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Illuminating the Economic Costs of Conflict: A Night Light Analysis of the Sri Lankan Civil War
No full textThis paper investigates the economic consequences of the Sri Lankan Civil War (1983-2009) by using event-based data on civilian and combatant fatalities in addition to night light imagery as a proxy for economic activity. By looking at regional economic activity across the island of Sri Lanka, this paper seeks to identify how violence led to declines or undershoots of economic activity in the areas in which it was most prevalent. The use of night light data gives a hyper-localized proxy measurement of this activity for each year of the war. The investigation finds that government and rebel deaths have strong, negative effects on economic activity, and that these effects spill over across time and space. Additionally, the manner in which civilian deaths occur is an important determinant of their subsequent economic impact. The paper offers new findings on the economic legacy of the Sri Lankan Civil War and extends existing work on the use of night light data to measure economic activity during conflict
Spatial fluctuations of fluid velocities in flow through a three-dimensional porous medium.
No full textWe use confocal microscopy to directly visualize the spatial fluctuations in fluid flow through a three-dimensional porous medium. We find that the velocity magnitudes and the velocity components both along and transverse to the imposed flow direction are exponentially distributed, even with residual trapping of a second immiscible fluid. Moreover, we find pore-scale correlations in the flow that are determined by the geometry of the medium. Our results suggest that despite the considerable complexity of the pore space, fluid flow through it is not completely random
Four reasons for scepticism about a human major transition in social individuality.
No full textThe 'major transitions in evolution' are mainly about the rise of hierarchy, new individuals arising at ever higher levels of nestedness, in particular the eukaryotic cell arising from prokaryotes, multicellular individuals from solitary protists and individuated societies from multicellular individuals. Some lists include human societies as a major transition, but based on a comparison with the non-human transitions, there are reasons for scepticism. (i) The foundation of the major transitions is hierarchy, but the cross-cutting interactions in human societies undermine hierarchical structure. (ii) Natural selection operates in three modes-stability, growth and reproductive success-and only the third produces the complex adaptations seen in fully individuated higher levels. But human societies probably evolve mainly in the stability and growth modes. (iii) Highly individuated entities are marked by division of labour and commitment to morphological differentiation, but in humans differentiation is mostly behavioural and mostly reversible. (iv) As higher-level individuals arise, selection drains complexity, drains parts, from lower-level individuals. But there is little evidence of a drain in humans. In sum, a comparison with the other transitions gives reasons to doubt that human social individuation has proceeded very far, or if it has, to doubt that it is a transition of the same sort. This article is part of the theme issue 'Human socio-cultural evolution in light of evolutionary transitions'
Impact of COVID-19 Pandemic on Patients' Perceptions of Safety and Need for Elective Foot and Ankle Surgery in the United States.
No full textBackgroundWith the development of the COVID-19 pandemic, elective foot and ankle surgeries were delayed throughout the United States to divert health care resources and limit exposure. Little is known about the impact of COVID-19 on patient's willingness to proceed with elective procedures once restrictions are lifted and factors contributing to such decision.MethodsPatients across 6 US orthopedic institutions who had their elective foot and ankle surgeries cancelled secondary to the pandemic were given a questionnaire. Specifically, patients were asked about their willingness to move forward with surgery once restrictions were lifted and if not why. Pain-level and pain medication use were also assessed. Univariate analysis was used to identify factors that contribute to patient's decisions.ResultsA total of 150 patients participated in this study. Twenty-one (14%) opted not to proceed with surgery once restrictions were lifted. Forty-three percent (n = 9) listed concern for COVID infection as the reason; however, 14% of them would proceed if procedures were performed in surgery center. Twenty-nine (19% of the total cohort) patients had increased pain and 11% of patients were taking more pain meds because of the delay to their procedure. Patients who decided not to proceed with surgery reported pain reduction (3% vs 14%) and lower increase in pain medication used (5% vs 12%).ConclusionCOVID-19 has made a significant impact on the health care system. Delay of elective foot and ankle procedures impact patient quality of life and outcomes. Access to surgery centers may provide a partial solution during the pandemic.Level of evidenceLevel III
Patient and procedural risk factors for decline in lower-extremity motor scores following adult spinal deformity surgery.
