1,756 research outputs found
Oral health of seafarers - a review
The research base needs to be expanded to cover all seafarers. Dental professional expertise should be sought in policy and guideline development relevant to oral health. A strategy comprising preventive, screening, and treatment service components should be developed and a certificate of dental health introduced. Funding strategies in a complex environment of transnational stakeholders for the improvement of oral-health services for seafarers are needed. Aspects of military oral health care systems could be an example for civilian operators
Sadism among sexual homicide offenders:Validation of the Sexual Sadism Scale
Sexual sadism is assumed to be a crucial factor in sexual homicide. Prevalence estimates vary greatly due to differences in the definition of sexual sadism. A nationwide sample of 350 male perpetrators who had committed a sexual homicide offense against a female 14 years of age or above in England or Wales was assessed based on archival records. Sexual sadism was assessed using the Sexual Sadism Scale (SeSaS). Item response theory (IRT) analyses were conducted focusing on the 2-parameter logistic model. The single-factor structure of the SeSaS Part 1 was tested using confirmatory factor analysis. Estimates of both internal consistency and interrater agreement were satisfactory to substantial. IRT analysis showed that the Part 1 items captured moderate to severe levels of the latent construct (i.e., theta levels >0). Based on the Posterior Probability of Diagnosis index, the prevalence of the disorder was estimated at 37% in the sample. The substantial correlation between the SeSaS Part 1 total score and original clinical diagnoses of sadism confirms the criterion validity of the scale. Exertion of control and infliction of torture were among the more informative items. In sum, the results support the usefulness of the SeSaS instrument for assessing forensically relevant forms of sadism
A Triphasic Sorting System: Coordination Cages in Ionic Liquids.
Host-guest chemistry is usually carried out in either water or organic solvents. To investigate the utility of alternative solvents, three different coordination cages were dissolved in neat ionic liquids. By using (19) F NMR spectroscopy to monitor the presence of free and bound guest molecules, all three cages were demonstrated to be stable and capable of encapsulating guests in ionic solution. Different cages were found to preferentially dissolve in different phases, allowing for the design of a triphasic sorting system. Within this system, three coordination cages, namely Fe4 L6 2, Fe8 L12 3, and Fe4 L4 4, each segregated into a distinct layer. Upon the addition of a mixture of three different guests, each cage (in each separate layer) selectively bound its preferred guest.This work was supported by the European Research Council (259352). We also thank the Cambridge Chemistry NMR service for experimental assistance.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/anie.20150577
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Controllability Modulates the Anticipatory Response in the Human Ventromedial Prefrontal Cortex
Research has consistently shown that control is critical to psychological functioning, with perceived lack of control considered to play a crucial role in the manifestation of symptoms in psychiatric disorders. In a model of behavioral control based on non-human animal work, Maier et al. (2006) posited that the presence of control activates areas of the ventromedial prefrontal cortex (vmPFC), which in turn inhibit the normative stress response in the dorsal raphe nucleus and amygdala. To test Maier’s model in humans, we investigated the effects of control over potent aversive stimuli by presenting video clips of snakes to 21 snake phobics who were otherwise healthy with no comorbid psychopathologies. Based on prior research documenting that disrupted neural processing during the anticipation of adverse events can be influenced by different forms of cognitive processing such as perceptions of control, analyses focused on the anticipatory activity preceding the videos. We found that phobics exhibited greater vmPFC activity during the anticipation of snake videos when they had control over whether the videos were presented as compared to when they had no control over the presentation of the videos. In addition, observed functional connectivity between the vmPFC and the amygdala is consistent with previous work documenting vmPFC inhibition of the amygdala. Our results provide evidence to support the extension of Maier’s model of behavioral control to include anticipatory function in humans
Using Graph Theory to Produce Emergent Behaviour in Agent-Based Systems
Cooperation is a defining trait of Multi-Agent Systems.
At the centre of these systems lies a communication network
which governs how information flows from one agent to the next.
However, the design of these networks is often overlooked despite
the profound impact it can have on both the task performance
of the agents and the emergent phenomena they produce. In this
work we aim to illustrate this by investigating whether network
centrality impacts the task performance and emergent inequality
(unequal distribution of resources) of resource gathering agents.
We achieve this by constructing several communication networks
with increasing centrality and use them with an Agent-Based
Model called GATHER. Our results indicate that as the variance
of the population’s centrality increases, the task performance of
an agent population will decrease. Furthermore, we demonstrate
that simply changing the centrality of the network can produce
distinct results and emergent phenomena (inequality or the lack
thereof in our case). We then further support this claim by
increasing the reciprocity of one of our communication networks
which results in a system with greater task performance and
significantly lower inequality, further illustrating the impact communication
network topology can have on Multi-Agent Systems
Inequality and the Emergence of Social Stratification.
In this work, we investigate whether differential (unequal) resource
access promotes social stratification (the partitioning of a population
into hierarchical groups based on socioeconomic factors).
