Background: Men who have sex with men (MSM) are highly vulnerable to HIV infection, but this population can be particularly difficult to reach in Thailand. This study aimed to estimate the number of MSM in Chiang Mai ...Background: Men who have sex with men (MSM) are highly vulnerable to HIV infection, but this population can be particularly difficult to reach in Thailand. This study aimed to estimate the number of MSM in Chiang Mai Thailand, in order to plan HIV control and prevention. Methods: The total of 348 potential MSM were identified at eight contact locations, including two public parks, two bars, two massage parlors and two pubs in Chiang Mai. Trained 16 research enumerators and 16 enumerators were trained to extend a recruitment of brooches to MSM. The MSMs were captured one week apart. A record was kept of when, where and by whom the invitation was extended and received, and of refusals. The total estimate of MSM was derived from capture-recapture calculation. Results: The total MSM in Chiang Mai Thailand estimated by capture and recapture method was 733 (95%CI = 480 - 948) or the estimate was 7.3% (95%CI = 7.1% - 14.1%). Conclusions: Capture and recapture method can be used to enumerate and provide accurate and reliable estimates of the MSM population in any area, provided that certain conditions are controlled. MSM who are engaged in personal community represent a sizeable population who urgently need to be targeted by HIV and STDs prevention strategies.展开更多
Movement activity levels of wild animals often differ consistently among individuals,reflecting different behavioral types.Previous studies have shown that laboratory-scored activity can predict several ecologically r...Movement activity levels of wild animals often differ consistently among individuals,reflecting different behavioral types.Previous studies have shown that laboratory-scored activity can predict several ecologically relevant characteristics.In an experiment on wild brown trout Salmo trutta,spanning from June to October,we investigated how spring swimming activity,measured in a standardized laboratory test,related to relative recapture probability in autumn.Based on laboratory activity scores,individuals clustered into 2 groups,which showed contrasting patterns in the size-dependency of their recapture probability.Size had a slightly positive effect on recapture probability for passive fish but a clear negative effect on active fish.Our results show that the population structure in a cohort,in terms of relative proportions of behavioral types in different size classes,can vary over time.The results of this study could depend on either selective mortality or migration.However,selective disappearance of individuals with specific phenotypes,regardless of the mechanism,will have implications for trout population management,such as stocking efficiency of hatchery fish with high growth rates or maintenance of fishways past migration barriers.展开更多
Background The Sterile insect technique(SIT)has been successfully used in agricultural pest control,leading to interest in its application for public health,particularly in controlling Aedes mosquitoes in the USA,Ital...Background The Sterile insect technique(SIT)has been successfully used in agricultural pest control,leading to interest in its application for public health,particularly in controlling Aedes mosquitoes in the USA,Italy,Cuba,and Greece.Malaysia has conducted a small-scale SIT pilot trial since 2019 for dengue control.This study evaluates mosquito populations in treated and untreated sites through three objectives:(1)comparing mean larvae per trap(MLT)and dengue cases for Ae.aegypti and Aedes albopictus;(2)estimating survival rates and wild populations using mark-release-recapture(MRR);and(3)analysing spatial distribution in treated and untreated sites.Methods Ae aegypti males,irradiated at 55 Gray,were released in three locations:Pangsapuri Kota Laksamana(KT),Malacca(19 months),Pangsapuri Taman Tasik Utama(TTU),Malacca(8 months),and the Customs,Immigration,and Quarantine Complex(CIQ),Johor(7 months).Statistical analyses assessed SIT effectiveness,including T-tests for larval density and ovitrap indices,Mulla's formula and relative variance(RV)for population reduction,and the Lin-coln Index for estimating wild male populations and probability of daily survival.Results Weekly releases of sterile Ae.aegypti males at doses of 1278-7942 males/ha achieved a sterile-to-wild male ratio of 5.85 and a mean daily survival rate of 0.61,leading to significant reductions in larval densities:76.25%in Kota Laksamana(KT),96.74%in Taman Tasik Utama(TTU),and 89.00%in CIQ Gelang Patah,thereby supporting dengue control efforts.In KT,the MLT was initially low but increased,although with suppression<90%,there was a reduce of dengue cases throughout the release period.The MRR's mean survival rate(±standard deviation)in KT was O.61(±0.08).The spatial clustering of Ae.aegypti was observed in central blocks during the high MLT period.However,larval densities rebounded after releases ceased.Spatial clustering revealed no initial clustering,though clustering patterns emerged over time in KT.Conclusions SIT effectively suppressed Ae.aegypti populations and supported dengue control.Optimizing sterile-to-wild male ratios,spatial distribution,and monitoring strategies is essential for sustainable vector control.These findings provide insights for scaling up SIT field trials,with future efforts focusing on refining release and monitoring strategies to enhance SIT as an effective dengue control tool.展开更多
