24,830 research outputs found
Beate Burtscher-Bechter/Martin Sexl (Hg.): Theory Studies?
No full textRezension zu Beate Burtscher-Bechter/Martin Sexl (Hg.): Theory Studies? Konturen komparatistischer Theoriebildung zu Beginn des 21. Jahrhunderts. Innsbruck, Wien, München, Bozen (Studien-Verlag) 2001 (= Comparanda; Bd. 4). 330 Seiten.
Eine Auseinandersetzung mit den unterschiedlichen literaturtheoretischen Ansätzen sowie eine kritische Reflexion des eigenen Faches gehören mittlerweile zur guten literaturwissenschaftlichen Praxis. Die an der Leopold-Franzens-Universität Innsbruck im November 2000 veranstaltete Tagung "Theory Studies? – Vergleichende Literaturwissenschaft und Literaturtheorie" nahm die von Erwin Koppen bereits zu Beginn der 70er Jahre gestellte Frage nach einer spezifischen Theorie der Vergleichenden Literaturwissenschaft zum Ausgangspunkt
How much resistance exercise is beneficial for healthy aging and longevity?
No full textResistance exercise (RE) is an important physical activity modality conferring major health benefits that are partially complementary to benefits from endurance exercise.
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Recent meta-analyses reveal a U-shaped relationship between RE volumes and mortality, with optimal benefits achieved at about 60 min of RE per week.
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The mechanisms for potential adverse effects at higher RE volumes are unknown and may be due to hitherto undefined confounders and/or specific individual vulnerabilities.
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Wearable technologies and advanced data analysis methods provide exciting tools to explore such risk factors.
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Presently, there is no convincing reason for healthy individuals to reduce their RE activities
Physiological Responses in Humans Acutely Exposed to High Altitude (3480 m): Minute Ventilation and Oxygenation Are Predictive for the Development of Acute Mountain Sickness
No full textBurtscher, Martin, Michael Philadelphy, Hannes Gatterer, Johannes Burtscher, Martin Faulhaber, Werner Nachbauer, and Rudolf Likar. Physiological responses in humans acutely exposed to high altitude (3480 m): Minute ventilation and oxygenation are predictive for the development of acute mountain sickness. High Alt Med Biol. 00:000-000, 2019.-The importance of arterial oxygen saturation for the prediction of acute mountain sickness (AMS) is still a matter of debate. Reasons for discrepancies may result from varying laboratory or field conditions and their interactions. Thus, we analyzed data from our prior high-altitude studies, including participants of a broad range of age of both sexes (20 males and 20 females, aged between 20 and 67 years) under strictly standardized conditions of pre-exposure and acute exposure to real high altitude (3480 m). A set of resting cardiovascular, respiratory, hematological, and metabolic variables were recorded at high altitude (Testa Grigia, Plateau Rosa, 3480 m; Swiss-Italian boarder) after performing pretests at low altitude (Innsbruck, 600 m, Austria). Our analyses indicate that (1) smaller changes in resting minute ventilation (VE) and a larger decrease of peripheral oxygen saturation (SpO(2)) during the first 3 hours of acute exposure to high altitude were independent predictors for subsequent development of AMS (90% correct prediction), (2) there are no differences of responses between sexes, and (3) there is no association of responses with age. Considering the independent effects of both responses (VE and SpO(2)) may be of clinical/practical relevance. Moreover, the presented data derived from a broad age range of both sexes might be of interest for comparative purposes.LMN
Hypoxia Sensing and Responses in Parkinson’s Disease
Full text linkParkinson’s disease (PD) is associated with various deficits in sensing and responding to reductions in oxygen availability (hypoxia). Here we summarize the evidence pointing to a central role of hypoxia in PD, discuss the relation of hypoxia and oxygen dependence with pathological hallmarks of PD, including mitochondrial dysfunction, dopaminergic vulnerability, and alpha-synuclein-related pathology, and highlight the link with cellular and systemic oxygen sensing. We describe cases suggesting that hypoxia may trigger Parkinsonian symptoms but also emphasize that the endogenous systems that protect from hypoxia can be harnessed to protect from PD. Finally, we provide examples of preclinical and clinical research substantiating this potential
A Celebration of the Extraordinary Life of Late Professor Tatiana V. Serebrovskaya (Kyiv, Ukraine) in Advancing Hypoxia Science and Medicine
Full text linkNo funding was received for this article
Synergy of exercise and hypoxia for brain health and aging – A narrative review
No full textRegular exercise is a well-established means to improve brain health and prevent age-related neurological diseases, including dementia (Marques-Aleixo et al., 2020). The precise mechanisms how direct exercise effects are transmitted to the brain remain incompletely understood. However, the increased oxygen demand and associated metabolic stress in the primarily affected tissues – the working skeletal muscle, the cardiovascular and the respiratory system – likely play crucial roles in exercise-signalling to the brain (Severinsen & Pedersen, 2020). Besides the mobilization of beneficial circulating factors, the modulation of blood properties and blood-flow, the immune system and the autonomous system are involved. Intriguingly, physiological stress induced by low environmental oxygen availability (hypoxia) can induce the activation of similar processes like exercise. The aim of this contribution is to evaluate the role of hypoxia in the benefits of exercise on the brain.
