Signalling centre vortices coordinate collective behaviour in social amoebae

Self-sustaining signalling waves provide a source of information in living systems. A classic example is the rotating spiral waves of cAMP (chemoattractant) release that encode Dictyostelium morphogenesis. These patterns remain poorly characterised due to limitations in tracking the signalling behaviour of individual cells in the context of the whole collective. Here, we have imaged Dictyostelium populations over millimetre length scales and track the emergence, structure, progression and biological effects of cAMP waves by monitoring the signalling states and motion of individual cells. Collective migration coincides with a decrease in the period and speed of waves that stem from an increase in the rotational speed and curvature of spiral waves. The dynamics and structure of spiral waves are generated by the vortex motion of the spiral tip. Spiral tip circulation spatially organises a small group of cells into a ring pattern, which also constrains spiral tip motion. Both the cellular ring and tip path gradually contract over time, resulting in the acceleration of spiral rotation and change in global wave dynamics. Aided by mathematical modelling, we show that this contraction is due to an instability driven by a deflection in cell chemotaxis around the spiral tip cAMP field, resulting in a deformation of the cellular ring pattern towards its centre. That is, vortex contraction modulates the source of information which, upon dissemination (excitable signal relay) and decoding (chemotaxis), triggers morphogenesis. By characterising rotating spiral waves at this level of detail, our results describe a mechanism by which information generated by a self-sustaining signal, and disseminated across the population, is modulated at the organisational source.

Comparison of Models of Single-Phase Diode Bridge Rectifiers for Their Use in Harmonic Studies with Many Devices

Harmonic modeling of low-voltage networks with many devices requires simple but accurate models. This paper investigates the advantages and drawbacks of such models to predict the current harmonics created by single-phase full-bridge rectifiers. An overview is given of the methods, limiting the focus to harmonic analysis. The error of each method, compared to an accurate numerical simulation model, is quantified in frequency and time domain considering realistic input scenarios, including background voltage distortion and different system impedances. The results of the comparison are used to discuss the applicability of the models depending on the harmonic studies scale and the required level of detail. It is concluded that all models have their applicability, but also limitations. From the simplest and fastest model, which does not require a numerical solution, to the more accurate one that allows discontinuous conduction mode to be included, the trade-off involves accuracy and computational complexity.

Simulationen des Einflusses verschiedener Anpassungsmaßnahmen auf die Luftqualität in Kurorten mit PALM-4U

<p>Der Einfluss von Bebauung auf die Schadstoffverteilung in der innerörtlichen Atmosphäre und damit auf die Gesundheit des Menschen ist grundsätzlich von großem Interesse, insbesondere im Hinblick auf den Kurbetrieb und die Erfolgsaussichten einer medizinischen Behandlung bzw. Rehabilitation. Das Zentrum für Medizin-Meteorologische Forschung (ZMMF) des Deutschen Wetterdienstes stellt mit seinen Messreihen sicher, dass die Luftqualität in Kurorten entsprechend gut ist. Um die Ortschaften bei der Entwicklung von Strategien zur Luftqualitätsverbesserung noch besser unterstützen zu können sollen zukünftig auch Modellrechnungen mit  PALM-4U (PALM for urban applications) durchgeführt werden. Dieses Modell erlaubt die Simulation sehr genauer Strömungs- und Turbulenzverhältnisse in der Nähe von sehr komplexen Hindernissen unter Einbindung von urbanen Einflussfaktoren wie zum Beispiel Schadstoffquellen aus dem Verkehr oder der Beheizung.</p> <p>In diesem Beitrag sollen die Anwendungsmöglichkeiten von PALM-4U am ZMMF aufgezeigt werden. Als Beispiel dient hierfür eine teilrealistische Ortschaft, welche teilweise dem Ort Prüm in der Eifel nachempfunden ist. Das Gelände ist stark orographisch gegliedert, die Bebauung wurde in der Genauigkeit LOD1 (level of detail 1) eingebunden. Es werden beispielhaft die Auswirkungen auf die Belastung durch NO<sub>2</sub>, PM<sub>10</sub> und bodennahem O<sub>3</sub> bei Änderungen der Verkehrsdichte und zusätzlich bei Einführung einer Umgehungsstraße untersucht. Des Weiteren werden Änderungen in der Schadstoffausbreitung bei Anpassungen in der Bebauung dargestellt sowie der Einfluss einzelner Schadstoffquellen auf die nähere Umgebung bei komplexer Bebauung.</p> <p>Somit lässt sich das Potential zur Schadstoffreduktion bei verschiedenen städtebaulichen oder anderen Anpassungsmaßnahmen abschätzen.</p>

