bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of clearfell harvesting on soil CO2, CH4 and N2O fluxes in an
upland Sitka spruce stand in England
Authors: Yamulki Sirwan , Forster Jack , Xenakis Georgios , Ash Adam , Brunt Jacqui , Perks Mike , Morison James I. L.
Published: February 2021

Abstract. The effect of clearfell harvesting on soil greenhouse gas (GHG) fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) was assessed in a Sitka spruce forest growing on a peaty gley organo-mineral soil in northern England. Fluxes from the soil and litter layer were measured monthly by the closed chamber method and gas chromatography over four years in two mature stands, with one area harvested after the first year. Concurrent measurements of soil temperature and moisture helped to elucidate reasons for the changes in fluxes. In the three years after felling, there was a significant increase in the soil temperature, particularly between June and November (3 to 5 °C higher), and in soil moisture which was 62 % higher in the felled area, and these had pronounced effects on the GHG balance, in addition to the removal of the trees and their carbon input to the soil. Annual soil CO2 effluxes reduced to almost a third in the first year after felling (a drop from 24.0 to 8.9 t CO2 ha−1 yr−1) and half in the second and third year (mean 11.8 t CO2 ha−1 yr−1) compared to before felling, while those from the unfelled area were little changed. Annual effluxes of N2O more than doubled in the first two years (from 1.0 to 2.3 and 2.5 t CO2e ha−1 yr−1, respectively), although by the third year they were only 20 % higher (1.2 t CO2e ha−1 yr−1). CH4 fluxes changed from a small net uptake of −0.03 t CO2e  ha−1 yr−1 before felling to a small efflux increasing over the 3 years to 0.34 t CO2e ha−1 yr−1, presumably because of the wetter soil after felling. Soil CO2 effluxes dominated the total net GHG emission calculated using the global warming potential (GWP) of the three gases, but N2O contributed up to 20 % of the total annual emissions. This study showed fluxes of CO2, CH4 and N2O responded differently to clearfelling due to the significant changes in soil biotic and abiotic factors and showed large variations between years. This demonstrates the need for multi-year measurements of all GHGs to enable a robust estimate of the effect of the clearfell phase on the GHG balance of managed forests. This is one of a very few multi-year monitoring studies to assess the effect of clearfell harvesting on soil GHG fluxes.
Growth rate rather than temperature affects the B / Ca ratio in the
calcareous red alga Lithothamnion corallioides
Authors: Piazza Giulia , Bracchi Valentina A. , Langone Antonio , Meroni Agostino N. , Basso Daniela
Published: February 2021

Abstract. The B / Ca ratio in calcareous marine species is informative of past seawater CO32− concentrations, but scarce data exist on B / Ca in coralline algae (CA). Recent studies suggest influences of temperature and growth rates on B / Ca, the effect of which could be critical for the reconstructions of surface ocean pH and atmospheric pCO2. In this paper, we present the first LA-ICP-MS analyses of Mg, Sr, Li and B in the CA Lithothamnion corallioides collected from different geographic settings and depths across the Mediterranean Sea and in the Atlantic Ocean. We produced the first data on temperature proxies (Mg, Li and Sr / Ca) and B / Ca in a CA species grown in different Basins (the Mediterranean Sea and the Atlantic Ocean), from shallow to deep waters (12 m, 40 m, 45 m and 66 m depth). We tested the B / Ca correlation with temperature proxies and growth rates, in order to evaluate their possible effect on B incorporation. Our results showed a growth rate influence on B / Ca, especially in the deepest sample (Pontian Isl., Italy; 66 m) and in the shallowest sample (Morlaix, Atlantic coast of France; 12 m), where the growth rates were respectively 0.11 mm/yr and 0.13 mm/yr and the B / Ca was respectively 462.8 ± 49.2 μmol/mol and 726.9 ± 102.8 μmol/mol. A positive correlation between B / Ca and the temperature proxies was found only in Morlaix, where the seasonal temperature variation (ΔT) was the highest (8.90 °C). These pieces of evidence suggest that growth rates, triggered by the different ΔT and light availability across depth, affect the B incorporation in L. corallioides.
Stalagmite carbon isotopes suggest deglacial increase in soil respiration in Western Europe driven by temperature change
Authors: Lechleitner Franziska A. , Day Christopher C. , Kost Oliver , Wilhelm Micah , Haghipour Negar , Henderson Gideon M. , Stoll Heather M.
Published: February 2021

