H. G Wells’s novel The Time Machine is a significant work of science fiction that dramatizes the themes of degeneration and social inequality, themes that were very relevant during the Victorian era in relation to the discovery of evolution. Degeneration was seen as the degradation of society into primitiveness far from the Victorian standards, and the problem of social difference, where the gap between poor and rich was very wide, became the visible proof of the difference between the evolved and civilized and the degenerated and primitive. The purpose of this essay is to analyse how the frame narrative, the story surrounding the main adventure, affects the theme of degeneration in the novel. The framework reveals the reactions of the people present at the dinner parties, where the Time Traveller recounts his journey into a degenerated future. The guests are all representing different factions of Victorian society, such as the Provincial Mayor, the Very Young Man and the Editor who all have their own motives and agendas in relation to degeneration, social differences and time travel. By examining the guests’ individual motives, the essay argues that they do not want to believe in time travel since it would include believing in a degenerated future where all the glory of their present-day Victorian era would crumble into chaos and pandemonium. This essay shows that by denying the relevance of the Time Traveller’s story, despite the evidence presented, the dinner guests are condemning themselves to the degenerated future they are afraid of, hence making the novel a warning example of not accepting new ideas.

ABSTRACT IMPORTANCE: Age-related macular degeneration (AMD) is a leading cause of low vision in elderly population. The association of vascular and renal conditions has been reported inconsistently. Unfolding the association may provide the insight to eye care providers to take account general health management into eye care. OBJECTIVES: To investigate the prevalence of the vascular and renal comorbidities with AMD, examine the association of a single or combination of these comorbidities with AMD. DSIGN AND PARTICIPANTS: Population-base cross-sectional study involved the adults aged 40 years or older (N=4596) who participated in the 2005 to 2008 National Health and Nutrition Examination Survey (NHANES), a national representative population-based survey of non-institutionalized US residents. MAIN OUTCOMES AND MEASURES: AMD was defined by the presence of drusen and presence of pigmental abnormality. Angina pectoris (AP), coronary heart disease (CHD), congestive heart failure (CHF) and myocardial infarction (MI), and stroke, assessed by self-report by the questionnaire of medical conditions, Chronic kidney disease (CKD), assessed by self-report and estimation of glomerular filtration rate (GFR) and the level of urine albumin. Heart disease (HD) was defined as having AP or CHF or CHD or MI. RESULTS: Among individuals with AMD, 6% had AP, 10% had CHD, 7% had CHF, 10% had MI, 13% had stroke, and 29% had CKD. The weighted prevalence of these conditions were significantly higher than those without AMD (All P-values CONCLUSION AND RELEVANCE: These findings from the nationally-representative sample of the US population highlight the prevalence of vascular and renal comorbidities associated with AMD, the modest evidence of relationship of each single comorbidity, and strong association of combination of stroke and CKD to AMD independent of age, gender, and other factors. Because of the cross-sectional design, the results of this study can not address a causal relationship between AMD and the examined comorbidities. It is unclear whether AMD and comorbidities arise from individual predisposition to vascular and renal diseases or whether complications from these morbidities increase the risk of AMD. However, the important caveat is that preventive and care management for the examined comorbidities may lessen the severity of symptoms or prevent AMD.

Inherited retinal degenerative diseases can affect various components of the retina leading to blindness. Five different mutant strains of chicken have been studied extensively as potential models for inherited retinal degeneration. The Smoky Joe (SJ) chicken is a sixth genetically blind strain of White Leghorns that shows various degrees of blindness at hatch and by 8 weeks post-hatch, have complete blindness for those that are homozygous. The objective of this study was to characterize the retinal degeneration in these birds by histology, both during embryonic and post-hatch development, and to the retinal function using electroretinograms (ERG). For both embryonic and post-hatch development, a significantly lower number of cells were found in the retina of blind birds compared to sighted (both p<0.0001). The significant contributor to cell number decrease was the loss of amacrine cells located in the inner nuclear layer. Photoreceptors were also found to potentially decrease in number, but at a later stage. ERG recordings revealed decreases in amplitudes of b-waves and oscillatory potentials in blind birds, but not in sighted. Both histology and ERG findings support the idea that the inner retinal cells are affected. The results indicate that degeneration in the Smoky Joe retina occurs mostly within the inner nuclear layer affecting amacrine cells. This hampers the functional capacity of the retina, causing blindness.

