IN the last year, 41 year-old Huang has suffered more frequently from chest pains and breathlessness, especially when she is tired or angry. These symptoms usually last three to five minutes but can linger for up to a...IN the last year, 41 year-old Huang has suffered more frequently from chest pains and breathlessness, especially when she is tired or angry. These symptoms usually last three to five minutes but can linger for up to an hour or two. Nitroglycerin sometimes helps alleviate the symptoms but not always. No tell-tale abnormal signs show up in Holter, heart supersonic or electrocardiogram checks when the problem is coming on.展开更多
Viability of decentralizing policing in Nigeria had been on the front burner of security discourse since Nigeria returned to democratic governance in 1999.Valid points had been put forward by both those in support and...Viability of decentralizing policing in Nigeria had been on the front burner of security discourse since Nigeria returned to democratic governance in 1999.Valid points had been put forward by both those in support and those in opposition.The Community Policing Department of the Nigeria Police had remained more of an administrative unit with little impact beyond the Police Community Relations Committee activities.Rising cases of herdsmen attacks of various communities,terrorist insurgency in the North-East,kidnappings across the different geo-political zones had resulted in the need to interrogate the efficacy of effective community policing and state policing as viable options to combating rising security challenges.The study adopted qualitative method,and being a library research relied entirely on secondary data.Sources of data included journals,relevant textbooks,newspapers,magazines,and materials downloaded from internet.The paper argues that the traditional security agencies had failed to effectively combat the many security challenges that Nigeria faces.The combination of the official security agencies and the military had failed to effectively combat insecurity in the country.The local vigilante groups on the other hand had made valuable inroad in curtailing some of the security challenges including terrorist insurgency as a result of their knowledge of the terrain.The paper concludes that to effectively combat the many security challenges,there is a need for new policy framework at the federal and state levels that would decentralize policing and give legal backing for collaboration between the official security agencies under the federal government and state security outfits including the vigilante.展开更多
As a core part of the electronic warfare(EW) system,de-interleaving is used to separate interleaved radar signals. The de-interleaving algorithm based on the fuzzy adaptive resonance theory(fuzzy ART) is plagued by th...As a core part of the electronic warfare(EW) system,de-interleaving is used to separate interleaved radar signals. The de-interleaving algorithm based on the fuzzy adaptive resonance theory(fuzzy ART) is plagued by the problems of premature saturation and performance improving dilemma. This study proposes a dual fuzzy vigilance ART(DFV-ART) algorithm to address these problems and make the following improvements. Firstly, a correction method is introduced to prevent the network from prematurely saturating;then, the fuzzy vigilance models(FVM) are constructed to replace the conventional vigilance parameter, reducing the error probability in the overlapping region;finally, a dual vigilance mechanism is introduced to solve the performance improving dilemma. Simulation results show that the proposed algorithm could improve the clustering accuracy(quantization error dropped60%) and the de-interleaving performance(clustering quality increased by 10%) while suppressing the excessive proliferation of categories.展开更多
In this paper, we study the epidemic spreading in scale-flee networks and propose a new susceptible-infected- recovered (SIR) model that includes the effect of individual vigilance. In our model, the effective sprea...In this paper, we study the epidemic spreading in scale-flee networks and propose a new susceptible-infected- recovered (SIR) model that includes the effect of individual vigilance. In our model, the effective spreading rate is dynamically adjusted with the time evolution at the vigilance period. Using the mean-field theory, an analytical result is derived. It shows that individual vigilance has no effect on the epidemic threshold. The numerical simulations agree well with the analytical result. Purthermore, we investigate the effect of individual vigilance on the epidemic spreading speed. It is shown that individual vigilance can slow the epidemic spreading speed effectively and delay the arrival of peak epidemic infection.展开更多
