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MXene and MBene, with diverse and adjustable surface and bulk structures, show many unique chemical properties and are applied in various energy storage technologies, and the latest developments for them are reviewed respectively. However, the current reports on the synthesis of the two materials and the application of related devices are still separate and limited to the macro details. In this review, the microscopic chemistry of synthesis strategies for MXene and MBene and the differences in synthesis strategies caused by the structure differences between them are elucidated. Later, the impact of synthesis strategies on their overall morphologies and subsequent material property differences are discussed, and key considerations in the field of energy storage are described. Next, it is elaborated on how the surface and bulk phases of MXene and MBene utilize these properties to participate in electrochemical reactions individually or synergistically. Unlike previous reviews, MXene and MBene are incorporated into a unified framework from a microscopic perspective for discussion, and the relationship of synthesis‐structure/properties‐function is elucidated. Finally, the “skipping strategy” and “joint devices” as the next‐generation design concepts of MXene in the synthesis and application fields, and the development template for MBene materials are proposed. [ABSTRACT FROM AUTHOR]

Coilia nasus are an important fish resource in the Yangtze River, and the Yangtze River Estuary is a crucial migration pathway for them. In this study, we used otolith microchemistry to analyze the strontium/calcium (Sr/Ca) ratios and Sr contents in the sagitta otolith of C. nasus from the south branch (SB) and north branch (NB) of the Yangtze River Estuary and obtained the diversity of migration patterns and spawning ground distribution for C. nasus. The results indicate that C. nasus from both branches include two types of habitat history: freshwater (F)–brackish water (B) (Type I) and F-B seawater (S) (Type II), with Type I being dominant at 62.50% in both branches. The C. nasus from the SB comprise six migration patterns, while that from the NB has seven migration patterns. The C. nasus from both branches hatch in F habitats. At the time of capture, the C. nasus from the SB predominantly remain in F, accounting for 62.5%, while C. nasus from the NB primarily stay in B, accounting for 87.5%. Throughout the migration process, C. nasus from both branches switch between different habitats, with C. nasus from the NB exhibiting more frequent transitions between F and B, showing a greater reliance on the estuarine brackish habitat. The radius of the first blue region near the core (Lf) and freshwater coefficient (Fc) of the otolith for C. nasus from both branches are divided into three groups: long-distance freshwater dependence (LD), medium-distance freshwater dependence (MD), and short-distance freshwater dependence (SD), with the LD only appearing in the SB, while the NB is primarily represented by MD. There is a correlation between the differences in Lf among different groups of C. nasus and the differences in the distance from the spawning grounds of C. nasus in different sections of the Yangtze River to the estuary (DYRE), reflecting the distribution pattern of C. nasus spawning grounds in different sections of the Yangtze River. This study provides theoretical guidance for the protection of migration pathways and maintenance of spawning grounds for C. nasus, which have significant practical value in the precise management of C. nasus resources in the Yangtze River Estuary. [ABSTRACT FROM AUTHOR]

In 2020, the presence of a novel non-indigenous species, eastern tubenose goby Proterorhinus semipellucidus (Kessler, 1877), was documented in the Gulf of Finland, Baltic Sea. As tubenose goby invasion may have a comprehensive ecological impact on the local ecosystem, it has to be confirmed whether the species has established an independently reproducing population or persists through continuous invasions in this area. We examined the otolith microstructure to determine the age of specimens sampled from the southern and northern coasts of the Gulf of Finland. Additionally, otolith microchemistry analysis was carried out on the southern coast specimens. Otolith microstructure revealed the population's age structure, showing the presence of different age classes, including younger individuals. The microchemistry analyses suggested that the specimens had hatched in brackish water salinities similar to those found in the sampling areas. This indicates local reproduction instead of introduction from the virtually freshwater Neva Bay, which is most likely the donor area of the studied populations. These data confirm the establishment of a self-sustaining reproducing population of eastern tubenose goby in the Gulf of Finland, eastern part of the brackish Baltic Sea. [ABSTRACT FROM AUTHOR]

As the amount of agricultural waste produced annually worldwide is very high, numerous studies have been conducted with the aim of using them in the structure of composite materials that have a minimal impact on the environment, reduced costs, and can be used in various fields of activity. In this research, four types of composite materials were cast, with a reinforcement of chopped corn cobs and with a matrix of acrylic resin, respectively, of three hybrid resins having various mass proportions, where Dammar natural resin prevailed. The chemical structure of the composites with hybrid matrix was determined using molecular spectroscopic microanalysis, and some mechanical properties of all the composites were investigated. It was found that the values of the obtained mechanical characteristics were limited. [ABSTRACT FROM AUTHOR]

Adult plaice in the Irish Sea have distinct traits that reflect the spawning locations that could suggest a number of different populations. However, do connectivity pathways support this concept? Different tools are directed at measuring exchange or connectivity between different life‐history stages, and the challenge is to integrate the signals to obtain full life‐cycle estimates. Collectively, the different methods reveal stable connectivity between known spawning and nursery grounds, with sufficient exchange to maintain a single population with weak genetic structure. [ABSTRACT FROM AUTHOR]

Fish scale microchemistry can be used to make life‐history inferences, although ecological studies examining scale composition are relatively rare. Salmon scales have an external layer of calcium phosphate hydroxyl apatite (HAP). The structure, hardness, and calcium content of this layer have been shown to vary within and between species. This variation may lead to misinterpretation of trace element profiles. This study uses backscatter scanning electron microscopy with electron dispersive spectrometry to compare scales from salmon populations and to present a more detailed analysis of scale HAP than was previously available. Our findings extend the range of salmon populations for which HAP Ca is available and confirm previous findings that the HAP Ca is relatively invariable within this species. [ABSTRACT FROM AUTHOR]

Migratory patterns of the catfish Genidens genidens in four estuaries along the Brazilian Atlantic coast are reconstructed from otolith Sr/Ca, a salinity proxy, to test estuarine‐dependency. To facilitate interpretation of this proxy in otolith core‐to‐edge profiles, a Sr/Ca Reference Value for High Salinity (RVHSSr/Ca) of 4.88 mmol/mol was established experimentally, from fish specimens reared in water with a salinity level (33 psu) between estuarine and high salinity (marine) water. All wild specimens exhibited otolith Sr/Ca values higher than RVHSSr/Ca, suggesting that G. genidens utilizes environments with marine salinity. Our results reveal highly variable environmental histories, with at least five major habitat usage patterns. Most distinctive among these, we find that (a) fish from Paranaguá Estuarine Complex (PEC) exhibit high intraindividual heterogeneity; (b) most fish (57%) from Guanabara Bay (GB) exhibit prolonged exposure to very high salinities, often exceeding 36.5 psu levels found in some shelf sectors; and (c) some fish from Paraiba do Sul River, GB and PEC exhibit Sr/Ca values below RVHSSr/Ca consistent with estuarine residence. These results suggest that G. genidens is not strictly estuarine‐dependent. [ABSTRACT FROM AUTHOR]

