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The cone penetration test (CPT) is widely used to determine soil stratigraphy and soil characteristics. Moreover, correlations derived from CPT measurements are used increasingly in geotechnical design, for instance, to estimate the bearing capacity of foundations and soil liquefaction susceptibility. Correlations based on the results of cyclic CPTs may also be useful in predicting cyclic events such as vibro-driving of open-ended piles or suction bucket installation using pressure cycling. This is because the wall thickness of open-ended piles or suction buckets is similar to the cone diameter, such that similar mechanisms are likely to apply. Consequently, this study focuses on the mechanisms that occur during cyclic cone penetration in sand using a combination of centrifuge and numerical modelling. The results of this study highlight the importance of cyclic displacement amplitudes, gap formation below the tip, advancement per cycle, and soil state change on the cone resistance. [ABSTRACT FROM AUTHOR]

Models of soil behaviour, in situ and laboratory testing techniques and system models for describing the geometry and time-dependent processes involved in the settlement of embankments on soft soils have reached a level of maturity where reliable predictions for this problem should be readily achievable. Despite this, there is clear evidence to demonstrate engineering predictions of embankment behaviour can be inaccurate, resulting in construction cost and schedule overruns. One key reason for this is the significant influence that personal judgement plays in processing soil test data to derive engineering parameters. In this paper, a method that makes progress toward overcoming this is developed using oedometer test results directly in a data-driven approach, thus avoiding the need to evaluate profiles of compression indices and yield pressures. The method has been deployed as an easy-to-access cloud-based application and its use demonstrated with a comprehensive case history. Data used in this paper are freely available in electronic format. [ABSTRACT FROM AUTHOR]

Field observations of semitaut mooring systems have shown severe trench development in front of suction caissons. Trenches extend back from where the chain emerges from the seabed under ambient mooring loads to relatively close to the caisson and with depths approaching the padeye depth. To help understand the process, a coupled Eulerian–Lagrangian (CEL) approach has been used to apply cyclic loading to a mooring chain system, treating the chain as a series of linked cylindrical elements and the soil as a strain-softening Tresca material. The chain extended through the soil into the water column, and cyclically changing boundary conditions were applied to the far end of the chain to reflect a typical mooring layout and metocean conditions. Despite rather idealized conditions, with loading restricted to the vertical plane of the chain and no consideration of hydrodynamic effects, a stable trench profile developed after only a few cycles of loading. The chain profile straightened during the cycles, with the section nearest to the padeye gradually cutting deeper into the soil and with the amplitude of cyclic motions of the chain, and hence tendency for a trench to form, increasing at shallower depths. The magnitude of soil resistance acting on the chain reduced by increasing cycles, with particularly low resistance in the zone where the trench was most developed. The long-term longitudinal profile of trenching was predicted based on the current modeling and was found comparable to that inferred from field observations, even without consideration of hydrodynamic and out-of-plane effects. [ABSTRACT FROM AUTHOR]

Particle image velocimetry (PIV) quantifies displacement of patches of pixels between successive images. We evaluated PIV as a tool for microscopists by measuring displacements of cells and of a surrounding granular medium in confocal laser scanning microscopy images of Arabidopsis thaliana roots labeled with cell-membrane targeted green fluorescent protein. Excellent accuracy (e.g., displacement standard deviation <0.006 pixels) was obtained for root images that had undergone rigid digital translations of up to 40 pixels. Analysis of zoomed images showed that magnifications of up to 5% maintained good linear relations between PIV-predicted and actual displacements ( r2 > 0.83). Root mean squared error for these distorted images was 0.4-1.1 pixels, increasing at higher magnification factors. Cell growth and rhizosphere deformation were tracked with good temporal (e.g., 1-min interval) and spatial resolution, with PIV patches located on recognizable cell features being tracked more successfully. Appropriate choice of GFP-label was important to decrease small-scale biological noise due to intracellular motion. PIV of roots grown in stiff 2% versus 0.7% agar showed patterns of cell expansion consistent with physically impeded roots of other species. Roots in glass ballotini underwent rapid changes in growth direction on a timescale of minutes, associated with localized arching of ballotini. By tracking cell vertices, we monitored automatically cell length, width, and area every minute for 0.5 h for cells in different stages of development. In conclusion, PIV measured displacements successfully in images of living root cells and the external granular medium, revealing much potential for use by microscopists. Microsc. Res. Tech., 2009. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Plant toots have considerable impact on the mechanical stability of soil, but to date the underlying mechanisms have been poorly quantified. In this study, controlled laboratory studies of soil reinforced with willow trees (Salix viminalis cv Tora) found a strong correlation between the cross-sectional area of soil covered by roots and shear reinforcement. We separated broken versus pulled-out roots and measured individual root diameters crossing the shear-plane. The shear strength of planted specimens compared with non-planted specimens increased eight-fold at 0.10-m shear depth, more than four-fold at 0.25-m depth, and more than doubled at 0.40-m depth. These data were used to evaluate several models of root-reinforcement. Models based on catastrophic and simultaneous failure of all roots overpredicted reinforcement by 33% on average. Better agreement between experimental and model results was found for a stress-based fiber-bundle-model, in which roots break progressively from weakest to strongest, with the load shared on the remaining roots at each step. Roots have a great capacity to reinforce soils, with existing models providing reasonable predictions of increased shear strength. However, deterministic understanding and modeling of the processes involved needs to consider root failure mechanisms. In particular, the role of root stiffness and root-soil adhesion is not considered in existing models of soil reinforcement by plant roots. [ABSTRACT FROM AUTHOR]

