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1.
Elife ; 122024 May 07.
Article in English | MEDLINE | ID: mdl-38712832

ABSTRACT

The fact that objects without proper support will fall to the ground is not only a natural phenomenon, but also common sense in mind. Previous studies suggest that humans may infer objects' stability through a world model that performs mental simulations with a priori knowledge of gravity acting upon the objects. Here we measured participants' sensitivity to gravity to investigate how the world model works. We found that the world model on gravity was not a faithful replica of the physical laws, but instead encoded gravity's vertical direction as a Gaussian distribution. The world model with this stochastic feature fit nicely with participants' subjective sense of objects' stability and explained the illusion that taller objects are perceived as more likely to fall. Furthermore, a computational model with reinforcement learning revealed that the stochastic characteristic likely originated from experience-dependent comparisons between predictions formed by internal simulations and the realities observed in the external world, which illustrated the ecological advantage of stochastic representation in balancing accuracy and speed for efficient stability inference. The stochastic world model on gravity provides an example of how a priori knowledge of the physical world is implemented in mind that helps humans operate flexibly in open-ended environments.


Subject(s)
Gravitation , Stochastic Processes , Humans , Female , Male , Adult , Young Adult
2.
Aerosp Med Hum Perform ; 95(5): 273-277, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38715261

ABSTRACT

INTRODUCTION: There is a current belief in aviation suggesting that aerobic training may reduce G-tolerance due to potential negative impacts on arterial pressure response. Studies indicate that increasing maximal aerobic capacity (V˙o2 max) through aerobic training does not hinder G-tolerance. Moreover, sustained centrifuge training programs revealed no instances where excessive aerobic exercise compromised a trainee's ability to complete target profiles. The purpose of this review article is to examine the current research in the hope of establishing the need for routine V˙o2-max testing in air force pilot protocols.METHODS: A systematic search of electronic databases including Google Scholar, PubMed, the Aerospace Medical Association, and Military Medicine was conducted. Keywords related to "human performance," "Air Force fighter pilots," "aerobic function," and "maximal aerobic capacity" were used in various combinations. Articles addressing exercise physiology, G-tolerance, physical training, and fighter pilot maneuvers related to human performance were considered. No primary data collection involving human subjects was conducted; therefore, ethical approval was not required.RESULTS: The V˙o2-max test provides essential information regarding a pilot's ability to handle increased Gz-load. It assists in predicting G-induced loss of consciousness by assessing anti-G straining maneuver performance and heart rate variables during increased G-load.DISCUSSION: V˙o2-max testing guides tailored exercise plans, optimizes cardiovascular health, and disproves the notion that aerobic training hampers G-tolerance. Its inclusion in air force protocols could boost readiness, reduce health risks, and refine training for fighter pilots' safety and performance. This evidence-backed approach supports integrating V˙o2-max testing for insights into fitness, risks, and tailored exercise.Zeigler Z, Acevedo AM. Re-evaluating the need for routine maximal aerobic capacity testing within fighter pilots. Aerosp Med Hum Perform. 2024; 95(5):273-277.


Subject(s)
Military Personnel , Pilots , Humans , Aerospace Medicine , Exercise Tolerance/physiology , Oxygen Consumption/physiology , Exercise/physiology , Exercise Test/methods , Centrifugation , Gravitation
3.
An Acad Bras Cienc ; 96(2): e20230840, 2024.
Article in English | MEDLINE | ID: mdl-38747838

ABSTRACT

The extraction of valuable compounds from dried fruits and vegetables by microwave hydrodiffusion and gravity (MHG) requires previous hydration of the plant material. In this work, ultrasound was used to speed up the hydration of guarana powder before MHG extraction and increase caffeine recovery. The humidification step was speeded up with ultrasound taking only 15 min over 60 min without ultrasound. Water and 50% (v/v) ethanol were evaluated as green solvents for humidification, with a higher concentration of caffeine obtained for the hydroalcoholic solution. Ultrasound pretreatment allowed guarana extracts from MHG with two times more caffeine for both solvents evaluated. Therefore, ultrasound can be used in the hydration step before MHG extraction to reduce time and increase caffeine recovery from guarana powder.


