984 resultados para Catastrophic Rupture


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During last decades, the Internet teleobotics has been growing at an enormous ratedue to the rapid improvement of Internet technology. This paper presents theinternet-based remote control of mobile robot. To face unpredictable Internet delaysand possible connection rupture, a direct continuous control based teleoperationarchitecture with “Speed Limit Module” (SLM) and “Delay Approximator” (DA) isproposed. This direct continuous control architecture guarantees the path error of therobot motion is restricted within the path error tolerance of the application.Experiment results show the feasibility and effectiveness of this direct Internet controlarchitecture in the real Internet environment.

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Background: The prevalence of sphincter rupture during childbirth has increased in Sweden from half percent to three percent from 1973 to 1993. Women who undergo planned home birth have sphincter injuries to a smaller extent than women who undergo planned hospital births. Objective: The purpose of this study was to describe women’s experience of the last stages of delivery during planned home birth. Design: Inductive content analysis of 150 randomly selected delivery reports. The delivery reports were gathered as a reply to an open question in a previously conducted survey.Findings: The woman´s confidence in the natural birthing process emerged as the overall theme of the delivery reports. Fourteen subcategories and five categories emerged during the analysis process: experience of support, physical experience, psychological experience, experience of birthplace and birth position and the woman’s awareness during birth. Conclusion: The support from the surrounding people was very important for the women and they felt calm and secure in the home environment. The women often gave birth in a birthing position that led to a reduced risk of perineal tears. Many risk factors for sphincter injuries were eliminated for the women who went thru planned home birth. For example the women often had experiences of prior deliveries and further no medical instruments were used during late stages of delivery in planned home births.

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Background: Sphincter injury is serious complication in connection to vaginal childbirth. Desire to avoid vaginal birth again is seen in women who previously suffered from a sphincter injury. Objective: To identify and evaluate obstetric guidelines in Sweden regarding sphincter injury in relation to childbirth Method: Content analysis with a combination of a deductive and inductive approach. Results: The most frequently occurring risk factors and prevention with help of perineal protection were described in the guidelines. The physician made diagnosis and repaired the sphincter injury at the theatre.  Complications such as coital pain and anal incontinence were described in the guidelines. Paracetamol and diclofenac was most common analgesic regimen given for pain. Prophylaxis such as antibiotic treatment and laxative were common. Information given to women was described. Follow-up by physician, midwife and physiotherapist was recommended after four weeks to six months. For future birth a cesarean section was recommended. Conclusion: The guidelines were constructed in the same way and had to a large extent similar content. The authors of the present work recommend a national guideline.

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In anaerobic degradation of substrates containing mainly particulate organic matter, solids hydrolysis is rate-limiting. In these investigations, the particle size of various substrates was reduced by comminution to support hydrolysis. Two positive effects of comminution were observed. For substrates with high fibre content, which are particularly resistant to biodegradation, a significant improvement of the degradation degree was observed as a result of comminution. Secondly, for all substrates tested, and particularly for those rich in fibres, the degradation rate of comminuted samples was significantly higher. The first reason for both effects is an increase of the sample surface area. Several methods for measuring the specific surface area of organic materials, including particle size analysis, Nitrogen-adsorption and enzyme adsorption, were used and compared for the purpose of this study, where the surface area accessible to microbial enzymes is critical. The significance of the surface area in anaerobic degradation of particulate substrates was investigated through a kinetic model where the hydrolysis rate was based on the sample surface area. Good agreements were obtained between model and experiments carried out with samples of various specific surface areas. These results reinforced the significance of the sample surface area in anaerobic degradation processes. However, other effects of comminution responsible for the increased degradation degree and degradation rate were identified and discussed. These include: the increase of dissolved compounds due to cell rupture, exposition of surface areas previously inaccessible for microbial degradation, and alteration of the sample structure such as the lignin-cellulose arrangements.

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This critique functions as an introduction to this special issue of Critical Perspectives on Accounting; an edition that embraces themes pertaining to the catastrophic collapse of Enron. In an effort to place the research published in this edition in context, I provide a critical analysis of the accounting and corporate governance implications of the demise of Enron, the subsequent public outcry, and the legislative reforms to date. I conclude with an exploration of how the studies in this special issue contribute to understanding the myriad of forces behind major events such as this.

