Apparent Discontinuity Research Articles

Orbit tomography in constants-of-motion phase-space

Tomographic reconstructions of a 3D fast-ion constants-of-motion phase-space distribution function are computed by inverting synthetic signals based on projected velocities of the fast ions along the diagnostic lines of sight. A spectrum of projected velocities is a key element of the spectrum formation in fast-ion D-alpha spectroscopy, collective Thomson scattering, and gamma-ray and neutron emission spectroscopy, and it can hence serve as a proxy for any of these. The fast-ion distribution functions are parameterised by three constants of motion, the kinetic energy, the magnetic moment and the toroidal canonical angular momentum. The reconstructions are computed using both zeroth-order and first-order Tikhonov regularisation expressed in terms of Bayesian inference to allow uncertainty quantification. In addition to this, a discontinuity appears to be present in the solution across the trapped-passing boundary surface in the three-dimensional phase space due to a singularity in the Jacobian of the transformation from position and velocity space to phase space. A method to allow for this apparent discontinuity while simultaneously penalising large gradients in the solution is demonstrated. Finally, we use our new methods to optimise the diagnostic performance of a set of six fans of sightlines by finding where the detectors contribute most complementary diagnostic information for the future COMPASS-Upgrade tokamak.

On the degrees of freedom of R2 gravity in flat spacetime

We study the degrees of freedom of R2 gravity in flat spacetime with two approaches. By rewriting the theory a la Stueckelberg, and implementing Lorentz-like gauges to the metric perturbations, we confirm that the pure theory propagates one scalar degree of freedom, while the full theory contains two tensor modes in addition. We then consider the degrees of freedom by directly examining the metric perturbations. We show that the degrees of freedom of the full theory match with those obtained with the manifestly covariant approach. In contrast, we find that the pure R2 gravity has no degrees of freedom. We show that a similar discrepancy between the two approaches appears also in a theory dual to the three-form, and appears due to the Lorentz-like gauges, which lead to the fictitious modes even after the residual gauge redundancy has been taken into account. At first sight, this implies a discontinuity between the full theory and the pure case. By studying the first-order corrections of the full R2 gravity beyond the linear regime, we show that at high-energies, both scalar and tensor degrees of freedom become strongly coupled. This implies that the apparent discontinuity of pure and full R2 gravity is just an artefact of the perturbation theory, and further supports the absence of degrees of freedom in the pure R2 gravity.

Comparative Analysis of TRGBs (CATs) from Unsupervised, Multi-halo-field Measurements: Contrast is Key

The tip of the red giant branch (TRGB) is an apparent discontinuity of the luminosity function (LF) due to the end of the red giant evolutionary phase and is used to measure distances in the local universe. In practice, tip localization via edge detection response (EDR) relies on several methods applied on a case-by-case basis. It is hard to evaluate how individual choices affect a distance estimation using only a single host field while also avoiding confirmation bias. To devise a standardized approach, we compare unsupervised, algorithmic analyses of the TRGB in multiple halo fields per galaxy. We first optimize methods for the lowest field-to-field dispersion, including spatial filtering, smoothing, and weighting of LF, color band selection, and tip selection based on the number of likely RGB stars and the ratio of stars below versus above the tip (R). We find R, which we call the tip contrast, to be the most important indicator of the quality of EDR measurements; higher R selection can decrease field-to-field dispersion. Further, since R is found to correlate with the age or metallicity of the stellar population based on theoretical modeling, it might result in a displacement of the detected tip magnitude. We find a tip-contrast relation with a slope of −0.023 ± 0.0046 mag/ratio, an ∼5σ result that can be used to correct these variations in the detections. When using TRGB to establish a distance ladder, consistent TRGB standardization using tip-contrast relation across rungs is vital to make robust cosmological measurements.

Microrheology of a thermosensitive gelling polymer for cell culture.