Subject(s)
Caffeine , Microwaves , Paullinia , Plant Extracts , Powders , Caffeine/analysis , Caffeine/isolation & purification , Paullinia/chemistry , Plant Extracts/chemistry , Gravitation , Ultrasonics , Solvents
4.
PLoS One ; 19(5): e0297442, 2024.
Article in English | MEDLINE | ID: mdl-38728324

ABSTRACT

In the post-epidemic era, the restart of China's inbound tourism is imminent. However, there are gaps in our current understanding of how distance perception dynamically affects inbound tourism in China. In order to understand the past patterns of inbound tourism in China, we mapped the data of 61 countries of origin from 2004 to 2018 into a dynamic expanding gravity model to understand the effects of cultural distance, institutional distance, geographical distance, and economic distance on inbound tourism in China and revealed the dynamic interaction mechanism of non-economic distance perception on inbound tourism in China. Our research results show that cultural distance has a positive impact on China's inbound tourism, while institutional distance has a negative impact. The significant finding is that the dynamic interaction of the above two kinds of perceived distance can still have a positive impact on China's inbound tourism. Its practical significance is that it can counteract the influence of institutional distance by strengthening the cultural distance. Generally speaking, geographical distance and institutional distance restrict China's inbound tourism flow, while cultural distance, economic distance, and interactive perceptual distance promote China's inbound tourism flow.


Subject(s)
Tourism , China , Humans , Models, Theoretical , Distance Perception , Travel/economics , Gravitation
5.
Brain Struct Funct ; 229(5): 1265-1277, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38700553

ABSTRACT

The plans of international space agencies to return to the Moon and explore deep space, including Mars, highlight the challenges of human adaptation and stress the need for a thorough analysis of the factors that facilitate, limit and modify human performance under extreme environments. This study investigates the influence of partial gravity on behavioural (error rate and reaction time) and neuronal parameters (event-related potentials) through parabolic flights. Brain cortical activity was assessed using EEG from 18 participants who solved a neurocognitive task, consisting of a mental arithmetic task and an auditory oddball paradigm, during Earth (1G), Lunar (0.16G + 0.25G) and Martian gravity (0.38G + 0.5G) for 15 consecutive parabolas. Data shows higher electrocortical activity in Earth gravity compared to Lunar and Martian gravity in the parietal lobe. No differences in participants' performance were found among the gravity levels. Event-related potentials displayed gravity-dependent variations, though limited stimuli recording suggests caution in interpretation. Data suggests a threshold between Earth and Martian gravity within the different gravities responsible for physiological changes, but it seems to vary greatly between individuals. The altered neuronal communication could be explained with a model developed by Kohn and Ritzmann in 2018. The increasing intracranial pressure in weightlessness changes the properties of the cell membrane of neurons and leads to a depolarisation of the resting membrane potential. The findings underscore the individuality of physiological changes in response to gravity alterations, signalling the need for further investigations in future studies.


Subject(s)
Cognition , Electroencephalography , Evoked Potentials , Humans , Male , Adult , Female , Evoked Potentials/physiology , Cognition/physiology , Young Adult , Brain/physiology , Gravitation , Reaction Time/physiology , Weightlessness , Moon
6.
Aerosp Med Hum Perform ; 95(6): 327-332, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38790129

ABSTRACT

INTRODUCTION: The absence of a consistent downward G vector can make separation of gases from liquids challenging, such as in field medicine without stable upright equipment or during spaceflight. This limits the use of medical equipment and procedures like administration of intravenous (IV) fluids in microgravity and can make field medicine hazardous. Administering IV fluids and medications in microgravity requires a technique to separate air from the liquid phase. Current commercial filters for separation of gases are incompatible with high flow and blood. We present a novel filter designed to provide adequate air clearance without a consistent downward G vector.METHODS: Inline air-eliminating filters were designed for use with IV fluid tubing in microgravity using computer-aided design software and printed using nylon 12 on an EOS Selective Laser Sintering 3D printer. A 0.2-µm membrane filter was adhered around a central, hollow pillar with external spiral baffles allowing separation and venting of air from the fluid. Results were compared against commercially available inline air-eliminating filters.RESULTS: The 3D-printed filters outperformed the commercial filters in both percentage of air removed and flow rates. The centrifugal, baffled filter had flow rates that far exceeded the commercial filters during rapid transfusion.DISCUSSION: IV fluid administration is an often underappreciated and a necessary basic requirement for medical treatment. An air-eliminating filter compatible with blood and rapid transfusion was developed and validated with crystalloid solutions to allow the successful administration of IV fluid and medication without a consistent downward G vector.Formanek A, Townsend J, Ottensmeyer MP, Kamine TH. A novel 3D-printed gravity-independent air-eliminating filter for rapid intravenous infusions. Aerosp Med Hum Perform. 2024; 95(6):327-332.


