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Aims: Ecosystem changes in the mesic savannas of West Africa are resulting in the formation of patches of ‘forest islands’ around local communities in an otherwise open savanna landscape. There have been conflicting reports on the origin of these forest islands with a very limited understanding of their biogeochemistry. This study evaluated the soil mineralogical and chemical characteristics of forest islands and their surrounding ecosystems comprising croplands and open savannas in Burkina Faso, Ghana, and Nigeria to provide information on the processes leading to the formation of forest islands. Methods: Soil mineralogy was determined using X-ray diffractometry (XRD) while the soil nutrients were analysed with ICP-OES and the other soil chemical properties were determined using standard conventional methodologies. Results: Overall, we found that quartz, kaolinite with significant quantities of 2:1 silicate minerals dominated the soil matrix irrespective of land use type. The minerals identified in most of the locations were independent of land use type. This suggests that the forest island formation is not directly related to soil mineralogy. Forest islands showed differences in soil nutrient contents, being richer in exchangeable potassium and dibasic cations than their surrounding savannas and agricultural fields. This superior fertility status of the soils could contribute to the luxuriant growth of the vegetation leading to the development of forest island. The soil nutrient characteristics of the ecosystem types reflect the land use practices with the forest island having higher nutrient and organic carbon contents. Conclusions: The study provided insight into how human-originated soil nutrient enhancement has induced forest island establishment in open savanna landscapes.

Over the last decade or so, laser scanning technology has become an increasingly popular and important tool for forestry inventory, enabling accurate capture of 3D information in a fast and environmentally friendly manner. To this end, the authors propose here a system for tropical tree species classification based on 3D scans of LiDAR sensing technology. In order to exploit the interrelated patterns of trees, skeleton representations of tree point clouds are extracted, and their structures are divided into overlapping equal-sized 3D segments. Subsequently, they represent them as third-order sparse structure tensors setting the value of skeleton coordinates equal to one. Based on the higher-order tensor decomposition of each sparse segment, they 1) estimate the mode-n singular values extracting intra-correlations of tree branches and 2) model tropical trees as linear dynamical systems extracting appearance information and dynamics. The proposed methodology was evaluated in tropical tree species and specifically in a dataset consisting of 26 point clouds of common Caatinga dry-forest trees.

Vivianite (Fe3(PO4)2·8H2O) has been reported to form as a secondary mineralization product during the microbial reduction of phosphate-containing Fe(III) minerals [1 – 3]. The phosphate-rich nature of vivianite makes it a suitable sink for phosphorus, which is a scarce and irreplaceable resource, and a major contributor to eutrophication in surface water bodies. There is, therefore, interest in synthesizing vivianite by Fe(III) reducing bacteria such as Geobacter sulfurreducens and Shewanella putrefaciens, to treat phosphate-rich waters, recovering the phosphate for re-use in agriculture. In this study, factors including the presence and absence of phosphate and electron shuttle, the buffer system, pH, microbial load, and the type of Fe(III)-reducing bacteria that influence the formation of vivianite under laboratory batch systems have been investigated. The rate of Fe(II) production, and its interaction with the residual Fe(III) and other oxyanions (e.g., PO43-, CO32-) was found to be the main driving factor for secondary mineral formation. Magnetite was formed in treatments with zero phosphates whereas vivianite and green rust were formed in treatments containing phosphate. The rate and extent of Fe(III) bioreduction were higher in Shewanella putrefaciens than in Geobacter sulfurreducens. Vivianite and green rust were both identified as the dominant endpoints in treatments with Geobacter sulfurreducens and Shewanella putrefaciens. [1] Fredrickson, Zachara, Kennedy, Dong, Onstott, Hinman, & Li (1998). Geochimica et Cosmochimica Acta 62, 3239-3257.[2] O’Loughlin, Boyanov, Gorski, Scherer, & Kemner (2021). Minerals 11, 149[3] Zachara, Kukkadapu, Fredrickson, Gorby, & Smith (2002). Geomicrobiology Journal 19, 179–207.

