bluuebunny/crossref_metadata_2025 huggingface dataset:
ETL Processes Security Modeling
Authors: Dammak Salma , Ghozzi Faiza , Gargouri Faiez
Published: March 2019

The development of information systems (IS) in a secure environment or condition is a complex task that involves many additional basic security protocols, policies as well as industry standards on passwords, anti-virus programs, firewalls and data encryption. However, in traditional IS development lifecycles, security is either ignored or added as an afterthought, which does not assure the system complete security. So, it is necessary to give more importance to this issue and consider it as part of IS development process. In this context, the authors should guarantee the security of ETL (Extract, Transform, Load) processes, which are among the most critical and complex tasks during DW development project. In this study, security management is carried out for ETL processes by proposing a meta-model integrating the security concepts from the security requirements to the necessary preventive and / or corrective treatments. The proposed meta-model is validated with instantiation.
Counterfactual Autoencoder for Unsupervised Semantic Learning
Authors: Sadiq Saad , Shyu Mei-Ling , Feaster Daniel J.
Published: March 2019

Deep Neural Networks (DNNs) are best known for being the state-of-the-art in artificial intelligence (AI) applications including natural language processing (NLP), speech processing, computer vision, etc. In spite of all recent achievements of deep learning, it has yet to achieve semantic learning required to reason about the data. This lack of reasoning is partially imputed to the boorish memorization of patterns and curves from millions of training samples and ignoring the spatiotemporal relationships. The proposed framework puts forward a novel approach based on variational autoencoders (VAEs) by using the potential outcomes model and developing the counterfactual autoencoders. The proposed framework transforms any sort of multimedia input distributions to a meaningful latent space while giving more control over how the latent space is created. This allows us to model data that is better suited to answer inference-based queries, which is very valuable in reasoning-based AI applications.
Supply Chain Risk Assessment in the Ornamental Fish Supply Chain
Authors: Iqbal Mohammed C. , Shalij P.R
Published: March 2019

Systematic risk management plays a key role in confronting the emerging challenges of business. A conceptual framework is presented here for the evaluation of risks in the ornamental fish supply chain. With a prolonged study and deliberations with field experts, various types of risks are brought out of the ornamental fish supply chain. From the study, the types of risks associated are clustered into six categories, namely macro level risk, demand risk, supply risk, quality risk, risk on asset and infrastructure and financial risk, to find out the major risks in this supply chain. Friedman's ranked data test is applied to find the significant difference in various risks clustered in the categories. The study allows a supply chain member to develop a clear view of risk related to the entire supply chain. The article can help the members of the ornamental fish supply chain to make use of the study and information to make more efficient and effective supply chain.
The Dynamics of Product Development in Software Startups
Authors: Shanbhag Narendranath , Pardede Eric
Published: March 2019

Software startups are increasingly under high pressure to deliver successful products to survive and thrive in the modern highly competitive technology market. Larger organizations with deep pockets can replicate the same business ideas used by startups with relative ease. So how does the average startup stand a chance at succeeding at this seemingly David vs. Goliath contest? This article looks at the available literature and identifies such factors that can affect the success of software development startups. Using causal loop constructs from the field of system dynamics, the interactions among the various identified factors are visualised to reveal the dynamics of the system. The result is as a three-dimensional view of success factors in form of time, capital and (product) differentiation. The modelled system is then simulated, and the resultant trend is reviewed and interpreted. This research acts as ground work for analysing the workings of software development startups and sets the stage for a more holistic study of the area, upon which further research can be carried out.
Clustering E-Shoppers on the Basis of Shopping Values and Web Characteristics
Authors: Prashar Sanjeev , Tata Sai Vijay , Parsad Chandan , Banerjee Abhishek , Sahakari Nikhil , Chatterjee Subham
Published: March 2019

This article describes how the exponential growth of e-commerce in India and the presence of many national and multinational e-retailers has set the trend for the major overhaul of the online industry. Most of the e-retailers have failed to differentiate themselves from the competitors. This has resulted in their failure to attract and retain the right set of consumers for their respective businesses. The present paper is aimed at identifying and developing the typology of online shoppers based on importance given by them to shopping values and web portal features. The data collected was analysed using factor, cluster and correspondence analyses. The article identifies four types of online shoppers – ‘Information Seekers,' ‘Utility Seekers,' ‘Value Seekers' and ‘Core Shoppers.' Each of these four segments display significant differences and this information can be strategically used by web retailers in targeting their markets effectively.
A Study of the Contribution of Information Technology on the Growth of Tourism Economy Using Cross-Sectional Data
Authors: Yin Ping , Zheng Xianrong , Duan Lian , Xu Xiaobo , He Min
Published: March 2019

