Cell coverage analysis of a low altitude aerial base station in wind perturbations

The use of Unmanned Aerial Vehicles (UAVs) as Aerial Base Station (ABSs) is emerging as an effective technique to provide high capacity wireless networks to ground users. In this paper, cell coverage of a low altitude UAV is investigated for supporting such networks. An analytical framework for cell coverage area of an ABS is provided for Suburban, Urban and Urban high rise environments using a solid angle approach including radio link propagation effects in air- to-ground channel obtained from ray tracing simulations. Here, we account for the change in Euler angles such as roll, pitch and yaw due to perturbations by wind gusts or intentional maneuvers which leads to an increase in the geometrical coverage area by approximately 40-50 %, given same transmission power and antenna gain of the ABS

A comparative study of MEA and DEA for post-combustion CO2 capture with different process configurations

This paper presented a comparative study of monoethanolamine (MEA) and diethanolamine (DEA) for post-combustion CO2 capture (PCC) process with different process configurations to study the interaction effect between solvent and process. The steady state process model of the conventional MEA-based PCC process was developed in Pro/II® and was validated with the experimental data. Then ten different process configurations were simulated for both MEA and DEA. Their performances in energy consumption were compared in terms of reboiler duty and total equivalent work. The results show that DEA generally has better thermal performances than MEA for all these ten process configurations. Seven process configurations provide 0.38%–4.61% total energy saving compared with the conventional PCC process for MEA, and other two configurations are not favourable. For DEA, except one configuration, other process configurations have 0.27%–4.50% total energy saving. This work also analyzed the sensitivities of three key parameters (amine concentration, stripper pressure and lean solvent loading) in conventional process and five process modifications to show optimization strategy

How Many Reindeer? UAV Surveys as an Alternative to Helicopter or Ground Surveys for Estimating Population Abundance in Open Landscapes

Conservation of wildlife depends on precise and unbiased knowledge on the abundance and distribution of species. It is challenging to choose appropriate methods to obtain a sufficiently high detectability and spatial coverage matching the species characteristics and spatiotemporal use of the landscape. In remote regions, such as in the Arctic, monitoring efforts are often resource-intensive and there is a need for cheap and precise alternative methods. Here, we compare an uncrewed aerial vehicle (UAV; quadcopter) pilot survey of the non-gregarious Svalbard reindeer to traditional population abundance surveys from ground and helicopter to investigate whether UAVs can be an efficient alternative technology. We found that the UAV survey underestimated reindeer abundance compared to the traditional abundance surveys when used at management relevant spatial scales. Observer variation in reindeer detection on UAV imagery was influenced by the RGB greenness index and mean blue channel. In future studies, we suggest testing long-range fixed-wing UAVs to increase the sample size of reindeer and area coverage and incorporate detection probability in animal density models from UAV imagery. In addition, we encourage focus on more efficient post-processing techniques, including automatic animal object identification with machine learning and analytical methods that account for uncertainties

Rabbit haemorrhagic disease: experimental study of a recent highly pathogenic GI.2/RHDV2/b strain and evaluation of vaccine efficacy

