Gradients of refractive index in the crystalline lens and transient changes in refraction among patients with diabetes

Transient hyperopic refractive shifts occur on a timescale of weeks in some patients after initiation of therapy for hyperglycemia, and are usually followed by recovery to the original refraction. Possible lenticular origin of these changes is considered in terms of a paraxial gradient index model. Assuming that the lens thickness and curvatures remain unchanged, as observed in practice, it appears possible to account for initial hyperopic refractive shifts of up to a few diopters by reduction in refractive index near the lens center and alteration in the rate of change between center and surface, so that most of the index change occurs closer to the lens surface. Restoration of the original refraction depends on further change in the refractive index distribution with more gradual changes in refractive index from the lens center to its surface. Modeling limitations are discussed.

The decline in activities of daily living at discharge (DADLD) index : stratifying patients at lower and higher risk

Background: Decreased ability to perform Activities of Daily Living (ADLs) during hospitalisation has negative consequences for patients and health service delivery. Objective: To develop an Index to stratify patients at lower and higher risk of a significant decline in ability to perform ADLs at discharge. Design: Prospective two cohort study comprising a derivation (n=389; mean age 82.3 years; SD� 7.1) and a validation cohort (n=153; mean age 81.5 years; SD� 6.1). Patients and setting: General medical patients aged = 70 years admitted to three university-affiliated acute care hospitals in Brisbane, Australia. Measurement and main results: The short ADL Scale was used to identify a significant decline in ability to perform ADLs from premorbid to discharge. In the derivation cohort, 77 patients (19.8%) experienced a significant decline. Four significant factors were identified for patients independent at baseline: 'requiring moderate assistance to being totally dependent on others with bathing'; 'difficulty understanding others (frequently or all the time)'; 'requiring moderate assistance to being totally dependent on others with performing housework'; a 'history of experiencing at least one fall in the previous 90 days prior to hospital admission' in addition to 'independent at baseline', which was protective against decline at discharge. 'Difficulty understanding others (frequently or all the time)' and 'requiring moderate assistance to being totally dependent on others with performing housework' were also predictors for patients dependent in ADLs at baseline. Sensitivity, specificity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) of the DADLD dichotomised risk scores were: 83.1% (95% CI 72.8; 90.7); 60.5% (95% CI 54.8; 65.9); 34.2% (95% CI 27.5; 41.5); 93.5% (95% CI 89.2; 96.5). In the validation cohort, 47 patients (30.7%) experienced a significant decline. Sensitivity, specificity, PPV and NPV of the DADLD were: 78.7% (95% CI 64.3; 89.3); 69.8% (95% CI 60.1, 78.3); 53.6% (95% CI 41.2; 65.7); 88.1% (95% CI 79.2; 94.1). Conclusions: The DADLD Index is a useful tool for identifying patients at higher risk of decline in ability to perform ADLs at discharge.

Prediction of age at menopause from assessment of ovarian reserve may be improved by using body mass index and smoking status

Objective: Menopause is the consequence of exhaustion of the ovarian follicular pool. AMH, an indirect hormonal marker of ovarian reserve, has been recently proposed as a predictor for age at menopause. Since BMI and smoking status are relevant independent factors associated with age at menopause we evaluated whether a model including all three of these variables could improve AMH-based prediction of age at menopause. Methods: In the present cohort study, participants were 375 eumenorrheic women aged 19–44 years and a sample of 2,635 Italian menopausal women. AMH values were obtained from the eumenorrheic women. Results: Regression analysis of the AMH data showed that a quadratic function of age provided a good description of these data plotted on a logarithmic scale, with a distribution of residual deviates that was not normal but showed significant leftskewness. Under the hypothesis that menopause can be predicted by AMH dropping below a critical threshold, a model predicting menopausal age was constructed from the AMH regression model and applied to the data on menopause. With the AMH threshold dependent on the covariates BMI and smoking status, the effects of these covariates were shown to be highly significant. Conclusions: In the present study we confirmed the good level of conformity between the distributions of observed and AMH-predicted ages at menopause, and showed that using BMI and smoking status as additional variables improves AMH-based prediction of age at menopause.

