bluuebunny/crossref_metadata_2025 huggingface dataset:
Lightweight Aggregate Shotcrete: Part 1
Authors: Bian Wen Hui , Li Peng Cheng , Bai Chang He
Published: August 2019

In this paper, preliminary research on lightweight aggregate shotcrete is carried out. The main discussion is the pumpability and sprayability of light aggregate injection by single-mixed and complex-doped mineral admixture, and the different dosages and different types are studied. The effect of mineral admixture on the physical and mechanical properties of lightweight aggregate shotcrete. The results show that the small amount of fly ash, silica fume and nano-silica can prevent the segregation and bleeding of the mixture. With the increase of the content of silica fume and nano-silica, the pumpability can be reduced. At the same time, the sprayability is increased. It has also been found that, due to the difference in particle size, the mutual complementation of particles between the complex mineral admixtures in terms of physical and mechanical properties results in a significant increase in sprayability and strength.
Detection of Defects in Layered Concrete Based on Rayleigh Surface Wave Method
Authors: Tian Xiu Shu , Hou Shuai
Published: August 2019

Based on the finite element model, the propagation characteristics of Rayleigh wave in layered structure is studied in this paper, the time-domain characteristics of wave form is analysed under different working conditions, and the identification parameters of surface wave method to detect the layered concrete is proposed. When the incident elastic wave propagates to the defect, due to the barrier effect of the defect, a part of the incident R wave is converted into a reflected R wave, which propagates along the track plate to the surface; the other part of the R wave is converted into a transmitted R wave, along the concrete. The energy amplitude can be used as one of the parameters to identify defects in the layered concrete structure.
Experimental Study on Water Permeability of Rubber Aggregate Concrete
Authors: Bai Jin Ting , Xue Zhong Quan , Zhou Mei , Wu Bin
Published: August 2019

In this paper, the water penetration resistance of rubber aggregate concrete is studied by using the water penetration height method. The experiment results show that: Under the condition of the same dosage, the greater the fineness module, the better the impermeability. Under the condition of the same particle size, the higher the dosage, the better the impermeability. Moreover, the strength of rubber aggregate concrete cannot determine its impermeability. The impermeability of rubber aggregate concrete is analyzed by binary regression analysis. The results show that: Rubber aggregate content and fineness module have obvious influence on the water permeability of concrete. The established permeability regression equation can estimate the permeability height of rubber aggregate concrete, which has certain guiding significance for practical engineering.
Atmospheric Corrosion State Evaluation Based on Surface Corrosion Morphology for Electrical Metal Frame Equipment in Chongqing Power Grid
Authors: Wu Gao Lin , Zhong Yao , Ren Xiao , Hao Jian , Wang Qian , Wang Xu Peng
Published: August 2019

This paper studies the atmospheric corrosion characteristics of grid metal frame equipment in Chongqing. Through the standard field test method of atmospheric corrosion -"exposure" method, this study carried out the substation site hanging test of the Q235 steel of the power transmission and transformation engineering structural material in the atmospheric environment, and mastered the corrosion data of Q235 steel in different corrosion stages. It was found that the morphology, quantity and characteristics of corrosion products on the metal surface varied greatly with the progress of corrosion. According to the metal corrosion morphology of different corrosion time, combined with image processing technology and wavelet transform algorithm, the parameters such as gray mean M, corrosion standard deviation σm, corrosion energy E, and energy percentage of wavelet image coefficient were selected as corrosion characteristic variable. At the same time, the BP neural network algorithm was used to qualitatively evaluate the corrosion state of the electrical equipment metal. By testing the on-site samples of the two substations, the corrosion state values of the samples were 0.946 and 0.8071, respectively, which is consistent with the actual corrosion degree, and the system had a good evaluation result.
Clustered Mutations at the Murine and Human IgH Locus Exhibit Significant Linkage Consistent with Templated Mutagenesis
Authors: Dale Gordon A. , Wilkins Daniel J. , Bohannon Caitlin D. , Dilernia Dario , Hunter Eric , Bedford Trevor , Antia Rustom , Sanz Ignacio , Jacob Joshy
Published: August 2019

Somatic hypermutation generates a myriad of Ab mutants in Ag-specific B cells, from which high-affinity mutants are selected. Chickens, sheep, and rabbits use nontemplated point mutations and templated mutations via gene conversion to diversify their expressed Ig loci, whereas mice and humans rely solely on untemplated somatic point mutations. In this study, we demonstrate that, in addition to untemplated point mutations, templated mutagenesis readily occurs at the murine and human Ig loci. We provide two distinct lines of evidence that are not explained by the Neuberger model of somatic hypermutation: 1) across multiple data sets there is significant linkage disequilibrium between individual mutations, especially among close mutations, and 2) among those mutations, those <8 bp apart are significantly more likely to match microhomologous regions in the IgHV repertoire than predicted by the mutation profiles of somatic hypermutation. Together, this supports the role of templated mutagenesis during somatic diversification of Ag-activated B cells.
Experiences of auxiliary nursing trainees of poverty alleviation programme regarding nursing and nursing profession in Vhembe District, Limpopo Province
Authors: Maputle Maria S. , Baloyi Florance N. , Nemathaga Livhuwani H.
Published: August 2019

