The SPARC DRC: Building a Resource for the Autonomic Nervous System Community
The Data and Resource Center (DRC) of the NIH-funded SPARC program is developing databases, connectivity maps, and simulation tools for the mammalian autonomic nervous system. The experimental data and mathematical models supplied to the DRC by the SPARC consortium are curated, annotated and semantically linked via a single knowledgebase. A data portal has been developed that allows discovery of data and models both via semantic search and via an interface that includes Google Map-like 2D flatmaps for displaying connectivity, and 3D anatomical organ scaffolds that provide a common coordinate framework for cross-species com...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Cardiomyocyte Deletion of Bmal1 Exacerbates QT- and RR-Interval Prolongation in Scn5a+/ ΔKPQ Mice
This study determined how inducing the deletion of Bmal1 in adult cardiomyocytes impacted the in vivo electrophysiological phenotype of a knock-in mouse model for the arrhythmogenic long QT syndrome (Scn5a+/ΔKPQ). Electrocardiographic telemetry showed inducing the deletion of Bmal1 in the cardiomyocytes of mice with or without the ΔKPQ-Scn5a mutation increased the QT-interval at RR-intervals that were ≥130 ms. Inducing the deletion of Bmal1 in the cardiomyocytes of mice with or without the ΔKPQ-Scn5a mutation also increased the day/night rhythm-adjusted mean in the RR-interval, but it did not change th...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Application of Machine Learning in Pulmonary Function Assessment Where Are We Now and Where Are We Going?
Analysis of pulmonary function tests (PFTs) is an area where machine learning (ML) may benefit clinicians, researchers, and the patients. PFT measures spirometry, lung volumes, and carbon monoxide diffusion capacity of the lung (DLCO). The results are usually interpreted by the clinicians using discrete numeric data according to published guidelines. PFT interpretations by clinicians, however, are known to have inter-rater variability and the inaccuracy can impact patient care. This variability may be caused by unfamiliarity of the guidelines, lack of training, inadequate understanding of lung physiology, or simply mental ...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

