Showing papers by "The Cyprus Institute published in 2018"
Aix-Marseille University1, Spanish National Research Council2, University of Paris3, Sciences Po4, Technical University of Madrid5, The Cyprus Institute6, Central Maine Community College7, University of Salento8, University of Barcelona9, University of Haifa10, City University of Hong Kong11, University of Giessen12
TL;DR: In this paper, a dedicated effort to synthesize existing scientific knowledge across disciplines is underway and aims to provide a better understanding of the combined risks posed in the Mediterranean Basin, where fewer systematic observations schemes and impact models are based.
Abstract: Recent accelerated climate change has exacerbated existing environmental problems in the Mediterranean Basin that are caused by the combination of changes in land use, increasing pollution and declining biodiversity. For five broad and interconnected impact domains (water, ecosystems, food, health and security), current change and future scenarios consistently point to significant and increasing risks during the coming decades. Policies for the sustainable development of Mediterranean countries need to mitigate these risks and consider adaptation options, but currently lack adequate information — particularly for the most vulnerable southern Mediterranean societies, where fewer systematic observations schemes and impact models are based. A dedicated effort to synthesize existing scientific knowledge across disciplines is underway and aims to provide a better understanding of the combined risks posed.
699 citations
Michigan State University1, University of Oxford2, Southern Methodist University3, College of William & Mary4, Thomas Jefferson National Accelerator Facility5, VU University Amsterdam6, Hampton University7, The Cyprus Institute8, University of Cyprus9, University of Pavia10, National Taiwan Ocean University11, University of Regensburg12, Temple University13, New Mexico State University14, Los Alamos National Laboratory15, University College London16, Shanghai Jiao Tong University17, University of Kentucky18, University of Virginia19, University of Washington20, University of Grenoble21, University of Tübingen22, University of Mainz23, University of Adelaide24
TL;DR: In this article, the authors present an overview of lattice-QCD and global-analysis techniques used to determine unpolarized and polarized proton PDFs and their moments.
170 citations
TL;DR: This first direct nonperturbative evaluation opens a most promising path to compute PDFs in an ab initio way on the lattice and provides a framework for investigating also a wider class of similar quantities, which require the evaluation of hadronic matrix elements of nonlocal operators.
Abstract: We extract parton distribution functions (PDFs) of the nucleon from lattice QCD using an ensemble of gauge field configurations simulated with light quark masses fixed to their physical values. Theoretical and algorithmic improvements that allow such a calculation include momentum smearing to reach large nucleon boosts with reduced statistical errors, nonperturbative renormalization, target mass corrections, and a novel modified matching of lattice QCD results to connect to what is extracted from experimental measurements. We give results on the unpolarized and helicity PDFs in the modified minimal subtraction scheme at a scale of 2 GeV and reproduce the main features of the experimentally determined quantities, showing an overlap for a range of Bjorken-x values. This first direct nonperturbative evaluation opens a most promising path to compute PDFs in an ab initio way on the lattice and provides a framework for investigating also a wider class of similar quantities, which require the evaluation of hadronic matrix elements of nonlocal operators.
142 citations
TL;DR: In this paper, a numerical comparative analysis between green roofs and cool roofs in a tropical climate like Singapore's was done by means of dynamic simulations in EnergyPlus software, taking into account climatological, thermal, optical and hydrological variables.
136 citations
TL;DR: In this article, the first direct calculation of the transversity parton distribution function within the nucleon from lattice QCD was performed using simulations with the light quark mass fixed to its physical value and at one value of the lattice spacing.
Abstract: We present the first direct calculation of the renormalized transversity parton distribution function within the nucleon from lattice QCD. The calculation is performed using simulations with the light quark mass fixed to its physical value and at one value of the lattice spacing. Apart from physically light quarks, novel elements of the calculations are nonperturbative renormalization and extraction of a formula for the matching to light-cone parton distribution functions. Final results are presented in the $\overline{\mathrm{MS}}$ scheme at a scale of $\sqrt{2}\text{ }\text{ }\mathrm{GeV}$.
119 citations
TL;DR: A cost-benefit assessment of ammonia emission abatement options for the EU indicates that the reduction of agricultural emissions generates net financial and social benefits.
95 citations
TL;DR: Measurements by aircraft in the Oxidation Mechanism Observations campaign show that the monsoon sustains a remarkably efficient cleansing mechanism by which contaminants are rapidly oxidized and deposited to Earth’s surface.
