scholarly journals Water sources aggregate parasites with increasing effects in more arid conditions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Georgia Titcomb ◽  
John Naisikie Mantas ◽  
Jenna Hulke ◽  
Ivan Rodriguez ◽  
Douglas Branch ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Animal Movement ◽  
Landscape Heterogeneity ◽  
Water Sources ◽  
East African ◽  
Small Areas ◽  
Arid Conditions ◽  
Animal Activity ◽  
Herbivore Species ◽  
And Function

AbstractShifts in landscape heterogeneity and climate can influence animal movement in ways that profoundly alter disease transmission. Water sources that are foci of animal activity have great potential to promote disease transmission, but it is unknown how this varies across a range of hosts and climatic contexts. For fecal-oral parasites, water resources can aggregate many different hosts in small areas, concentrate infectious material, and function as disease hotspots. This may be exacerbated where water is scarce and for species requiring frequent water access. Working in an East African savanna, we show via experimental and observational methods that water sources increase the density of wild and domestic herbivore feces and thus, the concentration of fecal-oral parasites in the environment, by up to two orders of magnitude. We show that this effect is amplified in drier areas and drier periods, creating dynamic and heterogeneous disease landscapes across space and time. We also show that herbivore grazing behaviors that expose them to fecal-oral parasites often increase at water sources relative to background sites, increasing potential parasite transmission at these hotspots. Critically, this effect varies by herbivore species, with strongest effects for two animals of concern for conservation and development: elephants and cattle.

scholarly journals Water sources aggregate parasites, with increasing effects in more arid conditions

2021 ◽  
Author(s):  
Georgia Titcomb ◽  
John Mantas ◽  
Jenna Hulke ◽  
Ivan Rodriguez ◽  
Douglas Branch ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Climate Changes ◽  
Landscape Heterogeneity ◽  
Land Use Changes ◽  
Water Sources ◽  
East African ◽  
Global Pattern ◽  
Small Areas ◽  
Animal Activity ◽  
And Function

Abstract Shifts in landscape heterogeneity and climate can influence animal behavior and movement in ways that profoundly alter disease transmission. Amid accelerating climate and land use changes, it is increasingly important to identify and monitor hotspots of increased animal activity and overlap where disease transmission is likely to occur. Water sources that are foci of animal activity have great potential to promote disease transmission, but there has been very little work to quantify this, nor any comparison across a range of hosts and climatic contexts. In the case of fecal-oral parasites, water resources can aggregate large groups of many different host species in small areas, concentrate infectious material, and function as disease hotspots. This may be exacerbated where water is scarce and for species that require frequent drinking water access. Working in an East African savanna, we show via experimental and observational methods that water sources increase the density of wild and domestic herbivore feces and thus, the concentration of fecal-oral parasites in the environment, by up to two orders of magnitude. Our results show that this effect is amplified in drier areas and following periods of low rainfall, creating dynamic and heterogeneous disease landscapes across space and time. In addition, we show via camera trapping methods that herbivore grazing behaviors that expose them to fecal-oral parasites are often increased at water sources relative to background sites, thereby creating landscape hotspots of potential disease transmission. Critically, this effect varies markedly by herbivore species, with strongest effects observed for two large, water-dependent animals that are of critical concern for conservation and development: elephants and cattle. When water availability is reduced – a global pattern that is increasing amid climate changes and growing anthropogenic water use – risk of parasite exposure may increase substantially, posing multiple threats to critical taxa. These findings are important for understanding shifting parasite dynamics for several threatened wildlife species and for pastoral livelihoods in response to changing water supply due to climate changes.

scholarly journals Landscape heterogeneity and the biodiversity of Arctic stream communities: a habitat template analysis

2005 ◽  
Vol 62 (8) ◽  
pp. 1905-1919 ◽  
Author(s):  
Alexander D Huryn ◽  
Karie A Slavik ◽  
Rex L Lowe ◽  
Stephanie M Parker ◽  
Dennis S Anderson ◽  
...  
Keyword(s):  
Landscape Heterogeneity ◽  
Detrended Correspondence Analysis ◽  
Functional Feeding Groups ◽  
Mountain Glacier ◽  
Stream Communities ◽  
Stream Community ◽  
Arctic Alaska ◽  
Template Analysis ◽  
Habitat Template ◽  
And Function