Background: The Limpopo Department of Health and Social Development introduced a system to train children from poor families as auxiliary nurses as a poverty alleviation strategy in 2003. The programme targeted the needy families, those who depended on social grants, orphaned or child-headed families. The programme has been implemented for more than 10 years and the experiences of trainees were never explored.Objectives: The purpose of this study was to explore the experiences of auxiliary nurse trainees of the poverty alleviation programme regarding nursing and the nursing profession.Methods: A qualitative approach was used. Purposive sampling was used to sample 15 auxiliary nurses who were trained under poverty alleviation programme in four of the seven hospitals of Vhembe District. Data were collected through in-depth individual interviews. One central question ‘As a beneficiary of poverty alleviation programme, could you describe your experiences of training as a nurse and of the nursing profession in this hospital’. Data were collected until no new information emerged. Note taking and a voice recording was performed to capture all the information reported by the participants. Open coding method was used to analyse data.Results: Two themes emerged, namely experiences of being a nurse and about nursing as a profession, and interpersonal relationships between auxiliary nurses and the ward staff.Conclusions: The Department of Health in Limpopo Province was commended and to be encouraged to develop other programmes as poverty alleviation strategy for other government departments, so that the affected children can have a wider career choice. The managers and supervisors in the wards to have moral and legal obligations to support initiatives that foster effective mentoring of neophyte nurses in the nursing profession.
The use of Bliss symbols as a first step into literacy with four children with Down syndrome
Authors: Alant Erna
Published: August 2019

This study describes the use of Bliss symbolics as a first step into literacy with four children with Down syndrome in a preschool setting. Initial stages of the intervention programme are discussed as well as the children's ability to read Bliss symbols six months after commencement of the programme. Symbol errors are analyzed and implications for further research discussed.
The current practices, training and concerns of a group of hospital-based speech therapists working in the area of dysphagia
Authors: Modi Naina , Ross Eleanor
Published: August 2019

The aim of the study was to investigate the current practices, training, and concerns of a group of hospital-based speech therapists regarding the area of dysphagia practice. Questionnaires were posted to 75 speech therapists working in the major hospitals around Gauteng, KwaZulu-Natal and the Cape Province and responses were obtained from 50 therapists within the stipulated time. Closed-ended questions were analysed quantitatively using descriptive statistics, while open-ended items were subjected to content analysis of themes articulated by respondents. Results indicated that the overwhelming majority of the respondents were involved in assessing and treating dysphagia patients. Specific problems faced by respondents included limited staff to share their workloads, large caseloads, restricted access to supervision/mentor systems and poor knowledge by other health personnel of their role in dysphagia. Almost half of the respondents also reported that they were involved in student training which included the area of dysphagia. Investigation of respondents' undergraduate and postgraduate training in dysphagia suggested that there were gaps in the theoretical content of these courses as well as a limited focus on practical training. Another finding was that respondents showed an awareness of the specific roles of the speech therapist in dysphagia intervention as well as the roles of the professionals constituting a multidisciplinary dysphagia team. Most of the respondents reported that they had access to dysphagia team members as well as to diet modification services. However, many of the respondents showed decreased knowledge of and awareness regarding accessibility of diagnostic procedures and suctioning methods used in dysphagia. The majority of the respondents rated their knowledge about specific theoretical areas as well as their counselling abilities to be better than their actual skills and confidence in assessing and treating dysphagia patients. Implications of the study included the need for clinicians, universities and professional organizations to work together to improve the existing situation.
Use of the CID W22 as a South African English speech discrimination test
Authors: Wilson Wayne J. , Moodley Selvarani
Published: August 2019

South Africa currently lacks a pre-recorded South African English (SAE) specific speech discrimination test. In the absence of such a test, the SAE speaker recording (Tygerberg recording) of the American (USA) English (AE) CID W22 wordlists - in combination with the original American CID W22 normative data - is the most widely used alternative. The reliability and validity of this method, however, has never been formally assessed. This study assessed the performance of 15 normal hearing, female, first language SAE speakers on the first two full-lists of Tygerberg CID W22 recording at 20, 30, 40, 50, 60 and 70 dBSPL, and compared their scores to the American CID W22 wordlist normative data. Overall, the South African subjects performed worse than the original American normative data at the lower presentation intensities( 40 dBSPL), however, was considered a viable option. These results reiterate the need for large scale, South African specific normative studies for the CID W22 wordlists if they are to continue their role as the dominant speech discrimination wordlists in South Africa.
Identity construction following Traumatic Brain Injury: A case study
Authors: Sabat Ayesha , Moodley Legini , Kathard Harsha
Published: August 2019

