White matter development during adolescents is crucial for a mature integration of neural networks in the brain. Autism spectrum condition (ASC), characterized by social and communication difficulties and rigid behaviour may interact with white matter development observed during adolescence. Changes in white matter development may link autistic symptoms to its genetic underpinnings and explain a 10-fold increase in susceptibility to ASC among siblings of individuals with ASC.

We used diffusion tensor imaging to study an association between age and white matter integrity measures, fractional anisotropy (FA) and mean diffusivity (MD), in adolescents with ASC, their siblings and age-matched healthy controls. Diffusion-weighted data were acquired with 64-direction protocol with 3mm slices and TR of 6600ms and tract-based spatial statistics analysis was performed.

The control subjects showed robust signs of increase in white matter integrity correlated with age. In contrast, individuals with ASC showed significantly lower negative correlation between MD and age in a broad area centred in the right superior longitudinal fasciculus (rSLF). When the three eigenvalues constituting a tensor ellipsoid were considered separately, siblings of individuals with ASC showed a diminished negative correlation between the second eigenvalue and age also centred in the rSLF.

Adolescents with ASC and their siblings experience alterations in white matter development in comparison to age-matched healthy controls, which are similar in direction yet different in scale for the two affected groups. The alterations are observed in the area associated with flexibility of behaviour and may explain both symptoms of ASC and increased susceptibility to ASC.

The densification of pure magnesia was examined along with mixtures containing 0·5 and 1·0 mol % of calcium oxide and forsterite. The sintering behaviour at temperatures between 1400 and 1800 °C was studied and measurements made of changes in shrinkage, porosity, bulk density, and grain size for sintering times of up to 8 h at sintering temperature. It was found that both the 0·5 and 1·0 mol % additions enhanced the sintering of pure magnesia in the temperature range 1500–1700 °C Increased grain growth was found for mixtures containing forsterite but little change occurred for mixtures containing lime. Examination of the grain growth data showed that the mixtures obeyed a relationship: Time at temperature × Constant = (grain size)n , where n = 2 for the grain growth of pure magnesia and mixtures containing lime, but n = 3 for mixtures of magnesia with additions of a silicate such as forsterite. A value of 78 kcal/mole was obtained for the grain growth of pure magnesia, which agrees with other researches.

The extent of the solubility of lime in periclase for each lime-magnesia mixture at each temperature was also examined using electron probe analysis and related to the sintering behaviour observed for these mixtures.

The Makatea Islands in the southern Cook Islands consist of a degraded volcanic core surrounded by emergent “makatea” limestones. While much of this reefal limestone is of Tertiary age, the seawardmost reefs are late Pleistocene. Last-interglacial reefs (oxygen isotope substage 5e) identified by U-series dating reach 12.2 m on Atiu (mean age of three samples 126,000 ± 5000 yr B.P.), 9.8 m on Mitiaro (mean age of five samples 119,000 ± 3000 yr B.P.), 10.0–12.7 m on Mauke (mean age of four samples 128,000 + 5000, −4,000 yr B.P.), and 14.5–20.0 m on Mangaia (mean age of four samples 115,000 ± 7000 yr B.P.). On Atiu, Mauke, and Mitiaro a lower reef unit has been identified, and is separated from the overlying substage 5e reef by a sharp discontinuity, often with a crust of coralline algae. U-series dating from Atiu and Mauke indicates that this is a stage 7 reef formed in the penultimate interglaciation. The Makatea Islands have emerged as a result of flexure of the lithosphere in response to loading by the Pleistocene volcanic island of Rarotonga. Isolated outcrops of makatea limestone on Rarotonga reach 3.5 m and are probably of substage 5e age. Elastic and viscoelastic models of lithospheric flexure predict that much of the compensatory movement should occur shortly after the emplacement of the load. However, the age and elevation of late Quaternary reefs on the southern Cook Islands, where a Pleistocene volcanic island has loaded relatively old ocean floor (>80 myr), indicate that differential uplift has been continuing over the last 250,000 yr.

Instrumental surveys of coastal profiles in the Cayman Islands, western Caribbean, reveal the presence of a horizontal erosional bench at +1.9 m on Grand Cayman and a deep horizontal notch at +6.4 m on Cayman Brac, but no raised erosional features on Little Cayman. Each island is surrounded by a horizontal constructional raised reef, usually below +2 m, here dated by U-series methods as 124,000 ± 8000 yr old, and hence broadly contemporary with other western Atlantic raised reefs of similar elevations. The different raised erosional features indicate independent vertical tectonic movement of the three islands, predating the formation of the raised reef. The accordance and horizontality of the raised reef indicates stability of the islands since the last interglacial times. An erosional notch at present sea level has formed since the sea reached its present level less than 2100 B.P., and algal benches on exposed coasts are also in equilibrium with present conditions.

The Wold Bison Jump (48JO966) is a communal bison (Bison bison) hunting site in Johnson County, Wyoming. It likely represents a single kill event precipitated by Great Plains foragers between A.D. 1433 and 1643. Operating the jump required that prehistoric hunters drive stampeding bison up a steep slope in order to position them within a V-shaped drive line configured to funnel them toward a cliff. Using iterative models of least cost paths, topographic cross-sections, and visibility analysis, we test which landscape-embedded variables are optimized at the jump site as compared to other potential localities across the study area. We find that this site’s placement is primarily explained by minimizing the distance at which the cliff face is visible and secondarily by minimizing the cost of slope and curvature routes ascending into the drive lines. Our procedure could hypothetically be used to predict optimal jump locations on similar landscapes.

Coffee is a relatively rich source of chlorogenic acids (CGA), which, as other polyphenols, have been postulated to exert preventive effects against CVD and type 2 diabetes. As a considerable proportion of ingested CGA reaches the large intestine, CGA may be capable of exerting beneficial effects in the large gut. Here, we utilise a stirred, anaerobic, pH-controlled, batch culture fermentation model of the distal region of the colon in order to investigate the impact of coffee and CGA on the growth of the human faecal microbiota. Incubation of coffee samples with the human faecal microbiota led to the rapid metabolism of CGA (4 h) and the production of dihydrocaffeic acid and dihydroferulic acid, while caffeine remained unmetabolised. The coffee with the highest levels of CGA (P< 0·05, relative to the other coffees) induced a significant increase in the growth of Bifidobacterium spp. relative to the control vessel at 10 h after exposure (P< 0·05). Similarly, an equivalent quantity of CGA (80·8 mg, matched with that in high-CGA coffee) induced a significant increase in the growth of Bifidobacterium spp. (P< 0·05). CGA alone also induced a significant increase in the growth of the Clostridium coccoides–Eubacteriumrectale group (P< 0·05). This selective metabolism and subsequent amplification of specific bacterial populations could be beneficial to host health.