Preconditioning Factor Research Articles

A review of submarine landslides associated with rapid sedimentation

Submarine landslides are a critical geological process that significantly influences seafloor stability and geological evolution, making them a focal point of geological disaster research. Particularly, rapid sedimentation as a crucial preconditioning factor for submarine landslide initiation is increasingly recognized in contemporary research. However, no comprehensive review currently examines the correlation between rapid sedimentation and submarine landslides. To elucidate the interaction mechanisms between submarine landslides and rapid sedimentation and to provide a new theoretical foundation for the prediction and prevention of geological hazards, the study categorizes three primary sedimentation patterns in marine environments and establishes a detailed historical database of sedimentation-related submarine landslide events. Moreover, the paper systematically reviews and critiques the existing research methods and advancements in addressing rapid sedimentation-related submarine landslides, and a bibliometric analysis of recent research progress is conducted. Finally, the study highlights several challenges in the study of rapid sedimentation and proposes future recommendations, aiming to provide robust support for the in-depth investigation of submarine landslides.

A Comprehensive Assessment of Submarine Landslides and Mass Wasting Processes Offshore Southern California

AbstractIt is critical to characterize submarine landslide hazards near dense coastal populations, especially in areas with active faults, which can trigger slope failure, subsequent tsunamis, and damage seabed infrastructure during earthquake shaking. Offshore southern California, numerous marine geophysical surveys have been conducted over the past decade, and high‐resolution bathymetric and subsurface data now cover about 60 percent of the total region between Point Conception and the United States‐Mexico border from the California coast out to the base of Patton Escarpment ∼200 km offshore. In a comprehensive compilation and interpretive mapping effort, we find evidence of seafloor failure throughout offshore southern California with nearly 1,500 submarine landslide‐related features, including 63 discrete slide deposits with debris and >1,400 slide‐related scarps. In our analysis, we highlight new mapping of submarine landslides in Catalina Basin, the Del Mar slide, the San Gabriel slide complex, and the 232 km2 San Nicolas slide, the largest area of any known submarine landslide mass offshore southern California. Analysis of the spatial distribution of submarine landslide features suggests that most mapped slide features are located relatively near coastal sediment sources, particularly during sea‐level lowstand conditions, which underscores the importance of sediment supply and sediment accumulation on low‐gradient slopes as failure preconditioning processes. Tectonically driven uplift at shelf edges and along basin flanks is another key preconditioning factor, and our results also suggest that earthquakes along active faults trigger mass wasting, especially for repeated, small‐scale failures on tectonically steepened slopes.

Improvement of density inversion efficiency with projected gradient method: Application to FTG data

With the development of instruments for measuring Earth's gravity gradient tensor, full tensor gravity (FTG) data can be obtained validly and accurately. The highly precise performance of FTG data ensures that they can play an important role in many domains. Generally, FTG data can be acquired from airborne platform, and large-scale data can be obtained by long term observations. For this type of data, research methods for large data processing are very important. Three-dimensional data inversion is an effective and significant method for the quantitative interpretation of FTG data, which has received much attention. Large-scale data inversion is inevitable, and may consume large amounts of time with increase in the amount of data and model parameters. The main aim of this study is to improve the calculation efficiency of FTG data inversion compared with general conjugate gradient (CG) method. Accordingly, an improved gradient method with projections onto a convex set (the projected gradient method) was applied to accelerate the recovery rate of the sub-surface rock density, and a corresponding preconditioning factor was introduced to further improve the calculation efficiency of inversion. This new projected gradient method can improve the calculation efficiency of large amounts of FTG data, which is very necessary for practical application of FTG data. The application of synthetic FTG data with Gaussian noise and the real data demonstrated the feasibility and application value of the proposed inversion method.

Climate-controlled submarine landslides on the Antarctic continental margin

Antarctica’s continental margins pose an unknown submarine landslide-generated tsunami risk to Southern Hemisphere populations and infrastructure. Understanding the factors driving slope failure is essential to assessing future geohazards. Here, we present a multidisciplinary study of a major submarine landslide complex along the eastern Ross Sea continental slope (Antarctica) that identifies preconditioning factors and failure mechanisms. Weak layers, identified beneath three submarine landslides, consist of distinct packages of interbedded Miocene- to Pliocene-age diatom oozes and glaciomarine diamicts. The observed lithological differences, which arise from glacial to interglacial variations in biological productivity, ice proximity, and ocean circulation, caused changes in sediment deposition that inherently preconditioned slope failure. These recurrent Antarctic submarine landslides were likely triggered by seismicity associated with glacioisostatic readjustment, leading to failure within the preconditioned weak layers. Ongoing climate warming and ice retreat may increase regional glacioisostatic seismicity, triggering Antarctic submarine landslides.

