Secondary Surgery Following Lapidus Bunionectomy.

While the Lapidus bunionectomy is a common procedure utilized to address hallux valgus, the incidence of secondary surgery is not well established. Our primary goal was to determine the incidence of revision surgery and hardware removal following the Lapidus bunionectomy in addition to the risk factors associated with each. A retrospective nested case-control study of adult patients who underwent a Lapidus bunionectomy for symptomatic hallux valgus over a nine-year period was performed. The incidence rates and 95% confidence intervals (CI) of secondary surgery in the three years following the procedure along with the estimated independent associations and odds ratios between baseline demographic, clinical, and radiographic characteristics were calculated. Of the original cohort of 2,540 patients, 127 were identified (5.0%; CI: 4.1%, 5.8%) who underwent revision surgery and 165 (6.5%; CI: 5.5%, 7.5%) who underwent hardware removal following Lapidus bunionectomy. Initially, the hallux valgus angle, intermetatarsal angle, and tibial sesamoid position were risk factors for revision surgery. However, in adjusted analyses for revision surgery, using a screw for third point of fixation emerged as the only independent risk factor (odds ratio [OR]=3.01; CI: 1.59, 5.69). In adjusted analyses for hardware removal, female sex (OR=2.33; CI: 1.08, 5.00) and third point of fixation (OR=2.92; CI: 1.82, 4.69) emerged as independent risk factors. While the overall risks associated with Lapidus bunionectomy are low and the need for revision surgery are low, this study helps to identify specific risk factors for secondary surgery and hardware removal to help in evaluation and discussion with patients. LEVEL OF EVIDENCE: : 4.

Minimal geological methane emissions during the Younger Dryas-Preboreal abrupt warming event.

Methane (CH4) is a powerful greenhouse gas and plays a key part in global atmospheric chemistry. Natural geological emissions (fossil methane vented naturally from marine and terrestrial seeps and mud volcanoes) are thought to contribute around 52 teragrams of methane per year to the global methane source, about 10 per cent of the total, but both bottom-up methods (measuring emissions) and top-down approaches (measuring atmospheric mole fractions and isotopes) for constraining these geological emissions have been associated with large uncertainties. Here we use ice core measurements to quantify the absolute amount of radiocarbon-containing methane (14CH4) in the past atmosphere and show that geological methane emissions were no higher than 15.4 teragrams per year (95 per cent confidence), averaged over the abrupt warming event that occurred between the Younger Dryas and Preboreal intervals, approximately 11,600 years ago. Assuming that past geological methane emissions were no lower than today, our results indicate that current estimates of today's natural geological methane emissions (about 52 teragrams per year) are too high and, by extension, that current estimates of anthropogenic fossil methane emissions are too low. Our results also improve on and confirm earlier findings that the rapid increase of about 50 per cent in mole fraction of atmospheric methane at the Younger Dryas-Preboreal event was driven by contemporaneous methane from sources such as wetlands; our findings constrain the contribution from old carbon reservoirs (marine methane hydrates, permafrost and methane trapped under ice) to 19 per cent or less (95 per cent confidence). To the extent that the characteristics of the most recent deglaciation and the Younger Dryas-Preboreal warming are comparable to those of the current anthropogenic warming, our measurements suggest that large future atmospheric releases of methane from old carbon sources are unlikely to occur.

Community-Based Measurements Reveal Unseen Differences during Air Pollution Episodes.

