Physiological Mechanisms Research Articles

Isometric Exercise for Blood Pressure and Endothelial Function in Metabolic Syndrome: A Review

Context: Metabolic syndrome (MetS) is characterized by a cluster of metabolic disorders, including hypertension, insulin resistance, and dyslipidemia, which collectively heighten the risk of cardiovascular diseases (CVDs). The global prevalence of MetS is steadily increasing, paralleling the rise in obesity and sedentary lifestyles. Pharmacological treatments for MetS often face challenges such as inadequate blood pressure (BP) control and limited improvements in cardiovascular outcomes. Consequently, there is a growing emphasis on non-pharmacological interventions, particularly exercise. Among various exercise modalities, isometric resistance training (IRT), which involves static muscle contractions without joint movement, has emerged as a promising strategy for effectively lowering BP and enhancing endothelial function, both of which are critical for cardiovascular health. Evidence Acquisition: This comprehensive literature review synthesizes existing research on the effects of isometric exercise on BP regulation and endothelial function in individuals diagnosed with MetS. The review examines studies sourced from databases such as PubMed, Scopus, and Web of Science, focusing on randomized controlled trials, meta-analyses, and observational studies published in peer-reviewed journals. Key discussion areas include the underlying physiological mechanisms of IRT, comparisons with other exercise modalities, clinical implications, and recommendations for future research. Articles were selected based on qualitative and descriptive reviews. Results: Evidence indicates that isometric resistance training effectively reduces both systolic and diastolic BP, achieving results comparable to other exercise forms like aerobic and dynamic resistance training. Furthermore, IRT has significantly improved endothelial function, particularly among populations with MetS. These physiological benefits are attributed to mechanisms such as enhanced nitric oxide bioavailability, reduced oxidative stress, and improved autonomic regulation. Conclusions: The review supports the integration of isometric exercise into hypertension management protocols, especially for individuals with MetS. Isometric resistance training offers a viable non-pharmacological alternative or adjunct to traditional treatments, with the added advantages of accessibility and adaptability for diverse populations. However, further research is necessary to optimize exercise protocols, determine long-term outcomes, and fully elucidate the molecular mechanisms underlying the cardiovascular benefits of IRT.

Physiological Evaluation of Salt Tolerance in Sunflower Seedlings Across Different Genotypes

Sunflower (Helianthus annuus L.) is an important oilseed crop cultivated extensively across the globe. High salinity adversely impacts plant growth and physiological processes. In this study, the data on the phenotypes, physiological indices, and expression of relevant genes from different pathways responding to the stress were collected to clarify the physiological mechanisms underlying sunflower’s salt tolerance with the seedlings of two salt-tolerant (182265 and 182283) and two salt-sensitive (182093 and 186096) genotypes, which were exposed to 350 mM NaCl for 5 days. The findings revealed that, during the seedling stage, salt-tolerant sunflowers accumulated less Na+ and more K+, resulting in a higher K+/Na+ ratio that mitigated ionic toxicity throughout the plants, compared to the salt-sensitive resources. Furthermore, the salt-tolerant germplasms also exerted salt tolerance through the following several pathways: they maintained robust osmotic regulation by accumulating higher levels of proline, soluble sugars, and other osmolytes; they neutralized reactive oxygen species (ROS) by elevating the activity of antioxidant enzymes such as POD, SOD, CAT, APX, and GR; and they sustained optimal growth by boosting photosynthesis. Taken together, this study provided a more comprehensive assessment of the sunflower’s physiological salt tolerance, providing insights that will inform further molecular studies on salt tolerance and accelerating the breeding process for sunflower varieties with improved salt resilience.

