1,721,047 research outputs found
K2 dalla conquista alla poesia.
No full textQuesto libro fotografico illustra il viaggio, verso la base della Grande montagna "il K2", di un gruppo di abruzzesi coinvolti in un progetto nazionale “K2 Dalla Conquista Alla Conoscenza 1954-2004” ideato e realizzato, in occasione del 50° anniversario della prima salita (italiana). Un racconto, per immagini, che a partire da Islamabad, attraverso la Karakorum Highway (strada asfaltata internazionale più alta del mondo) passando per Gilgit, Skardu, Askole e poi per la valle del Baltoro attraverso Julha, Bardumal, Paju, Urdukas, Gore, fino al Circo Concordia e quindi alla “Grande Montagna” il Chogori o più comunemente K2, rende possibile la conoscenza, almeno fotografica, di uomini, città, ghiacciai e montagne cariche di storia e di storie da riferire. Ed è nell'avvicendarsi delle immagini, che il racconto diviene ardua narrazione fotografica, perché la storia del K2 è legata inscindibilmente ad un complesso intreccio, appunto, di uomini, città, ghiacciai e montagne che si sono trovate, nella mischia degli anni, a tessere la memoria di profili mitici fatti di carne ed ossa ma anche di roccia e ghiaccio.
Aleister Crowley ed Oscar Eckenstein, Luigi Amedeo di Savoia “Duca degli Abruzzi”, Walter Bonatti, Lino Lacedelli e Achille Compagnoni, Ardito Desio, Kurt Diemberger ed Hermann Buhl, Reinhold Messner e poi Circo Concordia e ancora il Baltoro, il Godwin Austen, il Gasherbrum, il Broad Peak, il Chogolisa, Paiju Peaks, Biaho Tower, le Torri di Trango, le Cattedrali del Baltoro, il Masherbrum, Uli Biaho e la Torre Mustang sono solo alcuni dei nomi che, per sempre, echeggeranno tra i venti e tra le terre scure del Karakorum.
Sono imponenti le valli che conducono al secondo pezzetto di terra più alto del pianeta ed aride, ora sabbiose ora moreniche ed il cammino è variabile, arduo negli accessi a mezza costa e più assestato quando ci si approssima al correre del fiume. Descritto in questo libro vi è quel paesaggio delle terre alte prevalentemente brullo e disabitato con ampie zone pietrose e grandi ammassi di sabbia, originata dai venti. La parte della valle di sopra alla morena del ghiacciaio del Baltoro segna un limite che porta all’appuntamento con i ghiacciai di alta quota, caratterizzati da ampi depositi morenici, crepacci e seracchi e dalle affascinanti “vele” del Baltoro. I sentieri rocciosi conducono a pietraie moreniche posate alla vista delle grandi montagne. Lungo il cammino si incontrano tamerici e cespugli di rosa canina che ravvivano e colorano la monotonia marrone di pietre, sabbie, rocce e del fiume
Performances in extreme environments: effects of hyper/hypobarism and hypogravity on skeletal muscle.
No full textMany environmental factors may affect muscle plasticity but some have exclusive
characteristics that allow them to play a key role to maintain the muscle capacity to generate
force; these factors are: i) the oxygen availability and ii) the load applied to muscle fibres.
