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This paper presents a brief study of (2-dimensional, spacelike) wave surfaces to a null direction l on a space-time (M , g) and studies how certain imposed symmetries on the set of such wave surfaces can be used to describe other geometrical features of l and (M , g) . It is mainly a review of known material but contains some novelties. For example, the brief discussion of the nature of wave surfaces (when viewed geometrically as wave fronts to a null ray direction) in Wave Surfaces Section is new in the sense that although it appeared in the author's work by the present author, it has not, to the best of his knowledge, appeared in this form anywhere else. Further, the work on conical symmetry and plane waves are, to the best of the author's knowledge, original with him from earlier papers and are reviewed here while the work on complete wave surface (sectional curvature-) symmetry is believed to be entirely new. Geometrical use of the sectional curvature function is employed in many places. The consequences of the various symmetry conditions imposed on the collection of all wave surfaces to a null direction spanned by a null vector l are described in terms of l spanning a principal null direction of the Weyl tensor (if non-zero) at the point concerned (in the sense of Petrov and Bel). [ABSTRACT FROM AUTHOR]

This paper explores the situation regarding the zeros of a proper homothetic vector field X on a 4-dimensional manifold admitting a metric of neutral signature. The types of such zeros are described in terms of the algebraic types of the Ricci tensor and Weyl tensor at the said zero together with a geometrical description of the set of such zeros. A comparison is made between the situation occurring here and that for positive definite and Lorentz signatures. Examples are given to show that many of the theoretical possibilities derived for such zeros actually exist. [ABSTRACT FROM AUTHOR]

(It is trivially remarked that the conformal invariance is for the tensor HT ht and not for its associated tensor HT ht .) Thus HT ht is a linear map on HT ht and may be classified by its Jordan form/Segre type structure. For example, suppose I C i satisfies HT ht at I p i for HT ht . (I have taken the liberty of changing a sign in the HT ht form HT ht from that in [[1]]). [Extracted from the article]

Macrocyclic lactones (MLs) are some of the most pervasive chemicals used in cattle management to control internal parasites. However, the drenches can have a range of lethal and sublethal impacts, potentially impacting the efficiency of adult dung beetles at burying dung and negatively impacting their larval growth, development and survival. Here, we assess the impacts of adult dung beetles provisioning their larvae with cattle faecal residues containing three commonly used cattle drenches in Australia – moxidectin, abamectin and doramectin. We used the larvae of two introduced tunnelling (paracoprid) species: Onthophagus binodis and Onitis viridulus, and one introduced rolling (telecoprid) species: Sisyphus rubrus. We anticipated that dung beetle larvae feeding on dung containing an ML would have altered growth patterns to those larvae feeding on untreated dung. Further, beetle larvae exposed to an ML in the dung would have different growth patterns, depending on the time the chemical took to be excreted from the treated cattle, with the anticipation that the chemical may have a peak excretion time. We also expected that dung beetle larvae feeding on dung containing an ML would have a decreased survival rate compared to dung beetle larvae feeding on untreated dung. We found that abamectin and doramectin were more toxic to beetle larvae than moxidectin and control dung, across all three species, and these chemicals also had the greatest negative impact on larval growth and development. Abamectin excreted 7 days after treatment resulted in few live larvae. Overall, moxidectin was the least toxic ML to the larvae assessed, and generally, the drench impacts were reduced as time since exposure increased. [ABSTRACT FROM AUTHOR]

This article investigates how group speaking test candidates manage group talk during assessed, time-limited tasks. Drawing on recorded and transcribed data, it explores how higher-scoring learners manage spoken assessment tasks through their talk, moving conversations on or slowing them down in order to perform and complete the tasks' requirements in a timely way. These data are contrasted with the ways in which lower-scoring test candidates attempt to organize and manage assessed group talk. While the data and findings from this particular study can be used to teach students about, and prepare them for, multi-person discussions and, more specifically, task-oriented and time-limited group speaking tests, we also suggest that our awareness-raising investigatory approach, if brought into the classroom, offers learners (and teachers) a way of uncovering some of what actually occurs during talk, illuminating the 'invisible rules' that guide how participants engage in and manage interaction. [ABSTRACT FROM AUTHOR]

Migratory movements in response to seasonal resources often influence population structure and dynamics. Yet in mobile marine predators, population genetic consequences of such repetitious behaviour remain inaccessible without comprehensive sampling strategies. Temporal genetic sampling of seasonally recurring aggregations of planktivorous basking sharks, Cetorhinus maximus, in the Northeast Atlantic (NEA) affords an opportunity to resolve individual re-encounters at key sites with population connectivity and patterns of relatedness. Genetic tagging (19 microsatellites) revealed 18% of re-sampled individuals in the NEA demonstrated inter/multi-annual site-specific re-encounters. High genetic connectivity and migration between aggregation sites indicate the Irish Sea as an important movement corridor, with a contemporary effective population estimate (Ne) of 382 (CI = 241–830). We contrast the prevailing view of high gene flow across oceanic regions with evidence of population structure within the NEA, with early-season sharks off southwest Ireland possibly representing genetically distinct migrants. Finally, we found basking sharks surfacing together in the NEA are on average more related than expected by chance, suggesting a genetic consequence of, or a potential mechanism maintaining, site-specific re-encounters. Long-term temporal genetic monitoring is paramount in determining future viability of cosmopolitan marine species, identifying genetic units for conservation management, and for understanding aggregation structure and dynamics. [ABSTRACT FROM AUTHOR]