Information technology (IT) has dramatically changed tourism industry, particularly in facilitating and improving information discovery and dissemination in tourism industry. Prior research has identified the key role that IT plays in the development of tourism industry. However, IT is examined solely, while other factors that drive the development of tourism industry are neglected in these studies. Guided by the new economic growth theory, this paper integrates fixed capital, labor, and IT and further examine how they together affect the development of tourism industry. Based on the cross-sectional tourism data of 2014 in 30 provinces in China, this article runs gray correlation analysis first and then applies a Cobb-Douglas production function model. The results indicate that fixed capital, labor, and IT are all correlated with the total tourism revenue at a certain degree, and that the development of tourism industry replies more on labor and IT than on fixed capital. Labor is the factor that makes the largest contribution to the development of tourism industry.
Le malattie respiratorie nell'ottica di genere
Authors: Ambrosino Coordinatori: I. , Barbagelata E. , Gnerre Guest Editors: P. , Politi C.
Published: March 2019

IntroduzioneI. Ambrosino, E. Barbagelata

Differenze di genere nello sviluppo embrionale, nell’anatomia, nella fisiologia e nella patologia dell’apparato respiratorioE. Barbagelata, I. Ambrosino

Le principali malattie respiratorie in ottica di genere dall’epidemiologia alla diagnosi e alla terapia: asmaT. Ciarambino, O. Para, I. Ronga

Le principali malattie respiratorie in ottica di genere dall’epidemiologia alla diagnosi e alla terapia: broncopneumopatia cronica ostruttivaS. Mangiacapra

Le principali malattie respiratorie in ottica di genere dall’epidemiologia alla diagnosi e alla terapia: polmonitiT.M. Attardo

Le principali malattie respiratorie in ottica di genere dall’epidemiologia alla diagnosi e alla terapia: tromboembolia polmonareM. Porru, P. Pitto

Le principali malattie respiratorie in ottica di genere dall’epidemiologia alla diagnosi e alla terapia: versamento pleuricoC. Zaninetti, C. Tana

Come una società scientifica può diffondere la cultura di genere?P. Gnerre, C. Politi, A. Fontanella
The principled leadership scale: An integration of value-based leadership
Authors: Hendrikz Karen , Engelbrecht Amos S.
Published: March 2019

Orientation: A need exists to investigate leader behaviour necessary to curb the corruption that has infected and weakened South Africa’s moral fibre. Such leader behaviour would need to be underpinned by a set of universal moral values.Research purpose: The purpose of this study was to develop a new measure, the principled leadership scale (PLS), by integrating the value-based behaviours inherent in transformational, servant, authentic and ethical leadership.Motivation for the study: Leader behaviour intrinsic to value-based leadership was found to be closely aligned with universal moral values. Because the study found a considerable overlap between the behaviours mentioned in the value-based leadership theories, it sought to integrate these behaviours under one construct and to develop a reliable and valid scale to assess this construct.Research approach/design and method: Data from the quantitative study were analysed by means of item analysis, exploratory and confirmatory bi-factor analysis conducted via structural equation modelling.Main findings: The confirmatory bi-factor solution corroborated a strong general principled leadership factor and four moderately weak group factors. The statistical analyses provided good fit of the PLS measurement model with the empirical data.Practical and managerial implications: The study found acceptable measurement properties of the PLS that may be used for applications, such as the selecting, training and developing of ethical leadership in organisations.Contribution/value-add: The study adds value in that it is the first to integrate the four value-based leadership theories under one construct and to develop a potential psychometrically sound instrument to measure principled leadership.
Alteridade e dialogismo na pesquisa com professoras de bebês
Authors: Guimarães Daniela De Oliveira , Arenhart Deise , Santos Nubia Oliveira
Published: March 2019

Este artigo tem como objetivo refletir sobre o processo metodológico da pesquisa institucional “Linguagem e Educação Infantil: entre a experiência da docência e as práticas pedagógicas na educação das crianças de 0 a 3 anos”, em curso desde o segundo semestre de 2015. O propósito central da pesquisa é compreender as especificidades da docência na creche.  No presente trabalho, a partir da interlocução com Mikhail Bakhtin, focalizamos como são produzidas significações sobre as práticas, problematizações e teorização sobre elas no movimento dialógico constituído no campo, que se concretiza em encontros sistemáticos com grupos de professoras de bebês. Na perspectiva da pesquisa-formação, os encontros constituem-se como espaços reflexivos, a partir das relações alteritárias estabelecidas. Palavras e contrapalavras evidenciam consensos, dissensos e novas formas das professoras compreenderem a si mesmas e o próprio trabalho pedagógico com os bebês, construindo indicativos para esse trabalho.
“Xô, preconceito!” Um projeto de sensibilização sobre as diferenças, por meio das obras da autora Ruth Rocha
Authors: Gutierres Borges Juliana Diniz
Published: March 2019

