Physiological Investigations Research Articles

Pseudomonas oryzihabitans D1-104/3 and P. gessardii C31-106/3 differentially modulate the antioxidative response of duckweed (Lemna minor L.) to salt stress

IntroductionThe common duckweed (L. minor) is a model organism for investigation of plant physiology, especially stress-related responses. Its two physiological characteristics are of special interest: (1) salt-stressed duckweeds may accumulate starch, a precursor for biofuel; (2) duckweeds are associated with various beneficial (plant-growth promoting, PGP) bacterial strains. In this paper, we analyzed the role of two bacterial strains: Pseudomonas oryzihabitans D1-104/3 and P. gessardii C31-106/3 in regulation of duckweed's growth and antioxidative responses to salt (10 and 100 mM NaCl) and hypothesized that they alleviate salt-induced oxidative stress.MethodsFresh and dry weight, frond number, photosynthetic pigments, malondialdehyde (MDA) and hydrogen peroxide (H2O2), ascorbic acid (AsA), proline, total polyphenol (TPC) and starch content, as well as antioxidant capacity and antioxidant enzymatic activity were measured after 14 days. Fluorescence microscopy was used to visualize bacterial presence on duckweeds.ResultsFluorescence microscope revealed that Pseudomonas bacteria colonized all duckweed surfaces. The doubling time of duckweeds inoculated with P. gessardii C31-106/3 was significantly longer. Additionally, at 0 and 10 mM NaCl, this strain decreased chlorosis in duckweeds. Moreover, P. gessardii C31-106/3 increased dry-to-fresh-weight ratio, proline, chlorophyll a, b and carotenoid content at 100 mM, as well as AsA content in plants in NaCl-free medium, while P. oryzihabitans D1-104/3 increased AsA at 100 mM NaCl. Both bacterial strains decreased lipid peroxidation, while P. gessardii C31-106/3 increased and P. oryzihabitans D1-104/3 decreased H2O2 content at 100 mM and 0 mM NaCl, respectively. Bacteria significantly increased TPC and antioxidant capacity at 100 mM NaCl, particularly P. oryzihabitans D1-104/3. After 14 days, the SOD and POX activities were at the same level in all samples. At 100 mM NaCl, CAT activity was increased in all plants.DiscussionThe results of this study show that two Pseudomonas strains had markedly different effects on duckweed: while P. oryzihabitans D1-104/3 supported growth, P. gessardii C31-106/3 prioritized salt stress tolerance in duckweeds.

The Extraction Of Neural Strategies From The Surface Emg: 2004-2024.

This review follows two previous papers (Farina et al., 2004, 2014) in which we reflected on the use of surface EMG in the study of the neural control of movement. This series of papers began with an analysis of the indirect approaches of EMG processing to infer the neural control strategies and then closely followed the progress in EMG technology. In this third paper, we focus on three main areas: surface EMG modelling; surface EMG processing, with an emphasis on decomposition; and interfacing applications of surface EMG recordings. We highlight the latest advances in EMG models that allow fast generation of simulated signals from realistic volume conductors, with applications ranging from validation of algorithms to identification of non-measurable parameters by inverse modelling. Surface EMG decomposition is currently an established state-of-the-art tool for physiological investigations of motor units. It is now possible to identify large samples of motor units, to track motor units over multiple sessions, to partially compensate for the non-stationarities in dynamic contractions, and to decompose signals in real-time. The latter achievement has facilitated advances in myocontrol, by using the online decoded neural drive as a control signal, such as in the interfacing of prostheses. Looking back over the 20 years since our first review, we conclude that the recording and analysis of surface EMG signals has seen breakthrough advances in this period. Although challenges in its application and interpretation remain, surface EMG is now a solid and unique tool for the study of the neural control of movement.

