Selection Of Grains Research Articles

Stability of grain zinc concentrations across lowland rice environments favors zinc biofortification breeding.

One-third of the human population consumes insufficient zinc (Zn) to sustain a healthy life. Zn deficiency can be relieved by increasing the Zn concentration ([Zn]) in staple food crops through biofortification breeding. Rice is a poor source of Zn, and in countries predominantly relying on rice without sufficient dietary diversification, such as Madagascar, Zn biofortification is a priority. Multi-environmental trials were performed in Madagascar over two years, 2019 and 2020, to screen a total of 28 genotypes including local and imported germplasm. The trials were conducted in the highlands of Ankazomiriotra, Anjiro, and Behenji and in Morovoay, a location representative of the coastal ecosystem. Contributions of genotype (G), environment (E), and G by E interactions (GEIs) were investigated. The grain [Zn] of local Malagasy rice varieties was similar to the internationally established grain [Zn] baseline of 18-20 μg/g for brown rice. While several imported breeding lines reached 50% of our breeding target set at +12 μg/g, only few met farmers' appreciation criteria. Levels of grain [Zn] were stable across E. The G effects accounted for a main fraction of the variation, 76% to 83% of the variation for year 1 and year 2 trials, respectively, while GEI effects were comparatively small, contributing 23% to 9%. This contrasted with dominant E and GEI effects for grain yield. Our results indicate that local varieties tested contained insufficient Zn to alleviate Zn malnutrition, and developing new Zn-biofortified varieties should therefore be a priority. GGE analysis did not distinguish mega-environments for grain [Zn], whereas at least three mega-environments existed for grain yield, differentiated by the presence of limiting environmental conditions and responsiveness to improved soil fertility. Our main conclusion reveals that grain [Zn] seems to be under strong genetic control in the agro-climatic conditions of Madagascar. We could identify several interesting genotypes as potential donors for the breeding program, among those BF156, with a relatively stable grain [Zn] (AMMI stability value (ASV) = 0.89) reaching our target (>26 μg/g). While selection for grain yield, general adaptation, and farmers' appreciation would have to rely on multi-environment testing, selection for grain [Zn] could be centralized in earlier generations.

Grain factors in food and feed that influence digestion and gut fermentation outcomes

AbstractBackground and ObjectivesGrains are typically the main component in both human diets and animal feed. The factors in grains that influence digestion and fermentation in the gastrointestinal tract are incompletely understood, limiting both product innovation and rational selection of grains for desired nutritional outcomes. This review summarizes the current understanding of the multiple mechanisms operating within the digestive tract of humans and monogastric production animals, with a focus on the effects of grains.FindingsMolecular composition and residual cellular structures in grain‐based food and feed each have impacts on digestion and fermentation processes. There is a complex interplay between enzyme digestion rates, fermentation rates, and digesta transit processes in the gastrointestinal tract based on the material properties of grain foods/feeds and hormonal signals triggered by nutrient and fermentation product uptake. Opportunities for modulation of nutritional value in grain food and feed can be identified based on particle size, local molecular density, and hydration properties.ConclusionsMany advances in understanding the factors in grains that influence enzyme digestion and gut microbial fermentation have been made recently. Current nutritional labeling based on molecular composition and not digestion or fermentation properties ignores the important role that residual grain cellular structure plays in both human and animal nutrition.Significance and NoveltyBy comparing the effects of grain‐based foods and feeds on gastrointestinal digestion, fermentation, and digesta transit, opportunities and challenges for addressing nutritional targets for human health and monogastric animal production through grain innovation are discussed.