Short-term exposure to fine particulate matter (PM2.5) pollution is linked to numerous adverse health effects. Pollution episodes, such as wildfires, can lead to substantial increases in PM2.5 levels. However, sparse regulatory measurements provide an incomplete understanding of pollution gradients. Here, we demonstrate an infrastructure that integrates community-based measurements from a network of low-cost PM2.5 sensors with rigorous calibration and a Gaussian process model to understand neighborhood-scale PM2.5 concentrations during three pollution episodes (July 4, 2018, fireworks; July 5 and 6, 2018, wildfire; Jan 3-7, 2019, persistent cold air pool, PCAP). The firework/wildfire events included 118 sensors in 84 locations, while the PCAP event included 218 sensors in 138 locations. The model results accurately predict reference measurements during the fireworks (n: 16, hourly root-mean-square error, RMSE, 12.3-21.5 µg/m3, n(normalized)RMSE: 14.9-24%), the wildfire (n: 46, RMSE: 2.6-4.0 µg/m3; nRMSE: 13.1-22.9%), and the PCAP (n: 96, RMSE: 4.9-5.7 µg/m3; nRMSE: 20.2-21.3%). They also revealed dramatic geospatial differences in PM2.5 concentrations that are not apparent when only considering government measurements or viewing the US Environmental Protection Agency's AirNow visualizations. Complementing the PM2.5 estimates and visualizations are highly resolved uncertainty maps. Together, these results illustrate the potential for low-cost sensor networks that combined with a data-fusion algorithm and appropriate calibration and training can dynamically and with improved accuracy estimate PM2.5 concentrations during pollution episodes. These highly resolved uncertainty estimates can provide a much-needed strategy to communicate uncertainty to end users.

Long-term urban carbon dioxide observations reveal spatial and temporal dynamics related to urban characteristics and growth.

Cities are concentrated areas of CO2 emissions and have become the foci of policies for mitigation actions. However, atmospheric measurement networks suitable for evaluating urban emissions over time are scarce. Here we present a unique long-term (decadal) record of CO2 mole fractions from five sites across Utah's metropolitan Salt Lake Valley. We examine "excess" CO2 above background conditions resulting from local emissions and meteorological conditions. We ascribe CO2 trends to changes in emissions, since we did not find long-term trends in atmospheric mixing proxies. Three contrasting CO2 trends emerged across urban types: negative trends at a residential-industrial site, positive trends at a site surrounded by rapid suburban growth, and relatively constant CO2 over time at multiple sites in the established, residential, and commercial urban core. Analysis of population within the atmospheric footprints of the different sites reveals approximately equal increases in population influencing the observed CO2, implying a nonlinear relationship with CO2 emissions: Population growth in rural areas that experienced suburban development was associated with increasing emissions while population growth in the developed urban core was associated with stable emissions. Four state-of-the-art global-scale emission inventories also have a nonlinear relationship with population density across the city; however, in contrast to our observations, they all have nearly constant emissions over time. Our results indicate that decadal scale changes in urban CO2 emissions are detectable through monitoring networks and constitute a valuable approach to evaluate emission inventories and studies of urban carbon cycles.

Morphological alterations of the cornea following crosslinking treatment (CXL).

INTRODUCTION: Corneal crosslinking (CXL) has revolutionized the treatment of keratoconus during the past decade. In the present study, the morphological changes in the corneal collagen fibrils (CFs) following crosslinking treatment are described. MATERIALS AND METHODS: Ten pairs of porcine and rabbit corneas were retrieved. In each pair, one cornea was the control and the other underwent CXL treatment. The central corneal thickness (CCT) was measured before and after CXL treatment. Each treated and control cornea was examined with light microscopy and by transmission electron microscopy. RESULTS: (a) The mean CCT was significantly reduced following treatment. (b) CFs were more closely packed in the anterior region and loosely packed in the posterior region. (c) CF diameter increased significantly in the anterior and intermediate regions but declined gradually towards the deeper regions. (d) There was a statistically significant decrease in the interfibrillar distance over the different regions of the cornea, except for the posterior region in porcine corneas, where there was no change. (e) The distance between adjacent collagen lamellae was significantly decreased in all regions of treated rabbit corneas. There was no change in porcine corneas. CONCLUSION: CXL treatment resulted in increased the CF diameter and decreased interfibrillar distance in the anterior and intermediate regions, while its effects on the posterior region differed among species. The effect on interlamellar distance was more prominent in the rabbit model than the porcine model. CXL treatment stiffened the corneas by increasing CF diameter and decreasing interfibrillar distance in both rabbit and pig corneas.

