bluuebunny/crossref_metadata_2025 huggingface dataset:
Broad Infiltration of Macrophages Leads to a Proinflammatory State in Streptozotocin-Induced Hyperglycemic Mice
Authors: Niu Shuo , Bian Zhen , Tremblay Alexandra , Luo Youqun , Kidder Koby , Mansour Ahmed , Zen Ke , Liu Yuan
Published: September 2016

Chronic diseases are often associated with altered inflammatory response, leading to increased host vulnerability to new inflammatory challenges. Employing streptozotocin (STZ)-induced diabetes as a model, we further investigate mechanisms leading to enhanced neutrophil (polymorphonuclear leukocytes [PMN]) responses under hyperglycemia and compare them with those under chronic colitis. We show that, different from colitis under which the PMN response is significantly potentiated, the existence of a proinflammatory state associated with broad increases in macrophages in various organs plays a dominant role in promoting the PMN inflammatory response in diabetic mice. Studies of PMN infiltration during zymosan-induced peritonitis reveal that hyperglycemia enhances PMN recruitment not through inducing a high level of IL-17, which is the case in colitis, but through increasing F4/80+ macrophages in the peritoneal cavity, resulting in elevations of IL-6, IL-1β, TNF-α, and CXCL1 production. Insulin reversal of hyperglycemia, but not the neutralization of IL-17, reduces peritoneal macrophage numbers and ameliorates PMN infiltration during peritonitis. Significantly increased macrophages are also observed in the liver, kidneys, and intestines under hyperglycemia, and they are attributable to exacerbated nephropathy and colitis when inflammatory conditions are induced by doxorubicin and dextran sulfate sodium, respectively. Furthermore, analyses of monocyte production and macrophage proliferation in tissues suggest that significant monocytosis of inflammatory F4/80+Gr-1+ monocytes from the spleen and macrophage proliferation in situ synergistically contribute to the increased macrophage population under hyperglycemia. In conclusion, our results demonstrate that STZ-induced hyperglycemic mice develop a systemic proinflammatory state mediated by broad infiltration of macrophages.
Context-Specific Function of S6K2 in Th Cell Differentiation
Authors: Pai Christine , Walsh Craig M. , Fruman David A.
Published: September 2016

The mammalian target of rapamycin (mTOR) is essential for Th cell proliferation and effector differentiation, making the mTOR signaling network an attractive immunomodulatory target for autoimmune-related diseases. Although direct targeting of mTOR complex-1 (mTORC1) with rapamycin can provide clinical benefit, targeting downstream enzymes has the potential to offer more selective immunosuppression. In this study, we evaluated p70 ribosomal protein S6 Kinase 2 (S6K2), a downstream effector of mTORC1, for its role in T cell function and autoimmunity. S6K2 is a direct substrate of mTORC1, with a potential role in Th17 differentiation suggested by biochemical studies. Using a genetic approach with S6K2 knockout mice, we found that S6K2 loss reduces Th17 skewing and increases regulatory T cell differentiation in vitro when cultured in RPMI 1640 media. However, S6K2 was dispensable for Th17 differentiation in IMDM. In an in vivo experimental autoimmune encephalomyelitis model in which rapamycin suppresses disease, S6K2 knockout mice did not exhibit differences in clinical score or Th17 differentiation. These results suggest that S6K2 is dispensable for Th17-driven autoimmunity and highlight how distinct experimental conditions can produce significantly different results in T cell differentiation.
Progranulin Controls Sepsis via C/EBPα-RegulatedIl10Transcription and Ubiquitin Ligase/Proteasome-Mediated Protein Degradation
Authors: Yan Wenjun , Ding Aihao , Kim Ha-Jeong , Zheng Hua , Wei Fang , Ma Xiaojing
Published: September 2016

Progranulin (PGRN) is a widely expressed, pleiotropic protein that is involved in diverse biological processes, including cellular proliferation, neuron development, and wound healing. However, the role of PGRN in the regulation of pathogen-induced systemic inflammation and the mechanisms involved have not been established. In this study, we show that PGRN-deficient mice display heightened mortality in models of polymicrobial sepsis and endotoxinemia, with increased tissue levels of inflammatory cytokines and reduced IL-10 production. Conversely, administration of rPGRN decreases the susceptibility of PGRN-deficient mice to LPS-induced endotoxemic shock and augments IL-10 production by LPS-activated macrophages in a TNFR-dependent manner. Molecular analysis reveals a direct role of the transcription factor C/EBPα in PGRN-regulated IL-10 expression. C/EBPα-deficient macrophages produce less IL-10 in response to LPS. Furthermore, mice deficient in C/EBPα in hematopoietic cells are highly vulnerable to LPS-induced septic shock. Lastly, the defective IL-10 production by PGRN-deficient cells is primarily due to reduced C/EBPα protein stability via the E3 ubiquitin–conjugating enzyme E6AP and proteasome-mediated degradation. To our knowledge, this study provides the first evidence that PGRN is a nonredundant regulator of systemic inflammation via modulating the levels and activity of C/EBPα, IL-10, and the ubiquitin–proteasome proteolysis pathway. The results bear strong and profound implications for PGRN insufficiency and its mutation-associated systemic and organ-specific inflammatory human diseases.
SAJCE begins its journey
Authors: Henning Elizabeth
Published: September 2016