Effectiveness of a cherry coffee sorter prototype with image recognition using machine learning

The production of specialty coffees is the main objective of coffee growers worldwide and depends on the selection of optimal grains; however, especially in Latin America, they are processed manually and are influenced by subjectivity. The objective of the article was to verify the effectiveness of a cherry coffee sorting prototype with image recognition using machine learning in real time compared to the traditional method in the Valle Grande Association, Peru. Covolutional neural network processing was used. 24,000 images labeled in the Labellmg program of green, ripe, pinton, over-ripe and dry Catimor grains were trained with the YOLOv3 algorithm. The results describe the mechanical-electronic design and assembly procedure of the prototype with the necessary technical specifications for its replication; In addition, they demonstrate their effectiveness in reducing the selection time by approximately 3 hours, with a precision level of 94.0% in four samples of 100 kg of coffee. It is concluded that the prototype is a potential alternative, reducing cost, saving time and providing a useful tool to guarantee the selection of grains that allow obtaining quality higher than 83 SCAA points.

Direct and Indirect Selection for Grain Yield and Grain Weight in Late Generations of Bread Wheat under Drought Stress and Normal Irrigation Environments.

Two cycles of pedigree selection for grain yield/plant (GY/P) and grain weight (GW) (100-grain weight) were imposed under drought stress and normal irrigation to study the direct and indirect selection of GY/P and GW in bread wheat. The selection started in the F6-generation (Cycle0-C0) of bread wheat (Triticum aestivum L.) traced back to the cross (Giza 164/Sids 4) of two Egyptian cultivars. The narrow sense heritability was higher under drought than under normal irrigation and increased by selection. Under drought, the observed direct gain after two cycles of selection for GW was 21.51% (p ≤ 0.01), and accompanied with an indirect gain in GY/P of 15.52%. The observed direct gain for GY/P was 17.98% and the indirect gain in GW was 13.81%. Under normal irrigation, the observed direct gain for GW was 12.86% and the indirect gain for GY/P was 16.04%. The direct gain in GY/P was 16.04% and the indirect gain in GW was 11.95%. The genotypic correlations were different in both environments before and after selection. Single trait selection was effective in improving the selection criterion, and selection greatly affected gene associations.

Canonical interrelationships in morphological characters, yield and nutritional components of corn

The increase in the world population, the need to increase food production, both in quantity and quality, becomes increasingly prominent. The objective of this work was to identify the canonical correlations between yield components, morphological characters, micronutrients, bioactive compounds and amino acids in corn. The experimental design used was a randomized block containing 11 treatments arranged in three replications. The treatments consisted of 11 Top Crosses hybrid genotypes, these being made through crosses directed between a narrow genetic base tester hybrid for specific combining ability with 11 S5 inbred lines. It is inferred that groups considered yield components, secondary traits, bioactive compounds, micronutrients and amino acids are dependent. Promising characters are identified for the corn breeding for high yields, nutritional and energetic quality of corn grains. The indirect selection of grains with additions in essential amino acids can be directed to plants with superiority in height, mass and width of grains, phenols, flavonoids, soluble solids and zinc content.

