The range of attraction of birds as baits for Some West African mosquitoes (Diptera, Culicidae)

1974 ◽  
Vol 63 (4) ◽  
pp. 573-582 ◽  
Author(s):  
M. T. Gillies ◽  
T. J. Wilkes

AbstractThe long range orientation of West African mosquitoes to birds was studied using ramp-traps set up 3–23 m from the bait. The baits comprised chickens, ducks, pigeons and the carbon dioxide equivalent of the chickens. From the pattern of convergence of mosquitoes to the baits, it was shown that Anopheles melas Theo. and Culex thalassius Theo. were orienting to all the bird-baits from distances of at least seven metres. Responses to carbon dioxide were only apparent at a distance of three metres indicating the greater range of effect of the chickens over their carbon dioxide equivalent. Mosquitoes of the largely bird-biting C. decens group showed no long range response to any bait, even though they were entering pigeon-baited traps and to a limited extent feeding on the birds. Catches of A. melas in bird-baited traps were larger at the foot of a tall tree than in the foliage at 5·33 m; for Culex spp. the converse was true. Catches of Culex at 5·33 m outside the tree were smaller than within the foliage.

1970 ◽  
Vol 60 (2) ◽  
pp. 225-235 ◽  
Author(s):  
M. T. Gillies ◽  
T. J. Wilkes

Field experiments were conducted in the Gambia to measure the convergence of mosquitoes towards single bait-animals (calf or man) or to an equivalent source of carbon dioxide, the mosquitoes being caught in ramp-traps. Catches of unfed females of Anopheles melas Theo. fell off steeply with increasing distance up to 15 yd from animal bait; with carbon dioxide as bait, raised catches were only recorded out to 10 yd. Catches of other Anopheles spp. with calf-bait gave similar results to those for A. melas. A positive effect of the calf on densities at 15 yd was obtained for Culex tritaeniorhynchus Giles but this was less clear-cut in the case of C. thalassius Theo.; with carbon dioxide as bait, raised catches of both species were recorded at 10 yd but not at 15 yd. Both types of bait gave raised catches of the C. decens group only at 5 yd. It is concluded that A. melas and other Anopheles spp. were detecting and responding to the single animal bait from 15–20 yd, C. tritaeniorhynchus and C. thalassius from 10–20 yd, and the C. decens group from 5 yd. In all except the last named group, as also for the other Anopheles spp., on which data are lacking, the range of attraction of carbon dioxide was less than 15 yd. Olfactory cues were therefore held to be responsible for long-range orientation in these three species of mosquitoes, the effect being most marked with A. melas.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 430-430
Author(s):  
Andre Pastori D Aurea ◽  
Abmael S da Silva Cardoso ◽  
Lauriston Bertelli Fernandes ◽  
Ricardo Andrade Reis ◽  
Luis Eduardo Ferreira ◽  
...  

Abstract In Brazil beef cattle production is one of the most important activities in the agricultural sector and has an important impact on environmental and resources consumption. In this study assessed greenhouses gases (GHG) impacts from on farms representative productive system and the possible improvements of the production chain. Primary data from animal production index and feeding were collected from 17 farms, which covers 300.000 animals and 220.000 hectares. Emissions of methane, nitrous oxide and carbon dioxide were made using intergovernmental panel on climate change (IPCC) guidelines for national inventories. The GHG inventory included emissions from animals, feeds and operations for animal operation from “cradle to farm gate”. Emissions of each farm were converted to carbon dioxide equivalent (CO2eq) and divided by carcass production. Regression analysis between carbon dioxide equivalent and productive index was run to identify possible hotspot of GHG emissions. A large variation between farms were observed. The GHG yield ranged from 8.63 kg to 50.88 CO2eq kg carcass-1. The productive index age of slaughtering (P < 0.0001), average daily gain (P < 0.0001) and productivity (P = 0.058) per area were positive correlated to GHG yield. While no correlation was found with stocking rate (P = 0.21). Improvements of the production chain could be realized by accurate animal management strategies that reduce the age of slaughtering (feeding and genetic improvements) and gain individual or per area using strategic animal supplementation and pasture management, in order to obtains reduction of GHG emissions of beef cattle.


2017 ◽  
Vol 9 (5) ◽  
pp. 107
Author(s):  
Seied Mohsen Taghavi ◽  
Teodoro C. Mendoza ◽  
Bart Acero Jr ◽  
Tao Li ◽  
Sameer Ali Siddiq ◽  
...  

Breeding of rice varieties with low carbon dioxide equivalent (CO2e) emission is essential in reducing global greenhouse gas (GHG) emissions. In this study, we compared the gross CO2e emission of two newly developed green super rice (GSR) varieties with elite hybrids and nationally released farmer-cultivated varieties from production to post-production in the dry and wet seasons in Laguna, Philippines. The average gross CO2e emission was 17.9 tons CO2e ha-1 or 2.98 tons CO2e ton-1 rice (production 82%, post-production 18%). Contributing to this total were soil emissions at 72%, the use of chemicals at 5%, burning of rice straw at 3%, cooking at 12%, and transportation at 5%. The average social cost of carbon (SCC) per ton of rice was estimated at $119. Increasing grain yield per unit area with shorter growth duration decreased CO2e emission of rice per unit of weight. Cultivation of rice varieties GSR8 and GSR2 emitted 37.0% lower CO2e than the popular inbred varieties.


