ABSTRACT
Interspecific interactions can influence species' activity and movement patterns. In particular, species may avoid or attract each other through reactive responses in space and/or time. However, data and methods to study such reactive interactions have remained scarce and were generally limited to two interacting species. At this time, the deployment of camera traps opens new opportunities but adapted statistical techniques are still required to analyze interaction patterns with such data. We present the multivariate Hawkes process (MHP) and show how it can be used to analyze interactions between several species using camera trap data. Hawkes processes use flexible pairwise interaction functions, allowing us to consider asymmetries and variations over time when depicting reactive temporal interactions. After describing the theoretical foundations of the MHP, we outline how its framework can be used to study interspecific interactions with camera trap data. We design a simulation study to evaluate the performance of the MHP and of another existing method to infer interactions from camera trap-like data. We also use the MHP to infer reactive interactions from real camera trap data for five species from South African savannas (impala Aepyceros melampus, greater kudu Tragelaphus strepsiceros, lion Panthera leo, blue wildebeest Connochaetes taurinus and Burchell's zebra Equus quagga burchelli). The simulation study shows that the MHP can be used as a tool to benchmark other methods of interspecific interaction inference and that this model can reliably infer interactions when enough data are considered. The analysis of real data highlights evidence of predator avoidance by prey and herbivore-herbivore attraction. Lastly, we present the advantages and limits of the MHP and discuss how it can be improved to infer attraction/avoidance patterns more reliably. As camera traps are increasingly used, the multivariate Hawkes process provides a promising framework to decipher the complexity of interactions structuring ecological communities.
Subject(s)
Antelopes , Animals , HerbivoryABSTRACT
Carnivora occupy many ecological niches fundamental to ecosystem functioning. Within this diverse order, carnivore species compete to establish dominance, ensure survival and maintain fitness. Subordinate carnivores must, therefore, adapt their behaviour to coexist with dominant species. One such strategy is the partitioning of temporal activity patterns. We aim to determine interspecific avoidance patterns among sympatric carnivores by examining coexistence along a temporal axis. We compared the temporal activity patterns of 13 carnivore species using multi-seasonal camera trapping data from four protected areas across South Africa: Associated Private Nature Reserves, Madikwe Game Reserve, Mountain Zebra National Park and Tswalu Kalahari Reserve. Interspecific coefficients of overlap in diel and core activity periods were calculated over the study period and during the wet and dry seasons. Furthermore, interspecific spatiotemporal behaviour was examined using time-to-event analyses. Our results showed that complete avoidance of diel activity patterns was rare among South African carnivore species. Most species were predominantly nocturnal and, therefore, diel activity overlap was high, whereas core activity overlap was significantly lower (p < .001). Diel activity overlap was significantly lower during the dry than wet seasons (p = .045). Lastly, evidence of spatiotemporal aggregation revolved around scavenging species. We show the importance of seasonality in the temporal avoidance behaviours of South African carnivores while highlighting the need for fine-scaled behavioural analyses. Overall, we show that the daily activity patterns of most subordinate South African carnivore species are not influenced by top-down forces in the form of competitional suppression and risk exerted by dominant species. If avoidance is required, it is more likely to manifest as fine-scaled avoidance of core activity periods. We suggest that the focus on core activity periods might be a more suitable tool for interspecific temporal partitioning research.
ABSTRACT
Patients often provide untruthful information about their health to avoid embarrassment, evade treatment, or prevent financial loss. Privacy disclosures (e.g. HIPAA) intended to dissuade privacy concerns may actually increase patient lying. We used new mouse tracking-based technology to detect lies through mouse movement (distance and time to response) and patient answer adjustment in an online controlled study of 611 potential patients, randomly assigned to one of six treatments. Treatments differed in the notices patients received before health information was requested, including notices about privacy, benefits of truthful disclosure, and risks of inaccurate disclosure. Increased time or distance of device mouse movement and greater adjustment of answers indicate less truthfulness. Mouse tracking revealed a significant overall effect (p<0.001) by treatment on the time to reach their final choice. The control took the least time indicating greater truthfulness and the privacy + risk group took the longest indicating least truthfulness. Privacy, risk, and benefit disclosure statements led to greater lying. These differences were moderated by gender. Mouse tracking results largely confirmed the answer adjustment lie detection method with an overall treatment effect (p < .0001) and gender differences (p < .0001) on truthfulness. Privacy notices led to decreased patient honesty. Privacy notices should perhaps be administered well before personal health disclosure is requested to minimize patient untruthfulness. Mouse tracking and answer adjustment appear to be health care lie-detection methods to enhance optimal diagnosis and treatment.
