The fluvial geomorphology and stratigraphy on the middle Snake River at Bancroft Springs, Idaho, provide evidence for numerous episodes of Snake River aggradation and incision since the Bonneville Flood at ca. 18 ka. A suite of seven terraces ranging from 20–1 m above modern bankfull elevation records multiple cut-and-fill cycles during the latest Pleistocene and Holocene in response to local base-level controls, variations in sediment supply, and hydroclimate change. Radiocarbon and luminescence dating show that the ages of fluvial aggradation generally coincide with increased sediment supply and likely wetter hydroclimate during onset of the Younger Dryas stadial (ca. 13.2 ka), deglaciation and termination of the Younger Dryas stadial (ca. 11.3 ka), Early Holocene cooling (ca. 8.8 ka), and Neoglacial (ca. 4.5, 2.9, 1.1 ka). Six intervening periods of incision and channel stability may also reflect either reduced sediment supply, drier hydroclimate, or both. The terrace chronology can be correlated to a variety of local and regional paleoclimate proxy records and corresponds well with periods of continental- and global-scale rapid climate change during the Holocene. The fluvial record demonstrates the geomorphic response and sensitivity of large river systems to changes in hydroclimate variability, which has important implications for inferring paleoenvironmental conditions in the region.

From 2014 to 2020, we compiled radiocarbon ages from the lower 48 states, creating a database of more than 100,000 archaeological, geological, and paleontological ages that will be freely available to researchers through the Canadian Archaeological Radiocarbon Database. Here, we discuss the process used to compile ages, general characteristics of the database, and lessons learned from this exercise in “big data” compilation.

Type II diabetes is considered the most common metabolic disorder in the developed world and currently affects about one in ten globally. A therapeutic target for the management of type II diabetes is the inhibition of α- glucosidase, an essential enzyme located at the brush border of the small intestinal epithelium. The inhibition of α-glucosidase results in reduced digestion of carbohydrates and a decrease in postprandial blood glucose. Although pharmaceutical synthetic inhibitors are available, these are usually associated with significant gastrointestinal side effects. In the present study, the impact of inhibitors derived from edible brown algae is being investigated and compared for their effect on glycaemic control. Carbohydrate- and polyphenolic-enriched extracts derived from Ascophyllum nodosum, Fucus vesiculosus and Undaria pinnatifida were characterised and screened for their inhibitory effects on maltase and sucrase enzymes. Furthermore, enzyme kinetics and the mechanism of inhibition of maltase and sucrase were determined using linear and nonlinear regression methods. All tested extracts showed a dose-dependent inhibitory effect of α-glucosidase with IC50 values ranging from 0⋅26 to 0⋅47 mg/ml for maltase; however, the only extract that was able to inhibit sucrase activity was A. nodosum, with an IC50 value of 0⋅83 mg/ml. The present study demonstrates the mechanisms in which different brown seaweed extracts with varying composition and molecular weight distribution differentially inhibit α-glucosidase activities. The data highlight that all brown seaweed extracts are not equal in the inhibition of carbohydrate digestive enzymes involved in postprandial glycaemia.

Prevalence of type 2 diabetes mellitus has significantly increased in the last three decades and currently affects about 1 in 10 globally. A common therapeutic target for type 2 diabetes is α- glucosidase, an essential enzyme located at the brush border of the small intestinal epithelium. The inhibition of α-glucosidase results in a reduced digestion of carbohydrates and a decrease of postprandial blood glucose. Although, synthetic inhibitors are available in the market, these are usually associated with significant gastrointestinal side effects. In this study, natural inhibitors derived from edible brown algae are being investigated as an alternative.

Polysaccharide- and polyphenolic-enriched extracts from Ascophyllum nodosum and Fucus vesiculosus were characterized and screened for their inhibitory effects against α-glucosidase obtained from rat intestine using maltose, sucrose, and p-nitrophenyl (pNPG) as substrates. Acarbose was used as a synthetic inhibitor. Furthermore, enzyme kinetics and mechanism of inhibition of α- glucosidase were determined using linear and non-linear regression methods (GraphPad Prism ver. 6, GraphPad Software, La Jolla California USA).