O projeto foi desenvolvido em uma turma de pré-escola vinculada ao Centro de Atenção Integral à Criança e ao Adolescente, no município do Rio Grande – RS. A turma era formada por 15 crianças entre 4 e 5 anos e duas professoras, sendo uma delas deficiente visual. A maioria das crianças estava ingressando na escola pela primeira vez e ainda não haviam interagido com pessoas deficientes. Assim, buscando articular o encantamento da literatura infantil brasileira e o respeito às diferenças, as obras da Ruth Rocha foram escolhidas como norteadoras do projeto por serem narrativas originais e divertidas, que tematizam diferentes situações cotidianas, respeito à alteridade, bem como aspectos do imaginário infantil. Dentre os principais resultados alcançados, destaca-se que esse grupo de crianças foi aprendendo a conviver com as diferenças e as necessidades do outro desde cedo, evidenciados em uma relação de confiança e amizade com as professoras, sem mais distinção entre ambas. Atrelado a isso, está a inserção das crianças a práticas de letramento, compreendendo os usos sociais da escrita em seu cotidiano.
Participação social de crianças em brincadeiras: aproximações às culturas da infância na educação infantil
Authors: Campos Rafaely Karolynne do Nascimento , Ramos Tacyana Karla Gomes
Published: March 2019

O presente estudo focaliza a participação social de crianças no contexto da educação infantil, analisando as formas utilizadas pela criança para ingressar e permanecer numa brincadeira coletiva em curso, organizada por parceiros de idade. Inicialmente procura-se problematizar a noção de culturas da infância construída no campo dos estudos da sociologia da infância e situar as aproximações teóricas relativas à brincadeira em uma perspectiva social e cultural focalizando as relações entre o brincar e as culturas da infância. Em seguida, busca-se expor as configurações metodológicas da investigação. Os dados foram produzidos a partir dos aportes da Sociologia da Infância, numa perspectiva de pesquisa etnográfica, realizada com vinte e cinco crianças de ambos os sexos, com três anos. Os resultados indicam que as formações de grupos de brincadeiras foram regidas por estratégias que utilizaram a amizade como principal forma de acesso e permanência nas situações organizadas pelos pares que brincavam.
A importância da brincadeira de faz de conta na educação infantil: sob o olhar de professoras
Authors: Silva Isadhora Araújo Lucena , Silva Maria De Fátima Gomes da
Published: March 2019

Este artigo é um recorte de uma pesquisa de mestrado em educação que teve como objetivo principal investigar as contribuições de uma Brinquedoteca Universitária, criada na Universidade de Pernambuco, com o intuito de promover Formação Continuada para professores/as da Educação Infantil e também atender a crianças desse nível de escolarização, oferecendo-lhes experiências brincantes. O recorte aqui apresentado baseia-se nas concepções de professoras da Educação Infantil, refletindo sobre as contribuições da brincadeira de faz de conta para as crianças e para a prática pedagógica, a partir de uma das formações continuadas desenvolvidas na Brinquedoteca Universitária. Através da pesquisa-ação, foi possível concluir que a brincadeira de faz de conta contribui para a aprendizagem e o desenvolvimento da criança da Educação Infantil de forma imaginativa e criativa e que exerce, na prática pedagógica de professores/as, uma mais-valia pedagógica no que toca à necessária interação entre o brincar e o aprender.
Sensory Features and Family Functioning in Families of Children With Autism and Developmental Disabilities: Longitudinal Associations
Authors: Kirby Anne V. , Williams Kathryn L. , Watson Linda R. , Sideris John , Bulluck John , Baranek Grace T.
Published: March 2019

Importance: Children with autism spectrum disorder (ASD) and other developmental disabilities (DD) commonly display unusual responses to sensory input. Previous work has suggested concurrent associations linking sensory features with aspects of family functioning, including activity participation and caregiver strain. What is unknown, however, is the extent to which sensory features affect family functioning over time, as well as the influence of received services on these relationships.

Objective: To assess hypothesized longitudinal associations between sensory features and family functioning and examine interactions by group and service usage (i.e., educational and therapy services).

Design: Multigroup longitudinal observational study.

Setting: Community.

Participants: A volunteer sample of 81 children (50 with ASD, 31 with DD; 76% male), ages 2–12 yr, and their caregivers participated in assessments at two points, 3.3 yr apart on average.

Outcomes and Measures: Key measures included the Sensory Experiences Questionnaire, Sensory Profile, Sensory Processing Assessment for Young Children, Tactile Defensiveness and Discrimination Test–Revised, Caregiver Strain Questionnaire, and Home and Community Activities Scale. We also measured the amount of time children received educational and therapy services.

Results: Regression analyses confirmed long-term associations linking sensory features with aspects of activity participation and caregiver strain in this population; group and service usage interactions were also identified.

Conclusions and Relevance: Sensory features can affect the everyday experiences of both children and caregivers. It is important for practitioners to understand the potentially enduring effects of children’s sensory features on family functioning so as to begin to identify supportive interventions with more optimal long-term effects.
England’s Citizenship Education Experiment
Authors: Jerome Lee
Published: March 2019

How do we prepare young people to understand the complex problems confronting our society and their place as citizens in shaping solutions?