Many aspects of the performance of infrastructure slopes are affected by vegetation, but many are conventionally overlooked by engineers. This paper explores in detail the engineering aspects associated with vegetation on infrastructure slopes and the conflicts that must be managed in order to maintain safety and serviceability. It also examines the importance of roadside corridors as grassland habitats and the difficulties of managing and maintaining the diversity of species using safe and economic management practices. The biodiversity of roadside grassland habitats is discussed in this paper, but it is expected that these findings will offer general lessons for the vegetation management of infrastructure slopes. [ABSTRACT FROM AUTHOR]

This paper presents an experimental methodology using a geotechnical centrifuge and an environmental chamber to explore long-term embankment performance in light of the more severe conditions expected due to global climate change. The environmental chamber applies water and air input to control inundation and evaporation conditions at the soil surface. Example results show that a well-compacted intermediate-plasticity model embankment performs well when subjected to 19 years of alternating wet and dry periods. Finally, the paper reports an experimental methodology that will allow further model tests to be conducted to examine how different climate scenarios, soil types and compaction levels may affect long-term embankment response. [ABSTRACT FROM AUTHOR]

The UK biological and engineering impacts of climate change on slopes (Bionics) project was funded to bring together key stake-holder and academics to research advanced procedures for maintaining serviceability and safety of strategic embankments and cuttings in addition to advancing the science base. This paper summarises some of the evidence that suggests climate change will have an effect on the behaviour of infrastructure slope sand their management, and provides an overview of future climate scenarios for the UK. It also shows how climate data have been used in numerical and physical models and full-scale tests within the Bionics project to begin to determine the magnitude and timing of the effects of climate change on infrastructure slopes. [ABSTRACT FROM AUTHOR]

Axial and radial profiles of ion (Al+, V+, Cr+, Mn+, Fe+, Ni+, Co+, Cu+, Zn+, As+, Mo+, Sb+, La+, LaO+, Ce+and CeO+) distribution in inductively coupled plasma mass spectrometry were examined for solutions containing 1% v/v HNO3(i.e.0.16 M) with and without 0.02 M NaNO3, KNO3, CsNO3, HI or HCl. None of the latter matrices induced a significant change in sample introduction efficiency compared to 1% v/v HNO3alone. Nonetheless, although analyte signal suppression was predominant in the presence of the K and Cs matrices, 0.02 M Na induced an enhancement by 1.6 ± 0.3 across the mass range, which was irrespective of the analyte ionization potential (i.e.even analytes that should be completely ionized were enhanced). This may be rationalized using a Coulomb fission mechanism within the spray chamber, which shifts the droplet size distribution towards smaller ones that are then more efficiently transported through the spray chamber and ultimately result in more analyte ions in the plasma. Furthermore, desolvation of these smaller droplets is completed sooner in the ICP, as axial profiles of the oxide fraction of La and Ce were shifted lower in the plasma in the presence of a non-volatile ionic matrix (0.02 M NaNO3, KNO3, CsNO3) but were unaffected by 0.02 M HCl or HI. The broadened analyte radial profile in the presence of 0.02 M Na, which was observed at the optimum sampling depth for a 1% v/v HNO3matrix, also points to earlier desolvation. These results suggest that the Coulomb fission mechanism may be significant with a conventional sample introduction system. [ABSTRACT FROM AUTHOR]

