Towards an integrated experimental-theoretical approach for assessing the mechanistic basis of hair and feather morphogenesis

In his seminal 1952 paper, ‘The Chemical Basis of Morphogenesis’, Alan Turing lays down a milestone in the application of theoretical approaches to understand complex biological processes. His deceptively simple demonstration that a system of reacting and diffusing chemicals could, under certain conditions, generate spatial patterning out of homogeneity provided an elegant solution to the problem of how one of nature's most intricate events occurs: the emergence of structure and form in the developing embryo. The molecular revolution that has taken place during the six decades following this landmark publication has now placed this generation of theoreticians and biologists in an excellent position to rigorously test the theory and, encouragingly, a number of systems have emerged that appear to conform to some of Turing's fundamental ideas. In this paper, we describe the history and more recent integration between experiment and theory in one of the key models for understanding pattern formation: the emergence of feathers and hair in the skins of birds and mammals

COVID-19 and “New Normal” Tourism: Reconstructing Tourism

COVID-19 is an outbreak caused in China and caused by a new type of coronavirus. Declared as a pandemic by the World Health Organization, COVID-19 has caused and continues to have negative effects that leave deep traces throughout the world. The tourism industry is one of the area's most adversely aected by the pandemic. However, the restrictive effects of the outbreak, such as human mobility and interpersonal interaction in nature, mediated the balance of relations between nature and humans. In light of this information, this study aims to discuss the role of COVID-19 in the reconstruction of tourism. Curfews in the pandemic, while transforming people's lifestyles and behavior patterns around the world, it has allowed nature to renew itself. In the pandemic process, the reduction of air, noise and visual pollution in industrial cities and large metropolises, reduction of waste in water, reduction in environmental pollution and physical, social and environmental carrying capacity problems in many destinations have been eliminated. With the reduction of the eects of the pandemic, the foundations of a new normal life are being laid where people will pay attention to their social distance and wear masks. Within this new normal life, there is the possibility of building "new normal tourism" until medical requirements that can cure the outbreak are me

Les protestants d’Alsace et la Séparation des Églises et de l’État de 1870 à 1940 : éléments de contexte

Entre 1870 et 1940, des territoires limitrophes de l’Alsace (France, Länder allemands, cantons suisses) modifient les relations entre les Églises et l’État. Ces changements politiques complètent les réflexions plus théologiques et ecclésiastiques, fruits de la pensée des Réformateurs et de l’histoire. Ils interrogent le rôle de l’État ainsi que la nature et l’organisation des Églises, le mode d’adhésion des croyants. En 1924, devant l’éventualité de l’introduction des lois laïques françaises, les protestants d’Alsace se réfèrent à ces situations contemporaines géographiquement proches pour les analyser et les comparer. La loi française, jugée compatible avec la liberté religieuse et le fonctionnement des Églises, est toutefois considérée plus contraignante. C’est pourquoi les protestants d’Alsace ne sont pas demandeurs de la Séparation des Églises et de l’État, telle que prévue par la loi de 1905. Conscients de l’impossibilité politique d’une autre loi, ils savent que la seule marge de manœuvre porte sur des propositions d’amélioration. Pour faire connaître leur position, distincte de celle des catholiques, les autorités luthériennes et réformées parlent d’une seule voix et s’appuient sur les hommes politiques alsaciens protestants. Finalement, Édouard Herriot renonce à son projet et les Églises d’Alsace continuent à fonctionner sous un régime de nature concordataire, à l’exception de la période nazie. (Catherine Storne-Sengel).Between 1870 and 1940 the neighbouring territories of Alsace (France, German Länder, Swiss cantons) all modified their legislations concerning the relations between Church and State. These political changes were actually completing theological and ecclesiastical evolutions directly inspired from he Refrormers’ doctrine and history. They also questioned the role of the State and the nature and organisation of Churches, as well as the way believers subscribed to these creeds. In 1924, confronted with the possible introduction of the French secularisation legislation, the Protestants of Alsace decided to analyse it, comparing it with similar laws in neighbouring territories. The French legislation, altough considered to be congruent with religious liberty and with the normal functioning of Churches, seemed to be more restrictive. As a consequence, the Protestants in Alsace did not subscribe to the separation of Church and State as defined by the 1905 law. Perfectly aware that no alternative legislation was possible, they concluded that the only room for maneuvre consisted in proposing improvements. So as to voice their distinctive opinions -differing from the Catholics’- the authorities of the Lutheran and Reformed Churches decided to act jointly and to trust the Protestant politicians in Alsace. Finally Edpuard Herriot (Prime Minister) abandoned his project, so the Churches of Alsace have kept functioning (except under the Nazi regime) according to a local agreement regime. (trad. Pierre Boulay).Zwischen 1870 und 1940 verändern die das Elsass angrenzenden Gebiete (Frankreich, Deutsche Länder, Schweizer Kantone) die Beziehungen zwischen Kirche und Staat. Diese politischen Veränderungen ergänzen die mehr theologischen und kirchlichen Überlegungen, die aus dem Gedankengut der Reformatoren und der Geschichte entstanden sind. Sie hinterfragen die Rolle des Staates, so wie das Wesen und die Organisation der Kirchen, die Art des Bekenntnisses der Gläubigen. 1924, im Anbetracht der möglichen Einführung der laizistischen französischen Gesetze, beziehen sich die elsässischen Protestanten auf zeitgenössische, räumlich nahe Gegebenheiten, um sie zu analysieren und zu vergleichen. Das französische Gesetz, obwohl als verträglich mit religiöser Freiheit und kirchlichem Leben eingeschätzt, wird als viel einengender betrachtet. Aus diesem Grund erwünschen sich die elsässischen Protestanten nicht die Trennung von Kirche und Staat, so wie sie von dem Gesetz von 1905 vorgesehen ist. Sie wissen, dass es politisch unmöglich sein wird ein anderes Gesetz zu erhalten, und dass es nur einen Spielraum für Verbesserungsvorschläge gibt. Um ihre Position, die sich von der der Katholiken unterscheidet klar zu machen, sprechen die lutherischen und reformierten Behörden mit einer Stimme und stützen sich auf die protestantischen elsässischen Politiker. Letztendlich verzichtet Edouard Hériot auf sein Vorhaben und die Kirchen des Elsass können, ausgenommen in der Nazizeit, unter den Bedingungen des Konkordats weiterarbeiten. (trad. René Siegrist)

