We present a novel framework to evaluate multi‐agent crowd simulation algorithms based on real‐world observations of crowd movements. A key aspect of our approach is to enable fair comparisons by ...automatically estimating the parameters that enable the simulation algorithms to best fit the given data. We formulate parameter estimation as an optimization problem, and propose a general framework to solve the combinatorial optimization problem for all parameterized crowd simulation algorithms. Our framework supports a variety of metrics to compare reference data and simulation outputs. The reference data may correspond to recorded trajectories, macroscopic parameters, or artist‐driven sketches. We demonstrate the benefits of our framework for example‐based simulation, modeling of cultural variations, artist‐driven crowd animation, and relative comparison of some widely‐used multi‐agent simulation algorithms.
Rationale
Fluoxetine (Prozac®) is the most frequently prescribed drug to battle depression in pregnant women, but its safety in the unborn child has not yet been established. Fluoxetine, a selective ...serotonin reuptake inhibitor, crosses the placenta, leading to increased extracellular serotonin levels and potentially neurodevelopmental changes in the fetus.
Objectives
The purpose of this study was to elucidate the long-term consequences of prenatal fluoxetine in rats.
Methods
Pregnant rats were injected daily with 12 mg/kg fluoxetine or vehicle from gestational day 11 until birth, and the behavior of the offspring was monitored.
Results
Plasma fluoxetine transfer from mother to pup was 83%, and high levels of fluoxetine (13.0 μg/g) were detected in the pup brain 5 h after the last injection. Fluoxetine-treated dams gave birth to litters 15% smaller than usual and to pups of reduced weight (until postnatal day 7). Furthermore, prenatal fluoxetine exposure significantly increased anxiety in the novelty-suppressed feeding test, the footshock-induced conditioned place aversion test, and the elevated plus maze test (following footshock pre-exposure) during adulthood, and also significantly decreased components of social play behavior at 4 weeks of age, and a strong tendency for increased self-grooming and making less contact in adults. Behavioral despair, anhedonia, and sexual behavior were not different between treatment groups. Finally, the hypothermic response to the 5-HT
1A
agonist flesinoxan was observed at a lower dose in prenatally fluoxetine-exposed rats than in controls.
Conclusions
Prenatal fluoxetine exposure in rats leads to detrimental behavioral outcomes in later life, which may partly be due to altered 5-HT
1A
receptor signaling.
The real‐time simulation of human crowds has many applications. In a typical crowd simulation, each person ('agent') in the crowd moves towards a goal while adhering to local constraints. Many ...algorithms exist for specific local ‘steering’ tasks such as collision avoidance or group behavior. However, these do not easily extend to completely new types of behavior, such as circling around another agent or hiding behind an obstacle. They also tend to focus purely on an agent's velocity without explicitly controlling its orientation. This paper presents a novel sketch‐based method for modelling and simulating many steering behaviors for agents in a crowd. Central to this is the concept of an interaction field (IF): a vector field that describes the velocities or orientations that agents should use around a given ‘source’ agent or obstacle. An IF can also change dynamically according to parameters, such as the walking speed of the source agent. IFs can be easily combined with other aspects of crowd simulation, such as collision avoidance. Using an implementation of IFs in a real‐time crowd simulation framework, we demonstrate the capabilities of IFs in various scenarios. This includes game‐like scenarios where the crowd responds to a user‐controlled avatar. We also present an interactive tool that computes an IF based on input sketches. This IF editor lets users intuitively and quickly design new types of behavior, without the need for programming extra behavioral rules. We thoroughly evaluate the efficacy of the IF editor through a user study, which demonstrates that our method enables non‐expert users to easily enrich any agent‐based crowd simulation with new agent interactions.
Modelling crowd behavior is essential for the management of mass events and pedestrian traffic. Current microscopic approaches consider the individual's behavior to predict the effect of individual ...actions in local interactions on the collective scale of the crowd motion. Recent developments in the use of virtual reality as an experimental tool have offered an opportunity to extend the understanding of these interactions in controlled and repeatable settings. Nevertheless, based on kinematics alone, it remains difficult to tease out how these interactions unfold. Therefore, we tested the hypothesis that gaze activity provides additional information about pedestrian interactions. Using an eye tracker, we recorded the participant's gaze behavior whilst navigating through a virtual crowd. Results revealed that gaze was consistently attracted to virtual walkers with the smallest values of distance at closest approach (DCA) and time to closest approach (TtCA), indicating a higher risk of collision. Moreover, virtual walkers gazed upon before an avoidance maneuver was initiated had a high risk of collision and were typically avoided in the subsequent avoidance maneuver. We argue that humans navigate through crowds by selecting only few interactions and that gaze reveals how a walker prioritizes these interactions. Moreover, we pose that combining kinematic and gaze data provides new opportunities for studying how interactions are selected by pedestrians walking through crowded dynamic environments.
•Time until- and distance at-closest approach can be combined using a Pareto ranking.•Gaze fixations are drawn to walkers that pose the highest risk of collision.•The fixation prior to an avoidance maneuver is likely to have triggered this response.•Gaze is intricately linked to locomotor avoidance and can be used to study the interaction neighborhood.