64 Feeding elite equine athletes: Perspectives from high-goal polo and endurance riding competitors

Knowing equine stakeholder feeding practices can better inform research, extension, and education programs. The objective of this exploratory survey was to describe feeding management and activity of horses performing at elite levels in polo and endurance riding. High-goal polo participants were targeted for survey distribution through a polo magazine publication during the winter of 2018. A researcher recruited endurance riders to participate at an American Endurance Ride Conference sanctioned event held in Florida during March 2018. Participants were contacted 3 times to complete a questionnaire to describe horse management practices, dietary information, and preferences with regards to equine nutrition. Eight of 11 (72.7%) polo players and 9 of 22 (40.9%) endurance riders completed the survey. Seventy-six percent of barns (13/17) were located in Florida at the time of survey completion. To compare disciplines, continuous data were analyzed using t -test and categorical data using a Mann-Whitney U-Test. Polo ponies were fed alfalfa hay, with 50% (4/8) of respondents predominately feeding alfalfa hay, and the remaining feeding alfalfa/grass hay mixtures. Endurance horses were more likely ( P = 0.056) to have ad libitum access (7/9) to forage than polo ponies (2/8), likely because most endurance horses were housed on pasture (6/9). For hay, nutritional value was extremely important in forage selection decisions for both polo and endurance sports. Polo respondents were more likely to value ( P = 0.018) forage color and smell than endurance participants. All respondents reported feeding their horses grain or concentrate, a typical recommendation for feeding horses with elevated nutrient requirements due to increased workload. Nutritional value was the most important factor for selection of grain or concentrate, followed by feed availability, veterinarian or nutritionist recommendation, feed manufacturer reputation, cost, or industry professional recommendation, in order of preference. Polo ponies worked an average of 51 ± 24 min/d (STD DEV) 6 times per week. Endurance horses worked longer (115 ± 52 min/d, P = 0.007) but less frequently (4 times per week, P = 0.001) than polo ponies. Polo ponies tended to compete more frequently (3.9 ± 2.3 times per month, P = 0.101) than endurance horses (1.8 ± 0.7). During a race, endurance horses were fed more frequently and offered different feeds than the typical ration. These data indicate feeding management preferences are specific to athletic activities. Widespread use of this questionnaire could help target equine educational programs to the needs of the industry.

Formation of oat fresh yield and its protein yield in the conditions of the southern forest-steppe of Western Siberia

The results of the study of grain and fodder oat varieties in the competitive variety trial of the Omsk Agrarian Research Center are dis-cussed. The article provides data on the green food yield and its protein yield for the period from 2018 to 2020. The samples were tested under conditions with contrasting moisture content. Physiological indices of vari-eties are also analyzed: leaf area, accumulation and distribution of dry bi-omass as well as percentage of protein. The response of oat varieties by year to different weather conditions is shown. A favorable year has been identified for the formation of a common assimilating area of oat plants. It was revealed that the protein content in the vegetative mass of oats varies oppositely with the total yield. The accumulation of dry biomass in onto-genesis characterizes the photosynthetic activity of plants. It is in a positive relationship with their yieldability. The selection of grain and fodder oat varieties begins with the SP-2 nursery.

New Data for Malanite and Cuprorhodsite from Chromitites of the Bushveld Complex, South Africa

The 3D-mineralogical technology was used to study a representative selection of grains of thiospineles from three groups of chromitite horizons (lower LG6, middle MG1/MG2 and upper UG2): 46 grains of malanite (4–42 μm) and 34 grains of cuprorhodsite (9–42 μm). Their microprobe analysis was performed (n = 61). The statistics for this selection of grains have resulted in the following formulas: for malanite, (Сu2+,Fe2+)(Pt3+Rh3+,Ir3+,Co3+,Ni3+Fe3+)2S4 and for cuprorhodsite, (Сu2+,Fe2+)(Rh3+,Pt3+,Ir3+,Fe3+)2S4. According to morphological properties and their relationship with platinum-group minerals (PGMs) and base metal sulfides, thiospinel can be attributed to the earliest primary PGMs in chromitites. The distribution of cuprorhodsite and malanite in chromitites was controlled by the Rayleigh fractionation of the primary sulfide melt in the process of formation of Bushveld chromitite horizons.

Multiple traits selection in bread wheat under drought stress and normal irrigation

The genetic materials were F2, F3, F4 and F5 generations of the cross “Giza164/Sids4” of bread wheat. The experiments were conducted under drought stress and normal irrigation. Three cycles of single trait selection for grain yield/plant (GY/P) and five models of desired gain selection index (combinations from seven traits) were achieved in both environments separately. After the third cycle of selection, the selected families for the six types of selection under drought stress, and the selected families under normal irrigation were evaluated under both environments. The GCV in GY/P decreased from the F2 to the F5. The remained variability in GY/P for the five selection indices was higher after the three cycles of selection than the single trait selection for GY/P. Heritability estimates as calculated from regression of F5/F4 generations for the traits under selection pressure were higher under drought stress than under normal irrigation except few cases. The observed gain increased from index1 to index5, and all indices were better in improving GY/ P than direct selection for GY/P. It could be concluded that selection index was better in improving grain yield than single trait selection for GY/P. Furthermore, selection under drought stress (antagonistic selection) in these materials was better than selection under normal irrigation (synergistic selection) in improving GY/P either selection evaluated under drought stress or under normal irrigation. Selection index5 which involved GY/P, 100GW and NG/S was the best index in improving GY/P.

