scholarly journals Physiological Adaptations to Extreme Maternal and Allomaternal Care in Spiders

Author(s):  
Anja Junghanns ◽  
Christina Holm ◽  
Mads Fristrup Schou ◽  
Johannes Overgaard ◽  
Hans Malte ◽  
...  
2019 ◽  
pp. 11-20
Author(s):  
Mihai-Alexandru Citea ◽  
Marius Neculaes

High performance sport has a major impact on the physiological adaptations of the respiratory system. The importance of the optimal functioning of this system is essential to achieve top results in high performance sport but also in maintaining a long term health status. Science journals present numerous studies that highlight the benefits of practicing Tai Chi on the general population, with effects ranging from improving cardiac function, to influencing the immune system. The purpose of this study is to identify whether by practicing Tai Chi forms a athlete can change their breathing pattern and develop their respiratory amplitude. The subjects of the study were 22 fencing practitioners, accredited at the Iași Municipal Sports Club (C.S.M. Iași), aged between 14 and 18 years, with over 3 years of competitive activity. Materials and method: The study participants were evaluated initially and at the end of 7 months of practice. The frequency was 3 sessions per week, and the duration of each session was 20-30 minutes. The evaluation consisted in measuring the circumference of the thorax at 3 different levels: subaxillary, medial thorax (T6-T7) and lower rib (diaphragmatic) in maximal inspiration and expiration. Conclusions: A constant evolution is observed in most of the exposed cases. In cases where this evolution is not visible, a change in the breathing mode can be noticed, transforming from an upper rib breathing into a thoracic or abdominal breathing. With the exception of one case, all subjects had an improvement of the value in the lower rib level.


2021 ◽  
Vol 22 (11) ◽  
pp. 5495
Author(s):  
Felipe Borges Almeida ◽  
Graziano Pinna ◽  
Helena Maria Tannhauser Barros

Under stressful conditions, the hypothalamic-pituitary-adrenal (HPA) axis acts to promote transitory physiological adaptations that are often resolved after the stressful stimulus is no longer present. In addition to corticosteroids (e.g., cortisol), the neurosteroid allopregnanolone (3α,5α-tetrahydroprogesterone, 3α-hydroxy-5α-pregnan-20-one) participates in negative feedback mechanisms that restore homeostasis. Chronic, repeated exposure to stress impairs the responsivity of the HPA axis and dampens allopregnanolone levels, participating in the etiopathology of psychiatric disorders, such as major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). MDD and PTSD patients present abnormalities in the HPA axis regulation, such as altered cortisol levels or failure to suppress cortisol release in the dexamethasone suppression test. Herein, we review the neurophysiological role of allopregnanolone both as a potent and positive GABAergic neuromodulator but also in its capacity of inhibiting the HPA axis. The allopregnanolone function in the mechanisms that recapitulate stress-induced pathophysiology, including MDD and PTSD, and its potential as both a treatment target and as a biomarker for these disorders is discussed.


Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1017
Author(s):  
Mohammed Bakkali ◽  
Rubén Martín-Blázquez ◽  
Mercedes Ruiz-Estévez ◽  
Manuel A. Garrido-Ramos

We sequenced the sporophyte transcriptome of Killarney fern (Vandenboschia speciosa (Willd.) G. Kunkel). In addition to being a rare endangered Macaronesian-European endemism, this species has a huge genome (10.52 Gb) as well as particular biological features and extreme ecological requirements. These characteristics, together with the systematic position of ferns among vascular plants, make it of high interest for evolutionary, conservation and functional genomics studies. The transcriptome was constructed de novo and contained 36,430 transcripts, of which 17,706 had valid BLAST hits. A total of 19,539 transcripts showed at least one of the 7362 GO terms assigned to the transcriptome, whereas 6547 transcripts showed at least one of the 1359 KEGG assigned terms. A prospective analysis of functional annotation results provided relevant insights on genes involved in important functions such as growth and development as well as physiological adaptations. In this context, a catalogue of genes involved in the genetic control of plant development, during the vegetative to reproductive transition, in stress response as well as genes coding for transcription factors is given. Altogether, this study provides a first step towards understanding the gene expression of a significant fern species and the in silico functional and comparative analyses reported here provide important data and insights for further comparative evolutionary studies in ferns and land plants in general.