Background The practice of surgeons running overlapping operating rooms has recently come under scrutiny. Objective To examine the impact of hospital policy allowing overlapping rooms in the case of patients admitted to a tertiary care, safety-net hospital for urgent neurosurgical procedures. Methods The neurosurgery service at the hospital being studied transitioned from routinely allowing 1 room per day (period 1) to overlapping rooms (period 2), with the second room being staffed by the same attending surgeon. Patients undergoing neurosurgical intervention in each period were retrospectively compared. Demographics, indication, case type, complications, outcomes, and total charges were tracked. Results There were 59 urgent cases in period 1 and 63 in period 2. In the case of these patients, the length of stay was significantly decreased in period 2 (13.09 d vs 19.52; P = .006). The time from admission to surgery (wait time) was also significantly decreased in period 2 (5.12 d vs 7.00; P = .04). Total charges also trended towards less in period 2 (${\$}$150 942 vs ${\$}$200 075; P = .05). Surgical complications were no different between the groups (16.9% vs 14.3%; P = .59), but medical complications were significantly decreased in period 2 (14.3% vs 30.5%; P = .009). Significantly more patients were discharged to home in period 2 (69.8% vs 42.4%; P = .003). Conclusion As a matter of policy, allowing overlapping rooms significantly reduces the length of stay in the case of a vulnerable population in need of urgent surgery at a single safety-net academic institution. This may be due to a reduction in medical complications in these patients.

Made available in DSpace on 2021-06-25T10:27:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The forests of Amazonia are among the most biodiverse plant communities on Earth. Given the immediate threats posed by climate and land-use change, an improved understanding of how this extraordinary biodiversity is spatially organized is urgently required to develop effective conservation strategies. Most Amazonian tree species are extremely rare but a few are common across the region. Indeed, just 227 ‘hyperdominant’ species account for >50% of all individuals >10 cm diameter at 1.3 m in height. Yet, the degree to which the phenomenon of hyperdominance is sensitive to tree size, the extent to which the composition of dominant species changes with size class and how evolutionary history constrains tree hyperdominance, all remain unknown. Here, we use a large floristic dataset to show that, while hyperdominance is a universal phenomenon across forest strata, different species dominate the forest understory, midstory and canopy. We further find that, although species belonging to a range of phylogenetically dispersed lineages have become hyperdominant in small size classes, hyperdominants in large size classes are restricted to a few lineages. Our results demonstrate that it is essential to consider all forest strata to understand regional patterns of dominance and composition in Amazonia. More generally, through the lens of 654 hyperdominant species, we outline a tractable pathway for understanding the functioning of half of Amazonian forests across vertical strata and geographical locations. Institute of Environment Department of Biological Sciences Florida International University School of Geography University of Leeds Center for Global Discovery and Conservation Science Arizona State University Instituto Nacional de Pesquisas da Amazônia (INPA) Ecology and Evolutionary Biology University of Michigan Departamento de Ciencias Forestales Universidad Nacional de Colombia Departamento de Biología Universidad Autónoma de Madrid Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM) Universidad Autónoma de Madrid Naturalis Biodiversity Center Systems Ecology Vrije Universiteit Lancaster Environment Centre Lancaster University Environmental Change Institute University of Oxford Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences School of Geosciences University of Edinburgh Missouri Botanical Garden Brazilian Agricultural Research Corporation (Embrapa) Universidad Nacional de San Antonio Abad del Cusco Department of Intergrative Biology University of California Berkeley Department of Biology University of Turku Instituto de Investigaciones de la Amazonía Peruana UNELLEZ-Guanare Programa de Ciencias del Agro y el Mar Herbario Universitario (PORT) Compensation International Progress S. A.—Ciprogress Greenlife AMAP Université de Montpellier CIRAD CNRS INRAE IRD Environmental and Rural Science University of New England INRA UMR EcoFoG AgroParisTech CNRS CIRAD Université des Antilles Université de Guyane CIRAD UMR EcoFoG BIOMAS Universidad de Las Américas Instituto de Ecología Herbario Nacional de Bolivia Departamento de Biologia Universidade Federal de Rondônia Laboratoire Evolution et Diversité Biologique (EDB) CNRS/UPS School of Geography Earth and Environmental Sciences University of Plymouth Department of Ecology and Evolutionary Biology Cornell University Department of Geography University of Exeter Facultad de Ciencias Biológicas Universidad Nacional de la Amazonía Peruana Estación Biológica del Jardín Botánico de Missouri Institut de Ciència i Tecnologia Ambientals Universitat Autònoma de Barcelona School of Geography & Sustainable Development University of St Andrews Department of Environment and Development Federal University of Amapá Centre for Tropical Environmental and Sustainability Science (TESS) and College of Marine and Environmental Sciences James Cook University Department of Environmental Science and Policy George Mason University Inventory and Monitoring Program National Park Service Smithsonian Institution Department of Plant Sciences University of Cambridge Living with Lakes Centre Laurentian University DRGB Instituto Nacional de Innovación Agraria (INIA) Herbarium Amazonense (AMAZ) Universidad Nacional de la Amazonia Peruana Department of Ecology Universidade de São Paulo Institute for Biodiversity and Ecosystem Dynamics University of Amsterdam Centro de Estudos da Biodiversidade Universidade Federal de Roraima Museo de Historia Natural Noel Kempff Mercado Universidad Autónoma Gabriel Rene Moreno Faculdade de Ciências Agrárias Biológicas e Sociais Aplicadas Universidad do Estado de Mato Grosso Centro de Biociências Universidade Federal do Rio Grande do Norte Department of Ecology Evolution and Behaviour University of Minnesota Department of Geography University College London Departamento de Ciencias Biológicas Universidad de Los Andes (Colombia) Centro de Ciências Biológicas e da Natureza Universidade Federal do Acre Nicholas School of the Environment Duke University Iwokrama International Centre for Rainforest Conservation and Development Smithsonian’s National Zoo & Conservation Biology Institute Instituto de Ciencias Naturales Universidad Nacional de Colombia Universidade Federal Rural da Amazônia—UFRA/CAPES Museu Paraense Emílio Goeldi Laboratorio de Ecología de Bosques Tropicales y Primatología Fundación Natura Colombia Universidad de Los Andes Facultad de Forestales Universidad Nacional de la Amazonía Peruana Institute of Research for Forestry Development Universidad de los Andes School of Environmental and Forest Sciences (SEFS) University of Washington Universidad Regional Amazónica Ikiam Agteca-Amazonica Universidad Autónoma del Beni Instituto Amazónico de Investigaciones (IMANI) Universidad Nacional de Colombia Broward County Parks and Recreation Biological Sciences Florida Atlantic University-Davie Museu Universitário Universidade Federal do Acre Facultad de Ingeniería Ambiental Universidad Estatal Amazónica Department of Biology Washington University in St Louis National Institute for Space Research (INPE) Geoinformática & Sistemas (GeoIS) School of Earth Sciences and Environmental Sustainability Northern Arizona University Department of Geography and the Environment University of Texas at Austin Instituto de Ciência e Tecnologia São Paulo State University (UNESP) School of Anthropology and Conservation University of Kent Universidade Federal do Amazonas Herbario Alfredo Paredes (QAP) Universidad Central del Ecuador School of Geography Earth and Environmental Sciences University of Birmingham Department of Life Sciences Imperial College London Science and Education The Field Museum Universidad Tecnica del Norte Herbario Nacional del Ecuador Research Institute Alexander von Humboldt Instituto de Ciência e Tecnologia São Paulo State University (UNESP)

