scholarly journals Detection and perception of generic host volatiles by mosquitoes: responses to CO 2 constrains host-seeking behaviour

2017 ◽  
Vol 4 (5) ◽  
pp. 170189 ◽  
Author(s):  
Shahid Majeed ◽  
Sharon Rose Hill ◽  
Teun Dekker ◽  
Rickard Ignell
Keyword(s):  
Carbon Dioxide ◽  
Dynamic Range ◽  
Detection System ◽  
Host Recognition ◽  
Anopheles Coluzzii ◽  
Coding System ◽  
Host Volatiles ◽  
Host Seeking ◽  
Receptor Neurons ◽  
Carbon Dioxide Detection

Natural selection has favoured specialization in anthropophilic mosquito host choice, yet in the absence of human hosts, females feed on a selected range of vertebrates. For host recognition, we hypothesize that mosquitoes primarily rely on generic host volatiles. Detection and perception of such compounds would provide the mosquito with a flexible, yet constrained, odour coding system that could delineate host preference. In this study, we show that the quintessential generic volatile for host-seeking, carbon dioxide, activates and attracts the malaria mosquito, Anopheles coluzzii , and the arbovirus vectors, Aedes aegypti and Culex quinquefasciatus , within boundaries set by the dynamic range and coding capacity of the CO 2 -sensitive olfactory receptor neurons. These boundaries are sufficiently broad to elicit behavioural responses to various hosts within their preferred host range. This study highlights the significance of the sensitivity of the carbon dioxide detection system and its regulation of host seeking and recognition.

Carbon dioxide detection system based on TDLAS technology

2021 ◽  
Author(s):  
Shoulin Wang ◽  
Zhaowei Wang ◽  
Yanfang Li ◽  
Tingting Zhang ◽  
Weihua Gong ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Detection System ◽  
Carbon Dioxide Detection

scholarly journals Assessing Automated Facial Action Unit Detection Systems for Analyzing Cross-Domain Facial Expression Databases

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4222
Author(s):  
Shushi Namba ◽  
Wataru Sato ◽  
Masaki Osumi ◽  
Koh Shimokawa
Keyword(s):  
Affective Computing ◽  
Detection System ◽  
Characteristic Curve ◽  
Unmet Need ◽  
Systematic Evaluation ◽  
Dynamic Mode ◽  
Coding System ◽  
Static Mode ◽  
Action Unit ◽  
Facial Action

In the field of affective computing, achieving accurate automatic detection of facial movements is an important issue, and great progress has already been made. However, a systematic evaluation of systems that now have access to the dynamic facial database remains an unmet need. This study compared the performance of three systems (FaceReader, OpenFace, AFARtoolbox) that detect each facial movement corresponding to an action unit (AU) derived from the Facial Action Coding System. All machines could detect the presence of AUs from the dynamic facial database at a level above chance. Moreover, OpenFace and AFAR provided higher area under the receiver operating characteristic curve values compared to FaceReader. In addition, several confusion biases of facial components (e.g., AU12 and AU14) were observed to be related to each automated AU detection system and the static mode was superior to dynamic mode for analyzing the posed facial database. These findings demonstrate the features of prediction patterns for each system and provide guidance for research on facial expressions.

scholarly journals Age-dependent regulation of host seeking in Anopheles coluzzii

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. B. Omondi ◽  
M. Ghaninia ◽  
M. Dawit ◽  
T. Svensson ◽  
R. Ignell
Keyword(s):  
Anopheles Coluzzii ◽  
Host Seeking ◽  
Age Dependent

The effects of odours, wind direction and wind speed on the distribution of Glossina (Diptera: Glossinidae) and other insects near stationary targets

1983 ◽  
Vol 73 (1) ◽  
pp. 53-64 ◽  
Author(s):  
G. A. Vale
Keyword(s):  
Carbon Dioxide ◽  
Wind Speed ◽  
Wind Direction ◽  
Field Data ◽  
Visual Stimuli ◽  
Glossina Morsitans Morsitans ◽  
Host Recognition ◽  
Glossina Morsitans ◽  
Zambezi Valley

AbstractIn studies in the Zambezi Valley of Zimbabwe, Glossina morsitans morsitans Westw. and G. pallidipes Aust. were captured on electric nets at various points around stationary targets. The distribution of flies was affected by wind direction, wind speed and the presence or absence of an attractant odour consisting of carbon dioxide and acetone. The distributions suggested that tsetse attracted to baits by visual stimuli alone fly first to a point just downwind of the baits, where the perception of odour is important in host recognition. Changes in the distribution of catches when odour was used suggested that the distributions could form useful indices of assaying attractant odours in the field. Data for Muscidae, Tabanidae, Asilidae and Hymenoptera are also presented.

scholarly journals Expression Profiles and Binding Properties of the Chemosensory Protein PxylCSP11 from the Diamondback Moth, Plutella xylostella (Lepidoptera: Plutellidae)

2020 ◽  
Vol 20 (5) ◽  
Author(s):  
Shuhui Fu ◽  
Fangyuan Li ◽  
Xizhong Yan ◽  
Chi Hao
Keyword(s):  
Plutella Xylostella ◽  
Expression Profiles ◽  
Diamondback Moth ◽  
Expression Patterns ◽  
Host Recognition ◽  
Limited Information ◽  
Host Volatiles ◽  
Binding Characteristics ◽  
Chemosensory Protein ◽  
Cruciferous Plants