BACKGROUND Efficient detection of delirium and comorbid delirium-dementia is a key diagnostic challenge.Development of new,efficient delirium-focused methods of cognitive assessment is a key challenge for improved det...BACKGROUND Efficient detection of delirium and comorbid delirium-dementia is a key diagnostic challenge.Development of new,efficient delirium-focused methods of cognitive assessment is a key challenge for improved detection of neurocognitive disorders in everyday clinical practice.AIM To compare the accuracy of two novel bedside tests of attention,vigilance and visuospatial function with conventional bedside cognitive tests in identifying delirium in older hospitalized patients.METHODS 180 consecutive elderly medical inpatients(mean age 79.6±7.2;51%female)referred to a psychiatry for later life consultation-liaison service with delirium,dementia,comorbid delirium-dementia and cognitively intact controls.Participants were assessed cross-sectionally with conventional bedside cognitive tests[WORLD,Months Backward test(MBT),Spatial span,Vigilance A and B,Clock Drawing test and Interlocking Pentagons test]and two novel cognitive tests[Lighthouse test,Letter and Shape Drawing test(LSD)-4].RESULTS Neurocognitive diagnoses were delirium(n=44),dementia(n=30),comorbid delirium-dementia(n=60)and no neurocognitive disorder(n=46).All conventional tests had sensitivity of>70%for delirium,with best overall accuracy for the Vigilance-B(78.3%),Vigilance-A(77.8%)and MBT(76.7%)tests.The sustained attention component of the Lighthouse test was the most distinguishing of delirium(sensitivity 84.6%;overall accuracy 75.6%).The LSD-4 had sensitivity of 74.0%and overall accuracy 74.4%for delirium identification.Combining tests allowed for enhanced sensitivity(>90%)and overall accuracy(≥75%)with the highest overall accuracy for the combination of MBT-Vigilance A and the combined Vigilance A and B tests(both 78.3%).When analyses were repeated for those with dementia,there were similar findings with the MBTVigilance A the most accurate overall combination(80.0%).Combining the Lighthouse-SA with the LSD-4,a fail in either test had sensitivity for delirium of 91.4 with overall accuracy of 74.4%.CONCLUSION Bedside tests of attention,vigilance and visuospatial ability can help to distinguish neurocognitive disorders,including delirium,from other presentations.The Lighthouse test and the LSD-4 are novel tests with high accuracy for detecting delirium.展开更多
Background: A critical trait for successful urban dwelling by birds is the ability to tolerate high levels of disturbing stimulation by humans. If such tolerance is partly acquired gradually after colonization, specie...Background: A critical trait for successful urban dwelling by birds is the ability to tolerate high levels of disturbing stimulation by humans. If such tolerance is partly acquired gradually after colonization, species with a long history of residence in cities are likely to be more tolerant of such stimulation than recent urban colonists, but this has not often been tested.Methods: We tested whether introduced Rock(Columba livia) and Spotted(Streptopelis chinensis) Doves, historically long-term residents of Melbourne, Australia, were more tolerant of disturbance by humans than the very recent colonist, the native Crested Pigeon(Ochyphaps lophotes) by comparing the Flight Initiation Distances(FID) and time allocations to vigilance during foraging of all three species in urban Melbourne. That all three species are members of the Columbiformes reduces the possibility that any species differences in tolerance are simply phylogenetic in origin.Results: Flight initiation distance was shorter in Rock Doves than in the other two species, which did not differ in approachability by a human. Rock Doves retreated from an approaching human mainly by walking a relatively short distance, Crested Pigeons mainly by running a relatively short distance and Spotted Doves primarily by flying a comparatively long distance. The time allocation to anti-predator vigilance of Rock Doves was smaller than that of the other two species, whose allocations were similar.Conclusions: The very recent colonist of eastern Melbourne, the Crested Pigeon, was not the least tolerant of disturbance by humans of the three related species. Natural selection for tolerance therefore probably cannot entirely explain the pattern of tolerance evident among these urban dove species and behavioural flexibility is probably involved. Length of residency in a city is not an infallible guide to a species' level of tolerance of disturbance by humans.展开更多
Background:Animals need to adjust their vigilance strategies when foraging between physically contrasting veg-etated and non-vegetated habitats.Vegetated habitats may pose a greater risk for some if vegetation charact...Background:Animals need to adjust their vigilance strategies when foraging between physically contrasting veg-etated and non-vegetated habitats.Vegetated habitats may pose a greater risk for some if vegetation characteristics function as a visual obstruction but benefit others if they serve as protective shelter.Variation in group size,presence of similar species,along with variation in environmental conditions and anthropogenic disturbance can also influence vigilance investment.Methods:In this study,we quantified the vigilance behaviour of two large-bodied,sympatric migratory curlew species-Far Eastern Curlew(Numenius madagascariensis)and Eurasian Curlew(N.arquata)-in vegetated Suaeda salsa saltmarsh and non-vegetated mudflat habitat in Liaohekou National Nature Reserve,China.We used linear mixed models to examine the effects of habitat type,season,tide time,flock size(conspecific and heterospecific),and human disturbance on curlew vigilance investment.Results:Both species spent a higher percentage of time under visual obstruction in S.salsa habitat compared to mudflat habitat but in response,only Far Eastern Curlew increased their percentage of vigilance time,indicating that visual obstruction in this habitat is only a concern for this species.There was no evidence that S.salsa vegetation served as a form of cryptic background colouration since neither species decreased their vigilance effect in S.salsa habitat in spring compared to the autumn migration season.The effect of curlew social environment(i.e.flock size)was habitat dependent since percentage of vigilance time by curlews in saltmarsh increased with both the number of individual curlews and number of other birds present,but not in mudflat habitat.Conclusions:We conclude that both migratory curlew species exhibit a flexible vigilance adjustment strategy to cope with the different environmental and social conditions of adjacent and sharply contrasting coastal habitats,and that the trade-off between the risks of foraging and the abundance of prey may be a relatively common phenom-enon in these and other shorebird populations.展开更多
