Respiratory Measurements Research Articles

Nutrients (N, P, K, Na) and warming affect heterotrophic respiration in temperate forest litter

At present, ecosystems are facing changes caused by global warming and anthropogenic impacts on geochemical cycles. Both temperature and nutrient availability affect litter decomposition; however, little is known about their simultaneous effect on litter decomposition in temperate forests, especially for nutrients such as Na and K. To address this perspective, we investigated how changes in N, P, Na and K supply and increased temperature affect litter decomposition measured as respiration. Moreover, the study determines what changes can be expected in the functioning of two forest types of different fertility (deciduous and coniferous). The respiration measurements were conducted in the laboratory in mesocosms filled with litter from deciduous (oak-hornbeam) and coniferous (mixed pine-oak) forests fertilized by N, P, K, and Na. The experiment was conducted at ambient (14 °C; oak-hornbeam and mixed pine-oak litter) and increased temperatures (22 °C; oak-hornbeam litter). The respiration of oak-hornbeam litter increased with increasing temperature, with Q10 values ranging from 1.49 to 2.14. Our results showed different responses of respiration to nutrient addition between temperatures and litter types. In oak-hornbeam, at 14 °C, the addition of N, P and K decreased respiration, whereas at 22 °C, such an effect was noted only under N application, and P and Na addition increased respiration. In mixed pine-oak litter at 14 °C, respiration decreased after Na addition, and other nutrients had no effect. Together, our results suggest that forecasting the impact of nutrient deposition on ecosystem functioning should consider temperature rise as a factor altering ecosystem responses to fertilization in future research.

Evaluating the Clinical Impact of a Novel Pediatric Emergency Medicine Curriculum on Asthma Outcomes in Belize.

Respiratory-related complaints prompt most pediatric visits to Karl Heusner Memorial Hospital Authority's (KHMHA) Emergency Department (ED) in Belize. We developed and taught a novel pediatric respiratory emergencies module for generalist practitioners there. We assessed the curriculum's clinical impact on pediatric asthma emergency management. This study assesses the clinical impact of a pediatric emergency medicine curriculum on management of pediatric asthma emergencies at KHMHA in Belize City, Belize. We conducted a randomized chart review of pediatric (aged 2-16 y) visits for asthma-related diagnosis at the KHMHA ED between 2015 and 2018 to assess the training module's clinical impact. Primary outcomes included time to albuterol and steroids. Secondary outcomes included clinical scoring tool (Pediatric Respiratory Assessment Measure [PRAM]) usage, ED length of stay, usage of chest radiography, return visit within 7 days, and hospital admission rates. Kaplan-Meier survival analysis and Cox proportional hazard regression were used. Two hundred eighty-three pediatric asthma-related diagnoses met our inclusion criteria. The patients treated by trained and untrained physician groups were demographically and clinically similar. The time to albuterol was significantly faster in the trained (intervention) group compared with the untrained (control) physician group when evaluating baseline of the group posttraining (P < 0.05). However, the time to steroids did not reach statistical significance posttraining (P = 0.93). The PRAM score utilization significantly increased among both control group and intervention group. The untrained physician group was more likely to use chest radiography or admit patients. The trained physician group had higher return visit rates within 7 days and shorter ED length of stay, but this did not reach statistical significance. The curriculum positively impacted clinical outcomes leading to earlier albuterol administration, increased PRAM score use, obtaining less chest radiographs, and decreased admission rates. The timeliness of systemic steroid administration was unaffected.

FORWARDS-1: an adaptive, single-blind, placebo-controlled ascending dose study of acute baclofen on safety parameters in opioid dependence during methadone-maintenance treatment—a pharmacokinetic-pharmacodynamic study

