scholarly journals Limonene Emissions: Do Different Types Have Different Biological Effects?

2021 ◽  
Vol 18 (19) ◽  
pp. 10505
Author(s):  
Neda Nematollahi ◽  
Perran A. Ross ◽  
Ary A. Hoffmann ◽  
Spas D. Kolev ◽  
Anne Steinemann
Keyword(s):  
Air Quality ◽  
Aedes Aegypti ◽  
Biological Effects ◽  
Consumer Products ◽  
Photochemical Smog ◽  
Different Types ◽  
Fragrance Compound ◽  
Fragranced Consumer Products ◽  
Different Sources ◽  
Olfactory Abilities

Limonene is one of the most abundant pollutants indoors, and it contributes to the formation of additional pollutants, such as formaldehyde and photochemical smog. Limonene is commonly used in fragranced consumer products, such as cleaning supplies and air fresheners, which have also been associated with health problems. Limonene can exist in different enantiomeric forms (R-limonene and S-limonene) and be derived from different sources. However, little is known about whether different forms and sources of limonene may have different effects. This research explored whether different types of limonene, at the same concentrations, could elicit different biological effects. To investigate this question, the study employed Aedes aegypti mosquitoes, which have sophisticated olfactory abilities, in olfactometer tests of repellency/attraction. The results indicate that a synthetic source of R-limonene is more repellent than a natural source of R-limonene. In addition, synthetic sources of both R-limonene and S-limonene are not significantly different in repellency. These findings can contribute to our understanding and further exploration of the effects of a common fragrance compound on air quality and health.

scholarly journals Differential toxicological effects of natural and synthetic sources and enantiomeric forms of limonene on mosquito larvae

2021 ◽  
Author(s):  
Perran A. Ross ◽  
Neda Nematollahi ◽  
Anne Steinemann ◽  
Spas D. Kolev ◽  
Ary A. Hoffmann
Keyword(s):  
Human Health ◽  
Biological Effects ◽  
Consumer Products ◽  
Mosquito Larvae ◽  
Chiral Compounds ◽  
Toxicological Effects ◽  
Naturally Occurring ◽  
Different Types ◽  
Human Health Effects ◽  
Different Sources

Abstract Common fragranced consumer products, such as cleaning supplies and personal care products, emit chiral compounds such as limonene that have been associated with adverse effects on human health. However, those same compounds abound in nature, and at similar concentrations as in products, but without the same apparent adverse human health effects. We investigated whether different types of limonene may elicit different biological effects. In this study, we investigated the mortality rate of mosquito larvae in response to changes in their environment. Specifically, we tested different sources of naturally occurring R-limonene and chemically synthetized limonene, containing one of its enantiomeric forms (R-, S-) in mortality bioassays with Aedes aegypti mosquito larvae. We found that a natural source of limonene extracted from oranges induced lower mortality of mosquito larvae compared to synthetic sources at the same concentration. However, enantiomeric forms did not differ in their effects on mortality. Our results provide novel evidence that natural sources of a chemical can cause lower rates of mortality than synthetic sources.

A Review on Various Methodologies for AC Duct Cleaning

2020 ◽  
Vol 07 (3&4) ◽  
pp. 1-5
Author(s):  
Soyab A Jamadar ◽  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Health Issues ◽  
Conventional System ◽  
Rectangular Shape ◽  
Inspection Robot ◽  
Different Types ◽  
Robot Systems ◽  
Articulated Robot

Cleaning of the AC ducts is the need because it creates problems such as the bad indoor air quality which results in health issues and it also causes the large maintenance of the system. The uncleaned air ducts become home for fungi, dust and harmful microbial. The causes and effects of this thing are mentioned following. The AC ducts can be cleaned through various methodologies i.e. conventional and by using robots. In the conventional system, there is manual cleaning by using some equipment. Cleaning the ducts by using robots would be a good solution for this. Different types of robot systems i.e. crawling robot, articulated robot and inspection robot are deployed for the application. There are different types of robots and their equipment according to size and type of duct. The cleaning of rectangular shape ducts is quite difficult than others. Finally, it results that cleaning ducts is the most important thing and using robots is the best methodology for it.