This paper reviews the concept of pp-waves and plane waves in classical general relativity theory. The first four sections give discussions of some algebraic constructions and symmetry concepts which will be needed in what is to follow. The final sections deal with the definitions of such wave solutions, their associated geometrical tensors in space–time and their Killing, homothetic, conformal and wave surface symmetries. Some unusual geometrical features of these solutions (compared with standard positive definite geometry) are described. [ABSTRACT FROM AUTHOR]

We deployed satellite transmitters to provide the first detailed picture of the movement behaviour of Australian Wood Ducks (Chenonetta jubata) through agricultural landscapes where the availability and spatial arrangement of resources are highly predictable. We measured movement distances and home-range areas of individual Australian Wood Ducks and investigated their site fidelity by comparing the overlap of successive home-range areas on a fortnightly temporal scale. First passage time (FPT) analysis was used to determine the spatial scales at which foraging occurs within home-range areas. We found a peak of movement activity around the periods of dawn and dusk similar to many waterfowl species. The mean overlap of core home-range areas over successive 2 week periods was 89.81% (± 2.38 SD), which demonstrates strong site fidelity. Area-restricted search (ARS) occurred at the scale of individual foraging (ca.100 m), with no clear peaks at larger spatial scales. This finding implies that search effort was expended equally across the combined utilisation distribution of Australian Wood Ducks in this agricultural landscape. Our results support the conclusions of previous studies suggesting that the movement behaviour of Australian Wood Ducks is shaped strongly by the temporal and spatial predictability of their grazing areas and access to water in the form of farm dams. [ABSTRACT FROM AUTHOR]

Background and Objective: Chronic, low‐intensity air pollution exposure has been consistently associated with reduced lung function throughout childhood. However, there is limited research regarding the implications of acute, high‐intensity air pollution exposure. We aimed to determine whether there were any associations between early life exposure to such an episode and lung growth trajectories. Methods: We conducted a prospective cohort study of children who lived in the vicinity of the Hazelwood coalmine fire. Lung function was measured using respiratory oscillometry. Z‐scores were calculated for resistance (R5) and reactance at 5 Hz (X5) and area under the reactance curve (AX). Two sets of analyses were conducted: (i) linear regression to assess the cross‐sectional relationship between post‐natal exposure to mine fire‐related particulate matter with an aerodynamic diameter of less than 2.5 micrometres (PM2.5) and lung function at the 7‐year follow‐up and (ii) linear mixed‐effects models to determine whether there was any association between exposure and changes in lung function between the 3‐ and 7‐year follow‐ups. Results: There were no associations between mine fire‐related PM2.5 and any of the lung function measures, 7‐years later. There were moderate improvements in X5 (β: −0.37 [−0.64, −0.10] p = 0.009) and AX (β: −0.40 [−0.72, −0.08] p = 0.014), between the 3‐ and 7‐year follow‐ups that were associated with mean PM2.5, in the unadjusted and covariance‐adjusted models. Similar trends were observed with maximum PM2.5. Conclusion: There was a moderate improvement in lung stiffness of children exposed to PM2.5 from a local coalmine fire in infancy, consistent with an early deficit in lung function at 3‐years after the fire that had resolved by 7‐years. [ABSTRACT FROM AUTHOR]

Abstract This paper studies some general principles of metric (Killing) symmetry on a 4-dimensional, connected manifold M admitting a metric of neutral signature. First a general survey of neutral geometry is presented and this is followed by a discussion of the generalised distribution, integral manifolds and orbits which arise from a general Lie algebra of global smooth vector fields on M. Next, this theory is applied to the finite-dimensional Lie algebra of global Killing vector fields on M and gives a decomposition of M into its various Killing orbits. The zeros of Killing vector fields and the consequent isotropies are then introduced, the latter being described in terms of subalgebras of o ( 2 , 2 ). The concepts of stability and dimensional stability for orbits are described and theorems are proved which relate the dimension of the Killing algebra to the orbit and isotropy dimensions. Certain special subalgebras are then introduced and related to isotropies in dimensionally stable orbits. Several examples of metrics with symmetries are then presented and which reveal many of the above features. Finally, a theorem describing the consequences for the Ricci and Weyl tensors under Killing isotropy is given in terms of algebraic classifications of these tensors. A table is provided which gives full details of the above results. [ABSTRACT FROM AUTHOR]

