scholarly journals Long-term transmission dynamics of tick-borne diseases involving seasonal variation and co-feeding transmission

2021 ◽  
Vol 15 (1) ◽  
pp. 269-286
Author(s):  
Kyeongah Nah ◽  
Jianhong Wu
1984 ◽  
Vol 16 (5-7) ◽  
pp. 359-373 ◽  
Author(s):  
Anne R Henderson

The sublittoral macrobenthic invertebrate populations of the Upper Clyde Estuary are described. The estuary has a long history of organic pollution. The long term changes in species composition, faunal density and dominance patterns between 1974 and 1980 are presented. The fauna is dominated by brackish, pollution tolerant oligochaetes and polychaetes. Fluctuations in populations can be related to both seasonal variation in environmental conditions and long term improvements in water quality through a reduction in pollution loading to the estuary.


2013 ◽  
Vol 142 (9) ◽  
pp. 2000-2012 ◽  
Author(s):  
J. HUELS ◽  
K. M. CLEMENTS ◽  
L. J. McGARRY ◽  
G. J. HILL ◽  
J. WASSIL ◽  
...  

SUMMARYNeisseria meningitidis is the main cause of bacterial meningitis and sepsis in the UK, and can potentially be lethal or cause long-term sequelae. Bexsero® (4CMenB) is a new multi-component vaccine approved by the European Commission for use in individuals aged ⩾2 months. A theoretical transmission model was constructed to assess the long-term effectiveness of Bexsero compared to standard care. The model was populated with UK-specific demographic data and calibrated to ensure that the transmission dynamics of meningococcal disease in the UK were adequately simulated. The model showed the best strategy to be a routine vaccination programme at ages 2, 3, 4, 12 months and 14 years combined with a 5-year catch-up programme in toddlers aged 12–24 months and adolescents aged 15–18 years. This would lead to a 94% reduction in meningococcal cases or 150 000 cases and 15 000 deaths over a 100-year time-frame.


2018 ◽  
Vol 44 (2) ◽  
pp. 195-210
Author(s):  
Riaz Hossain Khan ◽  
Mohammad Saiful Islam

The study examines the long-term and seasonal climatic variations in north-western part of Bangladesh (NWPB). Long-term variation of different climatic parameters reveals that significant increases in temperature are associated with decreasing evaporation which could be attributed to wind speed variation and seasonal variation of temperature. Increase of monsoon rainfall during monsoon period and scarcity or absence of rainfall during dry periods increase the region’s vulnerability to monsoon flood and seasonal drought, respectively. The area witnesses a single peak of rainfall in July during the first half of the study period (1964-1985), whereas the same experiences bimodal peak of rainfall during July and September in the second half of the study period (1986-2007). This may signify the changes of climatic condition in the studied area. Annual variability of rainfall as well as the unpredictable shifting of rainfall periods might be a possible reason for the seasonal drought. The aridity index indicates that the overall dryness of the area has increased during winter season. The study shows that humidity increases at all stations throughout the year. The study also shows that long-term seasonal variation of both surface and groundwater level is also prominent. Gradual decrease of surface water level was observed in Teesta River which might be due to unilateral withdrawal of surface water in the upper riparian. Detailed investigation on hydrometeorology of the study area is required to see whether there is any trend of climate change in the area. Asiat. Soc. Bangladesh, Sci. 44(2): 195-210 December 2018


1987 ◽  
Vol 150 (2) ◽  
pp. 213-218 ◽  
Author(s):  
J. Bell ◽  
P. H. Garthwaite

This study follows the psychological profile of a group of Antarctic explorers on a remote base in British Antarctica. Each month for 1 year the 60-item General Health Questionnaire (GHQ) was administered to the 12-man complement and the results compared to those of a control group. Three men resigned and left, 4 months later, at the end of winter. Their scoring showed marked differences from the others, including the highest scores in the severe depression factor scale. The GHQ was accepted by the men despite the intrusive threat it offered in such a small community; there was also a seasonal variation in scoring, with higher scores in the winter, and no evidence of long-term psychological sequelae in those who stayed.


2016 ◽  
Vol 66 (3-4) ◽  
pp. 305-319 ◽  
Author(s):  
Pankaj Koparde

Odonates are considered to be good ecological indicators, hence, they are used in biological assessment of habitat quality. However, species responses may vary spatiotemporally and therefore, it is useful to establish species-habitat relationships at a regional level. To test if tropical urban odonates respond to seasons, and to explore species-habitat relationships with an emphasis on water pollution, I studied six wetlands in the city of Pune for a year. I also investigated whether combining data on dragonflies and damselflies, as is often done in many studies, skews the results. I recorded seasons, water pollution and habitat attributes as predictors of the odonate diversity and assemblage. I analyzed the data on dragonflies, damselflies and odonates (dragonfly-damselfly combined) separately for seasonal variation, and species-habitat relationships. I used multiple regression and canonical correspondence analyses. Forty-four species were recorded during the study. No seasonal variation was detected, except for damselflies, which showed an increase in the diversity and species number post-monsoon. Multiple regression analysis showed that damselfly and dragonfly diversity varied as a function of season and water pollution, and monsoon respectively. In pre-monsoon, damselfly diversity marginally increased with pollution. Both the analyses suggest that combining data on dragonflies and damselflies may skew the end results. Therefore, I recommend further intensive and long-term research using accurately sampled habitat and pollution attributes, as well as habitat restoration through conserving urban green spaces and promoting gardens with streams and ponds.


2008 ◽  
Vol 136 (11) ◽  
pp. 1496-1510 ◽  
Author(s):  
C. LANZAS ◽  
S. BRIEN ◽  
R. IVANEK ◽  
Y. LO ◽  
P. P. CHAPAGAIN ◽  
...  

SUMMARYThe objective of this study was to address the impact of heterogeneity of infectious period and contagiousness onSalmonellatransmission dynamics in dairy cattle populations. We developed three deterministic SIR-type models with two basic infected stages (clinically and subclinically infected). In addition, model 2 included long-term shedders, which were defined as individuals with low contagiousness but long infectious period, and model 3 included super-shedders (individuals with high contagiousness and long infectious period). The simulated dynamics, basic reproduction number (R0) and critical vaccination threshold were studied. Clinically infected individuals were the main force of infection transmission for models 1 and 2. Long-term shedders had a small impact on the transmission of the infection and on the estimated vaccination thresholds. The presence of super-shedders increasesR0and decreases the effectiveness of population-wise strategies to reduce infection, making necessary the application of strategies that target this specific group.


2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Xiao-Yan Zhao ◽  
Shu-Min Guo ◽  
Mini Ghosh ◽  
Xue-Zhi Li

The growing number of reported avian influenza cases has prompted awareness of the importance of research methods to control the spread of the disease. Seasonal variation is one of the important factors that affect the spread of avian influenza. This paper presents a “nonautonomous” model to analyze the transmission dynamics of avian influenza with the effects of climate change. We obtain and discuss the global stability conditions of the disease-free equilibrium; the threshold conditions for persistence, permanence, and extinction of the disease; and the parameters with periodicity for controlling and eliminating the avian influenza.


2002 ◽  
Vol 104 (1) ◽  
pp. 19-26 ◽  
Author(s):  
M Gracenea ◽  
M.S Gómez ◽  
J Torres ◽  
E Carné ◽  
J Fernández-Morán

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