Cause Of Collapse Research Articles

O-101 Elucidation of blastocyst collapse and its consequences: a comprehensive artificial intelligence-powered analysis of 1943 embryos from 643 couples

Abstract Study question What are the causes and consequences of blastocyst collapse? Summary answer ∼50% of blastocysts collapsed, especially if they are aneuploid and/or morphologically-poor. Yet, no impact on the live-birth-rate (LBR) per vitrified-warmed euploid single-embryo-transfer (SET) was reported. What is known already Time-lapse-microscopy (TLM) is a powerful tool to describe the peculiar dynamics of preimplantation development. Lately, artificial intelligence (AI) has been also implemented to automatize and standardize such description. Here, we adopted AI to comprehensively portray blastocyst collapse, namely the phenomenon of embryo contraction with an efflux of blastocoel fluid and the detachment of the trophectoderm (TE) from the Zona Pellucida (ZP). Although, the causes of this event are still undetermined, small blastocyst contractions have been reported beneficial for the hatching process, while a full collapse has been associated with lower competence. Study design, size, duration Observational study including 1943 blastocysts from 643 couples cultured in the Embryoscope between January-2013 and December-2020. TE biopsy without day3 ZP drilling and comprehensive-chromosome-testing were performed. The Fairtility® software automatically registered: (i)time of starting-blastulation (tSB), (ii)starting and ending time of each collapse (tSC and tEC), (iii)blastocysts’ areas, (iv)shrinkage% [(area at SC – area at EC)/area at SC)], (v)embryo:ZP ratio at EC (area of the collapsed embryo/area of the ZP), and (vi)time of biopsy (t-biopsy). Participants/materials, setting, methods Blastocyst quality was defined according to Istanbul Consensus (11, excellent; 12-21, good; 22-13-31, average; 33-23-32, poor) and with the Fairtility implantation score (IS) as well, i.e., a continuous variable from 0 to 1 generated by the KID+ software based on the TLM videos of preimplantation development. The main outcome was the LBR per euploid SET adjusted for confounders through logistic regressions. All couple and embryo features were also investigated for their association with blastocyst collapse. Main results and the role of chance 47.3% of the blastocysts collapsed 1- to 9-times (interval between collapses: 4-8hr), and 73% of the couples had ≥1 collapsed blastocyst (1.8±1.1, range:1-8). No couple feature, though, was associated with blastocyst collapse. The longest collapses lasted 1.5±1.1 (0.13-5.1)hr, while the largest shrinkage% and embryo:ZP ratio at EC were 35±14% (10-78%) and 81±9% (33-90%), respectively. In ∼50-60% of collapses a 20-40% blastocyst volume reduction was registered, 40-60% or 20-40% in ∼15-30%, 60-80% in 0-4%. In case of multiple collapses, the first three involved smaller shrinkages. Blastocysts undergoing ≥1 collapse showed similar tSB as not-collapsing blastocysts, but progressively longer tEB and t-biopsy. The earlier the first event, the more the consecutive collapses. Notably, the poorer the morphology, the higher the risk (excellent, good, average, and poor not-collapsing blastocysts were 64%,50%,44% and 37%), number (e.g.,≥4 collapses were 0.4%,2%,4% and 8%) and duration (1.2±1.0,1.4±1.0,1.6±1.1 and 1.9±1.3hr) of blastocyst collapse. Collapsing blastocysts were significantly less euploid than non-collapsing (35% vs 47%; multivariate-OR:0.75,95%CI 0.6-0.92,p<0.01); conversely, their LBR per euploid SET (39% vs 46%) and miscarriage rate per clinical pregnancy (17% vs 11%), were not significantly different (adjusted-OR:1.0,95%CI 0.69-1.48,p=0.96 and adjusted-OR:1.65,95%CI 0.79-3.42,p=0.18, respectively). All data were confirmed also by defining blastocyst quality through the Fairtility IS. Limitations, reasons for caution Gestational and perinatal outcomes were not assessed. Other culture strategies and media shall be assessed for their association with blastocyst collapse. Perhaps, future studies from other groups and with a larger sample size might unveil a significant impact on the clinical outcomes. Wider implications of the findings Collapse is common and delays blastocyst full-expansion. Moreover, poor morphology and aneuploidies involve a higher risk of collapse(s); however, no impact was reported on the clinical outcomes after euploid SET. AI appears to increase the throughput of the analysis, but additional data are required to research the causes of collapse. Trial registration number Not applicable