This construction of self-identity pre- and post-Traumatic Brain Injury (TBI) in a single case study is described. A life history research methodology was employed to explore the experience of a survivor of TBI, using a single case study design. The participant was a 31 year old White South African male who sustained TBI while on duty in the army. Multiple interviews were conducted with the participant to allow in-depth exploration of his self-identity formation pre- and post-TBI. Data analysis entailed transcribing the interviews, crafting a research story (narrative analysis) and an analysis of the narrative. The results illuminated the emergence and development of a resistance identity as a product of early pre-TBI experience, the loss of self following TBI as well as the emergence of a positive self-identity. The embedded issues of communication and self-identity are explained. The participant’s narrative espoused a hopeful optimism, strongly challenging the dominant disability discourse. The specific strengths and limitations, and potential value of using life histories as both a methodological and clinical tool when working with TBI survivors is described. Implications for research and clinical practice in the field of Speech and Language Therapy (SLT) is also provided.
Potential influence of social and technological developments on direct marketing in South Africa
Authors: Jordaan Yolanda
Published: August 2019

This article argues that social and technological events in South Africa are leading to the development of the direct marketing industry. The article reviews various social and technological aspects as well as the influence that government intervention has on the direct marketing industry, especially in terms of legislation regarding privacy. The role of the South African Post Office is put under the spotlight since the direct marketing industry is very reliant on the Post Office. The opportunities presented by the information age are discussed and future growth areas highlighted. Although this paper mainly concentrates on direct marketing, it also tries to explain the potential role of direct marketing in an economic system approach, as a driving force of economic progress in developing countries.
The portrayal of children in magazine advertising: A post-apartheid study
Authors: North E.
Published: August 2019

A content analysis is presented of the portrayal of child actors in advertisements obtained from nine consumer magazines over a three month period in 1983, 1987, and 1997. A limited number of studies have investigated the portrayal of children in magazine advertisements, but no previous study looked exclusively at the roles children depict in advertisements. The primary objective of the present study was to describe the various roles children portray in full page magazine advertisements. Secondary objectives focused on the age and sex of the models and the use of children of different races in the same advertisement. The results indicate that children are portrayed in seven different roles in the advertisements. Suggestions for further research are offered.
Separating the role of direct radiative heating and photolysis in modulating the atmospheric response to the amplitude of the 11-year solar cycle forcing
Authors: Bednarz Ewa M. , Maycock Amanda C. , Braesicke Peter , Telford Paul J. , Abraham N. Luke , Pyle John A.
Published: August 2019

Abstract. The atmospheric response to the 11-year solar cycle is separated into the
contributions from changes in direct radiative heating and photolysis rates
using specially designed sensitivity simulations with the UM-UKCA (Unified
Model coupled to the United Kingdom Chemistry and
Aerosol model) chemistry–climate model. We perform a number of idealised time-slice
experiments under perpetual solar maximum (SMAX) and minimum conditions
(SMIN), and we find that contributions from changes in direct heating and
photolysis rates are both important for determining the stratospheric
shortwave heating, temperature and ozone responses to the amplitude of the
11-year solar cycle. The combined effects of the processes are found to be
largely additive in the tropics but nonadditive in the Southern Hemisphere
(SH) high latitudes during the dynamically active season. Our results
indicate that, in contrast to the original mechanism proposed in the
literature, the solar-induced changes in the horizontal shortwave heating
rate gradients not only in autumn/early winter but throughout the
dynamically active season are important for modulating the dynamical
response to changes in solar forcing. In spring, these gradients are
strongly influenced by the shortwave heating anomalies at higher southern
latitudes, which are closely linked to the concurrent changes in ozone. In
addition, our simulations indicate differences in the winter SH dynamical
responses between the experiments. We suggest a couple of potential drivers
of the simulated differences, i.e. the role of enhanced zonally asymmetric
ozone heating brought about by the increased solar-induced ozone levels
under SMAX and/or sensitivity of the polar dynamical response to the
altitude of the anomalous radiative tendencies. All in all, our results
suggest that solar-induced changes in ozone, both in the
tropics/mid-latitudes and the polar regions, are important for modulating
the SH dynamical response to the 11-year solar cycle. In addition, the
markedly nonadditive character of the SH polar vortex response simulated in
austral spring highlights the need for consistent model implementation of
the solar cycle forcing in both the radiative heating and photolysis
schemes.
An instrument for in-situ measurement of total ozone reactivity
Authors: Sommariva Roberto , Kramer Louisa J. , Crilley Leigh R. , Alam Mohammed S. , Bloss William J.
Published: August 2019

