Physiological Effects Research Articles

Corazonin Stimulates Ecdysteroid Synthesis during the Molting Process of the Swimming Crab, Portunus trituberculatus.

The neuropeptide corazonin (Crz) exerts diverse physiological effects in insects, yet its role in crustaceans remains elusive. The abundant expression of Crz receptor (CrzR) in the Y-organs of several crustaceans suggests a potential involvement of Crz in regulating ecdysteroid synthesis. In this study, we examined the effects of PtCrz on ecdysteroid synthesis during the molting period of Portunus trituberculatus through PtCrz treatments and PtCrzR silencing. Our results showed that PtCrz peptide stimulates ecdysteroid levels and the gene expression involved in ecdysteroidogenesis both in vitro and in vivo, whereas dsPtCrzR treatments had opposite effects on ecdysteroid levels and associated gene expression. Thus, our study suggests that PtCrz may modulate ecdysteroid synthesis via Y-organ-expressed PtCrzR. Furthermore, we also discovered the involvement of PtCrz/PtCrzR signaling in regulating PtETH expression. Notably, the inhibitory effect of dsPtCrzR on ecdysteroid synthesis or PtETH expression can be reversed by PtCrz treatment, suggesting the potential existence of multiple receptors for PtCrz. This study provides new insights into the function of crustacean Crz and, for the first time, elucidates the presence of a neuropeptide that can stimulate ecdysteroid synthesis in crustaceans.

Effectiveness of virtual reality training compared to balance-specific training and conventional training on balance and gross motor functions of children with cerebral palsy: A double blinded randomized controlled trial.

The purpose of this study was to compare the clinical efficacy of a virtual reality rehabilitation-based training (VRT) with balance-specific training (BST) and conventional training (CT) on the balance and gross motor functions (GMF) of children with cerebral palsy (CwCP). This study was a double blinded, randomized controlled trial. Participants were recruited from different CP rehabilitation centers and clinics and were then randomly allocated using the block randomization method into three groups: (1) group 1 (VRT using a set of Xbox 360 games that triggered balance), (2) group 2 (BST applying a protocol of 13 exercises to enhance balance in different conditions), and (3) control group 3 (CT using traditional physiotherapy techniques). All groups received 18 sessions over six weeks, three sessions per week, each lasting 60 minutes. Participants were assessed at three timepoints (baseline, post-treatment, and follow-up) using the Pediatric Balance Scale (PBS), the Gross Motor Function Measure (GMFM D & E), the Five Times Sit-To-Stand Test, and upper and lower segments' center of mass (COM) displacement (UCOM and LCOM). A total of 46 CwCP participated in this study. The repeated measures ANOVA revealed a statistically significant difference between groups in the dependent variables, except for the GMFM (D & E) and the PBS (p < 0.05 and partial η2 = 0.473). The post-hoc test showed a statistically significant difference in favor of the VRT group compared to other groups in terms of right UCOM (p < 0.05) with a large effect size of the time*group interaction (partial η2 = 0.87). Moreover, there was a statistically significant effect of time (i.e., baseline to post-treatment and baseline to follow-up) with F (18, 23) = 59.954, p < 0.05, Wilks' lambda = 0.021, partial η2 = 0.979. The findings revealed that VRT was not superior to BST in the rehabilitation of balance and GMF in CwCP aged four to 12 years. However, when compared to CT, better results were reported. Furthermore, it appears that customized programs lead to greater improvements in balance than commercial programs. Future studies are needed to assess the physiological effects of the three types of rehabilitation interventions using more advanced measurement tools, such as functional magnetic resonance imaging, following VRT protocols.

The structural complexity of pyomelanin impacts UV shielding in Pseudomonas species with different lifestyles.

