bluuebunny/crossref_metadata_2025 huggingface dataset:
Limitations in our knowledge of the Sun’s variability and impact on stratospheric ozone
Authors: Ball William Thomas
Published: January 2020

Changes in the Sun over the 11-year solar cycle modify the amount of ozone in the atmosphere over the tropics above 20 km. It is thought that the temperature change resulting from the induced variations of ozone may lead to an impact on the surface climate. Knowing by how much the solar ultraviolet light changes over the cycle is key to understanding the size of that influence. We provide a new model dataset of solar irradiance variability and compare it to the standard model used in climate studies, and to solar observations. We have shown that our model agrees better with an older instrument observing solar irradiance than the standard solar model for climate, though the two solar models and the older observations display much lower solar cycle variability than more recent observations. We discuss the differences and the uncertainties in the measurements. We also demonstrate that the true effect of solar ultraviolet changes on ozone is highly uncertain. This is important to be aware of since our understanding of the Sun’s impact on climate depends, in part, on getting the solar cycle changes in the ultraviolet correct.
Surface lakes on Greenland will spread further inland as the climate warms
Authors: Leeson Amber A.
Published: January 2020

Each summer, a rash of lakes forms from ponded meltwater on top of the Greenland ice sheet. These 'supraglacial' (on top of ice) lakes can drain through the ice sheet, delivering their contents to its base. The ice sheet slides on a thin film of water, and when extra water is added to this film (for example from a draining supraglacial lake) the sliding (‘flow’) happens a bit faster. At present, under-ice pipe-like features enable excess water to drain out from under the ice sheet quickly and efficiently. However, in recent years supraglacial lakes have begun to form further inland, potentially supplying water to the base beyond the reach of these features. Here, we use a computer simulation of lake initiation and growth to show that the inland spread of supraglacial lakes will continue as the climate warms; by 2060, 100% more of South West Greenland and 50% more of the whole ice sheet will be populated by supraglacial lakes. Of these ‘new’ lakes, up to half will be large enough to drain, delivering the water they contain to the base of the ice sheet and all of these new lakes will form at locations where we would expect to see an ice sheet speed-up with the addition of more water at the base. If the ice sheet flows faster, it can thin out and melt quicker, thus contributing to global sea level rise. Supraglacial lakes and their impacts are not currently considered in our best predictions of future ice sheet change. Given that they possess significant leverage to affect ice sheet flow, and that they are likely to form (and drain) at locations more sensitive to their impact in future years, it is clear that they need to be accounted for in these predictions as a matter of priority.
Recent progress in perovskite solar cells: the perovskite layer
Authors: Dai Xianfeng , Xu Ke , Wei Fanan
Published: January 2020

Perovskite solar cells (PSCs) are set to be game changing components in next-generation photovoltaic technology due to their high efficiency and low cost. In this article, recent progress in the development of perovskite layers, which are the basis of PSCs, is reviewed. Achievements in the fabrication of high-quality perovskite films by various methods and techniques are introduced. The reported works demonstrate that the power conversion efficiency of the perovskite layers depends largely on their morphology and the crystalline quality. Furthermore, recent achievements concerning the scalability of perovskite films are presented. These developments aim at manufacturing large-scale perovskite solar modules at high speed. Moreover, it is shown that the development of low-dimensional perovskites plays an important role in improving the long-term ambient stability of PSCs. Finally, these latest advancements can enhance the competitiveness of PSCs in photovoltaics, paving the way for their commercialization. In the closing section of this review, some future critical challenges are outlined, and the prospect of commercialization of PSCs is presented.
Deriving the Stellar Labels of LAMOST Spectra with the Stellar LAbel Machine (SLAM)
Authors: Zhang Bo , Liu Chao , Deng Li-Cai
Published: January 2020

The LAMOST survey has provided 9 million spectra in its Data Release 5 (DR5) at R ∼ 1800. Extracting precise stellar labels is crucial for such a large sample. In this paper, we report the implementation of the Stellar LAbel Machine (SLAM), which is a data-driven method based on support vector regression (SVR), a robust nonlinear regression technique. Thanks to the capability to model highly nonlinear problems with SVR, SLAM can generally derive stellar labels over a wide range of spectral types. This gives it a unique capability compared to other popular data-driven methods. To illustrate this capability, we test the performance of SLAM on stars ranging from T
eff ∼ 4000 to ∼8000 K trained on LAMOST spectra and stellar labels. At g-band signal-to-noise ratio (S/N
g
) higher than 100, the random uncertainties of T
eff, log g, and [Fe/H] are 50 K, 0.09 dex, and 0.07 dex, respectively. We then set up another SLAM model trained by APOGEE and LAMOST common stars to demonstrate its capability of dealing with high dimensional problems. The spectra are from LAMOST DR5 and the stellar labels of the training set are from APOGEE DR15, including T
eff, log g, [M/H], [α/M], [C/M], and [N/M]. The cross-validated scatters at

are 49 K, 0.10 dex, 0.037 dex, 0.026 dex, 0.058 dex, and 0.106 dex for these parameters, respectively. This performance is at the same level as other up-to-date data-driven models. As a byproduct, we also provide the latest catalog of ∼1 million LAMOST DR5 K giant stars with SLAM-predicted stellar labels in this work.
Nonlinear Convergence of Solar-like Stars Chromospheres Using Millimeter, Submillimeter, and Infrared Observations
Authors: Tapia-Vázquez F. , De la Luz V.
Published: January 2020