We investigate the rheo-mechanical properties of Mebiol Gel®, a thermosensitive gel-forming polymer extensively used as a medium for cellular culture, using passive microrheology made either by standard dynamic light scattering or by photon correlation imaging. In the dilute limit, Mebiol displays a Newtonian behavior with an effective viscosity that decreases with temperature, consistent with a peculiar aggregation mechanism characterized by an increase of the molecular weight with a simultaneous reduction of the aggregate size. By increasing concentration and approaching gelation, both the storage and loss moduli show a nonmonotonic dependence with temperature, with a pronounced maximum around Tm ≃ 28-30 °C, the value above which, in the dilute limit, the individual Mebiol chains are fully compacted. Such a distinctive trend of the elastic and viscous properties persists within the gel, which, therefore, becomes "softer" above Tm. Although when temperature changes are performed adiabatically, the transition from the fluid to the gel phase takes place without any apparent discontinuity, a rapid T-jump leads to the formation of a hard gel at a concentration where a low heating rate conversely yields a fluid phase. This is a visible manifestation of the nonequilibrium nature of these physical gels.

Predicting and Scoring Estuary Ecological Health Using a Bayesian Belief Network

Excessive nutrient and sediment inputs threaten ecological condition in many estuaries. We describe a Bayesian Belief Network (BBN) that calculates an Estuary Trophic Index (ETI) score ranging between 0 (no symptoms of eutrophication) to 1 (grossly eutrophic) for estuaries in Aotearoa New Zealand (NZ). The ETI BBN includes estuary physiographic characteristics (estuary type, flushing time, intertidal area, estuary closure state, water column stratification) and nutrient and sediment loads available from existing geospatial tools and databases, that drive responses of ‘primary’ indicators (macroalgae and phytoplankton biomass) and ‘secondary’ indicators (or symptoms) of estuary ecological impairment (sediment carbon, sediment apparent redox potential discontinuity depth, water column oxygen, macrobenthos and seagrass condition). Relationships between the BBN nodes are based primarily on observational and model-based information from NZ and international studies rather than expert opinion. The model can be used in a purely predictive manner under knowledge-poor situations, using only the physiographic drivers and nutrient/sediment loads, or refined using field-derived observations of indicator values to reduce the uncertainty associated with the probabilistic BBN score. It is designed for shallow tidal lagoons, tidal river estuaries and coastal lakes; systems which are sensitive to eutrophication and sedimentation pressure and are common in NZ and globally. Modelled ETI BBN scores agreed well with ETI scores calculated from observed indicator values for 11 well-studied NZ estuaries. We predict ecological condition of 291 NZ estuaries, most of which have no monitored information on trophic state. We illustrate capabilities of the ETI BBN with two case studies: to evaluate improvements in estuary health arising from diversion of wastewater from an estuary via an ocean outfall, and to estimate catchment diffuse nutrient load reductions required to meet estuary health objectives. The ETI BBN may serve as a template for other agencies wishing to develop similar tools.

Weakly first-order transition in an athermal lattice gas

We investigate the phase behavior of a two-dimensional athermal lattice gas in which every hard-core particle can have two or fewer nearest neighboring occupied sites on the square lattice. The ground state and close packing density are determined and it is found that at large chemical potential the model undergoes an ordering phase transition with preferential sublattice occupation. Although near the transition point the particle density and entropy exhibit an apparent discontinuity, we find that the order parameter and fluctuations of thermodynamic quantities do not scale with the system volume. These paradoxical results are reconciled by analyzing the size-dependent flow of the thermal exponent by phenomenological renormalization and the curve-crossing method, which lead to a weakly first-order phase transition scenario.