Remote Sensing Technologies Quantify the Contribution of Ambient Air Pollution to Asthma Severity and Risk Factors in Greenness, Air Pollution, and Wildfire Ecological Settings: A Literature Review

Numerous epidemiologic studies have used remote sensing to quantify the contribution of greenness, air pollution, and wildfire smoke to asthma and other respiration outcomes. This is the first review paper to evaluate the influence of remote sensing exposures on specific outcome severity and risk factors in different ecological settings. Literature searches utilizing PubMed and Google Scholar identified 61 unique studies published between 2009 and 2023, with 198 specific outcomes. Respiration-specific outcomes were lower in greenness and higher in air pollution and wildfire ecological settings. Aerosol optical depth (AOD)-PM2.5 readings and specific outcomes were higher in economically developing than in economically developed countries. Prospective studies found prenatal and infant exposure to higher ambient AOD-PM2.5 concentration level readings contributed to higher childhood asthma incidence. Lung function was higher in greenness and lower in the other two ecological settings. Age, environment, gender, other, and total risk factors showed significant differences between health outcomes and ecological settings. Published studies utilized physiologic mechanisms of immune, inflammation, and oxidative stress to describe obtained results. Individual and total physiologic mechanisms differed between ecological settings. Study results were used to develop a descriptive physiologic asthma model and propose updated population-based asthma intervention program guidelines.

Regional dynamic cerebral autoregulation across anterior and posterior circulatory territories: A detailed exploration and its clinical implications.

Cerebral autoregulation (CA) is the mechanism that maintains stable cerebral blood flow (CBF) despite fluctuations in systemic blood pressure, crucial for brain homeostasis. Recent evidence highlights distinct regional variations in CA between the anterior (carotid) and posterior (vertebrobasilar) circulations. Non-invasive neuromonitoring techniques, such as transcranial Doppler, transfer function analysis, and near-infrared spectroscopy, facilitate the dynamic assessment of CBF and autoregulation. Studies indicate a robust autoregulatory capacity in the anterior circulation, characterized by rapid adjustments in vascular resistance. On the contrary, the posterior circulation, mainly supplied by the vertebral arteries, may have a lower autoregulatory capacity. in acute brain injuries such as intracerebral and subarachnoid hemorrhage, and traumatic brain injuries, dynamic CA can be significantly altered in the posterior circulation. Proposed physiological mechanisms of impaired CA in the posterior circulation include: (1) Decreased sympathetic innervation of the vasculature impairing compensatory vasoreactivity; (2) Endothelial dysfunction; (3) Increased cerebral metabolic rate of oxygen consumption within the visual cortex causing CBF-metabolism (i.e., neurovascular) uncoupling; and (4) Impaired blood-brain barrier integrity leading to impaired astrocytic mediated release of vasoactive substances (e.g. nitric oxide, potassium, and calcium ions). Furthermore, more research is needed on the effects of collateral circulation, as well as the circle of Willis variants, such as the fetal-type posterior cerebral artery, on dynamic CA. Improving our understanding of these mechanisms is crucial to improving the diagnosis, prognosis, and management of various cerebrovascular disorders.

Breath of Life: The Therapeutic Role of Pranayama in Enhancing Respiratory Health and Quality of Life in Cancer Care

This review systematically examines the therapeutic potential of Pranayama - controlled breathing techniques - in enhancing respiratory health and overall quality of life for cancer patients. The article provides a detailed analysis of key Pranayama practices, including Deep Breathing, Nadi Shodhana, Kapalabhati, and Bhramari, focusing on their physiological mechanisms and clinical impacts. Evidence suggests that these practices significantly improve pulmonary function, enhance oxygen saturation, and alleviate symptoms such as breathlessness - crucial factors in managing the respiratory challenges associated with cancer treatment. Furthermore, Pranayama has demonstrated efficacy in reducing psychological distress, including anxiety, depression, and stress, thereby improving emotional resilience and mental clarity in cancer patients. The review highlights the integration of Pranayama into oncology care, proposing practical, evidence-based guidelines for its safe and effective application. It also identifies critical research gaps, including the need for studies on personalized Pranayama protocols, the long-term effects on cancer survivorship, and the utilization of digital health technologies to enhance accessibility. By bridging traditional yogic practices with contemporary cancer care, Pranayama is presented as a complementary, holistic intervention that supports both physical recovery and emotional well-being, contributing to a higher quality of life for cancer patients.

