Structural Considerations of Filament Wound Cylindrical Shells. Report no. 6804

The structural response of filament-wound cylindrical shells to a combination of applied loadings is investigated. In many cases the membrane theory forms an adequate basis for the analysis. By suitable arrangement of the filament orientations and layer thicknesses, an efficient structure can be achieved. Numerical examples are given to show their influence on the stress components. The strength of the shells can be judged according to some criterion. In the Appendix, the determination of the elastic constants is given

The intimate connexion: bodily awareness and bodily agency

This thesis examines the relation between bodily awareness and bodily agency. Descartes‘s observation that we are not in our bodies as pilots in vessels suggests two thoughts about the special role of the body in experience and agency. The first is that we experience our bodies ‗from the inside‘ and not just as one more material body amongst other material objects of perception (Feeling). The second is that we are able to act with our bodies in ways in which we are not with any other bodies or objects (Direct Control). My goal is to articulate the proper relationship between Feeling and Direct Control. There are three broad options: they are independent (Independence); Feeling is because of Direct Control (Enaction); and Direct Control is because of Feeling (Necessity). Independence cannot make sense of the rational role of experience in guiding action. Finding Independence unsatisfactory is the force of intuition toward articulating some kind of intimate connexion between bodily awareness and bodily agency. Enaction is subject to counterexamples from paralysed subjects, pain in body parts (such as internal organs) that we cannot act with, and double dissociations between bodily awareness and bodily action. The most attractive option is Necessity, but it is still empirically inadequate. Whilst the intimacy between bodily awareness and agency is not in doubt, the counterexamples suggest that their relation cannot quite be understood in the way that Necessity claims. I develop a view on which bodily awareness is necessary for bodily agency, but not for the online control of actions (as Necessity claims). Rather, bodily awareness plays an essential role in action planning, since to plan an action is to have some conception of what you can do – which requires body schemata and awareness of current bodily dispositions

The Role of Heat Conduction in Leading Edge Heating: Theory and Experiment. Report no. 6901

The effect of heat conduction of material on the temperature distribution in the vicinity of a wing leading edge in hypersonic flight is investigated. The theory is based on a conducting plate subjected to aerodynamic heating. It is found that the role played by the conductivity of the material and the leading edge thickness in moderating the nose temperature is very significant. Detailed discussions of the numerical solutions for various shapes of leading edge are given. An experimental technique has been developed by which a number of models representing a wing leading edge can be tested and the results thus obtained are compared with those predicted by the theory

Thermal conductance of metallic contacts

Across a contact joint, different modes of heat transfer take place, namely, by conduction through the metallic junctions, by conduction of the fluid through the interstitial space and by radiation. They are in reality interrelated so that any solution to the problem must take into account the inter-dependent nature of these three modes. The greatest obstacle to the seeking of a satisfactory solution lies in the uncertainty of the size and distribution of metallic junctions engaged in contact and of the exact dimensions of the interstitial space which is usually filled with a fluid of a lower thermal conductivity than that of the metal. Under these circumstances, it is necessary to introduce an idealised contact model for the convenience of obtaining a mathematical solution. In this model the contact members are represented by two circular cylindrical blocks while the irregularities on the surfaces which are engaged in contact are represented by two protuberant junctions of cylindrical shape with a diameter smaller than that of the main blocks. The thermal resistance of these junctions, however small it may be, is considered to have a governing effect on the heat transfer characteristics of a contact joint and it is included in the formulation of the theory. The theory thus obtained can be conveniently extended to cover contact models other than the idealised one with cylindrical junctions. Since the shape of the asperities on a surface resembles a cone more than a circular cylinder, it is suggested that a more realistic contact model could be one having its contact junctions represented by a pair of conic frusta. By taking an appropriate equivalent thermal conductivity of the junctions, the theory derived from the idealised contact model can be applied without any modification. A simplified method for the solution of a contact problem is also suggested. This method under certain conditions yields results very close to those obtained by the analytical method. The merit of this method lies in its comparative ease of formulation. Experiments were carried out for the study of the fundamental phenomena of heat transfer across a metallic contact. In order to achieve this object it was necessary to eliminate some of the governing factors for others to be observed. To overcome the obscurity of the matching condition at a contact interface an artificial contact joint was introduced. This was done by inserting small steel balls and small aluminium discs between the contact surfaces for different experiments. The contact thermal conductance was measured under conditions in vacuum and with argon and helium gases, while the inserted objects were subjected to an applied load of various magnitudes. The test results agree favourably with the calculated values. They also confirm that the thermal conductance of a contact cannot be reliably determined from electrical measurements. The hysteresis phenomenon observed by a number of investigators was found to be due to the seizure of the contact junctions as well as due to the irreversible deformation of the material. The primary governing factors of heat transferred through the fluid path and through the solid path are the fluid contact parameter Kf, the solid contact parameter Ks and the contact area parameter X. By specifying the magnitudes of these parameters, it is possible to estimate the heat transfer rate through each path. By altering their values, it may also be possible to control the thermal contact conductance for a given purpose

