340 research outputs found
Analysis of nuclear microsatellites reveals limited differentiation between Colchic and Hyrcanian populations of the wind-pollinated relict tree Zelkova carpinifolia (Ulmaceae)
Premise of the study: The Caucasus represents one of the world’s biodiversity hotspots and includes the climatic refugia Hyrcan on the southern coast of the Caspian Sea and Colchis on the eastern coast of the Black Sea, where different species survived during the Quaternary climatic oscillations. We evaluated the genetic diversity of the relict tree Zelkova carpinifolia shared between the two refugia and distributed throughout the Caucasus and adjacent areas.Methods: Specimens were collected from 30 geographical sites in Azerbaijan, Georgia, Iran, and Turkey and screened for variability at eight nuclear microsatellite loci. The genetic diversity among and within populations was assessed using a set of statistical measures.Key results: We detected 379 different genotypes from a total of 495 individuals with varying degrees of clonal reproduction at the different sites. Low to intermediate levels of genetic diversity were observed at all sites, and strong differentiation between sampling sites was absent. In addition, we observed no clear genetic differentiation between the Colchis and Hyrcan. Bayesian clustering of the genotypes revealed three populations with high levels of admixture between the sampling sites.Conclusions: The lack of strong genetic structure of studied populations of Z. carpinifolia contrasts with a previous study based on chloroplast markers and suggests that long-distance pollen dispersal is an important factor of gene flow among populations of Z. carpinifolia. The present study does not reveal any particular site with particularly isolated genotypes that would deserve more attention for conservation purposes than others, although some sites should be considered for further investigation
The Effects And Efficiency Of Hearing Stories On Vocabulary Acquisition By Students Of German AS A Second Foreign Language In Japan
The usual approach to vocabulary learning is to present students with a list of words to be memorized, present them in the context of a text, and then provide exercises to “reinforce” the vocabulary. The purpose of these studies with beginning level German-as-a-foreign language university students in Japan was to determine whether beginning level students with limited vocabulary in German could sustain their interest in hearing a story for over 20 minutes, and to determine how much vocabulary could be gained just from hearing stories, without a list to memorize and supplementary vocabulary exercises. The first experiment showed that hearing a story had a higher acquisition/learning rate than a list method. The second and third experiments showed that supplementary focus on form activities were not worthwhile on vocabulary acquisition/learning, and that the rate of acquisition/learning was .10 words per minute during the seven weeks. It appears to be the case that students acquire six words per hour when they hear stories, while they learn 2.4 words per hour in traditional classes
Qualification of electron-beam welded joints between copper and stainless steel for cryogenic application
Joints between copper and stainless steel are commonly applied in cryogenic systems. A relatively new and increasingly important method to combine these materials is electron-beam (EB) welding. Typically, welds in cryogenic applications need to withstand a temperature range from 300K down to 4 K, and pressures of several MPa. However, few data are available for classifying EB welds between OFHC copper and 316L stainless steel. A broad test program was conducted in order to qualify this kind of weld. The experiments started with the measurement of the hardness in the weld area. To verify the leak-tightness of the joints, integral helium leak tests at operating pressures of 16MPa were carried out at roomand at liquid nitrogen temperature. The tests were followed by destructive tensile tests at room temperature, at liquid nitrogen and at liquid helium temperatures, yielding information on the yield strength and the ultimate tensile strength of the welds at these temperatures. Moreover, nondestructive tensile tests up to the yield strength, i.e. the range in which the weld can be stressed during operation, were performed. Also, the behavior of the weld upon temperature fluctuations between room- and liquid nitrogen temperature was tested. The results of the qualification indicate that EB welded joints between OFHC copper and 316L stainless steel are reliable and present an interesting alternative to other technologies such as vacuum brazing or friction welding
Case studies
