Respiratory Measurements Research Articles

Respiratory muscle training in people with cervical spinal cord injury - A systematic review.

Spinal cord injury is a physiological disruption often caused by trauma, leading to severe physical and psychological effects, including irreversible impairment and disability. Cervical injuries, particularly between C1 and C8, are the most severe, potentially causing diaphragm paralysis and requiring mechanical ventilation. Reduced respiratory muscle strength not only affects respiratory function but also significantly impacts voice, speech, and communication, which are crucial for quality of life. Conduct a systematic review of the literature on respiratory muscle training protocols in individuals with cervical spinal cord injury and evaluate the methodological quality of scientific publications. Studies were searched by two independent researchers in the Regional Portal of the Virtual Health Library, EMBASE, SCOPUS and PubMed databases, using the descriptors: "respiratory muscle strength", "breathing training", and "cervical spinal cord injury", with no restriction on the time of publication. Studies containing respiratory muscle strength measurements and respiratory muscle training in people with cervical SCI were included and those that associated other techniques with functional respiratory training, such as electrical stimulation and other complementary techniques were excluded. The studies had the methodological quality (internal and external validity) classified by the PEDro scale (Physiotherapy Evidence Database). Nine studies were identified and considered valid based on the inclusion criteria. The protocols presented varied parameters. The session time ranged from 15 to 45 minutes, the number of sessions per day ranged from 1 to 2, the number of days per week ranged from 3 to 7, and the number of intervention weeks ranged from 4 to 10. Only three studies presented internal and external validity for respiratory muscle training programs. This review identified that respiratory muscle training is an effective intervention to improve respiratory function in people with cervical SCI. However, due to the poor methodological quality of the studies, the effect size of the treatment, as well as the ideal dose and intensity, requires further investigation to better determine its overall effectiveness.

Pharmacokinetics and Pharmacodynamics of Intravenous Magnesium Sulfate in Pediatric Acute Asthma Exacerbations.

Pediatric asthma exacerbations represent a significant cause of emergency department use and hospitalizations. Despite available treatment options, many children's exacerbations are refractory to standard therapies and require adjunct treatments. The Intravenous Magnesium: Prompt use for Asthma in Children Treated in the Emergency Department study investigated the pharmacology of intravenous magnesium sulfate (IVMg) in treating pediatric asthma exacerbations. Specifically, the objectives of the study included (1) externally validating a previously published population pharmacokinetic model and (2) linking serum magnesium concentrations with outcomes including asthma severity score (efficacy) and hypotension (safety). Data were obtained from 49 children prospectively treated with IVMg (placebo, 50 or 75 mg/kg) after presenting to the pediatric emergency department with an acute asthma exacerbation. Reductions in Pediatric Respiratory Assessment Measure scores were associated with both total and ionized serum magnesium area under the concentration-time curve (AUC0-2 h). Despite frequent study-specific blood pressure monitoring, hypotension was uncommon in IVMg-treated participants (n = 2/31), and no concentration dependence was observed. The findings signal that IVMg may be an efficacious and safe option for treating moderate-severe pediatric acute asthma exacerbations in the ED. Importantly, this study is the first to suggest a serum exposure target (total serum magnesium AUC0-2 h >63.1 mg h/L) reflective of effective IVMg dosing in pediatric acute asthma. While further study in a larger clinical trial is needed to refine and validate this exposure target, these findings support the continued study of IVMg therapy as an adjunct therapeutic option in the setting of pediatric asthma exacerbations.

Repeatability of RRate measurements in children during triage in two Ugandan hospitals.