Despite the benefits that can come from coordinated movement, many diadromous fishes have evolved partial migration strategies, where a portion of a population does not migrate. Co‐occurring life‐history variants might nonetheless gain some advantage by exhibiting congruent phenologies, with key events timed to follow the same cue. Here, we assess this possibility by examining otolith microchemistry and structure to quantify the lunar periodicity of hatching and metamorphosis according to migration strategy in a facultative amphidromous goby endemic to Hawai'i. Our analyses corroborated prior evidence that Awaous stamineus exhibits partial migration and that residential A. stamineus are often proportionately more abundant than the migratory form. Contrary to expectation, we found a significant difference in hatching time between migratory and residential A. stamineus. A higher proportion of A. stamineus migrants hatched at the full moon and metamorphosed at the new moon, whereas residents exhibited the opposite phenology. Comparisons to Sicyopterus stimpsoni intended to provide a broader context revealed that the obligately amphidromous species tends to hatch at the new moon and metamorphose at the full moon, mirroring the phenology of residential A. stamineus. Evidence of convergent lunar phenologies suggests that synchronising life‐history events can confer benefits that extend beyond species boundaries. Notably, phenological discordance could be acting as a prezygotic isolating barrier between sympatric life‐history variants, pointing to the presence of heretofore unrecognised evolutionary diversity within partially migratory species like A. stamineus. [ABSTRACT FROM AUTHOR]

Objective: Nonlethally sampled pectoral fin rays are commonly used as aging structures for Lake Sturgeon Acipenser fulvescens, but they tend to underestimate the true age in older, slow‐growing individuals (age > 14 years). Current aging practices involve counting bands along the structure, which are construed as annuli. Oscillations of certain trace elements corresponding with annuli have been seen across various fish species, with patterns continuing to the marginal edge of hard structures. This study explored the aging of fin rays by using microchemistry patterns in Lake Sturgeon of known age (n = 94; ages 5–21) to determine the potential use of this method as an alternative or supplementary aging technique. Methods: Elements were chosen for age determination analysis by examining the relationship between profile minima/maxima and visually interpreted annuli. Fish were assigned ages using three different methods: (1) traditional interpretation (counting annuli along the structure), (2) chemical interpretation (examination of seasonal variations in elemental profiles with visually identified annuli), and (3) a statistical model (multivariate multiple changepoint analysis with finite differencing using raw elemental profiles). Result: Mean absolute differences between age estimates and known age were significantly higher for the traditional interpretation method than for the chemical interpretation method. The mean coefficient of variation in estimated age was 11.14% for the traditional interpretation method and 4.04% for the chemical interpretation method. The changepoint model was able to correctly classify age for 100% of the samples within ±1 year in one population (ages 5–8) but could not classify samples from the second population (ages 12–21). Conclusion: Our results suggest that chemical aging techniques could provide more reliable age estimates for juvenile and subadult Lake Sturgeon when fin rays are the only aging option. Further work is required to determine the applicability of the model for assigning ages to older fish and for use with different populations and structures. Impact statementThis is the first published account of chemically aging Lake Sturgeon. Our results suggest that seasonally fluctuating chemicals found in fin rays may prove useful in providing more reliable age estimates for juvenile and subadult Lake Sturgeon compared to the traditional aging method of counting seasonal growth rings. [ABSTRACT FROM AUTHOR]

The oceanic whitetip shark, Carcharhinus longimanus, is a highly migratory, epipelagic top predator that is classified as critically endangered. Although this species is widely distributed throughout the world's tropical oceans, its assumed mobility and pelagic behavior limit studies to derive required lifetime data for management. To address this data deficiency, we assessed variation in the habitat use of C. longimanus by oceanic region and over ontogeny through time series trace element and stable isotope values conserved along the vertebral centra (within translucent annulus bands) of 13 individuals sampled from the central and eastern Pacific Ocean. Elemental ratios of Mg:Ca, Mn:Ca, Fe:Ca, Zn:Ca, and Ba:Ca varied significantly among individuals from both sampling regions while principal component analysis of combined standardized elements revealed minimal overlap between the two areas. The limited overlap was also in agreement with stable isotope niches. These findings indicate that C. longimanus exhibit a degree of fidelity to sampling regions but also connectivity in a proportion of the population. The relatively stable Sr:Ca ratio supports its occurrence in oceanic environments. The decreasing trends in Ba:Ca, Mn:Ca, and Zn:Ca ratios, as well as in carbon and nitrogen isotope values along vertebral transects, indicate that C. longimanus undergo a directional habitat shift with age. Combined elemental and stable isotope values in vertebral centra provide a promising tool for elucidating lifetime data for complex pelagic species. For C. longimanus, management will need to consider subpopulation movement behavior in the Pacific to minimize the potential for localized depletions. Further work is now required to sample individuals across the entire Pacific and to link these findings with genetic and movement data to define population structure. [ABSTRACT FROM AUTHOR]

The identification of trace element anomalies in soils has been proven to assist semi-mechanized small-scale gold operations. This study employs soil geochemistry combined with the microchemical signature of particulate gold from the Batouri goldfield to (1) vector possible gold-endowed lithologies introducing particulate gold into the overlying regolith, and (2) assess anthropogenic Hg used in purification of both primary and alluvial/eluvial gold by artisans. The soil geochemistry shows irregularly distributed anomalies of elevated Cu especially in the saprolite soil layer. Whereas in the lateritic soil layer, a Au-Ag-Hg metal association is reported for the first time in this gold district and could be linked to anthropogenic Hg used in gold recovery. Particulate gold recovered from the soil varies in shape from euhedral and irregular to sub-rounded, indicating a proximal lode source. The gold grains range in size from nano-particles to >300 µm and are Au-Ag alloys. The gold particles reveal inclusions such as quartz, silicate, zircon and ilmenite suggesting that the grains were dislodged from quartz veins within the granitic basement. Systematic variation in the microchemical signature of the gold grains is suggestive of spatial and temporal evolution of the mineralizing fluid. These results are consistent with investigations from similar geologic settings worldwide and validate the combined utility of gold fingerprinting and pathfinder elements in soil to examine deposit genesis in other gold districts globally. [ABSTRACT FROM AUTHOR]

Salmonids are well known for their natal homing behaviour, meaning they return to breed in the same area where they originated. However, not all individuals return to their natal breeding grounds—a behavioural trait known as straying. The prevalence of straying is difficult to explore and therefore quantitative estimates for straying are seldom reported. In this study, otolith microchemistry and genetics were combined to investigate patterns of straying over ecological and evolutionary time, respectively, between neighbouring rivers flowing into Mariager fjord, Denmark. Otolith microchemistry was used to determine the river of origin for sea trout (Salmo trutta) upon their return to freshwater and 288 SNP markers were used to determine genetic structure among the rivers in the fjord. In this system, where the distance between rivers is short, otolith microchemistry achieved 80% accuracy in assigning juvenile brown trout to their natal river, thus allowing us to determine that approximately 43% of the adult sea trout had returned to non‐natal rivers to spawn, with a similar proportion of strayers and natal homers in all of the rivers. Genetic analysis further supported that there was substantial gene flow among individuals originating from different rivers, indicating that sea trout in Mariager fjord make up one population. The findings obtained from otolith microchemistry and genetics complement each other and provide further evidence that sea trout in this system migrate to non‐natal rivers and spawn there, which consequently affects the genetic structure of the population. [ABSTRACT FROM AUTHOR]