Abstract. We present an instrument for the measurement of total ozone reactivity (RO3), i.e. the reciprocal of the chemical lifetime of ozone (O3) in the troposphere. The Total Ozone Reactivity System (TORS) was developed with the objective to study the role of biogenic organic compounds (BVOCs) as chemical sinks of tropospheric ozone. The instrument was extensively characterized and tested in the laboratory using individual compounds and small plants (lemonthyme, Thymus citriodorus) in a Teflon bag and proved able to measure reactivities corresponding to > 4.5 × 10−5 s−1, corresponding to 20 ppb of α-pinene or 150 ppb of isoprene in isolation – larger than typical ambient levels but consistent with levels commonly found in environmental chamber and enclosure experiments. The functionality of TORS was demonstrated in quasi-ambient conditions with a deployment in a horticultural glasshouse containing a range of aromatic plants. The measurements of total ozone reactivity made in the glasshouse showed a clear diurnal pattern, following the emissions of BVOCs, and is consistent with mixing ratios of tens ppb of monoterpenes and several ppb of sesquiterpenes.
Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic Peninsula
Authors: Vorrath Maria-Elena , Müller Juliane , Esper Oliver , Mollenhauer Gesine , Haas Christian , Schefuß Enno , Fahl Kirsten
Published: August 2019

Abstract. Organic geochemical and micropaleontological analyses of surface
sediments collected in the southern Drake Passage and the Bransfield Strait, Western
Antarctic Peninsula, enable a proxy-based reconstruction of recent sea ice
conditions in this climate-sensitive area. We study the distribution of the
sea ice biomarker IPSO25, and biomarkers of open marine environments
such as more unsaturated highly branched isoprenoid alkenes and
phytosterols. Comparison of the sedimentary distribution of these biomarker
lipids with sea ice data obtained from satellite observations and
diatom-based sea ice estimates provide for an evaluation of the suitability
of these biomarkers to reflect recent sea surface conditions. The
distribution of IPSO25 supports earlier suggestions that the source
diatom seems to be common in near-coastal environments characterized by
annually recurring sea ice cover, while the distribution of the other
biomarkers is highly variable. Offsets between sea ice estimates deduced
from the abundance of biomarkers and satellite-based sea ice data are
attributed to the different time intervals recorded within the sediments and
the instrumental records from the study area, which experienced rapid
environmental changes during the past 100 years. To distinguish areas
characterized by permanently ice-free conditions, seasonal sea ice cover and
extended sea ice cover, we apply the concept of the PIP25 index from
the Arctic Ocean to our data and introduce the term PIPSO25 as a
potential sea ice proxy. While the trends in PIPSO25 are generally
consistent with satellite sea ice data and winter sea ice concentrations in
the study area estimated by diatom transfer functions, more studies on the
environmental significance of IPSO25 as a Southern Ocean sea ice proxy
are needed before this biomarker can be applied for semi-quantitative sea
ice reconstructions.
Effects of sterilization techniques on chemodenitrification and N2O production in tropical peat soil microcosms
Authors: Buessecker Steffen , Tylor Kaitlyn , Nye Joshua , Holbert Keith E. , Urquiza-Muñoz Jose D. , Glass Jennifer B. , Hartnett Hilairy E. , Cadillo-Quiroz Hinsby
Published: August 2019

Abstract. Chemodenitrification – the non-enzymatic process of nitrite reduction – may be an important sink for fixed nitrogen in tropical peatlands with low oxygen, low pH, high organic matter, and variable ferrous iron concentrations. Assessing abiotic reaction pathways is difficult because sterilization/inhibition agents can alter the availability of reactants by changing iron speciation and organic matter composition. We compared six commonly used soil sterilization techniques – γ-irradiation, chloroform, autoclaving, and chemical inhibitors (mercury, zinc, and azide) – for their compatibility with chemodenitrification assays for tropical peatland soils (organic-rich low pH soil from the Eastern Amazon). Out of the six techniques, γ-irradiation resulted in soil treatments with lowest cell viability and denitrification activity, and least effect on pH, iron speciation, and organic matter composition. Nitrite depletion rates in γ-irradiated soils were highly similar to untreated/live soils, whereas other sterilization techniques showed deviations. Chemodenitrification was a dominant process in tropical peatland soils assayed in this study. Abiotic N2O production was low to moderate (3–16 % of converted nitrite), and different sterilization techniques lead to significant variations on production rates due to inherent processes or potential artifacts. Our work represents the first methodological basis for testing the abiotic denitrification and N2O production potential in tropical peatland soil.
Gridded Emissions for CMIP6
Authors: Feng Leyang , Smith Steve J , Braun Caleb , Crippa Monica , Gidden Matthew J. , Hoesly Rachel , Klimont Zbigniew , van Marle Margreet , van den Berg Maarten , van der Werf Guido R.
Published: August 2019