In this work, we present a new methodology to fit the observed and synthetic spectrum of solar-like stars at millimeter, submillimeter, and infrared wavelengths through semiempirical models of the solar chromosphere. We use the Levenberg–Marquardt algorithm as a Nonlinear method, PakalMPI as the semiempirical model of the solar chromosphere, and recent observations from the Atacama Large Millimeter/submillimeter Array of Alpha Centauri A as a test case. Our results show that we can use solar chromospheric semiempirical models as an input model to reproduce the observed spectrum of solar-like stars. The new profiles show similarities to the solar chromosphere as a minimum of temperature (without the restriction from CO emission) and a plateau in the high chromosphere. Our method provides a new fast numerical tool to estimate the physical conditions of solar-like stars.
Migration intentions of graduate students of medical universities in Russia and some CIS countries
Authors: Oksinenko Valeriia G.
Published: January 2020

Abstract

The shortage of young medical workers in Russia is a long-standing and acute problem; its solution, even in part, is impossible without taking into account a whole set of factors. An empirical analysis of the results of the survey of graduates of medical and non-medical specializations in Russia and CIS countries gives grounds to identify graduates of medical faculties as a homogeneous group, which has similar migration patterns and relatively low variance in the impact of various factors on these patterns. When making decision about migration for employment graduates of medical specialties are less susceptible to the imbalance in the development of regions of Russia, but more sensitive to social factors. The findings of the paper confirm the importance of ongoing efforts in the field of social and economic policy keeping in mind its potential effectiveness to retain medical workers in regions of Russia.
The Cemented Femoral Stem: Selecting the Ideal Patient
Authors: Spitzer Andrew I
Published: January 2020

abstract

A woman who is elderly, lightweight, and low demand has traditionally been considered an ideal candidate for a cemented femoral stem, ffetients who are young, heavy, and high demand have been considered higher risk for failure and, therefore, better suited for cementless femoral stems. However, modern cement techniques and implants have improved outcomes in high-risk cohorts, and stress shielding, thigh pain, and osteolysis have emerged as long-term challenges for cementless femoral stems. Recently reported positive bone remodeling around a cemented, triple-tapered, polished, collarless stem behaving according to the taper-slip philosophy of femoral stem fixation may widen the traditional indications for cemented femoral stems. Paradoxically, patiente initially thought to be poor candidates for cemented fixation may benefit most from the long-term bone preservation and positive loading characteristics of this new generation of cemented stem technology.
Determinants of Foreign Direct Investment and its impact on Economic Growth: Evidence from South Asian Association for Regional Corporation (SAARC) Countries
Authors: Gunawardhana C. S. , Damayanthi N. M. M.
Published: January 2020

It is argued that Foreign Direct Investment (FDI) inflows benefits the recipient countries by providing capital, technology and long term foreign exchange and bridges savings and investment gap of the recipient country. Further, FDI provides an important role in achieving economic growth in the developing countries. This paper identifies the influential factors that determine FDI inflow in the South Asian Association for Regional Cooperation (SAARC) Countries and empirically investigates the relationship between economic growth and FDI. Further, this study uses time series data from 1980 to 2018 and considered the size of the economy, economic growth, potential of the host market, economic stability, degree of openness, income level and institutional developments in the host country to identify influential factors to determinants of FDI. Analysis reveal that countries with larger Gross Domestic Product (GDP) growth rate can successfully attract FDI and FDI on the other hand, significantly affect economic growth of a country. In addition, it was found that current account balance, financial deepening and trade openness significantly play a crucial role in determining the FDI flows into recipient countries.
Typhoid fever
Authors: Mukhopadhyay Bratati , Sur Dipika , Gupta Sanjukta Sen , Ganguly N.K.
Published: January 2020

Enteric fever is a common but serious disease that affects mostly children and adolescents in the developing countries. Salmonella enterica serovar Typhi remains responsible for most of the disease episodes; however, S. Paratyphi A has also been reported as an emerging infectious agent of concern. The control measures for the disease must encompass early diagnosis, surveillance and vaccine to protect against the disease. Sanitation and hygiene play a major role in reducing the burden of enteric diseases as well. The current status of diagnostics, the surveillance practices in the recent past and the vaccine development efforts have been taken into account for suggesting effective prevention and control measures. However, the challenges in all these aspects persist and cause hindrance in the implementation of the available tools. Hence, an integrative approach and a comprehensive policy framework are required to be in place for the prevention, control and elimination of typhoid fevers.
Frequent plateletpheresis donations & its effect on haematological parameters
Authors: Nayak Sweta , Coshic Poonam , Pandey R.M. , Chatterjee Kabita
Published: January 2020

Background & objectives:

The well-being of donors undergoing frequent plateletpheresis has been a matter of concern. The aim of this study was to analyze the effect of frequent plateletpheresis on the haematological parameters (HP) of repeat donors.

Methods:

The study was conducted during February 2016 to March 2017 on all the repeat plateletpheresis donors undergoing the 2nd plateletpheresis within a month of the first in a tertiary care centre. Donors repeating plateletpheresis 3rd and 4th times were also studied. The values of the HP observed on follow up after plateletpheresis done on three different separators were compared.

