High muscle mitochondrial volume and aerobic capacity in a small marsupial (Sminthopsis crassicaudata) reveals flexible links between energy-use levels in mammals

We investigated the muscle structure-function relationships that underlie the aerobic capacity of an insectivorous, small (~15?g) marsupial, Sminthopsis crassicaudata (Family: Dasyuridae), to obtain further insight into energy use patterns in marsupials relative to those in placentals, their sister clade within the Theria (advanced mammals). Disparate hopping marsupials (Suborder Macropodiformes), a kangaroo (Macropus rufus) and a rat-kangaroo (Bettongia penicillata), show aerobic capabilities as high as those of 'athletic' placentals. Equivalent muscle mitochondrial volumes and cardiovascular features support these capabilities. We examined S. crassicaudata to determine whether highly developed aerobic capabilities occur elsewhere in marsupials, rather than being restricted to the more recently evolved Macropodiformes. This was the case. Treadmill-trained S. crassicaudata attained a maximal aerobic metabolic rate (VO2,max or MMR) of 272ml O2min-1kg -1 (N=8), similar to that reported for a small (?20g), 'athletic' placental, Apodemus sylvaticus, 264ml O2min -1kg-1. Hopping marsupials have comparable aerobic levels when body mass variation is considered. Sminthopsis crassicaudata has a basal metabolic rate (BMR) about 75% of placental values but it has a notably large factorial aerobic scope (fAS) of 13, elevated fAS also features in hopping marsupials. The VO2,max of S. crassicaudata was supported by an elevated total muscle mitochondrial volume, which was largely achieved through high muscle mitochondrial volume densities, Vv(mt,f), the mean value being 14.0±1.33%. These data were considered in relation to energy use levels in mammals, particularly field metabolic rate (FMR). BMR is consistently lower in marsupials, but this is balanced by a high fAS, such that marsupial MMR matches that of placentals. However, FMR shows different mass relationships in the two clades, with the FMR of small (<, 125 g) marsupials, such as S. crassicaudata, being higher than that in comparably sized placentals, with the reverse applying for larger marsupials. The flexibility of energy output in marsupials provides explanations for this pattern. Overall, our data refute widely held notions of mechanistically closely linked relationships between body mass, BMR, FMR and MMR in mammals generally.

Reliability and validity of a new Building Environmental Quality Questionnaire

This study aimed to develop and then test the reliability and validity of a new self-report questionnaire method called the building environmental quality questionnaire (BEQQ) designed to assess the perceived environmental quality in residential apartments in Hong Kong. A total of 108 (46 men and 62 women) Chinese-speaking residents, between 16 and 81 years of age, took part and completed the questionnaire study. The subjects were recruited from 12 different buildings of three distinct quality ratings (low, medium and high) assigned by the building assessment tool called the building health and hygiene index (BHHI). The study was evaluated to determine reliability and this was assessed involving 20 of the participants (18% of the total sample size). The BEQQ was found to have good test-retest reliability, with intra-class correlation coefficient (ICC) values typically around 0.70. The validity testing, also using ICCs, generated moderate to high values for all BEQQ sub-categories (the mean value was around 0.80), indicating a good consistency among residents living within the same building. Finally, the summary BEQQ scores were significantly correlated (—0.68) with the BHHI ratings as the criterion standard. It is concluded that this eight-dimension instrument would provide a short and efficient questionnaire method to obtain self-reported information to determine the perceived residential building quality. The method was shown to yield adequate reliability and has been validated for use in empirical research.

Altered cardiac autonomic nervous function in depression

Background:
Depression is an independent risk factor for coronary artery disease. Autonomic instability may play a mediating or moderating role in this relationship; however this is not well understood. The objective of this study was to explore cardiac autonomic function and cardiac arrhythmia in depression, the correlation between depression severity and Heart Rate Variability (HRV) related indices, and the prevalence of arrhythmia.

Methods:
Individuals (n = 53) with major depression as assessed by the Diagnostic and Statistical Manual of Mental Disorders, who had a Hamilton Rating Scale for Depression (HAMD) score ≥20 and a Zung Self-Rating Depression Scale score > 53 were compared to 53 healthy individuals, matched for age and gender. Multichannel Electrocardiograph ECG-92C data were collected over 24 hours. Long-term changes in HRV were used to assess the following vagally mediated changes in autonomic tone, expressed as time domain indices: Standard deviation of the NN intervals (SDNN), standard deviation of 5 min averaged NN intervals (SDANN), Root Mean Square of the Successive Differences (RMSSD) and percentage of NN intervals > 50 ms different from preceding interval (pNN50). Pearson’s correlations were conducted to explore the strength of the association between depression severity (using the SDS and HRV related indices, specifically SDNN and low frequency domain / high frequency domain (LF/HF)).

