Before programs: The physical origination of multicellular forms

ABSTRACT By examining the formative role of physical processes in modern-day developmental systems, we infer that although such determinants are subject to constraints and rarely act in a “pure ” fashion, they are identical to processes generic to all viscoelastic, chemically excitable media, non-living as well as living. The processes considered are free diffusion, immiscible liquid behavior, oscillation and multistability of chemical state, reaction-diffusion coupling and mecha-nochemical responsivity. We suggest that such processes had freer reign at early stages in the history of multicellular life, when less evolution had occurred of genetic mechanisms for stabilization and entrenchment of functionally successful morphologies. From this we devise a hypothetical scenario for pattern formation and morphogenesis in the earliest metazoa. We show that the expected morphologies that would arise during this relatively unconstrained “physical” stage of evolution correspond to the hollow, multilayered and segmented morphotypes seen in the gastrulation stage embryos of modern-day metazoa as well as in Ediacaran fossil deposits of ~600 Ma. We suggest several ways in which organisms that were originally formed by predomi-nantly physical mechanisms could have evolved genetic mechanisms to perpetuate their mor-phologies

The mass and density of the dwarf planet (225088) 2007 OR10

The satellite of (225088) 2007 OR10 was discovered on archival Hubble Space Telescope images and along with new observations with the WFC3 camera in late 2017 we have been able to determine the orbit. The orbit's notable eccentricity, e$\approx$0.3, may be a consequence of an intrinsically eccentric orbit and slow tidal evolution, but may also be caused by the Kozai mechanism. Dynamical considerations also suggest that the moon is small, D$_{eff}$ $<$ 100 km. Based on the newly determined system mass of 1.75x10$^{21}$ kg, 2007 OR10 is the fifth most massive dwarf planet after Eris, Pluto, Haumea and Makemake. The newly determined orbit has also been considered as an additional option in our radiometric analysis, provided that the moon orbits in the equatorial plane of the primary. Assuming a spherical shape for the primary this approach provides a size of 1230$\pm$50 km, with a slight dependence on the satellite orbit orientation and primary rotation rate chosen, and a bulk density of 1.75$\pm$0.07 g cm$^{-3}$ for the primary. A previous size estimate that assumed an equator-on configuration (1535$^{+75}_{-225}$ km) would provide a density of 0.92$^{+0.46}_{-0.14}$ g cm$^{-3}$, unexpectedly low for a 1000 km-sized dwarf planet.Comment: Accepted for publication in Icaru

Graphene Schottky diodes: an experimental review of the rectifying graphene/semiconductor heterojunction

In the past decade graphene has been one of the most studied material for several unique and excellent properties. Due to its two dimensional nature, physical and chemical properties and ease of manipulation, graphene offers the possibility of integration with the exiting semiconductor technology for next-generation electronic and sensing devices. In this context, the understanding of the graphene/semiconductor interface is of great importance since it can constitute a versatile standalone device as well as the building-block of more advanced electronic systems. Since graphene was brought to the attention of the scientific community in 2004, the device research has been focused on the more complex graphene transistors, while the graphene/semiconductor junction, despite its importance, has started to be the subject of systematic investigation only recently. As a result, a thorough understanding of the physics and the potentialities of this device is still missing. The studies of the past few years have demonstrated that graphene can form junctions with 3D or 2D semiconducting materials which have rectifying characteristics and behave as excellent Schottky diodes. The main novelty of these devices is the tunable Schottky barrier height, a feature which makes the graphene/semiconductor junction a great platform for the study of interface transport mechanisms as well as for applications in photo-detection, high-speed communications, solar cells, chemical and biological sensing, etc. In this paper, we review the state-of-the art of the research on graphene/semiconductor junctions, the attempts towards a modeling and the most promising applications.Comment: 85 pages. Review articl

A Replicated Network Approach to 'Big Data' in Ecology

International audienceGlobal environmental change is a pressing issue as evidenced by the rise of extreme weather conditions in many parts of the world, threatening the survival of vulnerable species and habitats. Effective monitoring of climatic and anthropogenic impacts is therefore critical to safeguarding ecosystems, and it would allow us to better understand their response to stressors and predict long-term impacts. Ecological networks provide a biomonitoring framework for examining the system-level response and functioning of an ecosystem, but have been, until recently, constrained by limited empirical data due to the laborious nature of their construction. Hence, most experimental designs have been confined to a single network or a small number of replicate networks, resulting in statistical uncertainty, low resolution, limited spatiotemporal scale and oversimplified assumptions. Advances in data sampling and curation methodologies, such as next-generation sequencing (NGS) and the Internet 'Cloud', have facilitated the emergence of the 'Big Data' phenomenon in Ecology, enabling the construction of ecological networks to be carried out effectively and efficiently. This provides to ecologists an excellent opportunity to expand the way they study ecological networks. In particular, highly replicated networks are now within our grasp if new NGS technologies are combined with machine learning to develop network building methods. A replicated network approach will allow temporal and spatial variations embedded in the data to be taken into consideration, overcoming the limitations in the current 'single network' approach. We are still at the embryonic stage in exploring replicated networks, and with these new opportunities we also face new challenges. In this chapter, we discuss some of these challenges and highlight potential approaches that will help us build and analyse replicated networks to better understand how complex ecosystems operate, and the services and functioning they provide, paving the way for deciphering ecological big data reliably in the future