Author(s):  
Idrissa Dieng ◽  
Mignane Ndiaye ◽  
Marie Henriette Ndione ◽  
Safietou Sankhe ◽  
Moussa Moïse Diagne ◽  
...  

Globally 390 millions of people are at risk of dengue infection; over the past 50 years the virus incidence increased thirty-fold. In Senegal, an unprecedented occurrence of outbreaks and sporadic cases was noticed since 2017. In October 2018 an outbreak of DENV-2 was reported in Rosso area in the north of Senegal at the border with Mauritania. Out of the 187 blood specimen samples collected, 27 were positives by qRT-PCR and 8 were serologically positive for DENV IgM. Serotyping using qRT-PCR reveals that isolates were positive for DENV-2. A subset of DENV-2 positives samples was selected and subjected to full genome sequencing followed by phylogenetic analysis. Analysis of 06 nearly completed genome sequences (n= 6) revealed that isolates belong to the cosmopolitan genotype and are closely related to the Mauritanian strains detected between 2017 and 2018 and those detected in many West African countries such as Burkina Faso or Cote d’Ivoire. Our results suggest a transboundary circulation of the DENV-2 cosmopolitan genotype between Senegal and Mauritania and call for a need of coordinated surveillance of arboviruses between these two countries. Interestingly, high level of homology between West African isolates highlights endemicity and call for a set-up of sub-regional viral genomic surveillance which will lead to a better understanding of viral dynamic, transmission and spread across Africa.


2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Charles Oliveira da Silva ◽  
Henrique Trevisan ◽  
Thiago Sampaio de Souza ◽  
Acacio Geraldo de Carvalho

Scolytinae is a beetle group belonging to Order Coleoptera; these insects play an essential role in wood degradation in forest ecosystems, since they build galleries that enable substrate colonization by other saprophytic organisms, as well as nutrient cycling. Thus, the aim of the current study was to evaluate the occurrence of Scolytinae in the wood of 5 tree species exposed to mangrove environment, as well as to simultaneously survey Scolytinae specimens captured in ethanol-baited impact traps placed in the same environment. The study was carried out in a mangrove area located in Santa Cruz neighborhood - RJ. Five freshly-harvested Clitoria fairchildiana, Rhyzophora mangle, Corymbia citriodora, Melia azedarach and Eucalyptus pellita wood logs (1 m long and 5-10 cm diameter) were arranged perpendicular to the ground (1 m above it) and spaced 30 cm away from each other. Five impact traps were set up 50 m away from each other, 1.3 m above the ground. Insects were collected for 5 months. One hundred and thirty (130) Scolytinae individuals (14 species in 2 genera) were recorded in the wood logs; the relative frequency (Fr) of the species comprised Xyleborus affinis (33.9%) and Hypothenemus sp.4 (17.7%), which represented 51.6% of the total number of captured individuals. Hypothenemus sp.6 specimens were not collected in ethanol-baited traps, but the wood of C. fairchildiana. E. pellita did not show insect infestation. The traps captured 798 individuals (24 species belonging to 8 genera); the frequency of X. affinis (25.3%) and Hypothenemus eruditus (14.5%) represented 39.8% of the total number of captured insects.  


Author(s):  
Olof Magnusson ◽  
Rikard Teodorsson ◽  
Joakim Wennerberg ◽  
Stig Arne Knoph

LoRaWAN (long-range wide-area network) is an emerging technology for the connection of internet of things (IoT) devices to the internet and can as such be an important part of decision support systems. In this technology, IoT devices are connected to the internet through gateways by using long-range radio signals. However, because LoRaWAN is an open network, anyone has the ability to connect an end device or set up a gateway. Thus, it is important that gateways are designed in such a way that their ability to be used maliciously is limited. This chapter covers relevant attacks against gateways and potential countermeasures against them. A number of different attacks were found in literature, including radio jamming, eavesdropping, replay attacks, and attacks against the implementation of what is called beacons in LoRaWAN. Countermeasures against these attacks are discussed, and a suggestion to improve the security of LoRaWAN is also included.


Author(s):  
Reinhard Bork ◽  
Renato Mangano

This chapter deals with European cross-border issues concerning groups of companies. This chapter, after outlining the difficulties encountered throughout the world in defining and regulating the group, focuses on the specific policy choices endorsed by the EIR, which clearly does not lay down any form of substantive consolidation. Instead, the EIR, on the one hand, seems to permit the ‘one group—one COMI’ rule, even to a limited extent, and, on the other hand, provides for two different regulatory devices of procedural consolidation, one based on the duties of ‘cooperation and communication’ and the other on a system of ‘coordination’ to be set up between the many proceedings affecting companies belonging to the same group.


2018 ◽  
Vol 176 ◽  
pp. 05045 ◽  
Author(s):  
Erwan Cadiou ◽  
Jean-Baptiste Dherbecourt ◽  
Guillaume Gorju ◽  
Jean-Michel Melkonian ◽  
Antoine Godard ◽  
...  

We report on ground-based atmospheric concentration measurements of carbon dioxide, using a pulsed direct detection differential absorption lidar operating at 2051 nm. The transmitter is based on a tunable parametric source emitting 10-mJ energy, 10-ns duration Fourier-limited pulses. Range resolved concentration measurements have been carried out on the aerosol back-scattered signal. Cloud signals have been used to get long range integrated-path measurements.


Sign in / Sign up

Export Citation Format

Share Document