Search

Strontium isotope (87Sr/86Sr) analysis with reference to strontium isotope landscapes (Sr isoscapes) allows reconstructing mobility and migration in archaeology, ecology, and forensics. However, despite the vast potential of research involving 87Sr/86Sr analysis particularly in Africa, Sr isoscapes remain unavailable for the largest parts of the continent. Here, we measure the 87Sr/86Sr ratios in 778 environmental samples from 24 African countries and combine this data with published data to model a bioavailable Sr isoscape for sub-Saharan Africa using random forest regression. We demonstrate the efficacy of this Sr isoscape, in combination with other lines of evidence, to trace the African roots of individuals from historic slavery contexts, particularly those with highly radiogenic 87Sr/86Sr ratios uncommon in the African Diaspora. Our study provides an extensive African 87Sr/86Sr dataset which includes scientifically marginalized regions of Africa, with significant implications for the archaeology of the transatlantic slave trade, wildlife ecology, conservation, and forensics.

OBJECTIVES: Mint oil is used in various commercial applications world-wide. Mint oil is typically harvested from commercial clones of peppermint or spearmints. Spearmints are the product of a cross between two diploid species: Mentha longifolia (horse mint) and Mentha suaveolens (apple mint). Peppermints are the product of an additional hybridization step between spearmint and an octoploid Mentha aquatica (water mint). Here, we present a chromosome-scale assembly of the genome of a clone of M. suaveolens. Together with the previously assembled genome of M. longifolia, these assemblies are instrumental in addressing questions regarding the origins of spearmint and peppermint oil and the genomic composition of commercial spearmints, and to start elaborating strategies for mint cultivar improvement. DATA DESCRIPTION: A Falcon assembly of the genome of M. suaveolens was generated from 103X coverage of PacBio long reads. Additional scaffolding was conducted by Dovetail Genomics, using a Chicago library, and a HiC library. The resulting assembly had an N50 of 44.7 Mb, and 98.45% of the 536 Mb of the assembly were contained within 12 large superscaffolds. Finally, a genetic map was applied to correct persistent misjoins. Illumina RNA-Seq libraries from a variety of tissues were used to annotate the genome.

The deep continental biosphere is supported by chemolithoautotrophy and depends on rock-derived substrates for energy. The majority of microorganisms in these crustal environments are likely attached to mineral surfaces within rock fractures, making characterization of deep life challenging. To better understand both biogeochemical cycling and mineral-hosted microbial communities in the deep subsurface, we characterized naturally occurring mineral particulate and associated biomass collected from boreholes drilled into a 2.7 Ga banded iron formation within the southern Canadian Shield. Particulate mineralogy was characterized via X-ray diffraction and Fe X-ray absorption near edge structure (XANES) spectroscopy. The particulate in one borehole was identified as a mixture of hematite and quartz, while the other borehole contained a mixture of the iron sulfides mackinawite and greigite, suggesting an active sulfur cycle mediated by microbial activity. Carbon associated with the particulate was imaged via scanning transmission X-ray microscopy and characterized via C XANES spectroscopy. In both boreholes, the particulate was colonized by microbial cells; many samples contained abundant biofilm. The cells and biofilm were chemically distinct, with the C XANES spectra for the cells consisting primarily of a protein-like signal and the biofilm resembling a mixture of protein, saccharide, and lipid. In the borehole containing the sulfidic particulate, the abundance of cells and biofilm increased with sample depth. Mineral particulate found in boreholes, whether forming in situ or as a result of drilling and weathering, are a valuable way to access the deep subsurface without the contamination and disturbance caused by drilling new cores. To better understand the microbial community composition and function associated with the particulate-biofilm aggregates and surrounding groundwater, filtered-water and particulate samples were characterized via shotgun metagenomic sequencing. Metagenomic analyses showed that while microbial communities were distinct between boreholes, all communities contained the genetic potential for the oxidation and reduction of a variety of sulfur phases. This suggests that the biogeochemical cycling of S, potentially connected to Fe cycling in this iron-rich habitat, could be fueling life in deep crustal environments.

ABSTRACT: The objective was to investigate the effects of calcium and rumen buffer sources on lactational performance, ruminal fermentation, enteric gas emissions, apparent total-tract digestibility of nutrients, and blood variables of lactating dairy cows. A replicated 3 × 3 Latin square design experiment was conducted with 9 primi- and 9 multiparous mid-lactation Holstein cows. Cows were fed the same basal diet, except for the inclusion (as % DMI) of the following minerals: (1) CON, 0.80% limestone and 0.55% NaCl; (2) BICARB, 0.80% limestone and 0.80% NaHCO3; and (3) ARAG, 0.80% aragonite and 0.55% NaCl. Dry matter intake was decreased by ARAG compared with CON but not with BICARB. Treatments did not affect milk yield, ECM, or yields of milk components. Feed efficiency was increased by BICARB compared with CON but not with ARAG (i.e., 1.72, 1.64, and 1.70, respectively). Compared with CON, milk fat was increased by both BICARB and ARAG (3.32% vs. 3.58%, respectively). Milk protein concentration tended to be slightly decreased (i.e., 2%) by ARAG compared with CON but not with BICARB. Milk total solids and MUN concentrations were increased by BICARB and tended to be increased by ARAG, compared with CON. Treatments did not affect ruminal fermentation variables, except that ARAG increased butyrate molar proportion, compared with CON but not with BICARB. Additionally, ruminal NH3 concentration was greater for ARAG than for BICARB. Enteric gas emission and apparent total-tract digestibility of nutrients were not affected by treatments in the current study. Blood pH was not affected by treatments, and blood ionized Ca concentration was greater for ARAG than for BICARB, but neither was different from CON. Treatments did not affect plasma haptoglobin, β-hydroxybutyrate, or urea N concentrations. Overall, rumen buffering capacity of ARAG appears to be similar to that of BICARB, which was supported by increased milk fat, compared with CON. Compared with BICARB, ARAG increased ionized Ca concentration because of decreased base excess and HCO3− concentrations in blood.

