Visual function and the ageing visual system

The population is ageing. Globally, the number of older adults (aged 60 years or over) is expected to more than double, from 841 million people in 2013 to more than 2 billion in 2050.1 In light of the increasing size of the older adult population, there is a pressing need to better identify the nature of, and mechanisms underlying, age-related vision impairment and the functional impact it has on the performance of everyday activities in older adults. The content of this feature issue reflects the diversity of research currently being undertaken on the topic of the ageing visual system and the important visual challenges that this presents for our ageing patient population. The scope is broad and includes topics relating to three main related themes: 1) The treatment of age-related ocular disorders and diseases and their consequences, including presbyopia and AMD; 2) The impact of age-related visual changes on everyday activities in older people, including mobility, driving and falls, and; 3) The interaction of age-related visual impairments and other age-related impairments including hearing and cognitive changes.

Theoretical modelling of momentum transfer function of bi-disperse porous media

The aim of this paper is to obtain the momentum transfer coefficient between the two phases, denoted by f and p, occupying a bi-disperse porous medium by mapping the available experimental data to the theoretical model proposed by Nield and Kuznetsov. Data pertinent to plate-fin heat exchangers, as bi-disperse porous media, were used. The measured pressure drops for such heat exchangers are then used to give the overall permeability which is linked to the porosity and permeability of each phase as well as the interfacial momentum transfer coefficient between the two phases. Accordingly, numerical values are obtained for the momentum transfer coefficient for three different fin spacing values considered in the heat exchanger experiments.

Institutionalization

During the 18th and 19th centuries, prostitution came to be understood as a potentially disruptive element in the management of society. New forms of social control developed that sought to transform the souls of prostitutes to better control their bodies. Institutions for managing prostitutes, such as Magdalen Homes and lock hospitals, were introduced or increased in number throughout the British Empire, North America, and Western Europe. Often these institutions had as their stated objective the physical purification and moral reform of prostitutes, appearing to make a dramatic break with earlier methods of social control that had relied on practices of physical punishment and spatial segregation. Emergent institutions for the social control of prostitutes used a regimen of religious training, hard labor, and medical expertise. The objective of the Magdalen Home was not to punish sin but to absolve it, while the function of the lock hospital was not simply to confine the ill, but to confine the ill to "cure" them. The role of these institutions was not only symbolic, mirroring in some way the operation of earlier forms of social control, but was also practical and transformative. The mass institutionalization of prostitutes that occurred during the 18th and 19th centuries produced and emphasized sexual, class, and gender boundaries, grounded in the broad distinction between "pure" and "impure" women. Because of its association with sin, prostitution before the 18th century had been constructed as a religious problem relating to salvation and penitence. Throughout Western Europe during the Middle Ages, prostitutes, like the medieval leper and the Jew, were subject to restrictions designed to distinguish and isolate them from other members of their communities. The repression of prostitution during the Middle Ages was neither systematic nor highly organized, although it reinforced the image of the prostitute as sinful "other".

Comparison of ocular modulation transfer function determined by a ray-tracing aberrometer and a double-pass system in early cataract patients

BACKGROUND: The evaluation of retinal image quality in cataract eyes has gained importance and the clinical modulation transfer functions (MTF) can obtained by aberrometer and double pass (DP) system. This study aimed to compare MTF derived from a ray tracing aberrometer and a DP system in early cataractous and normal eyes. METHODS: There were 128 subjects with 61 control eyes and 67 eyes with early cataract defined according to the Lens Opacities Classification System III. A laser ray-tracing wavefront aberrometer (iTrace) and a double pass (DP) system (OQAS) assessed ocular MTF for 6.0 mm pupil diameters following dilation. Areas under the MTF (AUMTF) and their correlations were analyzed. Stepwise multiple regression analysis assessed factors affecting the differences between iTrace- and OQAS-derived AUMTF for the early cataract group. RESULTS: For both early cataract and control groups, iTrace-derived MTFs were higher than OQAS-derived MTFs across a range of spatial frequencies (P < 0.01). No significant difference between the two groups occurred for iTrace-derived AUMTF, but the early cataract group had significantly smaller OQAS-derived AUMTF than did the control group (P < 0.01). AUMTF determined from both the techniques demonstrated significant correlations with nuclear opacities, higher-order aberrations (HOAs), visual acuity, and contrast sensitivity functions, while the OQAS-derived AUMTF also demonstrated significant correlations with age and cortical opacity grade. The factors significantly affecting the difference between iTrace and OQAS AUMTF were root-mean-squared HOAs (standardized beta coefficient = -0.63, P < 0.01) and age (standardized beta coefficient = 0.26, P < 0.01). CONCLUSIONS: MTFs determined from a iTrace and a DP system (OQAS) differ significantly in early cataractous and normal subjects. Correlations with visual performance were higher for the DP system. OQAS-derived MTF may be useful as an indicator of visual performance in early cataract eyes.

