Physiological Characteristics Research Articles

Structural basis for linker histone H5–nucleosome binding and chromatin fiber compaction

The hierarchical packaging of chromatin fibers plays a critical role in gene regulation. The 30-nm chromatin fibers, a central-level structure bridging nucleosomal arrays to higher-order organizations, function as the first level of transcriptional dormant chromatin. The dynamics of 30-nm chromatin fiber play a crucial role in biological processes related to DNA. Here, we report a 3.6-angstrom resolution cryogenic electron microscopy structure of H5-bound dodecanucleosome, i.e., the chromatin fiber reconstituted in the presence of linker histone H5, which shows a two-start left-handed double helical structure twisted by tetranucleosomal units. An atomic structural model of the H5-bound chromatin fiber, including an intact chromatosome, is built, which provides structural details of the full-length linker histone H5, including its N-terminal domain and an HMG-motif-like C-terminal domain. The chromatosome structure shows that H5 binds the nucleosome off-dyad through a three-contact mode in the chromatin fiber. More importantly, the H5-chromatin structure provides a fine molecular basis for the intra-tetranucleosomal and inter-tetranucleosomal interactions. In addition, we systematically validated the physiological functions and structural characteristics of the tetranucleosomal unit through a series of genetic and genomic studies in Saccharomyces cerevisiae and in vitro biophysical experiments. Furthermore, our structure reveals that multiple structural asymmetries of histone tails confer a polarity to the chromatin fiber. These findings provide structural and mechanistic insights into how a nucleosomal array folds into a higher-order chromatin fiber with a polarity in vitro and in vivo.

Transcriptome analysis reveals candidate genes for different root types of alfalfa (Medicago sativa) after water stress induced by PEG-6000

BackgroundWe aimed to gain insight into the response mechanism of alfalfa (Medicago sativa) to drought stress by recognizing and analyzing drought-responsive genes in the roots of different root types of alfalfa. The rhizomatous-rooted M. sativa cv.‘Qingshui’ (QS), tap-rooted M. sativa cv.‘Longdong’ (LD), and creeping-rooted M. varia cv. ‘Gongnong No. 4’ (GN) were used to analyze the transcriptome information and physiological characteristics of the root systems of the cultivars under simulated drought stress using PEG-6000.ResultsIt was found that aridity caused a significant increase in the content of osmotic stress substances and antioxidant enzyme activity. The content of malondialdehyde (MDA) in QS was lower than that in LD and GN under moisture stress, indicating a stronger accumulation capacity of osmotic regulatory substances. Based on sequencing results, 14,475, 9336, and 9243 upregulated DEGs from QS, LD, and GN were annotated into 26, 29, and 28 transcription factor families, respectively. QS showed more DEGs than LD and GN. KEGG enrichment analysis identified that DEGs were significantly enriched in metabolic pathways such as amino acid biosynthesis, phenylpropanoid biosynthesis, plant hormone signaling transduction, and MAPK pathways. This suggests a strong correlation between these pathways and drought stress. The results also show that genes associated with ABA hormone signaling (MS. gene93372, MS. gene072046, and MS. gene012975) are crucial for plant’s adaptation to drought stress.ConclusionsThese genes, such as serine/threonine protein kinases and abscisic acid receptors, play a crucial role in plant hormone signaling and MAPK pathways. They could serve as potential candidate genes for drought resistance research in alfalfa, providing a molecular foundation for studying drought resistance.Graphical

Research Progress on Physiological, Biochemical, and Molecular Mechanisms of Potato in Response to Drought and High Temperature