Subject(s)
Confidentiality , Privacy , Disclosure , Data Collection , Delivery of Health CareABSTRACT
BACKGROUND: Organizations of all types require the use of teams. Poor team member engagement costs billions of US dollars annually. OBJECTIVE: This study aimed to explain how team building can be accomplished with team video gaming based on a team cohesion model enhanced by team flow theory. METHODS: In this controlled experiment, teams were randomly assigned to a team video gaming treatment or a control treatment. Team productivity was measured during both pretreatment and posttreatment team tasks. After the pretest, teams who were involved in the team video gaming treatment competed against other teams by playing the Halo or Rock Band video game for 45 minutes. After the pretest, teams in the control treatment worked alone for 45 minutes. Then, all teams completed the posttest team activity. This same experimental protocol was conducted on 2 different team tasks. RESULTS: For both tasks, teams in the team video gaming treatment increased their productivity significantly more (F1=8.760, P=.004) on the posttest task than teams in the control treatment. Our flow-based theoretical model explained team performance improvement more than twice as well (R2=40.6%) than prior related research (R2=18.5%). CONCLUSIONS: The focused immersion caused by team video gaming increased team performance while the enjoyment component of flow decreased team performance on the posttest. Both flow and team cohesion contributed to team performance, with flow contributing more than cohesion. Team video gaming did not increase team cohesion, so team video gaming effects are independent of cohesion. Team video gaming is a valid practical method for developing and improving newly formed teams.
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BACKGROUND: Modification and destruction of natural habitats are bringing previously unencountered animal populations into contact with humans, with bats considered important zoonotic transmission vectors. Caves and cave-dwelling bats are under-represented in conservation plans. In South Africa, at least two cavernicolous species are of interest as potential zoonotic hosts: the Natal long-fingered bat Miniopterus natalensis and the Egyptian fruit bat Rousettus aegyptiacus. Little information is available about the anthropogenic pressures these species face around important roost sites. Both bats are numerous and widespread throughout the country; land-use changes and urban expansions are a rising concern for both conservation and increased bat-human contact. RESULTS: Our study addressed this shortfall by determining the extent of land-cover change around 47 roosts between 2014 and 2018 using existing land cover datasets. We determined the land-cover composition around important roost sites (including maternity, hibernacula and co-roosts), distances to urban settlements and assessed the current protection levels of roost localities. We detected an overall 4% decrease in natural woody vegetation (trees) within 5 km buffer zones of all roost sites, with a 10% decrease detected at co-roost sites alone. Agricultural land cover increased the most near roost sites, followed by plantations and urban land-cover. Overall, roosts were located 4.15 ± 0.91 km from urban settlements in 2018, the distances decreasing as urban areas expand. According to the South African National Biodiversity Institute Ecosystem Threat Status assessment, 72% of roosts fall outside of well-protected ecosystems. CONCLUSIONS: The current lack of regulatory protection of cavernicolous bats and their roosts, increasing anthropogenic expansions and proximity to human settlements raises concerns about increased human-bat contact. Furthermore, uncontrolled roost visitation and vandalism are increasing, contributing to bat health risks and population declines, though the extent of roosts affected is yet to be quantified. In an era where pandemics are predicted to become more frequent and severe due to land-use change, our research is an urgent call for the formal protection of bat-inhabited caves to safeguard both bats and humans. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40850-021-00095-5.
