FGF8 Acts as a Right Determinant during Establishment of the Left-Right Axis in the Rabbit

AbstractBackground: FGF8 has been implicated in the transfer of left-right (L-R) asymmetry from the embryonic midline (node) to the lateral plate mesoderm (LPM). Surprisingly, opposite roles have been described in chick and mouse. In mouse, FGF8 is required for the left-asymmetric expression of nodal, lefty2, and Pitx2. In chick, FGF8 represses nodal and Pitx2 on the right side. This discrepancy could reflect evolutionary differences between birds and mammals. Alternatively, the right-asymmetric expression of fgf8, which is not found in mouse, at the chick node may be a prerequisite of right-sided function. Finally, chick (blastodisc) and mouse (egg cylinder) differ with respect to the topology of the early gastrula/neurula embryo.Results: The rabbit blastodisc was investigated as an additional mammalian L-R model system. While nodal, lefty, and Pitx2 showed asymmetric expression in the left LPM, fgf8 and all other midline marker genes were symmetrically expressed at the node like in mouse. Left-sided application of FGF8 repressed the endogenous transcription of nodal as well as ectopic expression induced by the parallel administration of BMP4. Right-sided inhibition of FGF8 signaling induced bilateral marker gene expression, demonstrating that, in rabbit, FGF8 acts as a right determinant like in chick.Conclusions: These findings suggest that the anatomy of the early embryo (blastodisc versus egg cylinder) rather than taxonomical differences or asymmetry in expression constitutes an important determinant of FGF8 function in L-R axis formation. The rabbit may provide a useful model for early human embryogenesis, as human embryos develop via a blastodisc as well

Simulationsbasierte Bewertung von Nachhaltigkeitskriterien im Transportbereich: Eine systematische Literaturrecherche

Transportation is crucial for economic prosperity and the quality of life. Yet, it is also associated with negative externalities (e.g. emissions). Developing and implementing more sustainable means of transportation is one of the major concerns of researchers and policy-makers to improve liveability and contribute to environmental conservation. The use of simulation to evaluate sustainability-related indicators of transportation systems has received increasing attention within the last decades. However, research and practice still lack a comprehensive overview of common performance indicators for different transportation modes that are particularly suitable to be analysed by means of simulation-based research. Therefore, we employ a systematic literature review to delineate and conceptualize the status quo of simulation-based sustainability research in the transportation sector. We provide insights on the appropriateness of different simulation methodologies and tools for various transportation modes and sustainability measures and identify research trends and knowledge gaps to provide guidance for prospective simulation-based research

Decreasing Shopping Duration by Altering Choice Environments? An Empirical Investigation of Individual and Hybrid Nudges in the Context of e-Grocery

Boosted by the Covid-19 pandemic, the utilization of online grocery shopping has gained an increasing relevance over recent years. Increasing customer value by reducing friction can be a key option for online grocers to maintain and increase growth, customer loyalty and satisfaction. Being easy and inexpensive to implement, digital nudges can offer distinct benefits for consumers and online grocers. In this context, we investigated the potentials of digital nudging, using anchoring, social norms and a hybrid nudging concept as rational choice triggers. Our results indicate that anchoring and hybrid nudges have a significant effect on purchase frequency, while none of the investigated concepts is capable of reducing the overall shopping duration. Interestingly, in combination with anchoring nudges, social norms do have a significantly influential effect, although individually proven to be ineffective in low involvement decision contexts such as buying groceries online

Integration of Passenger and Freight Transportation using Autonomous Shuttles: A Simulation Study on Sustainability-Related KPIs

Autonomous and integrated passenger and freight transport (APFIT) is a promising approach to tackle both, traffic and last-mile-related issues such as environmental emissions, social and spatial conflicts or operational inefficiencies. By conducting an agent-based simulation, we shed light on this widely unexplored research topic and provide first indications regarding influential target figures of such a system in the rural area of Sarstedt, Germany. Our results show that larger fleets entail inefficiencies due to suboptimal utilization of monetary and material resources and increase traffic volume while higher amounts of unused vehicles may exacerbate spatial conflicts. Nevertheless, to fit the given demand within our study area, a comparatively large fleet of about 25 vehicles is necessary to provide reliable service, assuming maximum passenger waiting times of six minutes to the expense of higher standby times, rebalancing effort, and higher costs for vehicle acquisition and maintenance