With the intensifying global warming trend, extreme heat and drought are becoming more frequent, seriously impacting potato yield and quality. To maintain sustainable potato production, it is necessary to breed new potato varieties that are adaptable to environmental changes and tolerant to adversity. Despite its importance, there is a significant gap in research focused on the potential mechanisms of potato resistance to abiotic stresses like drought and high temperatures. This article provides a comprehensive review of the recent research available in academic databases according to subject keywords about potato drought tolerance and high temperature tolerance with a view to providing an important theoretical basis for the study of potato stress mechanism and the selection and breeding of potato varieties with drought and high-temperature resistance. The suitable relative soil moisture content for potato growth and development is 55% to 85%, and the suitable temperature is 15 °C to 25 °C. The growth and development of potato plants under drought and high-temperature stress conditions are inhibited, and plant morphology is altered, which affects the process of potato stolon formation, tuberization and expansion, ultimately leading to a significant reduction in potato tuber yields and a remarkable degradation of the market grade of tubers, the specific gravity of tubers, and the processing quality of tubers. In addition, stress also adversely affects potato physiological and biochemical characteristics, such as reduction in root diameter and leaf area, decrease in net photosynthetic rate of leaves, production of reactive oxygen species (ROS), and increase in membrane lipid peroxidation. In addition, various types of genes and transcription factors are involved in the response to drought and heat at the molecular level in potato. This paper illustrates the effects of stress on potato growth and development and the molecular mechanisms of potato response to adversity in detail, which is intended to reduce the damage caused by drought and high temperature to potato in the context of global warming and frequent occurrence of extreme weather to ensure potato yield and quality and to further safeguard food security.

Photosynthetic Limitations and Growth Traits of Four Arabica Coffee (Coffea arabica L.) Genotypes under Water Deficit

Climate change increases the risk of coffee yield due to the genotype-dependent effects of water deficit on coffee physiology. The goal of this research was to evaluate how water deficit altered the physiological and growth characteristics of arabica coffee (Coffea arabica L.). Water status, photosynthetic response to CO2 intercellular concentration (A/Ci curves) and growth parameters were evaluated in seedlings of four genotypes (Catimor ECU 02, Cavimor ECU, red Caturra and Sarchimor 4260). Most of the physiological traits evaluated differed significantly among genotypes. Between control and water deficit plants, significant variations occurred in the A/Ci parameters, showing a wide range of values for net photosynthetic rate, stomatal conductance, and water use efficiency, with decreases ranging from 4 to 74%. Maximum electron transport rate through photosystem II, highest rate of RuBisCO carboxylation, and triose phosphate utilization rate were all strongly decreased by water deficit 61% (red Caturra and Sarchimor 4260), followed by Cavimor ECU (35%) and Catimor ECU 02 (24%). Differences in response to water deficit among genotypes suggest possible genotypic differences in tolerance. The results indicated that Catimor ECU 02 and Cavimor ECU were less sensitive to water deficit, while red Caturra and Sarchimor 4260 were the most susceptible.

Selective capture of PM2.5 by urban trees: The role of leaf wax composition and physiological traits in air quality enhancement

Human health risks from particles with a diameter of less than 2.5 µm (PM2.5) highlight the role of urban trees as bio-filters in air pollution control. However, whether the size and composition of particles captured by various tree species differ or not remain unclear. This study investigates how leaf attributes affect the capture of PM2.5, which can penetrate deep into the lungs and pose significant health risks. Using a self-developed particulate matter (PM) resuspension chamber and single-particle aerosol mass spectrometer, we measured the size distribution and mass spectra of particles captured by ten tree species. Notably, Cinnamomum camphora (L.) J.Presl and Osmanthus fragrans Lour. are more effective at capturing particles under 1 µm, which are most harmful because they can reach the alveoli, whereas Ginkgo biloba L. and Platanus × acerifolia (Aiton) Willd. tend to capture larger particles, up to 1.6 µm, which are prone to being trapped in the upper respiratory tract. Leaf physiological traits such as stomatal conductance and water potential significantly enhance the capture of larger particles. The Adaptive Resonance Theory neural network (ART-2a) algorithm classified a large number of single particles to determine their composition. Results indicate distinct inter-species variations in chemical composition of particles captured by leaves. Moreover, we identified how specific leaf wax compositions—beyond the known sticky nature of hydrophobic waxes—contribute to particle adhesion, particularly highlighting the roles of fatty acids and alkanes in adhering particles rich in organic carbon and heavy metals, respectively. This research advances our understanding by linking leaf physiological and wax characteristics to the selective capture of PM2.5, providing actionable insights for urban forestry management. The detailed exploration of particle size and composition, tied to specific tree species, enriches the current literature by quantifying how and why different species contribute variably to air quality improvement. This adds a crucial layer of specificity to the general knowledge that trees serve as bio-filters, offering a refined strategy for planting urban trees based on their particulate capture profiles.