Towards the development of a best practice index for the disclosure of organisations' climate change-related corporate governance practices

The aim of this study is to develop a disclosure guide for climate-change-related corporate governance (CCCG) practices. Drawing from existing climate change policy guidelines together with content analysis of leading Australian companies’ disclosure practices, we develop a best practice index for the disclosure of CCCG practises. The best practice index is further informed, validated and refined by the contribution of experts from a range of stakeholder groups. Our index represents the most comprehensive list generated to date, utilising experts’ opinions, in relation to CCCG disclosure practices. This CCCG disclosure index would be useful for companies seeking to provide information in relation their CCCG practices

Creative city index [Report]

The CCI Creative City Index (CCI-CCI) is a new approach to the measurement and ranking of creative global cities. It is constructed over eight principal dimensions, each with multiple distinct elements. Some of these dimensions are familiar from other global city indexes, such as the MORI or GaWC indexes, which account for the size of creative industries, the scale of cultural amenities, or the flows of creative people and global connectedness. In addition to these indicators, the CCI-CCI contributes several new dimensions. These measure the demand side of creative participation, the attention economy, user-created content, and the productivity of socially networked consumers. Global creative cities can often seem alike, in respect of per-capita measures of factors such as public spending on cultural amenities, or the number of hotels and restaurants. This is to be expected when people and capital are relatively free to move, and where economic and political institutions are broadly comparable. However, we find that different cities can register far larger differences at the level of consumer-co-creation and especially digital creative ‘microproductivity’. To explain this finding, we review the logic and rationale of creative and global city index construction and present a review of previous and contemporary indexes. We set out the case for our new model of a creative city index by showing why greater attention to consumer co-creation and microproductivity are important, as well as examining how these factors have been previously overlooked. We show how we have CCI-CCI Creative City Index measured these additional factors and indicate the effect they have on creative and global city indexes. We then present the findings from a pilot study of six cities, two Australian, two German and two from the UK, to indicate how the new index is calculated and applied. Our results indicate much greater variance arising from the new arguments between cities.

Creative city index 2012 - Data sources, calculation methods and tools [Report spreadsheet]

Spreadsheet for Creative City Index 2012

Ab initio studies of hydrogen desorption from low index magnesium hydride surface

The low index Magnesium hydride surfaces, MgH2(0 0 1) and MgH2(1 1 0), have been studied by ab intio Density Functional Theory (DFT) calculations. It was found that the MgH2(1 1 0) surface is more stable than MgH2(0 0 1) surface, which is in good agreement with the experimental observation. The H2 desorption barriers vary depending on the crystalline surfaces that are exposed and also the specific H atom sites involved – they are found to be generally high, due to the thermodynamic stability of the MgH2 system, and are larger for the MgH2(0 0 1) surface. The pathway for recombinative desorption of one in-plane and one bridging H atom from the MgH2(1 1 0) surface was found to be the lowest energy barrier amongst those computed (172 KJ/mol) and is in good agreement with the experimental estimates.

Optical data encryption using time-dependent dynamics of refractive index changes in LiNbO3

We present a method for optical encryption of information, based on the time-dependent dynamics of writing and erasure of refractive index changes in a bulk lithium niobate medium. Information is written into the photorefractive crystal with a spatially amplitude modulated laser beam which when overexposed significantly degrades the stored data making it unrecognizable. We show that the degradation can be reversed and that a one-to-one relationship exists between the degradation and recovery rates. It is shown that this simple relationship can be used to determine the erasure time required for decrypting the scrambled index patterns. In addition, this method could be used as a straightforward general technique for determining characteristic writing and erasure rates in photorefractive media.

Review essay -- Weber L and Pickering S (2011) Globalization and borders : death at the global frontier

The pertinence of this book cannot be overemphasised. The world’s refugee crisis has reached a two‐decade high with the United Nations recently announcing that ‘displacement is the new 21st century challenge’ (UNHCR 2013). The transnational movement of dislocated peoples fleeing conflict, persecution and poverty is a global responsibility requiring nation states to collaborate for humanitarian resolutions embedded in human rights. However, in times of human rights expansionism, and the relaxation of borders for maximising free‐trade and fiscal prosperity, the movement of people experiencing immense abuse and deprivation has witnessed an increase in draconian regulation within discourses of intolerance and deterrence. Weber and Pickering cogently and emphatically emphasise the human cost of inhumane and populist government immigration and border‐entry polices underpinned by ideologies of retribution, suspicion, and demonisation. It is a moving and engaging narrative: a book that exposes state prejudice and abuse, whilst advocating for the victims who undertake perilous journeys in search of safety from lives of violence and persecution. Moreover, it is a book that pushes ideological boundaries and seeks new criminological horizons, for which the authors must be sincerely congratulated. It is a text of innovation, inspired thinking and long lasting criminological value.

