Nonlinear surface plasmons

We derive an asymptotic equation for quasi-static, nonlinear surface plasmons propagating on a planar interface between isotropic media. The plasmons are nondispersive with a constant linearized frequency that is independent of their wavenumber. The spatial profile of a weakly nonlinear plasmon satisfies a nonlocal, cubically nonlinear evolution equation that couples its left-moving and right-moving Fourier components. We prove short-time existence of smooth solutions of the asymptotic equation and describe its Hamiltonian structure. We also prove global existence of weak solutions of a unidirectional reduction of the asymptotic equation. Numerical solutions show that nonlinear effects can lead to the strong spatial focusing of plasmons. Solutions of the unidirectional equation appear to remain smooth when they focus, but it is unclear whether or not focusing can lead to singularity formation in solutions of the bidirectional equation

MEASURING THE SUCCESS OF COUNTRY FOOTBALL CLUBS

Until the last quarter of the twentieth century, non-metropolitan Australian Rules football clubs prospered as volunteer organisations, operating in regions that were protected by distance from clubs in larger, competing leagues. They acted as places that people valued and were important components of social capital in their communities, and in turn, received subsidies from other community groups that reduced operating costs. Clubs appear to have measured success in terms of their ability to attract the talent needed to build a winning team that would boost the prestige of both the club and its local community. The Victorian Football League’s regulations about player payment and mobility gave country football clubs the opportunity to offer attractive terms to League players, and this prevented the game’s most powerful league, from crowding out its rivals. The circumstances that were favourable to country football clubs have changed with the formation of a major league, the Australian Football League. The televising of matches nationwide allowed people in even remote regions to watch AFL games. Economic and demographic decline in country areas, greater mobility and the lure of metropolitan jobs has made it difficult for clubs to retain players. In this challenging economic environment, many country football clubs have been unable to survive in their own right. This paper reports on a survey of administrators of Victorian country football clubs as to their perceptions of what constitutes ‘success’ in this new environment. It provides information about how individual clubs are responding to broad changes that are beyond their control, and offers evidence about the ability of local football clubs to continue to play their traditional role as places of importance and generators of social capital in regional communities.

The Creation: Haydn\u27s Drama

This paper focuses on Haydn’s use of drama in regard to his oratorio The Creation. To understand Haydn’s use of drama, we considered three main aspects. The first aspect is the means by which Haydn came about The Creation text and the meaning it held for him. The second aspect is an analysis of the work, particularly looking at text painting, comedic elements, and orchestration. Finally, we will discuss the reception of Haydn’s work and the importance it held in relation to the aesthetics of the time. The Creation was a staple of Haydn’s work, and would prove to be a large influence on future composers, as well as writers and artists

Factors contributing toward student performance in a distance education accounting degree

PURPOSE – The purpose of this paper is to examine the effects of five determinates of performance in students (N 677) who completed three years of financial accounting to obtain a Bachelor of Accounting Science (BCompt) degree by distance education through the University of South Africa. DESIGH / METHODOLOGY / APPROACH – Regression analysis is used on three yearly measures of performance with five independent variables (age, gender, prior accounting knowledge, mathematics background and academic aptitude). FINDINGS – Results show that mathematics background and academic aptitude are both significantly associated with student performance, throughout the financial accounting subjects. Prior accounting knowledge is also important in the first year of study but not thereafter. RESEARCH LIMITATIONS / IMPLICATIONS – Prior research has found that other factors may influence student performance, and future studies which include these variables will add to these findings. PRACTICAL IMPLICATIONS – The results of this study have important implications for instructors, students and career advisers, particularly as research linking various factors with performance in accounting subjects over the length of a degree is limited. ORIGINALITY / VALUE – The current study considers the determinants of student performance over three financial accounting years (rather than one year or one subject) and from a distance education perspective. As distance education becomes a more important delivery method of study in the future, these results have important implications.http://www.emeraldinsight.com/loi/medarhb201

Mycotoxin exposure and human cancer risk : a systematic review of epidemiological studies