Subject(s)
Equipment Design , Printing, Three-Dimensional , Humans , Infusions, Intravenous/instrumentation , Filtration/instrumentation , Aerospace Medicine , Weightlessness , Gravitation , Computer-Aided Design
7.
J Bodyw Mov Ther ; 38: 133-142, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38763552

ABSTRACT

INTRODUCTION: Posture is a facet of clinical assessment in several rehabilitative disciplines. Despite extensive clinical focus, the precision with which posture can be evaluated and intervened upon is limited by the very general terms used to describe it. The purpose of this crossover trial was to quantify the effects of targeted postural intervention motivated by theoretical sagittal gravitational collapsing (SGC) tendencies on: 1) distance from SGC, 2) intermuscular coherence (iCOH), and 3) kinematic chain connectivity. METHODS: Ten healthy adults (24.50 ± 1.18 years, 172.72 ± 10.19 cm, 76.47 ± 14.60 kg) completed pre- and post-intervention testing on two occasions involving contrasting interventions: promote postural muscle (PPM) vs. reduce compensatory muscle (RCM) engagement. Distance from SGC, iCOH, and kinematic chain connectivity were quantified from electromyography and/or kinematic data acquired during tests administered before and after interventions. Effects of Treatment [PPM, RCM] and Time [Pre, Post] were tested with linear mixed models. RESULTS: A Treatment*Time interaction was observed for distance from SGC. Post-intervention distance from SGC was greater following PPM only (p < 0.01). A Treatment*Time interaction was observed for hi-frequency trunk muscle iCOH, with a post-intervention increase corresponding to the RCM intervention (p < 0.007). Additional iCOH effects did not differ by intervention. CONCLUSION: Distance from SGC is acutely modifiable and increases following exercises to facilitate anti-SGC muscles. Convergent findings related to kinematic chain connectivity and prescriptive neural binding were not observed. These observations suggest that it may be possible to describe, evaluate, and intervene upon posture in reference to a specific, mechanistic theory regarding the function of postural alignment.


Subject(s)
Cross-Over Studies , Electromyography , Muscle, Skeletal , Posture , Humans , Male , Young Adult , Adult , Muscle, Skeletal/physiology , Female , Biomechanical Phenomena/physiology , Posture/physiology , Postural Balance/physiology , Gravitation
8.
Ying Yong Sheng Tai Xue Bao ; 35(3): 749-758, 2024 Mar 18.
Article in English | MEDLINE | ID: mdl-38646763

ABSTRACT

With the economic development, a large number of engineering accumulation bodies with Lou soil as the main soil type were produced in Guanzhong area, Northwest China. We examined the characteristics of runoff and sediment yield of Lou soil accumulation bodies with earth (gravel content 0%) and earth-rock (gravel content 30%) under different rainfall intensities (1.0, 1.5, 2.0, 2.5 mm·min-1) and different slope lengths (3, 5, 6.5, 12 m) by the simulating rainfall method. The results showed that runoff rate was relatively stable when rainfall intensity was 1.0-1.5 mm·min-1, while runoff rate fluctuated obviously when rainfall intensity was 2.0-2.5 mm·min-1. The average runoff rate varied significantly across different rainfall intensities on the same slopes, and the difference of average runoff rate of the two slopes was significantly increased with rainfall intensity. Under the same rainfall intensity, the difference in runoff rate between the slope lengths of the earth-rock slope was more obvious than that of the earth slope. When the slope length was 3-6.5 m, flow velocity increased rapidly at first and then increased slowly or tended to be stable. When the slope length was 12 m, flow velocity increased significantly. In general, with the increases of rainfall intensity, inhibition effect of gravel on the average flow velocity was enhanced. When rainfall intensity was 2.5 mm·min-1, the maximum reduction in the average flow velocity of earth-rock slope was 61.5% lower than that of earth slope. When rainfall intensity was less than 2.0 mm·min-1, sediment yield rate showed a trend of gradual decline or stable change, while that under the other rainfall intensities showed a trend of rapid decline and then fluctuated sharply. The greater the rainfall intensity, the more obvious the fluctuation. There was a significant positive correlation between the average sediment yield rate and runoff parameters, with the runoff rate showing the best fitting effect. Among the factors, slope length had the highest contribution to runoff velocity and rainfall erosion, which was 51.8% and 35.5%, respectively. This study can provide scientific basis for soil and water erosion control of engineering accumulation in Lou soil areas.