This master's thesis is entitled "Nietzsches Philosophie der Dekadenz in Thomas Mains Roman Der Zauberberg. Zu Rationalitat, Metaphysik and Erziehung." It focuses on Mann's treatment of Nietzsche's critiques of rationality, metaphysics and education. It is argued that the characters Settembrini and Naphta, who attempt to educate the main character, Castorp, personify Nietzsche's critiques of rationality and metaphysics, and their interweavement, as both rely on a common feature: belief. As a reaction to this confusion, the relativistic approach of Castorp increases and leads him to passivity and indifference. The failure of his education evokes Nietzsche's critique of an education which does not teach one to define one's own values and set oneself a goal. The fact that Castorp's fate evokes Nietzsche's in the novel is interpreted as Mann's critique of Nietzsche's philosophy, especially of his perspectivism.

No description available.

Low back pain is an ailment that affects a significant portion of the community. However, due to the complexity of the spine, which is a series of interconnected joints, and the loading conditions applied to these joints the causes for back pain are not well understood. Investigations of damage or failure of the spinal structures from a mechanical viewpoint may be viewed as a way of providing valuable information for the causes of back pain. Low back pain is commonly associated with injury to, or degeneration of, the intervertebral discs and involves the presence of tears or lesions in the anular disc material. The aim of the study presented in this thesis was to investigate the biomechanical effect of anular lesions on disc function using a finite element model of the L4/5 lumbar intervertebral disc. The intervertebral disc consists of three main components - the anulus fibrosus, the nucleus pulposus and the cartilaginous endplates. The anulus fibrosus is comprised of collagen fibres embedded in a ground substance while the nucleus is a gelatinous material. The components of the intervertebral disc were represented in the model together with the longitudinal ligaments that are attached to the anterior and posterior surface of the disc. All other bony and ligamentous structures were simulated through the loading and boundary conditions. A high level of both geometric and material accuracy was required to produce a physically realistic finite element model. The geometry of the model was derived from images of cadaveric human discs and published data on the in vivo configuration of the L4/5 disc. Material properties for the components were extracted from the existing literature. The anulus ground substance was represented as a Mooney-Rivlin hyperelastic material, the nucleus pulposus was modelled as a hydrostatic fluid in the healthy disc models and the cartilaginous endplates, collagen fibres and longitudinal ligaments were represented as linear elastic materials. A preliminary model was developed to assess the accuracy of the geometry and material properties of the disc components. It was found that the material parameters defined for the anulus ground substance did not accurately describe the nonlinear shear behaviour of the tissue. Accurate representation this nonlinear behaviour was thought to be important in ensuring the deformations observed in the anulus fibrosus of the finite element model were correct. There was no information found in the literature on the mechanical properties of the anulus ground substance. Experimentation was, therefore, carried out on specimens of sheep anulus fibrosus in order to quantify the mechanical response of the ground substance. Two testing protocols were employed. The first series of tests were undertaken to provide information on the strain required to initiate permanent damage in the ground substance. The second series of tests resulted in the acquisition of data on the mechanical response of the tissue to repeated loading. The results of the experimentation carried out to determine the strain necessary to initiate permanent damage suggested that during daily loading some derangement might be caused in the anulus ground substance. The results for the mechanical response of the tissue were used to determine hyperelastic constants which were incorporated in the finite element model. A second order Polynomial and a third order Ogden strain energy equation were used to define the anulus ground substance. Both these strain energy equations incorporated the nonlinear mechanical response of the tissue during shear loading conditions. Using these geometric data and material properties a finite element model of a representative L4/5 intervertebral disc was developed. When the measured material parameters for the anulus ground substance were implemented in the finite element model, large deformations were observed in the anulus fibrosus and excessive nucleus pressures were found. This suggested that the material parameters defining the anulus ground substance were overly compliant and in turn, implied the possibility that the stiffness of the sheep anulus ground substance was lower than the stiffness of the human tissue. Even so, the mechanical properties of the sheep joints had been shown to be similar to those of the human joint and it was concluded that the results of analyses using these parameters would provide valuable qualitative information on the disc mechanics. To represent the degeneration of the anulus fibrosus, the models included simulations of anular lesions - rim, radial and circumferential lesions. Degeneration of the nucleus may be characterised by a significant reduction in the hydrostatic nucleus pressure and a loss of hydration. This was simulated by removal of the hydrostatic nucleus pressure. Analyses were carried out using rotational loading conditions that were comparable to the ranges of motion observed physiologically. The results of these analyses showed that the removal of the hydrostatic nucleus pressure from an otherwise healthy disc resulted in a significant reduction in the stiffness of the disc. This indicated that when the nucleus pulposus is extremely degenerate, it offers no resistance to the deformation of the anulus and the mechanics of the disc are significantly changed. Specifically, the resistance to rotation offered by the intervertebral disc is reduced, which may affect the stability of the joint. When anular lesions were simulated in the finite element model they caused minimal changes in the peak moments resisted by the disc under rotational loading. This suggested that the removal of the nucleus pressure had a greater effect on the mechanics of the disc than the simulation of anular lesions. The results of the finite element model reproduced trends observed in both the healthy and degenerate intervertebral disc in terms of variations in nucleus pressure with loading conditions, axial displacement of the superior surface and bulge of the peripheral anulus. It was hypothesised that the reduced rotational stiffness of the degenerate disc may result in overload of the surrounding innervated osseoligamentous anatomy which may in turn cause back pain. Similarly back pain may result from the abnormal deformation of the innervated peripheral anulus in the vicinity of anular lesions. Furthermore, it was hypothesised that biochemical changes may result in the degeneration of the nucleus, which in turn may cause excessive strains in the anulus ground substance and lead to the initiation of permanent damage in the form of anular lesions. With further refinement of the components of the model and the methods used to define the anular lesions it was considered that this model would provide a powerful analysis tool for the investigation of the mechanics of intervertebral discs with and without significant degeneration.