Background: Limited evidence suggests that children have a lower incidence of perioperative respiratory adverse events when intravenous propofol is used compared with inhalational sevoflurane for the anesthesia induction. Limiting these events can improve recovery time as well as decreasing surgery waitlists and healthcare costs. This single center open-label randomized controlled trial assessed the impact of the anesthesia induction technique on the occurrence of perioperative respiratory adverse events in children at high risk of those events.Methods: Children (N = 300; 0 to 8 yr) with at least two clinically relevant risk factors for perioperative respiratory adverse events and deemed suitable for either technique of anesthesia induction were recruited and randomized to either intravenous propofol or inhalational sevoflurane. The primary outcome was the difference in the rate of occurrence of perioperative respiratory adverse events between children receiving intravenous induction and those receiving inhalation induction of anesthesia.Results: Children receiving intravenous propofol were significantly less likely to experience perioperative respiratory adverse events compared with those who received inhalational sevoflurane after adjusting for age, sex, American Society of Anesthesiologists physical status and weight (perioperative respiratory adverse event: 39/149 [26%] vs. 64/149 [43%], relative risk [RR]: 1.7, 95% CI: 1.2 to 2.3, P = 0.002, respiratory adverse events at induction: 16/149 [11%] vs. 47/149 [32%], RR: 3.06, 95% CI: 1.8 to 5. 2, P < 0.001).Conclusions: Where clinically appropriate, anesthesiologists should consider using an intravenous propofol induction technique in children who are at high risk of experiencing perioperative respiratory adverse events.Visual Abstract: An online visual overview is available for this article at http://links.lww.com/ALN/B725. [ABSTRACT FROM AUTHOR]

We consider the sectional curvature function on a 4-dimensional manifold admitting a metric g of neutral signature, (+,+,-,-) together with a review of the situation for the other two signatures. The main results of the paper are: first, that if the sectional curvature function is not a constant function at any m ∊ M (actually a slightly weaker assumption is made), the conformal class of g is always uniquely determined and in almost all cases g is uniquely determined on M, second, a study of the special cases when this latter uniqueness does not hold, third, the construction of the possible metrics in this latter case, fourth, some remarks on sectional curvature preserving vector fields and finally the complete solution when (M, g) is Ricci flat. [ABSTRACT FROM AUTHOR]

This paper considers 4--dimensional manifolds which admit a metric of any signature and examines the relationships between the metric, its Levi-Civita connection, its curvature tensor and sectional curvature function and its Weyl conformal tensor. It is shown that, with some special cases excepted (some of which will be discussed), these various curvature concepts are very closely related. The relationship between them and the holonomy group associated with the connection is also explored. Some of these results, in the case of positive definite and Lorentz signature, have been given before and so this paper will concentrate mainly on the case of neutral signature (+, +, -, -) and on the process of putting together simple arguments which cover all signatures simultaneously. [ABSTRACT FROM AUTHOR]

This work is a study of the Weyl conformal tensor on manifolds of dimension 4 and for each of the three possible signatures (+,+,+,-), (+,+,-,-) and (+,+,+, +). In it, the properties of the Weyl tensor and its algebraic classification will be compared and contrasted. [ABSTRACT FROM AUTHOR]

This paper presents a simple account of the algebraic classification of the Weyl conformal tensor on a 4 -dimensional manifold with metric g of neutral signature ( + , + , − , − ) . The classification is algebraically similar to the well-known Petrov classification in the Lorentz case and the various algebraic types and corresponding canonical forms are obtained. Criteria concerning principal, totally null 2 -spaces are explored and which lead to principal null directions similar to those of L. Bel in the Lorentz case. The uniqueness, or otherwise, of the tetrads in which the canonical forms appear are investigated and some topological and differentiability properties of the algebraic types are also established. [ABSTRACT FROM AUTHOR]

ABSTRACT Traditionally, spirometry testing tended to be confined to the realm of hospital-based laboratories but is now performed in a variety of health care settings. Regardless of the setting in which the test is conducted, the fundamental basis of spirometry is that the test is both performed and interpreted according to the international standards. The purpose of this Australian and New Zealand Society of Respiratory Science ( ANZSRS) statement is to provide the background and recommendations for the interpretation of spirometry results in clinical practice. This includes the benchmarking of an individual's results to population reference data, as well as providing the platform for a statistically and conceptually based approach to the interpretation of spirometry results. Given the many limitations of older reference equations, it is imperative that the most up-to-date and relevant reference equations are used for test interpretation. Given this, the ANZSRS recommends the adoption of the Global Lung Function Initiative ( GLI) 2012 spirometry reference values throughout Australia and New Zealand. The ANZSRS also recommends that interpretation of spirometry results is based on the lower limit of normal from the reference values and the use of Z-scores where available. [ABSTRACT FROM AUTHOR]