Introduction: The exposure to shift works, and especially to night shift, goes against the circadian rythmicity of the social man, which brings about a multitude of disruptive effects on health. In a hospital environm...Introduction: The exposure to shift works, and especially to night shift, goes against the circadian rythmicity of the social man, which brings about a multitude of disruptive effects on health. In a hospital environment, such night shift is necessary so as to ensure the continuity of care. Sleep and vigilance disorders related to this work mode are frequent and often pose adaptation problems. The objective of this study is to detect the harmful effects of night shift on sleep, vigilance and the quality of life of nurses in Farhat Hached Teaching Hospital in Sousse. Material and Methods: It is a cross-sectional study carried out among two groups of nurses: one group performing a fixed night work and the other one working permanently during the day at Farhat Hached Teaching Hospital in Sousse. Data collection is mainly based on validated questionnaires evaluating sleep quality (Pittsburg sleep quality index), daytime sleepiness (Epworth sleepiness scale), sleep typology (Horne and Ostberg questionnaire), and the quality of life (SF-12). An objective evaluation of vigilance was realized by the study of reaction time and error rates to different tasks of “Super lab” software. Results: 50 night and 50 day nurses have been colligated. Both groups were age- and gender-matched. Sleep quality mean index was significantly higher among night nurses in comparison with day nurses (10.2 ± 5.9 versus 6.76 ± 5.16). After multivariate analysis, sleep quality was significantly correlated to age, department, schedule and the choice of schedule. Night shift was not related to daytime sleepiness. The objective analysis of vigilance showed that the reaction time to different tasks exploring the attentional mechanisms, as well as errors rate, were significantly more important among the night group. The mental score of the quality of life was significantly higher among day nurses. However, such difference was not significant with regard to physical score. Conclusion: The findings of our study highlight not only the alteration of the health and the well being of paramedical staff secondary to night shift, but also a possible threat to safety care lavished by these teams, which involves the necessity to undertake preventive measures on an individual and collective scale.展开更多
The costs and benefits of group living are not evenly distributed among individuals that occupy different spatial positions within a group(central or peripheral).However,the definitions of central and peripheral posit...The costs and benefits of group living are not evenly distributed among individuals that occupy different spatial positions within a group(central or peripheral).However,the definitions of central and peripheral positions may artificially mask the true dynamics of cost and benefit of individuals.Using wintering foraging Greater Whitefronted Geese(Anser albifrons)flocks as our study system,we measured individual spatial position within a flock as distance to the flock edge.First,we tested the effects of distance to edge on the antipredation cost and foraging benefit of individual goose using generalized linear mixed models(GLMMs).Flock size and number of neighbors and their interactions with distance to edge were included as fixed effects in GLMMs.Then we used piecewise regression to determine the threshold value of distance to edge to classify central and peripheral individuals.Our results indicated distance to edge significantly affected percent of time spent on vigilance(vigilance time),percent of time spent on foraging(foraging time)and intake rate(pecks/min),whereas other factors had no effects.We found that the critical distance that predicted changes in behavior was around 2.5 m.Birds 2.5 m or less from the edge of the group were more vigilant,and had less efficient foraging than more central individuals.Behavioral differences between central and peripheral individuals were more easily detected when the birds were classified by the method introduced in this study than by the traditional minimum convex polygon method.Our research provides researchers a dichotomous classification scheme that places individuals into peripheral and central positions from an individual's perspective.展开更多