Hemi-field and full-field form-deprivation induce timing changes in multifocal ERG responses in chick

Purpose: In animal models hemi-field deprivation results in localised, graded vitreous chamber elongation and presumably deprivation induced localised changes in retinal processing. The aim of this research was to determine if there are variations in ERG responses across the retina in normal chick eyes and to examine the effect of hemi-field and full-field deprivation on ERG responses across the retina and at earlier times than have previously been examined electrophysiologically. Methods: Chicks were either untreated, wore monocular full-diffusers or half-diffusers (depriving nasal retina) (n = 6-8 each group) from day 8. mfERG responses were measured using the VERIS mfERG system across the central 18.2º× 16.7º (H × V) field. The stimulus consisted of 61 unscaled hexagons with each hexagon modulated between black and white according to a pseudorandom binary m-sequence. The mfERG was measured on day 12 in untreated chicks, following 4 days of hemi-field diffuser wear, and 2, 48 and 96 h after application of full-field diffusers. Results: The ERG response of untreated chick eyes did not vary across the measured field; there was no effect of retinal location on the N1-P1 amplitude (p = 0.108) or on P1 implicit time (p > 0.05). This finding is consistent with retinal ganglion cell density of the chick varying by only a factor of two across the entire retina. Half-diffusers produced a ramped retina and a graded effect of negative lens correction (p < 0.0001); changes in retinal processing were localized. The untreated retina showed increasing complexity of the ERG waveform with development; form-deprivation prevented the increasing complexity of the response at the 2, 48 and 96 h measurement times and produced alterations in response timing. Conclusions: Form-deprivation and its concomitant loss of image contrast and high spatial frequency images prevented development of the ERG responses, consistent with a disruption of development of retinal feedback systems. The characterisation of ERG responses in normal and deprived chick eyes across the retina allows the assessment of concurrent visual and retinal manipulations in this model. (Ophthalmic & Physiological Optics © 2013 The College of Optometrists.)

The effects and interactions of GABAergic and dopaminergic agents in the prevention of form deprivation myopia by brief periods of normal vision

Intravitreal injections of GABA antagonists, dopamine agonists and brief periods of normal vision have been shown separately to inhibit form-deprivation myopia (FDM). Our study had three aims: (i) establish whether GABAergic agents modify the myopia protective effect of normal vision, (ii) investigate the receptor sub-type specificity of any observed effect, and (iii) consider an interaction with the dopamine (DA) system. Prior to the period of normal vision GABAergic agents were applied either (i) individually, (ii) in combination with other GABAergic agents (an agonist with an antagonist), or (iii) in combination with DA agonists and antagonists. Water injections were given to groups not receiving drug treatments so that all experimental eyes received intravitreal injections. As shown previously, constant form-deprivation resulted in high myopia and when diffusers were removed for 2 h per day the period of normal vision greatly reduced the FDM that developed. GABA agonists inhibited the protective effect of normal vision whereas antagonists had the opposite effect. GABAA/C agonists and D2 DA antagonists when used in combination were additive in suppressing the protective effect of normal vision. A D2 DA agonist restored some of the protective effect of normal vision that was inhibited by a GABA agonist (muscimol). The protective effect of normal vision against form-deprivation is modifiable by both the GABAergic and DAergic pathways.

Monitoring and benchmarking government policies and actions to improve the healthiness of food environments : a proposed Government Healthy Food Environment Policy Index

Government action is essential to increase the healthiness of food environments and reduce obesity, diet-related non-communicable diseases (NCDs), and their related inequalities. This paper proposes a monitoring framework to assess government policies and actions for creating healthy food environments. Recommendations from relevant authoritative organizations and expert advisory groups for reducing obesity and NCDs were examined, and pertinent components were incorporated into a comprehensive framework for monitoring government policies and actions. A Government Healthy Food Environment Policy Index (Food-EPI) was developed, which comprises a ‘policy’ component with seven domains on specific aspects of food environments, and an ‘infrastructure support’ component with seven domains to strengthen systems to prevent obesity and NCDs. These were revised through a week-long consultation process with international experts. Examples of good practice statements are proposed within each domain, and these will evolve into benchmarks established by governments at the forefront of creating and implementing food policies for good health. A rating process is proposed to assess a government's level of policy implementation towards good practice. The Food-EPI will be pre-tested and piloted in countries of varying size and income levels. The benchmarking of government policy implementation has the potential to catalyse greater action to reduce obesity and NCDs.

