Age-dependence of the average and equivalent refractive indices of the crystalline lens

Lens average and equivalent refractive indices are required for purposes such as lens thickness estimation and optical modeling. We modeled the refractive index gradient as a power function of the normalized distance from lens center. Average index along the lens axis was estimated by integration. Equivalent index was estimated by raytracing through a model eye to establish ocular refraction, and then backward raytracing to determine the constant refractive index yielding the same refraction. Assuming center and edge indices remained constant with age, at 1.415 and 1.37 respectively, average axial refractive index increased (1.408 to 1.411) and equivalent index decreased (1.425 to 1.420) with age increase from 20 to 70 years. These values agree well with experimental estimates based on different techniques, although the latter show considerable scatter. The simple model of index gradient gives reasonable estimates of average and equivalent lens indices, although refinements in modeling and measurements are required.

Age, physical inactivity, obesity, health conditions, and health-related quality of life among patients receiving conservative management for musculoskeletal disorders

Background Musculoskeletal conditions and insufficient physical activity have substantial personal and economic costs among contemporary aging societies. This study examined the age distribution, comorbid health conditions, body mass index (BMI), self-reported physical activity levels, and health-related quality of life of patients accessing ambulatory hospital clinics for musculoskeletal disorders. The study also investigated whether comorbidity, BMI, and self-reported physical activity were associated with patients’ health-related quality of life after adjusting for age as a potential confounder. Methods A cross-sectional survey was undertaken in three ambulatory hospital clinics for musculoskeletal disorders. Participants (n=224) reported their reason for referral, age, comorbid health conditions, BMI, physical activity levels (Active Australia Survey), and health-related quality of life (EQ-5D). Descriptive statistics and linear modeling were used to examine the associations between age, comorbidity, BMI, intensity and duration of physical activity, and health-related quality of life. Results The majority of patients (n=115, 51.3%) reported two or more comorbidities. In addition to other musculoskeletal conditions, common comorbidities included depression (n=41, 18.3%), hypertension (n=40, 17.9%), and diabetes (n=39, 17.4%). Approximately one-half of participants (n=110, 49.1%) self-reported insufficient physical activity to meet minimum recommended guidelines and 150 (67.0%) were overweight (n=56, 23.2%), obese (n=64, 28.6%), severely obese (n=16, 7.1%), or very severely obese (n=14, 6.3%), with a higher proportion of older patients affected. A generalized linear model indicated that, after adjusting for age, self-reported physical activity was positively associated (z=4.22, P<0.001), and comorbidities were negatively associated (z=-2.67, P<0.01) with patients’ health-related quality of life. Conclusion Older patients were more frequently affected by undesirable clinical attributes of comorbidity, obesity, and physical inactivity. However, findings from this investigation are compelling for the care of patients of all ages. Potential integration of physical activity behavior change or other effective lifestyle interventions into models of care for patients with musculoskeletal disorders is worthy of further investigation.

Temporal Characterization of Ossification of the Crania in Australian Subadults: New standards for Age Estimation using Computed Tomography