Abstract: Air pollution is growing fastest in monsoon-affected South Asia. During the dry winter monsoon, the fumes disperse toward the Indian Ocean, creating a vast pollution haze, but their fate during the wet summer monsoon has been unclear. We performed atmospheric chemistry measurements by aircraft in the Oxidation Mechanism Observations campaign, sampling the summer monsoon outflow in the upper troposphere between the Mediterranean and the Indian Ocean. The measurements, supported by model calculations, show that the monsoon sustains a remarkably efficient cleansing mechanism by which contaminants are rapidly oxidized and deposited to Earth's surface. However, some pollutants are lofted above the monsoon clouds and chemically processed in a reactive reservoir before being redistributed globally, including to the stratosphere.
94 citations
TL;DR: It is estimated that in sub-Saharan Africa, ambient air pollution reduces the average life expectancy of children by 4-5 years, whereas childhood mortality from AAP-LRIs declined by nearly 30% in the same period.
92 citations
Abstract: The present study investigates the century-long and more recent rainfall trends over the greater region of Middle East and North Africa (MENA). Five up-to-date gridded observational datasets are employed. Besides mean annual values, trends of six indices of drought and extreme precipitation are also considered in the analysis. Most important findings include the significant negative trends over the Maghreb, Levant, Arabian Peninsula, and Sahel regions that are evident since the beginning of the twentieth century and are more or less extended to today. On the other hand, for some Mediterranean regions such as the Balkans and the Anatolian Plateau, precipitation records during the most recent decades indicate a significant increasing trend and a recovering from the dry conditions that occurred during the mid-1970s and mid-1980s. The fact that over parts of the study region the selected datasets were found to have substantial differences in terms of mean climate, trends, and interannual variability, motivated the more thorough investigation of the precipitation observational uncertainty. Several aspects, such as annual and monthly mean climatologies and also discrepancies in the monthly time-series distribution, are discussed using common methods in the field of climatology but also more sophisticated, nonparametric approaches such as the Kruskal–Wallis and Dunn’s tests. Results indicate that in the best case, the data sources are found to have statistically significant differences in the distribution of monthly precipitation for about 50% of the study region extent. This percentage is increased up to 70% when particular datasets are compared. Indicatively, the range between the tested rainfall datasets is found to be more than 20% of their mean annual values for most of the extent of MENA, while locally, for the hyper-arid regions, this percentage is increased up to 100%. Precipitation observational uncertainty is also profound for parts of southern Europe. Outlier datasets over individual regions are identified in order to be more cautiously used in future regional climate studies.
88 citations
TL;DR: 75 elementary-step unimolecular reactions of the simplest γ-ketohydroperoxide, 3-hydroperoxypropanal, were discovered by a combination of density functional theory with several automated transition-state search algorithms, demonstrating both the power and the weaknesses of existing fully automated approaches for reaction discovery.
Abstract: Ketohydroperoxides are important in liquid-phase autoxidation and in gas-phase partial oxidation and pre-ignition chemistry, but because of their low concentration, instability, and various analytical chemistry limitations, it has been challenging to experimentally determine their reactivity, and only a few pathways are known. In the present work, 75 elementary-step unimolecular reactions of the simplest γ-ketohydroperoxide, 3-hydroperoxypropanal, were discovered by a combination of density functional theory with several automated transition-state search algorithms: the Berny algorithm coupled with the freezing string method, single- and double-ended growing string methods, the heuristic KinBot algorithm, and the single-component artificial force induced reaction method (SC-AFIR). The present joint approach significantly outperforms previous manual and automated transition-state searches – 68 of the reactions of γ-ketohydroperoxide discovered here were previously unknown and completely unexpected. All of ...
80 citations
21 Dec 2018
TL;DR: Favez et al. as discussed by the authors found that secondary organic aerosols (SOA) are the most important determinant of the enhanced warming, which can be doubled by "lensing" from SOA.
