Evaluation of growth and changes in body composition following neonatal diagnosis of cystic fibrosis

Early deficits in nutritional status that might require specific treatment and early response to nutritional therapy were studied longitudinally in 25 infants with cystic fibrosis (CF) diagnosed by neonatal screening, using anthropometric and research body composition methodology, and evaluation of pancreatic function. At the time of confirmed diagnosis (mean 5.4 weeks), body mass, length, total body fat (TBF), and total body potassium (TBK) were all significantly reduced. Following diagnosis and commencement of therapy there was a normalization of weight, length, and TBK by 6-12 months of age, indicating catch-up growth. But in some individuals the response was incomplete, and as a group, mean total body fat remained significantly lower than normal at 1 year of age. Seven of 25 (28%) were pancreatic sufficient at diagnosis, and all but one had evidence of declining pancreatic function requiring the institution of pancreatic enzyme therapy during the next 1-9 months. The median age of commencement of enzyme therapy was 10 weeks (range 5 weeks to 11 months). These longitudinal assessments emphasize the dynamic changes occurring in absorptive function, body composition, and nutritional status following neonatal diagnosis of cystic fibrosis and may reflect previously described abnormalities of energy metabolism in this age group. Abnormal body composition is evident in most CF infants following diagnosis by neonatal screening but pancreatic damage may still be evolving. We suggest that early active nutritional therapy and surveillance for changes in pancreatic function are warranted in CF infants diagnosed by neonatal screening.

Survival, growth and quality of life in children after orthotopic liver transplantation: A 5 year experience

The aims of this study were to investigate outcome and to evaluate areas of potential ongoing concern after orthotopic liver transplantation (OLT) in children. Actuarial survival in relation to age and degree of undernutrition at the time of OLT was evaluated in 53 children (age 0.58-14.2 years) undergoing OLT for endstage liver disease. Follow-up studies of growth and quality of life were undertaken in those with a minimum follow-up period of 12 months (n = 26). The overall 3 year actuarial survival was 70%. Survival rates did not differ between age groups (actuarial 2 year survival for ages <1, 1-5 and >5 years were 70, 70 and 69% respectively) but did differ according to nutritional status at OLT (actuarial 2 year survival for children with Z scores for weight <-1 was 57%, >-1 was 95%; P = 0.004). Significant catch-up weight gain was observed by 18 months post-transplant, while height improved less rapidly. Quality of life (assessed by Vineland Adaptive Behaviour Scales incorporating socialization, daily living skills, communication and motor skills) was good (mean composite score 91 ± 19). All school-aged children except one were attending normal school. Two children had mild to moderate intellectual handicap related to post-operative intracerebral complications. Satisfactory long-term survival can be achieved after OLT in children regardless of age but the importance of pre-operative nutrition is emphasized. Survivors have an excellent chance of a good quality of life and of satisfactory catch-up weight gain and growth.

Estimation of growth parameters from multiple-recapture data

This article develops a method for analysis of growth data with multiple recaptures when the initial ages for all individuals are unknown. The existing approaches either impute the initial ages or model them as random effects. Assumptions about the initial age are not verifiable because all the initial ages are unknown. We present an alternative approach that treats all the lengths including the length at first capture as correlated repeated measures for each individual. Optimal estimating equations are developed using the generalized estimating equations approach that only requires the first two moment assumptions. Explicit expressions for estimation of both mean growth parameters and variance components are given to minimize the computational complexity. Simulation studies indicate that the proposed method works well. Two real data sets are analyzed for illustration, one from whelks (Dicathais aegaota) and the other from southern rock lobster (Jasus edwardsii) in South Australia.

Groucho homologue Grg5 interacts with the transcription factor Runx2-Cbfa1 and modulates its activity during postnatal growth in mice

Runx2-Cbfal, a Runt transcription factor, plays important roles during skeletal development. It is required for differentiation and function of osteoblasts. In its absence, chondrocyte hypertrophy is severely impaired and there is no vascularization of cartilage templates during skeletal development. These tissue-specific functions of Runx2 are likely to be dependent on its interaction with other proteins. We have therefore searched for proteins that may modulate the activity of Runx2. The yeast two-hybrid system was used to identify a groucho homologue, Grg5, as a Runx2-interacting protein. Grg5 enhances Runx2 activity in a cell culture-based assay and by analyses of postnatal growth in mice we demonstrate that Grg5 and Runx2 interact genetically. We also show that Runx2 haploinsufficiency in the absence of Grg5 results in a more severe delay in ossification of cranial sutures and fontanels than occurs with Runx2 haploinsufficiency on a wild-type background. Finally, we find shortening of the proliferative and hypertrophic zones, and expansion of the resting zone in the growth plates of Runx2(+/-)Grg5(-/-) mice that are associated with reduced Ihh expression and Indian hedgehog (Ihh) signaling. We therefore conclude that Grg5 enhances Runx2 activity in vivo.