Results:
The values of SDNN, SDANN, RMSSD, PNN50 and HF were lower in the depression group compared to the control group (P<.05). The mean value of the LF in the depression group was higher than the in control group (P<.05). Furthermore the ratio of LF/HF was higher among the depression group than the control group (P<.05). A linear relationship was shown to exist between the severity of the depression and HRV indices. In the depression group, the prevalence of arrhythmia was significantly higher than in the control group (P<.05), particularly supraventricular arrhythmias.

Conclusions:
Our findings suggest that depression is accompanied by dysfunction of the cardiac autonomic nervous system, and further, that depression severity is linked to severity of this dysfunction. Individuals with depression appear to be susceptible to premature atrial and/or ventricular disease.

Simplified physically based model for estimating effective floc density

This paper applies dimensional analysis to propose an alternative model for estimating the effective density of flocs (Δρf). The model takes into account the effective density of the primary particles, in addition to the sizes of the floc and primary particles, and does not consider the concept of self-similarity. The model contains three dimensionless products and two empirical parameters (αf and βf), which were calibrated by using data available in the literature. Values of αf=0.7 and βf=0.8 were obtained. The average value of the primary particle size (Dp) for the data used in the analysis, inferred from the new model, was found to vary from 0.05 μm to 100 μm with a mean value of 2.5 μm. Good comparisons were obtained in comparing the estimated floc-settling velocity on the basis of the proposed model for effective floc density with the measured value.

Does tobacco-control mass media campaign exposure prevent relapse among recent quitters?

OBJECTIVE: To determine whether greater mass media campaign exposure may assist recent quitters to avoid relapse. METHOD: Using date of data collection and postcode, media market estimates of televised tobacco-control advertising exposure measured by gross ratings points (GRPs) were merged with a replenished cohort study of 443 Australians who had quit in the past year. Participants' demographic and smoking characteristics prior to quitting, and advertising exposure in the period after quitting, were used to predict relapse 1 year later. RESULTS: In multivariate analysis, each increase in exposure of 100 GRPs (i.e., 1 anti-smoking advertisement) in the three-month period after the baseline quit was associated with a 5% increase in the odds of not smoking at follow-up (OR = 1.05, 95% CI 1.02-1.07, p < 0.001). This relationship was linear and unmodified by length of time quit prior to the baseline interview. At the mean value of 1081 GRPs in the 3 months after the baseline-quit interview, the predicted probability of being quit at follow-up was 52%, whereas it was 41% for the minimum (0) and 74% for the maximum (3,541) GRPs. CONCLUSION: Greater exposure to tobacco-control mass media campaigns may reduce the likelihood of relapse among recent quitters.

Estimating animal populations and body sizes from burrows: marine ecologists have their heads buried in the sand

Most ecological studies require knowledge of animal abundance, but it can be challenging and destructive of habitat to obtain accurate density estimates for cryptic species, such as crustaceans that tunnel deeply into the seafloor, beaches, or mudflats. Such fossorial species are, however, widely used in environmental impact assessments, requiring sampling techniques that are reliable, efficient, and environmentally benign for these species and environments.2.Counting and measuring the entrances of burrows made by cryptic species is commonly employed to index population and body sizes of individuals. The fundamental premise is that burrow metrics consistently predict density and size. Here we review the evidence for this premise. We also review criteria for selecting among sampling methods: burrow counts, visual censuses, and physical collections.3.A simple 1:1 correspondence between the number of holes and population size cannot be assumed. Occupancy rates, indexed by the slope of regression models, vary widely between species and among sites for the same species. Thus, 'average' or 'typical' occupancy rates should not be extrapolated from site- or species specific field validations and then be used as conversion factors in other situations.4.Predictions of organism density made from burrow counts often have large uncertainty, being double to half of the predicted mean value. Whether such prediction uncertainty is 'acceptable' depends on investigators' judgements regarding the desired detectable effect sizes.5.Regression models predicting body size from burrow entrance dimensions are more precise, but parameter estimates of most models are specific to species and subject to site-to-site variation within species.6.These results emphasise the need to undertake thorough field validations of indirect census techniques that include tests of how sensitive predictive models are to changes in habitat conditions or human impacts. In addition, new technologies (e.g. drones, thermal-, acoustic- or chemical sensors) should be used to enhance visual census techniques of burrows and surface-active animals.