A three electrode electrochemical enzymatic biosensor consisting of ZnO nanowires was successfully fabricated using flexographic printing technique. The incorporation of ZnO nanowires at the working electrode provides advantages such as simple functionalization and high surface area for enhanced sensitivity. The flexographic printing technique allows ultra-high throughput and low cost mass production of devices due to the roll-to-roll nature of the technique. Therefore, the techniques developed here are prudent to the development of technologies capable of meeting the vast market demand for biosensing. Carbon electrodes, silver/silver chloride reference electrodes and ZnO seed layer precursors were directly printed onto a flexible plastic substrate through flexographic printing. The printing process was optimised to allow a suitable seed layer to be formed on the porous printed-carbon electrode to allow selective growth of ZnO nanowires using a hydrothermal growth method. The ZnO nanowires were subsequently functionalised with glucose oxidase, which was used in this work to form a glucose sensor as an exemplary use of the device. The fabricated nanowire electrochemical biosensing devices showed a typical sensitivity of 1.2 ± 0.2 μA mM −1 cm −2 with a linear response to the addition of glucose over a concentration range of 0.1 mM to 3.6 mM.

The Microbiology of Nuclear Waste Disposal is a state-of-the-art reference featuring contributions focusing on the impact of microbes on the safe long-term disposal of nuclear waste. This book is the first to cover this important emerging topic, and is written for a wide audience encompassing regulators, implementers, academics, and other stakeholders. The book is also of interest to those working on the wider exploitation of the subsurface, such as bioremediation, carbon capture and storage, geothermal energy, and water quality. Planning for suitable facilities in the U.S., Europe, and Asia has been based mainly on knowledge from the geological and physical sciences. However, recent studies have shown that microbial life can proliferate in the inhospitable environments associated with radioactive waste disposal, and can control the long-term fate of nuclear materials. This can have beneficial and damaging impacts, which need to be quantified.