Results:

HPs of the 98 donors were similar at follow up except mean platelet volume (P<0.05). Of the 98 donors, 35 were followed up within a week and 63 were followed up within 8-30 days. No significant alteration was found in the HPs except a significant difference in the variation of platelet counts of the two groups (P=0.025). In 34 donors who presented 3rd time for plateletpheresis (mean gap between 1st and 3rd plateletpheresis=31 days), no significant differences in the HPs were found except the platelet distribution width (P<0.05). Minimal difference in the HP was found in the baseline and the follow up of 3rd plateletpheresis i.e., at 4th plateletpheresis donation. Plateletpheresis through all the three cell separators used had similar effects on the follow up HPs.

Interpretation & conclusions:

Repeated plateletpheresis can be done without any detrimental effects on the cell counts of the plateletpheresis donors. The three cell separators yielded similar post-donation follow up haematological parameters.
Assessing the susceptibility of highly pathogenic avian influenza H5N1 viruses to oseltamivir using embryonated chicken eggs
Authors: Tare Deeksha S. , Kode Sadhana S. , Hurt Aeron C. , Pawar Shailesh D.
Published: January 2020

Background & objectives:

The susceptibility of influenza viruses to neuraminidase inhibitors (NAIs) is studied using enzyme-based assays, sequence analysis and in vitro and in vivo studies. Oseltamivir carboxylate (OC) is the active prodrug of the NAI oseltamivir. There is lack of information on the use of embryonated chicken eggs for studying susceptibility of highly pathogenic avian influenza (HPAI) H5N1 viruses to antiviral drugs. The aim of the present study was to assess the use of 10 day old embryonated chicken eggs for studying antiviral susceptibility of HPAI H5N1 viruses.

Methods:

Two HPAI H5N1 viruses isolated from India were used in the study. Fluorescence-based NAI assay was performed to determine antiviral susceptibility of these viruses. In ovo antiviral assays were carried out using 10 day old embryonated chicken eggs. The virus dilutions were incubated with 14 μg/ml of OC and inoculated in the allantoic cavity. In the eggs, 50 per cent egg infectious dose (EID50) titres as well as mortality were quantitated.

Results:

The two viruses used were susceptible to OC in the NAI assay. It was found that there was a significant drop in EID50 titres; however, no significant protection from mortality after OC treatment was observed.

Interpretation & conclusions:

By measuring viral titres, the egg model was suitable to study the susceptibility of HPAI viruses to antiviral drugs along with NAI assay. The present study highlights the use of eggs as a model to study susceptibility of HPAI viruses to OC.
Is it necessary to focus on morphologically normal acrosome of sperm during intracytoplasmic sperm injection?
Authors: Zahiri Ziba , Ghasemian Fatemeh
Published: January 2020

Background & objectives:

The detailed assessment of sperm morphology is important in the semen of infertile men because there is a low proportion of normal spermatozoa. One of the parameters of such sperm morphology is the acrosome, and its effect on assisted reproductive outcomes is controversial. This study was undertaken to evaluate the association between different forms of acrosome on the chromatin status and the assisted reproductive outcomes.

Methods:

A total of 1587 unstained sperms from 514 infertile men were captured and analyzed for different acrosome forms (normal, large, small, skew, amorphous acrosome and without acrosome) in real time during intracytoplasmic sperm injection into oocytes. The association between the percentage of sperms with atypical acrosome and head shapes and the sperm chromatin status was studied. Fertilization, zygote and embryo quality and clinical pregnancy rates were calculated for different groups of sperms.

Results:

The highest frequency of irregular shapes of acrosomes, such as small, large and amorphous, was observed in abnormal ellipticity, anteroposterior symmetry and angularity parameters, respectively (P<0.05). The fertilization rate of injected sperms with large (P<0.01) and small (P=0.001) acrosomes and without acrosome (P=0.001) was significantly lower in comparison with normal acrosomes. The quality of zygotes (Z3, P=0.05), embryos (grade C, P<0.05) and the pregnancy rate (P=0.001) from injected sperms with large acrosomes were significantly lower compared with normal acrosomes.

Interpretation & conclusions:

Our findings showed that the different sperm acrosome morphologies (e.g., large, small, and without acrosome) might negatively relate with chromatin integrity and decrease the sperm's fertility potential and pregnancy rate during intracytoplasmic sperm injection (ICSI) cycles.
Very high stratospheric influence observed in the free troposphere over the northern Alps – just a local phenomenon?
Authors: Trickl Thomas , Vogelmann Hannes , Ries Ludwig , Sprenger Michael
Published: January 2020