Abstract. The temperate region of Western Europe underwent dramatic climatic and environmental change during the last deglaciation. Much of what is known about the terrestrial ecosystem response to deglacial warming stems from pollen preserved in sediment sequences, providing information on vegetation composition. Other ecosystem processes, such as soil respiration, remain poorly constrained over past climatic transitions, but are critical for understanding the global carbon cycle and its response to ongoing anthropogenic warming. Here we show that speleothem carbon isotope (δ13Cspel) records may retain information on local soil respiration, and allow its reconstruction over time. While this notion has been proposed in the past, our study is the first to rigorously test it, using a combination of multi-proxy geochemical analysis (δ13C, Ca isotopes, and radiocarbon) on three speleothems from Northern Spain, and quantitative forward modelling of processes in soil, karst, and cave. Our study is the first to quantify and remove the effects of prior calcite precipitation (PCP, using Ca isotopes) and bedrock dissolution (using the radiocarbon reservoir effect) from the δ13Cspel signal to derive changes in respired δ13C. Coupling of soil gas pCO2 and δ13C via a mixing line describing diffusive gas transport between an atmospheric and a respired end member allows modelling of changes in soil respiration in response to temperature. Using this coupling and a range of other parameters describing carbonate dissolution and cave atmospheric conditions, we generate large simulation ensembles from which the results most closely matching the measured speleothem data are selected. Our results robustly show that an increase in soil pCO2 (and thus respiration) is needed to explain the observed deglacial trend in δ13Cspel. However, the Q10 (temperature sensitivity) derived from the model results is higher than current measurements, suggesting that part of the signal may be related to a change in the composition of the soil respired δ13C, likely from changing substrate through increasing contribution from vegetation biomass with the onset of the Holocene.
Synchronized spatial shifts of Hadley and Walker circulations
Authors: Yun Kyung-Sook , Timmermann Axel , Stuecker Malte F.
Published: February 2021

Abstract. The El Niño–Southern Oscillation (ENSO) influences
the most extensive tropospheric circulation cells on our planet, known as
Hadley and Walker circulations. Previous studies have largely focused on the
effect of ENSO on the strength of these cells. However, what has remained
uncertain is whether interannual sea surface temperature anomalies can also
cause synchronized spatial shifts of these circulations. Here, by examining
the spatiotemporal relationship between Hadley and Walker cells in
observations and climate model experiments, we demonstrate that the
seasonally evolving warm-pool sea surface temperature (SST) anomalies in the
decay phase of an El Niño event generate a meridionally asymmetric
Walker circulation response, which couples the zonal and meridional
atmospheric overturning circulations. This process, which can be
characterized as a phase-synchronized spatial shift in Walker and Hadley
cells, is accompanied by cross-equatorial northwesterly low-level flow that
diverges from an area of anomalous drying in the western North Pacific and
converges towards a region with anomalous moistening in the southern central
Pacific. Our results show that the SST-induced concurrent spatial shifts of
the two circulations are climatically relevant as they can further amplify
extratropical precipitation variability on interannual timescales.
First ice thickness measurements in Tierra del Fuego at Schiaparelli Glacier, Chile
Authors: Gacitúa Guisella , Schneider Christoph , Arigony Jorge , González Inti , Jaña Ricardo , Casassa Gino
Published: February 2021

Abstract. Cordillera Darwin in Tierra del Fuego (Chile) remains one of the least studied glaciated regions in the world. However, this region being one of very few terrestrial sites at this latitude in the Southern Hemisphere has the potential to provide key information on the effect of climate variability and climate change on the cryosphere at sub-polar mid-latitudes of the Southern Hemisphere.
Schiaparelli Glacier is located at the northern side of the Cordillera Darwin draining the north side of Monte Sarmiento (2187 m a.s.l.). Despite being one of the largest glaciers in the Cordillera Darwin, no previous in situ observation of its ice thickness had been made either at this glacier or at any other location in the Cordillera Darwin. Ice thickness is one of the fundamental parameters to understand glacier dynamics, constrain ice dynamical modelling, and predict glacier evolution.
In April 2016 we performed the first successful ice thickness measurements using terrestrial ground-penetrating radar in the ablation area of Schiaparelli Glacier (Gacitúa et al., 2020, https://doi.org/10.1594/PANGAEA.919331). The measurements were made along a transect line perpendicular to the ice flow. Results show a valley-shaped bedrock with a maximum ice thickness of 324 m within a distinct glacier trough. The bedrock is located below current sea level for 51 % of the transect measurements with a minimum of −158 m, which illustrates that the local topography is subject to considerable glacier-related over-deepening.
Coupling threshold theory and satellite-derived channel width to estimate the formative discharge of Himalayan foreland rivers
Authors: Gaurav Kumar , Métivier François ,   A V Sreejith, Sinha Rajiv , Kumar Amit , Tandon Sampat Kumar
Published: February 2021

Abstract. We propose an innovative methodology to estimate the formative discharge of alluvial rivers from remote sensing images. This procedure involves automatic extraction of the width of a channel from Landsat Thematic Mapper, Landsat 8, and Sentinel-1 satellite images. We translate the channel width extracted from satellite images to discharge using a width–discharge regime curve established previously by us for the Himalayan rivers. This regime curve is based on the threshold theory, a simple physical force balance that explains the first-order geometry of alluvial channels. Using this procedure, we estimate the formative discharge of six major rivers of the Himalayan foreland: the Brahmaputra, Chenab, Ganga, Indus, Kosi, and Teesta rivers. Except highly regulated rivers (Indus and Chenab), our estimates of the discharge from satellite images can be compared with the mean annual discharge obtained from historical records of gauging stations. We have shown that this procedure applies both to braided and single-thread rivers over a large territory. Furthermore, our methodology to estimate discharge from remote sensing images does not rely on continuous ground calibration.
A new late Miocene bovid (Mammalia: Artiodactyla: Bovidae) from Çorakyerler (Turkey)
Authors: Kostopoulos Dimitris S. , Sevim Erol Ayla , Yavuz Alper Yener , Mayda Serdar
Published: February 2021