Pyomelanin, a polymeric pigment in Pseudomonas, arises mainly from alterations in tyrosine degradation. The chemical structure of pyomelanin remains elusive due to its heterogeneous nature. Here, we report strain-specific differences in pyomelanin structural features across Pseudomonas using PAO1 and PA14 reference strains carrying mutations in hmgA (a gene involved in pyomelanin synthesis), a melanogenic P. aeruginosa clinical isolate (PAM), and a melanogenic P. extremaustralis (PexM). UV spectra showed dual peaks for PAO1 and PA14 mutants and single peaks for PAM and PexM. FTIR phenol : alcohol ratio changes and complex NMR spectra indicated non-linear polymers. UVC radiation survival increased with pyomelanin addition, correlating with pigment absorption attenuation. P. extremaustralis UVC survival varied with melanin source, with PAO1 pyomelanin being the most protective. These findings delineate structure-based pyomelanin subgroups, having distinct physiological effects.

Physiological effects of using humidifiers in invasive mechanical ventilation: a literature review

Physiological effects of using humidifiers in invasive mechanical ventilation: a literature review

Integrative Analysis of Transcriptomic Profiles and Physiological Responses Provide New Insights into Drought Stress Tolerance in Oil Palm (Elaeis guineensis Jacq.).

Oil palm (Elaeis guineensis Jacq.) is a highly productive crop economically significant for food, cosmetics, and biofuels. Abiotic stresses such as low water availability, salt accumulation, and high temperatures severely impact oil palm growth, physiology, and yield by restricting water flux among soil, plants, and the environment. While drought stress's physiological and biochemical effects on oil palm have been extensively studied, the molecular mechanisms underlying drought stress tolerance remain unclear. Under water deficit conditions, this study investigates two commercial E. guineensis cultivars, IRHO 7001 and IRHO 2501. Water deficit adversely affected the physiology of both cultivars, with IRHO 2501 being more severely impacted. After several days of water deficit, there was a 40% reduction in photosynthetic rate (A) for IRHO 7001 and a 58% decrease in IRHO 2501. Further into the drought conditions, there was a 75% reduction in A for IRHO 7001 and a 91% drop in IRHO 2501. Both cultivars reacted to the drought stress conditions by closing stomata and reducing the transpiration rate. Despite these differences, no significant variations were observed between the cultivars in stomatal conductance, transpiration, or instantaneous leaf-level water use efficiency. This indicates that IRHO 7001 is more tolerant to drought stress than IRHO 2501. A differential gene expression and network analysis was conducted to elucidate the differential responses of the cultivars. The DESeq2 algorithm identified 502 differentially expressed genes (DEGs). The gene coexpression network for IRHO 7001 comprised 274 DEGs and 46 predicted HUB genes, whereas IRHO 2501's network included 249 DEGs and 3 HUB genes. RT-qPCR validation of 15 DEGs confirmed the RNA-Seq data. The transcriptomic profiles and gene coexpression network analysis revealed a set of DEGs and HUB genes associated with regulatory and transcriptional functions. Notably, the zinc finger protein ZAT11 and linoleate 13S-lipoxygenase 2-1 (LOX2.1) were overexpressed in IRHO 2501 but under-expressed in IRHO 7001. Additionally, phytohormone crosstalk was identified as a central component in the response and adaptation of oil palm to drought stress.

Evaluation of the inhalation of lavender oil on physiological and psychological effects: A pilot study

Evaluation of the inhalation of lavender oil on physiological and psychological effects: A pilot study

A newly identified algicidal bacterium of Pseudomonas fragi YB2: Algicidal compounds and effects