We predicted that substratum freezing and instability are major determinants of the variability of stream community structure in Arctic Alaska. Their effects were conceptualized as a two-dimensional habitat template that was assessed using a natural experiment based on five stream types (mountain-spring, tundra-spring, tundra, mountain, glacier). Detrended correspondence analysis (DCA) indicated distinct macroinvertebrate assemblages for each stream type. The contribution of functional feeding groups to assemblage biomass varied systematically among stream types, indicating that structure and function are linked. Assemblage position within a DCA biplot was used to assess factors controlling its structure. Springs separated from other stream types along a gradient of nutrient concentration and freezing probability. Glacier and mountain streams separated from springs and tundra streams along a gradient of substratum instability and freezing probability. Owing to differences in sources of discharge to streams, the effects of nutrients and substratum stability could not be separated from freezing. Although many factors likely contribute to the variability of Arctic stream communities, the major determinants may be conceptualized as a template structured by gradients in (i) nutrient supply and substratum freezing and (ii) substratum instability and substratum freezing. This template provides a basis for predicting the response of Arctic stream communities to climate change.

Perennial anthropogenic water sources and their interaction with East African browsers and grazers: Ndarakwai Ranch, Tanzania. A case study

2003 ◽  
Vol 5 (2) ◽  
pp. 170
Author(s):  
John Lofstedt ◽  
Victoria Brenner ◽  
Ryan Buchanan ◽  
Casey Crawford ◽  
Terri Crawford ◽  
...  
Keyword(s):  
Water Sources ◽  
East African

scholarly journals Machine-learning reveals that Mycobacterium tuberculosis genotypes and anatomic disease site impacts drug resistance and disease transmission among patients with proven extra-pulmonary tuberculosis

2020 ◽  
Author(s):  
Doctor Busizwe Sibandze ◽  
Beki Themba Magazi ◽  
Lesibana Anthony Malinga ◽  
Nontuthuko Excellent Maningi ◽  
Bong Akee Shey ◽  
...  
Keyword(s):  
Machine Learning ◽  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Disease Transmission ◽  
East Asian ◽  
Extrapulmonary Tuberculosis ◽  
Machine Learning Algorithms ◽  
East African ◽  
Development Of Resistance ◽  
Asian Lineage

Abstract Background: There is a general dearth of information on extrapulmonary tuberculosis (EPTB). Here, we investigated Mycobacterium tuberculosis (Mtb) drug resistance and transmission patterns in EPTB patients treated in the Tshwane metropolitan area, in South Africa.Methods: Consecutive Mtb culture-positive non-pulmonary samples from unique EPTB patients underwent mycobacterial genotyping and were assigned to phylogenetic lineages and transmission clusters based on spoligotypes. MTBDRplus assay was used to search mutations for isoniazid and rifampin resistance. Machine learning algorithms were used to identify clinically meaningful patterns in data. We computed odds ratio (OR), attributable risk (AR) and corresponding 95% confidence intervals (CI). Results: Of the 70 isolates examined, the largest cluster comprised 25 (36%) Mtb strains that belonged to the East Asian lineage. East Asian lineage was significantly more likely to occur within chains of transmission when compared to the Euro-American and East-African Indian lineages: OR= 10.11 (95% CI: 1.56-116). Lymphadenitis, meningitis and cutaneous TB, were significantly more likely to be associated with drug resistance: OR=12.69 (95% CI: 1.82-141.60) and AR = 0.25 (95% CI: 0.06-0.43) when compared with other EPTB sites, which suggests that poor rifampin penetration might be a contributing factor.Conclusions: The majority of Mtb strains circulating in the Tshwane metropolis belongs to East Asian, Euro-American and East-African Indian lineages. Each of these are likely to be clustered, suggesting on-going EPTB transmission. Since 25% of the drug resistance was attributable to sanctuary EPTB sites notorious for poor rifampin penetration, we hypothesize that poor anti-tuberculosis drug dosing might have a role in the development of resistance.

Climatic Changes in South-East India during Early Palaeolithic Times

1932 ◽  
Vol 69 (5) ◽  
pp. 193-205 ◽  
Author(s):  
F. J. Richards ◽  
L. A. Cammiade ◽  
M. C. Burkitt
Keyword(s):  
East Africa ◽  
Climatic Changes ◽  
East African ◽  
Geological Evidence ◽  
Arid Conditions ◽  
Lower Palaeolithic

