Volcanic activity and hazard in the East African Rift Zone.

Over the past two decades, multidisciplinary studies have unearthed a rich history of volcanic activity and unrest in the densely-populated East African Rift System, providing new insights into the influence of rift dynamics on magmatism, the characteristics of the volcanic plumbing systems and the foundation for hazard assessments. The raised awareness of volcanic hazards is driving a shift from crisis response to reducing disaster risks, but a lack of institutional and human capacity in sub-Saharan Africa means baseline data are sparse and mitigating geohazards remains challenging.

Unexpected large eruptions from buoyant magma bodies within viscoelastic crust.

Large volume effusive eruptions with relatively minor observed precursory signals are at odds with widely used models to interpret volcano deformation. Here we propose a new modelling framework that resolves this discrepancy by accounting for magma buoyancy, viscoelastic crustal properties, and sustained magma channels. At low magma accumulation rates, the stability of deep magma bodies is governed by the magma-host rock density contrast and the magma body thickness. During eruptions, inelastic processes including magma mush erosion and thermal effects, can form a sustained channel that supports magma flow, driven by the pressure difference between the magma body and surface vents. At failure onset, it may be difficult to forecast the final eruption volume; pressure in a magma body may drop well below the lithostatic load, create under-pressure and initiate a caldera collapse, despite only modest precursors.

Illuminating subduction zone rheological properties in the wake of a giant earthquake.

Deformation associated with plate convergence at subduction zones is accommodated by a complex system involving fault slip and viscoelastic flow. These processes have proven difficult to disentangle. The 2010 M w 8.8 Maule earthquake occurred close to the Chilean coast within a dense network of continuously recording Global Positioning System stations, which provide a comprehensive history of surface strain. We use these data to assemble a detailed picture of a structurally controlled megathrust fault frictional patchwork and the three-dimensional rheological and time-dependent viscosity structure of the lower crust and upper mantle, all of which control the relative importance of afterslip and viscoelastic relaxation during postseismic deformation. These results enhance our understanding of subduction dynamics including the interplay of localized and distributed deformation during the subduction zone earthquake cycle.

Constant strain accumulation rate between major earthquakes on the North Anatolian Fault.

Earthquakes are caused by the release of tectonic strain accumulated between events. Recent advances in satellite geodesy mean we can now measure this interseismic strain accumulation with a high degree of accuracy. But it remains unclear how to interpret short-term geodetic observations, measured over decades, when estimating the seismic hazard of faults accumulating strain over centuries. Here, we show that strain accumulation rates calculated from geodetic measurements around a major transform fault are constant for its entire 250-year interseismic period, except in the ~10 years following an earthquake. The shear strain rate history requires a weak fault zone embedded within a strong lower crust with viscosity greater than ~1020 Pa s. The results support the notion that short-term geodetic observations can directly contribute to long-term seismic hazard assessment and suggest that lower-crustal viscosities derived from postseismic studies are not representative of the lower crust at all spatial and temporal scales.

Complex multifault rupture during the 2016 Mw 7.8 Kaikoura earthquake, New Zealand.

On 14 November 2016, northeastern South Island of New Zealand was struck by a major moment magnitude (Mw) 7.8 earthquake. Field observations, in conjunction with interferometric synthetic aperture radar, Global Positioning System, and seismology data, reveal this to be one of the most complex earthquakes ever recorded. The rupture propagated northward for more than 170 kilometers along both mapped and unmapped faults before continuing offshore at the island's northeastern extent. Geodetic and field observations reveal surface ruptures along at least 12 major faults, including possible slip along the southern Hikurangi subduction interface; extensive uplift along much of the coastline; and widespread anelastic deformation, including the ~8-meter uplift of a fault-bounded block. This complex earthquake defies many conventional assumptions about the degree to which earthquake ruptures are controlled by fault segmentation and should motivate reevaluation of these issues in seismic hazard models.

Epidermal CYLD inactivation sensitizes mice to the development of sebaceous and basaloid skin tumors.