Pneumonia is the leading cause of death in children globally. In low- and middle-income countries (LMICs) pneumonia diagnosis relies on accurate assessment of respiratory rate, which can be unreliable when completed by nurses with less-advanced training. To inform more accurate measurements, we investigate the repeatability of the RRate app used by nurses in Ugandan district hospitals. This secondary analysis included 3,679 children aged 0-5 years. The dataset had two sequential measurements of respiratory rate collected by 14 nurses using the RRate app. We measured agreement between respiratory rate observations while indicating observations' clustering around WHO fast-breathing thresholds. WHO thresholds are 60 breaths per minute (bpm) for under two months (Age-1), 50 bpm for two to 12 months (Age-2), and 40 bpm for 12.1 to 60 months (Age-3). We assessed the repeatability of the paired measurements per user through the Intraclass Correlation Coefficient (ICC) and calculated an overall ICC value. The respiratory rate measurement took less than 15 seconds for 7,277 (98.9%) of the measurements. Despite respiratory rates clustering around WHO thresholds, breathing classification based on the thresholds (Fast vs normal) was altered between sequential measurements in only 12.6% of children. The mean (SD) respiratory rate by age group was 60 (13.1) bpm for Age-1, 49 (11.9) bpm for Age-2, and 38 (10.1) for Age-3, and the bias (Limits of Agreements) were 0.3 (-10.8-11.3) bpm, 0.4 (-8.5-9.3) bpm, and 0.1 (-6.8, 7.0) bpm for Age-1, Age-2, and Age-3 respectively. The repeatability of the paired respiratory rate measurements was high, with an ICC ≥ 90% for 12 of 14 users and an overall ICC value (95% CI) of 0.95 (0.94-0.95). The RRate measurements were efficient and repeatable. The simplicity, repeatability, and efficiency support its usage in LMICs healthcare facilities, and endorses a more widespread clinical adoption.

Comparison of respiratory mechanics measurement between pressure-controlled ventilation and volume-controlled ventilation

Comparison of respiratory mechanics measurement between pressure-controlled ventilation and volume-controlled ventilation

Unraveling the Role of Oxygen Pulse Variability in Endurance Exercise Training in Individuals with COPD: A Novel Approach to Response of Oxygen Pulse and Quality of Life in Pulmonary Rehabilitation.

Chronic obstructive pulmonary disease (COPD) is characterized by airway inflammation, airflow limitation, reduced health-related quality of life (HRQL), and exercise intolerance. Pulmonary rehabilitation (PR) is essential for COPD management, but outcomes may be influenced by individual physiological factors. Cardiopulmonary exercise testing (CPET) measures oxygen pulse (O2P), an indicator of stroke volume, yet the impact of baseline O2P on PR effectiveness remains unclear. This retrospective study included 97 participants with COPD who had received PR, of whom 48 were classified as Group 1 (normal O2P) and 49 as Group 2 (low O2P). PR involved 12weeks of hospital-based endurance training on a bike, performed twice a week. Participants were assessed before and after PR using spirometry, respiratory muscle strength measurements, CPET, and HRQL evaluation with the St. George's Respiratory Questionnaire (SGRQ). PR significantly improved exercise capacity (peak work rate and oxygen consumption), dyspnea score, and all domains of the SGRQ, maximum expiratory pressure, ventilatory equivalent, respiratory rate, and mean blood pressure at rest in both groups (p < 0.05). However, improvements in O2P, maximal inspiratory pressure, and tidal volume at rest were observed only in Group 2 but not in Group 1. PR improves exercise capacity, HRQL and specific respiratory function in participants with COPD, regardless of baseline O2P levels. Individuals with lower baseline O2P experience more benefits from PR, including a significant increase in O2P.

Plate-Based Measurement of Respiration by Isolated Mitochondria and by Intact Cells.

Measuring respiration rate can be a powerful way to assess energetic function in isolated mitochondria and intact cells. Current plate-based methods have several advantages over older suspension-based systems, including greater throughput and the requirement of only microgram quantities of material. In this chapter, we provide an update to our previously published methods for plate-based measurement of oxygen consumption in isolated adherent mitochondria in a 96-well format plate. We also describe methods for performing the same measurements on intact cells in a 96-well format.

Interaction Between Root Exudates and PFOS Mobility: Effects on Rhizosphere Microbial Health in Wetland Ecosystems

Perfluorooctanesulfonate (PFOS), a persistent organic pollutant, poses significant ecological risks. This study investigates the effects of PFOS on rhizosphere microbial communities of two wetland plants, Lythrum salicaria (LS) and Phragmites communis (PC). We conducted microcosm experiments to analyze the physiological status of soil microbes under varying PFOS concentrations and examined the role of root exudates in modulating PFOS mobility. Flow cytometry and soil respiration measurements revealed that PFOS exposure increased microbial mortality, with differential impacts observed between LS and PC rhizospheres. LS root exudates intensified microbial stress, whereas PC exudates mitigated PFOS toxicity. Thin-layer chromatography indicated that LS exudates decreased PFOS mobility, leading to higher local concentrations and increased microbial toxicity, while PC exudates enhanced PFOS mobility, reducing its local impact. Fourier-transform infrared spectroscopy and excitation-emission matrix fluorescence spectroscopy of root exudates identified compositional shifts under PFOS stress, highlighting distinct defense strategies in LS and PC. These findings underscore the importance of plant-microbe interactions and root exudate composition in determining microbial resilience to PFOS contamination.