Abstract: Atmospheric black carbon (BC) has a strong positive, but still controversial, effect on global warming. In particular, BC absorption enhancement (Eabs) due to internal mixing with other chemical species—so-called lensing effect—is poorly assessed. This bottleneck partly relies on the lack of long-term in situ measurements of both the optical and chemical properties of BC-containing particles. Here, we present experimental and computational results showing a significant Eabs increase with the aerosol photochemical aging. This was associated with the production of highly oxidized secondary organic aerosols (SOA), especially at summertime. The 3-year-long continuous aerosol chemical and optical measurements used for the present study was obtained in the Paris region, France, which might be representative of near-future air quality within developing countries. These findings suggest that SOA could represent one of the most critical chemical species to be considered within climate models. Tiny remnants of combustion, known as black carbon, absorb solar radiation and warm the atmosphere—an effect that can be doubled by “lensing” from secondary organic aerosols. A multi-institution team led by Olivier Favez at the Institut National de l’Environnement Industriel et des Risques conducted a three-year observational and modeling study near Paris. The researchers tested a range of atmospheric constituents and found that secondary organic aerosols—adhered to black carbon particles—are the most important determinant of the enhanced warming. The aerosols are produced by photochemical reactions with a wide variety of natural and human-produced volatile organic compounds, and act to focus solar radiation to the core of the black carbon particle, especially during the particle aging process during summer. The findings—although specific to Paris—provide insights into the specific compounds leading to enhanced warming, and reveal the most effective targets for remediating their effect.
TL;DR: In this paper, the authors present the QCD simulation of the first gauge ensemble of two degenerate light quarks, a strange and a charm quark with all quark masses tuned to their physical values within the twisted mass fermion formulation.
Abstract: We present the QCD simulation of the first gauge ensemble of two degenerate light quarks, a strange and a charm quark with all quark masses tuned to their physical values within the twisted mass fermion formulation. Results for the pseudoscalar masses and decay constants confirm that the produced ensemble is indeed at the physical parameters of the theory. This conclusion is corroborated by a complementary analysis in the baryon sector. We examine cutoff and isospin breaking effects and demonstrate that they are suppressed through the presence of a clover term in the action.
TL;DR: In this paper, a lattice QCD determination of the transition amplitude for the P$-wave was performed with two-pion clover fermions at a pion mass of approximately $320$ MeV, on a $32^3 \times 96$ lattice with $L\approx 3.6$ fm.
Abstract: We report a lattice QCD determination of the $\pi\gamma \to \pi\pi$ transition amplitude for the $P$-wave, $I=1$ two-pion final state, as a function of the photon virtuality and $\pi\pi$ invariant mass. The calculation was performed with $2+1$ flavors of clover fermions at a pion mass of approximately $320$ MeV, on a $32^3 \times 96$ lattice with $L\approx 3.6$ fm. We construct the necessary correlation functions using a combination of smeared forward, sequential and stochastic propagators, and determine the finite-volume matrix elements for all $\pi\pi$ momenta up to $|\vec{P}|= \sqrt{3} \frac{2\pi}{L}$ and all associated irreducible representations. In the mapping of the finite-volume to infinite-volume matrix elements using the Lellouch-Luscher factor, we consider two different parametrizations of the $\pi\pi$ scattering phase shift. We fit the $q^2$ and $s$ dependence of the infinite-volume transition amplitude in a model-independent way using series expansions, and compare multiple different truncations of this series. Through analytic continuation to the $\rho$ resonance pole, we also determine the $\pi\gamma \to \rho$ resonant transition form factor and the $\rho$ meson photocoupling, and obtain $|G_{\rho\pi\gamma}| = 0.0802(32)(20)$.
TL;DR: In this article, the spatial and temporal variability of sub-10μm (PM10), fine (PM2.5) and submicron (PM1) particulate matter in the eastern Mediterranean, the main source areas contributing to their levels and the relative contribution of regional and local anthropogenic and natural sources to PM levels.
TL;DR: Tests did not show any antibacterial effects of Au nanoparticles (NPs) as a result of their negligible diffusivity through the culture media, and Ag NPs exhibited a strong antimicrobial activity that was independent of their size.
Abstract: The use of disc diffusion susceptibility tests to determine the antibacterial activity of engineered nanoparticles (ENPs) is questionable because their low diffusivity practically prevents them from penetrating through the culture media. In this study, we investigate the ability of such a test, namely the Kirby-Bauer disc diffusion test, to determine the antimicrobial activity of Au and Ag ENPs having diameters from 10 to 40 nm on Escherichia coli cultures. As anticipated, the tests did not show any antibacterial effects of Au nanoparticles (NPs) as a result of their negligible diffusivity through the culture media. Ag NPs on the other hand exhibited a strong antimicrobial activity that was independent of their size. Considering that Ag, in contrast to Au, dissolves upon oxidation and dilution in aqueous solutions, the apparent antibacterial behavior of Ag NPs is attributed to the ions they release. The Kirby-Bauer method, and other similar tests, can therefore be employed to probe the antimicrobial activity of ENPs related to their ability to release ions rather than to their unique size-dependent properties.