No abstract available.
“Mama does not speak that (language) to me”: indigenous languages, educa-tional opportunity and black African preschoolers
Authors: Msila Vuyisile
Published: September 2016

This study explored the experiences of young black African preschoolers as well as their parents’ perceptions towards their mother tongue. It investigated the factors that influence black African parents to prefer English over their indigenous language. The paper also explores how aspects such as cultural and social capital affect parental choice of schools. This was a qualitative study conducted in the Eastern Cape, Port Elizabeth. Four daycare centres were purposefully selected for data collection where 30 parents and 80 preschoolers became part of the sample. Two of these daycare centres are situated in a historically black area (township), and the other two are historically white daycare centres situated in the centre of the city.The study’s findings show that there is much sociocultural influence on language acquisition and cognition. Parental choice of schools and how they socialise their children determine the kind of education their children have and this includes medium of instruction. The children preferred English to IsiXhosa and parental goals of education supported this as they fostered the English language. Yet one of the aspects captured by the article is how aspects such as cultural capital affect parental choice of the indigent parents. Learning a second language might not be simply seen as a pedagogic issue; it can also be perceived as a political issue, and children from a young age become passive participants in a political process.
The unavoidable need for distributed cognition in teaching literacy
Authors: Snow Catherine Elizabeth
Published: September 2016

Certain tasks are more likely to be solved by groups than by individuals, even when the individuals are highly skilled at aspects of the task. These are tasks such as filling out income tax forms or performing surgical operations, for which inputs from several individuals who have complementary domains of knowledge and skill are needed. I refer to such tasks as those that require ‘distributed cognition’, and argue that teachingchildren to read is a prime example of such a task. Teaching children to read requires distributed cognition because so much knowledge about language, about pedagogy, about child development, and about literacy development is needed to do it well. Expecting that individuals acquire all that knowledge in a relatively brief pre-service teacher education programme is unrealistic. I suggest that a model in which teachers work in teams, or in which novice teachers can call on experts for advice, would serve both students and teachers better. Such a model presupposes a career trajectory for teachers, in which greater experience and knowledge generates greater responsibility and higher status. We need to replace the apprenticeship of personal experience with professional learning communities that can nurture the development of every novice teacher. Teaching literacy also requires unlearning a long list of commonsense beliefs that are incorrect and that can disrupt optimal teaching. I suggest that, while stereotypes and group-based expectations are very difficult to eliminate, behavioursbased on those beliefs can be changed – and are more likely to be modified if work is undertaken collaboratively. Finally, distributed cognition is needed to compensate for the many difficult conditions under which teaching goes on. Overlarge classes, inadequate materials, poorly designed curricula, unsupportive school leaders, and many other challenges are faced regularly by teachers. Teachers should not be inthe position of facing these challenges alone. In this article, I sketch out the kinds of knowledge that are required in teaching literacy, the kinds of widespread and common sense beliefs that need to be overcome in order t
Levels of well-being and involvement of young children in centre-based provision in
Authors: Declercq Bart
Published: September 2016

This article reports on a study that examined the levels of young children’s wellbeing and involvement in centre-based provision (birth to five years) at child, group and setting level1 in Free State, South Africa. The study was funded by the FlemishDepartment of Education and was executed in collaboration with the Free State Department of Education and the University of Free State. Nineteen settings were included in the study. The average setting was registered for 121 children (with ratio’svarying from 30 to 326 children registered). Foundation Phase students from the 2nd and 3rd year of study at the University of Free State collected data through observation tools designed by the Centre for Experiential Education at Leuven University, Belgium. The core instrument uses the Leuven scales for well-being and involvement. Results of the study indicate that overall scores for well-being and involvement are low, but also that there are huge differences between different groups and settings. Thus, indicating that early childhood education in centre-based provision makes a difference.
Philosophy for children in South African schools: its role for citizens-in-waiting
Authors: Mathebula Thokozani
Published: September 2016

Historically, the concept ‘child’ has a Lockean (1960)connotation, as empty slates new born infants, are considered weak and helpless, until the improvement of growth and age has removed this deficient state of childhood. In modern societies, including South Africa, children are still viewed as citizens-in-waiting, and as citizens who need to be inducted into their future role. This deficit model of childhood is reflected in the construction of democratic citizenship education in post-apartheid South Africa. In this article we present a theoretical justification for Philosophy for Children (P4C) as an avenue to individual enlightenment i.e., education that entails the development of a child’s mind, of rationality or the capacity to think. In the light of a Philosophy for Children agenda as an educational pedagogy, we argue that doing philosophy with children starting from an early age has a special significance in education for democratic citizenship in post-apartheid South Africa.
How Grade R pupils make sense of the ‘scientist’ and ‘science’
Authors: Ramnarain Umesh Dewnarain
Published: September 2016

