Three kinds of opal-cristobalite, differentiated by the sharpness of the 4·1 Å XRD peak, were isolated from the Helms (Texas) bentonite by selective chemical dissolution followed by specific gravity separation. The δ18O value (oxygen isotope abundance) for these cristobalite isolates ranged from approximately 26–30‰ (parts per thousand), increasing with increased breadth of the 4·1 Å XRD peak. Opal-cristobalite isolated from the Monterey diatomite had a δ18O value of 34‰. These δ18O values are in the range for Cretaceous cherts (approximately 32‰) and are unlike the values of 9–11‰ obtained for low-cristobalite (XRD peaks at 4·05, 3·13, 2·4, and 2·49) formed hydrothermally or isolated from the vesicles of obsidian. The morphology pseudomorphic after diatoms, observed with the scanning electron microscope, was more apparent in the opal-cristobalite from the Monterey diatomite of Miocene age (approximately 10 million yr old) than in the spongy textured opal-cristobalite from the Helms bentonite, reflecting the 40 million yr available for crystallization since Upper Eocene.

The oxygen isotope abundance of Helms montmorillonite (δ18O = 26‰) indicates that it was formed in sea water while the δ18O values of the associated opal-cristobalite indicate that this SiO2 polymorph probably formed at approximately 25°C in meteoric water. Although both cristobalite and mont-montmorillonite in the bentonite were authigenic, the crystallization of the SiO2 phase apparently required a considerably longer period and occurred mainly after tectonic uplift.

In contrast to the results for cristobalite, quartz from the Helms and Upton (Wyoming) bentonites had δ18O values of 15 and 21‰ respectively. Such intermediate values, similar to those of aerosolic dusts of the Northern Hemisphere, loess, and many fluvial sediments and shales of the North Central United States (U.S.A.), preclude either a completely authigenic or a completely igneous origin for the quartz. These values probably result from a mixing of quartz from high and low temperature sources, detritally added to the ash or bentonite bed.

Resonant soft x-ray scattering (RSoXS) leverages chemical specificity to characterize thin films but is limited near the nitrogen edge. The challenge is that commercially available x-ray transparent substrates are composed of Si3N4 and thereby absorb incident x-rays and generate incoherent fluorescence. To overcome this challenge, we designed and fabricated Al2O3 free-standing films for use as RSoXS windows. Al2O3 films offer higher x-ray transmittance and minimal fluorescence near the nitrogen edge. As an example, Al2O3 windows allow for nitrogen RSoXS of conjugated block copolymer thin films that reveal domain spacings, which are not apparent with commercially available Si3N4 substrates.

Measurements in the infrared wavelength domain allow direct assessment of the physical state and energy balance of cool matter in space, enabling the detailed study of the processes that govern the formation and evolution of stars and planetary systems in galaxies over cosmic time. Previous infrared missions revealed a great deal about the obscured Universe, but were hampered by limited sensitivity.

SPICA takes the next step in infrared observational capability by combining a large 2.5-meter diameter telescope, cooled to below 8 K, with instruments employing ultra-sensitive detectors. A combination of passive cooling and mechanical coolers will be used to cool both the telescope and the instruments. With mechanical coolers the mission lifetime is not limited by the supply of cryogen. With the combination of low telescope background and instruments with state-of-the-art detectors SPICA provides a huge advance on the capabilities of previous missions.

SPICA instruments offer spectral resolving power ranging from R ~50 through 11 000 in the 17–230 μm domain and R ~28.000 spectroscopy between 12 and 18 μm. SPICA will provide efficient 30–37 μm broad band mapping, and small field spectroscopic and polarimetric imaging at 100, 200 and 350 μm. SPICA will provide infrared spectroscopy with an unprecedented sensitivity of ~5 × 10−20 W m−2 (5σ/1 h)—over two orders of magnitude improvement over what earlier missions. This exceptional performance leap, will open entirely new domains in infrared astronomy; galaxy evolution and metal production over cosmic time, dust formation and evolution from very early epochs onwards, the formation history of planetary systems.