Accumulating evidence demonstrates the potential of direct modulation of inspired oxygen levels to improve neurological diseases (Burtscher et al., 2021). Reduced all-cause mortality in people living at moderate altitudes (and therefore in chronic, mild hypobaric hypoxia) may also be associated with reduced risk of neurological diseases, including of stroke (Faeh et al., 2009). This is surprising, because the hypoxic stress at moderate altitudes (usually defined as altitudes between 1,500 and 2,500 m) is generally considered too low to induce substantial hypoxia adaptations. It is thus possible that the combination of moderate environmental hypoxia at moderate altitude with the increased oxygen demand during exercise is required to promote protective adaptations, such as of the brain. Considering this possibility, synergistic and complementary molecular and systemic responses and adaptations to exercise and hypoxia may benefit the brain. Among the involved molecular processes are mitochondrial changes following cellular stress that are also linked to the regulation of adaptations by the transcription factor hypoxia inducible factor, which is activated by both hypoxia and exercise. Mitochondria are the main molecular oxygen consumers, respond sensitively to stress and dispose of a wide array of intra- and intercellular communication modes (Memme et al., 2021). Moreover, exerkines, blood-borne factors released in response to exercise, have emerged as important mediators of inter-organ exercise-signalling (Severinsen & Pedersen, 2020) and modulate the autonomic and immune system in response to hypoxic and metabolic stress.
In conclusion, the activation of endogenous responses to hypoxic and metabolic stress are powerful means to improve brain health and healthy aging. Based on the overlapping and distinct physiological responses to hypoxia and exercise, brain benefits of exercising at higher altitudes and advances in the development of customized strategies to improve brain resilience are promising approaches to target neurological diseases. While the safe performance of exercise in moderate altitudes is already considered an impactful way to improve brain health, the optimization of combined exercise and (artificially induced) hypoxia for specific target groups requires further in-depth investigation.
References
Burtscher, J., Mallet, R. T., Burtscher, M., & Millet, G. P. (2021). Hypoxia and brain aging: Neurodegeneration or neuroprotection? Ageing Research Reviews, 68, Article 101343. https://doi.org/10.1016/j.arr.2021.101343
Faeh, D., Gutzwiller, F., Bopp, M., & Group, S. N. C. S. (2009). Lower mortality from coronary heart disease and stroke at higher altitudes in Switzerland. Circulation, 120(6), 495-501. https://doi.org/10.1161/CIRCULATIONAHA.108.819250
Marques-Aleixo, I., Beleza, J., Sampaio, A., Stevanović, J., Coxito, P., Gonçalves, I., Ascensão, A., & Magalhães, J. (2020). Preventive and therapeutic potential of physical exercise in neurodegenerative diseases. Antioxidants & Redox Signaling, 34(8), 674–693. https://doi.org/10.1089/ars.2020.8075
Memme, J. M., Erlich, A. T., Phukan, G., & Hood, D. A. (2021). Exercise and mitochondrial health. The Journal of Physiology, 599(3), 803-817. https://doi.org/10.1113/jp278853
Severinsen, M. C. K., & Pedersen, B. K. (2020). Muscle-organ crosstalk: The emerging roles of myokines. Endocrine Reviews, 41(4), 594-609. https://doi.org/10.1210/endrev/bnaa01
Jack Alive / Martin Dead : The Location of the "Author" in Jack London\u27s Martin Eden
No full textThis essay is an attempt to read Martin Eden, Jack Londonʼs autobiographical novel, in terms of the inextricable relationship between the author and the protagonist. Critics have often taken the unbalanced plot and the lack of ironic distance between narrator and character in Martin Eden as the technical weakness of London, but this paper argues that the achievement of this novel owes a great deal to the attachment of London to Martin. The unbalanced structure is a necessary product of the severe struggle of the author to kill his romantic alter ego. // Martin, who aspires to win Ruth Morse, tries to cross class boundaries by making a career of a writer. Even after realizing the emptiness of Ruth, who turns out to be nothing but a typical figure of the bourgeoisie, he somehow persists in loving her. The notion underlying here is that, for Martin, love, career and art are fundamentally inseparable. He objects to the aestheteʼs view of Brissenden on account of his separation of art from career. Martinʼs identity and life consist only in the triunity of love/career/art; the alternative is the repudiation of life. Thus, the unnatural delay of his disappointment in love can be regarded as Londonʼs strategy to set the suicide of Martin as the necessary consequence of the story. // By finishing the story and killing Martin, London finally detaches himself from Martin, reconstructs his self, and, unlike Martin, survives as a professional writer. In this sense, Martin Eden is a story about “writerʼs self-reconstruction.
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