A simplex, the convex hull of a set of
n
+
1
affinely independent points, is a useful tool in derivative-free optimization. The term
uniform simplex
was used by Audet and Hare (Derivative-free and ...blackbox optimization. Springer series in operations research and financial engineering, Springer, Cham,
2017
). The purpose of this paper is to provide a framework for constructing a uniform simplex in
R
n
, which can then be aligned with a given vector. We prove that a uniform simplex has the greatest normalized volume of any simplex. Moreover, we show how to create a
uniform minimal positive basis
from a uniform simplex.
Distributed Bragg reflector fiber laser with the dual-polarization mode is commonly used as a sensing element in optical sensors. Lateral force on such a fiber induces birefringence and results in ...beating frequency generation in it. Also, the change in the magnitude of the lateral force is correlated to the shift in the beating frequency. This article presents a multi-physics optomechanical model for a fiber laser force sensor based on the birefringence phenomenon. To this end, a theoretical model for the sensing principle was developed through employing the elastic beam theory, Hertzian contact mechanics, and optical birefringence principle. Based on the linearity of the developed optomechanical model to the lateral force and ambient temperature variation, a multi-linear regression calibration for the force sensor was proposed and experimentally validated. Also, the temperature-induced drift in the beating frequency was compensated through exponential adjustment. Moreover, the calibration results showed a relatively small sensitivity for temperature sensing with respect to the external force (cross-talk). This phenomenon was predicted with the theoretical model. Verification of the calibration revealed a root-mean-square error of 0.12°C and 0.04 N for temperature and force sensing, respectively. Furthermore, the validation study showed a root-mean-square error of 0.04± 0.03 N and zero hysteresis for the developed sensor. Moreover, the theoretical sensitivity to external force was similar to the experimental results. For future applications, the compliance of the sensor specifications with the requirements of three surgical procedures was confirmed through comparison with the available literature.
The strategy aiming at promoting the precipitation of the primary metastable L12-Al3X phase is the most widely used to refine grain size in Al alloys designed for additive manufacturing. It is ...generally admitted that Al grains nucleate onto the primary L12-Al3X precipitates by epitaxy resulting in a cube-cube orientation relationship. Here we report TEM observations showing clusters of precipitates of this primary L12-Al3X phase. Using Automated Crystallographic Orientation Mapping in the TEM, we show that such clusters consist of various orientations. Analysis of those clusters reveals that some orientations share common 5-fold rotational symmetry axes suggesting that they have nucleated from an icosahedral template. We conclude that Icosahedral Short Range Order (ISRO) in the liquid can play a role in the nucleation of the primary metastable L12-Al3Zr phase through the ISRO-mediated nucleation mechanism.
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Spine density in the hippocampus changes during the estrus cycle and is dependent on the activity of local aromatase, the final enzyme in estrogen synthesis. In view of the abundant ...gonadotropin-releasing hormone receptor (GnRH-R) messenger RNA expression in the hippocampus and the direct effect of GnRH on estradiol (E2) synthesis in gonadal cells, we asked whether GnRH serves as a regulator of hippocampal E2 synthesis. In hippocampal cultures, E2 synthesis, spine synapse density, and immunoreactivity of spinophilin, a reliable spine marker, are consistently up-regulated in a dose-dependent manner at low doses of GnRH but decrease at higher doses. GnRH is ineffective in the presence of GnRH antagonists or aromatase inhibitors. Conversely, GnRH-R expression increases after inhibition of hippocampal aromatase. As we found estrus cyclicity of spine density in the hippocampus but not in the neocortex and GnRH-R expression to be fivefold higher in the hippocampus compared with the neocortex, our data strongly suggest that estrus cycle-dependent synaptogenesis in the female hippocampus results from cyclic release of GnRH.
This study aims to examine two explanatory factors of relationship satisfaction and parental alliance among both parents of a new child, namely romantic attachment and perfectionism. A sample of 80 ...couples completed individual online questionnaires. Path analyses based on the Actor‐Partner Interdependence Model were carried out to explore the actor and partner effects of each explanatory variable (attachment, perfectionism) on both partners’ postnatal relationship satisfaction and parental alliance. Results revealed that attachment avoidance is negatively related to each partner’s own relationship satisfaction and parental alliance, whereas attachment anxiety is related to their own lower parental alliance. Maladaptive perfectionism is negatively related to each partner’s own relationship satisfaction, whereas adaptive perfectionism is positively related to each partner’s own relationship satisfaction. These results extend the understanding of the factors contributing to parental and couple adaptation in the postnatal period. They highlight the role of attachment and perfectionism for improving postnatal professionals’ interventions.