This paper takes an integrative approach to the communication and comprehension of humor from the perspectives of the humorist’s manipulation and the recipient’s vigilance informed by relevance theory.It is proposed...This paper takes an integrative approach to the communication and comprehension of humor from the perspectives of the humorist’s manipulation and the recipient’s vigilance informed by relevance theory.It is proposed that,in order to communicate humor,the humorist manipulates the recipient’s expectation of relevance in the setup and in the punchline in two different but related ways:misleading and guiding.It is also proposed that,in order to comprehend and appreciate humor,the recipient exercises vigilance against his/her own shallow processing in the setup and exercises vigilance for special cognitive effects in the punchline.On this approach,humorous communication and comprehension is viewed as an interaction between manipulation and epistemic vigilance.Strategies of manipulation and vigilance are described,and some essential issues arising from the relevance-theoretic approach to humor are reconsidered with some implications drawn.This paper contributes to enhancing the explanatory power of relevance theory for the communication and comprehension of humor.展开更多
<strong>Background and Aim: </strong>Vigilance is an essential element in intensive care nursing. This study was conducted to determine nursing vigilance in nurses working in the intensive care units of ed...<strong>Background and Aim: </strong>Vigilance is an essential element in intensive care nursing. This study was conducted to determine nursing vigilance in nurses working in the intensive care units of educational and medical centers in Ardabil, Iran. <strong>Methods: </strong>This was a cross-sectional descriptive-analytical study with 192 ICU nurses as the participants. The data were obtained through questionnaires regarding demographic characteristics and nursing vigilance. SPSS software version 24 was used for the statistical analysis. <strong>Results: </strong>The mean total vigilance score was 3.86 ± 0.23 of 5. The mean scores of the timely diagnosis of changes, pattern recognition, and clinical decision-making subscales were 4.07 ± 0.26, 04.04 ± 0.41, and 3.44 ± 0.25, respectively. No significant relationships were observed between the total or subscale vigilance scores and other demographic characteristics. <strong>Conclusion: </strong>We assessed ICU nurses’ vigilance behaviors and found that their mean vigilance score was higher than the expected average, indicating our participants had a high level of clinical vigilance. These results suggest a need for effective educational interventions to boost clinical decision-making skills in ICU nurses, especially younger nurses.展开更多
Escape behavior is a common antipredator strategy among wild animals.Here,we investigated the effect of four factors on the vigilance behavior of the endemic Cyprus rock agama(Laudakia cypriaca).Flight initiation dist...Escape behavior is a common antipredator strategy among wild animals.Here,we investigated the effect of four factors on the vigilance behavior of the endemic Cyprus rock agama(Laudakia cypriaca).Flight initiation distance(FID,the minimum distance to which an observer can approach a lizard before it flees)was measured in relation to the type of location(tourist vs.nontourist area),the observer’s starting distance,air temperature,and substrate temperature.We collected data for 39 agamas in tourist areas and 34 of these lizards in nontourist areas.As a whole,the mean starting distance was 10.5 m and the FID was 3.6 m.The average substrate temperature was 34.0℃ and the average air temperature 29.6℃.Only the type of area affected the agamas’escape decisions with FID being 1.8 m shorter in tourist areas than in nontourist areas(2.7 m vs.4.5 m).This is probably due to the habituation of lizards to the presence of humans in the former areas.This study shows that tourism strongly affects the behavior of lizards,which may have consequences for the functioning of the population.Tourists can increase the safety of lizards by creating a human shield to deter predators.Once the tourist season is over,lizards may become more vulnerable to predators.展开更多
Human disturbance,particularly road traffic,is one of the greatest threats to wildlife.Considering the association between alerting behavior and the survival of animals,it is important to study the effects of road tra...Human disturbance,particularly road traffic,is one of the greatest threats to wildlife.Considering the association between alerting behavior and the survival of animals,it is important to study the effects of road traffic on alerting behavior of wildlife.Previous studies assessing the shortterm impact of road traffic on alerting behavior of wildlife have focused on vigilance distances.However,studies on the use of alarm calls are scarce,and it is unclear whether such behavioral responses change after repeated exposure to road traffic.We assessed the alerting behavior of plateau pikas(Ochotona curzoniae)who were near or far from roads when facing a potential predator.We found that pikas near roads exhibited shorter vigilance and tolerance distances,and produced fewer alarm calls than those relatively far away from roads.Furthermore,both vigilance and tolerance distances of plateau pikas were significantly positively correlated with the distance from the burrow to the road.Road traffic reduced antipredator responses and shaped alerting behavior;that is,pikas near roads were bolder and more silent compared to those far away from roads.Our findings suggest that increasing urbanization will have corresponding effects on animal behavior,which may have significant fitness effects in the future.展开更多
文摘IN the last year, 41 year-old Huang has suffered more frequently from chest pains and breathlessness, especially when she is tired or angry. These symptoms usually last three to five minutes but can linger for up to an hour or two. Nitroglycerin sometimes helps alleviate the symptoms but not always. No tell-tale abnormal signs show up in Holter, heart supersonic or electrocardiogram checks when the problem is coming on.