The level of detail for 4D BIM modeling

4D modeling has been actively developing over the past decade along with the progress of BIM implementation. 4D model can provide enhanced early decisions about the space-temporal criticality of work elements. This models is a collection of graphical and scheduling information about an object. These inputs can have different levels of detail (LOD). In creating and using BIM projects, the LOD of datasets is an important aspect. However, to date there is limited research thoroughly investigating the issue of LOD within 4D models. The article provides an overview of studies related to the level of detail for 4D models, and also describes the impact of LOD on the final 4D model.

Parallel generation of extensive vascular networks with application to an archetypal human kidney model

Given the relevance of the inextricable coupling between microcirculation and physiology, and the relation to organ function and disease progression, the construction of synthetic vascular networks for mathematical modelling and computer simulation is becoming an increasingly broad field of research. Building vascular networks that mimic in vivo morphometry is feasible through algorithms such as constrained constructive optimization (CCO) and variations. Nevertheless, these methods are limited by the maximum number of vessels to be generated due to the whole network update required at each vessel addition. In this work, we propose a CCO-based approach endowed with a domain decomposition strategy to concurrently create vascular networks. The performance of this approach is evaluated by analysing the agreement with the sequentially generated networks and studying the scalability when building vascular networks up to 200 000 vascular segments. Finally, we apply our method to vascularize a highly complex geometry corresponding to the cortex of a prototypical human kidney. The technique presented in this work enables the automatic generation of extensive vascular networks, removing the limitation from previous works. Thus, we can extend vascular networks (e.g. obtained from medical images) to pre-arteriolar level, yielding patient-specific whole-organ vascular models with an unprecedented level of detail.

Penyuluhan Pelaksanaan Zakat Profesi oleh Kepala Keluarga

Zakat is the third pillar of Islam, zakat is the most important worship in the Qur'an, Allah explains zakat along with explaining prayer. Zakat in terms of fiqh terms means "a certain amount of property that is required by Allah to be handed over to those who are entitled" in addition to meaning "to spend a certain amount itself. Therefore, the law of zakat is obligatory (fard) on every Muslim who has met certain conditions. Zakat is included in the category of worship (such as prayer, pilgrimage, and fasting) which has been regulated in detail based on the Qur'an and as-Sunnah, as well as a social and humanitarian charity that can develop in accordance with the development of mankind. Ibn Zaid said, "Salat and zakat are obligatory together, not separately." Then he also said "Prayer will not be accepted without zakat. Congratulations to Abu Bakr who understands this matter correctly. One of the zakat that is obligatory for Muslims is professional zakat.The purpose of this study is to find out how the professional zakat system even though in Islam does not have a level of detail, it still carries out perfect zakat. So that people who have professions can issue zakat on wealth with existing provisions. Keywords : Zakat, Profession, Head of the family, PNS

A community-developed extension to Darwin Core for reporting the chronometric age of specimens