In this article we report on the ‘sense-making’ by children of a ‘scientist’ and ‘science’. We investigated these conceptions through drawings by using the Draw-a-Scientist Test (DAST) developed by Chambers. We conducted the research in two urban schools; a public school located in a low-income previously designated black (African) suburb, and a private school in an affluent suburb. In theorising on the sense makingof a ‘scientist’ and ‘science’ by children from these diverse learning contexts, we examined the notion of ‘semiotic mediation’, which is a central idea in Vygotsky’s work. The results of the study show that children in the previously designated black school have little or no conception of science or a scientist. The significance of these findings needs to be considered against the inequities in education, and in particular in science education in this country due to the apartheid system. Despite Grade R being the first year in the twelve-school career of children we believe that the findings of this study do signal that concerted steps need to be taken so that children developstronger conceptions of science and a scientist.
Linguistic liminality in the early years of school: Urban South African children ‘betwixt and between’1 languages of learning
Authors: Henning Elizabeth
Published: September 2016

This article is about an investigation into the English spoken language competence of 144 first graders in two urban (‘township’) schools in the Gauteng Province of South Africa. The study was conducted from an anthropological and a cognitive developmental perspective. In one school isiZulu and Sesotho are used mainly as medium of instruction, while in the other school the language of teaching and learning is English. The inquiry is part of longitudinal panel research in which children’s overall development and school progress over four years is documented by way of growth modelling. This initial assessment of the children’s basic interpersonal communication skills in English found, not unexpectedly, that the children in the first mentioned school know English mostly to the extent of the naming of objects, while the children in the other school are able to use morpho-syntactically more complex language. These findings may shed some light on the phenomenon of school culture liminality in its interplay with linguistic liminality, considering that children’s basic English may scaffold their academic English.
Test items and translation: capturing early conceptual development in mathematics reliably?
Authors: Dampier Graham , Mawila Daphney
Published: September 2016

Translating items of educational tests from one language to another is problematic. Arriving at accurate translations of concepts formulated in a language that is grammatically and syntactically incommensurable with a target language is a concern that probably won’t find resolution. And the very act of translation can obscure the accuracy of test items. Item Response Theory holds that only the ability of people tested and the difficulty of items should have an effect on the dataset. We report on an instance where a test was translated from German to English and then into isiZulu and Sesotho. We tested 106 pupils from similar socio economic backgrounds and schools. Our aim is to determine whether the translation had any effect on the accuracy of the instrument, which has been normed and standardised in Germany with a sample of 0ver 1000 grade 1 pupils.
Exploring the Role of the Speech-language Therapist in City Centre Preschools
Authors: Du Plessis Sandra
Published: September 2016

This study investigates the perception of the strengths and challenges that face city centre preschool teachers and preschool learners in the acquisition of English as medium of instruction and to use the results to explore the role of speech-language therapists in this context. A descriptive survey, incorporating a quantitative data collection method, was selected as the research design and a questionnaire was developed as a survey instrument. The findings identified the strengths as including the creative communication strategies employed by the pre-schoolers and the innovative techniques of the teachers. Perceived challenges include a cultural and linguistic mismatch between teachers and learners and communication barriers that cause emotional and behavioural problems in classrooms. The study suggests that speech-language therapists need to consider and employ service delivery models instead of traditional models with the preschool teachers.
Editorial:Toward More South African Research on Learning in Childhood
Authors: Henning Elizabeth
Published: September 2016

No abstract available.
Making sense of experience in preschool: Children’s encounters with numeracy and literacy through inquiry
Authors: Henningsen Marjorie Ann
Published: September 2016

Opening up space for authentic inquiry in preschool can influence the extent to which children can make use of their growing mathematical and linguistic understandings to make sense of themselves and the world around them. Authentic inquiry here refers to investigation that arises naturally from the interests and questions of the children as they experience the learning environment. Three authentic examples are presented from the work of four- to five-year-old children in the domains of mathematics and literacy development to illustrate how the two domains need to be viewed as intertwined at the preschool level. Reflections are also offered on the role of the learning environment, the role of curriculum and the role of teachers and other adults in the learning process. This manuscript is based on a plenary address given in Grahamstown, South Africa at the SARAECE Research and Development week: “Strengthening Foundation Phase Education” conference at Rhodes University in September 2012.
Improving some cognitive functions, specifically executive functions in grade R learners
Authors: Esterhuizen Stef
Published: September 2016