[EN] In 2010, a variant of the rabbit haemorrhagic disease virus (RHDV) belonging to a new GI.2 genotype was identified in France and rapidly spread worldwide. Due to antigenic difference, new vaccines including G1.2 strains have been developed to confer adequate protection. An increase in the pathogenicity of the circulating strains was recently reported. The objective of this experimental study was to characterise the infection with a highly pathogenic GI.2/RHDV2/b isolate (2017) and assess the efficacy of Filavac VHD K C+V vaccine (Filavie) against this strain. Four and 10-wk-old specific pathogen-free rabbits were inoculated with a recommended dose of vaccine. After 7 d, controls and vaccinated rabbits were challenged and clinically monitored for 14 d. All animals were necropsied and blood, organs and urine were sampled for quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis. In adult groups, regular nasal and rectal swabbing were performed, and faeces were collected after death to monitor RNA shedding. In control groups, the challenge strain induced acute RHD between 31 and 72 h post-inoculation, with a mortality rate of 100% for kits and 89% for adult rabbits. Except for a shorter mean time to death in kits, similar clinical signs and lesions were observed between age groups. The vaccination significantly prevented all mortality, clinical signs, detection of viral RNA in serum and gross lesions in kits and adult rabbits. In adult groups, we also demonstrated that vaccine significantly protected from detectable RNA shedding via naso-conjunctival and rectal routes. Two weeks after challenge, RNA copies were not detected by PCR in the liver, spleen, lungs, kidneys, faeces and urine of vaccinated adult rabbits. The findings for kits were similar, except that very low levels of RNA were present in the liver and spleen of a few rabbits. These data show that immunisation prevented any significant viral multiplication and/or allowed a rapid clearance. We concluded that, despite the quick evolution of GI.2/RHDV2/b strains, the protection conferred by the vaccine remains adequate. In the context of coexistence of both GI.1 and GI.2 genotypes in some countries, with the circulation of multiples recombinant viruses, the vaccination should be based on the association of strains from both genotypes.Le Minor, O.; Boucher, S.; Joudou, L.; Mellet, R.; Sourice, M.; Le Moullec, T.; Nicolier, A.... (2019). Rabbit haemorrhagic disease: experimental study of a recent highly pathogenic GI.2/RHDV2/b strain and evaluation of vaccine efficacy. World Rabbit Science. 27(3):143-156. https://doi.org/10.4995/wrs.2019.11082SWORD143156273Abrantes J., van der Loo W., Le Pendu J., Esteves P.J. 2012. Rabbit haemorrhagic disease (RHD) and rabbit haemorrhagic disease virus (RHDV): a review. Vet. Res., 43: 12. https://doi.org/10.1186/1297-9716-43-12Abrantes J., Lopes A.M., Dalton K.P., Melo P., Correia J.J., Ramada M., Alves P.C., Parra F., Esteves P.J. 2013. New variant of rabbit hemorrhagic disease virus, Portugal, 2012-2013. Emerg. Infect. Dis., 19: 1900-1902. https://doi.org/10.3201/eid1911.130908Calvete C., Sarto P., Calvo A.J., Monroy F., Calvo J.H. 2014. Letter - Could the new rabbit haemorrhagic disease virus variant (RHDVb) be fully replacing classical RHD strains in the Iberian Peninsula?. World Rabbit Sci., 22: 91-91. https://doi.org/10.4995/wrs.2014.1715Calvete C, Mendoza M, Alcaraz A, Sarto M.P., Jiménez-de-Bagüéss M.P., Calvo A.J., Monroy F., Calvo J.H., 2018. Rabbit haemorrhagic disease: Cross-protection and comparative pathogenicity of GI.2/RHDV2/b and GI.1b/RHDV lagoviruses in a challenge trial. Vet. Microbiol., 219: 87-95. https://doi.org/10.1016/j.vetmic.2018.04.018Capucci L., Cavadini P., Schiavitto M., Lombardi G., Lavazza A. 2017. Increased pathogenicity in rabbit haemorrhagic disease virus type 2 (RHDV2). Vet. Rec., 180: 426. https://doi.org/10.1136/vr.104132Carvalho C.L., Duarte E.L., Monteiro M., Botelho A., Albuquerque T., Fevereiro M., Henriques A.M., Barros SS., Duarte MD. 2017. Challenges in the rabbit haemorrhagic disease 2 (RHDV2) molecular diagnosis of vaccinated rabbits. Vet. Microbiol. 198: 43-50. https://doi.org/10.1016/j.vetmic.2016.12.006Dalton K.P., Balseiro A., Juste R.A., Podadera A., Nicieza I., Del Llano D., González R., Martin Alonso J.M., Prieto J.M., Parra F., Casais R. 2018. Clinical course and pathogenicity of variant rabbit haemorrhagic disease virus in experimentally infected adult and kit rabbits: Significance towards control and spread. Vet. Microbiol., 220: 24-32. https://doi.org/10.1016/j.vetmic.2018.04.033Dalton K.P., Nicieza I., Abrantes J., Esteves P.J., Parra F., 2014. Spread of new variant RHDV in domestic rabbits on the Iberian Peninsula. Vet. Microbiol., 169: 67-73. https://doi.org/10.1016/j.vetmic.2013.12.015Dalton K.P., Nicieza I., Balseiro A., Muguerza M.A., Rosell J.M., Casais R., Álvarez Á.L., Parra F. 2012. Variant rabbit hemorrhagic disease virus in young rabbits, Spain. Emerg. Infect. Dis., 18: 2009-2012. https://doi.org/10.3201/eid1812.120341Duarte M., Henriques M., Barros S.C., Fagulha T., Ramos F., Luís T., Fevereiro M., Benevides S., Flor L., Barros S.V., Bernardo S. 2015. Detection of RHDV variant 2 in the Azores. Vet. Rec.,176: 130. https://doi.org/10.1136/vr.h497Forrester N.L., Boag B., Moss S.R., Turner S.L., Trout R.C., White P.J., Hudson P.J., Gould E.A., 2003. Long-term survival of New Zealand rabbit haemorrhagic disease virus RNA in wild rabbits, revealed by RT-PCR and phylogenetic analysis. J. Gen.Virol., 84: 3079-3086. https://doi.org/10.1099/vir.0.19213-0Gall A., Schirrmeier H. 2006. Persistence of rabbit haemorrhagic disease virus genome in vaccinated rabbits after experimental infection. J. Vet. Med. B. Infect. Dis. Vet. Public Health, 53: 358-362. https://doi.org/10.1111/j.1439-0450.2006.00986.xGall A., Hoffmann B., Teifke J.P., Lange B., Schirrmeier H., 2007. Persistence of viral RNA in rabbits which overcome an experimental RHDV infection detected by a highly sensitive multiplex real-time RT-PCR. Vet. Microbiol.,120: 