Until 1997, the contribution of schools to these challenges was ad hoc and uncoordinated, but with the introduction of citizenship education into the National Curriculum in England a new political project began. Between 2002 and 2012, England has become a leading player in the debate about how to induct young people into democracy. Jerome explores the connections between the values promoted by the government and the forms of citizenship promoted through the National Curriculum and considers:

What did the politicians want the policy to achieve?

What kinds of citizens were teachers trying to create?

What kind of citizens do the young people feel that they have become?

To answer these questions this book considers a range of evidence from large scale national and international research projects to single school case studies, conducted with student co-researchers. The study illustrates the complexity of policy making and reveals the gap between curriculum policy and implementation.
Changing Pedagogy
Authors: Zheng Xin-min , Davison Chris
Published: March 2019

China’s growing economic, military and political stability have, for the first time, started to gain international recognition. As China increasingly opens up to the world, its unique role in the context of economic globalization is becoming more pronounced, which is exemplified by its recent membership of the WTO and Beijing’s successful bid to host the Olympic Games. Unsurprisingly, this has resulted in an explosion in the popularity of English language learning in China, which has, in turn, led to radical reform of the curricula, teaching methods, teacher education and assessment system in China in order to improve standards.

This fascinating monograph explores the nature of the implemented English language curriculum in China, focussing, in particular, on the pedagogy of secondary school teachers. There follows an insightful analysis into how such teachers, in different situations and with different backgrounds and motivations, make decisions about what and how they teach, and the extent to which they adapt the promoted methods in the their individual teaching environments. The authors then use their findings to propose an innovative and coherent framework, which has far-reaching consequences for pedagogy in China and across the world.
Parental Human Capital and Effective School Management
Authors: Blimpo Moussa P. , Evans David K. , Lahire Nathalie
Published: March 2019

Education systems in developing countries are often centrally managed in a top-down structure. In environments where schools have different needs and where localized information plays an important role, empowerment of the local community may be attractive, but low levels of human capital at the local level may offset gains from local information. This paper reports the results of a four-year, large-scale experiment that provided a grant and comprehensive school management training to principals, teachers, and community representatives in a set of schools. To separate the effect of the training from the grant, a second set of schools received the grant only with no training. A third set of schools served as a control group and received neither intervention. Each of 273 Gambian primary schools were randomized to one of the three groups. The program was implemented through the government education system. Three to four years into the program, the full intervention led to a 21 percent reduction in student absenteeism and a 23 percent reduction in teacher absenteeism, but produced no impact on student test scores. The effect of the full program on learning outcomes is strongly mediated by baseline local capacity, as measured by adult literacy. This result suggests that, in villages with high literacy, the program may yield gains on students’ learning outcomes. Receiving the grant alone had no impact on either test scores or student participation.
Charter School Entry and School Choice
Authors: Ferreyra Maria Marta , Kosenok Grigory
Published: March 2019

This paper develops and estimates an equilibrium model of charter school entry and school choice. In the model, households choose among public, private, and charter schools, and a regulator authorizes charter entry and mandates charter exit. The model is estimated for Washington, D.C. According to the estimates, charters generate net social gains by providing additional school options, and they benefit non-white, low-income, and middle-school students the most. Further, policies that raise the supply of prospective charter entrants in combination with high authorization standards enhance social welfare.
Participatory Accountability and Collective Action
Authors: Barr Abigail , Packard Truman , Serra Danila
Published: March 2019

There is general agreement that the existence of participatory institutions is a necessary condition for accountability, especially where top-down institutions are malfunctioning or missing. In education, the evidence on the effectiveness of participatory accountability is mixed. This paper argues that participation is a social dilemma and therefore depends, at least partly, on individuals’ propensity to cooperate with others for the common good. This being the case, the mixed evidence could be owing to society-level heterogeneities in individuals’ willingness and ability to overcome collective action problems. The authors investigate whether individuals’ propensity to cooperate plays a role in parents’ decisions to participate in both a school accountability system—a “short route” to accountability—and parliamentary elections—a “long route” to accountability—by combining survey data on 1,800 individuals’ participation decisions with measures of their willingness to contribute to a public good in the context of a very simple, clearly defined laboratory experiment. They conduct a study in a new democracy, Albania, involving parents of children enrolled in primary schools. The findings confirm that, both across individuals within communities and across communities, the decision to hold teachers and school directors accountable directly through participation at the school level, and indirectly through political participation correlates with cooperativeness in a simple public goods game.
Equality of Opportunity for Children in Egypt, 2000-2009
Authors: Velez C.E. , Al-Shawarby S. , El-Laithy H.
Published: March 2019

This paper provides relevant indicators and measurements useful for public policies seeking the expansion of equitable human development opportunities for Egyptian children and youth. To measure equitable access to opportunities, the authors use the Human Opportunity Index to examine the evolution of 16 basic opportunity indicators grouped in four sectors: education, basic housing services, early childhood development, and nutrition and hunger. The main findings show that during the last decade most opportunities for children and youth improved unambiguously, for the first two sectors, but were stagnant for nutrition and early childhood development opportunities. Although the urban-rural and interregional gaps were partially reduced, there are still substantial opportunity gaps between children in favorable and unfavorable circumstances. Parents’ education, income per capita, urban-rural location, number of siblings, and regional location, are the five most important factors affecting equality of opportunity, although their impact varies across indicators.
Egypt
Authors: Ersado Lire , Gignoux Jeremie
Published: March 2019

