Gravity Changes Research Articles

Correlation between baropodometric variables, disability, and intensity of low back pain in pregnant women in the third trimester

BackgroundGrowth of uterus, enlargement of breasts and weight gain result from the development and growth of the fetus during pregnancy. The posture and the displacement of the center of gravity change. ObjectiveCorrelate baropodometric variables with low back pain in pregnant women in the third trimester of pregnancy. MethodsThis is a cross-sectional analytical study conducted in São Luís (MA, Brazil). For data collection, we used a form containing sociodemographic and clinical data, Oswestry Disability Questionnaire for disability evaluation of the lumbar spine, Numerical Rating Scale to measure pain intensity, and baropodometric evaluation. ResultsTwenty-five pregnant women took part in the study. There was a significant and positive correlation (r = 0.404, p = 0.045) between functional disability and hindfoot pressure and a significant and negative correlation (r = −0.404, p = 0.045) between functional disability and plantar pressure in the forefoot of the right foot. In addition, there was a positive and significant correlation between the intensity of pain and the contact area on the left (r = 0.504, p = 0.010) and right (r = 0.509, p = 0.009) foot. ConclusionThere is a relation between disability and plantar pressure and between pain intensity and area of contact of feet in pregnant women.

Combined Environment Simulator for Low-Dose-Rate Radiation and Partial Gravity of Moon and Mars.

Deep space exploration by humans has become more realistic, with planned returns to the Moon, travel to Mars, and beyond. Space radiation with a low dose rate would be a constant risk for space travelers. The combined effects of space radiation and partial gravity such as on the Moon and Mars are unknown. The difficulty for such research is that there are no good simulating systems on the ground to investigate these combined effects. To address this knowledge gap, we developed the Simulator of the environments on the Moon and Mars with Neutron irradiation and Gravity change (SwiNG) for in vitro experiments using disposable closed cell culture chambers. The device simulates partial gravity using a centrifuge in a three-dimensional clinostat. Six samples are exposed at once to neutrons at a low dose rate (1 mGy/day) using Californium-252 in the center of the centrifuge. The system is compact including two SwiNG devices in the incubator, one with and one without radiation source, with a cooling function. This simulator is highly convenient for ground-based biological experiments because of limited access to spaceflight experiments. SwiNG can contribute significantly to research on the combined effects of space radiation and partial gravity.

Coastal sea level anomalies and associated trends from Jason satellite altimetry over 2002\u20132018

Climate-related sea level changes in the world coastal zones result from the superposition of the global mean rise due to ocean warming and land ice melt, regional changes caused by non-uniform ocean thermal expansion and salinity changes, and by the solid Earth response to current water mass redistribution and associated gravity change, plus small-scale coastal processes (e.g., shelf currents, wind & waves changes, fresh water input from rivers, etc.). So far, satellite altimetry has provided global gridded sea level time series up to 10–15 km to the coast only, preventing estimation of sea level changes very close to the coast. Here we present a 16-year-long (June 2002 to May 2018), high-resolution (20-Hz), along-track sea level dataset at monthly interval, together with associated sea level trends, at 429 coastal sites in six regions (Northeast Atlantic, Mediterranean Sea, Western Africa, North Indian Ocean, Southeast Asia and Australia). This new coastal sea level product is based on complete reprocessing of raw radar altimetry waveforms from the Jason-1, Jason-2 and Jason-3 missions.

Modelling ground displacement and gravity changes with the MUFITS simulator

Abstract. We present an extension of the MUFITS reservoir simulator for modelling the ground displacement and gravity changes associated with subsurface flows in geologic porous media. Two different methods are implemented for modelling the ground displacement. The first approach is simple and fast and is based on an analytical solution for the extension source in a semi-infinite elastic medium. Its application is limited to homogeneous reservoirs with a flat Earth surface. The second, more comprehensive method involves a one-way coupling of MUFITS with geomechanical code presented for the first time in this paper. We validate the accuracy of the development by considering a benchmark study of hydrothermal activity at Campi Flegrei (Italy). We investigate the limitations of the first approach by considering domains for the geomechanical problem that are larger than those for the fluid flow. Furthermore, we present the results of more complicated simulations in a heterogeneous subsurface when the assumptions of the first approach are violated. We supplement the study with the executable of the simulator for further use by the scientific community.