Obesity as the main factor of metabolic syndrome influencing on respiratory function

In the review, a generalized analysis of current scientific data explaining the physiological mechanisms of the influence of obesity on respiratory system is carried out. The multifactorial nature of the respiratory effect of obesity, including mechanical and inflammatory effects, is emphasized. The consequences of restrictive and obstructive changes in the biomechanics of respiration, changes in the topographic distribution of lung ventilation, mismatch of ventilation and perfusion, and a decrease in the efficiency of the respiratory muscles are considered. Elucidation of the central mechanisms of the respiratory action of proinflammatory mediators expressed by adipose tissue cells is recognized as a promising area of research. Special attention is paid to the action of leptin, which is the main regulator of metabolism and respiratory control in obesity. Its ability to modulate the central respiratory chemosensitive is discussed. It is assumed that an increase in pulmonary ventilation due to an increase in leptin production in obesity has a compensatory character and allows obese patients to maintain normocapnia despite an increase in mechanical load on respiration system. Whereas leptin resistance and suppressed hypercapnic ventilation response play a key role in the development of obesity–hypoventilation syndrome. It is concluded that it is necessary to further study the physiological mechanisms of the influence of obesity on the respiratory function in order to find new effective therapeutic methods for the treatment of diseases associated with obesity, which is the main factor in the development of metabolic syndrome.

Diffusion‐Based Causality‐Preserving Neural Network for Dementia Recognition

ABSTRACTAnalyzing large‐scale functional brain networks for brain disorders often relies on undirected correlations in activation signals between brain regions. While focusing on co‐occurring activations, this approach overlooks the potential for directionality inherent in brain connectivity. Established research indicates the causal nature of brain networks, suggesting that activation patterns co‐occur and potentially influence one another. To this end, we propose a novel dffusion vector auto‐regressive (Diff‐VAR) method, enabling the assessment of whole‐brain effective connectivity (EC) as a directed and weighted network by integrating the search objectives into the deep neural network model as learnable parameters. The EC learned by our method identifies widespread differences in flow of influence within the brain network for individuals with impaired brain function compared to those with normal brain function. Moreover, we introduce an adaptive smoothing mechanism to enhance the stability and reliability of inferred EC. We evaluated the results of our proposed method on the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. The model's performance is compared with existing correlation‐based and causality‐based methods. The results revealed that the brain networks constructed by our method achieve high classification accuracy and exhibit features consistent with physiological mechanisms. The code is available at https://github.com/SaqibMamoon/Diff‐VAR.

Drastic mycorrhizal community shifts in Sceptridium ferns during the generation transition from fully mycoheterotrophic gametophytes to photosynthetic sporophytes.

Many plant species experience a prolonged subterranean phase during which they rely entirely on mycorrhizal fungi for carbon. While this mycoheterotrophic strategy spans liverworts, lycophytes, and ferns, most empirical research has centered on angiosperms. This study explores the fungal associations of Sceptridium (Ophioglossaceae), an early-diverging fern with mycoheterotrophic gametophytes. We analyzed germination patterns and fungal associations in Sceptridium gametophytes, comparing them to the distribution and mycorrhizal partners of photosynthetic sporophytes. High-throughput sequencing data reveal that mycoheterotrophic gametophytes consistently associate with a single Entrophospora fungus in the order Entrophosporales (Glomeromycotina), while photosynthetic sporophytes primarily partner with fungi from Glomeraceae (Glomerales, Glomeromycotina). Consequently, gametophytes exhibit spatial clustering without association with adult plants. This is the first documentation of an association between Entrophosporaceae (and the order Entrophosporales) and mycoheterotrophic plants. The drastic shifts in Sceptridium mycorrhizal communities across life stages likely reflect changing physiological needs during development. Further research is essential to determine whether the association with Entrophosporaceae is widespread among mycoheterotrophic species and to elucidate the functional and physiological mechanisms underlying these mycorrhizal shifts.

