Leaf ecological stoichiometry and anatomical structural adaptation mechanisms of Quercus sect. Heterobalanus in southeastern Qinghai-Tibet Plateau.

BACKGROUND: With the dramatic uplift of the Qinghai-Tibet Plateau (QTP) and the increase in altitude in the Pliocene, the environment became dry and cold, thermophilous plants that originally inhabited ancient subtropical forest essentially disappeared. However, Quercus sect. Heterobalanus (QSH) have gradually become dominant or constructive species distributed on harsh sites in the Hengduan Mountains range in southeastern QTP, Southwest China. Ecological stoichiometry reveals the survival strategies plants adopt to adapt to changing environment by quantifying the proportions and relationships of elements in plants. Simultaneously, as the most sensitive organs of plants to their environment, the structure of leaves reflects of the long-term adaptability of plants to their surrounding environments. Therefore, ecological adaptation mechanisms related to ecological stoichiometry and leaf anatomical structure of QSH were explored. In this study, stoichiometric characteristics were determined by measuring leaf carbon (C), nitrogen (N), and phosphorus (P) contents, and morphological adaptations were determined by examining leaf anatomical traits with microscopy. RESULTS: Different QSH life forms and species had different nutrient allocation strategies. Leaves of QSH plants had higher C and P and lower N contents and higher N and lower P utilization efficiencies. According to an N: P ratio threshold, the growth of QSH species was limited by N, except that of Q. aquifolioides and Q. longispica, which was limited by both N and P. Although stoichiometric homeostasis of C, N, and P and C: N, C: P, and N: P ratios differed slightly across life forms and species, the overall degree of homeostasis was strong, with strictly homeostatic, homeostatic, and weakly homeostatic regulation. In addition, QSH leaves had compound epidermis, thick cuticle, developed palisade tissue and spongy tissue. However, leaves were relatively thin overall, possibly due to leaf leathering and lignification, which is strategy to resist stress from UV radiation, drought, and frost. Furthermore, contents of C, N, and P and stoichiometric ratios were significantly correlated with leaf anatomical traits. CONCLUSIONS: QSH adapt to the plateau environment by adjusting the content and utilization efficiencies of C, N, and P elements. Strong stoichiometric homeostasis of QSH was likely a strategy to mitigate nutrient limitation. The unique leaf structure of the compound epidermis, thick cuticle, well-developed palisade tissue and spongy tissue is another adaptive mechanism for QSH to survive in the plateau environment. The anatomical adaptations and nutrient utilization strategies of QSH may have coevolved during long-term succession over millions of years.

CsREV-CsTCP4-CsVND7 module shapes xylem patterns differentially between stem and leaf to enhance tea plant tolerance to drought.

Cultivating drought-tolerant tea varieties enhances both yield and quality of tea plants in northern China. However, the mechanisms underlying their drought tolerance remain largely unknown. Here we identified a key regulator called CsREV, which differentially regulates xylem patterns between leaves and stems, thereby conferring drought tolerance in tea plants. When drought occurs, upregulation of CsREV activates the CsVND7a-dependent xylem vessel differentiation. However, when drought persists, the vessel differentiation is hindered as CsVND7a is downregulated by CsTCP4a. This, combined with the CsREV-promoted secondary-cell-wall thickness of xylem vessel, leads to the enhanced curling of leaves, a characteristic closely associated with plant drought tolerance. Notably, this inhibitory effect of CsTCP4a on CsVND7a expression is absent in stems, allowing stem xylem vessels to continuously differentiate. Overall, the CsREV-CsTCP4-CsVND7 module is differentially utilized to shape the xylem patterns in leaves and stems, potentially balancing water transportation and utilization to improve tea plant drought tolerance.

Anti-Neuroinflammatory Effects of Adaptogens: A Mini-Review.