Herbicides are used in the production of almost 100% of agronomic crops in the United States and in most horticultural row crops. By volume, herbicides represent nearly two-thirds of all pesticides used in crop production. However, public pressure is mounting to force industry to develop safer, more environmentally responsible approaches for controlling weeds. Biological weed control with plant pathogenic fungi used as mycoherbicides offers such an approach. But there are several biological and environmental limitations which are inherent to nearly all mycoherbicides which must be overcome before they will be widely acceptable for practical use. Recent advances in adjuvant formulation and delivery systems have been used to overcome some of these limitations, such as lengthy dew requirements, inconsistent efficacy, and limited host ranges. Examples of current research to overcome these limitations will be presented in this review.

We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.

Assume ZF + AD + V = L(ℝ) and let κ < Θ be an uncountable cardinal. We show that κ is Jónsson, and that if cof (κ) = ω then κ is Rowbottom. We also establish some other partition properties.

The purpose of the present study is to identify child and adult correlates that differentiate (a) individuals with persistent alcohol dependence from individuals with developmentally limited alcohol dependence and (b) individuals with adult-onset alcohol dependence from individuals who never diagnose. There are 1,037 members of the Dunedin Longitudinal Study, which is a birth cohort followed prospectively from birth until age 32. Past-year DSM-IV alcohol dependence diagnoses are ascertained with structured diagnostic interviews at ages 18, 21, 26, and 32. Individuals are classified as developmentally limited, persistent, or adult-onset subtypes based on their time-ordered pattern of diagnoses. The persistent subtype generally exhibits the worst scores on all correlates, including family psychiatric history, adolescent and adult externalizing and internalizing problems, adolescent and adult substance use, adult quality of life, and coping strategies. The prospective predictors that distinguished them from the developmentally limited subtype involved family liability, adolescent negative affectivity, daily alcohol use, and frequent marijuana use. Furthermore, young people who develop the persistent subtype of alcohol dependence are distinguished from the developmentally limited subtype by an inability to reduce drinking and by continued use despite problems by age 18. The adult-onset group members are virtually indistinguishable from ordinary cohort members as children or adolescents; however, in adulthood, adult-onset cases are distinguished by problems with depression, substance use, stress, and strategies for coping with stress. Information about age of onset and developmental course is fundamental for identifying subtypes of alcohol dependence. Subtype-specific etiologies point to targeted prevention and intervention efforts based on the characteristics of each subtype.

We report on 475 measurements of depth to ice-cemented ground in four high-elevation valleys of the Quartermain Mountains, McMurdo Dry Valleys, Antarctica. These valleys have pervasive ice-cemented ground, and the depth to ice-cemented ground and the ice composition may be indicators of climate change. In University Valley, the measured depth to ice-cemented ground ranges from 0–98 cm. There is an overall trend of increasing depth to ice-cemented ground with distance from a small glacier at the head of the valley, with a slope of 32 cm depth per kilometre along the valley floor. For Farnell Valley, the depth to ice-cemented ground is roughly constant (c. 30 cm) in the upper and central parts of the valley, but increases sharply as the valley descends into Beacon Valley. The two valleys north of University Valley also have extensive ice-cemented ground, with depths of 20–40 cm, but exhibit no clear patterns of ice depth with location. For all valleys there is a tendency for the variability in depth to ice-cemented ground at a site to increase with increasing depth to ice. Snow recurrence, solar insolation, and surface albedo may all be factors that cause site to site variations in these valleys.

EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The primary goal of EMU is to make a deep (rms ∼ 10 μJy/beam) radio continuum survey of the entire Southern sky at 1.3 GHz, extending as far North as +30° declination, with a resolution of 10 arcsec. EMU is expected to detect and catalogue about 70 million galaxies, including typical star-forming galaxies up to z ∼ 1, powerful starbursts to even greater redshifts, and active galactic nuclei to the edge of the visible Universe. It will undoubtedly discover new classes of object. This paper defines the science goals and parameters of the survey, and describes the development of techniques necessary to maximise the science return from EMU.