The endangered Asian tapir(Tapirus indicus)is threatened by large-scale habitat loss,forest fragmentation and increased hunting pressure.Conservation planning for this species,however,is hampered by a severe paucity o...The endangered Asian tapir(Tapirus indicus)is threatened by large-scale habitat loss,forest fragmentation and increased hunting pressure.Conservation planning for this species,however,is hampered by a severe paucity of information on its ecology and population status.We present the first Asian tapir population density estimate from a camera trapping study targeting tigers in a selectively logged forest within Peninsular Malaysia using a spatially explicit capture-recapture maximum likelihood based framework.With a trap effort of 2496 nights,17 individuals were identified corresponding to a density(standard error)estimate of 9.49(2.55)adult ta-pirs/100 km2.Although our results include several caveats,we believe that our density estimate still serves as an important baseline to facilitate the monitoring of tapir population trends in Peninsular Malaysia.Our study also highlights the potential of extracting vital ecological and population information for other cryptic individual-ly identifiable animals from tiger-centric studies,especially with the use of a spatially explicit capture-recapture maximum likelihood based framework.展开更多
While there are numerous wildlife ecology studies in lowland areas of Nepal,there are no in-depth studies of the hilly Churia habitat even though it comprises 7642 km2 of potential wildlife habitat across the Terai Ar...While there are numerous wildlife ecology studies in lowland areas of Nepal,there are no in-depth studies of the hilly Churia habitat even though it comprises 7642 km2 of potential wildlife habitat across the Terai Arc.We investigated tiger,leopard and prey densities across this understudied habitat.Our camera trapping survey covered 536 km2 of Churia and surrounding areas within Chitwan National Park(CNP).We used 161 trapping locations and accumulated 2097 trap-nights in a 60-day survey period during the winter season of 2010-2011.In addition,we walked 136 km over 81 different line transects using distance sampling to estimate prey density.We photographed 31 individual tigers,28 individual leopards and 25 other mammalian species.Spatial capture-recapture methods resulted in lower density estimates for tigers,ranging from 2.3 to 2.9 tigers per 100 km2,than for leopards,which ranged from 3.3 to 5.1 leopards per 100 km2.In addition,leopard densities were higher in the core of the Churia compared to surrounding areas.We estimated 62.7 prey animals per 100 km2 with forest ungulate prey(sambar,chital,barking deer and wild pig),accounting for 47%of the total.Based on prey availability,Churia habitat within CNP could potentially support 5.86 tigers per 100 km2 but our density estimates were lower,perhaps indicating that the tiger population is below carrying capacity.Our results demonstrate that Churia habitat should not be ignored in conservation initiatives,but rather management efforts should focus on reducing human disturbance to support higher predator numbers.展开更多
文摘Background: Men who have sex with men (MSM) are highly vulnerable to HIV infection, but this population can be particularly difficult to reach in Thailand. This study aimed to estimate the number of MSM in Chiang Mai Thailand, in order to plan HIV control and prevention. Methods: The total of 348 potential MSM were identified at eight contact locations, including two public parks, two bars, two massage parlors and two pubs in Chiang Mai. Trained 16 research enumerators and 16 enumerators were trained to extend a recruitment of brooches to MSM. The MSMs were captured one week apart. A record was kept of when, where and by whom the invitation was extended and received, and of refusals. The total estimate of MSM was derived from capture-recapture calculation. Results: The total MSM in Chiang Mai Thailand estimated by capture and recapture method was 733 (95%CI = 480 - 948) or the estimate was 7.3% (95%CI = 7.1% - 14.1%). Conclusions: Capture and recapture method can be used to enumerate and provide accurate and reliable estimates of the MSM population in any area, provided that certain conditions are controlled. MSM who are engaged in personal community represent a sizeable population who urgently need to be targeted by HIV and STDs prevention strategies.
基金The Swedish Society for Nature Conservation(Miljöfonden),the University of Gothenburg and the Swedish Anglers Association funded this studyCompletion of the manuscript was realized with support from the SoWa Research Infrastructure(MEYS CZ grant LM2015075)to JNNeither funding agencies,nor the affiliations of DA to Vattenfall AB and of NW to Swedish Anglers Association have influenced the results,their interpretation or their presentation.
文摘Movement activity levels of wild animals often differ consistently among individuals,reflecting different behavioral types.Previous studies have shown that laboratory-scored activity can predict several ecologically relevant characteristics.In an experiment on wild brown trout Salmo trutta,spanning from June to October,we investigated how spring swimming activity,measured in a standardized laboratory test,related to relative recapture probability in autumn.Based on laboratory activity scores,individuals clustered into 2 groups,which showed contrasting patterns in the size-dependency of their recapture probability.Size had a slightly positive effect on recapture probability for passive fish but a clear negative effect on active fish.Our results show that the population structure in a cohort,in terms of relative proportions of behavioral types in different size classes,can vary over time.The results of this study could depend on either selective mortality or migration.However,selective disappearance of individuals with specific phenotypes,regardless of the mechanism,will have implications for trout population management,such as stocking efficiency of hatchery fish with high growth rates or maintenance of fishways past migration barriers.