Evaluation of Respiratory Function, Respiratory Muscle Strength, Physical Activity, and Functionality in Patients with Lower Extremity Lymphedema.

Background: Lymphedema is a chronic, progressive condition that has major physical and psychological consequences. It was aimed to examine the respiratory functions, respiratory muscle strength, physical activity level, and functionality of patients with lower extremity lymphedema and to compare them with healthy controls. Methods and Results: A total of 82 individuals (29.3% male, 70.7% female, with a mean age of 49.89 ± 15.07 years) with lower extremity lymphedema (Group 1) and healthy individuals (Group 2) were included. Respiratory functions of the participants were evaluated by spirometry, respiratory muscle strength by maximum oral pressure measurements, physical activity levels using the International Physical Activity Questionnaire-Short Form (IPAQ-SF), functionality by Lower Extremity Functional Scale (LEFS) and Timed Up and Go test (TUG test). All respiratory function test measurements were lower in mean Group 1 than in Group 2 (p < 0.05). While inspiratory muscle strength did not differ between the groups (p > 0.05), expiratory muscle strength was lower in Group 1 than Group 2 (p < 0.05). Although spent time and energy for sitting were higher in Group 1 (p < 0.05), IPAQ vigorous-, moderate-, and light-intensity physical activity (MET-min/week) and IPAQ-total score did not differ between groups (p > 0.05). In Group 1, mean of LEFS score was lower and TUG test (seconds) in Group 1 was longer compared to Group 2 (p < 0.05). Conclusions: Respiratory functions, expiratory muscle strength, and functionality in patients with lower extremity lymphedema were adversely affected; however, inspiratory muscle strength and physical activity levels were similar to those of healthy controls.

A New Perspective on Drugs for Duchenne Muscular Dystrophy: Proposals for Better Respiratory Outcomes and Improved Regulatory Pathways.

New drugs for Duchenne muscular dystrophy (DMD) are emerging rapidly. However, we and others believe these drugs are achieving regulatory approval prematurely. It is the cardiorespiratory complications of DMD that cause the disease's major morbidities and that determine survival. Thus, to be truly effective, a new drug must improve cardiorespiratory function; instead, new drugs are approved for patient use via accelerated regulatory pathways that rely on surrogate outcome measures with unproven clinical benefits (such as tissue levels of non-biologic, truncated dystrophin) and on scales that reflect muscle strength (such as small improvements in timed activities). In DMD, cardiorespiratory complications occur in "older" individuals who are in the non-ambulatory stage of the disease. In contrast, accelerated approvals are based on data from young, ambulatory subjects, a group that essentially never experiences cardiorespiratory complications. When drug studies do obtain cardiorespiratory data, their methodologies are suboptimal. We critically review these methodologies in detail, including problems with the use of threshold levels of respiratory function as outcome measures; problems with the use of historical controls, whose results vary widely, and are influenced by uncontrolled variables related to their observational nature; and the limitations of using percent predicted forced vital capacity (FVC %pred), and its single rate of decline across a wide range of age and function, as a preferred respiratory outcome measure. We discuss the advantages of an alternative respiratory outcome, the absolute value of FVC with aging (the "Rideau plot"). Unlike FVC %pred, the Rideau plot considers distinct phenotypes rather than aggregating all individuals into a single respiratory trajectory. Key features of the Rideau plot can show the nature and timing of a drug's effect on respiratory function, making it a potentially better outcome measure for assessing the respiratory effects of a drug. With this article, we use our respiratory perspective to critically examine the DMD drug development process and to propose improvements in study methodologies and in the regulatory processes that approve new drugs.

Association Among MCT1 rs1049434 Polymorphism, Athlete Status, and Physiological Parameters in Japanese Long-Distance Runners.

