Properties of pedestrians walking in line - Fundamental diagrams

We present experimental results obtained for a one-dimensional flow using high precision motion capture. The full pedestrians' trajectories are obtained. In this paper, we focus on the fundamental diagram, and on the relation between the instantaneous velocity and spatial headway (distance to the predecessor). While the latter was found to be linear in previous experiments, we show that it is rather a piecewise linear behavior which is found if larger density ranges are covered. Indeed, our data clearly exhibits three distinct regimes in the behavior of pedestrians that follow each other. The transitions between these regimes occur at spatial headways of about 1.1 and 3 m, respectively. This finding could be useful for future modeling.Comment: 9 figures, 3 table

Biomarkers for Drug Discovery: Important Aspects of in vitro Assay Design for HTS and HCS Bioassays

High throughput screening (HTS) is the foundation of current drug discovery to assay drug candidates for toxicity and biological effects (i.e. off-target and on-target responses, respectively). HTS is typically based on measuring thousands of drug candidates per day with a single endpoint assay on a limited number of doses or even a single dose of compound. The assays can be either based on absorbance or fluorescence measurements (i.e. Alamar Blue, MTT, Fluo-4 for calcium, etc.). Conversely, high content screening (HCS) is based on measuring a limited number of drugs per day, but measuring up to eight different assays simultaneously with multiple drug doses and even kinetic measurements. HCS assays typically are based on fluorescence microscopy and automatic image analysis algorithms. With HCS technology, tedious and time consuming assays can now be automated (i.e. nuclear size, micronucleus assay, lysosomal mass, mitochondrial membrane potential, neurite outgrowth, etc.). Multi-channel FACS (fluorescence activated cell sorting) can also be considered to be »high content« analysis. The purpose of this essay is to review important aspects of in vitro assay design common to both HTS and HCS screening technologies

Properties of pedestrians walking in line: Stepping behavior

In human crowds, interactions among individuals give rise to a variety of self-organized collective motions that help the group to effectively solve the problem of coordination. However, it is still not known exactly how humans adjust their behavior locally, nor what are the direct consequences on the emergent organization. One of the underlying mechanisms of adjusting individual motions is the stepping dynamics. In this paper, we present first quantitative analysis on the stepping behavior in a one-dimensional pedestrian flow studied under controlled laboratory conditions. We find that the step length is proportional to the velocity of the pedestrian, and is directly related to the space available in front of him, while the variations of the step duration are much smaller. This is in contrast with locomotion studies performed on isolated pedestrians and shows that the local density has a direct influence on the stepping characteristics. Furthermore, we study the phenomena of synchronization -walking in lockstep- and show its dependence on flow densities. We show that the synchronization of steps is particularly important at high densities, which has direct impact on the studies of optimizing pedestrians flow in congested situations. However, small synchronization and antisynchronization effects are found also at very low densities, for which no steric constraints exist between successive pedestrians, showing the natural tendency to synchronize according to perceived visual signals.Comment: 8 pages, 5 figure

Galactic interstellar filaments as probed by LOFAR and Planck

Recent Low Frequency Array (LOFAR) observations at 115-175 MHz of a field at medium Galactic latitudes (centered at the bright quasar 3C196) have shown striking filamentary structures in polarization that extend over more than 4 degrees across the sky. In addition, the Planck satellite has released full sky maps of the dust emission in polarization at 353GHz. The LOFAR data resolve Faraday structures along the line of sight, whereas the Planck dust polarization maps probe the orientation of the sky projected magnetic field component. Hence, no apparent correlation between the two is expected. Here we report a surprising, yet clear, correlation between the filamentary structures, detected with LOFAR, and the magnetic field orientation, probed by the Planck satellite. This finding points to a common, yet unclear, physical origin of the two measurements in this specific area in the sky. A number of follow-up multi- frequency studies are proposed to shed light on this unexpected finding.Comment: 6 pages, 4 figures, accepted for publication in MNRAS Letter

Foregrounds for observations of the cosmological 21 cm line: II. Westerbork observations of the fields around 3C196 and the North Celestial Pole

In the coming years a new insight into galaxy formation and the thermal history of the Universe is expected to come from the detection of the highly redshifted cosmological 21 cm line. The cosmological 21 cm line signal is buried under Galactic and extragalactic foregrounds which are likely to be a few orders of magnitude brighter. Strategies and techniques for effective subtraction of these foreground sources require a detailed knowledge of their structure in both intensity and polarization on the relevant angular scales of 1-30 arcmin. We present results from observations conducted with the Westerbork telescope in the 140-160 MHz range with 2 arcmin resolution in two fields located at intermediate Galactic latitude, centred around the bright quasar 3C196 and the North Celestial Pole. They were observed with the purpose of characterizing the foreground properties in sky areas where actual observations of the cosmological 21 cm line could be carried out. The polarization data were analysed through the rotation measure synthesis technique. We have computed total intensity and polarization angular power spectra. Total intensity maps were carefully calibrated, reaching a high dynamic range, 150000:1 in the case of the 3C196 field. [abridged]Comment: 20 pages, 22 figures, accepted for publication in A&A. A version with full resolution figures is available at http://www.astro.rug.nl/~bernardi/NCP_3C196/bernardi.pd