Potential physiological tolerance mechanisms in faba bean to Orobanche spp. parasitism

Orobanche spp. are root parasitic plants that cause severe yield losses in faba bean (Vicia faba L.). The use of tolerant varieties remains a pivotal component of a successful integrated control strategy. In this study, we investigated the potential physiological mechanisms associated with tolerance to O. crenata and O. foetida in faba bean. The results showed that Orobanche parasitism significantly affected faba bean plants’ growth and seed production, especially in the sensitive Bachaar variety (up to 61.77% and 83.53% in shoot dry weight, up to 79.59% in pod number and no pod development when infected with O. foetida and O. crenata, respectively). This reduction was correlated with photosynthetic capacity (Amax) decreases in response to both O. foetida and O. crenata parasitism. This decrease was highly pronounced in the sensitive Bachaar variety with 24.57% and 63.43% decreases, respectively. Significant decreases were also observed in the sensitive Bachaar cultivar for the photochemical efficiency of PSII (Fv/Fm) (1.1% and 4.78%), the maximum transpiration (Emax) (11.8% and 39.13%), and the maximum water use efficiency (WUEmax) (24.97% and 41.77%) in response to O. foetida and O. crenata parasitism, respectively, compared to non-significant differences for the tolerant Chams, Chourouk, and Zaher varieties. The tolerant faba bean varieties were able to maintain a normal function of their photosynthesis capacity (An) and conserve their growth and seed production level as a result of an acclimation to parasitic attack (Maintaining WUEmax). Our results suggest that yield components such as shoot dry weight, pod and leaf numbers, and photosynthetic parameters, notably the transpiration rate, can serve as suitable traits for assessing tolerance to Orobanche parasitism in faba bean plants.

MicroRNA and Hypertension.

Several microRNAs (miRNAs) strongly influence blood pressure and the development of hypertension by modulating vascular, renal, and other physiological mechanisms. In addition, miRNAs may contribute to the genetic regulation of blood pressure. Future research should focus on investigating select miRNAs with potent physiological effects, understanding cellular context-dependent mechanisms conferring specificity to miRNA action, and integrating miRNAs as powerful modulators into the molecular system that underlies the regulation of blood pressure and the development of hypertension.

Response of soybean root exudates and related metabolic pathways to low phosphorus stress.

Phosphorus (P) is an essential elemental nutrient required in high abundance for robust soybean growth and development. Low P stress negatively impacts plant physiological and biochemical processes, such as photosynthesis, respiration, and energy transfer. Soybean roots play key roles in plant adaptive responses to P stress and other soil-related environmental stressors. Study the changes in soybean root exudates and differences in related metabolic pathways under low phosphorus stress, analyzing the response mechanism of soybean roots to phosphorus stress from the perspective of root exudates, which provide a theoretical basis for further analyzing the physiological mechanism of phosphorus stress on soybean. In this study, soybean roots were exposed to three phosphate levels: 1 mg/L (P stress), 11 mg/L (P stress) and 31 mg/L (Normal P) for 10 days and 20 days, then root exudates were analyzed via ultra-high-performance liquid chromatography-mass spectrometry to identify effects of P stress on root metabolite profiles and associated metabolic pathways. Our results revealed that with increasing P stress severity and/or duration, soybean roots produced altered types, quantities, and increased numbers of exudate metabolites (DMs in the P1 group were primarily upregulated, whereas those in the P11 group were predominately downregulated) caused by changes in regulation of activities of numerous metabolic pathways. These pathways had functions related to environmental adaptation, energy metabolism, and scavenging of reactive oxygen species and primarily included amino acid, flavonoid, and nicotinate and nicotinamide metabolic pathways and pathways related to isoquinoline alkaloid biosynthesis, sugar catabolism, and phospholipid metabolism. These metabolites and metabolic pathways lay a foundation to support further investigations of physiological mechanisms underlying the soybean root response to P deficiency.