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Background: At the height of the food crisis in southern Africa, the Government of Lesotho declared a state of famine and emergency in April 2002 and launched a Famine Relief Appeal for over $137 million. World Vision, in partnership with the World Food Program, became involved in December 2002 providing food aid to affected communities.
Objective: to document mortality rates, causes of death, malnutrition prevalence, and the proportion of lost pregnancies after almost three years of humanitarian response to the food crisis in Lesotho and to propose a way forward.
Design: A two-stage, 30 cluster household survey was undertaken in three districts from the 16th to the 26th of May 2005, with a sample size of 3610 people.
Results: The crude mortality rate (CMR) of 0.8/10,000/day (95%CI: 0.7-0.9). The reported CMR was significantly lower than the CMR emergency threshold (<1/10,000/day). Using 2000 as a pre-drought baseline, 38528 excess deaths occurred between 2000 and 2005. The under-five mortality rate (U5MR) of 3.2 deaths/10,000/day (95%CI: 2.8-3.6/10,000/day) was 4 times the reported CMR and 1.4 times higher the U5MR emergency threshold for sub-Saharan Africa (2.3/10,000/day). CMR was lower among food aid beneficiaries (0.68; 95%CI: 0.57-0.79) than non-beneficiaries (1.42; 95%CI: 1.13-1.70). This was also true for U5MR (2.94; 95%CI: 2.39-3.50 versus 6.44; 95%CI: 5.21-7.68). The prevalence of wasting increased from 5.4% to 12% while that of stunting declined from 45.4% to 36.2% between 2000 and 2005, but the nutritional status did not vary by beneficiary status.
Conclusion: Despite the alarming U5MR, findings suggest that the food aid program ensured survival mainly among adults. The situation could have been catastrophic in the absence of humanitarian assistance.

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Achilles tendon injury (tendinopathy) and pain occur in active individuals, when the tendon is subject to high or unusual load. Achilles tendinopathy can be resistant to treatment, and symptoms may persist despite both conservative and surgical intervention. The pathology of overuse tendinopathy is non-inflammatory, with a degenerative or failed healing tendon response. The diagnosis of Achilles tendinopathy requires excellent differential diagnosis and an understanding of the role of tendon imaging. Conservative treatment must include exercise, with a bias to eccentric contractions. Surgical treatment is effective after complete tendon rupture, but may not assist recovery from overuse tendinopathy. Further research into the clinical aspects of Achilles tendinopathy is required.

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The microstructure evolution during hot deformation of a 23Cr-5Ni-3Mo duplex stainless steel was investigated in torsion. The presence of a soft δ ferrite phase in the vicinity of austenite caused strain partitioning, with accommodation of more strain in the δ ferrite. Furthermore, owing to the limited number of austenite/austenite grain boundaries, the kinetics of dynamic recrystallisation (DRX) in austenite was very slow. The first DRX grains in the austenite phase formed at a strain beyond the peak and proceeded to <15% of the microstructure at the rupture strain of the sample. On the other hand, the microstructure evolution in δ ferrite started by formation of low angle grain boundaries at low strains and the density of these boundaries increased with increasing strain. There was clear evidence of continuous dynamic recrystallisation in this phase at strains beyond the peak. However, in the δ ferrite phase at high strains, most grains consisted of δ/δ and δ/γ boundaries.

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A new genus of ophiuroid, Huangzhishania, is created based on new material from the Permian/Triassic boundary beds at the Huangzhishan section, South China. The age of the new genus is constrained as earliest Griesbachian by means of faunal correlation of the associated bivalves and stratigraphical correlation with the Mixed Fauna Beds of the neighbouring Meishan section. Taphonomic and palaeoecological evidence suggest that the collapse of the ophiuroid association was related to a catastrophic event, and Huangzhishania was rapidly buried in life position.

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Overuse tendon conditions have traditionally been considered to result from an inflammatory process and were treated as such. Microscopic examination of abnormal Achilles-tendon tissues, however, reveals a non-inflammatory degenerative process. The histopathology found in surgical specimens in patients with chronic overuse Achilles tendinopathy and those with Achilles-tendon rupture are reviewed. Seminal studies suggest that so-called tendinitis is a rare condition that might occur occasionally in the Achilles tendon in association with a primary tendinosis. These data have clinical implications and require a review of the traditional classification of pathologies seen in tendon conditions, The authors recommend that nomenclature be based on histopathological findings rather than traditional hypothesis.