Abstract The diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae) is one of the most destructive pests to cruciferous plants worldwide. The oligophagous moth primarily utilizes its host volatiles for foraging and oviposition. Chemosensory proteins (CSPs) are soluble carrier proteins with low molecular weight, which recognize and transport various semiochemicals in insect chemoreception. At present, there is limited information on the recognition of host volatiles by CSPs of P. xylostella. Here, we investigated expression patterns and binding characteristics of PxylCSP11 in P. xylostella. The open reading frame of PxylCSP11 was 369-bp encoding 122 amino acids. PxylCSP11 possessed four conserved cysteines, which was consistent with the typical characteristic of CSPs. PxylCSP11 was highly expressed in antennae, and the expression level of PxylCSP11 in male antennae was higher than that in female antennae. Fluorescence competitive binding assays showed that PxylCSP11 had strong binding abilities to several ligands, including volatiles of cruciferous plants, and (Z)-11-hexadecenyl acetate (Z11-16:Ac), a major sex pheromone of P. xylostella. Our results suggest that PxylCSP11 may play an important role in host recognition and spouse location in P. xylostella.

Ultraviolet Spectral Analysis and Quantitative Detection of Heptafluoroisobutyronitrile (C4F7N) in a C4F7N–Carbon Dioxide (CO2) Gas Mixture

2019 ◽  
Vol 73 (8) ◽  
pp. 917-926 ◽  
Author(s):  
Yin Zhang ◽  
Xiaoxing Zhang ◽  
Chang Liu ◽  
Yi Li ◽  
Zhaolun Cui ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Absorption Spectroscopy ◽  
Density Functional ◽  
Sulfur Hexafluoride ◽  
Detection System ◽  
Spectral Characteristics ◽  
Uv Absorption ◽  
Quantitative Detection ◽  
Gas Mixture ◽  
Uv Absorption Spectroscopy

As an alternative to sulfur hexafluoride (SF6) with great potential for application, heptafluoroisobutyronitrile–carbon dioxide (C4F7N–CO2) gas mixture has been applied in various gas-insulated equipment. The insulation performance of the gas mixture is closely related to the mixing ratio. Therefore, accurate quantification of C4F7N in the C4F7N–CO2 gas mixture has very important engineering significance. At present, there are few reports on the rapid quantitative detection of the concentration of C4F7N in the gas mixture. In this paper, a rapid analytical method for C4F7N concentration based on ultraviolet (UV) absorption spectroscopy is constructed. The UV spectral characteristics of C4F7N molecules are calculated by density functional theory. The appropriate bands that can be detected are determined by analyzing the calculated results. A concentration detection system of C4F7N based on UV absorption spectroscopy is built. Through analysis of the calculated results and experimental results, a quantitative detection method of C4F7N in the C4F7N/CO2 gas mixture is determined. The method can achieve accurate detection of the concentration of the gas mixture in the conventional application range (including 4–10% C4F7N). The coefficient of the determination R2 of the concentration inversion curve reaches 0.999 and the inversion error ratio does not exceed 5%. The related research results provide an important reference for the engineering application of the gas mixture.

scholarly journals Semifield Evaluation of Improved Passive Outdoor Host Seeking Device (POHD) for Outdoor Control of Anopheles arabiensis Mosquitoes

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Stella T. Kessy ◽  
Bruno A. Nyundo ◽  
Ladslaus L. Mnyone ◽  
Issa N. Lyimo
Keyword(s):  
Carbon Dioxide ◽  
Anopheles Arabiensis ◽  
Mosquito Control ◽  
Real Life ◽  
Residual Activity ◽  
Optimal Placement ◽  
Treatment Combination ◽  
Host Seeking ◽  
Outdoor Biting ◽  
Control Devices

Despite the considerable progress made so far, the effectiveness and mass application of odour-baited outdoor mosquito control devices in pipelines is limited by several factors. These include the design and size of the devices, optimal placement of attractive blends, and nature of materials into which the blends are impregnated. The primary aim of this study was to manipulate these factors to improve the attractiveness of our recently developed passive outdoor host seeking device (POHD) to outdoor biting Anopheles arabiensis. Specifically, the study aimed to determine optimal placement of odour blends and killing bioactives in POHD for maximum attraction and killing of An. arabiensis and to assess the effects of blend types, formulation, and residual activity on attractiveness of the POHD to An. arabiensis. The POHDs baited with attractive blends, carbon dioxide (CO2), and bendiocarb-treated electrostatic netting were placed either towards the top or bottom openings, and other modifications were exposed to An. arabiensis under the semifield system at Ifakara Health Institute (IHI). Each night, a total of 100 starved female, 3–7-day-old, semifield reared An. arabiensis mosquitoes were released, collected the next morning (alive or dead), counted, and recorded. Live mosquitoes were maintained in the semifield insectary and monitored for 24 hours mortality. Each treatment combination of the POHD was tested in three replicates. Overall, the results indicated that the proportion of mosquitoes attracted to and killed in the POHD varied with position of attractants and killing agent (bendiocarb). The POHD with bottom placed attractants and bendiocarb attracted and killed higher proportion of mosquitoes compared to the POHD with top placed attractants and bendiocarb. The highest mortalities were observed when the POHD was baited with a combination of attractive blends and CO2. Moreover, the residual activity of attractive blends applied inside POHD varied with type and formulation of attractive blend. The POHD packed with Mbita and Ifakara blend in microencapsulated pellets (granules) attracted higher proportion of mosquitoes than that baited with soaked nylon-strip formulation of either blends. Interestingly, POHD baited with Mbita blend in microencapsulated pellets (granules) formulation attracted and killed higher proportion of mosquitoes (>90%) than that baited with Ifakara blend even 9 months after application. Conclusively, the POHD remained effective for a relatively longer period of time when baited with bottom placed synthetic blends and CO2 combination, thus warranting further trials under real life situations.

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