TRP Channel Agonists Activate Different Afferent Neuromodulatory Mechanisms in Guinea Pig Urinary Bladder
Activation of TRP channels expressed in urinary bladder afferent nerves and urothelium releases neurotransmitters that influence bladder function. Experiments were undertaken to examine the mechanisms underlying effects of TRPA1 (allyl isothiocyanate, AITC), TRPV1 (capsaicin, CAPS), and TRPC (oleoyl-2-acetyl-sn-glycerol, OAG) agonists on guinea pig bladder activity. Effects of these agonists were compared with effects of nitro-oleic acid (OA-NO2), an electrophilic nitro-fatty acid, known to activate TRPV1, TRPA1 or TRPC channels in sensory neurons. AITC (100 μM) increased (231%) area of spontaneous bladder contractions ...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Strength Training Intensity and Volume Affect Performance of Young Kayakers/Canoeists
ConclusionYoung sprint kayakers and canoeists benefit from LIHV more than MILV strength training in terms of 2,000 m performance and muscular endurance (i.e., 2 min bench pull power). (Source: Frontiers in Physiology)
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Deep Learning Approaches to Surrogates for Solving the Diffusion Equation for Mechanistic Real-World Simulations
In many mechanistic medical, biological, physical, and engineered spatiotemporal dynamic models the numerical solution of partial differential equations (PDEs), especially for diffusion, fluid flow and mechanical relaxation, can make simulations impractically slow. Biological models of tissues and organs often require the simultaneous calculation of the spatial variation of concentration of dozens of diffusing chemical species. One clinical example where rapid calculation of a diffusing field is of use is the estimation of oxygen gradients in the retina, based on imaging of the retinal vasculature, to guide surgical interv...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Reduction in Hindquarter Vascular Resistance Supports 5-HT7 Receptor Mediated Hypotension
The 5-HT7 receptor is the primary mediator of both the acute (
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Pharmacokinetic Modeling of Morphine ’s Effect on Plasma Concentrations of Ticagrelor and Its Metabolite in Healthy Volunteers
This study aimed to build a mathematical model describing the pharmacokinetics of ticagrelor and its active metabolite (AR-C124910XX) in a stable setting with concomitant administration of morphine. The model consists of a set of four differential equations prepared upon the available knowledge regarding the biological processes in the pharmacokinetics of ticagrelor. The set of equations was solved numerically using the Runge–Kutta method. The data were obtained in a double-blind, randomized, placebo-controlled, crossover trial. Twenty-four healthy volunteers received a 180-mg ticagrelor loading dose together with ei...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Leptin and Melanocortin Signaling Mediates Hypertension in Offspring From Female Rabbits Fed a High-Fat Diet During Gestation and Lactation
Maternal high-fat diet in rabbits leads to hypertension and elevated renal sympathetic nerve activity (RSNA) in adult offspring but whether this is due to adiposity or maternal programming is unclear. We gave intracerebroventricular (ICV) and ventromedial hypothalamus (VMH) administration of leptin-receptor antagonist, α-melanocyte-stimulating hormone (αMSH), melanocortin-receptor antagonist (SHU9119), or insulin-receptor (InsR) antagonist to conscious adult offspring from mothers fed a high-fat diet (mHFD), control diet (mCD), or mCD offspring fed HFD for 10d (mCD10d, to deposit equivalent fat but not during d...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Perceptual and Biochemical Responses in Relation to Different Match-Day +2 Training Interventions in Soccer Players
The aim of this study was to examine the impact of two different post-match training interventions on the subsequent recovery of perceptual and biochemical parameters after the game. In a crossover design, eight sub-elite players underwent a soccer-specific training (SST) and an active recovery (AR) regimen on the second day after a match (+48 h). Muscle soreness as well as muscle damage (creatine kinase, CK), inflammatory (C-reactive protein and interleukin 6), immunological (e.g., lymphocytes, neutrophils, and monocytes), and endocrine (cortisol) markers were obtained at baseline (−72 h), immediately after (0 h), a...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Investigating the Association of Wallerian Degeneration and Diaschisis After Ischemic Stroke With BOLD Cerebrovascular Reactivity
IntroductionWallerian degeneration and diaschisis are considered separate remote entities following ischemic stroke. They may, however, share common neurophysiological denominators, since they are both related to disruption of fiber tracts and brain atrophy over time. Therefore, with advanced multimodal neuroimaging, we investigate Wallerian degeneration and its association with diaschisis.MethodsIn order to determine different characteristics of Wallerian degeneration, we conducted examinations on seventeen patients with chronic unilateral ischemic stroke and persisting large vessel occlusion, conducting high-resolution a...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Epithelial Barrier Dysfunction in Chronic Respiratory Diseases
Mucosal surfaces are lined by epithelial cells, which provide a complex and adaptive module that ensures first-line defense against external toxics, irritants, antigens, and pathogens. The underlying mechanisms of host protection encompass multiple physical, chemical, and immune pathways. In the lung, inhaled agents continually challenge the airway epithelial barrier, which is altered in chronic diseases such as chronic obstructive pulmonary disease, asthma, cystic fibrosis, or pulmonary fibrosis. In this review, we describe the epithelial barrier abnormalities that are observed in such disorders and summarize current know...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

NMDA Receptor Hypofunction in the Aging-Associated Malfunction of Peripheral Tissue
Glutamatergic transmission through NMDA receptors (NMDARs) is important for the function of peripheral tissues. In the bone, NMDARs and its co-agonist, D-serine participate in all the phases of the remodeling. In the vasculature, NMDARs exerts a tonic vasodilation decreasing blood perfusion in the corpus cavernosum and the filtration rate in the renal glomerulus. NMDARs are relevant for the skin turnover regulating the proliferation and differentiation of keratinocytes and the formation of the cornified envelope (CE). The interference with NMDAR function in the skin leads to a slow turnover and repair. As occurs with the b...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

The Comparison of Different Constitutive Laws and Fiber Architectures for the Aortic Valve on Fluid –Structure Interaction Simulation
In conclusion, both constitutive laws and fiber architectures can affect AV dynamics. Our results further suggest that the strain energy function with exponential terms for both the fiber and cross-fiber directions could be more suitable for describing the AV leaflet mechanical behaviors. Future experimental studies are needed to identify competent constitutive laws for the AV leaflets and their associated fiber orientations with controlled experiments. Although limitations exist in the present AV model, our results provide important information for selecting appropriate constitutive laws and fiber architectures when model...
Source: Frontiers in Physiology - June 24, 2021 Category: Physiology Source Type: research