The paper examines the levels and trends in access to education and educational outcomes across generations of Egyptian youth. Examination of three cohorts of individuals aged 21 to 24 (born between 1964 and 1967, 1974 and 1977, and 1982 and 1985) shows that access to education has substantially improved during the last three decades. Completion rates increased by more than 60 percent at the preparatory level and 70 percent at the secondary level and the college completion rate more than doubled. However, significant inequities remain in access to education and educational outcomes. The fraction of never enrolled among the cohorts is still large, affecting more girls than boys, more rural than urban areas, and more children of parents with lower level of education and in elementary occupations, such as subsistence agriculture. The analysis of test-scores from the Trends in International Mathematics and Science Study (TIMSS) and national examinations shows that more than a quarter of learning outcome inequality is attributable to circumstances beyond the control of a student, such as parental education, socioeconomic background and place of birth. In Egypt, inequality of opportunity in learning outcomes emerges early and builds up progressively throughout the education levels. Access to higher education continues to remain significantly lower for children from rural areas and for those whose parents have a low level of education or are engaged in elementary occupations. Tracking into vocational and general secondary schools, which depends on a high-stakes national examination, and high and unequal levels of household expenditures in private tutoring substantially contribute to unequal learning outcomes.
The Fiscal Cost of Weak Governance
Authors: Muralidharan Karthik , Das Jishnu , Holla Alaka , Mohpal Aakash
Published: March 2019

The relative return to input-augmentation versus inefficiency-reduction strategies for improving education system performance is a key open question for education policy in low-income countries. Using a new nationally-representative panel dataset of schools across 1297 villages in India, this paper shows that the large investments over the past decade have led to substantial improvements in input-based measures of school quality, but only a modest reduction in inefficiency as measured by teacher absence. In the data, 23.6 percent of teachers were absent during unannounced visits with an associated fiscal cost of $1.5 billion/year. There are two robust correlations in the nationally-representative panel data that corroborate findings from smaller-scale experiments. First, reductions in student-teacher ratios are correlated with increased teacher absence. Second, increases in the frequency of school monitoring are strongly correlated with lower teacher absence. Simulations using these results suggest that investing in better governance by increasing the frequency of monitoring could be over ten times more cost effective at increasing teacher-student contact time (net of teacher absence) than hiring more teachers. Thus, at current margins, policies that decrease the inefficiency of public spending in India are likely to yield substantially higher returns than those that augment inputs.
Double for Nothing?
Authors: De Ree Joppe , Muralidharan Karthik , Pradhan Menno , Rogers Halsey
Published: March 2019

How does a large unconditional increase in salary affect the performance of incumbent employees in the public sector? This paper presents experimental evidence on this question in the context of a policy change in Indonesia that led to a permanent doubling of teachers’ base salaries. The analysis uses a large-scale, randomized experiment across a representative sample of Indonesian schools that accelerated this pay increase for teachers in treated schools. The findings show that the large pay increase significantly improved teachers’ satisfaction with their income, reduced the incidence of teachers holding outside jobs, and reduced self-reported financial stress. Nevertheless, after two and three years, the increase in pay led to no improvement in student learning outcomes. The effects are precisely estimated, making it possible to rule out even modest positive impacts on test scores. The results suggest that unconditional pay increases are unlikely to be an effective policy option for improving the effort and productivity of incumbent employees in public sector settings.
Can Free Provision Reduce Demand for Public Services?
Authors: Bold Tessa , Kimenyi Mwangi , Mwabu Germano , Sandefur Justin
Published: March 2019

In 2003 Kenya abolished user fees in all government primary schools. Analysis of household survey data shows this policy contributed to a shift in demand away from free schools, where net enrollment stagnated after 2003, toward fee-charging private schools, where both enrollment and fee levels grew rapidly after 2003. These shifts had mixed distributional consequences. Enrollment by poorer households increased, but segregation between socio-economic groups also increased. The shift in demand toward private schooling was driven by more affluent households who (i) paid higher ex ante fees and thus experienced a larger reduction in school funding, and (ii) appear to have exited public schools partially in reaction to increased enrollment by poorer children.
Moving Teachers to Malawi’s Remote Communities
Authors: Asim Salman , Chimombo Joseph , Chugunov Dmitry , Gera Ravinder
Published: March 2019