TL;DR: This research encourages further analysis into the persistent weather conditions prevalent during HWs stimulating ozone formation for higher temperatures by examining how ozone levels changed under heatwave conditions with emphasis on specific air quality and meteorological parameters with respect to non-heatwave summer conditions.
Abstract: Near-surface ozone is enhanced under particular chemical reactions and physical processes. This study showed the seasonal variation of near-surface ozone in Nicosia, Cyprus and focused in summers when the highest ozone levels were noted using a seven year hourly dataset from 2007 to 2014. The originality of this study is that it examines how ozone levels changed under heatwave conditions (defined as 4 consecutive days with daily maximum temperature over 39 °C) with emphasis on specific air quality and meteorological parameters with respect to non-heatwave summer conditions. The influencing parameters had a medium-strong positive correlation of ozone with temperature, UVA and UVB at daytime which increased by about 35% under heatwave conditions. The analysis of the wind pattern showed a small decrease of wind speed during heatwaves leading to stagnant weather conditions, but also revealed a steady diurnal cycle of wind speed reaching a peak at noon, when the highest ozone levels were noted. The negative correlation of NOx budget with ozone was further increased under heatwave conditions leading to steeper lows of ozone in the morning. In summary, this research encourages further analysis into the persistent weather conditions prevalent during HWs stimulating ozone formation for higher temperatures.
TL;DR: The results showed the increase of mortality risk particularly for men of age 65–69 and women of ages 65–74 in the urban area, showing that women were more vulnerable to heat extremities.
Abstract: Extreme temperatures impose thermal stress on human health, resulting in increased hospitalizations and mortality rate. We investigated the circulatory and respiratory causes of death for the years 2007 to 2014 inclusive for the urban and rural areas of Nicosia, Cyprus under urban heatwave and non-heatwave conditions. Heatwaves were defined as four or more consecutive days with mean urban daily temperature over the 90th percentile threshold temperature of the eight investigated years. Lag period of adverse health effects was found to be up to three days following the occurrence of high temperatures. The relative risk (RR) for mortality rate under heatwave and non-heatwave conditions was found taking in consideration the lag period. The results showed the increase of mortality risk particularly for men of ages 65⁻69 (RR = 2.38) and women of ages 65⁻74 (around RR = 2.54) in the urban area, showing that women were more vulnerable to heat extremities. High temperatures were also associated with high ozone concentrations, but they did not impose an excess risk factor, as they did not reach extreme values. This analysis highlights the importance of preparing for potential heat related health impacts even in Cyprus, which is an island with frequent heatwaves.
TL;DR: In this paper, the authors used laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) to understand the chemical characteristics of the Igbo Olokun glass beads in comparison with previously analyzed beads.
TL;DR: In this paper, a multilevel logistic regression model was applied to investigate the labour productivity of the six main agricultural systems across European NUTS2 regions, and significant differences were revealed between northern central regions and the continental peripheries (Mediterranean, Eastern).
TL;DR: In this paper, the authors used the MODIS-based land cover classification, vegetation, clay fraction and topography data to improve the aeolian dust budget calculations with the global ECHAM/MESSy atmospheric chemistry-climate model.
Abstract: . To improve the aeolian dust budget calculations with the global ECHAM/MESSy
atmospheric chemistry–climate model (EMAC), which combines the Modular Earth
Submodel System (MESSy) with the ECMWF/Hamburg (ECHAM) climate model developed
at the Max Planck Institute for Meteorology in Hamburg based on a weather
prediction model of the European Centre for Medium-Range Weather Forecasts (ECMWF), we have
implemented new input data and updates of the emission scheme. The data set comprises land cover classification, vegetation, clay fraction and
topography.
It is based on up-to-date observations, which are crucial to account for the
rapid changes of deserts and semi-arid regions in recent decades.
The new Moderate Resolution Imaging Spectroradiometer (MODIS)-based land cover
and vegetation data are time dependent, and the effect of long-term trends and
variability of the relevant parameters is therefore considered by the emission
scheme.
