Characterization Of Human Stability Using Vector Acceleration Signals

Biomedical signals carry information about a physiological event. The part of the signal pertaining to a specific event is called an epoch. Once the event has been determined, the corresponding waveform may be segmented and analyzed based on many parameters[1]. As falls have increased in recent years due to an aging population, it is important to gain insight to the reaction of an individual to perturbations. One common method of studying human reaction is by using a balance aperture. This thesis describes the physical actions that produce acceleration on a balance apparatus and captures the acceleration on an accelerometer. Algorithms were developed to segment the unstable periods of the accelerometer signal. Wavelets were used as well as non-linear filters. The non-linear filters increased the amplitudes of periods of instability, simple signal models of the output of the non-linear filters where formulated and analyzed. Vector processing techniques were also developed. The experimental results demonstrate that the acceleration during unstable periods can be differentiated by its frequency content, by its discontinuous nature and by using vector relationships. The algorithms were tested with five individuals and had over 80% accuracy.

Characterization Of Human Stability Using Vector Acceleration Signals

Biomedical signals carry information about a physiological event. The part of the signal pertaining to a specific event is called an epoch. Once the event has been determined, the corresponding waveform may be segmented and analyzed based on many parameters[1]. As falls have increased in recent years due to an aging population, it is important to gain insight to the reaction of an individual to perturbations. One common method of studying human reaction is by using a balance aperture. This thesis describes the physical actions that produce acceleration on a balance apparatus and captures the acceleration on an accelerometer. Algorithms were developed to segment the unstable periods of the accelerometer signal. Wavelets were used as well as non-linear filters. The non-linear filters increased the amplitudes of periods of instability, simple signal models of the output of the non-linear filters where formulated and analyzed. Vector processing techniques were also developed. The experimental results demonstrate that the acceleration during unstable periods can be differentiated by its frequency content, by its discontinuous nature and by using vector relationships. The algorithms were tested with five individuals and had over 80% accuracy.

Hormone replacement therapy: update and practical prescribing

Peri-menopause and menopause are a normal part of ageing. Nikki Noble gives an overview of hormone replacement therapy and practical prescribing tips Menopause is a physiological event of ovarian failure due to a loss of ovarian follicular activity. This leads to a lack of oestrogen, resulting in the cessation of menstruation and loss of reproductive function. This article discusses the symptoms of menopause and treatment with hormone replacement therapy. This includes practical prescribing, side effects and long-term benefits and risks. The current shortages of hormone replacement therapy are also addressed. The aim of this article is to enable health professionals to define menopause and gain an understanding of the symptoms associated with it. After reading this article you should be able to: describe when peri-menopause and menopause occur, describe the common symptoms that may be experienced during peri-menopause and menopause, understand of the hormones used in hormone replacement therapy, and understand the practical prescribing of hormone replacement therapy and the benefits, risks, contraindications and side-effects.

MENSTRUAL CYCLE CONTROL - A CONTROVERSIAL EXAMPLE OF HUMAN ENHANCEMENT IN RELATION TO WOMEN'S BODY AND PSYCHE

By discussing the position of bio-conservatism and transhumanism, we question if the women menstrual cycle control would represent a new way toward a more responsive relation with one’s own physical and mental health, a choice of freedom from undesired physiological conditions, a medicalization of a natural physiological event or an innovative carrier of social stigma against the women. We argue that the advancement of medical science may allow women a choice if to regulate own menstrual cycle, offering them as well a right to intervene responsibly on their own body and psyche. Accordingly, a post-human society could provide a suitable coexistence between women who claim menstruation as the biological essence and those who claim it as an option.

Hormone replacement therapy: update and practical prescribing

Menopause is a physiological event of ovarian failure due to a loss of ovarian follicular activity. This leads to a lack of oestrogen, resulting in the cessation of menstruation and loss of reproductive function. This article discusses the symptoms of menopause and treatment with hormone replacement therapy. This includes practical prescribing, side effects and long term benefits and risks. The current shortages of hormone replacement therapy are also addressed. The aim of this article is to enable healthcare professionals to define menopause and gain an understanding of the symptoms associated with it. After reading this article you should be able to: describe when peri-menopause and menopause occur, describe the common symptoms that may be experienced during peri-menopause and menopause, understand of the hormones used in hormone replacement therapy, and understand the practical prescribing of hormone replacement therapy and the benefits, risks, contraindications and side-effects.

Asparagine endopeptidase cleaves tau at N167 after uptake into microglia

BackgroundTau cleavage by different proteolytic enzymes generates short, aggregation-prone fragments that have been implicated in the pathogenesis of Alzheimer’s disease (AD). Asparagine endopeptidase (AEP) activity in particular has been associated with tau dysfunction and aggregation, and the activity of the protease is increased in both aging and AD.Methods and ResultsUsing a mass spectrometry approach we identified a novel tau cleavage site at N167 and confirmed its processing by AEP. In combination with the previously known site at N368, we show that AEP cleavage yields a tau fragment that is present in both control and AD brains at similar levels. AEP is a lysosomal enzyme, and our data suggest that it is expressed in microglia rather than in neurons. Accordingly, we observe tau cleavage at N167 and N368 after endocytotic uptake into microglia, but not neurons. However, tau168-368 does not accumulate in microglia and we thus conclude that the fragment is part of a proteolytic cascade leading to tau degradation.ConclusionsWhile we confirm previous studies showing increased overall AEP activity in AD brains, our data suggests that AEP-mediated cleavage of tau is a physiological event occurring during microglial degradation of the secreted neuronal protein. The disease-associated increase in active AEP may thus be related to pro-inflammatory conditions in AD brains, and our findings argue against AEP inhibition as a therapeutic approach in AD.

Phagocytosis: a repertoire of receptors and Ca2+ as a key second messenger

Receptor-mediated phagocytosis is a complex process that mediates the internalization, by a cell, of other cells and large particles; this is an important physiological event not only in mammals, but in a wide diversity of organisms. Of simple unicellular organisms that use phagocytosis to extract nutrients, to complex metazoans in which phagocytosis is essential for the innate defence system, as a first line of defence against invading pathogens, as well as for the clearance of damaged, dying or dead cells. Evolution has armed multicellular organisms with a range of receptors expressed on many cells that serve as the molecular basis to bring about phagocytosis, regardless of the organism or the specific physiological event concerned. Key to all phagocytic processes is the finely controlled rearrangement of the actin cytoskeleton, in which Ca2+ signals play a major role. Ca2+ is involved in cytoskeletal changes by affecting the actions of a number of contractile proteins, as well as being a cofactor for the activation of a number of intracellular signalling molecules, which are known to play important roles during the initiation, progression and resolution of the phagocytic process. In mammals, the requirement of Ca2+ for the initial steps in phagocytosis, and the subsequent phagosome maturation, can be quite different depending on the type of cell and on the type of receptor that is driving phagocytosis. In this review we discuss the different receptors that mediate professional and non-professional phagocytosis, and discuss the role of Ca2+ in the different steps of this complex process.