Harmful Algae ◽  
2017 ◽  
Vol 63 ◽  
pp. 13-22 ◽  
Author(s):  
Masafumi Natsuike ◽  
Hiroshi Oikawa ◽  
Kohei Matsuno ◽  
Atsushi Yamaguchi ◽  
Ichiro Imai

2020 ◽  
Vol 34 (8) ◽  
pp. 2258-2266
Author(s):  
Apostolos Papandreou ◽  
Anastassios Philippou ◽  
Elias Zacharogiannis ◽  
Maria Maridaki

2017 ◽  
Vol 372 (1717) ◽  
pp. 20160077 ◽  
Author(s):  
Anna Honkanen ◽  
Esa-Ville Immonen ◽  
Iikka Salmela ◽  
Kyösti Heimonen ◽  
Matti Weckström

Night vision is ultimately about extracting information from a noisy visual input. Several species of nocturnal insects exhibit complex visually guided behaviour in conditions where most animals are practically blind. The compound eyes of nocturnal insects produce strong responses to single photons and process them into meaningful neural signals, which are amplified by specialized neuroanatomical structures. While a lot is known about the light responses and the anatomical structures that promote pooling of responses to increase sensitivity, there is still a dearth of knowledge on the physiology of night vision. Retinal photoreceptors form the first bottleneck for the transfer of visual information. In this review, we cover the basics of what is known about physiological adaptations of insect photoreceptors for low-light vision. We will also discuss major enigmas of some of the functional properties of nocturnal photoreceptors, and describe recent advances in methodologies that may help to solve them and broaden the field of insect vision research to new model animals. This article is part of the themed issue ‘Vision in dim light’.


2005 ◽  
Vol 30 (5) ◽  
pp. 543-553 ◽  
Author(s):  
Sebastien Libicz ◽  
Belle Roels ◽  
Gregoire P. Millet

While the physiological adaptations following endurance training are relatively well understood, in swimming there is a dearth of knowledge regarding the metabolic responses to interval training (IT). The hypothesis tested predicted that two different endurance swimming IT sets would induce differences in the total time the subjects swam at a high percentage of maximal oxygen consumption [Formula: see text]. Ten trained triathletes underwent an incremental test to exhaustion in swimming so that the swimming velocity associated with [Formula: see text][Formula: see text] could be determined. This was followed by a maximal 400-m test and two intermittent sets at [Formula: see text] (a) 16 × 50 m with 15-s rest (IT50); (b) 8 × 100 m with 30-s rest (IT100). The times sustained above 95% [Formula: see text] (68.50 ± 62.69 vs. 145.01 ± 165.91 sec) and 95% HRmax (146.67 ± 131.99 vs. 169.78 ± 203.45 sec, p = 0.54) did not differ between IT50 and IT100 (values are mean ± SD). In conclusion, swimming IT sets of equal time duration at [Formula: see text] but of differing work-interval durations led to slightly different [Formula: see text] and HR responses. The time spent above 95% of [Formula: see text]max was twice as long in IT100 as in IT50, and a large variability between mean [Formula: see text] and HR values was also observed. Key words: interval training, maximal oxygen consumption, triathletes


2002 ◽  
Vol 93 (5) ◽  
pp. 1567-1582 ◽  
Author(s):  
David R. Bassett

Beginning in 1910, A. V. Hill performed careful experiments on the time course of heat production in isolated frog muscle. His research paralleled that of the German biochemist Otto Meyerhof, who measured the changes in muscle glycogen and lactate during contractions and recovery. For their work in discovering the distinction between aerobic and anaerobic metabolism, Hill and Meyerhof were jointly awarded the 1922 Nobel Prize for Physiology or Medicine. Because of Hill's interest in athletics, he sought to apply the concepts discovered in isolated frog muscle to the exercising human. Hill and his colleagues made measurements of O2 consumption on themselves and other subjects running around an 85-m grass track. In the process of this work, they defined the terms “maximum O2 intake,” “O2requirement,” and “steady state of exercise.” Other contributions of Hill include his discoveries of heat production in nerve, the series elastic component, and the force-velocity equation in muscle. Around the time of World War II, Hill was a leading figure in the Academic Assistance Council, which helped Jewish scientists fleeing Nazi Germany to relocate in the West. He served as a member of the British Parliament from 1940 to 1945 and as a scientific advisor to India. Hill's vision and enthusiasm attracted many scientists to the field of exercise physiology, and he pointed the way toward many of the physiological adaptations that occur with physical training.


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