Direct and Indirect Selection for Grain Yield in Bread Wheat (Triticum aesitivum L.)

Direct and indirect selection for grain yield through 1000grain weight, spikelet fertility and spike density were achieved in bread wheat at the Exper. Farm Fac. Agric., Minia Univ. Egypt during the three successive seasons of 2016/17 to 2018/19. After two cycles of pedigree selection phenotypic variation of grain yield/plant, 1000grain weight, spikelet fertility and spike density decreased rapidly from F2 base population to F4. Indirect selection through high 1000 grain weight resulted in the highest grain yield/plant (23.62g) followed by direct selection for grain yield/plant (20.66 g). Average direct gain for the ten selected families of direct selection for grain yield showed highly significant increase in percentage of the bulk sample of 62.95% and the better parent of 39.25%. Pedigree selection was effective in detecting the high yielding families. Family No. 145 gave significant (P≤0.01) grain yield in percentage of the better parent and bulk sample by 77.09 and 107.23%, respectively. Average direct response in percentage of the bulk sample was significant and reached 21.08% for 1000 grain weight, 31.12% for spikelet fertility and 7.27% for spike density. Three families; No. 15, No. 72 and No. 153 surpassed significantly the bulk sample by 33.83, 43.01 and 29.28%, respectively, when selection practiced for 1000 grain weight. Family No. 145 considered to be a promising line in grain yield and spikelet fertility. High strong positive genotypic correlation was found between grain yield with each of weight of spikes/plant (0.81), no. of grains/spike(0.71), weight of grains/spike (0.91), 1000grain weight(0.92) and spikelet fertility(0.70).

A novel polymorphism in the 5′ UTR of HvDEP1 is associated with grain length and 1000-grain weight in barley (Hordeum vulgare)

The gene HvDEP1, on barley (Hordeum vulgare L.) chromosome 5H, encodes a γ-subunit of the heterotrimeric G-protein complex and was previously determined to be a candidate gene underlying a major quantitative trait locus for grain length. In the present study, we identified a 9 bp indel (insertion–deletion mutation) at position –84 bp from the start codon within a reported upstream open reading frame located in the 5′ UTR (untranslated region) and developed a diagnostic molecular marker. We also identified a 13 bp indel (–514 bp) in linkage disequilibrium that bridges an important regulatory motif. Using a doubled-haploid population and a barley diversity panel, we were able to show that the effects of these indels were environmentally stable and consistently delineated phenotypic groups based on grain length and 1000-grain weight. Genotypes represented by deletions at these two positions relative to the reference cv. Morex had consistently shorter grains, by 3.69–3.96%, and lower 1000-grain weight, by 2.38–4.21%, in a doubled-haploid population studied. Additionally, a diversity panel was tested but consistent differences were observed only for grain length, reinforcing literature indicating the importance of this gene for grain-length regulation. The frequency of the longer and heavier grained reference allele was higher in modern cultivars, suggesting that indirect selection for longer grain may have occurred through direct selection for grain yield via grain-weight improvement. These results indicate that grain length and 1000-grain weight in barley can be manipulated by targeting variation in gene promoters through marker-assisted selection.