A method for structural monitoring of multispan bridges using satellite InSAR data with uncertainty quantification and its pre-collapse application to the Albiano-Magra Bridge in Italy

Synthetic Aperture Radar Interferometry (InSAR) using satellite data is revealing a promising tool for monitoring long-term deformation phenomena in critical infrastructural systems. Nevertheless, its use in structural engineering is still quite limited and a general understanding of its potential is still missing, especially when dealing with bridge structures for which specific methods of data processing and displacement assessment with error quantification need to be developed, accounting for the type of deformation phenomena and for the orientation of the bridge. In order to partly fill this research gap, this paper proposes a post-processing methodology to derive two-dimensional displacement configurations of multi-span bridges with properly defined error bounds, using both ascending and descending Synthetic Aperture Radar acquisitions. In order to obtain an engineering meaningful estimate of the uncertainties affecting the reconstructed bridge deformations, both random and systematic errors are quantified, accounting for the orientation of the bridge with respect to the Line-Of-Sights of the satellites, the hypothesized deformation plane and the accuracy of InSAR measurements. The proposed procedure has been applied to the illustrative case study of the Albiano-Magra Bridge in Italy, collapsed on 8 April 2020. The results, referred to the monitoring period 2015–2020, demonstrate the effectiveness of the proposed method in supporting engineering assessments. In particular, an initially temperature-induced stationary deformation phenomenon has been observed, with all spans moving upwards or downwards during summer and winter. Afterwards, displacements of increasing amplitude for two side spans have been observed during the three years preceding the failure, providing information on the possible cause of collapse.

Parametric Study on Fatigue Behaviour of Beam - Column Joint Retrofitted with Various Patterns of Fibre Reinforced Polymer Sheets

Shear failure of B-C joints is recognized as the primary cause of collapse of various moment-resisting frame buildings during recent earthquakes. When B-C joint subjected to huge forces during severe ground shaking and its behaviour has a very much influencing on the structure, sometimes it may Leeds to collapse of entire structure. To study the energy dissipation of B-C joint with different types and combinations of FRP sheets used to retrofit the BC joint in this study. Fiber reinforced polymer is composite material made up of polymer matrix reinforced with fibres. It is alternative method for retrofitting of structures. In this project work, a RC beam- column joint model was developed and externally wrapped with FRP sheets using ABAQUS-CAE. Then parametric study was carried out for beam-column joint retrofitted with various pattern of FRP sheets like different orientation, layers and material of fibres. Various materials of the fibres used carbon, glass and basalt. Orientation of fibres were used like 00,- 450,450,900 and combinations of CFRP&GFRP, CFRP&BFRP and GFRP&BFRP were used in this parametric study. Finally FEA analysis was compared and discussed with respect to layers and materials of fibres. Specimens with B-C joint are retrofitted with FRP and their performances are compared with corresponding un-retrofitted specimens under cyclic loading. It has been found that after retrofitted with CFRP, GFRP and BFRP the energy dissipation capacity had increases to 44.56, 46.3 and 60.58% and stiffness, ductility also increased. Key Words: Finite Element Method (FEM); Beam- column joints; Carbon fibre reinforced polymer (CFRP); Glass fibre reinforced polymer (GFRP); Basalt fibre reinforced polymer (BFRP); Strengthening.

Aortic stenosis: An important cause of collapse to be considered in a polytrauma patient

Undiagnosed and underlying medical co-morbidities are known to have a role in the causation of or contribution to injuries sustained in cases of polytrauma. Syncope provoked by valvular heart disease is one such example. Thorough clinical assessment is needed to ensure such diagnoses are detected and treated, whilst ensuring a patient’s ongoing rehabilitation needs are met. Here, the authors report a case of polytrauma, most likely secondary to severe aortic stenosis, causing syncope which was diagnosed at a later stage due to ongoing symptomatology. Delay in picking up such diagnoses can contribute to mortality in these patients or affect morbidity by having a detrimental impact on a patient’s functional recovery.