After attending this presentation, attendees will gain awareness of the ontogeny of cranial maturation, specifically: (1) the fusion timings of primary ossification centers in the basicranium; and (2) the temporal pattern of closure of the anterior fontanelle, to develop new population-specific age standards for medicolegal death investigation of Australian subadults. This presentation will impact the forensic science community by demonstrating the potential of a contemporary forensic subadult Computed Tomography (CT) database of cranial scans and population data, to recalibrate existing standards for age estimation and quantify growth and development of Australian children. This research welcomes a study design applicable to all countries faced with paucity in skeletal repositories. Accurate assessment of age-at-death of skeletal remains represents a key element in forensic anthropology methodology. In Australian casework, age standards derived from American reference samples are applied in light of scarcity in documented Australian skeletal collections. Currently practitioners rely on antiquated standards, such as the Scheuer and Black1 compilation for age estimation, despite implications of secular trends and population variation. Skeletal maturation standards are population specific and should not be extrapolated from one population to another, while secular changes in skeletal dimensions and accelerated maturation underscore the importance of establishing modern standards to estimate age in modern subadults. Despite CT imaging becoming the gold standard for skeletal analysis in Australia, practitioners caution the application of forensic age standards derived from macroscopic inspection to a CT medium, suggesting a need for revised methodologies. Multi-slice CT scans of subadult crania and cervical vertebrae 1 and 2 were acquired from 350 Australian individuals (males: n=193, females: n=157) aged birth to 12 years. The CT database, projected at 920 individuals upon completion (January 2014), comprises thin-slice DICOM data (resolution: 0.5/0.3mm) of patients scanned since 2010 at major Brisbane Childrens Hospitals. DICOM datasets were subject to manual segmentation, followed by the construction of multi-planar and volume rendering cranial models, for subsequent scoring. The union of primary ossification centers of the occipital bone were scored as open, partially closed or completely closed; while the fontanelles, and vertebrae were scored in accordance with two stages. Transition analysis was applied to elucidate age at transition between union states for each center, and robust age parameters established using Bayesian statistics. In comparison to reported literature, closure of the fontanelles and contiguous sutures in Australian infants occur earlier than reported, with the anterior fontanelle transitioning from open to closed at 16.7±1.1 months. The metopic suture is closed prior to 10 weeks post-partum and completely obliterated by 6 months of age, independent of sex. Utilizing reverse engineering capabilities, an alternate method for infant age estimation based on quantification of fontanelle area and non-linear regression with variance component modeling will be presented. Closure models indicate that the greatest rate of change in anterior fontanelle area occurs prior to 5 months of age. This study complements the work of Scheuer and Black1, providing more specific age intervals for union and temporal maturity of each primary ossification center of the occipital bone. For example, dominant fusion of the sutura intra-occipitalis posterior occurs before 9 months of age, followed by persistence of a hyaline cartilage tongue posterior to the foramen magnum until 2.5 years; with obliteration at 2.9±0.1 years. Recalibrated age parameters for the atlas and axis are presented, with the anterior arch of the atlas appearing at 2.9 months in females and 6.3 months in males; while dentoneural, dentocentral and neurocentral junctions of the axis transitioned from non-union to union at 2.1±0.1 years in females and 3.7±0.1 years in males. These results are an exemplar of significant sexual dimorphism in maturation (p<0.05), with girls exhibiting union earlier than boys, justifying the need for segregated sex standards for age estimation. Studies such as this are imperative for providing updated standards for Australian forensic and pediatric practice and provide an insight into skeletal development of this population. During this presentation, the utility of novel regression models for age estimation of infants will be discussed, with emphasis on three-dimensional modeling capabilities of complex structures such as fontanelles, for the development of new age estimation methods.

Lens shape and refractive index distribution in type 1 diabetes

Purpose: To compare lens dimensions and refractive index distributions in type 1 diabetes and age-matched control groups. Methods: There were 17 participants with type 1 diabetes, consisting of two subgroups (7 young [23 ± 4 years] and 10 older [54 ± 4 years] participants), with 23 controls (13 young, 24 ± 4 years; 10 older, 55 ± 4 years). For each participant, one eye was tested with relaxed accommodation. A 3T clinical magnetic resonance imaging scanner was used to image the eye, employing a multiple spin echo (MSE) sequence to determine lens dimensions and refractive index profiles along the equatorial and axial directions. Results: The diabetes group had significantly smaller lens equatorial diameters and larger lens axial thicknesses than the control group (diameter mean ± 95% confidence interval [CI]: diabetes group 8.65 ± 0.26 mm, control group 9.42 ± 0.18 mm; axial thickness: diabetes group 4.33 ± 0.30 mm, control group 3.80 ± 0.14 mm). These differences were also significant within each age group. The older group had significantly greater axial thickness than the young group (older group 4.35 ± 0.26 mm, young group 3.70 ± 0.25 mm). Center refractive indices of diabetes and control groups were not significantly different. There were some statistically significant differences between the refractive index fitting parameters of young and older groups, but not between diabetes and control groups of the same age. Conclusions: Smaller lens diameters occurred in the diabetes groups than in the age-matched control groups. Differences in refractive index distribution between persons with and without diabetes are too small to have important effects on instruments measuring axial thickness.

Teacher-child relationship quality for young children with parent reported language concerns