ABSTRACT
The reservoir host of Mokola virus (MOKV), a rabies-related lyssavirus species endemic to Africa, remains unknown. Only sporadic cases of MOKV have been reported since its first discovery in the late 1960s, which subsequently gave rise to various reservoir host hypotheses. One particular hypothesis focusing on non-volant small mammals (e.g. shrews, sengis and rodents) is buttressed by previous MOKV isolations from shrews (Crocidura sp.) and a single rodent (Lophuromys sikapusi). Although these cases were only once-off detections, it provided evidence of the first known lyssavirus species has an association with non-volant small mammals. To investigate further, retrospective surveillance was conducted in 575 small mammals collected from South Africa. Nucleic acid surveillance using a pan-lyssavirus quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assay of 329 brain samples did not detect any lyssavirus ribonucleic acid (RNA). Serological surveillance using a micro-neutralisation test of 246 serum samples identified 36 serum samples that were positive for the presence of MOKV neutralising antibodies (VNAs). These serum samples were all collected from Gerbilliscus leucogaster (Bushveld gerbils) rodents from Meletse in Limpopo province (South Africa). Mokola virus infections in Limpopo province have never been reported before, and the high MOKV seropositivity of 87.80% in these gerbils may indicate a potential rodent reservoir.
Subject(s)
Lyssavirus , Rabies , Animals , Mammals , Rabies/epidemiology , Rabies/veterinary , Retrospective Studies , South Africa/epidemiologyABSTRACT
Using various sources, including the Global Biodiversity Information Facility (GBIF), published literature, recent (2015-2017) collections, as well as bat detector and camera trap surveys with opportunistic sightings and live capture in the upper Okavango catchment in central Angola, we present an updated mammal checklist of 275 species from 15 different orders for Angola (including the Cabinda region). Recent surveys (captures and bat detectors) of small mammals from the upper Okavango catchment yielded 46 species (33 species of bats, ten species of rodents and three species of shrews). One bat (Pipistrellusrusticus, rusty pipistrelle); two rodents (Mussetzeri, Setzer's mouse and Zelotomyswoosnami, Woosnam's broad-faced mouse) and one shrew (Suncusvarilla, lesser dwarf shrew) were captured for the first time, in Angola. While our species lists of bats conformed to predicted totals, terrestrial small mammals were under sampled, with only 13 species recorded by our trapping survey compared to a total of 42 shrew and rodent species expected based on GBIF records for the central Angolan highlands. Seven terrestrial small mammal species (one shrew and six rodents) are endemic to the central and western Angolan highlands but none of these were captured in our survey. The bat detector surveys added three further bat species to the country list: Pipistrellushesperidus, Kerivoulaargentata, and Mopsmidas. Camera trap surveys and opportunistic sightings in the upper Okavango catchment in 2016 yielded a total of 35 species of medium-large mammals, from 17 families, although all of these had been reported previously in Angola. GBIF proved to be an excellent source of biodiversity data for Angolan mammals, most importantly for documenting dramatic historical range changes of larger mammals such as the sable (Hippotragusnigerniger), Kirk's sable (H.nigerkirkii) and the giant sable (H.nigervariani).
ABSTRACT
This dataset includes data derived from camera trap surveys and questionnaire surveys relating to small carnivores in agro-ecosystems in the Vhembe Biosphere Reserve, South Africa. The data were collected as part of the study "Predation by small mammalian carnivores in rural agro-ecosystems: An undervalued ecosystem service?" (Williams et al., 2017a) [1]. Camera trap locations were stratified by land use: settlement, crops, and grazing areas. The camera trap data provide an insight into the ecology of the nine species of small carnivores that were recorded: striped polecat (Ictonyx striatus), honey badger (Mellivora capensis), large-spotted genet (Genetta maculata), African civet (Civettictis civetta), slender mongoose (Galerella sanguinea), Meller's mongoose (Rhynchogale melleri), Selous' mongoose (Paracynictis selousi), white tailed mongoose (Ichneumia albicauda), and dwarf mongoose (Helogale parvula). We also recorded domesticated animals such as domestic cats (Felis catus), domestic dogs (Canis lupus familiaris), and cattle (Bos taurus) on the camera traps. The questionnaire data are comprised of responses of stakeholders to questions regarding the impacts of these species on rural farming communities. In the accompanying data repository hosted on Figshare (doi 10.6084/m9.figshare.4750807, (Williams et al., 2017b) [2]) we provide raw data, along with processed data and R code used to analyse these data to determine the impact of land use and domestic animals on the species richness and occupancy of small carnivores in rural agro-ecosystems (Williams et al., 2017a) [1].
