Hydrothermal alteration of andesitic lava domes can lead to explosive volcanic behaviour

Dome-forming volcanoes are among the most hazardous volcanoes on Earth. Magmatic outgassing can be hindered if the permeability of a lava dome is reduced, promoting pore pressure augmentation and explosive behaviour. Laboratory data show that acid-sulphate alteration, common to volcanoes worldwide, can reduce the permeability on the sample lengthscale by up to four orders of magnitude and is the result of pore- and microfracture-filling mineral precipitation. Calculations using these data demonstrate that intense alteration can reduce the equivalent permeability of a dome by two orders of magnitude, which we show using numerical modelling to be sufficient to increase pore pressure. The fragmentation criterion shows that the predicted pore pressure increase is capable of fragmenting the majority of dome-forming materials, thus promoting explosive volcanism. It is crucial that hydrothermal alteration, which develops over months to years, is monitored at dome-forming volcanoes and is incorporated into real-time hazard assessments

Aarhus Regenerative Orthopaedics Symposium (AROS)

The combination of modern interventional and preventive medicine has led to an epidemic of ageing. While this phenomenon is a positive consequence of an improved lifestyle and achievements in a society, the longer life expectancy is often accompanied by decline in quality of life due to musculoskeletal pain and disability. The Aarhus Regenerative Orthopaedics Symposium (AROS) 2015 was motivated by the need to address regenerative challenges in an ageing population by engaging clinicians, basic scientists, and engineers. In this position paper, we review our contemporary understanding of societal, patient-related, and basic science-related challenges in order to provide a reasoned roadmap for the future to deal with this compelling and urgent healthcare problem

Controls on explosive-effusive volcanic eruption styles

One of the biggest challenges in volcanic hazard assessment is to understand how and why eruptive style changes within the same eruptive period or even from one eruption to the next at a given volcano. This review evaluates the competing processes that lead to explosive and effusive eruptions of silicic magmas. Eruptive style depends on a set of feedbacks involving interrelated magmatic properties and processes. Foremost of these are magma viscosity, gas loss, and external properties such as conduit geometry. Ultimately, these parameters control the speed at which magmas ascend, decompress and outgas en route to the surface, and thus determine eruptive style and evolution

Periodontitis destructions are restored by synthetic glycosaminoglycan mimetic.

Periodontitis are bacterium-driven inflammatory diseases that destroy tooth-supporting tissues whose complete restoration is not currently possible. RGTA(R), a new class of agents, have this capacity in an animal model. Periodontitis was induced in hamsters and, starting 8 weeks later, injected RG1503, a glycosaminoglycan synthesized from a 40 kDa dextran behaving like a heparan sulfate mimetic (1.5 mg kg(-1) w(-1)) or saline for 8 weeks. The three periodontium compartments were evaluated by immunohistochemistry and morphometry. The gingival extracellular matrix disorganized by inflammation was restoring under treatment. The collagen network was repaired and resumed its previous organization. Fibrillin-1 expression was restored so that the elastic network rebuilt at a distance from the pocket and began to reconstruct near the pocket. Apoptotic cell numbers were decreased in the pocket epithelium, and more so in the infiltrated connective tissue. The continuity and the thickness of the basement membrane were restored and testified normalization of epithelium connective tissue interaction. The amount of alveolar bone increased around the first molar, and the interradicular bone was rebuilt. The root cementum was thickened and the number of proliferating cells in the periodontal ligament was increased close to the cementum. RG1503 treatment induces potent anabolic reactions in the extracellular matrices of the different tissues of the periodontium and recruitment of progenitors. In particular, the cell proliferation close to the root surface suggests the reformation of a functional attachment apparatus. These results demonstrate that RG1503 reverses the degenerative changes induced by inflammation and favors the conditions of a regenerative process. Thus, RGTA, a known matrix component mimetic and protector, may be considered as a new therapeutic tool to regenerate the tissues destroyed by periodontitis

Aarhus regenerative orthopaedics symposium (AROS)

The combination of modern interventional and preventive medicine has led to an epidemic of ageing. While this phenomenon is a positive consequence of an improved lifestyle and achievements in a society, the longer life expectancy is often accompanied by decline in quality of life due to musculoskeletal pain and disability. The Aarhus Regenerative Orthopaedics Symposium (AROS) 2015 was motivated by the need to address regenerative challenges in an ageing population by engaging clinicians, basic scientists, and engineers. In this position paper, we review our contemporary understanding of societal, patient-related, and basic science-related challenges in order to provide a reasoned roadmap for the future to deal with this compelling and urgent healthcare problem