In this chapter, case studies are used as examples of how to gain a better understanding of the risks posed by extreme weather and climate-related events while identifying lessons and best practices from past responses to such occurrences. Using the information in Chapters 1 to 8, it was possible to focus on particular examples to reflect the needs of the whole Special Report. The chosen case studies are illustrative of an important range of disaster risk reduction, disaster risk management, and climate change adaptation issues. They are grouped to examine representative types of extreme events, vulnerable regions, and methodological approaches
Label-free imaging flow cytometry for analysis and sorting of enzymatically dissociated tissues
Biomedical research relies on identification and isolation of specific cell types using molecular biomarkers and sorting methods such as fluorescence or magnetic activated cell sorting. Labelling processes potentially alter the cells’ properties and should be avoided, especially when purifying cells for clinical applications. A promising alternative is the label-free identification of cells based on physical properties. Sorting real-time deformability cytometry (soRT-DC) is a microfluidic technique for label-free analysis and sorting of single cells. In soRT-FDC, bright-field images of cells are analyzed by a deep neural net (DNN) to obtain a sorting decision, but sorting was so far only demonstrated for blood cells which show clear morphological differences and are naturally in suspension. Most cells, however, grow in tissues, requiring dissociation before cell sorting which is associated with challenges including changes in morphology, or presence of aggregates. Here, we introduce methods to improve robustness of analysis and sorting of single cells from nervous tissue and provide DNNs which can distinguish visually similar cells. We employ the DNN for image-based sorting to enrich photoreceptor cells from dissociated retina for transplantation into the mouse eye
Stable Carbon Isotope Signature of Methane Released From Phytoplankton
Unidad de excelencia María de Maeztu CEX2019-000940-MAquatic ecosystems play an important role in global methane cycling and many field studies have reported methane supersaturation in the oxic surface mixed layer (SML) of the ocean and in the epilimnion of lakes. The origin of methane formed under oxic condition is hotly debated and several pathways have recently been offered to explain the "methane paradox." In this context, stable isotope measurements have been applied to constrain methane sources in supersaturated oxygenated waters. Here we present stable carbon isotope signatures for six widespread marine phytoplankton species, three haptophyte algae and three cyanobacteria, incubated under laboratory conditions. The observed isotopic patterns implicate that methane formed by phytoplankton might be clearly distinguished from methane produced by methanogenic archaea. Comparing results from phytoplankton experiments with isotopic data from field measurements, suggests that algal and cyanobacterial populations may contribute substantially to methane formationobserved in the SML of oceans and lakes
Эмерджентные свойства магнитных ионов и наночастиц в мицеллярных растворах ПАВ: Использование для тонких технологий
Objectives. To establish expected emergent (unexpected) properties of magnetic materials when obtained in aqueous micellar solutions of surfactants (aqueous quantum materials), and their use in fine technologies.Methods. Chemical synthesis of magnetic nanoparticles in aqueous micellar solutions of surfactants of various nature. Characterization of magnetic solutions and nanoparticles by magnetic measurements, spectroscopy, diffractometry, small-angle X-ray diffraction, scanning probe microscopy, and others.Results. The term “water quantum material” refers to materials (micellar solutions) whose properties are mainly determined by the nuclear quantum effect on macroscopic scales (emergent property). Micellar solutions exhibit phenomena and functionality not always consistent with the classical theory of micellization. The article presents in detail the experimental results that suggest the manifestation of the emergent properties of magnetic materials obtained in aqueous micellar solutions of surfactants. In particular, Gd3+ ions in an aqueous micellar solution of sodium dodecyl sulfate exhibit paramagnetic properties, possibly indicating their random arrangement in solution contrary to the classical theory of micellization with an ordered adsorption layer on micelles. Hybrid Pt–Gd nanoparticles are formed in a quantum material with cetylpyridinium chloride as a matrix, although Gd3+ ions must be repelled by CP+ ions on micelles. Nanosized powders of cobalt ferrite and nickel ferrite obtained in a micellar solution of sodium dodecyl sulfate have superparamagnetic properties, although the presence of their precursor ions in the adsorption layer in classical micelles should lead to ferromagnetic properties.Conclusions. The synthesis of nanoparticles in a quantum material opens up the possibility of reducing ions of different signs in one stage during the processing of metallurgy waste, in order to obtain nanoparticles of various metals and their composites. Magnetic nanoparticles obtained in a quantum surfactant material self-assemble on various substrates, enabling the creation of materials whose residual magnetization and coercive field can be controlled at room temperatures.