Abstract. We describe here five new bovid crania from the Çorakyerler fossil site (Tüglu Formation, Çankırı Basin, north-central Anatolia, Turkey), the fauna of which is dated by magneto- and biostratigraphy to the late Miocene, around the Vallesian–Turolian boundary. The material is assigned to a new bovid taxon of medium-to-large size, Gangraia anatolica gen. and sp. nov., characterized by horn cores that are long, keelless, compressed, obliquely inserted on the frontals, transversally ridged, moderately diverging from each other, slightly twisted homonymously, and sigmoidally curved in lateral view with long, fairly straight tips. The horn core features, along with the presence of a single large sinus occupying the pedicle and the base of the horn core, a strong cranial flexion, a short braincase, the presence of a distinct dorsal parietal boss, wide-apart temporal crests, and a widened anteriorly basioccipital, indicate a mixture of caprine-like and alcelaphine-like features that relate Gangraia anatolica gen. and sp. nov. to the Alcelaphini–Caprini–Hippotragini clade.
Direct U–Pb dating of carbonates from micron-scale femtosecond laser ablation inductively coupled plasma mass spectrometry images using robust regression
Authors: Hoareau Guilhem , Claverie Fanny , Pecheyran Christophe , Paroissin Christian , Grignard Pierre-Alexandre , Motte Geoffrey , Chailan Olivier , Girard Jean-Pierre
Published: February 2021

Abstract. Uranium–lead (U–Pb) dating of carbonates by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) spot analysis is
an increasingly used method in the field of geosciences, as it brings very
strong constraints over the geological history of basins, faults or
reservoirs. Most ages currently published are based on the measurement of U
and Pb ratios on spot ablations, using nanosecond lasers coupled to
sector field or multi-collector ICP-MS. Here, we test a new strategy for the
U–Pb dating of carbonates from 2D isotopic ratio maps, based on the use of a
robust regression approach in the data reduction workflow. The isotopic
maps, with a minimum area of 0.65 mm2 (∼ 1000 pixels of 13×25 µm resolution), are obtained using a 257 nm femtosecond laser
ablation system at a high repetition rate (500 Hz) coupled to a high-resolution ICP-MS. The maps commonly show significant variations in isotope
ratios at the pixel scale, allowing the plotting of pixel U–Pb ratios in
concordia or isochron diagrams and the calculation of U–Pb ages. Due to the
absence of individual ratio uncertainties, the ages are calculated using
MM-robust linear regression rather than the more commonly used York-type
regression. The goodness of fit to the data is assessed by the calculation
of the residual standard error (RSE) of the regression and by the
calculation of a mean square of weight deviates (MSWD) on discretised data. Several examples are provided
that compare the ages calculated by robust regression with those obtained by
other techniques (e.g. isotope dilution, LA-ICP-MS spot analyses and the pixel-pooling
approach). For most samples, characterised by high U concentrations
(> 1 ppm), robust regression allows for the calculation of ages and
uncertainties similar to those obtained with the other approaches. However,
for samples with lower U concentrations (< 0.5 ppm), the ages
obtained are up to 10 % too young due to pixels with high U ∕ Pb acting as
leverage points for the regression. We conclude that the U–Pb ages
calculated by the regression method tested here, although
statistically robust, should be critically analysed before validation,
especially for samples with low U concentrations.
CoupModel (v6.0): an ecosystem model for coupled phosphorus, nitrogen, and carbon dynamics – evaluated against empirical data from a climatic and fertility gradient in Sweden
Authors: He Hongxing , Jansson Per-Erik , Gärdenäs Annemieke I.
Published: February 2021

Abstract. This study presents the integration of the phosphorus (P) cycle into
CoupModel (v6.0, referred to as Coup-CNP). The extended Coup-CNP, which
explicitly considers the symbiosis between soil microbes and plant roots,
enables simulations of coupled carbon (C), nitrogen (N), and P dynamics for
terrestrial ecosystems. The model was evaluated against observed forest
growth and measured leaf C∕P, C∕N, and N∕P ratios in four managed forest
regions in Sweden. The four regions form a climatic and fertility gradient
from 64∘ N (northern Sweden) to 56∘ N (southern Sweden),
with mean annual temperature varying from 0.7–7.1 ∘C and soil C∕N
and C∕P ratios varying between 19.8–31.5 and 425–633, respectively. The
growth of the southern forests was found to be P-limited, with harvested
biomass representing the largest P losses over the studied rotation period.
The simulated P budgets revealed that southern forests are losing P, while
northern forests have balanced P budgets. Symbiotic fungi accounted for half
of total plant P uptake across all four regions, which highlights the
importance of fungal-tree interactions in Swedish forests. The results of a
sensitivity analysis demonstrated that optimal forest growth occurs at a
soil N∕P ratio between 15–20. A soil N∕P ratio above 15–20 will result in
decreased soil C sequestration and P leaching, along with a significant
increase in N leaching. The simulations showed that Coup-CNP could describe
shifting from being mostly N-limited to mostly P-limited and vice versa. The potential
P-limitation of terrestrial ecosystems highlights the need for
biogeochemical ecosystem models to consider the P cycle. We conclude that
the inclusion of the P cycle enabled the Coup-CNP to account for various
feedback mechanisms that have a significant impact on ecosystem C
sequestration and N leaching under climate change and/or elevated N
deposition.
WAP-1D-VAR v1.0: Development and Evaluation of a One-Dimensional Variational Data Assimilation Model for the Marine Ecosystem Along the West Antarctic Peninsula
Authors: Kim Hyewon Heather , Luo Ya-Wei , Ducklow Hugh W. , Schofield Oscar M. , Steinberg Deborah K. , Doney Scott C.
Published: February 2021