Vitamin D Deficiency Reduces Postthyroidectomy Protracted Hypoparathyroidism Risk. Is Gland Preconditioning Possible?

Hypoparathyroidism is the most frequent complication after total thyroidectomy (PT-hypoPTH). After 1 year, most patients recover parathyroid function; however, the implicated physiologic dynamics remain unknown. Vitamin D deficiency (VDD) is the main cause of secondary hyperparathyroidism. Whether this compensatory hyperparathyroidism could influence parathyroid function recovery (PFR) in the setting of PT-hypoPTH has not been studied. This work aimed to evaluate the effect of preoperative VDD on PFR. A retrospective study was conducted with a prospectively maintained database including patients undergoing a total thyroidectomy between May 2014 and June 2019. Preoperative vitamin D (25(OH)D) less than 20 mg/mL was defined as VDD. Intact PTH less than 14 pg/mL on postoperative day 1 was defined as PT-hypoPTH. Transient PT-hypoPTH displayed PFR within the first year (early recovery: < 30 days; protracted recovery: > 30 days) whereas definite PT-hypoPTH did not. Survival analysis evaluated the effect of preoperative VDD on PFR, and a binary logistic regression model identified associated factors. A total of 397 patients were identified. The observed rates of transient, protracted, and definite PT-hypoPTH were 32.9%, 15.1%, and 5.2%, respectively. Rates of VDD were higher in the early-recovery PT-hypoPTH group (55.2% vs 31.5%; P = .01). Preoperative VDD was associated with faster PFR (19 vs 35 days; P = .03) and behaved as a protective factor for protracted PT-hypoPTH (odds ratio 0.47; 95% CI, 0.25-0.881; P = .016) in the multivariable analysis. Preoperative VDD could act as a preconditioning factor of the parathyroid glands prior to the surgical aggression exerted against them during surgery aiding PFR. Basic research studies and prospective clinical trials are needed to explain the underlying physiological mechanisms and to provide further evidence to improve clinical management.

An Osteosarcoma Model by 3D Printed Polyurethane Scaffold and In Vitro Generated Bone Extracellular Matrix.

Simple SummaryDevelopment of new therapeutics to treat osteosarcoma is fundamental to decreasing its current health impact. 3D in vitro models are gaining tremendous momentum as, compared to traditional 2D in vitro models and in vivo models, can speed up new treatment discovery and provide clarification of the pathology development, by ultimately offering a reproducible and biomimetic tool. However, engineering a 3D osteosarcoma in vitro model is challenging, since the reliability of the models strictly depends on their ability to correctly mimic the physical, mechanical, and biological properties of the pathological tissue to be replicated. Here, we designed 3D printed polyurethane scaffolds enriched by in vitro pre-generated bone extracellular matrix, synthesized by osteo-differentiated human mesenchymal stromal cells, to replicate in vitro an osteosarcoma model, which can be potentially used to study tumor progression and to assess new treatments.Osteosarcoma is a primary bone tumor characterized by a dismal prognosis, especially in the case of recurrent disease or metastases. Therefore, tools to understand in-depth osteosarcoma progression and ultimately develop new therapeutics are urgently required. 3D in vitro models can provide an optimal option, as they are highly reproducible, yet sufficiently complex, thus reliable alternatives to 2D in vitro and in vivo models. Here, we describe 3D in vitro osteosarcoma models prepared by printing polyurethane (PU) by fused deposition modeling, further enriched with human mesenchymal stromal cell (hMSC)-secreted biomolecules. We printed scaffolds with different morphologies by changing their design (i.e., the distance between printed filaments and printed patterns) to obtain different pore geometry, size, and distribution. The printed PU scaffolds were stable during in vitro cultures, showed adequate porosity (55–67%) and tunable mechanical properties (Young’s modulus ranging in 0.5–4.0 MPa), and resulted in cytocompatible. We developed the in vitro model by seeding SAOS-2 cells on the optimal PU scaffold (i.e., 0.7 mm inter-filament distance, 60° pattern), by testing different pre-conditioning factors: none, undifferentiated hMSC-secreted, and osteo-differentiated hMSC-secreted extracellular matrix (ECM), which were obtained by cell lysis before SAOS-2 seeding. Scaffolds pre-cultured with osteo-differentiated hMSCs, subsequently lysed, and seeded with SAOS-2 cells showed optimal colonization, thus disclosing a suitable biomimetic microenvironment for osteosarcoma cells, which can be useful both in tumor biology study and, possibly, treatment.