This study established the effects of a researcher-developed curriculum-based intervention programme. The intervention was grounded on principles of Feuerstein’s ideas about ‘mediated learning’. The aim of the intervention was specifically to address children’s executive functions, which are generally regarded as prerequisites for cognitive development. We studies a selected group of South African grade R learners (n = 20). A quasi-experimental design was employed to collect quantitative data on rotational
basis from experimental groups A and B, by means of dynamic assessment with the Children’s Inferential Thinking Modifiability (CITM) test during pretest, post-test and
delayed post-test occasions. The test data was intended to elicit the extent to which the intervention that had focused on enhancing executive functions had contributed to the participants’ application of cognitive and metacognitive skills and strategies. Qualitative data captured participants’ application of cognitive processes in the input, elaboration,
and output phases of the designed learning process, as well as the characteristics of their inhibitory control functions. A striking finding was the improvement noted in the children’s application of the following executive functions, namely working memory, cognitive flexibility and inhibitory control.
Masekitlana re-membered: A performance-based ethnography of South African black children’s pretend play
Authors: Phetlhu Esther Ofenste
Published: September 2016

The extensive empirical research inspired by Piaget and Vygotsky’s theories of make-believe play has been criticised for restricting data to western, urban, middle-class children. We seek to redress this bias by researching a traditional black South African Pedi children’s game Masekitlana. Our data relies on embodied memories enacted by Mapelo (one of the authors), and interviews of two other informants. The analytical framework draws upon ‘emergent methods’ in ethnography such as performance ethnography, autoethnography and memory elicitation through ‘bodynotes’ within a Vygotskyian orientation to play. The findings show that Masekitlana shares features common to all pretend play, but others unique to it  including: i) extended monologue, ii) metacommunicative frames for realistic thinking, and iii) a complex relation between social and solitary play. These findings support Vygotsky. However, ‘the long childhood’ of Masekitlana suggests that the stages theory of Piaget, as well as  Vygotskyian ideas that have come down to us via Cole & Scribner and Valsiner, require revision in the light of Bruner’s two modes of cognition, and Veresov’s reinterpretation of the theatre movement, within which Vygotsky’s central ideas are embedded.
Biography, policy and language teaching practices in a multilingual context: Early childhood classrooms in Mauritius
Authors: Ankiah-Gangadeen Aruna , Samuel Michael Anthony
Published: September 2016

Language policies in education in multilingual postcolonial contexts are often driven by ideological considerations more veered towards socio-economic and political viability for the country than towards the practicality at implementation level. Centuries after the advent of colonisation, when culturally and linguistically homogenous countries helped to maintain the dominion of colonisers, the English language still has a stronghold in numerous countries due to the material rewards it offers. How then are the diversity of languages – often with different statuses and functions in society – reconciled in the teaching and learning process? How do teachers deal with the intricacies that are generated within a situation where children are taught in a language that is foreign to them? This paper is based on a study involving pre-primary teachers in Mauritius, a developing multilingual African country. The aim was to understand how their approach to the teaching of English was shaped by their biographical experiences of learning the language. The narrative inquiry methodology offered rich possibilities to foray into these experiences, including the manifestations of negotiating their classroom pedagogy in relation to their own personal historical biographies of language teaching and learning, the policy environment, and the pragmatic classroom specificities of diverse, multilingual learners. These insights become resources for early childhood education and teacher development in multilingual contexts caught within the tensions between language policy and pedagogy.
South African teachers’ use of national assessment data
Authors: Kanjee Anil , Moloi Qetelo
Published: September 2016

This paper reports on the perceptions and experiences of primary school teachers of the challenges they faced and the prospects of using data from the Annual National Assessments (ANAs). While the majority stated that information from the ANAs can assist teachers to improve learning, responses on the use of the ANAs in the classroom were mixed, with most reporting that teachers did not know how to use ANA results to improve learning, and that no plans were in place at their schools for the use of ANA data. A significant proportion also indicated that they received little or no support from the school district on how to use ANA results. These findings were consistent across the school quintiles as well as the foundation and intermediate phases. Given the potential value of the ANAs, the paper highlights two initiatives aimed at enhancing the meaningful use of ANA results to improve learning and teaching in schools.
Approaches to teaching primary level mathematics
Authors: Long Caroline , Dunne Tim
Published: September 2016