Growth defect in Grg5 null mice is associated with reduced Ihh signaling in growth plates

Gene-targeted disruption of Grg5, a mouse homologue of Drosophila groucho (gro), results in postnatal growth retardation in mice. The growth defect, most striking in approximately half of the Grg5 null mice, occurs during the first 4-5 weeks of age, but most mice recover retarded growth later. We used the nonlinear mixed-effects model to fit the growth data of wild-type, heterozygous, and Grg5 null mice. On the basis of preliminary evidence suggesting an interaction between Grg5 and the transcription factor Cbfa1/Runx2, critical for skeletal development, we further investigated the skeleton in the mice. A long bone growth plate defect was identified, which included shorter zones of proliferative and hypertrophic chondrocytes and decreased trabecular bone formation. This decreased trabecular bone formation is likely caused by a reduced recruitment of osteoblasts into the growth plate region of Grg5 null mice. Like the growth defect, the growth plate and trabecular bone abnormality improved as the mice grew older. The growth plate defect was associated with reduced Indian hedgehog expression and signaling. We suggest that Grg5, a transcriptional coregulator, modulates the activities of transcription factors, such as Cbfa1/Runx2 in vivo to affect Ihh expression and the function of long bone growth plates.

Estimating equations for parameters in stochastic growth models from tag-recapture data

James (1991, Biometrics 47, 1519-1530) constructed unbiased estimating functions for estimating the two parameters in the von Bertalanffy growth curve from tag-recapture data. This paper provides unbiased estimating functions for a class of growth models that incorporate stochastic components and explanatory variables. a simulation study using seasonal growth models indicates that the proposed method works well while the least-squares methods that are commonly used in the literature may produce substantially biased estimates. The proposed model and method are also applied to real data from tagged rack lobsters to assess the possible seasonal effect on growth.

An improved Fabens method for estimation of growth parameters in the vonBertalanffy model with individual asymptotes

In the analysis of tagging data, it has been found that the least-squares method, based on the increment function known as the Fabens method, produces biased estimates because individual variability in growth is not allowed for. This paper modifies the Fabens method to account for individual variability in the length asymptote. Significance tests using t-statistics or log-likelihood ratio statistics may be applied to show the level of individual variability. Simulation results indicate that the modified method reduces the biases in the estimates to negligible proportions. Tagging data from tiger prawns (Penaeus esculentus and Penaeus semisulcatus) and rock lobster (Panulirus ornatus) are analysed as an illustration.

Growth curves with explanatory variables and estimation of the effect of tagging

The von Bertalanffy growth model is extended to incorporate explanatory variables. The generalized model includes the switched growth model and the seasonal growth model as special cases, and can also be used to assess the tagging effect on growth. Distribution-free and consistent estimating functions are constructed for estimation of growth parameters from tag-recapture data in which age at release is unknown. This generalizes the work of James (1991, Biometrics 47 1519-1530) who considered the classical model and allowed for individual variability in growth. A real dataset from barramundi (Lates calcarifer) is analysed to estimate the growth parameters and possible effect of tagging on growth.

Modelling growth rate of Penaeus monodon Fabricius in intensively managed ponds: effects of temperature, pond age and stocking density

Records of shrimp growth and water quality made during 12 crops from each of 48 ponds, over a period of 6.5 years, were provided by a Queensland, Australia, commercial shrimp farm, These data were analysed with a new growth model derived from the Gompertz model. The results indicate that water temperature, mortality and pond age significantly affect growth rates. After 180 days, shrimp reach 34 g at constant 30 degrees C, but only 15 g after the same amount of time at 20 degrees C. Mortality, through thinning the density of shrimp in the ponds, increased the growth rate, but the effect is small. With continual production, growth rates at first remained steady, then appeared to decrease for the sixth and seventh crop, after which they have increased steadily with each crop. It appears that conservative pond management, together with a gradual improvement in husbandry techniques, particularly feed management, brought about this change. This has encouraging implications for the long-term sustainability of the farming methods used. The growth model can be used to predict productivity, and hence, profitability, of new aquaculture locations or new production strategies.