Integrative Multi-PTM Proteomics Reveals Dynamic Global, Redox, Phosphorylation, and Acetylation Regulation in Cytokine-Treated Pancreatic Beta Cells

Studying regulation of protein function at a systems level necessitates an understanding of the interplay among diverse post-translational modifications (PTMs). A variety of proteomics sample processing workflows are currently used to study specific PTMs but rarely characterize multiple types of PTMs from the same sample inputs. Method incompatibilities and laborious sample preparation steps complicate large-scale physiological investigations and can lead to variations in results. The single-pot, solid-phase-enhanced sample preparation (SP3) method for sample cleanup is compatible with different lysis buffers and amenable to automation, making it attractive for high-throughput multi-PTM profiling. Herein, we describe an integrative SP3 workflow for multiplexed quantification of protein abundance, cysteine thiol oxidation, phosphorylation, and acetylation. The broad applicability of this approach is demonstrated using cell and tissue samples, and its utility for studying interacting regulatory networks is highlighted in a time-course experiment of cytokine-treated β-cells. We observed a swift response in global regulation of protein abundances consistent with rapid activation of JAK-STAT and NF-κB signaling pathways. Regulators of these pathways as well as proteins involved in their target processes displayed multi-PTM dynamics indicative of a complex cellular response stages: acute, adaptation, and chronic (prolonged stress). PARP14, a negative regulator of JAK-STAT, had multiple co-localized PTMs that may be involved in intraprotein regulatory crosstalk. Our workflow provides a high-throughput platform that can profile multi-PTMomes from the same sample set, which is valuable in unraveling the functional roles of PTMs and their co-regulation.

BN SO33 - The complex benign multi-disciplinary team meeting - a paradigm shift in decision making for benign oesophagogastric surgery

Abstract Background Decision making in benign OG pathology can be particularly challenging given the overlap with functional disorders, such as reflux hypersensitivity. A specialist benign oesophagogastric (OG) multidisciplinary team (MDT) may improve our ability to triage potential surgical candidates from those with functional conditions. Unlike in OG cancer, there is a paucity of evidence to support an MDT based approach in benign OG surgery. This study aims to report our experience of introducing a specialist benign OG MDT in an OG tertiary centre in the UK, examining the effect on decision making and an assessment of its acceptability and utility to clinicians. Method A review of consecutive cases discussed in the specialist benign OG MDT since inception in 2022 was undertaken. We reviewed indications, treatment plans and outcomes, any alteration in treatment pathway and final decisions. The primary outcome was the proportion of patients with a change in management as a result of MDT discussion. Where applicable, results were reported using descriptive statistics. A seven-item electronic questionnaire was also circulated to MDT members (OG surgeons, specialist gastroenterologists, GI radiographers, GI physiologists, and doctors in training), to assess the acceptability and perceived utility of the meetings. Results 74 patient cases were discussed (median age 57.5 (25-79) years). 71/74 (96.0%) of referrals were made by OG surgeons, most commonly to discuss anti-reflux procedures (53/74 (71.6%)). 34/74 (45.9%) patients had undergone previous surgery, most commonly laparoscopic fundoplication. MDT discussion led to a change in management in 43/74 (58.1%) case with recommendations of further investigation (23.0%), further OG clinic review (18.9%) and 21.6% listed for surgery. 12/74 (16.2%) were referred to other specialist services, including clinical psychology. Survey confirmed that all MDT members found their understanding of oesophageal physiology and subsequent decision-making ability in clinic was greatly enhanced. Conclusion Our results show that the complex benign MDT is an effective tool, demonstrating changes to management in over half of cases discussed, including recommending surgery less frequently following specialist review of physiology investigations. Such tests effectively identify functional disorders, such as rumination, highlighting a need for clear onward referral pathways involving specialist psychologists. The meetings have also proven to be valuable learning tools for all attendees of all grades. We strongly believe that adopting an MDT approach to benign OG conditions will enhance collaborative decision making, improve patient outcomes and therefore should be nationally mandated and recommended through AUGIS guidelines.

Hypersalinity tolerance of mummichogs (Fundulus heteroclitus): A branchial transcriptomic analysis

Along the east coast of North America, mummichogs (Fundulus heteroclitus) are subjected to a broad range of salinities in their nearshore habitats. However, there is a paucity of information regarding the molecular and cellular processes that mummichogs (and other highly osmotolerant fishes) engage to survive environmental salinities greater than seawater (SW). To reveal branchial processes underlying their extraordinarily broad salinity tolerance, we performed an RNA-Seq analysis to identify differentially expressed genes (DEGs) in mummichogs residing in 3, 35, and 105 ppt conditions. We identified a series of DEGs previously associated with both freshwater (FW)- and SW-type ionocytes; however, the heightened expression of anoctamin 1a, a Ca2+-activated Cl− channel, in 35 and 105 ppt indicates that an undescribed Cl−-secretion pathway may operate within the SW-type ionocytes of mummichogs. Concerning FW-adaptive branchial processes, we identified claudin 5a as a gene whose product may limit the diffusive loss of ions between cellular tight junctions. Further, in response to hypersaline conditions, we identified DEGs linked with myo-inositol synthesis and kinase signaling. This study provides new molecular targets for future physiological investigations that promise to reveal the mechanistic bases for how mummichogs and other euryhaline species tolerate hypersaline conditions.