Every neuron is part of a network, exerting its function by transforming multiple spatiotemporal synaptic input patterns into a single spiking output. This function is specified by the particular ...shape and passive electrical properties of the neuronal membrane, and the composition and spatial distribution of ion channels across its processes. For a variety of physiological or pathological reasons, the intrinsic input/output function may change during a neuron's lifetime. This process results in high variability in the peak specific conductance of ion channels in individual neurons. The mechanisms responsible for this variability are not well understood, although there are clear indications from experiments and modeling that degeneracy and correlation among multiple channels may be involved. Here, we studied this issue in biophysical models of hippocampal CA1 pyramidal neurons and interneurons. Using a unified data-driven simulation workflow and starting from a set of experimental recordings and morphological reconstructions obtained from rats, we built and analyzed several ensembles of morphologically and biophysically accurate single cell models with intrinsic electrophysiological properties consistent with experimental findings. The results suggest that the set of conductances expressed in any given hippocampal neuron may be considered as belonging to two groups: one subset is responsible for the major characteristics of the firing behavior in each population and the other is responsible for a robust degeneracy. Analysis of the model neurons suggests several experimentally testable predictions related to the combination and relative proportion of the different conductances that should be expressed on the membrane of different types of neurons for them to fulfill their role in the hippocampus circuitry.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
With this document, we provide a standard for PET/(diagnostic) CT imaging procedures in cardiovascular diseases that are inflammatory, infective, infiltrative, or associated with dysfunctional ...innervation (4Is). This standard should be applied in clinical practice and integrated in clinical (multicenter) trials for optimal procedural standardization. A major focus is put on procedures using
18
FFDG, but 4Is PET radiopharmaceuticals beyond
18
FFDG are also described in this document. Whilst these novel tracers are currently mainly applied in early clinical trials, some multicenter trials are underway and we foresee in the near future their use in clinical care and inclusion in the clinical guidelines. Finally, PET/MR applications in 4Is cardiovascular diseases are also briefly described. Diagnosis and management of 4Is-related cardiovascular diseases are generally complex and often require a multidisciplinary approach by a team of experts. The new standards described herein should be applied when using PET/CT and PET/MR, within a multimodality imaging framework both in clinical practice and in clinical trials for 4Is cardiovascular indications.
Summary Objectives The aim of this study was to estimate the seroprevalence of Q fever and prevalence of chronic Q fever in patients with abdominal aortic and/or iliac disease after the Q fever ...outbreak of 2007–2010 in the Netherlands. Methods In November 2009, an ongoing screening program for Q fever was initiated. Patients with abdominal aortic and/or iliac disease were screened for presence of IgM and IgG antibodies to phase I and II antigens of Coxiella burnetii using immunofluorescence assay and presence of C. burnetii DNA in sera and/or vascular wall tissue using polymerase chain reaction (PCR). Results A total of 770 patients with abdominal aortic and/or iliac disease were screened. Antibodies against C. burnetii were detected in 130 patients (16.9%), of which 40 (30.8%) patients showed a serological profile of chronic Q fever. Three patients presented with acute Q fever, one of which developed to chronic Q fever over time. The number of aneurysm-related acute complications in patients with chronic Q fever was significantly higher compared to patients negative for Q fever ( p = 0.013); 9.0% (30/333) vs. 30.0% (6/20). Eight out of 46 patients with past resolved Q fever (8/46, 17.4%) presented with aneurysm-related acute complications (no significant difference). Conclusion The prevalence of chronic Q fever in C. burnetii seropositive patients with abdominal aortic and/or iliac disease living in an epidemic area in the Netherlands is remarkably high (30.8%). Patients with an aneurysm and chronic Q fever present more often with an aneurysm-related acute complication compared to patients without evidence of Q fever infection.
Transradial access (TRA) is increasingly used worldwide for percutaneous interventional procedures and associated with lower bleeding and vascular complications than transfemoral artery access. ...Radial artery occlusion (RAO) is the most frequent post-procedural complication of TRA, restricting the use of the same radial artery for future procedures and as a conduit for coronary artery bypass graft. The authors review recent advances in the prevention of RAO following percutaneous TRA diagnostic or interventional procedures. Based on the available data, the authors provide easily applicable and effective recommendations to prevent periprocedural RAO and maximize the chances of access in case of repeat catheterization or coronary artery bypass grafting surgery.
The aim of this systematic review and meta-analysis is to evaluate whether the design and methodology of drug-treatment studies of premature ejaculation affect the efficacy outcome differently. ...Therefore, methodological, design and efficacy data from 79 studies (3034 males), published between 1943 and 2003, are reviewed. A meta-analysis is performed on 43 selective serotonin reuptake inhibitors (SSRIs) and clomipramine studies (1514 males), published between 1973 and 2003; these studies were pooled to provide a summary variance-weighted effect size. The antidepressant-induced percentage increase of the intravaginal ejaculation latency time (IELT) was calculated and examined against various methodological items. A significant difference in efficacy between SSRIs was observed. Using daily treatment, paroxetine appeared more effective than the other SSRIs. Retrospective use of a questionnaire, subjective reports, single-blind and open study designs generate far greater variability of ejaculation time both at baseline and during active drug treatment than real time assessment by stopwatch. In conclusion, at daily treatment, the overall efficacy of paroxetine, clomipramine, sertraline and fluoxetine is comparable, but paroxetine exerts the strongest ejaculation delay. Only eight (18.5%) studies on antidepressant treatment fulfilled all criteria used in evidence-based medicine, for example, randomised, double-blind studies with prospective real time (stopwatch) assessment of the IELT at each intercourse. Single-blind studies, open designs, retrospective reporting, or the use of a questionnaire to assess ejaculation time should be avoided.
Cardiac amyloidosis is emerging as an underdiagnosed cause of heart failure and mortality. Growing literature suggests that a noninvasive diagnosis of cardiac amyloidosis is now feasible. However, ...the diagnostic criteria and utilization of imaging in cardiac amyloidosis are not standardized. In this paper, Part 2 of a series, a panel of international experts from multiple societies define the diagnostic criteria for cardiac amyloidosis and appropriate utilization of echocardiography, cardiovascular magnetic resonance imaging, and radionuclide imaging in the evaluation of patients with known or suspected cardiac amyloidosis.
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