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Frontiers in Human Neuroscience 2022One hypothesis for why humans enjoy musical rhythms relates to their prediction of when each beat should occur. The ability to predict the timing of an event is...
One hypothesis for why humans enjoy musical rhythms relates to their prediction of when each beat should occur. The ability to predict the timing of an event is important from an evolutionary perspective. Therefore, our brains have evolved internal mechanisms for processing the progression of time. However, due to inherent noise in neural signals, this prediction is not always accurate. Theoretical considerations of optimal estimates suggest the occurrence of certain systematic errors made by the brain when estimating the timing of beats in rhythms. Here, we tested psychophysically whether these systematic errors exist and if so, how they depend on stimulus parameters. Our experimental data revealed two main types of systematic errors. First, observers perceived the time of the last beat of a rhythmic pattern as happening earlier than actual when the inter-beat interval was short. Second, the perceived time of the last beat was later than the actual when the inter-beat interval was long. The magnitude of these systematic errors fell as the number of beats increased. However, with many beats, the errors due to long inter-beat intervals became more apparent. We propose a Bayesian model for these systematic errors. The model fits these data well, allowing us to offer possible explanations for how these errors occurred. For instance, neural processes possibly contributing to the errors include noisy and temporally asymmetric impulse responses, priors preferring certain time intervals, and better-early-than-late loss functions. We finish this article with brief discussions of both the implications of systematic errors for the appreciation of rhythm and the possible compensation by the brain's motor system during a musical performance.
PubMed: 36438641
DOI: 10.3389/fnhum.2022.1009219 -
Sports Medicine - Open Apr 2024Ultra-endurance events are gaining popularity in multiple exercise disciplines, including cycling. With increasing numbers of ultra-cycling events, aspects influencing... (Review)
Review
BACKGROUND
Ultra-endurance events are gaining popularity in multiple exercise disciplines, including cycling. With increasing numbers of ultra-cycling events, aspects influencing participation and performance are of interest to the cycling community.
MAIN BODY
The aim of this narrative review was, therefore, to assess the types of races offered, the characteristics of the cyclists, the fluid and energy balance during the race, the body mass changes after the race, and the parameters that may enhance performance based on existing literature. A literature search was conducted in PubMed, Scopus, and Google Scholar using the search terms 'ultracycling', 'ultra cycling', 'ultra-cycling', 'ultra-endurance biking', 'ultra-bikers' and 'prolonged cycling'. The search yielded 948 results, of which 111 were relevant for this review. The studies were classified according to their research focus and the results were summarized. The results demonstrated changes in physiological parameters, immunological and oxidative processes, as well as in fluid and energy balance. While the individual race with the most published studies was the Race Across America, most races were conducted in Europe, and a trend for an increase in European participants in international races was observed. Performance seems to be affected by characteristics such as age and sex but not by anthropometric parameters such as skin fold thickness. The optimum age for the top performance was around 40 years. Most participants in ultra-cycling events were male, but the number of female athletes has been increasing over the past years. Female athletes are understudied due to their later entry and less prominent participation in ultra-cycling races. A post-race energy deficit after ultra-cycling events was observed.
CONCLUSION
Future studies need to investigate the causes for the observed optimum race age around 40 years of age as well as the optimum nutritional supply to close the observed energy gap under consideration of the individual race lengths and conditions. Another research gap to be filled by future studies is the development of strategies to tackle inflammatory processes during the race that may persist in the post-race period.
PubMed: 38679655
DOI: 10.1186/s40798-024-00715-7 -
Nature Communications Oct 2021The axonemal central pair (CP) are non-centrosomal microtubules critical for planar ciliary beat. How they form, however, is poorly understood. Here, we show that...
The axonemal central pair (CP) are non-centrosomal microtubules critical for planar ciliary beat. How they form, however, is poorly understood. Here, we show that mammalian CP formation requires Wdr47, Camsaps, and microtubule-severing activity of Katanin. Katanin severs peripheral microtubules to produce central microtubule seeds in nascent cilia. Camsaps stabilize minus ends of the seeds to facilitate microtubule outgrowth, whereas Wdr47 concentrates Camsaps into the axonemal central lumen to properly position central microtubules. Wdr47 deficiency in mouse multicilia results in complete loss of CP, rotatory beat, and primary ciliary dyskinesia. Overexpression of Camsaps or their microtubule-binding regions induces central microtubules in Wdr47 ependymal cells but at the expense of low efficiency, abnormal numbers, and wrong location. Katanin levels and activity also impact the central microtubule number. We propose that Wdr47, Camsaps, and Katanin function together for the generation of non-centrosomal microtubule arrays in polarized subcellular compartments.