Downscaling investigations in Tree Physiology: mechanisms and context.

Downscaling investigations in Tree Physiology: mechanisms and context.

Technical development and preliminary physiological response investigation of a tendon-based robotic system for gait rehabilitation

Cable-driven robots are commonly applied in the rehabilitation field. Many tendon-based systems use parallel end-effector structures because of the advantages of fast reactions and high force outputs. We previously developed an active cable-driven robotic system that enabled accurate force control and was applied while walking on a treadmill. However, the kinematic and kinetic assistance methods need to be improved. Given the advantages of tendon-based parallel systems, this study investigated walking generated by four cables that were directly attached around the ankle. The aim of this work was to develop a tendon-based parallel robotic system to provide assisted walking on a treadmill with gait-specific position guidance and force compensation. To demonstrate the assistance effects, preliminary physiological responses of leg muscles during walking with the system were investigated. A parallel robotic system with four cable-driven units was developed. Kinematic and kinetic analyses of walking were performed, followed by the development of control algorithms for walking with impedance assistance only and walking with impedance assistance plus kinetic compensation. The muscle activity of the rectus femoris, vastus lateralis, gluteus maximus, biceps femoris, and gastrocnemius muscles was recorded and analyzed. On the basis of the kinematic and kinetic analyses, the tendon-based parallel robotic system produced treadmill walking with position and force assistance. The force control algorithms tracked the target force profile with a mean error of 6.4 N. During impedance-assisted walking, the rectus femoris, gluteus maximus and biceps femoris muscles produced a mean electromyography of 115.1% of the activity during independent walking (without assistance). However, the activity of the vastus lateralis and gastrocnemius reduced to only 82.5% of that during independent walking. Further kinetic compensation generally reduced the muscle activity, with the mean electromyography result being 88.7% of that during independent walking. From a technical point of view, the tendon-based parallel robotic system provided walking-specific position and force assistance in leg movement, accompanied by reduced muscle activity compared with independent walking. A technical feasibility study will be conducted to evaluate whether the tendon-based parallel robotic system is feasible for assisted treadmill walking in the general population and whether position guidance and force assistance are acceptable.

Detrended fluctuation analysis to determine physiologic thresholds, investigation and evidence from incremental cycling test.

Training zones are generally assessed by gas-exchange thresholds (GET). Several mathematical analyses of heart rate variability (HRV) are proposed for indirect GET determination. Our study aimed to investigate the accordance of the detrend fluctuation analysis (DFA α1) for determining GET with first (VT1) and second ventilatory (VT2) thresholds in well-trained subjects. Eighteen female and 38 male sub-elite cyclists performed a maximal incremental cycling test of 2-min stage duration with continuous gas exchange and HR measurements. Power output (PO), Oxygen uptake ( O2) and HR at VT1 and VT2 were compared with DFA α1 0.75 (HRVT1) and 0.50 (HRVT2). Agreements between PO, O2 and HR values were analyzed using Bland-Altman analysis. Large limits of agreement between VT1 and HRVT1 were observed for measures of O2 expressed in mL.min-1.kg-1 [-21.3; + 14.1], HR [39.2; + 26.9] bpm and PO [-118; + 83] watts. Indeed, agreements were also low between VT2 and HRVT2 for measures of O2 [-26.7; + 4.3] mL.min-1.kg-1, HR [-45.5; + 10.6] bpm and PO [-157; + 35] watts. Our results also showed a sex effect: women obtained worst predictions based on DFA α1 than men for HR (p = 0.014), PO (p = 0.044) at VT1 and (p = 0.045), HR (p = 0.003) and PO (p = 0.004) at VT2. There was unsatisfactory agreement between the GET and DFA α1 methods for VT1 and VT2 determination in both sex well-trained cyclists. Trial registrationnumber 2233534 on 2024/03/05 retrospectively registered.