We achieve this by conducting scenario experimentation with Neo-
COOP, an ABM that utilizes a Cultural Algorithm to simulate the
evolution of resource sharing preferences in an artificial society. By
varying the agents’ initial resource sharing beliefs, the intensity of
differential access, and the frequency at which the agents experience
environmental stress. We find that while social stratification
does increase when differential access increases, the effect is attenuated
at the extremes with agents instead favouring an increase
in selfish behaviour across the social strata. We also show that the
severity (magnitude) of social stratification is most prominent in
societies with initially selfish agents regardless of the intensity of
differential access. Interestingly, our results also suggest that heterogeneous
populations (agents with greater diversity of resource
sharing beliefs) exhibit emergent social stratification to a lesser
degree than homogenized populations (even in populations where
agents are initialized to be altruistic)
Multiple Rieske/cytb complexes in a single organism
AbstractMost organisms contain a single Rieske/cytb complex. This enzyme can be integrated in any respiratory or photosynthetic electron transfer chain that is quinone-based and sufficiently energy rich to allow for the turnover of three enzymes — a quinol reductase, a Rieske/cytb complex and a terminal oxidase. Despite this universal usability of the enzyme a variety of phylogenetically distant organisms have multiple copies thereof and no reason for this redundancy is obvious. In this review we present an overview of the distribution of multiple copies among species and describe their properties from the scarce experimental results, analysis of their amino acid sequences and genomic context. We discuss the predicted redox properties of the Rieske cluster in relation to the nature of the pool quinone. It appears that acidophilic iron-oxidizing bacteria specialized one of their two copies for reverse electron transfer, archaeal Thermoprotei adapted their three copies to the interaction with different oxidases and several, phylogenetically unrelated species imported a second complex with a putative heme ci that may confer some yet to be determined properties to the complex. These hypothesis and all the more the so far completely unexplained cases call for further studies and we put forward a number of suggestions for future research that we hope to be stimulating for the field. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes
Hilft das zahnmedizinische Bonussystem den stationär Pflegebedürftigen?
Zusammenfassung: Die Mundgesundheit bei Pflegebedürftigen ist mangelhaft. Zufällig ausgewählte Pflegebedürftige (Berlin n=75, Nordrhein-Westfalen n=94, Sachsen n=73) aus 30 stationären Pflegeeinrichtungen wurden u.a. zu ihrem Verhalten der zahnmedizinischen Inanspruchnahme und der Nutzung ihres zahnmedizinischen Bonusheftes (zBH) befragt. Von 242Befragten (Median: 82Jahre, Range: 43-100Jahre, Frauen: 78,5%) besaßen nur 18,6% ein zBH, dabei gab es keine signifikanten geschlechts- und altersspezifischen Unterschiede. Regionale Unterschiede waren signifikant (Berlin 5,3%, Nordrhein-Westfalen 18,1%, Sachsen 32,9%; χ2-Test p<0,01). Die Zahnzahl war bei Bonusheftinhabern größer (Mann-Whitney-Test p=0,01), die Zeitspanne zum letzten Zahnarztbesuch geringer (p<0,01). Von den Bonusheftinhabern gaben 18,6% an, den Zahnarzt länger als 12Monate nicht aufgesucht zu haben (stationär Pflegebedürftige ohne Bonusheft 51,3%). Als Beitrag zur Qualitätssicherung, zur oralen Infektionskontrolle sowie zur Verbesserung der mundbezogenen und allgemeinen Lebensqualität wird die regelmäßige jährliche Durchführung zahnmedizinischer Reihenuntersuchungen mit dem Führen eines zBH für jeden Bewohner vorgeschlage
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Pyrene-edged Fe(II)4L6 cages adaptively reconfigure during guest binding.
Differential guest-binding behavior was observed between two pyrene-edged Fe4L6 cages, prepared from isomeric bis(4-aminophenyl)pyrene derivatives, 2-formylpyridine and iron(II). The cage based on a 1,6-pyrene scaffold possesses an enclosed cavity suitable for the encapsulation of large hydrophobic guests including fullerenes, polycyclic aromatic hydrocarbons, and large, structurally complex natural products such as steroids. Addition of the fullerenes C60 and C70 to the cage brought about a re-equilibration among the different cage diastereomers in order to maximize the binding affinity of the system. Density functional theory was employed to rationalize the experimentally observed energy differences for C60 binding within the cage diastereomers. In contrast, the cage isomer based on a 2,7-pyrene scaffold has a more porous cavity and did not show affinity for neutral hydrophobic guests.This work was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) and the US National Science Foundation (NSF CHE-1124244)This is the final version of the article. It was first published by ACS at http://pubs.acs.org/doi/abs/10.1021/ja507617
Parity and Time Reversal in the Spin-Rotation Interaction
A recently reported discrepancy between experimental and theoretical values
of the muon's g-2 factor is interpreted as due to small violations of the
conservation of P and T in the spin-rotation coupling. The experiments place an
upper limit on these violations and on the weight change of spinning
gyroscopes.Comment: 3 page
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