Previous research has demonstrated the importance of the qualities of the teacher-child relationship on children’s development. Close teacher-child relationships are especially important for children at risk. Positive relationships have been shown to have beneficial effects on children’s social and academic development (Birch & Ladd, 1997; Pianta & Stuhlman, 2004). Children with language difficulties are likely to face increased risks with regard to long term social and academic outcomes. The purpose of the current research was to gain greater understanding of the qualities of teacher-child relationships for young children with parent reported language concerns. The research analyses completed for this thesis involved the use of data from the public-access database of Growing Up in Australia: The Longitudinal Study of Australian Children (LSAC). LSAC is a longitudinal study involving a nationally representative sample of 10,000 Australian children. Data are being collected biennially from 2004 (Wave 1 data collection) until 2010 (Wave 4 data collection). LSAC has a cross-sequential research design involving two cohorts, an infant cohort (0-1 year at age of recruitment) and a kindergarten cohort (4-5 years at age of recruitment). Two studies are reported in this thesis using data for the LSAC Kindergarten Cohort which had 4983 child participants at recruitment. Study 1 used Wave 1 data to identify the differences between teacher-child relationship qualities for children with parent reported language concerns and their peers. Children identified by parents for whom concerns were held about their receptive and expressive language, as measured by items from the Parents’ Evaluation of Developmental Status (PEDS) (Glascoe, 2000) were the target (at risk) group in the study (n = 210). A matched case control group of peers (n = 210), matched on the child characteristics of sex, age, cultural and linguistic differences (CALD), and socio-economic positioning (SEP), were the comparison group for this analysis. Teacher-child relationship quality was measured by teacher reports on the Closeness and Conflict scales from the short version of the Student-Teacher Relationship Scale (STRS) (Pianta, 2001). There were statistically significant differences in the levels of closeness and conflict between the two groups. The target group had relationships with their teachers that had lower levels of closeness and higher levels of conflict than the control group. Study 2 reports analyses that examined the stability of the qualities of the teacher-child relationships at Wave 1 (4-5 years) and the qualities of the teacher-child relationships at Wave 2 (6-7 years). This time frame crosses the period of the children’s transition to school. The study examined whether early patterns in the qualities of the teacher-child relationship for children with parent reported language concerns at Wave 1 predicted the qualities of the teacher-child relationship outcomes in the early years of formal school. The sample for this study consisted of the group of children identified with PEDS language concerns at Wave 1 who also had teacher report data at Wave 2 (n = 145). Teacher-child relationship quality at Wave 1 and Wave 2 was again measured by the STRS scales of Closeness and Conflict. Results from multiple regression models indicated that teacher-child relationship quality at Wave 1 significantly contributed to the prediction of the quality of the teacher-child relationship at Wave 2, beyond other predictor variables included in the regression models. Specifically, Wave 1 STRS Closeness scores were the most significant predictor for STRS Closeness scores at Wave 2, while Wave 1 STRS Conflict scores were the only significant predictor for Wave 2 STRS Conflict outcomes. These results indicate that the qualities of the teacher-child relationship experienced prior to school by children with parent reported language concerns remained stable across transitions into formal schooling at which time the child had a different teacher. The results of these studies provide valuable insight into the nature of teacher-child relationship quality for young children with parent reported language concerns. These children experienced teacher-child relationships of a lower quality when compared with peers and, additionally, the qualities of these relationships prior to formal schooling were predictive of the qualities of the relationships in the early years of formal schooling. This raises concerns, given the increased risks of poorer social and academic outcomes already faced by children with language difficulties, that these early teacher-child relationships have an impact on future teacher-child relationships. Results of these studies are discussed with these considerations in mind and also discussed in terms of the implications for educational theory, policy and practice.

Corneal sensitivity and slit scanning in vivo confocal microscopy of the subbasal nerve plexus of the normal central and peripheral human cornea

Purpose: To determine the subbasal nerve density and tortuosity at 5 corneal locations and to investigate whether these microstructural observations correlate with corneal sensitivity. Method: Sixty eyes of 60 normal human subjects were recruited into 1 of 3 age groups, group 1: aged ,35 years, group 2: aged 35–50 years, and group 3: aged .50 years. All eyes were examined using slit-lamp biomicroscopy, noncontact corneal esthesiometry, and slit scanning in vivo confocal microscopy. Results: The mean subbasal nerve density and the mean corneal sensitivity were greatest centrally (14,731 6 6056 mm/mm2 and 0.38 6 0.21 millibars, respectively) and lowest in the nasal mid periphery (7850 6 4947 mm/mm2 and 0.49 6 0.25 millibars, respectively). The mean subbasal nerve tortuosity coefficient was greatest in the temporal mid periphery (27.3 6 6.4) and lowest in the superior mid periphery (19.3 6 14.1). There was no significant difference in mean total subbasal nerve density between age groups. However, corneal sensation (P = 0.001) and subbasal nerve tortuosity (P = 0.004) demonstrated significant differences between age groups. Subbasal nerve density only showed significant correlations with corneal sensitivity threshold in the temporal cornea and with subbasal nerve tortuosity in the inferior and nasal cornea. However, these correlations were weak. Conclusions: This study quantitatively analyzes living human corneal nerve structure and an aspect of nerve function. There is no strong correlation between subbasal nerve density and corneal sensation. This study provides useful baseline data for the normal living human cornea at central and mid-peripheral locations