Growth and meaning from negotiating the complex journey of being an Emergency Medical Dispatcher

Emergency Medical Dispatchers (EMDs) are charged with taking the calls of those who ring the national emergency number for urgent medical assistance, for dispatching paramedical crews, and for providing as much assistance as can be offered remotely until paramedics arrive. In a job role which is filled with vicarious trauma, emergency situations, pressure, abuse, grief and loss, EMDs are often challenged in maintaining their mental health. The seemingly senseless death of a teenager who commits suicide, the devastating loss of a baby to Sudden Infant Death Syndrome, lives lost through natural disasters, and multiple vehicle fatalities are only a few of the types of experiences EMDs are faced with in the course of their work. However, amongst the horror are positive stories such as coaching a caller to negotiate the birth of a baby and saving a life in jeopardy from heart failure. EMD’s need to cope with the daily challenges of the role; make sense of their work and create meaning in order to have a fulfilled and sustainable career. Although some people in this work struggle greatly to withstand the impacts of vicarious trauma, there are also stories of personal growth. In this Chapter we use a case study to explore how meaning is made for those who are an auditory witness to a continual flux of trauma for others and how the traumatic experiences EMDs bear witness to can also be a catalyst for posttraumatic growth.

A biomechanical investigation of fusionless growth modulation implants for spinal scoliosis treatment

This thesis studied a new minimally invasive implant for scoliosis correction that aims to correct the deformity without fusing the spine, thereby allowing movement and growth in the spine following surgery. The effect of two different vertebral body implant (staple) designs on the stiffness of the spine, using calf spines as an in vitro model, was studied. The results showed that the implants decreased spinal stiffness, with associated potential damage to the growth plates due to the staple tips. There were no significant differences in stiffness between the two staple designs tested.

Insights into the growth of newly formed particles in a subtropical urban environment

The role of different chemical compounds, particularly organics, involved in the new particle formation (NPF) and its consequent growth are not fully understood. Therefore, this study was conducted to investigate the chemical composition of aerosol particles during NPF events in an urban subtropical environment. Aerosol chemical composition was measured along with particle number size distribution (PNSD) and several other air quality parameters at five sites across an urban subtropical environment. An Aerodyne compact Time-of-Flight Aerosol Mass Spectrometer (c-TOF-AMS) and a TSI Scanning Mobility Particle Sizer (SMPS) measured aerosol chemical composition (particles above 50 nm in vacuum aerodynamic diameter) and PNSD (particles within 9-414 nm in mobility diameter), respectively. Five NPF events, with growth rates in the range 3.3-4.6 nm, were detected at two of the sites. The NPF events happened on relatively warmer days with lower condensation sink (CS). Temporal percent fractions of organics increased after the particles grew enough to have a significant contribution to particles volume, while the mass fraction of ammonium and sulphate decreased. This uncovered the important role of organics in the growth of newly formed particles. Three organic markers, factors f43, f44 and f57, were calculated and the f44 vs f43 trends were compared between nucleation and non-nucleation days. K-means cluster analysis was performed on f44 vs f43 data and it was found that they follow different patterns on nucleation days compared to non-nucleation days, whereby f43 decreased for vehicle emission generated particles, while both f44 and f43 decreased for NPF generated particles. It was found for the first time that vehicle generated and newly formed particles cluster in different locations on f44 vs f43 plot and this finding can be potentially used as a tool for source apportionment of measured particles.

Internet marketing capabilities and international market growth

The Internet has been shown to facilitate elements of internationalisation such as information accumulation and network opportunities. However, there is limited understanding of how the Internet combined with marketing capabilities drives international market growth. This study, based on a sample of 224 Australian firms, develops and tests, using structural equation modelling (SEM), a conceptual model of Internet marketing capabilities and international market growth. Results indicate that firms deploying Internet marketing capabilities will benefit due to the reduction of information uncertainty and increased capacity to develop international network capabilities. Moreover, Internet marketing capabilities indirectly lead to international market growth when the firm has a high level of international strategic orientation and international network capabilities. Overall, Internet marketing capabilities enhance the firm's ability to generate other internal capabilities within the firm, which in turn have a positive impact on the international market growth of the firm.

Catalyst-free plasma enhanced growth of graphene from sustainable sources

Details of a fast and sustainable bottom-up process to grow large area high quality graphene films without the aid of any catalyst are reported in this paper. We used Melaleuca alternifolia, a volatile natural extract from tea tree plant as the precursor. The as-fabricated graphene films yielded a stable contact angle of 135°, indicating their potential application in very high hydrophobic coatings. The electronic devices formed by sandwiching pentacene between graphene and aluminum films demonstrated memristive behavior, and hence, these graphene films could find use in nonvolatile memory devices also.