In recent years, there has been an increasing interest in investigating the carcinogenicity of mycotoxins in humans. This systematic review aims to provide an overview of data linking exposure to different mycotoxins with human cancer risk. Publications (2019 and earlier) of case–control or longitudinal cohort studies were identified in PubMed and EMBASE. These articles were then screened by independent reviewers and their quality was assessed according to the Newcastle–Ottawa scale. Animal, cross‐sectional, and molecular studies satisfied criteria for exclusion. In total, 14 articles were included: 13 case–control studies and 1 longitudinal cohort study. Included articles focused on associations of mycotoxin exposure with primary liver, breast, and cervical cancer. Overall, a positive association between the consumption of aflatoxin‐contaminated foods and primary liver cancer risk was verified. Two case–control studies in Africa investigated the relationship between zearalenone and its metabolites and breast cancer risk, though conflicting results were reported. Two case–control studies investigated the association between hepatocellular carcinoma and fumonisin B1 exposure, but no significant associations were observed. This systematic review incorporates several clear observations of dose‐dependent associations between aflatoxins and liver cancer risk, in keeping with IARC Monograph conclusions. Only few human epidemiological studies investigated the associations between mycotoxin exposures and cancer risk. To close this gap, more in‐depth research is needed to unravel evidence for other common mycotoxins, such as deoxynivalenol and ochratoxin A. The link between mycotoxin exposures and cancer risk has mainly been established in experimental studies, and needs to be confirmed in human epidemiological studies to support the evidence‐based public health strategies

Defining adenoma detection rate benchmarks in average-risk male veterans

Background and Aims Veterans have higher prevalence of colorectal neoplasia than non-veterans; however, it is not known whether specific Veterans Affairs (VA) adenoma detection rate (ADR) benchmarks are required. We compared ADRs of a group of endoscopists for colonoscopies performed at a VA to their ADRs at a non-VA academic medical center. Methods This was a retrospective review of screening colonoscopies performed by endoscopists who practice at the Indianapolis VA and Indiana University (IU). Patients were average-risk males aged 50 years or older. ADR, proximal adenoma detection rate, advanced adenoma detection rate, and adenomas per colonoscopy were compared between IU and the VA groups. Results Six endoscopists performed screening colonoscopies at both locations during the study period (470 at IU vs 608 at the VA). The overall ADR was not significantly different between IU and the VA (58% vs 61%; p =0.21). Advanced neoplasia detection rate (13% vs 17%; p=0.46), proximal adenoma detection rate (46% vs 47%; p=0.31), and adenoma per colonoscopy (1.59 vs 1.84; p=0.24) were not significantly different. There were no significant differences in cecal intubation rate (100% vs 99%; p=0.13) or withdrawal time (10.9 vs 11.1 min; p=0.28). In regression analysis, there was significant correlation between the attending-specific ADRs at IU and the VA (p=0.041, r-square=0.69). Conclusions In this study of average-risk males undergoing screening colonoscopies by the same group of endoscopists, the ADRs of VA and non-VA colonoscopies were not significantly different. This suggests that a VA-specific ADR target is not required for endoscopists with high ADR

An investigation of the efficiency of South Africa’s sector education and training authorities (SETA’s)

The performance of South African Sector Education and Training Authorities (SETA’s) has been increasingly questioned. On this premise, the paper investigated the efficiency of the SETAs with respect to their utilization of funds in order to promote a range of education and training outputs was investigated. More specifically, the study investigated the quantity and quality of five training and education outputs, set by the National Skills Development Strategy (NSDS), in relation to the funding received. Furthermore, the study examined the amount of money spend on administrative expenditure by the various SETAs, as well as the SETAs management of financial reserves. In order to guide the study, as well as analyze the data, a conceptual framework to measure efficiency was based on an input-output model developed by Gupta and Verhoeven (2001). Data were obtained from the published accounting and annual reports for the period 2006 – 2009. The results indicated only two of the SETA’s were efficient with respect to their utilization of funds and that only five SETA’s consistently met their own targets. The study also shows that if the SETA’ s funds had been applied to education and training outputs, rather than for investment purposes, training outputs could have been considerably increased. The paper has implications for the use of public funds with respect to the critical skills shortage confronting the economy