BackgroundTreatment of opiate addiction with opiate substitution treatment (e.g. methadone) is beneficial. However, some individuals desire or would benefit from abstinence but there are limited options to attenuate problems with opiate withdrawal. Preclinical and preliminary clinical evidence suggests that the GABA-B agonist, baclofen, has the desired properties to facilitate opiate detoxification and prevent relapse. This study aims to understand whether there are any safety issues in administering baclofen to opioid-dependent individuals receiving methadone.MethodsOpiate-dependent individuals (DSM-5 severe opioid use disorder) maintained on methadone will be recruited from addiction services in northwest London (NHS and third sector providers). Participants will be medically healthy with no severe chronic obstructive pulmonary disease or type 2 respiratory failure, no current dependence on other substances (excluding nicotine), no current severe DSM-5 psychiatric disorders, and no contraindications for baclofen or 4800 IU vitamin D (placebo). Eligible participants will be randomised in a 3:1 ratio to receive baclofen or placebo in an adaptive, single-blind, ascending dose design. A Bayesian dose-escalation model will inform the baclofen dose (10, 30, 60, or 90 mg) based on the incidence of ‘dose-limiting toxicity’ (DLT) events and participant-specific methadone dose. A range of respiratory, cardiovascular, and sedative measures including the National Early Warning Score (NEWS2) and Glasgow Coma Scale will determine DLT. On the experimental day, participants will consume their usual daily dose of methadone followed by an acute dose of baclofen or placebo (vitamin D3) ~ 1 h later. Measures including oxygen saturation, transcutaneous CO2, respiratory rate, QTc interval, subjective effects (sedation, drug liking, craving), plasma levels (baclofen, methadone), and adverse events will be obtained using validated questionnaires and examinations periodically for 5 h after dosing.DiscussionStudy outcomes will determine what dose of baclofen is safe to prescribe to those receiving methadone, to inform a subsequent proof-of-concept trial of the efficacy baclofen to facilitate opiate detoxification. To proceed, the minimum acceptable dose is 30 mg of baclofen in patients receiving ≤ 60 mg/day methadone based on the clinical experience of baclofen’s use in alcoholism and guidelines for the management of opiate dependence.Trial registrationClinicaltrials.gov NCT05161351. Registered on 16 December 2021.

Prolonged Noninvasive Respiratory Support Before Intubation Is Associated With Increased Duration of Extracorporeal Membrane Oxygenation.

Prolonged Noninvasive Respiratory Support Before Intubation Is Associated With Increased Duration of Extracorporeal Membrane Oxygenation.

Changes in lung fluid levels with variations in the respiratory cycle.

The association between respirophasic variation and lung fluid levels is unknown. Remote dielectric sensing (ReDS™) is a novel non-invasive technology to quantify lung fluid levels. We investigated the change in ReDS values over the course of the respiratory cycle. Patients with clinically stable chronic heart failure at outpatient clinics were prospectively included. ReDS values were measured at three respiratory statuses and compared: (1) at rest with normal breathing, (2) at inspiration, and (3) at expiration. A total of 11 patients were included. Median age was 73 (58, 78) years and 9 were men. ReDS value was 28% (25%, 32%) at rest and decreased significantly with inspiration down to 26% (24%, 30%) (p = 0.004). ReDS value were significantly higher on expiration as 30% (27%, 34%) as compared with rest (p = 0.003). Lung fluid levels in chronic heart failure patients can vary with changes in the respiratory cycle-attention should be paid to what point in the respiratory cycle measurements are taken when interpreting results in each modality, such as chest X-ray (measured at inspiratory status) and right heart catheterization (measured at expiratory status). ReDS system might be a physiologically ideal modality to assess lung fluid amount under natural breathing.

Cluster Analysis of Home Polygraphic Recordings in Symptomatic Habitually-Snoring Children: A Precision Medicine Perspective.