Fasting as a Therapeutic Strategy to Alleviate Heat-Induced Liver and Kidney Damage in mice: A Physiological and Histological Investigation

Fasting as a Therapeutic Strategy to Alleviate Heat-Induced Liver and Kidney Damage in mice: A Physiological and Histological Investigation

Measurement of respiratory-swallowing coordination using an oronasal facemask in healthy individuals.

Respiratory-swallowing coordination (RSC)is well established as an essential airway-protective mechanism. Previous studies have used nasal airflow and/or kinematic rib cage and abdominal measures to assess respiration surrounding swallowing, meaning that the direct influence of oral respiration on RSC remains unknown. This study used a partitioned oronasal facemask to compare respiratory phase patterns measured using isolated nasal airflow with those measured using combined oronasal airflow during non-ingestive and ingestive swallowing tasks. Twenty-four healthy individuals with no respiratory or swallowing disorders were assessed at rest and during cued dry, 10mL water, continuous drinking and cracker swallowing tasks. Respiratory phase patterns were determined for discrete swallows using the nasal and combined oronasal channels separately. There was variable agreement between respiratory phase patterns according to the nasal and oronasal channels across swallowing conditions. The frequency of exhale-swallow-exhale, inhale-swallow-exhale and exhale-swallow-inhale patterns increased by 2%-3% each with the addition of oral flow data to nasal data, whereas the prevalence of inhale-swallow-inhale and ambiguous patterns decreased. This suggests that estimates of respiratory phase patterns are altered minimally by inclusion of oral respiratory estimates in a healthy sample. There were several additional findings of note, including lower within-participant, within-session trial consistency (test-retest reliability) than expected, suggesting high variability in respiratory phase patterns across trials. Additionally, data showed evidence of swallowing non-respiratory flow at the beginning and end of the respiratory-swallowing pause, moving in both inward and outward directions, potentially expanding current understanding of swallowing non-respiratory flow. Further in-depth physiological investigations are required to improve understanding of these findings.

Comprehensive Husbandry Protocol for Corydoras Catfish and Many Other Amazonian Species.

A variety of fish species have proven instrumental in the investigation of evolution, behavior, ecology, and physiology, among many other fields. Many model systems (e.g., zebrafish, guppies, and three-spined sticklebacks) have been maintained by institutions and have had protocols written with respect to their husbandry. Here we present the protocols we have developed to maintain and breed a variety of Corydoras catfish species, which are native to the tropical Americas. Corydoras species are excellent systems for investigating behavior, ecology, and other topics, and our husbandry protocols would be suitable for nearly every species in the genus. In addition, these protocols are appropriate for a variety of softwater Amazonian species, and we present options for a variety of housing and husbandry conditions. On the whole, we suggest that, in a scientific laboratory setting, the use of remineralized reverse osmosis water is most appropriate and that in context, a single measure, total dissolved solids, can be used to monitor the water chemistry for water introduced to fish enclosures.

Single and Combinations of Rosuvastatin, Celecoxib, and Colchicine Effects on Biochemical and CBC Parameters of Wistar Albino Rats

Drug resistance became a well-known problem in different areas of pharmacology, including anti-cancer therapy and antibiotics. The overcoming of drug resistance either by different drugs or doses, increases the risk of tissue toxicity. The combination of single FDA-approved drugs became one of the solutions shorting the time for new drug approval, and lowering the cost of manufacturing and transporting of drug to pharmacy shelves. Every day a new combination is investigated to narrow the gap in different pharmacological requirements. Lipid-lowering and anti-inflammatory drugs are widely used and are widely available globally. The study aimed to investigate four probabilities of combinations of three single drugs Rosuvastatine (Ro), Celecoxib (Ce), and Colchicine (Co) on biochemical and Complete Blood Count parameters (CBC) to evaluate the reliability and probable effects of these drugs on normal body function. Nine groups (n=6) of Wistar Albino Rats were inoculated with single and combinations of drugs for eight days using the maximum normal human doses of each drug, blood samples were collected in the middle, and at the end of the experiment. Results showed that combinations induced abnormal biochemical, and CBC parameters in ALT, AST, Creatinine, and RBC parameters in all but one (Rosuvastatine-Celecoxibe-Colchicine) of the combination. The study concluded that the combination could be used except that showed a higher level of abnormal physiological parameters, and percussions should taken by more pharmacological and physiological investigation in a bigger scale of studies including longer durations and different animal models before the combinations utilized by human.