Introduction: Adaptogens are a group of plants that exhibit complex, nonspecific effects on the human body, increasing its ability to adapt, develop resilience, and survive in stress conditions. They are found in many traditional medicinal systems and play a key role in restoring the body's strength and stamina. Research in recent years has attempted to elucidate the mechanisms behind their pharmacological effects, but it appears that these effects are difficult to define precisely and involve multiple molecular pathways. Neuroinflammation: In recent years, chronic inflammation has been recognized as one of the common features of many central nervous system disorders (dementia and other neurodegenerative diseases, depression, anxiety, ischemic stroke, and infections). Because of the specific nature of the brain, this process is called neuroinflammation, and its suppression can result in an improvement of patients' condition and may promote their recovery. Adaptogens as anti-inflammatory agents: As has been discovered, adaptogens display anti-inflammatory effects, which suggests that their application may be broader than previously thought. They regulate gene expression of anti- and proinflammatory cytokines (prostaglandins, leukotriens) and can modulate signaling pathways (e.g., NF-κB). Aim: This mini-review aims to present the anti-neuroinflammatory potential of the most important plants classified as adaptogens: Schisandra chinensis, Eleutherococcus senticosus, Rhodiola rosea and Withania somnifera.

Sequential maturation of stimulus-specific adaptation in the mouse lemniscal auditory system.

Stimulus-specific adaptation (SSA), the reduction of neural activity to a common stimulus that does not generalize to other, rare stimuli, is an essential property of our brain. Although well characterized in adults, it is still unknown how it develops during adolescence and what neuronal circuits are involved. Using in vivo electrophysiology and optogenetics in the lemniscal pathway of the mouse auditory system, we observed SSA to be stable from postnatal day 20 (P20) in the inferior colliculus, to develop until P30 in the auditory thalamus and even later in the primary auditory cortex (A1). We found this maturation process to be experience-dependent in A1 but not in thalamus and to be related to alterations in deep but not input layers of A1. We also identified corticothalamic projections to be implicated in thalamic SSA development. Together, our results reveal different circuits underlying the sequential SSA maturation and provide a unique perspective to understand predictive coding and surprise across sensory systems.

Transgenerational plasticity in morphological characteristics and biomass of the invasive plant Xanthium strumarium.

Transgenerational plasticity (TGP) allows a plant to acclimate to external variable environments and is a potential mechanism that explains the range expansion and invasion success of some exotic plants. Most studies explored the traits of TGP associated with the success of exotic plant invasions by comparison studies among exotic, native, invasive, and noninvasive species. However, studies on the TGP of invasive plants in different resource environments are scarce, and the biological mechanisms involved are not well understood. This study aimed to determine the role of TGP in the invasiveness of Xanthium strumarium in northeast China. We measured the plant morphology of aboveground parts and the growth of three generations of the invader under different environmental conditions. The results showed that the intergenerational plasticity of X. strumarium was stronger under stress conditions. We found that the X. strumarium parent generation (F0) grown under water and/or nutrient deficiency conditions transferred the environmental information to their offspring (F1 and F2). The F1 generation grown under high-resource conditions has greater height with larger crown sizes, thicker basal diameters, and higher biomass. Both water and nutrients can affect the intergenerational transmission of plant plasticity, nutrients play a more important role compared with water. The high morphological intergenerational plasticity of X. strumarium under a pressure environment can help it quickly adapt to the new environment and accelerate the rapid expansion of the population in the short term. The root:shoot ratio and reproductive and nutrient distribution of the X. strumarium F0 and F1 generations showed high stability when the growth environment of the F0 generation differed from that of the F1 generation. The stable resource allocation strategy can ensure that the obtained resources are evenly distributed to each organ to maintain the long-term existence of the community. Therefore, the study of intergenerational transmission plasticity is of great significance for understanding the invasion process, mechanism, and prevention of invasive plants.

Sophora tonkinensis: response and adaptation of physiological characteristics, functional traits, and secondary metabolites to drought stress.