Abstract. The atmospheric composition is strongly influenced by a
change in atmospheric dynamics, which is potentially related to climate
change. A prominent example is the doubling of the stratospheric ozone
component at the Zugspitze summit station (2962 m a.s.l.,
Garmisch-Partenkirchen, Germany) between the mid-seventies and 2005, roughly
from 11 to 23 ppb (43 %). Systematic efforts for identifying and
quantifying this influence have been made since the late 1990s. Meanwhile,
routine lidar measurements of ozone and water vapour carried out at
Garmisch-Partenkirchen (German Alps) since 2007, combined with in situ and
radiosonde data and trajectory calculations, have revealed that
stratospheric intrusion layers are present on 84 % of the yearly
measurement days. At Alpine summit stations the frequency of intrusions
exhibits a seasonal cycle with a pronounced summer minimum that is
reproduced by the lidar measurements. The summer minimum disappears if one
looks at the free troposphere as a whole. The mid- and upper-tropospheric
intrusion layers seem to be dominated by very long descent on up to
hemispheric scale in an altitude range starting at about 4.5 km a.s.l.
Without interfering air flows, these layers remain very dry, typically with
RH ≤5 % at the centre of the intrusion. Pronounced ozone
maxima observed above Garmisch-Partenkirchen have been mostly related to a
stratospheric origin rather than to long-range transport from remote
boundary layers. Our findings and results for other latitudes seem to
support the idea of a rather high contribution of ozone import from the
stratosphere to tropospheric ozone.
To what extents do urbanization and air pollution affect fog?
Authors: Yan Shuqi , Zhu Bin , Huang Yong , Zhu Jun , Kang Hanqing , Lu Chunsong , Zhu Tong
Published: January 2020

Abstract. The remarkable development of China has resulted in rapid urbanization (urban heat island and dry island) and severe air pollution (aerosol pollution). Previous studies demonstrate that these two factors have either suppressing or promoting effects on fog, but what are the extents of their individual and combined effects? In this study, a dense radiation fog event in East China in January 2017 was reproduced by the WRF-Chem model, and the individual and combined effects of urbanization and aerosols on fog (indicated by liquid water content (LWC)) are quantitatively revealed. Results show that urbanization inhibits low-level fog, delays its formation and advances its dissipation due to higher temperatures and lower saturations. In contrast, upper-level fog could be enhanced because of the updraft-induced vapour convergence. Aerosols promote fog by increasing LWC, increasing droplet concentration and decreasing droplet effective radius. Further experiments show that the current pollution level in China is still below the critical aerosol concentration that suppresses fog. Urbanization influences fog to a larger extent than do aerosols. When urbanization and aerosol pollution are combined, the much weaker aerosol promoting effect is counteracted by the stronger urbanization suppressing effect on fog. Budget analysis of LWC reveals that urban development (urbanization and aerosols) alters LWC profile and fog structure mainly by modulating condensation/evaporation process. Our results infer that urban fog will be further reduced if urbanization keeps developing and air quality keeps deteriorating in the future.
Evaluating China's fossil-fuel CO2 emissions from a comprehensive dataset of nine inventories
Authors: Han Pengfei , Zeng Ning , Oda Tom , Lin Xiaohui , Crippa Monica , Guan Dabo , Janssens-Maenhout Greet , Ma Xiaolin , Liu Zhu , Shan Yuli , Tao Shu , Wang Haikun , Wang Rong , Wu Lin , Yun Xiao , Zhang Qiang , Zhao Fang , Zheng Bo
Published: January 2020

Abstract. China's fossil-fuel CO2 emissions (FFCO2) account for 28 % of the global total FFCO2 in 2016. An accurate estimate of China’s FFCO2 is a prerequisite for global and regional carbon budget analyses and monitoring of carbon emission reduction efforts. However, large uncertainties and discrepancies exist in China’s FFCO2 estimations due to lack of detailed traceable emission factors and multiple statistical data sources. Here, we evaluated China's FFCO2 emissions from 9 published global and regional emission datasets. These datasets show that the total emission increased from 3.4 (3.0–3.7) in 2000 to 9.8 (9.2–10.4) Gt CO2 yr−1 in 2016. The variations in their estimates were due largely to the different emission factors (0.491–0.746 for coal) and activity data. The large-scale patterns of gridded emissions showed a reasonable agreement with high emissions concentrated in major city clusters, and the standard deviation mostly ranged 10–40 % at provincial level. However, patterns beyond the provincial scale vary greatly with the top 5 % of grid-level account for 50–90 % of total emissions for these datasets. Our findings highlight the significance of using locally-measured EF for the Chinese coals. To reduce the uncertainty, we call on the enhancement of physical CO2 measurements and use them for datasets validation, key input data sharing (e.g. point sources) and finer resolution validations at various levels.
Ionospheric total electron content responses to HILDCAA intervals
Authors: da Silva Regia Pereira , Denardini Clezio Marcos , Marques Manilo Soares , Resende Laysa Cristina Araujo , Moro Juliano , da Silva Picanço Giorgio Arlan , Borba Gilvan Luiz , Santos Marcos Aurelio Ferreira dos
Published: January 2020

Abstract. The High-Intensity Long-Duration and Continuous AE Activities (HILDCAA)
intervals are capable of causing a global disturbance in the terrestrial
ionosphere. However, the ionospheric storms' behavior due to these intervals
is still not widely understood. In the current study, we seek to comprise
the HILDCAA disturbance time effects in the total electron content (TEC)
values with respect to the quiet days' pattern by analyzing local time and
seasonal dependences, and the influences of the solar wind velocity on a
sample of 10 intervals that occurred in the years 2015 and 2016. The main results
showed that the hourly distribution of the disturbance TEC may vary
substantially between one HILDCAA interval and another. An
equinoctial anomaly was found since the equinoxes represent more ionospheric TEC
responses than the solstices. Regarding the solar wind velocities, although
HILDCAA intervals are associated with high-speed streams, this association
does not present a direct relation to TEC disturbance magnitudes at low and
equatorial latitudes.
An emergent constraint on Transient Climate Response from simulated historical warming in CMIP6 models
Authors: Nijsse Femke J. M. M. , Cox Peter M. , Williamson Mark S.
Published: January 2020