In this article we explore approaches to curriculum in the primary school in order to map and manage the omissions implicit in the current unfolding of the Curriculum and Assessment Policy Statement for mathematics. The focus of school-based research has been on curriculum coverage and cognitive depth. To address the challenges of teaching mathematics from the perspective of the learner, we ask whether the learners engage with the subject in such a way that they build foundations for more advanced mathematics. We firstly discuss three approaches that inform the teaching of mathematics in the primary school and which may be taken singly or in conjunction into organising the curriculum: the topics approach, the process approach, and the conceptual fields approach. Each of the approaches is described and evaluated by presenting both their advantages and disadvantages. We then expand on the conceptual fields approach by means of an illustrative example. The planning of an instructional design integrates both a topics and a process approach into a conceptual fields approach. To address conceptual depth within this approach, we draw on five dimensions required for understanding a mathematical concept. In conclusion, we reflect on an approach to curriculum development that draws on the integrated theory of conceptual fields to support teachers and learners in the quest for improved teaching and learning.
Learning support pedagogy for children who struggle to develop the concepts underlying the operations of addition and subtraction of numbers: the ‘Calculia’ programme
Authors: Fritz-Stratmann Annemarie , Ehlert Antje , Klüsener Gabriele
Published: September 2016

This paper argues for teaching pre-service teachers about remediation strategies for learners who encounter problems in mathematics in the early grades. The premise is that all teachers should be equipped with theory-based practical knowledge to support learning. A few teaching sessions to develop the concepts that underlie the mathematical operations of addition and subtraction are introduced in this paper. An empirically validated, comprehensive model of cumulative arithmetic competence development from the ages of four to eight years forms the basis for the construction of the suggested teaching unit. The model distinguishes five competence levels of arithmetical conceptual development, and proposes that concepts build on one another hierarchically. A ‘part plus part is equivalent to whole’ model was constructed based on this hierarchical structure and the understanding that the concept of addition is a dynamic process. The teaching examples include exercises for all children, not only ones who struggle. Possibilities for adapting the exercises to the individual development level of slower or faster learners are also included. All exercises are accompanied by a reflection on the procedure and strategies applied in order to support meaningful and sustainable learning and to give student teachers the opportunity to use knowledge of mathematical cognition theory during their pre-service years.
The status and the power of a foundation phase teacher
Authors: Petersen Nadine , Gravett Sarah
Published: September 2016

No abstract available.
The South African national school curriculum: Implications for collaboration between teachers and speech-language therapists working in schools
Authors: Wium Anna-Marie , Louw Brenda
Published: September 2016

This critical review addresses the implications of the Curriculum and Assessment Plan Statement (CAPS) for collaboration between teachers and speech-language therapists (SLTs) in schools. A historical perspective on changes in the roles and responsibilities of SLTs is provided, reflecting a shift from supporting the child to supporting the teacher. Based on the role of SLTs and audiologists in schools, an innovative approach to the support of teachers is conceptualized. The curriculum content and methods support learners who experience challenges and barriers to learning in main stream classrooms. The implementation of the curriculum necessitates close collaboration between teachers and SLTs in order to ensure the best possible outcomes for all learners. This collaboration is reviewed by identifying the benefits of, and barriers to, the process, as well as crucial areas of collaboration. Inclusive education is mandated by White Paper 6, and collaborative support of teachers by SLTs is presented from the learners’ perspective within the context of the curriculum. An example of teacher support through the response to intervention (RTI) approach is described.
Visual arts and the teaching of the mathematical concepts of shape and space in Grade R classrooms
Authors: Wilmot Dianne , Schäfer Jean
Published: September 2016

This article addresses the need for research in the areas of Grade R curriculum and pedagogy, Grade R teacher professional development, and early years mathematics teaching. More specifically, it responds to the need for teacher professional development in Grade R mathematics teaching of the geometric concepts of space and shape. The article describes a study about teachers’ understanding of how visual arts can be used as pedagogical modality. The study was prompted by the findings of a ‘Maths and Science through Arts and Culture Curriculum’ intervention undertaken with Grade R teachers enrolled for a Bachelor of Education (Foundation Phase) degree at a South African university. Post-intervention, teachers’ classroom practices did not change, and they were not using visual arts to teach mathematical concepts. The lessons learned from the research intervention may contribute to the wider debate about Grade R teaching and children’s learning.
Fostering pre-service teachers’ motivation-related practical wisdom through a mentoring procedure
Authors: Loukomies Anni , Lavonen Jari , Juuti Kalle
Published: September 2016

This article introduces a procedure aimed at fostering pre-service teachers’ reflective thinking and practical wisdom and encouraging them to adopt a theory-based view of promoting learners’ motivation while taking into account learners’ different motivational profiles. The procedure is based on a study about the promotion of science-related motivation among students with different motivational orientations by employing an inquiry-based science teaching approach and out-of-school learning, as well as supporting learners’ basic psychological needs, in order to provide relevant and meaningful conditions for learning. The procedure for pre-service teacher education encompasses lessons intended to familiarize student teachers with theoretical perspectives, authentic case studies of learners with different motivational orientations, support for lesson planning, and reflection on the implemented plans. The described procedure may be used in teacher education during mentoring sessions in practicum periods.
Continuous assessment and matriculation examination marks – An empirical examination
Authors: Van der Berg Servaas , Shepherd Debra
Published: September 2016