Early earthquake detection capabilities of different types of future-generation gravity gradiometers

SUMMARY Since gravity changes propagate at the speed of light, gravity perturbations induced by earthquake deformation have the potential to enable faster alerts than the current earthquake early warning systems based on seismic waves. Additionally, for large earthquakes (Mw > 8), gravity signals may allow for a more reliable magnitude estimation than seismic-based methods. Prompt elastogravity signals induced by earthquakes of magnitude larger than 7.9 have been previously detected with seismic arrays and superconducting gravimeters. For smaller earthquakes, down to Mw ≃ 7, it has been proposed that detection should be based on measurements of the gradient of the gravitational field, in order to mitigate seismic vibration noise and to avoid the cancelling effect of the ground motions induced by gravity signals. Here we simulate the five independent components of the gravity gradient signals induced by earthquakes of different focal mechanisms. We study their spatial amplitude distribution to determine what kind of detectors is preferred (which components of the gravity gradient are more informative), how detectors should be arranged and how earthquake source parameters can be estimated. The results show that early earthquake detections, within 10 s of the rupture onset, using only the horizontal gravity strain components are achievable up to about 140 km distance from the epicentre. Depending on the earthquake focal mechanism and on the detector location, additional measurement of the vertical gravity strain components can enhance the detectable range by 10–20 km. These results are essential for the design of gravity-based earthquake early warning systems.

The NEWTON-g Gravity Imager: Toward New Paradigms for Terrain Gravimetry

Knowledge of the spatio-temporal changes in the characteristics and distribution of subsurface fluids is key to properly addressing important societal issues, including: sustainable management of energy resources (e.g., hydrocarbons and geothermal energy), management of water resources, and assessment of hazard (e.g., volcanic eruptions). Gravimetry is highly attractive because it can detect changes in subsurface mass, thus providing a window into processes that involve deep fluids. However, high cost and operating features associated with current instrumentation seriously limits the practical field use of this geophysical method. The NEWTON-g project proposes a radical change of paradigm for gravimetry through the development of a field-compatible measuring system (the gravity imager), able to real-time monitor the evolution of the subsurface mass changes. This system includes an array of low-costs microelectromechanical systems-based relative gravimeters, anchored on an absolute quantum gravimeter. It will provide imaging of gravity changes, associated with variations in subsurface fluid properties, with unparalleled spatio-temporal resolution. During the final ∼2 years of NEWTON-g, the gravity imager will be field tested in the summit of Mt. Etna volcano (Italy), where frequent gravity fluctuations, easy access to the active structures and the presence of a multiparameter monitoring system (including traditional gravimeters) ensure an excellent natural laboratory for testing the new tools. Insights from the gravity imager will be used to i) improve our knowledge of the cause-effect relationships between volcanic processes and gravity changes observable at the surface and ii) develop strategies to best incorporate the gravity data into hazards assessments and mitigation plans. A successful implementation of NEWTON-g will open new doors for geophysical exploration.

Focal mechanism of the great 2004 Sumatra earthquake by joint inversion of GPS deformation field and GRACE gravity change

In this study, the gravity changes observed by GRACE satellites along with the deformation field determined from GPS velocity vectors are used to estimate the fault parameters of 2004 Sumatra-Andaman Earthquake (SAE) by the inversion of PSGRN/PSCMP dislocation model. To do so, the co-seismic gravity changes are determined by fitting a time-series function to the GRACE monthly gravity fields and the effects of hydrology are suppressed with the aid of Global Land Data Assimilation (GLDAS) model. To increase the accuracy of inversion process, the GPS observed co-seismic and post-seismic displacements from 90 stations scattered across the deformed area are also used to constrain the inversion algorithm.The inversion is performed via the Particle Swarm Optimization (PSO) method that minimizes the error between the model-predicted and observed deformation and gravity changes. To this end, the PSGRN/PSMCP dislocation model predicts the deformation and gravity changes for each candidate fault in the PSO iterative process. It is shown that the joint use of the GPS and GRACE data in determination of focal mechanism, results in a fault model that is better consistent with the geometry of the existing subduction zone compared to the inverted fault using only GPS or GRACE data. Due to the complex geometry of the Sunda Trench, a discretized rectangular fault system is considered that allows the depth, slip, strike angle and dip angle vary between the sub-faults. In fact, the estimated fault model consists of 100 sub-faults with a total moment magnitude of Mw = 9.23 that matches the curved geometry of the Sunda Trench. The fault model reveals that the slip has a greater magnitude in segments near the northern Sumatra and Nicobar islands while for the segments of the fault, near the Andaman Islands, the slip is relatively smaller and has its greater magnitudes at depth. The depths and dip angles of the estimated fault model are compared to the SLAB2 3D geometry provided for the Sumatra and Java subduction zones and through this comparison, the RMSEs of 6.0 km for the depth and 3.1 ° for the dip angle are obtained.