The marked cyclical physiological angiogenesis in the developing follicle, corpus luteum and endometrium implies a critical role in health and disease. Our approach to understanding its regulation has been to localise and quantify the temporal changes in putative angiogenic factors, and their receptors, in human and non-human primate tissue and to use antagonists to dissect their role by specific inhibition at defined periods during the ovulatory cycle in non-human primates in vivo. The course of angiogenesis throughout the cycle and the cellular and molecular effects of inhibitory treatments have been investigated in the marmoset ovary and uterus, whereas consequences on pituitary–ovarian function have been monitored in macaques. Inhibition of vascular endothelial growth factor (VEGF) at the time of follicle recruitment or selection prevents endothelial cell proliferation, leading to inhibition of follicular development. VEGF inhibition during the early luteal phase prevents angiogenesis and restricts development of the luteal microvasculature. Inhibition of angiogenesis at all stages of the cycle leads to profound suppression of ovarian function. Even during the ‘post-angiogenic' period of the luteal phase, inhibition of VEGF precipitates a suppression of progesterone secretion, pointing to additional roles for VEGF in the ovary. In the endometrium, oestrogen drives endometrial angiogenesis through VEGF. Thus, oestrogen can restore angiogenesis after ovariectomy, but not in the presence of VEGF inhibitors. These investigations enhance our understanding of the regulation of angiogenesis in the ovary and uterus and inform studies on conditions with abnormal vascularisation, such as polycystic ovary syndrome, endometriosis, uterine fibroids and menstrual dysfunction. [ABSTRACT FROM AUTHOR]

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Root growth in the field is often slowed by a combination of soil physical stresses, including mechanical impedance, water stress, and oxygen deficiency. The stresses operating may vary continually, depending on the location of the root in the soil profile, the prevailing soil water conditions, and the degree to which the soil has been compacted. The dynamics of root growth responses are considered in this paper, together with the cellular responses that underlie them. Certain root responses facilitate elongation in hard soil, for example, increased sloughing of border cells and exudation from the root cap decreases friction; and thickening of the root relieves stress in front of the root apex and decreases buckling. Whole root systems may also grow preferentially in loose versus dense soil, but this response depends on genotype and the spatial arrangement of loose and compact soil with respect to the main root axes. Decreased root elongation is often accompanied by a decrease in both cell flux and axial cell extension, and recent computer-based models are increasing our understanding of these processes. In the case of mechanical impedance, large changes in cell shape occur, giving rise to shorter fatter cells. There is still uncertainty about many aspects of this response, including the changes in cell walls that control axial versus radial extension, and the degree to which the epidermis, cortex, and stele control root elongation. Optical flow techniques enable tracking of root surfaces with time to yield estimates of two-dimensional velocity fields. It is demonstrated that these techniques can be applied successfully to time-lapse sequences of confocal microscope images of living roots, in order to determine velocity fields and strain rates of groups of cells. In combination with new molecular approaches this provides a promising way of investigating and modelling the mechanisms controlling growth perturbations in response to environmental stresses. [ABSTRACT FROM PUBLISHER]

To estimate the degree of familial aggregation of juvenile idiopathic arthritis (JIA), determine whether the aggregation of JIA and the aggregation of type 1 diabetes mellitus (type 1 DM) overlap, and identify multiplex JIA pedigrees. Records of individuals with JIA or type 1 DM were probabilistically linked with records in the Utah Population Database (UPDB), a large computerized family history database. For each case of JIA or type 1 DM, 10 matched controls or 5 matched controls, respectively, were selected. All familial relationships among cases of JIA or type 1 DM were established. A familial risk score was calculated for each subject. For various levels of familial exposure to JIA or type 1 DM, one's risk (odds ratio [OR]) of developing JIA or type 1 DM was established (cases compared with controls). Recurrence risks for JIA were computed for relatives of JIA cases compared with relatives of controls. Extended JIA families were identified from a list of common ancestors. Records of a total of 443 patients were linked with the UPDB. Of these, 381 (86.0%) met criteria for JIA. An increased risk for JIA was observed among relatives of probands with JIA. The prevalence of type 1 DM among JIA cases was higher than the US prevalence of type 1 DM (P < 0.003). The recurrence risk for JIA was significantly elevated among first‐degree relatives of cases with JIA (OR 30.4). The overall prevalence of JIA was 28/100,000. Four extended JIA pedigrees were identified. There is familial aggregation of JIA in the Intermountain West region of the US. We have demonstrated that multiplex JIA pedigrees can be identified using a genealogic database. [ABSTRACT FROM AUTHOR]