Subject(s)
Geologic Sediments , Rain , Soil , Water Movements , China , Soil/chemistry , Ecosystem , Environmental Monitoring/methods , Gravitation , Engineering
9.
Physiol Rep ; 12(7): e15983, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38605405

ABSTRACT

Siphons are devices that transport liquids uphill between two containers. It has been proposed that a siphon principle operates in closed circulatory systems, as best exemplified by the circulation of blood in mammals. This principle is supposed to ensure that no additional work is necessary to pump blood above the level of the heart, and that there is no gravitational static pressure gradient in the column of blood. The first statement is correct, while we demonstrate that, ignoring hydraulic resistance to blood flow, the static pressure gradient is equal to the hydrostatic gradient in a siphon model of blood circulation, although the details of the proof do not depend on the geometry of the circulatory system and the proof can be trivially extended to other models such as a vascular waterfall. This implies that the controversy over the siphon principle has no implications for the description of blood circulation, and that mechanisms such as the "baffle," which some authors have appealed to in order to obtain the expected gradient, are not necessary. In our discussion, we also discuss empirical data that appear to provide additional verification of our results, as well as several everyday occurrences that provide additional support.


Subject(s)
Heart , Hemodynamics , Animals , Gravitation , Mammals
10.
Forensic Sci Int ; 357: 111986, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38492269

ABSTRACT

The first point of contact between a spherical blood drop and a surface is related to the angle between the trajectory of the blood drop and the surface being struck. This angle is often referred to as the impact angle which can be estimated by knowing the width and length of the resultant elliptical bloodstain. Most software programs dedicated to area of origin analysis indicate the location of the backtracked bloodstain trajectory to be at the geometric centre or at the tip of the bloodstain ellipse. However, it is unknown how the first point of contact and the blood drop trajectory (here defined as the locus of the centre of mass of the drop as it travels) are related empirically. Thus, this study aims to look at how the initial point of contact and the trajectory at the impact of a blood drop relates to the formed bloodstain ellipse. Two volumes of blood (0.013 ml and 0.071 ml) were dropped from a height of 10 cm and 40 cm onto an inclined surface at 0°, 15°, 30°, 45°, 60°, and 75°. The transition from a spherical blood drop to an elliptically shaped bloodstain was recorded using a high-speed camera for all tests. A total of 72 ellipses were analyzed to determine the location of the first point of contact and trajectory point of the blood drop and how they relate to the formed elliptical bloodstain. A relationship was found between the first point of contact and the bloodstain trajectory which was dependent on the impact angle. However, there were clear deviations from theoretical assumptions due to blood drop oscillations, the effects of gravity, and the natural fluid characteristics of blood. The results of this study may assist bloodstain pattern analysts and software developers by more accurately applying the location of the blood drop trajectory based on empirical data.