Reliable reconstructions of global and regional climate during the Holocene (11,700 years ago to present) are vital to constraining the natural range of climate variability and testing state-of-the-art models, which seek to forecast the near- and long-term impact of anthropogenic greenhouse forcing. Much of continental Eurasia is still underrepresented, however, in geological proxy reconstructions of Holocene climate variability, and the vast majority of paleoclimate data only reflect conditions during peak summer months (JJA) or the growing season. The paucity of winter proxy data has therefore been cited as a possible explanation for the current mismatch between geological proxy-based and climate-model reconstructions of Holocene temperature, but testing the hypothesis first requires additional datasets. In this series of studies, I seek to strengthen our knowledge of Holocene climate evolution in continental western Eurasia and mitigate the seasonal bias in paleoclimate proxy datasets by investigating two sites of freshwater carbonate deposition in western Russia: 1) Kinderlinskaya Cave, located in the southern Ural Mountains, and 2) the Izhora Plateau, south of the Gulf of Finland. Two speleothems collected from Kinderlinskaya Cave, which grew over the entire Holocene epoch, were analyzed for stable isotopes of oxygen and carbon. Carbon-isotope data constrain the timing of permafrost degradation and afforestation for the southern Ural Mountains, and the stable-isotope composition of oxygen in speleothem calcite is shown to reflect Holocene temperature evolution during the winter season. Centennial-scale trends in oxygen-isotope data are further utilized to establish a climate dynamic relationship between winter air temperature over western Russia and perturbations to the North Atlantic Current system over the last 11,700 years, providing a foundation from which to evaluate the regional climate response to feedbacks associated with anthropogenic warming. EarlyÐMiddle Holocene deposits of meteogenic (cool-water) travertine were also analyzed for stable isotopes of oxygen and carbon, as well as their major-cation concentrations (Mg and Sr). The oxygen-isotope composition of travertine deposits is shown to reflect winter climate variability in the Peribaltic region, for which our dataset constitutes the first winter paleoclimate archive, whereas the remaining geochemical proxies document changes to the surface hydrology and environment of the Izhora Plateau from approximately 9,500 to 6,800 years ago. From the results of these studies, we conclude that the winter and summer climate evolution of western continental Eurasia followed opposing trajectories for much of the Holocene. We further corroborate the hypothesis that geological proxy reconstructions of Holocene surface temperature are likely biased toward conditions during the summer half year by presenting data that strongly support the veracity of existing climate model reconstructions.

In this study, a uniformly mixed sensing layer of typically immiscible compounds, such as tetrathiafulvalene (TTF) mediator and glucose oxidase (GOx) enzyme, was developed using a simultaneous spray deposition technique ideal for mass production of glucose sensors at low cost while exhibiting enhanced amperometric response. For comparison, the sensors were fabricated via three different methods: conventional drop-cast of TTF and GOx compounds in subsequent layers (DL), spray deposition of the compounds in subsequent layers (SL), and spray mixing of the compounds as one uniform layer (SM). Uniformity of the sensing layers was investigated via Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX) techniques demonstrating an even distribution of the TTF and GOx throughout the sensing layer for the SM sensors. The amperometric studies showed a significantly larger maximum current response, Imax and sensitivity for the SM sensors as compared to the SL and DL sensors. The significantly better performance of the SM sensors correlated well with the even distribution of TTF and GOx throughout the sensing layer, resulting in enhanced electron transfer and redox reaction between GOx and TTF. The SM spray technique was then applied to deposit a uniformly mixed sensing layer on to 3D microneedle arrays to provide minimally invasive continuous glucose monitoring (CGM). In-vivo studies showed amperometric response from the microneedle CGM device was compatible to changes in blood glucose levels measured via the standard finger prick tests. Importantly, the deposition technique is suitable for mass production of the microneedle CGM at very low cost.