The deubiquitinase-encoding gene Cyld displays a dominant genetic linkage to a wide spectrum of skin-appendage tumors, which could be collectively designated as CYLD mutant-syndrome (CYLDm-syndrome). Despite recent advances, little is understood about the molecular mechanisms responsible for this painful and difficult-to-treat skin disease. Here, we generated a conditional mouse model with epidermis-targeted expression of a catalytically deficient CYLDm through K14-Cre-mediated deletion of exon 9 (hereafter refer to CyldEΔ9/Δ9 ). CyldEΔ9/Δ9 mice were born alive but developed hair and sebaceous gland abnormalities and dental defects at 100% and 60% penetrance, respectively. Upon topical challenge with DMBA/TPA, these animals primarily developed sebaceous and basaloid tumors resembling human CYLDm-syndrome as opposed to papilloma, which is most commonly induced in WT mice by this treatment. Molecular analysis revealed that TRAF6-K63-Ubiquitination (K63-Ub), c-Myc-K63-Ub, and phospho-c-Myc (S62) were markedly elevated in CyldEΔ9/Δ9 skin. Topical treatment with a pharmacological c-Myc inhibitor induced sebaceous and basal cell apoptosis in CyldEΔ9/Δ9 skin. Consistently, c-Myc activation was readily detected in human cylindroma and sebaceous adenoma. Taken together, our findings demonstrate that CyldEΔ9/Δ9 mice represent a disease-relevant animal model and identify TRAF6 and c-Myc as potential therapeutic targets for CYLDm-syndrome.

Prefrontal cortex stroke induces delayed impairment in spatial memory.

Stroke is the leading cause of long-term disability. Little is known about the effects of stroke on cognitive deficits. The subtle nature of cognition and its respective domains in areas such as working memory and attention can make this difficult to diagnose and treat. We aimed to establish a model of focal ischemia that targets the prefrontal cortex (PFC) and induce memory impairments. Stroke and sham mice were assessed at one and four-weeks post-stroke on various tests: open-field task to assess activity; grid-walk and cylinder task to assess motor impairments; elevated plus maze to assess anxiety; novel-object and object-location recognition tasks to assess memory impairment. Stroke mice in the open-field showed a small increase in activity with no effects on gross motor tasks or anxiety levels (P ≥ 0.05) at one and four-weeks post-stroke. Assessment of stroke mice on the novel object task showed no differences at either one or four-weeks compared to sham mice (P ≥ 0.05). However, assessment of stroke mice on the object-location recognition task revealed a significant (P ≥ 0.05) impairment in spatial memory by four-weeks compared to controls. Further, we show that stroke results in a small decrease in volume of the medial dorsal nucleus of the thalamus (P ≥ 0.05). This is the first evidence that demonstrates stroke to the PFC results in delayed onset impairment in spatial memory, similar to findings in human epidemiological data. We suggest that this model may be a useful tool in assessing potential rehabilitative/cognitive therapies after stroke.

First recorded eruption of Nabro volcano, Eritrea, 2011.

We present a synthesis of diverse observations of the first recorded eruption of Nabro volcano, Eritrea, which began on 12 June 2011. While no monitoring of the volcano was in effect at the time, it has been possible to reconstruct the nature and evolution of the eruption through analysis of regional seismological and infrasound data and satellite remote sensing data, supplemented by petrological analysis of erupted products and brief field surveys. The event is notable for the comparative rarity of recorded historical eruptions in the region and of caldera systems in general, for the prodigious quantity of SO2 emitted into the atmosphere and the significant human impacts that ensued notwithstanding the low population density of the Afar region. It is also relevant in understanding the broader magmatic and tectonic significance of the volcanic massif of which Nabro forms a part and which strikes obliquely to the principal rifting directions in the Red Sea and northern Afar. The whole-rock compositions of the erupted lavas and tephra range from trachybasaltic to trachybasaltic andesite, and crystal-hosted melt inclusions contain up to 3,000 ppm of sulphur by weight. The eruption was preceded by significant seismicity, detected by regional networks of sensors and accompanied by sustained tremor. Substantial infrasound was recorded at distances of hundreds to thousands of kilometres from the vent, beginning at the onset of the eruption and continuing for weeks. Analysis of ground deformation suggests the eruption was fed by a shallow, NW-SE-trending dike, which is consistent with field and satellite observations of vent distributions. Despite lack of prior planning and preparedness for volcanic events in the country, rapid coordination of the emergency response mitigated the human costs of the eruption.