Abstract. The West Antarctic Peninsula (WAP) is a rapidly warming region, with substantial ecological and biogeochemical responses to climate change and variability for the past decades, revealed by multi-decadal observations from the Palmer Antarctica Long-Term Ecological Research (LTER) program. The wealth of these long-term observations provides an important resource for ecosystem modelling, but there has been a lack of focus on the development of numerical models that simulate time-evolving plankton dynamics over the Austral growth season along the coastal WAP. Here we developed a one-dimensional, data assimilation planktonic ecosystem model (i.e., the WAP-1D-VAR model v1.0) equipped with a variational adjoint and model parameter optimization scheme. We first demonstrate the modified and newly added model schemes to the pre-existing food-web and biogeochemical components of the WAP-1D-VAR model, including diagnostic sea-ice forcing and trophic interactions specific to the WAP region. We then conducted model experiments by assimilating eleven different data types from an example Palmer LTER growth season (October 2002–March 2003) directly related to corresponding model state variables and intercompartmental flows. The iterative, data assimilation procedure reduced by 80 % the misfits between observations and model results, compared to before optimization, via an optimized set of 14 parameters out of total 72 free parameters. The optimized model results captured key WAP ecological features, such as blooms during seasonal sea-ice retreat, the lack of macronutrient limitation, and comparable values of the assimilated and non-assimilated model state variables and flows to other studies, as well as several important ecosystem metrics. One exception was slightly underestimated particle export flux, for which we discuss fully potential underlying reasons. The data assimilation scheme of the WAP-1D-VAR model enabled the available observational data to constrain previously poorly understood processes, including the partitioning of primary production by different phytoplankton groups, the optimal chlorophyll to carbon ratio of the WAP phytoplankton community, and the partitioning of dissolved organic carbon pools with different lability. The WAP-1D-VAR model was successfully employed to glue the snapshots from a range of the available data sets together to explain and understand the observed dynamics along the coastal WAP.
Optimal design and experimental study of fixed abrasive pads based on coupling of damping regulation and pellet arrangement
Authors: Xu Chaoqun , Fang Congfu , Li Yuan , Liu Chong
Published: February 2021

Abstract. Lapping and polishing technology is an efficient processing method for wafer planarization processing. The structure of the fixed abrasive pad (FAP) is one of the most concerning issues in the research. The FAP structure affects the pressure distribution on the wafer surface, and the pressure distribution during processing has a significant influence on the wafer surface. Therefore, in this paper, a better pressure distribution is obtained by adjusting the angle of the spiral arrangement and the damping distribution of the damping layer of the FAP, thereby obtaining better processing quality. Based on the above theory, a new type of FAP, with coupling between the arrangement of the pellets and the damping regulation of the damping layer, was designed and optimized. The machining effects of different FAPs on the workpiece surface are compared in terms of material removal rate, material removal thickness, and surface roughness. The test results show that the workpiece material removal rate is higher than that of the traditional FAP when using the optimized FAP. The non-uniformity of the optimized FAP for that of material removal was 4.034 µm, which was lower than the traditional FAPs by 24.4 % and 17.6 %, respectively. The average surface roughness, Ra, of the optimized FAP is 0.21 µm, which is lower than 19.1 % and 12.5 % of the two traditional FAPs, respectively. Therefore, workpiece material removal and distribution are more uniform, and the surface quality of the workpiece is better when the optimized FAP processing is used. The test results prove that the optimized pellet arrangement and damping can achieve a better surface quality of the workpiece, which can meet the precision lapping
process requirements for high-quality surfaces and large-scale production of brittle and hard materials such as sapphire.
A simulation-optimization framework for post-disaster allocation of
mental health resources
Authors: Cunningham Stephen , Schuldt Steven , Chini Christopher , Delorit Justin
Published: February 2021