Computational model for synthesizing auditory brainstem responses to assess neuronal alterations in aging and autistic animal models.

This study presents a novel computational model of the auditory brainstem, capable of synthesizing auditory brainstem response (ABR) traces by simulating large-scale neuronal activities. Addressing limitations of traditional ABR measurements, the model links ABR waveform features to underlying neuronal properties. Validated using empirical ABRs from animal models of autism and aging, the model accurately reproduced observed ABR alterations, revealing influences of myelin deficits and hyperexcitability in Fragile X syndrome, and degraded inhibitory activity in aging. These findings, supported by experimental data, demonstrate the model's potential for predicting changes in auditory brainstem physiology and guiding further physiological investigations, thus advancing our understanding of auditory neural processes.

Dissecting the mechanism of synergistic interactions between Aspergillus fumigatus and the microalgae Synechocystis sp. PCC6803 under Cd(II) exposure: insights from untargeted metabolomics

Co-culturing fungi and microalgae may effectively remediate wastewater containing Cd and harvest microalgae. Nevertheless, a detailed study of the mechanisms underlying the synergistic interactions between fungi and microalgae under Cd(II) exposure is lacking. In this study, Cd(II) exposure resulted in a significant enhancement of antioxidants, such as glutathione (GSH), malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide dismutase (SOD) compared to the control group, suggesting that the cellular antioxidant defense response was activated. Extracellular proteins and extracellular polysaccharides of the symbiotic system were increased by 60.61 % and ,24.29 %, respectively, after Cd(II) exposure for 72 h. The adsorption behavior of Cd(II) was investigated using three-dimensional fluorescence excitation-emission matrix (3D-EEM), fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM). Metabolomics results showed that the TCA cycle provided effective material and energy supply for the symbiotic system to resist the toxicity of Cd(II); Proline, histidine, and glutamine strengthened the synergistic adsorption capacity of the fungus and microalgae. Overall, the theoretical foundation for a deep comprehension of the beneficial interactions between fungi and microalgae under Cd(II) exposure and the role of the fungal-algal symbiotic system in the management of heavy metal pollution is provided by this combined physiological and metabolomic investigation.

Morphological and physiological investigations reveal the regulatory effect of exogenous paclobutrazol on flowering promotion by winter warming in Chaenomeles speciosa ‘Changshouguan’

The application of exogenous paclobutrazol (PP333) can improve the ability of winter warming to promote flowering in Chaenomeles speciosa, but the underlying mechanism is unclear. In this study, the cultivar ‘Changshouguan’ was sprayed with different concentrations of PP333 during flower bud differentiation, and the changes in the anatomical structures and physiological characteristics of the flower buds during the differentiation process, as well as the growth state of the flower buds and the effect on flowering promotion after winter warming treatment, were comprehensively investigated. The results showed that different concentrations of PP333 could advance the flowering time of ‘Changshouguan’ by 15–24 d under the warming treatment and increase the flowering duration to 17 d compared with those under the warming treatment alone (CK), and 1000 mg/L was the best treatment. Compared with the CK treatment, the PP333 treatment decreased the contents of indole acetic acid (IAA) and gibberellic acid (GAs) and increased the contents of zeatin ribosides (ZRs) and abscisic acid (ABA), thus changing the balance of hormones during flower bud differentiation. The inflection point (low point) of the curve shapes of the ZRs/GAs and ZRs/IAA ratios appeared significantly earlier, which showed a pattern consistent with soluble sugar and protein content and antioxidant activity. Interestingly, the above changes also corresponded to earlier flowering times during the warming process. Taken together, these results indicate that spraying an appropriate concentration of PP333 in the early stage of ‘Changshouguan’ flower bud differentiation promotes the early differentiation of flower buds and early flowering under winter warming treatment by altering their endogenous hormone content and homeostasis and changing their physiological state. The key to maintaining a relatively long flowering period in plants in the PP333 treatment group after flowering promotion was the increased accumulation of sugars and proteins.