Performance of GRACE Mascon Solutions in Studying Seismic Deformations

AbstractGRACE (Gravity Recovery and Climate Experiment) mascon (mass concentration) solutions are widely used in cryosphere science and hydrology research. Mascon solutions have been demonstrated to perform analogous to or better than spherical harmonic (SH) solutions at the basin scale. Although the mascon solutions are expected to facilitate an improved local recovery of seismic gravity signals of large earthquakes, the application of mascon solutions to earthquake analysis remains to be investigated. In this study, we examine the performance of the mascon solutions for seismic gravity signals induced by three M9 class (2011 Tohoku‐Oki, 2004 Sumatra, and 2010 Chile) and three smaller earthquakes and compare them with SH solutions and theoretical gravity changes modeled according to the dislocation theory. We analyze the coseismic and postseismic gravity changes and conclude that the mascon solutions contain information almost identical to the SH solutions and retrieve coseismic gravity change signals with resolutions equivalent to Gaussian filter radii of 210–270 km. The mascon solutions have strengthened gravity change signals of approximately twice the strength of the SH solutions. However, mascon solution cannot fully recover the complete seismic deformation since it is still a spatially “band‐limited” data set that uses the spatial smoothing in the aggressive regularization. We found that the mascon solutions contain “seismic‐like” gravity change signals several months before the Tohoku‐Oki and Chile earthquakes occurred.

The effect of hypergravity on upright balance and voluntary sway.

We compared voluntary oscillatory sway for eight subjects tested in 1.8-g and 1-g gravito-inertial force (GIF) levels of parabolic flight. Subjects performed voluntary forward-backward (FB) and lateral left-right (LR) swaying as the forces and moments under the soles of each foot were measured. We calculated the experimental values of three parameters: two ankle stiffness parameters KSAP and KSML acting in orthogonal FB and LR directions and one parameter KED related to leg pivot shifting. Simulations of the engaged leg model (Bakshi A, DiZio P, Lackner JR. J Neurophysiol 121: 2042-2060, 2019; Bakshi A, DiZio P, Lackner JR. J Neurophysiol 121: 2028-2041, 2019) correctly predicted the experimentally determined stability bounds of upright balance and also the scaling of the postural parameters as a function of GIF magnitude. The effective stiffness, KSAP, at the ankles played the primary role to prevent falling in FB swaying and both model predictions, and experimental data showed KSAP to scale up in proportion to GIF magnitude. For LR swaying, the model predicted a 3:4 scaling of anterior-posterior stiffness to change in GIF magnitude, which was borne out by the experimental data. Simulations predict stability (nonfalling) not to depend on lateral stiffness, KSML, which was experimentally found not to depend on the GIF magnitude. Both model and experiment showed that the geometry-dependent pivot shift parameter KED was invariant to a change in GIF magnitude. Thus the ELM explains voluntary sway and balance in altered GIF magnitude conditions, rotating environments with Coriolis perturbations of sway, as well as normal terrestrial conditions.NEW & NOTEWORTHY A nonparallel leg model of balance, the engaged leg model (ELM), was previously developed to characterize adaptive balance control in a rotating environment. Here we show the ELM also explains sway in hypergravity. It predicts the changes in balance control parameters with changes in gravity. ELM is currently the only balance model applicable to artificial and hypergravity conditions. ELM can also be applied to terrestrial clinical situations for pathologies that generate postural asymmetries.