Weddell Sea polynya analysis using SMOS–SMAP apparent sea ice thickness retrieval

Abstract. The Weddell Sea is known to feature large openings in its winter sea ice field, otherwise known as open-ocean polynyas. An area within the Weddell Sea region that has repeatedly featured open-ocean polynyas in the past is that which encompasses the Maud Rise seamount. Within this area, after 40 years of intermittent, smaller openings, a larger, more persistent polynya appeared in early September 2017​​​​​​​ and remained open for approximately 80 d until spring ice melt. In this study we present proof that polynya-favorable activity in the Maud Rise area is taking place more frequently and on a larger scale than previously assumed. By investigating thin (&lt; 50 cm) apparent sea ice thickness (ASIT) retrieved from the satellite microwave sensors Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP), we find an anomaly of thin sea ice spanning an area comparable to the polynya of 2017 over Maud Rise which occurred in September 2018. In this paper, we look at sea ice above Maud Rise in August and September of 2017 and 2018 as well as all years from 2010 until 2020 in an 11-year time series. Using fifth-generation ECMWF Reanalysis (ERA5) surface wind reanalysis data, we corroborate previous findings (e.g., Campbell et al., 2019; Francis et al., 2019; Wilson et al., 2019) on the strong impact that storm activity can have on sea ice above Maud Rise and help consolidate the theory that the evolution of the Weddell Sea polynya is controlled by local atmospheric as well as oceanographic variability. Based on the results presented, we propose that the Weddell Sea polynya, rather than being a binary phenomenon with one principal cause, is a dynamic process caused by various different preconditioning factors that must occur simultaneously for it to appear and persist. Moreover, we show that rather than an abrupt stop to anomalous activity above Maud Rise in 2017, the very next year shows signs of polynya-favorable activity that, although insufficient to open the polynya, were present in the region. This phenomenon, as we have shown in the 11-year SMOS record, was not unique to 2018 and was also identified in 2010, 2013 and 2014. It is demonstrated that L-band microwave radiometry from the SMOS and SMAP satellites can provide additional useful information, which helps to better understand dynamic sea ice processes like polynya events when compared to the use of satellite sea ice concentration products alone.

A new methodology to assess the potential of conjectural trigger mechanisms of submarine landslides exemplified by marine gas occurrence on the Balearic Promontory

The destructive potential of submarine landslides for populated coastal areas and maritime infrastructure has been described many times. However, the geological processes that can trigger such landslide events have not yet been fully established. In order to be able to conclusively assess the trigger potential of these processes, a quantification of the slope stability is indispensable. This requires a precise knowledge of the geotechnical and geological boundary conditions before and after the investigated landslide event, as well as the change in these boundary conditions caused by the alleged trigger mechanism. In order to make these described preconditions and the work process generally applicable, a universally adaptable methodology for the identification of trigger mechanisms was developed. Here, it is successfully applied to marine gas occurrence, which has recently been considered as a trigger mechanism due to the negative influence of enclosed gas bubbles on the shear strength of fine-grained soils. The constitutive model by Sultan and Garziglia (2014) is applied to simulate the gas-influenced undrained shear strength of a marine soil from a sediment starved margin on the Balearic Promontory and a range of Finite Element Limit Analyses (FELA) are conducted to determine the resulting loss of stability of different slope geometries. Within the scope of these calculations, the first set of Modified Cam Clay model parameters for a soil from the western Mediterranean is introduced. Based on the simulations, it can be concluded that marine gas occurrence decreases the overall stability of a slope compared to the saturated state. However, it also becomes obvious that the prevailing slope geometries with low inclinations are stable with a substantial capacity reserve for all simulated scenarios. Conclusively, gassy soil can be designated as a preconditioning factor decreasing the slope stability, as the state of failure can only be reached if the slope was in a precarious state before, or in combination with other impacts.