Droplets and bubbles have a wide range of applications in industry, agriculture, and daily life, and their controllable manipulation is of significant scientific and technological importance. Versatile magnetically responsive manipulation strategies have been developed to achieve precise control over droplets and bubbles. To manipulate nonmagnetic droplets or bubbles with magnetic fields, the presence of magnetic medium is indispensable. Magnetic additives can be added to the surface or interior of droplets and bubbles, allowing for on‐demand manipulation by direct magnetic actuation. Alternatively, magnetically responsive elastomer substrates can be used to actuate droplets and bubbles by controlling the deformation of microstructures on the substrates through magnetic stimulation. Another strategy is based on untethered magnetic devices, which enables free mobility, facilitating versatile manipulation of droplets and bubbles in a flexible manner. This paper reviews the advances in magnetically responsive manipulation strategies from the perspective of droplets and bubbles. An overview of the different classes of magnetic medium, along with their respective corresponding droplet/bubble manipulation methods and principles, is first introduced. Then, the applications of droplet/bubble manipulation in biomedicine, microchemistry, and other fields are presented. Finally, the remaining challenges and future opportunities related to regulating droplet/bubble behavior using magnetic fields are discussed. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the study was to analyze the microchemistry of human bone in different regions of interest (ROIs) on histologic samples of implants retrieved postmortem by the innovative use of an environmental scanning electronic microscope (ESEM) connected to energy-dispersive x-ray spectroscopy (EDX). Materials and Methods: Maxillary and mandibular bone blocks with inserted implants (n = 12) were obtained postmortem from a patient. The histologic samples were observed uncoated using ESEM in quadrant backscattered condition. Two ROIs (approximately 750 x 500 μm) for each implant were analyzed corresponding to the cortical thread (cortical ROI) and the middle part of each implant (approximately 3.0 mm below; middle ROI). Different electron-dense bone tissue areas were detected through grayscale intensity quantification of ESEM images. Calcium (Ca), phosphorous (P), and titanium (Ti; atomic %) were evaluated by EDX, and Ca/P ratios were calculated and used as the index to identify areas with different mineralization. The presence of Ti contaminants was investigated by EDX microanalysis. Additional ROIs approximately 2.0 mm from the implant interface and not in connection with the implant surface were analyzed as the control. Results: Four bone areas (BAs) with different degrees of mineralization (from 1 as the lowest mineralized to 4 as the highest mineralized) were identified by Ca and P content and by tissue electron density. BA1 (bone marrow areas) and BA2 (areas with active bone remodeling) proved to have low levels of Ca and P, while BA3 (mineralized new bone areas) and BA4 (control cortical bone) had higher content of Ca and P and higher electron density. Mandibular ROIs displayed higher percentages of BA3 and BA4, while maxillary ROIs revealed a greater presence of BA2 and moderate presence of BA1. Control bone showed a high percentage of BA4. Cortical and middle ROIs showed similar BA distribution within mandibular bone, whereas in maxillary bone, a slightly higher presence of BA1 was observed. Ti ions were detected in ROIs of all specimens; the atomic % significantly decreased in the most distant areas. Ti particles were observed close to the implant interface. Analyses 2.0 mm distant from the implant thread revealed low traces of Ti in healthy bone tissue. Conclusion: The high percentage of BA3 and BA4 in mandibular blocks associated with low presence of BA2 suggested the fast formation of compact bone tissue after 7 months from the implant placement. The presence of BA2 in maxilla blocks suggested active bone remodeling still present after 7 months. Ti particles were observed throughout the ROIs with and without bone remodeling activity. ESEM-EDX resulted as a suitable technique to obtain more complete information on microchemistry composition and density/mineralization of bone around implants. For clinical significance, maxillary and mandibular peri-implant bone revealed different mineralization patterns, which means different healing times. The presence of Ti particles at the bone-implant interface and ion translocation, likely due to wear forces in the times following the implant insertion, do not affect the bone remodeling process. [ABSTRACT FROM AUTHOR]

To clarify potential trans-oceanic connectivity and variation in the natal origin of albacore tuna (Thunnus alalunga) from the southwest Indian Ocean (SWI) and the southeast Atlantic (SA), lifetime otolith elemental signatures were assessed from 46 adults sampled from Reunion Island, and 26 juveniles(group 2+) sampled from two locations along the Atlantic coast of South Africa. LA-ICP-MS analysis was used to assess the multi-elemental composition in B, Ba, Mg, P, Sr, and Zn along the otolith edge (chemical signatures of the capture area), but also near the otolith primordium (spawning origin) and in an area located at 1400–1600 µm from it (nursery origin). Two groups of distinct near-primordium multi-elemental signatures, denoting potentially discrete spawning origins (SpO), were identified using hierarchical clustering. Each of the two SpO was found to contribute to the albacore stocks from all the areas sampled, suggesting a common spawning origin in some fish from the SWI and from the SA, and complex migrations between the two oceans. Three potentially discrete primary nursery sites were identified, each contributing to SA juvenile and SWI adult capture sites differently. The timing for the trans-oceanic movements observed for each albacore capture zone and its implications for local stock management are discussed. [ABSTRACT FROM AUTHOR]

Although otoliths are widely used as archives to infer life‐history traits and habitat use in fishes, their biomineralization process remains poorly understood. This lack of knowledge is problematic as it can lead to misinterpretation of the different types of signals (e.g., optical or chemical) that provide basic data for research in fish ecology, fisheries management, and species conservation. Otolith calcification relies on a complex system involving a pericrystalline fluid, the endolymph, whose organic and inorganic compositions are spatially heterogeneous for some constituents. This property stems from the particular structure of the calcifying saccular epithelium. In this study, we explored the spatial heterogeneity of elemental incorporation in otoliths for two species of high economic interest, European hake Merluccius merluccius (L. 1758) and European sea bass Dicentrarchus labrax (L. 1758). Two‐dimensional mappings of chemical elements were obtained using UV high‐repetition‐rate femtosecond laser ablation (fs‐LA) system coupled to a high‐resolution inductively coupled plasma sector field mass spectrometer analyses on transverse sections of sagittae. Results highlighted a clear asymmetry between proximal (sulcus) and distal (antisulcus) concentrations for elements such as magnesium (Mg), phosphorus (P), manganese (Mn), and potassium (K) with concentration gradient directions that varied depending on the element. Strontium (Sr) and barium (Ba) did not show a proximo‐distal gradient. These results are discussed in light of current knowledge on the endolymph composition and the mechanisms that lead to its compartmentalization, highlighting the need for further research on otolith biomineralization. Operational implications for studies based on otolith chemical composition are also discussed with emphasis on advice for sampling strategies to avoid analytical biases and the need for in‐depth analyses of analytical settings before comparing otolith signatures between species or geographical areas. [ABSTRACT FROM AUTHOR]

