Surficial slip distribution on the central Emerson fault during the June 28, 1992, Landers earthquake, California

We present the results of our mapping of a 5.6‐km length of the central Emerson fault that ruptured during the 1992 Landers earthquake in the southwestern Mojave Desert, California. The right‐lateral slip along this portion of the rupture varied from about 150 to 530 cm along the main rupture zone. In some locations a total of up to 110 cm of additional right‐lateral slip occurred on secondary faults up to 1.7 km away from the main rupture zone. Other secondary faults carried up to several tens of centimeters of left‐lateral or thrust displacement. The maximum net vertical displacement was 175 cm, east‐side‐up. The sense of vertical slip across the main fault zone varied along strike, but in most cases it was consistent with the sense of vertical slip in previous earthquakes, as indicated by the locations of areas of older, uplifted, and abandoned alluvial fan surfaces. Although variations in surficial slip have been reported along previous strike‐slip ruptures, our closely spaced slip measurements allow a much more detailed study of slip variability than was possible previously. We document variations in slip as large as 1 m or more over distances ranging from 1–2 km to a few tens of meters, suggesting that strains of the order of 10−1 may have occurred locally within the surficial sediments. The long‐wavelength (kilometer‐scale) variations in surficial slip may be influenced by fault geometry and perhaps by the thickness of unconsolidated sediments. The slip variations over shorter length scales (tens of meters) may be caused by variations in the proportion of the total shear that occurs on visible, brittle fractures versus that which occurs as distributed shear, warping or rotation. The variability of slip along the ruptures associated with the Landers earthquake calls for caution in interpreting geomorphic offsets along prehistoric fault ruptures

Slip on the Superstition Hills fault and on nearby faults associated with the 24 November 1987 Elmore Ranch and Superstition Hills earthquakes, southern California

Alignment arrays and creepmeters spanning several faults in southern California recorded slip associated with the 24 November 1987 Elmore Ranch and Superstition Hills earthquakes. No precursory slip had occurred on the Superstition Hills fault up to 27 October 1987, when the last measurement before the earthquakes was made. About 23 days before the earthquake, dextral creep events of about 13 mm and 0.5 mm may have occurred simultaneously on the Imperial and southern San Andreas faults, respectively, but the tectonic origin of the smaller event is questionable. Within 12 hr after the Superstition Hills earthquake, 20.9 cm of dextral slip occurred on the main fault trace at the Superstition Hills alignment array, and 39.8 cm of dextral slip was recorded over the entire 110-m width of the array. Despite this initial wide distribution of slip, nearly all of the postseismic slip is occurring on the main fault trace. As of 3 August 1988, the alignment array had recorded a total of 80.2 cm of dextral slip. As of 5 days after the earthquakes, 65 to 80 per cent of the total slip measured by the alignment array had occurred on discrete, mappable fractures. In addition, the two earthquakes triggered slip on the Coyote Creek fault, the southern San Andreas fault, and on the Imperial fault. Telemetered data from creepmeters on the southern San Andreas and Imperial faults indicate that triggered slip began there within 3 min or less of each of the two earthquakes. Additional triggered slip occurred on the Imperial fault beginning 3.5 hr after the second earthquake

Impact of Scotland’s comprehensive, smoke-free legislation on stroke

<p>Background: Previous studies have reported a reduction in acute coronary events following smoke-free legislation. Evidence is lacking on whether stroke is also reduced. The aim was to determine whether the incidence of stroke, overalland by sub-type, fell following introduction of smoke-free legislation across Scotland on 26 March 2006.</p> <p>Methods and Findings: A negative binomial regression model was used to determine whether the introduction of smokefree legislation resulted in a step and/or slope change in stroke incidence. The model was adjusted for age-group, sex, socioeconomic deprivation quintile, urban/rural residence and month. Interaction tests were also performed. Routine hospital administrative data and death certificates were used to identify all hospital admissions and pre-hospital deaths due to stroke (ICD10 codes I61, I63 and I64) in Scotland between 2000 and 2010 inclusive. Prior to the legislation, rates of all stroke, intracerebral haemorrhage and unspecified stroke were decreasing, whilst cerebral infarction was increasing at 0.97% per annum. Following the legislation, there was a dramatic fall in cerebral infarctions that persisted for around 20 months. No visible effect was observed for other types of stroke. The model confirmed an 8.90% (95% CI 4.85, 12.77, p,0.001) stepwise reduction in cerebral infarction at the time the legislation was implemented, after adjustment for potential cofounders.</p> <p>Conclusions: Following introduction of national, comprehensive smoke-free legislation there was a selective reduction in cerebral infarction that was not apparent in other types of stroke.</p&gt