17-32. https://doi.org/10.1016/j.vetmic.2006.10.006Hall R.N., Mahar J.E., Haboury S., Stevens V., Holmes E.C., Strive T. 2015. Emerging Rabbit Hemorrhagic Disease Virus 2 (RHDVb), Australia. Emerg. Infect. Dis., 21: 2276-2278. https://doi.org/10.3201/eid2112.151210Le Gall G., Boilletot E., Morisse J.P. 1992. Viral haemorrhagic disease of rabbit: purification and characterization of a strain isolated in France. Ann. Rech. Vet., 23: 381-387.Le Gall-Reculé G., Zwingelstein F., Boucher S., Le Normand B., Plassiart G., Portejoie Y., Decors A., Bertagnoli S., Guérin J.L., Marchandeau S. 2011. Detection of a new variant of rabbit haemorrhagic disease virus in France. Vet. Rec., 168: 137-138. https://doi.org/10.1136/vr.d697Le Gall-Reculé G., Lavazza A., Marchandeau S., Bertagnoli S., Zwingelstein F., Cavadini, P., Martinelli N., Lombardi G., Guérin J.L., Lemaitre E., Decors A., Boucher S., Le Normand B., Capucci L. 2013. Emergence of a new lagovirus related to Rabbit Haemorrhagic Disease Virus. Vet. Res., 44: 81. https://doi.org/10.1186/1297-9716-44-81Le Gall-Reculé G., Lemaitre E., Bertagnoli S., Hubert C., Top S., Decors A., Marchandeau S., Guitton J.S., 2017. Large-scale lagovirus disease outbreaks in European brown hares (Lepus europaeus) in France caused by RHDV2 strains spatially shared with rabbits (Oryctolagus cuniculus). Vet. Res., 48: 70. https://doi.org/10.1186/s13567-017-0473-yLe Minor O., Beilvert F., Le Moullec T., Djadour D., Martineau J. 2013. Evaluation de l'efficacité d'un nouveau vaccin contre le virus variant de la maladie hémorragique virale du lapin (VHD).15èmes Journées de la Recherche Cunicole, 19-20 novembre, Le Mans, France.Le Minor O., Joudou L., Le Moullec T., Beilvert F. 2017. Innocuité et efficacité de la vaccination à 2 et 3 semaines d'âge contre le virus RHDV2 de la maladie hémorragique virale du lapin (VHD).17èmes Journées de la Recherche Cunicole, 22-13 novembre, Le Mans, France.Le Pendu J., Abrantes J., Bertagnoli S., Guitton J.S., Le Gall-Reculé G., Lopes A.M., Marchandeau S., Alda F., Almeida T., Célio A.P., Bárcena J., Burmakina G., Blanco E., Calvete C., Cavadini P., Cooke B., Dalton K., Delibes Mateos M., Deptula W., Eden J.S., Wang F., Ferreira C.C., Ferreira P., Foronda P., Gonçalves D., Gavier-Widén D., Hall R., Hukowska-Szematowicz B., Kerr P., Kovaliski J., et al. 2017. Proposal for a unified classification system and nomenclature of lagoviruses. J. Gen. Virol., 98:1658-1666. https://doi.org/10.1099/jgv.0.000840Lopes A.M., Correia J., Abrantes J., Melo P., Ramada M., Magalhães M.J., Alves P.C., Esteves P.J. 2015. Is the new variant RHDV replacing genogroup 1 in Portuguese wild rabbit populations? Viruses, 7: 27-36. https://doi.org/10.3390/v7010027Mahar J.E., Hall R.N., Peacock D., Kovaliski J., Piper M., Mourant R., Huang N., Campbell S., Gu X., Read A., Urakova N., Cox T., Holmes E.C., Strive T. 2018. Rabbit haemorrhagic disease virus 2 (GI.2) is replacing endemic strains of RHDV in the Australian landscape within 18 months of its arrival. J. Virol., https://doi.org/10.1128/JVI.01374-17Martin-Alonso A., Martin-Carrillo N., Garcia-livia K., Valladares B., Foronda P. 2016. Emerging rabbit haemorrhagic disease virus 2 (RHDV2) at the gates of the African continent. Infect. Genet. Evol., 44: 46-50. https://doi.org/10.1016/j.meegid.2016.06.034Morin H., Le Minor O., Beilvert F., Le Moullec T. 2015. Durée d'immunité conférée par un vaccin vis-à-vis des calicivirus classique et variant de la maladie virale hémorragique. 16èmes Journées de la Recherche Cunicole, 18-19 novembre, Le mans, France.Neimanis A., Larsson Pettersson U., Huang N., Gavier‑Widén D.,Strive T. 2018. Elucidation of the pathology and tissue distribution of Lagovirus europaeus GI.2/RHDV2 (rabbit haemorrhagic disease virus 2) in young and adult rabbits (Oryctolagus cuniculus). Vet. Res., 49: 46. https://doi.org/10.1186/s13567-018-0540-zOIE, 2017. Manual of Diagnostic Tests and Vaccines for Terrestrial Animals 2017. Chapter 2.6.2. Rabbit Haemorrhagic disease. Available at: (Accessed 8 February 2018): http://www.oie.int/fileadmin/Home/fr/Health_standards/tahm/3.06.02_RHD.pdfOIE, 2016. Rabbit Haemorrhagic disease, Canada-immediate notification report. Available at: http://www.oie.int/wahis_2/public/wahid.php/Reviewreport/Review?page_refer=MapFullEventReport&reportid=20799.Puggioni G., Cavadini P., Maestrale C., Scivoli R., Botti G., Ligios C., Le Gall- Recule G., Lavazza A., Capucci L. 2013. The new French 2010 Rabbit Hemorrhagic Disease Virus causes an RHD-like disease in the Sardinian Cape hare (Lepus capensis mediterraneus). Vet. Res., 44: 96.https://doi.org/10.1186/1297-9716-44-96Read A.J., Kirkland P.D. 2017. Efficacy of a commercial vaccine against different strains of rabbit haemorrhagic disease virus. Aust. Vet. J., 95: 223-226. https://doi.org/10.1111/avj.12600Silvério D., Lopes A.M., Melo-Ferreira J., Magalhães M.J., Monterroso P., Serronha A., Maio E., Alves P.C., Esteves P.J., Abrantes J. 2018. Insights into the evolution of the new variant rabbit haemorrhagic disease virus (GI.2) and the identification of novel recombinant strains. Transbound. Emerg. Dis., 65: 983-992. https://doi.org/10.1111/tbed.12830Shien, J.H., Shieh, H.K., Lee, L.H. 2000. Experimental infections of rabbits with rabbit haemorrhagic disease virus monitored by polymerase chain reaction. Res. Vet. Sci., 68, 255-259. https://doi.org/10.1053/rvsc.1999.0372Spikey N., McCabe V.J., Greenwood N.M., Jack S.C., Sutton D., van der Waart L. 2012. Novel bivalent vectored vaccine for control of myxomatosis and rabbit haemorrhagic disease. Vet. Rec., 170: 309. https://doi.org/10.1136/vr.100366Strive T., Wright J., Kovaliski J., Botti G., Capucci L. 2010. The non-pathogenic Australian lagovirus RCV-A1 causes a prolonged infection and elicits partial crossprotection to rabbit haemorrhagic disease virus. Virology, 398, 125-134. https://doi.org/10.1016/j.virol.2009.11.045Westcott D.G., Frossard J.P., Everest D., Dastjerdi A., Duff J.P., Choudhury B. 2014. Incursion of RHDV2- like variant in Great Britain. Vet. Rec., 174: 333-333. https://doi.org/10.1136/vr.g234