The Lebranche mullet (Mugil liza) is an economically important estuarine species found along the coast of Brazil. The southern population of this species ranges from the coast of the state of São Paulo (23°S) to the coast of Argentina (36°S). It migrates annually among estuaries in Argentina, Uruguay, and southern Brazil to reproduce in their marine spawning grounds (~26°S). We evaluated whether variations in the otolith chemical composition for fish acquired at nursery grounds can be used to make distinctions among 4 nursery areas of the southern population. Analysis of otolith microchemistry included concentrations of 9 elements: lithium (Li), magnesium (Mg), copper, zinc, strontium (Sr), cadmium, barium, lanthanum, and lead. When using random forest classification algorithms, the maximum accuracy of 96% in assignment of nursery habitat for Lebranche mullet between 2 groups (fish caught at nurseries in Brazil and fish migrating from waters of Uruguay and Argentina) was achieved with the combination of Li, Mg, and Sr. Our results indicate that the elemental composition of otoliths can be an important tool for establishing connectivity between nursery areas used by Lebranche mullet. We discuss the implications of this result for the structure of the population and the management of the mullet fishery in southern Brazil relative to the limitations of the methods we employed. [ABSTRACT FROM AUTHOR]

Yellowstone cutthroat trout inhabiting Yellowstone Lake have declined substantially over the past 25 years as a result of predation by invasive lake trout, the presence of whirling disease, and periods of persistent drought. We used otolith microchemistry to assess whether cutthroat trout recruitment patterns have changed in response to these environmental stressors. Though water chemistry variation among the 22 sampled spawning tributaries was low, we identified 9 distinct spawning stream clusters. Random forest models were developed for assessing relative recruitment, yielding a high classification accuracy of 84.4% for known-origin cutthroat trout fry otoliths and 79.0% for simulated otolith signatures based on water chemistry. Proportion of recruitment varied significantly between pre- and post-stressor samples (X2 = 15.40, P = 0.03). The majority of pre- (0.84) and post-stressor (0.77) recruitment occurred in the same three stream clusters, but there was a notable decrease in recruitment in streams with high whirling disease prevalence, and a notable increase from the tributary cluster without whirling disease and with low lake trout predation risk. Conservation efforts should be focused on protecting important spawning tributaries and improving cutthroat trout recruitment in spawning streams that in the past likely contributed much greater numbers of fish. [ABSTRACT FROM AUTHOR]

SmCo‐based permanent magnets with nanocellular structure exhibit significant advantage for high‐temperature applications. Due to the lack of experimental intrinsic magnetic parameters and unclear nanocellular interface, a fully understanding on coercivity mechanism is still limited. Here the intrinsic magnetic properties of designed two single‐phase alloys representing nanocellular structure at various temperatures are acquired. Using 3D atom probe and high‐angle annular dark‐field scanning transmission electron microscopy, the existence of the nanoscale transition zones located at nanocellular interface is revealed. Moreover, the transition zones exhibiting high magnetocrystalline anisotropy is found to contribute dominantly to the coercivity. The calculated coercivity via micromagnetic simulation considering transition zones agrees well with the tested coercivity at various temperatures. This knowledge deepens the fundamental understanding on coercivity mechanism. [ABSTRACT FROM AUTHOR]

Copyright of Journal of University of Anbar for Pure Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Uroteuthis edulis is a widespread neritic cephalopod with a complex population structure and wide migration range. The life history of this species is still ambiguous. Statolith microchemistry is an effective indicator to reveal individual life history and migration route. In this study, the statolith microchemistry of U. edulis in different stocks was determined by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and the statolith diameter was clustered by using a multiple regression tree model (MRT) to analyze differences in the ratio of various elements to Ca at different life history stages. The analysis results showed that sodium (Na), magnesium (Mg), iron (Fe), strontium (Sr), and Barium (Ba) were the effective elements in four stocks. Five clusters were divided according to MRT and represented five ontogenetic stages. The Sr/Ca, Ba/Ca, and Mg/Ca ratios in summer and autumn stocks were significantly different from those of spring and winter stocks (P < 0.05). From the embryonic stage to sub-adult stage, the Sr/Ca ratio in spring and winter stocks was higher than those of summer and autumn stocks. The Sr/Ca ratio in spring, summer, and winter stocks were significantly different among different ontogenetic stages (P < 0.05). The Ba/Ca ratio in the four stocks were significantly different between larva and adults (P < 0.05). Therefore, the Sr/Ca and Ba/Ca ratios can be selected as the key indicators to speculate on the migration route of U. edulis. This study improves understanding of the statolith microchemistry differences among different stocks of U. edulis. [ABSTRACT FROM AUTHOR]

Processes responsible for population structuring across spatial and temporal scales represent key components in understanding speciation and evolution. We use a hierarchical approach to investigate the degree and mechanisms of structuring in landlocked and diadromous populations of the facultatively amphidromous fsh Galaxias brevipinnis (kōaro) across various temporal and spatial scales in southern New Zealand. To determine long-term structuring of kōaro, populations in multiple lakes and coastal sites were compared genetically. Short-term population structuring was assessed using otolith microchemistry for a subset of sites, and behavioural mechanisms driving population structuring were assessed via larval distributions. Genetic data show that lakes foster divergence of lake-developing kōaro populations from each other and from coastal stream populations, but there is relatively little structuring within coast or lake populations. Otolith analyses, however, indicate that on a shorter timescale, most kōaro larvae do not disperse widely, i.e. recruitment is local. Thus, lake and coastal populations show a distinct meta-population structure based on catchment, in contrast to the prevailing assumption of widespread dispersal, with implications for management. Most kōaro larvae were distributed in river plumes, suggesting that a simple larval behavioural mechanism, e.g. positive rheotaxis, may result in larval retention within catchments and lakes. Larvae not retained in plumes create opportunities for genetic exchange within-lake or among coastal sites. Genetic divergence of lake populations of kōaro, resulting from both intrinsic behavior and extrinsic landscape, provides insight into the potential of G. brevipinnis to diversify and speciate when landscape and circumstances align, with implications for the management of this and other facultatively amphidromous species. [ABSTRACT FROM AUTHOR]

Copyright of Ecosphere is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fish stocking occurs in aquatic systems for conservation purposes, to create or enhance recreational fisheries and to enhance wild-catch commercial fisheries. Identifying and quantifying the contribution of stocking efforts to wild populations is crucial to informing these management objectives. Provenance determination methods trade off accuracy, replicability, and cost-effectiveness at fishery-relevant scales. We present and assess multiple methods for provenance determination using a case study of barramundi (Lates calcarifer) in the Dry Tropics region of northern Australia. A novel application of near-infrared spectroscopy (NIRS) is compared to two established methods for fish provenance, otolith microchemistry and genetic parentage analysis using microsatellites. The otolith microchemistry method was able to provide extremely high provenance resolution (>99% accuracy). The microsatellite parentage analysis method had a slightly lower overall accuracy (95%), likely as a result of genetic introgression in this region. Provenance determination using otolith NIRS had the lowest overall accuracy (76%). Once limitations regarding spectral noise, image resolution, and sample size are addressed, NIRS may have potential for cost-effectively determining provenance in fish. [ABSTRACT FROM AUTHOR]