(1) Background: Sleep-disordered breathing (SDB) is a frequent problem in children. Cluster analyses offer the possibility of identifying homogeneous groups within a large clinical database. The application of cluster analysis to anthropometric and polysomnographic measures in snoring children would enable the detection of distinctive clinically-relevant phenotypes; (2) Methods: We retrospectively collected the results of nocturnal home-based cardiorespiratory polygraphic recordings and anthropometric measurements in 326 habitually-snoring otherwise healthy children. K-medoids clustering was applied to standardized respiratory and anthropometric measures, followed by Silhouette-based statistics. Respiratory Disturbance Index (RDI) and oxygen desaturation index (≤3%) were included in determining the optimal number of clusters; (3) Results: Mean age of subjects was 8.1 ± 4.1 years, and 57% were males. Cluster analyses uncovered an optimal number of three clusters. Cluster 1 comprised 59.5% of the cohort (mean age 8.69 ± 4.14 years) with a mean RDI of 3.71 ± 3.23 events/hour of estimated sleep (e/ehSleep). Cluster 2 included 28.5% of the children (mean age 6.92 ± 3.43 years) with an RDI of 6.38 ± 3.92 e/ehSleep. Cluster 3 included 12% of the cohort (mean age 7.58 ± 4.73 years) with a mean RDI of 25.5 ± 19.4 e/ehSleep. Weight z-score was significantly lower in cluster 3 [−0.14 ± 1.65] than in cluster 2 [0.86 ± 1.78; p = 0.015] and cluster 1 [1.04 ± 1.78; p = 0.002]. Similar findings emerged for BMI z scores. However, the height z-score was not significantly different among the 3 clusters; (4) Conclusions: Cluster analysis of children who are symptomatic habitual snorers and are referred for clinical polygraphic evaluation identified three major clusters that differed in age, RDI, and anthropometric measures. An increased number of children in the cluster with the highest RDI had reduced body weight. We propose that the implementation of these approaches to a multicenter-derived database of home-based polygraphic recordings may enable the delineation of objective unbiased severity categories of pediatric SDB. Our findings could be useful for clinical implementation, formulation of therapeutic decision guidelines, clinical management, prevision of complications, and long-term follow-up.

Thoracic configuration in patients ageing with cystic fibrosis: A retrospective single-blinded cohort study

BackgroundIn patients with cystic fibrosis (CF), thoracic morphology and its role in respiratory function is conditioned by anthropometric factors, as well as by pathological changes. While the lungs are continuously monitored, examinations of potential thoracic cage adaptations to the disease are rare. Hence, the aim of this study was to investigate thoracic configuration, and its correlation to spirometry measures over time. MethodsIn total, 344 high-resolution computed tomography (HRCT) examinations from 90 patients were assessed and analysed. Those results were subsequently related to spirometry measurements performed within the same period. ResultsThe cohort displayed no homogenous change in thoracic configuration over time, and correlation between thoracic area and spirometry variables could not be supported statistically. ConclusionsAlthough the current study included a larger cohort of patients with CF compared to previous studies on thoracic morphology, no patient group-specific changes in thoracic configuration were revealed. Furthermore, no correlations between structural findings and functional respiratory measurements were found.

Accurate respiratory rate determination using a novel insertable cardiac monitor algorithm: implications for diagnostic and monitoring potentials beyond heart rhythm disorders

Abstract Background Respiratory rate (RR) is a critical vital sign that is highly relevant in patients with cardiopulmonary disorders. The implantable cardiac monitor (ICM) provides useful data pertaining to heart rhythm, but little is known up to this point regarding its potential diagnostic value in the direct measurement of respiratory parameters. The addition of respiration information could improve understanding of overall health status of heart rhythm patients with ICM. Objective The primary objective of this study was to evaluate the accuracy of the RR detected by an existing implanted ICM as compared to gold-standard polysomnography (PSG) measurement of respiration. Methods This prospective single center study enrolled 25 patients (17 male, 62.7±12.2 yesrs) with an implanted ICM and suspected sleep-disordered breathing. The ICM was custom configured with research software to collect respiration data (Fig. 1). Simultaneous, time-synchronized PSG and ICM data were evaluated in two-minute epochs episodically during the night. The offline novel prototype RR algorithm was evaluated on episodes collected by the ICM and compared against expert manual adjudicated RR from PSG by two separate investigators. The interobserver agreement was assessed using intraclass correlation coefficient (ICC). The performance of the novel algorithm was assessed using Bland-Altman analysis with 95% limits of agreement (LOA). Results A total of 495 epochs were graded by two independent observers, with good ICC of 0.83 (95% C.I. 0.79–0.86). Epochs free of severe sleep disordered breathing/apnea (n=363) were included in this analysis with 106 of these containing periods of hypopnea. The development and validation datasets were comprised of 235 and 128 epochs, respectively. In the development data, the mean RR was 14.99±3 breaths per minute, and the mean RR was 13.44±2 breaths per minute in the test data. Using Bland-Altman analysis, the bias for the novel prototype algorithm was only −0.13 and +0.32 breaths per minute with 95% LOA of −2.24 to +1.98 and −2.56 to +3.19 breaths per minute (Fig. 2), in the in the development and test dataset respectively. Conclusion The novel prototype algorithm applied to the ICM data provided accurate determination of respiratory rate as compared to gold-standard PSG data. The capability to determine respiratory rate accurately from an existing ICM platform demonstrates the potential to extend the diagnostic power of ICMs beyond heart rhythm abnormalities to address a broad range of comorbidities including breathing disorders and heart failure. Funding Acknowledgement Type of funding sources: None.

