Inference is considered for the marginal distribution of X, when (X, Y) has a truncated bivariate normal distribution. The Y variable is truncated, but only the X values are observed. The relationship of this distribution to Azzalini's “skew-normal” distribution is obtained. Method of moments and maximum likelihood estimation are compared for the three-parameter Azzalini distribution. Samples that are uniformative about the skewness of this distribution may occur, even for large n. Profile likelihood methods are employed to describe the uncertainty involved in parameter estimation. A sample of 87 Otis test scores is shown to be well-described by this model.

Debate surrounds the early peopling of the Arabian Peninsula. The first evidence of the Levallois lithic technology in the Huqf area of south-eastern Arabia now extends the Middle Palaeolithic record of hominin activity into central Oman and helps to diversify the picture of Arabian prehistory.

Given the rising numbers of older adults in Canada experiencing falls, evidence-based identification of fall risks and plans for prevention across the continuum of care is a significant priority for health care providers. A scoping review was conducted to synthesize published international clinical practice guidelines (CPGs) and recommendations for fall risk screening and assessment in older adults (defined as 65 years of age and older). Of the 22 CPGs, 6 pertained to multiple settings, 9 pertained to community-dwelling older adults only, 2 each pertained to acute care and long-term care settings only, and 3 did not specify setting. Two criteria, prior fall history and gait and balance abnormalities, were applied either independently or sequentially in 19 CPG fall risk screening algorithms. Fall risk assessment components were more varied across CPGs but commonly included: detailed fall history; detailed evaluation of gait, balance, and/or mobility; medication review; vision; and environmental hazards assessment. Despite these similarities, more work is needed to streamline assessment approaches for heterogeneous and complex older adult populations across the care continuum. Support is also needed for sustainable implementation of CPGs in order to improve health outcomes.

Greenhouse and growth chamber studies were conducted to investigate effects of herbicide placement in soil on toxicity to emerging seedlings. The use of a technique involving a plastic bag over the plants for 3 to 4 weeks to reduce soil moisture loss did not change the apparent site of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) uptake by green foxtail (Setaria viridis (L.) Beauv.) or oats (Avena sativa L.). Atrazine was more effective on oats through root exposure and more effective on green foxtail through shoot exposure when an untreated buffer zone around the seed was used. But in subsequent studies without the buffer zone, atrazine was most active when placed immediately below the seed of both oats and green foxtail. Proximity to the seed increased effectiveness of atrazine, S-ethyl dipropylthiocarbamate (EPTC), and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron). Also, a narrow concentrated layer of these three herbicides adjacent to the seed was more effective than a wider dilute layer above or below the seed. A diurnal fluctuating temperature regime with a low night temperature increased toxicity of EPTC to oats through root exposure, when compared to a constant temperature regime.

Increased summer ice velocities on the Greenland ice sheet are driven by meltwater input to the subglacial environment. However, spatial patterns of surface input and partitioning of meltwater between different pathways to the base remain poorly understood. To further our understanding of surface drainage, we apply a supraglacial hydrology model to the Paakitsoq region, West Greenland for three contrasting melt seasons. During an average melt season, crevasses drain ~47% of surface runoff, lake hydrofracture drains ~3% during the hydrofracturing events themselves, while the subsequent surface-to-bed connections drain ~21% and moulins outside of lake basins drain ~15%. Lake hydrofracture forms the primary drainage pathway at higher elevations (above ~850 m) while crevasses drain a significant proportion of meltwater at lower elevations. During the two higher intensity melt seasons, model results show an increase (~5 and ~6% of total surface runoff) in the proportion of runoff drained above ~1300 m relative to the melt season of average intensity. The potential for interannual changes in meltwater partitioning could have implications for how the dynamics of the ice sheet respond to ongoing changes in meltwater production.

We studied neuroinflammation in individuals with late-life, depression, as a risk factor for dementia, using [11C]PK11195 positron emission tomography (PET). Five older participants with major depression and 13 controls underwent PET and multimodal 3T magnetic resonance imaging (MRI), with blood taken to measure C-reactive protein (CRP). We found significantly higher CRP levels in those with late-life depression and raised [11C]PK11195 binding compared with controls in brain regions associated with depression, including subgenual anterior cingulate cortex, and significant hippocampal subfield atrophy in cornu ammonis 1 and subiculum. Our findings suggest neuroinflammation requires further investigation in late-life depression, both as a possible aetiological factor and a potential therapeutic target.

