Arbeitszeiterfassung : Rechtslage und Praxis der Arbeitszeiterfassung in Deutschland, Frankreich, Italien und Österreich

In der Schweiz wird verschiedentlich der Wunsch nach einer Lockerung der arbeitsgesetzlichen Pflicht zur Aufzeichnung der Arbeitszeit geäussert. Das Staatssekretariat für Wirtschaft SECO hat das Zentrum für Sozialrecht der Zürcher Hochschule für angewandte Wissenschaften (ZHAW) in diesem Zusammenhang mit einem Gutachten beauftragt. Es ging darum, die Rechtslage wie auch die Praxis der Arbeitsinspektorate in Deutschland, Frankreich, Italien und Österreich zu erheben. Obwohl diese vier Staaten dem europäischen Recht unterstehen und (wie die Schweiz) das ILO-Abkommen Nr. 81 über die Arbeitsinspektion ratifiziert haben, ergeben sich gemäss schriftlichen und telefonischen Befragungen der relevanten Akteure in den jeweiligen Ländern gewisse Unterschiede im innerstaatlichen Recht und in der praktischen Umsetzung

Parent–offspring conflict and its outcome under uni-and biparental care

Conflicts over parental investment are predicted to be common among family members, especially between parents and their offspring. Parent–offspring conflict has been studied in many brood-caring organisms, but whether its outcome is closer to the parental or offspring optimum is usually unknown, as is whether the presence of a second parent, a caring male partner, can affect the outcome. Here, we manipulated the initial brood size of single and paired female burying beetles to examine how many offspring are necessary to maintain parental care in the current brood. We found that mothers continued to invest in small broods even if their reproductive output would have been higher if they had discontinued their care and produced a second brood instead. Consequently, our data suggests that the offspring have the upper hand in the conflict. However, our results further show that paired females laid a second egg clutch more often and produced more offspring than single females, suggesting that the presence of a male partner shifts the conflict outcome towards the parental optimum. This latter result not only is a novel aspect of parent–offspring theory, but also represents an additional factor that might explain the evolution of biparental care

Differences in sibling cooperation in presence and absence of parental care in a genus with interspecific variation in offspring dependence

The widely spread evolutionary strategy of parental care is considered an important driver of social evolution. While offspring were long thought to primarily interact competitively, recent studies revealed the potential importance of sibling cooperation. Theories suggest that the degree of cooperation in offspring interactions depends on the degree of offspring dependence on parental care: offspring unable to forage on their own should compete more, whereas more independent juveniles may increase the degree of cooperation. In this study, we tested the occurrence of sibling cooperation in the absence of post-hatching care in several burying beetle species exhibiting varying degrees of offspring dependence. To this end, we measured larval growth rate and survival in the presence and absence of pre-hatching care using different brood sizes. We found that sibling cooperation cannot be exclusively explained by offspring dependence on parental care. While only species with more independent larvae cooperated when receiving pre-hatching care, larval cooperation occurred across species in the absence of care. The latter result suggests that sibling cooperation was already present in an early ancestor of the genus Nicrophorus. Overall, these findings give important insights into the transition from facultative to obligate family life.This is the data file associated with the cooperation experiment. Please check the first sheet in the file for further details regarding the individual columns. The second sheet contains the data for the experiment. Funding provided by: German Research Foundation (Deutsche Forschungsgemeinschaft)*Crossref Funder Registry ID: Award Number: STE 1874/6-1This excel file contains data from the laboratory described in the article

The Role of Sexual Selection in the Evolution of Chemical Signals in Insects

Chemical communication is the most ancient and widespread form of communication. Yet we are only beginning to grasp the complexity of chemical signals and the role they play in sexual selection. Focusing on insects, we review here the recent progress in the field of olfactory-based sexual selection. We will show that there is mounting empirical evidence that sexual selection affects the evolution of chemical traits, but form and strength of selection differ between species. Studies indicate that some chemical signals are expressed in relation to an individual’s condition and depend, for example, on age, immunocompetence, fertility, body size or degree of inbreeding. Males or females might benefit by choosing based on those traits, gaining resources or “good genes”. Other chemical traits appear to reliably reflect an individual’s underlying genotype and are suitable to choose a mating partner that matches best the own genotype