Improved IMU Preintegration with Gravity Change and Earth Rotation for Optimization-Based GNSS/VINS

IMU preintegration technology has been widely used in the optimization-based sensor fusion framework, in order to avoid reintegrating the high-frequency IMU measurements at each iteration and maintain the ability of bias correction when bias estimation changes. Since IMU preintegration technology was first proposed, several improved versions have been designed by changing the attitude parameterization or the numerical integration method in the most current related research. However, all of these versions have failed to take the change of gravity and the earth rotation into consideration. In this paper, we redesign the IMU preintegration algorithm in which the earth rotation and gravity vector are calculated from the geodetic position. Compared with the covariance matrix form, in this paper, the uncertainty of the preintegrated IMU measurements is propagated in the form of a square root information matrix (SRIM) for better numerical stability and easy use in the optimization-based framework. We evaluate the improved IMU preintegration algorithm by using the dataset collected by our sensor platform equipped with two different-grade IMUs. The test results show that the improved IMU preintegration algorithm can cope well with the gravity change and earth rotation. The earth rotation must be taken into consideration for the high-grade IMU that can effectively sense the earth rotation. If the change of gravity is omitted, the root-mean-square error (RMSE) of the horizontal attitude is about 1.38 times greater than the geodetic displacement. Additionally, the positioning RMSE does not increase obviously within a limited range, which means tens of kilometers and several hundred meters for the low-grade and high-grade IMU used in the experiment, respectively.

Measuring Aquifer Specific Yields With Absolute Gravimetry: Result in the Choushui River Alluvial Fan and Mingchu Basin, Central Taiwan

AbstractAccurate and densely covered specific yields (Sy) are essential for estimating the storage capacity of a groundwater reservoir. A cross‐well pumping test can determine Sy, but its high cost often makes it unsuitable for sampling high‐resolution Sy. The gravity‐based method (GBM) based on gravity changes near existing groundwater wells may outperform cross‐well pumping tests in estimating Sy. We established 10 gravity sites close to groundwater wells in the aquifer‐rich Choushui River Alluvial Fan and Mingchu Basin in central Taiwan and measured gravity changes with two FG5 gravimeters from 2012 to 2017. Thirty‐nine Sy values with formal errors are determined by natural rises and falls in gravity and groundwater level. The representative Sy values (0.04 to 0.29) from GBM are in general consistent with those from cross‐well pumping tests (0.03 to 0.24). Repeated groundwater level changes over similar depth range at different times serve as revisit tests, showing that GBM can reproduce a reliable Sy value at a given site and depth. Soil moisture and compaction data show that the effects of gravity changes originating from unsaturated zones and deep aquifer layers are minor. Using the cylinder model for aquifers with limited lateral extents, we assess the validity of the Bouguer model by quantifying gravity differences and relative Sy differences originating from the model assumption. Improvements in environmental resilience and transportability achieved by recent atomic gravimeters may increase the potential of GBM to replace or supplement cross‐well pumping tests in densifying Sy point densities for an improved groundwater resource management.

Accuracy Analysis of Gravity Field Changes from Grace RL06 and RL05 Data Compared to in Situ Gravimetric Measurements in the Context of Choosing Optimal Filtering Type

Abstract Global satellite gravity measurements provide unique information regarding gravity field distribution and its variability on the Earth. The main cause of gravity changes is the mass transportation within the Earth, appearing as, e.g. dynamic fluctuations in hydrology, glaciology, oceanology, meteorology and the lithosphere. This phenomenon has become more comprehensible thanks to the dedicated gravimetric missions such as Gravity Recovery and Climate Experiment (GRACE), Challenging Minisatellite Payload (CHAMP) and Gravity Field and Steady-State Ocean Circulation Explorer (GOCE). From among these missions, GRACE seems to be the most dominating source of gravity data, sharing a unique set of observations from over 15 years. The results of this experiment are often of interest to geodesists and geophysicists due to its high compatibility with the other methods of gravity measurements, especially absolute gravimetry. Direct validation of gravity field solutions is crucial as it can provide conclusions concerning forecasts of subsurface water changes. The aim of this work is to present the issue of selection of filtration parameters for monthly gravity field solutions in RL06 and RL05 releases and then to compare them to a time series of absolute gravimetric data conducted in quasi-monthly measurements in Astro-Geodetic Observatory in Józefosław (Poland). The other purpose of this study is to estimate the accuracy of GRACE temporal solutions in comparison with absolute terrestrial gravimetry data and making an attempt to indicate the significance of differences between solutions using various types of filtration (DDK, Gaussian) from selected research centres.