All input data have a spatial resolution of at least 0.1∘ compared to
1∘ in the previous version, equipping the model for high-resolution
simulations. We validate the updates by comparing the aerosol optical depth (AOD) at 550 nm
wavelength from a 1-year simulation at T106 (about 1.1∘ ) resolution
with Aerosol Robotic Network (AERONET) and MODIS observations, the
10 µ m dust AOD (DAOD) with Infrared Atmospheric Sounding
Interferometer (IASI) retrievals, and dust concentration and deposition
results with observations from the Aerosol Comparisons between Observations and Models (AeroCom) dust benchmark data set. The
update significantly improves agreement with the observations and is therefore
recommended to be used in future simulations.
TL;DR: In this article, the vertical profiles of the aerosol mass concentration derived from light detection and ranging (lidar) observations and in situ measurements using an optical particle counter on board a UAV during moderate and weak Saharan dust episodes were compared.
Abstract: . In situ measurements using unmanned aerial vehicles (UAVs) and
remote sensing observations can independently provide dense
vertically resolved measurements of atmospheric aerosols, information which
is strongly required in climate models. In both cases, inverting the recorded
signals to useful information requires assumptions and constraints, and this
can make the comparison of the results difficult. Here we compare, for the
first time, vertical profiles of the aerosol mass concentration derived from
light detection and ranging (lidar) observations and in situ measurements
using an optical particle counter on board a UAV during moderate and
weak Saharan dust episodes. Agreement between the two measurement methods was
within experimental uncertainty for the coarse mode (i.e. particles having
radii >0.5 µm ), where the properties of dust particles can be assumed
with good accuracy. This result proves that the two techniques can be used
interchangeably for determining the vertical profiles of aerosol
concentrations, bringing them a step closer towards their systematic
exploitation in climate models.
TL;DR: In this article, a 1-month field campaign was conducted at the Cyprus Atmospheric Observatory (CAO) to provide an improved understanding of the sources and the fate of VOCs in the eastern Mediterranean.
Abstract: . As a part of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx) and
Cyprus Aerosols and Gas Precursors (ENVI-Med CyAr) programs, this study aims
primarily to provide an improved understanding of the sources and the fate of
volatile organic compounds (VOCs) in the eastern Mediterranean. More than 60
VOCs, including biogenic species (isoprene and eight monoterpenes) and
oxygenated VOCs, were measured during a 1-month intensive field campaign
performed in March 2015 at the Cyprus Atmospheric Observatory (CAO), a
regional background site in Cyprus. VOC measurements were conducted using
complementary online and offline techniques. Biogenic VOCs (BVOCs) were
principally imputed to local sources and characterized by compound-specific
daily cycles such as diurnal maximum for isoprene and nocturnal maximum for
α - and β -pinenes, in connection with the variability of emission
sources. The simultaneous study of pinene and isoprene temporal evolution and
meteorological parameters has shown that BVOC emissions were mainly
controlled by ambient temperature, precipitation and relative humidity. It
was found that isoprene daytime emissions at CAO depended on temperature and
solar radiation changes, whereas nocturnal BVOC concentrations (e.g., from
oak and pine forests) were more prone to the relative humidity and
temperature changes. Significant changes in monoterpene mixing ratios
occurred during and after rainfall. The second part of the study focused on
new particle formation (NPF) events at CAO. BVOCs are known to potentially
play a role in the growth as well as in the early stages of formation of new
atmospheric particles. Based on observations of the particle size
distribution performed with a differential mobility particle sizer (DMPS) and
the total number concentrations of particles larger than 1 nm diameter
measured by particle size magnifier (PSM), NPF events were found on 14 out of
20 days of the field campaign. For all possible proxy parameters
(meteorological parameters, calculated H2SO4 and measured gaseous
compounds) having a role in NPF, we present daily variations of different
classes during nucleation event and non-event days. NPF can occur at various
condensational sink (CS) values and both under polluted and clean atmospheric
conditions. High H2SO4 concentrations coupled with high BVOC
concentrations seemed to be one of the most favorable conditions to observe
NPF at CAO in March 2015. NPF event days were characterized by either
(1) a predominant anthropogenic influence (high concentrations of
anthropogenic source tracers observed), (2) a predominant biogenic influence
(high BVOC concentrations coupled with low anthropogenic tracer
concentrations), (3) a mixed influence (high BVOC concentrations coupled with
high anthropogenic tracer concentrations) and (4) a marine influence (both
low BVOC and anthropogenic tracer
concentrations). More pronounced NPF events were identified during mixed
anthropogenic–biogenic conditions compared to the pure anthropogenic or
biogenic ones, for the same levels of precursors. Analysis of a specific NPF
period of the mixed influence type highlighted that BVOC interactions with
anthropogenic compounds enhanced nucleation formation and growth of newly
formed particles. During this period, the nucleation-mode particles may be
formed by the combination of high H2SO4 and isoprene amounts, under
favorable meteorological conditions (high temperature and solar radiation and
low relative humidity) along with low CS. During the daytime, growth of the
newly formed particles, not only sulfate but also oxygen-like organic aerosol
(OOA) mass contributions, increased in the particle phase. High BVOC
concentrations were observed during the night following NPF events,
accompanied by an increase in CS and in semi-volatile OOA contributions,
suggesting further BVOC contribution to aerosol nighttime growth by
condensing onto pre-existing aerosols.