Commentary: Photoplethysmography for Quantitative Assessment of Sympathetic Nerve Activity (SNA) During Cold Stress
(Source: Frontiers in Physiology)
Source: Frontiers in Physiology - June 23, 2021 Category: Physiology Source Type: research

Validation of a Motor Competence Assessment Tool for Children and Adolescents (KTK3+) With Normative Values for 6- to 19-Year-Olds
The use of the short form of the Körperkoordinationstest für Kinder (KTK3) to evaluate children's and adolescents' motor competence (MC) is increasing. When combined with an alternating one-handed catching and throwing ball task, assessing eye-hand coordination (EHC), it has been shown that the different aspects of motor skills are adequately covered in one compact KTK3+ test battery, studied in 6- to 10-year-old children. The present study aimed to validate the KTK3+ test battery and to provide contemporary MC normative values for boys and girls from 6- to 19-year-olds. A total of 2,271 children and adolescents ...
Source: Frontiers in Physiology - June 23, 2021 Category: Physiology Source Type: research

Hypoxic Signaling in Skeletal Muscle Maintenance and Regeneration: A Systematic Review
In skeletal muscle tissue, oxygen (O2) plays a pivotal role in both metabolism and the regulation of several intercellular pathways, which can modify proliferation, differentiation and survival of cells within the myogenic lineage. The concentration of oxygen in muscle tissue is reduced during embryogenesis and pathological conditions. Myogenic progenitor cells, namely satellite cells, are necessary for muscular regeneration in adults and are localized in a hypoxic microenvironment under the basal lamina, suggesting that the O2 level could affect their function. This review presents the effects of reduced oxygen levels (hy...
Source: Frontiers in Physiology - June 23, 2021 Category: Physiology Source Type: research

Gravity-Induced Lower-Leg Swelling Can Be Ameliorated by Ingestion of α-Glucosyl Hesperidin Beverage
The most likely cause of lower-leg swelling is prolonged sitting, which sometimes induces deep vein thrombosis, also known as, economy class syndrome. We aimed to clarify the influence of intake of 4G-α-glucopyranosyl hesperidin (G-Hsp) beverage on the lower-leg swelling caused by 6 h of sitting in six healthy women. All subjects ingested 100 mL of G-Hsp or Placebo beverages with 100 mL of mineral water after 10 min of rest in a chair. Subsequently, subjects were requested to sit in the chair in a relaxed position for 6 h with two breaks to walk for urination. Calf water content measured by impedance plethysmography,...
Source: Frontiers in Physiology - June 23, 2021 Category: Physiology Source Type: research

Intensity of Glycemic Exposure in Early Adulthood and Target Organ Damage in Middle Age: The CARDIA Study
AimTo determine whether long-term intensity of glycemic exposure (IGE) during young adulthood is associated with multiple target organs function at midlife independent of single fasting glucose (FG) measurement.MethodsWe included 2,859 participants, aged 18–30 years at Y0, in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. IGE was calculated as the sum of (average FG of two consecutive examinations × years between the examinations) over 25 years. Target organs function was indicated by cardiac structure, left ventricular (LV) systolic function, LV diastolic function, coronary artery calcium...
Source: Frontiers in Physiology - June 23, 2021 Category: Physiology Source Type: research

Ischemic Preconditioning: Modulating Pain Sensitivity and Exercise Performance
Purpose The purpose of this study was to examine whether an individual’s IPC-mediated change in cold pain sensitivity is associated with the same individual’s IPC-mediated change in exercise performance.Methods Thirteen individuals (8 males; 5 females, 27 ± 7 years, 55 ± 5 ml.kgs–1.min–1) underwent two separate cold-water immersion tests: with preceding IPC treatment and without. In addition, each participant undertook two separate 5-km cycling time trials: with preceding IPC treatment and without. Pearson correlation coefficients were used to assess the relationship between an individ...
Source: Frontiers in Physiology - June 22, 2021 Category: Physiology Source Type: research