Avalanche accidents, particularly those resulting in fatalities, attract substantial attention from policy makers and organizations, as well as from the media and the public. Placing fatal accidents ...in a wider context requires long-term and robust statistics. However, avalanche accident statistics, like most other accident statistics, often rely on relatively small sample sizes, with single multi-fatality events and random effects having a potentially large influence on summary and trend statistics. Additionally, trend interpretation is challenging because statistics are generally explored at a national level, and studies vary in both the period covered and the methods. Here, we addressed these issues by combining the avalanche fatality data from the European Alps (Austria, France, Germany, Liechtenstein, Italy, Slovenia, and Switzerland) for three different periods between 1937 and 2015 and applying the same data analysis methodology. During the last four decades, about 100 people lost their lives each year in the Alps. Despite considerable inter-annual variation, this number has remained relatively constant in the last decades. However, exploring fatality numbers by the location of the victims at the time of the avalanche revealed two partly opposing trends. The number of fatalities in controlled terrain (settlements and transportation corridors) has decreased significantly since the 1970s. In contrast to this development, the number of fatalities in uncontrolled terrain (mostly recreational accidents) almost doubled between the 1960s and 1980s and has remained relatively stable since then, despite a strong increase in the number of winter backcountry recreationists. Corresponding to these trends, the proportion of fatalities in uncontrolled terrain increased from 72 to 97 %. These long-term trends were evident in most national statistics. Further, the temporal correlation between subsets of the Alpine fatality data, and between some of the national statistics, suggests that time series covering a longer period may be used as an indicator for missing years in shorter-duration datasets. Finally, statistics from countries with very few incidents should be compared to, or analysed together with, those from neighbouring countries exhibiting similar economical and structural developments and characteristics.
Three pyrrolo1,2-aquinoxalines, 15 bispyrrolo1,2-aquinoxalines, bispyrido3,2-epyrrolo1,2-apyrazines, and bispyrrolo1,2-athieno3,2-epyrazines were synthesized from various substituted nitroanilines or ...nitropyridines and tested for their in vitro activity upon the erythrocytic development of Plasmodium falciparum strains with different chloroquine-resistance status. Bispyrrolo1,2-aquinoxalines showed superior antimalarial activity with respect to monopyrrolo1,2-aquinoxalines. The best activity was observed with bispyrrolo1,2-aquinoxalines linked by a bis(3-aminopropyl)piperazine. Moreover, it was observed that the presence of a methoxy group on the pyrrolo1,2-aquinoxaline nucleus increased the pharmacological activity. Drug effects upon β-hematin formation were assayed and showed similar or higher inhibitory activities than CQ. A possible mechanism of interaction implicating binding of pyrroloquinoxalines to β-hematin was supported by molecular modeling.
•Nurses need situation awareness to detect early signs of deterioration.•Eye-tracking is a promising alternative to measure nurses’ situation awareness.•Before the cardiac arrest, designated nurses ...focused on the patient and monitor.•Teammates checked the patient and monitor less frequently and more briefly.•Designated nurses had higher situation awareness than teammates.
Eye tracking has emerged as a new technology for assessing nurses' visual attention in simulation, but its relationship with situation awareness, a precursor to clinical decision-making, remains to be defined. This study compared role-based situation awareness and visual attention using eye-tracking in simulation.
Newly hired nurses participated in a cardiac arrest simulation as part of an orientation program. Eye-tracking data were collected to assess visual attention during the prearrest period. Participants completed a situation awareness questionnaire after the simulation. Data were compared according to participants' roles in the simulation.
Results suggest a role-based difference in nurses' visual attention and situation awareness: designated nurses (n = 12) looked at the patient more often, for longer periods and were more aware of signs of patient deterioration than teammates (n = 14).
: This study was the first to combine eye-tracking and situation awareness data to compare two nursing roles during a precardiac arrest simulation. The findings also suggest gaps and learning needs in nurses' understanding of signs of patient deterioration and other nontechnical skills.
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