Graphite is used as a moderating material and as a structural component in a number of current generation nuclear reactors. During reactor operation stresses develop in the graphite components, causing them to deform. It is important to understand how the microstructure of graphite affects the material's response to these stresses. A series of experiments were performed to investigate how the pore structures of Pile Grade A and Gilsocarbon graphites respond to loading stresses. A compression rig was used to simulate the build-up of operational stresses in graphite components, and a confocal laser microscope was used to study variation of a number of important pore properties. Values of elastic modulus and Poisson's ratio were calculated and compared to existing literature to confirm the validity of the experimental techniques. Mean pore areas were observed to decrease linearly with increasing applied load, mean pore eccentricity increased linearly, and a small amount of clockwise pore rotation was observed. The response to build-up of stresses was dependent on the orientation of the pores and basal planes and the shapes of the pores with respect to the loading axis. It was proposed that pore closure and pore reorientation were competing processes. Pore separation was quantified using ‘nearest neighbour’ and Voronoi techniques, and non-pore regions were found to shrink linearly with increasing applied load. [ABSTRACT FROM AUTHOR]

Objective. Intravenous thrombolysis with tissue plasminogen activator (tPA) improves patient outcomes in acute ischaemic stroke. Because its benefit is time-dependant, treatment delays must be minimised. The aim of the present study was to review patient characteristics, timeliness of tPA delivery and clinical outcome in patients receiving t-PA in a tertiary hospital stroke unit in Queensland, and to compare the findings with those of other Australian studies. Methods. The present study was a retrospective study conducted between 1 January 2010 and 31 December 2012. Information was collected regarding demographics, stroke characteristics, timeliness of tPA delivery, clinical outcome, safety outcome and protocol deviation. Results. Of 490 patients admitted with ischaemic stroke, 57 (11.6%) received tPA. Compared with other studies, the patients in the present study had more severe stroke (median National Institutes of Health Stroke Scale (NIHSS) score), more cardioembolic strokes and more patients receiving tPA between 3 and 4.5 h of symptoms onset. Median symptom onset to treatment time was 175 min and median door to needle time was 97 min. At 3 months, 21.1% of patients had died and 41.5% had a favourable outcome (modified Rankin scale≤2). Symptomatic intracerebral haemorrhage occurred in 5.3% of patients and protocol deviations occurred in 21.1%. Overall, delivery and outcomes of tPA at the Princess Alexandra Hospital were comparable to those reported in other Australian studies of usual care. Several challenges and strategies for optimal thrombolysis were identified, with supporting evidence from selected Australian sites. Conclusion. The proportion of eligible stroke patients who receive tPA in a timely manner remains less than ideal at our centre. More accurate patient selection and reductions in treatment delays serve as targets for quality improvement efforts that have broad applicability. [ABSTRACT FROM AUTHOR]

This paper studies the recurrence structure of second order symmetric tensors on a 4 -dimensional manifold M admitting a metric g of neutral signature ( + , + , − , − ) . The technique used is to first solve the problem when the tensor in question is either parallel (covariantly constant) or can be scaled so that it is parallel. Then one considers those recurrent tensors which are not in this category. The general approach is based on a (known) classification scheme for second order symmetric tensors (which will be reviewed) and a method of distinguishing those tensor types which may be (up to a scaling) parallel and those which may not be. The analysis is based on the holonomy group of (the Levi-Civita connection associated with) g , the possible Lie algebras of which are known. The results are then applied to the Ricci tensor of the structure ( M , g ) (Ricci-recurrence), including the study of those holonomy types which permit Einstein spaces, and also to the problem of finding the complete set of metrics associated with a particular Levi-Civita connection of ( M , g ) . Some of the results hold quite generally for any dimension of M and signature of g and this will be used to (very briefly) consider the same problem for Lorentz and positive definite signature (and whose solution is known). A by-product of this study is the finding of certain useful, direct techniques to study the properties of the various holonomy types using direct algebraic methods and the Ambrose–Singer theorem. [ABSTRACT FROM AUTHOR]

Background: Young adulthood is a critical life period for health and health behaviours. Related measurements collected before and after birth, and during childhood and adolescence can provide a life-course analysis of important factors that contribute to health and behaviour in young adulthood. The Western Australian Pregnancy Cohort (Raine) Study has collected a large number of such measurements during the fetal, perinatal, infancy, childhood and adolescence periods and plans to relate them to common health issues and behaviours in young adults, including spinal pain, asthma, sleep disorders, physical activity and sedentary behaviour and, work absenteeism and presenteeism. The aim of this paper is to describe the rationale, design and methods of the 22 year follow-up of the Raine Study cohort. Methods/Design: The Raine Study is a prospective cohort study. Participants still active in the cohort (n = 2,086) were contacted around the time of their 22nd birthday and invited to participate in the 22 year follow-up. Each was asked to complete a questionnaire, attend a research facility for physical assessment and an overnight sleep study, wear activity monitors for a week, and to maintain a sleep and activity diary over this week. The questionnaire was broad and included questions related to sociodemographics, medical history, quality of life, psychological factors, lifestyle factors, spinal pain, respiratory, sleep, activity and work factors. Physical assessments included anthropometry, blood pressure, back muscle endurance, tissue sensitivity, lung function, airway reactivity, allergic status, 3D facial photographs, cognitive function, and overnight polysomnography. Discussion: Describing the prevalence of these health issues and behaviours in young adulthood will enable better recognition of the issues and planning of health care resources. Providing a detailed description of the phenotype of these issues will provide valuable information to help educate health professionals of the needs of young adults. Understanding the life-course risk factors of health issues and behaviours in young adulthood will have important health planning implications, supporting the development of targeted interventions to improve current health status and reduce the onset and development of further ill-health across adulthood. [ABSTRACT FROM AUTHOR]