Access to food retail outlets in County Durham, UK: a pragmatic cross-sectional study.

BACKGROUND: Strong links exist between deprivation, obesity, and dietary quality. Increasing interest has focussed on the concept of access to food and so-called food deserts, defined by a policy working group of the UK Low Income Project Team in 1995 as "areas of relative exclusion where people experience physical and economic barriers to accessing healthy food". We aimed to establish the accessibility of food retail outlets in County Durham, a county in north-east England, UK, considering physical access, affordability, and food range and quality. METHODS: In a pragmatic cross-sectional study in County Durham, we used information from town surveys and food business databases to locate and identify food retail outlets. The prevalence of deprivation, obesity, retail outlets, takeaway outlets, and ratio of retail to takeaway outlets was mapped, to establish local food access, and any associations with deprivation and obesity. The times taken to travel from residences to supermarkets using private car and public transport were also measured. 400 members of the community participated in eight focus groups and commissioned on-street surveys. Focus group transcripts were reviewed alongside the on-street survey responses to identify key issues. FINDINGS: Most residents shopped at least weekly for food (n=368, 92%), used a supermarket for their main food shop (372, 93%), travelled for up to 15 min (340, 85%), and used a car for transport (188, 47%). Many survey respondents indicated high levels of satisfaction with food retail outlets (average rating 8·7 out of 10 for agreement with the statement "Overall I am satisfied with the shop where I do my main food shopping"), although financial constraints and transport inconvenience were identified as barriers. Difficulties with food shopping were more widely described in focus groups, and many individuals felt that local shopping provision had declined, with an emergent excess of takeaway outlets. Food retail access was reduced for the disabled, full-time workers, elderly people, and people with children. INTERPRETATION: These findings suggest a potential role for individual behaviour change, planning and policy bodies, and the food retail industry in addressing food access. The multiple methods used in this study enabled triangulation; however, the conclusions are limited by the pragmatic nature of data collection and analysis. FUNDING: Durham County Council.

Remineralization effect of CPP-ACP and fluoride for white spot lesions in vitro.

OBJECTIVES: This in vitro study compared the remineralization effect on white spot lesions of casein phosphopeptide-amorphous calcium phosphate crème, or CPP-ACP (MI Paste™), 1.1% NaF dentifrice containing 5000ppm of fluoride (ControlRX™), or CPP-ACP crème with 900ppm of fluoride (MI Paste Plus™) with that of a control. METHODS: Artificial white spot lesions were created on smooth enamel surfaces of sound molars using a previously reported demineralization model. Specimens were randomly assigned to four treatments (n=35) with a pH-cycling model over 30 days: Control (no treatment); MI Paste (10% CPP-ACP crème); F5000 (1.1% NaF dentifrice); or MI Paste Plus (10% CPP-ACP plus 900ppm fluoride crème). Products were applied following manufacturers' directions. Changes in mean lesion depth expressed by percent fluorescence loss (ΔF%), and lesion area (mm(2)) from baseline to after treatment were measured with light-induced fluorescence (QLF). Mean values of each parameter were compared between groups (p<0.05). RESULTS: The remineralization pattern for the F5000 group was unique with marked initial remineralization during the first 10 days and little subsequent change. Based on mean lesion area, the F5000 demonstrated greater remineralization than Control, MI Paste and MI Paste Plus groups. Based on mean fluorescence loss, the F5000 group showed improved remineralization relative to MI Paste Plus, but did not differ statistically from the Control at the end of 30 days. CONCLUSIONS: The 1.1% NaF dentifrice demonstrated overall greater remineralization ability than 10% CPP-ACP crème. However, the 1.1% NaF dentifrice was only as effective as the Control to reduce fluorescence loss. CLINICAL SIGNIFICANCE: This study showed that a 1.1% NaF dentifrice (5000ppm) demonstrated greater remineralization ability than the CPP-ACP topical tooth crème and that the addition of fluoride to its formulation seems to enhance remineralization. Saliva also has the ability to exert an important remineralization effect over time.