scholarly journals The fragranced products phenomenon: air quality and health, science and policy

2020 ◽  
Author(s):  
Anne Steinemann
Keyword(s):  
Air Quality ◽  
Human Health ◽  
Consumer Products ◽  
Health Science ◽  
Future Research ◽  
Research Directions ◽  
Science And Policy ◽  
New Findings ◽  
Future Research Directions ◽  
Indoor And Outdoor

Abstract Fragrance is used in consumer products around the world. However, fragrance has been associated with adverse effects on indoor and outdoor air quality and human health. Questions arise, such as the following: Why does fragrance in products pose problems? What are sources of emissions and exposures? What are health and societal effects? What are possible solutions? This paper examines the issue of fragranced consumer products and its science and policy dimensions, with a focus on the implications for air quality and human health. Results include new findings and new questions for future research directions.

scholarly journals How to measure uncertainty in uncertainty sampling for active learning

2021 ◽  
Author(s):  
Vu-Linh Nguyen ◽  
Mohammad Hossein Shaker ◽  
Eyke Hüllermeier
Keyword(s):  
Machine Learning ◽  
Active Learning ◽  
Sampling Strategies ◽  
Total Uncertainty ◽  
Uncertainty Sampling ◽  
Different Types ◽  
Alternative Approaches ◽  
Active Learner ◽  
Probabilistic Nature ◽  
Different Sources

AbstractVarious strategies for active learning have been proposed in the machine learning literature. In uncertainty sampling, which is among the most popular approaches, the active learner sequentially queries the label of those instances for which its current prediction is maximally uncertain. The predictions as well as the measures used to quantify the degree of uncertainty, such as entropy, are traditionally of a probabilistic nature. Yet, alternative approaches to capturing uncertainty in machine learning, alongside with corresponding uncertainty measures, have been proposed in recent years. In particular, some of these measures seek to distinguish different sources and to separate different types of uncertainty, such as the reducible (epistemic) and the irreducible (aleatoric) part of the total uncertainty in a prediction. The goal of this paper is to elaborate on the usefulness of such measures for uncertainty sampling, and to compare their performance in active learning. To this end, we instantiate uncertainty sampling with different measures, analyze the properties of the sampling strategies thus obtained, and compare them in an experimental study.

scholarly journals Model-Based Probabilistic Inversion Using Magnetic Data: A Case Study on the Kevitsa Deposit

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 150
Author(s):  
Nilgün Güdük ◽  
Miguel de la Varga ◽  
Janne Kaukolinna ◽  
Florian Wellmann
Keyword(s):  
Structural Parameters ◽  
Rock Properties ◽  
Magnetic Data ◽  
Geological Model ◽  
Borehole Data ◽  
Likelihood Functions ◽  
Different Types ◽  
Geophysical Information ◽  
Different Sources

Structural geological models are widely used to represent relevant geological interfaces and property distributions in the subsurface. Considering the inherent uncertainty of these models, the non-uniqueness of geophysical inverse problems, and the growing availability of data, there is a need for methods that integrate different types of data consistently and consider the uncertainties quantitatively. Probabilistic inference provides a suitable tool for this purpose. Using a Bayesian framework, geological modeling can be considered as an integral part of the inversion and thereby naturally constrain geophysical inversion procedures. This integration prevents geologically unrealistic results and provides the opportunity to include geological and geophysical information in the inversion. This information can be from different sources and is added to the framework through likelihood functions. We applied this methodology to the structurally complex Kevitsa deposit in Finland. We started with an interpretation-based 3D geological model and defined the uncertainties in our geological model through probability density functions. Airborne magnetic data and geological interpretations of borehole data were used to define geophysical and geological likelihoods, respectively. The geophysical data were linked to the uncertain structural parameters through the rock properties. The result of the inverse problem was an ensemble of realized models. These structural models and their uncertainties are visualized using information entropy, which allows for quantitative analysis. Our results show that with our methodology, we can use well-defined likelihood functions to add meaningful information to our initial model without requiring a computationally-heavy full grid inversion, discrepancies between model and data are spotted more easily, and the complementary strength of different types of data can be integrated into one framework.