PEDIGREE SELECTION IN BREAD WHEAT UNDER WATER DEFICIT FOR YIELD IN TOSHKA CONDITIONS

The present work aimed to study the effect of two cycles of pedigree selection for highly grain yield in two segregating populations of wheat under water stress, during the two winter seasons of 2015/2016 and 2016/2017at Toshka Research Station, Desert Research Center, Aswan, Egypt. The water treatments were 100 and 67% of the irrigation requirements of wheat in Toshka as normal and drought condition, respectively. A transgressive segregation in both populations for all studied traits inducted the suitability of those material for pedigree selections. The genetic advanced for grain yield/plant and its components were greater in population 2 than in population 1 in the first cycle in pedigree selection. Highly significant differences among the selected families for all the studies traits were observed in both populations under normal and drought conditions. After one cycles of selection, the broad sense heritability was very high for most traits and reached 77.79 and 92.02% for grain yield/plant under normal irrigation, while were 87.53 and 93.12% under drought stress in population 1 and population 2, respectively. Two cycles of pedigree selection for grain yield/plant was enough to detect the best families and could be performed in the early segregating generations. It could be concluded that single trait selection was efficient to improve the selection criteria in these populations. These genotypes could be sources for drought tolerance.

Effect of variety and environment on the contents of crude nutrients and amino acids in organically produced cereal and legume grains

Cereals and home-grown grain legumes are main feedstuffs for monogastric animals. Thus, knowledge on variations of their crude nutrient and amino acid composition is of great interest in animal nutrition. Genetic and environmental factors are known to be able to affect the nutrient composition of crops. Thus, the aim of the study was to analyse a selection of grains of organic cereal and grain legume species for their crude nutrient and amino acid contents and to determine the effect of variety and environmental conditions on the variations. Furthermore, the use of equations to predict amino acid contents from the crude protein content of cereals and grain legumes was tested. The contents of the crude nutrients and 18 amino acids of 835 samples of ten different cereal and grain legume species were analysed. Selected nutrients were subjected to correlation analyses. Furthermore, generalised linear models with multiple comparisons were conducted to assess the effect of species as well as of variety, harvest site and harvest year on the analysed ingredients. The contents of all crude nutrients and amino acids varied depending on the species and the considered nutrient. The lowest variation coefficients (1.3–2.6% in cereals and 3.1, 3.5 and 6.8% in field peas, field beans and blue lupins, respectively) were observed for the contents of nitrogen-free extracts. The crude protein contents varied widely, specifically in winter rye (coefficient of variation: CV = 17.4%). However, compared to table values, the cereals and grain legumes of the present study tended to contain low amounts of crude protein and high amounts of starch. Due to the wide variations, there is no distinct consistency between table values and the results of this study. High negative correlations between starch and crude protein contents were observed in eight species. Furthermore, the amino acid profile of cereals and grain legumes varied depending on the crude protein contents. Higher crude protein contents were often related to lower contents of several essential amino acids in favour of glutamine/glutamic acid, proline and phenylalanine in cereals as well as of arginine in grain legumes. Furthermore, variety, harvest site and harvest year affected the contents of the analysed ingredients depending on the species. However, the environmental factors had a greater influence than the variety. The observed variations must be regarded in diet formulation. Equations can be used to estimate the amino acid contents of cereals and grain legumes from their crude protein content. However, additional analysis results are needed to improve the predictability with equations.

Новые данные о маланите и купрородсите из хромититов Бушвельдского комплекса, Южная Африка

Изучена (с использованием оригинальной 3D-минералогической технологии) представительная выборка зерен тиошпинелей из трех групп горизонтов хромититов (нижней LG6, средней MG1/MG2 и верхней UG2): 46 зерен маланита (размером 4—42 мкм) и 34 зерна купрородсита (9—42 мкм). Проведен их микрозондовый анализ ( n  = 61). По результатам статистической обработки, формула маланита — (Сu 2+ ,Fe 2+ )(Pt 3+ Rh 3+ ,Ir 3+ ,Co 3+ ,Ni 3+ Fe 3+ )S 4 , купрородсита — (Сu 2+ ,Fe 2+ )(Rh 3+ ,Pt 3+ ,Ir 3+ , Fe 3+ )S 4 . Морфология зерен тиошпинелей, их взаимоотношения с минералами платиновой группы (МПГ) и вмещающими их сульфидами позволяет отнести тиошпинели к числу ранних первичных МПГ в хромититах. Распределение купрородсита и маланита в хромититах контролировалось рэлеевским фракционированием первичного сульфидного расплава в процессе формирования хромититовых горизонтов.