Constraining Urban CO2 Emissions Using Mobile Observations from a Light Rail Public Transit Platform.

Urban environments are characterized by pronounced spatiotemporal heterogeneity, which can present sampling challenges when utilizing conventional greenhouse gas (GHG) measurement systems. In Salt Lake City, Utah, a GHG instrument was deployed on a light rail train car that continuously traverses the Salt Lake Valley (SLV) through a range of urban typologies. CO2 measurements from a light rail train car were used within a Bayesian inverse modeling framework to constrain urban emissions across the SLV during the fall of 2015. The primary objectives of this study were to (1) evaluate whether ground-based mobile measurements could be used to constrain urban emissions using an inverse modeling framework and (2) quantify the information that mobile observations provided relative to conventional GHG monitoring networks. Preliminary results suggest that ingesting mobile measurements into an inverse modeling framework generated a posterior emission estimate that more closely aligned with observations, reduced posterior emission uncertainties, and extends the geographical extent of emission adjustments.

Local delivery of corticosteroids in clinical ophthalmology: A review.

Locally administered steroids have a long history in ophthalmology for the treatment of inflammatory conditions. Anterior segment conditions tend to be treated with topical steroids whilst posterior segment conditions generally require periocular, intravitreal or systemic administration for penetration. Over recent decades, the clinical applications of periocular steroid delivery have expanded to a wide range of conditions including macular oedema from retino-vascular conditions. Formulations have been developed with the aim to provide practical, targeted, longer-term and more efficacious therapy whilst minimizing side effects. Herein, we provide a comprehensive overview of the types of periocular steroid delivery, their clinical applications in ophthalmology and their side effects.

Radiographic Comparison of Heterotopic Ossification After Primary Total Ankle Arthroplasty in Fourth-Generation Implants.

LEVEL OF EVIDENCE: Level III: Retrospective comparative.

Outcomes and Complications of the INFINITY Total Ankle: A Systematic Review.

LEVEL OF EVIDENCE: IV.

A multi-city urban atmospheric greenhouse gas measurement data synthesis.

Urban regions emit a large fraction of anthropogenic emissions of greenhouse gases (GHG) such as carbon dioxide (CO2) and methane (CH4) that contribute to modern-day climate change. As such, a growing number of urban policymakers and stakeholders are adopting emission reduction targets and implementing policies to reach those targets. Over the past two decades research teams have established urban GHG monitoring networks to determine how much, where, and why a particular city emits GHGs, and to track changes in emissions over time. Coordination among these efforts has been limited, restricting the scope of analyses and insights. Here we present a harmonized data set synthesizing urban GHG observations from cities with monitoring networks across North America that will facilitate cross-city analyses and address scientific questions that are difficult to address in isolation.

Animal model with structural similarity to human corneal collagen fibrillar arrangement.

Rabbit and porcine corneas have been used in scientific research due to their structural similarity to the human cornea. Currently, there are no studies that have compared corneal collagen fibrillar diameter, interfibrillar distance and interlamellar distance between human and animal models. Ten pairs of porcine, rabbit, and human corneas were used. These were analysed using light and Transmission Electron microscopy. The collagen fibrillar diameter, interfibrillar distance and interlamellar distance were statistically compared between porcine, rabbit and human corneas. The human, porcine and rabbit; mean collagen fibrillar diameters were: 24.52 ± 2.09 nm; 32.87 ± 0.87 nm; and 33.67 ± 1.97 nm. The mean interfibrillar distances were: 46.10 ± 2.44 nm; 53.33 ± 2.24 nm; and 52.87 ± 2.73 nm, respectively. The collagen fibrillar diameter and interfibrillar distance of porcine and rabbit corneas were significantly different (p < 0.001) to the human corneal values but not form each other. The interlamellar distance of human, porcine and rabbit corneas was: 2190 ± 820 nm; 6460 ± 1180 nm; and 4410 ± 1330 nm, respectively. All the comparisons were statistically different, in porcine versus rabbit at the p < 0.01 level and both porcine and rabbit versus human at the p < 0.001 level. Histologically, all five layers (epithelium, Bowman's layer, stroma, Descemet membrane and endothelium) of the cornea were visible in all the three species. While neither animal model was structurally identical to the human cornea, they are both relatively close to being used as models to study the biomechanical effects of external insults/treatments to be extrapolated to the human cornea.