Orbital‐ and Millennial‐Scale Changes in Lake‐Levels Facilitate Earthquake‐Triggered Mass Failures in the Dead Sea Basin

AbstractThe possible link between the occurrence of submarine mass failure and climate‐driven factors is highly disputed. This is due largely to the lack of comprehensive records of mass failures in the geologic record for which ages, triggers, and preconditioning factors can be reliably constrained. Such controls would allow accurate testing of cause‐and‐effect relationships. We present a record that comprises 490 earthquake‐triggered mass failure deposits from the Dead Sea depocenter over the past 220 kyr that permits a robust statistical evaluation and correlation with potential preconditioning factors. Our data set reveals that (a) at the orbital‐ and millennial‐scale, variable sedimentation rates are not a preconditioning factor for these mass failure deposits; (b) at the centennial‐to decadal‐scale, earthquake‐triggered mass failures can occur at any lake‐level state; (c) at the orbital‐ and millennial‐scale, the mass failures are more frequent when lake‐levels were high and punctuated by large‐amplitude fluctuations.

Submarine landslides on a carbonate platform slope: forward numerical modelling of mechanical stratigraphy and scenarios of failure precondition

Slope failure and landslides are widespread on the submarine slopes of carbonate platforms. They represent a key component of their stratigraphic evolution and a major geohazard. Several Quaternary slope failures and mass transport complexes were identified on the western slope and margin of the Great Bahama Bank (GBB) platform. This study evaluates several hypotheses for the preconditions associated to these events, in relation with the stratigraphic and environmental history of the platform. The forward stratigraphic simulator Dionisos Flow™ allows the slope stratigraphic evolution to be reconstructed on a 2D platform-to-basin section at high temporal resolution according to the eustatic and environmental history of the last 1.7 Myr. The hydromechanical simulator A2 is applied on this high-resolution stratigraphic grid for computing the mechanical stratigraphy of the section, that is the spatiotemporal pore pressure and stress state distribution. The simulated precondition of the platform margin during glacial lowstands results from the combination of two factors: transient overpressure generation by lateral fluid flow from the emerged platform and the steepening stratigraphic trend of the platform. No significant pore fluid overpressure is generated under high sedimentation rates or as a result of shift in hydrostatic gradient during sea-level falls. Precondition in the lower slope is not achieved in this 2D simulation, with the horizontal stress distribution counteracting the effect of overpressure build-up. It is found that cemented levels in the lower slope succession do not represent a significant preconditioning factor.

Assessment of impact of varied preconditioning factors, used in isolation and combination, for enhancement of cytokine secretions in stem cell conditioned medium

Assessment of impact of varied preconditioning factors, used in isolation and combination, for enhancement of cytokine secretions in stem cell conditioned medium

Comparing characteristics of rainfall- and earthquake-triggered landslides in the Upper Minjiang catchment, China

The Upper Minjiang catchment is located at the eastern margin of the Tibetan Plateau and is frequently affected by landslides. The two main triggering factors in the region are rainfall and high magnitude seismic shocks, such as the 2008 Wenchuan earthquake. In this paper, we present a comparison study of pre-conditioning factors that drive the spatial occurrence of landslides in this high elevation region. We used a multi-temporal landslide inventory that differentiates between rainfall and earthquake triggers based on the analyses of satellite imagery, aerial photos, and field investigations. Our investigation revealed that the strongest influences on landslides are lithology and topographic factors. The difference between these two triggering factors can also be observed with respect to the relative slope positions: rainfall-triggered landslides are more frequently found at lower slopes, while seismic-induced landslides are more evenly distributed on very steep slope sections. In particular, the steep and deeply incised river terraces in this region are prone to landslides due to their rapid formation. This study presents the first analysis that differentiates two main triggering factors in order to understand the influence of rainfall and earthquakes on landslide occurrences in this region. Our results can also aid in the sustainable management of performance-based slope engineering and landslide risk reduction by reporting the differences regarding the spatial distribution of rainfall- and seismic-triggered slope failures. Consequently, these results can be used by local and regional decision-makers for risk management and spatial planning.

On the potential of gassy marine soils triggering submarine slope instabilities

The development of debris flows and turbidity currents in the course of a submarine slope failure event can cause major damage in offshore infrastructure. Additionally, the tsunamogenic potential of large slope failures at continental margins poses a direct threat to coastal communities. Therefore, the trigger mechanisms of submarine slope failures have been thoroughly investigated in the past. However, the influence of free gas in the sediment, which has been observed close to several slide events, remains unexplained. In order to evaluate the potential of gassy marine soils to precondition or trigger slope failure the mechanical behaviour of gassy soils is assessed based on an extensive literature review. It is found that gas-induced excess pore pressures can lead to liquefaction failure in sands, while cohesive, gassy soils show a less conclusive response. Hence, fine-grained soils and approaches to implement the gas impact into relevant existing constitutive soil models are assessed in greater detail. Concludingly, based on the predominant boundary conditions in failure prone regions at the continental margins, free gas occurrence can be defined as a preconditioning factor rather than as a definite trigger mechanism.