An Interpretable Computer-Aided Diagnosis Method for Periodontitis From Panoramic Radiographs
Periodontitis is a prevalent and irreversible chronic inflammatory disease both in developed and developing countries, and affects about 20–50% of the global population. The tool for automatically diagnosing periodontitis is highly demanded to screen at-risk people for periodontitis and its early detection could prevent the onset of tooth loss, especially in local communities and health care settings with limited dental professionals. In the medical field, doctors need to understand and trust the decisions made by computational models and developing interpretable models is crucial for disease diagnosis. Based on thes...
Source: Frontiers in Physiology - June 22, 2021 Category: Physiology Source Type: research

The Nutrient-Responsive Molecular Chaperone Hsp90 Supports Growth and Development in Drosophila
Animals can sense internal nutrients, such as amino acids/proteins, and are able to modify their developmental programs in accordance with their nutrient status. In the fruit fly, Drosophila melanogaster, amino acid/protein is sensed by the fat body, an insect adipose tissue, through a nutrient sensor, target of rapamycin (TOR) complex 1 (TORC1). TORC1 promotes the secretion of various peptide hormones from the fat body in an amino acid/protein-dependent manner. Fat-body-derived peptide hormones stimulate the release of insulin-like peptides, which are essential growth-promoting anabolic hormones, from neuroendocrine cells...
Source: Frontiers in Physiology - June 22, 2021 Category: Physiology Source Type: research

Function of Chick Subcutaneous Adipose Tissue During the Embryonic and Posthatch Period
Since excess abdominal fat is one of the main problems in the broiler industry for the development of modern broiler and layer industry, the importance of subcutaneous adipose tissue has been neglected. However, chick subcutaneous adipose tissue appeared earlier than abdominal adipose tissue and more than abdominal adipose tissue. Despite a wealth of data, detailed information is lacking about the development and function of chick subcutaneous adipose tissue during the embryonic and posthatch period. Therefore, the objective of the current study was to determine the developmental changes of adipocyte differentiation, lipid...
Source: Frontiers in Physiology - June 22, 2021 Category: Physiology Source Type: research

Strenuous Physical Training, Physical Fitness, Body Composition and Bacteroides to Prevotella Ratio in the Gut of Elderly Athletes
Regular physical activity seems to have a positive effect on the microbiota composition of the elderly, but little is known about the added possible benefits of strenuous endurance training. To gain insight into the physiology of the elderly and to identify biomarkers associated with endurance training, we combined different omics approaches. We aimed to investigate the gut microbiome, plasma composition, body composition, cardiorespiratory fitness, and muscle strength of lifetime elderly endurance athletes (LA) age 63.5 (95% CI 61.4, 65.7), height 177.2 (95% CI 174.4, 180.1) cm, weight 77.8 (95% CI 75.1, 80.5) kg, VO2max ...
Source: Frontiers in Physiology - June 22, 2021 Category: Physiology Source Type: research

The New Concept of Physiological “Riolan’s Arch” and the Reconstruction Mechanism of Pathological Riolan’s Arch After High Ligation of the Inferior Mesenteric Artery by CT Angiography-Based Small Vessel Imaging
ConclusionsOur results show the mechanism of pathological Riolan’s arch formation and provide new anatomic thinking for the battle between high and low ligation of IMA in colorectal cancer surgery. (Source: Frontiers in Physiology)
Source: Frontiers in Physiology - June 22, 2021 Category: Physiology Source Type: research

Gestational Low Protein Diet Modulation on miRNA Transcriptome and Its Target During Fetal and Breastfeeding Nephrogenesis
BackgroundThe kidney ontogenesis is the most structurally affected by gestational protein restriction, reducing 28% of their functional units. The reduced nephron number is predictive of hypertension and cardiovascular dysfunctions that are generally observed in the adult age of most fetal programming models. We demonstrate miRNAs and predict molecular pathway changes associated with reduced reciprocal interaction between metanephros cap (CM) and ureter bud (UB) and a 28% decreased nephron stem cells in the 17 gestational days (17GD) low protein (LP) intake male fetal kidney. Here, we evaluated the same miRNAs and predicte...
Source: Frontiers in Physiology - June 22, 2021 Category: Physiology Source Type: research