Harmful algal bloom (HAB) is an unresolved existing problem worldwide. Here, we reported a novel algicidal bacterium, Pseudomonas fragi YB2, capable of lysing multiple algal species. To Chlorella vulgaris, YB2 exhibited a maximum algicidal rate of 95.02 % at 120 h. The uniqueness of YB2 lies in its ability to self-produce three algicidal compounds: 2-methyl-1, 3-cyclohexanedione (2-MECHD), N-phenyl-2-naphthylamine, and cyclo (Pro-Leu). The algicidal properties of 2-MECHD have not been previously reported. YB2 significantly affected the chloroplast and mitochondrion, thus decreasing in chlorophyll a by 4.74 times for 120 h and succinate dehydrogenase activity by 103 times for 36 h. These physiological damages disrupted reactive oxygen species and Ca2+ homeostasis at the cellular level, increasing cytosolic superoxide dismutase (23 %), catalase (35 %), and Ca2+ influx. Additionally, the disruption of Ca2+ homeostasis rarely reported in algicidal bacteria–algae interaction was observed using the non-invasive micro-test technology. We proposed a putative algicidal mechanism based on the algicidal outcomes and physiological algicidal effects and explored the potential of YB2 through an algicidal simulation test. Overall, this study is the first to report the algicidal bacterium P. fragi and identify a novel algicidal compound, 2-MECHD, providing new insights and a potent microbial resource for the biocontrol of HAB.

Exercise and training in sickle cell disease: Safety, potential benefits, and recommendations.

Sickle cell disease (SCD) is a genetic disorder characterized by complex pathophysiological mechanisms leading to vaso-occlusive crisis, chronic pain, chronic hemolytic anemia, and vascular complications, which require considerations for exercise and physical activity. This review aims to elucidate the safety, potential benefits, and recommendations regarding exercise and training in individuals with SCD. SCD patients are characterized by decreased exercise capacity and tolerance. Acute intense exercise may be accompanied by biological changes (acidosis, increased oxidative stress, and dehydration) that could increase the risk of red blood cell sickling and acute clinical complications. However, recent findings suggest that controlled exercise training is safe and well tolerated by SCD patients and could confer benefits in disease management. Regular endurance exercises of submaximal intensity or exercise interventions incorporating resistance training have been shown to improve cardiorespiratory and muscle function in SCD, which may improve quality of life. Recommendations for exercise prescription in SCD should be based on accurate clinical and functional evaluations, taking into account disease phenotype and cardiorespiratory status at rest and in response to exercise. Exercise programs should include gradual progression, incorporating adequate warm-up, cool-down, and hydration strategies. Exercise training represents promising therapeutic strategy in the management of SCD. It is now time to move through the investigation of long-term biological, physiological, and clinical effects of regular physical activity in SCD patients.

Regimen on Dnaja3 haploinsufficiency mediated sarcopenic obesity with imbalanced mitochondrial homeostasis and lipid metabolism.

Sarcopenic obesity is characterized by excess fat mass and diminished muscular mass/function. DNAJA3, a mitochondrial co-chaperone protein, plays a crucial role in skeletal muscle development. GMI, an immunomodulatory protein, promotes myogenic differentiation through DNAJA3 activation. This study aims to elucidate the physiological effects of muscular Dnaja3 haploinsufficiency on mitochondrial dysfunction and dysregulated lipid metabolism and to assess the efficacy of GMI in rescuing sarcopenic obesity both in vitro and in vivo. We generated mouse strain with Dnaja3 heterozygosity (HSA-Dnaja3f/+) specifically in skeletal muscle. The body weight, body composition, and locomotor activity of WT and HSA-Dnaja3f/+ mice were examined. The isolated skeletal muscles and primary myoblasts from the WT and HSA-Dnaja3f/+ mice, at young or old age, were utilized to study the molecular mechanisms, mitochondrial respiration and ROS level, mitochondrial proteomes, and serological analyses, respectively. To evaluate the therapeutic efficacy of GMI, both short-term and long-term GMI treatment were administrated intraperitoneally to the HSA-Dnaja3f/+ young (4weeks old) or adult (3months old) mice for a duration of either 1 or 6months, respectively. Muscular Dnaja3 heterozygosity resulted in impaired locomotor activity (P<0.05), reduced muscular cross-sectional area (P<0.0001), and up-regulation of lipogenesis (ACC2) and pro-inflammation (STAT3) in skeletal muscles (P<0.05). Primary myoblasts from the HSA-Dnaja3f/+ mice displayed impaired mitochondrial respiration (P<0.01) and imbalanced mitochondrial ROS levels. A systemic proteomic analysis of the purified mitochondria from the primary myoblasts was conducted to show the abnormalities in mitochondrial function and fatty acid metabolism (P<0.0001). At age of 13 to 14months, the HSA-Dnaja3f/+ mice displayed increased body fat mass (P<0.001), reduced fat-free mass (P<0.01), and impaired glucose and insulin tolerance (P<0.01). The short-term GMI treatment improved locomotor activity (P<0.01) and down-regulated the protein levels of STAT3 (P<0.05), ACC2, and mitochondrial respiratory complex III (UQCRC2) (P<0.01) via DNAJA3 activation. The long-term GMI treatment ameliorated fat mass accumulation, glucose intolerance, and systemic inflammation (AST) (P<0.05) in skeletal muscle, while enhancing thermogenesis (UCP1) (P<0.01) in eWAT. GMI treatment promoted myogenesis, enhanced oxygen consumption, and ameliorated STAT3 (P<0.01) through DNAJA3 activation (P<0.05) in vitro. Muscular Dnaja3 haploinsufficiency dysregulates mitochondrial function and lipid metabolism then leads to sarcopenic obesity. GMI emerges as a therapeutic regimen for sarcopenic obesity treatment through DNAJA3 activation.