文摘Viability of decentralizing policing in Nigeria had been on the front burner of security discourse since Nigeria returned to democratic governance in 1999.Valid points had been put forward by both those in support and those in opposition.The Community Policing Department of the Nigeria Police had remained more of an administrative unit with little impact beyond the Police Community Relations Committee activities.Rising cases of herdsmen attacks of various communities,terrorist insurgency in the North-East,kidnappings across the different geo-political zones had resulted in the need to interrogate the efficacy of effective community policing and state policing as viable options to combating rising security challenges.The study adopted qualitative method,and being a library research relied entirely on secondary data.Sources of data included journals,relevant textbooks,newspapers,magazines,and materials downloaded from internet.The paper argues that the traditional security agencies had failed to effectively combat the many security challenges that Nigeria faces.The combination of the official security agencies and the military had failed to effectively combat insecurity in the country.The local vigilante groups on the other hand had made valuable inroad in curtailing some of the security challenges including terrorist insurgency as a result of their knowledge of the terrain.The paper concludes that to effectively combat the many security challenges,there is a need for new policy framework at the federal and state levels that would decentralize policing and give legal backing for collaboration between the official security agencies under the federal government and state security outfits including the vigilante.
基金supported by the National Natural Science Foundation of China(61571043)the 111 Project of China(B14010)。
文摘As a core part of the electronic warfare(EW) system,de-interleaving is used to separate interleaved radar signals. The de-interleaving algorithm based on the fuzzy adaptive resonance theory(fuzzy ART) is plagued by the problems of premature saturation and performance improving dilemma. This study proposes a dual fuzzy vigilance ART(DFV-ART) algorithm to address these problems and make the following improvements. Firstly, a correction method is introduced to prevent the network from prematurely saturating;then, the fuzzy vigilance models(FVM) are constructed to replace the conventional vigilance parameter, reducing the error probability in the overlapping region;finally, a dual vigilance mechanism is introduced to solve the performance improving dilemma. Simulation results show that the proposed algorithm could improve the clustering accuracy(quantization error dropped60%) and the de-interleaving performance(clustering quality increased by 10%) while suppressing the excessive proliferation of categories.
基金Project supported by the National Natural Science Foundation of China(Grant No.60874091)the Six Projects Sponsoring Talent Summits of Jiangsu Province,China(Grant No.SJ209006)+1 种基金the Natural Science Foundation of Jiangsu Province,China(Grant No.BK2010526)the Graduate Student Innovation Research Project of Jiangsu Province,China(Grant No.CXLX110417)
文摘In this paper, we study the epidemic spreading in scale-flee networks and propose a new susceptible-infected- recovered (SIR) model that includes the effect of individual vigilance. In our model, the effective spreading rate is dynamically adjusted with the time evolution at the vigilance period. Using the mean-field theory, an analytical result is derived. It shows that individual vigilance has no effect on the epidemic threshold. The numerical simulations agree well with the analytical result. Purthermore, we investigate the effect of individual vigilance on the epidemic spreading speed. It is shown that individual vigilance can slow the epidemic spreading speed effectively and delay the arrival of peak epidemic infection.
基金This work was supported by a research project grant from the Health Research Board(HRA 2011/48).