Thiol-gelatin-norbornene bioink for laser‐based high‐definition bioprinting

Two-photon polymerization (2PP) is a lithography-based 3D printing method allowing the fabrication of 3D structures with sub-micrometer resolution. This work focuses on the characterization of gelatin-norbornene (Gel-NB) bioinks which enables the embedding of cells via 2PP. The high reactivity of the thiol-ene system allows 2PP processing of cell-containing materials at remarkably high scanning speeds (1000 mm s(-1)) placing this technology in the domain of bioprinting. Atomic force microscopy results demonstrate that the indentation moduli of the produced hydrogel constructs can be adjusted in the 0.2-0.7 kPa range by controlling the 2PP processing parameters. Using this approach gradient 3D constructs are produced and the morphology of the embedded cells is observed in the course of 3 weeks. Furthermore, it is possible to tune the enzymatic degradation of the crosslinked bioink by varying the applied laser power. The 3D printed Gel-NB hydrogel constructs show exceptional biocompatibility, supported cell adhesion, and migration. Furthermore, cells maintain their proliferation capacity demonstrated by Ki-67 immunostaining. Moreover, the results demonstrate that direct embedding of cells provides uniform distribution and high cell loading independently of the pore size of the scaffold. The investigated photosensitive bioink enables high-definition bioprinting of well-defined constructs for long-term cell culture studies

Microbial management as a driver of parental care and family aggregations in carrion feeding insects

Social behaviors and lifestyles have evolved as successful strategies to cope with adverse and challenging living conditions, often by manipulating the immediate environment. These manipulations can extend to the surrounding microbiome, both in terms of combating harmful agents such as pathogens but also by facilitating the growth of beneficial microbes. In contrast to the largely antagonistic role traditionally assigned to microbes in social systems, these host–microbe interactions are receiving increasing attention as potential facilitators of social evolution. Here, we explore this perspective using Nicrophorus burying beetles, a group of insect carrion breeders which offer insights into the evolutionary interactions between sociality and microbial mutualists in a relatively simple family model. Recent studies have demonstrated the constant microbial challenges faced by Nicrophorus nurseries and the costly consequences they entail. Here, we provide an overview of these challenges and then explore the role of microbial mutualists in this social endeavor, focusing on the advantages they confer in terms of development and immunity. Additionally, we discuss how these mutualistic associations may select for committed parental care and more obligate forms of social life by promoting prolonged social associations through vertical transmission. Our review highlights the hypothesis that microbial mutualists not only provide immediate benefits but may also encourage social interactions in their hosts. However, the occurrence, degree, and underlying mechanisms of this phenomenon remain largely theoretical, as do the evolutionary feedbacks on microbes. Empirical evidence in this area is currently limited, emphasizing the need for further research. Nicrophorus burying beetles represent an ideal system to investigate the interplay between microbial mutualists and social evolution, offering a promising avenue for future studies. Overall, this review underscores the importance of understanding the complex interactions between microbial mutualists and social behaviors in challenging environments, and beyond

Polymer architecture as key to unprecedented high-resolution 3D-printing performance : the case of biodegradable hexa-functional telechelic urethane-based poly-ε-caprolactone

Two-photon polymerization (2PP) is a high-resolution 3D-printing technology with a very rapidly expanding field of applications, including tissue engineering (TE). In this field, 2PP offers unprecedented possibilities for systematic studies of both cell–cell and cell–material interactions in 3D. For TE applications, the reliable production of biodegradable micro-scaffolds in porous, complex architectures is essential. However, the number of biodegradable materials that support the required level of spatial resolution is very limited, being a major bottleneck for the use of 2PP in the TE field. Herein, we introduce a hexa-functional urethane-based biodegradable precursor that overcomes the limitations associated with the high-resolution printing of current biodegradable precursors. The precursor is a telechelic urethane-based poly-ε-caprolactone (PCL) possessing three acrylate functionalities at each polymer end group which enables the reliable production of complex architectures owing to its superior physical properties as compared to the traditional di-acrylate terminated analogs. The newly developed hexa-functional telechelic urethane-based PCL reveals enhanced crosslinking kinetics and one order of magnitude higher Young’s modulus compared to the di-functional precursor (57.8 versus 6.3 MPa), providing an efficient and solvent-free 2PP processing at fast scanning speeds of up to 100 mm s−1 with unprecedented feature resolutions (143 ± 18 nm at 100 mm s−1 scanning speed). The crosslinked hexa-functional polymer combines strength and flexibility owing to the segregation between its hard polyacrylate and soft PCL segments, which makes it suitable for biological systems in contrast to the highly crosslinked and rigid structures typically manufactured by 2PP. Furthermore, it revealed lower degradation rate compared to its di-functional analog, which can be considered as an advantage in terms of biocompatibility due to the slower formation of acidic degradation products. Extracts of the developed polymers did not show a cytotoxic effect on the L929 fibroblasts as confirmed via ISO 10993-5 standard protocol. The presented precursor design constitutes a simple and effective approach that can be easily translated towards other biodegradable polymers for the manufacturing of biodegradable constructs with nano-scale precision, offering for the first time to use the true capabilities of 2PP for TE applications with the use of synthetic biodegradable polymers