A genome-wide investigation of the worldwide invader Sargassum muticum shows high success albeit (almost) no genetic diversity

Twenty years of genetic studies of marine invaders have shown that successful invaders are often characterized by native and introduced populations displaying similar levels of genetic diversity. This pattern is presumably due to high propagule pressure and repeated introductions. The opposite pattern is reported in this study of the brown seaweed, Sargassum muticum, an emblematic species for circumglobal invasions. Albeit demonstrating polymorphism in the native range, microsatellites failed to detect any genetic variation over 1,269 individuals sampled from 46 locations over the Pacific-Atlantic introduction range. Single-nucleotide polymorphisms (SNPs) obtained from ddRAD sequencing revealed some genetic variation, but confirmed severe founder events in both the Pacific and Atlantic introduction ranges. Our study thus exemplifies the need for extreme caution in interpreting neutral genetic diversity as a proxy for invasive potential. Our results confirm a previously hypothesized transoceanic secondary introduction from NE Pacific to Europe. However, the SNP panel unexpectedly revealed two additional distinct genetic origins of introductions. Also, conversely to scenarios based on historical records, southern rather than northern NE Pacific populations could have seeded most of the European populations. Finally, the most recently introduced populations showed the lowest selfing rates, suggesting higher levels of recombination might be beneficial at the early stage of the introduction process (i.e., facilitating evolutionary novelties), whereas uniparental reproduction might be favored later in sustainably established populations (i.e., sustaining local adaptation).Agence Nationale de la Recherche - ANR-10-BTBR-04; European Regional Development Fund; Fundacao para a Ciencia e a Tecnologia - SFRH/BPD/107878/2015, UID/Multi/04326/2016, UID/Multi/04326/2019; Brittany Region;info:eu-repo/semantics/publishedVersio

Elemental, isotopic, and geochronological variability in Mogollon-Datil volcanic province archaeological obsidian, southwestern USA: Solving issues of intersource discrimination

Solving issues of intersource discrimination in archaeological obsidian is a recurring problem in geoarchaeological investigation, particularly since the number of known sources of archaeological obsidian worldwide has grown nearly exponentially in the last few decades, and the complexity of archaeological questions asked has grown equally so. These two parallel aspects of archaeological investigation have required more exacting understanding of the geological relationship between sources and the more accurate analysis of these sources of archaeological obsidian. This is particularly the case in the North American Southwest where the frequency of archaeological investigation is some of the highest in the world, and the theory and method used to interpret that record has become increasingly nuanced. Here, we attempt to unravel the elemental similarity of archaeological obsidian in the Mogollon-Datil volcanic province of southwestern New Mexico where some of the most important and extensively distributed sources are located and the elemental similarity between the sources is great even though the distance between the sources is large. Uniting elemental, isotopic, and geochronological analyses as an intensive pilot study, we unpack this complexity to provide greater understanding of these important sources of archaeological obsidian

Serological diagnosis of typhoid fever : a review of the limitations of the Widal test

Typhoid fever remains an infectious disease of major importance worldwide. Even in developed countries, sporadic outbreaks continue to occur, often localised around a single origin -an asymptomatic carrier or an infected food source particularly shellfish. The severity of presentation, potential life-threatening complications as well as the serious side-effects of the antibiotics used in its treatment necessitates prompt and accurate diagnosis. The only definite diagnostic investigation remains the isolation of Salmonella typhi from samples of blood, bone marrow, faeces, bile and urine. Nevertheless serological tests are still commonly requested in the form of the Widal reaction.peer-reviewe

Top startups worldwide. An investigation on entrepreneurial and organisational profiles

Research into entrepreneurial factors of success and failure continuously improves through observing and studying new players in the business world. This work focuses on top startups in the world and seeks to understand their current habitat, what they excel in, and also the challenges awaiting them. An effort to link strategic, organisational and social profiles has been made, creating a model for understanding entrepreneurship which will also be useful for comparing future evidence

Microanalytical study of some cosmic dust discovered in sea-floor sediments in China

The study of cosmic dust can provide useful data in the investigation of the origin of the Earth and the evolution of celestial bodies. Three types of cosmic dust (ferriginous, siliceous, and glassy) were discovered in the seafloor sediments near China. Their chemical composition and microstructure were examined by X-ray diffraction, fractography, and electron microscopy. The major mineral in an iron-containing cosmic dust is magnetite. The silicate spheres contain sundry metals and metal oxides. Glassy microtektites are similar in composition to tektites, and are found in all the major meteorite areas worldwide

Peer mediation for conflict management: a Singaporean case study

The burgeoning interest in conflict and its management has recently begun to impact on schools and school systems worldwide. Motivated by a concern for increasing levels of violence in schools and student�student conflict, many school administrators are looking at conflict management programs as a means of dealing with the problem. Most of the more widely used programs have their origins in the United States; their appropriateness and effectiveness in other countries and cultures is, at best, unknown, and in some respects open to conjecture. In this paper the cultural appropriateness of a peer mediation program in a primary school in Singapore is the subject of investigation. The study also addresses, in an exploratory manner, the effectiveness of peer mediation as a mechanism for student�student conflict management

Assessing radiative transfer models trained by numerical weather forecasts using sun-tracking radiometric measurements for satellite link characterization up to W band

Radio communications, and in particular Earth-to-satellite links, are worldwide used for delivering digital services. The bandwidth demand of such services is increasing accordingly to the advent of more advanced applications (e.g., multimedia services, deep-space explorations, etc.) thus pushing the scientific community toward the investigation of channel carriers at higher frequencies. When using carrier frequencies above X band, the main drawback is how to tackle the impact of tropospheric processes (i.e., rain, cloud, water vapor). This work assesses the joint use of weather forecast models, radiative transfer models and Sun-tracking radiometric measurements to explore their potential benefits in predicting path attenuation and sky noise temperature for slant paths at frequencies between K and W band, thus paving the way to the optimization of satellite link-budgets

Stimulating the innovation potential of 'routine' workers through workplace learning

Governments worldwide seek to upgrade the ‘basic skills' of employees deemed to have low literacy and numeracy, in order to enable their greater productivity and participation in workplace practices. A longitudinal investigation of such interventions in the United Kingdom has examined the effects on employees and on organizations of engaging in basic skills programmes offered in and through the workplace. ‘Tracking’ of employees in selected organizational contexts has highlighted ways in which interplay between formal and informal workplace learning can help to create the environments for employees in lower grade jobs to use and expand their skills. This workplace learning is a precondition, a stimulus and an essential ingredient for participation in employee-driven innovation, as workers engage with others to vary, and eventually to change, work practices. © 2010, SAGE Publications. All rights reserved

Paper making from bagasse

Though the revolution of technology has reduced paper production everywhere around the world, the amount of paper consumed each day is still tremendously large. The paper industry remains a growth industry globally, with volumes forecast to increase 50% by 2035 with most of the growth occurring in the packaging and tissues sector. The main material used in paper production is wood fibre. In order to satisfy the large demand for paper, thousands of trees must be cut down every year. Deforestation caused by worldwide consumption of wood-based paper has been a huge environmental issue. As the awareness of sustainability continues to rise, the demand for sustainable paper increases. The investigation of looking for alternatives has been a critical issue. The new alternative on the market is sugarcane fibre paper [1]