Physiological and Biochemical Analysis of Selenium-Enriched Rice

Selenium is an essential trace element in the human body. However, its intake is generally low. Therefore, the production and utilisation of selenium-enriched foods is currently a research hotspot. In this study, the effects of low (0.2 mg·kg−1), medium (1.0 mg·kg−1), and high (5.0 mg·kg−1) concentrations of selenium on the physiological and biochemical characteristics of rice were investigated to develop selenium-enriched rice. High concentrations of selenium have been found to inhibit the growth, physiology, and biochemistry of rice, while low concentrations of selenium promote its growth. The height of mature rice plants exposed to high concentrations of selenium was reduced by 7.20% compared with the height of control rice. Selenium decreased the proline content of rice during the growth period except in mature rice treated with medium and high concentrations of selenium. Excluding high concentrations, selenium treatment increased the soluble sugar content of rice from the tillering to the mature stages. The peroxidase activity of rice at the heading stage treated with medium levels of selenium was significantly higher than that of the control rice, while the superoxide dismutase activity of rice exposed to selenium was significantly enhanced at the mature stage. The malondialdehyde levels of mature rice treated with medium and high levels of selenium were significantly lower than those of the control rice. The selenium content of each plant part was significantly correlated with the soil selenium level. An increase in the soil selenium level facilitated the production of selenium-enriched rice.

Hierarchical gradients of multiple timescales in the mammalian forebrain.

Many anatomical and physiological features of cortical circuits, ranging from the biophysical properties of synapses to the connectivity patterns among different neuron types, exhibit consistent variation along the hierarchical axis from sensory to association areas. Notably, the scale of temporal correlation of neural activity at rest, known as the intrinsic timescale, increases systematically along this hierarchy in both primates and rodents, analogous to the growing scale and complexity of spatial receptive fields. However, how the timescales for task-related activity vary across brain regions and whether their hierarchical organization appears consistently across different mammalian species remain unexplored. Here, we show that both the intrinsic timescale and the timescales of task-related activity follow a similar hierarchical gradient in the cortices of monkeys, rats, and mice. We also found that these timescales covary similarly in both the cortex and basal ganglia, whereas the timescales of thalamic activity are shorter than cortical timescales and do not conform to the hierarchical order predicted by their cortical projections. These results suggest that the hierarchical gradient of cortical timescales might be a universal feature of intra-cortical circuits in the mammalian brain.

Effects of Low-Temperature Stress on Cold Resistance Biochemical Characteristics of Dali and Siqiu Tea Seedlings

Cold stress causes considerable damage to tender tea seedlings. Previous studies have explored changes in the physiological and biochemical factors of tea in response to cold stress; however, the mechanisms of cold resistance in ancient tea tree plants are unclear. The aim of this study was to analyze the effects of 0 °C cold stress for 15 days and 24 °C ambient temperature recovery for 5 days on the physiological and biochemical characteristics of two representative old tea varieties: Dali tea and Siqiu tea. The results revealed significant changes in antioxidant, photosynthetic efficiency, and physiological and biochemical indicators in response to cold stress, with the two species exhibiting different patterns. Cold stress decreased chlorophyll and carotene content, Fv/Fm, Y(II), non-photochemical quenching coefficient, photochemical quenching, and superoxide dismutase (SOD) activity, and increased intercellular CO2 concentration and ascorbate peroxidase activity. Siqiu tea showed a higher increase in soluble sugar content and antioxidant enzyme activity and a lower accumulation of malondialdehyde and minimal fluorescence (F0) than Dali, indicating a greater tolerance to cold stress. Based on partial least-squares discriminant analysis, six key differential physiological indicators of cold resistance—water-soluble sugar, F0, peroxidase, catalase, SOD, and gas conductance—were identified. Our findings provide technical support for identifying ways to protect ancient tea trees from extreme weather conditions.

