Streptococcal superantigens and the return of scarlet fever

Streptococcus pyogenes (group A Streptococcus) is a globally disseminated and human-adapted bacterial pathogen that causes a wide range of infections, including scarlet fever. Scarlet fever is a toxin-mediated disease characterized by the formation of an erythematous, sandpaper-like rash that typically occurs in children aged 5 to 15. This infectious disease is caused by toxins called superantigens, a family of highly potent immunomodulators. Although scarlet fever had largely declined in both prevalence and severity since the late 19th century, outbreaks have now reemerged in multiple geographical regions over the past decade. Here, we review recent findings that address the role of superantigens in promoting a fitness advantage for S. pyogenes within human populations and discuss how superantigens may be suitable targets for vaccination strategies.

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History and Morality

10.1093/oso/9780198858713.001.0001 ◽

2020 ◽

Author(s):

Donald Bloxham

Keyword(s):

Foreign Country ◽

Moral Thought ◽

Majority Opinion ◽

The Past ◽

Wide Range ◽

Moral Judgements ◽

Value Judgements ◽

The Impact

Against majority opinion within his profession, Donald Bloxham argues that it is legitimate, often unavoidable, and frequently important for historians to make value judgements about the past. History and Morality draws on a wide range of historical examples, and its author’s insights as a practising historian. Examining concepts like impartiality, neutrality, contextualization, and the use and abuse of the idea of the past as a foreign country, Bloxham’s book investigates how the discipline has got to the point where what is preached can be so inconsistent with what is practised. It illuminates how far tacit moral judgements infuse works of history, and how strange those histories would look if the judgements were removed. Bloxham argues that rather than trying to eradicate all judgemental elements from their work historians need to think more consistently about how, and with what justification, they make the judgements that they do. The importance of all this lies not just in the responsibilities that historians bear towards the past—responsibilities to take historical actors on those actors’ own terms and to portray the impact of those actors’ deeds—but also in the role of history as a source of identity, pride, and shame in the present. The account of moral thought in History and Morality has ramifications far beyond the activities of vocational historians.

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Different historical generation intervals in human populations inferred from Neanderthal fragment lengths and patterns of mutation accumulation

10.1101/2021.02.25.432907 ◽

2021 ◽

Author(s):

Moisès Coll Macià ◽

Laurits Skov ◽

Benjamin Marco Peter ◽

Mikkel Heide Schierup

Keyword(s):

Fragment Length ◽

Human Populations ◽

Female Age ◽

Generation Interval ◽

The Past ◽

Geographical Regions ◽

Neanderthal Admixture ◽

Rate Of Decay ◽

Out Of Africa ◽

Insight Into

AbstractAfter the main out-of-Africa event, humans interbred with Neanderthals leaving 1-2% of Neanderthal DNA scattered in small fragments in all non-African genomes today1,2. Here we investigate the size distribution of these fragments in non-African genomes3. We find consistent differences in fragment length distributions across Eurasia with 11% longer fragments in East Asians than in West Eurasians. By comparing extant populations and ancient samples, we show that these differences are due to a different rate of decay in length by recombination since the Neanderthal admixture. In line with this, we observe a strong correlation between the average fragment length and the accumulation of derived mutations, similar to what is expected by changing the ages at reproduction as estimated from trio studies4. Altogether, our results suggest consistent differences in the generation interval across Eurasia, by up to 20% (e.g. 25 versus 30 years), over the past 40,000 years. We use sex-specific accumulations of derived alleles to infer how these changes in generation intervals between geographical regions could have been mainly driven by shifts in either male or female age of reproduction, or both. We also find that previously reported variation in the mutational spectrum5 may be largely explained by changes to the generation interval and not by changes to the underlying mutational mechanism. We conclude that Neanderthal fragment lengths provide unique insight into differences of a key demographic parameter among human populations over the recent history.

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1. Savanna landscapes

Savannas: A Very Short Introduction ◽

10.1093/actrade/9780198717225.003.0001 ◽

2016 ◽

pp. 1-15

Author(s):

Peter A. Furley

Keyword(s):

Seasonal Variation ◽

Human Populations ◽

Dry Spells ◽

Wide Range ◽

Local Topography ◽

The Tropics ◽

Nearly Continuous ◽

Trees And Shrubs

What are savannas and where are they? ‘Savanna landscapes’ considers these dynamic and diverse biomes—the most widespread form of vegetation in the tropics and sub-tropics. They are areas covered by a nearly continuous grassy layer, interspersed with trees and shrubs of varying densities and heights, but their nature and distribution is affected by the local topography and is closely allied with continental evolution. Marked seasonal variation is characterized by unpredictably long wet or dry spells and there is a wide range of flora and fauna across the major continental savannas. There are numerous theories on the role of savannas in shaping the emergence and spread of human populations.