Promotion and succession management and associated retention issues in Australian law firms

The focus of this research was promotion and succession management in Australian law firms. Two staff retention issues currently faced by the Australian legal industry were identified as suggesting possible failures in this area: 1) Practitioners are leaving law firms early in their careers, 2) Female representation is disproportionally low at partnership level. The research described current Australian law firm promotion and succession practices and then explained their possible relevance to the two retention issues. The overall aim of the research was to uncover key findings and present practical recommendations to law firm managers and partners ready for incorporation into their future promotion and succession planning practice. In so doing the research aimed to benefit the Australian legal community as a whole. Four areas of literature relevant to the topic were reviewed, 1) law firm governance concluding that the fundamental values of the P²-Form remained constant (Cooper, Hinings, Greenwood & Brown, 1996; Morris & Pinnington, 1998) with ownership and strategic control of law firms remaining in the hands of partners; 2) the importance of individual practitioners to law firms concluding that the actual and opportunity costs relating to practitioner turnover were significant due to the transient nature of knowledge as a key asset of law firms (Gottschalk & Khandelwal, 2004; Rebitzer & Taylor, 2007); 3) generational differences concluding with support for the work of Finegold, Mohrman and Spreitzer (2002), Davis, Pawlowski and Houston (2006), Kuhnreuther (2003), and Avery, McKay, and Wilson (2007) which indicated that generational cohort differences were of little utility in human resources management practice; and 4) previous research relating to law firm promotion and succession practices indicating that five practices were relevant in law firm promotion outcomes; 1) firm billing requirements (Gorman & Kmec, 2009; Phillips, 2001; Noonan & Corcoran, 2004; Webley & Duff, 2007); 2) mentoring programs (Phillips, 2001; Noonan & Corcoran, 2004); 3) the existence of female partners (Gorman & Kmec, 2009; Beckman & Phillips, 2005); 4) non-partner career paths (Phillips, 2001; Corcoran & Noonan, 2004); and 5) the existence of family friendly policies (Gorman & Kmec, 2009; Phillips, 2001; Noonan & Corcoran, 2004; Webley & Duff, 2007.) The research was carried out via a sequential mixed method approach. The initial quantitative study was based upon a theoretical framework grounded in the literature and provided baseline information describing Australian law firm promotion and succession practices. The study was carried out via an on-line survey of Australian law firm practitioners. The results of the study provided the basis for the second qualitative study. The qualitative study further explained the statistically generated results and focused specifically on the two identified retention issues. The study was conducted via one-on-one interviews with Australian law firm partners and experienced law firm managers. The results of both studies were combined within the context of relevant literature resulting in eight key findings: Key findings 1) Organisational commitment levels across generational cohorts are more homogenous than different. 2) Law firm practitioners are leaving law firms early in their careers due to the heavy time commitment behaviour demanded of them, particularly by clients. 3) Law firm promotion and succession practices reinforce practitioner time commitment behaviour marking it as an indicator of practitioner success. 4) Law firm practitioners believe that they have many career options outside law firms and are considering these options. 5) Female practitioners are considering opting out of law firms due to time commitment demands related to partnership conflicting with family commitment demands. 6) A masculine, high time commitment culture in law firms is related to the decision by female practitioners to leave law firms. 7) The uptake of alternative work arrangements by female practitioners is not fatal to their partnership prospects particularly in firms with supportive policies, processes and organisational culture. 8) Female practitioners are less inclined than their male counterparts to seek partnership as an ultimate goal and are more likely to opt out of law firms exhibiting highly competitive, masculine cultures. Practical recommendations Further review of the data collected in relation to the key findings provided the basis for nine practical recommendations specifically geared towards implementation by law firm managers and partners. The first recommendation relates to the use of generational differences in practitioner management. The next six relate to recommended actions to reduce the time commitment demands on practitioners. The final two recommendations relate to the practical implementation of these actions both at an individual and organisational level. The recommendations are as follows: 1) "Generationally driven," age based generalisations should not be utilised in law firm promotion and succession management practice. 2) Expected levels of client access to practitioners be negotiated on a client by client basis and be included in client retention agreements. 3) Appropriate alternative working arrangements such as working off-site, flexible working hours or part-time work be offered to practitioners in situations where doing so will not compromise client serviceability. 4) The copying of long working hour behaviours of senior practitioners should be discouraged particularly where information technology can facilitate remote client serviceability. 5) Refocus the use of timesheets from an employer monitoring tool to an employee empowerment tool. 6) Policies and processes relating to the offer of alternative working arrangements be supported and reinforced by law firm organisational culture. 7) Requests for alternative working arrangements be determined without regard to gender. 8) Incentives and employment conditions offered to practitioners to be individualised based on the subjective need of the individual and negotiated as a part of the current employee performance review process. 9) Individually negotiated employment conditions be negotiated within the context of the firm’s overall strategic planning process. Through the conduct of the descripto-explanatory study, a detailed discussion of current law firm promotion and succession practices was enabled. From this discussion, 7 eight key findings and nine associated recommendations were generated as well as an insight into the future of the profession being given. The key findings and recommendations provide practical advice to law firm managers and partners in relation to their everyday promotion and succession practice. The need to negotiate individual employee workplace conditions and their integration into overall law firm business planning was put forward. By doing so, it was suggested that both the individual employee and the employing law firm would mutually benefit from the arrangement. The study therefore broadened its practical contribution from human resources management to a contribution to the overall management practice of Australian law firms. In so doing, the research has provided an encompassing contribution to the Australian legal industry both in terms of employee welfare as well as firm and industry level success.