Abstract. Spatially distributed anthropogenic and open burning emissions are fundamental data needed by Earth system models. We describe the methods used for generating gridded data sets produced for use by the modelling community, particularly for the Coupled Model Inter-comparison Project Phase 6. The development of three sets of gridded data for historical open burning, historical anthropogenic, and future scenarios were coordinated to produce consistent data over 1750–2100. Historical data up to 2014 were provided with annual resolution and future scenario data in 10-year intervals. Emissions are provided on a sectoral basis, along with additional files for speciated non-Methane Volatile Organic Compounds (NMVOCs). An automated framework was developed to produce these datasets to ensure that they are reproducible and facilitate future improvements. We discuss the methodologies used to produce these data along with limitations and potential for future work.
Hierarchical Sensitivity Analysis for Large Scale Process-based
Hydrological Modeling with Application in an Amazonian
Watershed
Authors: Liu Haifan , Dai Heng , Niu Jie , Hu Bill X. , Qiu Han , Gui Dongwei , Ye Ming , Chen Xingyuan , Wu Chuanhao , Zhang Jin , Riley William
Published: August 2019

Abstract. Sensitivity analysis is an effective tool for identifying important uncertainty sources and improving model calibration and predictions, especially for integrated systems with heterogeneous parameter inputs and complex processes coevolution. In this work, an advanced hierarchical global sensitivity analysis framework, which integrates a hierarchical uncertainty framework and a variance-based global sensitivity analysis, was implemented to quantitatively analyze several uncertainties of a three-dimensional, process-based hydrologic model (PAWS). The uncertainty sources considered include model parameters, model structures (with/without overland flow module), and climate forcing. We apply the approach in a ~ 9000 km2 Amazon catchment modeled at 1 km resolution to provide a demonstration of multiple uncertainty source quantification using a large-scale process-based hydrologic model. The sensitivity indices are assessed based on three important hydrologic outputs: evapotranspiration (ET), ground evaporation (EG), and groundwater contribution to streamflow (QG). It is found that, in general, model parameters (especially those within the streamside model grid cells) are the most important uncertainty contributor for all sensitivity indices. In addition, the overland flow module significantly contributes to model predictive uncertainty. These results can assist model calibration and provide modelers a better understanding of the general sources of uncertainty in predictions of complex hydrological systems in Amazonia. We demonstrated a pilot example for comprehensive global sensitivity analysis of large-scale complex hydrological models in this research. The hierarchical sensitivity analysis methodology used is mathematically rigorous and can be applied to a wide range of large-scale hydrological models with various sources of uncertainty.
Technical note: Stochastic simulation of streamflow time series using phase randomization
Authors: Brunner Manuela I. , Bárdossy András , Furrer Reinhard
Published: August 2019

Abstract. Stochastically generated streamflow time series are widely used in water resource planning and management. Such series represent sets of plausible yet unobserved streamflow realizations which should reproduce the main characteristics of observed data. These characteristics include the distribution of daily streamflow values and their temporal correlation as expressed by short- and long-range dependence. Existing streamflow generation approaches have mainly focused on the time domain, even though simulation in the frequency domain provides good properties. These properties comprise the simulation of both short- and long-range dependence as well as extension to multiple sites. Simulation in the frequency domain is based on the randomization of the phases of the Fourier transformation. We here combine phase randomization simulation with a flexible, four-parameter kappa distribution, which allows for the extrapolation to as yet unobserved low and high flows. The simulation approach consists of seven steps: (1) fitting the theoretical kappa distribution,
(2) normalization and deseasonalization of the marginal distribution,
(3) Fourier transformation, (4) random phase generation, (5) inverse Fourier transformation, (6) back transformation, and (7) simulation. The simulation approach is applicable to both individual and multiple sites. It was applied to and validated on a set of four catchments in Switzerland. Our results show that the stochastic streamflow generator based on phase randomization produces realistic streamflow time series with respect to distributional properties and temporal correlation. However, cross-correlation among sites was in some cases found to be underestimated. The approach can be recommended as a flexible tool for various applications such as the dimensioning of reservoirs or the assessment of drought persistence. Highlights.
Stochastic simulation of streamflow time series for individual and multiple sites by combining phase randomization and the kappa distribution. Simulated time series reproduce temporal correlation, seasonal distributions, and extremes of observed time series. Simulation procedure suitable for use in water resource planning and management.
Assessment of the 1783 Scilla landslide–tsunami's effects on the Calabrian and Sicilian coasts through numerical modeling
Authors: Zaniboni Filippo , Pagnoni Gianluca , Gallotti Glauco , Paparo Maria Ausilia , Armigliato Alberto , Tinti Stefano
Published: August 2019