The medicinal plant Sophora tonkinensis is a characteristic Chinese shrub of karst areas. The arid climate in karst areas produces high-quality S. tonkinensis; however, the mechanisms of drought tolerance are not clear, which restricts sustainable plantings of S. tonkinensis. This study involved a 20-day drought stress experiment with potted S. tonkinensis and threee soil water regimes: control (CK), mild drought (MDT), and severe drought (SDT). Plant morphology, biomass, physiological indicators, alkaloid content, and other changes under drought stress were monitored. The content of soluble sugars and proteins, and activity of antioxidant enzymes in leaves and roots were higher under drought than CK, indicating that S. tonkinensis is tolerant to osmotic stress in early drought stages. Content of matrine and oxymatrine increased gradually with increasing drought duration in the short term. The epidermis of S. tonkinensis leaves have characteristics of desert plants, including upper epidermal waxy layer, lower epidermal villi, and relatively sunken stomata, suggesting that S. tonkinensis has strong drought tolerance. In conclusion, drought stress changed the cell structure of S. tonkinensis, induced antioxidant enzyme activity and increased its resistance to drought.

Evolutionary roles of polyploidization-derived structural variations in the phenotypic diversification of Panax species.

Genomic structural variations (SVs) are widespread in plant and animal genomes and play important roles in phenotypic novelty and species adaptation. Frequent whole genome duplications followed by (re)diploidizations have resulted in high diversity of genome architecture among extant species. In this study, we identified abundant genomic SVs in the Panax genus that are hypothesized to have occurred through during the repeated polyploidizations/(re)diploidizations. Our genome-wide comparisons demonstrated that although these polyploidization-derived SVs have evolved at distinct evolutionary stages, a large number of SV-intersecting genes showed enrichment in functionally important pathways related to secondary metabolites, photosynthesis and basic cellular activities. In line with these observations, our metabolic analyses of these Panax species revealed high diversity of primary and secondary metabolites both at the tissue and interspecific levels. In particular, genomic SVs identified at ginsenoside biosynthesis genes, including copy number variation and large fragment deletion, appear to have played important roles in the evolution and diversification of ginsenosides. A further herbivore deterrence experiment demonstrated that, as major triterpenoidal saponins found exclusively in Panax, ginsenosides provide protection against insect herbivores. Our study provides new insights on how polyploidization-derived SVs have contributed to phenotypic novelty and plant adaptation.

Pyramidal resistance training: A brief review of acute responses and long-term adaptations.

INTRODUCTION: One of the most popular training methods in weight rooms is the pyramidal. Despite this, its superiority over traditional training is still speculative. OBJECTIVE: To review the effects of pyramid strength training on acute responses and long-term adaptations of this training method. METHOD: The research was performed in PubMed, BIREME/BVS and Google Scholar databases using the search words in different combinations: 'strength training', 'resistance training', 'resistance exercise', 'strength exercise', 'pyramid', 'system pyramidal', 'crescent pyramid' and 'decrescent pyramid'. As inclusion criteria were considered: studies in English, which compared the effects of pyramidal training versus traditional training on acute responses and long-term adaptations. The TESTEX scale (0-15 points) was used to assess the methodological quality of the studies. RESULTS: This article included 15 studies (6 acute effect studies and 9 longitudinal studies), which evaluated hormonal, metabolic and performance responses, strength gains and muscle hypertrophy of strength training in pyramidal and traditional format. Studies were rated between good and excellent quality. CONCLUSION: The pyramid training protocol was not superior to the traditional protocol on acute physiological responses, strength gains and muscle hypertrophy. From a practical point of view, these findings allow us to say that the manipulation of this training method could be based on issues of periodization, motivation and/or even in personal preference. But, this is based on studies developed with repetition zones between 8 and 12 and/or intensities between 67% and 85% of 1RM.

Extensive representation of sensory deviance in the responses to auditory gaps in unanesthetized rats.