Effect of various flavors in starter diets on growth, behavior, and blood parameters of Holstein calves

This study investigated the effect of adding various flavors to calf starter concentrates on the performance, behavior, and blood parameters of Holstein dairy calves. The hypothesis was that an optimal flavor enhancer would increase starter intake, improve growth performance, and possibly enable earlier weaning without adverse physiological effects. In Experiment 1, a cafeteria test was conducted with 80 pre-weaned calves to evaluate four synthetic flavor enhancers (salty, sweet, sour, bitter) at levels of 3.3, 6.6, and 9.9 g/kg dry matter (DM)11DM; Dry matter, and a control without a flavor enhancer. Experiment 2 tested higher levels (9.9, 19.8, 29.7 g/kg DM) of the sweet flavor enhancer sodium saccharin in a single cafeteria test with 20 calves. Experiment 3 compared three sweet flavor enhancers (sodium saccharin, stevia, sucralose) at 9.9 g/kg DM in another cafeteria test with 20 calves. After selecting sodium saccharin at 9.9 g/kg DM as the optimal flavor enhancer, Experiment 4 was conducted with 40 calves divided into a treatment group receiving the flavored starter and a control group without flavor. In Experiment 1, sodium saccharin at 9.9 g/kg DM resulted in the highest dry matter intake (DMI)22DMI; Dry matter intake of 347 g/d, significantly higher than the control (173 g/d). Experiment 2 revealed a quadratic effect with DMI peaking at 9.9 g/kg DM sodium saccharin (201.0 g/d) and declining at higher levels. Experiment 3 confirmed that sodium saccharin outperformed other sweet flavor enhancers, increasing DMI to 350 g/d compared to 251 g/d for the control. In Experiment 4, calves fed the starter concentrate with 9.9 g/kg DM sodium saccharin showed significantly higher DMI (1749 g/d), average daily gain (ADG33ADG; Average daily gain; 730 g/d), and feed conversion ratio (FCR;44FCR; feed conversion ratio 2.05) compared to the control group (DMI 1470 g/d, ADG 650 g/d, FCR 2.36). Furthermore, calves in the flavored treatment were weaned earlier (59 days) than the control group (64 days). Behavioral observations showed that the sweet flavor treatment increased the time spent on solid feed intake, rumination, and standing behavior. Calves fed the flavored starter had lower levels of cholesterol, triglycerides, and blood urea nitrogen, suggesting improved nutrient utilization. Overall, the results demonstrated the potential benefits of incorporating sodium saccharin as a sweet flavor enhancer in calf starter concentrates, leading to improved feed intake, growth performance, feed efficiency, final body weight (FBW)55FBW; final body weight, and behavioral patterns during the critical pre-weaning and post-weaning periods.

