876 research outputs found

    Police selection via psychological testing : A United Arab Emirates study.

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    The selection of effective police officers is not a new concern, but in the UAE and many other countries, particularly in Arabic-speaking contexts, these issues have not been given considerable attention until recently. Most published studies appear to focus on the relationships between psychopathological personality tests and police performance, and very little has been written about other normal personality taxonomies (such as the Big Five). This study was therefore conducted to fill this gap, with its main goal to investigate the relationships between the five-factor model of personality, general cognitive ability, emotional intelligence (El), and work-related behaviours (i.e., job performance, training performance, perceived job stress, coping with stress, and counterproductive work behaviours, or CWB) amongst a sample of current and newly hired police officers at theAbu Dhabi Police Force in the UAE.More specifically, following an exhaustive literature review, a research gap has been identified, as there is little meaningful research available on the role of normal personality traits, cognitive ability, and El in predicting work-related behaviours in police organisations, particularly within Arab countries. Accordingly, the main question in the present research was: "To what extent could the use of psychometric testing enhance the effectiveness of police officer selection processes in the UAE?" Based on this objective, three different studies were conducted. Study One (n = 30) investigated existing processes of hiring police officers at Abu Dhabi Police in the UAE. Results have indicated that although the current processes of police officer selection may be simple and cost-efficient, there are several criticisms levelled against them, such as that they are less valid and less fair, and thus more likely to lead to negative outcomes, such as poor selection and low police performance levels. In addition, senior police managers believe that using psychometric tests such as personality and cognitive ability measures in the selection process may play a role in selecting the best entry-level police officers; and that Conscientiousness, Emotional Stability, and Extraversion are important dimensions for high performance police officers.Results of Study Two (using cross-sectional research design, and based on current officers from the Abu Dhabi Police, n = 310) and results of Study Three (using longitudinal data collection methods, and based on newly hired officers at the Abu Dhabi Police, n = 385), showed that cognitive ability, Conscientiousness, Extraversion, Neuroticism, and emotional intelligence are all significantly correlated with job performance, training performance, perceived job stress, and CWB. Moreover, consistent support was found for the validity of cognitive ability, Conscientiousness, and emotional intelligence in predicting overall actual job performance.These results suggest that measuring candidates' personality traits, cognitive ability, and emotional intelligence may enhance the police personnel selection process. It also supports the validity of selecting the best applicants, rather than screening out unfit candidates to enhance police outcomes. These findings were discussed in the framework of the Big Five and El models, and their implications for police research were analysed particularly in the areas of personnel selection and training. Further research was also explored in light of the study's findings and potential limitations

    A review on femoropopliteal arterial deformation during daily lives and nickel-titanium stent properties

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    The increasing number of studies on the behaviour of stent placement in recent decades provides a clear understanding of peripheral artery disease (PAD). The severe mechanical loads (axial ten�sion and compression, bending, radial compression and torsion) deformation of the femoropopli�teal artery (FPA) is responsible for the highest failure rate of permanent nickel-titanium (Nitinol) stents. Therefore, the purpose of this article is to review research papers that examined the deformation of the natural load environment of FPA, the properties of Nitinol and mechanical considerations. In conclusion, a better understanding of mechanical behaviour for FPA Nitinol stents contributes to increased mechanical performance and fatigue-life

    A Systematic Review on Cardiovascular Stent and Stenting Failure: Coherent Taxonomy, Performance Measures, Motivations, Open Challenges and Recommendations