From gravity cores to overpressure history: the importance of measured sediment physical properties in hydrogeological models

Abstract The development of overpressure in continental margins is typically evaluated with hydrogeological models. Such approaches are used to both identify fluid flow patterns and to evaluate the development of high pore pressures within layers with particular physical properties that may promote slope instability. In some instances, these models are defined with sediment properties based on facies characterization and proxy values of porosity; permeability or compressibility are derived from the existing literature as direct measurements are rarely available. This study uses finite-element models to quantify the differences in computed overpressure generated by fine-grained hemipelagic sediments from the Gulf of Cadiz, offshore Martinique and the Gulf of Mexico, and their consequences in terms of submarine slope stability. By comparing our simulation results with in situ pore pressure data measured in the Gulf of Mexico, we demonstrate that physical properties measured on volcanic-influenced hemipelagic sediments underestimate the computed stability of a submarine slope. Physical properties measured on sediments from the study area are key to improving the reliability and accuracy of overpressure models, and when that information is unavailable, literature data from samples with similar lithologies, composition and depositional settings enable better assessment of the overpressure role as a pre-conditioning factor in submarine landslide initiation.

Statistical and expert-based landslide susceptibility modeling on a national scale applied to North Macedonia

Abstract This article presents a Geographic Information System (GIS) assessment of Landslide Susceptibility Zonation (LSZ) in North Macedonia. Because of the weak landslide inventory, statistical method (frequency ratio) is combined with Analytical Hierarchy Process (AHP). In this study, lithology, slope, plan curvature, precipitations, land cover, distance from streams, and distance from roads were selected as precondition factors for landslide occurrence. There are two advantages of the approach used. The first is the possibility of comparing of the results and cross-validation between the statistical and expert based methods with an indication of the advantages and drawbacks of each of them. The second is the possibility of better weighting of precondition factors for landslide occurrence, which can be useful in cases of weak landslide inventory. The final result shows that in the case of weak landslide inventory, LSZmap created with the combination of both models provide better overall results than each model separately.

Late Detection of Atrial Fibrillation after Stroke: Implications for the Secondary Prevention

Background: This study is aimed at investigating the incidence of atrial fibrillation (AF) within 5 years after an acute cerebrovascular event in AF-naive patients and its relevance for secondary prevention. Methods: The current case-control study sample included patients who had received an initial ischemic stroke diagnosis documented in the Disease Analyzer database (IQVIA), which compiles data such as risk factors, drug prescriptions, and diagnoses obtained from 1,262 general practices in Germany. Results: After the selection procedure, the stroke and non-stroke groups each included 22,774 patients. In both groups, the mean age of the population was 68.0 years (SD ±12 years), and the proportion of male participants was 51.1%. Within 5 years of follow-up, we calculated a higher probability for detecting AF in stroke patients than in controls (hazard ratio 4.95; 95% CI 1.93–2.09, p < 0.001). In the stroke group, AF was detected in 2,369 individuals (10.4%), whereas AF was only evident in 1,101 patients (4.8%) in the non-stroke group. In 1,741 (73.5%) patients (out of 2,369), oral anticoagulants had been prescribed after the AF diagnosis. In stroke patients, factors like diabetes mellitus and ischemic heart disease were associated with restraint in prescribing oral anticoagulants; age did not influence the decision for or against oral anticoagulants (mean age 72.9 vs. 72.7 years). Conclusion: A recent stroke is a strong preconditioning factor for detecting AF within 5 years after an acute event. The majority of these patients are treated with oral anticoagulants, regardless of their age.