NONLINEAR FE ANALYSIS OF A MASONRY SPIRAL STAIRCASE IN NISIDA: A REFINED NUMERICAL CASE STUDY

Following previous work by some of the present authors based on the linear arch static analysis (LASA), which models the masonry material as a no-tension material according to Heyman (Heyman, J., The Stone Skeleton, Int. J. Solids Struct., vol. 2, no. 2, pp. 249-279, 1966) and on the safe theorem of the limit analysis (LA), an in-depth numerical study of a case study based on a masonry spiral staircase in Nisida, near Naples, is here presented by means of an accurate finite element (FE) model. The nonlinear FE model has been obtained by the use of the ANSYS Parametric Design Language (APDL), and a precise representation of all the material involved and of the boundary conditions, has been obtained. The results confirm that LASA can be an alternative to much more complex numerical analyses, such as FE, but it cannot account for the main cause of collapse or stress redistribution in these type of structures, that is sagging and subsidences. The results are presented and discussed in some detail.

Analysis of the Causes of the Collapse of a Deep-Buried Large Cross-Section of Loess Tunnel and Evaluation of Treatment Measures

To address the problem of the collapse of the roof of the Bailuyuan tunnel during construction, the causes of collapse were analyzed, targeted treatment measures were proposed, and the effects of the treatment measures were evaluated through on-site monitoring and three-dimensional numerical simulations. The results showed that the particular characteristics of loess and the synergy of groundwater were the internal causes of the tunnel’s collapse as well as, to a certain extent, atmospheric precipitation. Therefore, the combination of multiple factors contributed to the tunnel’s collapse. Untimely monitoring and measurement, as well as the low initial support parameters, reflect a lack of human understanding of the collapse. Based on the analysis of the causes of the collapse, comprehensive treatment measures for inside and outside the tunnel are proposed, which are shown to be effective and to be capable of preventing the occurrence of further collapses. After the collapse treatment, the measured maximum settlement of the tunnel vault was 65.1 mm, the maximum horizontal convergence was 25 mm, the maximum surrounding rock pressure was 0.56 MPa, and the maximum stress on the steel arch frame was 54.34 MPa. Compared with the original design plan, the vertical stress, horizontal stress, and shear stress of the surrounding rock obtained from numerical simulation after the collapse treatment were greatly reduced, the reduction rate at the vault reached 50%, and the safety factors of the initial support positions after treatment met the specification requirements. The research results can provide engineering guidance for the design and construction of large-section tunnels crossing deep-loess strata, and they are of important engineering significance.

Statistical damage model for dry and saturated rock under uniaxial loading based on infrared radiation for possible stress prediction

Rock fracture is the root cause of collapses of the overburden and mine water inrush. Monitoring and identifying the precursor information of the mine surrounding rock during the progressive failure process are the foundation for an advancement of mine safety. In this paper, the infrared radiation observation experiments of both dry and water saturated sandstone under uniaxial loading was carried out. The representative dry and water saturated sandstone samples with specific microstructure and composition, mechanical, and infrared radiation characteristics during the fracture process were studied. The results show that water saturation not only weakens the mechanical properties of rock, but also promotes infrared radiation which can be used as a precursor for stresses. The saturated rock uniaxial compressive strength, elastic modulus, compaction stress decreased and the magnitude of Infrared Radiation Variance (IRV) increased: which are 0.55, 0.54, 0.67 and 10.69 times that of the dry rock, respectively. Furthermore, water saturation changes the failure mode of rock from tensile failure to tensile shear composite failure. In addition, an innovative constitutive model of rock under uniaxial loading based on infrared radiation is established. The model considers the compaction stage and integrates the advantages of the lognormal distribution and Weibull distribution. The established piecewise constitutive model gives the coefficient of performance of more than 0.95, therefore, this model can be effectively used for the prediction of stress in both dry and saturated rocks. The research results can lay a theoretical and experimental foundation for monitoring the stability of engineering rock masses using infrared radiation.

