scholarly journals Nipah virus dynamics in bats and implications for spillover to humans

2020 ◽  
Vol 117 (46) ◽  
pp. 29190-29201 ◽  
Author(s):  
Jonathan H. Epstein ◽  
Simon J. Anthony ◽  
Ariful Islam ◽  
A. Marm Kilpatrick ◽  
Shahneaz Ali Khan ◽  
...  

Nipah virus (NiV) is an emerging bat-borne zoonotic virus that causes near-annual outbreaks of fatal encephalitis in South Asia—one of the most populous regions on Earth. In Bangladesh, infection occurs when people drink date-palm sap contaminated with bat excreta. Outbreaks are sporadic, and the influence of viral dynamics in bats on their temporal and spatial distribution is poorly understood. We analyzed data on host ecology, molecular epidemiology, serological dynamics, and viral genetics to characterize spatiotemporal patterns of NiV dynamics in its wildlife reservoir,Pteropus mediusbats, in Bangladesh. We found that NiV transmission occurred throughout the country and throughout the year. Model results indicated that local transmission dynamics were modulated by density-dependent transmission, acquired immunity that is lost over time, and recrudescence. Increased transmission followed multiyear periods of declining seroprevalence due to bat-population turnover and individual loss of humoral immunity. Individual bats had smaller host ranges than otherPteropusspecies (spp.), although movement data and the discovery of a Malaysia-clade NiV strain in eastern Bangladesh suggest connectivity with bats east of Bangladesh. These data suggest that discrete multiannual local epizootics in bat populations contribute to the sporadic nature of NiV outbreaks in South Asia. At the same time, the broad spatial and temporal extent of NiV transmission, including the recent outbreak in Kerala, India, highlights the continued risk of spillover to humans wherever they may interact with pteropid bats and the importance of limiting opportunities for spillover throughoutPteropus’s range.

Author(s):  
Danika L. Bannasch ◽  
Christopher B. Kaelin ◽  
Anna Letko ◽  
Robert Loechel ◽  
Petra Hug ◽  
...  

AbstractDistinctive colour patterns in dogs are an integral component of canine diversity. Colour pattern differences are thought to have arisen from mutation and artificial selection during and after domestication from wolves but important gaps remain in understanding how these patterns evolved and are genetically controlled. In other mammals, variation at the ASIP gene controls both the temporal and spatial distribution of yellow and black pigments. Here, we identify independent regulatory modules for ventral and hair cycle ASIP expression, and we characterize their action and evolutionary origin. Structural variants define multiple alleles for each regulatory module and are combined in different ways to explain five distinctive dog colour patterns. Phylogenetic analysis reveals that the haplotype combination for one of these patterns is shared with Arctic white wolves and that its hair cycle-specific module probably originated from an extinct canid that diverged from grey wolves more than 2 million years ago. Natural selection for a lighter coat during the Pleistocene provided the genetic framework for widespread colour variation in dogs and wolves.


Information ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 153
Author(s):  
Penglong Li ◽  
Zuoqin Shi ◽  
Yi Ding ◽  
Ling Zhao ◽  
Zezhong Ma ◽  
...  

Museum cultural relics represent a special material cultural heritage, and modern interpretations of them are needed in current society. Based on the catalogue data of cultural relics published by the State Administration of Cultural Heritage, this paper analyzes the continuity and intermittentness of cultural relics in time series by using the method of continuity judgment of cultural relics, analyzes the aggregation and migration of cultural relics in space by using the method of spatial analysis, and then uses cosine similarity to explain the similarity distribution in space and time. The results show that the overall distribution of cultural relics exhibits the characteristics of class aggregation, dynasty aggregation and regional aggregation. From the perspective of a time scale, cultural relics have different “life cycles”, displaying continuity, intermittentness, and similarity. From the perspective of a spatial scale, the cultural relic distribution forms a small “cultural communication circle”, showing aggregation, migration, and similarity. The temporal and spatial distribution of cultural relics exhibited more similar characteristics among dynasties that were closer together than those that were far away.


2002 ◽  
Vol 3 (2) ◽  
pp. 93-101 ◽  
Author(s):  
F E Corcione ◽  
S S Merola ◽  
B M Vaglieco

In the last few years, there has been an increasing concern about the emissions of ultrafine particles in the atmosphere. A detailed study of the formation and oxidation of these particles in the environment of the diesel engine cylinder presents many experimental difficulties due to the high temperatures, pressures and extremely reactive intermediate species. To allow investigation of the different phases of the diesel combustion process, high temporal and spatial resolution optical techniques were applied in the optically accessible chamber of a diesel engine at fixed engine speed and air-fuel ratio. Simultaneous extinction, scattering and flame chemiluminescence measurements from the ultraviolet to the visible region were carried out in order to study the diesel combustion process from the soot inception to the formation of soot particles, through the growth of their precursors. These species were characterized as carbonaceous nanometric structures and their sizes were evaluated by the Mie theory.


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