Abstract. The 1783 Scilla landslide–tsunami (Calabria, southern Italy) is a well-studied
event that caused more than 1500 fatalities on the beaches close to the
town. This paper complements a previous work that was based on numerical
simulations and was focused on the very local effects of the tsunami in
Scilla. In this study we extend the computational domain to cover a wider
portion of western Calabria and northeastern Sicily, including the western
side of the Straits of Messina. This investigation focuses on Capo Peloro
area (the easternmost cape of Sicily), where the highest tsunami effects
outside Scilla were reported. Important tsunami observations, such as the
wave height reaching 6 m at Torre degli Inglesi and flooding that reached
over 600 m inland, have been successfully modeled but only by means of a
high-resolution (10 m) topo-bathymetric grid, since coarser grids were
inadequate for the purpose. Interestingly, the inundation of the small lake
of Pantano Piccolo could not be reproduced by using today's coastal
morphology, since a coastal dune now acts as a barrier against tsunamis.
Historical analysis suggests that this dune was not in place at the time of
the tsunami occurred and that a ground depression extending from the lake
to the northern coast is a remnant of an ancient channel that was used as
a pathway in Roman times. The removal of such an obstacle and the remodeling of
the coeval morphology allows the simulations to reproduce the tsunami
penetration up to the lake, thus supporting the hypothesis that the
1783 tsunami entered the lake following the Roman channel track. A further
result of this study is that the computed regional tsunami propagation
pattern provides a useful hint for assessing tsunami hazards in the Straits of Messina area, which is one of the most exposed areas to tsunami threats in Italy
and in the Mediterranean Sea overall.
Erosion after an extreme storm event in an arid fluvial system of the southern Atacama Desert: an assessment of magnitude, return time, and conditioning factors of erosion caused by debris flows
Authors: Aguilar Germán , Cabré Albert , Fredes Victor , Villela Bruno
Published: August 2019

Abstract. We have calculated a mean erosion of 1.3 mm caused by an individual storm event in March 2015 that impacted a large mountainous area of the southernmost Atacama Desert. The calculated erosion agrees with millennial erosion rates and with return time of high sediment discharge events previously reported in the study area. Here, we quantify for the first time the contribution of an individual extreme storm event to long-term erosion rates in the Atacama Desert. This is significant because erosion rates, related to high sediment discharge events in arid fluvial systems, are hard to measure with sediment load due the destruction of gauges by devastating flashfloods and thus have not been directly measured yet. During the March 2015 storm, debris flows were reported as the main sediment transport process. Erosion of gullies and channels are the main source of sediments that finally generate debris flows that reach the tributary junctions and the trunk valleys. The sediment yield to the tributary outlets strongly depends on the hydraulic capacity of catchments to store sediments in the drainage network between storms. Larger tributary catchments, high hydrological hierarchy, low topographic gradient and gentle slopes are the most susceptible catchments to generate debris flows that reach alluvial fans at any storm event from large debris volumes stored in the drainage network. Our findings better assess debris flow susceptibility of arid catchments, which is significant for the southernmost Atacama Desert valleys because human settlements and industries are mostly established in alluvial fans.
Global-scale drought risk assessment for agricultural systems
Authors: Meza Isabel , Siebert Stefan , Döll Petra , Kusche Jürgen , Herbert Claudia , Eyshi Rezaei Ehsan , Nouri Hamideh , Gerdener Helena , Popat Eklavyya , Frischen Janna , Naumann Gustavo , Vogt Jürgen V. , Walz Yvonne , Sebesvari Zita , Hagenlocher Michael
Published: August 2019

Abstract. Droughts continue to affect ecosystems, communities, and entire economies. Agriculture bears much of the impact, and in many countries it is the most heavily affected sector. Over the past decades, efforts have been made to assess drought risk at different spatial scales. Here, we present for the first time an integrated assessment of drought risk for both irrigated and rain-fed agricultural systems at the global scale. Composite hazard indicators were calculated for irrigated and rain-fed systems separately using different drought indices based on historical climate conditions (1980–2016). Exposure was analyzed for irrigated and non-irrigated crops. Vulnerability was assessed through a social-ecological systems perspective, using social-ecological susceptibility and lack of coping capacity indicators that were weighted by drought experts from around the world. The analysis shows that drought risk of rain-fed and irrigated agricultural systems displays heterogeneous pattern at the global level with higher risk for southeastern Europe, as well as northern and southern Africa. By providing information on the drivers and spatial patterns of drought risk in all dimensions of hazard, exposure, and vulnerability, the presented analysis can support the identification of tailored measures to reduce drought risk and increase the resilience of agricultural systems.
Seasonal and regional variations of sinking in the subpolar North Atlantic from a high-resolution ocean model
Authors: Sayol Juan-Manuel , Dijkstra Henk , Katsman Caroline
Published: August 2019