Background: Young adulthood is a critical life period for health and health behaviours. Related measurements collected before and after birth, and during childhood and adolescence can provide a life-course analysis of important factors that contribute to health and behaviour in young adulthood. The Western Australian Pregnancy Cohort (Raine) Study has collected a large number of such measurements during the fetal, perinatal, infancy, childhood and adolescence periods and plans to relate them to common health issues and behaviours in young adults, including spinal pain, asthma, sleep disorders, physical activity and sedentary behaviour and, work absenteeism and presenteeism. The aim of this paper is to describe the rationale, design and methods of the 22 year follow-up of the Raine Study cohort. Methods/Design: The Raine Study is a prospective cohort study. Participants still active in the cohort (n = 2,086) were contacted around the time of their 22nd birthday and invited to participate in the 22 year follow-up. Each was asked to complete a questionnaire, attend a research facility for physical assessment and an overnight sleep study, wear activity monitors for a week, and to maintain a sleep and activity diary over this week. The questionnaire was broad and included questions related to sociodemographics, medical history, quality of life, psychological factors, lifestyle factors, spinal pain, respiratory, sleep, activity and work factors. Physical assessments included anthropometry, blood pressure, back muscle endurance, tissue sensitivity, lung function, airway reactivity, allergic status, 3D facial photographs, cognitive function, and overnight polysomnography. Discussion: Describing the prevalence of these health issues and behaviours in young adulthood will enable better recognition of the issues and planning of health care resources. Providing a detailed description of the phenotype of these issues will provide valuable information to help educate health professionals of the needs of young adults. Understanding the life-course risk factors of health issues and behaviours in young adulthood will have important health planning implications, supporting the development of targeted interventions to improve current health status and reduce the onset and development of further ill-health across adulthood. [ABSTRACT FROM AUTHOR]

One of the most significant complications of preterm birth is bronchopulmonary dysplasia ( BPD). The pathophysiology of BPD has changed in recent years as advances in neonatal care have led to increased survival of smaller, more preterm, infants who display alterations to alveolar and pulmonary microvascular development. It is becoming clear that infants with 'new' BPD experience lung disease that persists into later childhood, however, the oldest of these children are just now entering young adulthood and therefore the longer term pulmonary implications remain unknown. The role of lung function testing in the identification and subsequent management of patients with lung disease resulting from a neonatal classification of BPD is reviewed based on the underlying pathophysiology of the disease. [ABSTRACT FROM AUTHOR]

In this paper contains some remarks regarding projectively related (metric) connections on a 4-dimensional manifold, that is, Levi-Civita connections which yield the same paths for their (unparametrised) geodesics. Some techniques for such an investigation are briefly outlined. The signature of the metric is arbitrary but special emphasis is laid on the Lorentz case and the connection with the Einstein principle of equivalence in general relativity theory. The results are based on joint work with David Lonie and Zhixiang Wang in Aberdeen. [ABSTRACT FROM AUTHOR]

Background: The recently generated spirometry reference equations from the Global Lung Function Initiative (GLI2012) provide a long-awaited opportunity for the adoption of a globally applicable set of normal reference values. Objective: The aim of this study was to document the likely interpretative effects of changing from commonly used current spirometry reference equations to the GLI2012 equations on interpretation of test results in a clinical spirometry dataset. Methods: Spirometry results from 2,400 patients equally distributed over the age range of 5-85 years were obtained from clinical pulmonary function laboratories at three public hospitals. The frequency of obstruction [FEV1/FVC below the lower limits of normal (LLN)] and spirometric restriction (FVC below the LLN) was assessed using the GLI2012, the National Health and Nutrition Assessment Survey (NHANES III), the European Community of Steel and Coal (ECSC) and the Stanojevic all-ages reference equations. Results: The rates of obstruction (range 20.0-28.5%) and spirometric restriction (range 14.2-25.8%) were similar across the four sets of reference equations. The highest level of agreement with the new GLI2012 equations was seen with the NHANES III equations (97.6% for obstruction and 93.6% for spirometric restriction) and the lowest with those from the ECSC (96.0 for obstruction and 92.0% for restriction). These data can be used to estimate likely diagnostic spirometry interpretation effects in the clinical setting when switching to GLI2012 spirometry reference data. Conclusions: We have found the effects on interpretation of changing to GLI2012 reference data to be minimal when changing from NHANES III and most significant when changing from ECSC reference data. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