No full textObjectiveThe purpose of this study was to discern factors that differentiate patients who experience postoperative lower-extremity motor function decline in the early postoperative period.MethodsAdult spinal deformity (ASD) patients who were enrolled in a multicenter, observational, and prospectively collected study from 2018 to 2021 at 18 spinal deformity centers in North America were queried. Eligible participants met at least one of the following radiographic and/or procedural inclusion criteria: pelvic incidence minus lumbar lordosis (PI-LL) ≥ 25°, T1 pelvic angle (T1PA) ≥ 30°, sagittal vertical axis (SVA) ≥ 15 cm, thoracic scoliosis ≥ 70°, thoracolumbar scoliosis ≥ 50°, global coronal malalignment ≥ 7 cm, 3-column osteotomy, spinal fusion ≥ 12 levels, and/or age ≥ 65 years with ≥ 7 levels of instrumentation. Patients with an inflammatory or autoimmune disease and those who were incarcerated or pregnant were excluded, as were non-English speakers. Only patients with baseline and 6-week postoperative lower-extremity motor score (LEMS) were analyzed. Patient information, including demographic data, operative data, patient-reported outcomes, and radiographic parameters, were collected. Univariate and multivariable logistic regression models were built to quantify the degree to which a patient's postoperative LEMS decline was related to demographic and clinical characteristics.ResultsIn total, 205 patients (mean age 61.5 years, mean total instrumented levels 12.6, 67.3% female, 54.2% primary cases, 79.5% with pelvic fixation) were evaluated. Of these 205 patients, 32 (15.5%) experienced LEMS decline in the perioperative period. These patients were older (p = 0.0014) and had greater BMI (p = 0.0176), higher frailty scores (p = 0.047), longer operating room times (p = 0.033), and greater estimated blood loss (p ConclusionsIn this study, 15.6% of ASD patients incurred LEMS decline in the perioperative period. The magnitude of change in global sagittal alignment, specifically T1PA, was the strongest independent predictor of LEMS decline, which has implications for surgical planning, patient counseling, and clinical research
Charcot-Marie-Tooth: From Molecules to Therapy
No full textCharcot-Marie-Tooth (CMT) is the most prevalent category of inherited neuropathy. The most common inheritance pattern is autosomal dominant, though there also are X-linked and autosomal recessive subtypes. In addition to a variety of inheritance patterns, there are a myriad of genes associated with CMT, reflecting the heterogeneity of this disorder. Next generation sequencing (NGS) has expanded and simplified the diagnostic yield of genes/molecules underlying and/or associated with CMT, which is of paramount importance in providing a substrate for current and future targeted disease-modifying treatment options. Considerable research attention for disease-modifying therapy has been geared towards the most commonly encountered genetic mutations (PMP22, GJB1, MPZ, and MFN2). In this review, we highlight the clinical background, molecular understanding, and therapeutic investigations of these CMT subtypes, while also discussing therapeutic research pertinent to the remaining less common CMT subtypes.</jats:p
Management of Patients With Cystic Fibrosis and Allergic Bronchopulmonary Aspergillosis Using Anti-Immunoglobulin E Therapy (Omalizumab)
No full textOmalizumab is a recombinant DNA-derived humanized immunoglobulin G (IgG) anti-IgE monoclonal antibody approved for use in patients with allergic asthma. However, it is not approved for allergic bronchopulmonary aspergillosis (ABPA). Conflicting reports exist about the effects of omalizumab on ABPA in patients with cystic fibrosis (CF). We report 2 patients with CF treated with omalizumab, in whom frequency of ABPA exacerbations was markedly reduced with treatment. Additionally, hospitalizations were reduced from 5 per year to once in 18 months in the first patient and from twice to once per year in the second patient. Free IgE decreased by 87.9% after 6 months of therapy in the first patient and by 95.6% after 7 months of therapy in the second patient. Neither of the two patients had evidence of asthma. Omalizumab may be useful in treating ABPA in patients with CF, and including free IgE in monitoring the response to therapy will be helpful.</jats:p
Investigations into the Adhesion and Detachment of Dust Particles to Characterize the Reversibility of Photovoltaic Panel Soiling
No full textAs the use of renewable energy is spreading, the degrading effects of pollutant accumulation on the surface of photovoltaic (PV) panels become more apparent, especially in arid climates. Dust deposition reduces light transmittance to the panel and decreases the energy output. Cleaning of PV modules can cost millions of dollars per year; therefore, it is important to study the reversibility of the soiling process. Mitigation strategies would not only increase energy production and revenues, but also the attractiveness of more PV installations due to lengthened optimal performance. Hence, soiling losses are widely monitored to understand the complex process driven by several factors, such as system design, soiling material, or environmental conditions. This work aims to fill the gap in knowledge on how the reversibility of solar panel fouling varies with the composition of dust in the atmosphere and panel surface features. The primary objectives of this study were to (1) characterize the attachment efficiency of dust particles at different locations; (2) determine whether particle composition influences particle-surface interactions through direct adhesion force measurements; (3) relate particle adhesion to particle detachment through centrifugation; (4) evaluate the feasibility of the centrifugal detachment technique to analyze PV panel coating performance and durability. The experimental methods were first tested using model pollutants that represented the major classes of soiling material, followed by dust samples obtained from the field. In addition to the laboratory studies, the impact of prolonged outdoor exposure was also tested to consider the complex mechanisms relevant to PV panel soiling.
The comparison of predicted soiling loss based on a dust deposition model with collected soiled mass revealed that the attachment efficiency of dust varies seasonally and spatially, which could be influenced by changes in dust composition. This was confirmed by adhesion and detachment studies, as organic and carbon-based materials exhibited a significantly larger adhesion force to the glass surface than the rest of the samples. The centrifugal detachment technique could successfully measure the soiling rate on coated solar panels both with model pollutants and outdoor exposure. Coatings significantly differed in their ability to decrease particle accumulation on the surface, but all treatments lost at least 30% of their original hydrophobicity at the end of the 34-week exposure period. The results suggest that local dust composition influences solar panel soiling and should be considered for predictive models and maintenance needs. In addition, detachment studies could be used to establish a metric to quantitatively describe the efficiency of various PV panel surface treatments.
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Illposedness of C<sup>2</sup> Vortex Patches
No full textIt is well known that vortex patches are wellposed in C1,α if 0 0 , though it regains C2 regularity precisely at all integer times without being time periodic. The key ingredient is the evolution equation for the curvature, the dominant term in which turns out to be linear and dispersive