This study analyses information and feedback from matriculation level continuous assessment in the South African education system. Continuous assessment (CASS) at the time carried a 25% weight in the final matriculation (Grade 12) mark, and it provides feedback that affects examination preparation and effort. Weak assessment in schools sends wrong signals to students that may have important consequences for the way they approach the final examination. Moreover, similarly wrong signals earlier in their school careers may also have affected their subject choice and career planning.
This study compares CASS data to the externally assessed matric exam marks for a number of subjects. There are two signalling dimensions to inaccurate assessments: (i) Inflated CASS marks can give students a false sense of security and lead to diminished exam effort. (ii) A weak correlation between CASS and the exam marks could mean poor signalling in another dimension: Relatively good students may get relatively low CASS marks. Such low correlations indicate poor assessment reliability, as the examination and continuous assessment should both be testing mastery of the same national curriculum. The paper analyses the extent of each of these dimensions of weak signalling in South African schools and draws disturbing conclusions for a large part of the school system.
Informing principal policy reforms in South Africa through data-based evidence
Authors: Wills Gabrielle
Published: September 2016

In the past decade there has been a notable shift in South African education policy that raises the value of school leadership as a lever for learning improvements. Despite a growing discourse on school leadership, there has been a lack of empirical based evidence on principals to inform, validate or debate the efficacy of proposed policies in raising the calibre of school principals. Drawing on findings from a larger study to understand the labour market for school principals in South Africa, this paper highlights four overarching characteristics of this market with implications for informing principal policy reforms. The paper notes that improving the design and implementation of policies guiding the appointment process for principals is a matter of urgency. A substantial and increasing number of principal replacements are taking place across South African schools given a rising age profile of school principals. In a context of low levels of principal mobility and high tenure, the leadership trajectory of the average school is established for nearly a decade with each principal replacement. Evidence-based policy making has a strong role to play in getting this right.
Teacher characteristics and student performance: An analysis using hierarchical linear modelling
Authors: Armstrong Paula
Published: September 2016

This research makes use of hierarchical linear modelling to investigate which teacher characteristics are significantly associated with student performance. Using data from the SACMEQ III study of 2007, an interesting and potentially important finding is that younger teachers are better able to improve the mean mathematics performance of their students. Furthermore, younger teachers themselves perform better on subject tests than do their older counterparts. Identical models are run for Sub Saharan countries bordering on South Africa, as well for Kenya and the strong relationship between teacher age and student performance is not observed. Similarly, the model is run for South Africa using data from SACMEQ II (conducted in 2002) and the relationship between teacher age and student performance is also not observed. It must be noted that South African teachers were not tested in SACMEQ II so it was not possible to observe differences in subject knowledge amongst teachers in different cohorts and it was not possible to control for teachers’ level of subject knowledge when observing the relationship between teacher age and student performance. Changes in teacher education in the late 1990s and early 2000s may explain the differences in the performance of younger teachers relative to their older counterparts observed in the later dataset.
Bloodstream infections in febrile neutropenic patients at a tertiary cancer institute in South India: A timeline of clinical and microbial trends through the years
Authors: Babu K Govind , Lokanatha D , Lakshmaiah K C , Suresh Babu M C , Jacob Linu A , Bhat Gita R , Vardhana Harsha , Sinha Mahua , Vijaykumar B R , Sumati B G , Jayshree R S
Published: September 2016

Introduction: Febrile neutropenia (FN) is an oncological emergency. The choice of empiric therapy depends on the locally prevalent pathogens and their sensitivities, the sites of infection, and cost. The Infectious Diseases Society of America guidelines are being followed for the management of FN in India. Methods: This is a prospective observational study conducted at a tertiary care cancer centre from September 2012 to September 2014. Objectives: The objectives of this study were as follows: (1) To review the pattern of microbial flora, susceptibility pattern, and important clinical variables among bloodstream infections in febrile neutropenic patients with solid tumors and hematological malignancies. (2) As per the institutional protocol to periodically review the antibiotic policy and susceptibility pattern, and compare the findings with an earlier study done in our institute in 2010. This was a prospective study conducted from September 2012 to September 2014. Results: About 379 episodes of FN were documented among 300 patients. About 887 blood cultures were drawn. Of these, 137 (15%) isolates were cultured. Isolates having identical antibiograms obtained from a single patient during the same hospitalization were considered as one. Hence, 128 isolates were analyzed. About 74 (58%) cultures yielded Gram-negative bacilli, 51 (40%) were positive for Gram-positive cocci, and 3 (2%) grew fungi. Among Gram-negative organisms, Escherichia coli followed by Acinetobacter baumannii and Klebsiella pneumoniae accounted for 78% of the isolates. Among Gram-positive cocci, Staphylococcus species accounted for 84% of the isolates. We have noted a changing trend in the antibiotic sensitivity pattern over the years. Following the switch in empirical antibiotics, based on the results of the study done in 2010 (when the empirical antibiotics were ceftazidime + amikacin), the sensitivity to cefoperazone-sulbactam has plunged from about 80% to 60%%. Similar reduction in susceptibility was noted for piperacillin-tazobactam, imipenem, and meropenem. On the contrary, there was a marked increase in sensitivity to ceftazidime (50–76%). Based on these results, we have reverted to ceftazidime + amikacin as the empirical antibiotics. Conclusion: Every institute must have a regular revision of antibiotic policy based on periodic assessment of the clinical and microbiological profile in FN. This will combat antibiotic resistance.
PET/CT in paediatric malignancies - An update
Authors: Padma Subramanyam , Sundaram Palaniswamy Shanmuga , Tewari Anshu
Published: September 2016