Differences in the respiratory swings in COPD and ILD candidates for lung transplantation: a critical concern interpreting central pulmonary pressures

Abstract Background In different clinical scenarios (i.e., obesity, COPD, exercise, mechanical ventilation), the swings in intrathoracic pressure are much larger, and end-expiratory (Pee) pressure can be significantly greater than atmospheric pressure. In these scenarios, the intravascular (Piv) pulmonary pressure can overestimate the true transmural (tm) value and it is recommended to read the average of Piv over a few respiratory cycles (Pmrc) [1–3]. Purpose To analyze the respiratory swings and the effect of esophageal pressure (PES) (as a surrogate of intrathoracic pressure) on the reading of Piv tracings during the RHC at rest in COPD and interstitial lung disease (ILD) candidates for lung transplantation (LTx). Methods Thirty-one COPD (15) and ILD (16) candidates for LTx underwent RHC. End-expiratory and mean respiratory cycle measurements were obtained. The respiratory swing was estimated as the difference between maximum-minimum values of Piv. Ten patients (5 COPD/5 ILD) underwent simultaneous RHC and PES (Micro-balloon Esophageal Catheter, LATITUDE) to assess the Ptm (Piv − PES) [4]. Results Both demographic (11F/20M, 60±7 yrs, 25±4 kg/m2) and hemodynamic data (mPAP 24±9 mmHg, pulmonary arterial occlusion pressure [PAOP] 8.6±4 mmHg, right atrial pressure [RAP] 5.2±3.9 mmHg, pulmonary vascular resistance 3.5±2.6 Wu) did not show significant differences between ILD and COPD except the cardiac index (ILD: 2.8±0.8 vs. COPD: 2.4±0.3 L/min/m2). Intravascular RAPee and PAOPee were higher than mrc values in both groups (Fig 1). However, transmural RAPee and PAOPee were similar to and correlated with (r=0.62 and 0.69, respectively; p&amp;lt;0.05) transmural Pmrc values. PESee values were positive in COPD and ILD (3.0±2.2 vs. 3.3±2.0 mmHg, NS). All ILD had negative PESmrc values and were lower than COPD patients (−1.76±1.7 vs. 0.78±1.6 mmHg, p&amp;lt;0.05). ILD PES swings were higher than COPD (10.9±3.7 vs. 8.3±1.4 mmHg), although it did not reach statistical significance (p=0.08). The lower forced vital capacity (%), the more negative the PESmrc (Fig 2A). ILD pts showed higher transmural to intravascular Pmrc (p&amp;lt;0.05) (Fig 2B). Conclusion End-expiratory intravascular RAP and PAOP overestimates the mean respiratory cycle pressures in COPD and ILD candidates for LTx. Averaging pulmonary vascular pressure tracings over the respiratory cycle would be accurate in COPD but could underestimate transmural values in ILD candidates for LTx. The reading of mean respiratory cycle pressure could not be enough to correct the pulmonary pressures measurement error associated with the presence of large swings of intrathoracic pressure. Funding Acknowledgement Type of funding sources: None.

Eight Weeks of Pilates Training Improves Respiratory Measures in People With a History of COVID-19: A Preliminary Study.