Effects of ammonia nitrogen stress on the physiological, biochemical, and metabolic levels of the gill tissue of juvenile four-finger threadfin (Eleutheronema tetradactylum)

In this study, the impact of ammonia nitrogen stress on juvenile four-finger threadfin in pond culture was examined. The 96-hour median lethal concentration (LC50-96h) and safe concentration of ammonia nitrogen were assessed in juveniles with a body weight of 7.4 ± 0.6 g using ecotoxicological methods. The study design included a stress group exposed to LC50-96h levels of ammonia nitrogen and a control group without ammonia nitrogen exposure. To examine the physiological, biochemical, and metabolic effects of ammonia nitrogen on gill tissue, gill tissue samples were collected after 12, 24, 48, and 96 h of stress, with a resumption of treatment after 48 h. Compared to the control group, ammonia nitrogen adversely affected juvenile four-finger threadfin, with LC50-96h and safe concentration values of 20.70 mg/L and 2.07 mg/L, respectively. Exposure to ammonia nitrogen resulted in substantial gill damage, including fusion of lamellae, epithelial cell loss, and proliferation of chlorine-secreting cells. This tissue damage persisted even after a 48-h recovery period. Ammonia nitrogen stress triggered an increase in antioxidant enzyme activity (superoxide dismutase, catalase, and glutathione peroxidase) and malondialdehyde levels in gills, indicating oxidative stress from 12 h onwards. Although enzyme activity decreased over time, oxidative stress persisted even after recovery, suggesting an ongoing need for antioxidant defense. Metabolomics analysis showed significant alterations in 423 metabolites under ammonia nitrogen stress. Key metabolites such as L-arginine, taurine, 20-hydroxyarachidonic acid, 11,12-dihydroxy-5Z, 8Z, and 14Z eicosotrienic acid followed an increasing trend; uridine, adenosine, L-glutathione, and thymidine 5′-triphosphate followed a decreasing trend. These changes reflect metabolic adaptations to stress. In enriched metabolic pathways, the main differential pathways are membrane transport, lipid metabolism, and amino acid metabolism. After 48 h, significant differences were observed in 396 metabolites compared to the control group. Notably, L-arginine, choline, and L-histidine increased, while linoleic acid, adenosine, and glutathione decreased. Amino acid and lipid metabolism pathways were key affected pathways. Under ammonia nitrogen stress, juvenile four-finger threadfin increased the synthesis of unsaturated and saturated fatty acids to cope with low temperatures and bolster immune function by consuming spermidine. This adaptation helps to clear peroxides generated during fatty acid synthesis, thereby protecting cells from oxidative damage. This study provides insights for pond aquaculture and breeding of ammonia nitrogen-tolerant fish strains.

Resection of the adipose fin from rainbow trout acutely alters the cerebral transcriptome and respiratory frequency

As many as 100 million salmonid fish are tagged annually by removing the adipose fin, usually for recovery statistics and the fishing industry. In a multi-parametrical approach, we evaluated the response to resection of the adipose fin in rainbow trout Oncorhynchus mykiss over the course of 72 h. Both the concentrations of lactate and the cerebral transcriptomes differed in rainbow trout early after adipose fin clipping compared to the matching intact controls. The number of differentially expressed genes significantly increased, first in the midbrain and later in the forebrain, in fin-clipped compared to intact trout. Several of these genes were predicted to be involved in pain-induced and synaptogenesis-related pathways, suggesting that adipose fin resection may affect the architecture of neuronal networks. In an experimental setup applying swimming tunnels, we tested whether removal of the adipose fin had any consequences on the behavior of fin-clipped versus intact trout exposed to a regularly recurring water flow. Concomitant with increased and prevailing breath frequencies after repeated exposure to water flows, we observed a marked transcriptional response in the forebrain of fin-clipped trout compared with intact unchallenged controls at later time points after the resection. The resulting list of differentially expressed genes was assigned to a broad range of signaling pathways involved in trans-synaptic signaling, neuronal interaction dynamics, and neuroplasticity. Taken together, our findings suggest that resection of the potentially flow-sensory adipose fin alters pathways related to pain perception and likely enhances the physiological response to the current, probably indicating increased physical effort. We also deduce from the transcriptomic data that amputation of the adipose fin leads to reorganization of the high-level integration system in the brain. The short-term effects observed in the present study require further validation to estimate the prevailing stress for the organism. Nevertheless, we propose considering alternative tagging methods for salmonid fish that do not conflict with fish welfare, as the amputation of the adipose fin may have more far-reaching physiological effects than previously assumed.