Monocarboxylate transporters (MCTs) comprise 14 known isoforms, with MCT1 being particularly important for lactate transport. Variations in lactate metabolism capacity and aerobic performance are associated with the T1470A polymorphism in MCT1. We aimed to investigate the frequency of the T1470A polymorphism and compare relevant physiological parameters among long-distance runners, wherein these parameters are fundamental to athletic performance. We included 158 Japanese long-distance runners (LD) and 649 individuals from the general Japanese population (CON). The frequency of the T1470A polymorphism was compared between these groups and across athletic levels using the chi-square test. Additionally, physiological data were collected from 57 long-distance runners, and respiratory gas measurements were obtained using the mixing-chamber method during a graded incremental exercise test. We observed a significant difference between the LD and CON groups in the dominant model and between the sub-28 min group and 28 min or above group in the recessive model. As the competitive level increased, the frequency of the AA genotype also increased. When comparing physiological parameters between the AA genotype and T allele, subjects with the AA genotype showed significantly higher values for oxygen uptake at lactate threshold (p = 0.001), oxygen uptake at onset of blood lactate accumulation (p = 0.01), maximal oxygen uptake (p = 0.005), and maximal blood lactate concentration (p = 0.038). These results suggest that the AA genotype of the T1470A polymorphism of MCT1 is an effective genotype associated with athletic status and aerobic capacity in Japanese long-distance runners.

In-silico simultaneous respiratory and circulatory measurement during voluntary breathing, exercise, and mental stress: A computational approach.

Voluntary breathing (VB), short-term exercise (STE), and mental stress (MS) can modulate breathing rate (BR), heart rate (HR), and blood pressure (BP), thereby affecting human physical and mental state. While existing experimental studies have explored the relationship between VB, STE, or MS and BR, HR, and BP changes, their findings remain fragmented due to individual differences and challenges in simultaneous, BR, HR, and BP measurements. We propose a computational approach for in-silico simultaneous measurements of the physiological values by comprehensive prediction of the respiratory and circulatory system responses to VB, STE, or MS. Our integrated model combines a respiratory system with a circulatory model, leveraging actor-critic reinforcement learning to control respiratory muscles. We introduce specific parameters to account for involuntary or VB and hyperventilation induced by STE. We modeled mental stress as an electrical input to the amygdala based on prior studies indicating that stress leads to amygdala hyperactivity. Our predictions for breathing rate (BR), tidal volume, minute ventilation, HR, and BP are validated against literature data obtained during various conditions, including different VB patterns (ranging from 6 to 14 bpm), active or passive knee flexion STE, and MS load. The model demonstrates good agreement with experimental results and highlights its ability to explore the mechanism of individual differences. Our model predicts heart rate variability (HRV) indices of total power spectral density and the ellipse area of Poincaré plot. Notably, slow deep breathing at a BR of 6 bpm increases HRV indices, promoting relaxation and cognitive performance. Conversely, MS elevates BP but reduces HRV indices, indicating an unstable and risky state for mental and physical health. Overall, our proposed computational approach provides simultaneous and reasonable predictions of various physiological values, accounting for individual variations through specific parameters.

The optimal duration of continuous respiratory rate monitoring to predict in-hospital mortality within seven days of admission – A pilot study in a low resource setting

BackgroundCurrently there are no established benefits from the continuous monitoring of vital signs, and the optimal time period for respiratory rate measurement is unknown. SettingLow resource Ugandan hospital, MethodsProspective observational study. Respiratory rates of acutely ill patients were continuously measured by a piezoelectric device for up to seven hours after admission to hospital. Results22 (5.5%) out of 402 patients died within 7 days of hospital admission. The highest c-statistic of discrimination for 7-day mortality (0.737 SE 0.078) was obtained after four hours of continuously measured respiratory rates transformed into a weighted respiratory rate score (wRRS). After seven hours of measurement the c-statistic of the wRRS fell to 0.535 SE 0.078. 20% the patients who died within seven days did not have an elevated National Early Warning Score (NEWS) on admission but were identified by the 4-hour wRRS. None of the 88 patients whose average respiratory rate remained between 12 and 20 bpm throughout four hours of observation died within 7 days of admission. A simple predictive model that included the four-hour wRRS, Shock Index and altered mental status had a c-statistic for 7-day in-hospital mortality of 0.843 SE. 0.057. ConclusionFour hours of continuously measured respiratory rates was the observation period that best predicted 7-day in-hospital mortality. After four hours the discrimination of a weighted respiratory rate score deteriorated rapidly.

Dynamic inflation prevents and standardized lung recruitment reverts volume loss associated with percutaneous tracheostomy during volume control ventilation: results from a Neuro-ICU population.