Coronavirus disease 2019 (COVID-19) can result in prolonged and severe damage to the lungs and quality of life (QoL). This study was designed to investigate the effects of 8-week Pilates and Aqua-Pilates training on pulmonary function and QoL in patients with COVID-19. Pilates and Aqua-Pilates training promotes similar changes on pulmonary function and QoL in people with a history of COVID-19. Randomized controlled trial. Level 3. A total of 45 participants (24 men and 21 women) with a history of COVID-19 were assigned randomly to 3 groups: Pilates training (standard Pilates), Aqua-Pilates training (Pilates in water), and Control. The training protocol was performed for 8 weeks (3 sessions per week). Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and the ratio of FEV1 to the FVC (FEV1/FVC) indices were measured by a spirometer. The 26-item questionnaire World Health Organization Quality of Life (WHOQOL) BREF was used to assess QoL. Data were analyzed using paired-sample t test and analysis of covariance with an alpha level <0.05. The mean age of the participants was 49.9 ± 6.4 years. After 8 weeks of Pilates and Aqua-Pilates training, there were significant increases in FVC (21.4% for Pilates and 22.1% for Aqua-Pilates, P < 0.05), FEV1 (32.3% for Pilates and 34.7% for Aqua-Pilates, P < 0.05), and FEV1/FVC% (9% for Pilates and 10.3% for Aqua-Pilates, P < 0.05) for the experimental groups, but not for control. Changes for Pilates and Acqua-Pilates were significantly higher than for control. The QoL scores were significantly different within and between the experimental groups, with greater improvements in the Aqua Pilates group than in the Pilates group. An 8-week Pilates or Aqua-Pilates training can improve pulmonary function as much as 34%, depending on the parameter, and QoL in people with a history of COVID-19. Aqua-Pilates training appears to be preferable to standard Pilates. The findings provide important insights into how healthcare professionals can prescribe exercise for COVID-19 survivors.

Longitudinal lung function in urban firefighters: A group-based multi-trajectory modelling approach.

Urban firefighters are routinely exposed to both physical and chemical hazards that can negatively impact lung health, but it is unclear if firefighters experience accelerated decline in spirometry parameters due to chronic exposure and acute insults. This study aimed to describe sub-groups of firefighters with differing spirometry trajectories and examine the relationship between the identified trajectories and demographic, lifestyle and occupational characteristics. Data from six waves of the Respiratory Function Measurement and Surveillance for South Australian Metropolitan Fire Service Study (2007-2019) were used to identify spirometry parameter z-score trajectories, using group-based multi-trajectory modelling (GBMTM). Analysis of variance and chi-square statistics were used to assess trajectory group differences in baseline self-reported demographic, lifestyle and occupational characteristics. In the 669 included firefighters, we identified five trajectories for the combination of Forced Expiratory Volume in the first second z-score (FEV1 z), Forced Vital Capacity z-score (FVCz) and the ratio of FEV1 and FVC z-score (FEV1 /FVCz). There were three stable trajectories of low, average and very high lung function and two declining trajectories of average and high lung function. Analysis of subgroup characteristics revealed no significant differences between expected and actual group proportions for the occupational characteristics of years of service and respiratory protection use. Significant differences were seen in respiratory health and body mass index. GBMTM defined distinct, plausible spirometry trajectory sub-groups. Firefighter longitudinal spirometry trajectory group membership was associated with BMI and respiratory disease or symptoms but not with self-reported smoking history or occupational factors.

Breastfeeding Practices During Covid-19

The covid-19 has disrupted all parts of life especially maternal-child relationship. Many lactating women were quarantined in covid-19 which has affected nourishment of their infant. Breastfeeding has innumerable benefits for both mother and infants as it provides them protection. The Maternal-child relationship is drastically affected if an infant is separated from its mother. It greatly affects lactation, which acts as a shield against infectious diseases. It is approved by all the international agencies and government bodies to promote breastfeeding including the neonates of infected mothers. It is suggested to adopt proper hand and respiratory hygiene measures to prevent transmission from mother to infant. Although many studies and literature reviews have confirmed that there are no direct transmission cases related to coronavirus during breastfeeding. However, WHO, UNICEF, and many other organizations suggested to adopt some hygiene-specific guidelines while practicing lactation. These include wearing a mask, washing hands, and disinfecting surfaces. As we are in the middle of this pandemic and new information is being gathered by scientists, it is hoped that they will also support promoting breastfeeding. As its advantages outweigh the risks of COVID-19. The main aim of this review is to promote early initiation and exclusive breastfeeding during COVID-19.