Seed Priming: Molecular and Physiological Mechanisms Underlying Biotic and Abiotic Stress Tolerance

Seed Priming: Molecular and Physiological Mechanisms Underlying Biotic and Abiotic Stress Tolerance

Brain physiology during photoperiod-related caste determination in the primitively eusocial wasp Polistes jokahamae

Adult females of the primitively eusocial wasp Polistes jokahamae can change caste in response to photoperiod length. Short-day photoperiod females store more lipids but have less developed ovaries for hibernation (becoming gynes), whereas long-day photoperiod females have fewer lipid stores but more developed ovaries under queenless conditions (becoming egg-laying workers). To explore the physiological mechanisms underlying photoperiod-related caste determination, analyses of gene expression levels in the brains of short- or long-day females were performed. Results suggest that short-day females may exhibit higher expression of genes involved in tryptophan metabolism, insulin signaling, and nutrition, including the digestion of sugars and lipids, and production of royal jelly proteins. Oral administration of tryptophan resulted in a positive correlation between tryptophan levels in the brain and lipid stores in the abdomen, suggesting that tryptophan promotes lipid storage in gynes. Long-day females showed enhanced expression of genes involved in tyramine/dopamine syntheses, epidermal growth factor receptor, insulin degradation, and oogenesis. In these females, tyramine administration increased the brain levels of tyramine and dopamine, and activated initial ovarian development under queenless conditions. Together, these results indicate that photoperiod-related caste determination in P. jokahamae may involve gene expression pathways similar to those involved in caste determination during the preimaginal stage in other Polistes species.

Loss of Sult1a1 reduces body weight and increases browning of white adipose tissue

Background and objectiveOverweight and obesity affects millions of individuals worldwide and consequently represents a major public health concern. Individuals living with overweight and obesity have difficulty maintaining a low body weight due to known physiological mechanisms which prevent further weight loss and drive weight regain. In contrast, mechanisms which promote low body weight maintenance receive less attention and are largely unknown. To uncover these intrinsic mechanisms, we investigated a human cohort of constitutionally thin (CT) individuals which maintain a low body weight and are resistant to weight gain despite exposure to an obesogenic environment.MethodsTo identify novel genes that contribute to low body weight maintenance, we performed transcriptomics on adipose tissue biopsies collected from CT and normal body weight (NBW) individuals and identified sulfotransferase 1A1 (SULT1A1) as a target for further investigation in mice. Sult1a1 knockout (KO) mice were fed a standard diet to assess the impact of Sult1a1 deletion on metabolic traits. To determine if high-fat feeding recapitulated the CT weight gain resistance phenotype, Sult1a1 KO mice were fed a high-fat diet for 13-weeks. A subset of wild-type and Sult1a1 KO mice from the standard diet were further analyzed for characterization of adipose tissue respiratory capacity.ResultsIn comparison to NBW controls, adipose tissue from CT individuals expresses less SULT1A1. Sult1a1 KO mice weigh 10% less at the end of the study period and on a high-fat diet, Sult1a1 KO mice tended to gain less weight and had reduced fat mass at 14-weeks of age. These changes were associated with reduced fasting insulin and lessened adipose tissue inflammation and fibrosis. Subcutaneous adipose tissue from Sult1a1 KO mice on a standard chow diet had elevated leak respiration, uncoupling protein 1 (UCP1) expression and increased expression of a mitochondrial marker, VDAC, associating Sult1a1 deletion to adipose tissue browning.ConclusionsOur results associate Sult1a1 deletion with a tendency for lower body weight through remodeling of white adipose tissue towards a brown phenotype. The presence of UCP1, the expression of an additional mitochondrial protein and increased respiratory capacity suggest browning of the subcutaneous adipose tissue depot of Sult1a1 KO mice.