Abstract. Extreme events, such as natural or human-caused disasters, cause mental health stress in affected communities. While the severity of these outcomes varies based on socioeconomic standing, age group, and degree of exposure, disaster planners can mitigate potential stress-induced mental health outcomes by assessing the capacity and scalability of early, intermediate, and long-term treatment interventions by social workers and psychologists. However, local and state authorities are typically underfunded, understaffed, and have ongoing health and social service obligations that constrain mitigation and response activities. In this research, a resource assignment framework is developed as a coupled-state transition and linear optimization model that assists planners in optimally allocating constrained resources and satisfying mental health recovery priorities post-disaster. The resource assignment framework integrates the impact of a simulated disaster on mental health, mental health provider capacities, and the Center for Disease Control and Prevention's (CDC) Social Vulnerability Index (SVI) to identify vulnerable populations needing additional assistance post-disaster. In this study, we optimally distribute mental health clinicians to treat the affected population based upon rulesets that simulate decision-maker priorities, such as economic and social vulnerability criteria. Finally, the resource assignment framework maps the mental health recovery of the disaster-affected populations over time, providing agencies a means to prepare for and respond to future disasters given existing resource constraints. These capabilities hold the potential to support decision-makers in minimizing long-term mental health impacts of disasters on communities through improved preparation and response activities.
A revision of the Combined Drought Indicator (CDI) used in the European Drought Observatory (EDO)
Authors: Cammalleri Carmelo , Arias-Muñoz Carolina , Barbosa Paulo , de Jager Alfred , Magni Diego , Masante Dario , Mazzeschi Marco , McCormick Niall , Naumann Gustavo , Spinoni Jonathan , Vogt Jürgen
Published: February 2021

Abstract. Building on almost 10 years of expertise and operational application of the
Combined Drought Indicator (CDI), which is implemented within the European
Commission's European Drought Observatory (EDO) for the purposes of early
warning and monitoring of agricultural droughts in Europe, this paper
proposes a revised version of the index. The CDI conceptualizes drought as a
cascade process, where a precipitation shortage (WATCH stage) develops into
a soil water deficit (WARNING stage), which in turn leads to stress for
vegetation (ALERT stage). The main goal of the revised CDI proposed here is
to improve the indicator's performance for those events that are currently
not reliably represented, without altering either the modelling conceptual
framework or the required input datasets. This is achieved by means of two
main modifications: (a) use of the previously occurring CDI value to improve
the temporal consistency of the time series and (b) introduction of two
temporary classes – namely TEMPORARY RECOVERY for soil moisture and
vegetation greenness, respectively – to avoid brief discontinuities in a
stage. The efficacy of the modifications is tested by comparing the
performances of the revised and currently implemented versions of the
indicator for actual drought events in Europe during the last 20 years. The
revised CDI reliably reproduces the evolution of major droughts,
outperforming the current version of the indicator, especially for
long-lasting events, and reducing the overall temporal inconsistencies in
stage sequencing of about 70 %. Since the revised CDI does not need
supplementary input datasets, it is suitable for operational implementation
within the EDO drought monitoring system.
Very early identification of a bimodal frictional behavior during the
post-seismic phase of the 2015 Mw8.3 Illapel, Chile, earthquake
Authors: Twardzik Cedric , Vergnolle Mathilde , Sladen Anthony , Tsang Louisa L. H.
Published: February 2021

Abstract. It is well-established that the post-seismic slip results from the combined contribution of seismic slip and aseismic slip. However, the partitioning between these two modes of slip remains unclear due to the difficulty to infer detailed and robust descriptions of how both evolve in space and time. This is particularly true just after a mainshock when both processes are expected to be the strongest. Using state-of-the-art sub-daily processing of GNSS data, along with dense catalogs of aftershocks obtained from template-matching techniques, we unravel the spatiotemporal evolution of post-seismic slip and aftershocks over the first 12 hours following the 2015 Mw8.3 Illapel, Chile, earthquake. We show that the very early post-seismic activity occurs over two regions with distinct behaviors. To the north, post-seismic slip appears to be purely aseismic and precedes the occurrence of late aftershocks. To the south, aftershocks are the primary cause of the post-seismic slip. We suggest that this difference in behavior could be inferred only few hours after the mainshock, and thus could contribute to a more data-driven forecasts of long-term aftershocks.
Thinning leads to calving-style changes at Bowdoin Glacier, Greenland
Authors: van Dongen Eef C. H. , Jouvet Guillaume , Sugiyama Shin , Podolskiy Evgeny A. , Funk Martin , Benn Douglas I. , Lindner Fabian , Bauder Andreas , Seguinot Julien , Leinss Silvan , Walter Fabian
Published: February 2021

Abstract. Ice mass loss from the Greenland ice sheet is the largest single contributor to sea level rise in the 21st century. The mass loss rate has accelerated in recent decades mainly due to thinning and retreat of its outlet glaciers. The diverse calving mechanisms responsible for tidewater glacier retreat are not fully understood yet. Since a tidewater glacier’s sensitivity to external forcings depends on its calving style, detailed insight into calving processes is necessary to improve projections of ice sheet mass loss by calving. As tidewater glaciers are mostly thinning, their calving styles are expected to change. Here, we study calving behaviour changes under a thinning regime at Bowdoin Glacier, north-western Greenland, by combining field and remote-sensing data from 2015 to 2019. Previous studies showed that major calving events in 2015 and 2017 were driven by hydro-fracturing and melt-undercutting. New observations from uncrewed aerial vehicle (UAV) imagery and a GPS network installed at the calving front in 2019 suggest ungrounding and buoyant calving have recently occurred as they show (1) increasing tidal modulation of vertical motion compared to previous years, (2) absence of a surface crevasse prior to calving, and (3) uplift and horizontal surface compression prior to calving. Furthermore, an inventory of calving events from 2015 to 2019 based on satellite imagery provides additional support for a change towards buoyant calving since it shows an increasing occurrence of calving events outside of the melt season. The observed change in calving style could lead to a possible retreat of the terminus, which has been stable since 2013. We therefore highlight the need for high-resolution monitoring to detect changing calving styles and numerical models that cover the full spectrum of calving mechanisms to improve projections of ice sheet mass loss by calving.
A simple parametrization of mélange buttressing for calving glaciers
Authors: Schlemm Tanja , Levermann Anders
Published: February 2021