Migratory fishes exert important influences on tropical river food webs, but these species are often most vulnerable to environmental change. Movement patterns of fishes in tropical rivers are also generally poorly understood, hindering conservation efforts.Common snook, Centropomus undecimalis, depend on connected coastal habitats for reproduction and growth and can migrate extensively up rivers when not hindered by barriers to movement. In southern Mexico, they are frequently captured 300 river km or more upstream from the delta of the Usumacinta River. The Usumacinta is a large river system with no mainstem dams, providing an expansive network of connected river, stream and wetland habitats which form a much larger migratory domain that exists in many other systems where common snook have been studied.To assess whether fish captured in different zones were associated with different natal habitats or distinct migratory patterns, variation in common snook otolith chemical signatures was examined in the Usumacinta River from the Gulf of Mexico coast to as far as 600 river km upriver.Otolith microchemistry was useful for characterizing migratory histories of individuals, but there was no clear evidence that fish captured in different river zones used different types of natal habitats. Based on lifetime Sr:Ca in otoliths, a diverse array of movement patterns was evident in the Usumacinta system, with 97% of common snook showing evidence of freshwater habitat use.Prevalent use of riverine habitats by common snook far from the coast reinforces the need to preserve connectivity in the Usumacinta River and other undammed systems supporting migratory species. The natural flow regime and lack of barriers allow for longitudinal and lateral connectivity in this system, providing pathways for migratory species to move extensively and have access to an array of habitats, including productive floodplain lagoons. [ABSTRACT FROM AUTHOR]

The identification of trace element anomalies in soils has been proven to assist semi-mechanized small-scale gold operations. This study employs soil geochemistry combined with the microchemical signature of particulate gold from the Batouri goldfield to (1) vector possible gold-endowed lithologies introducing particulate gold into the overlying regolith, and (2) assess anthropogenic Hg used in purification of both primary and alluvial/eluvial gold by artisans. The soil geochemistry shows irregularly distributed anomalies of elevated Cu especially in the saprolite soil layer. Whereas in the lateritic soil layer, a Au-Ag-Hg metal association is reported for the first time in this gold district and could be linked to anthropogenic Hg used in gold recovery. Particulate gold recovered from the soil varies in shape from euhedral and irregular to sub-rounded, indicating a proximal lode source. The gold grains range in size from nano-particles to >300 µm and are Au-Ag alloys. The gold particles reveal inclusions such as quartz, silicate, zircon and ilmenite suggesting that the grains were dislodged from quartz veins within the granitic basement. Systematic variation in the microchemical signature of the gold grains is suggestive of spatial and temporal evolution of the mineralizing fluid. These results are consistent with investigations from similar geologic settings worldwide and validate the combined utility of gold fingerprinting and pathfinder elements in soil to examine deposit genesis in other gold districts globally.

Recent genomic study on Greenland halibut Reinhardtius hippoglossoides throughout the Northwest Atlantic revealed genetic differentiation between the Gulf of St. Lawrence and the remainder of the Northwest Atlantic. Knowledge of migration and thus connectivity among fish populations is key to understanding the stock dynamics of commercial species and establishing effective management strategies. In this study, we use otolith microchemistry to assess the population structure and define more clearly the potential connectivity of Greenland halibut among Saguenay Fjord, the Estuary, and the Gulf of St. Lawrence (EGSL) and outside this system. Otolith margins and cores were analyzed to determine the elemental fingerprints. The margin elemental fingerprints (Mg, Sr, and Ba) were used to infer spatial differentiation, and quadratic discriminant analysis resulted in an overall reclassification success of fish to their capture site of 59%. The core elemental fingerprints indicated three chemically distinct juvenile sources, suggesting high connectivity in the EGSL supporting the St. Lawrence Estuary as a main nursery. Our results also suggest that one of these three sources has a smaller contribution relative to the other sites. [ABSTRACT FROM AUTHOR]

Objective: A recent expansion of the northern stock of Black Sea Bass Centropristis striata into the northern Gulf of Maine raises questions about this species' movement and population dynamics in this region. Determining the origin of these fish is essential, as dramatic changes in migration patterns or current population boundaries could have profound effects on stock assessment estimates and subsequent management regulations. Methods: In this study, we measured otolith core concentrations of stable isotopes (δ18O, δ13C) and trace element:calcium ratios (Mg:Ca, Mn:Ca, Cu:Ca, Zn:Ca, Ba:Ca, Sr:Ca) to assess the natal origin of Black Sea Bass that were caught off the coast of Maine. Spawning condition adults from southern New England (SNE) and the mid‐Atlantic Bight (MAB) were used to characterize the chemical fingerprint of these known spawning regions. Result: Unique chemical fingerprints were identified for fish from SNE and the MAB, with high reclassification success using random forest analysis (16% error rate). The classification of Black Sea Bass of unknown origin that were caught in Maine waters indicated that 85% of the samples matched to SNE and 13% to the MAB, whereas one sample remained unclassified. Conclusion: Results from this study support the current management population separation of the northern stock of Black Sea Bass between SNE and the MAB and lends additional information to the understanding of this species' movement into the northern Gulf of Maine. As fish stocks around the world continue to shift into new regions due to climate change, knowledge of their natal origin will be critical to long‐term sustainable management of this species. Impact statementDetermining which population Black Sea Bass located in Maine came from helps scientists understand how these fish migrated there, their potential for success, and their expected growth and maturity. If this species becomes more abundant in the region, this information could help inform regulation surrounding conservation and fishing practices. [ABSTRACT FROM AUTHOR]

Tub gurnard, Chelidonichthys lucerna (Linnaeus, 1758), is a Mediterranean-Atlantic benthic species usually captured as by-catch by Portuguese traditional fisheries and considered the most important commercial fish species of the family Triglidae. However, to date, little is known about its habitat residency and whether the species can be considered a marine estuarine-dependent fish. Otolith microchemistry has proven effective in providing information about fish movement patterns throughout different water salinities. In this study, core-to-edge transects of Sr:Ca in the fish saccular otoliths of 35 juveniles of C. lucerna captured in March 2007 by a scientific survey along the Portuguese coast were used to assess the species movement between brackish and marine waters. Data suggest that most individuals (97%) have an estuarine-dependent profile, with 63% showing a clear presence in marine waters during the early life history periods. Evidence of an estuarine residence throughout the fish life cycle was found in only 3% of individuals. Ba:Ca profiles did not reflect an inverse relationship with Sr:Ca salinity results but corroborated findings from other authors about the influence of upwelling processes and freshwater runoffs on Ba incorporation into the otoliths of coastal fish. Furthermore, the data also showed that C. lucerna can occupy and migrate among habitats with diverse salinity degrees, showing high environmental plasticity and adaptation. [ABSTRACT FROM AUTHOR]

