial interests