Strategies for the Codelivery of Osteoclasts and Mesenchymal Stem Cells in 3D-Printable Osteochondral Scaffolds.

Osteochondral defects, characterized by structural compromises to articular cartilage and subchondral bone, can cause pain and lead to progressive cartilage damage and eventual osteoarthritis. Unfortunately, repairing these defects remains difficult because of the poor regenerative properties of cartilage and complex mechanical demands of the joint. As such, the field of tissue engineering aims to develop multiphasic implants that replace pathological cartilage and bone tissue and restore mechanical functionality to the joint. Recent bone physiology investigations have demonstrated that osteoclast (OC) lineage cells are inextricably involved in osteoblastic bone formation through an extensive network of anabolic signaling pathways, and so the codelivery OC and osteoblast (OB) lineage cells within scaffolds is being actively explored for bone tissue engineering purposes. However, it remains unclear how these cells can be incorporated into the design of multiphasic osteochondral scaffolds to potentially enhance subchondral bone formation and subsequent implant osseointegration. To explore this question, we examined direct surface seeding and hydrogel encapsulation as potential scaffold cellularization strategies. First, we examined how OC precursor cells and peripheral blood monocytes (PBMCs) influence early-stage bone matrix development and osteogenesis in 2D coculture. Then, we evaluated the osteogenic potential of mesenchymal stem cells (MSCs) and PBMCs cocultures encapsulated within a gelatin methacrylate (GelMA) hydrogel system. Our findings demonstrate that coculturing PBMCs with MSCs in 2D cultures significantly enhanced cell proliferation, early bone matrix deposition, and the formation of cell clusters by Day 28. However, we observed no significant difference in type I collagen deposition between GelMA hydrogel scaffolds cultured in basal and OC conditions during the same period. In addition, we found that the GelMA hydrogel system with MSC/PBMC cocultures in OC conditions exhibited decreased osteogenic activity by Day 28. Collectively, our findings support the osteogenic potential of OC-lineage cells in 2D culture conditions, and the potential benefits of surface-seeding for the codelivery of OC-lineage cells and MSCs in osteo-scaffolds for enhanced osteochondral regeneration and broader bone tissue engineering purposes.

N-SREBP2 Provides a Mechanism for Dynamic Control of Cellular Cholesterol Homeostasis.

Cholesterol is required to maintain the functional integrity of cellular membrane systems and signalling pathways, but its supply must be closely and dynamically regulated because excess cholesterol is toxic. Sterol regulatory element-binding protein 2 (SREBP2) and the ER-resident protein HMG-CoA reductase (HMGCR) are key regulators of cholesterol biosynthesis. Here, we assessed the mechanistic aspects of their regulation in hepatic cells. Unexpectedly, we found that the transcriptionally active fragment of SREBP2 (N-SREBP2) was produced constitutively. Moreover, in the absence of an exogenous cholesterol supply, nuclear N-SREBP2 became resistant to proteasome-mediated degradation. This resistance was paired with increased occupancy at the HMGCR promoter and HMGCR expression. Inhibiting nuclear N-SREBP2 degradation did not increase HMGCR RNA levels; this increase required cholesterol depletion. Our findings, combined with previous physiological and biophysical investigations, suggest a new model of SREBP2-mediated regulation of cholesterol biosynthesis in the organ that handles large and rapid fluctuations in the dietary supply of this key lipid. Specifically, in the nucleus, cholesterol and the ubiquitin-proteasome system provide a short-loop system that modulates the rate of cholesterol biosynthesis via regulation of nuclear N-SREBP2 turnover and HMGCR expression. Our findings have important implications for maintaining cellular cholesterol homeostasis and lowering blood cholesterol via the SREBP2-HMGCR axis.

The effect of self-identified arm dominance on exercising forearm hemodynamics and skeletal muscle desaturation.