Elasticity of the Achilles Tendon in Individuals With and Without Plantar Fasciitis: A Shear Wave Elastography Study
The elastic properties of the Achilles tendon (AT) are altered in local injury or other diseases and in response to changes in mechanical load. Recently, elastography has been used to evaluate variations in tendon elastic properties, mainly among healthy individuals or athletes. Therefore, this study evaluated the biomechanical changes in ATs in individuals with and without plantar fasciitis (PF). The purposes were as follows: (1) to evaluate the passive stiffness of three regions of the AT which defined as 0 (AT0 cm), 3 (AT3 cm), and 6 cm (AT6 cm) above the calcaneal tuberosity in participants with and without PF, (2) to ...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

The Endosymbiotic Coral Algae Symbiodiniaceae Are Sensitive to a Sensory Pollutant: Artificial Light at Night, ALAN
Artificial Light at Night, ALAN, is a major emerging issue in biodiversity conservation, which can negatively impact both terrestrial and marine environments. Therefore, it should be taken into serious consideration in strategic planning for urban development. While the lion’s share of research has dealt with terrestrial organisms, only a handful of studies have focused on the marine milieu. To determine if ALAN impacts the coral reef symbiotic algae, that are fundamental for sustainable coral reefs, we conducted a short experiment over a period of one-month by illuminating isolated Symbiodiniaceae cell cultures from...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Acute Effects of Different Blood Flow Restriction Protocols on Bar Velocity During the Squat Exercise
The main goal of the present study was to evaluate the effects of different blood flow restriction (BFR) protocols (continuous and intermittent) on peak bar velocity (PV) and mean bar velocity (MV) during the squat exercise at progressive loads, from 40 to 90% 1RM. Eleven healthy men (age = 23.4 ± 3.1 years; body mass = 88.5 ± 12.1 kg; squat 1RM = 183.2 ± 30.7 kg; resistance training experience, 5.7 ± 3.6 years) performed experimental sessions once a week for 3 weeks in random and counterbalanced order: without BFR (NO-BFR), with intermittent BFR (I-BFR), and with continuous BFR (C-BFR). During ...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Quantification of Inter-Limb Symmetries With Rate of Force Development and Relaxation Scaling Factor
The inter-limb (a)symmetries have been most often assessed with the tests that quantify the maximal muscle capacity. However, the rapid force production and relaxation during submaximal tasks is equally important for successful sports performance. This can be evaluated with an established rate of force development and relaxation scaling factor (RFD-SF/RFR-SF). The aims of our study were (1) to assess the intra-session reliability of shortened RFD-SF/RFR-SF protocol and its absolute and symmetry outcome measures, (2) to compare the main absolute RFD-SF/RFR-SF outcome measures (slopes of RFD-SF and RFR-SF: kRTD–SF and ...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Proportional Assist Ventilation Improves Leg Muscle Reoxygenation After Exercise in Heart Failure With Reduced Ejection Fraction
BackgroundRespiratory muscle unloading through proportional assist ventilation (PAV) may enhance leg oxygen delivery, thereby speeding off-exercise oxygen uptake (V.⁢O2) kinetics in patients with heart failure with reduced left ventricular ejection fraction (HFrEF).MethodsTen male patients (HFrEF = 26 ± 9%, age 50 ± 13 years, and body mass index 25 ± 3 kg m2) underwent two constant work rate tests at 80% peak of maximal cardiopulmonary exercise test to tolerance under PAV and sham ventilation. Post-exercise kinetics of V.⁢O2, vastus lateralis deoxyhemoglobin ([deoxy-Hb + Mb]) by near-infrared spect...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Effect of Short-Term Desiccation, Recovery Time, and CAPA –PVK Neuropeptide on the Immune System of the Burying Beetle Nicrophorus vespilloides
Environmental conditions, especially related to winter, are crucial for shaping activity of insect immune system. However, our previous research clearly indicates differences in the immune system functioning when the cold stress was induced in the laboratory conditions and when the beetles were collected from natural environment during winter. This is probably related to the multiplication of observed effects by simultaneous presence of different stress factors characteristic of winter, including desiccation. For these reasons, our next step was analysis of the effects of short-term desiccation and recovery time on the fun...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