Abstract. The transient climate response (TCR) is the metric of temperature sensitivity that is most relevant to warming in the next few decades, and contributes the biggest uncertainty to estimates of the carbon budgets consistent with the Paris targets (Arora et al., 2019). In the IPCC 5th Assessment Report (AR5), the stated likely range of TCR was given as 1.0 to 2.5 K, with a central estimate which was broadly consistent with the ensemble mean of the CMIP5 Earth System Models (ESMs) available at the time (1.8 ± 0.4 K). Many of the latest CMIP6 ESMs have larger climate sensitivities, with 6 of 23 models having TCR values above 2.5 K, and an ensemble mean TCR of 2.1 ± 0.4 K. On the face of it, these latest ESM results suggest that the IPCC likely range of TCR may need revising upwards, which would cast further doubt on the feasibility of the Paris targets. Here we show that rather than increasing the uncertainty in climate sensitivity, the CMIP6 models help to further constrain the likely range of TCR to 1.5–2.2 K, with a central estimate of 1.82 K. We reach this conclusion through an emergent constraint approach which relates the value of TCR to the global warming from 1970 onwards. We confirm a consistent emergent constraint on TCR when we apply the same method to CMIP5 models (Jiménez-de-la Cuesta and Mauritsen, 2019). Our emergent constraint on TCR benefits from both the large range of TCR values across the CMIP6 models, and also from the extension of the historical simulations into a period when the uncertain changes in aerosol forcing have had a far less significant impact on the trend in global warming.
Cloud_cci Advanced Very High Resolution Radiometer post meridiem (AVHRR-PM) dataset version 3: 35-year climatology of global cloud and radiation properties
Authors: Stengel Martin , Stapelberg Stefan , Sus Oliver , Finkensieper Stephan , Würzler Benjamin , Philipp Daniel , Hollmann Rainer , Poulsen Caroline , Christensen Matthew , McGarragh Gregory
Published: January 2020

Abstract. We present version 3 of the Cloud_cci Advanced Very High Resolution Radiometer post meridiem (AVHRR-PM) dataset, which contains a comprehensive set of cloud and radiative flux properties on a global scale covering the period of 1982 to 2016. The properties were retrieved from AVHRR measurements recorded by the afternoon (post meridiem – PM) satellites of the National Oceanic and Atmospheric Administration (NOAA) Polar Operational Environmental Satellite (POES) missions. The cloud properties in version 3 are of improved quality compared with the precursor dataset version 2, providing better global quality scores for cloud detection, cloud phase and ice water path based on validation results against A-Train sensors.
Furthermore, the parameter set was extended by a suite of broadband radiative flux properties. They were calculated by combining the retrieved cloud properties with thermodynamic profiles from reanalysis and surface properties. The flux properties comprise upwelling and downwelling and shortwave and longwave broadband fluxes at the surface (bottom of atmosphere – BOA) and top of atmosphere (TOA). All fluxes were determined at the AVHRR pixel level for all-sky and clear-sky conditions, which will particularly facilitate the assessment of the cloud radiative effect at the BOA and TOA in future studies. Validation of the BOA downwelling fluxes against the Baseline Surface Radiation Network (BSRN) shows a very good agreement. This is supported by comparisons of multi-annual mean maps with NASA's Clouds and the Earth's Radiant Energy System (CERES) products for all fluxes at the BOA and TOA. The Cloud_cci AVHRR-PM version 3 (Cloud_cci AVHRR-PMv3) dataset allows for a large variety of climate applications that build on cloud properties, radiative flux properties and/or the link between them. For the presented Cloud_cci AVHRR-PMv3 dataset a digital object identifier has been issued: https://doi.org/10.5676/DWD/ESA_Cloud_cci/AVHRR-PM/V003 (Stengel et al., 2019).
Climate-dependent propagation of precipitation uncertainty into the water cycle
Authors: Fallah Ali , O Sungmin , Orth Rene
Published: January 2020