The strong couplings of massive Yang-Mills theory

We study the massive Yang-Mills theory in which the mass term is added by hand. The standard perturbative approach suggests that the massless limit of this theory is not smooth. We confirm that this issue is related to the existence of additional degrees of freedom, which are absent in the massless theory. Nevertheless, we show that the longitudinal modes become strongly coupled at the Vainshtein scale, which coincides with the scale of the unitarity violation. Beyond this scale, they decouple from the remaining degrees of freedom, and the massless theory is restored up to small corrections. From here, it follows that the apparent discontinuity in the massless limit is only an artefact of the perturbation theory. The massless limit of massive Yang-Mills theory is smooth, as originally proposed in [21].

Signs of late infall and possible planet formation around DR Tau using VLT/SPHERE and LBTI/LMIRCam

Context. Protoplanetary disks around young stars often contain substructures like rings, gaps, and spirals that could be caused by interactions between the disk and forming planets. Aims. We aim to study the young (1–3 Myr) star DR Tau in the near-infrared and characterize its disk, which was previously resolved through submillimeter interferometry with ALMA, and to search for possible substellar companions embedded into it. Methods. We observed DR Tau with VLT/SPHERE both in polarized light (H broad band) and total intensity (in Y, J, H, and K spectral bands). We also performed L′ band observations with LBTI/LMIRCam on the Large Binocular Telescope (LBT). We applied differential imaging techniques to analyze both the polarized data, using dual beam polarization imaging, and the total intensity data, using angular and spectral differential imaging. Results. We found two previously undetected spirals extending north-east and south of the star, respectively. We further detected an arc-like structure north of the star. Finally a bright, compact and elongated structure was detected at a separation of 303 ± 10 mas and a position angle 21.2 ± 3.7 degrees, just at the root of the north-east spiral arm. Since this feature is visible both in polarized light and total intensity and has a blue spectrum, itis likely caused by stellar light scattered by dust. Conclusions. The two spiral arms are at different separations from the star, have very different pitch angles, and are separated by an apparent discontinuity, suggesting they might have a different origin. The very open southern spiral arm might be caused by infalling material from late encounters with cloudlets into the formation environment of the star itself. The compact feature could be caused by interaction with a planet in formation still embedded in its dust envelope and it could be responsible for launching the north–east spiral. We estimate a mass of the putative embedded object of the order of few MJup.

Negotiating hegemonies in language policy: ideological synergies in media recontextualizations of audit culture

ABSTRACT One of the products of globalization in sociolinguistics is the emergence of transnational regimes in language policy, in which power is exercised across boundaries of traditional nation states. This paper engages with audit culture, a transnational policy mechanism which involves the continuous evaluation of nation states’ performance through the use of purportedly neutral, typically quantitative instruments. As achieving broader visibility in public discourse is a key part of how such evaluations enforce language policy regimes, the paper presents an analysis of how an audit instrument, the Education First English Proficiency Index, was recontextualized in media discourse in Thailand over a 6-year period. The findings highlight an apparent discontinuity, as much of the neoliberal rhetoric in the audit instrument was not taken up in Thai media. Rather, the recontextualization was selective, with elements of the audit texts being integrated into an already established language policy regime in Thailand, built on nationalism and developmentalism. These findings point to the need to consider how language policy mechanisms like audit culture can facilitate synergies between hegemonic ideologies, particularly when they are recontextualized across different scales.

Understanding Parents’ Perspectives of Support Services for People Living with Spina Bifida and/or Hydrocephalus in Ireland: A Qualitative Exploration

Purpose: In Ireland, the complex needs of people with Spina Bifida and/or Hydrocephalus (SB and/or H) are treated across primary care and tertiary specialist services. Traditionally, there has been much variation in how primary care services are delivered. To increase equity, ‘Progressing Disability Services for Children and Young People’ is a policy which is being implemented to reconfigure children’s services into multidisciplinary teams, for all disabilities. These changes, and an apparent discontinuity of support in the transition to adult services, requires further research exploring service delivery processes. Method: This study explored parents’ perspectives of support services for people with SB and/or H. Eight parents of people with SB and/or H participated in semi-structured interviews which were transcribed and analysed using thematic analysis. Results: Six themes were generated: (1) Difficulty accessing services; (2) Impact of waiting lists; (3) Onus on parents; (4) Importance of communication; (5) Reduced service provision following the implementation of ‘Progressing Disability Services’; and (6) Lack of adult services. Conclusions: While the service redesign for people with SB and/or H and their families is still in the implementation stage, this research contributes to the evolution of these changes by identifying the enhancing aspects such as effective communication and the inhibiting aspects including a parent’s perception of increased responsibility for supporting their family member and barriers in access to services.