Darwin Core, the data standard used for sharing modern biodiversity and paleodiversity occurrence records, has previously lacked proper mechanisms for reporting what is known about the estimated age range of specimens from deep time. This has led to data providers putting these data in fields where they cannot easily be found by users, which impedes the reuse and improvement of these data by other researchers. Here we describe the development of the Chronometric Age Extension to Darwin Core, a ratified, community-developed extension that enables the reporting of ages of specimens from deeper time and the evidence supporting these estimates. The extension standardizes reporting about the methods or assays used to determine an age and other critical information like uncertainty. It gives data providers flexibility about the level of detail reported, focusing on the minimum information needed for reuse while still allowing for significant detail if providers have it. Providing a standardized format for reporting these data will make them easier to find and search and enable researchers to pinpoint specimens of interest for data improvement or accumulate more data for broad temporal studies. The Chronometric Age Extension was also the first community-managed vocabulary to undergo the new Biodiversity Informatics Standards (TDWG) review and ratification process, thus providing a blueprint for future Darwin Core extension development.

The influence of the cardinality of the alphabet on the quality of reconstruction of a symbolic periodic sequence from a sequence with noise

В статье рассмотрена задача восстановления символьных периодических последовательностей, искаженных шумами вставки, а также замены и удаления символов. Поскольку степень детализации символьного описания процесса определяется мощностью алфавита, представляет интерес исследование влияния степени детализации символьного описания на возможность восстановления полной информации об исходной периодической последовательности. Представлено экспериментальное исследование зависимости характеристик качества предложенного авторами метода восстановления периода от мощности алфавита. Для алфавитов разной мощности приводятся доля последовательностей с удовлетворительно восстановленным периодом и относительная погрешность определения длины периода. Качество восстановления оценивается отношением редакционного расстояния от восстановленной периодической последовательности до исходной строго периодической последовательности The relevance of this study is associated with the presence of a wide range of applied problems in real-world data processing and analysis. It is sensible to encode information using symbols from a finite alphabet in such problems. By varying the cardinality of the alphabet, in the description of the process, the symbolic representation provides a level of detail sufficient for real-world data analysis. However, for a number of subject areas in which it is possible to use symbolic coding of trajectories of the examined processes researchers face the presence of distortions, noise, and fragmentation of information. This occurs in bioinformatics, medicine, digital economy, time series forecasting and analysis of business processes. Periodic processes are widely represented in these subject areas. Without noise, these processes correspond to periodic symbolic sequences, i.e. words over a finite alphabet. A researcher often receives a sequence distorted by noises of various origins as the experimental data, instead of the expected periodic symbolic sequence. Under these conditions, when solving the problem of identifying the periodicity, which includes both the determination of a periodically repeating symbolic fragment and its length, hereinafter called the period, the problem requires reducing the effect of noise on the experimental results. The article deals with the problem of recovering periodic sequences, distorted by presence of noise along the replaced and deleted symbols. Since the level of detail in the description of the process depends on the cardinality of the alphabet, it is of interest to study the influence of the level of detail in the symbolic description on the possibility of recovering complete information about the initially periodic sequences. The article experimentally examines the dependence of the cardinality of the alphabet on the quality characteristics of the period recovery method proposed by the authors. For alphabets of different cardinalities, the proportion of sequences with a satisfactorily reconstructed period and the relative error in determining the length of the period are given. The quality of reconstruction of a periodically repeating fragment is estimated by the ratio of the editing distance from the reconstructed periodic sequence to the original sequence distorted by noise

A Literature Review: Detection of COVID-19 in Computed Tomography Images Using Deep Learning

Through the development of the COVID-19 disease, various diagnosis methods have been studied. One of them is the computed tomography (CT), which has the best level of detail among medical image exams. The CT generates a repeatable and tiring workload, in addition to needing a team that is familiar with the findings that indicate pneumonia caused by COVID-19. To reduce this manual work and collaborate with these teams, several studies have been carried out using deep learning techniques. In this way, this study presents a review of the literature regarding the detection of COVID-19 in CT that uses deep learning to collaborate with a theoretical basis for future works.