The ReInvigorate Study—phrenic nerve-to-diaphragm stimulation for weaning from mechanical ventilation: a protocol for a randomized pivotal clinical trial

BackgroundIn the United States in 2017, there were an estimated 903,745 hospitalizations involving mechanical ventilation (MV). Complications from ventilation can result in longer hospital stays, increased risk of disability, and increased healthcare costs. It has been hypothesized that electrically pacing the diaphragm by phrenic nerve stimulation during mechanical ventilation may minimize or reverse diaphragm dysfunction, resulting in faster weaning.MethodsThe ReInvigorate Trial is a prospective, multicenter, randomized, controlled clinical trial evaluating the safety and efficacy of Stimdia’s pdSTIM System for facilitating weaning from MV. The pdSTIM system employs percutaneously placed multipolar electrodes to stimulate the cervical phrenic nerves and activate contraction of the diaphragm bilaterally. Patients who were on mechanical ventilation for at least 96 h and who failed at least one weaning attempt were considered for enrollment in the study. The primary efficacy endpoint was the time to successful liberation from mechanical ventilation (treatment vs. control). Secondary endpoints will include the rapid shallow breathing index and other physiological and system characteristics. Safety will be summarized for both primary and additional analyses. All endpoints will be evaluated at 30 days or at the time of removal of mechanical ventilation, whichever is first.DiscussionThis pivotal study is being conducted under an investigational device exception with the U.S. Food and Drug Administration. The technology being studied could provide a first-of-kind therapy for difficult-to-wean patients on mechanical ventilation in an intensive care unit setting.Trial registrationClinicaltrials.gov, NCT05998018, registered August 2023.

Effect of expressway exit deceleration markings on distracted drivers in China

Expressway exit areas experience traffic diversion and complex road conditions, making them accident-prone areas. In this study, transverse and fishbone visual illusion deceleration markings were selected to optimize the induction facilities at expressway exits. The research aims to investigate the impact of these markings on the driving behavior, cognitive load, and physiological characteristics of drivers in various distracted scenarios at expressway exit areas. Furthermore, a comprehensive evaluation of each experimental scheme is conducted using the Matter-Element Extension Model. The study found that the implementation of deceleration markings can effectively enhance driver alertness and lane change awareness, enabling drivers to reduce their speed to near the speed limit in exit areas without compromising driving comfort. Compared to the situation without markings, drivers begin to decelerate approximately 600 m earlier and exit the ramp when markings are present. Fishbone deceleration markings, in contrast to transverse markings, result in lower vehicle speeds, smoother deceleration, and more effectively stimulate drivers' intention to change lanes, guiding them to make the final lane change earlier. Based on the comprehensive evaluation results, it is recommended that transverse or fishbone deceleration markings be considered in engineering practice. These markings have not produced significant effects on driver visual fatigue and driving load, with fishbone markings demonstrating superior comprehensive evaluation outcomes. These research findings can provide valuable insights for future expressway exit area marking design schemes, further enhancing driver safety.

A GENERATIVE APPROACH TO TESTING THE PERFORMANCE OF PHYSIOLOGICAL CONTROL ALGORITHMS.