Sensory organization for postural control in children with strabismus-A systematic review and meta-analysis.

BACKGROUND: Postural control requires the interaction of somatosensory, vestibular and visual systems to prevent disequilibrium. Children with strabismus have an impaired visual input which can lead to postural control deficits. RESEARCH QUESTION: Does strabismus affect sensory organization for postural control in children? METHODS: A systematic comprehensive search of multiple electronic databases for relevant articles was performed using a predetermined search strategy. Peer-reviewed journal publications that assessed sensory organization and postural performance in children with strabismus were included in this review. Methodological quality of the articles was evaluated using the modified Downs and Black quality assessment tool. A total of 10 articles were included in this review. RESULTS: Eight of the 10 articles reviewed were included in the meta-analysis. Meta-analysis for Centre of Pressure CoP velocity (n = 3) (eyes open, stable support), was statistically significant (P = 0.01) in favor of controls over children with strabismus (MD, 3.08; 95 % CI -0.66, 5.51). Meta-analysis for CoP surface area (n = 5) (eyes open, stable support) was also statistically significant (P < 0.001) in favor of the control group (MD, 130.14; 95 % CI 70.01, 190.260). Meta-analysis with standardized mean difference (n = 6) for eyes open vs closed, stable support was statistically significant (P = 0.02) in favor of eyes open (MD, -0.94; 95 % CI, -1.74, -0.15). Overall, there was a high level of heterogeneity throughout the studies. SIGNIFICANCE: This is the first systematic review of its kind to collate and synthesize evidence on the effect of strabismus on postural control in children. This review suggests that postural control performance in children with strabismus is inferior to that of age-matched control children. Further investigation is needed to understand the influence of the three sensory systems.

Coupled Air Quality and Boundary-Layer Meteorology in Western U.S. Basins during Winter: Design and Rationale for a Comprehensive Study.

Wintertime episodes of high aerosol concentrations occur frequently in urban and agricultural basins and valleys worldwide. These episodes often arise following development of persistent cold-air pools (PCAPs) that limit mixing and modify chemistry. While field campaigns targeting either basin meteorology or wintertime pollution chemistry have been conducted, coupling between interconnected chemical and meteorological processes remains an insufficiently studied research area. Gaps in understanding the coupled chemical-meteorological interactions that drive high pollution events make identification of the most effective air-basin specific emission control strategies challenging. To address this, a September 2019 workshop occurred with the goal of planning a future research campaign to investigate air quality in Western U.S. basins. Approximately 120 people participated, representing 50 institutions and 5 countries. Workshop participants outlined the rationale and design for a comprehensive wintertime study that would couple atmospheric chemistry and boundary-layer and complex-terrain meteorology within western U.S. basins. Participants concluded the study should focus on two regions with contrasting aerosol chemistry: three populated valleys within Utah (Salt Lake, Utah, and Cache Valleys) and the San Joaquin Valley in California. This paper describes the scientific rationale for a campaign that will acquire chemical and meteorological datasets using airborne platforms with extensive range, coupled to surface-based measurements focusing on sampling within the near-surface boundary layer, and transport and mixing processes within this layer, with high vertical resolution at a number of representative sites. No prior wintertime basin-focused campaign has provided the breadth of observations necessary to characterize the meteorological-chemical linkages outlined here, nor to validate complex processes within coupled atmosphere-chemistry models.

Dynamic Pupillometry in Type 2 Diabetes: Pupillary Autonomic Dysfunction and the Severity of Diabetic Retinopathy.