TL;DR: It is argued that RPMD represents a useful tool for further studies of numerous ZPE-sensitive chemical reactions that are of high interest in astrochemistry and is able to describe the transition from direct to indirect mechanisms below room temperature.
Abstract: Because of its fundamental importance in astrochemistry, the H2 + H3+ → H3+ + H2 reaction has been studied experimentally in a wide temperature range. Theoretical studies of the title reaction significantly lag primarily because of the challenges associated with the proper treatment of the zero-point energy (ZPE). As a result, all previous theoretical estimates for the ratio between a direct proton-hop and indirect exchange (via the H5+ complex) channels deviate from the experiment, in particular, at lower temperatures where the quantum effects dominate. In this work, the ring polymer molecular dynamics (RPMD) method is applied to study this reaction, providing very good agreement with the experiment. RPMD is immune to the shortcomings associated with the ZPE leakage and is able to describe the transition from direct to indirect mechanisms below room temperature. We argue that RPMD represents a useful tool for further studies of numerous ZPE-sensitive chemical reactions that are of high interest in astroc...
TL;DR: In this article, atmospheric concentrations of the hydroxyl radical (OH) and the hydroperoxyl radical(HO2) were measured during an intensive field campaign (CYprus PHotochemistry EXperiment, CYPHEX-2014) in the northwest of Cyprus in the summer of 2014 very low local anthropogenic and biogenic emissions around the measurement location provided a vantage point to study the contrasts in atmospheric oxidation pathways under highly processed marine air masses and those influenced by relatively fresh emissions from mainland Europe.
Abstract: The Mediterranean is a climatically sensitive region located at the crossroads of air masses from three continents: Europe, Africa, and Asia The chemical processing of air masses over this region has implications not only for the air quality but also for the long-range transport of air pollution To obtain a comprehensive understanding of oxidation processes over the Mediterranean, atmospheric concentrations of the hydroxyl radical (OH) and the hydroperoxyl radical (HO2) were measured during an intensive field campaign (CYprus PHotochemistry EXperiment, CYPHEX-2014) in the northwest of Cyprus in the summer of 2014 Very low local anthropogenic and biogenic emissions around the measurement location provided a vantage point to study the contrasts in atmospheric oxidation pathways under highly processed marine air masses and those influenced by relatively fresh emissions from mainland Europe The CYPHEX measurements were used to evaluate OH and HO2 simulations using a photochemical box model (CAABA/MECCA) constrained with CYPHEX observations of O3, CO, NOx, hydrocarbons, peroxides, and other major HOx (OH + HO2) sources and sinks in a low-NOx environment (
TL;DR: In this paper, a field experiment has been set up on a degrading terraced hillslope in the Troodos Mountains of Cyprus, to quantify the effectiveness of terrace maintenance on protecting cultivated land against soil erosion.