Long-Term Follow-Up of Intravitreal Ranibizumab for the Treatment of Choroidal Neovascularization due to Choroidal Osteoma

Choroidal osteoma is an uncommon benign osseous intraocular tumor that typically affects young adult women. Choroidal neovascularization (CNV) is one of the complications that can develop in eyes with choroidal osteoma. We present a case of CNV secondary to choroidal osteoma treated with intravitreal ranibizumab. A 57-year-old lady presented with painless loss of vision with a right-eye visual acuity of 20/800. Fundus examination showed a well-demarcated yellowish peripapillary choroidal osteoma with associated retinal and subretinal hemorrhage due to CNV. Three intravitreal ranibizumab injections at monthly intervals were given and her visual acuity improved to 20/30 following treatment. After 1.2 years of follow-up, the right eye visual acuity was maintained at 20/30 with no evidence of CNV recurrence. Our findings suggest that intravitreal ranibizumab may be an effective therapeutic option for treating CNV secondary to choroidal osteoma

Modulation of Androgen Receptor Transcriptional Activity

Androgens, testosterone (T) and 5a-dihydrotestosterone (DHT), are important for male and female physiology, in particular for male sexual differentiation, development of secondary male characteristics and spermatogenesis. These hormones exert their actions by binding to the androgen receptor (AR), a transcription factor that belongs to the family of steroid hormone receptors (SHRs). After ligand binding, the AR migrates to the nucleus and binds to androgen response elements (AREs), which are present in the promoter and enhancer regions of androgen regulated genes. After DNA binding, chromatin remodelling factors, other co-factors (co-activators or co-repressors) and proteins of the transcription initiation complex, including RNA polymerase II, are recruited by the AR to regulate gene transcription. Several modulating processes and factors can influence AR transactivation. Not only co-factors play a role in AR transactivation, but also post-translational mod! ifications of the AR, such as acetylation, ubiquitylation, sumoylation and phosphorylation, can modify AR transactivation. In addition, mutations in the AR gene can have dramatic consequences for AR transactivation. In general, AR mutations result in the androgen insensitivity syndrome, in which the male phenotype is affected. However, the exact influence of these modulating processes and factors is still not clear. In this thesis we focused on the influence of phosphorylation on the AR. The influence of mutation F826L on the AR activity has also been studied. Finally, it has been determined whether co-factors can be isolated with a DNA bound AR

Protective actions of des-acylated ghrelin on brain injury and blood-brain barrier disruption after stroke in mice

The major ghrelin forms, acylated ghrelin and des-acylated ghrelin, are novel gastrointestinal hormones. Moreover, emerging evidence indicates that these peptides may have other functions including neuro- and vaso-protection. Here, we investigated whether post-stroke treatment with acylated ghrelin or des-acylated ghrelin could improve functional and histological endpoints of stroke outcome in mice after transient middle cerebral artery occlusion (tMCAo). We found that des-acylated ghrelin (1 mg/kg) improved neurological and functional performance, reduced infarct and swelling, and decreased apoptosis. In addition, it reduced blood-brain barrier (BBB) disruption in vivo and attenuated the hyper-permeability of mouse cerebral microvascular endothelial cells after oxygen glucose deprivation and reoxygenation (OGD + RO). By contrast, acylated ghrelin (1 mg/kg or 5 mg/kg) had no significant effect on these endpoints of stroke outcome. Next we found that des-acylated ghrelin's vasoprotective actions were associated with increased expression of tight junction proteins (occludin and claudin-5), and decreased cell death. Moreover, it attenuated superoxide production, Nox activity and expression of 3-nitrotyrosine. Collectively, these results demonstrate that post-stroke treatment with des-acylated ghrelin, but not acylated ghrelin, protects against ischaemia/reperfusion-induced brain injury and swelling, and BBB disruption, by reducing oxidative and/or nitrosative damage