The human forearm model is commonly employed in physiological investigations exploring local vascular function and oxygen delivery; however, the effect of arm dominance on exercising forearm hemodynamics and skeletal muscle oxygen saturation (SmO2) in untrained individuals is poorly understood. Therefore, the purpose of this study was to explore the effect of self-identified arm dominance on forearm hemodynamics and SmO2 in untrained individuals during submaximal, non-ischemic forearm exercise. Twenty healthy individuals (23±4 years, 50% female; 80% right-handed) completed three-minute bouts of supine rhythmic (1 second contraction: 2 second relaxation duty cycle) forearm handgrip exercise at both absolute (10kg; 98N) and relative (30% of maximal voluntary contraction) intensities in each forearm. Beat-by-beat measures of forearm blood flow (FBF; ml/min), mean arterial blood pressure (MAP; mmHg) and flexor digitorum superficialis SmO2 (%) were obtained throughout and averaged during the final 30 seconds of rest, exercise, and recovery while forearm vascular conductance was calculated (FVC; ml/min/100mmHg). Data are Δ from rest (mean±SD). Absolute force production did not differ between non-dominant and dominant arms (97±11 vs. 98±13 N, p = 0.606) whereas relative force production in females did (69±24 vs. 82±25 N, p = 0.001). At both exercise intensities, FBFRELAX, FVCRELAX, MAPRELAX, and the time constant tau for FBF and SmO2 were unaffected by arm dominance (all p>0.05). While arm dominance did not influence SmO2 during absolute intensity exercise (p = 0.506), the non-dominant arm in females experienced an attenuated reduction in SmO2 during relative intensity exercise (-14±10 vs. -19±8%, p = 0.026)-though exercise intensity was also reduced (p = 0.001). The present investigation has demonstrated that arm dominance in untrained individuals does not impact forearm hemodynamics or SmO2 during handgrip exercise.

The Use of Photo-Biological Parameters to Assess the Establishment Success of Posidonia oceanica Cuttings after Transplantation

Seagrass meadows are increasingly threatened by anthropogenic activities and climate change, necessitating restoration efforts such as cutting transplantation. Understanding the complex interactions between plant morphology and physiology is crucial for designing robust restoration strategies and assessing the success of transplantation and recovery processes. A pilot transplantation experiment with the Mediterranean seagrass Posidonia oceanica (L.) Delile was conducted in Northwestern Corsica (Calvi, France) to evaluate the feasibility of meadows degraded due to boat anchoring. The effects of the cuttings’ origin and transplanting depth were investigated. The establishment success of transplanted fragments was assessed by investigating the photo-physiological parameters, carbohydrate content, and biometric parameters of both transplanted and control plants one year after transplantation at depths of 20 and 28 m. After one year, there was a high survival rate (90%) of the transplants, but their leaf surface area and biomass were significantly reduced compared to the control plants. Photosynthetic activity remained consistent between both depths, emphasizing the ability of P. oceanica cuttings to acclimate to a new light environment in a relatively short period of time (<3 months). Furthermore, light-harvesting pigments, photoprotective pigments, and carbohydrate concentration were greater at the deeper sites. This implies that transplantation at greater depths might be more effective. Furthermore, additional research is necessary to enhance our understanding of the relationship between photosynthesis and the overall health of the plant. This study emphasizes the essential integration of morphological and physiological investigations to offer an ecologically meaningful understanding of how marine ecosystems respond to various restoration methods.

Water-saving and water-spending strategy: The physiological, proteomic and metabolomic investigation of wheat response to drought and the following recovery

Drought as water deficit in the soil represents the most commonly occurring and the most variable environmental stress factor worldwide. Plants have evolved various strategies to cope with drought stress in relation to their other needs such as the necessity to supply carbon in plants with a C3 type of photosynthetic assimilation. In the present study, two wheat cultivars, Baletka and Tobak, representing two contrasting water management strategies, were studied at physiological, proteomic and metabolomic levels to provide a complex view on their phenotypic responses to drought treatment and subsequent recovery. Physiological characteristics clearly distinguished Baletka and Tobak and, moreover, in water-saving Baletka, both proteomics and metabolomics analyses revealed significant remodelling of cell wall, changes in endocytosis and cell signalling, and, especially, changes in synthesis of other defence proteins and LTI65kDa protein (also known as RD29B protein) which has been detected in wheat for the first time. LEA1 protein was proposed as a component of drought stress memory in Baletka. An amazing finding was the enhanced accumulation of oxalate oxidase implying enhanced oxalate oxidase activity leading to faster degradation of oxalate with the simultaneous gain of two molecules of CO2 which may represent an alternative source of CO2 for C3 plants exposed to drought stress.