ABSTRACT
Human-dominated landscapes comprise the bulk of the world's terrestrial surface and Africa is predicted to experience the largest relative increase over the next century. A multi-scale approach is required to identify processes that maintain diversity in these landscapes. Here we identify scales at which animal diversity responds by partitioning regional diversity in a rural African agro-ecosystem between one temporal and four spatial scales. Human land use practices are the main driver of diversity in all seven animal assemblages considered, with medium sized mammals and birds most affected. Even the least affected taxa, bats and non-volant small mammals (rodents), responded with increased abundance in settlements and agricultural sites respectively. Regional turnover was important to invertebrate taxa and their response to human land use was intermediate between that of the vertebrate extremes. Local scale (< 300 m) heterogeneity was the next most important level for all taxa, highlighting the importance of fine scale processes for the maintenance of biodiversity. Identifying the triggers of these changes within the context of functional landscapes would provide the context for the long-term sustainability of these rapidly changing landscapes.
Subject(s)
Biodiversity , Birds/physiology , Conservation of Natural Resources , Human Activities , Mammals/physiology , Population Dynamics , Urbanization , Africa , Agriculture , Animals , Ecosystem , HumansABSTRACT
[This corrects the article DOI: 10.1371/journal.pone.0174554.].
ABSTRACT
Rodent pests are especially problematic in terms of agriculture and public health since they can inflict considerable economic damage associated with their abundance, diversity, generalist feeding habits and high reproductive rates. To quantify rodent pest impacts and identify trends in rodent pest research impacting on small-holder agriculture in the Afro-Malagasy region we did a systematic review of research outputs from 1910 to 2015, by developing an a priori defined set of criteria to allow for replication of the review process. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We reviewed 162 publications, and while rodent pest research was spatially distributed across Africa (32 countries, including Madagascar), there was a disparity in number of studies per country with research biased towards four countries (Tanzania [25%], Nigeria [9%], Ethiopia [9%], Kenya [8%]) accounting for 51% of all rodent pest research in the Afro-Malagasy region. There was a disparity in the research themes addressed by Tanzanian publications compared to publications from the rest of the Afro-Malagasy region where research in Tanzania had a much more applied focus (50%) compared to a more basic research approach (92%) in the rest of the Afro-Malagasy region. We found that pest rodents have a significant negative effect on the Afro-Malagasy small-holder farming communities. Crop losses varied between cropping stages, storage and crops and the highest losses occurred during early cropping stages (46% median loss during seedling stage) and the mature stage (15% median loss). There was a scarcity of studies investigating the effectiveness of various management actions on rodent pest damage and population abundance. Our analysis highlights that there are inadequate empirical studies focused on developing sustainable control methods for rodent pests and rodent pests in the Africa-Malagasy context is generally ignored as a research topic.
Subject(s)
Agriculture , Crops, Agricultural/parasitology , Pest Control, Biological , Rodentia , Africa , Animals , HumansABSTRACT
Understanding of animal spatial behavior is essential for informed management decisions. In southern Africa, reintroduction of lions (Panthera leo) to small reserves (<1000 km2 ) has increased since the early 2000s, however studies on their ranging behavior in these enclosed systems remain lacking. We applied Time Local Convex Hull (T-LoCoH) methods to study the home range establishment and utilization of 11 lions reintroduced to Dinokeng Game Reserve, South Africa, during 2011 through 2014. Lions established home ranges close to their release sites and during the following 3 years their home range sizes continued to increase, but in each individual case the size remained smaller than half of the reserve area (<70 km2 ). Space use strategies differed between the core and the entire home range, with higher frequency of visits found in core areas. Exceptionally high rates (>60 separate visits) around the largest dam and along rivers suggest the importance of water and its surrounding vegetation in the lions' space utilization pattern. The home range size did not differ with season or sex of the individuals, whereas shifts in locations of home ranges revealed differences in the response of the 2 sexes to territorial conflicts and management interventions. Our study shows a dynamic home range utilization pattern and highlights the importance of both fine-scale space use patterns (frequency and duration of visits) and broad-scale home range changes in understanding the ranging behavior of reintroduced animals.