This note investigates the possibility of converses of the Weyl theorems that two conformally related metrics on a manifold have the same Weyl conformal tensor and that two projectively related connections on a manifold have the same Weyl projective tensor. It shows that, in all relevant cases, counterexamples to each of Weyl's theorems exist except for his conformal theorem in the 4-dimensional, positive definite case, where the converse actually holds. This (conformal) 4-dimensional problem is then solved completely for the other possible signatures. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the development and validation of an empirical model of fast neutron damage and radiolytic oxidation effects on bending strength for the moulded Gilsocarbon graphites used in Advanced Gas-cooled Reactors (AGRs). The inert environment model is based on evidence of essentially constant strength as fast neutron dose increases in inert environment. The model of combined irradiation and oxidation calibrates that constant along with an exponential function representing the degree of radiolytic oxidation as measured by weight loss. The change in strength with exposure was found to vary from one AGR station to another. The model was calibrated to data on material trepanned from AGR moderator bricks after varying operating times. [Copyright &y& Elsevier]

Abstract: This paper presents the development and validation of an empirical model of combined fast neutron damage and radiolytic oxidation effects on Young’s modulus for the Gilsocarbon graphites used in advanced gas-cooled reactors. The combined irradiation and oxidation model is based on a model of fast neutron damage in an inert environment and the degree of radiolytic oxidation as measured by weight loss. The change in Young’s modulus with exposure was found to vary from one power reactor to another and with the relative contributions of oxidation and fast neutron damage in data from materials test reactors. The model was calibrated to data from material trepanned from advanced gas-cooled reactor moderator bricks after varying operating times. The model also predicts materials test reactor data that extend beyond the range of currently-available trepanned data. The model is convenient to use because it is an analytic function that eliminates the interpolation on temperature and dose that is used in an earlier model. [Copyright &y& Elsevier]

Abstract: This paper presents the development and validation of an empirical model of radiation effects on coefficient of thermal expansion (CTE) for the Gilsocarbon graphites used in Advanced Gas-cooled Reactors (AGRs). The combined irradiation and oxidation model is based in part on a new model of fast neutron damage in inert environment. The new inert model shows an increase to an “upper shelf” irradiated CTE value at very low dose, then CTE values decrease with increasing dose following a hyperbolic tangent function. The effect of the actual exposure in AGRs is modelled by shifting the inert model in both dose and CTE directions to agree with the CTE measurements on material trepanned from moderator bricks in operating AGRs. The shift in the inert model that is needed to match the trepanned data varies significantly by reactor. The new model predicts randomly-selected validation data that were not used in model fitting as well as it fits the calibration data. [Copyright &y& Elsevier]

Abstract: This paper considers the situation for a 4-dimensional manifold admitting two metric connections, one of which is compatible with a metric of signature , and which have the same unparametrised geodesics. It shows how, in many cases (decided on holonomy type), the relationship between these connections and metrics can be found. In many of these cases, the connections are found to be necessarily equal. The general techniques used are based on holonomy theory. [Copyright &y& Elsevier]

This article identifies patterns and trends within ‘Key Concepts in ELT’, both since the inception of the feature in ELT Journal in 1993 and during the 17 years of the current editorship. After outlining the aims of the series, the article identifies key themes that have emerged over time, exploring the links between ‘Key Concepts’ pieces and the trends and developments in ELT more generally. It finds that although earlier articles tended to focus on ‘teaching’, ‘learning’, and ‘language’, more recent pieces have examined issues surrounding ‘teachers’, ‘learners’, and the ‘social context’ of ELT. The article then considers the ‘reach’, readership, and potential relevance of ‘Key Concepts’ to debates and practices within ELT, drawing upon publisher records of ELT Journal’s most accessed articles online and most cited articles, and concludes with a discussion of possible future directions for the series. [ABSTRACT FROM PUBLISHER]

Abstract: This paper considers the situation on a 4-dimensional manifold admitting two metric connections, one of which is compatible with a positive definite metric, and which have the same unparametrised geodesics. It shows how, in many cases, the relationship between these connections and metrics can be found. In many of these cases, the connections are found to be necessarily equal. The general technique used is that based on a certain classification of the curvature tensor together with holonomy theory. [Copyright &y& Elsevier]

Background: In school-aged children with cystic fibrosis (CF) structural lung damage assessed using chest CT is associated with abnormal ventilation distribution. The primary objective of this analysis was to determine the relationships between ventilation distribution outcomes and the presence and extent of structural damage as assessed by chest CT in infants and young children with CF. Methods: Data of infants and young children with CF diagnosed following newborn screening consecutively reviewed between August 2005 and December 2009 were analysed. Ventilation distribution (lung clearance index and the first and second moment ratios [LCI, M1/M0 and M2/M0, respectively]), chest CT and airway pathology from bronchoalveolar lavage were determined at diagnosis and then annually. The chest CT scans were evaluated for the presence or absence of bronchiectasis and air trapping. Results: Matched lung function, chest CT and pathology outcomes were available in 49 infants (31 male) with bronchiectasis and air trapping present in 13 (27%) and 24 (49%) infants, respectively. The presence of bronchiectasis or air trapping was associated with increased M2/M0 but not LCI or M1/M0. There was a weak, but statistically significant association between the extent of air trapping and all ventilation distribution outcomes. Conclusion: These findings suggest that in early CF lung disease there are weak associations between ventilation distribution and lung damage from chest CT. These finding are in contrast to those reported in older children. These findings suggest that assessments of LCI could not be used to replace a chest CT scan for the assessment of structural lung disease in the first two years of life. Further research in which both MBW and chest CT outcomes are obtained is required to assess the role of ventilation distribution in tracking the progression of lung damage in infants with CF. [ABSTRACT FROM AUTHOR]