There are severe geographical disparities in pupil-teacher ratios (PTR) across Malawi, with most teachers concentrated near commercial centers and in rural schools with better amenities. Most of the variation in PTR is concentrated in small sub-district areas, suggesting a central role for micro-geographic factors in teacher distribution. Employing administrative data from several government sources, regression analysis reveals that school-level factors identified by teachers as desirable are closely associated with PTR, including access to roads, electricity, and water, and distance to the nearest trading center, suggesting a central role for teachers’ interests in PTR variation. Political economy network mapping reveals that teachers leverage informal networks and political patronage to resist placement in remote schools, while administrative officials are unable to stand up to these formal and informal pressures, in part because of a lack of reliable databases and objective criteria for the allocation of teachers. This study curates a systematic database of the physical placement of all teachers in Malawi and links it with data on school facilities and geo-spatial coordinates of commercial centers. The study develops a consistent and objective measure of school remoteness, which can be applied to develop policies to create rules for equitable deployments and targeting of incentives. Growing awareness of disparities in PTRs among district education officials is already showing promising improvements in targeting of new teachers. Simulation results of planned policy applications show significant potential impacts of fiscally-neutral approaches to targeted deployments of new cohorts, as well as retention of teachers through data-calibrated incentives.
School Resource and Performance Inequality
Authors: Yamauchi Futoshi , Parandekar Suhas
Published: March 2019

This paper examines inequality patterns of school and teacher resources as well as student performance in the Philippines. School and teacher resources, measured by pupil classroom and teacher ratios and per-pupil teacher salary, became more unequal over time. Strikingly, a large portion of the variation is attributed to their within division distributions, especially the non-city areas in each province (rural schools), where pupil classroom and teacher ratios have significantly positive returns in terms of student test scores. Concavity built into the education production function implies that reallocation of teachers and classrooms within a division can potentially increase average test scores. The estimates also imply that it is optimal to deploy young, inexperienced teachers to rural schools and reassign them to urban schools when the teachers are more experienced.
Observations of Highly Oxidised Molecules and Particle Nucleation in the Atmosphere of Beijing
Authors: Brean James , Harrison Roy M. , Shi Zongbo , Beddows David C. S. , Acton W. Joe F. , Hewitt C. Nicholas
Published: March 2019

Abstract. Particle nucleation is one of the main sources of atmospheric particulate matter by number, with new particles having great relevance for human health and climate. Highly oxidised multifunctional organic molecules (HOMs) have been recently identified as key constituents in the growth, and, sometimes, in initial formation of new particles. While there have been many studies of HOMs in atmospheric chambers, flow tubes and clean environments, analyses of data from polluted environments are scarce. Here, measurements of HOMs and particle size distributions down to small molecular clusters are presented alongside VOC and trace gas data from a campaign in Beijing. Many gas phase HOMs have been characterised and their temporal trends and behaviours analysed in the context of new particle formation. The HOMs identified have a comparable degree of oxidation to those seen in other, cleaner, environments, likely due to an interplay between the higher temperatures facilitating rapid hydrogen abstractions and the higher concentrations of NOx and other RO2. terminators ending the autoxidation sequence more rapidly. Our data indicate that alkylbenzenes, monoterpenes, and isoprene are important precursor VOCs for HOMs in Beijing. Many of the C5 and C10 compounds derived from isoprene and monoterpenes have a slightly greater degree of average oxidation state of carbon compared to those from other precursors. Most HOMs except for large dimers have daytime peak concentrations, indicating the importance of OH. chemistry in the formation of HOMs, as O3 is lower on the days with higher HOM concentrations; similarly, VOC concentrations are lower on the days with higher HOM concentrations. The daytime peaks of HOMs coincide with the growth of freshly formed new particles, and their initial formation coincides with the peak in sulphuric acid vapours, suggesting that the nucleation process is sulphuric acid-dependent, with HOMs contributing to subsequent particle growth.
Effects of grass leaf anatomy, development and light/dark alternation on the triple oxygen isotope signature of leaf water and phytoliths: insights for a new proxy of continental atmospheric humidity
Authors: Alexandre Anne , Webb Elizabeth , Landais Amaelle , Piel Clément , Devidal Sébastien , Sonzogni Corinne , Couapel Martine , Mazur Jean-Charles , Pierre Monique , Prié Frédéric , Vallet-Coulomb Christine , Roy Jacques
Published: March 2019