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Mitochondrial Dysfunction in Obesity and Reproduction

Endocrinology ◽

10.1210/endocr/bqaa158 ◽

2020 ◽

Vol 162 (1) ◽

Author(s):

Manasi Das ◽

Consuelo Sauceda ◽

Nicholas J G Webster

Keyword(s):

Mitochondrial Dysfunction ◽

Energy Production ◽

Molecular Mechanisms ◽

Human Populations ◽

Metabolic Alterations ◽

Genetic Manipulations ◽

The Past ◽

Calcium Buffering

Abstract Mounting evidence suggests a role for mitochondrial dysfunction in the pathogenesis of many diseases, including type 2 diabetes, aging, and ovarian failure. Because of the central role of mitochondria in energy production, heme biosynthesis, calcium buffering, steroidogenesis, and apoptosis signaling within cells, understanding the molecular mechanisms behind mitochondrial dysregulation and its potential implications in disease is critical. This review will take a journey through the past and summarize what is known about mitochondrial dysfunction in various disorders, focusing on metabolic alterations and reproductive abnormalities. Evidence is presented from studies in different human populations, and rodents with genetic manipulations of pathways known to affect mitochondrial function.

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From Nursery to Nursing Home: Emerging Concepts in Clostridioides difficile Pathogenesis

Infection and Immunity ◽

10.1128/iai.00934-19 ◽

2020 ◽

Vol 88 (7) ◽

Author(s):

Alexander B. Smith ◽

Joshua Soto Ocana ◽

Joseph P. Zackular

Keyword(s):

Pharmaceutical Drugs ◽

Human Gastrointestinal Tract ◽

Content Type ◽

The Past ◽

Clostridioides Difficile ◽

Wide Range ◽

Pediatric Populations ◽

The Impact ◽

Shed Light

ABSTRACT Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium that infects the human gastrointestinal tract, causing a wide range of disorders that vary in severity from mild diarrhea to toxic megacolon and/or death. Over the past decade, incidence, severity, and costs associated with C. difficile infection (CDI) have increased dramatically in both the pediatric and adult populations. The factors driving this rapidly evolving epidemiology remain largely unknown but are likely due in part to previously unappreciated host, microbiota, and environmental factors. In this review, we will cover the risks and challenges of CDI in adult and pediatric populations and examine asymptomatic colonization in infants. We will also discuss the emerging role of diet, pharmaceutical drugs, and pathogen-microbiota interactions in C. difficile pathogenesis, as well as the impact of host-microbiota interactions in the manifestation of C. difficile-associated disease. Finally, we highlight new areas of research and novel strategies that may shed light on this complex infection and provide insights into the future of microbiota-based therapeutics for CDI.

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The Flame Retardancy of Polyethylene Composites: From Fundamental Concepts to Nanocomposites

Molecules ◽

10.3390/molecules25215157 ◽

2020 ◽

Vol 25 (21) ◽

pp. 5157

Author(s):

Erfan Rezvani Ghomi ◽

Fatemeh Khosravi ◽

Zahra Mossayebi ◽

Ali Saedi Ardahaei ◽

Fatemeh Morshedi Dehaghi ◽

...

Keyword(s):

Mechanical Properties ◽

Flame Retardancy ◽

Cost Efficiency ◽

Research Papers ◽

The Past ◽

Wide Range ◽

Fire Retardance ◽

Low Toxicity ◽

Implementing Strategies

Polyethylene (PE) is one the most used plastics worldwide for a wide range of applications due to its good mechanical and chemical resistance, low density, cost efficiency, ease of processability, non-reactivity, low toxicity, good electric insulation, and good functionality. However, its high flammability and rapid flame spread pose dangers for certain applications. Therefore, different flame-retardant (FR) additives are incorporated into PE to increase its flame retardancy. In this review article, research papers from the past 10 years on the flame retardancy of PE systems are comprehensively reviewed and classified based on the additive sources. The FR additives are classified in well-known FR families, including phosphorous, melamine, nitrogen, inorganic hydroxides, boron, and silicon. The mechanism of fire retardance in each family is pinpointed. In addition to the efficiency of each FR in increasing the flame retardancy, its impact on the mechanical properties of the PE system is also discussed. Most of the FRs can decrease the heat release rate (HRR) of the PE products and simultaneously maintains the mechanical properties in appropriate ratios. Based on the literature, inorganic hydroxide seems to be used more in PE systems compared to other families. Finally, the role of nanotechnology for more efficient FR-PE systems is discussed and recommendations are given on implementing strategies that could help incorporate flame retardancy in the circular economy model.

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Molecular Detection of Rotavirus in Mollusks from the Oued El Maleh Estuary of Mohammedia, Morocco

Journal of Pure and Applied Microbiology ◽

10.22207/jpam.15.4.60 ◽

2021 ◽

Author(s):

Abderrahim Hatib ◽

Najwa Hassou ◽

Abdelouahab Benani ◽

Jamal Eddine Hafid ◽

Moulay Mustapha Ennaji

Keyword(s):