International audience; Remediation techniques for toxic/persistant contaminants in groundwater are often technologically difficult. Nanoparticles (NP) like nZVI (Zero-Valent Iron) applicable as in-situ reduction or oxidation agents for groundwater treatment give promising results. However, they may also represent an additional contamination. This study aims to evaluate the mobility and the reactivity of NP in the presence or absence of biofilm by column transport assays mimicking aquifer conditions, and to evaluate the impact of NP on planktonic nitrate-reducing bacteria. Biofilms were grown on sand using environmental groundwater samples as inoculum in nitrate reducing conditions. Suspensions of nZVI were then injected into the columns and the outlet Fe concentrations monitored. Biofilm-NP interactions were characterized using SEM/STEM observations of sand after the NP breakthrough. Biofilms were further characterized using molecular approaches. The predicted travel distances of nZVI are found to be 1.5 to 25 m for a 10 m d-1 flow. The presence of biofilm in the column decreased the total porosity of column from 35% to 25%. Though the recoveries of nZVI at the column outlet in the presence or absence of biofilm were similar, the analysis of the sand suggested NP-biofilm interactions (correlation TOC vs Fe concentrations). These interactions are confirmed by the SEM/STEM observations. Results also show a toxicity of NP on planktonic bacteria. It appears therefore that reactive NP, very useful for in situ groundwater treatment, can represent a source of emerging contamination. Indeed, a toxicity of manufactured NPs toward bacteria could be highlighted and interactions between bacterial biofilm and NPs could be observed.

Introduction Glycaemic control is an important predictor of mortality in sepsis. Various international organizations including the Surviving Sepsis campaign recommend glycaemic control in critical illness with a glucose target between 6.1-10 mmol/L. The NICE-SUGAR Trial in 2009 was a landmark in the debate over tight versus liberal glycaemic control in the critically ill and subsequent guidelines have been adjusted to reflect a move towards moderate glycaemic control. Methods We conducted a nation-wide study comparing glucose targets used in intensive care units in the United Kingdom in 2007 with those used in 2014 to 2015 to see the impact of the NICE-SUGAR study and subsequent guideline changes. Results We received a combined response from 81% of intensive care units in the UK. There was an increase in the average median glucose target in 2014/2015 compared with 2007 (7.8 versus 7.2; p Conclusions There is an overall trend towards using a more moderate glucose target in critical care in the UK reflecting changes in international guidelines. However, it is likely that controversies, which still exist in the literature, are reflected in the variability of glycaemic control targets. It is possible that the advent of closed-loop or continuous glucose monitoring may have a further impact on this.

Understanding the resilience of moist tropical forests to treefall disturbance events is important for understanding the mechanisms that underlie species coexistence and for predicting the future composition of these ecosystems. Here, we test whether variation in the functional composition of Amazonian forests determines their resilience to disturbance. We studied the legacy of natural treefall disturbance events in four forests across Amazonia that differ substantially in functional composition. We compared the composition and diversity of all free-standing woody stems 2-10 cm diameter in previously disturbed and undisturbed 20 × 20 m subplots within 55, one-hectare, long-term forest inventory plots. Overall, stem number increased following disturbance, and species and functional composition shifted to favour light-wooded, small-seeded taxa. Alpha-diversity increased, but beta-diversity was unaffected by disturbance, in all four forests. Changes in response to disturbance in both functional composition and alpha-diversity were, however, small (2 - 4% depending on the parameter) and similar among forests. Synthesis. This study demonstrates that variation in the functional composition of Amazonian forests does not lead to large differences in the response of these forests to treefall disturbances, and overall, these events have a minor role in maintaining the diversity of these ecosystems. Understanding how the diversity of tropical forests responds to treefall disturbance events is important for understanding mechanisms of species coexistence and for predicting the future composition of these ecosystems. Previous studies have focussed on single sites and have contradictory results. By studying four sites in Amazonia, we demonstrate that these events have a consistent, but minor, role in maintaining the diversity of these ecosystems. © 2016 British Ecological Society.

We propose a pseudopotential for the electron-electron Coulomb interaction to improve the efficiency of many-body electronic structure calculations. The pseudopotential accurately replicates the scattering properties of the Coulomb interaction, and recovers the analytical solution for two electrons in a parabolic trap. A case study for the homogeneous electron gas using the diffusion Monte Carlo and configuration interaction methods recovers highly accurate values for the ground state energy, and the smoother potential reduces the computational cost by a factor of $\ensuremath{\sim}30$. Finally, we demonstrate the use of the pseudopotential to study isolated lithium and beryllium atoms.

