Changes in co-existence mechanisms along a long-term soil chronosequence revealed by functional trait diversity

1. Functional trait diversity can reveal mechanisms of species co-existence in plant communities. Few studies have tested whether functional diversity for foliar traits related to resource use strategy increases or decreases with declining soil phosphorus (P) in forest communities. 2. We quantified tree basal area and four foliar functional traits (i.e. nitrogen (N), phosphorus (P), thickness and tissue density) for all woody species along the c. 120 kyr Franz Josef soil chronosequence in cool temperate rainforest, where strong shifts occur in light and soil nutrient availability (i.e. total soil P declines from 805 to 100 mg g–1). We combined the abundance and trait data in functional diversity indices to quantify trait convergence and divergence, in an effort to determine whether mechanisms of co-existence change with soil fertility. 3. Relationships between species trait means and total soil N and P were examined using multiple regression, with and without weighting of species abundances. We used Rao’s quadratic entropy to quantify functional diversity at the plot scale, then compared this with random expectation, using a null model that randomizes abundances across species within plots. Taxonomic diversity was measured using Simpson’s Diversity. Relationships between functional and taxonomic diversity and total soil P were examined using jackknife linear regression. 4. Leaf N and P declined and leaf thickness and density increased monotonically with declining total soil P along the sequence; these relationships were unaffected by abundance-weighting of species in the analyses. Inclusion of total soil N did not improve predictions of trait means. All measures of diversity calculated from presence/absence data were unrelated to total soil N and P. There was no evidence for a relationship between Rao values using quantitative abundances and total soil P. However, there was a strongly positive relationship between Rao, expressed relative to random expectation, and total soil P, indicating trait convergence of dominant species as soil P declined. 5. Synthesis: Our results demonstrate that at high fertility dominant species differ in resource use strategy, but as soil fertility declines over the long-term, dominant species increasingly converge on a resource-retentive strategy. This suggests that differentiation in resource use strategy is required for co-existence at high fertility but not in low fertility ecosystems

Spectral tripartitioning of networks

We formulate a spectral graph-partitioning algorithm that uses the two leading eigenvectors of the matrix corresponding to a selected quality function to split a network into three communities in a single step. In so doing, we extend the recursive bipartitioning methods developed by Newman [Proc. Nat. Acad. Sci. 103, 8577 (2006); Phys. Rev. E 74, 036104 (2006)] to allow one to consider the best available two-way and three-way divisions at each recursive step. We illustrate the method using simple "bucket brigade" examples and then apply the algorithm to examine the community structures of the coauthorship graph of network scientists and of U. S. Congressional networks inferred from roll-call voting similarities.Comment: 12 pages with 4 figures, resubmitted version accepted for publication in Physical Review

A Phase Diagram for Morphology and Properties of Low Temperature Deposited Polycrystalline Silicon Grown by Hot-wire Chemical Vapor Deposition

The fabrication of low temperature polycrystalline silicon with internal surface passivation and with lifetimes close to single crystalline silicon is a promising direction for thin film polycrystalline silicon photovoltaics. To achieve high lifetimes, large grains with passivated low-angle grain boundaries and intragranular defects are required. We investigate the low-temperature (300-475 °C) growth of thin silicon films by hot-wire chemical vapor deposition (HWCVD) on Si (100) substrates and on large-grained polycrystalline silicon template layers formed by selective nucleation and solid phase epitaxy (SNSPE). Phase diagrams for dilute silane deposition varying substrate temperature and for pure silane varying hydrogen dilution are shown. We will discuss the relationship between the microstructure and photoconductive decay lifetimes of these undoped layers on Si (100) and SNSPE templates as well as their suitability for use in thin-film photovoltaic applications

Opinion Piece: The case for establishing a minimal medication alternative for psychosis and schizophrenia

The development of severe mental health conditions is strongly linked to our environments, particularly experiences of trauma and adversity. However treatments for severe mental health conditions are often primarily biomedical, centred around medication. For people diagnosed with schizophrenia or psychosis, this is antipsychotic medication. Although antipsychotics have been found to reduce symptoms and risk of relapse, some patients derive little benefit from these drugs, and they can lead to severe adverse effects. Subsequently, a high proportion of people do not want to take antipsychotics and request an alternative. Yet in the UK and in many countries there are currently no guidelines for stopping antipsychotics or formal treatment alternatives, despite such alternatives being available in some countries. For example, in Norway and Vermont (USA), in response to pressure from service user organisations, governments have mandated the establishment of “minimal medication” services. We examine whether everyone with a psychotic condition needs long-term antipsychotic treatment and evidence for alternative models of care. We recommend that healthcare providers should be encouraged to develop a psychosocial treatment package for people with psychosis or schizophrenia that provides a realistic possibility of minimising antipsychotic exposure