To determine how percutaneous tracheostomy (PT) impacts on respiratory system compliance (Crs) and end-expiratory lung volume (EELV)during volume control ventilation and to test whether a recruitment maneuver (RM) at the end of PT may reverse lung derecruitment. This is a single center, prospective, applied physiology study. 25 patients with acute brain injury who underwent PT were studied. Patients were ventilated in volume control ventilation. Electrical impedance tomography (EIT) monitoring and respiratory mechanics measurements were performed in three steps: (a) baseline, (b) after PT, and (c) after a standardized RM (10 sighs of 30 cmH2O lasting 3s each within 1min). End-expiratory lung impedance (EELI) was used as a surrogate of EELV. PT determined a significant EELI loss (mean reduction of 432 arbitrary units p = 0.049) leading to a reduction in Crs (55 ± 13 vs. 62 ± 13 mL/cmH2O; p < 0.001) as compared to baseline. RM was able to revert EELI loss and restore Crs (68 ± 15 vs. 55 ± 13 mL/cmH2O; p < 0.001). In a subgroup of patients (N = 8, 31%), we observed a gradual but progressive increase in EELI. In this subgroup, patients did not experience a decrease of Crs after PT as compared to patients without dynamic inflation. Dynamic inflation did not cause hemodynamic impairment nor raising of intracranial pressure. We propose a novel and explorative hyperinflation risk index (HRI) formula. Volume control ventilation did not prevent the PT-induced lung derecruitment. RM could restore the baseline lung volume and mechanics. Dynamic inflation is common during PT, it can be monitored real-time by EIT and anticipated by HRI. The presence of dynamic inflation during PT may prevent lung derecruitment.

Effects of hyperthermia and acidosis on mitochondrial oxidative phosphorylation.

The intracellular environment of skeletal muscle can develop pronounced hyperthermia and acidosis during strenuous exercise, and these alterations in the typical intracellular conditions have been shown to alter mitochondrial respiration. However, the impact of these conditions on ATP synthesis is poorly understood. We used Thoroughbred racehorses to test the hypothesis that both hyperthermia and acidosis decrease the rate of ATP synthesis, but that athletic conditioning mitigates this loss of phosphorylation capacity. Isolated mitochondria were harvested from skeletal muscle before and after a 9-wk racetrack conditioning program that increased whole body aerobic capacity by 19%, and oxidative phosphorylation capacity was tested ex vivo under normothermic and hyperthermic conditions, as well as normal pH and acidic pH created by the addition of lactic acid. In unfit horses, hyperthermia caused a 30-55% decrease in the rate of ATP synthesis and loss of phosphorylation efficiency (P/O ratio decreased from 4.2 to 1.7 during maximal oxidative phosphorylation). Aerobic conditioning resulted in increased phosphorylation efficiency under hyperthermic conditions. Lactic acidosis had a small negative effect on ATP synthesis in unfit horses, but aerobic conditioning increased the sensitivity of isolated mitochondria to the deleterious effects of lactic acidosis. These data support the prominent role of hyperthermia in skeletal muscle fatigue during exercise, particularly in unfit subjects. However, acidosis may be a more important cause of failure of ATP synthesis in fit subjects.NEW & NOTEWORTHY This study reports the use of a novel method for the measurement of ATP synthesis and concurrent mitochondrial respiration. Although acidosis is often considered a leading cause of exercise fatigue, this study shows that tissue hyperthermia, which often occurs concurrently with acidosis, has a larger role in decreasing the maximal rate of skeletal muscle ATP synthesis.

Contactless and continuous monitoring of respiratory rate in a hospital ward: a clinical validation study.