SARS-related Perceptions in Hong Kong

To understand different aspects of community responses related to severe acute respiratory syndrome (SARS), 2 population-based, random telephone surveys were conducted in June 2003 and January 2004 in Hong Kong. More than 70% of respondents would avoid visiting hospitals or mainland China to avoid contracting SARS. Most respondents believed that SARS could be transmitted through droplets, fomites, sewage, and animals. More than 90% believed that public health measures were efficacious means of prevention; 40.4% believed that SARS would resurge in Hong Kong; and ≈70% would then wear masks in public places. High percentages of respondents felt helpless, horrified, and apprehensive because of SARS. Approximately 16% showed signs of posttraumatic symptoms, and ≈40% perceived increased stress in family or work settings. The general public in Hong Kong has been very vigilant about SARS but needs to be more psychologically prepared to face a resurgence of the epidemic

Predicting dementia diagnosis from cognitive footprints in electronic health records: a case-control study protocol

INTRODUCTION: Dementia is a group of disabling disorders that can be devastating for persons living with it and for their families. Data-informed decision-making strategies to identify individuals at high risk of dementia are essential to facilitate large-scale prevention and early intervention. This population-based case-control study aims to develop and validate a clinical algorithm for predicting dementia diagnosis, based on the cognitive footprint in personal and medical history. METHODS AND ANALYSIS: We will use territory-wide electronic health records from the Clinical Data Analysis and Reporting System (CDARS) in Hong Kong between 1 January 2001 and 31 December 2018. All individuals who were at least 65 years old by the end of 2018 will be identified from CDARS. A random sample of control individuals who did not receive any diagnosis of dementia will be matched with those who did receive such a diagnosis by age, gender and index date with 1:1 ratio. Exposure to potential protective/risk factors will be included in both conventional logistic regression and machine-learning models. Established risk factors of interest will include diabetes mellitus, midlife hypertension, midlife obesity, depression, head injuries and low education. Exploratory risk factors will include vascular disease, infectious disease and medication. The prediction accuracy of several state-of-the-art machine-learning algorithms will be compared. ETHICS AND DISSEMINATION: This study was approved by Institutional Review Board of The University of Hong Kong/Hospital Authority Hong Kong West Cluster (UW 18-225). Patients' records are anonymised to protect privacy. Study results will be disseminated through peer-reviewed publications. Codes of the resulted dementia risk prediction algorithm will be made publicly available at the website of the Tools to Inform Policy: Chinese Communities' Action in Response to Dementia project (https://www.tip-card.hku.hk/)

Development and characterization of poly-epsilon-caprolactone-based polymer electrolyte for lithium rechargeable battery development and characterization of poly-ε-caprolactone-based polymer electrolyte for lithium rechargeable battery

A biodegradable polymer electrolyte based on Poly-epsilon-caprolactone (PCL) with various level of concentrations of Lithium salt and plasticizer have been synthesized under both the ambient and vacuum environments. The ionic conductivity, morphology, topology and structural properties are examined using EIS, SEM and XRD respectively. Conductivity as high as 3.48E-(04) Scm(-1) and 4.99E(-04) Scm(-1) are obtained for the ambient and vacuum environment respectively. Ionic mobility is improved by increasing the amorphousity content of the polymer and degree of salt dissociation with plasticizer. Ionic conductivity is further enhanced with the addition Li salt to increase the free ions concentration. Ionic conductivity measurements are further supported by the XRD data which reveal that sample with higher amorphous content tends to show higher conductivity. The dielectric relaxation study in terms of characteristic of the structural molecular interaction and ionic transportation properties are also carried out. Both of the conductivity and XRD results are further verified by SEM images