PURPOSE: Autonomic dysfunction may precede the microvascular changes that characterise diabetic retinopathy. The aim of this pilot study was to measure and compare pupillometry indices in type 2 diabetes (T2DM) patients - with and without diabetic retinopathy - and in healthy, age-matched controls. METHODS: Two hundred and eleven participants with T2DM aged 45-80 years were recruited from Dunedin Hospital Eye Department, Dunedin, New Zealand. They were categorised into three groups - no, mild/moderate, or severe diabetic retinopathy. Seventy age-matched, diabetes screen negative control participants were recruited from the Dunedin city community. Dynamic pupillometry was performed using an infrared pupillometer. The main outcome measures were maximum constriction velocity, average constriction velocity, absolute constriction amplitude, relative reflex amplitude, average dilation velocity and 75% re-dilation (recovery) time. Outcome measures were compared between study groups using the Kruskal-Wallis nonparametric test (with Dunn's multiple comparison post-test). RESULTS: Pupillary parasympathetic function differed between groups. Maximum constriction velocity (p <0.001) and average constriction velocity (p <0.001) were slower, and absolute constriction amplitude (p <0.001) and relative reflex amplitude (p <0.05) were lower in the three diabetes groups compared with controls. There were no significant differences in pupillary sympathetic function between the four groups for re-dilation time, but the diabetes groups had significantly slower average dilation velocity times. CONCLUSION: Pupillary light reflex is significantly impaired with diabetic retinal neuropathy, before clinically observable signs of diabetic retinopathy. Dynamic pupillometry may be a cheap, clinically relevant test, but sensitivity and specificity need to be determined before utilising as a screening tool for diabetic retinopathy.

Otago Glaucoma Surgery Outcome Study: Examining the Development of Strabismus Causing Diplopia in Patients Who Have Received Molteno Implant Surgery.

OBJECTIVE: To evaluate the development of postoperative strabismus causing diplopia in patients who received Molteno implant surgery for the treatment of glaucoma. METHODS: The Otago Glaucoma Surgery Outcome study (OGSOS) was used to select cases who had undergone Molteno implant surgery to examine the effect on the development of strabismus causing diplopia. Information was collected on treatments provided to correct motility disturbance, and their success, in this retrospective non-comparative study. RESULTS: 32 cases (3.3%) were found to have developed diplopia following the Molteno implant surgery from a total of 977 cases. Of these, the strabismus in 23 cases was described in sufficient detail to permit clinical categorization. Most (19/23) demonstrated an exodeviation, hyperdeviation, or a combination thereof, although 2/6 cases with superonasal plate location demonstrated a hypodeviation. Diplopia generally resolved spontaneously (20/32 cases). Treatment was required in eight cases, usually conservative and successful (6/8 cases), but strabismus surgery was required in two cases, and was unsuccessful. CONCLUSIONS: This study found a low incidence of diplopia developing post-Molteno implant surgery. Strabismus features suggested a restrictive etiology, and spontaneous recovery was common (62.5%). Surgical correction proved unsuccessful - confirming persistent postoperative diplopia after Molteno implant surgery to be a rare but surgically challenging complication.

Vision screening in New Zealand: an audit of the B4 School Check.

AIMS: To assess the accuracy of the B4 School Check (B4SC) vision screening programme in two distinct regions of New Zealand. METHODS: A retrospective audit of all children who were screened for vision in the Southern and Tairawhiti District Health Boards, between 1 April and 30 September 2016. Results from the B4SC screening programme (n=2,109) were compared to records for all children who were screened and subsequently presented to an optometrist at a DHB eye clinic (n=116). RESULTS: The B4SC produced a sensitivity in the range of 54.7% to 94.7% and a specificity of 93.8% to 95.7%. There was a low positive predictive value (PPV), between 29.5% and 51.1%, with a relatively high number of false positive referrals. The negative predictive value (NPV) was higher, however, between 97.8% and 99.7%, meaning nearly all children who passed screening had no visual impairment. CONCLUSIONS: The high NPV is reassuring that very few children with visual impairment are missed by screening. The low PPV was consistent with the international literature and is related to a tendency for over-referral from the B4CS programme. Further work could evaluate increasing the threshold for referral to reduce the number of false positive cases.