Continuous monitoring of respiratory rate in hospital wards can provide early detection of clinical deterioration, thereby reducing mortality, reducing transfers to intensive care units, and reducing the hospital length of stay. Despite the advantages of continuous monitoring, manually counting every 1-12 h remains the standard of care in most hospital wards. The objective of this study was to validate continuous respiratory rate measurements from a radar-based contactless patient monitor [Vitalthings Guardian M10 (Vitalthings AS, Norway)] in a hospital ward. An observational study (clinicaltrials.gov: NCT06083272) was conducted at the emergency ward of a university hospital. Adult patients were monitored during rest with Vitalthings Guardian M10 in both a stationary and mobile configuration simultaneously with a reference device [Nox T3s (Nox Medical, Alpharetta, GA, United States)]. The agreement was assessed using Bland-Altman 95% limits of agreement. The sensitivity and specificity of clinical alarms were evaluated using a Clarke Error grid modified for continuous monitoring of respiratory rate. Clinical aspects were further evaluated in terms of trend analysis and examination of gaps between valid measurements. 32 patients were monitored for a median duration of 42 min [IQR (range) 35-46 (30-59 min)]. The bias was 0.1 and 0.0 breaths min-1 and the 95% limits of agreement ranged from -1.1 to 1.2 and -1.1 to 1.1 breaths min-1 for the stationary and mobile configuration, respectively. The concordances for trends were 96%. No clinical alarms were missed, and no false alarms or technical alarms were generated. No interval without a valid measurement was longer than 5 min. Vitalthings Guardian M10 measured respiratory rate accurately and continuously in resting patients in a hospital ward.

Assessing the long‐term effect of different organic amendments on the quality of acidic sandy soil

AbstractSandy soils are susceptible to the adverse effects of intensive land use and climate change, which can cause a decline in soil quality. As agricultural practices have an important role in soil processes, the objective of this research was to monitor the soil parameters determining the soil quality by studying the long‐term effects of different organic amendments on soil. The research was done in long‐term soil improvement experiments on Dystric Lamellic Arenosol. In addition to conventional organic fertilizers (farmyard manure with or without chemical fertilizers, green manure), alternative fertilizers such as sewage sludge compost were also applied. For the complex evaluation, we have been carrying out soil physical, chemical, and enzyme activity tests and field soil respiration measurements for 3 years. The beneficial effect of sewage sludge compost on the parameters determining the soil quality was more pronounced compared to the effect of conventional fertilization methods. The long‐term incorporation of sewage sludge compost into the soil significantly increased the soil organic matter content and pH, and improved the physico‐chemical parameters of the soil. The positive changes in soil parameters as a result of compost application contributed to the stimulation of soil life, which resulted in more intensive soil respiration and enzyme activities. The research confirmed the significance of the long‐term supply of organic matter on sandy soil that can be implemented sustainably through the agricultural utilization of sewage sludge compost and contributes to the enhancement of soil organic carbon storage and the improvement of soil quality in acidic sandy soil.

Differentiated and mature neurons are more responsive to neurotoxicant exposure at both transcriptional and translational levels

SH-SY5Y human neuroblastoma cells have been extensively used as an in vitro model system in a diverse range of studies involving neurodevelopment, neurotoxicity, neurodegeneration, and neuronal ageing. Both naïve and differentiated phenotypes of SH-SY5Y cells are utilized to model human neurons under in vitro conditions. The process of differentiation causes extensive remodeling of neuronal cells at multiple omic levels, including the epigenome and proteome. In the present investigation, the miRNAome and proteome profiles of arsenic-treated naïve and differentiated SH-SY5Y cells were generated using the miRNA OpenArray technology and high-resolution mass spectrometry. Our findings demonstrated that differentiation dramatically affected the response of SH-SY5Y cells to toxicant exposure, as indicated by increased tolerance of differentiated cells against arsenic exposure compared to naïve cells in cell viability assay. Arsenic-exposed naïve and differentiated SH-SY5Y cells possess distinct miRNA and protein profiles with few similarities. Compared to naïve cells, differentiated cells have undergone higher deregulation in the expression of brain-enriched miRNAs and proteins and have shown a more drastic decrease in oxygen consumption rate, which is a measure of mitochondrial respiration after exposure to arsenic. Proteins identified in arsenic-treated differentiated SH-SY5Y cells were more enriched in pathways underlying multifactorial neurotoxic events. Additionally, more functional regulatory modules have been identified between the miRNAs and proteins differentially expressed in arsenic-treated differentiated SH-SY5Y cells relative to naïve cells. Collectively, our studies have shown that differentiated SH-SY5Y cells displayed alterations in the expression of a greater number of miRNAs and proteins following neurotoxicant exposure, indicating their higher responsivity.