Salamahavainnot 2016 - Lightning observations in Finland, 2016

Ilmatieteen laitos on koonnut ja julkaissut salamanlaskijoiden havainnot vuosilta 1960–1997. Vuodesta 1998 lähtien kaikki järjestelmälliset maasalamahavainnot perustuvat salamanpaikantimeen, jonka nykyinen malli aloitti toimintansa elokuussa 1997. Se käsitti 2016 kahdeksan anturia, pohjoisin Lokassa. Vuodesta 2002 mukana ovat olleet lisäksi Norjan ja Ruotsin anturit, joiden ansiosta koko Lappi on katettu ja suorituskyky on parantunut myös muualla Suomessa, sekä yksi anturi Virossa (mukaan vuonna 2005) ja kolme anturia Liettuassa (mukaan 2014). Laitteisto paikantaa maasalamoista erikseen jokaisen osaiskun ja ryhmittelee ne kokonaisiksi salamoiksi. Paikannettu salama voi sisältää 1-15 iskua; keskiarvo Suomessa on vajaa kaksi iskua/salama. Tilastoinnin pohjana käytetään salama- eikä iskumääriä, koska salama on ilmastollisesti edustavampi suure. Kesän 2016 aikana paikannettiin Suomen noin 115 000 maasalamaa, joka on hieman alle keskimääräisen (138 000). Suurin osa salamoista esiintyi heinäkuussa (80 000), ja touko-, kesä- ja elokuussa määrät olivat noin puolet keskimääräisestä

CheXpert: A Large Chest Radiograph Dataset with Uncertainty Labels and Expert Comparison

Large, labeled datasets have driven deep learning methods to achieve expert-level performance on a variety of medical imaging tasks. We present CheXpert, a large dataset that contains 224,316 chest radiographs of 65,240 patients. We design a labeler to automatically detect the presence of 14 observations in radiology reports, capturing uncertainties inherent in radiograph interpretation. We investigate different approaches to using the uncertainty labels for training convolutional neural networks that output the probability of these observations given the available frontal and lateral radiographs. On a validation set of 200 chest radiographic studies which were manually annotated by 3 board-certified radiologists, we find that different uncertainty approaches are useful for different pathologies. We then evaluate our best model on a test set composed of 500 chest radiographic studies annotated by a consensus of 5 board-certified radiologists, and compare the performance of our model to that of 3 additional radiologists in the detection of 5 selected pathologies. On Cardiomegaly, Edema, and Pleural Effusion, the model ROC and PR curves lie above all 3 radiologist operating points. We release the dataset to the public as a standard benchmark to evaluate performance of chest radiograph interpretation models. The dataset is freely available at https://stanfordmlgroup.github.io/competitions/chexpert .Comment: Published in AAAI 201

Labor induction with oxytocin in pregnant rats is not associated with oxidative stress in the fetal brain

Despite the widespread use of oxytocin for induction of labor, mechanistic insights into fetal/neonatal wellbeing are lacking because of the absence of an animal model that recapitulates modern obstetric practice. Here, we create and validate a hi-fidelity pregnant rat model that mirrors labor induction with oxytocin in laboring women. The model consists of an implantable preprogrammed microprocessor-controlled infusion pump that delivers a gradually escalating dose of intravenous oxytocin to induce birth at term gestation. We validated the model with molecular biological experiments on the uterine myometrium and telemetry-supported assessment of changes in intrauterine pressure. Finally, we applied this model to test the hypothesis that labor induction with oxytocin would be associated with oxidative stress in the newborn brain. Analysis of biomarkers of oxidative stress and changes in the expression of associated genes were no different between oxytocin-exposed and saline-treated pups, suggesting that oxytocin-induced labor was not associated with oxidative stress in the developing brain. Collectively, we provide a viable and realistic animal model for labor induction and augmentation with oxytocin that would enable new lines of investigation related to the impact of perinatal oxytocin exposure on the mother-infant dyad