Abstract. Both ice sheets in Greenland and Antarctica are discharging ice into the ocean. In many regions along the coast of the ice sheets, the icebergs calve into a bay. If the addition of icebergs through calving is faster than their transport out of the embayment, the icebergs will be frozen into a mélange with surrounding sea ice in winter. In this case, the buttressing effect of the ice mélange can be considerably stronger than any buttressing by mere sea ice would be. This in turn stabilizes the glacier terminus and leads to a reduction in calving rates. Here we propose a simple parametrization of ice mélange buttressing which leads to an upper bound on calving rates and can be used in numerical and analytical modelling.
Active Flap Control with the Trailing Edge Flap Hinge Moment as a
Sensor: Using it to Estimate Local Blade Inﬂow Conditions and to
Reduce Extreme Blade Loads and Deﬂections
Authors: Perez-Becker Sebastian , Marten David , Paschereit Christian Oliver
Published: February 2021

Abstract. Active trailing edge flaps are a promising technology that can potentially enable further increases in wind turbine sizes without the disproportionate increase in loads, thus reducing the cost of wind energy even further. Extreme loads and critical deflections of the blade are design driving issues that can effectively be reduced by flaps. In this paper, we consider the flap hinge moment as a local input sensor for a simple flap controller that reduces extreme loads and critical deflections of the DTU 10 MW Reference Wind Turbine blade. We present a model to calculate the unsteady flap hinge moment that can be used in aeroelastic simulations in the time domain. This model is used to develop an observer that estimates the local angle of attack and relative wind velocity of a blade section based on local sensor information including the flap hinge moment of the blade section. For steady wind conditions that include yawed inflow and wind shear, the observer is able to estimate the local inflow conditions with errors in the mean angle of attack below 0.2° and mean relative wind speed errors below 0.4 %. For fully turbulent wind conditions, the observer is able to estimate the low frequency content of the local angle of attack and relative velocity even when it is lacking information on the incoming turbulent wind. We include this observer as part of a simple flap controller to reduce extreme loads and critical deflections of the blade. The flap controller’s performance is tested in load simulations of the reference turbine with active flaps according to the IEC 61400-1 power production with extreme turbulence group. We used the lifting line free vortex wake method to calculate the aerodynamic loads. Results show a reduction of the maximum out-of-plane and resulting blade root bending moment of 8 % and 7.6 % respectively when compared to a baseline case without flaps. The critical blade tip deflection is reduced by 7.1 %. Furthermore, a sector load analysis considering extreme loading in all load directions shows a reduction of the extreme resulting bending moment in an angular region covering 30° around the positive out-of-plane blade root bending moment. Further analysis reveals that a fast reaction time of the flap system proves to be critical for its performance. This is achieved with the use of local sensors as input for the flap controller. A larger reduction potential of the system is identified but not reached mainly because of a combination of challenging controller objectives and the simple controller architecture.
Redesign of an upwind rotor for a downwind configuration: design changes and cost evaluation
Authors: Wanke Gesine , Bergami Leonardo , Zahle Frederik , Verelst David Robert
Published: February 2021

Abstract. Within this work, an existing model of a Suzlon S111 2.1 MW turbine is used
to estimate potential cost savings when the conventional upwind rotor concept
is changed into a downwind rotor concept. A design framework is used to get
realistic design updates for the upwind configuration, as well as two design
updates for the downwind configuration, including a pure material cost out of
the rotor blades and a new planform design. A full design load basis according
to the standard has been used to evaluate the impact of the redesigns on the
loads. A detailed cost model with load scaling is used to estimate the impact
of the design changes on the turbine costs and the cost of energy. It is shown
that generally lower blade mass of up to 5 % less than the upwind redesign can be achieved with the downwind
configurations. Compared
to an upwind baseline, the upwind redesign shows an estimated cost of energy
reduction of 2.3 %, and the downwind designs achieve a maximum
reduction of 1.3 %.
Pressure-based lift estimation and its application to feedforward load control employing trailing-edge flaps
Authors: Bartholomay Sirko , Wester Tom T. B. , Perez-Becker Sebastian , Konze Simon , Menzel Christian , Hölling Michael , Spickenheuer Axel , Peinke Joachim , Nayeri Christian N. , Paschereit Christian Oliver , Oberleithner Kilian
Published: February 2021