Towards a structured understanding of caregivers’ safety behaviour in the domestic and driveway setting

Slow speed run-overs represent a major cause of injury and death among Australian children, with higher rates of incidents being reported in Queensland than in the remaining Australian states. Yet, little attention has been given to how caregivers develop their safety behaviour in and around the driveway setting. To address this gap, the current study aimed to develop a conceptual model of driveway child safety behaviours among caregivers of children aged five years or younger. Semi-structured interviews were conducted with 26 caregivers (25 females/1 male, mean age, 33.24 year) from rural and metropolitan Queensland. To enable a comparison and validation of findings from the driveway, the study analysed both driveway and domestic safety behaviours. Domestic safety behaviours were categorised and validated against driveway safety behaviours, uncovering a process of risk appraisal and safety behaviour that was applicable in both settings (the Safety System Model). However, noteworthy differences between the domestic and driveway setting were uncovered. Unlike in the domestic setting, driveway risks were perceived as shifting according the presence of moving vehicles, which resulted in inconsistent safety behaviours. While the findings require further validation, they have implications for the design and implementation of driveway run-over interventions.

Exploring young student's functional thinking (Exploración del pensamiento funcional de estudiantes jóvenes)

The Early Years Generalizing Project (EYGP) involves Australian years 1 to 4 (age 5 to 9) students and investigates how they grasp and express generalizations. This paper focuses on data collected from 6 Year 1 students in an exploratory study within a clinical interview setting that required students to identify function rules. Preliminary findings suggest that the use of gestures (both by students and interviewers), self-talk (by students), and concrete acting out, assisted students to reach generalizations and to begin to express these generalities. It also appears that as students became aware of the structure, their use of gestures and selftalk tended to decrease.

Good choices, great future : an applied theatre prevention program to reduce alcohol-related risky behaviours during Schoolies

Introduction and Aims. The contextual and temporal factors of post-school celebratory events ('Schoolies') place young people at elevated risk of excessive drinking compared with other social occasions. This study investigates the impact of an applied theatre prevention program 'Choices' in reducing the risk of drinking and other risk behaviours during Schoolies celebrations. Design and Methods. Choices was delivered in the last term of Year 12 across 28 North Queensland schools. A total of 352 school leavers (43.1% male, mean age=17.14years) completed a questionnaire at Whitsunday Schoolies, Queensland, Australia on 23-24 November 2010. Nearly 49% of respondents had attended Choices. The survey included measures of alcohol use, illicit drug use and associated problems during Schoolies and a month prior to Schoolies. Results. After controlling for gender and pre-Schoolies drinking, school leavers who attended Choices were significantly less likely to report illicit drug use (OR=0.51, P<0.05) and problem behaviours (OR=0.40, P<0.01) than those who did not attend Choices. There was, however, no intervention effect in risky drinking (i.e. drank on 5 or more days, typical amount five or more standard drink and binge drank on 3 or more days) at Schoolies (OR=0.92, P=0.80). Discussion and Conclusions. Delivery of a youth-specific applied theatre prevention program employing a harm minimisation framework may be effective in reducing high-risk behaviours associated with alcohol consumption at celebratory events, even if young people expect to engage in excessive alcohol consumption. [Quek L-H, White A, Low C, Brown J, Dalton N, Dow D, Connor JP. Good choices, great future: An applied theatre prevention program to reduce alcohol-related risky behaviours during Schoolies. Drug Alcohol Rev 2012;31:897–902]