We have determined that Borrelia burgdorferi strain B31 MI carries 21 extrachromosomal DNA elements, the largest number known for any bacterium. Among these are 12 linear and nine circular plasmids, whose sequences total 610 694 bp. We report here the nucleotide sequence of three linear and seven circular plasmids (comprising 290 546 bp) in this infectious isolate. This completes the genome sequencing project for this organism; its genome size is 1 521 419 bp (plus about 2000 bp of undetermined telomeric sequences). Analysis of the sequence implies that there has been extensive and sometimes rather recent DNA rearrangement among a number of the linear plasmids. Many of these events appear to have been mediated by recombinational processes that formed duplications. These many regions of similarity are reflected in the fact that most plasmid genes are members of one of the genome's 161 paralogous gene families; 107 of these gene families, which vary in size from two to 41 members, contain at least one plasmid gene. These rearrangements appear to have contributed to a surprisingly large number of apparently non-functional pseudogenes, a very unusual feature for a prokaryotic genome. The presence of these damaged genes suggests that some of the plasmids may be in a period of rapid evolution. The sequence predicts 535 plasmid genes ≥300 bp in length that may be intact and 167 apparently mutationally damaged and/or unexpressed genes (pseudogenes). The large majority, over 90%, of genes on these plasmids have no convincing similarity to genes outside Borrelia , suggesting that they perform specialized functions. [ABSTRACT FROM AUTHOR]

Produce-associated foodborne disease outbreaks have increased worldwide highlighting the importance of proper implementation of risk management practices (RMP). We determined the relationship between environmental characteristics (i.e., physical resources) of produce farms and implementation of RMP. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses principles, we identified 36 studies to include in our analysis. Most study data were collected through surveys administered to growers in developed countries. Quality assessment results showed that studies on this topic should be more rigorously conducted (e.g., powering sample sizes and training data collectors) to yield better quality evidence. Agricultural waters were the most common environmental characteristic assessed, with many farms using unsafe water sources. Hygiene aids (e.g., accessible handwashing facilities), were lacking across many farms. Animal intrusion RMP were the least commonly assessed environmental characteristic. Only one study tested the relationship between on-farm environmental characteristics and RMP implementation reporting a positive relationship between accessible handwashing and worker hygiene practices. Grower knowledge and perception of RMP combined with cost and ease in carrying out RMP might influence the availability of physical resources for proper RMP implementation. These results can inform practical interventions aimed to increase adoption of RMP on produce farms. [ABSTRACT FROM AUTHOR]

An inhomogeneous fractal set is one which exhibits different scaling behaviour at different points. The Assouad dimension of a set is a quantity which finds the ‘most difficult location and scale’ at which to cover the set and its difference from box dimension can be thought of as a first-level overall measure of how inhomogeneous the set is. For the next level of analysis, we develop a quantitative theory of inhomogeneity by considering the measure of the set of points around which the set exhibits a given level of inhomogeneity at a certain scale. For a set of examples, a family of -invariant subsets of the 2-torus, we show that this quantity satisfies a large deviations principle. We compare members of this family, demonstrating how the rate function gives us a deeper understanding of their inhomogeneity. [ABSTRACT FROM AUTHOR]

Nebular-phase observations and spectral models of Type Ic superluminous supernovae (SLSNe) are presented. LSQ14an and SN 2015bn both display late-time spectra similar to galaxy-subtracted spectra of SN 2007bi, and the class shows strong similarity with broad-lined SNe Ic such as SN 1998bw. Near-infrared observations of SN 2015bn show a strong Ca ii triplet, O i 9263, O i 1.13 μm, and Mg i 1.50 μm, but no distinct He, Si, or S emission. The high Ca ii NIR/[Ca ii] 7291, 7323 ratio of ∼2 indicates a high electron density of cm−3. Spectral models of oxygen-zone emission are investigated to put constraints on the emitting region. Models require M⊙ to produce enough [O i] 6300, 6364 luminosity, irrespective of the powering situation and the density. The high oxygen-zone mass, supported by high estimated magnesium masses, points to explosions of massive CO cores, requiring . Collisions of pair-instability pulsations do not provide enough mass to account for the emission. [O ii] and [O iii] lines emerge naturally in many models, which strengthens the identification of broad [O ii] 7320, 7330, [O iii] 4363, and [O iii] 4959, 5007 in some spectra. A small filling factor for the O/Mg zone is needed to produce enough luminosity in Mg i] 4571, Mg i 1.504 μm, and O i recombination lines, which shows that the ejecta is clumped. We review the constraints from the nebular spectral modeling in the context of the various scenarios proposed for SLSNe. [ABSTRACT FROM AUTHOR]