Subject(s)
Blood Stains , Forensic Medicine , Forensic Medicine/methods , Software , Gravitation
11.
Phys Med Biol ; 69(8)2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38484392

ABSTRACT

Objective.Monolithic crystal detectors are increasingly being applied in positron emission tomography (PET) devices owing to their excellent depth-of-interaction (DOI) resolution capabilities and high detection efficiency. In this study, we constructed and evaluated a dual-ended readout monolithic crystal detector based on a multiplexing method.Approach.We employed two 12 × 12 silicon photomultiplier (SiPM) arrays for readout, and the signals from the 12 × 12 array were merged into 12 X and 12 Y channels using channel multiplexing. In 2D reconstruction, three methods based on the centre of gravity (COG) were compared, and the concept of thresholds was introduced. Furthermore, a light convolutional neural network (CNN) was employed for testing. To enhance depth localization resolution, we proposed a method by utilizing the mutual information from both ends of the SiPMs. The source width and collimation effect were simulated using GEANT4, and the intrinsic spatial resolution was separated from the measured values.Main results.At an operational voltage of 29 V for the SiPM, an energy resolution of approximately 12.5 % was achieved. By subtracting a 0.8 % threshold from the total energy in every channel, a 2D spatial resolution of approximately 0.90 mm full width at half maximum (FWHM) can be obtained. Furthermore, a higher level of resolution, approximately 0.80 mm FWHM, was achieved using a CNN, with some alleviation of edge effects. With the proposed DOI method, a significant 1.36 mm FWHM average DOI resolution can be achieved. Additionally, it was found that polishing and black coating on the crystal surface yielded smaller edge effects compared to a rough surface with a black coating.Significance.The introduction of a threshold in COG method and a dual-ended readout scheme can lead to excellent spatial resolution for monolithic crystal detectors, which can help to develop PET systems with both high sensitivity and high spatial resolution.


Subject(s)
Neural Networks, Computer , Positron-Emission Tomography , Positron-Emission Tomography/methods , Photons , Gravitation
12.
Stud Hist Philos Sci ; 104: 119-129, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38513468

ABSTRACT

In this paper I discuss the first "multi-messenger" observations of a binary neutron star merger and kilonova. These observations, touted as "revolutionary," included both gravitational-wave and electromagnetic observations of a single source. I draw on analogies between astrophysics and historical sciences (e.g., paleontology) to explain the significance of this for (gravitational-wave) astrophysics. In particular, I argue that having independent lines of evidence about a target system enables the use of argumentative strategies-the "Sherlock Holmes" method and consilience-that help overcome the key challenges astrophysics faces as an observational and historical science.


Subject(s)
Gravitation , Neutrons , Paleontology
13.
Stud Hist Philos Sci ; 104: 130-149, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38518509

ABSTRACT

The early history of string theory is marked by a shift from strong interaction physics to quantum gravity. The first string models and associated theoretical framework were formulated in the late 1960s and early 1970s in the context of the S-matrix program for the strong interactions. In the mid-1970s, the models were reinterpreted as a potential theory unifying the four fundamental forces. This paper provides a historical analysis of how string theory was developed out of S-matrix physics, aiming to clarify how modern string theory, as a theory detached from experimental data, grew out of an S-matrix program that was strongly dependent upon observable quantities. Surprisingly, the theoretical practice of physicists already turned away from experiment before string theory was recast as a potential unified quantum gravity theory. With the formulation of dual resonance models (the "hadronic string theory"), physicists were able to determine almost all of the models' parameters on the basis of theoretical reasoning. It was this commitment to "non-arbitrariness", i.e., a lack of free parameters in the theory, that initially drove string theorists away from experimental input, and not the practical inaccessibility of experimental data in the context of quantum gravity physics. This is an important observation when assessing the role of experimental data in string theory.


Subject(s)
Gravitation , Quantum Theory , Vibration
14.
J Exp Child Psychol ; 242: 105896, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38520769

ABSTRACT

Decisions about how to divide resources have profound social and practical consequences. Do explanations regarding the source of existing inequalities influence how children and adults allocate new resources? When 3- to 6-year-old children (N = 201) learned that inequalities were caused by structural forces (stable external constraints affecting access to resources) as opposed to internal forces (effort), they rectified inequalities, overriding previously documented tendencies to perpetuate inequality or divide resources equally. Adults (N = 201) were more likely than children to rectify inequality spontaneously; this was further strengthened by a structural explanation but reversed by an effort-based explanation. Allocation behaviors were mirrored in judgments of which allocation choices by others were appropriate. These findings reveal how explanations powerfully guide social reasoning and action from childhood through adulthood.