TdP Incidence in Methoxamine-Sensitized Rabbit Model Is Reduced With Age but Not Influenced by Hypercholesterolemia
Metabolic syndrome is associated with hypercholesterolemia, cardiac remodeling, and increased susceptibility to ventricular arrhythmias. Effects of diet-induced hypercholesterolemia on susceptibility to torsades de pointes arrhythmias (TdP) together with potential indicators of arrhythmic risk were investigated in three experimental groups of Carlsson’s rabbit model: (1) young rabbits (YC, young control, age 12–16 weeks), older rabbits (AC, adult control, age 20–24 weeks), and older age-matched cholesterol-fed rabbits (CH, cholesterol, age 20–24 weeks). TdP was induced by α-adrenergic stimulat...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Effects of Short-Term Fasting on mRNA Expression of Ghrelin and the Peptide Transporters PepT1 and 2 in Atlantic Salmon (Salmo salar)
Food intake is a vital process that supplies necessary energy and essential nutrients to the body. Information regarding luminal composition in the gastrointestinal tract (GIT) collected through mechanical and nutrient sensing mechanisms are generally conveyed, in both mammals and fish, to the hypothalamic neurocircuits. In this context, ghrelin, the only known hormone with an orexigenic action, and the intestinal peptide transporters 1 and 2, involved in absorption of dietary di- and tripeptides, exert important and also integrated roles for the nutrient uptake. Together, both are potentially involved in signaling pathway...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Cdan1 Is Essential for Primitive Erythropoiesis
Congenital dyserythropoietic anemia type I (CDA I) is an autosomal recessive disease characterized by moderate to severe macrocytic anemia and pathognomonic morphologic abnormalities of the erythroid precursors, including spongy heterochromatin. The disease is mainly caused by mutations in CDAN1 (encoding for Codanin-1). No patients with homozygous null type mutations have been described, and mouse null mutants die during early embryogenesis prior to the initiation of erythropoiesis. The cellular functions of Codanin-1 and the erythroid specificity of the phenotype remain elusive. To investigate the role of Codanin-1 in er...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Mechanisms and Therapeutic Prospects of Diabetic Cardiomyopathy Through the Inflammatory Response
The incidence of heart failure (HF) continues to increase rapidly in patients with diabetes. It is marked by myocardial remodeling, including fibrosis, hypertrophy, and cell death, leading to diastolic dysfunction with or without systolic dysfunction. Diabetic cardiomyopathy (DCM) is a distinct myocardial disease in the absence of coronary artery disease. DCM is partially induced by chronic systemic inflammation, underpinned by a hostile environment due to hyperglycemia, hyperlipidemia, hyperinsulinemia, and insulin resistance. The detrimental role of leukocytes, cytokines, and chemokines is evident in the diabetic heart, ...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Dynamic Systems Approach in Sensorimotor Synchronization: Adaptation to Tempo Step-Change
This paper presents a dynamic systems model of a sensorimotor synchronization (SMS) task. An SMS task typically gives temporally discrete human responses to some temporally discrete stimuli. Here, a dynamic systems modeling approach is applied after converting the discrete events to regularly sampled time signals. To collect data for model parameter fitting, a previously published pilot study was expanded. Three human participants took part in an experiment: to tap a finger on a keyboard, following a metronome which changed tempo in steps. System identification was used to estimate the transfer function that represented th...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Time-Restricted Feeding in Commercial Layer Chickens Improves Egg Quality in Old Age and Points to Lack of Adipostat Activity in Chickens
In mammals, time-restricted feeding (TRF) with no caloric restriction provides health benefits and extends longevity, usually with a minor (∼3%) or no reduction in total food consumption. In the current study, a TRF regimen of 6 h free access to food (08:00–14:00 h) was applied to Leghorn chickens from 25 to 86 weeks of age; control birds ate freely during the light hours (06:00–20:00 h). Unexpectedly, the TRF-treated birds consumed, on average, 11.7% less food than the controls. This was manifested by an average reduction of 9.6% in body weight, 2.6-fold in visceral fat accumulation, and 6.5% in egg weight...
Source: Frontiers in Physiology - June 21, 2021 Category: Physiology Source Type: research