Effect of Potassium Optimization on Wheat Drought Tolerance in Controlled Conditions

Potassium is an essential nutrient that influences key processes in plants, including osmotic regulation, photosynthesis, and nitrogen assimilation. This study investigated the drought tolerance of wheat (Triticum spp.) plants treated with sufficient potassium (SK, 1 mM) and low potassium (LK, 0.05 mM) under PEG-induced drought stress. Plant physiological development, canopy temperature, photosynthetic efficiency, antioxidant defense enzymes, and nitrogen assimilation enzymes were assessed. In non-drought conditions, LK increased canopy temperature and reduced dry matter yield and photosynthetic performance, with these effects becoming more pronounced under drought stress. SK-treated plants exhibited higher biomass, chlorophyll content, maximum quantum efficiency of photosystem II, and lower canopy temperatures, even under drought conditions. Furthermore, LK restricted the accumulation of key osmotic regulators, including proline, amino acids, and soluble sugars. Under drought stress, LK plants also showed increased hydrogen peroxide and superoxide anion levels, while SK plants had lower reactive oxygen species accumulation and higher antioxidant enzyme activities (catalase and superoxide dismutase). Additionally, LK resulted in reduced activity of nitrogen assimilation enzymes (nitrate reductase, NR, and nitrite reductase, NiR) under both normal and drought conditions. In contrast, SK-treated wheat seedlings maintained higher NR and NiR activities and higher soluble protein content during drought stress. These findings underscore the critical role of potassium management in enhancing wheat yield, particularly in water-scarce regions, as optimal potassium supply strengthens essential physiological and biochemical mechanisms that improve plant tolerance to drought stress.

Polyploidy confers better cold tolerance in Daphnia

Despite decades of studies on the differential distribution of polyploid organisms, the causes of this pattern have yet to be elucidated. This study aimed to explore some of the possible physiological mechanisms explaining the differential northern distribution of polyploid clones of Daphnia pulex compared to the one of the diploid parental species. The critical thermal minimum (CTmin) was measured in 17 D. pulex clones of contrasted ploidy (diploid and triploid) and geographic origins (temperate and subarctic climates) reared under low and high temperatures (16 and 24°C). Triploid clones had better cold tolerance (lower CTmin) than both sympatric and temperate diploid clones. No significant association was found between CTmin and body size nor with cell size. We suggest that triploids might express a cold shock resistant phenotype related to higher gene expression and/or fatty acid profiles. Cold tolerance can be viewed as one of the possible reasons for polyploid preponderance in subarctic climates.

Investigating droplet emission during speech interaction

AbstractConversations (normal speech) or professional interactions (e.g. projected speech in the classroom) have been identified as situations which increase individuals’ risk of exposure to respiratory viruses (including SARS-CoV-2) due to the high production of potentially infectious droplets. The few studies addressing this topic contain several methodological and linguistic limitations. This paper describes and validates an original combination of various methods, aimed at providing a global understanding of the complex physiological mechanisms underlying droplet emission during speech production. Twenty-one French speakers produced pseudowords and sentences under different phonetic conditions (e.g. loud vs normal intensity). In Experiment 1, we measured the airflow volume and airflow velocity exhaled from the mouth during speech. In Experiment 2, we measured the airflow velocity exhaled from different positions in the space around the mouth. In Experiment 3, we measured the number and size of expelled droplets. In all experiments, participants were asked to produce pseudowords and sentences under different phonetic conditions in an interactive setting. To validate our methodology, we tested the impact of voice intensity on the physiological measurements. We found that pseudowords and sentences spoken with loud intensity generated increased airflow volume and velocity compared to those spoken with normal intensity. Additionally, the number of droplets was higher for pseudowords spoken with loud intensity compared to normal intensity. From a methodological point of view, our study went beyond previous research by using multiple measures characterising droplet emission during speech. Furthermore, we applied an innovative experimental design, considering droplet emission in an interactive linguistic setting.