Subject(s)
Problem Solving , Social Behavior , Child , Adult , Humans , Child, Preschool , Judgment , Gravitation
15.
J Vis ; 24(3): 2, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38436983

ABSTRACT

Humans can accurately estimate and track object motion, even if it accelerates. Research shows that humans exhibit superior estimation and tracking performance for descending (falling) than ascending (rising) objects. Previous studies presented ascending and descending targets along the gravitational and body axes in an upright posture. Thus, it is unclear whether humans rely on congruent information between the direction of the target motion and gravity or the direction of the target motion and longitudinal body axes. Two experiments were conducted to explore these possibilities. In Experiment 1, participants estimated the arrival time at a goal for both upward and downward motion of targets along the longitudinal body axis in the upright (both axes of target motion and gravity congruent) and supine (both axes incongruent) postures. In Experiment 2, smooth pursuit eye movements were assessed while tracking both targets in the same postures. Arrival time estimation and smooth pursuit eye movement performance were consistently more accurate for downward target motion than for upward motion, irrespective of posture. These findings suggest that the visual experience of seeing an object moving along an observer's leg side in everyday life may influence the ability to accurately estimate and track the descending object's motion.


Subject(s)
Gravitation , Posture , Humans , Motion , Pursuit, Smooth
16.
J Exp Psychol Hum Percept Perform ; 50(5): 451-463, 2024 May.
Article in English | MEDLINE | ID: mdl-38421793

ABSTRACT

A wealth of converging research lines has led support to the notion that specialized neural processes output a priori information about the expected effects of gravity to fine-tune motor and perceptual responses to dynamic events. Arguably, these putative internal models of gravity might modulate the efficiency in visual search for objects conforming or not to gravitationally coherent dynamics. In the present work, we explored this possibility with a visual search task involving arrays of two to eight objects moving periodically back and forth. The target could be an accelerating/decelerating ball (as if bouncing on earth's surface-1g) with distractors moving at a constant speed (0g) or the reverse. Moreover, the direction of the gravitational pull, as implied by the 1g motion patterns, could be aligned or misaligned with Earth's gravity. Overall, searches for 1g targets were more efficient than 0g targets except, notably, when stimuli displays were congruent with Earth's gravitational pull, in which case the visual search asymmetry is significantly reduced. Outcomes are interpreted as reflecting the joint and mutually cancelling contribution of low-level detection of acceleration patterns and higher level detection of unexpected violations of gravitational motion. (PsycInfo Database Record (c) 2024 APA, all rights reserved).


Subject(s)
Motion Perception , Humans , Motion Perception/physiology , Gravitation , Photic Stimulation
17.
Environ Sci Pollut Res Int ; 31(11): 17206-17225, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38334925

ABSTRACT

Extreme flood events have been recorded recently in the Mahanadi River basin in India with a high destructive potential that causes large social and economic damages. Because fewer hydrometeorological stations can record the flood magnitude in the basin, exploring new datasets like Gravity Recovery and Climate Experiment (GRACE) becomes important to overcome the barriers of assessing the hydrological extremes. The study estimates the flood potential using the GRACE-based terrestrial water storage (TWS) and analytical hierarchy process (AHP)-based topographic flood susceptibility to model the non-stationary flood frequency. During extreme flood events, the magnitude of the combined flood potential index (CFPI) is high (CFPI > 0.6), which correlates with higher river discharge. The CFPI value for the 2012 flood event with a discharge of 11,000 m3/sec (corresponds to a 35-year return period) is recorded at 0.67. Likewise, the CFPI for the flood event in 2011, which corresponds to a return period of 17 years, also stands at 0.63. The overall correlation between the discharge values of various flood events and CFPI values is above 0.8 for all locations, indicating GRACE-based CFPI's applicability for identifying the flood risk for larger basins like Mahanadi. Furthermore, on integrating CFPI as a covariate in non-stationary flood frequency modeling, the study found its superior performance when compared to both stationary models and non-stationary models with time or other climate indices as covariates, thus, helping in accurate estimation of flood return levels that are very useful in the hydrological design of water resources projects.