Cold water immersion enhances recovery of submaximal muscle function after resistance exercise

We investigated the effect of cold water immersion (CWI) on the recovery of muscle function and physiological responses following high-intensity resistance exercise. Using a randomized, cross-over design, 10 physically active men performed high-intensity resistance exercise, followed by one of two recovery interventions: 10 min of cold water immersion at 10°C, or 10 min active recovery (low-intensity cycling). After the recovery interventions, maximal muscle function was assessed after 2 h and 4 h by measuring jump height and isometric squat strength. Submaximal muscle function was assessed after 6 h by measuring the average load lifted during six sets of 10 squats at 80% 1RM. Intramuscular temperature (1 cm) was also recorded, and venous blood samples were analyzed for markers of metabolism, vasoconstriction and muscle damage. CWI did not enhance recovery of maximal muscle function. However, during the final three sets of the submaximal muscle function test, the participants lifted a greater load (p<0.05; 38%; Cohen’s d 1.3) following CWI compared with active recovery. During CWI, muscle temperature decreased 6°C below post-exercise values, and remained below pre-exercise values for another 35 min. Venous blood O2 saturation decreased below pre-exercise values for 1.5 h after CWI. Serum endothelin-1 concentration did not change after CWI, whereas it decreased after active recovery. Plasma myoglobin concentration was lower, whereas plasma interleukin-6 concentration was higher after CWI compared with active recovery. These results suggest that cold water immersion after resistance exercise allow athletes to complete more work during subsequent training sessions, which could enhance long-term training adaptations.

Effect of tocopherol on atherosclerosis, vascular function and inflammation in Apolipoprotein E knockout mice with subtotal nephrectomy

Background/Aims: Inflammation and endothelial dysfunction contribute to cardiovascular disease, prevalent in chronic kidney disease (CKD). Antioxidant supplements such as tocopherols may reduce inflammation and atherosclerosis. This study aimed to investigate the effect of tocopherol supplementation on vascular function, aortic plaque formation, and inflammation in apolipoprotein E−/− mice with 5/6 nephrectomy as a model of combined cardiovascular and kidney disease. Methods: Nephrectomized mice were assigned to a normal chow diet group (normal chow), a group receiving 1000 mg/kg diet of α-tocopherol supplementation or a group receiving 1000 mg/kg diet mixed-tocopherol (60% γ-tocopherol). Results: Following 12 weeks, in vitro aortic endothelial-independent relaxation was enhanced with both α-tocopherol and mixed-tocopherol (P < 0.05), while mixed-tocopherol enhanced aortic contraction at noradrenaline concentrations of 3 × 10−7 M to 3 × 10−5 M (P < 0.05), when compared to normal chow. Supplementation with α- and mixed-tocopherol reduced systemic concentrations of IL-6 (P < 0.001 and P < 0.001, respectively) and IL-10 (P < 0.05 and P < 0.001, respectively), while α-tocopherol also reduced MCP-1 (P < 0.05) and tumor necrosis factor (TNF)-α (P < 0.05). Aortic sinus plaque area was significantly reduced with α-tocopherol supplementation when compared to normal chow (P < 0.01). Conclusion: Tocopherol supplementation favorably influenced vascular function and cytokine profile, while it was also effective in reducing atherosclerosis in the apolipoprotein E−/− mouse with CKD.