文摘Background The Sterile insect technique(SIT)has been successfully used in agricultural pest control,leading to interest in its application for public health,particularly in controlling Aedes mosquitoes in the USA,Italy,Cuba,and Greece.Malaysia has conducted a small-scale SIT pilot trial since 2019 for dengue control.This study evaluates mosquito populations in treated and untreated sites through three objectives:(1)comparing mean larvae per trap(MLT)and dengue cases for Ae.aegypti and Aedes albopictus;(2)estimating survival rates and wild populations using mark-release-recapture(MRR);and(3)analysing spatial distribution in treated and untreated sites.Methods Ae aegypti males,irradiated at 55 Gray,were released in three locations:Pangsapuri Kota Laksamana(KT),Malacca(19 months),Pangsapuri Taman Tasik Utama(TTU),Malacca(8 months),and the Customs,Immigration,and Quarantine Complex(CIQ),Johor(7 months).Statistical analyses assessed SIT effectiveness,including T-tests for larval density and ovitrap indices,Mulla's formula and relative variance(RV)for population reduction,and the Lin-coln Index for estimating wild male populations and probability of daily survival.Results Weekly releases of sterile Ae.aegypti males at doses of 1278-7942 males/ha achieved a sterile-to-wild male ratio of 5.85 and a mean daily survival rate of 0.61,leading to significant reductions in larval densities:76.25%in Kota Laksamana(KT),96.74%in Taman Tasik Utama(TTU),and 89.00%in CIQ Gelang Patah,thereby supporting dengue control efforts.In KT,the MLT was initially low but increased,although with suppression<90%,there was a reduce of dengue cases throughout the release period.The MRR's mean survival rate(±standard deviation)in KT was O.61(±0.08).The spatial clustering of Ae.aegypti was observed in central blocks during the high MLT period.However,larval densities rebounded after releases ceased.Spatial clustering revealed no initial clustering,though clustering patterns emerged over time in KT.Conclusions SIT effectively suppressed Ae.aegypti populations and supported dengue control.Optimizing sterile-to-wild male ratios,spatial distribution,and monitoring strategies is essential for sustainable vector control.These findings provide insights for scaling up SIT field trials,with future efforts focusing on refining release and monitoring strategies to enhance SIT as an effective dengue control tool.
文摘The endangered Asian tapir(Tapirus indicus)is threatened by large-scale habitat loss,forest fragmentation and increased hunting pressure.Conservation planning for this species,however,is hampered by a severe paucity of information on its ecology and population status.We present the first Asian tapir population density estimate from a camera trapping study targeting tigers in a selectively logged forest within Peninsular Malaysia using a spatially explicit capture-recapture maximum likelihood based framework.With a trap effort of 2496 nights,17 individuals were identified corresponding to a density(standard error)estimate of 9.49(2.55)adult ta-pirs/100 km2.Although our results include several caveats,we believe that our density estimate still serves as an important baseline to facilitate the monitoring of tapir population trends in Peninsular Malaysia.Our study also highlights the potential of extracting vital ecological and population information for other cryptic individual-ly identifiable animals from tiger-centric studies,especially with the use of a spatially explicit capture-recapture maximum likelihood based framework.
文摘While there are numerous wildlife ecology studies in lowland areas of Nepal,there are no in-depth studies of the hilly Churia habitat even though it comprises 7642 km2 of potential wildlife habitat across the Terai Arc.We investigated tiger,leopard and prey densities across this understudied habitat.Our camera trapping survey covered 536 km2 of Churia and surrounding areas within Chitwan National Park(CNP).We used 161 trapping locations and accumulated 2097 trap-nights in a 60-day survey period during the winter season of 2010-2011.In addition,we walked 136 km over 81 different line transects using distance sampling to estimate prey density.We photographed 31 individual tigers,28 individual leopards and 25 other mammalian species.Spatial capture-recapture methods resulted in lower density estimates for tigers,ranging from 2.3 to 2.9 tigers per 100 km2,than for leopards,which ranged from 3.3 to 5.1 leopards per 100 km2.In addition,leopard densities were higher in the core of the Churia compared to surrounding areas.We estimated 62.7 prey animals per 100 km2 with forest ungulate prey(sambar,chital,barking deer and wild pig),accounting for 47%of the total.Based on prey availability,Churia habitat within CNP could potentially support 5.86 tigers per 100 km2 but our density estimates were lower,perhaps indicating that the tiger population is below carrying capacity.Our results demonstrate that Churia habitat should not be ignored in conservation initiatives,but rather management efforts should focus on reducing human disturbance to support higher predator numbers.
