scholarly journals Measuring the host-seeking ability of Aedes aegypti destined for field release

2019 ◽  
Author(s):  
Meng-Jia Lau ◽  
Nancy M. Endersby-Harshman ◽  
Jason K. Axford ◽  
Scott A. Ritchie ◽  
Ary A. Hoffmann ◽  
...  

AbstractHost-seeking is an essential process in mosquito reproduction. Field releases of modified mosquitoes for population transformation rely on successful host-seeking by female mosquitoes, but host-seeking ability is rarely tested in a realistic context. We tested the host-seeking ability of female Aedes aegypti mosquitoes using a semi-field system. Females with different Wolbachia infection types (wMel-, wAlbB-infected and uninfected) or from different origins (laboratory and field) were released at one end of a semi-field cage and recaptured as they landed on human experimenters fifteen meters away. Mosquitoes from each population were then identified with molecular tools or through marking with a consistent weight of fluorescent powder. Wolbachia-infected and uninfected populations had similar average durations to landing and overall recapture proportions, as did laboratory and field-sourced A. aegypti. These results suggest that the host-seeking ability of mosquitoes is not negatively affected by Wolbachia infection or long-term laboratory maintenance. This method provides an approach to study the host-seeking ability of mosquitoes across a long distance which will be useful when evaluating strains of mosquitoes that are planned for releases into the field to suppress arbovirus transmission. An adjustment of this method may also be useful in sterile insect release programs because male host-seeking and swarming around female feeding sites can also be investigated.

2008 ◽  
Vol 35 (S 01) ◽  
Author(s):  
K Kollewe ◽  
S Baloush ◽  
K Krampfl ◽  
H Bigalke ◽  
R Dengler ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jesse R. Conklin ◽  
Simeon Lisovski ◽  
Phil F. Battley

AbstractGlobally, bird migration is occurring earlier in the year, consistent with climate-related changes in breeding resources. Although often attributed to phenotypic plasticity, there is no clear demonstration of long-term population advancement in avian migration through individual plasticity. Using direct observations of bar-tailed godwits (Limosa lapponica) departing New Zealand on a 16,000-km journey to Alaska, we show that migration advanced by six days during 2008–2020, and that within-individual advancement was sufficient to explain this population-level change. However, in individuals tracked for the entire migration (50 total tracks of 36 individuals), earlier departure did not lead to earlier arrival or breeding in Alaska, due to prolonged stopovers in Asia. Moreover, changes in breeding-site phenology varied across Alaska, but were not reflected in within-population differences in advancement of migratory departure. We demonstrate that plastic responses can drive population-level changes in timing of long-distance migration, but also that behavioral and environmental constraints en route may yet limit adaptive responses to global change.


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3281
Author(s):  
Xu He ◽  
Yong Yin

Recently, deep learning-based techniques have shown great power in image inpainting especially dealing with squared holes. However, they fail to generate plausible results inside the missing regions for irregular and large holes as there is a lack of understanding between missing regions and existing counterparts. To overcome this limitation, we combine two non-local mechanisms including a contextual attention module (CAM) and an implicit diversified Markov random fields (ID-MRF) loss with a multi-scale architecture which uses several dense fusion blocks (DFB) based on the dense combination of dilated convolution to guide the generative network to restore discontinuous and continuous large masked areas. To prevent color discrepancies and grid-like artifacts, we apply the ID-MRF loss to improve the visual appearance by comparing similarities of long-distance feature patches. To further capture the long-term relationship of different regions in large missing regions, we introduce the CAM. Although CAM has the ability to create plausible results via reconstructing refined features, it depends on initial predicted results. Hence, we employ the DFB to obtain larger and more effective receptive fields, which benefits to predict more precise and fine-grained information for CAM. Extensive experiments on two widely-used datasets demonstrate that our proposed framework significantly outperforms the state-of-the-art approaches both in quantity and quality.


Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Attila Molnár V ◽  
András Máté ◽  
Gábor Sramkó

AbstractOne flowering specimen of Ophrys bertolonii (s. str.) — a plant with a Circum-Adriatic distribution and hitherto unknown in other regions — was found on 7th May 2010 in the vicinity of Kunadacs (Central Hungary; N 47°00′ E 19°17′). The nearest known populations of this Mediterranean plant inhabit the Adriatic coast (ca. 450 km away) in Croatia, therefore this new occurrence represents a significant long distance dispersal event. The circumstances of the occurrence argue against introduction, but we can not decide now whether this new appearance is temporary or permanent. The permanent establishment of this strictly entomophilous plant requires the presence of its specific pollinator in the close neighbourhood of the habitat. However, no pollination was observed on the three flowers of the plant until 9th May, and one day later the stem had disappeared most likely due to grazing. Whatever the long-term fate of the plant is, this discovery represents a significant long distance (jump) dispersal event, and testifies to the dispersal ability of Ophrys species. Additionally, the appearance of a mature Adriatic plant in Central Europe fits well into the currently observed, climate change driven northward expansion of European orchids, therefore this finding most likely reflects a growing Mediterranean-like climatic influence in the region.