Abstract. Previous studies have indicated that most of the net sinking associated with the downward branch of the Atlantic Meridional Overturning Circulation (AMOC) must occur near the subpolar North Atlantic boundaries. In this work we have used monthly mean fields of a high-resolution ocean model (0.1∘ at the Equator) to quantify this sinking. To this end we have calculated the Eulerian net vertical transport (W∑) from the modeled vertical velocities, its seasonal variability, and its spatial distribution under repeated climatological atmospheric forcing conditions. Based on this simulation, we find that for the whole subpolar North Atlantic W∑ peaks at about −14 Sv at a depth of 1139 m, matching both the mean depth and the magnitude of the meridional transport of the AMOC at 45∘ N. It displays a seasonal variability of around 10 Sv. Three sinking regimes are identified according to the characteristics of the accumulated W∑ with respect to the distance to the shelf: one within the first 90 km and onto the bathymetric slope at around the peak of the boundary current speed (regime I), the second between 90 and 250 km covering the remainder of the shelf where mesoscale eddies exchange properties (momentum, heat, mass) between the interior and the boundary (regime II), and the third at larger distances from the shelf where W∑ is mostly driven by the ocean's interior eddies (regime III). Regimes I and II accumulate ∼90 % of the total sinking and display smaller seasonal changes and spatial variability than regime III. We find that such a distinction in regimes is also useful to describe the characteristics of W∑ in marginal seas located far from the overflow areas, although the regime boundaries can shift a few tens of kilometers inshore or offshore depending on the bathymetric slope and shelf width of each marginal sea. The largest contributions to the sinking come from the Labrador Sea, the Newfoundland region, and the overflow regions. The magnitude, seasonal variability, and depth at which W∑ peaks vary for each region, thus revealing a complex picture of sinking in the subpolar North Atlantic.
Overprinting translational domains in passive margin salt basins: insights from analogue modelling
Authors: Ge Zhiyuan , Rosenau Matthias , Warsitzka Michael , Gawthorpe Rob L.
Published: August 2019

Abstract. Current models of gravitational tectonics on the structural styles
of salt-influenced passive margins typically depict domains of upslope
extension and corresponding downslope contraction separated by a mid-slope
domain of translation that is rather undeformed. However, an undeformed
translational domain is rarely observed in natural systems as extensional
and contractional structures tend to interfere in the mid-slope area. In
this study, we use sandbox analogue modelling analysed by digital image
correlation (DIC) to investigate some of the factors that control the
structural evolution of translational domains. As in nature, experimental
deformation is driven by slowly increasing gravitational forces associated
with continuous basal tilting. The results show that a translational domain
persists throughout the basin evolution when the pre-kinematic layer is
evenly distributed. However, a thin (1 mm in the experiment, 100 m in
nature) pre-kinematic layer can render the translational domain relatively
narrow compared to settings with a thicker (5 mm) pre-kinematic layer.
In contrast, early differential sedimentary loading in the mid-slope area
creates minibasins separated by salt diapirs overprinting the translational
domain. Similarly, very low sedimentation rate (1 mm per day in the
experiment, < 17 m Ma−1 in nature) in the early stage of the
experiment results in a translational domain quickly overprinted by
downslope migration of the extensional domain and upslope migration of the
contractional domain. Our study suggests that the architecture of passive
margin salt basins is closely linked to the pre- and syn-kinematic cover
thickness. The translational domain, as an undeformed region in the
supra-salt cover, is a transient feature and overprinted in passive margins
with either low sedimentation rate or a heterogeneous sedimentation pattern.
Colonoscopy Indication Algorithm Performance Across Diverse Health Care Systems in
the PROSPR Consortium
Authors: Burnett-Hartman Andrea N. , Kamineni Aruna , Corley Douglas A. , Singal Amit G. , Halm Ethan A. , Rutter Carolyn M. , Chubak Jessica , Lee Jeffrey K. , Doubeni Chyke A. , Inadomi John M. , Doria-Rose V. Paul , Zheng Yingye
Published: August 2019

Background: Despite the importance of characterizing colonoscopy indication for
quality monitoring and cancer screening program evaluation, there is no standard
approach to documenting colonoscopy indication in medical records.Methods: We applied
two algorithms in three health care systems to assign colonoscopy indication to persons
50–89 years old who received a colonoscopy during 2010–2013. Both algorithms used
standard procedure, diagnostic, and laboratory codes. One algorithm, the KPNC algorithm,
used a hierarchical approach to classify exam indication into: diagnostic, surveillance,
or screening; whereas the other, the SEARCH algorithm, used a logistic regression-based
algorithm to provide the probability that colonoscopy was performed for screening. Gold
standard assessment of indication was from medical records abstraction.Results: There
were 1,796 colonoscopy exams included in analyses; age and racial/ethnic distributions
of participants differed across health care systems. The KPNC algorithm’s sensitivities
and specificities for screening indication ranged from 0.78–0.82 and 0.78–0.91,
respectively; sensitivities and specificities for diagnostic indication ranged from
0.78–0.89 and 0.74–0.82, respectively. The KPNC algorithm had poor sensitivities
(ranging from 0.11–0.67) and high specificities for surveillance exams. The Area Under
the Curve (AUC) of the SEARCH algorithm for screening indication ranged from 0.76–0.84
across health care systems. For screening indication, the KPNC algorithm obtained higher
specificities than the SEARCH algorithm at the same sensitivity.Conclusion: Despite
standardized implementation of these indication algorithms across three health care
systems, the capture of colonoscopy indication data was imperfect. Thus, we recommend
that standard, systematic documentation of colonoscopy indication should be added to
medical records to ensure efficient and accurate data capture.
Theory – Practice Gap: Challenges Experienced by Nursing Students at the Satellite Campus of a Higher Education Institution in Namibia
Authors: Saara Kertu Hatupopi , Nuuyoma Vistolina
Published: August 2019

