Nonlinear growth generates age changes in the moments of the frequency distribution: the example of height in puberty

Higher moments of the frequency distribution of child height and weight change with age, particularly during puberty, though why is not known. Our aims were to confirm that height skewness and kurtosis change with age during puberty, to devise a model to explain why, and to test the model by analyzing the data longitudinally. Heights of 3245 Christ's Hospital School boys born during 1927-1956 were measured twice termly from 9 to 20 years (n = 129 508). Treating the data as independent, the mean, standard deviation (SD), skewness, and kurtosis were calculated in 40 age groups and plotted as functions of age t. The data were also analyzed longitudinally using the nonlinear random-effects growth model H( t) = h( t - epsilon) + alpha, with H( t) the cross-sectional data, h( t) the individual mean curve, and epsilon and alpha subject-specific random effects reflecting variability in age and height at peak height velocity (PHV). Mean height increased monotonically with age, while the SD, skewness, and kurtosis changed cyclically with, respectively, 1, 2, and 3 turning points. Surprisingly, their age curves corresponded closely in shape to the first, second, and third derivatives of the mean height curve. The growth model expanded as a Taylor series in e predicted such a pattern, and the longitudinal analysis showed that adjusting for age at PHV on a multiplicative scale largely removed the trends in the higher moments. A nonlinear growth process where subjects grow at different rates, such as in puberty, generates cyclical changes in the higher moments of the frequency distribution

A study into the demand for apartments in central Auckland

Property developers have been reported as 'shunning Auckland's inner city marketâ in 2007 reducing their investments from around 2000 units (worth $600 million) in 2006 to around 150 units (worth$45 million) in 2008 (Gibson, 2007). The sale activities of apartments in the Auckland city central have dropped significantly in the first quarter of 2008 compared to the similar period last year. In spite of this however, there are new apartments under constructing or on the drawing board. The Reserve Bank of New Zealand (RBNZ) has raised its benchmark interest rate four times between March and July 2007 to 8.25, and is still under pressure to increase this further. What then is the trend of apartment prices in Auckland central city and whether apartments are worthy of investment in the near future? In order to answer these questions, this paper aims at studying the main determinants for the demand of apartments in the near future using the statistical method, analysing collected sales data. A total of 4,460 validated sale transactions of inner-city apartments in Auckland have been analysed in this study. A key finding of the study is that the number of international students and the net migration of residents are two factors that have an immediate impact on the sales of apartment in the Aucklandâs inner city. The main demand for apartments, especially those with an internal floor area of less than 50 square meters, are from the international students who would mainly rent the apartments, fuelling investor demands in turn. A consistent policy for overseas students to accommodate demand for apartments is thus an important ingredient in stabilising prices of apartment in Auckland

Assessing individual dietary intake in food sharing scenarios with food and human pose detection

Food sharing and communal eating are very common in some countries. To assess individual dietary intake in food sharing scenarios, this work proposes a vision-based approach to first capturing the food sharing scenario with a 360-degree camera, and then using a neural network to infer different eating states of each individual based on their body pose and relative positions to the dishes. The number of bites each individual has taken of each dish is then deduced by analyzing the inferred eating states. A new dataset with 14 panoramic food sharing videos was constructed to validate our approach. The results show that our approach is able to reliably predict different eating states as well as individual’s bite count with respect to each dish in food sharing scenarios

Solitary Esophageal Varix Simulating a Neoplasm

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73070/1/j.1440-1673.1988.tb02785.x.pd

Nucleation mechanism for the direct graphite-to-diamond phase transition

Graphite and diamond have comparable free energies, yet forming diamond from graphite is far from easy. In the absence of a catalyst, pressures that are significantly higher than the equilibrium coexistence pressures are required to induce the graphite-to-diamond transition. Furthermore, the formation of the metastable hexagonal polymorph of diamond instead of the more stable cubic diamond is favored at lower temperatures. The concerted mechanism suggested in previous theoretical studies cannot explain these phenomena. Using an ab initio quality neural-network potential we performed a large-scale study of the graphite-to-diamond transition assuming that it occurs via nucleation. The nucleation mechanism accounts for the observed phenomenology and reveals its microscopic origins. We demonstrated that the large lattice distortions that accompany the formation of the diamond nuclei inhibit the phase transition at low pressure and direct it towards the hexagonal diamond phase at higher pressure. The nucleation mechanism proposed in this work is an important step towards a better understanding of structural transformations in a wide range of complex systems such as amorphous carbon and carbon nanomaterials

Assessment of GFR by four methods in adults in Ashanti, Ghana: the need for an eGFR equation for lean African populations