Abstract. Continental relative humidity (RH) is a key-climate parameter. However, there is a lack of quantitative RH proxies suitable for climate model-data comparisons. Recently, a combination of climate chamber and natural transect calibrations laid the groundwork for examining the robustness of the triple oxygen isotope composition (δ18O, δ17O) of phytoliths as a new proxy for past changes in RH. However, it was recommended that besides RH, additional factors that may impact δ18O and δ17O of plant water and phytoliths be examined. Here, the effects of leaf anatomy, leaf development stage and day/night alternations are addressed from the growth of the grass species F. arundinacea in climate chambers. Plant water and phytoliths are analyzed in δ18O and δ17O. Silicification patterns are examined using light and scanning electron observation of phytoliths. The isotope data show the increasing contribution of evaporated epidermal water to the bulk leaf water, from sheath to proximal and apical leaf blade. However, despite this isotope heterogeneity, δ18O and δ17O of the bulk leaf water can be predicted by the Craig and Gordon model, in the given experimental conditions (high RH). Regarding phytoliths, their forming water (mainly epidermal) is, as expected, more impacted by evaporation than the bulk leaf water. This discrepancy increases from sheath to proximal and apical blade and can be explained by the steepening of the radial concentration gradient of evaporated water along the leaf. However, we show that because most of silica polymerizes in epidermal long cells of the apical blade of the leaves, the δ18O and δ17O of bulk grass phytoliths should not be impacted by the diversity in grass anatomy. The data additionally show that most of silica polymerizes at the end of the leaf elongation stage and at the transition towards leaf senescence. Thus, climate conditions at that time should be considered when interpreting δ18O and δ17O of phytoliths from the natural environment. At least, no light/dark effect was detected on the δ18O and δ17O signature of plant water and phytoliths of F. arundinacea. However, when day/night alternations are characterized by significant changes in RH, the lowest RH conditions favoring evaporation and silica polymerization should be considered when calibrating the phytolith proxy. This study contributes to the identification of the parameters driving the δ18O and δ17O of bulk grass phytoliths. It additionally brings elements to further understand and model the δ18O and δ17O of grass leaf water, which influences the isotope signal of several processes at the soil/plant/atmosphere interface.
Insensitivity of alkenone carbon isotopes to atmospheric CO2 at low to moderate CO2 levels
Authors: Badger Marcus P. S. , Chalk Thomas B. , Foster Gavin L. , Bown Paul R. , Gibbs Samantha J. , Sexton Philip F. , Schmidt Daniela N. , Pälike Heiko , Mackensen Andreas , Pancost Richard D.
Published: March 2019

Abstract. Atmospheric pCO2 is a critical component of the global
carbon system and is considered to be the major control of Earth's past,
present, and future climate. Accurate and precise reconstructions of its
concentration through geological time are therefore crucial to our
understanding of the Earth system. Ice core records document pCO2 for
the past 800 kyr, but at no point during this interval were CO2 levels
higher than today. Interpretation of older pCO2 has been hampered by
discrepancies during some time intervals between two of the main ocean-based
proxy methods used to reconstruct pCO2: the carbon isotope fractionation
that occurs during photosynthesis as recorded by haptophyte biomarkers
(alkenones) and the boron isotope composition (δ11B) of
foraminifer shells. Here, we present alkenone and δ11B-based
pCO2 reconstructions generated from the same samples from the Pliocene
and across a Pleistocene glacial–interglacial cycle at Ocean Drilling Program (ODP) Site 999. We find
a muted response to pCO2 in the alkenone record compared to
contemporaneous ice core and δ11B records, suggesting caution
in the interpretation of alkenone-based records at low pCO2 levels. This
is possibly caused by the physiology of CO2 uptake in the haptophytes.
Our new understanding resolves some of the inconsistencies between the
proxies and highlights that caution may be required when interpreting
alkenone-based reconstructions of pCO2.
Global variability of belowground autotrophic respiration in terrestrial ecosystems
Authors: Tang Xiaolu , Fan Shaohui , Zhang Wenjie , Gao Sicong , Chen Guo , Shi Leilei
Published: March 2019

Abstract. Belowground autotrophic respiration (RA) is one of the largest, but highly uncertain carbon flux components in terrestrial ecosystems. It has not been explored globally before and still acted as a “black box” in global carbon cycling. Such progress and uncertainty motivate a development of global RA dataset and understand its spatial and temporal pattern, causes and responses to future climate change. This study used Random Forest to study RA's spatial and temporal pattern at the global scale by linking the updated field observations from Global Soil Respiration Database (v4) with global grid temperature, precipitation and other environmental variables. Globally, mean RA was 43.8 ± 0.4 Pg C a−1 with a temporally increasing trend of 0.025 ± 0.006 Pg C a−1 over 1980–2012. Such increment trend was widely spread with 58 % global land areas. For each 1 °C increase in annual mean temperature, global RA increased by 0.85 ± 0.13 Pg C a−1, and it was 0.17 ± 0.03 Pg C a−1 for 10 mm increase in annual mean precipitation, indicating a positive feedback of RA to future climate change. At a global scale, precipitation was the main dominant climatic drivers of the spatial pattern of RA, accounting for 56 % of global land areas with widely spread globally, particularly in dry or semi-arid areas, followed by shortwave radiation (25 %) and temperature (19 %). Different temporal patterns for varying climate zones and biomes indicated uneven response of RA to future climate change, challenging the perspective that the parameters of global carbon stimulation independent on climate zones and biomes. The developed RA database, the missing carbon flux component that is not constrained and validated in terrestrial ecosystem models and earth system models, will provide insights into understanding mechanisms underlying the spatial and temporal variability of belowground carbon dynamics. RA database also has great potentials to serve as a benchmark for future data-model comparisons. The RA product is freely available at https://doi.org/10.6084/m9.figshare.7636193.
Devito (v3.1.0): an embedded domain-specific language for finite differences and geophysical exploration
Authors: Louboutin Mathias , Lange Michael , Luporini Fabio , Kukreja Navjot , Witte Philipp A. , Herrmann Felix J. , Velesko Paulius , Gorman Gerard J.
Published: March 2019