A generalized study of the breeding potential of large heavy water moderated power reactors fueled with thoria and urania

"January 1967.""MIT-2073-5."Also issued as a Ph. D. thesis by the first author and supervised by the second and third authors, Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1966Includes bibliographical references (pages 324-328)U.S. Atomic Energy Commission contract AT(30-1)-207

Aggregation of Rare Earth Coordination Complexes in Solution Studied by Paramagnetic and DOSY NMR

The degree of aggregation of neutral, 9‐coordinate rare earth coordination complexes has been shown to affect their ligand field, as revealed by diffusion‐ordered NMR spectroscopy (DOSY‐NMR) measurements on Y(III) complexes, paramagnetic NMR analyses of Yb and Tb analogues and emission spectral studies with the EuIII systems. In non‐polar media a lipophilic tris‐isopropyl complex, [Ln.L2] tends to aggregate in chloroform and dichloromethane giving rise to oligomers, whereas in acetic and trifluoroacetic acid the more polar parent complex, [Ln.L1], also aggregates, profoundly affecting the pseudocontact shift and the form of the Eu emission spectrum. Such behaviour has important implications in the design of responsive spectral probes

Biochar-based wastewater treatment to combat antimicrobial resistance

Antimicrobial resistance (AMR) is driven in part by environmental reservoirs of antimicrobial-resistant organisms and genes, as well as antimicrobials themselves, which drive resistance via selective pressure. According to the UN, 80% of all wastewater flows into the environment untreated. When wastewater is treated, treatment plants can act as hotspots of horizontal gene transfer from resistant to non-resistant organisms. There is therefore an urgent need to filter wastewater from sources rich in resistant bacteria and antimicrobials, like hospitals and pharmaceutical plants, before they reach environmental reservoirs where resistance can spread. Biochars produced from waste lignocellulosic biomass are ideal for this purpose, as they are highly adsorbent, affordable, and sustainable, with morphologies and surface chemistries that are tunable by choice of production conditions. Here, we link peak pyrolysis temperatures and alkaline pretreatment of walnut shell biochars to their filtration performance, showing these materials are suitable for in-line filtration of wastewater to combat AMR

Exit block in emergency departments: a rapid evidence review.

BACKGROUND: Exit block (or access block) occurs when 'patients in the ED requiring inpatient care are unable to gain access to appropriate hospital beds within a reasonable time frame'. Exit block is an increasing challenge for Emergency Departments (EDs) worldwide and has been recognised as a major factor in leading to departmental crowding. This paper aims to identify empirical evidence, highlighting causes, effects and strategies to limit exit block. METHODS: A computerised literature search was conducted of English language empirical evidence published between 2008 and 2014 using a combination of terms relating to exit block in ED. RESULTS: 233 references were identified following the computerised search. Of these, 32 empirical articles of varying scientific quality were identified as relevant and results were presented under a number of headings. The majority of studies presented data relating to the impact of exit block on departments, patients and staff. A smaller number of articles evaluated interventions designed to reduce exit block. Evidence suggests that exit block is more likely to occur in more densely populated areas and less likely to occur in paediatric settings. Bed occupancy appears to be associated with exit block. Evidence supporting the impact of initiatives pointed towards increasing workforce and inpatient bed resources within the hospital setting to reduce block. CONCLUSIONS: Further evidence is needed, especially within the NHS setting to increase the understanding around factors that cause exit block, and interventions that are shown to relieve it without compromising patient outcomes

'A beginning and not the end’: Work after a diagnosis of dementia

YesWhile there is a growing literature on the experiences of disabled workers, this article presents an account of a work experience not frequently documented: being employed while living with dementia. It does this through the account of Elizabeth Draper, an NHS Hospital Trust manager, who received a diagnosis of dementia while employed. The article offers new ways of conceptualizing the struggles of disabled workers to continue with their project of self-becoming through work. It shows how work practices can enact violence through ‘non-recognition’ and how workers can subvert this violence to create opportunities for future development