Physiological closed-loop control algorithms play an important role in the development of autonomous medical care systems, a promising area of research that has the potential to deliver healthcare therapies meeting each patient's specific needs. Computational approaches can support the evaluation of physiological closed-loop control algorithms considering various sources of patient variability that they may be presented with. In this paper, we present a generative approach to testing the performance of physiological closed-loop control algorithms. This approach exploits a generative physiological model (which consists of stochastic and dynamic components that represent diverse physiological behaviors across a patient population) to generate a select group of virtual subjects. By testing a physiological closed-loop control algorithm against this select group, the approach estimates the distribution of relevant performance metrics in the represented population. We illustrate the promise of this approach by applying it to a practical case study on testing a closed-loop fluid resuscitation control algorithm designed for hemodynamic management. In this context, we show that the proposed approach can test the algorithm against virtual subjects equipped with a wide range of plausible physiological characteristics and behavior, and that the test results can be used to estimate the distribution of relevant performance metrics in the represented population. In sum, the generative testing approach may offer a practical, efficient solution for conducting pre-clinical tests on physiological closed-loop control algorithms.

Comparative physiology and morphology of BLA-projecting NBM/SI cholinergic neurons in mouse and macaque.

Cholinergic projection neurons of the nucleus basalis and substantia innominata (NBM/SI) densely innervate the basolateral amygdala (BLA) and have been shown to contribute to the encoding of fundamental and life-threatening experiences. Given the vital importance of these circuits in the acquisition and retention of memories that are essential for survival in a changing environment, it is not surprising that the basic anatomical organization of the NBM/SI is well conserved across animal classes as diverse as teleost and mammal. What is not known is the extent to which the physiology and morphology of NBM/SI neurons have also been conserved. To address this issue, we made patch-clamp recordings from NBM/SI neurons in ex vivo slices of two widely divergent mammalian species, mouse and rhesus macaque, focusing our efforts on cholinergic neurons that project to the BLA. We then reconstructed most of these recorded neurons post hoc to characterize neuronal morphology. We found that rhesus macaque BLA-projecting cholinergic neurons were both more intrinsically excitable and less morphologically compact than their mouse homologs. Combining measurements of 18 physiological features and 13 morphological features, we illustrate the extent of the separation. Although macaque and mouse neurons both exhibited considerable within-group diversity and overlapped with each other on multiple individual metrics, a combined morpho-electric analysis demonstrates that they form two distinct neuronal classes. Given the shared purpose of the circuits in which these neurons participate, this finding raises questions about (and offers constraints on) how these distinct classes result in similar behavior.

Abstract Mo121: Sarcomere activation biosensor reveals key functional differences in live cell active states between cardiac and skeletal muscle

The sarcomere is the functional unit of striated muscle contraction. Previous studies have provided valuable information about the sarcomeric proteins and modulators that are necessary for activation of contraction through inter-myofilament signaling. This work has revealed key differences in contraction kinetics and paradigms between cardiac, slow skeletal, and fast skeletal muscle. We seek here to expand these studies through the use of myofilament incorporated Förster Resonance Energy Transfer (FRET) fluorescent biosensor in live, intact muscle. This biosensor fuses fluorescent donor and acceptor proteins to the N- and C-terminals of fast skeletal and cardiac (slow) troponin C, respectively, and allows for the monitoring in real-time of the stepwise physiological mechanism of muscle sarcomere activation in an intact system which preserves significant features of the muscle, including excitation-contraction coupling and load. This biosensor has been designed and validated in both cardiac and skeletal muscle and using intact muscles from transgenic animals we have demonstrated FRET fluorescence in cardiac papillaries, extensor digitorum longus, and soleus muscles. This biosensor has shown unique sarcomere activation properties between cardiac and skeletal muscle, notably the emergence of a prolonged return to baseline of the FRET signal in loaded fast and slow skeletal muscle, which is evidence of a “primed state” of myofilament activation unique to skeletal muscles under load. Elucidation of the “primed state” of sarcomere activation is evidence of a transient memory of recent activity enabling the enhanced contraction properties of skeletal muscle. This finding advances previous understanding of skeletal muscle activation, including summation and tetanic contraction, which is not possible in cardiac muscle. The implementation of this biosensor provides a new approach to interrogate the essential physiological features of muscle sarcomere activation and contraction and adds a valuable new tool for small molecule and gene-based discoveries for muscle disease remediation.