Children’s opportunities for play in the built environment: a scoping review

Designing opportunities for play in the built environment is crucial to support children’s health and development. A growing research focus on child-friendly environments has evidenced a shift toward creating spaces and buildings that take children’s needs seriously and work with children as capable experts and active collaborators. Yet, limited attention has focused on how different scholars conceptualise and operationalise research on understanding and designing opportunities for play in the built environment. This paper reports on the findings of a scoping review of peer-reviewed empirical literature (51 publications) from 1994 to 2019. We examine the trends and trajectories in conceptualising and operationalising research on understanding and designing opportunities for play and map the landscape of scholarship through four analytical categories: (1) who is involved in play and research studies, (2) what is the thematic focus and in what ways is play investigated in reviewed studies, (3) how are opportunities for play explored methodologically, including how/when are children involved in research, and (4) where do play and research studies occur. Our findings reveal three key challenges for future work: (i) greater appreciation and engagement with children’s diversity; (ii) ensuring a nuanced understanding of play as a spectrum of opportunities and types; and (iii) exploring the democratic context of play between formal and informal play spaces to bolster children’s right to the city. We invite researchers, practitioners, and policy makers to work closely with children, engage with their diversity and explore interdisciplinary and interprofessional avenues to promote opportunities for play across the built environment

MOST FREQUENT CARP (Cyprinus carpio L.) DISEASES IN PONDS FROM 1994. TO 1998

Zdravstveno stanje šarana praćeno je na 252 ribnjaka od godine 1994. do 1998. Rezultati zdravstvenoga stanja varirali su ovisno o primjeni ihtiotehnoloških, ihtiosanitarnih i ihtiohigijenskih profilaktičnih mjera. Najčešće utvr|ene bolesti bile su eritrodermatitis šarana u 5,82 %, ihtioftirijaza u 13,51 %, trihodinijaza u 33,568 %, daktilogiroza i girodaktiloza u 35,75 %, botriocefaloza u 14,99 % te upala ribljega mjehura uzrokovana mikroorganizmom Sphaerospora angulata u 17,77 % pregledanih ribnjaka.Fish health monitoring was carried out in the period from 1994. to 1998. for 252 fresh water ponds. Findings about health status depended upon the quality of health control measures such as ichthyotechnic, ichthyosanitary and ichthyohygieni methods. Most frequently diagnosed diseases and their percentages of incidence were: carp erythrodermatytis in 5,82 %, ichthyophtiriasis in 13,51 %, trihodiniasis in 33,568 %, dactylogirosis and gyrodactilosis in 35,75 %, botriocephalosis in 14,99 % and swimbladder inflammation caused by Sphaerospora angulata in 17,77 % examined ponds

MOST FREQUENT CARP (Cyprinus carpio L.) DISEASES IN PONDS FROM 1994. TO 1998

Zdravstveno stanje šarana praćeno je na 252 ribnjaka od godine 1994. do 1998. Rezultati zdravstvenoga stanja varirali su ovisno o primjeni ihtiotehnoloških, ihtiosanitarnih i ihtiohigijenskih profilaktičnih mjera. Najčešće utvr|ene bolesti bile su eritrodermatitis šarana u 5,82 %, ihtioftirijaza u 13,51 %, trihodinijaza u 33,568 %, daktilogiroza i girodaktiloza u 35,75 %, botriocefaloza u 14,99 % te upala ribljega mjehura uzrokovana mikroorganizmom Sphaerospora angulata u 17,77 % pregledanih ribnjaka.Fish health monitoring was carried out in the period from 1994. to 1998. for 252 fresh water ponds. Findings about health status depended upon the quality of health control measures such as ichthyotechnic, ichthyosanitary and ichthyohygieni methods. Most frequently diagnosed diseases and their percentages of incidence were: carp erythrodermatytis in 5,82 %, ichthyophtiriasis in 13,51 %, trihodiniasis in 33,568 %, dactylogirosis and gyrodactilosis in 35,75 %, botriocephalosis in 14,99 % and swimbladder inflammation caused by Sphaerospora angulata in 17,77 % examined ponds

Coarsening Kinetics of a Two Dimensional O(2) Ginzburg-Landau Model: Effect of Reversible Mode Coupling

We investigate, via numerical simulations, the phase ordering kinetics of a two- dimensional soft-spin O(2) Ginzburg-Landau model when a reversible mode cou- pling is included via the conserved conjugate momentum of the spin order parameter (the model E). Coarsening of the system, when quenched from a dis- ordered state to zero temperature, is observed to be enhanced by the existence of the mode coupling terms. The growth of the characteristic length scale L(t) exhibits an effective super-diffusive growth exponent that can be interpreted as a positive logarithmic-like correction to a diffusive growth, i.e., L(t) ~ (t ln t)^{1/2}. In order to understand this behavior, we introduced a simple phenomenological model of coarsening based on the annihilation dynamics of a vortex-antivortex pair, incorporating the effect of vortex inertia and logarithmically divergent mobility of the vortex. With a suitable choice of the parameters, numerical solutions of the simple model can fit the full simulation results very adequately. The effective growth exponent in the early time stage is larger due to the effect of the vortex inertia, which crosses over into late time stage characterized by positive logarithmic correction to a diffusive growth. We also investigated the non-equilibrium autocorrelation function from which the so called {\lambda} exponent can be extracted. We get {\lambda} = 1.99(2) which is distinctively larger than the value of {\lambda} = 1.17 for the purely dissipative model-A dynamics of non-conserved O(2) models.Comment: 19 pages, 8 figure

Simple and Low-cost Fiber-optic Sensors for Detection of UV Radiation

In this paper two simple and low-cost fiberoptic sensors for detection of UV radiation are presented. A U-shaped sensor covered with an UV marker for UV radiation detection and a fiber-optic sensor with one end covered with powder from a mercury lamp are produced and described in details. Both sensors are made of large-core PMMA plastic optical fibers. As UV sources, a solar simulator and four different UV lamps are used. The light spectrum on the fiber output is measured by using an USB spectrometer. Dependence of output light intensity on the distance of end-type sensor with powder from a mercury lamp from UV lamp is investigated as well. On the output of the sensor covered with powder from a mercury lamp are obtained peaks of fluorescent emission at approximately 616 nm and 620 nm wavelengths