Co-Seismic and Post-Seismic Temporal and Spatial Gravity Changes of the 2010 Mw 8.8 Maule Chile Earthquake Observed by GRACE and GRACE Follow-on

The Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-on (GRACE-FO) satellites are important for studying regional gravitational field changes caused by strong earthquakes. In this study, we chose Chile, one of Earth’s most active seismic zones to explore the co-seismic and post-seismic gravitational field changes of the 2010 Mw 8.8 Maule earthquake based on longer-term GRACE and the newest GRACE-FO data. We calculated the first-order co-seismic gravity gradient changes (GGCs) and probed the geodynamic characteristics of the earthquake. The earthquake caused significant positive gravity change on the footwall and negative gravity changes on the hanging wall of the seismogenic fault. The time series of gravity changes at typical points all clearly revealed an abrupt change caused by the earthquake. The first-order northern co-seismic GGCs had a strong suppressive effect on the north-south strip error. GRACE-FO results showed that the latest post-seismic gravity changes had obvious inherited development characteristics, and that the west coast of Chile maybe still affected by the post-seismic effect. The cumulative gravity changes simulated based on viscoelastic dislocation model is approximately consistent with the longer-term GRACE and the newest GRACE-FO observations. Our results provide important reference for understanding temporal and spatial gravity variations associated with the co-seismic and post-seismic processes of the 2010 Maule earthquake.

Repeated absolute gravity measurements on a dense network at Campi Flegrei – a reliable tool for volcano monitoring

Abstract. Since 1981, relative gravity measurements have routinely carried out at the Campi Flegrei caldera, a densely populated area. The gravity network also includes two absolute stations periodically measured with a laboratory absolute gravimeter, which does not permit field measurements. At the end of 2014, the Osservatorio Vesuviano, Section of Napoli of the Istituto Nazionale di Geofisica e Vulcanologia (INGV-OV), acquired a portable absolute gravimeter that allows field operations on outdoor sites. Therefore, in 2015 a dense absolute gravity network was established in Campi Flegrei. This will permit an advanced approach for volcano monitoring. The net consists of 36 stations, 34 of which located inside the caldera and placed upon or very close to gravity stations belonging to the relative network. Five surveys were carried out on June 2015, on February and November 2017, on October 2018 and on October 2019. The comparison with height changes suggests that significant Δg are partly due to the uplift occurred over the same time intervals and mostly to shallow processes associated to the dynamic of the local hydrothermal system. The comparison with the gradients observed during the last large uplift (1982–1984) and the following subsidence (1985–2003) confirms this observation. These results suggest that the present activity may be due to a transient or pulsating phenomenon as the alternating recharge/discharge of fluids in the surface hydrothermal system. Gravity changes detected by absolute measurements are in good agreement with those obtained by relative ones, and confirms the feasibility of this methodology for volcano monitoring. Finally, they also encourage replacing the relative networks with absolute ones, with all the consequent advantages.

An illustration of topology change in quantum gravity using the topspin network formalism

We present an algorithm which determines the fundamental group of a spatial section using topspin networks. Tracking the topology of the spatial section is a unique feature of this approach, which is not possible in standard Loop Quantum Gravity. This leads to an example of spatial topology change in a smooth 4-manifold represented by a topspin foam.

Superconducting gravimeter and seismometer shedding light on FG5\u2019s offsets, trends and noise: what observations at Onsala Space Observatory can tell us

Ten-year worth of absolute gravity (AG) campaigns at Onsala Space Observatory (OSO), Sweden, are simultaneously reduced using synchronous data from a superconducting gravimeter (SG). In this multi-campaign adjustment, the a priori models commonly applied for each setup in AG-alone experiments are sidestepped in favour of SG records and a model to estimate its drift. We obtain a residual (hourly samples) at the 5 nm/s^2 RMS level, reducing the SG data with a range of ancillary data for the site’s exposure to ocean and atmospheric loading, and hydrology effects. The target quantity in AG projects in the Baltic Shield area is the secular change of gravity dominated by glacial isostatic adjustment with land uplift as its major part. Investigating into the details of the associated processes using AG requires a long-term stable reference, which is the aim of international comparison campaigns of FG5 instruments. Two of these have been campaigning at OSO since 2009 when the SG had been installed. In the simultaneous inversion of all sixteen campaigns, we identify weaknesses of AG observations, like varying systematic offsets over time, excess microseismic sensitivity, trends in the AG data and side effects on the SG’s scale factor when campaigns are evaluated one by one. The simultaneous adjustment afforded us an SG scale factor very near the result from a campaign with a prototype quantum gravimeter. Whence, we propose that single-campaign results may be biased and conjectures into their variation, let alone its causes misleading. The OSO site appears to present manageable problems as far as environmental influences are concerned. Our findings advocate the use of AG instruments and procedures that are more long-term stable (reference realization), more short-term stable too (setup drifts), less service craving and more resilient to microseismic noise.