Abstract. Precipitation is a crucial variable for hydro-meteorological applications. Unfortunately, rain gauge measurements are sparse and unevenly distributed, which substantially hampers the use of in-situ precipitation data in many regions of the world. The increasing availability of high-resolution gridded precipitation products presents a valuable alternative, especially over gauge-sparse regions. Nevertheless, uncertainties and corresponding differences across products can limit the applicability of these data. This study examines the usefulness of current state-of-the-art precipitation datasets in hydrological modelling. For this purpose, we force a conceptual hydrological model with multiple precipitation datasets in > 200 European catchments. We consider a wide range of precipitation products, which are generated via (1) interpolation of gauge measurements (E-OBS and GPCC V.2018), (2) combination of multiple sources (MSWEP V2) and (3) data assimilation into reanalysis models (ERA-Interim, ERA5, and CFSR). For each catchment, runoff and evapotranspiration simulations are obtained by forcing the model with the various precipitation products. Evaluation is done at the monthly time scale during the period of 1984–2007. We find that simulated runoff values are highly dependent on the accuracy of precipitation inputs, and thus show significant differences between the simulations. By contrast, simulated evapotranspiration is generally much less influenced. The results are further analysed with respect to different hydro-climatic regimes. We find that the impact of precipitation uncertainty on simulated runoff increases towards wetter regions, while the opposite is observed in the case of evapotranspiration. Finally, we perform an indirect performance evaluation of the precipitation datasets by comparing the runoff simulations with streamflow observations. Thereby, E-OBS yields the best agreement, while furthermore ERA5, GPCC V.2018 and MSWEP V2 show good performance. In summary, our findings highlight a climate-dependent propagation of precipitation uncertainty through the water cycle; while runoff is strongly impacted in comparatively wet regions such as Central Europe, there are increasing implications on evapotranspiration towards drier regions.
Seasonal variation of the principal tidal constituents in the Bohai Sea
Authors: Wang Daosheng , Pan Haidong , Jin Guangzhen , Lv Xianqing
Published: January 2020

Abstract. The seasonal variation of tides plays a significant role
in water level changes in coastal regions. In this study, seasonal
variations of four principal tidal constituents, M2, S2, K1,
and O1, in the Bohai Sea, China, were studied by applying an enhanced
harmonic analysis method to two time series: 1-year sea level observations
at a mooring station (named E2) located in the western Bohai Sea and 17-year
sea level observations at Dalian. At E2, the M2 amplitude and phase lag
have annual frequencies, with large values in summer and small values in
winter, while the frequencies of S2 and K1 amplitudes are also
nearly annual. In contrast, the O1 amplitude increases constantly from
winter to autumn. The maxima of phase lags appear twice in 1 year for
S2, K1, and O1, taking place near winter and summer. The
seasonal variation trends estimated by the enhanced harmonic analysis at
Dalian are different from those at E2, except for the M2 phase lag. The
M2 and S2 amplitudes show semi-annual and annual cycles,
respectively, which are relatively significant at Dalian. The results of
numerical experiments indicate that the seasonality of vertical eddy
viscosity induces seasonal variations of the principal tidal constituents at
E2. However, the tested mechanisms, including seasonally varying
stratification, vertical eddy viscosity, and mean sea level, do not
adequately explain the observed seasonal variations of tidal constituents at
Dalian.
Controversies and consensus in research on dialogic teaching and learning
Authors: Asterhan Christa S. C. , Howe Christine , Lefstein Adam , Matusov Eugene , Reznitskaya Alina
Published: January 2020

Scholarly interest in dialogic pedagogy and classroom dialogue is multi-disciplinary and draws on a variety of theoretical frameworks. On the positive side, this has produced a rich and varied body of research and evidence. However, in spite of a common interest in educational dialogue and learning through dialogue, cross-disciplinary engagement with each other’s work is rare. Scholarly discussions and publications tend to be clustered in separate communities, each characterized by a particular type of research questions, aspects of dialogue they focus on, type of evidence they bring to bear, and ways in which standards for rigor are constructed. In the present contribution, we asked four leading scholars from different research traditions to react to four provocative statements that were deliberately designed to reveal areas of consensus and disagreement[1]. Topic-wise, the provocations related to theoretical foundations, methodological assumptions, the role of teachers, and issues of inclusion and social class, respectively. We hope that these contributions will stimulate cross- and trans-disciplinary discussions about dialogic pedagogy research and theory.[1] The authors of this article are five scholars, the dialogic provocateur and the four respondents. The order of appearance of the authors was determined alphabetically.
The banality of WhatsApp: On the everyday politics of backstage activism in Mexico and Spain
Authors: Treré Emiliano
Published: January 2020

Drawing on interviews with social movements and organizations in Mexico and Spain, this paper sheds light on the dynamics of ‘backstage activism’ with a focus on WhatsApp. It illustrates how activists have integrated this app into their media ecologies to reinforce collective identity, cement internal solidarity and lower the pressure of protest. It shows that within WhatsApp groups, campaigners have countered the paranoia experienced in the frontstage of social media exchanging ironical material and intimate messages. It demonstrates that WhatsApp has been used as a robust organizational device and it is now firmly integrated into the mechanisms of organizations and movements. Its communicative affordances (speed, reliability, mobility, multimediality) in conjunction with the omnipresent smartphone are often emphasized. Nuancing characterizations that tend to either disregard its role or stress its negative side, this qualitative exploration foregrounds the banality of WhatsApp. This article unpacks the multiple roles of this app within the submerged practices of movements and organizations.
What about WhatsApp? A systematic review of WhatsApp and its role in civic and political engagement
Authors: Pang Natalie , Woo Yue Ting
Published: January 2020