Macrophage-derived Wnt opposes Notch signaling to specify hepatic progenitor cell fate in chronic liver disease

During chronic injury a population of bipotent hepatic progenitor cells (HPCs) become activated to regenerate both cholangiocytes and hepatocytes. Here we show in human diseased liver and mouse models of the ductular reaction that Notch and Wnt signaling direct specification of HPCs via their interactions with activated myofibroblasts or macrophages. In particular, we found that during biliary regeneration, expression of Jagged 1 (a Notch ligand) by myofibroblasts promoted Notch signaling in HPCs and thus their biliary specification to cholangiocytes. Alternatively, during hepatocyte regeneration, macrophage engulfment of hepatocyte debris induced Wnt3a expression. This resulted in canonical Wnt signaling in nearby HPCs, thus maintaining expression of Numb (a cell fate determinant) within these cells and the promotion of their specification to hepatocytes. By these two pathways adult parenchymal regeneration during chronic liver injury is promoted

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Surficial offsets on the central and eastern garlock fault associated with prehistoric earthquakes

Geomorphic features offset along the central and eastern Garlock fault record the amount of surface slip associated with prehistoric earthquakes. Along the easternmost 90 km of the fault, the smallest offsets cluster around 2–3 m of left-lateral slip, apparently associated with the most recent earthquake on this portion of the fault. Larger offsets along this part of the fault, especially in Pilot Knob Valley, cluster around values consistent with 2–4 m of slip in each of the past several events. Farther west, south of El Paso Mountains, offset geomorphic features suggest that each of the past two earthquakes on this stretch of the Garlock fault was produced by about 7 m of slip, whereas the third event back was produced by about 4 m of slip. Vertical displacements of geomorphic features range from 0% to 30% of the left-lateral offsets. Within Pilot Knob Valley (along the southern side of the Slate Range), vertical displacements are consistently up on the northern side, whereas within the Avawatz Mountains both north- and south-side-up vertical displacements are present. On the basis of the geomorphic offsets, the geometry of the Garlock fault, and the precedents set by historical strike-slip earthquakes elsewhere, a number of different rupture patterns are plausible. These range from rupture of the entire Garlock fault in a single event with a maximum magnitude of about M w =7.8, to separate rupture of the western segment and of the central and eastern segments combined, with approximate magnitudes M w ≤1.1 and M w =7.5, respectively, to separate rupture of even shorter segments, producing earthquakes of magnitudes M w =6.6 to M w =7.5. In conjunction with available slip rates for the Garlock fault, the geomorphic offsets suggest that average recurrence intervals are probably within the range of 600–1200 years south of El Paso Mountains, about 200–750 years in Searles Valley, about 200–1300 years in Pilot Knob Valley, and about 200–3000 years near Leach Lake and in the Avawatz Mountains.Published versio

Straightening of the Northern San Jacinto Fault, California, as Seen in the Fault-Structure Evolution of the San Jacinto Valley Stepover

We investigate a releasing stepover between the Casa Loma and Claremont strands of the northern San Jacinto fault zone to evaluate the late Quaternary structural evolution of the fault zone, and to assess the likelihood of a rupture jumping across the stepover. Our new cone penetration test (CPT) and trench observations along the Claremont fault at Mystic Lake indicate that the main strand of the Claremont fault has jumped nearly a half kilometer westward into the San Jacinto releasing stepover during the late Quaternary. Multiple faults are inferred from the CPT data within a small sag at the northeast side of the stepover that cuts through younger stratigraphy to the west of the basin‐bounding fault near Mystic Lake. Previous seismic‐reflection data also suggest the presence of a young fault that cuts basin strata beneath the middle of Mystic Lake farther west of our study area. Numerous tectono‐geomorphic features observed in satellite and Light Detection and Ranging Digital Elevation Model (LiDAR DEM) imagery are interpreted to delineate the location of the currently active faults, including a zone of faults that cut across the basin from the northern end of the Casa Loma fault to the Claremont fault. Seismicity observations suggest the presence of many faults within the stepover zone. Finally, new paleoseismic data from the Mystic Lake site suggest that some late Holocene earthquakes may have jumped the stepover. All of these observations suggest that the San Jacinto stepover, which has been used as the primary basis for segmenting the northern San Jacinto fault zone, is being bypassed and that the fault zone may now be capable of larger earthquakes than previously expected