Gilvirhabdus luticola gen. nov., sp. nov., a mesophilic and halophilic bacterium isolated from tidal flat sediment.

Two novel bacteria, MJ-SS3T and MJ-SS4, were isolated from tidal flat sediment sampled in Gochang, Republic of Korea. The isolates were Gram-stain-negative, aerobic, non-motile, rod-shaped, yellow-coloured, oxidase-positive, and catalase-positive. Strains MJ-SS3T and MJ-SS4 grew at 20-37 °C (optimum, 30 °C), at pH 6-8 (optimum, pH 7.0) and in the presence of 0-7 % (w/v) NaCl (optimum, 2.0 % NaCl). Strains MJ-SS3T and MJ-SS4 showed 99.9 % 16S rRNA gene sequence similarity. Phylogenetic analysis based on genome and 16S rRNA gene sequences indicated that strains MJ-SS3T and MJ-SS4 were affiliated with the family Flavobacteriaceae and most closely related to Formosa maritima 1494T (95.3 %), Hanstruepera flava NBU2984T (95.2 %), Yeosuana marina JLT21T (95.2 %), Meridianimaribacter flavus NH57NT (95.1 %), and Geojedonia litorea YCS-16T (95.1 %). The major respiratory quinone was menaquinone-6. The major identified polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and amino lipids. The major cellular fatty acids of strain MJ-SS3T were iso-C15 : 1 G (24.6 %), iso-C15 : 0 (21.6 %), and iso-C17 : 0 3-OH (15.8 %). The genome length of strain MJ-SS3T is 3.1 Mbp (DNA G+C content, 32.5 mol%) and it has 2822 coding and 59 tRNA genes. The average amino acid identity and average nucleotide identity values, as well as biochemical, phylogenetic, and physiological characteristics, strongly supported the genotypic and phenotypic differentiation of strains MJ-SS3T and MJ-SS4 from other members of the family Flavobacteriaceae. Hence, strains MJ-SS3T and MJ-SS4 are considered to represent a novel species of a new genus in the family Flavobacteriaceae, for which the Gilvirhabdus luticola gen. nov., sp. nov. is proposed. The type strain is MJ-SS3T (=KCTC 102114T=KEMB 20189T=JCM 36595T), with reference strain MJ-SS4 (=KCTC 102115=KEMB 20190).

Modeling the Intent to Interact With VR Using Physiological Features.

Mixed-Reality (XR) technologies promise a user experience (UX) that rivals the interactive experience with the real-world. The key facilitators in the design of such a natural UX are that the interaction has zero lag and that users experience no excess mental load. This is difficult to achieve due to technical constraints such as motion-to-photon latency as well as false-positives during gesture-based interaction. In this paper, we explored the use of physiological features to model the user's intent to interact with a virtual reality (VR) environment. Accurate predictions about when users want to express an interaction intent could overcome the limitations of an interactive device that lags behind the intention of a user. We computed time-domain features from electroencephalography (EEG) and electromyography (EMG) recordings during a grab-and-drop task in VR and cross-validated a Linear Discriminant Analysis (LDA) for three different combinations of (1) EEG, (2) EMG and (3) EEG-EMG features. We found the classifiers to detect the presence of a pre-movement state from background idle activity reflecting the users' intent to interact with the virtual objects (EEG: 62 % ± 10 %, EMG: 72 % ± 9 %, EEG-EMG: 69 % ± 10 %) above simulated chance level. The features leveraged in our classification scheme have a low computational cost and are especially useful for fast decoding of users' mental states. Our work is a further step towards a useful classification of users' intent to interact, as a high temporal resolution and speed of detection is crucial. This facilitates natural experiences through zero-lag adaptive interfaces.

Effect of carvacrol on the inhibitory of gas-producing spoilage microbes and volatile flavor in fermented pepper (Capsicum annuum L.)