Many fossil assemblages are time-averaged, with multiple generations of organisms mixed into a single stratigraphic horizon. A time-averaged sample of a taxon should be more variable than a single-generation sample if enough morphologic change occurred during the interval of time-averaging. Time-averaging may also alter correlations between morphologic variables and obscure allometric relationships in an evolving population. To investigate these issues, we estimated the variability of six modern, single-generation samples of the bivalve Mercenaria campechiensis using Procrustes analysis and compared them with several time-averaged Pleistocene samples of M. campechiensis and M. permagna. Both the modern and the fossil samples ranged in variability, but these ranges were virtually identical. Morphology was quite stable over the hundreds to many thousands of years that passed as the assemblages accumulated, and the variabilities of the fossil samples could be used to estimate single-generation variability. At one fossil locality, the environment and paleocommunity changed partway through the collection interval; the morphology of Mercenaria appears stable above and below the transition but changes across it. This change is similar in magnitude to the differences between geographically separated modern populations, whereas temporal variation within single environmental settings is distinctly less than geographic variation. Analytical time-averaging (the mixing of fossils from different horizons) between paleocommunities increased variability slightly (but not significantly) above that found in living populations. While its constituent populations appear stable on millennial timescales, M. campechiensis has been evolutionarily static since at least the early to middle Pleistocene.

A 40-year-old female with a recurrent mixed astrocytoma/oligodendroglioma was treated with intraarterial BCNU at six week intervals. Phosphorus magnetic resonance spectroscopy was performed before, and on two occasions after her third treatment.

Before treatment, phosphodiesters were 25% less than normal and intracellular pH was 7.14 (normal 6.97 ± 0.02). Eight hours following treatment phosphocreatine and phosphodiesters were reduced by ∼40% and pHi increased to 7.24. Thirty-two hours after treatment, phosphocreatine and phosphodiesters had reversed their decline, but pHi had increased further to 7.35. MRI and x-ray CT scans did not show any change during this period.

This study demonstrates that chemical changes can be observed in a glioma by magnetic resonance spectroscopy shortly after chemotherapy in a clinical setting and before changes are observable by imaging modalities. This approach evidently offers a possible means of monitoring the acute metabolic response of tumours to chemotherapy or other forms of treatment by a non-invasive repeatable quantitative method.

The evolutionary origin of Morozovella angulata from its immediate ancestor, Praemurica uncinata, is preserved in Paleocene sediments from the Gulf of Mexico. This event represents the beginning of the morozovellid radiation and marks the first appearance of keeled planktonic foraminifera after the Cretaceous/Tertiary extinction. Parallel biometric and isotopic analyses were performed on size-segregated specimens from a succession of stratigraphic horizons. The biometric data reveal a temporal pattern of variation consistent with paedomorphosis. The appearance of angulose juvenile chambers in the otherwise rounded ancestral form (Praemurica uncinata) results in an allometry that becomes more pronounced upsection. At the origin of M. angulata, the juvenile morphology of the ancestor is retained throughout the entire ontogeny. Isotopic analysis of this sequence reveals the gradual acquisition of an increasingly heavy adult δ13C signal relative to that of the juvenile, while the δ18O data display no temporal or size-related trends. The temporal increase seen in the slope of the δ13C/size relationship may reflect the evolution of an increased dependency on photosymbionts.

The government's cocoa spraying gangs in Ghana treat about two million hectares of the crop against black pod disease and mirids, the key insect pests of cocoa in West Africa, each August through to December, based on recommendations issued in the 1950s. A few cocoa farmers use additional pesticides. We studied the temporal distribution of two important mirid species, Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl., in 1991, 1999, 2003 and 2012 to determine the appropriate timing for the application of control measures in current farming systems. There was a significant correlation between mirid abundance and pod availability on trees, as well as the number of basal shoots and the cocoa variety grown. Mirid populations peaked between January and April and from September to October. Surveys (interviews and focus group discussions involving over 300 farmers in 33 cocoa-growing districts) on pesticide use, sources of recommendations, and perceived successes and failures of current cocoa pest treatments suggested that the 1950 recommendations on the timing of insecticide application need revising.

We present preliminary results of a 4-month campaign carried out in the framework of the Mons project, where time-resolved Hα observations are used to study the wind and circumstellar properties of a number of OB stars.

We present the results from the spectroscopic follow-up of WR140 (WC7 + O4-5) during its last periastron passage in january 2009. This object is known as the archetype of colliding wind binaries and has a relatively large period (≃8 years) and eccentricity (≃0.89). We provide updated values for the orbital parameters, new estimates for the WR and O star masses and new constraints on the mass-loss rates.

The network approach proposed by Cramer et al. suggests fascinating new directions of research on mental disorders. Research is needed to find evidence for the causal power of symptoms, to examine symptoms thoroughly, to investigate individual differences in edge strength, to discover etiological processes for each symptom, and to determine whether and why symptoms cohere into distinct mental disorders.