Abstract. This experimental load control study presents results of an active trailing-edge flap feedforward controller for wind turbine applications. The controller input is derived from pressure-based lift estimation methods that rely either on a quasi-steady method, based on a three-hole probe, or on an unsteady method that is based on three selected surface pressure ports. Furthermore, a standard feedback controller, based on force balance measurements, is compared to the feedforward control.
A Clark-Y airfoil is employed for the wing that is equipped with a trailing-edge flap of x/c=30% chordwise extension. Inflow disturbances are created by a two-dimensional active grid. The Reynolds number is Re=290 000, and reduced frequencies of k=0.07 up to k=0.32 are analyzed. Within the first part of the paper, the lift estimation methods are compared. The surface-pressure-based method shows generally more accurate results, whereas the three-hole probe estimate overpredicts the lift amplitudes with increasing frequencies. Nonetheless, employing the latter as input to the feedforward controller is more promising as a beneficial phase lead is introduced by this method. A successful load alleviation was achieved up to reduced frequencies of k=0.192.
The Impact of Globalisation Towards Bank Performance in Malaysia
Authors: Murugiah Logasvathi , Supramaniam Mugeshmani
Published: February 2021

The purpose of this study is to shed some crucial light on the relationship between globalisation and performance of the banking system in Malaysia. This study uses a range of bank-characteristic determinants (internal factors), macroeconomic determinants (external factors) and three different dimensions of globalisation including economic globalisation, social globalisation and political globalisation to explain local commercial bank performance in Malaysia. This study uses regression analysis based on the secondary data for local commercial banks in Malaysia. The period for this secondary data is 10 years which is from the year 2008 till 2017. This study indicates that there is strong evidence stating both economic and politic globalisation have negatively significant effects on the bank performance in Malaysia. Meanwhile, social globalisation shows an insignificant result on this. As for bank characteristics variables, credit risk shows a negatively significant result towards bank performance in Malaysia while bank size shows a positive and significant result towards bank performance in Malaysia. Sole macroeconomic variable which is GDP does not show any significant result towards the bank performance in Malaysia. Therefore, central bank of Malaysia should give some incentive training for local bankers on how to adopt new supervision and risk management. This will give the local bankers some new knowledge to handle better risk management and directly boost the bank performance. Besides that, banks should develop their credit risk management to overcome any default loans and for better financial performances. Banks in Malaysia also need to expand their businesses as larger banks give a larger facility which directly boots the bank performance. It is also recommended for Malaysian banks to improve their forecasting of macroeconomic fluctuations in future to achieve greater efficiency levels.
Reviewer Acknowledgements for Global Journal of Health Science, Vol. 13, No. 2
Authors: Grey Erica
Published: February 2021

Reviewer Acknowledgements for Global Journal of Health Science, Vol. 13, No. 2, 2021.
Role of Exergame Play on Cardiorespiratory Fitness and Body Composition in Overweight and Obese Children
Authors: van Biljon Anneke , Longhurst Glynis , Shaw Ina , Shaw Brandon Stuwart
Published: February 2021

Background: Exergaming is an ideal vehicle for promoting regular physical activity among children who may be reluctant to participate in traditional types of exercise. Objectives: The purpose of this study was to investigate the effects of six weeks of exergaming and traditional video gaming on body composition and cardiovascular fitness variables among overweight and obese children. Methods: Thirty-one overweight and obese children (11.40 ± 0.86 years) were recruited from three primary schools in KwaZulu Natal, South Africa. Participants were assigned to either an exergaming group (n = 11), traditional gaming group (n = 10) or control group (n = 10). Body composition variables (body mass index (BMI), waist-to-hip ratio (WHR)) and cardiovascular fitness variables (resting heart rate (RHR), resting systolic (SBP) and diastolic blood pressure (DBP) and peak oxygen consumption (VO2peak)) were measured. A paired sample t-test was used to determine changes from baseline to post-assessment within each group. Results: No significant improvements were observed in BMI percentile among the exergaming group (P = 0.25), traditional gaming group (P = 0.06) and control group (P = 0.25). Waist-to-hip ratio significantly decreased following exergaming (P = 0.050), but not following traditional gaming (P = 0.060) and in control group (P = 0.200). Significant improvement in RHR was found in the exergaming group (P = 0.010), but none in the traditional gaming group (P = 0.280) and control group (P = 0.720). No significant improvements were noted in resting SBP following exergaming (P = 0.790), traditional video gaming (P = 0.730) and in the control group (P = 0.610). Diastolic blood pressure did not significantly improve in the exergaming group (P = 0.070), traditional video gaming group (P = 0.360) or control group (P = 0.100). Peak oxygen consumption (VO2peak) did not significantly improve in the exergaming group (P = 0.830), traditional gaming group (P = 0.710) or control group (P = 0.450). Conclusions: Findings indicate that six weeks of exergaming induced favorable changes in waist-to-hip ratio and RHR among overweight and obese children. Thereby demonstrating that non-traditional modes of exercise such as exergaming can be used as an alternative to traditional modes of exercise to induce somebody composition and cardiovascular changes.
The Prevalence of Neonate Resuscitation and Some Related Factors in an Academic Center in the North of Iran
Authors: Mansour Ghanaie Mandana , Rafiei Sorouri Zahra , Farzi Farnoush , Biazar Gelareh , Shahrokhi Rad Reyhaneh , Ahmadi Mohadese , Rafiei Elahe , Haghi Parisa
Published: February 2021