Etiologies of outpatient medically attended acute respiratory infections among young Ecuadorian children prior to the start of the 2020 SARS-CoV-2 pandemic.

BackgroundImplementation of respiratory virus prevention measures requires detailed understanding of regional epidemiology; however, data from many tropical countries are sparse. We describe etiologies of ambulatory pediatric acute respiratory tract infections (ARTI) in Ecuador immediately preceding the onset of the SARS‐CoV‐2 pandemic.MethodsChildren < 5 years presenting to a designated study site with an ARTI were eligible. Informed consent was obtained. Demographic and clinical data were recorded. A nasopharyngeal swab was collected, processed, and analyzed using multiplex polymerase chain reaction (PCR) for common respiratory pathogens. Rhinovirus/enterovirus positive samples were further characterized by genomic sequencing.ResultsA total of 820 subjects were enrolled in the study between July 2018 and March 2020. A total of 655 (80%) samples identified at least one pathogen. Rhinoviruses (44%) were most common, followed by enteroviruses (17%), parainfluenza viruses (17%), respiratory syncytial virus (RSV) (15%), and influenza viruses (13%). Enterovirus D68 was the most common enterovirus detected and was among the leading causes of bronchiolitis. Seasonal RSV and influenza virus activity were different along the coast compared with the highlands.ConclusionsOngoing regional surveillance studies are necessary to optimize available and emerging pathogen‐specific preventative measures.

Soil Respiration Is Influenced by Seasonality, Forest Succession and Contrasting Biophysical Controls in a Tropical Dry Forest in Northwestern Mexico

Soil respiration (RS) is an important component of the C cycle because it contributes significant CO2 emissions to the atmosphere that result from metabolism and respiration of its autotrophic and heterotrophic components. However, the relative importance of different biophysical controls that drive the variability of this flux and their influence along forest succession pathways is still unknown. We incorporate multiyear RS, ecosystem flux and meteorological measurements in old-growth (OG), mid-secondary (MS) and early-secondary (ES) tropical dry forests (TDFs) with the goal of assessing the temporal variation of RS and identifying the biophysical controls at each site by applying structural equation models (SEM). Along forest succession, RS followed the pattern of precipitation events; we identified by the end of the wet season that RS was sustained by a longer period at OG, while in MS and ES, RS decreased according to the soil moisture availability. According to SEM, soil moisture and soil temperature exert an effect on the variability of RS in all sites. However, we found that RS was also controlled by the vapor pressure deficit at MS and gross primary production at OG and ES. Our results suggest that seasonality has a different impact on RS along forest succession in TDFs found in northwestern Mexico and highlights the relevance of considering additional biophysical controls of RS for a better understanding this critical process of the C cycle.

Reverse microdialysis: A window into root exudation hotspots

Plant roots release a variety of low-molecular weight compounds, such as sugars, amino acids or organic acids into the soil, impacting microbial activities and physico-chemical soil processes in their surroundings. These compounds are a source of easily available Carbon (C) and energy for soil microbes, potentially accelerating microbial decomposition of soil organic matter in the immediate vicinity of roots. However, knowledge about processes in root exudation hotspots remains limited due to experimental difficulties in investigating such hotspots in soil.Microdialysis, a passive sampling technique based on diffusion, has been successfully used to collect soil solutes at small spatial scales. Reverse microdialysis, also termed retrodialysis, can be used to introduce solutes into the soil, mimicking passive root exudation. However, little is known about the dynamics of substances released by passive diffusion into intact soil, a crucial prerequisite for applying reverse microdialysis to study root exudation hotspots in undisturbed soils.Here, we used reverse microdialysis to investigate the spatial and temporal dynamics of thirteen different organic compounds passively introduced into two different intact soils. Diffusion of compounds into soils was substantially lower than into water, and was not – as in water – determined by molecular size. Interestingly, butyrate, oxalate and propionate showed the highest diffusive fluxes into soil combined with the lowest rate of back retrieval after input, indicating that they were quickly removed from the soil solution by biotic or abiotic processes. In contrast, glucose and fructose unexpectedly accumulated around the membrane after input without removal. Furthermore, diffusive fluxes of compounds into soils showed a fluctuating temporal pattern, which may be explained by an observed 2-h delay of microbial respiration of added 13C-labelled compounds. During the course of 12 days, approximately one third of 13C-labelled compounds introduced into soil was respired while 8% ended up in microbial biomass.Our results demonstrate that introducing compounds into intact soil triggers complex biotic and abiotic responses at the time scale of hours. Reverse microdialysis proved to be an excellent tool to investigate such responses as well as the dynamics and metabolic consequences of passively released compounds into intact soil, and – in combination with 13C labelled substrate and respiration measurements - to shed light on potential priming effects that may be triggered by them.