Antipodal seismic reflections upon shear wave velocity structures within Earth's inner core

Seismic evidence is presented for a high shear wave velocity, apparent discontinuity near ~100 km depth within a portion of Earth's inner core. Antipodally (>179°) focused data are stacked for five source–receiver diametric ray paths traversing the inner core. Two antipodal paths follow ray surfaces which are aligned with diameters between Tamanrasset (TAM), Algeria and Tonga earthquakes and Pitinga (PTGA), Brazil and Sulawesi earthquakes, providing clear examples of precursors to PKIIKP (an underside reflection at the inner core boundary). Waveform and stacked data (T > 4 s) were engaged in testing more than 16 inner core model series, varying compressional and shear wave velocities in upper inner core structures. The precursory seismic phases are successfully modeled as reflecting beneath a core liquid/solid interface at 100 km depth below the inner core boundary. This interface is highly reflective, and sensitive to a shear wave velocity contrast ≥5 km/s. An earlier precursory phase is observed at TAM and PTGA which may be modeled as an apparent discontinuity near ~250 km depth. This intermediate region has high shear wave velocities more akin to hcp-Fe mineralogy than Preliminary Reference Earth Model (PREM) values. Three other antipodal observations (China–Chile) nearly orthogonal to TAM paths exhibit seismic waves whose waveforms are more consistent with the PREM velocities above 100 km depth, while offering modest evidence for a solid/solid discontinuity at 100-km-depth. This research focused on seismology of the inner core potentially has mineral physics and geodynamic implications too broad to be simply encapsulated herein. Acknowledging some of these implications, we have focused upon measuring and mapping the seismic anomalies.

Understanding the role of homeownership in wealth inequality: Evidence from urban China (1995–2018)

Many scholars have evaluated the wealth creation effects of homeownership over different time periods and have agreed on the positive role of homeownership. However, there are no consistent mechanisms to measure the impact of homeownership on wealth inequality. Based on data from 1995 to 2018, this paper finds that the expansion of the homeownership rate in urban China was an equalizing force in the distribution of wealth from 1995 to 2008, driven by the increased homeownership and housing acquisition of low- and moderate-income households (LMIs) during the era of housing reform in the 1990s. The forces were exogenous and dominated by a redistributive logic. In the post-reform era after 2008, the decline in the homeownership rate led to a concentration of wealth distribution that was driven by the widening wealth gap between owners and non-owners, which represented an endogenous market force. The results indicate that there was an apparent discontinuity of the trends of homeownership and wealth inequality because new immigrants could not afford the price of housing in the cities. The wealth position of the middle and lower classes (mainly new immigrant non-owners) was crippled, not only by the inaccessibility of homeownership, but also by the reinforcing effect of the increase in housing prices. This study reveals the different mechanisms of homeownership on wealth inequality and the policy implications for the redistributive effects of the allocation of housing resources.