Regional aspects of atmospheric air

Monitoring of atmospheric air in urban and rural areas of the Irkutsk region revealed the presence of pollutants. Air pollution is affected by emissions from the largest industrial enterprises in the aluminum, petrochemical and chemical, woodworking and forest industries of the region; annual forest fires significantly aggravate the situation; small boiler houses, furnace heating contribute. The surveys determined a part of the atmospheric air samples with increased MPC in urban and rural areas. Observations of changes in the specific gravity of air pool samples indicate an increase in the inconsistency of hygiene regulations in Bratsk, Irkutsk and Angarsk. Recommendations on reducing exceeded levels of pollutants are given.

Estimating the specific yield of the Pampeano aquifer, Argentina, using superconducting gravimeter data

Specific yield is a key parameter for the sustainable management of unconfined aquifers, since it relates water-table fluctuations to aquifer storage-changes and thus impacts water supply. However, estimating specific yield is still a challenge due to theoretical and methodological limitations. Water-storage changes in the aquifer and in the overlying unsaturated soil profile cause local changes in gravity that can be recorded by high-precision superconducting gravimeters. In this work, a novel methodology to estimate specific yield from superconducting gravimeter data is presented. The proposed methodology is based on a hydrogravimetric model that estimates the gravity response due to the loss and gain of water mass in the soil profile using rainfall, water-table and air-temperature data. The model is applied to a study site of the Pampeano aquifer in Argentina where a continuous 1-year record of superconducting gravimeter measurements is available. The specific yield value obtained using this methodology is 0.11 ± 0.039, which is validated by means of a long-term pumping test performed at the study site. The proposed method constitutes a promising alternative to the available tools for estimating specific yield, by taking advantage of superconducting gravity data.

CMG-based anthropomorphic test device for human rider behavior reproduction for two-wheeled self-balancing personal mobility

With the expansion of the self-balancing personal mobility (SBPM) market, an increasing number of accidents have been reported in recent years, while the relevant safety regulations have not been established yet. Safety and dynamic stability of the SBPM is critical for their operation, and they must be evaluated for them. SBPMs are operated by a human rider even for the evaluation tests, so the objectivity and the repeatability of the tests cannot be ensured. Also, there could even be a safety issue with the test rider. To solve this problem, we propose an anthropomorphic test device (ATD), which is a type of dummy robot. The ATD reproduces the human rider's dynamic behavior using a control moment gyroscope (CMG), so it can drive the SBPM instead of a human rider for the evaluation tests. Just like a human rider controls the SBPM by the disturbance torque made by the posture (i.e. the center of gravity) change, the CMG-based ATD reproduces the dynamic behavior of the SBPM by creating the same disturbance torque using the CMG. A detailed working principle and the design of the CMG-based ATD is introduced in this paper. For the validation of the CMG-based ATD's human rider behavior reproduction performance, the dynamic behavior of the SBPM measured from the actual human ride is compared with the data from the computer simulations.

Sperm Motility of Mice under Simulated Microgravity and Hypergravity.

For deep space exploration, reproductive health must be maintained to preserve the species. However, the mechanisms underlying the effect of changes in gravity on male germ cells remain poorly understood. The aim of this study was to determine the effect of simulated micro- and hypergravity on mouse sperm motility and the mechanisms of this change. For 1, 3 and 6 h, mouse sperm samples isolated from the caudal epididymis were subjected to simulated microgravity using a random position machine and 2g hypergravity using a centrifuge. The experimental samples were compared with static and dynamic controls. The sperm motility and the percentage of motile sperm were determined using microscopy and video analysis, cell respiration was determined by polarography, the protein content was assessed by Western blotting and the mRNA levels were determined using qRT-PCR. The results indicated that hypergravity conditions led to more significant changes than simulated microgravity conditions: after 1 h, the speed of sperm movement decreased, and after 3 h, the number of motile cells began to decrease. Under the microgravity model, the speed of movement did not change, but the motile spermatozoa decreased after 6 h of exposure. These changes are likely associated with a change in the structure of the microtubule cytoskeleton, and changes in the energy supply are an adaptive reaction to changes in sperm motility.