| 1. |
- Bertilsson, Johan, et al.
(författare)
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Stress Levels Escalate When Repeatedly Performing Tasks Involving Threats
- 2019
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Ingår i: Frontiers in Psychology. - : Frontiers Media SA. - 1664-1078. ; 10, s. 1562-1562
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Tidskriftsartikel (refereegranskat)abstract
- Police work may include performing repeated tasks under the influence of psychological stress, which can affect perceptual, cognitive and motor performance. However, it is largely unknown how repeatedly performing stressful tasks physically affect police officers in terms of heart rate and pupil diameter properties. Psychological stress is commonly assessed by monitoring the changes in these biomarkers. Heart rate and pupil diameter was measured in 12 male police officers when performing a sequence of four stressful tasks, each lasting between 20 and 130 s. The participants were first placed in a dimly illuminated anteroom before allowed to enter a brightly lit room where a scenario was played out. After each task was performed, the participants returned to the anteroom for about 30 s before performing the next sequential task. Performing a repeated sequence of stressful tasks caused a significant increase in heart rate (p = 0.005). The heart rate started to increase already before entering the scenario room and was significantly larger just after starting the task than just before starting the task (p < 0.001). This pattern was more marked during the first tasks (p < 0.001). Issuance of a verbal "abort" command which terminated the tasks led to a significant increase of heart rate (p = 0.002), especially when performing the first tasks (p = 0.002). The pupil diameter changed significantly during the repeated tasks during all phases but in a complex pattern where the pupil diameter reached a minimum during task 2 followed by an increase during tasks 3 and 4 (p ≤ 0.020). During the initial tasks, the pupil size (p = 0.014) increased significantly. The results suggest that being repeatedly exposed to stressful tasks can produce in itself an escalation of psychological stress, this even prior to being exposed to the task. However, the characteristics of both the heart rate and pupil diameter were complex, thus, the findings highlight the importance of studying the effects and dynamics of different stress-generating factors. Monitoring heart rate was found useful to screen for stress responses, and thus, to be a vehicle for indication if and when rotation of deployed personnel is necessary to avoid sustained high stress exposures.
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| 2. |
- Bertilsson, Johan, et al.
(författare)
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Towards systematic and objective evaluation of police officer performance in stressful situations
- 2020
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Ingår i: Police Practice and Research. - : Informa UK Limited. - 1561-4263 .- 1477-271X. ; 21:6, s. 655-669
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Tidskriftsartikel (refereegranskat)abstract
- To ensure a continuous high standard of police units, it is critical to recruit people who perform well in stressful situations. Today, this selection process includes performing a large series of tests, which still may not objectively reveal a person’s capacity to handle a life-threatening situation when subjected to high levels of stress. To obtain more systematic and objective data, 12 police officers were exposed to six scenarios with varying levels of threat while their heart rate and pupil size were monitored. The scenarios were filmed and six expert evaluators assessed the performance of the police officers according to seven predefined criteria. Four of the scenarios included addressing a moderate threat level task and the scenarios were executed in a rapid sequence. Two further scenarios included a familiar firearm drill performed during high and low threat situations. The results showed that there was a large agreement between the experts in how they judged the performance of the police officers (p < 0.001). Performance increased significantly over tasks in four of the seven evaluation criteria (p ≤ 0.037). There was also a significant effect of pupil size (p = 0.004), but not heart rate, when comparing the different sequential scenarios. Moreover, a high level of threat considerably impaired the motor performance of the police officers during the firearms drill (p = 0.002). Finally, the pupil seemed to systematically dilate more when a threat appeared immediately than with a delay in the scenarios (p = 0.007). We conclude that systematic and quantitative judgments from experts provide valuable and reliable information about the performance of participants in realistic and stressful policing scenarios. Furthermore, objective physiological measures of heart rate and pupil size may help to explain and understand why performance sometimes deteriorates.
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| 3. |
- Hudson, Lawrence N, et al.
(författare)
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The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
- 2017
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 7:1, s. 145-188
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Tidskriftsartikel (refereegranskat)abstract
- The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
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| 4. |
- McGinn, Steven, et al.
(författare)
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New Technologies for DNA analysis-A review of the READNA Project.
- 2016
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Ingår i: New Biotechnology. - : Elsevier BV. - 1876-4347 .- 1871-6784.