High seasonal overlap in habitat suitability in a nonmigratory High Arctic ungulate

Understanding drivers of space use and habitat selection is essential for management and conservation, especially under rapid environmental change. Here, we develop summer and winter habitat suitability models for the endemic wild Svalbard reindeer (Rangifer tarandus platyrhynchus). The High Arctic Svalbard tundra is currently subject to the fastest temperature increases on Earth, and reindeer spatial responses to associated environmental change are strongly restricted due to landscape barriers (including 60% glacial coverage) and lack of sea ice as movement corridors. We used an extensive dataset of GPS-collared adult females (2009–2018; N = 268 individual-years) to model seasonal habitat selection as a function of remotely sensed environmental variables , and subsequently built habitat suitability models using an ensemble modelling framework. As expected, we found that reindeer preferred productive habitats, described by the normalized difference vegetation index (NDVI) and plant biomass (derived from a vegetation map), in both seasons. This was further supported by selection for bird cliff areas, rich in forage, improving habitat suitability especially in winter. Contrary to our expectations, the terrain variables had similar, impact on habitat suitability in the two seasons, except for use of higher elevations in winter, likely related to improved forage access due to less snow. Suitable habitat patches covered only a small proportion of the landscape and were highly clustered in both seasons. About 13.0% of the total land area was suitable in both seasons, while summer-only and winter-only areas contributed a marginal addition of around 4.7% and 1.5%, respectively. This suggests, that unlike many continental and migratory Rangifer populations, even small geographic areas may encompass suffiscient suitable habitat. These first archipelago-wide habitat suitability models provide seasonal baseline maps relevant for the management and conservation of Svalbard reindeer, particularly under rapid environmental alterations from climate change

