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Large Pleistocene ice sheets have produced glacial structures both at and below the surface in northern Europe. Some of the largest and most erosive structures are so-called tunnel valleys (TVs): large and deep channels (typically up to 5 km wide and up to 400 m deep, with lengths up to 100 km), which formed below ice sheets. Although the subject of many studies, the details of their formation and fill are still not well understood. Here, we present an update on the distribution of TVs in the southeastern North Sea between Amrum and Heligoland based on a very dense grid of high-resolution 2D multi-channel reflection seismic data (400 m line spacing). The known tunnel valleys (TV1–TV3) in that area can now be traced in greater detail and further westwards, which results in an increased resolution and coverage of their distribution. Additionally, we were able to identify an even deeper and older tunnel valley, TV0, whose orientation parallels the thrust direction of the Heligoland Glacitectonic Complex (HGC). This observation implies a formation of TV0 before the HGC during an early-Elsterian or pre-Elsterian ice advance. For the first time, we acquired high-resolution longitudinal seismic profiles following the thalweg of known TVs. These longitudinal profiles offer clear indications of an incision during high-pressure bank-full conditions. The fill indicates sedimentation in an early high-energy environment for the lower part and a subsequent low-energy environment for the upper part. Our results demonstrate that a very dense profile spacing is required to decipher the complex incisions of TVs during multiple ice advances in a specific region. We also demonstrate that the time- and cost-effective acquisition of high-resolution 2D reflection seismic data holds the potential to further our understanding of the incision and filling mechanisms as well as of the distribution, complexity and incision depths of TVs in different geological settings.

Abstract Seabed pockmarks are among the most prominent morphologic structures in the oceans. They are usually interpreted as surface manifestation of hydrocarbon fluids venting from sediments. Here we suggest an alternative hypothesis of pockmark formation based on latest multibeam echosounder data with a centimeter resolution. In the North Sea, >40,000 enigmatically shaped shallow depressions or ‘pits’ with a mean depth of 0.11 m were documented, that do not resemble known pockmark morphologies. Combining the new echosounder data with information from behavioral biology, physical oceanography, satellite remote sensing and habitat mapping, we conclude that harbor porpoises excavate sediments during benthic foraging. By grubbing the seabed, they cause sandeels to escape from the sediment and initiate the formation of seafloor pits. Time-lapse data reveals that the initially feeding pits serve as nuclei for scouring and eventually merge into larger scour-pits. With the immense number of vertebrates in the ocean, such megafauna-driven macro-bioturbation reshapes the seafloor, modulates sediment transport, and ultimately impacts associated ecosystems on a global scale.

A circular city builds upon the principles of circular economy, which key concepts of reduce, reuse, recycle, and recover lead to a coupling of resources: products and by-products of one production process become the input of another one, often in local vicinity. However, sources, types and available quantities of underutilised resources in cities are currently not well documented. Therefore, there is a missing link in the information flow of the circular city between potential users and site-specific data. To close this gap, this study introduces the concept of a site resource inventory in conjunction with a new information model that can manage the data needed for advancing the circular city. A core taxonomy of terms is established as the foundation for the information model: the circular economy is defined as a network of circular economy entities which are regarded as black boxes and connected by their material and energy inputs and outputs. This study proposes a site resource inventory, which is a collection of infrastructural and building-specific parameters that assess the suitability of urban sites for a specific circular economy entity. An information model is developed to manage the data that allows the entities to effectively organise the allocation and use of resources within the circular city and its material and energy flows. The application of this information model was demonstrated by comparing the demand and availability of required alternative resources (e.g. greywater) at a hypothetical site comprising a commercial aquaponic facility (synergistic coupling of fish and vegetables production) and a residential building. For the implementation of the information model a proposal is made which uses the publicly available geodata infrastructure of OpenStreetMap and adopts its tag system to operationalise the integration of circular economy data by introducing new tags. A site resource inventory has the potential to bring together information needs and it is thus intended to support companies when making their business location decisions or to support local authorities in the planning process.