Subject(s)
Homing Behavior , Lions , Africa, Southern , Animals , Animals, Wild , Female , Male , South AfricaABSTRACT
In coastal waters of the Pearl River Delta (PRD) region, the Indo-Pacific humpback dolphin (Sousa chinensis) is thought to number approximately 2500 individuals. Given these figures, the putative PRD population may appear strong enough to resist demographic stochasticity and environmental pressures. However, living in close proximity to the world's busiest seaport/airport and several densely populated urban centres with major coastal infrastructural developments comes with challenges to the long-term survival of these animals. There are few other small cetacean populations that face the range and intensity of human-induced pressures as those present in the PRD and current protection measures are severely inadequate. Recent mark-recapture analyses of the animals in Hong Kong waters indicate that in the past two decades the population parameters have not been well understood, and spatial analyses show that only a very small proportion of the dolphins' key habitats are given any form of protection. All current marine protected areas within the PRD fail to meet a minimum habitat requirement that could facilitate the population's long-term persistence. Demographic models indicate a continuous decline of 2.5% per annum, a rate at which the population is likely to drop below the demographic threshold within two generations and lose 74% of the current numbers within the lifespan of three generations. In Hong Kong, the case of humpback dolphins represents a particularly explicit example of inadequate management where a complete revision of the fundamental approach to conservation management is urgently needed.
Subject(s)
Animal Distribution , Conservation of Natural Resources , Dolphins/physiology , Endangered Species , Rivers , Animals , China , Ecosystem , Female , Hong Kong , Human Activities , Male , Reproduction/physiologyABSTRACT
While African leopard populations are considered to be continuous as demonstrated by their high genetic variation, the southernmost leopard population exists in the Eastern and Western Cape, South Africa, where anthropogenic activities may be affecting this population's structure. Little is known about the elusive, last free-roaming top predator in the region and this study is the first to report on leopard population structuring using nuclear DNA. By analyzing 14 microsatellite markers from 40 leopard tissue samples, we aimed to understand the populations' structure, genetic distance, and gene flow (Nm). Our results, based on spatially explicit analysis with Bayesian methods, indicate that leopards in the region exist in a fragmented population structure with lower than expected genetic diversity. Three population groups were identified, between which low to moderate levels of gene flow were observed (Nm 0.5 to 3.6). One subpopulation exhibited low genetic differentiation, suggesting a continuous population structure, while the remaining two appear to be less connected, with low emigration and immigration between these populations. Therefore, genetic barriers are present between the subpopulations, and while leopards in the study region may function as a metapopulation, anthropogenic activities threaten to decrease habitat and movement further. Our results indicate that the leopard population may become isolated within a few generations and suggest that management actions should aim to increase habitat connectivity and reduce human-carnivore conflict. Understanding genetic diversity and connectivity of populations has important conservation implications that can highlight management of priority populations to reverse the effects of human-caused extinctions.
ABSTRACT
Transitional cell carcinoma of the bladder (TCC) represents nearly 90% of genitourinary malignancies and typically presents with locally invasive symptoms. Metastasis to the central nervous system (CNS) is uncommon occurring in <5% of patients. When present, metastatic lesions are typically solid, isolated and located in the cerebrum. We report a case of a patient with a history of TCC who presented with lethargy and ataxia and was found to have a solitary cystic cerebellar lesion consistent with metastatic disease. Unfortunately, the prognosis for patients with TCC and CNS metastases is poor. Treatment options include debulking surgery, whole brain radiation, stereotactic radiosurgery and chemotherapy. Unfortunately, treatment may not appreciably extend survival and care is often supportive in previously reported cases. Though uncommon, TCC can metastasise to the CNS and should be considered in the differential diagnosis of patients, particularly those who were treated with aggressive surgery or combination chemotherapy previously.