Root cause analysis of liner collapse and crack of bi-metal composite pipe used for gas transmission

An underground gas storage company adopted bimetallic composite pipes for gas transmission. The pipelines were inspected with industrial camera, it was found that a large number of pipelines had liner collapsed, and some of collapsed liner had suspected cracks. In order to analyze the reasons for the collapse and cracking of the liner, visual inspection, non-destructive testing, material examination, crack analysis, bend fatigue test and pressure test were conducted. The results showed that the material properties of the bimetal composite pipe meet standard requirements. The external pressure test was imposed on Φ168 composite pipe, the liner collapse under the pressure of 1.76 MPa which is lower than the calculated value. The cause of collapse was analyzed from manufacturing process and service condition. There are micro-cracks around the main crack of the liner, the fracture showed fatigue striations and thickness thinning characteristic. The root cause of the liner collapse is that the water enters the interlayer during the manufacturing of bimetallic composite pipe, and the thermal expansion coefficient of base pipe and lining pipe is different. When external anti-corrosion coating was manufactured and temperature changed during operation, collapse tendency of the liner increased. The root cause of the crack of the liner is bending fatigue, and the load originates from pressure fluctuations during operation. In order to avoid such incidents, the online inspection should be performed for the effusion part of the pipeline to check whether the remaining wall thickness of the base pipe meets the requirements for safe operation. The carbon steel pipe with regular pigging was recommended for this application situation.

Volcanic climate impacts can act as ultimate and proximate causes of Chinese dynastic collapse

State or societal collapses are often described as featuring rapid reductions in socioeconomic complexity, population loss or displacement, and/or political discontinuity, with climate thought to contribute mainly by disrupting a society’s agroecological base. Here we use a state-of-the-art multi-ice-core reconstruction of explosive volcanism, representing the dominant global external driver of severe short-term climatic change, to reveal a systematic association between eruptions and dynastic collapse across two millennia of Chinese history. We next employ a 1,062-year reconstruction of Chinese warfare as a proxy for political and socioeconomic stress to reveal the dynamic role of volcanic climatic shocks in collapse. We find that smaller shocks may act as the ultimate cause of collapse at times of high pre-existing stress, whereas larger shocks may act with greater independence as proximate causes without substantial observed pre-existing stress. We further show that post-collapse warfare tends to diminish rapidly, such that collapse itself may act as an evolved adaptation tied to the influential “mandate of heaven” concept in which successive dynasties could claim legitimacy as divinely sanctioned mandate holders, facilitating a more rapid restoration of social order.

Piping Criteria for Hydraulically Stable Anisotropic Slopes

AbstractPiping has been a documented cause of collapse of multiple tailings dams, hydraulic structures and natural slopes. Important limitation of the existing piping criteria for a sloped ground i...

Operationalising the concept of ecosystem collapse for conservation practice

Concern is growing about ecosystem collapse, namely the abrupt decline or loss of an ecosystem resulting from human activities. While efforts to assess the risk of ecosystem collapse have developed at large spatial scales, less attention has been given to the local scales at which conservation management decisions are typically made. Development of appropriate management responses to ecosystem collapse has been limited by uncertainty regarding how collapse may best be identified, together with its underlying causes. Here we operationalise ecosystem collapse for conservation practice by providing a robust definition of collapse, in a form that is relevant to the scale of conservation decision-making. We provide an overview of different causes of collapse, and then explore the implications of this understanding for conservation practice, by examining potential management responses. This is achieved through development of a decision tree, which we illustrate through a series of case studies. We also explore the role of indicators for the early detection of collapse and for monitoring the effectiveness of management responses. Ecosystem collapse represents a significant challenge to conservation practice, as abrupt changes in ecosystem structure, function and composition can occur with little warning, leading to profound impacts on both biodiversity and human society. The risks of ecosystem collapse are likely to increase in future, as multiple forms of environmental change continue to intensify. We suggest that selection of management responses should be based on an understanding of the causal mechanisms responsible for collapse, which can be identified through appropriate monitoring and research activities.