Purchase and disinfection costs together with medication delivery factors may influence the choice of drug delivery options. This study assessed salbutamol delivery habits used in respiratory laboratories and quantified the delivered salbutamol dose of locally available spacers. An online survey was used to obtain data on disinfection processes, costs and delivery device choices. The delivered dose of six commercial spacers was assessed. Particle size distribution of salbutamol (Ventolin, GSK, 100 µg/actuation) from six spacers of each type was measured by quantifying the amount of drug (µg) deposited on each stage of an Anderson Cascade Impactor (ACI) using UV spectrophotometry. Clinical conditions were simulated using a flow volume simulator (FVS) and delivery of salbutamol via a pressurized metered dose inhaler and spacer to a low-resistance filter was measured. Fifty survey responses were obtained, with 37 (74%) using ≥1 type of spacer of which 92% processed single use spacers. The most commonly used spacers were Volumatic ( n = 24), Breath-a-tech ( n = 8) and Space Chamber ( n = 7). The median disinfection cost was $2.45. Delivered salbutamol dose varied significantly and ranged from 16.98 to 38.28 µg with the ACI and 22.56 to 58.82 µg with the FVS. Using the FVS, small-volume spacers delivered similar doses (22.56 to 28.46 µg), while large-volume spacers delivery was more varied (24.31 to 58.82 µg). The majority of respiratory laboratories had not updated re-processing policies to comply with new regulations. The delivered salbutamol dose varied significantly and this might effect the choice of preferred spacer type. Delivered salbutamol dose from spacers using physiologically relevant methods was determined. Respiratory laboratories were surveyed on spacer usage habits.Knowledge of salbutamol delivery and local operational costs of spacer purchase and usage provides for important evidence-based practice. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies the situation when two four-dimensional Lorentz manifolds (that is, space–times) admit the same (unparametrised) geodesics, that is, when they are projectively related. A review of some known results is given and then the problem is considered further by treating each holonomy type in turn for the space–time connection. It transpires that all holonomy possibilities can be dealt with completely except the most general one and that the consequences of two space–times being projectively related leads, in many cases, to their associated Levi-Civita connections being identical. [Copyright &y& Elsevier]

Uysal's article provides a research agenda for IELTS and lists numerous issues concerning the test's reliability and validity. She asks useful questions, but her analysis ignores the uncertainties inherent in all language test development and the wider social and political context of international high-stakes language testing. In this response, I suggest there is ample evidence that, in the normal course of its test development and review processes, IELTS is aware of and addressing problematic issues in its testing as they arise. However, I also argue that to address some of the issues arising from Uysal's discussion, we need to take a broader perspective and examine the social, economic, and political dimensions of international high-stakes English language testing. [ABSTRACT FROM PUBLISHER]

Abstract: One of Weyl’s classical theorems states that a certain tensor, the Weyl tensor, is unchanged when the metric from which it is constructed is replaced by another metric conformally related to it. This paper explores the converse of this theorem. [Copyright &y& Elsevier]

The article presents a study on the application of adenosine-5'- monophosphate (AMP), an indirect challenge agent which is used to make diagnosis of allergic asthma, to young children utilizing the forced oscillation technique (FOT). It notes the demonstration on a high degree of concordance in responsiveness between a shortened challenge and the standard AMP protocol. It stresses the conclusion stating the applicability of the AMP challenge to young children giving concordant responses.

Abstract: Dimensional and material property changes caused by fast neutron damage, radiolytic oxidation or a combination of both have been measured over many years on the Gilsocarbon graphites. The data have been gathered together in a comprehensive database and are being used to develop dose–damage relationships of irradiated graphite material properties for use in irradiated graphite component stress analyses up to a fast neutron dose of ∼200×1020 n/cm2 equivalent DIDO nickel dose (EDND) in the temperature range ∼300–650°C. This paper covers development and validation of an empirical model for Young’s modulus of Gilsocarbon graphite when irradiated in an inert environment. The new model provides a good fit over the range of the primary modelling variables: dose, irradiation temperature, and graphite group. The proposed model is convenient to use in component stress analysis, as it features an analytic function of temperature and dose that eliminates the need in the existing model for interpolation on those variables. [Copyright &y& Elsevier]

