Economic Impacts of Aquatic Vegetation to Angling in Two South Carolina Reservoirs

Angler creel surveys and economic impact models were used to evaluate potential expansion of aquatic vegetation in Lakes Murray and Moultrie, South Carolina. (PDF contains 4 pages.

A carbonate-banded iron formation transition in the Early Protorezoicum of South Africa

Seven new and two resurveyed stratigraphic sections through the important carbonate-BIF transition in Griqualand West are presented and compared with six published sections. Lateral correlation within this zone is attempted but the variability was found to be too great for meaningful subdivision. Substantial lithological irregularity is the only unifying character of this zone, for which the new name Finsch Member (Formation) is proposed. Vertical and lateral lithological variations as well as chemical changes across this zone are discussed with reference to environmental aspects. Local and regional considerations lead to the conclusion that fresh water-sea water mixing occurred in a shallowing basin

The Midpoint Rule as a Variational--Symplectic Integrator. I. Hamiltonian Systems

Numerical algorithms based on variational and symplectic integrators exhibit special features that make them promising candidates for application to general relativity and other constrained Hamiltonian systems. This paper lays part of the foundation for such applications. The midpoint rule for Hamilton's equations is examined from the perspectives of variational and symplectic integrators. It is shown that the midpoint rule preserves the symplectic form, conserves Noether charges, and exhibits excellent long--term energy behavior. The energy behavior is explained by the result, shown here, that the midpoint rule exactly conserves a phase space function that is close to the Hamiltonian. The presentation includes several examples.Comment: 11 pages, 8 figures, REVTe

Positive-P and Wigner representations for quantum-optical systems with nonorthogonal modes

We generalize the basic concepts of the positive-P and Wigner representations to unstable quantum-optical systems that are based on nonorthogonal quasimodes. This lays the foundation for a quantum description of such systems, such as, for example an unstable cavity laser. We compare both representations by calculating the tunneling times for an unstable resonator optical parametric oscillator

Characterisation of Phomopsis spp. associated with die-back of rooibos (Aspalathus linearis) in South Africa

Die-back of rooibos (Aspalathus linearis) causes substantial losses in commercial Aspalathus plantations in South Africa. In the past, the disease has been attributed to Phomopsis phaseoli (teleomorph: Diaporthe phaseolorum). Isolates obtained from diseased plants, however, were highly variable with regard to morphology and pathogenicity. The aim of the present study was thus to identify the Phomopsis species associated with die-back of rooibos. Isolates were subjected to DNA sequence comparisons of the internal transcribed spacer region (ITS1, 5.8S, ITS2) and partial sequences of the translation elongation factor-1 alpha gene. Furthermore, isolates were also compared in glasshouse inoculation trials on 8-mo-old potted plants to evaluate their pathogenicity. Five species were identified, of which D. aspalathi (formerly identified as D. phaseolorum or D. phaseolorum var. meridionalis) proved to be the most virulent, followed by D. ambigua, Phomopsis theicola, one species of Libertella and Phomopsis, respectively, and a newly described species, P. cuppatea. A description is also provided for D. ambigua based on a newly designated epitype specimen

Considerações Sôbre dois Casos de Epiglotectomia

Os A.A. estudam 2 casos de epiglotectomia do Instituto Nacional de Câncer, tendo antes feito um estudo da anatomia e da função da laringe. Enquanto no 1° caso, não tivesse sido possível, verificar das modificações tanto respiratórias como da deglutição por ter ocorrido o êxito letal, quase imediatamente após o ato cirúrgico, o mesmo não se verificou com o caso n.° 2, que teve sobrevida de 3 anos e 9 meses permitindo estudo da fisiologia da epiglote. Em ambos os casos, não foi praticada após a epiglotectomia, a traqueotomia complementar, tendo-se usado no caso 1 a anestesia local e no caso 2 a anestesia geral por entubação

Restricted spirometry and cardiometabolic comorbidities: Results from the international population based BOLD study