Topics: Animals; Axoneme; Cilia; Ciliary Motility Disorders; Gene Expression; Katanin; Mice; Microtubule-Associated Proteins; Microtubules; Nerve Tissue Proteins
PubMed: 34608154
DOI: 10.1038/s41467-021-26058-5 -
The Journal of Physiology Feb 2011We perceive the world around us as stable. This is remarkable given that our body parts as well as we ourselves are constantly in motion. Humans and other primates move... (Review)
Review
We perceive the world around us as stable. This is remarkable given that our body parts as well as we ourselves are constantly in motion. Humans and other primates move their eyes more often than their hearts beat. Such eye movements lead to coherent motion of the images of the outside world across the retina. Furthermore, during everyday life, we constantly approach targets, avoid obstacles or otherwise move in space. These movements induce motion across different sensory receptor epithels: optical flow across the retina, tactile flow across the body surface and even auditory flow as detected from the two ears. It is generally assumed that motion signals as induced by one's own movement have to be identified and differentiated from the real motion in the outside world. In a number of experimental studies we and others have functionally characterized the primate posterior parietal cortex (PPC) and its role in multisensory encoding of spatial and motion information. Extracellular recordings in the macaque monkey showed that during steady fixation the visual, auditory and tactile spatial representations in the ventral intraparietal area (VIP) are congruent. This finding was of major importance given that a functional MRI (fMRI) study determined the functional equivalent of macaque area VIP in humans. Further recordings in other areas of the dorsal stream of the visual cortical system of the macaque pointed towards the neural basis of perceptual phenomena (heading detection during eye movements, saccadic suppression, mislocalization of visual stimuli during eye movements) as determined in psychophysical studies in humans.
Topics: Animals; Brain Mapping; Eye Movements; Humans; Macaca mulatta; Magnetic Resonance Imaging; Parietal Lobe; Photic Stimulation; Proprioception; Space Perception
PubMed: 20921203
DOI: 10.1113/jphysiol.2010.195537 -
Journal of Medical Entomology Jan 2022Effective management of insect disease vectors requires a detailed understanding of their ecology and behavior. In Anopheles gambiae sensu lato (s.l.) (Diptera:... (Review)
Review
Effective management of insect disease vectors requires a detailed understanding of their ecology and behavior. In Anopheles gambiae sensu lato (s.l.) (Diptera: Culicidae) mating occurs during swarming, but knowledge of their mating behavior under natural conditions is limited. Mosquitoes mate in flight over specific landmarks, known as swarm markers, at particular locations. Swarms consist of males; the females usually approach the swarm and depart following copulation. The number of mating pairs per swarm is closely associated with swarm size. The shape and height of swarm markers vary and may depend on the environmental conditions at the swarm's location. Male-male interactions in mosquito swarms with similar levels of attractive flight activity can offer a mating advantage to some individuals. Flight tone is used by mosquitoes to recognize the other sex and choose a desirable mate. Clarifying these and other aspects of mosquito reproductive behavior can facilitate the development of population control measures that target swarming sites. This review describes what is currently known about swarming behavior in Anopheles gambiae s.l., including swarm characteristics; mating within and outside of swarms, insemination in females, and factors affecting and stimulating swarming.
Topics: Animals; Anopheles; Female; Male; Mosquito Vectors; Sexual Behavior, Animal
PubMed: 34617121
DOI: 10.1093/jme/tjab157 -
Bulletin of Emergency and Trauma Oct 2019To derive findings from different studies done on drug related hospital admissions and comprehensively express the incidence and preventability of drug related hospital... (Review)
Review
OBJECTIVE
To derive findings from different studies done on drug related hospital admissions and comprehensively express the incidence and preventability of drug related hospital admissions; identify the common types of drug related problems that caused hospital admission, and identify factors associated with drug related hospital admission.
METHODS
Literatures that assessed hospitalization due to drug related problems were searched online using Pub Med and Google Scholar databases. The relevant reference lists of retrieved articles were also searched manually on Google. Prospective and retrospective studies conducted anywhere in the world on drug related hospitalization, published from January 2012 to January 2017 as an original article and written in English language were included.
RESULT
The prevalence of drug related hospital admission varies from 1.3% to 41.3% with the average rate of 15.4%. Among hospitalized patients 2.7% were died due to drug-related problems (DRPs). Drugs that were frequently reported as causing drug related admission were antithrombotic drugs, antihypertensive drugs, analgesics, anti-diabetics, antipsychotics, and anti-neoplastic drugs. Poly pharmacy, old age and female sex were mentioned as determinants for drug related hospitalization by a number of studies. About one third of drug related hospital admissions were definitely preventable and more than 40% were also potentially preventable.
CONCLUSION
Drug related problems contribute for more than 15% of hospital admissions. Higher risk of admission due to DRPs was observed in patients who were on poly pharmacy and those who were old. As most of drug related hospital admissions were preventable an emphasis should be given for preventive strategies to avoid complications and costs associated with admission.