Einfluss von Heukonservierung, -lagerung und Silierung auf die Wiederfindung von Parasitenlarven

Ziel dieser Studie war es, den Einfluss zweier Konservierungsverfahren (Heutrocknung, Silierung) auf die Wiederfindungsraten von Endoparasitenlarven zu eruieren. Bei der Heutrocknung konnte nur ein numerischer Unterschied zwischen den Gruppen und den Untersuchungszeitpunkten nachgewiesen werden. Bei der Lagerung waren sowohl die Feuchtigkeit als auch die Lagerungsdauer als signifikante Einflussgrößen nachweisbar. Bei der Silierung zeigte sich ein Einfluss von der Qualität des Siliergutes und der Zeitdauer des Silierprozeßes auf die Wiederfindungsraten der Endoparasiten

The effect of stay home intention in the imperative stay at home periods on physical activity at home: Mediating role of social media addiction

This study aimed to determine the effect of people's stay home intentions on physical activity at home using the social media addiction mediator. In addition, developing the scale of stay home intention, which is not found in the literature, is another goal of study. Quantitate research techniques were used in the research, and questionnaire was used as the data collected method. The questionnaire was shared on social media platforms and e-mails sent to registered mail pools. Data was collected from 575 participants in Turkey. According to the results, social media addiction has a mediating role in the effect of the stay home intention on physical activity at home. This study is thought to be important and fill a gap in the literature in terms of revealing the relationship between physical activity and social media usage variables of individuals who must stay at home in situations of COVID-19 and similar crises. Staying at home causes people to have some problems with social and physical activities. The fact that staying at home is mandatory and unplanned brings the need and difficulty associated with physical activity.

Rational Design Principles for De Novo α-Helical Peptide Barrels with Dynamic Conductive Channels

Despite advances in peptide and protein design, the rational design of membrane-spanning peptides that form conducting channels remains challenging due to our imperfect understanding of the sequence-to-structure relationships that drive membrane insertion, assembly, and conductance. Here, we describe the design and computational and experimental characterization of a series of coiled coil-based peptides that form transmembrane α-helical barrels with conductive channels. Through a combination of rational and computational design, we obtain barrels with 5 to 7 helices, as characterized in detergent micelles. In lipid bilayers, these peptide assemblies exhibit two conductance states with relative populations dependent on the applied potential: (i) low-conductance states that correlate with variations in the designed amino-acid sequences and modeled coiled-coil barrel geometries, indicating stable transmembrane α-helical barrels; and (ii) high-conductance states in which single channels change size in discrete steps. Notably, the high-conductance states are similar for all peptides in contrast to the low-conductance states. This indicates the formation of large, dynamic channels, as observed in natural barrel-stave peptide channels. These findings establish rational routes to design and tune functional membrane-spanning peptide channels with specific conductance and geometry

Using stem cells in skin regeneration: possibilities and reality

Tissue-engineered skin has a long history of clinical applications, yet current treatments are not capable of completely regenerating normal, uninjured skin. Nonetheless, the field has experienced a tremendous development in the past 10 years, encountering the summit of tissue engineering (TE) and the arising of stem cell research. Since then, unique features of these cells such as self-renewal capacity, multi-lineage differentiation potential, and wound healing properties have been highlighted. However, a realistic perspective of their outcome in skin regenerative medicine applications is still absent. This review intends to discuss the directions that adult and embryonic stem cells (ESCs) can take, strengthening the skin regeneration field. Distinctively, a critical overview of stem cellsâ differentiation potential onto skin main lineages, along with a highlight of their participation in wound healing mechanisms, is herein provided. We aim to compile and review significant work to allow a better understanding of the best skin TE approaches, enabling the embodiment of the materialization of a new era in skin regeneration to come, with a conscious overview of the current limitations