The use of instant messaging platforms such as WhatsApp for civic and political purposes has been observed and reported to be growing faster than other social media platforms especially in recent years. Using empirical research on WhatsApp studies published from 2009 to 2019 as its corpus of data, this article systematically reviews them to provide more robust conclusions about WhatsApp and its relationship with political and/or civic engagement. This paper seeks to answer three central questions related to WhatsApp and engagement: 1) What are the motivations in using WhatsApp and how do they manifest in the use of WhatsApp as a communication tool? 2) What is the role of WhatsApp in civic and political engagement? 3) How do researchers study the use of WhatsApp in civic and political engagement? The review finds that across empirical studies, while WhatsApp is used by activists and organisational networks for mobilisation and coordinating actions, it is also used by users who draw on the affordances of the medium for informal and ‘de-politicised’ conversations. The findings contribute to the theorising of social media-mediated movements and activism and highlight methodological gaps of ongoing research on WhatsApp.
Determining the Views of School Principals and Guidance Teachers on Inclusive Practices at Anatolian High-Schools
Authors: Yazicioglu Tansel
Published: January 2020

The number of students who attend an inclusive school in Turkey has been increasing. This increase in the number of students attending inclusive education makes the inclusive policies more significant and requires that schools of all types and levels should be ready for inclusive practices. This study aims at uncovering the views of school administrators and guidance teachers working at Anatolian high schools concerning the inclusive education. The data of the study were collected through focus group interviews. The study was carried out in Ankara during the school year of 2018–2019 with a sample of school administrators and guidance teachers working at different Anatolian high schools. The findings of the study indicate that there are serious problems in inclusive education practices at Anatolian high schools, the educational setting needed for students with special education needs cannot be provided and teachers do not have necessary experience in inclusive education.
The Urban Food-Truck Phenomenon: History, Regulations and Prospect
Authors: M.A. Sobaihi Mamdouh
Published: January 2020

The city streets and spaces have for the duration of the city’s existence provided an area where people may trade and enjoy food. In the twentieth and twenty-first millennium, this activity is changing in form and conception. The food-truck industry is growing throughout the world and in particular in North America. This paper reviews the growth, its origins, its existing situation and prospect. Through a literature review of existing regulations governing the food-truck industry a compilation of these regulations will be made. After a description of the food-truck industry status in Jeddah, Saudi Arabia a comparison of the previously compiled regulations to the regulations that exist in Jeddah will be made. These comparisons have highlighted some issues with the regulations that exist in Jeddah. Main finding is the relatively insufficient regulations in place to govern the industry in the city, which may hinder the growth and prosperity of the industry and all those involved. Thus one of the main aims of the paper is to provide a basis upon which future regulations for the city of Jeddah may be created. Further discussions on the future of the food-truck industry in the city of Jeddah and beyond are put forth in the concluding section.
Niet-aangeboren hersenletsel bij kinderen en jongeren, de gevolgen voor het onderwijs
Authors: Hendriks C.M.C.M.
Published: January 2020

Niet aangeboren hersenletsel bij kinderen en jongeren, de gevolgen voor het onderwijs

Langetermijngevolgen van niet-aangeboren hersenletsel (NAH) op de kinderleeftijd zijn divers en complex. Vroege signalering en tijdige interventie kunnen de nadelige gevolgen voor het onderwijs aan deze kinderen en jongeren beperken.
Verplichte court-ordered mediation in commerciële geschillen in Australië, een voorbeeld voor Europese landen?
Authors: Hoefnagel Justus
Published: January 2020

Mandatory court-ordered mediation in commercial conflicts in Australia, a model for European countries?

In this article, the author discusses mediation law and practice in Australia, with a focus on commercial disputes. Statistical data collected in several Australian jurisdictions suggest that mandatory referral works out positively. The author concludes with some observations as to the potential usefulness of the Australian model for court-referred mediation in Europe.
Analisando a governabilidade presidencial a partir de padrões de homofilia na Câmara dos Deputados: Estudos de Casos no Brasil e nos EUA
Authors: Matos Breno de Sousa , Ferreira Carlos H. G. , Almeida Jussara M.
Published: January 2020

Neste trabalho, propomos uma abordagem para analisar a governabilidade do presidente com base nas votações realizadas na Câmara dos Deputados. Para isso, modelamos as votações em forma de um grafo, de modo a identificar padrões de homofilia entre a base do governo e os demais deputados em dois páıses, isto é, Brasil e Estados Unidos.
Opinion Mining and Active Learning: a Comparison of Sampling Strategies
Authors: Vitório Douglas , Souza Ellen , Oliveira Adriano  L. I.
Published: January 2020

There are two main problems when performing Opinion Mining (OM) with data streams: the lack of labeled data and the need to update the learning model. The most used OM techniques cannot deal well with these challenges, so, an alternative is to use semi-supervised methods, such as the Active Learning, which is a method to label only selected data rather than the entire data set; however, it requires the choice of a sampling strategy to select the data to be labeled. In this paper, we evaluated eight strategies in ten data sets, in order to identify the best ones for OM with Twitter streams. According to our experiments, the Entropy strategy showed the best results, but it selects a large number of instances to be labeled, requiring further investigation.
Tweet Sentiment Analysis Regarding the Brazilian Stock Market
Authors: Medeiros Murilo C. , Borges Vinicius  R. P.
Published: January 2020