Heat Flow in Fractured Rocks: Stress and Moisture-Dependent Thermal Contact Resistance

The thermal conductivity of fractured rock masses is an important parameter for the analysis of energy geosystems, yet, its measurement is challenged by specimen size requirements. Fluids within fractures have lower thermal conductivities than rock minerals and heat flow lines constrict through contacting asperities. Together, heat flow constriction and phonon boundary scattering cause an apparent temperature discontinuity across the fracture, typically represented as a thermal contact resistance. We investigate the thermal contact resistance in fractured limestone and its evolution during loading and unloading (σ’=10 kPa to σ’=3000 kPa) for clean and gouge-filled fractures, under both air-dry and water-saturated conditions. The fracture thermal contact resistance decreases during loading because of the increase in the true contact area, gouge and asperity crushing, and fracture filling by produced fines that contribute new conduction pathways. These processes convey high stress sensitivity and loading hysteresis to the fracture thermal contact resistance. Water fills the fracture interstices and forms menisci at mineral contacts that significantly improve heat conduction even in partially saturated rock masses. The rock mass effective thermal conductivity can be estimated by combining the intact rock thermal conductivity with measurements of the thermal contact resistance of a single fracture under field boundary conditions.

Sediment Profile Imaging: Laboratory Study Into the Sediment Smearing Effect of a Penetrating Plate

Sediment profiling imaging (SPI) is a versatile and widely used method to visually assess the quality of seafloor habitats (e.g., around fish farms and oil and gas rigs) and has been developed and used by both academics and consultancy companies over the last 50 years. Previous research has shown that inserting the flat viewport of an SPI camera into the sediment can have an impact on particle displacement pushing oxygenated surface sediments to deeper sediment depths and making anthropogenically-disturbed sediment appear healthier than they may actually be. To investigate the particle displacement that occurs when a flat plate is inserted into seafloor sediments, a testing device, termed the SPI purpose-built sediment chamber (SPI-PUSH) was designed and used in a series of experiments to quantify smearing where luminophores were used to demonstrate the extent of particle displacement caused by a flat plate being pushed into the sediment. Here, we show that the plate of the SPI-PUSH caused significant smearing, which varied with sediment type and the luminophore grain size. The mean particle smearing measured directly behind the inserted plate was 2.9 ± 1.5 cm for mud sediments with sand-like luminophores, 4.3 ± 2.5 cm for fine sand sediments with sand-like luminophores and 1.9 ± 1.1 cm for medium sand sediments with mud-like luminophores. When the mean depth of particle smearing was averaged over a larger sediment volume (11 cm3) next to the inserted plate, substantial differences were seen between the plate-insertion experiments and controls highlighting the potential extent of smearing artefacts that may be produced when a SPI camera penetrates the seafloor. This experimental data shows that future studies using the SPI camera, or any other periscope-like device (e.g., planar optodes) need to acknowledge that smearing may be significant. Furthermore, it highlights that a correction factor may need to be applied to these data (e.g., the depth of apparent redox potential discontinuity layer) to correctly interpret SPI camera images and better determine the effect of anthropogenic impacts on seafloor habitats.

Sounds like a dynamic system: a unifying approach to Language

AbstractWhile nativist linguistic theory readily captures the regular processes of adult language, it struggles to account for often-unwieldy data collected from children. Any theory of language must house both the predictable and unpredictable turns a linguistic system takes. Some usage-based theories make strides in accounting for connections between multiple linguistic factors contributing to linguistic representation. Dynamic systems theory (DST) is capable of describing the interaction between numerous factors both linguistic and extra-linguistic. Grounded in embodiment, DST accounts for continuity between bodily and cognitive processes, which together are crucial in understanding the development of language. Conceptualizing systems as self-organizing, DST allows for the emergence of novel forms alongside the predictable. Furthermore, DST explains both continuity between unexpected child forms and eventual target forms and also apparent discontinuity that gives the illusion of discrete developmental stages. To illustrate the advantages of DST in describing language processes, this paper presents data from one American English-acquiring child, which comes from a larger study investigating phonological development beginning at the onset of word production. The data demonstrate the role of phonological templates in development as part of a dynamic system, entailing the interaction between developing phonological categories, lexical representation, and linguistic environment.