PubMed: 31857995
DOI: 10.29252/beat-070401 -
The European Physical Journal. E, Soft... Apr 2021We present a multi-scale modeling and simulation framework for low-Reynolds number hydrodynamics of shape-changing immersed objects, e.g., biological microswimmers and...
We present a multi-scale modeling and simulation framework for low-Reynolds number hydrodynamics of shape-changing immersed objects, e.g., biological microswimmers and active surfaces. The key idea is to consider principal shape changes as generalized coordinates and define conjugate generalized hydrodynamic friction forces. Conveniently, the corresponding generalized friction coefficients can be pre-computed and subsequently reused to solve dynamic equations of motion fast. This framework extends Lagrangian mechanics of dissipative systems to active surfaces and active microswimmers, whose shape dynamics is driven by internal forces. As an application case, we predict in-phase and anti-phase synchronization in pairs of cilia for an experimentally measured cilia beat pattern.
PubMed: 33834308
DOI: 10.1140/epje/s10189-021-00016-x -
Methods in Molecular Biology (Clifton,... 2022Risk assessment assays for chemically induced arrhythmia are critical, but significant limitations exist with current cardiotoxicity testing, including a focus on single...
Risk assessment assays for chemically induced arrhythmia are critical, but significant limitations exist with current cardiotoxicity testing, including a focus on single select ion channels, the use of non-human species in vitro and in vivo, and limited direct physiological translation. To be predictive of actual adverse clinical arrhythmic risk, arrhythmia assessment models for chemicals and drugs should be fit-for-purpose and suited for evaluating compounds in which the mechanism of action may not be entirely known. Here, we describe methods for efficient and reliable screening for arrhythmogenic cardiotoxicity with a 3D human cardiac microtissue model using purified human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes and human cardiac fibroblasts. Applying optical mapping of voltage and calcium-sensitive dyes-an established approach to evaluate cardiac action potentials and calcium transients-to 3D heterotypic cardiac myocyte-fibroblast tissues allows for the generation and functional analysis of a large number of individual microtissues to provide greater throughput and high statistical power in analyses. Hundreds of microtissues in standard cell culture plates can be produced with low variability beat-to-beat, microtissue-to-microtissue, and across hiPSC-cardiomyocyte differentiation batches, reducing the number of microtissues required per condition for predictive outputs. The platform described here can be used as a sensitive, efficient, and predictive preclinical model validated for the purpose of assessing human pro-arrhythmic risk.
Topics: Arrhythmias, Cardiac; Calcium; Cardiotoxicity; Fibroblasts; Humans; Myocytes, Cardiac
PubMed: 35618904
DOI: 10.1007/978-1-0716-2261-2_10 -
Bulletin of Emergency and Trauma Jul 2021To determine the instructional programs required by volunteers based on the studies carried out worldwide. (Review)
Review
OBJECTIVE
To determine the instructional programs required by volunteers based on the studies carried out worldwide.
METHODS
A systematic search was carried out by PubMed, Cochran Library, Scopus, EMBASE, Science Direct, Web of Science and ProQuest databases between January 1970 and the end of June 2019. The articles were selected based on the keywords chosen by the author. In the end, the volunteer's instructional titles were extracted from the articles in disasters.
RESULTS
Eleven articles were chosen for final analysis after studying the titles, abstracts, and complete articles texts which 45 instructional titles were extracted. The most frequent scales in terms of repetition were ethics, kinds of exercises, personal protection instruments, general hygiene, awareness of certain disasters, accident command system, disaster triage and emergency planning.
CONCLUSION
Governments should offer programs that can best serve the improvement of their performance by considering the daily increasing growth in the number of volunteers and in natural and manmade disasters. Universities and schools play determinant roles in this regard. It is hoped that the present study findings can be effective in codify an efficient instructional program for elevating the performance of the volunteers by taking part in disasters response.
PubMed: 34307700
DOI: 10.30476/BEAT.2021.89340.1230 -
Frontiers in Aging 2022The process of aging strongly correlates with maladaptive architectural, mechanical, and biochemical alterations that contribute to the decline in cardiac function.... (Review)
Review
The process of aging strongly correlates with maladaptive architectural, mechanical, and biochemical alterations that contribute to the decline in cardiac function. Consequently, aging is a major risk factor for the development of heart disease, the leading cause of death in the developed world. In this review, we will summarize the classic and recently uncovered pathological changes within the aged heart with an emphasis on the mitochondria. Specifically, we describe the metabolic changes that occur in the aging heart as well as the loss of mitochondrial fitness and function and how these factors contribute to the decline in cardiomyocyte number. In addition, we highlight recent pharmacological, genetic, or behavioral therapeutic intervention advancements that may alleviate age-related cardiac decline.
PubMed: 35958271
DOI: 10.3389/fragi.2022.951417