Abstract: Samples of Gilsocarbon graphite have been recently irradiated in the High Flux Reactor at Petten. They were irradiated in an inert atmosphere to a fast neutron dose of between 3 and 10dpa, at temperatures of between 650 and 750°C, this irradiation dose equates to approximately dimensional change ‘turnaround’. The present understanding of the irradiation induced microstructural changes considered to lead to the irradiation induced dimensional and material property changes are discussed and correlations between the various property changes noted. However, at present there are few microstructural studies to confirm or refute these theories. A methodology proposed to convert graphite CTE measurement, for all types graphite, from one temperature range to another is shown to be applicable to both unirradiated and irradiated Gilsocarbon graphite. In addition an important relationship for the thermal conductivity temperature dependence of irradiated Gilsocarbon graphite is shown to be reasonable. [Copyright &y& Elsevier]

This article examines a small-scale ethnographic survey of a single classroom. Drawing on the collected data, the discussion focuses on some of the problems encountered whilst collecting and interpreting data through self-report diaries. Amongst the issues considered are the perceptions of teachers and learners and their ability to articulate these perceptions, revealing that key assumptions need to be made explicit before appropriate conclusions can be drawn from the data. The article also discusses how variation within the data might be the result of the specific diary approach developed. The article concludes positively, however, suggesting that explicit recognition of these difficulties can still lead to fruitful, localized approaches to the data. [ABSTRACT FROM AUTHOR]

Background: Monitoring of respiratory function is important in the diagnosis and management of respiratory disease. The forced oscillation technique requires minimal patient cooperation and is ideal for the determination of respiratory function in young children. This study aimed to develop reference ranges and to document the repeatability in healthy young children using commercially available forced oscillation equipment. Methods: The forced oscillation technique, which uses a pseudo-random noise forcing signal between 4 and 48 Hz, was used to measure respiratory function in healthy young children. Repeatability over a 15 mm period was also assessed. Regression equations and standardised Z scores were determined for respiratory resistance (Rrs) and reactance (Xrs) at 6, 8 and 10 Hz. Results: Respiratory function was obtained in 158 healthy children aged two to seven years and between 92 and 127 cm in height. Oscillatory respiratory mechanics exhibited linear relationships with height. Within-test variability for resistance ranged between 6% and 9% and between 17% and 20% for reactance. Resistance and reactance did not change significantly over a 15 mm period. Conclusions: Reference ranges for respiratory impedance variables in healthy children aged two to seven years are presented. The short-term repeatability of forced oscillatory variables in this age group is reported, allowing appropriate cut-off values for therapeutic interventions to be defined. [ABSTRACT FROM AUTHOR]

Deer were introduced to Australia in the 19th century, and today 6 species have been established in the wild. Australians have considered deer a pest and an important economic and hunting resource since their early introduction. We recommend promoting the management of wild deer for the joint outcomes of reducing adverse impacts on agriculture, forestry, and conservation values, and for exploitation and harvest. We also recommend that managers recognize deer as an established component of many Australian ecosystems. If Australians are to have a professional approach to wildlife management, we must move away from the traditional paradigms of protection of native species and eradication of exotic species and embrace wildlife management for all its complexities, challenges, and positive outcomes. We discuss wild deer management as a test case to explore these issues. [ABSTRACT FROM AUTHOR]

Background: In infants the impedance of the nasal pathways (Zn) is a significant proportion of the total respiratory impedance (Zrs).Methods: In 11 infants Zrs was partitioned into Zn and lower respiratory system impedance (Zlrs) using a nasal catheter. A low frequency oscillatory signal (0.5-20 Hz) was applied during a pause in breathing to obtain the impedance spectra. A model of the respiratory system containing an airway and tissue compartment was then fitted to Zrs and Zlrs. The airway compartment consisted of a frequency independent resistance (R) and inertance (I), while the tissue compartment was described by coefficients of tissue damping (G) and elastance (H).Results: Zrs could be reliably partitioned into Zn and Zlrs. The nasal pathway acted as a purely resistive-inertive impedance and contributed approximately half of the airway resistance (mean (SE) 44.6 (4.9)%) and most of the respiratory system inertance (71.7 (3.5)%).Conclusions: In studies investigating changes in airway resistance in nasally breathing infants, the separation of nasal and lower respiratory system mechanics will increase the sensitivity of the tests. [ABSTRACT FROM AUTHOR]

Discusses the ontogeny of apolipoprotein expression in rat liver mRNA levels in developing liver and cultured fetal rat hepatocytes. Detection of the transcripts after gestation; Establishment of cultured hepatocytes; Similarity of the response of fetal and adult hepatocytes to tested hormones.

Examines the circumstances under which market-share and profitability are causally related. Reliability of profit impact of market strategies program; Multiple regression of the returns of investment (ROI) of strategic business units; Reasons for the relationship between market-share and ROI and their implications; Cost of achieving market share.

Describes how sixth-form biology students from King's College in London, England made a practical contribution to the conservation of the Mediterranean Loggerhead turtle on the Greek Ionian Island of Zakynthos. Threats to the turtles resulting from tourism; Features of the project by the students; Aims of the expedition by the students.

See related Article [ABSTRACT FROM AUTHOR]