Unexpected changes in incoming sensory streams are associated with large errors in predicting the deviant stimulus relative to a memory trace of past stimuli. Mismatch negativity (MMN) in human studies and the release from stimulus-specific adaptation (SSA) in animal models correlate with prediction errors and deviance detection.1 In human studies, violation of expectations elicited by an unexpected stimulus omission resulted in an omission MMN.2,3,4,5 These responses are evoked after the expected occurrence time of the omitted stimulus, implying that they reflect the violation of a temporal expectancy.6 Because they are often time locked to the end of the omitted stimulus,4,6,7 they resemble off responses. Indeed, suppression of cortical activity after the termination of the gap disrupts gap detection, suggesting an essential role for offset responses.8 Here, we demonstrate that brief gaps in short noise bursts in the auditory cortex of unanesthetized rats frequently evoke offset responses. Importantly, we show that omission responses are elicited when these gaps are expected but are omitted. These omission responses, together with the release from SSA of both onset and offset responses to rare gaps, form a rich and varied representation of prediction-related signals in the auditory cortex of unanesthetized rats, extending substantially and refining the representations described previously in anesthetized rats.

Therapeutic compounds from medicinal plant endophytes: molecular and metabolic adaptations.

During the last few decades, endophytes have attracted increased attention due to their ability to produce a plethora of bioactive secondary metabolites. These compounds not only help the endophytes to outcompete other plant-associated microbes or pathogens through quorum sensing, but also enable them to surmount the plant immune system. However, only a very few studies have described the interlink between various biochemical and molecular factors of host-microbe interactions involved in the production of these pharmacological metabolites. The peculiar mechanisms by which endophytes modulate plant physiology and metabolism through elicitors, as well as how they use transitional compounds of primary and secondary metabolism as nutrients and precursors for the synthesis of new compounds or enhancing existing metabolites, are still less understood. This study thus attempts to address the aspects of synthesis of such metabolites used in therapeutics by the endophytes in the light of their ecological significance, adaptation, and intercommunity interactions. Our study explores how endophytes adapt to the specific host environment, especially in medicinal plants that produce metabolites with pharmacological potential and simultaneously modulate host gene expression for the biosynthesis of these metabolites. We also discuss the differential interactions of fungal and bacterial endophytes with their hosts.

[End of life at home, guiding relatives on what to do in case of dyspnea]. / Fin de vie à domicile, guider les proches sur les conduites à tenir en cas de dyspnée.

Respiratory difficulties presented by a loved one at the end of life at home can leave those around him or her unable to cope and lead to emergency hospitalizations that are not clinically justified in this context. This is why the educational role of nurses is so important. They contribute, through anticipated explanations and indications, to allow adapted attitudes likely to reduce anguish, even panic, and to make it possible to continue to live at home.

Practical approaches of PULSE Racing in training their athlete for the Cybathlon Global Edition Functional Electrical Stimulation bike race: a case report.

During the Cybathlon Global Edition 2020, athletes compete in a Functional Electrical Stimulation (FES) bike race. In this event, athletes with a spinal cord injury cover a distance of 1200 m on an adapted bike by using electrostimulation to activate their leg muscles in order to evoke a pedalling movement. This report reviews the training regimen, as designed by the PULSE Racing team, and the experience of one athlete in preparation for the Cybathlon Global Edition 2020. The training plan was designed to vary exercise modes in order to optimize physiological adaptations and minimize monotony for the athlete. Additional constraints due to coronavirus pandemic, e.g., postponement of the Cybathon Global Edition and modification from a live cycling track to a virtual stationary race, along with the health concerns of the athlete, e.g. unwanted effects from the FES and bladder infection, required creativity to ensure an effective and safe training protocol. The individual needs of the athlete and task requirements for the FES bike race made the design of a suitable training programme challenging, emphasizing the importance of monitoring. Several objective and subjective measures to assess the athlete's health and progress are presented, all with their own advantages and disadvantages. Despite these limitations, the athlete achieved a gold medal in the FES bike race Cybathlon Global Edition 2020 through discipline, team collaboration and the athlete's own motivation.

Adaptation to a limiting element involves mitigation of multiple elemental imbalances.