Defining marine important bird areas: testing the foraging radius approach

Recent international initiatives have promoted a number of different approaches to identify marine Important Bird and biodiversity Areas (IBAs), which are important areas for foraging, migrating or over-wintering seabirds. The 'Foraging Radius Approach' is one of these and uses known foraging range and habitat preferences to predict the size and location of foraging areas around breeding colonies. Here we assess the performance of the Foraging Radius Approach using GPS tracking data from six seabird species with a variety of foraging modes. For each species we compared the population home-range areas of our six study species with the home-range areas defined using the Foraging Radius Approach. We also assessed whether basic information on depth preferences from tracking data could improve these home-range area estimates. Foraging Radius Approach home-range areas based on maximum foraging radii encompassed the entire population home-range of five out of six of our study species but overestimated the size of the population home-range area in every case. The mean maximum foraging radius overestimated the population home-range areas by a factor of 4-14 for five of the six species whilst the mean foraging radius overestimated the population home-range area for half of the species and underestimated for the rest. In the absence of other data, the Foraging Radius Approach appears to provide a reasonable basis for preliminary marine IBA identification. We suggest that using the mean value of all previously reported maximum foraging radii, informed by basic depth preferences provides the most appropriate prediction, balancing the needs of seabirds with efficient use of marine space.

It's in your hands : the value of handsearching in conducting systematic reviews of public health interventions

Background While there is an emerging evidence base in public health, the evidence can often be difficult to find. Indexing of journals in MEDLINE has assisted those conducting systematic reviews to more easily identify published studies. However, information technology and the processes associated with indexing are not infallible. Studies may not be correctly marked by study design which may mean they are missed in the electronic searching process. Handsearching for evidence of intervention effectiveness has therefore become a recognized tool in the systematic review process.

Methods Resources to guide handsearching activity currently are clinically focused, and may not be sensitive to the characteristics of public health studies where study terminology may differ. In response to this issue, the Cochrane Health Promotion and Public Health Field (the Field) developed and implemented a small study to recruit and support handsearchers from around the world to identify health promotion and public health trials and systematic reviews. A strategic framework was developed to recruit and support handsearchers to search six public health-related journals.

Results In total, 131 trials and 21 systematic reviews were identified. The greatest value of handsearching was found to be in supplement editions and abstract sections of journals

Conclusions The study focused exclusively on indexed journals with the intention that tools and methods developed could be used to explore the potential for handsearching in non-indexed journals and for unpublished studies. The findings from this study will continue to support handsearching efforts and in doing so contribute to high quality systematic reviews of public health interventions.

Mean reversion in stock prices: new evidence from panel unit root tests

Purpose – There are several studies that investigate evidence for mean reversion in stock prices. However, there is no consensus as to whether stock prices are mean reverting or random walk (unit root) processes. The goal of this paper is to re-examine mean reversion in stock prices.
Design/methodology/approach – The authors use five different panel unit root tests, namely the Im, Pesaran and Shin t-bar test statistic, the Levin and Lin test, the Im, Lee, and Tieslau Lagrangian multiplier test statistic, the seemingly unrelated regression test, and the multivariate augmented Dickey Fuller test advocated by Taylor and Sarno.
Findings – The main finding is that there is no mean reversion of stock prices, consistent with the efficient market hypothesis.
Research limitations/implications – One issue not considered by this study is the role of structural breaks. It may be the case that the efficient market hypothesis is contingent on structural breaks in stock prices. Future studies should model structural breaks.
Practical implications – The findings have implications for econometric modelling, in particular forecasting.
Originality/value – This paper adds to the scarce literature on the mean reverting property of stock prices based on panel data; thus, it should be useful for researchers.

Montessori place-value and number expander cards

Montessori Cards are shown in the recently reprinted classic curriculum handbook (yellowcovered) 'Guidelines in Number' (1985, p 18). Unfortunately, exactly what this small, and limited sketch-picture might mean, in practice, is not necessarily clear. The use of Montessori number cards is discussed.

A boarding school outbreak of pertussis in adolescents : value of laboratory diagnostic methods

Culture for Bordetella pertussis (B. pertussis) is the traditional gold standard for laboratory diagnosis of pertussis but is insensitive, especially later in the course of illness and in vaccinated persons. Interpretation of serology is limited by the lack of an appropriate reference standard. An outbreak of pertussis in a crowded boarding-school dormitory allowed evaluation of laboratory correlates of infection. Questionnaires, serum samples and throat swabs were collected from members of the exposed group. Serum samples from unexposed controls of a similar age group were used for comparison. B. pertussis PCR was performed on throat swabs, and sera were tested for IgA antibodies against whole-cell (WC) B. pertussis antigen and IgG antibodies to pertussis toxin (PT). The Centers for Disease Control and Prevention definition for pertussis was used to define clinical cases. We evaluated the use of a previously published cut-off for PT IgG of 125 EIA units (EU)/ml. Completed questionnaires were obtained from 115 students, of whom 85 (74%) reported coughing symptoms, including 32 (28%) who met the clinical case definition for pertussis. B. pertussis was detected by PCR in 17 (15%) and WC IgA in 22 (19%) students; neither correlated with symptoms, but dormitory of residence strongly predicted PCR status. The mean PT IgG geometric mean concentration, in this situation of high pertussis exposure, correlated with severity of symptoms and was significantly higher in both symptomatic and asymptomatic children exposed during the outbreak (P<0·001) than in control children. A cut-off for PT IgG of 125 EU/ml was too high in an outbreak situation to be sensitive enough to identify pertussis cases. A case of pertussis in a crowded boarding-school dormitory resulted rapidly in an outbreak. Serology and PCR were useful in identifying the outbreak and commencing disease control measures. The use of serology has mostly been evaluated in community serosurveys, where it is not possible to determine if immunity reflects vaccination, asymptomatic disease or symptomatic disease. This outbreak gave us the opportunity to evaluate the value of serology and PCR in the presence of confirmed exposure to pertussis.

