[1] Observations of coseismic and postseismic deformation associated with the 2010 Mw = 8.8 Maule earthquake in south-central Chile provide constraints on the spatial heterogeneities of frictional properties on a major subduction megathrust and how they have influenced the seismic rupture and postseismic effects. We find that the bulk of coseismic slip occurs within a single elongated patch approximately 460 km long and 100 km wide between the depths of 15 and 40 km. We infer three major patches of afterslip: one extends northward along strike and downdip of the major coseismic patch between 40 and 60 km depth; the other two bound the northern and southern ends of the coseismic patch. The southern patch offshore of the Arauco Peninsula is the only place showing resolvable afterslip shallower than 20 km depth. Estimated slip potency associated with postseismic slip in the 1.3 years following the earthquake amounts to 20-30% of that generated coseismically. Our estimates of the megathrust frictional properties show that the Arauco Peninsula area has positive but relatively low (aÀb)s n values (0.01~0.22 MPa), that would have allowed dynamic rupture propagation into this rate-strengthening area and afterslip. Given the only modestly rate-strengthening megathrust friction in this region, the barrier effect may be attributed to its relatively large size of the rate-strengthening patch. Coseismic and postseismic uplift of the Arauco Peninsula exceeds interseismic subsidence since the time of the last major earthquake in 1835, suggesting that coseismic and postseismic deformation has resulted in some permanent strain in the forearc.

.[1] We present a new approach to extracting spatially and temporally continuous ground deformation fields from interferometric synthetic aperture radar (InSAR) data. We focus on unwrapped interferograms from a single viewing geometry, estimating ground deformation along the line-of-sight. Our approach is based on a wavelet decomposition in space and a general parametrization in time. We refer to this approach as MInTS (Multiscale InSAR Time Series). The wavelet decomposition efficiently deals with commonly seen spatial covariances in repeat-pass InSAR measurements, since the coefficients of the wavelets are essentially spatially uncorrelated. Our time-dependent parametrization is capable of capturing both recognized and unrecognized processes, and is not arbitrarily tied to the times of the SAR acquisitions. We estimate deformation in the wavelet-domain, using a cross-validated, regularized least squares inversion. We include a model-resolution-based regularization, in order to more heavily damp the model during periods of sparse SAR acquisitions, compared to during times of dense acquisitions. To illustrate the application of MInTS, we consider a catalog of 92 ERS and Envisat interferograms, spanning 16 years, in the Long Valley caldera, CA, region. MInTS analysis captures the ground deformation with high spatial density over the Long Valley region.

[1] When targeting small amplitude surface deformation, using repeat orbit Interferometric Synthetic Aperture Radar (InSAR) observations can be plagued by propagation delays, some of which correlate with topographic variations. These topographically-correlated delays result from temporal variations in vertical stratification of the troposphere. An approximate model assuming a linear relationship between topography and interferometric phase has been used to correct observations with success in a few studies. Here, we present a robust approach to estimating the transfer function, K, between topography and phase that is relatively insensitive to confounding processes (earthquake deformation, phase ramps from orbital errors, tidal loading, etc.). Our approach takes advantage of a multiscale perspective by using a band-pass decomposition of both topography and observed phase. This decomposition into several spatial scales allows us to determine the bands wherein correlation between topography and phase is significant and stable. When possible, our approach also takes advantage of any inherent redundancy provided by multiple interferograms constructed with common scenes. We define a unique set of component time intervals for a given suite of interferometric pairs. We estimate an internally consistent transfer function for each component time interval, which can then be recombined to correct any arbitrary interferometric pair. We demonstrate our approach on a synthetic example and on data from two locations: Long Valley Caldera, California, which experienced prolonged periods of surface deformation from pressurization of a deep magma chamber, and one coseismic interferogram from the 2007 Mw 7.8 Tocapilla earthquake in northern Chile. In both examples, the corrected interferograms show improvements in regions of high relief, independent of whether or not we pre-correct the data for a source model. We believe that most of the remaining signals are predominately due to heterogeneous water vapor distribution that requires more sophisticated correction methods than those described here.