Constraining timescales of focused magmatic accretion and extension in the Afar crust using lava geochronology.

As continental rift zones mature the tectonic and volcanic processes associated with crustal extension become confined to narrow magmatic rift zones, reminiscent of oceanic spreading ridges. The formation of these rift zones and the development of ocean-ridge type topography is a significant milestone in rift evolution as it signifies the localization of crustal extension and rift-related volcanism. Here we show that lavas, which erupted since ~200 ka along part of the on-land Red Sea rift system in Afar, Ethiopia, have a consistent age-progression from the rift axis outwards, indicating that axial dyke intrusion has been the primary mechanism of segment growth and that focused magmatic accretion and extension in the crust have remained stable here over this period. Our results suggest that as this rift segment has formed, in thinned and intruded continental crust, the time-averaged surface opening rate has closely approximated the total extension rate between Africa and Arabia.

An investigation of the validity of the virtual spatial navigation assessment.

This correlational study investigated a new measure of environmental spatial ability (i.e., large scale spatial ability) called the virtual spatial navigation assessment (VSNA). In the VSNA, participants must find a set of gems in a virtual 3D environment using a first person avatar on a computer. The VSNA runs in a web browser and automatically collects the time taken to find each gem. The time taken to collect gems in the VSNA was significantly correlated to three other spatial ability measures, math standardized test scores, and choice to be in a STEM (science, technology, engineering, or math) career. These findings support the validity of the VSNA as a measure of environmental spatial ability. Finally, self-report video game experience was also significantly correlated to the VSNA suggesting that video game may improve environmental spatial ability. Recommendations are made for how the VSNA can be used to help guide individuals toward STEM career paths and identify weaknesses that might be addressed with large scale spatial navigation training.

A new era in the ICU: the case for telemedicine.

Management of the patient in the intensive care unit requires constant vigilance and monitoring. The nursing staff, and physicians must be readily available to alter therapy in response to adverse physiological changes and life-threatening events. In the face of limited staffing and overwhelming workloads, telemedicine has become a mainstay in ensuring safety for the critically ill patient. Nurses must respond to the challenge to utilize every aspect of this technology, and to become an active partner in improving the utilization of this tool for accessing physician interface and ensuring support when decision-making and immediate actions are required for optimum clinical outcomes.

Utilization of robotic "remote presence" technology within North American intensive care units.

OBJECTIVE: To describe remote presence robotic utilization and examine perceived physician impact upon care in the intensive care unit (ICU). STUDY DESIGN: Data were obtained from academic, university, community, and rural medical facilities in North America with remote presence robots used in ICUs. Objective utilization data were extracted from a continuous monitoring system. Physician data were obtained via an Internet-based survey. RESULTS: As of 2010, 56 remote presence robots were deployed in 25 North American ICUs. Of 10,872 robot activations recorded, 10,065 were evaluated. Three distinct utilization patterns were discovered. Combining all programs revealed a pattern that closely reflects diurnal ICU activity. The physician survey revealed staff are senior (75% >40 years old, 60% with >16 years of clinical practice), trained in and dedicated to critical care. Programs are mature (70% >3 years old) and operate in a decentralized system, originating from cities with >50,000 population and provided to cities >50,000 (80%). Of the robots, 46.6% are in academic facilities. Most physicians (80%) provide on-site and remote ICU care, with 60% and 73% providing routine or scheduled rounds, respectively. All respondents (100%) believed patient care and patient/family satisfaction were improved. Sixty-six percent perceived the technology was a "blessing," while 100% intend to continue using the technology. CONCLUSIONS: Remote presence robotic technology is deployed in ICUs with various patterns of utilization that, in toto, simulate normal ICU work flow. There is a high rate of deployment in academic ICUs, suggesting the intensivists shortage also affects large facilities. Physicians using the technology are generally senior, experienced, and dedicated to critical care and highly support the technology.