Music Synchronizes the Bodies of Its Audience

Synchronization and the bodily coordination of people in social interaction is by now a regular finding in psychotherapy research and social psychology. Recently, we have expanded the scope of synchrony research to empirical aesthetics and music. Studying audience members of public classical concerts, we hypothesized that the shared musical stimuli synchronize the physiological dynamics of listeners and, if so, the individual degree of synchrony is linked to a listener’s aesthetic experiences, music appreciation, affect and personality traits. The same may be expected for synchronized movement. After data acquisition with over 900 participants, we can now report significant evidence of physiological synchrony (cardiac and respiratory measures, skin conductance response) as well as movement synchrony in classical audiences, and distinct patterns of association with self-rated subjective experience. We believe this shows how the experience of music is embodied in listeners??? synchronies. We conclude this empirical review with suggestions how the embodiment approach may be situated in the philosophy of mind.

Effects of experimental nutrient enrichment and eutrophication on microbial community structure and function in “marine lakes”

Biogeochemical cycling of nitrogen (N) and carbon (C) are regulated by microbial communities that can respond to altered N and C availability, yet the form, consistency, and magnitude of these responses remain poorly constrained. We enriched and eutrophied distinct microbial communities in “marine lakes” through experimental additions of N (5 μM NH4Cl), C (100 μM sucrose), and combined N+C (same forms and concentrations), examining microbial community responses via 16S rRNA sequencing in conjunction with functional responses represented by net community production (NCP) and community respiration (CR) measurements. Individual N or C additions drove significant shifts in microbial community structure only sporadically, and rarely with a corresponding difference in NCP or CR rates. In contrast, the combined addition of N+C elicited strong coincident responses in microbial community structure and function: NCP and CR rates shifted sharply toward heterotrophy and were correlated with multiple microbial networks (r2 = 0.309–0.599, P &amp;lt; 0.001) that included globally distributed marine bacteria. Across multiple experiments, the consistent response of one network, comprised primarily of gammaproteobacterial heterotrophs (particularly Vibrio and Alteromonas), led initially dissimilar communities to converge toward similar composition. However, the distinct response patterns of other more diverse networks were superimposed on top of this network, indicating that inorganic N and organic C enrichment have multilayered effects on microbial communities. Collectively our results demonstrate that elevated N and C alter microbial community structure and function, selecting for multiple microbial networks that compete for, and rapidly cycle, N and C.

Quantitative mapping of cerebrovascular reactivity amplitude and delay with breath-hold BOLD fMRI when end-tidal CO2 quality is low.

Cerebrovascular reactivity (CVR), the ability of cerebral blood vessels to dilate or constrict in order to regulate blood flow, is a clinically useful measure of cerebrovascular health. CVR is often measured using a breath-hold task to modulate blood CO2 levels during an fMRI scan. Measuring end-tidal CO2 (PETCO2) with a nasal cannula during the task allows CVR amplitude to be calculated in standard units (vascular response per unit change in CO2, or %BOLD/mmHg) and CVR delay to be calculated in seconds. The use of standard units allows for normative CVR ranges to be established and for CVR comparisons to be made across subjects and scan sessions. Although breath-holding can be successfully performed by diverse patient populations, obtaining accurate PETCO2 measurements requires additional task compliance; specifically, participants must breathe exclusively through their nose and exhale immediately before and after each breath hold. Meeting these requirements is challenging, even in healthy participants, and this has limited the translational potential of breath-hold fMRI for CVR mapping. Previous work has focused on using alternative regressors such as respiration volume per time (RVT), derived from respiratory belt measurements, to map CVR. Because measuring RVT does not require additional task compliance from participants, it is a more feasible measure than PETCO2. However, using RVT does not produce CVR in standard units. In this work, we explored how to achieve CVR maps, in standard units, when breath-hold task PETCO2 data quality is low. First, we evaluated whether RVT could be scaled to units of mmHg using a subset of PETCO2 data of sufficiently high quality. Second, we explored whether a PETCO2 timeseries predicted from RVT using deep learning allows for more accurate CVR measurements. Using a dense-mapping breath-hold fMRI dataset, we showed that both rescaled RVT and rescaled, predicted PETCO2 can be used to produce maps of CVR amplitude and delay in standard units with strong absolute agreement to ground-truth maps. However, the rescaled, predicted PETCO2 regressor resulted in superior accuracy for both CVR amplitude and delay. In an individual with regions of increased CVR delay due to Moyamoya disease, the predicted PETCO2 regressor also provided greater sensitivity to pathology than RVT. Ultimately, this work will increase the clinical applicability of CVR in populations exhibiting decreased task compliance.