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    Cardiovascular stenting is a mature topic but it is still being developed in the research community because of its importance. To provide worthy information about cardiovascular stenting environments and to give support to the researchers, attention must be given to understand the obtainable choices and gaps in this research field. This work aims to examine and examine the literature of each work related to the placement of cardiovascular stents, the failure of the stents and the models of stent designs to provide a good understanding through the investigation of articles published in various contextual aspects, such as motivations, open-challenges and recommendations to improve the field of stent placement. A systematic review is carried-out to map and examine the articles related to cardiovascular stents, the failure of the stents and the models of stent designs through a coherent-taxonomy used in three well-known scientific databases: ScienceDirect, IEEE Explore, and Web of Science. These databases involve literature that highlight arterial stenting. Based-on our inclusion and exception, a total of 90 articles composed the final set that offer various classes and sub-classes. The first class includes the development studies with (42/90) of experimental, computational and combined experimental and computational studies related to stent models performance and stent failure, the second class discussed studies that have been performed on stent design with (32/90), the third class is focused on the framework studies with (10/90), and the fourth class includes problems of stenting long-term with (6/90). The performance of stent designs, which is a research area that requires periodic controls, tools and procedures that could provide a stent design with good mechanical performance, reduce restenosis in the stent and increase fatigue resistance and durability. There have been numerous studies on stent performance that could promise good results in this field. The fields of research in stent designs vary, but all fields are fundamental equally. The expectation of this work could help to emphasize present research chances and, therefore, expand and make further research fields

    Femtosecond Laser Induced Structural Dynamics and Melting of Cu (111) Single Crystal. An Ultrafast Time-Resolved X-Ray Diffraction Study

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    Femtosecond, 8.04 keV x-ray pulses are used to probe the lattice dynamics of a 150 nm Cu (111) single crystal on a mica substrate irradiated with 400 nm, 100 fs laser pulses. For pump fluences below the damage and melting thresholds, we observed lattice contraction due to the formation of a blast force and coherent acoustic phonons with a period of ∼69 ps. At larger pump fluence, solid to liquid phase transition, annealing, and recrystallization were measured in real time by monitoring the intensity evolution of the probing fs x-ray rocking curves, which agreed well with theoretical simulation results. The experimental data suggest that the melting process is a purely thermal phase transition. This study provides, in real time, an ultrafast time-resolved detailed description of the significant processes that occur as a result of the interaction of a femtosecond light-pulse with the Cu (111) crystal surface. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.4975198

    Femtosecond Laser Induced Structural Dynamics and Melting of Cu (111) Single Crystal. An Ultrafast Time-Resolved X-Ray Diffraction Study

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    Femtosecond, 8.04 keV x-ray pulses are used to probe the lattice dynamics of a 150 nm Cu (111) single crystal on a mica substrate irradiated with 400 nm, 100 fs laser pulses. For pump fluences below the damage and melting thresholds, we observed lattice contraction due to the formation of a blast force and coherent acoustic phonons with a period of ∼69 ps. At larger pump fluence, solid to liquid phase transition, annealing, and recrystallization were measured in real time by monitoring the intensity evolution of the probing fs x-ray rocking curves, which agreed well with theoretical simulation results. The experimental data suggest that the melting process is a purely thermal phase transition. This study provides, in real time, an ultrafast time-resolved detailed description of the significant processes that occur as a result of the interaction of a femtosecond light-pulse with the Cu (111) crystal surface. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.4975198

    Sequence-Specific, Nanomolar Peptide Binding via Cucurbit[8]uril-Induced Folding and Inclusion of Neighboring Side Chains

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    This paper describes the molecular recognition of the tripeptide Tyr-Leu-Ala by the synthetic receptor cucurbit[8]uril (Q8) in aqueous buffer with nanomolar affinity and exceptional specificity. This combination of characteristics, which also applies to antibodies, is desirable for applications in biochemistry and biotechnology but has eluded supramolecular chemists for decades. Building on prior knowledge that Q8 binds to peptides with N-terminal aromatic residues, a library screen of 105 peptides was designed to test the effects of residues adjacent to N-terminal Trp, Phe, or Tyr. The screen used tetramethylbenzobis(imidazolium) (MBBI) as a fluorescent indicator and resulted in the unexpected discovery that MBBI can serve not only as a turn-off sensor via the simultaneous inclusion of a Trp residue but also as a turn-on sensor via the competitive displacement of MBBI upon binding of Phe- or Tyr-terminated peptides. The unusual fluorescence response of the Tyr series prompted further investigation by 1H NMR spectroscopy, electrospray ionization mass spectrometry, and isothermal titration calorimetry. From these studies, a novel binding motif was discovered in which only 1 equiv of peptide binds to Q8, and the side chains of both the N-terminal Tyr residue and its immediate neighbor bind within the Q8 cavity. For the peptide Tyr-Leu-Ala, the equilibrium dissociation constant value is 7.2 nM, whereas that of its sequence isomer Tyr-Ala-Leu is 34 μM. The high stability, recyclability, and low cost of Q8 combined with the straightforward incorporation of Tyr-Leu-Ala into recombinant proteins should make this system attractive for the development of biological applications