Developing of Measurement of Independence Characteristic in Middle School Students Mathematics and Science

<span lang="EN-US">The purpose of this study to design a measurement instrument independence character of middle school students. Research using research and development (R & D). Stages of the research process include: reviewing the concept, making the construct and design the instruments, experts’ assessment, the empirical pre-test, and empirical testing. Test experts were conducted by experts through quantitative and qualitative assessments were followed by improvements to the instrument. Pre empirical testing was done by trial and instruments in small-scale followed by repair and selection of items. Empirical testing is a field test on a large scale at middle school students who were followed by the selection of grains and calculation of reliability of the instrument. Research and development results obtained as follows. (1) Measurement code developed with the student independence four dimensions: freedom, initiative, progressive and resilient, and confident. The dimension of freedom comprising: able to make their own choices and able to perform his own activities. Dimension Initiative consists of: being able to think and act in an indigenous, and doing creative activities. The results of this study are expected secondary school teachers can have a reference or guidelines for measuring the character of student independenc</span><span lang="EN-US">e</span>

Correlation, path and regression analysis in some bread wheat genotypes under normal irrigation and drought conditions

THE OBJECTIVE of this study was to assess correlation, path and regression analysis in 39 F6 bread wheat (Triticum aestivum L) genotypes during two seasons, i.e., 2015/2016 (F7) and 2016/2017 (F8) under irrigation and drought stress conditions at Fac. Agric. Edu. Farm, Minia University, Egypt. A positive correlation was found between grain yield and each of the number of spikes/plant and number of grains/spike under the two conditions. Path analysis revealed high positive direct effects on grain yield/plant via the number of grains/spike (0.929) under irrigation and number of spikes/plant (0.973) under drought. The direct effect of 100-grain weight on grain yield/plant was positive under irrigation (0.649) and drought (0.260). The indirect effects of these traits were negative under the two conditions. Stepwise regression analysis revealed that three models no. 8, 9 and 10 were fitted for each environment. The model no. 8 included one trait; the number of grains/spike under irrigation and number of spikes/plant under drought. Its relative contributions in grain yield were 0.180 and 0.693 under irrigation and drought; respectively. The model no. 9 in the two environments included two traits; the number of grains/spike and number of spikes/plant, its relative contributions in grain yield/plant were 0.544 and 0.836 under normal and drought conditions, respectively. The model no. 10 included three traits number of grains/spike, number of spikes/plant and 100-grain weight, its relative contribution in grain yield/plant were 0.0.931 and 0.978 under normal and drought conditions, respectively. This model no. 10 is fit and superior to use in selection for grain yield/plant.

Maize grain soluble sugar and protein contents in response to simulated hail damage

Production of grain of high nutritional quality is essential in maize (Zea mays L.) as a food grain crop. Grain quality may be influenced by environmental and management factors, such as hail, plant density and grain selection. A study was conducted to determine the effect of hail damage on maize grain contents of soluble sugars and total proteins in relation to grain position on the cob and planting density. Maize was grown at three planting densities (65 000 plants ha−1 [high], 46 000 plants ha−1 [moderate] and 28 000 plants ha−1 [low]) at two sites (Baynesfield and Swayimane) in KwaZulu-Natal, South Africa. Approximately 80% hail damage was simulated on the leaves at the seventh leaf (V7) and tasseling (VT) stages of development of three maize cultivars (‘SC701’, ‘Mac Medium Pearl’ and ‘Zama Star’), whereas undamaged plants served as the control. After harvest at maturity, grains from the proximal and distal portions of the cob were divided and analysed for grain nutritional quality, i.e. soluble sugars and proteins. Soluble sugar analysis focused on the predominant sugars, namely glucose, fructose and sucrose. Although not significant, hail damage typically at VT reduced grain soluble sugar and protein contents by at least 3.2% and 3.8%, respectively, and grains produced at Baynesfield were more resilient to damage compared with those produced at Swayimane. Selection of seeds from the distal cob portion, especially for ‘SC701’, and low plant density reduced the detrimental effect of hail damage on grain sugar and protein content. The present results indicate that in areas prone to hail ‘SC701’ is a cultivar of choice, and a low plant density and selection of grains from the distal cob portion can mitigate the detrimental effects of hail on grain nutritional quality.