Subject(s)
Floods , Rivers , India , Climate , Gravitation
18.
Plant Physiol ; 195(2): 1229-1255, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38366651

ABSTRACT

Trees with weeping shoot architectures are valued for their beauty and are a resource for understanding how plants regulate posture control. The peach (Prunus persica) weeping phenotype, which has elliptical downward arching branches, is caused by a homozygous mutation in the WEEP gene. Little is known about the function of WEEP despite its high conservation throughout Plantae. Here, we present the results of anatomical, biochemical, biomechanical, physiological, and molecular experiments that provide insight into WEEP function. Our data suggest that weeping peach trees do not have defects in branch structure. Rather, transcriptomes from the adaxial (upper) and abaxial (lower) sides of standard and weeping branch shoot tips revealed flipped expression patterns for genes associated with early auxin response, tissue patterning, cell elongation, and tension wood development. This suggests that WEEP promotes polar auxin transport toward the lower side during shoot gravitropic response, leading to cell elongation and tension wood development. In addition, weeping peach trees exhibited steeper root systems and faster lateral root gravitropic response. This suggests that WEEP moderates root gravitropism and is essential to establishing the set-point angle of lateral roots from the gravity vector. Additionally, size exclusion chromatography indicated that WEEP proteins self-oligomerize, like other proteins with sterile alpha motif domains. Collectively, our results from weeping peach provide insight into polar auxin transport mechanisms associated with gravitropism and lateral shoot and root orientation.


Subject(s)
Gravitropism , Indoleacetic Acids , Plant Proteins , Prunus persica , Indoleacetic Acids/metabolism , Gravitropism/physiology , Gravitropism/genetics , Prunus persica/genetics , Prunus persica/physiology , Prunus persica/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Shoots/genetics , Plant Shoots/physiology , Plant Shoots/growth & development , Gene Expression Regulation, Plant , Gravitation , Trees/physiology , Trees/genetics
19.
Prog Biophys Mol Biol ; 188: 24-30, 2024 May.
Article in English | MEDLINE | ID: mdl-38395203

ABSTRACT

There is a consensus that we are conscious of something greater than ourselves, as if we are derived from some other primordial set of principles. Classical or Newtonian physics is based on the Laws of Nature. Conversely, in a recent series of articles, it has been hypothesized that the cell was formed from lipid molecules submerged in the primordial ocean that covered the earth 100 million years after it formed. Since lipids are amphiphiles, with both a positively- and negatively-charged pole, the negatively-charged pole is miscible in water. Under the influence of earth's gravity, the lipid molecules stand up perpendicularly to the surface of the water, packing together until the negative charge neutralizes the Van der Waals force for surface tension, causing the lipid molecules to 'leap' into the micellar form as a sphere with a semi-permeable membrane. Particles in the water freely enter and exit such spheres based on mass action. Over time such protocells evolved Symbiogenesis, encountering factors that posed existential threats, assimilating them to form physiology to maintain homeostatic control. Importantly, when differentiated lung or bone cells are exposed to zero gravity, they lose their phenotypic identity in their evolved state, which has been interpreted as transiting from local to non-local consciousness.


Subject(s)
Consciousness , Physics , Gravitation , Water , Lipids
20.
Environ Sci Pollut Res Int ; 31(10): 15900-15919, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38308779

ABSTRACT

The long-term dynamic comprehensive evaluation of the water resource carrying capacity (WRCC) and the analysis of its potential driving mechanism in arid areas are contemporary research issues and technical means of mitigating and coordinating the conflict between severe resource shortages and human needs. The purpose of this study was to explore the distribution of the WRCC and the spatiotemporal heterogeneity of drivers in arid areas based on an improved two-dimensional spatiotemporal dynamic evaluation model. The results show that (1) the spatial distribution of the WRCC in Xinjiang, China, is high in the north, low in the south, high in the west, and low in the east. (2) From 2005 to 2020, the centers of gravity of the WRCC in northern and southern Xinjiang moved to the southeast and west, respectively, and the spatial distribution exhibited slight diffusion. (3) The factors influencing the WRCC exhibit more obvious spatial and temporal heterogeneity. The domestic waste disposal rate and ecological water use rate were the main factors influencing the WRCC in the early stage, while the GDP per capita gradually played a dominant role in the later stage. (4) In the next 30 years, the WRCC in Xinjiang will increase. The results provide a theoretical reference for the sustainable development of water resources in arid areas.


Subject(s)
Gravitation , Water Resources , Humans , China , Diffusion , Head
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