Farmer participatory assessment of soil health from Conservation Agriculture adoption in three regions of East Africa

The challenges of soil degradation and low crop yield are being addressed in East Africa using a number of soil health-promoting farming systems including Conservation Agriculture (CA). CA is based on principles of minimal soil disturbance, continuous soil cover, and crop diversity, though implementation on farms may vary due to local circumstances. This study evaluated the effect of CA, as practiced by farmers, and compared farmer descriptions of soil health with scientific measures. CA and non-CA fields were compared in regions of Ethiopia (23 farms), Kenya (23 farms), and Tanzania (13 farms) with most fields repeatedly sampled for 2 to 3 years. CA and non-CA fields were located within meters, on soils with the same texture, growing similar crops. CA systems used precision planting, mostly with basins. Soil parameters were assessed using a participatory approach where farmers and field technicians collected data. CA practices improved qualitative soil characteristics as sensed by farmers (e.g., hoe-ability, crusting, smell, water infiltration), and this positive response was consistent across most fields. For qualitative data, the logarithm of the odds ratio estimates method was used to test the probability that CA would provide soil improvement. Fields under the CA treatment had a higher probability of rating better than non-CA fields. Quantitative measurements of pH and microbial respiration validated farmer assessments. CA-managed soils were weakly associated with darker colour, indicating higher soil organic matter. Sandy soils did not appear to improve with CA as dramatically as clay and loam soils, suggesting different CA strategies may be required. We discuss both benefits and drawbacks of this type of participatory, on-farm research. We conclude that farmer participation as citizen scientists will advance soil restoration in East Africa and increase the potential for farmer-to-farmer knowledge exchange of soil-improving practices.

Respiration regimes in rivers: Partitioning source‐specific respiration from metabolism time series

AbstractRespiration in streams is controlled by the timing, magnitude, and quality of organic matter (OM) inputs from internal primary production and external fluxes. Here, we estimated the contribution of different OM sources to seasonal, annual, and event‐driven characteristics of whole‐stream ecosystem respiration (ER) using an inverse modeling framework that accounts for possible time‐lags between OM inputs and respiration. We modeled site‐specific, dynamic OM stocks contributing to ER: autochthonous OM from gross primary production (GPP); allochthonous OM delivered during flow events; and seasonal pulses of leaf litter. OM stored in the sediment and dissolved organic matter (DOM) transported during baseflow were modeled as a stable stock contributing to baseline respiration. We applied this modeling framework to five streams with different catchment size, climate, and canopy cover, where multi‐year time series of ER and environmental variables were available. Overall, the model explained between 53% and 74% of observed ER dynamics. Respiration of autochthonous OM tracked seasonal peaks in GPP in spring or summer. Increases in ER were often associated with high‐flow events. Respiration associated with litter inputs was larger in smaller streams. Time lags between leaf inputs and respiration were longer than for other OM sources, likely due to lower biological reactivity. Model estimates of source‐specific ER and OM stocks compared well with existing measures of OM stocks, inputs, and respiration or decomposition. Our modeling approach has the potential to expand the scale of comparative analyses of OM dynamics within and among freshwater ecosystems.