The Behavioral Consequences of Conflict Exposure on Risk Preferences

2021 ◽  
Author(s):  
Enrique Fatas ◽  
Nathaly Jiménez ◽  
Lina Restrepo-Plaza ◽  
Gustavo Rincón
Keyword(s):  
Substantial Effect ◽  
Risk Attitudes ◽  
Behavioral Consequences ◽  
Criminal Violence ◽  
Incentive Compatible ◽  
Attitudinal Factors ◽  
Different Types ◽  
Close Relatives ◽  
Different Sources ◽  
Consequences Of Violence

Violent conflict is a polyhedric phenomenon. Beyond the destruction of physical and human capital and the economic, political, and social costs war generates, there is an additional burden carried by victims: persistent changes in the way they make decisions. Exposure to violence generates changes in how individuals perceive other individuals from their group and other groups, how they discount the future, and how they assess and tolerate risk. The behavioral consequences of violence exposure can be documented using experiments in which participants make decisions in a controlled, incentive-compatible scenario. The external validity of experiments is reinforced when the studies are run in postconflict scenarios, for example, in Colombia, with real victims of conflict. The experimental tasks, therefore, may map risk attitudes among victims and nonvictims of the conflict who share a common background, and distinguish between different types of exposure (direct versus indirect) and different sources of violence (conflict-related versus criminal violence). The experimental evidence collected in Colombia is consistent with a long-lasting and substantial effect of conflict exposure on risk attitudes. Victims are more likely to take risks and less likely to make safe choices than nonvictims, controlling for demographic, socioeconomic, and attitudinal factors. The effect is significant only when the source of violence is conflict (exerted by guerrilla or paramilitary militias) and when violence is experienced directly by individuals. Indirect conflict exposure (suffered by close relatives) and criminal violence leave no significant mark on participants’ risk attitudes in the study.

A Review on Green Synthesis and Applications of Iron Oxide Nanoparticles

2021 ◽  
Vol 21 (12) ◽  
pp. 5812-5834
Author(s):  
Rachana Yadwade ◽  
Saili Kirtiwar ◽  
Balaprasad Ankamwar
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Aqueous System ◽  
Oxide Nanoparticles ◽  
Plant Parts ◽  
Different Types ◽  
Removal Of Heavy Metals ◽  
Biological Sources ◽  
Different Sources

Bio-fabrication of iron oxide nanoparticles by using different sources of plants, plant parts and microbial cells have become a great topic of interest nowadays due to its eco-friendly nature. The stabilizing and capping agents in biological sources are biocompatible, stable and non-toxic which make its use beneficial for various biomedical applications. The bacteria are able to utilize metal ions and convert them into their respective nanoparticles by secreting different biomolecules. The plants and plant parts contain different types of phytochemicals which play a key role in synthesis and bio-fabrication of nanoparticles. Iron oxide nanoparticles are known to have various applications in the fields of medicine, environment etc. This review summarizes the applications of iron oxide nanoparticles as antimicrobial agent, drug delivery agent, material for removal of heavy metals and dyes from aqueous system etc. Due to these wide applications of iron oxide nanoparticles its demand in various fields is increasing considerably. This review describes different approaches which are used for biosynthesis of iron oxide nanoparticles and their applications. The review also summarizes about the surface modification strategies of iron oxide nanoparticles by using different polymers, polyelectrolytes which can be used for in-vivo applications.

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