About 20 elements underlie biology and thus constrain biomass production. Recent systems-level observations indicate that altered supply of one element impacts the processing of most elements encompassing an organism (i.e. ionome). Little is known about the evolutionary tendencies of ionomes as populations adapt to distinct biogeochemical environments. We evolved the bacterium Serratia marcescens under five conditions (i.e. low carbon, nitrogen, phosphorus, iron or manganese) that limited the yield of the ancestor compared with replete medium, and measured the concentrations and use efficiency of these five, and five other elements. Both physiological responses of the ancestor, as well as evolutionary responses of descendants to experimental environments involved changes in the content and use efficiencies of the limiting element, and several others. Differences in coefficients of variation in elemental contents based on biological functions were evident, with those involved in biochemical building (C, N, P, S) varying least, followed by biochemical balance (Ca, K, Mg, Na), and biochemical catalysis (Fe, Mn). Finally, descendants evolved to mitigate elemental imbalances evident in the ancestor in response to limiting conditions. Understanding the tendencies of such ionomic responses will be useful to better forecast biological responses to geochemical changes.

Strong evidence for positive and negative correlational selection revealed by recreating ancestral variation.

The study of adaptation helps explain biodiversity and predict future evolution. Yet the process of adaptation can be difficult to observe due to limited phenotypic variation in contemporary populations. Furthermore, the scarcity of male fitness estimates has made it difficult to both understand adaptation and evaluate sexual conflict hypotheses. We addressed both issues in our study of two anther position traits in wild radish (Raphanus raphanistrum): anther exsertion (long filament - corolla tube lengths) and anther separation (long - short filament lengths). These traits affect pollination efficiency and are particularly interesting due to the unusually high correlations among their component traits. We measured selection through male and female fitness on wild radish plants from populations artificially selected to recreate ancestral variation in each anther trait. We found little evidence for conflicts between male and female function. We found strong evidence for stabilizing selection on anther exsertion and disruptive selection on anther separation, indicating positive and negative correlational selection on the component traits. Intermediate levels of exsertion are likely an adaptation to best contact small bees. The function of anther separation is less clear, but future studies might investigate pollen placement on pollinators and compare species possessing multiple stamen types.

Selective sweeps linked to the colonization of novel habitats and climatic changes in a wild tomato species.

Positive selection is the driving force underpinning local adaptation and leaves footprints of selective sweeps on the underlying major genes. Quantifying the timing of selection and revealing the genetic bases of adaptation in plant species occurring in steep and varying environmental gradients are crucial to predict a species' ability to colonize new niches. We use whole-genome sequence data from six populations across three different habitats of the wild tomato species Solanum chilense to infer the past demographic history and search for genes under strong positive selection. We then correlate current and past climatic projections with the demographic history, allele frequencies, the age of selection events and distribution shifts. Several selective sweeps occur at regulatory networks involved in root-hair development in low altitude and response to photoperiod and vernalization in high-altitude populations. These sweeps appear to occur in a concerted fashion in a given regulatory gene network at particular periods of substantial climatic change. Using a unique combination of genome scans and modelling of past climatic data, we quantify the timing of selection at genes likely underpinning local adaptation to semiarid habitats.

Physiological effects of microcurrent and its application for maximising acute responses and chronic adaptations to exercise.

Microcurrent is a non-invasive and safe electrotherapy applied through a series of sub-sensory electrical currents (less than 1 mA), which are of a similar magnitude to the currents generated endogenously by the human body. This review focuses on examining the physiological mechanisms mediating the effects of microcurrent when combined with different exercise modalities (e.g. endurance and strength) in healthy physically active individuals. The reviewed literature suggests the following candidate mechanisms could be involved in enhancing the effects of exercise when combined with microcurrent: (i) increased adenosine triphosphate resynthesis, (ii) maintenance of intercellular calcium homeostasis that in turn optimises exercise-induced structural and morphological adaptations, (iii) eliciting a hormone-like effect, which increases catecholamine secretion that in turn enhances exercise-induced lipolysis and (iv) enhanced muscle protein synthesis. In healthy individuals, despite a lack of standardisation on how microcurrent is combined with exercise (e.g. whether the microcurrent is pulsed or continuous), there is evidence concerning its effects in promoting body fat reduction, skeletal muscle remodelling and growth as well as attenuating delayed-onset muscle soreness. The greatest hindrance to understanding the combined effects of microcurrent and exercise is the variability of the implemented protocols, which adds further challenges to identifying the mechanisms, optimal patterns of current(s) and methodology of application. Future studies should standardise microcurrent protocols by accurately describing the used current [e.g. intensity (µA), frequency (Hz), application time (minutes) and treatment duration (e.g. weeks)] for specific exercise outcomes, e.g. strength and power, endurance, and gaining muscle mass or reducing body fat.