Low back pain is a common cause of disability and work inability, often associated with intervertebral disc degeneration. The current understanding of disc degeneration is limited and none of the available treatments is entirely effective. The work described herein investigates potential strategies for the biological herapeutic restoration of disc degeneration. Firstly, an in vitro study to investigate the effects of BMP-7 on human discal cellular viability was performed. Cultured cells were treated with TNF-a or H202 to induce apoptosis, resulting in the down regulation of extracellular matrix proteins, decreased cell viability, morphological changes and activation of caspase-3; however, addition of BMP-7 alone prevented the observed effects, demonstrating the ability of BMP-7 to prevent apoptosis of human disc cells in vitro. Secondly, the differentiation potential of stem cells towards disc-like cells was studied. Rodent mesenchymal stem cells (rMSCs) were cultured alone or co-cultured with rat disc tissue. Differentiation potential of rMSCs was evaluated by mRNA and protein expression, cellular function and morphological studies. The co-culture conditions led to the expression of chondrocytic markers in rMSCs, whereas rMSCs cultured alone did not express the chondrocytic markers. Cellular contact between the co-cultured rMSCs and the discal tissue were observed. This study demonstrated that rMSCs can differentiate into functional disc-like cells in a tissue influenced co-culture environment. Finally, the survival and differentiation of CD34+ or CD34?? bone marrow (hBM) cells, in an intra-discal xenogeneic transplantation rat model was investigated. Human CD34+ or CD34?? cells were isolated, fluorescent-labelled and injected into rat coccygeal discs. The survival of transplanted cells was confirmed by fluorescent positive cells as well as a human nuclear specific marker. Interestingly, CD34?? cells survived until day 42 in the injected discs, and differentiated into cells ex:pressing a chondrocytic phenotype. In contrast, CD34+ cells could not be detected by day 21. This data suggests that transplanted hBM CD34?? cells, in contrast to CD34+ cells, were able to survive and differentiate within the intervertebral disc. Together, the results of these studies can both encourage and contribute to the basis of potential biological therapies in the restoration of intervertebral disc degeneration.

Zugl.: Köln, Univ., Diss., 2003

Diss. (sammanfattning) Linköping : Linköpings universitet, 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol inst., 2003. / Härtill 7 uppsatser.