AlphaFold accelerated discovery of psychotropic agonists targeting the trace amine-associated receptor 1.

Artificial intelligence is revolutionizing protein structure prediction, providing unprecedented opportunities for drug design. To assess the potential impact on ligand discovery, we compared virtual screens using protein structures generated by the AlphaFold machine learning method and traditional homology modeling. More than 16 million compounds were docked to models of the trace amine-associated receptor 1 (TAAR1), a G protein-coupled receptor of unknown structure and target for treating neuropsychiatric disorders. Sets of 30 and 32 highly ranked compounds from the AlphaFold and homology model screens, respectively, were experimentally evaluated. Of these, 25 were TAAR1 agonists with potencies ranging from 12 to 0.03 μM. The AlphaFold screen yielded a more than twofold higher hit rate (60%) than the homology model and discovered the most potent agonists. A TAAR1 agonist with a promising selectivity profile and drug-like properties showed physiological and antipsychotic-like effects in wild-type but not in TAAR1 knockout mice. These results demonstrate that AlphaFold structures can accelerate drug discovery.

Opportunities and challenges for immunosuppression in the context of pig-to-human xenotransplantation

The transplantation of organ(s) across species may alleviate the shortage of available donor kidneys for an ever-growing number of patients on transplant waiting lists. However, this potential remains limited by uncharacterized physiologic and immune effects of xenotransplants in recipients, which Pan etal.1 investigated in the current study.

Imaging Dopamine Modulation in Brain Acute Slices for Cocaine Addiction Study with Near-Infrared Carbon Nanotube Sensors

Drug addiction is a pressing issue in modern American society that demands thorough research into its mechanisms. Cocaine locomotor sensitization is a well-established model for understanding the physiological effects of cocaine abuse. Previous studies have established loss of dopamine D2 autoreceptors in striatal tissue as a consequence of locomotor sensitization, yet how these differences in autoreceptor expression affect dopamine signaling remains unclear. Herein, we utilized non-genetically encoded near-infrared fluorescent nanosensors based on carbon nanotubes to image dopamine modulation in live acute coronal brain slices. By leveraging dopamine D2 receptor agonists along with the dopamine nanosensor, we developed a method to identify changes in density of functional D2 autoreceptors and dopamine signaling aberrations that accompany addiction, at the level of individual dopamine synapses. We apply the method to compare changes in D2 autoreceptor activity in the Nucleus Accumbens core in cocaine sensitized and saline (control) mice after prolonged cocaine exposure (5 days). Our preliminarily data indicates the decrease in the number of D2 autoreceptor in cocaine sensitized mice, consistent with the previous studies, and suggests that it leads to higher level of dopamine signaling. Furthermore, we confirm dopamine signaling changes by application of D2 Agonists (quinpirole) are from loss of individual dopamine release sites rather than changes in the quantity of dopamine released, or changes in dopamine reuptake kinetics. Our study provides a route to understand the changes in neuromodulation that underlie the neurobiology of addiction and other dopamine-centric neurological conditions.