18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established imaging modality in adult oncological practice. Its role in childhood malignancies needs to be discussed as paediatric malignancies differ from adults in tumor subtypes and they have different tumor biology and FDG uptake patterns. This is also compounded by smaller body mass, dosimetric restrictions, and physiological factors that can affect the FDG uptake. It calls for careful planning of the PET study, preparing the child, the parents, and expertise of nuclear physicians in reporting pediatric positron emission tomography/computed tomography (PET/CT) studies. In a broad perspective, FDG-PET/CT has been used in staging, assessment of therapy response, identifying metastases and as a follow-up tool in a wide variety of pediatric malignancies. This review outlines the role of PET/CT in childhood malignancies other than hematological malignancies such as lymphoma and leukemia.
Prevalence of metabolic disorders and effect on subsequent daily milk quantity and quality in Holstein cows
Authors: Gantner Vesna , Bobić Tina , Potočnik Klemen
Published: September 2016

Abstract. Aiming at the determination of the metabolic disorder prevalence as well as the effect of subclinical disorders on daily milk traits of Holsteins, over 1 million (1 962 831) test day records were analysed. The metabolic disorder (ketosis or acidosis) prevalence was indicated by the fat-to-protein (F ∕ P) ratio, while subclinical disorder was indicated by the F ∕ P ratio and cows' daily production. The effect of subclinical disorders on daily milk traits was tested by Scheffe's method (SAS/STAT). The highest ketosis prevalence occurred in early lactation. In first-parity cows ketosis prevalence was highest in the first 15 days of lactation, while in cows in higher lactations, the prevalence peak occurred on the 25th day. A higher ketosis prevalence during the entire lactation was observed in multiparous cows compared to first-parity cows. Regarding the acidosis prevalence, high values were determined at the beginning of the lactation with a decreasing trend until mid-lactation, when the prevalence increased up to 22 %. The highest decrease in daily milk yield as a consequence of subclinical ketosis was determined as 4.21 and 3.72 kg day−1 in first-parity cows and those with more than four lactations, respectively. A significant negative effect of subclinical acidosis on daily milk yield (2.79 kg day−1) was highest in cows in the third lactation. A production decline in subsequent milk controls due to subclinical ketosis or acidosis in all cows was also determined. Subclinical disorders also significantly alter daily milk quality. This indicates that the test day records could be used as a cost-effective and non-invasive method for monitoring herd health.
Surface–atmosphere exchange of ammonia over peatland using QCL-based eddy-covariance measurements and inferential modeling
Authors: Zöll Undine , Brümmer Christian , Schrader Frederik , Ammann Christof , Ibrom Andreas , Flechard Christophe R. , Nelson David D. , Zahniser Mark , Kutsch Werner L.
Published: September 2016

Abstract. Recent advances in laser spectrometry offer new opportunities to investigate ecosystem–atmosphere exchange of environmentally relevant trace gases. In this study, we demonstrate the applicability of a quantum cascade laser (QCL) absorption spectrometer to continuously measure ammonia concentrations at high time resolution and thus to quantify the net exchange between a seminatural peatland ecosystem and the atmosphere based on the eddy-covariance approach. Changing diurnal patterns of both ammonia concentration and fluxes were found during different periods of the campaign. We observed a clear tipping point in early spring with decreasing ammonia deposition velocities and increasingly bidirectional fluxes that occurred after the switch from dormant vegetation to CO2 uptake but was triggered by a significant weather change. While several biophysical parameters such as temperature, radiation, and surface wetness were identified to partially regulate ammonia exchange at the site, the seasonal concentration pattern was clearly dominated by agricultural practices in the surrounding area. Comparing the results of a compensation point model with our measurement-based flux estimates showed considerable differences in some periods of the campaign due to overestimation of non-stomatal resistances caused by low acid ratios. The total cumulative campaign exchange of ammonia after 9 weeks, however, differed only in a 6 % deviation with 911 and 857 g NH3-N ha−1 deposition being found by measurements and modeling, respectively. Extrapolating our findings to an entire year, ammonia deposition was lower than reported by Hurkuck et al. (2014) for the same site in previous years using denuder systems. This was likely due to a better representation of the emission component in the net signal of eddy-covariance fluxes as well as better adapted site-specific parameters in the model. Our study not only stresses the importance of high-quality measurements for studying and assessing land surface–atmosphere interactions but also demonstrates the potential of QCL spectrometers for continuous observation of reactive nitrogen species as important additional instruments within long-term monitoring research infrastructures such as ICOS or NEON at sites with strong nearby ammonia sources leading to relatively high mean background concentrations and fluxes.
A multi-scale comparison of modeled and observed seasonal methane emissions in northern wetlands
Authors: Xu Xiyan , Riley William J. , Koven Charles D. , Billesbach Dave P. , Chang Rachel Y.-W. , Commane Róisín , Euskirchen Eugénie S. , Hartery Sean , Harazono Yoshinobu , Iwata Hiroki , McDonald Kyle C. , Miller Charles E. , Oechel Walter C. , Poulter Benjamin , Raz-Yaseef Naama , Sweeney Colm , Torn Margaret , Wofsy Steven C. , Zhang Zhen , Zona Donatella
Published: September 2016