Small differences in the contents of surface active elements can change flow direction and thus heat transfer, even for different batches of a given alloy. This study aims to determine the effects of sulfur on weld bead morphology in the laser process. The paper presents the results related to the weld bead shape of two thin AISI 304 industrial stainless steel casts. One cast contains 80 ppm (0.008%) of sulfur, considered as a high sulfur content, and the other one contains 30 ppm (0.003%) sulfur, which can be considered low sulfur. The welds were executed using a CO2 laser. The effects of laser power (3.75, 3.67, 6 kW), welding speed (1.25, 2.40, 2.45, 3.6 m/min), focus point position (2, 7, 12 mm), and shield gas (Helium, mixed 40% helium + 60% argon and mixed 70% helium + 30% argon) with a flow rate of 10 L/min on the depth of the weld (D) and the aspect ratio (R = D/W) were investigated using RSM (response surface methodology). The experimental results show that the transfer of energy from the laser beam to the workpiece can be total in cases where the selected welding parameters prevent plasma formation. For the 304 HS cast, the focus point is the major factor in determining the depth of penetration, and its contribution is up to 52.35%. However, for 304 LS, the interaction between shield gas and focus point seems to play an important role, and the contribution of their interaction raises to 28% in relation to the laser depth of the weld. Moreover, the study shows that sulfur plays a surface-active role only in the case of partial penetration beads, so that a 56% partially penetrated weld supports the hypothesis of its surface-active role in the formation of the weld pool. However, a penetration of only 36% confirms the effects of a sulfur surface-active when the bead is fully penetrated. [ABSTRACT FROM AUTHOR]

Draining into the northern Baltic Sea, River Simojoki is an important spawning river for Atlantic salmon. The present study aimed to preliminary explore the potential of analysing the elemental composition of otoliths to distinguish the within-river nursery area of origin for salmon. Parr were sampled at three nursery areas in the river and smolts of unknown origin were sampled near the river mouth during the migration to the sea. The concentrations of multiple elements and the strontium 87Sr/86Sr isotopic ratio in the otoliths were analysed using single- and multi-collector laser ablation inductively coupled plasma mass spectrometry, respectively. Based on the otolith elemental variables, parr could be reclassified to the sampled nursery areas using discriminant function analysis and random forest with a success rate of 53.3% and 63.3%, respectively. However, for parr sampled at the uppermost nursery area in the river, the success rates were 90% and 100%, respectively. Applying the classification models trained on the parr samples to determine which nursery area sampled smolt originated from was constrained by the limited sampling of parr, both in sample sizes and the coverage of the nursery areas found in the river. [ABSTRACT FROM AUTHOR]

Titanium and its alloys are widely employed in commercial dental devices. Because the surface morphology and chemical composition of Ti‐based dental implants play a relevant role in osseointegration, three different commercial threaded implants have been investigated by scanning electron microscopy and X‐ray photoelectron spectroscopy (XPS). The Implants A and C were made of pure Ti whereas the Implant B was made of Ti6Al4V alloy. Obtained results evidenced the common features and differences due to specific process parameters used in the treatments of mordanting and sandblasting for surface roughening. Implant A exhibits a uniform surface covered by very small dimples of about 1–2 μm. The surface of Implant B is not homogeneous: The thread tops present an irregular morphology (dimples size >10 μm) while finer dimples (about 1 μm) are observed along the thread flanks and valleys. Implant C shows an irregular morphology with dimples of different sizes and shapes distributed on thread tops, flanks, and valleys. XPS analyses revealed the presence of metal oxides: TiO2 in all the implants; Al2O3 and V2O5 only in the implant B. Moreover, these results demonstrated that Mg2SiO4 is present on the surface of Implant A, probably due to a specific preparation process. Obtained results have been discussed on the basis of the factors promoting the osseointegration. [ABSTRACT FROM AUTHOR]

New petrographic and microanalytical studies of mineral inclusions in the Purang ophiolitic chromitites (SW Tibet) are used to scrutinize the evolution of the associated Cretaceous sub-oceanic lithospheric mantle section. Silicate inclusions in the chromite grains include composite and single-phase orthopyroxene, clinopyroxene, amphibole, and uvarovite. Most inclusions are sub-rounded or globular, whereas a few inclusions exhibit cubic/octahedral crystal morphologies. The latter are randomly distributed in the large chromite grains, though discrete aggregates are consistently confined to the grain centers. Abundant micrometer-scale, clinopyroxene inclusions are topotaxially aligned along crystallographic planes. Less-abundant sulfide, wüstite, apatite, and uvarovite inclusions are observed in some samples. The trace element geochemistry of the Purang chromitite evoke parental MORB- and boninitelike melts, consistent with the supra-subduction zone setting. The δ26Mg values of the high-Cr and high-Al chromitites range from –0.25 to –0.29‰ and –0.05 to –0.32‰, respectively. The associated harzburgite has nearly overlapping δ26Mg values of –0.13 to –0.37‰, but pyroxenite sills show distinct δ26Mg values (–0.61 to –0.67‰). The variable Mg isotope signatures, combined with abundant exotic, ultrahigh-pressure and super reduced (UHP-SuR) mineral inclusions in the chromite grains, suggest that recycling and recrystallization under different mantle conditions played an important role in the genesis and evolution of these rocks. Furthermore, discrete silicate, sulfide, and metal alloy inclusions in the Purang chromitites are comparable to those reported in other Tethyan ophiolites, and collectively suggest a common geodynamic evolution. [ABSTRACT FROM AUTHOR]

In a system that uses supplemental stocking to enhance a fishery that serves a dual purpose, an understanding of the contributions from natural and hatchery-produced fish is important so that hatchery resources can be appropriately allocated. Kokanee Oncorhynchus nerka were first stocked in Flaming Gorge Reservoir (FGR), Wyoming–Utah, in 1963 and serve a dual purpose as a prey resource and sport fish. Although natural recruitment occurs in the reservoir, a supplemental stocking program was initiated in 1991. We sought to identify the natal origin (i.e., natural, hatchery) of kokanee in FGR using otolith microchemistry. We evaluated return to the creel, composition of spawning aggregates, and growth of kokanee in FGR and focused on differences associated with natal origin. We analyzed kokanee otoliths that we collected from hatcheries (n = 60) and FGR (n = 1,003) for the strontium isotope ratio, 87Sr/86Sr, using laser ablation and a multicollector inductively coupled plasma mass spectrometer. We conducted Kruskal–Wallis tests to compare the strontium isotope ratios from the otolith edge of kokanee that we sampled from hatcheries and FGR. Based on 87Sr/86Sr ratios, we could distinguish natural-origin kokanee from 11 of the 12 hatcheries (P < 0.01); however, the Wigwam Hatchery was not significantly different from FGR (P = 0.84). We used model-based discriminant function analysis to assign natal origins for kokanee caught in FGR. Hatchery contribution to the population at large varied from 21 to 50% among year classes from 2014 to 2018. The percentage of hatchery origin kokanee in the creel (18–50%) was similar to what we observed in the population. Hatchery-produced kokanee contributed a higher proportion to tributary-spawning aggregates (40–90%) than shoreline-spawning aggregates (19–58%) by sample year. Growth of natural and hatchery kokanee was similar, suggesting similar performance in the system. Results from this study identify that hatchery supplementation contributes to the population and recreational harvest of kokanee in FGR. This research also provides insight into the ecology of kokanee that is useful for better understanding kokanee population dynamics in reservoir systems. [ABSTRACT FROM AUTHOR]