Microstructural development in Al/MgAl2O4 in situ metal matrix composite using value-added silica sources

Al/MgAl2O4 in situ metal matrix composites have been synthesized using value-added silica sources (microsilica and rice husk ash) containing ~97% SiO2 in Al-5 wt.% Mg alloy. The thermodynamics and kinetics of MgAl2O4 formation are discussed in detail. The MgO and MgAl2O4 phases were found to dominate in microsilica (MS) and rice husk ash (RHA) value-added composites, respectively, during the initial stage of holding the composites at 750 °C. A transition phase between MgO and MgAl2O4 was detected by the scanning electron microscopy and energy-dispersive spectroscopy (SEM–EDS) analysis of the particles extracted from the composite using 25% NaOH solution. This confirms that MgO is gradually transformed to MgAl2O4 by the reaction 3SiO2(s)+2MgO(s)+4Al(l)→2MgAl2O4(s)+3Si(l). The stoichiometry of MgAl2O4, n, computed by a new methodology is between 0.79 and 1.18. The reaction between the silica sources and the molten metal stopped after 55% of the silica source was consumed. A gradual increase in mean MgAl2O4 crystallite size, D, from 24 to 36 nm was observed in the samples held for 10 h.

Residential auction clearance rates – what do they really mean?

The residential market in Melbourne is often referred to as the ‘auction capital of the world’ with approximately 30-35% of housing transfers undertaken via the auction process, most of which are conducted on the weekend and then reported in the media the following day. The most quoted measurement of auction success is via the clearance rate which simply indicates the proportion of signed contracts of sale within the auction process. At the same time the clearance rate can have a relatively large variance where the residential market can traditionally range from very good (i.e. a high clearance rate) to very poor (i.e. a low clearance rate). The subsequent effect on the market can directly increase or decrease demand, predominantly based only on this single measure of the perceived level of auction clearance rates only.

This paper examines the concept of the auction clearance rates and the heavy reliance on the only one measure of success (i.e. the clearance rates), regardless of other variables. The emphasis is placed on the auction clearance rate as one measure of demand in the housing market but within the context of the definition of market value i.e. willing buyer-willing seller. This is supported by a discussion about other variables including the asking price, the auction process itself, marketing considerations and seasonal adjustments. The findings provide an insight into how to correctly interpret the auction clearance rate in the context of the overall supply-demand interactions. Whilst the auction process is clearly an integral part of the residential transfer process it is essential that the auction clearance rate is used with caution and also in conjunction with other variables.

Students' perceptions of the value of the elements of an online learning environment : an investigation of discipline differences

This paper presents a large scale, quantitative investigation of the impact of discipline differences on the student experience of using an online learning environment (OLE). Based on a representative sample of 2526 respondents, a number of significant differences in the mean rating by broad discipline area of the importance of, and satisfaction with, a range of elements of an OLE were found. Broadly speaking, the Arts and Science and Technology discipline areas reported the lowest importance and satisfaction ratings for the OLE, while the Health and Behavioural Sciences area was the most satisfied with the OLE. A number of specific, systematic discipline differences are reported and discussed. Compared to the observed significant differences in mean importance ratings, there were fewer significant differences in mean satisfaction ratings, and those that were observed were less systematic than for importance ratings.

Missing value estimation for mixed-attribute data sets

Missing data imputation is a key issue in learning from incomplete data. Various techniques have been developed with great successes on dealing with missing values in data sets with homogeneous attributes (their independent attributes are all either continuous or discrete). This paper studies a new setting of missing data imputation, i.e., imputing missing data in data sets with heterogeneous attributes (their independent attributes are of different types), referred to as imputing mixed-attribute data sets. Although many real applications are in this setting, there is no estimator designed for imputing mixed-attribute data sets. This paper first proposes two consistent estimators for discrete and continuous missing target values, respectively. And then, a mixture-kernel-based iterative estimator is advocated to impute mixed-attribute data sets. The proposed method is evaluated with extensive experiments compared with some typical algorithms, and the result demonstrates that the proposed approach is better than these existing imputation methods in terms of classification accuracy and root mean square error (RMSE) at different missing ratios.