文摘BACKGROUND Efficient detection of delirium and comorbid delirium-dementia is a key diagnostic challenge.Development of new,efficient delirium-focused methods of cognitive assessment is a key challenge for improved detection of neurocognitive disorders in everyday clinical practice.AIM To compare the accuracy of two novel bedside tests of attention,vigilance and visuospatial function with conventional bedside cognitive tests in identifying delirium in older hospitalized patients.METHODS 180 consecutive elderly medical inpatients(mean age 79.6±7.2;51%female)referred to a psychiatry for later life consultation-liaison service with delirium,dementia,comorbid delirium-dementia and cognitively intact controls.Participants were assessed cross-sectionally with conventional bedside cognitive tests[WORLD,Months Backward test(MBT),Spatial span,Vigilance A and B,Clock Drawing test and Interlocking Pentagons test]and two novel cognitive tests[Lighthouse test,Letter and Shape Drawing test(LSD)-4].RESULTS Neurocognitive diagnoses were delirium(n=44),dementia(n=30),comorbid delirium-dementia(n=60)and no neurocognitive disorder(n=46).All conventional tests had sensitivity of>70%for delirium,with best overall accuracy for the Vigilance-B(78.3%),Vigilance-A(77.8%)and MBT(76.7%)tests.The sustained attention component of the Lighthouse test was the most distinguishing of delirium(sensitivity 84.6%;overall accuracy 75.6%).The LSD-4 had sensitivity of 74.0%and overall accuracy 74.4%for delirium identification.Combining tests allowed for enhanced sensitivity(>90%)and overall accuracy(≥75%)with the highest overall accuracy for the combination of MBT-Vigilance A and the combined Vigilance A and B tests(both 78.3%).When analyses were repeated for those with dementia,there were similar findings with the MBTVigilance A the most accurate overall combination(80.0%).Combining the Lighthouse-SA with the LSD-4,a fail in either test had sensitivity for delirium of 91.4 with overall accuracy of 74.4%.CONCLUSION Bedside tests of attention,vigilance and visuospatial ability can help to distinguish neurocognitive disorders,including delirium,from other presentations.The Lighthouse test and the LSD-4 are novel tests with high accuracy for detecting delirium.
文摘Background: A critical trait for successful urban dwelling by birds is the ability to tolerate high levels of disturbing stimulation by humans. If such tolerance is partly acquired gradually after colonization, species with a long history of residence in cities are likely to be more tolerant of such stimulation than recent urban colonists, but this has not often been tested.Methods: We tested whether introduced Rock(Columba livia) and Spotted(Streptopelis chinensis) Doves, historically long-term residents of Melbourne, Australia, were more tolerant of disturbance by humans than the very recent colonist, the native Crested Pigeon(Ochyphaps lophotes) by comparing the Flight Initiation Distances(FID) and time allocations to vigilance during foraging of all three species in urban Melbourne. That all three species are members of the Columbiformes reduces the possibility that any species differences in tolerance are simply phylogenetic in origin.Results: Flight initiation distance was shorter in Rock Doves than in the other two species, which did not differ in approachability by a human. Rock Doves retreated from an approaching human mainly by walking a relatively short distance, Crested Pigeons mainly by running a relatively short distance and Spotted Doves primarily by flying a comparatively long distance. The time allocation to anti-predator vigilance of Rock Doves was smaller than that of the other two species, whose allocations were similar.Conclusions: The very recent colonist of eastern Melbourne, the Crested Pigeon, was not the least tolerant of disturbance by humans of the three related species. Natural selection for tolerance therefore probably cannot entirely explain the pattern of tolerance evident among these urban dove species and behavioural flexibility is probably involved. Length of residency in a city is not an infallible guide to a species' level of tolerance of disturbance by humans.
基金supported by National Key Research and Develop-ment Program of China(No.2017YFC1403500 to JL)National Natural Science Foundation of China(No.31911540468 and 31672316 to DL)+1 种基金non-profit Foundation of Marine Environment and Ecological Conservation of CNOOC(CF-MEEC/TR/2020-20 to ZZ)Natural Science Foundation of Liaoning Province of China(2019-MS-154 to DL).
