Purpose of Review
This review summarizes studies highlighting perfluoroalkyl substances (PFAS) and their effects on the placenta, pregnancy outcomes, and child health. It highlights human ...population-based associations as well as in vitro-based experimental data to inform an understanding of the molecular mechanisms underlying these health effects. Among the mechanisms by which PFAS may induce toxicity is via their interaction with the peroxisome proliferator-activated receptors (PPARs), nuclear receptors that regulate lipid metabolism and placental functions important to healthy pregnancies, as well as fetal and child development.
Recent Findings
In utero exposure to prevalent environmental contaminants such as PFAS is associated with negative health outcomes during pregnancy, birth outcomes, and later in life. Specifically, PFAS have been associated with increased incidence of gestational diabetes, childhood obesity, preeclampsia, and fetal growth restriction. In terms of placental molecular mechanisms underlying these associations, studies demonstrate that PFAS interfere with trophoblast lipid homeostasis, inflammation, and invasion. Moreover these effects could be mediated in part by the interaction between PFAS and PPARs, as well as other biological mechanisms.
Summary
This review summarizes how PFAS, critical environmental contaminants, may contribute to diseases of pregnancy as well as early and later child health.
The author discusses Montelius's, Aspelin's and Kossinna's ethnohistoric research and the development up to 1951.The starting point is a letter written by Kossinna in 1896 to Montelius in Stockholm. ...Kossinna's Siedlungsgeschichte and his tribal principle that cultural areas or cultural groups embodied a "Valk", are based on Montelius's paper from 1884/88 on the immigration ofthe ancestors of the Scandinavian peoples. Stringent European critics pointed out that Kossinna's method lacks any viable basis in theory. In spite of this the Scandinavian archaeologists continued the ethnohistoric tradition. In Finland there was marked criticism during the 1930s
Purpose of Review
Epidemiologic studies have observed elevated health risks in populations living near unconventional oil and gas development (UOGD). In this narrative review, we discuss strengths ...and limitations of UOG exposure assessment approaches used in or available for epidemiologic studies, emphasizing studies of children’s health outcomes.
Recent Findings
Exposure assessment challenges include (1) numerous potential stressors with distinct spatiotemporal patterns, (2) critical exposure windows that cover long periods and occur in the past, and (3) limited existing monitoring data coupled with the resource-intensiveness of collecting new exposure measurements to capture spatiotemporal variation. All epidemiologic studies used proximity-based models for exposure assessment as opposed to surveys, biomonitoring, or environmental measurements. Nearly all studies used aggregate (rather than pathway-specific) models, which are useful surrogates for the complex mix of potential hazards.
Summary
Simple and less-specific exposure assessment approaches have benefits in terms of scalability, interpretability, and relevance to specific policy initiatives such as set-back distances. More detailed and specific models and metrics, including dispersion methods and stressor-specific models, could reduce exposure misclassification, illuminate underlying exposure pathways, and inform emission control and exposure mitigation strategies. While less practical in a large population, collection of multi-media environmental and biological exposure measurements would be feasible in cohort subsets. Such assessments are well-suited to provide insights into the presence and magnitude of exposures to UOG-related stressors in relation to spatial surrogates and to better elucidate the plausibility of observed effects in both children and adults.
We examine the link between ethnic diversity and food insecurity. Using data from the Ghana Living Standards Survey, we measure food insecurity using the Food Insecurity Experience Scale and measure ...ethnic diversity at the district level using information from the Ghana Population and Housing Census. After addressing endogeneity, we find that an increase in ethnic diversity is associated with an increase in food insecurity. This result is robust to different approaches to addressing endogeneity, different measures of ethnic diversity and alternative ways of conceptualising food insecurity. Our findings further show that trust, threat of criminal violence and threat of war/conflict are important channels through which ethnic diversity influences food insecurity.