Makouré area belongs to the Nyong group and is located in the eastern vicinity of the Bidou polymetallic project. It is a green field terrain. To investigate the gold prospectivity of the area, 72 stream sediment samples were collected from which visible gold particles were picked and subjected to microchemical analysis; also, induced polarization geophysical surveys were done on eight (08) E-W lines, for a total distance of 26 km, using a pole-dipole array with 100 m long receiver dipoles and a station spacing of 50 m. Stream sediments in Makouré contain gold particles; the visible gold grains are subangular, subrounded, and dendritic with complex outlines. BSE images and microchemistry revealed two types of gold particles in Makouré area: the high-Ag gold particles showing Ag-depleted rim (Au: 77 to 98 wt%, Ag: 1.34 to 20.8 wt%) and the low-Ag gold particles having no zonation (Au: 98.14 to 99.85 wt%, Ag: 1.97 to 3.2 wt%). Cu contents of all the samples are less than 2.5 wt%, and other elements such as Pt, Ni, and Cr are almost undetectable in all the studied grains. Their fineness varies from 787.4 to 986.6. The overall composition of various studied particles infers mesothermal orogenic gold deposits in Makouré. The induced polarization geophysical surveys reveal two gold targets, namely, ME and MW, characterized by low resistivity (less than 700 Ohm-m) and high chargeability (more than 30 Mv/V). The almost perfect overlapping of low resistivity and high chargeability in the identified targets inferred a disseminated gold mineralization associated with sulfide and clay in Makouré area. The ubiquity of ME and MW in various surveyed IP lines suggests that the mineralization is controlled by structures trending N-S, subparallel to the regional shear zone affecting the Nyong group. To strengthen the reliability of ME and MW prospects defined from geophysical data in Makouré, geochemical surveys and diamond drilling are recommended. [ABSTRACT FROM AUTHOR]

ABSTRACTThe Balikumbat area is located within the Mount Bamenda, Cameroon. The area hosts a significant quantity of undocumented coarse-grained detrital rutiles, and It is made-up of rhyolites, granites, and banded gneisses. The rutiles grains are zoned, the core is yellowish-brown and composed mainly of pure TiO2 (TiO2>98 wt. % and FeO

We estimated the proportion of hatchery and natural fall spawning chum salmon returning to the Amur River using chemical markers specific to hatchery-origin fry. We used otolith microchemistry technique to identify fish with artificial origin among returning spawners. First, we found that juveniles of artificial origin had higher values of the Sr:Ca molar ratio of the otoliths' edge zone compared with juveniles of natural origin, what can be related to the use of rearing feed produced from raw materials of marine origin rich in strontium. Then we observed that most of the spawners from Anyuisky Hatchery and from the Amur River mouth at the start of the spawning migration has also the higher value of Sr:Ca molar ratio of the juvenile zone of otoliths. Also, adults with higher values of the Sr:Ca molar ratio are characterized by a skewed right in the peak of the age distribution. Both, the age structure and phenological shift in the time of spawning migration of individuals with higher value of the used chemical marker corresponds to results of studies on hatchery-produced chum salmon completed at different parts on Northern Pacific. The results of this study will be used in the management of Amur fall chum salmon fisheries, and also demonstrates the necessity of the development of specific measures for increasing the survival of juvenile anadromous salmonids released at large rivers and exposed to prolonged freshwater migration to the ocean. As a further application of the methodology, we plan to identify the markers specific to each of the hatcheries and main spawning tributaries belonging to Amur River catchments. This will be an important step in the evaluation of the contribution of different stocks in mixed fisheries and also in the estimation of the effect of hatchery releases on naturally spawning stocks of Amur fall chum. Following to, our results may indicate the applicability of this approach for the determination of artificialorigin fish in a mixed sample of the Amur fall chum salmon. [ABSTRACT FROM AUTHOR]

Life-history traits of eels display a high level of phenotypic plasticity in response to large-scale biogeographical drivers, as well as local conditions encountered during the continental phase. Here, we provided a biogeographical snapshot of the variability of life-history traits of eels (Anguilla anguilla), across a large proportion of their natural distribution range. Silver eels (n = 99) were collected across eleven European catchments to investigate how life-history traits vary along geographical and saline habitats, as it was inferred from the Sr:Ca ratio in otoliths. Among 13 life-history traits tested, 3 of them such as total length, body or liver weight were related to geographical coordinates. Overall, eels grow faster in southern Europe and migrate earlier suggesting that the silvering process is related to the local growth conditions more than fish age. The salinity profiles revealed by the otoliths' Sr:Ca ratios indicate that eels with a brackish life-history generally grow faster, reach larger size-at-age, and have a better condition than eels living in freshwater. This observation associated with the lower abundance of the sanguivorous swimbladder nematode, Anguillicola crassus, confirms the importance of brackish areas for sustaining the eel production. A large proportion of the observed variation of life-history traits remained unexplained by the biogeographical trends and salinity condition, which suggests that other drivers act at the catchment scale. [ABSTRACT FROM AUTHOR]

The Cu-Fe ore deposits of the Chouichia abandoned mine are considered among the most complex mineralizations in the northwest Tunisia due, in particular, to their multi-phased poly-metallic character. The deposits fit into the front of the North African thrust domain of Alpine and Atlas orogenies. The mineralization is associated with hydrothermal fluid circulations through the Fej-Et-Tamer deep-rooted accident. Petrography, microanalysis by transmission electron microscopy and scanning electron microprobe allowed to determine the mineral association, the paragenetic phases and to retrace the thermodynamic conditions of the mineralizing fluids. Five mineralizing phases are defined. Native silver, silver minerals (proustite-pyrargyrite, acanthite-argentite), native gold, molybdenite, cinnabar, pyrrhotite, barite and bornite are first observed. Native silver is frequently in association with silver minerals during the later mineralizing phases. Native gold is observed in polished sections in intergranular vug of siliceous facies or as inclusions in quartz. Sulfides and sulfosalts can be enriched in many metallic elements (Bi, Hg, Ag, Au, Sn). The calculated empirical formulae for the Fahlore's solid solution (tetrahedrite-tennantite) show high Cu values reaching 11.832 apfu for tetrahedrite. According to the literature (Repstock et al. 2016; Shapovalova et al. 2019), such a Cu-excess makes the tetrahedrite from the Chouichia deposits the richest in copper so far cited. The thermodynamic approach using minerals/mineral associations as geothermometers suggests mineralizing fluid temperatures, for the main vein phases, between 200 and 500 °C providing a subsurface heat source. The last mineralizing phase is marked by native silver, silver minerals and by cooling below 178.85 °C. [ABSTRACT FROM AUTHOR]

Preparation of high-quality sequencing libraries is a costly and time-consuming component of metagenomic next generation sequencing (mNGS). While the overall cost of sequencing has dropped significantly over recent years, the reagents needed to prepare sequencing samples are likely to become the dominant expense in the process. Furthermore, libraries prepared by hand are subject to human variability and needless waste due to limitations of manual pipetting volumes. Reduction of reaction volumes, combined with sub-microliter automated dispensing of reagents without consumable pipette tips, has the potential to provide significant advantages. Here, we describe the integration of several instruments, including the Labcyte Echo 525 acoustic liquid handler and the iSeq and NovaSeq Illumina sequencing platforms, to miniaturize and automate mNGS library preparation, significantly reducing the cost and the time required to prepare samples. Through the use of External RNA Controls Consortium (ERCC) spike-in RNAs, we demonstrated the fidelity of the miniaturized preparation to be equivalent to full volume reactions. Furthermore, detection of viral and microbial species from cell culture and patient samples was also maintained in the miniaturized libraries. For 384-well mNGS library preparations, we achieved cost savings of over 80% in materials and reagents alone, and reduced preparation time by 90% compared to manual approaches, without compromising quality or representation within the library.