Background: Theory practice gap is the discrepancies found between what students learn in the formal classroom setting and what they experience in the clinical settings.  Observations reveal that nursing as practised is task-centred and students rarely get involved in anything approaching the total care of individual patients, thus leading to theory-practice gap.Objectives: The study explored and described the challenges faced by Bachelor of Nursing (clinical) honours students when integrating theory into practice in the clinical settings.Method: The study, which was granted ethical clearances from two institutions, drew on an exploratory phenomenology methodology to gather data from ten nursing students registered at a satellite campus. The participants were purposively selected with data collected via focus group interviews. Thereafter, data were transcribed verbatim and analysed using content analysis. The study data collection and analysis adhered to ethical principles and quality measures in order to ensure credibility, transferability, dependability and confirmability. Results: Nursing students experience challenges in integrating theory and practice. These challenges are grouped into four themes; theory verses practice, limited resources in clinical settings, discriminatory attitudes and communication barriers.Conclusion:  Nursing students appreciated accompaniment and supervision by nurse educators. However, the accompaniment’s impact on learning may be undermined through the students’ limited exposure to clinical cases. Therefore, long-term strategies are recommended for effective integration of theory with practice.
Role of Consent in Arbitration between States and Nationals of Other Countries before the International Center for the Settlement of Investment Disputes
Authors: Shwarah Jalal Aead
Published: August 2019

This research aims at addressing important issues surrounding settling the investment disputes between the states and the national of other states when they decide resort to the international center for settling the disputes.

Specifically, this research focused on role of consent in arbitration, and degree to which the center commitment to Washington convention especially to article (25) from the convention. To avoid any possible contradictions in the process settling the dispute which will have negative impacts on the parties.

To achieve the objectives of this research, the researcher depended on the descriptive research method through in –depth review of a set of articles dissertations, websites and books.

Results of this research have implications to the parties involved in organizing the arbitration procedures according to principles of Washington convention underlying the arbitration centers provisions.
Políticas públicas en torno a los ex Centros Clandestinos de Detención Tortura y Extermino de Argentina: aproximaciones a partir de un estudio de caso
Authors: Garbero Vanesa
Published: August 2019

La meta de este artículo es reconstruir el conflictivo proceso de transformación del ex Centro Clandestino de Detención Tortura y Exterminio Campo de la Ribera en un Espacio para la Memoria, Promoción y Defensa de los Derechos Humanos, entre los años inmediatamente anteriores al retorno de la democracia en 1983 y su apertura al público en 2010. Con este propósito se retoman las políticas públicas e iniciativas de actores nacionales, provinciales y locales que intervinieron para imponer en el sitio determinadas representaciones del pasado y prácticas conmemorativas específicas. La investigación muestra el proceso de lucha social, política y simbólica de constitución de los espacios de memoria en los mismos lugares que se produjo la violación sistemática de derechos humanos, las dificultades de nombrarlos y reconocerlos como tales y la importancia del espacio como anclaje y soporte material de las disputas por el sentido del pasado reciente. Palabras clave: Centro Clandestino de Detención, Tortura y Exterminio Campo de la Ribera. Políticas Públicas. Espacios de Memoria. Procesos de Resignificación. Memoria Social.
O Memorial da Resistência em fotos de visitantes no Instagram: modos de ver, sentir e pensar o passado, o presente e o futuro
Authors: Santos Ana Carolina Lima
Published: August 2019

Este artigo visa investigar as múltiplas temporalidades que embasam as imagens feitas e publicadas nas redes sociais por visitantes do Memorial da Resistência de São Paulo. Por meio da análise de algumas dessas fotografias, coletadas no Instagram, busca-se evidenciar aquilo que elas iluminam sobre visões, sentimentos e pensamentos acerca do passado, do presente e do futuro – como permitidos por esse museu e lugar de memória e como traduzida visualmente pelos indivíduos que experienciaram o espaço.Palavras-chave: Fotografia. Redes Sociais. Museus. Memorial da Resistência de São Paulo