HUMAN artifacts can often be very useful to the geologist. When they occur in sufficient numbers and are characteristic, prehistorians can be definite in assigning the industries to a certain culture or cultures, and they can then be utilized by the geologist in the same way as are fossils. In Europe during a part of Quaternary times Lower Palaeolithic cultures flourished. Now Quaternary times in Europe can, of course, be readily subdivided into glacial and interglacial periods, but these naturally did not occur further south. In East Africa geological evidence has been adduced to show that intense pluvial periods took the place of our European glaciations, while during the interglacial phases the African areas suffered from arid conditions. Lower Palaeolithic industries are found at certain levels in East Africa and they enable the geologist to correlate the East African and European sequences. South-East India (Madras) is also not an area where glaciations ever occurred: but, we ask, can geological evidence be adduced to demonstrate climatic changes corresponding to those found to have occurred in East Africa ? Lower Palaeolithic industries occur in great numbers in South-East India; whereas most of them have been merely collected from the surface, and are therefore useless for the purposes of exact dating, a number of finds in situ in definite layers have been made, and as in East Africa these can be used as datum lines for correlating purposes.

scholarly journals Fatal attraction: vegetation responses to nutrient inputs attract herbivores to infectious anthrax carcass sites

2014 ◽  
Vol 281 (1795) ◽  
pp. 20141785 ◽  
Author(s):  
Wendy C. Turner ◽  
Kyrre L. Kausrud ◽  
Yathin S. Krishnappa ◽  
Joris P. G. M. Cromsigt ◽  
Holly H. Ganz ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Camera Traps ◽  
Nutrient Inputs ◽  
Trade Off ◽  
Nutrient Effects ◽  
Fatal Attraction ◽  
Herbivore Species ◽  
Indirect Cues ◽  
Parasite Avoidance ◽  
Grazing Behaviour

Parasites can shape the foraging behaviour of their hosts through cues indicating risk of infection. When cues for risk co-occur with desired traits such as forage quality, individuals face a trade-off between nutrient acquisition and parasite exposure. We evaluated how this trade-off may influence disease transmission in a 3-year experimental study of anthrax in a guild of mammalian herbivores in Etosha National Park, Namibia. At plains zebra ( Equus quagga ) carcass sites we assessed (i) carcass nutrient effects on soils and grasses, (ii) concentrations of Bacillus anthracis (BA) on grasses and in soils, and (iii) herbivore grazing behaviour, compared with control sites, using motion-sensing camera traps. We found that carcass-mediated nutrient pulses improved soil and vegetation, and that BA is found on grasses up to 2 years after death. Host foraging responses to carcass sites shifted from avoidance to attraction, and ultimately to no preference, with the strength and duration of these behavioural responses varying among herbivore species. Our results demonstrate that animal carcasses alter the environment and attract grazing hosts to parasite aggregations. This attraction may enhance transmission rates, suggesting that hosts are limited in their ability to trade off nutrient intake with parasite avoidance when relying on indirect cues.

scholarly journals Structural and functional profile of livestock markets in India

2020 ◽  
Vol 1 (2) ◽  
pp. 87-92
Author(s):  
Vishnu Dev R. S. ◽  
S. Harikumar
Keyword(s):  
Disease Transmission ◽  
Animal Movement ◽  
Epidemiological Studies ◽  
Marketing Strategies ◽  
State Governments ◽  
Contagious Diseases ◽  
Livestock Markets ◽  
Exchange Function ◽  
Structural Base

Abstract: Livestock markets perform major exchange function of animals in India. These markets play a considerable share in the economic gain of farmers and act as a social and cultural migration hub for the domestic and foreign tourists also. But they are largely unorganized and dominated by informal traders. The structural base of livestock markets determines the sales pattern and the major price value of animals is bagged by middlemen. These markets are functioning under the jurisdiction of the state governments and supervision is under the control of the local bodies. The different marketing strategies in the markets and pricing are affected by qualitative and quantitative factors of animals. The major constraints regarding the livestock markets are the lack of facilities and unawareness of knowledge among the sellers and buyers. The role of livestock markets in disease transmission is also a matter of concern. Details regarding animal movement will facilitate epidemiological studies to prevent contagious diseases from outside the country. In the present COVID-19 pandemic, conventional livestock markets are closed and virtual markets based on online platforms such as Facebook, WhatsApp and E-commerce sites are coming up and these transformations are absolutely inevitable. Keywords: Livestock markets, Marketing strategies, India

scholarly journals Accounting for animal movement improves vaccination strategies against wildlife disease in heterogeneous landscapes

2021 ◽  
Author(s):  
Katherine M McClure ◽  
Guillaume Bastille-Rousseau ◽  
Amy J Davis ◽  
Carolyn A Stengel ◽  
Kathleen Nelson ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Animal Movement ◽  
Landscape Heterogeneity ◽  
Habitat Preferences ◽  
Movement Ecology ◽  
Suburban Areas ◽  
Preferred Habitat ◽  
Animal Populations ◽  
Oral Rabies Vaccine ◽  
Better Than