Hyperbarism is a condition that occurs when a man is subjected to pressure increases. To keep
the lungs from collapsing, the air is supplied to him under high pressure which exposes the
blood in the lungs to high alveolar gas pressures. Under this condition, the PO2 become
sufficiently increased, serious disorders may occur, such as modification of oxygen delivery
and/or oxygen availability to permit regular muscle contraction. Also altitude hypobaric
hypoxia induces modification of muscle capacity to generate work. Prolonged exposure to high
altitude leads significant loss in body mass, thigh muscle mass, muscle fiber area and volume
density of muscle mitochondria. Spaceflight results in a number of adaptations to skeletal
muscle, including atrophy and early muscle fatigue. Muscle atrophy is observed in a wide
range of muscles, with the most extensive loss occurring in the legs, because astronauts are no
longer needed to support the body's weight. This review will describe the background on these
topics suggesting the strategies to correct the specific muscle changes in presence of
environmental stresses, such as the alteration in oxygen-derived signaling pathways or the
metabolic consequence of microgravity that may indicate rational interventions to maintain
muscle mass and function
Comments on: Electromyographic signature of isometric squat in the highest refuge in Europe
No full textWe read the comment by Šarabon and Sašek (Eur J Transl Myol 11846, 2023 doi: 10.4081/ejtm.2023.11846) on our study on the electromyographic results during squat at high-altitude. Their highlighting of the factors that may have biased our results is commendable, despite they criticized our work as if it were a controlled laboratory study. We considered the limitations and argued our interpretation with caution. We found no changes in median frequency, frequency's slope and conduction velocity of EMG signals at high altitude, and a slight decrease of root mean square. We argued that our results may have been due to a preventative mechanism that compensates for relatively greater effort during a fatiguing strength test involving large muscle masses, or to cumulative exertional stress on the muscles. The authors of the comment themselves somehow agree with these interpretations. Guidelines for collecting, reporting and interpreting data from EMG to obtain original information on the neuromuscular system should be integrated with the effort to maintain as much as possible those field conditions that offer unique opportunities
Study of the physiological urination mechanism and its modulation by hypoxic altitudes in reproductive-age women.
No full text
“Hypoxic Ventilatory Depression during the first 7 days of exposure in intermittent altitude between 4400 and 6960 m.”
No full textThe aim of this study is to chart the hypoxic ventilatory decline experienced by climbers exposed to hypoxic stimulus with and without 7 days of acclimatisation to intermittent altitude increases of 4400 to 6960 m. Our results revealed that hypoxic ventilatory depression was present during day 1 of hypoxia and decreased thereafter, returning to control values by day 7. These results indicate that the hypoxic ventilatory response, which
is mediated by carotid body chemoreceptors, depends on the pattern and intensity of hypoxia exposure. Chronic intermittent hypoxia could facilitate this recovery, yielding faster returns to ventilatory baseline levels
Effects of auto-selected intensity in neuromuscular electrical stimulation and resistance training on muscle responses and functional capacity of elderly people
No full textAim: Resistance training (RT) and neuromuscular electrical stimulation
(NMES) are often used to combat sarcopenia and functional decline
in elderly people. However, intensity is a barrier to adherence and
regularity in training programs for this population. This study aimed to
evaluate and compare the effects of RT and NMES, performed at autoselected
intensity, on adaptive responses of the neuromuscular system
and functional capacity in healthy elderly people.
Methods: After health screening, the total sample (n = 18) was
randomized into three groups: control group CO (age = 71.7 (1.9)
yrs.; n = 6), NMES group (age = 68.8 (5.3) yrs.; n = 6) or RT group
(age = 72.3 (6.1) yrs.; n = 6).The training groups performed a tenweek
training period, while the CO group were advised to maintain
their habitual lifestyle. Auto-selected load was determined as training
intensity: The RT group used the maximal load to perform a range of
8–12 repetitions; the NMSE group trained at the pain threshold.
Biopsies in the quadriceps muscles, strength and functional capacity
were performed at the pre and post-training moments. Dependent
variables included: (MVIC), predicted (1-RM), concentric isokinetic
peak power and concentric power resistance of the quadriceps muscles
and handgrip test to evaluate strength responses; the Five Times
Sit-to-Stand test and the Timed Up and Go test performances, to
evaluate the functional capacity; single fibre characteristics and
satellite cell responses were used to evaluate muscle fibre responses.
Results:RT positively affected 1-RM and MVIC performances. Both
training protocols positively affected handgrip and functional capacity
test performances. The CO group did not demonstrate
improvements in strength performance, but did demonstrate decrements
in functional capacity tests. Molecular and cellular responses
did not present alterations after the training period.
Conclusions: This study revealed that both RT and NMES protocols,
using auto-selected loads, are valid strategies for promoting significant
improvements in functional capacity in elderly people, even with
modest improvements in strength capacity and an absence of alterations
in myofibre responses
- …