Establishing the phase diagram of hydrogen is a major challenge for experimental and theoretical physics. Experiment alone cannot establish the atomic structure of solid hydrogen at high pressure, because hydrogen scatters X-rays only weakly. Instead, our understanding of the atomic structure is largely based on density functional theory (DFT). By comparing Raman spectra for low-energy structures found in DFT searches with experimental spectra, candidate atomic structures have been identified for each experimentally observed phase. Unfortunately, DFT predicts a metallic structure to be energetically favoured at a broad range of pressures up to 400 GPa, where it is known experimentally that hydrogen is non-metallic. Here we show that more advanced theoretical methods (diffusion quantum Monte Carlo calculations) find the metallic structure to be uncompetitive, and predict a phase diagram in reasonable agreement with experiment. This greatly strengthens the claim that the candidate atomic structures accurately model the experimentally observed phases., Experimental studies of hydrogen at high pressure are challenging, so theory is central to understanding its phase behaviour; however, computed phase diagrams do not agree with previous measurements. Here, the authors use a quantum Monte Carlo method and present results in qualitative agreement with experiment.

In this paper, we have presented the use of flexographic printing techniques in the selective patterning of gold nanoparticles (AuNPs) onto a substrate. Highly uniform coverage of AuNPs was selectively patterned on the substrate surface, which was subsequently used in the development of a glucose sensor. These AuNPs provide a biocompatible site for the attachment of enzymes and offer high sensitivity in the detection of glucose due to their large surface to volume ratio. The average size of the printed AuNPs is less than 60 nm. Glucose sensing tests were performed using printed carbon-AuNP electrodes functionalized with glucose oxidase (GOx). The results showed a high sensitivity of 5.52 μA mM−1 cm−2 with a detection limit of 26 μM. We have demonstrated the fabrication of AuNP-based biosensors using flexographic printing, which is ideal for low-cost, high-volume production of the devices. Electronic supplementary material The online version of this article (doi:10.1186/s11671-015-0835-1) contains supplementary material, which is available to authorized users.

The palladium-catalyzed carbonylation of phenol to form diphenyl carbonate (DPC) requires the presence of a metal co-catalyst to catalyze the reoxidation of palladium from Pd 0 to Pd 2+ in the presence of oxygen. In this study, we utilize a high throughput screening (HTS) methodology to rapidly study the nature of the co-catalyst with an emphasis on combinations of metal co-catalysts that appear to work in a synergistic manner to increase palladium usage. Critical new developments were made in using a small-scale reactor in diffusion controlled systems. The HTS system is described along with the optimized catalyst packages that were determined. Additionally, the results from HTS were used to better elucidate the mechanism of this potentially important commercial reaction.

The thermal annealing of zinc precursors to form suitable seed layers for the growth of ZnO nanowires is common. However, the process is relatively long and involves high temperatures which limit substrate choice. In this study the use of a low temperature, ultra-violet (UV) exposure is demonstrated for photodecomposition of zinc acetate precursors to form suitable seed layers. Comparisons are made between ZnO nanowire growth performed on seed layers produced through thermal annealing and exposure to UV. The dependence of growth density and nanowire diameter on UV exposure time is investigated. Growth quality is confirmed with energy dispersive x-ray (EDX) and x-ray diffraction analyses. The chemical composition of the exposed layers is investigated with EDX and x-ray photoelectron spectroscopy (XPS). Atomic force microscopy (AFM) is utilized to investigate morphological changes with respect to UV exposure. The diameter and density of the resultant growth was found to be strongly dependent on the UV exposure time. UV exposure times of only 25–30 s led to maximum density of growth and minimum diameter, significantly faster than thermal annealing. EDX, XPS and AFM analyses of the seed layers confirmed decomposition of the zinc precursor and morphological changes which influenced the growth.

We study the direct calculation of total energy derivatives for lattice dynamics and electron-phonon coupling calculations using supercell matrices with non-zero off-diagonal elements. We show that it is possible to determine the response of a periodic system to a perturbation characterized by a wave vector with reduced fractional coordinates $(m_1/n_1,m_2/n_2,m_3/n_3)$ using a supercell containing a number of primitive cells equal to the least common multiple of $n_1$, $n_2$, and $n_3$. If only diagonal supercell matrices are used, a supercell containing $n_1n_2n_3$ primitive cells is required. We demonstrate that the use of non-diagonal supercells significantly reduces the computational cost of obtaining converged zero-point energies and phonon dispersions for diamond and graphite. We also perform electron-phonon coupling calculations using the direct method to sample the vibrational Brillouin zone with grids of unprecedented size, which enables us to investigate the convergence of the zero-point renormalization to the thermal and optical band gaps of diamond.