Oral baiting is used to deliver vaccines to wildlife to prevent, control, and eliminate infectious diseases. A central challenge is how to spatially distribute baits to maximize encounters by target animal populations, particularly in urban and suburban areas where wildlife like raccoons (Procyon lotor) are abundant and baits are delivered along roads. Methods from movement ecology that quantify movement and habitat selection could help to optimize baiting strategies by more effectively targeting wildlife populations across space. We developed a spatially explicit, individual-based model of raccoon movement and oral rabies vaccine seroconversion to examine whether and when baiting strategies that match raccoon movement patterns perform better than currently employed baiting strategies in an oral rabies vaccination zone in greater Burlington, Vermont, USA. Habitat selection patterns estimated from locally radio-collared raccoons were used to parameterize movement simulations. We then used our simulations to estimate raccoon population rabies seroprevalence under currently used baiting strategies (actual baiting) relative to habitat selection-based baiting strategies (habitat baiting). We conducted simulations on the Burlington landscape and artificial landscapes that varied in heterogeneity relative to Burlington in the proportion and patch size of preferred habitats. We found that the benefits of habitat baiting strongly depended on the magnitude and variability of raccoon habitat selection and the degree of landscape heterogeneity within the baiting area. Habitat baiting improved seroprevalence over actual baiting for raccoons characterized as habitat specialists but not for raccoons that displayed weak habitat selection similar to radio-collared individuals - except when baits were delivered off roads where preferred habitat coverage and complexity was more pronounced. In contrast, in artificial landscapes with either more strongly juxtaposed favored habitats and/or higher proportions of favored habitats, habitat baiting performed better than actual baiting, even when raccoons displayed weak habitat preferences and where baiting was constrained to roads. Our results suggest that habitat selection-based baiting could increase raccoon population seroprevalence in urban-suburban areas, where practical, given the heterogeneity and availability of preferred habitat types in those areas. Our novel simulation approach provides a flexible framework to test alternative baiting strategies in multiclass landscapes to optimize bait distribution strategies.

An Examination of Personal Mobility Patterns in Space and Time Using Twitter

2014 ◽  
Vol 5 (3) ◽  
pp. 55-72 ◽  
Author(s):  
Mark Birkin ◽  
Kirk Harland ◽  
Nicolas Malleson ◽  
Philip Cross ◽  
Martin Clarke
Keyword(s):  
Activity Patterns ◽  
Mobility Patterns ◽  
Personal Mobility ◽  
Small Areas ◽  
Form And Function ◽  
Space And Time ◽  
Frequency Of Use ◽  
User Groups ◽  
And Function

New sources of data relating to personal mobility and activity patterns are now providing a unique opportunity to explore movement patterns at increasing scales of spatial and temporal refinement. In this article, a corpus of messages from the Twitter social networking platform are examined. An elementary classification of users is proposed on the basis of frequency of use in space and time. The behaviour of different user groups is investigated across small areas in the major conurbation of Leeds. Substantial variations can be detected in the configuration of individual networks. An interpretation of the patterns which result is provided in terms of the underlying demographic structures, and the basic form and function of the urban area.

Landscape Effects on Ecosystem Structure and Function

2019 ◽  
pp. 512-546
Author(s):  
Kimberly A. With
Keyword(s):  
Nutrient Dynamics ◽  
Landscape Heterogeneity ◽  
Landscape Management ◽  
Structure And Function ◽  
Landscape Context ◽  
Ecological Resilience ◽  
Ecosystem Structure ◽  
The Face ◽  
And Function ◽  
Ecosystem Structure And Function

Landscape ecosystem ecology is concerned with the study of how landscape structure affects ecosystem structure and function, and how landscape heterogeneity in turn is generated or sustained by the redistribution of nutrients or organisms within and among ecosystems. This chapter begins with an overview of how landscape context influences ecosystem processes, including the effects of land management and land-cover change on nutrient dynamics and productivity. Next, the chapter considers the linkages among systems (metaecosystems) and how spatial subsidies are important for understanding ecosystem function in a landscape context. The chapter then explores under what conditions landscape function becomes disrupted, possibly precipitating irreversible system state changes, before concluding with a clarion call for landscape sustainability; that is, landscape management that preserves the productivity, multifunctionality, and ecological resilience of landscapes in the face of future societal demands, intensifying land use, and rapid climate change.

Sign in / Sign up

Export Citation Format

Share Document