Abstract. We introduce Devito, a new domain-specific
language for implementing high-performance finite-difference partial
differential equation solvers. The motivating application is exploration
seismology for which methods such as full-waveform inversion and reverse-time
migration are used to invert terabytes of seismic data to create images of
the Earth's subsurface. Even using modern supercomputers, it can take weeks
to process a single seismic survey and create a useful subsurface image. The
computational cost is dominated by the numerical solution of wave equations
and their corresponding adjoints. Therefore, a great deal of effort is
invested in aggressively optimizing the performance of these wave-equation
propagators for different computer architectures. Additionally, the actual
set of partial differential equations being solved and their numerical
discretization is under constant innovation as increasingly realistic
representations of the physics are developed, further ratcheting up the cost
of practical solvers. By embedding a domain-specific language within Python
and making heavy use of SymPy, a symbolic mathematics library, we make it
possible to develop finite-difference simulators quickly using a syntax that
strongly resembles the mathematics. The Devito compiler reads this code and
applies a wide range of analysis to generate highly optimized and parallel
code. This approach can reduce the development time of a verified and
optimized solver from months to days.
The biophysics, ecology, and biogeochemistry of functionally diverse, vertically- and horizontally-heterogeneous ecosystems: the Ecosystem Demography Model, version 2.2 — Part 1: Model description
Authors: Longo Marcos , Knox Ryan G. , Medvigy David M. , Levine Naomi M. , Dietze Michael C. , Kim Yeonjoo , Swann Abigail L. S. , Zhang Ke , Rollinson Christine R. , Bras Rafael L. , Wofsy Steven C. , Moorcroft Paul R.
Published: March 2019

Abstract. Earth System Models (ESMs) have been developed to represent the role of terrestrial ecosystems on the energy, water, and carbon cycles. However, many ESMs still lack representation of within-ecosystem heterogeneity and diversity. In this manuscript, we present the Ecosystem Demography Model version 2.2 (ED-2.2). In ED-2.2, the biophysical and physiological cycles account for the horizontal and vertical heterogeneity of the ecosystem: the energy, water, and carbon cycles are solved separately for each group of individual trees of similar size and functional group (cohorts) living in a micro-environment with similar disturbance history (patches). We define the equations that describe the energy, water, and carbon cycles in terms of total energy, water, and carbon, which simplifies the ordinary differential equations and guarantees excellent conservation of these quantities in long-term simulation ( < 0.1 % error over 50 years). We also show examples of ED-2.2 simulation results at single sites and across tropical South America. These results demonstrate the model's ability to characterize the variability of ecosystem structure, composition and functioning both at stand- and continental-scales. In addition, a detailed model evaluation was carried out and presented in a companion paper. Finally, we highlight some of the ongoing developments in ED-2.2 that aim at reducing the uncertainties identified in this study and the inclusion of processes hitherto not represented in the model.
Using GRACE to derive corrections to precipitation data sets and improve modelled snow mass at high latitudes
Authors: Robinson Emma L. , Clark Douglas B.
Published: March 2019

Abstract. The amount of lying snow calculated by a land surface model depends in part on the amount of snowfall in the meteorological data that are used to drive the model. We show that commonly-used data sets differ in the amount of snowfall, and more generally precipitation, over four large Arctic basins. An independent estimate of the cold season precipitation is obtained by combining water balance information from the Gravity Recovery and Climate Experiment (GRACE) with estimates of evaporation and river discharge, and is generally higher than that estimated by four commonly-used meteorological data sets. We use the Joint UK Land Environment Simulator (JULES) land surface model to calculate the snow water equivalent (SWE) over the four basins. The modelled seasonal maximum SWE is 38 % less than observation-based estimates on average and the modelled basin discharge is significantly underestimated, consistent with the lack of snowfall. We use the GRACE-derived estimate of precipitation to define per-basin scale factors that are applied to the driving data and increase the amount of cold season precipitation by 28 % on average. In turn this increases the modelled seasonal maximum SWE by 30 %, although this is still underestimated compared to observations by 19 % on average. A correction for undercatch of precipitation by gauges is compared with the the GRACE-derived correction. Undercatch correction increases the amount of cold season precipitation by 23 % on average, which indicates that some, but not all, of the underestimation can be removed by implementing existing undercatch correction algorithms. However, even undercatch-corrected data sets contain less precipitation than the GRACE-derived estimate in some regions, and it is likely that there are other biases that that are not currently accounted for in gridded meteorological data sets. This study shows that revised estimates of precipitation can lead to improved modelling of SWE, but much more modest improvements are found in modelled river discharge. By providing methods to better define the precipitation inputs to the system, the current study paves the way for subsequent work on key hydrological processes in high-latitude basins.