文摘Background:Animals need to adjust their vigilance strategies when foraging between physically contrasting veg-etated and non-vegetated habitats.Vegetated habitats may pose a greater risk for some if vegetation characteristics function as a visual obstruction but benefit others if they serve as protective shelter.Variation in group size,presence of similar species,along with variation in environmental conditions and anthropogenic disturbance can also influence vigilance investment.Methods:In this study,we quantified the vigilance behaviour of two large-bodied,sympatric migratory curlew species-Far Eastern Curlew(Numenius madagascariensis)and Eurasian Curlew(N.arquata)-in vegetated Suaeda salsa saltmarsh and non-vegetated mudflat habitat in Liaohekou National Nature Reserve,China.We used linear mixed models to examine the effects of habitat type,season,tide time,flock size(conspecific and heterospecific),and human disturbance on curlew vigilance investment.Results:Both species spent a higher percentage of time under visual obstruction in S.salsa habitat compared to mudflat habitat but in response,only Far Eastern Curlew increased their percentage of vigilance time,indicating that visual obstruction in this habitat is only a concern for this species.There was no evidence that S.salsa vegetation served as a form of cryptic background colouration since neither species decreased their vigilance effect in S.salsa habitat in spring compared to the autumn migration season.The effect of curlew social environment(i.e.flock size)was habitat dependent since percentage of vigilance time by curlews in saltmarsh increased with both the number of individual curlews and number of other birds present,but not in mudflat habitat.Conclusions:We conclude that both migratory curlew species exhibit a flexible vigilance adjustment strategy to cope with the different environmental and social conditions of adjacent and sharply contrasting coastal habitats,and that the trade-off between the risks of foraging and the abundance of prey may be a relatively common phenom-enon in these and other shorebird populations.
文摘Introduction: The exposure to shift works, and especially to night shift, goes against the circadian rythmicity of the social man, which brings about a multitude of disruptive effects on health. In a hospital environment, such night shift is necessary so as to ensure the continuity of care. Sleep and vigilance disorders related to this work mode are frequent and often pose adaptation problems. The objective of this study is to detect the harmful effects of night shift on sleep, vigilance and the quality of life of nurses in Farhat Hached Teaching Hospital in Sousse. Material and Methods: It is a cross-sectional study carried out among two groups of nurses: one group performing a fixed night work and the other one working permanently during the day at Farhat Hached Teaching Hospital in Sousse. Data collection is mainly based on validated questionnaires evaluating sleep quality (Pittsburg sleep quality index), daytime sleepiness (Epworth sleepiness scale), sleep typology (Horne and Ostberg questionnaire), and the quality of life (SF-12). An objective evaluation of vigilance was realized by the study of reaction time and error rates to different tasks of “Super lab” software. Results: 50 night and 50 day nurses have been colligated. Both groups were age- and gender-matched. Sleep quality mean index was significantly higher among night nurses in comparison with day nurses (10.2 ± 5.9 versus 6.76 ± 5.16). After multivariate analysis, sleep quality was significantly correlated to age, department, schedule and the choice of schedule. Night shift was not related to daytime sleepiness. The objective analysis of vigilance showed that the reaction time to different tasks exploring the attentional mechanisms, as well as errors rate, were significantly more important among the night group. The mental score of the quality of life was significantly higher among day nurses. However, such difference was not significant with regard to physical score. Conclusion: The findings of our study highlight not only the alteration of the health and the well being of paramedical staff secondary to night shift, but also a possible threat to safety care lavished by these teams, which involves the necessity to undertake preventive measures on an individual and collective scale.
基金the National Natural Science Foundation of China(grant numbers 31800325,31970500,31770571)the Anhui Provincial Natural Science Foundation(grant numbers 1808085QC59,1908085QC128).
文摘The costs and benefits of group living are not evenly distributed among individuals that occupy different spatial positions within a group(central or peripheral).However,the definitions of central and peripheral positions may artificially mask the true dynamics of cost and benefit of individuals.Using wintering foraging Greater Whitefronted Geese(Anser albifrons)flocks as our study system,we measured individual spatial position within a flock as distance to the flock edge.First,we tested the effects of distance to edge on the antipredation cost and foraging benefit of individual goose using generalized linear mixed models(GLMMs).Flock size and number of neighbors and their interactions with distance to edge were included as fixed effects in GLMMs.Then we used piecewise regression to determine the threshold value of distance to edge to classify central and peripheral individuals.Our results indicated distance to edge significantly affected percent of time spent on vigilance(vigilance time),percent of time spent on foraging(foraging time)and intake rate(pecks/min),whereas other factors had no effects.We found that the critical distance that predicted changes in behavior was around 2.5 m.Birds 2.5 m or less from the edge of the group were more vigilant,and had less efficient foraging than more central individuals.Behavioral differences between central and peripheral individuals were more easily detected when the birds were classified by the method introduced in this study than by the traditional minimum convex polygon method.Our research provides researchers a dichotomous classification scheme that places individuals into peripheral and central positions from an individual's perspective.