Peripheral sensory information and postural control in children with strabismus.

BACKGROUND: Sensory feedback from the visual system along with the vestibular and somatosensory systems is essential for the regulation of normal postural control. Children with strabismus and, therefore, with abnormal binocular vision, may have an altered perception of space and use different sets of cues to determine depth perception when compared with children without strabismus. OBJECTIVE: To explore the postural control of children with and without strabismus, when the three sensory systems are challenged. METHOD: Forty-six children (21 with strabismus and 25 age-matched controls) aged between 5 and 10 years completed ophthalmic screening and then underwent assessment for postural control, which included Paediatric Balance Scale (PBS) and six conditions of the Sensory Organization Test (SOT). Four primary outcome measures were: PBS summary score, Equilibrium Score (ES), Strategy Score (SS) and Sensory Analysis Score of the SOT. RESULTS: A significant difference (P < 0.05) was observed between the strabismus and non-strabismus group in the PBS and, ES and SS of SOT condition 1. The Sensory Analysis scores were significantly different (P = 0.03) between the groups for 'Somatosensory'. Simple linear regression analysis suggested that the strabismus condition was significantly (P ≤ 0.02) associated with the PBS and, the ES and SS of condition 1, with a variance of 14.6%, 16.1% and 12.8%, respectively. Subgroup analysis suggested that age was a significant (P ≤ 0.001) correlate for balance scores in non-strabismus group (R2 ranged from 32% to 58.4%), but not for the strabismus group. SIGNIFICANCE: Postural control in children with strabismus is not equivalent to that of children without strabismus, when their somatosensory system is challenged. Additionally, the functional balance performance of children with strabismus is lower than their counterparts without strabismus. Collectively, the results suggest that the usual improvement in balance performance with increasing age is observed in children without strabismus but not in children with strabismus.

Spiritual beliefs in bipolar affective disorder: their relevance for illness management.

BACKGROUND: There has been growing interest in investigating religion as a relevant element in illness outcome. Having religious beliefs has been shown repeatedly to be associated with lessened rates of depression. Most of the limited published research has been restricted to elderly samples. Religious coping is thought to play a key role in religion's effects. Strangely, psychiatric research has neglected this area. METHODS: A questionnaire covering religious, spiritual and philosophical beliefs and religious practice was given to a sample of patients with bipolar affective disorder in remission. RESULTS: Most patients often held strong religious or spiritual beliefs (78%) and practised their religion frequently (81.5%). Most saw a direct link between their beliefs and the management of their illness. Many used religious coping, and often religio-spiritual beliefs and practice put them in conflict with illness models (24%) and advice (19%) used by their medical advisors. LIMITATIONS: This was a cross-sectional design without a control group and thus it is not possible to determine causal associations from the data set. CONCLUSIONS: Religio-spiritual ideas are of great salience to many patients with bipolar disorder and shape the ways in which they think about their illness. Many reported experiencing significant paradigm conflict in understanding and managing their illness between medical and their spiritual advisors. These data suggest that the whole area of religion and spirituality is directly relevant to people living with a chronic psychiatric illness and should be firmly on the discussion agenda of clinicians working with patients with bipolar disorder.

Constraints on the late holocene anthropogenic contribution to the atmospheric methane budget.

The origin of the late preindustrial Holocene (LPIH) increase in atmospheric methane concentrations has been much debated. Hypotheses invoking changes in solely anthropogenic sources or solely natural sources have been proposed to explain the increase in concentrations. Here two high-resolution, high-precision ice core methane concentration records from Greenland and Antarctica are presented and are used to construct a high-resolution record of the methane inter-polar difference (IPD). The IPD record constrains the latitudinal distribution of emissions and shows that LPIH emissions increased primarily in the tropics, with secondary increases in the subtropical Northern Hemisphere. Anthropogenic and natural sources have different latitudinal characteristics, which are exploited to demonstrate that both anthropogenic and natural sources are needed to explain LPIH changes in methane concentration.