In this study, two gas-producing spoilage microbes, namely CQ17 and CQ22, were isolated from fermented pepper. Combining the physiological and biochemical characteristics, molecular biological identification, and specific colony morphology, CQ17 was identified as Pichia manshurica while CQ22 was identified as Lentilactobacillus buchneri. Subsequently, our findings indicated that the CQ17 and CQ22 strains exhibited resistance to high temperature, low-pH, and high salinity environments. Meanwhile, our findings revealed that carvacrol, a commonly utilized preservative, exhibited remarkable inhibitory activities against Pichia manshurica and Lentilactobacillus buchneri with the EC50 values of 0.28 and 0.68 mg/L respectively, effectively suppressing the growth of gas-producing strains to prolong the shelf life of fermented pepper. Simultaneously, volatile components of the fermented pepper were analyzed using HS-GC-IMS technology resulting in identification of 55 volatile flavor compounds including acids, alcohols, esters, aldehydes, ketones, alkenes, and other compounds. Among them, (R/S)-linalool, 3-methyl-1-butanol acetate butanoic acid ethyl ester, 2-methyl butanoic acid ethyl ester, and ethyl 2-methylpropionate were identified as crucial components contributing to sensory attributes in fermented pepper as well as (E)-3-hexen-1-ol and l-Pentanol exhibited the highest VIP values and can be considered as the best reliable markers for differentiating fermented pepper samples with the addition of carvacrol as a preservative.

Understanding the metabolism of infants using whole-body metabolic models

A whole-body model is a computational representation of sex-specific and organ-resolved whole-body metabolism. In this issue of Cell Metabolism, Zaunseder etal. report whole-body models of infants that represent metabolic, physiological, energetic, and nutritional features, accurately simulating the growth of infants and providing foundations for personalized medicine for infants.

Lineage-tracing reveals an expanded population of NPY neurons in the inferior colliculus.

Growing evidence suggests that neuropeptide signaling shapes auditory computations. We previously showed that neuropeptide Y (NPY) is expressed in the inferior colliculus (IC) by a population of GABAergic stellate neurons and that NPY regulates the strength of local excitatory circuits in the IC. NPY neurons were initially characterized using the NPY-hrGFP mouse, in which humanized renilla green fluorescent protein (hrGFP) expression indicates NPY expression at the time of assay, i.e., an expression-tracking approach. However, studies in other brain regions have shown that NPY expression can vary based on several factors, suggesting that the NPY-hrGFP mouse might miss NPY neurons not expressing NPY on the experiment date. Here, we hypothesized that neurons with the ability to express NPY represent a larger population of IC GABAergic neurons than previously reported. To test this hypothesis, we used a lineage-tracing approach to irreversibly tag neurons that expressed NPY at any point prior to the experiment date. We then compared the physiological and anatomical features of neurons labeled with this lineage-tracing approach to our prior data set, revealing a larger population of NPY neurons than previously found. In addition, we used optogenetics to test the local connectivity of NPY neurons and found that NPY neurons provide inhibitory synaptic input to other neurons in the ipsilateral IC. Together, our data expand the definition of NPY neurons in the IC, suggest that NPY expression might be dynamically regulated in the IC, and provide functional evidence that NPY neurons form local inhibitory circuits in the IC.NEW & NOTEWORTHY Across brain regions, neuropeptide Y (NPY) expression is dynamic and influenced by extrinsic and intrinsic factors. We previously showed that NPY is expressed by a class of inhibitory neurons in the auditory midbrain. Here, we find that this neuron class also includes neurons that previously expressed NPY, suggesting that NPY expression is dynamically regulated in the auditory midbrain. We also provide functional evidence that NPY neurons contribute to local inhibitory circuits in the auditory midbrain.

Factors contributing to stillbirth in young hyper-prolific sows in a tropical free-farrowing system.