Understanding the Role of Homeownership in Wealth Inequality: Evidence from Urban China (1990-2018)

Many scholars have evaluated the wealth creation effects of homeownership over different periods and have agreed on the positive role of homeownership. However, there are contradictory mechanisms regarding the impact of homeownership on wealth inequality. Based on panel data from 1995 to 2018, this paper found that the expansion of the homeownership rate was an equalizing force in the distribution of wealth during the era of housing reform from 1995 to 2002, driven by the housing acquisition of low- and moderate-income households (LMI) and middle-class housing conversion. The forces were exogenous and dominated by the redistributive logic. In the post-reform era after 2010, the decline in the homeownership rate led to the concentration of wealth distribution that was driven by the widening wealth gap between owners and non-owners, which was an endogenous market driving force. The result shows that there is an apparent discontinuity in the trends of homeownership and wealth inequality when new immigrants cannot afford the price of housing in the city. The wealth position of the middle and lower class (mainly new immigrant non-owners) was crippled not only by the inaccessibility of housing ownership, but also by the reinforcing effect of the housing price upsurge. This research reveals the differential effects of homeownership on wealth inequality and the policy implications on the redistributive effects of the allocation of housing resources.

Assessment of sediment penetrability as an integrated in situ measure of intertidal softsediment conditions

Infauna have an intimate relationship with the sediments they inhabit, and any study conducted upon infauna must, at the very least, describe sediment conditions. Common sediment assessments in intertidal systems include particle size distribution, as well as water and organic matter contents. These measures require extracting and processing a sediment core, and this disturbance may result in data that do not necessarily reflectin situconditions. Sediment penetrability measuredin situusing a penetrometer can circumvent this limitation. However, relationships between sediment penetrability and other sediment variables are poorly understood, especially in coastal systems. We evaluated the relationship between sediment penetrability and depth to the apparent redox potential discontinuity, mean particle size, organic matter content, and water content on tidal flats along the Pacific and Atlantic coasts of Canada. We also assessed whether adding penetrability into environmental models of the infaunal community improved model performance. We observed that while penetrability is statistically related to other sediment variables, relationships to covariates were weak. Further, inclusion of penetrability with other sediment variables improved the performance of models predicting infaunal community composition. Therefore, penetrability can be considered a separate variable, and contributes to an integrated assessment of environmental conditions experienced by biota. Finally, since we evaluated this method in different soft-sediment intertidal ecosystems (mudflats to sandflats), this method is applicable to a range of systems in other geographical areas.

Experimental and theoretical study of dense YBO3 and the influence of non-hydrostaticity

YBO3 is used in photonics applications as a host for red phosphors due to its desirable chemical stability, high quantum efficiency and luminescence intensity. Despite its fundamental thermodynamic nature, the isothermal bulk modulus of YBO3 has remained a contentious issue due to a lack of comprehensive experimental and theoretical data and its vibrational modes are far from being understood. Here, we present an experimental-theoretical structural and vibrational study of YBO3. From structural data obtained from synchrotron X-ray diffraction data and ab initio calculations, we have determined the YBO3 bulk modulus, isothermal compressibility tensor and pressure-volume (P-V) equation of state (EoS). The isothermal compressibility tensor reveals that the compressibility of YBO3 is highly anisotropic, with the principal compression axis lying perpendicular to the ab-plane being approximately twice as stiff as the two axes perpendicular to it. From the vibrational data obtained from Raman scattering measurements and ab initio calculations, the experimental and calculated pressure response of the YBO3 Raman modes is also determined with the corresponding Grüneisen parameters and the symmetry of the experimental modes has been tentatively assigned and discussed. No evidence for a pressure-induced phase transition in YBO3 is observed up to 27 GPa, however we note that an apparent discontinuity in the compressibility at 8 GPa, likely due to the onset of non-hydrostaticity, could lead to the misinterpretation of an atypically high bulk modulus.

What lies beneath: Posterior capsular imaging in posterior polar cataracts.