文摘This paper takes an integrative approach to the communication and comprehension of humor from the perspectives of the humorist’s manipulation and the recipient’s vigilance informed by relevance theory.It is proposed that,in order to communicate humor,the humorist manipulates the recipient’s expectation of relevance in the setup and in the punchline in two different but related ways:misleading and guiding.It is also proposed that,in order to comprehend and appreciate humor,the recipient exercises vigilance against his/her own shallow processing in the setup and exercises vigilance for special cognitive effects in the punchline.On this approach,humorous communication and comprehension is viewed as an interaction between manipulation and epistemic vigilance.Strategies of manipulation and vigilance are described,and some essential issues arising from the relevance-theoretic approach to humor are reconsidered with some implications drawn.This paper contributes to enhancing the explanatory power of relevance theory for the communication and comprehension of humor.
文摘<strong>Background and Aim: </strong>Vigilance is an essential element in intensive care nursing. This study was conducted to determine nursing vigilance in nurses working in the intensive care units of educational and medical centers in Ardabil, Iran. <strong>Methods: </strong>This was a cross-sectional descriptive-analytical study with 192 ICU nurses as the participants. The data were obtained through questionnaires regarding demographic characteristics and nursing vigilance. SPSS software version 24 was used for the statistical analysis. <strong>Results: </strong>The mean total vigilance score was 3.86 ± 0.23 of 5. The mean scores of the timely diagnosis of changes, pattern recognition, and clinical decision-making subscales were 4.07 ± 0.26, 04.04 ± 0.41, and 3.44 ± 0.25, respectively. No significant relationships were observed between the total or subscale vigilance scores and other demographic characteristics. <strong>Conclusion: </strong>We assessed ICU nurses’ vigilance behaviors and found that their mean vigilance score was higher than the expected average, indicating our participants had a high level of clinical vigilance. These results suggest a need for effective educational interventions to boost clinical decision-making skills in ICU nurses, especially younger nurses.
文摘Escape behavior is a common antipredator strategy among wild animals.Here,we investigated the effect of four factors on the vigilance behavior of the endemic Cyprus rock agama(Laudakia cypriaca).Flight initiation distance(FID,the minimum distance to which an observer can approach a lizard before it flees)was measured in relation to the type of location(tourist vs.nontourist area),the observer’s starting distance,air temperature,and substrate temperature.We collected data for 39 agamas in tourist areas and 34 of these lizards in nontourist areas.As a whole,the mean starting distance was 10.5 m and the FID was 3.6 m.The average substrate temperature was 34.0℃ and the average air temperature 29.6℃.Only the type of area affected the agamas’escape decisions with FID being 1.8 m shorter in tourist areas than in nontourist areas(2.7 m vs.4.5 m).This is probably due to the habituation of lizards to the presence of humans in the former areas.This study shows that tourism strongly affects the behavior of lizards,which may have consequences for the functioning of the population.Tourists can increase the safety of lizards by creating a human shield to deter predators.Once the tourist season is over,lizards may become more vulnerable to predators.
基金supported by Sichuan Science and Technology Program(2022JDTD0026)National Natural Science Foundation of China(31772464,32001095)Youth Innovation Promotion Association CAS(2012274).
文摘Human disturbance,particularly road traffic,is one of the greatest threats to wildlife.Considering the association between alerting behavior and the survival of animals,it is important to study the effects of road traffic on alerting behavior of wildlife.Previous studies assessing the shortterm impact of road traffic on alerting behavior of wildlife have focused on vigilance distances.However,studies on the use of alarm calls are scarce,and it is unclear whether such behavioral responses change after repeated exposure to road traffic.We assessed the alerting behavior of plateau pikas(Ochotona curzoniae)who were near or far from roads when facing a potential predator.We found that pikas near roads exhibited shorter vigilance and tolerance distances,and produced fewer alarm calls than those relatively far away from roads.Furthermore,both vigilance and tolerance distances of plateau pikas were significantly positively correlated with the distance from the burrow to the road.Road traffic reduced antipredator responses and shaped alerting behavior;that is,pikas near roads were bolder and more silent compared to those far away from roads.Our findings suggest that increasing urbanization will have corresponding effects on animal behavior,which may have significant fitness effects in the future.