Цели. Выявить предполагаемые эмерджентные (неожиданные) свойства магнитных материалов при их получении в водных мицеллярных растворах поверхностно-активных веществ (ПАВ) (водных квантовых материалах), которые можно использовать для тонких технологий.Методы. Химический синтез магнитных наночастиц в водных мицеллярных растворах ПАВ различной природы; характеризация магнитных растворов и наночастиц методами магнитных измерений, спектроскопии, дифрактометрии, малоугловой рентгеновской дифракции, сканирующей зондовой микроскопии и другими.Результаты. Термин «водный квантовый материал» относится к материалам (мицеллярным растворам), свойства которых в основном определяются ядерным квантовым эффектом в макроскопических масштабах (эмерджентное свойство). Мицеллярные растворы демонстрируют явления и функциональные возможности, не всегда соотносимые с классической теорией мицеллобразования. В статье подробно представлены экспериментальные результаты, которые позволяют предположить проявление эмерджентных свойств магнитных материалов, получаемых в водных мицеллярных растворах ПАВ. В частности, ионы гадолиния Gd3+ в водно-мицеллярном растворе додецилсульфата натрия проявляют парамагнитные свойства, что, возможно, указывает на их беспорядочное расположение в растворе вопреки классической теории мицеллообразования с адсорбционным упорядоченном слое на мицеллах. Гибридные наночастицы Gd–Pt образуются в квантовом материале с хлоридом цетилпиридиния в качестве матрицы, хотя ионы Gd3+ должны отталкиваться ионами цетилпиридиния ЦП+ на мицеллах. Наноразмерные порошоки феррита кобальта и феррита никеля, получаемые в мицеллярном растворе додецилсулфата натрия, обладают суперпарамагнитными свойствами, хотя присутствие их прекурсорных ионов в адсорбионном слое в классических мицеллах должно было бы привести к ферромагнитным свойствам.Выводы. Синтез наночастиц в квантовом материале открывает возможность восстановления ионов разных знаков за одну стадию при переработке отходов металлургии с целью получения наночастиц различных металлов и их композитов. Магнитные наночастицы, получаемые в квантовом материале ПАВ, самоорганизуются на различных подложках, что позволяет создавать материалы, остаточная намагниченность и коэрцитивное поле которых можно регулировать при комнатных температурах. Таким образом, показано, каким образом эмерджентные свойства квантовых материалов можно применять для тонких технологий
Unemployment and retirement and ill-health: a cross-sectional analysis across European countries
Objective
To determine the associations between different measures of health and labor market position across ten European countries.
Methods
We studied 11,462 participants of the Survey on Health and Ageing in Europe (SHARE) who were 50–64 years old. Logistic regression was used to calculate the associations between health and other determinants and being retired, unemployed, or a homemaker.
Results
A large variation across European countries was observed for the proportion of persons 50–65 years with paid employment, varying among men from 42% in Austria to 75% in Sweden and among women from 22% in Italy to 69% in Sweden. Among employed workers 18% reported a poor health, whereas this proportion was 37% in retirees, 39% in unemployed persons, and 35% in homemakers. A perceived poor health was strongly associated with non-participating in labor force in most European countries. A lower education, being single, physical inactivity and a high body mass index were associated with withdrawal from the labor force. Long-term illnesses such as depression, stroke, diabetes, chronic lung disease, and musculoskeletal disease were significantly more common among those persons not having paid employment.
Conclusion
In many European countries a poor health, chronic diseases, and lifestyle factors were associated with being out of the labor market. The results of this study suggest that in social policies to encourage employment among older persons the role of ill-health and its influencing factors needs to be incorporated
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