This study adhered to the tenets of Declaration of Helsinki, ethics committee clearance was obtained and written informed consent was taken. A 52-year-old male presented with complaints of defective vision in the right eye since one year. Corrected distance visual acuity was 20/80 and 20/40 in the right and left eye, respectively. Slit lamp bio microscopic evaluation revealed a dense posterior polar cataract (PPC) with apparent equator-to equator discontinuity of the posterior capsule (PC) in the right eye [Fig. 1]. Left eye demonstrated an early cataract.Figure 1: Slit lamp image of the crystalline lens showing a posterior polar cataract. A spindle-shaped posterior capsular defect is seen around the polar opacitySwept-source OCT in the IOL Master-700 (Zeiss Medical, Germany) revealed an irregular and discontinuous PC [Fig. 2]. Femtosecond laser assisted cataract surgery with intraocular lens implantation was advised for the right eye. The built-in ASOCT in the Catalys Platform (Johnsons and Johnsons Vision, USA) demonstrated a clear discontinuity of the PC. The system additionally enables the surgeon to adjust the posterior laser offset, leaving a thick epinuclear layer behind, which protects the PC from mechanical and hydraulic turbulence during phacoemulsification [Fig. 3].[1]Figure 2: IOL Master 700 Swept source OCT of the crystalline lens showing a bumpy and irregular posterior capsule with discontinuityFigure 3: Femtosecond laser integrated OCT demonstrating discontinuity of the posterior capsule (arrow) and increased posterior laser offset (arrowhead) of 1000 micronsThe microscope-integrated OCT (MIOCT) (Rescan 700, ZEISS, Germany) showed an intraoperative preexisting break in the PC with herniation of cortical matter in the anterior vitreous [Fig. 4]. Cataract extraction was completed maintaining a closed chamber technique and low parameter fluidics. A discontinuity of the PC with a dome-shaped forward herniation of anterior vitreous face was seen [Fig. 5].Figure 4: MIOCT Showing an obvious PC defect, and possible herniation of cortical matter into the anterior vitreousFigure 5: MIOCT scan taken after nuclear emulsification showing a discontinuity of the PC, and a dome-shaped anteriorly herniating blob of vitreous (arrow)Discussion Imaging of the PC using adjunctive tools allows differentiation of a true PPC from a pseudo-polar opacity in doubtful cases following slit lamp evaluation.[2] Additional information regarding the presence and size of PC discontinuity better prepares a surgeon regarding the increased risk of vitreous loss. Imaging modalities additionally delineate subsequent vitreous loss if any and allow optimal management. In conclusion PC imaging allows safe phacoemulsification in PPC, decreasing the risk of rupture from 36% to 0%,[34] with concomitant use of better machines, fluidics, and Femtolaser Assisted cataract Surgery (FLACS). Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Passive reclamation of soft-sediment ecosystems on the North Coast of British Columbia, Canada

Estuarine ecosystems are degraded through anthropogenic development, leading to reduced habitat suitability for biological communities. The Skeena River estuary (British Columbia, Canada) is undergoing passive reclamation from historical salmon canneries and pulp mills, while localized disturbances continue at present. To reveal both current impacts and the trajectory of passive reclamation from historical activities, the intertidal mudflat surrounding the longest operating salmon cannery, Cassiar Cannery, within the Skeena estuary was surveyed. Nutrient availability (chlorophyll a concentration/organic matter content), sediment variables (particle size, water content, penetrability, woody debris/macroalgae cover, apparent redox potential discontinuity depth), and infaunal community composition varied spatiotemporally, and suggest that an old dock may be influencing the infaunal community given the abundance of disturbance indicating taxa below the dock. However, with populations of amphipods, mobile polychaetes, and a complex community structure, the mudflat as a whole appears to be relatively healthy. Therefore, cessation of historic activities has allowed for passive reclamation to a reasonably unstressed state, though a threshold of recovery may exist for intertidal mudflats beyond which passive reclamation will not be effective.