Abstract: Mountain depopulation in the Mediterranean region over the past decades has led to a decline in the use and maintenance of agricultural terraces and consequently the collapsing of dry-stone walls, which can increase soil erosion rates and downstream sedimentation. A field experiment has been set up on a degrading terraced hillslope in the Troodos Mountains of Cyprus, to quantify the effectiveness of terrace maintenance on protecting cultivated land against soil erosion. The monitored site is cultivated with grapes. The terrace riser (22 m long) that forms the linear outlet of the hillslope has 11.4 m of standing dry-stone wall and 10.6 m of collapsed wall. It has been instrumented with seven 1 m wide sediment traps, three on standing sections of the wall and four on collapsed sections. When dry, sediment was collected from the traps after rainfall events, from December 2015 to November 2017. Uncertainties in the drainage areas of the 31.5-m long slope were quantified both for the terrace wall and for the individual traps through hydrologic delineations based on a detailed topographic survey. The sediment data were complemented by laser scanner surveys that were conducted in November 2015, May 2016 and April 2017, on a dry-stone terrace wall upslope from the outlet section. Wall degradation was assessed from the consecutive 3D model reconstructions. Rainfall was 469 mm in the first year and 515 mm in the second year and the average erosivity was 1148 MJ mm ha−1 h−1 y−1. The average soil erosion rate was 2.4 Mg ha−1 y−1, when linear drainage areas are considered (693 m2), 3.2 Mg ha−1 y−1 when the borders are delineated with the topographic data (520 m2). Nearly half of the soil erosion (43%) occurred during two very intense rainfall events (maximum 30-min intensity exceeding 35 mm h−1), out of the 34 monitored events. Erosion from standing terrace sections was 3.8 less than the erosion from the collapsed sections. For the scanned terrace wall, soil erosion from the standing sections was 2.2 lower than from the degraded sections. The laser scanner surveys identified some preferential erosion paths, but failed to recognize single stone collapses, whereas possible wall displacement was masked by scanning artifacts. The sediment traps were found to be an effective method for understanding and quantifying soil erosion in terraced mountain environments, while further research is needed to develop a more rigorous acquisition procedure for laser scanner surveys to derive useful information on wall degradation.
TL;DR: In this article, a methodology for the calculation of thermal rate coefficients of gas phase chemical reactions is proposed, which is based on combining ring polymer molecular dynamics (RPMD) and machine-learning interatomic potentials actively learning on-the-fly.
Abstract: We propose a methodology for the fully automated calculation of thermal rate coefficients of gas phase chemical reactions, which is based on combining ring polymer molecular dynamics (RPMD) and machine-learning interatomic potentials actively learning on-the-fly. Based on the original computational procedure implemented in the RPMDrate code, our methodology gradually and automatically constructs the potential energy surfaces (PESs) from scratch with the data set points being selected and accumulated during the RPMDrate simulation. Such an approach ensures that our final machine-learning model provides a reliable description of the PES that avoids artifacts during exploration of the phase space by RPMD trajectories. We tested our methodology on two representative thermally activated chemical reactions studied recently by RPMDrate at temperatures within the interval of 300–1000 K. The corresponding PESs were generated by fitting to only a few thousand automatically generated structures (less than 5000) while the RPMD rate coefficients showed deviation from the reference values within the typical convergence error of RPMDrate. In future, we plan to apply our methodology to chemical reactions that proceed via complex-formation thus providing a completely general tool for calculating RPMD thermal rate coefficients for any polyatomic gas phase chemical reaction.
Autonomous University of Madrid1, University of Trento2, Bulgarian Academy of Sciences3, Finnish Environment Institute4, University of Bucharest5, United Nations Environment Programme6, VU University Amsterdam7, University of Kiel8, University of the Azores9, Sofia University10, Wageningen University and Research Centre11, University of Hong Kong12, Flemish Institute for Technological Research13, Commonwealth Scientific and Industrial Research Organisation14, Academy of Sciences of the Czech Republic15, Mykolas Romeris University16, University of Patras17, European Environment Agency18, University of Copenhagen19, ETH Zurich20, Environmental Protection Agency21, Regional Environmental Center for Central and Eastern Europe22, Foundation for Sustainable Development23, The Cyprus Institute24, Tel Aviv University25, Adam Mickiewicz University in Poznań26, University of Lisbon27, University of Göttingen28, University of Latvia29, Estonian University of Life Sciences30, Slovenian Academy of Sciences and Arts31, European Union32
TL;DR: The European Union (EU) Horizon 2020 Coordination and Support Action ESMERALDA aimed at developing guidance and a flexible methodology for mapping and assessment of ecosystems and their services (MAES) to support the EU member states in the implementation of the EU Biodiversity Strategy's Target 2 Action 5 as mentioned in this paper.