Effective conservation of endangered species requires knowledge of the full range of life-history strategies used to maximize population resilience within a stochastic and ever-changing environment. California's endemic Delta Smelt (Hypomesus transpacificus) is rapidly approaching extinction in the San Francisco Estuary, placing it in the crossfire between human and environmental uses of limited freshwater resources. Though managed as a semi-anadromous species, recent studies have challenged this lifecycle model for Delta Smelt, suggesting the species is an estuarine resident with several localized "hot-spots" of abundance. Using laser-ablation otolith strontium isotope microchemistry, we discovered three distinct life-history phenotypes including freshwater resident (FWR), brackish-water resident (BWR), and semi-anadromous (SA) fish. We further refined life-history phenotypes using an unsupervised algorithm and hierarchical clustering and found that in the last resilient year-class, the FWR (12%) and BWR (7%) comprised a small portion of the population, while the majority of fish were SA (81%). Furthermore, the semi-anadromous fish could be clustered into at least four additional life-history phenotypes that varied by natal origin, dispersal age and adult salinity history. These diverse life-history strategies should be incorporated into future conservation and management efforts aimed at preventing the extinction of Delta Smelt in the wild.

Silver Carp Hypophthalmichthys molitrix are highly mobile and fecund planktivorous cyprinids that have invaded much of the Mississippi River and are known to alter food webs and compete with native planktivores. In 2016, for the first time, an abundance of age‐0 Silver Carp (n = 12,208; 16–231 mm) were captured at many (n = 11) sites upstream of Lock and Dam 19 on the upper Mississippi River. Previous reports were of a few individuals at a few locations; however, effort to capture juveniles of this size was likely less in previous years. Determining the origin, frequency, and timing of the reproductive events that led to this large year‐class is important for determining control strategies. We used otolith microstructure and microchemistry from age‐0 Silver Carp to estimate timing and frequency of spawning and early life environments of these fish. Hatch dates were determined from the lapillus otoliths of 190 age‐0 Silver Carp (16–231 mm), and early life environments were identified from otolith microchemistry for 124 of these fish (64–231 mm). Age‐0 Silver Carp were collected from Pools 18 and 19 during July–October 2016 by using a variety of sampling gears. We identified 10 cohorts with hatch dates ranging from May to August 2016 and with main‐stem Mississippi River (75%) and tributary (23%) early life signatures. Tributary otolith chemistry signatures were present in all cohorts between May and July (n = 8) but were absent from the August cohorts (n = 2). Our results indicate that tributaries and small tributary streams, in addition to the main‐stem river, play an important role in Silver Carp recruitment in areas near the reproductive front, where management actions (e.g., contract removal and deterrents) are often targeted. [ABSTRACT FROM AUTHOR]

Invasive Silver Carp (Hypophthalmichthys molitrix) have established populations throughout the Missouri River basin. The main-stem Missouri River has undergone a multitude of alterations, creating a channel with greater mean depths and velocities, limiting optimal habitat for Silver Carp. Tributaries to the Missouri River may provide refuge from the swift flows within the main-stem Missouri River and, therefore, may play a vital role in the life-cycle of Silver Carp throughout the basin. Understanding the spatial extent under which these invasive fish function in this large, open river system is crucial to inform management efforts. Here, we used otolith microchemistry of Silver Carp from the Kansas River, a major tributary to the Missouri River, to reconstruct environmental histories as a means to assess the proportions of resident (individuals who never left the Kansas River system) and transient (individuals who at some point occupied the Missouri River) individuals. Silver Carp within the Kansas River were predominantly residents (adults = 54%; juveniles = 65%) with the majority of reproduction coming from within the Kansas River itself. These results suggest removal efforts in the Kansas River may be effective means of managing this invasive fish species. Transient fish exhibited short durations of signatures indicative of the Missouri River (mean percent of data points for adults = 10% and juveniles = 36%), suggesting movements into the Missouri River were brief. These results highlight the importance of connectivity of tributary habitat among large rivers and provides important information for invasive species management. [ABSTRACT FROM AUTHOR]

Conifer (Pinaceae) needles are the most frost‐hardy leaves. During needle freezing, the exceptional leaf anatomy, where an endodermis separates the mesophyll from the vascular tissue, could have consequences for ice management and photosynthesis. The eco‐physiological importance of needle freezing behaviour was evaluated based on the measured natural freezing strain at the alpine treeline. Ice localisation and cellular responses to ice were investigated in mountain pine needles by cryo‐microscopic techniques. Their consequences for photosynthetic activity were assessed by gas exchange measurements. The freezing response was related to the microchemistry of cell walls investigated by Raman microscopy. In frozen needles, ice was confined to the central vascular cylinder bordered by the endodermis. The endodermal cell walls were lignified. In the ice‐free mesophyll, cells showed no freeze‐dehydration and were found photosynthetically active. Mesophyll cells had lignified tangential cell walls, which adds rigidity. Ice barriers in mountain pine needles seem to be realised by a specific lignification patterning of cell walls. This, additionally, impedes freeze‐dehydration of mesophyll cells and enables gas exchange of frozen needles. At the treeline, where freezing is a dominant environmental factor, the elaborate needle freezing pattern appears of ecological importance. [ABSTRACT FROM AUTHOR]

Emanuel Bořický (*11 December 1840 Milín, +27 January 1881 Prague) was a prominent Czech petrologist and mineralogist, professor at Charles University in Prague and custodian of the mineralogical collections of the National Museum in Prague. Ha was the first in Bohemia who systematically used a petrological microscope in his work. He was the first in the world to introduce the methods of microchemistry into petrology. He published about 100 scientific articles, short communications and monographs. As a mineralogist, he mainly devoted his career to chemical analyzes of minerals. He recognized then new minerals as zepharovichite (today wavellite), uranotile (today uranophane), přílepite (fossil resin) and parankerite (Fe-dolomite). In 1868, James Dwight Dana named the mineral borickite (bořickýite, now delvauxite) in his honor. He published four extensive studies: on Czech basalts (1873), phonolites (1874), melaphyres (1876) and porphyrites (1881). He published his method of microchemical determination of rock-forming minerals in 1877. [ABSTRACT FROM AUTHOR]

Conservation research has a main role to play during the decision-making process of restoration - how an object should look, what should be removed, what should be clearly exposed, and how to connect history and conservation with the aesthetic effects expected by the owner. In many situations we do not have enough historic material to fully establish this. In this article we would like to describe the process and steps taken during micro-chemistry research to identify the original technology used in the painting and gilding layers of a terracotta sculpture, dated to the late nineteenth century. [ABSTRACT FROM AUTHOR]