This paper describes a methodology for analyzing sentiments and for knowledge discovery in tweets regarding the Brazilian stock market. The proposed methodology starts by preprocessing and characterizing tweets to obtain an associated vector-space model. After that, a dimensionality reduction is em- ployed by using Principal Component Analysis and t-Stochastic Neighbor Embedding. Sentiment analysis of stock market tweets is performed by considering the tasks of sentiment classification, topic modeling and clustering, along with a visual analysis process. Experiments results showed satisfactory performances in single and multi-label sentiment classification scenarios. The visual analysis process also revealed interesting relationships among topics and clusters.
Classificação multi-rótulo de aspectos em avaliações online
Authors: Da Frota Lucas Vinicius M. , Figueiredo Carlos  Maurı́cio S.
Published: January 2020

Com o a popularização da internet nos últimos anos houve o acúmulo de grandes volumes de dados não estruturados na forma de comentários ou avaliações, de tal maneira que interpretá-los pode gerar informações fundamentais para qualquer empresa que deseja melhorar seus serviços ou produtos. Tendo isso em vista este artigo visa criar um modelo de aprendizagem de máquina capaz de inferir quais tópicos estão sendo mencionados dentro de uma amostra de texto livre de avaliação online. Isto é mostrado em estudo de caso de avaliação de restaurante.
Aplicação de Mineração de Dados para Predição de Mortalidade em UTI: balanceamento, dados ausentes e classificadores
Authors: Barreto Jorge S. A. M. , Loula Angelo C.
Published: January 2020

Escores de severidade fornecem um ı́ndice consolidado do estado de saúde do paciente na UTI. Estes escores são baseados em modelos lineares e em análises das variáveis isoladamente. Trabalhos prévios aplicaram mineração de dados para indução de modelos mais complexos de predição, mas não se aprofundaram na análise do desbalanceamento de classes e tratamento dos da- dos ausentes. Este trabalho analisou técnicas de balanceamento e imputação de valores, em conjunto com modelos de classificação de Random Forest (RF), Redes Neurais Artificiais (RNA) e Regressão Logı́stica (RL). Como resultado a RF obteve o melhor desempenho, com a AUC média de 0.784±0.006, sensibi- lidade de 0.738±0.002 e especificidade de 0.700±0.003 com valores ausentes substituı́dos por valores padrões e treinada com a base com sub-amostragem NCL.
The Minimum Labeling Spanning Tree and Related Problems
Authors: Da Silva Thiago Gouveia
Published: January 2020

The minimum labeling spanning tree problem (MLSTP) is a combinatorial optimization problem that consists in finding a spanning tree in a simple edge-labeled graph, i.e., a graph in which each edge has one label associated, by using a minimum number of labels. It is an NP-hard problem that has attracted substantial research attention in recent years. In its turn, the generalized minimum labeling spanning tree problem (GMLSTP) is a generalization of the MLSTP that allows the situation in which multiple labels can be assigned to an edge. Both problems have several practical applications in important areas such as computer network design, multimodal transportation network design, and data compression. The thesis addresses several connectivity problems defined over edge-labeled graphs, in special the minimum labeling spanning tree problem and its generalized version. The contributions in the work can be classified between theoretical and practical. On the theoretical side, it has introduced new useful concepts, definitions, properties and theorems regarding edge-labeled graphs, as well as a polyhedral study on the GMLSTP. On the practical side, we have proposed new heuristics and new mathematical formulations and branch-and-cut algorithms. The new approaches introduced have achieved the best results for both heuristic and exact methods in comparison with the state-of-the-art.
Desenvolvendo o pensamento computacional no ensino fundamental com Arduino e Scratch
Authors: Pereira Amanda C. , Franco Matheus E.
Published: January 2020

In despite of the frequent use of technological resources part of the population does not understand the basic concepts of computing, being subjected as passive users. In this way, it is important to develop a little explored intellectual capacity: computational thinking, which refers to the ability to solve problems efficiently and systematically. The present project copes with the proposal of a methodology for the development of computational thinking in young people. The results were satisfactory since the students demonstrated a positive return on what they were taught, demonstrating that they felt motivated to learn something new that goes beyond the basic school curriculum.
On Tuza's conjecture for graphs with treewidth at most 6
Authors: Botler Fábio , Fernandes Cristina G. , Gutiérrez Juan
Published: January 2020

Tuza (1981) conjectured that the size τ (G) of a minimum set of edges that meets every triangle of a graph G is at most twice the size ν(G) of a maximum set of edge-disjoint triangles of G. In this paper we verify this conjecture for graphs with treewidth at most 6. In this paper, all graphs considered are simple and the notation and terminology are standard. A triangle transversal of a graph G is a set of edges of G whose deletion results in a triangle-free graph; and a triangle packing of G is a set of edge-disjoint triangles of G. We denote by τ (G) (resp. ν(G)) the size of a minimum triangle transversal (resp. triangle packing) of G. In [Tuza 1981] the following conjecture was posed: Conjecture (Tuza, 1981). For every graph G, we have τ (G) ≤ 2ν(G).
Jogos de Transporte Sequenciais⇤
Authors: Silva Francisco J. M. , Miyazawa Flávio K. , Schouery Rafael C. S.
Published: January 2020

Neste artigo, consideramos um jogo de transporte onde todos os jogadores querem ser transportados a um destino em comum o mais rápido possível, e para isso eles devem escolher um dentre os õnibus disponíveis. Apresentamos limitantes para o Preço da Anarquia Sequencial considerando duas funções sociais, para ambas instâncias métricas e não-métricas.