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Simultaneous Localization and Mapping (SLAM) is a crucial function for most autonomous systems, allowing them to both navigate through and create maps of unfamiliar surroundings. Traditional Visual SLAM, also commonly known as VSLAM, relies on frame-based cameras and structured processing pipelines, which face challenges in dynamic or low-light environments. However, recent advancements in event camera technology and neuromorphic processing offer promising opportunities to overcome these limitations. Event cameras inspired by biological vision systems capture the scenes asynchronously, consuming minimal power but with higher temporal resolution. Neuromorphic processors, which are designed to mimic the parallel processing capabilities of the human brain, offer efficient computation for real-time data processing of event-based data streams. This paper provides a comprehensive overview of recent research efforts in integrating event cameras and neuromorphic processors into VSLAM systems. It discusses the principles behind event cameras and neuromorphic processors, highlighting their advantages over traditional sensing and processing methods. Furthermore, an in-depth survey was conducted on state-of-the-art approaches in event-based SLAM, including feature extraction, motion estimation, and map reconstruction techniques. Additionally, the integration of event cameras with neuromorphic processors, focusing on their synergistic benefits in terms of energy efficiency, robustness, and real-time performance, was explored. The paper also discusses the challenges and open research questions in this emerging field, such as sensor calibration, data fusion, and algorithmic development. Finally, the potential applications and future directions for event-based SLAM systems are outlined, ranging from robotics and autonomous vehicles to augmented reality.
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There are growing demands globally to use safe, efficacious and environmentally friendly sanitizers for post-harvest treatment of fresh produce to reduce or eliminate spoilage and foodborne pathogens. Here, we compared the efficacy of a pH-neutral electrolyzed oxidizing water (Ecas4 Anolyte; ECAS) with that of an approved peroxyacetic acid-based sanitizer (Ecolab Tsunami® 100) in reducing the total microbial load and inoculated Escherichia coli, Salmonella Enteritidis and Listeria innocua populations on post-harvest baby spinach leaves over 10 days. The impact of both sanitizers on the overall quality of the spinach leaves during storage was also assessed by shelf life and vitamin C content measurements. ECAS at 50 ppm and 85 ppm significantly reduced the bacterial load compared to tap water-treated or untreated (control) leaves, and at similar levels (approx. 10-fold reduction) to those achieved using 50 ppm of Ecolab Tsunami® 100. While there were no obvious deleterious effects of treatment with 50 ppm Tsunami® 100 or ECAS at 50 ppm and 85 ppm on plant leaf appearance, tap water-treated and untreated leaves showed some yellowing, bruising and sliming. Given its safety, efficacy and environmentally-friendly characteristics, ECAS could be a viable alternative to chemical-based sanitizers for post-harvest treatment of fresh produce.
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Eletrólise , Contaminação de Alimentos/análise , Folhas de Planta/microbiologia , Spinacia oleracea/microbiologia , Água/química , Bactérias/classificação , Escherichia coli , Microbiologia de Alimentos , Inocuidade dos Alimentos , Armazenamento de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Concentração de Íons de Hidrogênio , Listeria , Oxirredução , Ácido Peracético , Salmonella enteritidis , TemperaturaRESUMO
An electrochemically activated solution (ECAS), generated by electrolysis of a dilute sodium chloride solution in a four-chamber electrolytic cell (Ecas4), was tested as a sanitising aerosol in eliminating bacteria from the environment of a weaning room vacated 24-48h earlier, at a continuous flow pig farm. An ultrasonic humidifier was used to fill the environment with a fog (droplets with diameters of 1-5 µm) containing 0.25 ppm of hypochlorous acid. The weaning room was fogged for 3 min at 30 min intervals during five hours of aerosol disinfection. An innovative sample treatment with propidium monoazide dye in conjunction with cyclonic air sampling was optimised and adapted for discerning live/dead bacteria in subsequent molecular quantification steps. Without fogging, total bacterial load ranged from 5.06 ± 0.04 to 5.75 ± 0.04 Log10 CFU/m3. After the first hour of fogging, a 78% total bacterial reduction was observed, which further increased to > 97% after the second hour, > 99.4% after the third and 99.8% after the fourth hour, finally resulting in a 99.99% reduction from the farm environment over five hours. Unlike the current formaldehyde spray disinfection protocol, which requires a long empty period because of its hazardous properties, this economically viable and environmentally friendly disinfection protocol may significantly lower downtime. Moreover, ECAS fogging can be easily adapted to a variety of applications, including the elimination of pathogens from livestock farm air environment for disease prevention, as well as decontamination after disease outbreaks.
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Bactérias/efeitos dos fármacos , Infecções Bacterianas/prevenção & controle , Descontaminação/métodos , Desinfetantes/administração & dosagem , Fazendas , Actinobacillus pleuropneumoniae/efeitos dos fármacos , Actinobacillus pleuropneumoniae/isolamento & purificação , Aerossóis , Microbiologia do Ar , Animais , Bactérias/isolamento & purificação , Infecções Bacterianas/microbiologia , Infecções Bacterianas/veterinária , Carga Bacteriana , Desinfetantes/química , Eletrólise , Fumigação/métodos , Umidificadores , Concentração de Íons de Hidrogênio , Ácido Hipocloroso/administração & dosagem , Ácido Hipocloroso/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Suínos/microbiologiaRESUMO
Reliable population estimates are lacking for many South Asian primate species, including the golden langur (Trachypithecus geei), which is endangered and restricted to Bhutan and northeast India. Although well studied in India, few studies exist on this species in Bhutan. In November 2017, we undertook a nationwide survey of golden langurs in Bhutan using double observers along trail-based transects in 17 blocks within its habitat, and modeled its distribution using MaxEnt. A total of 2439 golden langurs in 222 groups were collectively encountered by 17 teams of double observers, from which, an overall population of 2516 ± SE 363 individuals and 236 ± SE 9 groups were estimated. Group sizes varied from 2 to 35 individuals with a mean of 11 ± SD 0.38 individuals. A total of 468 adult males (19%), 924 adult females (38%), 649 juveniles (27%), and 398 infants (16%) were counted. Adult male-to-female sex ratio was 1:1.97 and adult female-to-infant ratio was 1:0.43. We determined 2848 km2 of suitable area for golden langurs in Bhutan and estimated a density of 0.88 individuals/km2. Our population estimate of golden langurs in Bhutan is much lower than the current IUCN estimate of 4000 individuals for Bhutan, necessitating a reassessment of its current conservation status due to threats from road kills, electrocution, and development activities like road construction, hydropower, and electrical transmission lines. We further recommend our refined double-observer survey method to reliably estimate primate populations in rugged terrain.