[1] Discrete scarps that are created or reactivated during large earthquakes are a locus of concentrated hazard. A number of the coseismic scarps activated in the 1999 Chi-Chi earthquake are actually fold scarps, which display several types of ground deformation characterized by localized folding and are distinct from classic fault scarps, which form by a fault cutting the surface. This paper documents and analyzes fold scarps that formed or reactivated in the 1999 Chi-Chi Taiwan earthquake. Our results show the Chi-Chi fold scarps can be generally divided into two types: (1) those associated with folding ahead of the tip of a blind thrust fault at shallow depths and (2) those associated with folding by kink band migration above fault bends at substantial depths ranging from $0.8 to 5 km). The previously published trishear model can be applied to model the former type, while a new curved hinge kink band migration model is provided to describe the behavior of the latter type. A key feature of fold scarps of the second type is that hinge zones are typically wide (25-100 m) relative to the displacement in a single earthquake (1-10 m), which exerts a significant control on fold scarp morphology and evolution. Because the coseismic strains of both types of fold scarps display relatively wide deformation zones (10-100 m) relative to fault scarps, wider set-back zones might be appropriate from a public policy point of view to alleviate the risk to structural damage and collapse resulting from permanent ground deformation.

Nano-sized hydroxyapatite (nanoHA) reinforced composites, mimicking natural bone, were produced. Examination by transmission electron microscopy revealed that the nanoHA particles had a rod-like morphology, 20-30 nm in width and 50-80 nm in length. The phase composition of hydroxyapatite was confirmed by X-ray diffraction. The nanoHA particles were incorporated into poly-2-hydroxyethylmethacrylate (PHEMA)/polycaprolactone (PCL) matrix to make new nanocomposites: nanoHA-PHEMA/PCL. Porous nanocomposite scaffolds were then produced using a porogen leaching method. The interconnectivity of the porous structure of the scaffolds was revealed by non-destructive X-ray microtomography. Porosity of 84% was achieved and pore sizes were approximately around 300-400 microm. An in vitro study found that the nanocomposites were bioactive as indicated by the formation of a bone-like apatite layer after immersion in simulated body fluid. Furthermore, the nanocomposites were able to support the growth and proliferation of primary human osteoblast (HOB) cells. HOB cells developed a well organized actin cytoskeletal protein on the nanocomposite surface. The results demonstrate the potential of the nanocomposite scaffolds for tissue engineering applications for bone repair.

L-Fucose-containing glycoconjugates are essential for a myriad of physiological and pathological activities, such as inflammation, bacterial and viral infections, tumor metastasis, and genetic disorders. Fucosyltransferases and fucosidases, the main enzymes involved in the incorporation and cleavage of L-fucose residues, respectively, represent captivating targets for therapeutic treatment and diagnosis. We herein review the important breakthroughs in the development of fucosyltransferase and fucosidase inhibitors. To demonstrate how the synthesized small molecules interact with the target enzymes, i.e. delineation of the structure-activity relationship, we cover the reaction mechanisms and resolved X-ray crystal structures, discuss how this information guides the design of enzyme inhibitors, and explain how the molecules were optimized to achieve satisfying potency and selectivity.

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The a1,2-fucosyltransferase (a1,2-FucT) from Helicobacter pylori catalyzes the fucosylation of acceptor oligosaccharides at the C2-OH of terminal Galb units. The enzyme from strain NCTC11639 was evaluated for its ability to synthesize cancer-associated antigens. The a1,2-FucT was determined to be active over a pH range between 4.0 and 8.0 with the optimum occurring at pH 5.0. Although a divalent metal ion cofactor was not required for catalysis, enhancement of the enzyme activity was detected upon supplement with Mn 2+ . Detailed substrate specificity analysis revealed that a1,2-FucT can catalyze the fucosylation of a wide variety of oligosaccharide substrates. The a1,2-FucT preferentially fucosylated type 1 structure (Galb1-3GlcNAc)-containing glycans over type 2 structure (Galb1-4GlcNAc)-containing glycans. The Lewis a trisaccharide [Galb1-3-