Der vorliegende Aufsatz behandelt das Thema “Demokratie” angesichts der Ideen von “Herrschaft” und “Volk”. Ausgehend von der Bestimmung der Prämisse “Aktivvolk” wird versucht, die Rolle von diesem in ...einem demokratischen Rechtsstaat zu enthüllen. Das Problem der sozialen Exklusion betrifft essentiell dieses Konzept und seine praktische Anwendung in den modernen Staaten, wobei die weniger entwickelten und Schwellenländer am stärksten benachteiligt sind. Die Globalisierung wird als entscheidender Faktor für die Verschärfung dieser sozialen Ausgrenzung analysiert. Schließlich werden politische, rechtliche und soziale Maßnahmen vorgeschlagen, um die Globalisierung des oligopolistischen Kapitals zu bekämpfen und dagegen die Globalisierung der Demokratie zu entwickeln.
Resumo: O estudo realiza levantamento dos primeiros fotógrafos que atuaram em Curitiba/PR, na segunda metade do século XIX, destacando suas condições de trabalho e as modificações operadas nos ...procedimentos e recursos por eles empregados. Observa-se que, naquele contexto, Curitiba se caracterizava como uma pequena vila com um ritmo de vida campesino, na qual predominaram os fotógrafos itinerantes. Somente transcorridas algumas décadas, a cidade pode contar com a presença dos primeiros estúdios que ali se instalaram de forma mais perene. É o caso daquele que foi mantido por Adolpho Volk a partir de 1881, quando, mais que simplesmente fazer retratos, tornou-se necessário que sua produção funcionasse como uma estratégia de distinção social.
Abstract: The study surveys the first photographers who worked in Curitiba/PR, in the second half of 19th century, highlighting their working conditions and the modifications occurred in the procedures and resources available. In that context, Curitiba was just a small village with a peasant lifestyle where itinerant photographers predominated. Only after a few decades would the city have the presence of the first studios that stayed there for longer. This is the case of Adolpho Volk's studio, inaugurated in 1881, when the production of portraits became, not only necessary, but a way of showing social distinction.
Purpose
To explore the factors affecting the linear magnification of the intermediate fundus image during indirect ophthalmoscopy with a slit‐lamp biomicroscope.
Methods
A simple paraxial model, ...based on a ‘reduced’ eye and a ‘thin’ ophthalmoscopy lens, is used to develop equations showing the effects of the power and ametropia of the eye, and the equivalent power and position of the ophthalmoscopy lens on fundus magnification. Predicted magnifications are compared with practical results found in earlier published experimental studies, which used Volk ophthalmoscopy lenses in conjunction with physical model eyes with adjustable levels of axial ametropia.
Results
The model's magnification predictions, as a function of the eye's ametropia, are in good agreement with previous experimental measurements, provided that the equivalent powers of the Volk lenses are used rather than their labelled nominal powers. Magnification values typically change by approximately ±10% over the practical range of each parameter if other parameters are held constant. In particular, normal variations in the equivalent power of the adult emmetropic eye result in magnifications which range from about 90–120% of the nominal value given for an eye power of +60.00 D. It is demonstrated that the recommended working distances for different powers of Volk ophthalmoscopy lenses approximate optimal matching between the various pupils of the eye‐Volk lens‐slit‐lamp biomicroscope system.
Conclusions
All the parameters considered have marked effects on magnification. The magnification values quoted by manufacturers can be regarded as only approximations of those which may be found in practice. Better estimates of magnification can be obtained by inserting the appropriate parameter values into the equations derived in this paper, using, where appropriate, the equivalent power of the indirect ophthalmoscopy lens, rather than the lens' labelled, ‘nominal’ power.
Disease and discrimination are processes linked to class in the early American colonies. Many early colonists fell victim to mass sickness as Old and New World systems collided and new social, ...political, economic, and ecological dynamics allowed disease to spread.
Dale Hutchinson argues that most colonists, slaves, servants, and nearby Native Americans suffered significant health risks due to their lower economic and social status. With examples ranging from indentured servitude in the Chesapeake to the housing and sewage systems of New York to the effects of conflict between European powers, Hutchinson posits that poverty and living conditions, more so than microbes, were often at the root of epidemics.
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