1991 ◽  
Vol 24 (3-4) ◽  
pp. 373-383 ◽  
Author(s):  
A. Grimvall ◽  
H. Borén ◽  
S. Jonsson ◽  
S. Karlsson ◽  
R. Sävenhed

The long-term fate of chlorophenols and adsorbable organic halogens (AOX) was studied in two large recipients of bleach-plant effluents: Lake Vättern in Sweden and the Baltic Sea. The study showed that there is a long-distance transport (>100 km) of chloroguaiacols from bleach-plants to remote parts of receiving waters. However, there was no evidence of several-year-long accumulation of chloro-organics in the water-phase. A simple water-exchange model for Lake Vättern showed that the cumulated bleach-plant discharges from the past 35 years would have increased the AOX concentration in the lake by more than 100 µg Cl/l, if no AOX had been removed from the water by evaporation, sedimentation or degradation. However, the observed AOX concentration in Lake Vättern averaged only about 15 µg Cl/l, which was less than the average AOX concentration (32 µg Cl/l) in the “unpolluted” tributaries of the lake. Similar investigations in the Baltic Sea showed that non-point sources, including natural halogenation processes, accounted for a substantial fraction of the AOX in the open sea. The presence of 2,4,6-trichlorophenol in precipitation and “unpolluted” surface waters showed that non-point sources may also make a considerable contribution to the background levels of compounds normally regarded as indicators of bleach-plant effluents.


Author(s):  
Gordon J. Gallivan ◽  
Andrea Spickett ◽  
Heloise Heyne ◽  
Arthur M. Spickett ◽  
Ivan G. Horak

Despite many studies regarding tick ecology, limited information on long-term changes in tick populations exist. This study assessed the long-term population dynamics of the less frequently collected questing ixodid ticks in the Kruger National Park (KNP). From 1988 to 2002, monthly dragging of the vegetation was performed in three habitats (grassland, woodland and gully) at two sites in the KNP (Nhlowa Road, Landscape Zone 17, and Skukuza, Landscape Zone 4). Amblyomma marmoreum and Rhipicephalus evertsi evertsi were collected as larvae most commonly. Most A. marmoreum larvae were collected at Skukuza and numbers peaked from March to July. More R. evertsi evertsi larvae were collected at Nhlowa Road and numbers peaked in summer and in winter, while at Skukuza there was a single peak in spring. Haemaphysalis elliptica, Rhipicephalus simus and Rhipicephalus turanicus were collected as adults most commonly. More Ha. elliptica and R. turanicus were collected at Nhlowa Road than at Skukuza, while R. simus numbers from the two sites were approximately equal. Ha. elliptica were collected most often between February and June, and R. simus and R. turanicus during February and March. All three species were collected more frequently in gullies than in grassland or woodland. Their numbers increased in 1994/1995 following an eruption of rodents, the preferred hosts of the immature stages. The different host-seeking strategies of ticks largely determine the development stage at which they are likely to be collected during vegetation dragging and reflect a complex interaction between ticks, their hosts and the environment.


LWT ◽  
2019 ◽  
Vol 101 ◽  
pp. 789-798 ◽  
Author(s):  
Zoltán Kállai ◽  
Walter P. Pfliegler ◽  
Judit Mitercsák ◽  
Gergő Szendei ◽  
Matthias Sipiczki

Author(s):  
Yuri P. Perevedentsev ◽  
Konstantin M. Shantalinskii ◽  
Boris G. Sherstukov ◽  
Alexander A. Nikolaev

Long-term changes in air temperature on the territory of the Republic of Tatarstan in the 20th–21st centuries are considered. The periods of unambiguous changes in the surface air temperature are determined. It is established that the average winter temperature from the 1970s to 2017, increased in the Kazan region by more than 3 °C and the average summer temperature increased by about 2 °C over the same period. The contribution of global scale processes to the variability of the temperature of the Kazan region is shown: it was 37 % in winter, 23 % in summer. The correlation analysis of the anomalies of average annual air temperature in Kazan and the series of air temperature anomalies in each node over the continents, as well as the ocean surface temperature in each coordinate node on Earth for 1880 –2017, was performed. Long-distance communications were detected in the temperature field between Kazan and remote regions of the Earth. It is noted that long-period climate fluctuations in Kazan occur synchronously with fluctuations in the high latitudes of Asia and North America, with fluctuations in ocean surface temperature in the Arctic ocean, with fluctuations in air temperature in the Far East, and with fluctuations in ocean surface temperature in the Southern hemisphere in the Indian and Pacific oceans, as well as air temperature in southern Australia. It is suggested that there is a global mechanism that regulates long-term climate fluctuations throughout the Earth in the considered interval of 200 years of observations. According to the CMIP5 project, climatic scenarios were built for Kazan until the end of the 21st century.


2021 ◽  
pp. 167-178
Author(s):  
Ewa Pudłowska

The aim of this study is to analyze a new social phenomenon that appeared during the SARS-CoV-2 pandemic, i.e. zoom fatigue. Zoom fatigue is the result of fatigue from long-term conferences, which can also be related to long-term school lessons during distance learning. The main considerations will focus on teenagers, namely on the impact of zoom fatigue on teenagers in Polish schools and on observation of students from technical secondary schools by a school psychologist. This paper, based on the results of research conducted at Stanford University and by Social Changes, is also an attempt to answer the questions: what risks may arise from the phenomenon of zoom fatigue and the threat posed by distance learning for teenagers in the era of Covid-19. It will also attempt to answer the question of how to help students cope with the fatigue of long distance school activities and find ways to help teens deal with isolation and the negative effects of zoom fatigue and find ways to overcome zoom fatigue.


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