Background. Equations for estimating glomerular filtration rate (GFR) have not been validated in Sub-Saharan African populations, and data on GFR are few. Methods. GFR by creatinine clearance (Ccr) using 24-hour urine collections and estimated GFR (eGFR) using the four-variable Modification of Diet in Renal Disease (MDRD-4)[creatinine calibrated to isotope dilution mass spectrometry (IDMS) standard], Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Cockcroft–Gault equations were obtained in Ghanaians aged 40–75. The population comprised 1013 inhabitants in 12 villages; 944 provided a serum creatinine and two 24-hour urines. The mean weight was 54.4 kg; mean body mass index was 21.1 kg/m2. Results. Mean GFR by Ccr was 84.1 ml/min/1.73m2; 86.8% of participants had a GFR of 60 ml/min/1.73m2. Mean MDRD-4 eGFR was 102.3 ml/min/1.73m2 (difference vs. Ccr, 18.2: 95% CI: 16.8–19.5); when the factor for black race was omitted, the value (mean 84.6 ml/min/1.73m2) was close to Ccr. Mean CKD-EPI eGFR was 103.1 ml/min/1.73m2, and 89.4 ml/min/1.73m2 when the factor for race was omitted. The Cockcroft–Gault equation underestimated GFR compared with Ccr by 9.4 ml/min/1.73m2 (CI: 8.3–10.6); particularly in older age groups. GFR by Ccr, and eGFR by MDRD-4, CKD-EPI and Cockcroft–Gault showed falls with age: MDRD-4 5.5, Ccr 7.7, CKD-EPI 8.8 and Cockcroft–Gault 11.0 ml/min/1.73m2/10 years. The percentage of individuals identified with CKD stages 3–5 depended on the method used: MDRD-4 1.6% (7.2 % without factor for black race; CKD-EPI 1.7% (4.7% without factor for black race), Ccr 13.2% and Cockcroft–Gault 21.0%. Conclusions. Mean eGFR by both MDRD-4 and CKD-EPI was considerably higher than GFR by Ccr and Cockcroft–Gault, a difference that may be attributable to leanness. MDRD-4 appeared to underestimate the fall in GFR with age compared with the three other measurements; the fall with CKD-EPI without the adjustment for race was the closest to that of Ccr. An equation tailored specifically to the needs of the lean populations of Africa is urgently needed. For the present, the CKD-EPI equation without the adjustment for black race appears to be the most useful

Agile methods for agile universities

We explore a term, Agile, that is being used in various workplace settings, including the management of universities. The term may have several related but slightly different meanings. Agile is often used in the context of facilitating more creative problem-solving and advocating for the adoption, design, tailoring and continual updating of more innovative organizational processes. We consider a particular set of meanings of the term from the world of software development. Agile methods were created to address certain problems with the software development process. Many of those problems have interesting analogues in the context of universities, so a reflection on agile methods may be a useful heuristic for generating ideas for enabling universities to be more creative

Point2Volume: A vision-based dietary assessment approach using view synthesis

Dietary assessment is an important tool for nutritional epidemiology studies. To assess the dietary intake, the common approach is to carry out 24-h dietary recall (24HR), a structured interview conducted by experienced dietitians. Due to the unconscious biases in such self-reporting methods, many research works have proposed the use of vision-based approaches to provide accurate and objective assessments. In this article, a novel vision-based method based on real-time three-dimensional (3-D) reconstruction and deep learning view synthesis is proposed to enable accurate portion size estimation of food items consumed. A point completion neural network is developed to complete partial point cloud of food items based on a single depth image or video captured from any convenient viewing position. Once 3-D models of food items are reconstructed, the food volume can be estimated through meshing. Compared to previous methods, our method has addressed several major challenges in vision-based dietary assessment, such as view occlusion and scale ambiguity, and it outperforms previous approaches in accurate portion size estimation

The role of gentle touch in perinatal osteopathic manual therapy.

Osteopathic medicine is a system of manual diagnosis and treatment. While there is growing evidence that osteopathy is effective in a range of clinical conditions, the underlying biological basis of its therapeutic effects remain largely unknown. Given that the sense of touch plays a critical role in osteopathy, in this perspective article, with a particular focus on perinatal care, we explore the potential mechanisms by which stimulation of the skin senses can exert beneficial physiological and psychological effects, aiding growth and development. We propose that a class of low threshold mechanosensitive c-fibre, named c-tactile afferents, which respond optimally to gentle, slow moving touch are likely to play a direct and significant role in the efficacy of manual therapies. A greater understanding of the impact the type and quality of touch plays in therapeutic tactile interventions and in particular the neuroscience underpinning these effects will aid the development of more targeted, population specific interventions

Education research in Australia: where is it conducted?

Research assessment exercises aim to identify research quantity and quality and provide insights into research capacity building strategies for the future. Yet with limited knowledge of the ecology of Australian educational research, there is little chance of understanding what research audits might contribute towards a capacity building agenda for such a complex field. This paper draws on secondary data analysis of research outputs submitted by 13 Australian higher education institutions to the Excellence in Research for Australia (ERA) 2010 and 2012 national research assessment exercises, to show where Australian educational research is conducted. Findings offer a profile of education researchers by location in academic organisational units within universities. By analyzing data not accessible through reported ERA data we were also able to present information about appointment profiles, specifically levels and type of appointment within universities, as well as data on institutional and geographic region, and patterns associated with type of outputs (books, book chapters, journal articles, conference papers and other outputs) and field of research. Analysis of the data reveals definitive shifts in the nature of the published outputs and in employment profiles of researchers and their location across university and regional groupings. Research audits are administrative processes that reshape institutional and disciplinary governance structures, policies, individual outputs, work practices and careers, but they are not the sum total of the field per se