All tested extracts showed a dose-dependent inhibitory effect against α-glucosidase. However, the type of inhibition varied between the extracts. Most importantly, the composition analysis showed that the seaweed extracts had different polysaccharide and phenolic contents, suggesting different mode of actions against α-glucosidase. The relation between chemical composition and inhibitory activity of the compounds are discussed.

In summary, the current study demonstrates the mechanisms in which different brown seaweed extracts with various composition effectively inhibit α-glucosidase. Therefore, this natural inhibitor can be considered as a potential candidate for the management of type 2 diabetes mellitus.

We report the discovery in the Greenland ice sheet of a discrete layer of free nanodiamonds (NDs) in very high abundances, implying most likely either an unprecedented influx of extraterrestrial (ET) material or a cosmic impact event that occurred after the last glacial episode. From that layer, we extracted n-diamonds and hexagonal diamonds (lonsdaleite), an accepted ET impact indicator, at abundances of up to about 5×106 times background levels in adjacent younger and older ice. The NDs in the concentrated layer are rounded, suggesting they most likely formed during a cosmic impact through some process similar to carbon-vapor deposition or high-explosive detonation. This morphology has not been reported previously in cosmic material, but has been observed in terrestrial impact material. This is the first highly enriched, discrete layer of NDs observed in glacial ice anywhere, and its presence indicates that ice caps are important archives of ET events of varying magnitudes. Using a preliminary ice chronology based on oxygen isotopes and dust stratigraphy, the ND-rich layer appears to be coeval with ND abundance peaks reported at numerous North American sites in a sedimentary layer, the Younger Dryas boundary layer (YDB), dating to 12.9 ± 0.1 ka. However, more investigation is needed to confirm this association.

In this study we used individual differences concepts and analyses to examine whether older people achieve different ageing-well states universally or whether there are identifiable key groups that achieve them to different extents. The data used in the modelling were from a prospective 16-year longitudinal study of 1,000 older Australians. We examined predictors of trajectories for ageing well using self-rated health, psychological wellbeing and independence in daily living as joint indicators of ageing well in people aged over 65 years at baseline. We used group-trajectory modelling and multivariate regression to identify characteristics predicting ‘ageing well’. The results showed three distinct and sizeable ageing trajectory groups: (a) ‘stable-good ageing well’ (classified as ageing well in all longitudinal study waves; which was achieved by 30.2% of women and 28.0% of men); (b) ‘initially ageing well then deteriorating’ (50.5% women and 47.6% men); and (c) ‘stable-poor’ (not ageing well in any wave; 19.3% women and 24.4% men). Significant gender differences were found in membership in different ageing-well states. In the stable-poor groups there were 103/533 females which was significantly lower than 114/467 men (z-statistic = −2.6, p = 0.005); women had a ‘zero’ probability of progressing to a better ageing-well classification in later years, whilst males had a one-in-five probability of actually improving. Robust final state outcome predictors at baseline were lower age and fewer medical conditions for both genders; restful sleep and Australian-born for women; and good nutrition, decreased strain, non-smoker and good social support for men. These results support that ageing-well trajectories are influenced by modifiable factors. Findings will assist better targeting of health-promoting activities for older people.

Poor annual bluegrass control was reported in golf course roughs following treatment with prodiamine (1120 gaiha−1) and glyphosate (840 gaeha−1) during hybrid bermudagrass dormancy. Research was conducted to determine if this annual bluegrass phenotype was resistant to both prodiamine and glyphosate and to determine the efficacy of herbicide mixtures for controlling this phenotype in the field. In PRE or POST dose-response experiments, 9 to 31 times more prodiamine or glyphosate was needed to control (or reduce dry biomass of) this resistant phenotype by 50% compared to an herbicide-susceptible phenotype. Moreover, glyphosate-susceptible plants accumulated 50% more shikimic acid (898 mgkg−1) 6 d after treatment than those resistant to glyphosate (394 mgkg−1). October (fall) applications of herbicide mixtures containing trifloxysulfuron, simazine, S-metolachlor, or mesotrione controlled this resistant annual bluegrass phenotype 84 to 98% in April (spring), with no differences detected among treatments. Our findings document the second instance of annual bluegrass evolving multiple resistance in a managed turfgrass system. However, several herbicide mixtures can be used to effectively manage this resistant phenotype.