Across undergraduate STEM learning contexts in several countries, students' intrapersonal attributes of epistemic beliefs, self-efficacy beliefs, intrinsic motivation, and sense of identity have been found to influence learning and to change in response to educational practices. However, research can mask individual and demographic differences in student's attributes that may moderate or mediate the relationship between educational practices and learning outcomes. We employed variable-centered and person-centered methods to examine individual and demographic differences in changes in students' intrapersonal attributes and patterns of interrelationship among attributes with a study sample of students (N = 4,500) in 14 STEM undergraduate courses (8 biology, 4 chemistry, and 2 statistics) at three research universities in the United States. Variable-centered analyses revealed overall increases in students' science self-efficacy beliefs and epistemic beliefs even though these outcomes were not intentionally targeted as learning objectives. However, person-centered analyses indicated that not all students experienced these gains. For example, self-identified Asian/Pacific Islander and Black students were more likely to be members of groups demonstrating a decrease in science self-efficacy, whereas Asian/Pacific Islander students and men were less likely to be members of the subgroup with consistently evaluativist epistemic beliefs and higher GPAs. Using latent profile analysis (LPA), we identified five distinct student profiles that reflected different patterns of interrelationship of epistemic beliefs, science and writing self-efficacy beliefs, and science identity. We discuss the implications of these findings for educational practices, particularly with regard to intentionally fostering diverse students' self-efficacy, sense of identity, and adaptive epistemic beliefs.

The ocean carbonate system consists of pH, alkalinity, inorganic carbon and the partial pressure of carbon dioxide, and during the current era of anthropogenic change, its dynamics are key for understanding changes in the ocean and its ecosystem over time. The focus of this study is to estimate the carbonate system in the Labrador Sea with time series methods, using direct observations from the ocean surface and interior, and chemical relationships between variables. Interior ocean observations are minimal for some of these variables, however, connections between the variables rooted in chemistry were used to create pseudo-observations using CO2SYS, increasing the information available. A state space model was designed that combined GLODAP and SOCAT observations along with pseudo-observations in a time series estimate of the carbonate system. The Labrador Sea between 1993 and 2016 shows increasing rates for DIC (0.57-1.16 µmol kg−1 year−1) and fCO2 (0.70-2.45 µatm year−1), as well as acidification via pH trends (0.0007-0.0018 year−1). These ranges describe the scale of rates that are occurring at various depths through the water column, though they do not change linearly with depth. Largest rates are found at the surface for DIC, 500-1500 m for fCO2, and 500-1500 m for pH. Total alkalinity also decreased and is correlated with the freshening of salinity. With the core carbonate variables estimated, other aspects of the carbonate system are calculated using CO2SYS, such as the aragonite and calcite saturation states, the Revelle factor, and the carbonate species. Our method also calculates uncertainties that vary over time and depth based on the availability of observations and their variance, which has lowered the uncertainty for pH by 71% and for fCO2 by 64% compared to time-independent methods.

Alistipes onderdonkii (A. onderdonkii) is a newly characterised species of bacteria that has been extensively studied in humans as a part of the normal gut microbiota; its role in gastrointestinal diseases and some types of cancer is under debate. In this study A. onderdonkii is detected in animal stools using PCR and sequencing of the PCR products. A total of 146 faecal samples from ruminants, precisely 32 domestic sheep (Ovis aries), 10 domestic and 34 free-ranging goats (Capra hircus) and 70 wild mouflons (Ovis gmelini ophion) were examined, and 2 of them were positive for A. ondendonkii (2/146=1.4 %), both belonging to goats (2/44=4.5 %), one belonging to a domestic goat and the second belonging to a free-ranging goat. To our knowledge, this is the first report of A. onderdonkii in ruminants. This study aimed to evaluate the prevalence of A. onderdonkii in domestic and wild small ruminants in Cyprus. More research is required to elucidate the role of A. onderdonkii in animal health.

Abstract Insufficient physical activity is associated with increased relative risk of cardiometabolic disease and is an independent risk factor for mortality. Experimentally reducing physical activity rapidly induces insulin resistance, impairs glucose handling, and drives metabolic inflexibility. These adaptations manifest during the early stages of physical inactivity, even when energy balance is maintained, suggesting that inactivity‐mediated metabolic reprogramming is an early event that precedes changes in body composition. To identify mechanisms that promote metabolic adaptations associated with physical inactivity, we developed a mouse model of physical activity reduction that permits the study of inactivity in animals prior to the onset of overt changes in body composition. Adult mice were randomized into three groups: an inactive control group (standard rodent housing), an active control group (treadmill running 5 d/week for 6‐weeks), and an activity reduction group (treadmill running for 4‐weeks, followed by 2‐weeks of inactivity). Transcriptional profiling of gastrocnemius muscle identified seven transcripts uniquely altered by physical activity reduction compared to the inactive and active control groups. Most identified transcripts had reported functions linked to bioenergetic adaptation. Future studies will provide deeper characterization of the function(s) of each the identified transcripts while also determining how inactivity affects transcriptional regulation in other tissues.

* Better Money: Gold, Fiat, or Bitcoin? By Lawrence H. White New York: Cambridge University Press, 2023. Pp. xi, 236. $29.95 paperback. Larry White has written another fine book on [...]