Long-term herbivore removal experiments reveal how geese and reindeer shape vegetation and ecosystem CO2-fluxes in high-Arctic tundra

1. Given the current rates of climate change, with associated shifts in herbivore population densities, understanding the role of different herbivores in ecosystem functioning is critical for predicting ecosystem responses. Here, we examined how migratory geese and resident, non-migratory reindeer—two dominating yet functionally contrasting herbivores—control vegetation and ecosystem processes in rapidly warming Arctic tundra. 2. We collected vegetation and ecosystem carbon (C) flux data at peak plant growing season in the two longest running, fully replicated herbivore removal experiments found in high-Arctic Svalbard. Experiments had been set up independently in wet habitat utilised by barnacle geese Branta leucopsis in summer and in moist-to-dry habitat utilised by wild reindeer Rangifer tarandus platyrhynchus year-round. 3. Excluding geese induced vegetation state transitions from heavily grazed, mossdominated (only 4 g m−2 of live above-ground vascular plant biomass) to ungrazed, graminoid-dominated (60 g m−2 after 4-year exclusion) and horsetail-dominated (150 g m−2 after 15-year exclusion) tundra. This caused large increases in vegetation C and nitrogen (N) pools, dead biomass and moss-layer depth. Alterations in plant N concentration and CN ratio suggest overall slower plant community nutrient dynamics in the short-term (4-year) absence of geese. Long-term (15-year) goose removal quadrupled net ecosystem C sequestration (NEE) by increasing ecosystem photosynthesis more than ecosystem respiration (ER). 4. Excluding reindeer for 21 years also produced detectable increases in live aboveground vascular plant biomass (from 50 to 80 g m−2; without promoting vegetation state shifts), as well as in vegetation C and N pools, dead biomass, moss-layer depth and ER. Yet, reindeer removal did not alter the chemistry of plants and soil or NEE. 5. Synthesis. Although both herbivores were key drivers of ecosystem structure and function, the control exerted by geese in their main habitat (wet tundra) was much more pronounced than that exerted by reindeer in their main habitat (moist-todry tundra). Importantly, these herbivore effects are scale dependent, because geese are more spatially concentrated and thereby affect a smaller portion of the tundra landscape compared to reindeer. Our results highlight the substantial heterogeneity in how herbivores shape tundra vegetation and ecosystem processes, with implications for ongoing environmental change