2019 Proceedings of the 2nd International Conference on Trauma Surgery Technology in Giessen (Germany)

It is now for a second time that we can invite researchers to come to Giessen for an international exchange of the latest research and a discussion of ideas. This year again, the Deutsche Forschungsgemeinschaft (DFG) is sponsoring the event. The main topic for 2019 is 'Vibration in antibacterial and oncological therapy'. Many effects of mechanical vibration on tissue have been discovered so far. Clinical applications relying on vibration exist for a variety of conditions. The intracellular processes, however, are still largely not understood. And reproducibility remains a matter of potential for improvement. DFG funds for the 3rd conference in 2020 have already been approved for a focus on multifunctional trauma surgery implants.Deutsche Forschungsgemeischaft (DFG), German

The importance of the cellular stress response in the pathogenesis and treatment of type 2 diabetes

Organisms have evolved to survive rigorous environments and are not prepared to thrive in a world of caloric excess and sedentary behavior. A realization that physical exercise (or lack of it) plays a pivotal role in both the pathogenesis and therapy of type 2 diabetes mellitus (t2DM) has led to the provocative concept of therapeutic exercise mimetics. A decade ago, we attempted to simulate the beneficial effects of exercise by treating t2DM patients with 3 weeks of daily hyperthermia, induced by hot tub immersion. The short-term intervention had remarkable success, with a 1 % drop in HbA1, a trend toward weight loss, and improvement in diabetic neuropathic symptoms. An explanation for the beneficial effects of exercise and hyperthermia centers upon their ability to induce the cellular stress response (the heat shock response) and restore cellular homeostasis. Impaired stress response precedes major metabolic defects associated with t2DM and may be a near seminal event in the pathogenesis of the disease, tipping the balance from health into disease. Heat shock protein inducers share metabolic pathways associated with exercise with activation of AMPK, PGC1-a, and sirtuins. Diabetic therapies that induce the stress response, whether via heat, bioactive compounds, or genetic manipulation, improve or prevent all of the morbidities and comorbidities associated with the disease. The agents reduce insulin resistance, inflammatory cytokines, visceral adiposity, and body weight while increasing mitochondrial activity, normalizing membrane structure and lipid composition, and preserving organ function. Therapies restoring the stress response can re-tip the balance from disease into health and address the multifaceted defects associated with the disease

European surveillance of antimicrobial consumption (ESAC) : systemic antiviral use in Europe

Objectives: To assess the total systemic antiviral use in Europe and to identify the antiviral substances most commonly used.Methods: Within the European Surveillance of Antimicrobial Consumption (ESAC; www.esac.ua.ac.be), using the anatomical therapeutic chemical (ATC) classification and defined daily dose (DDD) measurement unit, data on total (out- and inpatient) systemic antiviral use (ATC J05), aggregated at the level of the active substance, were collected for 2008, and use was expressed in DDD (WHO ATC/DDD, version 2010) per 1000 inhabitants per day (DID). Antiviral substances were grouped according to their main indication.Results: In Europe, 12 countries (Belgium, Croatia, Denmark, Estonia, Finland, France, Hungary, Italy, Luxembourg, Russia, Slovenia and Sweden) provided total (out- and inpatient) data and 4 countries (Austria, the Netherlands, Portugal and Norway) provided outpatient data only. Total systemic antiviral use varied by a factor of 10.95 between the country with the highest (3.53 DID in France) and the country with the lowest (0.32 DID in Croatia) use. HIV/AIDS antivirals represented more than 50% of the total antiviral use in most countries. The amount and spectrum of antivirals used varied greatly between countries.Conclusions: Our study demonstrated a wide variation of total systemic antiviral use in several European countries, as striking as that of outpatient systemic antibiotic, antimycotic and antifungal use. The variation is mainly determined by the use of HIV/AIDS antivirals. These observations should stimulate further analysis to understand the variation of specific antiviral substances. The ESAC data facilitate auditing of antiviral prescriptions and evaluation of the implementation of guidelines and public health policies.peer-reviewe

A genome wide association study links glutamate receptor pathway to Sporadic Creutzfeldt-Jakob disease risk.

We performed a genome-wide association (GWA) study in 434 sporadic Creutzfeldt-Jakob disease (sCJD) patients and 1939 control