A reciprocal relationship between mitochondria and lipid peroxidation determines the chondrocyte intracellular redox environment

In orthopedic research, many studies have applied vitamin E as a protective antioxidant or used tert-butyl hydroperoxide to induce oxidative injury to chondrocytes. These studies often support the hypothesis that joint pathology causes oxidative stress and increased lipid peroxidation that might be prevented with lipid antioxidants to improve cell survival or function and joint health; however, lipid antioxidant supplementation was ineffective against osteoarthritis in clinical trials and animal data have been equivocal. Moreover, increased circulating vitamin E is associated with increased rates of osteoarthritis. This disconnect between benchtop and clinical results led us to hypothesize that oxidative stress-driven paradigms of chondrocyte redox function do not capture the metabolic and physiologic effects of lipid antioxidants and prooxidants on articular chondrocytes. We used ex vivo and in vivo cartilage models to investigate the effect of lipid antioxidants on healthy, primary, articular chondrocytes and applied immuno-spin trapping techniques to provide a broad indicator of high levels of oxidative stress independent of specific reactive oxygen species. Key findings demonstrate lipid antioxidants were pro-mitochondrial while lipid prooxidants decreased mitochondrial measures. In the absence of injury, radical formation was increased by lipid antioxidants; however, in the presence of injury, radical formation was decreased. In unstressed conditions, this relationship between chondrocyte mitochondria and redox regulation was reproduced in vivo with overexpression of glutathione peroxidase 4. In mice aged 18 months or more, overexpression of glutathione peroxidase 4 significantly decreased the presence of pro-mitochondrial peroxisome proliferation activated receptor gamma and deranged the relationship between mitochondria and the redox environment. This complex interaction suggests strategies targeting articular cartilage may benefit from adopting more nuanced paradigms of articular chondrocyte redox metabolism.

Dynamics of physiological and biochemical effects of heat, drought and combined stress on potato seedlings

BackgroundHeat and drought stresses usually occur together in nature, and both are expected to increase in frequency and intensity as a result of climate change. The synergistic impacts of these compound climate extremes on potatoes are far from the effects of individual stresses. However, the dynamics of the effects of combined heat and drought stresses on potato physiology and biochemistry have yet to be thoroughly assessed. To elucidate this point, we set up a pot experiment using ‘Atlantic’ potato seedlings as test material. A total of six treatments were set up: CK (normal growth conditions: 21 ℃, 0 PEG), A1B1 (31 ℃, 20% PEG), A1B2 (31 ℃, 10% PEG), A1B3 (31 ℃, 0 PEG), A2B1 (21 ℃, 20% PEG), and A2B2 (21 ℃, 10% PEG), and 15 physiological indices were determined with the stress time of 0, 6, 12 and 18 days.ResultsAfter 18 days of stress, the phenotype of potato seedlings was significantly different. Compared with CK, the thickness of potato leaves and palisade tissue increased under heat and drought stress, and the combined stress reduced the photosynthetic efficiency of potato leaves. In all treatments except CK, the chlorophyll content decreased significantly, the antioxidant enzyme activity increased first and then decreased, and the relative conductivity and malondialdehyde content increased significantly. The heat and combined treatment made the content of the osmotic regulator first increase and then decrease, while the treatment of 21 ℃ had no significant change. According to the correlation, principal component and interaction analysis, both heat and drought treatment had significant effects on each index, and the longer the stress time, the greater the effect, and the effect of combined stress was greater than that of single stress. However, after 6 days of stress, the activity of antioxidant enzymes and the content of transparent regulatory substances increased.ConclusionsIn conclusion, potato can cope with heat, drought and combined stress by adjusting leaf tissue structure, antioxidant enzyme activity and osmotic regulatory substances in a short time.Graphical

The Influence of Environmental Conditions and Coinfection by Blood-Feeding Parasites on Red Blood Cell Physiology of an Ectothermic Host.