Coastal landslide monitoring at Aldbrough, East Riding of Yorkshire, UK

The paper describes results to date of a continuing monitoring study of coastal ‘soft cliff’ recession at the British Geological Survey's (BGS's) Coastal Landslide Observatory (CLO) on the east coast of England at Aldbrough, East Riding of Yorkshire. The cliffed site, part of the 50 km long Holderness coast, consists of glacial deposits, and is one of the most rapidly eroding coastlines in Europe. This rapid rate of erosion provides an ideal opportunity for observation and process understanding because it facilitates the collection of data over periods of time encompassing significant new landslide events at the same location. The results of two approaches are reported: first, terrestrial Light Detection and Ranging (LiDAR) surveying (TLS); second, the installation of instrumented boreholes. The aim of the research is to combine these to investigate the role of landslides and their pre-conditioning factors and the influence of geology, geotechnics, topography and environmental factors on cliff recession. To date, an average recession rate of 1.8 m a −1 and a maximum rate of 3.4 m a −1 have been recorded for the site. The establishment of the CLO and its conceptual geological–geotechnical model are described in a related paper.

Analysis of Thermal Decomposition of Solid Rocket Propellants

The paper presents results of thermal decomposition analysis of selected solid rocket propellants. Homogeneous propellant PAC and heterogeneous propellant H2 were subjected to simultaneous thermal analysis with the use of NETZSCH STA 2500 Regulus device with five heating rates of 2.5, 5, 7.5, 10 and 15 K/min. The method combines TG, DTG and DTA analytical techniques in a single measurement. The aim of the conducted experiments was to study thermal decomposition of these energetic materials as well as to determine activation energy of the decomposition process and the preconditioning factor from the TG curves. The tested materials properties and chemical composition along with a brief description of the experimental procedure are described. The inverse procedure of calculating the activation energy, based on the Ozawa-Flynn-Wall model is described. Finally, the results of thermal decomposition of two tested solid rocket propellants are presented along with maximum decomposition rates and percentage of mass loss.

Establishment of a coastal landslide observatory at Aldbrough, East Riding of Yorkshire, UK

The paper describes the establishment of the British Geological Survey (BGS)’s field-based ‘Coastal Landslide Observatory’, designed for the study of coastal ‘soft cliff’ recession on the east coast of England at Aldbrough, East Riding of Yorkshire. The cliffed site is part of the 50 km long Holderness coast which is one of the most rapidly eroding coastlines in Europe. The site features a 16–17 m high sea-cliff formed by Late Devensian (18–13 ka) glacial deposits dominated by tills. The aim of the research is to investigate the role of landslides and their pre-conditioning factors, including geology, geotechnics and topography, in cliff recession with a view to developing coastal landslide forecasting capability. Two research approaches are encompassed in the observatory: firstly, terrestrial LiDAR surveying, from 2001 to present, to create digital elevation models of the cliff and, secondly, installation of instrumented boreholes from 2012. The design, methods, conceptual ground model, implementation of the observatory and geotechnical laboratory test results are described in this article. The interpretation of results and the final ground model are presented in a related article in this volume.

Potentiation of the hypoxic preconditioning effect by antihypoxants

The development of effective methods to increase the organism resistance to hypoxia is an important task of current medicine. One of such methods is preconditioning, as a result of which, a potent mobilization of the adaptive organism abilities occurs under a preconditioning factor action.&#x0D; Aim. To study the possibility of potentiating of the hypoxic preconditioning effect with help of antihypoxants.&#x0D; Methods. Evaluation of the effectiveness of combined preconditioning (antihypoxants + moderate hypobaric hypoxia) was performed on experimental models of acute hypoxia with hypercapnia, acute hypobaric hypoxia in mice, and bilateral occlusion of the common carotid arteries in rats. Investigated antihypoxants are amtizol, hypoxen, cobazole, metaprot, mexidol, mildronate, substances under the codes VM-606, pQ-4 and pQ-1104.&#x0D; Results. PreC with use of amtizol at dose 25 mg/kg, cobazole at dose 30 mg/kg, VM-606, pQ-4 and pQ-1104 at doses 50 mg/kg in combination with moderate hypoxia increased the lifespan of mice in acute hypoxia with hypercapniamodel and acute hypobaric hypoxia from 57 to 170%. Combined preconditioning with amtizol, cobazole and pQ-4 significantly increased the survival rate of rats in cerebral ischemia, amtizol and pQ-4 reduced neurological deficiency in the post ischemic period as well.&#x0D; Conclusion. Antitipoxants as amtizol, cobazole, VM-606, pQ-4, pQ-1104 potentiate the hypoxic preconditioning effect on acute hypoxia with hypercapnia, acute hypobaric hypoxia and occlusion of the common carotid arteries models, the most significant effect was noted for amtizol and pQ-4. Signal role in the adaptation induction to hypoxia and ischemia by combined preconditioning with use of antihypoxants hypoxia-inducible factor HIF-1α can play.