Study of the source material for breeding forage-grain cultures

As a result of many years of research, working collections have been created for the selection of grain and sugar sorghum, foxtail millet and Sudan grass, promising breeding lines have been identified. Patents were obtained and included in the State Register of Protected Selection Achievements Garant and 4 best parent forms of the synthetic population: GVI 25, GVI 32, MEV 89/2, MEV 93/2. The selection line for grain sorghum MEV-1/16 was transferred to the state strain testing in 2016. Selection lines of sugar sorghum: L-109, L-9, L-23, L-1898/2 are recommended for further evaluation in competitive variety testing. Based on the results of a comprehensive assessment of breeding material, the line of Sudan grass MEV - 117/2015 was transferred to the State Variety Test.

On the microstructure and mechanical property of as-extruded Mg–Sn–Zn alloy with Cu addition

This work explored the effect of Cu addition on the microstructure characteristics and tensile properties of as-extruded Mg–8Sn–2Zn alloys. Results indicated that adding Cu caused the formation of MgZnCu phase with a face-center cubic structure (α = 0.7169 nm) and exhibited subtle grain refinement effect of the as-cast alloys. Moreover, the volume fraction of MgZnCu phase increased as Cu content increased. Appropriate Cu addition could refine the precipitates and increase the number density of precipitate of as-extruded alloys, which resulted in the refinement of grains and weakening of texture intensity. However, extensive addition of Cu increased the size of secondary phases, thereby resulted in weak grain boundary pinning effect and growth of dynamic recrystallized grains. Such grain growth might cause the growth selection of grains with the predominant orientation of extruded fiber texture. The as-extruded Mg–8Sn–2Zn–0.5Cu alloy exhibited the optimal yield strength of 365.9 MPa and ultimate tensile strength of 388.4 MPa. High strength values were expected due to the high number density of micron-sized broken MgZnCu and Mg2Sn particles, as well as nano-sized Mg2Sn precipitates and fine grains.

Origin and diversity of testate amoebae shell composition: Example of Bullinularia indica living in Sphagnum capillifolium

Testate amoebae are free-living shelled protists that build a wide range of shells with various sizes, shapes, and compositions. Recent studies showed that xenosomic testate amoebae shells could be indicators of atmospheric particulate matter (PM) deposition. However, no study has yet been conducted to assess the intra-specific mineral, organic, and biologic grain diversity of a single xenosomic species in a natural undisturbed environment. This study aims at providing new information about grain selection to develop the potential use of xenosomic testate amoebae shells as bioindicators of the multiple-origin mineral/organic diversity of their proximal environment. To fulfil these objectives, we analysed the shell content of 38 Bullinularia indica individuals, a single xenosomic testate amoeba species living in Sphagnum capillifolium, by scanning electron microscope (SEM) coupled with X-ray spectroscopy. The shells exhibited high diversities of mineral, organic, and biomineral grains, which confirms their capability to recycle xenosomes. Mineral grain diversity and size of B. indica matched those of the atmospheric natural mineral PM deposited in the peatbog. Calculation of grain size sorting revealed a discrete selection of grains agglutinated by B. indica. These results are a first step towards understanding the mechanisms of particle selection by xenosomic testate amoebae in natural conditions.