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A community network often operates with the same Internet service provider domain or the virtual network of different entities who are cooperating with each other. In such a federated network environment, routers can work closely to raise early warning of DDoS attacks to void catastrophic damages. However, the attackers simulate the normal network behaviors, e.g. pumping the attack packages as poisson distribution, to disable detection algorithms. It is an open question: how to discriminate DDoS attacks from surge legitimate accessing. We noticed that the attackers use the same mathematical functions to control the speed of attack package pumping to the victim. Based on this observation, the different attack flows of a DDoS attack share the same regularities, which is different from the real surging accessing in a short time period. We apply information theory parameter, entropy rate, to discriminate the DDoS attack from the surge legitimate accessing. We proved the effectiveness of our method in theory, and the simulations are the work in the near future. We also point out the future directions that worth to explore in the future.

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As embodied social agents our lives are preoccupied with the production and reproduction of bodies. Making, unmaking and remaking our embodiment are ongoing activities. Eating, exercise, washing, grooming, dressing, for example, are activities in which the body engages in routine tasks of bodily management. Such activities can be seen as everyday rehabilitation. The study explores the impact of major physical impairment on embodiment, and on the processes involved in re-embodiment after catastrophic injury or disease. The experiences of the people in this study dramatically highlight the continuous, but largely taken for granted processes involved in our embodiment. Four analytical strands are interwoven throughout the study. The first strand relates to the frailty and vulnerability of the human body, characteristics which are epitomised by the bodies of the informants in this study. The second strand engages with key aspects of the context in which re-embodiment takes place, namely a context replete with crisis, danger, fear, uncertainty and risk. The third strand projects into the future in considering the ongoing project of self. The fourth strand addresses the institutional and social impediments which may confine vulnerable bodies and limit the exploration of more expansive bodies. The study is situated within the general theoretical approach of the sociology of the body. While recognizing the powerful impact of social discourse in the production of bodies, the study focuses on the critical role of embodiment in the reconstitution of self. The people in this study have experienced profound bodily change, but although this damage has disrupted, it has not annihilated their embodied selves. The people still possess and occupy their bodies. It is the obduracy of embodiment which directs the processes involved in remaking the body.

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Amyloid aggregates, found in patients that suffer from Alzheimer's disease, are composed of fibril-forming peptides in a β-sheet conformation. One of the most abundant components in amyloid aggregates is the β-amyloid peptide 1–42 (Aβ 1–42). Membrane alterations may proceed to cell death by either an oxidative stress mechanism, caused by the peptide and synergized by transition metal ions, or through formation of ion channels by peptide interfacial self-aggregation. Here we demonstrate that Langmuir films of Aβ 1–42, either in pure form or mixed with lipids, develop stable monomolecular arrays with a high surface stability. By using micropipette aspiration technique and confocal microscopy we show that Aβ 1–42 induces a strong membrane destabilization in giant unilamellar vesicles composed of palmitoyloleoyl-phosphatidylcholine, sphingomyelin, and cholesterol, lowering the critical tension of vesicle rupture. Additionally, Aβ 1–42 triggers the induction of a sequential leakage of low- and high-molecular-weight markers trapped inside the giant unilamellar vesicles, but preserving the vesicle shape. Consequently, the Aβ 1–42 sequence confers particular molecular properties to the peptide that, in turn, influence supramolecular properties associated to membranes that may result in toxicity, including: 1), an ability of the peptide to strongly associate with the membrane; 2), a reduction of lateral membrane cohesive forces; and 3), a capacity to break the transbilayer gradient and puncture sealed vesicles.

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When a robotic manipulator is fault tolerant it is beneficial to study the configurations which tolerate non-catastrophic locked joint failures with a minimum relative change for the joint velocities. This problem is addressed using the properties of the condition number of the Jacobian matrix. The relationship between the faults within the joints of the manipulators and the condition number of the Jacobean matrix is used to introduce the optimal configurations for fault recovery. These optimum configurations require a minimum reconfiguration for fault tolerance of robotics manipulators. Then these configurations are studied for a 4-DOF planar manipulator to validate the proposed framework.

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An effort to maintain the availability of partially failed manipulator is addressed based on redundant trajectories obtained by primitive constraints. The objective is to facilitate the existing manipulators to continue their point to point motion tasks when a non catastrophic fault occurs into a joint. The fault is assumed as a joint locked failure. This is achieved through fault to primitive constraints mapping which gives the primitive constraints due to the faults. Then they are applied to update the manipulator constraints for the trajectory planning. Then it purposes a new trajectory in the case of availability. Finally the method is applied for a 6DOF manipulator and validated under a fault scenario within a simulation study and the results are presented.