Collapse Analysis on 500kV Transmission Tower under Combined Action of Typhoon and Microtopography

This paper studies the stress state and collapse cause of transmission tower of 500kV Zhangquan II line under the combined action of wind speed, wind direction and wind speed up effect when Typhoon Meranti passes Xiamen. Based on the historical meteorological data and the destruction pattern of the tower, the input conditions of wind speed and direction which are most likely to cause the tower to collapse are determined. Based on CFD simulation analysis, the wind speed-up factor of 24 wind angles at the inverted tower position was determined, and the stress of the main member and inclined member under two wind angles conforming to the site failure pattern was analyzed, and the internal relationship between the failure pattern of transmission tower and wind speed, wind direction and wind speed up factor was clarified. The influence of wind speed, wind direction and wind speed up effect which widely existing in mountainous region should be considered comprehensively in the design of Fujian coastal high voltage transmission line to against typhoon.

Causes of the Collapse of the Polcevera Viaduct in Genoa, Italy

The article investigates the causes of the Morandi viaduct collapse in Genoa. This three-span viaduct was a part of the A10 motorway leading to Savona. The structure design of the viaduct supports and diagonal stay cables was unique. The viaduct included three cable-stayed system, each supported a three-span continuous beam by two sets of prestressed concrete cables on the two sides of the pylon across the width. The pair of V shapes piers supported upside-down V pylons that supported the top ends of two pairs of diagonal stay cables. The stays were constructed from steel cables with prestressed concrete shells poured on. This article provides information on the technical condition of the viaduct and the way of strengthening the cables in the early 1990s. At that time, the author of the article visited the structure. In August 2018, the viaduct collapse occurred, and one of the structure supports collapsed. In June 2019, during the demolition process, the other two supports were destroyed. Since in Venezuela and Libya there are still two more bridges with a structure similar to that in Italy, the concept of strengthening the structure, as proposed by the author of the article 25 years ago, may still be useful.

Study on seismic failure mechanism of shallow buried underground frame structures based on dynamic centrifuge tests

During the Kobe earthquake in 1995, Daikai subway station suffered the severe collapse, which aroused people's more attention to the earthquake damage response of underground structures. In order to investigate the seismic failure mechanism of underground frame structures, a series of 1/50-scaled dynamic centrifuge tests were conducted. To make the underground structures produce a reasonable seismic failure mode in tests, an experimental scheme was designed in detail based on the author's previous numerical studies. With the purpose of simulating the vertical inertial effect of the overburden soil in the dynamic centrifuge tests, a certain proportion of steel grits were mixed into the overlying soil. A model structure finally occurred the overall collapse mode, which was similar to that of Daikai subway station. Based dynamic centrifuge tests, the seismic failure mechanism of shallow buried underground frame structure was analyzed and summarized in the paper. It could offer a reference for the cause of collapse of Daikai subway station. The series of tests provided valuable experimental data for further studies of the earthquake damage response of underground frame structures, and also enriched the testing technique for destructive model tests.

Paediatric residents deliver similar quality simulated neonatal resuscitation using 3:1 and 15:2 ratios.

About 10% of babies need assistance to start breathing at birth and around 1% need chest compressions (CC).1 However the optimal CC to ventilation ratio (CC:V) remains unclear. Current recommendation: three compressions/one ventilation (3:1), is based on consensus and expert opinions1,2 . Guidelines also state that higher ratios (15:2) can be used if the primary cause of collapse is cardiac or when arrest happen days after birth.2 Guidelines for newborns focus on resuscitation in delivery rooms,2 but babies may be born outside specialist environments and even have to be resuscitated by laypeople and COVID-19 pandemic has also had impact on resuscitation training. This study explored two CC:V rations (neonatal vs. paediatric). Our hypothesis was that cardiopulmonary resuscitation (CPR) quality would be similar with 3:1 (neonatal) and 15:2 (paediatric) sequences.

Ambulatory ECG monitoring for syncope and collapse in United States, Europe, and Japan: The patients' viewpoint.