Natural convection due to differential heating of inclined walls and heat source placed on bottom wall of an attic shaped space

Numerical investigation of free convection heat transfer in an attic shaped enclosure with differentially heated two inclined walls and filled with air is performed in this study. The left inclined surface is uniformly heated whereas the right inclined surface is uniformly cooled. There is a heat source placed on the right side of the bottom surface. Rest of the bottom surface is kept as adiabatic. Finite volume based commercial software ANSYS 15 (Fluent) is used to solve the governing equations. Dependency of various flow parameters of fluid flow and heat transfer is analyzed including Rayleigh number, Ra ranging from 103 to 106, heater size from 0.2 to 0.6, heater position from 0.3 to 0.7 and aspect ratio from 0.2 to 1.0 with a fixed Prandtl number of 0.72. Outcomes have been reported in terms of temperature and stream function contours and local Nusselt number for various Ra, heater size, heater position, and aspect ratio. Grid sensitivity analysis is performed and numerically obtained results have been compared with those results available in the literature and found good agreement.

Acoustic identification of 12 species of echolocating bat by discriminant function analysis and artificial neural networks

We recorded echolocation calls from 14 sympatric species of bat in Britain. Once digitised, one temporal and four spectral features were measured from each call. The frequency-time course of each call was approximated by fitting eight mathematical functions, and the goodness of fit, represented by the mean-squared error, was calculated. Measurements were taken using an automated process that extracted a single call from background noise and measured all variables without intervention. Two species of Rhinolophus were easily identified from call duration and spectral measurements. For the remaining 12 species, discriminant function analysis and multilayer back-propagation perceptrons were used to classify calls to species level. Analyses were carried out with and without the inclusion of curve-fitting data to evaluate its usefulness in distinguishing among species. Discriminant function analysis achieved an overall correct classification rate of 79% with curve-fitting data included, while an artificial neural network achieved 87%. The removal of curve-fitting data improved the performance of the discriminant function analysis by 2 %, while the performance of a perceptron decreased by 2 %. However, an increase in correct identification rates when curve-fitting information was included was not found for all species. The use of a hierarchical classification system, whereby calls were first classified to genus level and then to species level, had little effect on correct classification rates by discriminant function analysis but did improve rates achieved by perceptrons. This is the first published study to use artificial neural networks to classify the echolocation calls of bats to species level. Our findings are discussed in terms of recent advances in recording and analysis technologies, and are related to factors causing convergence and divergence of echolocation call design in bats.

A hybrid quality function deployment and cybernetic analytic network process model for project manager selection

Identifying appropriate decision criteria and making optimal decisions in a structured way is a complex process. This paper presents an approach for doing this in the form of a hybrid Quality Function Deployment (QFD) and Cybernetic Analytic Network Process (CANP) model for project manager selection. This involves the use of QFD to translate the owner's project management expectations into selection criteria and the CANP to weight the expectations and selection criteria. The supermatrix approach then prioritises the candidates with respect to the overall decision-making goal. A case study is used to demonstrate the use of the model in selecting a renovation project manager. This involves the development of 18 selection criteria in response to the owner's three main expectations of time, cost and quality.

Androgen-targeted therapy-induced epithelial mesenchymal plasticity and neuroendocrine transdifferentiation in prostate cancer : an opportunity for intervention

Androgens regulate biological pathways to promote proliferation, differentiation, and survival of benign and malignant prostate tissue. Androgen receptor (AR) targeted therapies exploit this dependence and are used in advanced prostate cancer to control disease progression. Contemporary treatment regimens involve sequential use of inhibitors of androgen synthesis or AR function. Although targeting the androgen axis has clear therapeutic benefit, its effectiveness is temporary, as prostate tumor cells adapt to survive and grow. The removal of androgens (androgen deprivation) has been shown to activate both epithelial-to-mesenchymal transition (EMT) and neuroendocrine transdifferentiation (NEtD) programs. EMT has established roles in promoting biological phenotypes associated with tumor progression (migration/invasion, tumor cell survival, cancer stem cell-like properties, resistance to radiation and chemotherapy) in multiple human cancer types. NEtD in prostate cancer is associated with resistance to therapy, visceral metastasis, and aggressive disease. Thus, activation of these programs via inhibition of the androgen axis provides a mechanism by which tumor cells can adapt to promote disease recurrence and progression. Brachyury, Axl, MEK, and Aurora kinase A are molecular drivers of these programs, and inhibitors are currently in clinical trials to determine therapeutic applications. Understanding tumor cell plasticity will be important in further defining the rational use of androgen-targeted therapies clinically and provides an opportunity for intervention to prolong survival of men with metastatic prostate cancer.

