Lava geochemistry as a probe into crustal formation at the East Pacific Rise

Author Posting. © The Oceanography Society, 2012. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 25, no. 1 (2012): 89–93, doi:10.5670/oceanog.2012.06.Basalt lavas comprise the greatest volume of volcanic rocks on Earth, and most of them erupt along the world's mid-ocean ridges (MORs). These MOR basalts (MORBs) are generally thought to be relatively homogeneous in composition over large segments of the global ridge system (e.g., Klein, 2005). However, detailed sampling of two different regions on the northern East Pacific Rise (EPR) and extensive analysis of the samples show that fine-scale mapping and sampling of the ridge axis can reveal significant variations in lava chemistry on both small spatial and short temporal scales. The two most intensely sampled sites within the EPR Integrated Study Site (ISS) lie on and off axis between 9°17'N and 10°N, and from a wide region centered around 9°N where two segments of the EPR overlap (see Fornari et al., 2012, Figure 3, in this issue). The chemical composition of erupted lavas, similar to the genotype of an organism, can be used by igneous petrologists to trace the evolution of magmas from the mantle to the seafloor. The extensive and detailed geochemical studies at the EPR highlight how a thorough understanding of the variability in lava compositions on small spatial scales (i.e., between lava flows) and large spatial scales (i.e., from segment center to segment end and including discontinuities in the ridge crest) can be used in combination with seafloor photography, lava morphology, and bathymetry to provide insights into the magmatic system that drives volcanism and influences hydrothermal chemistry and biology at a fast-spreading MOR.Grants that supported EPR ISS field and laboratory studies for our research programs include: MRP: OCE-0138088, OCE-0819469, OCE-825265, OCE-638406, OCE-527077, OCE-535532; DJF: OCE-9819261, OCE-0525863, OCE-0838923, OCE-0096468, OCE-0732366, and OCE-0112737

A randomised controlled trial of extended brief intervention for alcohol dependent patients in an acute hospital setting (ADPAC)

<p>Abstract</p> <p>Background</p> <p>Alcohol dependence affects approximately 3% of the English population, and accounts for significant medical and psychiatric morbidity. Only 5.6% of alcohol-dependent individuals ever access specialist treatment and only a small percentage ever seek treatment. As people who are alcohol dependent are more likely to have experienced health problems leading to frequent attendance at acute hospitals it would seem both sensible and practical to ensure that this setting is utilised as a major access point for treatment, and to test the effectiveness of these treatments.</p> <p>Methods/Design</p> <p>This is a randomised controlled trial with a primary hypothesis that extended brief interventions (EBI) delivered to alcohol-dependent patients in a hospital setting by an Alcohol Specialist Nurse (ASN) will be effective when compared to usual care in reducing overall alcohol consumption and improving on the standard measures of alcohol dependence. Consecutive patients will be screened for alcohol misuse in the Emergency Department (ED) of a district general hospital. On identification of an alcohol-related problem, following informed written consent, we aim to randomize 130 patients per group. The ASN will discharge to usual clinical care all control group patients, and plan a programme of EBI for treatment group patients. Follow-up interview will be undertaken by a researcher blinded to the intervention at 12 and 24 weeks. The primary outcome measure is level of alcohol dependence as determined by the Severity of Alcohol Dependence Questionnaire (SADQ) score. Secondary outcome measures include; Alcohol Use Disorders Identification Test (AUDIT) score, quantity and frequency of alcohol consumption, health-related quality of life measures, service utilisation, and patient experience. The trial will also allow an assessment of the cost-effectiveness of EBI in an acute hospital setting. In addition, patient experience will be assessed using qualitative methods.</p> <p>Discussion</p> <p>This paper presents a protocol for a RCT of EBI delivered to alcohol dependent patients by an ASN within an ED. Importantly; the trial will also seek to understand patients' perceptions and experiences of being part of a RCT and of receiving this form of intervention.</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN78062794">ISRCTN78062794</a></p

Phenological sensitivity to climate across taxa and trophic levels

Differences in phenological responses to climate change among species can desynchronise ecological interactions and thereby threaten ecosystem function. To assess these threats, we must quantify the relative impact of climate change on species at different trophic levels. Here, we apply a Climate Sensitivity Profile approach to 10,003 terrestrial and aquatic phenological data sets, spatially matched to temperature and precipitation data, to quantify variation in climate sensitivity. The direction, magnitude and timing of climate sensitivity varied markedly among organisms within taxonomic and trophic groups. Despite this variability, we detected systematic variation in the direction and magnitude of phenological climate sensitivity. Secondary consumers showed consistently lower climate sensitivity than other groups. We used mid-century climate change projections to estimate that the timing of phenological events could change more for primary consumers than for species in other trophic levels (6.2 versus 2.5–2.9 days earlier on average), with substantial taxonomic variation (1.1–14.8 days earlier on average)

Archiving primary data: solutions for long-term studies

The recent trend for journals to require open access to primary data included in publications has been embraced by many biologists, but has caused apprehension amongst researchers engaged in long-term ecological and evolutionary studies. A worldwide survey of 73 principal investigators (Pls) with long-term studies revealed positive attitudes towards sharing data with the agreement or involvement of the PI, and 93% of PIs have historically shared data. Only 8% were in favor of uncontrolled, open access to primary data while 63% expressed serious concern. We present here their viewpoint on an issue that can have non-trivial scientific consequences. We discuss potential costs of public data archiving and provide possible solutions to meet the needs of journals and researchers

Circular designs balanced for neighbours at distances one and two

We define three types of neighbour-balanced designs for experiments where the units are arranged in a circle or single line in space or time. The designs are balanced with respect to neighbours at distance one and at distance two. The variants come from allowing or forbidding self-neighbours, and from considering neighbours to be directed or undirected. For two of the variants, we give a method of constructing a design for all values of the number of treatments, except for some small values where it is impossible. In the third case, we give a partial solution that covers all sizes likely to be used in practice.PostprintPeer reviewe

On Perfect Sequence Covering Arrays

A PSCA$(v, t, \lambda)$ is a multiset of permutations of the $v$-element alphabet $\{0, \dots, v-1\}$ such that every sequence of $t$ distinct elements of the alphabet appears in the specified order in exactly $\lambda$ of the permutations. For $v \geq t \geq 2$, we define $g(v, t)$ to be the smallest positive integer $\lambda$ such that a PSCA$(v, t, \lambda)$ exists. We show that $g(6, 3) = g(7, 3) = g(7, 4) = 2$ and $g(8, 3) = 3$. Using suitable permutation representations of groups we make improvements to the upper bounds on $g(v, t)$ for many values of $v \leq 32$ and $3\le t\le 6$. We also prove a number of restrictions on the distribution of symbols among the columns of a PSCA