BackgroundPractice guidelines provide clinicians direction for the selection of ambulatory ECG (AECG) monitors in the evaluation of syncope/collapse. However, whether patients’ understand differences among AECG systems is unknown.Methods and ResultsA survey was conducted of USA (n = 99), United Kingdom (UK)/Germany (D) (n = 75) and Japan (n = 40) syncope/collapse patients who underwent diagnostic AECG monitoring. Responses were quantitated using a Likert‐like 7‐point scale (mean ± SD) or percent of patients indicating a Top 2 box (T2B) for a particular AECG attribute. Patient ages and diagnosed etiologies of syncope/collapse were similar across geographies. Patients were queried on AECG attributes including the ability to detect arrhythmic/cardiac causes of collapse, instructions received, ease of use, and cost. Patient perception of the diagnostic capabilities and ease of use did not differ significantly among the AECG technologies; however, USA patients had a more favorable overall view of ICM/ILRs (T2B: 42.4%) than did UK/D (T2B: 28%) or Japan (T2B: 17.5%) patients. Similarly, US patient rankings for education received regarding device choice and operation tended to be higher than UK/D or Japan patients; nevertheless, at their best, the Likert scores were low (approximately 4.7‐6.0) suggesting need for education improvement. Finally, both US and UK/D patients were similarly concerned with ICM costs (T2B, 31% vs 20% for Japan).ConclusionsPatients across several geographies have a similar but imperfect understanding of AECG technologies. Given more detailed education the patient is likely to be a more effective partner with the clinician in establishing a potential symptom‐arrhythmia correlation.

Revised Comparison of Tunnel Collapse Frequencies and Tunnel Failure Probabilities

Comparison of calculated failure probabilities of technical systems with observed failure frequencies is an important part of the assessment of probabilistic calculations and can point to significant factors that are neglected in the calculations. Recent comparisons of failure probabilities and failure frequencies of nuclear power plants, bridges, and dams have shown that the calculated and observed values correspond surprisingly well. In addition, although various factors could be identified which have both positive and negative influences on the observed values, they almost cancel each other out. This study focuses on the comparison as it relates to tunnels. Extensive statistics indicate that most tunnel collapses occur during construction. Although this is also seen to a certain extent in bridges, it is not to the extent seen in tunnels. Events such as earthquakes and floods, which are the major causes of collapse of other structures, account for only about 10% to 20% of all tunnel collapses. Increasingly, tunnels are also being proven probabilistically. Based on these calculations, the available failure statistics can be compared with representative probabilistic tunnel proofs. The comparison shows large deviations between individual computations as well as between the mean value of all computations and the observed collapse frequencies.

Влияние антропогенной деятельности на состояние озеры Алаколь

In this article, the tasks and problems of destruction of the shoreline of the lake and the analysis of possible causes of collapse and erosion of the coast, and recommendations for the development of strengthening measures of the shore of Lake Alakol are considered. The anthropogenic factor, as a rule, has a negative impact that destabilizes the processes of self-regulation of the natural environment. In some cases at loads, exceeding critical, intensive influences lead to full irreversible infringement of processes of self-regulation of the river systems and as a result - to their destruction. The critical situation for Lake Alakol has come, probably, in the last two centuries. The advancing waters of Lake Alakol have blocked the pebble beaches and began to destroy the shore, thereby bringing harm to human life activities. The bijection, lithology, and geo geography of the device are not possible in this case. The following table describes the results of the anthropogenic treatment and the geological and geophysical studies of the device.

Contribution of analysis and detection the risks appearing in roads using GPR method: A case study in Morocco

This work aims to analysis and detects the reasons of the collapse of a road in northern Morocco using simulation based on the Finite-Difference Time-Domain method (FDTD) and a real survey by ground-penetrating radar (GPR) method. In the simulation, we test several targets buried in dry soil at the same depth. Depending on the simulation results GPR survey is done in two zones. The first zone shows multiple strong reflections, it indicates the presence of cavities. In the second zone, the profiles show the presence of the cavities and fragile lands saturated. Based on the results of the analysis and investigation experimental results, it is found that the causes of collapses on the road are due to the presence of the cavities and fragile lands saturated with water. This contribution can be effective and successful in studying areas when establishing infrastructure projects to avoid any risks that in the future.

Experimental investigation of redundancy of twin steel box-girder bridges under concentrated loads

Experimental testing was performed to evaluate the redundancy of twin steel box-girder bridges under concentrated loads. Results from a series of elastic load tests, a cyclic load test, and ultimate load tests are presented. The results indicated that fracture of tension member(s) was not the immediate cause of collapse of the system. The deck and intact girder together were able to provide stability and reserve load-resisting capability for the bridge. The railings, continuity and external intermediate cross-frames were additional factors that improved the redundancy level in twin steel box-girder bridges when one girder was completed fractured.