Abstract. Wetlands are the largest global natural methane (CH4) source, and emissions between 50 and 70° N latitude contribute 10–30 % to this source. Predictive capability of land models for northern wetland CH4 emissions is still low due to limited site measurements, strong spatial and temporal variability in emissions, and complex hydrological and biogeochemical dynamics. To explore this issue, we compare wetland CH4 emission predictions from the Community Land Model 4.5 (CLM4.5-BGC) with site- to regional-scale observations. A comparison of the CH4 fluxes with eddy flux data highlighted needed changes to the model's estimate of aerenchyma area, which we implemented and tested. The model modification substantially reduced biases in CH4 emissions when compared with CarbonTracker CH4 predictions. CLM4.5 CH4 emission predictions agree well with growing season (May–September) CarbonTracker Alaskan regional-level CH4 predictions and site-level observations. However, CLM4.5 underestimated CH4 emissions in the cold season (October–April). The monthly atmospheric CH4 mole fraction enhancements due to wetland emissions are also assessed using the Weather Research and Forecasting-Stochastic Time-Inverted Lagrangian Transport (WRF-STILT) model coupled with daily emissions from CLM4.5 and compared with aircraft CH4 mole fraction measurements from the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) campaign. Both the tower and aircraft analyses confirm the underestimate of cold-season CH4 emissions by CLM4.5. The greatest uncertainties in predicting the seasonal CH4 cycle are from the wetland extent, cold-season CH4 production and CH4 transport processes. We recommend more cold-season experimental studies in high-latitude systems, which could improve the understanding and parameterization of ecosystem structure and function during this period. Predicted CH4 emissions remain uncertain, but we show here that benchmarking against observations across spatial scales can inform model structural and parameter improvements.
Temperature exerts no influence on organic matter δ13C of
surface soil along the 400 mm isopleth of mean annual precipitation in China
Authors: Jia Yufu , Wang Guoan , Tan Qiqi , Chen Zixun
Published: September 2016

Abstract. Soil organic carbon is the largest pool of carbon in the terrestrial ecosystem, and its isotopic composition is affected by a number of factors. However, the influence of environmental factors, especially temperature, on soil organic carbon isotope values (δ13CSOM) is poorly constrained. This impedes the application of the variability of organic carbon isotopes to reconstructions of paleoclimate, paleoecology, and global carbon cycling. Given the considerable temperature gradient along the 400 mm isohyet (isopleth of mean annual precipitation – MAP) in China, this isohyet provides ideal experimental sites for studying the influence of temperature on soil organic carbon isotopes. In this study, the effect of temperature on surface soil δ13C was assessed by a comprehensive investigation of 27 sites across a temperature gradient along the isohyet. Results demonstrate that temperature does not play a role in soil δ13C. This suggests that organic carbon isotopes in sediments cannot be used for paleotemperature reconstruction and that the effect of temperature on organic carbon isotopes can be neglected in the reconstruction of paleoclimate and paleovegetation. Multiple regressions with MAT (mean annual temperature), MAP, altitude, latitude, and longitude as independent variables and δ13CSOM as the dependent variable show that these five environmental factors together account for only 9 % of soil δ13C variance. However, one-way ANOVA analyses suggest that soil type and vegetation type are significant factors influencing soil δ13C. Multiple regressions, in which the five aforementioned environmental factors were taken as quantitative variables, and vegetation type, soil type based on the Chinese Soil Taxonomy, and World Reference Base (WRB) soil type were separately used as dummy variables, show that 36.2, 37.4, and 29.7 %, respectively, of the variability in soil δ13C are explained. Compared to the multiple regressions in which only quantitative environmental variables were introduced, the multiple regressions in which soil and vegetation were also introduced explain more of the isotopic variance, suggesting that soil type and vegetation type exert a significant influence on δ13CSOM.