Real Time ◽

Enteric Bacteria ◽

Human Populations ◽

Rt Pcr ◽

Wet Season ◽

Rotavirus A ◽

Viral Loads ◽

Wide Range ◽

Group A Rotaviruses ◽

Group A

Viral outbreaks can result from the consumption of contaminated bivalve mollusks. However, despite the regulation related to enteric bacteria in food products, the consumption of raw and undercooked mollusks remains linked to viral epidemics in human populations. Real-time RT-PCR is a highly sensitive approach for detecting and quantifying enteric viruses, and after eliminating enzymatic amplification inhibitors from samples of interest, sensitive and specific tests, like real-time RT-PCR, can facilitate the detection and quantification of a wide range of viruses that are concentrated in mollusk digestive tissues. The aim of the present study was to evaluate the prevalence of Group-A rotaviruses in mussel (Mytilus edulis Linnaeus, 1758) specimens (n=576) collected downstream of the Oued El Maleh Estuary, which is along the coast of Mohammedia City in Morocco, using real-time RT-PCR. Rotavirus A RNA was detected in 37.5% (n=18) of the 48 sample batches, and viral loads ranged from 0.42×101 to 1.8603×104 genomic copies per g digestive tissue. Most (72.22%) of the positive samples were collected during the wet season (September-April), and the probability of detecting rotaviruses was significantly greater during the wet season than during the dry season (P<0.001). Monitoring Rotavirus A and similar viruses in shellfish may help prevent viral contamination and preserve public health.

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International trade in services: The role of international shipping

Medjunarodni problemi ◽

10.2298/medjp0703376p ◽

2007 ◽

Vol 59 (2-3) ◽

pp. 376-399

Author(s):

Ivana Popovic-Petrovic

Keyword(s):

International Trade ◽

Trade In Services ◽

National Interests ◽

Transportation Services ◽

The Past ◽

Wide Range ◽

The World ◽

Increasing Demand ◽

Merchandise Trade

The General Agreement on Trade in Services (GATS) is one of the World Trade Organization's most important agreements. This accord is the first and only set of multilateral rules covering international trade in services. It is a framework for international trade in services and a legal basis for resolving conflicting national interests. For the past two decades, trade in services has grown faster than merchandise trade. Currently, they represent more than two thirds of the World Gross Domestic Product. As the term services covers a wide range of intangible and heterogeneous products and activities, there has been an increasing demand for detailed, relevant and internationally comparable statistical information on trade in services. In the last ten years, the share of transportation services in international trade in commercial services was steady and amounted to about one quarter.

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Quality assurance in Irish schools: Inspection and school self-evaluation

Administration ◽

10.2478/admin-2020-0029 ◽

2020 ◽

Vol 68 (4) ◽

pp. 161-180

Author(s):

Gerry McNamara ◽

Joe O’Hara ◽

Martin Brown ◽

Irene Quinn

Keyword(s):

Quality Assurance ◽

Public Sector ◽

School Evaluation ◽

School Inspection ◽

The Public ◽

Policy Actors ◽

Self Evaluation ◽

The Past ◽

Wide Range

AbstractIn this paper, we provide an overview of the development of school inspection in Ireland over the past twenty years using the analytic and critical lens developed by Richard Boyle in partnership with the current authors. The paper is fundamentally a reflection on the nature, purpose and operation of evaluation in the Irish public sector through the lens of education. The paper provides a historical overview of developments in the linked areas of school evaluation and inspection, and goes on to explore how the implementation of this mode of quality assurance has influenced, and been influenced by, a wide range of policy actors. The argument made is that education has embedded a culture of evaluation in a unique yet systemically resonant manner and that a reflection on this reality will help illuminate our understanding of the role of evaluation across the public sector as a whole.

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Exploring the Role of Nanoparticles in Enhancing Mechanical Properties of Hydrogel Nanocomposites

Nanomaterials ◽

10.3390/nano8110882 ◽

2018 ◽

Vol 8 (11) ◽

pp. 882 ◽

Cited By ~ 15

Author(s):

Josergio Zaragoza ◽

Scott Fukuoka ◽

Marcus Kraus ◽

James Thomin ◽

Prashanth Asuri

Keyword(s):

Mechanical Properties ◽

Elastic Moduli ◽

Maximum Modulus ◽

Polymer Particle ◽

Particle Interactions ◽

Polyacrylamide Hydrogels ◽

The Past ◽

Wide Range ◽

Hydrogel Nanocomposites

Over the past few decades, research studies have established that the mechanical properties of hydrogels can be largely impacted by the addition of nanoparticles. However, the exact mechanisms behind such enhancements are not yet fully understood. To further explore the role of nanoparticles on the enhanced mechanical properties of hydrogel nanocomposites, we used chemically crosslinked polyacrylamide hydrogels incorporating silica nanoparticles as the model system. Rheological measurements indicate that nanoparticle-mediated increases in hydrogel elastic modulus can exceed the maximum modulus that can be obtained through purely chemical crosslinking. Moreover, the data reveal that nanoparticle, monomer, and chemical crosslinker concentrations can all play an important role on the nanoparticle mediated-enhancements in mechanical properties. These results also demonstrate a strong role for pseudo crosslinking facilitated by polymer–particle interactions on the observed enhancements in elastic moduli. Taken together, our work delves into the role of nanoparticles on enhancing hydrogel properties, which is vital to the development of hydrogel nanocomposites with a wide range of specific mechanical properties.

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