AbstractVector-borne blood parasites cause myriad sublethal effects and can even be deadly to endotherms, but far less is known about their impacts on ectothermic hosts. Moreover, the pathologies documented in endotherms are generally linked to infection by blood parasites rather than by their vectors. Here, we measured hematocrit, hemoglobin, and relative proportions of immature red blood cells to evaluate the physiological effects of two blood-feeding parasites and coinfection on ectothermic hosts, differentiating among pathological responses, extrinsic factors, and natural variations. We investigated a population of wild eastern hellbender salamanders (Cryptobranchus alleganiensis), which harbor leeches (Placobdella appalachiensis) that transmit blood parasites (Trypanosoma spp.) to their hosts, often resulting in coinfection. We observed seasonal changes in host hematology corresponding to water temperature and demonstrated their ability to modulate hematological parameters in response to acute stress. We reveal seasonal relationships between parasite dynamics and host physiology, in which peak parasitemia occurred when hosts had seasonally high hematocrit and hemoglobin concentrations. We found that coinfected individuals expressed symptoms of anemia, including a regenerative response to depletion of their red blood cells. We also documented a more pronounced pathological response to leech vectors than to the trypanosomes they transmit. Our research underscores the complex interactions between host physiology, multiple parasites, and environmental factors and highlights the pathologies associated with the vector in coinfections. Given the contributions of climate change and disease in the rapid global decline of ectotherms such as amphibians, our study provides timely foundational insights into multiple factors that influence their red blood cell physiology.

Experimental evidence that activewear retail imagery elicits physiological, attentional and self-reported markers of body image threat in women

Online apparel retail imagery is a prominent threat to women’s body image, particularly segments such as activewear which emphasize the value of women’s bodies. In a within-subjects experiment, we exposed women (N = 128) to imagery randomly selected from activewear, casualwear and homewares websites and measured their gaze behavior, physiological arousal, as well as subjective emotional states and body image ratings. Exposure to activewear retail imagery elicited significantly lower body image ratings, a higher negative emotional state, and a lower positive emotional state compared to the other website imagery conditions. Physiological arousal was significantly higher for both apparel imagery conditions compared to the homewares imagery condition. Body biased gaze behavior was significantly higher for the activewear imagery condition compared to the casualwear imagery condition. Notably, body shame moderated the self-reported but not the physiological experimental effects, such that women with higher body shame experienced stronger adverse changes in their body image and emotional state ratings following activewear exposure. Correlations revealed that self-reported experimental responses to activewear imagery were strongly associated with self-objectification, appearance comparison, disordered eating and body image coping attitudes. Thus, exposure to popular apparel may play a role in maintaining maladaptive body image attitudes and behaviors in women.

Field validation of 4,8‐dihydroxy‐1‐tetrahydronaphthone phytotoxicity on forestland weeds and physiological mechanism analysis on Lindernia procumbens

Abstract4,8‐Dihydroxy‐1‐tetrahydronaphthone (4,8‐DHT), an allelochemical, was isolated from the Carya cathayensis epicarp and was discovered to have phytotoxicity in laboratory tests. In this study, field experiments were designed to assess the phytotoxicity of 4,8‐DHT on weeds in Cerasus yedoensis and Lagerstroemia indica forestlands after pre‐ and post‐emergence application, in addition to physiological effect on Lindernia procumbens were also measured. The phytotoxic results of 4,8‐DHT demonstrated that the total inhibition rate of weeds was 81.3% and 68.2% in C. yedoensis forestland and L. indica forestland after pre‐emergence applied for 24 days in 2021, and enhanced by 9.9% and 27.8% compared with post‐emergence treatment. Especially, in C. yedoensis forestland, a high concentration of 4,8‐DHT sprayed at the pre‐emergence stage after 8 days had a significant inhibition rate on all weeds except Cyperus rotundus, and was still above 80.0% after 24 days of exposure. Comprehensive control efficacy of 4,8‐DHT indicates that pre‐emergence application is more favorable for weeds control. Physiological analysis showed that 4,8‐DHT stimulated the contents of thiobarbituric acid reactive substances (TBARS), hydrogen peroxide (H2O2), and proline and declined in the activities of antioxidant enzymes, meanwhile, accompanied by a decrease in the root vitality and chlorophyll content in L. procumbens. These results warrant further investigations of 4,8‐DHT applied in early pre‐emergence as a potential source of weed control agent.