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Distribuição Animal , Espécies em Perigo de Extinção , Presbytini/fisiologia , Animais , Butão , Ecossistema , Feminino , Masculino , Densidade DemográficaRESUMO
Despite the golden langur's (Trachypithecus geei) endangered and totally protected status, local awareness and attitude toward this species is poorly understood. We investigated local awareness and attitude in Bhutan by interviewing 1,143 households in the districts of Dagana, Sarpang, Trongsa, Tsirang, and Zhemgang, and analyzing data through a conditional inference tree analysis. Most respondents were not aware of the golden langur's nationally protected (53%; n = 604) and globally endangered status (64%; n = 730), but their location of residence (inside/outside a protected area; p < .001) and education level (p < .001) significantly influenced awareness. The majority of respondents (87%; n = 999) liked the golden langur but the attitude was significantly influenced primarily by whether or not they experienced crop damage by golden langurs (p < .001), and subsequently by location of residence (p < .001), local belief (p < .01), gender (p < .05), and personal encounter with a golden langur (p < .001). Socioeconomic variables like age, education level, and annual income did not influence attitude. We recommend environmental education and awareness campaigns outside protected areas, and intensifying existing programs inside protected areas to forge harmonious human-golden langur coexistence.
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Espécies em Perigo de Extinção , Presbytini , Opinião Pública , Adulto , Animais , Butão , Produção Agrícola , Cultura , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , População Rural , Fatores Socioeconômicos , Inquéritos e QuestionáriosRESUMO
Foot-and-mouth disease (FMD) is a highly contagious disease of livestock affecting animal production and trade throughout Asia and Africa. Understanding FMD virus (FMDV) global movements and evolution can help to reconstruct the disease spread between endemic regions and predict the risks of incursion into FMD-free countries. Global expansion of a single FMDV lineage is rare but can result in severe economic consequences. Using extensive sequence data we have reconstructed the global space-time transmission history of the O/ME-SA/Ind-2001 lineage (which normally circulates in the Indian sub-continent) providing evidence of at least 15 independent escapes during 2013-2017 that have led to outbreaks in North Africa, the Middle East, Southeast Asia, the Far East and the FMD-free islands of Mauritius. We demonstrated that sequence heterogeneity of this emerging FMDV lineage is accommodated within two co-evolving divergent sublineages and that recombination by exchange of capsid-coding sequences can impact upon the reconstructed evolutionary histories. Thus, we recommend that only sequences encoding the outer capsid proteins should be used for broad-scale phylogeographical reconstruction. These data emphasise the importance of the Indian subcontinent as a source of FMDV that can spread across large distances and illustrates the impact of FMDV genome recombination on FMDV molecular epidemiology.
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Vírus da Febre Aftosa/genética , Febre Aftosa/epidemiologia , Pandemias/estatística & dados numéricos , África do Norte/epidemiologia , Animais , Ásia/epidemiologia , Proteínas do Capsídeo/genética , Evolução Molecular , Febre Aftosa/transmissão , Febre Aftosa/virologia , Genoma Viral/genética , Maurício/epidemiologia , Epidemiologia Molecular , Filogeografia , Recombinação GenéticaRESUMO
Highly pathogenic avian influenza A(H5N1), clade 2.3.2.1a, with an H9-like polymerase basic protein 1 gene, isolated in Bhutan in 2012, replicated faster in vitro than its H5N1 parental genotype and was transmitted more efficiently in a chicken model. These properties likely help limit/eradicate outbreaks, combined with strict control measures.
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Genótipo , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Aves Domésticas/virologia , Vírus Reordenados/genética , Animais , Butão/epidemiologia , Surtos de Doenças , Geografia Médica , Humanos , Influenza Humana/epidemiologia , Filogenia , RiscoRESUMO
Community knowledge, attitudes and practices are important both for prevention of human deaths due to rabies and for control of the disease in animals. This study was a cross-sectional survey investigating the level of community knowledge as well as attitudes and perceptions about rabies in Gelephu, south-central Bhutan, a region endemic for rabies. A total of 615 household respondents were interviewed, of which 224 (36%) were male and 391 (64%) were female. The majority of respondents had a high level of knowledge, attitudes and perception of rabies and had a positive attitude towards the prevention and control of rabies. Multivariate logistic regression modelling showed that better knowledge of rabies was predicted by gender, educational level and dog ownership status of respondents, whilst health-seeking behaviour of animal bite injuries was predicted by dog ownership status, presence of children in the household and occupation of the respondents. The majority of respondents believed that stray dogs are a problem in the community and felt that it was important to control the dog population in Gelephu. These findings also indicate that there exists a knowledge gap about rabies in the community that could be improved by creating an awareness education programme.