Return to valued activities: Survivors' experiences of adaptation and growth after treatment for head and neck cancer.

OBJECTIVE: The objective of this study was to explore the experiences of head and neck cancer (HNC) survivors who returned to valued activities to understand how they reconstruct their lives following HNC diagnosis and treatment. METHODS: A qualitative research approach based on social constructionist theory was used. A total of 21 in-depth semi-structured interviews were conducted with adults diagnosed with any type of HNC in the previous 6 years. Reflexive thematic analysis was used to identify themes. RESULTS: HNC presents a unique trauma following which some survivors navigate paths back to meaningful activities. The experiences of HNC survivors who adapted to life after treatment described internal and external change and development, identified by three themes; Mindfulness; Gratitude; and Adaptation. CONCLUSION: People diagnosed with HNC frequently experience lasting effects and other survivorship issues, however some survivors were able to return to valued activities and recreate a meaningful lifestyle reflecting the possibility of post traumatic growth. This study provides insight into the experiences of head and neck cancer survivors who were able to make meaning and find internal and external growth following treatment. These findings can be used to inform advanced communication skills training for oncology health professionals and psychoeducational courses for people diagnosed with head and neck cancer in the future.

The use of transcutaneous Vagal Nerve Stimulation as an effective countermeasure for Simulator Adaptation Syndrome.

This research focused on investigating the effectiveness of Transcutaneous Vagal Nerve Stimulation (tVNS) as compared to Galvanic Cutaneous Stimulation (GCS) at mitigating Simulator Adaptation Syndrome (SAS). Fifty drivers (mean age = 23.04 ± 17.71 years old, twenty-two men) participated in a driving simulation experiment. The total scores of the Simulator Sickness Questionnaire, head movements (body balance index), and driving performance variables were measured under five stimulation conditions: i) baseline (no stimulation delivered), ii) sham GCS, iii) sham tVNS, iv) active GCS, and v) active tNVS. The results showed that tVNS alleviated SAS and improved driving performance variables more effectively than GCS. We conclude that GCS and tVNS have similar neurological mechanisms to reduce SAS, providing possible explanations for the greater effectiveness of tVNS. We encourage the use of tVNS to decrease SAS.

An experimental test of the growth rate hypothesis as a predictive framework for microevolutionary adaptation.

The growth rate hypothesis (GRH) posits that the relative body phosphorus content of an organism is positively related to somatic growth rate, as protein synthesis, which is necessary for growth, requires P-rich rRNA. This hypothesis has strong support at the interspecific level. Here, we explore the use of the GRH to predict microevolutionary responses in consumer body stoichiometry. For this, we subjected populations of the rotifer Brachionus calyciflorus to selection for fast population growth rate (PGR) in P-rich (HPF) and P-poor (LPF) food environments. With common garden transplant experiments, we demonstrate that in HP populations evolution toward increased PGR was concomitant with an increase in relative phosphorus content. In contrast, LP populations evolved higher PGR without an increase in relative phosphorus content. We conclude that the GRH has the potential to predict microevolutionary change, but that its application is contingent on the environmental context. Our results highlight the potential of cryptic evolution in determining the performance response of populations to elemental limitation of their food resources.

[Aspiration test as dental anesthesia safety criterion]. / Aspiratsionnyi test kak kriterii bezopasnosti obezbolivaniya v stomatologii.

Intravascular anesthetic injection can lead to acute toxic reaction even the minimal dose of the drug was administered. The aspiration test is a generally accepted standard for local anesthesia in medicine, specially designed to reduce the risk of emergency conditions. Medical instruments should be adapted for aspiration test, the local anesthetic carpule should have a retention notch, and the dental syringe plunger need to have retention elements. The aspiration test protocol may vary. For legal protection of the doctor the aspiration test result should be described in the patient's medical record.