Quantifying the Speed of Chromatophore Activity at the Single-Organ Level in Response to a Visual Startle Stimulus in Living, Intact Squid
The speed of adaptive body patterning in coleoid cephalopods is unmatched in the natural world. While the literature frequently reports their remarkable ability to change coloration significantly faster than other species, there is limited research on the temporal dynamics of rapid chromatophore coordination underlying body patterning in living, intact animals. In this exploratory pilot study, we aimed to measure chromatophore activity in response to a light flash stimulus in seven squid, Doryteuthis pealeii. We video-recorded the head/arms, mantle, and fin when squid were presented with a light flash startle stimulus. Ind...
Source: Frontiers in Physiology - June 18, 2021 Category: Physiology Source Type: research

On the Optimization of a Centrifugal Maglev Blood Pump Through Design Variations
Centrifugal blood pumps are usually designed with secondary flow paths to avoid flow dead zones and reduce the risk of thrombosis. Due to the secondary flow path, the intensity of secondary flows and turbulence in centrifugal blood pumps is generally very high. Conventional design theory is no longer applicable to centrifugal blood pumps with a secondary flow path. Empirical relationships between design variables and performance metrics generally do not exist for this type of blood pump. To date, little scientific study has been published concerning optimization and experimental validation of centrifugal blood pumps with s...
Source: Frontiers in Physiology - June 18, 2021 Category: Physiology Source Type: research

Radiofrequency Catheter Ablation of Supraventricular Tachycardia in Patients With Pulmonary Hypertension: Feasibility and Long-Term Outcome
ConclusionThe findings suggest that RFCA of SVT in PH patients is feasible and has a good long-term success rate. Cavotricuspid isthmus-independent atrial flutter and a wider PAD could increase the risk for ablation failure. (Source: Frontiers in Physiology)
Source: Frontiers in Physiology - June 18, 2021 Category: Physiology Source Type: research

Optimizing Reservoir Computers for Signal Classification
Reservoir computers are a type of recurrent neural network for which the network connections are not changed. To train the reservoir computer, a set of output signals from the network are fit to a training signal by a linear fit. As a result, training of a reservoir computer is fast, and reservoir computers may be built from analog hardware, resulting in high speed and low power consumption. To get the best performance from a reservoir computer, the hyperparameters of the reservoir computer must be optimized. In signal classification problems, parameter optimization may be computationally difficult; it is necessary to comp...
Source: Frontiers in Physiology - June 18, 2021 Category: Physiology Source Type: research

Mitochondrial Adaptation to Diet and Swimming Activity in Gilthead Seabream: Improved Nutritional Efficiency
This study assesses for differences in growth rate, tissue composition and energy metabolism in gilthead seabream juveniles fed two diets: high-protein (HP; 54% protein, 15% lipid) or high energy (HE; 50% protein, 20% lipid), under voluntary swimming (VS) or moderate-to-low-intensity sustained swimming (SS) for 6 weeks. HE fed fish under VS conditions showed lower body weight and higher muscle lipid content than HP fed fish, but no differences between the two groups were observed under SS conditions. Irrespective of the swimming regime, the white muscle stable isotopes profile of the HE group revealed increased nitrogen an...
Source: Frontiers in Physiology - June 18, 2021 Category: Physiology Source Type: research

The Release of Nitric Oxide Is Involved in the β-Arrestin1-Induced Antihypertensive Effect in the Rostral Ventrolateral Medulla
β-Arrestin1 is a multifunctional scaffold protein with the ability to interact with diverse signaling molecules independent of G protein-coupled receptors. We previously reported that overexpression of β-arrestin1 in the rostral ventrolateral medulla (RVLM) decreased blood pressure (BP) and renal sympathetic nerve activity (RSNA) in spontaneously hypertensive rats (SHRs). Nitric oxide (NO) is widely reported to be involved in central cardiovascular regulation. The goal of this study was to investigate whether NO signaling contributes to the β-arrestin1-mediated antihypertensive effect in the RVLM. It was fou...
Source: Frontiers in Physiology - June 18, 2021 Category: Physiology Source Type: research

Transcriptomic and Metabolomic Data Reveal the Key Metabolic Pathways Affecting Streltzoviella insularis (Staudinger) (Lepidoptera: Cossidae) Larvae During Overwintering
Streltzoviella insularis (Staudinger) (Lepidoptera: Cossidae) is a woodboring insect feeding on Fraxinus pennsylvanica, Sophora japonica, and Ginkgo biloba, as well as many other species used for urban greening and plain afforestation in northern China, including the temperate north. There is also a risk that S. insularis could spread through the transportation of seedlings, thereby increasing urban greening costs. However, how S. insularis increases the cold tolerance then reduces it to survive winter temperature below 0°C remains unclear. In the transcriptomic of S. insularis, we identified three profiles (profile 25...
Source: Frontiers in Physiology - June 18, 2021 Category: Physiology Source Type: research