Nutritional Studies Evaluating Ketogenic Diets as a Treatment for Obesity and Obesity-Associated Morbidities: Underlying Mechanisms and Potential for Clinical Implementation

Background: The ketogenic diet (KD), characterized by high-fat content, virtually no carbohydrates, and adequate protein intake, induces a metabolic state resembling fasting, as the absence of carbohydrates forces the body to rely on the energetic supply from hepatically produced ketone bodies using free fatty acids as substrate. While the KD is clinically used in pharmacologically refractory epilepsy and specific genetic conditions such as GLUT1 deficiency, recent research suggests that, due to its “fasting mimicking” properties, the KD may also beneficially affect obesity and obesity-associated metabolic diseases. Results: Here, we present a narrative review discussing completed and ongoing nutritional studies in human volunteers specifically addressing the potential of the ketogenic diet as an anti-obesity approach and, from a larger perspective, as an intervention to ameliorate the metabolic state in conditions such as type 1 and 2 diabetes and polycystic ovary syndrome (PCOS). Published studies as well as ongoing clinical trials will be discussed. Efficacy and safety considerations will be discussed, as well as the potential physiological mechanisms mediating the effects of the KD in humans in the context of the (i) energy balance model (EBM) and (ii) carbohydrate–insulin model (CIM) of body weight control. Conclusion: Ketogenic diets may be beneficial to attenuate obesity and improve obesity-related metabolic disease, and here, we try, based on current evidence, to define the boundaries of the KD’s nutritional and clinical usefulness.

The Link between Loneliness, Social Isolation, and Cardiovascular Disease

Introduction: Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Loneliness, a subjective feeling of social isolation, and social isolation, an objective lack of social connections, contribute to social vulnerability and physical frailty. Psychological factors and social support play important roles in CVD, affecting health behaviors and physiological mechanisms. This review aims to provide an understanding of how loneliness and social isolation impact CVD. Methods: A literature review was conducted to identify relevant studies investigating the association between loneliness, social isolation, and cardiovascular disease. Results: The findings indicate that social isolation and loneliness are significant risk factors for CVD, independent of other risk factors. The prevalence of loneliness has increased in modern society, affecting individuals of all ages. Loneliness and social isolation influence physiological processes such as activating the HPA axis, causing inflammation and alterations in immune function, and activating the sympathetic nervous system. These effects contribute to an increased risk of CVD, including elevated blood pressure, hypertension, atherosclerosis, and potential cardiac autonomic dysregulation. Conclusion: Loneliness and social isolation pose significant risks for cardiovascular disease (CVD), influencing physiological processes such as inflammation, immune function, and sympathetic nervous system activation. Understanding these relationships is crucial for developing effective strategies to prevent and manage CVD, emphasizing the importance of interventions targeting both psychological and physiological aspects of social well-being. Keywords: Loneliness, Social Isolation, Cardiovascular Disease

Adaptations of Rice Seed Germination to Drought and Hypoxic Conditions: Molecular and Physiological Insights

Seed germination is crucial for plant survival, crop stand establishment, and achieving optimal grain yield. The main objective of this review is to explore the physiological and molecular mechanisms governing rice seed germination under aerobic (water stress) and anaerobic (hypoxic) conditions in direct-seeded rice (DSR) systems. Moreover, it discusses the recent genomic advancements and innovations to improve rice seed germination. Here, we discuss how coleoptile and mesocotyl elongation plays a vital role in anaerobic germination (AG) and the function of raised antioxidants, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in maintaining Reactive Oxygen Species (ROS), and malondialdehyde (MDA) homeostasis for stabilizing seed germination in water-scarce conditions. This study comprehensively highlights the functions and dynamics of phytohormones—GA (gibberellic acid) and ABA (abscisic acid)—key regulatory genes, transcription factors (TFs), key proteins, and regulatory metabolic pathways, including glycolysis, the pentose phosphate pathway (PPP), and the tricarboxylic acid cycle (TCA), in regulating seed germination under both conditions. Conventional agronomic and cultural practices, such as seed selection, seed priming, seed coating, and hardening, have proven to improve seed germination. Moreover, the utilization of molecular and novel approaches—such as clustered regularly interspaced short palindromic repeat (CRISPR-Cas9) mediated genome editing, marker-assisted selection (MAS), genome-wide associations studies (GWAS), single nucleotide polymorphisms (SNPs), multi-omics, RNA sequencing—combined with beneficial quantitative trait loci (QTLs) has expanded knowledge of crop genomics and inheritance. These advancements aid the development of specific traits for enhancing seed germination in DSR.