The present study investigated factors associated with the incidence of stillbirth in young hyper-prolific sows within free farrowing systems in tropical environments. A total of 714 live-born and 54 stillborn piglets from 57 Landrace × Yorkshire sows, with an average parity of 2.7 ± 1.0 (range: 1 - 4), were comprehensively investigated. Reproductive variables of the sows, including gestation length, farrowing duration, the total number of piglets born per litter, and the birth order and status of each piglet, were recorded. Differences in the physiological characteristics of live-born and stillborn piglets, such as birth interval, cumulative birth interval, body weight at birth, crown-rump length, body mass index (BMI), ponderal index (PI), meconium staining score, and the percentage of piglets with a broken umbilical cord, were analysed. Piglets were divided into four groups based on the quartiles of birth order (Q1-Q4). On average, the duration of farrowing was 173.3 ± 85.9 min, and the total number of piglets born and number of piglets born alive-per litter were 14.1 ± 3.8 and 12.5 ± 3.5, respectively. The incidence of stillbirth was 6.7% (54/801 piglets). The higher percentages of stillbirths were detected in sows with large litter sizes (≥17 piglets, 10.9%) compared to those with small (≤13 piglets, 6.1%) and moderate (14 - 16 piglets, 2.8%) litter sizes (p < .001). The incidences of stillbirth in Q3 and Q4 of the litters were higher than in Q1 and Q2 (p < .001). Compared to live-born piglets, stillborn piglets had higher cumulative birth interval (103.0 ± 3.71 vs. 142.4 ± 9.35 min, p < .001), BMI (17.1 ± 0.15 vs. 18.4 ± 0.39 kg/m2, p = .002), PI (63.7 ± 0.59 vs. 70.8 ± 1.59 kg/m3, p < .001), meconium staining scores (1.78 ± 0.04 vs. 2.04 ± 0.10, p = .021), and the percentage of piglets born with a ruptured umbilical cord (45.2% vs. 66.0%, p = .004). An increase in the incidence of stillbirth was detected at 60, 120, 150, 180, and ≥ 210 min after the first piglet was born, compared to those born within the first 30 min of farrowing (p < .05). In conclusion, the study found that stillbirths in young, hyper-prolific sows were linked to several factors: large litter sizes (≥17 piglets per litter), prolonged cumulative birth intervals (142.4 min), elevated BMI of 18.4 kg/m2, high PI values of 70.8 kg/m3, increased meconium staining scores, and a higher occurrence of ruptured umbilical cords. To reduce the risk of stillbirth, particularly among piglets with high body indices born later in the birthing process, it is recommended to enhance farrowing supervision for young sows, starting at a cumulative birth interval of 60 min.

Гинекологические проблемы у подростков: тенденции обращений к гинекологам и жалоб

Adolescence represents a pivotal phase in the transition from childhood to adulthood. Adolescent gynecology is the clinical specialty that focuses on the management of gynecologic problems during this period. This study's primary objective is to emphasize the importance of adolescent gynecology by examining the gynecological causes of adolescent presentations and highlighting the differences that warrant consideration in the clinical approach to adolescent patients. The study was designed as a retrospective cohort study in an academic tertiary hospital and included adolescent individuals presenting to the obstetrics and gynecology emergency department or outpatient clinic. The analysis encompassed a range of factors, including age, presenting symptoms, examination findings, ultrasound results, laboratory data, and the necessity for hospital admission. The study cohort comprised 750 adolescent patients, 71.3% seeking gynecological care. Adolescents most frequently presented for menstrual irregularities (57.6%) and secondly for dysmenorrhea. The results of the gynecological clinical evaluations indicated that 62.9% of the patients had menstrual disorders. Of these, 53.4% had irregular menstrual cycles, 4.5% had prolonged and/or heavy bleeding, and 3% had amenorrhea. Ultrasound imaging revealed the presence of pathological findings in 25.8% of the patients. In conclusion, this study's findings indicate that irregular menstrual cycles are the most common gynecological condition in the adolescent population. The physiological characteristics of adolescents require a distinct approach to diagnosis and treatment compared to adult women, which can significantly impact future fertility and overall reproductive health.