Background: Whether restricted spirometry, i.e. low Forced Vital Capacity (FVC), predicts chronic cardiometabolic disease is not definitely known. In this international population-based study, we assessed the relationship between restricted spirometry and cardiometabolic comorbidities. Methods: A total of 23,623 subjects (47.5% males, 19.0% current smokers, age: 55.1 ± 10.8 years) from five continents (33 sites in 29 countries) participating in the Burden of Obstructive Lung Disease (BOLD) study were included. Restricted spirometry was defined as post-bronchodilator FVC < 5th percentile of reference values. Self-reports of physician-diagnosed cardiovascular disease (CVD; heart disease or stroke), hypertension, and diabetes were obtained through questionnaires. Results: Overall 31.7% of participants had restricted spirometry. However, prevalence of restricted spirometry varied approximately ten-fold, and was lowest (8.5%) in Vancouver (Canada) and highest in Sri Lanka (81.3%). Crude odds ratios for the association with restricted spirometry were 1.60 (95% CI 1.37–1.86) for CVD, 1.53 (95% CI 1.40–1.66) for hypertension, and 1.98 (95% CI 1.71–2.29) for diabetes. After adjustment for age, sex, education, Body Mass Index (BMI) and smoking, the odds ratios were 1.54 (95% CI 1.33–1.79) for CVD, 1.50 (95% CI 1.39–1.63) for hypertension, and 1.86 (95% CI 1.59–2.17) for diabetes. Conclusion: In this population-based, international, multi-site study, restricted spirometry associates with cardiometabolic diseases. The magnitude of these associations appears unattenuated when cardiometabolic risk factors are taken into account

The Trade-Off between Phosphorus Recycling and Health Protection during the BSE Crisis in Switzerland. A “Disposal Dilemma”

Phosphorus (P) is an essential, finite resource whose geological, economic, and geopolitical accessibility may become critical in the future. Because P losses from agriculture, sewage and waste have serious environmental impacts such as eutrophication, it would be desirable to close P cycles. However, there may arise dilemmas due to trade-offs with other issues. For instance, recycling of animal bones – containing relatively high amounts of P – was prohibited in Switzerland after the BSE crisis (1989 to 2000) due to perceived health risks. Our analysis indicates that the great- est potentials for closing the P cycle in Switzerland are to reduce P losses in agriculture and to increase P recovery from sewage and waste. Whereas in agriculture significant improvements have been made, the disposal dilemma of animal bones led to diminishing amounts of P being recycled from waste. Based on their risk perception, the involved stakeholders prioritized preventing potential harm to (human) health over maximizing P recycling

An electronic survey of preferred podcast format and content requirements among trainee emergency medicine specialists in four Southern African universities

CITATION: Ekambaram, K., et al. 2021. An electronic survey of preferred podcast format and content requirements among trainee emergency medicine specialists in four Southern African universities. African Journal of Emergency Medicine, 11(1): 3-9, doi:10.1016/j.afjem.2020.10.014.The original publication is available at https://www.sciencedirect.com/journal/african-journal-of-emergency-medicinestudy aims to explore the desired content, format and delivery characteristics of a potential educational, context- specific Southern African EM podcast, by investigating current podcast usages, trends and preferences among Southern African EM registrars of varying seniority. Methods: We developed an electronic survey - using a combination of existing literature, context-specific specialist-training guidance, and input from local experts – exploring preferred podcast characteristics among EM registrars from four Southern African universities. Results: The study’s response rate was 75%, with 24 of the 39 respondents being junior registrars. Ninety-four percent (94%) of respondents used EM podcasts as an educational medium: 64% predominantly using pod- casts to supplement a personal EM study program. The primary mode of accessing podcasts was via personal mobile devices (84%). Additionally, respondents preferred a shorter podcast duration (5–15 min), favoured multimedia podcasts (56%) and showed an apparent aversion toward recorded faculty lectures (5%). Eighty-two percent (82%) of respondents preferred context-specific podcast content, with popular topics including toxi- cology (95%), cardiovascular emergencies (79%) and medico-legal matters (74%). Just-in-Time learning proved an unpopular learning strategy in our study population, despite its substantial educational value. Conclusion: Podcast-usage proved to be near-ubiquitous among the studied Southern African EM registrars. Quintessentially, future context-specific podcast design should cater for mobile device-use, shorter duration podcasts, more video content, context-specific topics, and content optimised for both Just-in-Time learning.https://www.sciencedirect.com/science/article/pii/S2211419X20301312Publisher’s versio

Efficient unidirectional nanoslit couplers for surface plasmons

Plasmonics is based on surface plasmon polariton (SPP) modes which can be laterally confined below the diffraction limit, thereby enabling ultracompact optical components. In order to exploit this potential, the fundamental bottleneck of poor light-SPP coupling must be overcome. In established SPP sources (using prism, grating} or nanodefect coupling) incident light is a source of noise for the SPP, unless the illumination occurs away from the region of interest, increasing the system size and weakening the SPP intensity. Back-side illumination of subwavelength apertures in optically thick metal films eliminates this problem but does not ensure a unique propagation direction for the SPP. We propose a novel back-side slit-illumination method based on drilling a periodic array of indentations at one side of the slit. We demonstrate that the SPP running in the array direction can be suppressed, and the one propagating in the opposite direction enhanced, providing localized unidirectional SPP launching.Comment: 13 pages, 4 figure