    Comparison of low versus high (standard) intraabdominal pressure during laparoscopic colorectal surgery:systematic review and meta-analysis

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    Background: To evaluate outcomes of low with high intraabdominal pressure during laparoscopic colorectal resection surgery. Methods: A systematic search of multiple electronic data sources was conducted, and all studies comparing low with high (standard) intraabdominal pressures were included. Our primary outcomes were post-operative ileus occurrence and return of bowel movement/flatus. The evaluated secondary outcomes included: total operative time, post-operative haemorrhage, anastomotic leak, pneumonia, surgical site infection, overall post-operative complications (categorised by Clavien-Dindo grading), and length of hospital stay. Revman 5.4 was used for data analysis. Results: Six randomised controlled trials (RCTs) and one observational study with a total of 771 patients (370 surgery at low intraabdominal pressure and 401 at high pressures) were included. There was no statistically significant difference in all the measured outcomes; post-operative ileus [OR 0.80; CI (0.42, 1.52), P = 0.50], time-to-pass flatus [OR -4.31; CI (-12.12, 3.50), P = 0.28], total operative time [OR 0.40; CI (-10.19, 11.00), P = 0.94], post-operative haemorrhage [OR 1.51; CI (0.41, 5.58, P = 0.53], anastomotic leak [OR 1.14; CI (0.26, 4.91), P = 0.86], pneumonia [OR 1.15; CI (0.22, 6.09), P = 0.87], SSI [OR 0.69; CI (0.19, 2.47), P = 0.57], overall post-operative complications [OR 0.82; CI (0.52, 1.30), P = 0.40], Clavien-Dindo grade ≥ 3 [OR 1.27; CI (0.59, 2.77), P = 0.54], and length of hospital stay [OR -0.68; CI (-1.61, 0.24), P = 0.15]. Conclusion: Low intraabdominal pressure is safe and feasible approach to laparoscopic colorectal resection surgery with non-inferior outcomes to standard or high pressures. More robust and well-powered RCTs are needed to consolidate the potential benefits of low over high pressure intra-abdominal surgery

    Necessary and sufficient condition for longitudinal magnetoresistance

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    Since the Lorentz force is perpendicular to the magnetic field, it should not affect the motion of a charge along the field. This argument seems to imply absence of longitudinal magnetoresistance (LMR) which is, however, observed in many materials and reproduced by standard semiclassical transport theory applied to particular metals. We derive a necessary and sufficient condition on the shape of the Fermi surface for non-zero LMR. Although an anisotropic spectrum is a pre-requisite for LMR, not all types of anisotropy can give rise to the effect: a spectrum should not be separable in any sense. More precisely, the combination kρvϕ/vρk_{\rho}v_{\phi}/v_{\rho}, where kρk_\rho is the radial component of the momentum in a cylindrical system with the z-axis along the magnetic field and vρ(vϕv_{\rho} (v_{\phi}) is the radial (tangential) component of the velocity, should depend on the momentum along the field. For some lattice types, this condition is satisfied already at the level of nearest-neighbor hopping; for others, the required non-separabality occurs only if next-to-nearest-neighbor hopping is taken into account.Comment: 7 pages, 2 figure
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