Subject(s)
Carcinoma, Transitional Cell , Cerebellar Neoplasms/secondary , Urinary Bladder Neoplasms , Aged , Cerebellar Ataxia/etiology , Cerebellar Neoplasms/diagnosis , Diagnosis, Differential , Fatal Outcome , Humans , Lethargy/etiology , Magnetic Resonance Imaging , MaleABSTRACT
OBJECTIVES: To evaluate end-of-life care in a cohort of oncology patients in Olmsted County, Minnesota, USA, and compare differences between patients participating in clinical trials and those not in clinical trials. METHODS: A population-based cohort of subjects with active oncological disease who died between 2000 and 2002 was constructed retrospectively using institutional databases. Clinical trial participation and care during the last 2 months of life were analysed. RESULTS: A total of 395 eligible patients were identified. In the 2 months prior to death, 94 (24%) patients received chemotherapy, 232 (59%) were hospitalised, 249 (63%) were in hospice and 315 (80%) had a do not resuscitate (DNR) code status. Only 8 (2%) patients received cardiopulmonary resuscitation (CPR) and 26 (7%) patients participated in a clinical trial. Patients in clinical trials were more likely to receive chemotherapy (69.2% vs 20.6%; p<0.001), undergo intubation/mechanical ventilation (15.4% vs 5.4%; p=0.040) and less likely to have DNR code status (50.0% vs 81.8%; p<0.001) when compared with patients not in clinical trials. However, no differences in hospice enrolment, days in hospice, days in the hospital, CPR or location of death were noted. CONCLUSIONS: Although opportunities for improvement exist, high quality end-of-life care was found in this study of patients with active malignancy. A majority (over 60%) of patients enrolled in hospice prior to death, 80% had a DNR status and only 2% received CPR. Although clinical trial participants received more aggressive treatments during the last 2 months of life, they did not appear to have lower quality end-of-life care.
Subject(s)
Clinical Trials as Topic/statistics & numerical data , Neoplasms/therapy , Palliative Care/statistics & numerical data , Standard of Care/statistics & numerical data , Terminal Care/statistics & numerical data , Aged , Cardiopulmonary Resuscitation/statistics & numerical data , Cohort Studies , Female , Hospice Care/standards , Hospice Care/statistics & numerical data , Hospitalization/statistics & numerical data , Humans , Intubation, Intratracheal/statistics & numerical data , Length of Stay , Male , Minnesota , Neoplasms/drug therapy , Palliative Care/standards , Respiration, Artificial/statistics & numerical data , Resuscitation Orders , Retrospective Studies , Standard of Care/standards , Terminal Care/standardsABSTRACT
INTRODUCTION: Pulmonary arterial hypertension (PAH) is a progressive and ultimately fatal disease of the pulmonary circulation. There has never been an investigation of the end-of-life symptoms in patients with PAH. In this investigation, we surveyed surrogates of recent decedents with PAH. We evaluate their responses to better understand the end-of-life experience of patients with PAH. METHODS: The survey instrument includes demographic information and the Edmonton Symptoms Assessment Scale. Accredo Therapeutics mailed the survey to surrogates of recent decedents with PAH, and responses were anonymously returned to investigators at Virginia Commonwealth University and used in our descriptive analysis. RESULTS: Of 100 surveys distributed over 24 months (February 2009 to February 2011), we obtained 36 responses (response rate 36%). We found that most patient deaths (90%) were related to PAH, that the majority of patients died in the hospital (67%), with the majority of in-hospital deaths (83%) occurring in intensive care. Palliative care was infrequently involved in patients' care, and many surrogates were unaware of palliative care and hospice services available to the decedents. Patients died with a high symptom burden, especially dyspnea. CONCLUSION: In this cohort, patients with PAH usually died from their disease, often in the hospital setting with a high symptom burden. Further study will be needed to confirm the findings from this study and to better understand the forces leading to the trends uncovered in this investigation.