Method of symptom assessment influences cognitive, affective and somatic post-concussion-like symptom base rates

Primary objective: To investigate whether assessment method influences the type of post-concussion-like symptoms. Methods and procedures: Participants were 73 Australian undergraduate students (Mage = 24.14, SD = 8.84; 75.3% female) with no history of mild traumatic brain injury (mTBI). Participants reported symptoms experienced over the previous 2 weeks in response to an open-ended question (free report), mock interview and standardized checklist (British Columbia Post-concussion Symptom Inventory; BC-PSI). Main outcomes and results: In the free report and checklist conditions, cognitive symptoms were reported significantly less frequently than affective (free report: p < 0.001; checklist: p < 0.001) or somatic symptoms (free report: p < 0.001; checklist: p = 0.004). However, in the mock structured interview condition, cognitive and somatic symptoms were reported significantly less frequently than affective symptoms (both p < 0.001). No participants reported at least one symptom from all three domains when assessed by free report, whereas most participants did so when symptoms were assessed by a mock structured interview (75%) or checklist (90%). Conclusions: Previous studies have shown that the method used to assess symptoms affects the number reported. This study shows that the assessment method also affects the type of reported symptoms.

Spectrophotometric analysis of phenols, which involves a hemin-graphene hybrid nanoparticles with peroxidase-like activity

Phenols are well known noxious compounds, which are often found in various water sources. A novel analytical method has been researched and developed based on the properties of hemin–graphene hybrid nanosheets (H–GNs). These nanosheets were synthesized using a wet-chemical method, and they have peroxidase-like activity. Also, in the presence of H2O2, the nanosheets are efficient catalysts for the oxidation of the substrate, 4-aminoantipine (4-AP), and the phenols. The products of such an oxidation reaction are the colored quinone-imines (benzodiazepines). Importantly, these products enabled the differentiation of the three common phenols – pyrocatechol, resorcin and hydroquinone, with the use of a novel, spectroscopic method, which was developed for the simultaneous determination of the above three analytes. This spectroscopic method produced linear calibrations for the pyrocatechol (0.4–4.0 mg L−1), resorcin (0.2–2.0 mg L−1) and hydroquinone (0.8–8.0 mg L−1) analytes. In addition, kinetic and spectral data, obtained from the formation of the colored benzodiazepines, were used to establish multi-variate calibrations for the prediction of the three phenol analytes found in various kinds of water; partial least squares (PLS), principal component regression (PCR) and artificial neural network (ANN) models were used and the PLS model performed best.

Mitochondrial genome acquisition restores respiratory function and tumorigenic potential of cancer cells without mitochondrial DNA

We report that tumor cells devoid of their mitochondrial genome (mtDNA) show delayed tumor growth and that tumor formation is associated with acquisition of mtDNA from host cells. This leads to partial recovery of mitochondrial function in cells derived from primary tumors grown from cells without mtDNA and a shorter lag in tumor growth. Cell lines from circulating tumor cells showed further recovery of mitochondrial respiration and an intermediate lag to tumor growth, while cells from lung metastases exhibited full restoration of respiratory function and no lag in tumor growth. Stepwise assembly of mitochondrial respiratory supercomplexes was correlated with acquisition of respiratory function. Our findings indicate horizontal transfer of mtDNA from host cells in the tumor microenvironment to tumor cells with compromised respiratory function to re-establish respiration and tumor-initiating efficacy. These results suggest a novel pathophysiological process for overcoming mtDNA damage and support the notion of high plasticity of malignant cells.