Abstract: The European Union (EU) Horizon 2020 Coordination and Support Action ESMERALDA aimed at developing guidance and a flexible methodology for Mapping and Assessment of Ecosystems and their Services (MAES) to support the EU member states in the implementation of the EU Biodiversity Strategy’s Target 2 Action 5. ESMERALDA’s key tasks included network creation, stakeholder engagement, enhancing ecosystem services mapping and assessment methods across various spatial scales and value domains, work in case studies and support of EU member states in MAES implementation. Thus ESMERALDA aimed at integrating various project outcomes around four major strands: i) Networking, ii) Policy, iii) Research and iv) Application. The objective was to provide guidance for integrated ecosystem service mapping and assessment that can be used for sustainable decision-making in policy, business, society, practice and science at EU, national and regional levels. This article presents the overall ESMERALDA approach of integrating the above-mentioned project components and outcomes and provides an overview of how the enhanced methods were applied and how they can be used to support MAES implementation in the EU member states. Experiences with implementing such a large pan-European Coordination and Support Action in the context of EU policy are discussed and recommendations for future actions are given.
TL;DR: The proposed method provides an effective way to capture quantitatively the shape of sexually dimorphic cranial structures; it gives more accurate results relative to other existing methods and it does not require specialized equipment.
Abstract: OBJECTIVES This paper proposes a method for the quantification of the shape of sexually dimorphic cranial traits, namely the glabella, mastoid process and external occipital protuberance. MATERIALS AND METHODS The proposed method was developed using 165 crania from the documented Athens Collection and tested on 20 Cretan crania. It is based on digital photographs of the lateral view of the cranium, drawing of the profile of three sexually dimorphic structures and calculation of variables that express the shape of these structures. RESULTS The combinations of variables that provide optimum discrimination between sexes are identified by means of binary logistic regression and discriminant analysis. The best cross-validated results are obtained when variables from all three structures are combined and range from 75.8 to 85.1% and 81.1 to 94.6% for males and females, respectively. The success rate is 86.3-94.1% for males and 83.9-93.5% for females when half of the sample is used for training and the rest for prediction. Correct classification for the Cretan material based upon the standards developed for the Athens sample was 80-90% for the optimum combinations of discriminant variables. DISCUSSION The proposed method provides an effective way to capture quantitatively the shape of sexually dimorphic cranial structures; it gives more accurate results relative to other existing methods and it does not require specialized equipment. Equations for sex estimation based on combinations of variables are provided, along with instructions on how to use the method and Excel macros for calculation of discriminant variables with automated implementation of the optimum equations.
TL;DR: In this paper, a new method for increasing the detection efficiency of condensation particle counters (CPCs) for sub-2-nm particles, which relies mainly on controlling the spatial distribution of the supersaturation profile by simply modifying the operating temperatures of the CPC.
TL;DR: Attention at day care center, having siblings in the family and having both parents originating from Cyprus, statistically increased the risk of pneumococcal colonization, which appears to be a protective factor against colonization by pneumococcus.
Abstract: During the past decades Streptococcus pneumoniae has developed significant resistance to many classes of antimicrobial drugs. Potential risk factors for colonization of the nasopharynx by Streptococcus pneumoniae in children and for carriage of drug resistant strains were examined. Between 2007 and 2008 nasopharyngeal swabs were collected from 402 children 6 months to 5 years old visiting the public sector immunization centers and outpatient departments as well as offices of paediatricians from private practice in Nicosia district in Cyprus. Information on demographic characteristics and potential risk factors of participating children were collected using a standardized questionnaire distributed to parents. In multivariable analyses we found that attendance at day care center, having siblings in the family and having both parents originating from Cyprus, statistically increased the risk of pneumococcal colonization. Full immunization with PCV7 appears to be a protective factor against colonization by pneumococcus. Previous administration of antimicrobials during the last month prior to specimen collection appeared to be the most consistent risk factor for carrying a non susceptible strain of Streptococcus pneumoniae to either penicillin or erythromycin. Factors such as age, nationality, previous or current breastfeeding, passive exposure to cigarette smoke and attendance in a day care center do not appear as independent risk factors for colonization by non susceptible strains. Prudent use of antibiotics especially for upper respiratory tract infections in children as well as increased vaccination coverage by the pneumococcal conjugate vaccines could prove effective in reducing levels of colonization by drug resistant pneumococcal strains.