Annual ring growth of a widespread high arctic shrub reflects past fluctuations in community-level plant biomass

Norges Forskningsråd. Grant Numbers: 223257, 244647, 246054, 276080Peer reviewedPostprin

A Molecular Epidemiological and Genetic Diversity Study of Tuberculosis in Ibadan, Nnewi and Abuja, Nigeria

Background Nigeria has the tenth highest burden of tuberculosis (TB) among the 22 TB high-burden countries in the world. This study describes the biodiversity and epidemiology of drug-susceptible and drug-resistant TB in Ibadan, Nnewi and Abuja, using 409 DNAs extracted from culture positive TB isolates. Methodology/Principal Findings DNAs extracted from clinical isolates of Mycobacterium tuberculosis complex were studied by spoligotyping and 24 VNTR typing. The Cameroon clade (CAM) was predominant followed by the M. africanum (West African 1) and T (mainly T2) clades. By using a smooth definition of clusters, 32 likely epi-linked clusters related to the Cameroon genotype family and 15 likely epi-linked clusters related to other “modern” genotypes were detected. Eight clusters concerned M. africanum West African 1. The recent transmission rate of TB was 38%. This large study shows that the recent transmission of TB in Nigeria is high, without major regional differences, with MDR-TB clusters. Improvement in the TB control programme is imperative to address the TB control problem in Nigeria

Growth rings show limited evidence for ungulates' potential to suppress shrubs across the Arctic

Global warming has pronounced effects on tundra vegetation, and rising mean temperatures increase plant growth potential across the Arctic biome. Herbivores may counteract the warming impacts by reducing plant growth, but the strength of this effect may depend on prevailing regional climatic conditions. To study how ungulates interact with temperature to influence growth of tundra shrubs across the Arctic tundra biome, we assembled dendroecological data from 20 sites, comprising 1153 individual shrubs and 223 63 annual growth rings. Evidence for ungulates suppressing shrub radial growth was only observed at intermediate summer temperatures (6.5 degrees C-9 degrees C), and even at these temperatures the effect was not strong. Multiple factors, including forage preferences and landscape use by the ungulates, and favourable climatic conditions enabling effective compensatory growth of shrubs, may weaken the effects of ungulates on shrubs, possibly explaining the weakness of observed ungulate effects. Earlier local studies have shown that ungulates may counteract the impacts of warming on tundra shrub growth, but we demonstrate that ungulates' potential to suppress shrub radial growth is not always evident, and may be limited to certain climatic conditions

Summer warming explains widespread but not uniform greening in the Arctic tundra biome

Arctic warming can influence tundra ecosystem function with consequences for climate feedbacks, wildlife and human communities. Yet ecological change across the Arctic tundra biome remains poorly quantified due to field measurement limitations and reliance on coarse-resolution satellite data. Here, we assess decadal changes in Arctic tundra greenness using time series from the 30 m resolution Landsat satellites. From 1985 to 2016 tundra greenness increased (greening) at ~37.3% of sampling sites and decreased (browning) at ~4.7% of sampling sites. Greening occurred most often at warm sampling sites with increased summer air temperature, soil temperature, and soil moisture, while browning occurred most often at cold sampling sites that cooled and dried. Tundra greenness was positively correlated with graminoid, shrub, and ecosystem productivity measured at field sites. Our results support the hypothesis that summer warming stimulated plant productivity across much, but not all, of the Arctic tundra biome during recent decades