Associations of body mass index and waist circumference with: energy intake and percentage energy from macronutrients, in a cohort of Australian children

Background It is evident from previous research that the role of dietary composition in relation to the development of childhood obesity remains inconclusive. Several studies investigating the relationship between body mass index (BMI), waist circumference (WC) and/or skin fold measurements with energy intake have suggested that the macronutrient composition of the diet (protein, carbohydrate, fat) may play an important contributing role to obesity in childhood as it does in adults. This study investigated the possible relationship between BMI and WC with energy intake and percentage energy intake from macronutrients in Australian children and adolescents. Methods Height, weight and WC measurements, along with 24 h food and drink records (FDR) intake data were collected from 2460 boys and girls aged 5-17 years living in the state of Queensland, Australia. Results Statistically significant, yet weak correlations between BMI z-score and WC with total energy intake were observed in grades 1, 5 and 10, with only 55% of subjects having a physiologically plausible 24 hr FDR. Using Pearson correlations to examine the relationship between BMI and WC with energy intake and percentage macronutrient intake, no significant correlations were observed between BMI z-score or WC and percentage energy intake from protein, carbohydrate or fat. One way ANOVAs showed that although those with a higher BMI z-score or WC consumed significantly more energy than their lean counterparts. Conclusion No evidence of an association between percentage macronutrient intake and BMI or WC was found. Evidently, more robust longitudinal studies are needed to elucidate the relationship linking obesity and dietary intake.

Reported consumption of takeaway food and its contribution to socioeconomic inequalities in body mass index

The aim of this study was to examine whether takeaway food consumption mediated (explained) the association between socioeconomic position and body mass index (BMI). A postal-survey was conducted among 1500 randomly selected adults aged between 25 and 64 years in Brisbane, Australia during 2009 (response rate 63.7%, N=903). BMI was calculated using self-reported weight and height. Participants reported usual takeaway food consumption, and these takeaway items were categorised into "healthy" and "less healthy" choices. Socioeconomic position was ascertained by education, household income, and occupation. The mean BMI was 27.1kg/m(2) for men and 25.7kg/m(2) for women. Among men, none of the socioeconomic measures were associated with BMI. In contrast, women with diploma/vocational education (β=2.12) and high school only (β=2.60), and those who were white-collar (β=1.55) and blue-collar employees (β=2.83) had significantly greater BMI compared with their more advantaged counterparts. However, household income was not associated with BMI. Among women, the consumption of "less healthy" takeaway food mediated BMI differences between the least and most educated, and between those employed in blue collar occupations and their higher status counterparts. Decreasing the consumption of "less healthy" takeaway options may reduce socioeconomic inequalities in overweight and obesity among women but not men.

Escape from apoptosis after prolonged serum deprivation is associated with the regulation of the mitochondrial death pathway by Bcl-x(l)

Bcl-x(l) and Bax play important roles in the regulation of apoptosis. This study investigated the involvement of the mitochondrial death pathway and the role of Bcl-x(l) and Bax in the escape from apoptosis after prolonged serum deprivation in Madin-Darby canine kidney (MDCK) cells. Low level apoptosis and basal activity of the mitochondrial death pathway were detectable in normal cell growth. In serum deprivation, mitosis was partially suppressed, and the mitochondrial activity was stimulated. The level of apoptosis continuously rose over 48 h. This rise was concomitant with the increasing presence of cytochrome c in cytosol. However, both apoptosis and cytosolic cytochrome c fell dramatically at 72 h. Elevation of whole cell Bcl-x(l) and redistribution of Bcl-x(l) protein from cytosol to the membrane at 48 h and 72 h was observed. Redistribution of Bax protein from the membrane to cytosol occurred at 24 h, and remained steady to 72 h. Bax/Bcl-x(l) coimmunoprecipitation by anti-Bax antibody showed reduced Bax/Bcl-x(l) interaction at the membrane at 72 h, but not at 24 or 48 h. These results suggest that apoptosis upon serum withdrawal results from the leakage of cytochrome c to cytosol. Amelioration of the leakage of cytochrome c and apoptosis requires not only the increase of Bcl-x(l)/Bax ratio, but also the release of Bcl-x(l) from Bax at the membrane.