Identification of major loci controlling clinical manifestations of ankylosing spondylitis

Objective. To identify genomic regions linked with determinants of age at symptom onset, disease activity, and functional impairment in ankylosing spondylitis (AS). Methods. A whole genome linkage scan was performed in 188 affected sibling pair families with 454 affected individuals. Traits assessed were age at symptom onset, disease activity assessed by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and functional impairment assessed by the Bath Ankylosing Spondylitis Functional Index (BASFI). Parametric and nonparametric quantitative linkage analysis was performed using parameters defined in a previous segregation study. Results. Heritabilities of the traits studied in this data set were as follows: BASDAI 0.49 (P = 0.0001, 95% confidence interval [95% CI] 0.23-0.75), BASFI 0.76 (P = 10-7, 95% CI 0.49-1.0), and age at symptom onset 0.33 (P = 0.005, 95% CI 0.04-0.62). No linkage was observed between the major histocompatibility complex (MHC) and any of the traits studied (logarithm of odds [LOD] score <1.0). "Significant" linkage (LOD score 4.0) was observed between a region on chromosome 18p and the BASDAI. Age at symptom onset showed "suggestive" linkage to chromosome 11p (LOD score 3.3). Maximum linkage with the BASFI was seen at chromosome 2q (LOD score 2.9). Conclusion. In contrast to the genetic determinants of susceptibility to AS, clinical manifestations of the disease measured by the BASDAI, BASFI, and age at symptom onset are largely determined by a small number of genes not encoded within the MHC.

The prevalence, predictors and associations of hypertension in Sri Lanka: A cross-sectional population based national survey

We studied the community prevalence, patterns and predictors of hypertension in a large sub-population of South Asian adults with a view of identifying differential risk factors. Data were collected between years 2005-2006 and 5000 adults were invited for the study. The sample size was 4485, and about 39.5% were males. Mean systolic and diastolic blood pressures were 127.1 ± 19.8 mmHg and 75.4 ± 11.3 mmHg, respectively. Age-adjusted prevalence in all adults, males and females was 23.7%, 23.4% and 23.8%, respectively. Urban adults had a significantly higher prevalence of hypertension than rural adults. In the binary logistic-regression analysis, male gender (OR: 1.2), increasing age, Sri Lankan Moor ethnicity (OR: 1.6), physical inactivity (OR: 1.7), presence of diabetes (OR: 2.2) and central obesity (OR: 2.3) all were significantly associated with hypertension. In conclusion, nearly one-third of the Sri Lankan adult population is hypertensive. Hence, public health initiatives should encourage healthier lifestyles with emphasis on preventing obesity and increasing physical activity.

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.

Age-related loss of brain volume and T2 relaxation time in youth with type 1 diabetes

OBJECTIVE: Childhood-onset type 1 diabetes is associated with neurocognitive deficits, but there is limited evidence to date regarding associated neuroanatomical brain changes and their relationship to illness variables such as age at disease onset. This report examines age-related changes in volume and T2 relaxation time (a fundamental parameter of magnetic resonance imaging that reflects tissue health) across the whole brain. RESEARCH DESIGN AND METHODS: Type 1 diabetes, N = 79 (mean age 20.32 ± 4.24 years), and healthy control participants, N = 50 (mean age 20.53 ± 3.60 years). There were no substantial group differences on socioeconomic status, sex ratio, or intelligence quotient. RESULTS: Regression analyses revealed a negative correlation between age and brain changes, with decreasing gray matter volume and T2 relaxation time with age in multiple brain regions in the type 1 diabetes group. In comparison, the age-related decline in the control group was small. Examination of the interaction of group and age confirmed a group difference (type 1 diabetes vs. control) in the relationship between age and brain volume/T2 relaxation time. CONCLUSIONS: We demonstrated an interaction between age and group in predicting brain volumes and T2 relaxation time such that there was a decline in these outcomes in type 1 diabetic participants that was much less evident in control subjects. Findings suggest the neurodevelopmental pathways of youth with type 1 diabetes have diverged from those of their healthy peers by late adolescence and early adulthood but the explanation for this phenomenon remains to be clarified.