We present the results of optical, near-infrared, and mid-infrared observations of M101 OT2015-1 (PSN J14021678+5426205), a luminous red transient in the Pinwheel galaxy (M101), spanning a total of 16 years. The light curve showed two distinct peaks with absolute magnitudes and , on 2014 November 11 and 2015 February 17, respectively. The spectral energy distributions during the second maximum show a cool outburst temperature of K and low expansion velocities ( km s−1) for the H i, Ca ii, Ba ii, and K i lines. From archival data spanning 15–8 years before the outburst, we find a single source consistent with the optically discovered transient, which we attribute to being the progenitor; it has properties consistent with being an F-type yellow supergiant with L ∼ 8.7 L⊙, K, and an estimated mass of M⊙. This star has likely just finished the H-burning phase in the core, started expanding, and is now crossing the Hertzsprung gap. Based on the combination of observed properties, we argue that the progenitor is a binary system, with the more evolved system overfilling the Roche lobe. Comparison with binary evolution models suggests that the outburst was an extremely rare phenomenon, likely associated with the ejection of the common envelope of a massive star. The initial mass of the primary fills the gap between the merger candidates V838 Mon (5−10 M⊙) and NGC 4490-OT (30 M⊙). [ABSTRACT FROM AUTHOR]

We present observations of SN 2015bn (=PS15ae = CSS141223-113342+004332 = MLS150211-113342+004333), a Type I superluminous supernova (SLSN) at redshift z = 0.1136. As well as being one of the closest SLSNe I yet discovered, it is intrinsically brighter () and in a fainter galaxy () than other SLSNe at . We used this opportunity to collect the most extensive data set for any SLSN I to date, including densely sampled spectroscopy and photometry, from the UV to the NIR, spanning −50 to +250 days from optical maximum. SN 2015bn fades slowly, but exhibits surprising undulations in the light curve on a timescale of 30–50 days, especially in the UV. The spectrum shows extraordinarily slow evolution except for a rapid transformation between +7 and +20–30 days. No narrow emission lines from slow-moving material are observed at any phase. We derive physical properties including the bolometric luminosity, and find slow velocity evolution and non-monotonic temperature and radial evolution. A deep radio limit rules out a healthy off-axis gamma-ray burst, and places constraints on the pre-explosion mass loss. The data can be consistently explained by a M stripped progenitor exploding with erg kinetic energy, forming a magnetar with a spin-down timescale of ∼20 days (thus avoiding a gamma-ray burst) that reheats the ejecta and drives ionization fronts. The most likely alternative scenario—interaction with ∼20 M of dense, inhomogeneous circumstellar material—can be tested with continuing radio follow-up. [ABSTRACT FROM AUTHOR]

Auger-ionized free-carriers in a one-dimensional semiconductor are predicted to result in a strong band-gap renormalization. Isolated single-walled carbon nanotubes (SWCNT) under high-intensity laser irradiation exhibit strong nonlinear photoluminescence (PL) due to exciton–exciton annihilation (EEA). The presence of exciton disassociation during the rapid Auger-ionization caused by EEA would lead to a strong nonlinear absorption. By simultaneously measuring SWCNT–PL and optical absorption of isolated SWCNT clusters in the PL saturation regime, we give evidence that Auger-ionized excitons do not disassociate but remain bound. [ABSTRACT FROM AUTHOR]

Scanning optics enable many laser applications in manufacturing because their low inertia allows rapid movement of the process beam across the sample. We describe our method of inline coherent imaging for real-time (up to 230 kHz) micron-scale (7–8 µm axial resolution) tracking and control of laser machining depth through a scanning galvo-telecentric beam delivery system. For 1 cm trench etching in stainless steel, we collect high speed intrapulse and interpulse morphology which is useful for further understanding underlying mechanisms or comparison with numerical models. We also collect overall sweep-to-sweep depth penetration which can be used for feedback depth control. For trench etching in silicon, we show the relationship of etch rate with average power and scan speed by computer processing of depth information without destructive sample post-processing. We also achieve three-dimensional infrared continuous wave (modulated) laser machining of a 3.96 × 3.96 × 0.5 mm3 (length × width × maximum depth) pattern on steel with depth feedback. To the best of our knowledge, this is the first successful demonstration of direct real-time depth monitoring and control of laser machining with scanning optics. [ABSTRACT FROM AUTHOR]