Preliminary Investigative Study on the Blood Pressure-Lowering Potential of Aqueous Leaf Extract of Simarouba glauca (AESG) on Normotensive Adult Wistar Rats

Studies have shown that plants possess medicinal properties and compounds are beneficial in managing and treating diseases, including high blood pressure and related cardiovascular conditions. Simarouba glauca (SG) has been widely reported to possess antibacterial activity, anti-oxidant, anti-proliferative and hemolytic activity; amongst others. However, there is paucity of data on its effect on blood pressure. Hence, the study research aimed at assessing the hypotensive prospect inherent in the aqueous leaf extract of Simarouba glauca (AESG) on normotensive male Wistar rats. The study was conducted using adult male Wistar rats (n = 3), a urethane/thiopental (1205/20 mg/kg) anesthesia and a chart paper attached to Ugo Basile Uni-recorder Model 400700 data capsule. Under full anesthesia, the rat’s trachea and the carotid artery were cannulated for assisted respiration and blood pressure measurement. At stable variables; following the administration of 0.2 mL normal saline, the AESG was administered intravenously via the caudal vein at 2.5 and 5.0 mg/kg body weight dose respectively. The data was recorded on a chart; indicated the characteristic dose-dependent hypotensive effect of AESG on normotensive rats; at doses of 2.5 mg/kg and 5.0 mg/kg, with marked decreases in the systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) from basal levels of 127.83 ± 1.01 mmHg, 91.00 ± 1.00 mm Hg and 103.27 ± 0.99 mm Hg respectively. The outcome of the preliminary investigation indicates that the AESG demonstrated a hypotensive effect on the BP of normotensive male Wistar rats dependent on varying doses administered; indicative of further evaluation.

Quantitative and Real-Time Evaluation of Human Respiration Signals with a Shape-Conformal Wireless Sensing System.

Respiration signals reflect many underlying health conditions, including cardiopulmonary functions, autonomic disorders and respiratory distress, therefore continuous measurement of respiration is needed in various cases. Unfortunately, there is still a lack of effective portable electronic devices that meet the demands for medical and daily respiration monitoring. This work showcases a soft, wireless, and non-invasive device for quantitative and real-time evaluation of human respiration. This device simultaneously captures respiration and temperature signatures using customized capacitive and resistive sensors, encapsulated by a breathable layer, and does not limit the user's daily life. Further a machine learning-based respiration classification algorithm with a set of carefully studied features as inputs is proposed and it is deployed into mobile clients. The body status of users, such as being quiet, active and coughing, can be accurately recognized by the algorithm and displayed on clients. Moreover, multiple devices can be linked to a server network to monitor a group of users and provide each user with the statistical duration of physiological activities, coughing alerts, and body health advice. With these devices, individual and group respiratory health status can be quantitatively collected, analyzed, and stored for daily physiological signal detections as well as medical assistance.

Detection of Influencing Factors of Spatial Variability of Soil Respiration in Pangquangou Nature Reserve

Soil respiration is an important process in maintaining global carbon balance. Taking the Pangquangou Nature Reserve as the research area, based on the field measurement of soil respiration (Rs) data combined with altitude (ELE), soil temperature (T), soil moisture (SWC), normalized vegetation index (NDVI), slope (slope), soil total carbon (C), total nitrogen (N), and soil bulk density (BD), we analyzed the main driving forces and interactions of Rs spatial differentiation by using the geographic detector model. The results showed that:① the spatial variation of Rs and its influencing factors in the study area was moderate. The Rs was significantly positively correlated with NDVI, T, and N (P<0.01) and negatively with ELE, slope, and SWC (P<0.01). The Rs was significantly correlated with BD(P<0.05) but not with C(P>0.05). ② The multivariate linear model composed of NDVI and T explained 64.3% of Rs spatial variation. ③ ELE, T, and NDVI were the dominant driving forces of Rs spatial differentiation in the study area, which could explain 64%, 59%, and 48% of the spatial variability. ④ The interaction of the two factors enhanced the explanatory power of Rs spatial differentiation, and the maximum interaction factors were ELE∩BD (q=0.73), and T∩slope (q=0.74), respectively. Therefore, in the process of Rs estimation, combined with topographical and environmental conditions, the interaction between multiple factors should be considered.