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Forskningsöversikt (refereegranskat)abstract
- The REvolutionary Approaches and Devices for Nucleic Acid analysis (READNA) project received funding from the European Commission for 4 1/2 years. The objectives of the project revolved around technological developments in nucleic acid analysis. The project partners have discovered, created and developed a huge body of insights into nucleic acid analysis, ranging from improvements and implementation of current technologies to the most promising sequencing technologies that constitute a 3(rd) and 4(th) generation of sequencing methods with nanopores and in situ sequencing, respectively.
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| 5. |
- Bjarnegård, Mattias, 1970, et al.
(författare)
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Endothelium-specific ablation of PDGFB leads to pericyte loss and glomerular, cardiac and placental abnormalities
- 2004
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Ingår i: DEVELOPMENT. - : The Company of Biologists. - 0950-1991 .- 1477-9129. ; 131:8, s. 1847-1857
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor-B (PDGFB) is necessary for normal cardiovascular development, but the relative importance of different cellular sources of PDGFB has not been established. Using Cre-lox techniques, we show here that genetic ablation of Pdgfb in endothelial cells leads to impaired recruitment of pericytes to blood vessels. The endothelium-restricted Pdgfb knockout mutants also developed organ defects including cardiac, placental and renal abnormalities. These defects were similar to those observed in Pdgfb null mice. However, in marked contrast to the embryonic lethality of Pdgfb null mutants, the endothelium-specific mutants survived into adulthood with persistent pathological changes, including brain microhemorrhages, focal astrogliosis, and kidney glomerulus abnormalities. This spectrum of pathological changes is reminiscent of diabetic microangiopathy, suggesting that the endothelium-restricted Pdgfb knockouts may serve as models for some of the pathogenic events of vascular complications to diabetes. Key words: PDGFB, Endothelium, Cre, loxP, Pericytes, Microaneurysm
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| 6. |
- Dahl, Mats, et al.
(författare)
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Analysis of eyewitness testimony in a police shooting with fatal outcome - Manifestations of spatial and temporal distortions
- 2018
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Ingår i: Cogent Psychology. - : Taylor & Francis. - 2331-1908. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- Eyewitness statements are commonly used in the criminal justice system and viewed as having a high-probative value, especially when the witness has no motive to lie, other witness recollection corroborates the account, orthe witness is highly confident. A fatal police shooting incident in Sweden had 13 witnesses (nine civilians and four police officers) and was also filmed with two mobile phones. All interviews were conducted before witnesses viewed the films, allowing for the analysis of discrepancies between their statements and the videos. In this incident, a police patrol was sent to find out a man who was reported to have attacked two persons with a knife. When found, the perpetrator refused to obey the officer's commands, and the police eventually shot at him. The analysis showed clear differences between the witness testimonies and the film. Elements associated with perceived threat, for example, the assailant's armament and movement direction and number of shots fired, were remembered fairly accurately. However, most witnesses poorly recollected when, that is, after which shot, the assailant fell to the ground. Moreover, memory of the actual order of events was altered and important aspects omitted that were crucial from a legal point of view.
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| 7. |
- Zelinka, Samuel L., et al.
(författare)
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Interlaboratory study of the operational stability of automated sorption balances
- 2024
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Ingår i: Adsorption. - 0929-5607.
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Tidskriftsartikel (refereegranskat)abstract
- Automated sorption balances are widely used for characterizing the interaction of water vapor with hygroscopic materials. These instruments provide an efficient way to collect sorption isotherm data and kinetic data. A typical method for defining equilibrium after a step change in relative humidity (RH) is using a particular threshold value for the rate of change in mass with time. Recent studies indicate that commonly used threshold values yield substantial errors and that further measurements are needed at extended hold times as a basis to assess the accuracy of abbreviated equilibration criteria. However, the mass measurement accuracy at extended times depends on the operational stability of the instrument. Published data on the stability of automated sorption balances are rare. An interlaboratory study was undertaken to investigate equilibration criteria for automated sorption balances. This paper focuses on the mass, temperature, and RH stability and includes data from 25 laboratories throughout the world. An initial target for instrument mass stability was met on the first attempt in many cases, but several instruments were found to have unexpectedly large instabilities. The sources of these instabilities were investigated and greatly reduced. This paper highlights the importance of verifying operational mass stability of automated sorption balances, gives a method to perform stability checks, and provides guidance on identifying and correcting common sources of mass instability.
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