Cloning and Expression of the Neuropeptide F and Neuropeptide F Receptor Genes and Their Regulation of Food Intake in the Chinese White Pine Beetle Dendroctonus armandi
Neuropeptide F (NPF) is an important signaling molecule that acts as a neuromodulator to regulate a diversity of physiological and behavioral processes from vertebrates to invertebrates by interaction with NPF receptors, which are G protein-coupled receptors (GPCR). However, nothing is known about NPF in Chinese white pine beetle, Dendroctonus armandi, a destructive pest of natural and coniferous forests in the middle Qinling Mountains of China. We have cloned and characterized cDNAs encoding one NPF precursor and two NPF receptors in D. armandi and made bioinformatics predictions according to the deduced amino acid sequen...
Source: Frontiers in Physiology - June 18, 2021 Category: Physiology Source Type: research

Exercise Capacity, Ventilatory Response, and Gas Exchange in COPD Patients With Mild to Severe Obstruction Residing at High Altitude
BackgroundExercise intolerance, desaturation, and dyspnea are common features in patients with chronic obstructive pulmonary disease (COPD). At altitude, the barometric pressure (BP) decreases, and therefore the inspired oxygen pressure and the partial pressure of arterial oxygen (PaO2) also decrease in healthy subjects and even more in patients with COPD. Most of the studies evaluating ventilation and arterial blood gas (ABG) during exercise in COPD patients have been conducted at sea level and in small populations of people ascending to high altitudes. Our objective was to compare exercise capacity, gas exchange, ventila...
Source: Frontiers in Physiology - June 18, 2021 Category: Physiology Source Type: research

p21-Activated Kinase 1 Is Permissive for the Skeletal Muscle Hypertrophy Induced by Myostatin Inhibition
Skeletal muscle, the most abundant tissue in the body, plays vital roles in locomotion and metabolism. Understanding the cellular processes that govern regulation of muscle mass and function represents an essential step in the development of therapeutic strategies for muscular disorders. Myostatin, a member of the TGF-β family, has been identified as a negative regulator of muscle development. Indeed, its inhibition induces an extensive skeletal muscle hypertrophy requiring the activation of Smad 1/5/8 and the Insulin/IGF-I signaling pathway, but whether other molecular mechanisms are involved in this process remains ...
Source: Frontiers in Physiology - June 17, 2021 Category: Physiology Source Type: research

Selective β2-Adrenoceptor Blockade Rescues Mandibular Growth Retardation in Adolescent Rats Exposed to Chronic Intermittent Hypoxia
This study aimed to investigate the role of β2-adrenergic receptors in IH-induced mandibular growth retardation and bone metabolic alterations. Male 7-week-old Sprague–Dawley rats were subjected to IH for 3 weeks. IH conditions were established using original customized hypoxic chambers; IH was induced at a rate of 20 cycles per hour (oxygen levels changed from 4 to 21% in one cycle) for 8 h per day during the 12 h “lights on” period. The rats received intraperitoneal administration of a β2-adrenergic antagonist (butoxamine) or saline. To exclude dietary effects on general growth, the normoxic r...
Source: Frontiers in Physiology - June 17, 2021 Category: Physiology Source Type: research

Integrated Transcriptomic and Proteomic Analysis Reveals Up-Regulation of Apoptosis and Small Heat Shock Proteins in Lens of Rats Under Low Temperature
Cold cataract is the reversible opacification of the lens when the temperature decreases. However, we observed that when temperature of the rats’ lens was maintained at a lower temperature for a prolonged time, the opacification of lens was only partly reversible. To review the potential molecular mechanism of the irreversible part of opacification under cold stimulation, we applied comparative transcriptomic and proteomic analysis to systematically investigate the molecular changes that occurred in the lens capsules of rats under low temperature treatments. The RNA sequencing based transcriptomic analysis showed a s...
Source: Frontiers in Physiology - June 17, 2021 Category: Physiology Source Type: research