Background: The phenomena of transformation from the intrauterine environment to independent breathing proceeds successfully in 90% of newborns. However, timely resuscitation is crucial for the 10% remaining. Objectives: We investigated the neonate resuscitation (NR) status, predisposing factors, and outcomes. Methods: This retrospective descriptive research was conducted at Al-Zahra hospital (Guilan-Iran) between April 2018 to March 2019. During the study period, all files of born neonates were reviewed, and relevant maternal and neonate information was extracted and analyzed. Results: A total of 4,850 files were reviewed, and the data from 2,131 complete ones were analyzed. Among them, 14.1% needed resuscitation, 10.2% basic interventions, while 3.9% required advanced interventions. Neonate resuscitation outcome was significantly associated with gestational age (in less than 32 gestation weeks, 84.9% of neonates needed resuscitation) (P < 0.001), meconium staining of amniotic fluid (in 38.3% of cases whose amniotic fluid was stained with meconium, resuscitation was required) (P < 0.001), mode of delivery (in cesarean delivery, 18.7% of infants were resuscitated) (P < 0.001), birth weight (49.3% of infants weighing less than 2,500 grams needed resuscitation) (P < 0.001), multiple pregnancies (in multiple pregnancies, 66.1% resuscitation was needed (P < 0.001), Apgar score at minute 1 and 5 (in infants with an Apgar score below 7 in minute 1, 57.7% and in infants with an Apgar score below 7 in minute 5, 90.8% of neonates needed resuscitation) (P < 0.001). Conclusions: Screening pregnant women for early detection of high-risk cases and attendance of a skilled NR team at the time of delivery results in better outcomes.
Comparing the Effect of Aromatherapy and Distraction on the Pain Caused by Venipuncture in Hospitalized Children: Evidence from a Clinical Trial Study
Authors: Karimi Afshar Shiva , Ghaljaei Fereshteh , Mahmoodi Nasrin , Payandeh Abolfazl
Published: February 2021

Background: Pain is defined as an unpleasant sensory experience associated with actual or potential damage to body tissues. Therapeutic procedures cause fear in children, which in turn leads to physical and mental stress. Objectives: This study aimed to investigate and compare the effects of aromatherapy and distraction on the pain caused by venipuncture among hospitalized children. Methods: In this clinical trial study, 90 children hospitalized in the pediatric ward of Ali-Ebne-Abitaleb Hospital in Zahedan in 2018 are examined. The eligible children were selected using the convenience sampling technique and were divided into three groups (n = 30) using stratified permuted block randomization. In the distraction group, a Kolah Ghermezi (Red Hat) puppet was used to play with the children before and during venipuncture. In the aromatherapy group, lavender essence was used 20 minutes before the beginning of venipuncture. No intervention was provided in the control group. The children’s pain intensity was measured using OUCHER standard instrument 10 minutes after the end of venipuncture. Data were analyzed by SPSS version 24 using descriptive statistics, one-way ANOVA, Kruskal-Wallis, and post-hoc tests analyses. Results: A significant difference was found between the two intervention groups and the control group. Accordingly, both interventions could significantly decrease the pain intensity (P < 0.001). However, there was no significant difference between the two intervention groups concerning the impacts of interventions on the pain intensity. Conclusions: A significant difference was found between the two intervention groups and the control group. Accordingly, both interventions could significantly decrease the pain intensity (P < 0.001). However, there was no significant difference between the two intervention groups concerning the impacts of interventions on the pain intensity.
Five-Year Follow-up of Routine Outpatient Test Turnaround Time: A College of American Pathologists Q-Probes Study
Authors: Valenstein Paul , Walsh Molly
Published: February 2021

Context.—Timely reporting of outpatient tests can increase efficiency of care and improve customer satisfaction.

Objectives.—We conducted a survey in 2002 to determine how quickly hospital-based laboratories turned around routine requests for 3 common assays and compared the results with a similar survey conducted in 1997.

Design.—One hundred eighteen laboratories prospectively recorded the collection-to-verification turnaround time for 9252 complete blood cell counts (CBCs), 8832 thyroid tests, and 9193 basic metabolic panels.

Results.—The median facility reported all test results by 7:00 am of the weekday immediately after the date of specimen collection. The bottom 10% of institutions reported 99% of CBCs and basic metabolic panels within 1 day and 60% of thyroid tests within 1 day. The 65 institutions that participated in both the 1997 and 2002 surveys showed significant overall improvement in turnaround time for all 3 types of tests (P < .001). In 2002, federal institutions had significantly slower turnaround times than nonfederal institutions for CBC tests (P < .001), thyroid tests (P = .03), and basic metabolic panels (P < .001). Other demographic and practice variables were not associated with turnaround time.

Conclusion.—The turnaround time of routine outpatient tests appears to have improved between 1997 and 2002.