Budding yeast cell polarization is known to self-assemble, but it is still not clear what controls the size of the resulting septin ring. Here the authors show that the septin ring diameter is set by cell volume, ensuring that larger cells have larger rings.

The Baltic Sea basins, some of which only submerged in the mid-Holocene, preserve Stone Age structures that did not survive on land. Yet, the discovery of these features is challenging and requires cross-disciplinary approaches between archeology and marine geosciences. Here, we combine shipborne and autonomousunderwater vehicle hydroacoustic data with up to a centimeter range resolution, sedimentological samples, and optical images to explore a Stone Age megastructure located in 21 m water depth in the Bay of Mecklenburg, Germany. The structure is made of 1,673 individual stones which are usually less than 1 m in height, placed side by side over a distance of 971 m in a way that argues against a natural origin by glacial transport or ice push ridges. Running adjacent to the sunken shoreline of a paleolake (or bog), whose youngest phase was dated to 9,143 ±36 ka B.P., the stonewall was likely used for hunting the Eurasian reindeer (Rangifer tarandus) during the Younger Dryas or early Pre-Boreal. It was built by hunter-gatherer groups that roamed the region after the retreat of the Weichselian Ice Sheet. Comparable Stone Age megastructures have become known worldwide in recent times but are almost unknown in Europe. The site represents one of the oldest documented man-made hunting structures on Earth, and ranges among the largest known Stone Age structure in Europe. It will become important for understanding subsistence strategies, mobility patterns, and inspire discussions concerning the territorial development in the Western Baltic Sea region. [ABSTRACT FROM AUTHOR]

Abstract Background The lymphatic vascular pattern in the head of mice has rarely been studied, due to problems of sectioning and immunostaining of complex bony structures. Therefore, the association of head lymphoid tissues with the lymphatics has remained unknown although the mouse is the most often used species in immunology. Results Here, we studied the association of nasal and nasolacrimal duct lymphatics with lymphoid aggregates in 14-day-old and 2-month-old mice. We performed paraffin sectioning of whole, decalcified heads, and immunostaining with the lymphatic endothelial cell-specific antibodies Lyve-1 and Podoplanin. Most parts of the nasal mucous membrane do not contain any lymphatics. Only the region of the inferior turbinates contains lymphatic networks, which are connected to those of the palatine. Nose-associated lymphoid tissue (NALT) is restricted to the basal parts of the nose, which contain lymphatics. NALT is continued occipitally and can be found at both sides along the sphenoidal sinus, again in close association with lymphatic networks. Nasal lymphatics are connected to those of the ocular region via a lymphatic network along the nasolacrimal duct (NLD). By this means, lacrimal duct-associated lymphoid tissue (LDALT) has a dense supply with lymphatics. Conclusions NALT and LDALT play a key role in the immune system of the mouse head, where they function as primary recognition sites for antigens. Using the dense lymphatic networks along the NLD described in this study, these antigens reach lymphatics near the palatine and are further drained to lymph nodes of the head and neck region. NALT and LDALT develop in immediate vicinity of lymphatic vessels. Therefore, we suggest a causative connection of lymphatic vessels and the development of lymphoid tissues.

Urban agricultural heritage is an essential subject when investigating urban history. The preservation of it contributes to inheriting farming traditions, supporting local food, and reinforcing the cities' cultural identity. To emphasize the significance and urgency of preserving urban agricultural heritage, this article first describes the concept of urban agricultural heritage from historical, ecological, social, and economic dimensions. We then choose the traditional urban grape garden in the Ancient City of Xuanhua as a case study. According to a new method we have developed, we provide a comprehensive description of the existing issues in the grape garden and the external factors that impact the study area. The results show that the traditional farming technique has been inherited; the urban fabric of courtyards containing grape funnels has not changed; the study area still lacks social concerns; and a part of households should optimize their business models. [ABSTRACT FROM AUTHOR]