Exploring Digital Social Norms Nudges in E-Grocery: Typical Consumer Testimonials with a Warm Glow

Digitization offers several possibilities to alter consumer decisions to support social concerns. The objective of this study is to examine the impact of personalized digital social norm nudges on consumer decisions enriched with the theory of warm glow on e-grocery buying decisions with the aim of supporting social projects. Specific pro-social behaviors targeted were supporting fair payment of the producers of grocery goods, social inclusion projects and initiatives against poverty by deciding for a specific choice option. A between-subjects experiment was performed with the help of a questionnaire using a mock-up mobile grocery store to measure product choices. Results showed that claims supporting pro-social initiatives have a significant impact on buying decisions. Perceived product recommendation influenced our model positively, while we had a negative price impact. The study suggests that warm glow theory and enriched social norm nudges are effective tools for behavior change towards social initiatives

On death and dying – an exploratory and evaluative study of a reflective, interdisciplinary course element in undergraduate anatomy teaching

BACKGROUND: Teaching in palliative care aims not only at providing students with specialized knowledge in symptom therapy in advanced disease, but also at developing a professional attitude consistent with the principles and philosophy of palliative care. Reflecting about one’s own or the patient’s death and dying is considered essential for empathic patient care. In medical education the dissection course is often the first encounter with the issue of death and dying and represents a significant emotional challenge to many medical students. Against this background we implemented a new course element in preparation for the dissection course, offering opportunity to reflect own experiences with death and dying and providing support in finding a balance between authentic empathy and pragmatic action towards deceased persons. We discuss issues such as dignity and professional distance and reason whether guided support for medical students regarding these issues might influence their future attitude as doctors caring for their patients. METHODS: In tandem, we performed a formal evaluation of the seminar and explored the students’ experiences with death and dying, their expectations and fears in the run-up to the dissection course and their attitude towards dissection. RESULTS: This article describes the structure and the concept of this new interdisciplinary course element and presents the results of the formal course evaluation as well as the explorative part of the accompanying research. Medical students had broad experiences with death and dying even before the dissection course. 89.1% of students had worried about some kind of emotional stress during the dissection course before, but 61.7% stated to have actually perceived emotional stress afterwards. The willingness to donate one's own body for anatomy purposes decreased significantly during the course. The given room for reflection and discussion was appreciated by the students, who felt that the effects of this seminar might be of use even beyond the dissection course. CONCLUSION: This new course element successfully assisted medical students during the dissection room experience and gave opportunity to reflection and discussion on death and dying. The accompanying research confirmed the demand for support and gave insight into experiences, emotions and attitudes of medical students

BMP signals and the transcriptional repressor BLIMP1 during germline segregation in the mammalian embryo

Molecular factors and tissue compartments involved in the foundation of the mammalian germline have been mainly described in the mouse so far. To find mechanisms applicable to mammals in general, we analyzed temporal and spatial expression patterns of the transcriptional repressor BLIMP1 (also known as PRDM1) and the signaling molecules BMP2 and BMP4 in perigastrulation and early neurulation embryos of the rabbit using whole-mount in situ hybridization and high-resolution light microscopy. Both BMP2 and BMP4 are expressed in annular domains at the boundary of the embryonic disc, which—in contrast to the situation in the mouse—partly belong to intraembryonic tissues. While BMP2 expression begins at (pregastrulation) stage 1 in the hypoblast, BMP4 expression commences—distinctly delayed compared to the mouse—diffusely at (pregastrulation) stage 2; from stage 3 onwards, BMP4 is expressed peripherally in hypoblast and epiblast and in the mesoderm at the posterior pole of the embryonic disc. BLIMP1 expression begins throughout the hypoblast at stage 1 and emerges in single primordial germ cell (PGC) precursors in the posterior epiblast at stage 2 and then in single mesoderm cells at positions identical to those identified by PGC-specific antibodies. These expression patterns suggest that function and chronology of factors involved in germline segregation are similar in mouse and rabbit, but higher temporal and spatial resolution offered by the rabbit demonstrates a variable role of bone morphogenetic proteins and makes “blimping” a candidate case for lateral inhibition without the need for an allantoic germ cell niche